FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Kailasanath, K Patnaik, G AF Kailasanath, K Patnaik, G TI Performance estimates of pulsed detonation engines SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID INCIDENT SHOCK-WAVES; INITIATION AB Pulsed detonation engines have recently received increasing attention. Various advantages claimed for the pulsed detonation engines depend on performance estimates. A review of previous computational studies of pulsed detonation engines shows a wide variation in the predicted performance of even an idealized system. In this paper, detailed, time-dependent numerical simulations are used to explore some plausible reasons for the observed differences, The system simulated consists of a tube closed at one end and open at the other. The relaxation of the pressure at the exit of the tube to the ambient value is found to be a critical factor determining the specific impulse. Higher specific impulse can be attained with a gradual relaxation of the pressure at the exit of the tube. Numerically, different specifications of the outflow boundary conditions result in different relaxation rates and hence different values for die specific impulse. Experimentally, different effective rates of relaxation can be attained with different exhaust nozzle design. The initial renditions used in simulations to initiate detonations are also found to contribute significantly to the overall performance. The results from these studies are used to reconcile previous performance estimates. C1 USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. RP USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. NR 27 TC 18 Z9 18 U1 1 U2 9 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1540-7489 EI 1873-2704 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 595 EP 601 PN 1 PG 7 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 451HQ UT WOS:000169795900074 ER PT J AU Li, CP Kailasanath, K AF Li, CP Kailasanath, K TI Detonation transmission and transition in channels of different sizes SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID MIXTURES AB Numerical simulations were conducted to investigate two types of detonation diffraction phenomena: (1) detonation transmission From a small two-dimensional channel to a large one, both filled with the same ethylene-based mixture; and (2) detonation transition from a small channel filled with a stoichiometric ethylene-oxygen mixture into a large channel filled with a stoichiometic ethylene-air mixture. The transmission cases show that in the stoichiometic ethylene-oxygen mixture, the detonation originally generated in the small channel, containing eight pairs of triple points (8 Lambda), successfully transmits into the large channel, and in the stoichiometic ethylene-air mixture, the detonation from the small channel, containing only four pairs of triple points (4 Lambda). fails after its transmission into the large channel. In the transition case, the detonation front from the small channel also containing eight pairs of triple points (8 Lambda), survives its transition into the stoichiometic ethylene-air mixture in the large channel. It is interesting to note that die mixture in the large channel is the same as the mixture used in the transmission case where the detonation fails to transmit into the large channel. After the transition, the triple-point spacing increases from that observed when the detonation was still in the small channel. In all cases, the expansion waves generated at the exit of thr small channel weaken the detonation front From its edges. However. the expansion wave is only able to quench the detonation in the ethylene-air to ethylene-air case. Also, the reflected shocks From the channel walls can create local regions of high pressure and temperature and. therefore, re-ignite the mixture near the walls. However, the overall effect of the reflected shocks is quite limited in the cases studied here. The significance of these results to research on the pulse detonation engine is also discussed. C1 USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. RP USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. NR 28 TC 13 Z9 14 U1 0 U2 3 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1540-7489 EI 1873-2704 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 603 EP 609 PN 1 PG 7 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 451HQ UT WOS:000169795900075 ER PT J AU Gamezo, VN Vasil'ev, AA Khokhlov, AM Oran, ES AF Gamezo, VN Vasil'ev, AA Khokhlov, AM Oran, ES TI Fine cellular structures produced by marginal detonations SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID SHOCK AB A new regime of unstable detonation near the propagation limits was observed experimentally in a Aat channel. Highly resolved, two-dimensional reactive Navier-Stokes numerical simulations with one-step Arrhenius kinetics were used to reproduce and analyze the detonation structures involved in this regime. The regime included three kinds of detonation instability: (1) the primary instability, which causes detonation waves moving in transverse directions (transverse detonations) to appear and disappear at regular intervals behind the leading shock; (2) the instability of the overdriven parts of the leading front, which is responsible for the formation of secondary detonation cells that coexist with transverse detonation waves; and (3) the instability of transverse detonations, which produces the fine structure called transverse detonation cells. Numerical simulations showed that transverse detonations appeared when a large induction zone formed behind the leading shock. The resulting reaction-zone structure was similar to that observed for spin detonations. The transverse detonation wave burned most of the material in the induction zone, thus preventing the Formation of large unreacted pockets and leaving behind only thin tails of unreacted material. The material involved in transverse detonations was compressed by two shocks, which makes transverse detonation waves more unstable than the overdriven parts of the leading detonation front. C1 Berkeley Res Associates Inc, Springfield, VA 22150 USA. SB Russian Acad Sci, Lavrientyev Inst Hydrodynam, Novosibirsk 630090, Russia. USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. RP Gamezo, VN (reprint author), Berkeley Res Associates Inc, Springfield, VA 22150 USA. NR 22 TC 24 Z9 26 U1 0 U2 2 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 611 EP 617 PN 1 PG 7 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 451HQ UT WOS:000169795900076 ER PT J AU Smooke, MD Yetter, RA Parr, TP Hanson-Parr, DM AF Smooke, MD Yetter, RA Parr, TP Hanson-Parr, DM TI Experimental and modeling studies of two-dimensional ammonium perchlorate diffusion flames SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID COMBUSTION; GASES; CO AB We investigated two-dimensional axisymmetric diffusion flames in which the surface decomposition products of ammonium perchlorate (AP) combustion provided the coflow for a methane fuel stream. The two-dimensional problem was solved using the fully elliptic formulation of the governing equations. By utilizing recent developments in hydrocarbon, chlorine, NOx, and AP kinetics, we formulated a detailed transport, finite rate chemistry system for the temperature, velocities, vorticity, and species mass fractions of the combined flame system. We compared the results of this model with a series of experimental measurements in which the temperature was measured with OH rotational population distribution, and the transient species OH, CN, and NH were measured with planar laser-induced fluorescence and emission spectroscopy. The kinetic mechanism, previously validated in one-dimensional experiments, was found to give good results in two-dimensional model when compared with the experiments. The two-dimensional model can be used to understand the effects of solid propellant heterogeneity on combustion zone microstructure and the location and structure of heat release zones that control the propellant ballistic properties. It is a first step in developing computer codes that can a priori predict propellant ballistic behavior via modeling, thereby partially supplanting expensive physical formulation and testing. C1 Yale Univ, Dept Mech Engn, New Haven, CT 06520 USA. Penn State Univ, Dept Mech & Nucl engn, University Pk, PA 16802 USA. USN, Air Warfare Ctr, Weapons Div, China Lake, CA 93555 USA. RP Smooke, MD (reprint author), Yale Univ, Dept Mech Engn, New Haven, CT 06520 USA. NR 22 TC 9 Z9 9 U1 1 U2 6 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 839 EP 846 PN 1 PG 8 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 451HQ UT WOS:000169795900103 ER PT J AU Ernst, LF Dryer, FL Yetter, RA Parr, TP Hanson-Parr, DM AF Ernst, LF Dryer, FL Yetter, RA Parr, TP Hanson-Parr, DM TI Aluminum droplet combustion in fluorine and mixed oxygen/fluorine containing environments SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH AB Experimental and numerical results are reported on the combustion of single aluminum (Al) droplets, 187 mum diameter, that were laser ignited in quiescent environments of SF(6) and SF(6)/O(2) or Ar mixtured. Combustion measurements consisted of luminosity versus time traces, photographic observations, and electron probe microanalysis (EPMA) and electron microscope inspection of condensed-phase products of combustion surrounding burn-intercepted droplets. Planar laser-induced fluorescence (PLIF) was employed to image the gaseous intermediate reaction species AlO during droplet combustion in SF(6)/O(2) mixtures. Aluminum droplets burning in pure SF(6) burned without condensed-phase products in the surrounding envelope flames. Accordingly, no condensed-phase products were found on surfaces of droplets captured by quenching into an inert environment. In SF(6), classical d(2) law burning behavior was observed. Droplets burned in SF(6)/Ar mixtures exhibited similar behavior, with diminished burning rates. Disruptive burning was not observed for pure SF(6) or any of the SF(6)/Ar mixtures. Condensed-phase deposits on quench plates intercepting burning droplets showed the surrounding gaseous flame structure to consist of two zones for burning in SF(6) and three zones in SF(6)/O(2) mixtures. For each system, near the surface where the gas phase was aluminum rich, significant amounts of sulfur were found in the condensed products. PLIF showed the species profile of AlO to shift closer to the surface with increasing fluorine content in SF(6)/O(2) mixtures. Experimental results were compared with a local equilibrium combustion model. The model predicted burn rates within 20% and qualitatively predicted radial profile speciation. As the O/F ratio was increased, the final equilibrium products were predicted to shift from AlF(3) to AlF(2)O to Al(2)O(3). The formation of Alf(2)O reduced condensed-phase products at the reaction temperature for a wide range of O/F ratios. C1 Princeton Univ, Dept Mech & Aerosp Engn, Princeton, NJ 08544 USA. Penn State Univ, Dept Mech & Nucl Engn, University Pk, PA 16802 USA. USN, Combust Diagnost Lab, Air Warfare Ctr, China Lake, CA 93555 USA. RP Ernst, LF (reprint author), Princeton Univ, Dept Mech & Aerosp Engn, Princeton, NJ 08544 USA. NR 21 TC 2 Z9 2 U1 1 U2 6 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1540-7489 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 871 EP 878 PN 1 PG 8 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 451HQ UT WOS:000169795900107 ER PT J AU Cole, JA Parr, TP Widmer, NC Wilson, KJ Schadow, KC Seeker, WMR AF Cole, JA Parr, TP Widmer, NC Wilson, KJ Schadow, KC Seeker, WMR TI Scaling criteria for the development of an acoustically stabilized dump combustor SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID PERIODIC-FLOW FIELD; PREMIXED COMBUSTION; MIXING LAYERS AB Acoustic stabilization of combustion in a dump configuration results in completion of combustion in a relatively short residence time with simultaneously low emissions of oxides of nitrogen, carbou monoxide. and hydrocarbons. Acoustically stabilized combustion is also a potential means for achieving closed-loop active control of combustion. Therefore, a promising burner configuration identified through laboratory bench-top experiments was developed and scaled up for application as an afterburner for a starved-air incinerator with the objective of providing a compact device capable of achieving pollutant emissions performance better than required by current International Maritime Organization regulations. In the absence of established scaling criteria, factors governing vortex generation and jet mixing theory were examined. These provided useful guidelines for burner design as the dump combustor was successively scaled up from a 4.75 kW laboratory experiment to a nominal 700 kW unit tested on a starved-air incinerator Key parameters considered were the central air jet velocity, jet diameter (and area) acoustic driving frequency, and characteristic jet mixing time. Burner performance was maintained or improved as both jet velocity and jet area were increased approximately as the square root of burner scale. This resulted in increased in the acoustic driving frequency and bumps pressure drop with scale, which have implications for development of even larger burners using this technology. Initial development was contucted using simulated low-Btu gas mixtures at ambient temperature. Application as an afterburner required hardware modifications to accommodate higher gas volumes at higher temperatures. Despite significant changes in burner geometry, coherent vortex generation was established by acoustic excitation and contained to effect reductions in NOx and CO emissions. The higher combustion temperatures encountered with hot simulated and real pyrolysis products led to, higher CO and NOx emissions, but emission performance continued to exceed applicable regulatory guidelines by a substantial margin. C1 GE Energy & Environm Res Corp, Irvine, CA USA. USN, Warfare Ctr, Weap Div, China Lake, CA USA. Univ Erlangen Nurnberg, D-8520 Erlangen, Germany. Princeton Univ, Princeton, NJ 08544 USA. RP Cole, JA (reprint author), GE Energy & Environm Res Corp, Irvine, CA USA. NR 17 TC 4 Z9 4 U1 0 U2 1 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 1297 EP 1304 PN 1 PG 8 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 451HQ UT WOS:000169795900158 ER PT J AU Smooke, MD Yetter, RA Parr, TP Hanson-Parr, DM Tanoff, MA Colket, MB Hall, RJ AF Smooke, MD Yetter, RA Parr, TP Hanson-Parr, DM Tanoff, MA Colket, MB Hall, RJ TI Computational and experimental study of ammonium perchlorate/ethylene counterflow diffusion flames SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID SOOT AB Mie investigated the modeling of counterflow diffusion flames in which the products of ammonium perchlorate (AP) combustion were counterflowed against an ethylene fuel stream. The hvo-dimensional problem can be reduced to a one-dimensional boundary value problem along the stagnation point streamline through the introduction of a similarity transformation. By utilizing recent developments in hydrocarbon, chlorine, NO, and AP kinetics, we formulated a detailed transport, finite-rate chemistry system for the temperature, velocity, and species mass fractions of the combined flame system. A detailed soot model is included which can predict soot volume fractions as a function of the strain rate and the fuel mole fraction. We compare the results of this model with a series of experimental measurements in which the temperature was measured with radiation-corrected thermocouples and OH rotational population distribution; several important species were measured with planar laser-induced fluorescence, UV-visible absorption, and Raman spectroscopies; and the soot volume fraction was measured with laser-induced incandescence and visible absorption spectroscopy. C1 Yale Univ, Dept Mech Engn, New Haven, CT 06520 USA. Penn State Univ, Dept Mech & Nucl Engn, University Pk, PA 16802 USA. USN, Weapon Div, Air Warfare Ctr, China Lake, CA 93555 USA. WK Kellogg Inst, Battle Creek, MI 49016 USA. United Technol Res Ctr, E Hartford, CT 06108 USA. Univ Delaware, Newark, DE 19716 USA. Case Western Reserve Univ, Cleveland, OH 44106 USA. RP Smooke, MD (reprint author), Yale Univ, Dept Mech Engn, New Haven, CT 06520 USA. NR 29 TC 14 Z9 15 U1 1 U2 4 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 2013 EP 2020 PN 2 PG 8 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 452QN UT WOS:000169870400067 ER PT J AU Golden, DM AF Golden, DM TI Interaction of combustion with the atmosphere SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH AB The goal of this paper is to provide the combustion community with some chemical insight into why control of effluents from combustion processes is important. An overview of atmospheric chemistry in the troposphere and stratosphere is presented with emphasis on anthropogenic effects. These effects have large contributions from applications of combustion of fossil fuels. An overview of the makeup of atmospheric regions and some of the background chemistry is followed by consideration of the chemical consequences of release to the atmosphere of chemicals related to combustion processes. A chemical mechanistic explanation for specific atmospheric effects is discussed. These include: photochemical smog-an urban effect: acid rain-a regional problem; stratospheric ozone depletion-a global problem; polar ozone depletion-a corollary to global depletion: and possible climate change-an effect whose dimensions are still being questioned. The chemistry of the "clean" troposphere is a balance between the production and loss of ozone in the process of oxidizing CO to CO2. The balance is controlled by the NOx concentration. The addition of hydrocarbons into urban atmospheres starts a chemical process that resembles tow-temperature, photochemically driven combustion, Stratospheric ozone depletion is discussed in terms of the chemistry of HO, NO, and Cl, all of which take part in chain processes that catalyze the ozone destruction process represented by the reaction: O + O-3 --> 2O(2). The effects of reactions on particulates manifesting in phenomena such as the "antarctic ozone hole" are detailed. The "natural greenhouse effect" is discussed, and the potential for anthropogenic enhancement is considered. C1 Stanford Univ, Dept Mech Engn, Stanford, CA 94305 USA. SRI Int, Phys Mol Lab, Menlo Park, CA 94025 USA. USN, Res Lab, Washington, DC 20375 USA. RP Golden, DM (reprint author), Stanford Univ, Dept Mech Engn, Stanford, CA 94305 USA. NR 10 TC 5 Z9 5 U1 0 U2 1 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 2383 EP 2392 PN 2 PG 10 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 452QN UT WOS:000169870400110 ER PT J AU Moskaleva, LV Lin, MC AF Moskaleva, LV Lin, MC TI The spin-conserved reaction CH+N-2 -> H+NCN: A major pathway to prompt NO studied by quantum /statistical theory calculations and kinetic modeling of rate constant SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID TRANSITION-STATE-THEORY; POTENTIAL-ENERGY SURFACES; TEMPERATURE-DEPENDENCE; MECHANISM; PRESSURE; NITROGEN; DENSITY; FLAMES; NCN; SPECTROSCOPY AB A new spin-conserved path for the CH((II)-I-2) + N-2 reaction at temperatures relevant to prompt NO formation has been theoretically investigated by means of nb initio MO calculations at the G2M level of theory. The result of the calculation reveals that the CH((II)-I-2) + N-2 reaction takes place primarily via the ground electronic doublet potential energy surface,producing H + NCN instead of the commonly assumed, spin-forbidden HCN + N(S-4) products. The overall rate constant for NCN production has been computed by a multichannel canonical variational Rice Ramsperger-Kassel-Marcus theory calculation for the temperature range 1500-4000 K at 0.5-2 atm pressure: k(3) = 2.22 X 10(7) T-1.48 exp (-11760/T) cm(3)/(mol.s). The theoretically predicted rate constant was found to be in good agreement with high-temperature shock tube data kinetically modeled with the new mechanism that includes NCN reactions. In addition, k(3) was also found to be consistent with the apparent rate constants previously modeled for prompt NO formation in several flame studies. C1 Emory Univ, Dept Chem, Atlanta, GA 30322 USA. Univ Karlsruhe, Karlsruhe, Germany. USN, Res Lab, Washington, DC 20375 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. RP Moskaleva, LV (reprint author), Emory Univ, Dept Chem, Atlanta, GA 30322 USA. RI Moskaleva, Lyudmila/D-1889-2012 OI Moskaleva, Lyudmila/0000-0003-0168-7126 NR 42 TC 86 Z9 89 U1 0 U2 12 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 2393 EP 2401 PN 2 PG 9 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 452QN UT WOS:000169870400111 ER PT J AU Ju, YG Law, CK AF Ju, YG Law, CK TI Dynamics and extinction of non-adiabatic particle-laden premixed flames SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID RADIATION-AFFECTED DYNAMICS; SPHERICAL FLAMES; TEMPERATURE-LAGS; GASEOUS FLAMES; PROPAGATION; PREMIXTURES AB Propagation and extinction of gaseous premixed flames seeded with inert particles were analytically and numerically investigated for the one-dimensional, planar H-2/O-2/N-2. and CH4/air flames, with particular interest on the joint effects of gas-particle heat conduction, gas-particle radiation heat loss, and gas-particle velocity lag. Analytical expressions were derived for the non-adiabatic particle-laden flame speed and the state of extinction allowing for the first two effects. These results reduce to the classical theories for the non-adiabatic particle-free flame and the adiabatic particle-laden flame in the limits of vanishing particle concentration and vanishing radiative heat loss, respectively. It is shown that small particles behave lih a diluent gas and induce a flammability limit based on the particle concentration. For moderate particle size, there are multiple flame regimes and extinction points due to the combined effects of the gas-particle conduction heat transfer and radiative heat loss. For large particle size, the fast flame extinction limit is extended, while the slow flame regime is narrowed. Numerical calculations allowing for all effects show that the particle velocity lag greatly affects the flame speed and the state of extinction. Comparison of the numerical and analytical results with the literature experimental data shows good agreement for small particle size. It is emphasized that the existence of multiple solutions is an intrinsic Feature of particle-laden flames. C1 Princeton Univ, Dept Mech & Aerosp Engn, Princeton, NJ 08544 USA. Purdue Univ, W Lafayette, IN 47907 USA. USN, Res Lab, Washington, DC 20375 USA. RP Ju, YG (reprint author), Princeton Univ, Dept Mech & Aerosp Engn, Princeton, NJ 08544 USA. RI Law, Chung /E-1206-2013 NR 16 TC 3 Z9 3 U1 1 U2 2 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 2913 EP 2920 PN 2 PG 8 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 452QN UT WOS:000169870400175 ER PT J AU Zegers, EJP Williams, BA Sheinson, RS Fleming, JW AF Zegers, EJP Williams, BA Sheinson, RS Fleming, JW TI Dynamics and suppression effectiveness of monodisperse water droplets in non-premixed counterflow flames SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID EXTINCTION AB In situ measurements of velocity and size distributions of initially monodisperse water mists of initial diameters ranging from 14 mum to 42 mum seeded into the air stream of non-premixed propane/air counterflow flames are reported. Droplets were generated piezoelectrically, and the size and velocity distributions and the number density were determined by phase-Doppler particle anemometry Droplets having initial diameters of 18 mum underwent complete vaporization in a counterflow flame at a strain rate of approximately 170 s(-1), while droplets of 30 mum penetrated slightly beyond the visible flame zone. Measurements of the effect of water droplets on the extinction strain rates of propane/air counterflow flames were performed. Droplets having initial diameters of 14 mum and 30 mum where found to have similar suppression effectiveness, while droplets of 42 mum were substantially less effective at reducing the extinction strain rates. Both the 14 mum and 30 mum water droplets were found to be more effective, on a mass basis, than CF3Br The present experimental results are in excellent agreement with the predictions of recent modeling studies exploring the behavior of various sized water droplets in counterflow flame. C1 USN, Res Lab, Div Chem, Combust Dynam Sect, Washington, DC 20375 USA. USN, Res Lab, Washington, DC 20375 USA. RP Zegers, EJP (reprint author), USN, Res Lab, Div Chem, Combust Dynam Sect, Code 6185, Washington, DC 20375 USA. NR 10 TC 33 Z9 33 U1 0 U2 3 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 2931 EP 2937 PN 2 PG 7 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 452QN UT WOS:000169870400177 ER PT B AU Goodman, IR Nguyen, HT AF Goodman, IR Nguyen, HT BE Wang, PP TI Computational aspects of quantitative second order probability logic and fuzzy if-then rules: Part 1, basic representations as integrals SO PROCEEDINGS OF THE FIFTH JOINT CONFERENCE ON INFORMATION SCIENCES, VOLS 1 AND 2 LA English DT Proceedings Paper CT 5th Joint Conference on Information Sciences (JCIS 2000) CY FEB 27-MAR 03, 2000 CL ATLANTIC CITY, NJ SP Assoc Intelligent Machinery, Machine Intelligent & Fussy Log Lab, Elsevier Publishing Co, Inc, Informat Sci Journal, USA Res Off DE probability logic; second order probabilities; deduction; if-then rules; integral representations AB This paper shows how the general quantitative aspects of a newly emerging probability logic based upon second order probability considerations can be established within a setting of exponential integral representations which may, in turn, be amenable to various implementation and approximation techniques recently developed in polytope theory and related areas. C1 USN, Space & Naval Warfare Syst Ctr, San Diego, CA 92152 USA. RP USN, Space & Naval Warfare Syst Ctr, Code D44215, San Diego, CA 92152 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU ASSOC INTELLIGENT MACHINERY PI DURHAM PA PO BOX 90291, DURHAM, NC 27708-0291 USA BN 0-9643456-9-2 PY 2000 BP 64 EP 67 PG 4 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BV66Q UT WOS:000179698300019 ER PT B AU Moskowitz, IS Chang, LW AF Moskowitz, IS Chang, LW BE Wang, PP TI A decision theoretical based system for information downgrading SO PROCEEDINGS OF THE FIFTH JOINT CONFERENCE ON INFORMATION SCIENCES, VOLS 1 AND 2 LA English DT Proceedings Paper CT 5th Joint Conference on Information Sciences (JCIS 2000) CY FEB 27-MAR 03, 2000 CL ATLANTIC CITY, NJ SP Assoc Intelligent Machinery, Machine Intelligent & Fussy Log Lab, Elsevier Publishing Co, Inc, Informat Sci Journal, USA Res Off AB It is sometimes necessary for the owner of proprietary data to publicize some of it while keeping the rest as private. For example, when releasing census data or corporate financial information, the release must be conducted in a manner consistent with individual privacy. The process of publicly releasing formerly private data is called downgrading. However, it may be possible to infer unreleased private information from the downgraded public information-the so-called inference problem. Here, we discuss some of the design decisions that we have made, and continue to make, concerning our prototype for a high assurance system that evaluates downgrading decisions based upon the amount of private information that may be deduced through inference. Our software system, the Rational Downgrader, is composed of a knowledge-based decision maker to determine the rules that may be inferred, a GUARD to measure the amount of leaked information, and a parsimonious downgrader to modify the initial downgrading decisions. At present, we have restricted the Rational Downgrader to relational databases. Of course, the underlying theories apply to all forms of data. In this paper, we concentrate on design decisions made with the aim of achieving high assurance with respect to an optimality condition. C1 USN, Res Lab, Ctr High Assurance Comp Syst, Washington, DC 20375 USA. RP Moskowitz, IS (reprint author), USN, Res Lab, Ctr High Assurance Comp Syst, Mail Code 5540, Washington, DC 20375 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU ASSOC INTELLIGENT MACHINERY PI DURHAM PA PO BOX 90291, DURHAM, NC 27708-0291 USA BN 0-9643456-9-2 PY 2000 BP 349 EP 354 PG 6 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BV66Q UT WOS:000179698300089 ER PT B AU Jablonski, NH Caruso, J AF Jablonski, NH Caruso, J GP IEEE IEEE TI Data extraction in a real-time environment using COTS equipment SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc DE AEGIS; AN/SPY-1; radar; VxWorks; data recording AB The evaluation and certification of tactical radar systems is a complex undertaking, which requires extensive data collection,; analysis, and testing. In the past, the radar community has been limited in its ability to extract data for offline evaluation by relatively low peripheral device speeds, storage capacity, and Limited computing resources. The Naval Surface Warfare Center, Dahlgren Division (NSWCDD) has been investigating distributed computing techniques using commercial components for an Advanced Radar Control Computer system. A portion of this project is dedicated to enhancing the tools and methodologies required to debug, evaluate, and certify tactical radar control systems. This paper describes the evaluation system and the performance levels that were achieved using widely available, commercial-off-the-shelf components (COTS). The final product provides more than adequate data extraction capacity while minimizing impact on the radar application, and consuming less than 30% of computer processing time. Achieving this level of performance allows analysts to gather data from all possible data collection points simultaneously throughout an evaluation run, thus providing unconstrained analysis capability. Data compression is employed to produce extended recording times and enhance the performance of slower data peripherals such as those using magneto-optical media. C1 USN, Ctr Surface Warfare, Radar Control Syst Branch, Dahlgren, VA 22448 USA. RP Jablonski, NH (reprint author), USN, Ctr Surface Warfare, Radar Control Syst Branch, Dahlgren, VA 22448 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 58 EP 65 DI 10.1109/NAECON.2000.894892 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900005 ER PT J AU Blank, DA Wu, C AF Blank, DA Wu, C TI Cooling and heating rate limits of a reversed reciprocating Ericsson cycle at steady state SO PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART A-JOURNAL OF POWER AND ENERGY LA English DT Article DE Ericsson cycle; cooling; air conditioning; heat pumps; heating; irreversible thermodynamics AB The optimal cooling and heating rates for the reversed reciprocating Ericsson cycle with ideal regeneration are determined for heat pump operations. These limiting rates are based on the upper and lower thermal reservoir temperature bounds and are obtained using time and entropy minimization procedures from irreversible thermodynamics. Use is made of time symmetry (a second law constraint) to minimize cycle time. This optimally allocates the thermal capacitances of the cycle and minimizes internal cycle entropy generation. Although primarily a theoretical work, a very practical and extensive parametric study using several environmentally friendly working fluids (neon, nitrogen and helium) is included. This study evaluates the relative contributions of various system parameters to rate-optimized design. The coefficient of performance (COP), and thus the quantity of cooling or heating for a given energy input, is the traditional focus; instead this work aims at the rate of cooling or heating in heat pumps under steady state conditions and using ideal gases as their working substances. The results obtained provide additional criteria for use in the study, design and performance evaluation of employing Ericsson cycles in refrigeration, air conditioning and heat pump applications. They give direct insight into what is required in designing a reversed Ericsson heat pump to achieve maximum heating and cooling rates, The choices of working,fluids and pressure ratios were found to be very significant design parameters, together with selection of regenerator and source-sink heat transfer parameters. The parameter most influencing both the heating and cooling mode COPs and the heat transfer rates was found to be the heat conductance of the thermal sink. C1 USN Acad, Dept Mech Engn, Annapolis, MD 21402 USA. RP Wu, C (reprint author), USN Acad, Dept Mech Engn, 121 Blake Rd, Annapolis, MD 21402 USA. NR 23 TC 1 Z9 1 U1 2 U2 3 PU PROFESSIONAL ENGINEERING PUBLISHING LTD PI BURY ST EDMUNDS PA NORTHGATE AVENUE,, BURY ST EDMUNDS IP32 6BW, SUFFOLK, ENGLAND SN 0957-6509 J9 P I MECH ENG A-J POW JI Proc. Inst. Mech. Eng. Part A-J. Power Energy PY 2000 VL 214 IS A1 BP 75 EP 85 DI 10.1243/0957650001537877 PG 11 WC Engineering, Mechanical SC Engineering GA 292AG UT WOS:000085771500009 ER PT J AU Wu, C AF Wu, C TI Intelligent computer aided optimization of power and energy systems - Reply SO PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART A-JOURNAL OF POWER AND ENERGY LA English DT Editorial Material C1 US Naval Acad, Dept Navy, Dept Mech Engn, Annapolis, MD 21402 USA. RP Wu, C (reprint author), US Naval Acad, Dept Navy, Dept Mech Engn, Annapolis, MD 21402 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PROFESSIONAL ENGINEERING PUBLISHING LTD PI BURY ST EDMUNDS PA NORTHGATE AVENUE,, BURY ST EDMUNDS IP32 6BW, SUFFOLK, ENGLAND SN 0957-6509 J9 P I MECH ENG A-J POW JI Proc. Inst. Mech. Eng. Part A-J. Power Energy PY 2000 VL 214 IS A3 BP 288 EP 289 PG 2 WC Engineering, Mechanical SC Engineering GA 355KY UT WOS:000089385900011 ER PT J AU Song, G Schmidt, SP Agrawal, BN AF Song, G Schmidt, SP Agrawal, BN TI Active vibration suppression of a flexible structure using smart material and a modular control patch SO PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART G-JOURNAL OF AEROSPACE ENGINEERING LA English DT Article DE miniaturized digital controller; positive position feedback control; strain rate feedback control; vibration suppression; multimode vibration suppression; smart sensors and actuators AB This paper presents experimental results of vibration suppression of a flexible structure using smart materials and a miniaturized digital controller, called the modular control patch (MCP). The MCP employs a TI-C30 digital signal processor and was developed by TRW for the United States Air Force for future space vibration control. In this research, the MCP is used to implement different control algorithms for vibration suppression of a cantilevered aluminium beam. The beam is equipped with smart sensors and actuators, and both are made of piezoceramics. Positive position feedback (PPF) control, strain rate feedback (SRF) control and their combinations were implemented. Experiments found that PPF control is most effective for single-mode vibration suppression, and two PPF filters in parallel are most effective for multimode vibration suppression. Experiments also demonstrated the capacity of smart material being used as sensors and actuators for vibration suppression. The MCP was shown to be capable of implementing various real-time control laws. C1 Univ Akron, Dept Mech Engn, Akron, OH 44325 USA. USN, Postgrad Sch, Dept Aeronaut & Astronaut, Spacecraft Res & Design Ctr, Monterey, CA 93943 USA. RP Song, G (reprint author), Univ Akron, Dept Mech Engn, ASEC-107D, Akron, OH 44325 USA. NR 7 TC 29 Z9 32 U1 1 U2 13 PU PROFESSIONAL ENGINEERING PUBLISHING LTD PI BURY ST EDMUNDS PA NORTHGATE AVENUE,, BURY ST EDMUNDS IP32 6BW, SUFFOLK, ENGLAND SN 0954-4100 J9 P I MECH ENG G-J AER JI Proc. Inst. Mech. Eng. Part G-J. Aerosp. Eng. PY 2000 VL 214 IS G4 BP 217 EP 229 DI 10.1243/0954410001532024 PG 13 WC Engineering, Aerospace; Engineering, Mechanical SC Engineering GA 386EN UT WOS:000166047400003 ER PT B AU Zolper, JC AF Zolper, JC GP IPAP IPAP IPAP TI Prospects for gallium nitride based electronic devices SO PROCEEDINGS OF THE INTERNATIONAL WORKSHOP ON NITRIDE SEMICONDUCTORS SE IPAP CONFERENCE SERIES LA English DT Proceedings Paper CT International Workshop on Nitride Semiconductors (IWN 2000) CY SEP 24-27, 2000 CL NAGOYA, JAPAN SP Japan Soc Appl Phys, Solid State Phys & Applicat Div, Japan Soc Promot Sci, Comm Short Wavelength Optoelectr Devices, 162, Japan Soc Promot Sci, Comm Convers Light & Elect, 125 DE gallium nitride; AlGaN; HEMTs; HBTs; power amplifiers; low noise amplifiers ID FIELD-EFFECT TRANSISTOR; NOISE-FIGURE; MICROWAVE; MOBILITY; CHARGE; PERFORMANCE AB GaN, along with the other binary Nitrides (InN and AIN), represent a class of wide bandgap semiconductors that can be used to realized several electronic devices that are now, or will soon, outperform the GaAs or InP counterpart. AlGaN/GaN High Electron Mobility Transistors (HEMTs) are the most promising for microwave power generation. In addition, AlGaN HEMTs are now competitive for low noise receiver amplifiers. In addition, GaN-based HBTs and microwave limiters also show great promise. C1 Off Naval Res, Arlington, VA 22217 USA. RP Zolper, JC (reprint author), Off Naval Res, Code 312,800 N Quincy St, Arlington, VA 22217 USA. NR 29 TC 0 Z9 0 U1 0 U2 0 PU INST PURE APPLIED PHYSICS PI TOKYO PA DAINI TOYOKAIJI BLDG 24-8 SHINBASHI 4 CHOME, TOKYO, 105-0004, JAPAN BN 4-900526-13-4 J9 IPAP CONFERENCE SER PY 2000 VL 1 BP 997 EP 1002 PG 6 WC Engineering, Electrical & Electronic; Optics; Physics, Applied; Physics, Condensed Matter SC Engineering; Optics; Physics GA BS99R UT WOS:000171608500256 ER PT S AU Gomez, J Shukla, A AF Gomez, J Shukla, A GP SEM SEM TI Static/dynamic behavior of concrete and granite with induced damage SO PROCEEDINGS OF THE SEM IX INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS SE PROCEEDINGS OF THE INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS LA English DT Proceedings Paper CT SEM 9th International Congress on Experimental Mechanics CY JUN 05-08, 2000 CL ORLANDO, FL SP British Soc Strain Measurement, Chinese Soc Mech Engineers, Japan Soc Mech Engineers Mat & Mech Div, Machinery Failure Pervent Technol Soc, Korean Soc, Mech Engineers, Mat & Fracture Div, SEM Republic China Local Sect, Shock & Vibrat Informat Analy Ctr, strain Soc South Africa AB A series of dynamic and static tensile-splitting experiments were performed on concrete and granite specimens to investigate the effect of induced damage on their tensile strength. These experiments were performed as part of a larger effort investigating the penetration process into the two materials. The strain rate each specimen was subjected to remained constant for these experiments, while the level of induced damage was increased. Damage was induced into the specimens through repeated drop-weight impacts and quantified using a statistical technique. The dynamic splitting experiments were performed using a Split Hopkinson Pressure Bar (SHPB), while the static splitting experiments were conducted per the ASTM standard procedures D3967 and C496. As part of the investigation, photoelastic dynamic tensile-splitting experiments were also performed to establish the validity of using static relations for the determination of dynamic tensile strength. The experiments showed that the static splitting strength was highly dependent on the orientation of the induced damage with regard to the applied loading, however the dynamic tensile strength decreased with increasing damage with no apparent dependency on the random damage orientation. An ongoing photoelastic experimental investigation is continuing to examine the insensitivity of dynamic splitting strength to damage orientation. C1 USN, Undersea Warfare Ctr, Newport, RI 02841 USA. RP Gomez, J (reprint author), USN, Undersea Warfare Ctr, Code 8232, Newport, RI 02841 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 1046-672X BN 0-91205-369-0 J9 P INT CONG EXPERIT M PY 2000 BP 245 EP 248 PG 4 WC Engineering, Mechanical; Mechanics; Physics, Applied SC Engineering; Mechanics; Physics GA BU51C UT WOS:000176203100066 ER PT S AU Chang, CC Vohra, S AF Chang, CC Vohra, S GP SEM SEM TI Development of fiber Bragg grating based transducers SO PROCEEDINGS OF THE SEM IX INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS SE PROCEEDINGS OF THE INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS LA English DT Proceedings Paper CT SEM 9th International Congress on Experimental Mechanics CY JUN 05-08, 2000 CL ORLANDO, FL SP British Soc Strain Measurement, Chinese Soc Mech Engineers, Japan Soc Mech Engineers Mat & Mech Div, Machinery Failure Pervent Technol Soc, Korean Soc, Mech Engineers, Mat & Fracture Div, SEM Republic China Local Sect, Shock & Vibrat Informat Analy Ctr, strain Soc South Africa ID TEMPERATURE; SENSORS; LOAD AB Some issues pertaining to the design and development of practical fiber Bragg grating (FBG) based transducers are addressed. In general, FBG sensors are attached to sensing elements by two methods, as (i) surface-mounted FBG and (ii) embedded FBG. For the surface-mounted case, the investigation of strain gradient induced spectral broadening in FBG attached-based transducer has been conducted. Because Bragg spectral broadening can have adverse effects on the sensor interrogation, a circular diaphragm pressure transducer is used as an example. We derive analytical closed form results for describing measurand-induced strain gradients in circular geometry transducers. In addition, Bragg spectral broadening analysis by use of T-matrix calculation is also conducted to validate some of the experimental results. For the embedded case, the investigation of strain transfer between FBG and host transducers has been conducted. Therefore, a transducer, made by aluminum epoxy with embedded FBG material, subjected to transverse load is used as an example, where FBGs are subjected to lateral expansion of the host epoxy. A shear-lag analysis with incorporation of the experimental result was given. Finally, the three FBG normal strain estimations (one longitudinal and two transverses) are all verified by finite element approach. C1 USN, Res Lab, Washington, DC 20375 USA. RP Chang, CC (reprint author), USN, Res Lab, Code 5673,4555 Overlook Ave SW, Washington, DC 20375 USA. NR 13 TC 0 Z9 0 U1 1 U2 1 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 1046-672X BN 0-91205-369-0 J9 P INT CONG EXPERIT M PY 2000 BP 826 EP 829 PG 2 WC Engineering, Mechanical; Mechanics; Physics, Applied SC Engineering; Mechanics; Physics GA BU51C UT WOS:000176203100221 ER PT S AU Ricci, V Kavaturu, M Shukla, A AF Ricci, V Kavaturu, M Shukla, A GP SEM SEM TI Using strain gages to investigate subsonic interfacial fracture SO PROCEEDINGS OF THE SEM IX INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS SE PROCEEDINGS OF THE INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS LA English DT Proceedings Paper CT SEM 9th International Congress on Experimental Mechanics CY JUN 05-08, 2000 CL ORLANDO, FL SP British Soc Strain Measurement, Chinese Soc Mech Engineers, Japan Soc Mech Engineers Mat & Mech Div, Machinery Failure Pervent Technol Soc, Korean Soc, Mech Engineers, Mat & Fracture Div, SEM Republic China Local Sect, Shock & Vibrat Informat Analy Ctr, strain Soc South Africa ID ORTHOTROPIC COMPOSITE-MATERIALS; STRESS INTENSITY FACTOR; CRACK-GROWTH; DYNAMIC FRACTURE; BIMATERIAL INTERFACES; TIP FIELDS; DECOHESION; CRITERIA; GAUGES C1 USN, Undersea Warfare Ctr Div, Strateg Planning & Dev Off, Newport, RI 02841 USA. RP Ricci, V (reprint author), USN, Undersea Warfare Ctr Div, Strateg Planning & Dev Off, 1176 Howell St,Code 31B, Newport, RI 02841 USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 1046-672X BN 0-91205-369-0 J9 P INT CONG EXPERIT M PY 2000 BP 872 EP 875 PG 2 WC Engineering, Mechanical; Mechanics; Physics, Applied SC Engineering; Mechanics; Physics GA BU51C UT WOS:000176203100234 ER PT B AU Kirsteins, IP Rangaswamy, M AF Kirsteins, IP Rangaswamy, M GP IEEE IEEE TI Approximate CFAR signal detection in strong low rank non-Gaussian interference SO PROCEEDINGS OF THE TENTH IEEE WORKSHOP ON STATISTICAL SIGNAL AND ARRAY PROCESSING LA English DT Proceedings Paper CT 10th IEEE Workshop on Statistical Signal and Array Processing CY AUG 13-16, 2000 CL POCONO MANOR, PA SP IEEE, Signal Proc Soc AB We have devised a new generalized likelihood ratio test for detecting a signal in unknown, strong non-Gaussian low rank interference plus white Gaussian noise which needs no knowledge of the non-Gaussian distribution. From perturbation expansions of the test statistic, we establish the connection of the proposed GLRT detector to the UMPI test and show that it is approximately CFAR. Computer simulations indicate that the new detector significantly outperforms traditional adaptive methods in non-Gaussian interference. C1 USN, Undersea Warfare Ctr, Newport, RI 02841 USA. RP Kirsteins, IP (reprint author), USN, Undersea Warfare Ctr, Code 8212, Newport, RI 02841 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5988-7 PY 2000 BP 286 EP 290 DI 10.1109/SSAP.2000.870129 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA BR09H UT WOS:000165630400061 ER PT B AU Chen, VC AF Chen, VC GP IEEE IEEE TI Analysis of radar micro-doppler signature with time-frequency transform SO PROCEEDINGS OF THE TENTH IEEE WORKSHOP ON STATISTICAL SIGNAL AND ARRAY PROCESSING LA English DT Proceedings Paper CT 10th IEEE Workshop on Statistical Signal and Array Processing CY AUG 13-16, 2000 CL POCONO MANOR, PA SP IEEE, Signal Proc Soc AB Micro-Doppler induced by mechanical vibrating or rotating of structures in a radar target is potentially useful for target detection, classification and recognition. While the Doppler frequency induced by the target body is constant, the micro-Doppler due to vibrating or rotating structures of the target is a function of dwell time. Analysis of the time-varying Doppler signature in the joint time-frequency domain can provide useful information for target detection, classification and recognition. C1 USN, Res Lab, Washington, DC 20375 USA. RP Chen, VC (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 8 TC 98 Z9 151 U1 1 U2 11 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5988-7 PY 2000 BP 463 EP 466 DI 10.1109/SSAP.2000.870167 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BR09H UT WOS:000165630400098 ER PT B AU Fiedler, R Jansen, R AF Fiedler, R Jansen, R GP IEEE IEEE TI Joint time-frequency analysis of SAR data SO PROCEEDINGS OF THE TENTH IEEE WORKSHOP ON STATISTICAL SIGNAL AND ARRAY PROCESSING LA English DT Proceedings Paper CT 10th IEEE Workshop on Statistical Signal and Array Processing CY AUG 13-16, 2000 CL POCONO MANOR, PA SP IEEE, Signal Proc Soc AB The image formation process associated with coherent imaging sensors is particularly sensitive to and is often corrupted by non-stationary processes. In the case of synthetic aperture radar (SAR), non-stationary processes result from motion within the scene, variable radar cross section, multi-path, topographic variations, sensor anomalies, and deficiencies in the image formation processing chain. This paper addresses SAR image formation processing, the complex response function for a point source, and SAR JTF image formation implementations. Each of these topics is described within the context of applying JTF processing to all aspects of SAR image formation and analysis. C1 USN, Res Lab, Washington, DC 20375 USA. RP Fiedler, R (reprint author), USN, Res Lab, 4555 Overlook Ave SW, Washington, DC 20375 USA. NR 6 TC 4 Z9 4 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5988-7 PY 2000 BP 480 EP 484 DI 10.1109/SSAP.2000.870171 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA BR09H UT WOS:000165630400102 ER PT B AU Groutage, D Bennink, D AF Groutage, D Bennink, D GP IEEE IEEE TI A new matrix decomposition based on optimum transformation of the singular value decomposition basis sets yields principal features of time-frequency distributions SO PROCEEDINGS OF THE TENTH IEEE WORKSHOP ON STATISTICAL SIGNAL AND ARRAY PROCESSING LA English DT Proceedings Paper CT 10th IEEE Workshop on Statistical Signal and Array Processing CY AUG 13-16, 2000 CL POCONO MANOR, PA SP IEEE, Signal Proc Soc ID SIGNALS; KERNELS AB The classification of objects or quantities in all fields of science depends on the quality of the features used for classifying them. This includes, for example, classification of phenomenon described by nonstationary processes such as electrocardiograms, seismic geophysics signals, submarine transient acoustic signals, and speech signals for recognition. This paper presents a new matrix decomposition that is used to obtain a set of principal features from time-frequency representations for classifying nonstationary time series processes. This new matrix decomposition is based a transformation of the orthonormal basis from singular value decomposition (SVD). The new basis set yields extrema of the first moment for each vector in the new basis set. These basis sets for time and frequency can then be used to construct features relating to the location and spread of each energy density highlight in the time-frequency plane. This new matrix decomposition is presented in this paper along with a simple example to illustrate its application. C1 NSWC, Puget Sound Detachment, Carderock Div, Bremerton, WA 98314 USA. RP Groutage, D (reprint author), NSWC, Puget Sound Detachment, Carderock Div, 530 Farragut Ave, Bremerton, WA 98314 USA. NR 14 TC 6 Z9 6 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5988-7 PY 2000 BP 598 EP 602 DI 10.1109/SSAP.2000.870195 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA BR09H UT WOS:000165630400126 ER PT B AU Kirschenbaum, SS Gray, WD AF Kirschenbaum, SS Gray, WD BE Gleitman, LR Joshi, AK TI The precis of Project Nemo, phase 2: Levels of expertise SO PROCEEDINGS OF THE TWENTY-SECOND ANNUAL CONFERENCE OF THE COGNITIVE SCIENCE SOCIETY LA English DT Proceedings Paper CT 22nd Annual Conference of the Cognitive-Science-Society CY AUG 13-15, 2000 CL UNIV PENNSYLVANIA, INST RES COGNIT SCI, PHILADELPHIA, PA SP Cognit Sci Soc HO UNIV PENNSYLVANIA, INST RES COGNIT SCI AB Project Nemo examines the cognitive processes and representational structures used by submarine Commanders while attempting to locate an enemy submarine hiding in deep water. In phase 2 we collected performance and protocol data from junior, mid-career, and senior submarine officers. The data support the conclusions from phase 1 (Gray, Kirschenbaum & Ehret, 1997) that most AO actions can be characterized as a sequence of small, steps in a shallow goal hierarchy (rather than as following a detailed master plan). The nature of these successive choices vary as a function of the officer's expertise. The results are congruent with an interpretation in which the process of schema instantiation provides the control of cognition. C1 USN, Undersea Warfare Ctr Div, Newport, RI 02841 USA. RP Kirschenbaum, SS (reprint author), USN, Undersea Warfare Ctr Div, Code 2214,Bldg 1171-1, Newport, RI 02841 USA. RI Gray, Wayne/C-1809-2008 OI Gray, Wayne/0000-0002-1704-7433 NR 4 TC 0 Z9 0 U1 0 U2 0 PU LAWRENCE ERLBAUM ASSOC PUBL PI MAHWAH PA 10 INDUSTRIAL AVE, MAHWAH, NJ 07430 USA BN 0-8058-3879-1 PY 2000 BP 753 EP 758 PG 6 WC Language & Linguistics; Psychology; Psychology, Multidisciplinary; Psychology, Experimental SC Linguistics; Psychology GA BS01S UT WOS:000168323000127 ER PT J AU Sausen, KP Bower, EA Stiney, M Buchanan, BS Muller, MS Feigl, C Moore, JL Clark, JB AF Sausen, KP Bower, EA Stiney, M Buchanan, BS Muller, MS Feigl, C Moore, JL Clark, JB TI Mental challenge exacerbates cardiac but not vascular responses to hypoxia SO PSYCHOSOMATIC MEDICINE LA English DT Meeting Abstract C1 USN, Aerosp Med Res Lab, Pensacola, FL USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0033-3174 J9 PSYCHOSOM MED JI Psychosom. Med. PD JAN-FEB PY 2000 VL 62 IS 1 MA 1405 BP 140 EP 140 PG 1 WC Psychiatry; Psychology; Psychology, Multidisciplinary SC Psychiatry; Psychology GA 286BM UT WOS:000085423800234 ER PT J AU Jacobs, KM Hirsch, KA AF Jacobs, KM Hirsch, KA TI Psychiatric complications of Ma-huang SO PSYCHOSOMATICS LA English DT Article ID ALTERNATIVE MEDICINE; HERBAL STIMULANT; INDUCED MANIA; EPHEDRINE; PSYCHOSIS C1 USN, Med Ctr, Med Editing Div, Dept Clin Invest, San Diego, CA 92134 USA. USN, Med Ctr, Dept Mental Hlth Serv, San Diego, CA 92134 USA. RP Jacobs, KM (reprint author), USN, Med Ctr, Med Editing Div, Dept Clin Invest, 34800 Bob Wilson Dr,Suite 5, San Diego, CA 92134 USA. NR 20 TC 25 Z9 25 U1 2 U2 3 PU AMER PSYCHIATRIC PRESS, INC PI WASHINGTON PA 1400 K ST, N W, STE 1101, WASHINGTON, DC 20005 USA SN 0033-3182 J9 PSYCHOSOMATICS JI Psychosomatics PD JAN-FEB PY 2000 VL 41 IS 1 BP 58 EP 62 PG 5 WC Psychiatry; Psychology SC Psychiatry; Psychology GA 277CF UT WOS:000084914600008 PM 10665269 ER PT J AU Schneider, DP Hill, GJ Fan, X Ramsey, LW MacQueen, PJ Weedman, DW Booth, JA Eracleous, M Gunn, JE Lupton, RH Adams, MT Bastian, S Bender, R Berman, E Brinkmann, J Csabai, I Federwitz, G Gurbani, V Hennessy, GS Hill, GM Hindsley, RB Ivezic, Z Knapp, GR Lamb, DQ Lindenmeyer, C Mantsch, P Nance, C Nash, T Pier, JR Rechenmacher, R Rhoads, B Rivetta, CH Robinson, EL Roman, B Sergey, G Shetrone, M Stoughton, C Strauss, MA Szokoly, GP Tucker, DL Wesley, G Willick, J Worthington, P York, DG AF Schneider, DP Hill, GJ Fan, X Ramsey, LW MacQueen, PJ Weedman, DW Booth, JA Eracleous, M Gunn, JE Lupton, RH Adams, MT Bastian, S Bender, R Berman, E Brinkmann, J Csabai, I Federwitz, G Gurbani, V Hennessy, GS Hill, GM Hindsley, RB Ivezic, Z Knapp, GR Lamb, DQ Lindenmeyer, C Mantsch, P Nance, C Nash, T Pier, JR Rechenmacher, R Rhoads, B Rivetta, CH Robinson, EL Roman, B Sergey, G Shetrone, M Stoughton, C Strauss, MA Szokoly, GP Tucker, DL Wesley, G Willick, J Worthington, P York, DG TI The Low-Resolution Spectrograph of the Hobby-Eberly Telescope. II. Observations of quasar candidates from the Sloan Digital Sky Survey SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID DESIGN AB This paper describes spectra of quasar candidates acquired during the commissioning phase of the Low-Resolution Spectrograph of the Hobby-Eberly Telescope. The objects were identified as possible quasars from multicolor image data from the Sloan Digital Sky Survey. The 10 sources had typical r' magnitudes of 19-20, except for one extremely red object with r' approximate to 23. The data, obtained with exposure times between 10 and 25 minutes, reveal that the spectra of four candidates are essentially featureless and are not quasars, live are quasars with redshifts between 2.92 and 4.15 (including one broad absorption line quasar), and the red source is a very late M star or early L dwarf. C1 Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Univ Texas, McDonald Observ, Dept Astron, Austin, TX 78712 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Sternwarte, D-81679 Munich, Germany. Apache Point OBserv, Sunspot, NM 88349 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Eotvos Lorand Univ, Dept Phys Comples Syst, H-1117 Budapest, Hungary. USN Observ, Washington, DC 20392 USA. USN Observ, Flagstaff, AZ 86002 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Univ Chicago, Ctr Astron & Astrophys, Chicago, IL 60637 USA. RP Schneider, DP (reprint author), Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. EM dps@astro.psu.edu RI Csabai, Istvan/F-2455-2012; OI Csabai, Istvan/0000-0001-9232-9898 NR 24 TC 21 Z9 21 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD JAN PY 2000 VL 112 IS 767 BP 6 EP 11 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 279TP UT WOS:000085061500003 ER PT J AU Imamura, JN Steiman-Cameron, TY Wolff, MT AF Imamura, JN Steiman-Cameron, TY Wolff, MT TI Coordinated optical and X-ray observations of the AM Herculis objects VV Puppis, V834 Centauri, and EF Eridani SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID QUASI-PERIODIC OSCILLATIONS; DRIVEN RADIATIVE SHOCKS; DEGENERATE DWARFS; TIMING EXPLORER; UV-RADIATION; WHITE-DWARFS; BL HYDRI; E1405-451; SPECTROSCOPY; PERFORMANCE AB We obtained coordinated broadband optical photometry and hard X-ray data on the AM Her objects VV Pup, V834 Cen,and EF Eri. The X-ray data were obtained using the Proportional Counter Array detectors of the Rossi X-Ray Timing Explorer, and the optical data were obtained using the 1 m telescope of the Cerro Tololo Inter-American Observatory. During our observations, VV Pup and V834 Cen were in their high optical luminosity states with average m(V) similar to 17 and 15.1, respectively. EF Eri was in a very low state at the time of our observation: m(V) > 17.7. VV Pup and V834 Cen had average 2-10 keV X-ray fluxes of 1.7 x 10(-12) and 2.13 x 10(-11) ergs cm(-2) s(-1), respectively. EF Eri was not detected in X-rays. The X-ray spectrum of V834 Cen was adequately modeled using an absorbed bremsstrahlung continuum with a Gaussian emission line. The best-fit model had continuum temperature kT(X) = 11.8 +/- 1.0 keV and absorption column n(H) = (1.03 +/- 0.39) x 10(22) cm(-2). The Gaussian emission line had line center energy E = 6.7 +/- 0.1 keV and equivalent width EW = 0.64 keV. VV Pup was too faint to produce reliable spectral fits. The 2-10 keV flux for VV Pup quoted above was based on the best-lit spectral model. Holding kT(X) fixed in the fitting process yielded roughly the same flux for kT(X) = 0.5-30 keV. We detected similar to 1 Hz optical quasi-periodic oscillations (QPOs) with amplitude similar to 2.2% from VV Pup and similar to 1% from V834 Cen. We did, not detect optical QPOs over the range 0.2-1 Hz from EF Eri at a 90% confidence upper limit of 4.5%. The QPO properties are consistent with those found in the literature. None of the targets showed X-ray QPO activity. However, only V834 Cen yielded a meaningful upper limit: similar to 14% at the 90% confidence level over 0.2-1.2 Hz. C1 Univ Oregon, Dept Phys, Eugene, OR 97403 USA. Univ Oregon, Inst Theoret Sci, Eugene, OR 97403 USA. Indiana Univ, Dept Astron, Bloomington, IN 47405 USA. USN, Res Lab, Washington, DC USA. RP Imamura, JN (reprint author), Univ Oregon, Dept Phys, Eugene, OR 97403 USA. NR 32 TC 12 Z9 12 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD JAN PY 2000 VL 112 IS 767 BP 18 EP 30 DI 10.1086/316478 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 279TP UT WOS:000085061500005 ER PT B AU Lazio, TJW Cordes, JM AF Lazio, TJW Cordes, JM BE Kramer, M Wex, N Wielebinski, R TI A VLA survey for radio pulsars in the Galactic center SO PULSAR ASTRONOMY - 2000 AND BEYOND: IAU COLLOQUIUM 177 SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 177th IAU Colloquium on Pulsar Astronomy - 2000 and Beyond CY AUG 30-SEP 03, 1999 CL BONN, GERMANY SP Int Astronom Union, Deutsch Forschgsgemein, Max Planck Inst Radioastronom, Max Planck Inst Ecxtraterrest Phys AB A radio pulsar in the Galactic center will suffer 350 v(GHz)(-4) seconds of pulse broadening. An imaging search for compact sources is far less desensitized by angular broadening than a periodicity search is affected by pulse broadening. We have conducted an imaging survey of the GC using the VLA and have detected approximately 200 sources. Six compact, steep-spectrum sources have been identified; additional compact sources with no spectral information have also been identified. Additional observations are in progress. C1 USN, Res Lab, Washington, DC 20375 USA. RP Lazio, TJW (reprint author), USN, Res Lab, Code 7213, Washington, DC 20375 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-029-3 J9 ASTR SOC P PY 2000 VL 202 BP 39 EP 40 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ44S UT WOS:000088366000012 ER PT B AU Kassim, NE Lazio, TJW AF Kassim, NE Lazio, TJW BE Kramer, M Wex, N Wielebinski, R TI A VLA search for the Geminga pulsar at 74 and 326 MHz SO PULSAR ASTRONOMY - 2000 AND BEYOND: IAU COLLOQUIUM 177 SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 177th IAU Colloquium on Pulsar Astronomy - 2000 and Beyond CY AUG 30-SEP 03, 1999 CL BONN, GERMANY SP Int Astronom Union, Deutsch Forschgsgemein, Max Planck Inst Radioastronom, Max Planck Inst Ecxtraterrest Phys ID RADIO PULSAR AB We have used the VLA to image the location of the gamma-ray pulsar Geminga at 74 and 326 MHz. Upper limits to the pulse-averaged flux density, taking diffractive scintillation (DISS) into account, are S < 56 mJy (2 sigma; DISS quenched) at 74 MHz and S < 5 mJy (95% confidence) at 326 MHz. Intrinsic variability appears to be required in order to reconcile our upper limits with previous low-frequency detections. C1 USN, Res Lab, Washington, DC 20375 USA. RP Kassim, NE (reprint author), USN, Res Lab, Code 7213, Washington, DC 20375 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-029-3 J9 ASTR SOC P PY 2000 VL 202 BP 239 EP 240 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ44S UT WOS:000088366000074 ER PT J AU Schauer, DA Cassata, JR King, JJ AF Schauer, DA Cassata, JR King, JJ TI A comparison of measured and calculated photon backscatter from dosemeter calibration phantoms SO RADIATION PROTECTION DOSIMETRY LA English DT Article AB Personnel dosemeter calibration for the determination of operational quantities used in individual monitoring requires placement on a phantom that provides a reasonable approximation to the backscatter properties of the part of the body on which it is worn. The operational quantities of interest for personnel dosimetry are defined for a person and for calibration in a 30 cm x 30 cm x 15 cm ICRU four-element tissue phantom. However, since ICRU tissue is not readily available, a phantom of alternative composition must be used for calibration. The extent to which phantom composition affects dosemeter response was measured with a widely used personnel thermoluminescence dosemeter (TLD) system. Measured backscatter results from PMMA and ISO water-filled phantoms over the photon energy range 35 to 662 keV are reported and compared with calculated backscatter factors (BSFs) for an ICRU tissue slab, Measured PMMA slab backscatter agreed with calculated ICRU tissue slab BSFs to within 2-3% for the NIST X ray spectra used in this study. C1 Uniformed Serv Univ Hlth Sci, Bethesda, MD 20814 USA. USN, Dosimetry Ctr, Bethesda, MD 20889 USA. Puget Sound Naval Shipyard, Bremerton, WA 98314 USA. RP Schauer, DA (reprint author), Uniformed Serv Univ Hlth Sci, Bethesda, MD 20814 USA. NR 7 TC 9 Z9 9 U1 0 U2 1 PU NUCLEAR TECHNOLOGY PUBL PI ASHFORD PA PO BOX 7, ASHFORD TN23 1YW, KENT, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PY 2000 VL 88 IS 4 BP 319 EP 321 PG 3 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 346QC UT WOS:000088881700006 ER PT B AU Olsen, RG AF Olsen, RG BE Klauenberg, BJ Miklavcic, D TI SAR measurements in the rhesus monkey ankle: Implications for humans SO RADIO FREQUENCY RADIATION DOSIMETRY AND ITS RELATIONSHIP TO THE BIOLOGICAL EFFECTS OF ELECTROMAGNETIC FIELDS SE NATO ADVANCED SCIENCE INSTITUTE SERIES, SUB-SERIES 3, HIGH TECHNOLOGY LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Radio Frequency Radiation Dosimetry and its Relationship to the Biological Effects of Electromagnetic Fields CY OCT 12-16, 1998 CL GOZD MARTULJEK, SLOVENIA SP NATO, Sci Affairs Div, High Technol Area, NATO, Res & Technol Org, USAF, Res Lad, USAF, Secur Assistance Command, USAF, European Off Aerosp Res & Dev, European BioElectromagnet Assoc, Bioelectromagnet Soc, Holaday Ind Inc, Univ Ljubljana, Agr Inst Slovenia, Elletra 2000, Minist Def, Minist Environm, Minist Sci & Technol, Minist Foreign Affairs, Minist Hlth, Inst Publ Hlth C1 USN, Hlth Res Ctr Detachment, Brooks AFB, TX 78235 USA. RP Olsen, RG (reprint author), USN, Hlth Res Ctr Detachment, 8301 Navy Rd, Brooks AFB, TX 78235 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6404-X J9 NATO ASI 3 HIGH TECH PY 2000 VL 82 BP 367 EP 373 PG 7 WC Engineering, Electrical & Electronic; Medicine, Research & Experimental SC Engineering; Research & Experimental Medicine GA BR40S UT WOS:000166318800040 ER PT B AU D'Andrea, JA AF D'Andrea, JA BE Klauenberg, BJ Miklavcic, D TI Summary of session G: Responses of man and animals II SO RADIO FREQUENCY RADIATION DOSIMETRY AND ITS RELATIONSHIP TO THE BIOLOGICAL EFFECTS OF ELECTROMAGNETIC FIELDS SE NATO ADVANCED SCIENCE INSTITUTE SERIES, SUB-SERIES 3, HIGH TECHNOLOGY LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Radio Frequency Radiation Dosimetry and its Relationship to the Biological Effects of Electromagnetic Fields CY OCT 12-16, 1998 CL GOZD MARTULJEK, SLOVENIA SP NATO, Sci Affairs Div, High Technol Area, NATO, Res & Technol Org, USAF, Res Lad, USAF, Secur Assistance Command, USAF, European Off Aerosp Res & Dev, European BioElectromagnet Assoc, Bioelectromagnet Soc, Holaday Ind Inc, Univ Ljubljana, Agr Inst Slovenia, Elletra 2000, Minist Def, Minist Environm, Minist Sci & Technol, Minist Foreign Affairs, Minist Hlth, Inst Publ Hlth C1 USN, Hlth Res Ctr Detachment, Brooks AFB, TX 78235 USA. RP D'Andrea, JA (reprint author), USN, Hlth Res Ctr Detachment, Brooks AFB, TX 78235 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6404-X J9 NATO ASI 3 HIGH TECH PY 2000 VL 82 BP 393 EP 394 PG 2 WC Engineering, Electrical & Electronic; Medicine, Research & Experimental SC Engineering; Research & Experimental Medicine GA BR40S UT WOS:000166318800043 ER PT B AU D'Andrea, JA Chalfin, S AF D'Andrea, JA Chalfin, S BE Klauenberg, BJ Miklavcic, D TI Effects of microwave and millimeter wave radiation on the eye SO RADIO FREQUENCY RADIATION DOSIMETRY AND ITS RELATIONSHIP TO THE BIOLOGICAL EFFECTS OF ELECTROMAGNETIC FIELDS SE NATO ADVANCED SCIENCE INSTITUTE SERIES, SUB-SERIES 3, HIGH TECHNOLOGY LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Radio Frequency Radiation Dosimetry and its Relationship to the Biological Effects of Electromagnetic Fields CY OCT 12-16, 1998 CL GOZD MARTULJEK, SLOVENIA SP NATO, Sci Affairs Div, High Technol Area, NATO, Res & Technol Org, USAF, Res Lad, USAF, Secur Assistance Command, USAF, European Off Aerosp Res & Dev, European BioElectromagnet Assoc, Bioelectromagnet Soc, Holaday Ind Inc, Univ Ljubljana, Agr Inst Slovenia, Elletra 2000, Minist Def, Minist Environm, Minist Sci & Technol, Minist Foreign Affairs, Minist Hlth, Inst Publ Hlth C1 USN, Hlth Res Ctr Detachment, Brooks AFB, TX 78235 USA. RP D'Andrea, JA (reprint author), USN, Hlth Res Ctr Detachment, Brooks AFB, TX 78235 USA. NR 27 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6404-X J9 NATO ASI 3 HIGH TECH PY 2000 VL 82 BP 395 EP 402 PG 8 WC Engineering, Electrical & Electronic; Medicine, Research & Experimental SC Engineering; Research & Experimental Medicine GA BR40S UT WOS:000166318800044 ER PT B AU Ziriax, JM Mason, PA Hurt, WD D'Andrea, JA Arce, MA Petri, JF AF Ziriax, JM Mason, PA Hurt, WD D'Andrea, JA Arce, MA Petri, JF BE Klauenberg, BJ Miklavcic, D TI Dosimetry measurements and modeling: Interactive presentations in the new dosimetry handbook SO RADIO FREQUENCY RADIATION DOSIMETRY AND ITS RELATIONSHIP TO THE BIOLOGICAL EFFECTS OF ELECTROMAGNETIC FIELDS SE NATO ADVANCED SCIENCE INSTITUTE SERIES, SUB-SERIES 3, HIGH TECHNOLOGY LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Radio Frequency Radiation Dosimetry and its Relationship to the Biological Effects of Electromagnetic Fields CY OCT 12-16, 1998 CL GOZD MARTULJEK, SLOVENIA SP NATO, Sci Affairs Div, High Technol Area, NATO, Res & Technol Org, USAF, Res Lad, USAF, Secur Assistance Command, USAF, European Off Aerosp Res & Dev, European BioElectromagnet Assoc, Bioelectromagnet Soc, Holaday Ind Inc, Univ Ljubljana, Agr Inst Slovenia, Elletra 2000, Minist Def, Minist Environm, Minist Sci & Technol, Minist Foreign Affairs, Minist Hlth, Inst Publ Hlth C1 USN, Hlth Res Ctr Detachment, Brooks AFB, TX 78235 USA. RP Ziriax, JM (reprint author), USN, Hlth Res Ctr Detachment, Brooks AFB, TX 78235 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6404-X J9 NATO ASI 3 HIGH TECH PY 2000 VL 82 BP 555 EP 564 PG 10 WC Engineering, Electrical & Electronic; Medicine, Research & Experimental SC Engineering; Research & Experimental Medicine GA BR40S UT WOS:000166318800063 ER PT J AU Liu, Y Iz, HB Chen, Y AF Liu, Y Iz, HB Chen, Y TI Calibration of zenith hydrostatic delay model for local GPS applications SO RADIO SCIENCE LA English DT Article ID METEOROLOGY AB Determination of dry zenith delay, DZD, is important for separating wet zenith delay with high accuracy from Global Positioning System (GPS) measurements. The existing models are usually for the calculation of the zenith hydrostatic delay, ZHD. Because the zenith hydrostatic delay includes the contribution of water vapor and is also not accurate enough, the DZD, approximately replaced by ZHD, will induce similar to 2 cm error into local GPS applications. In this study we calibrate a popular ZHD model, namely, the Saastamoinen model for local GPS meteorology, using radiosonde data. We test the calibrated model by comparing the predicted delays from the calibrated model against the observed delays from radiosonde data that are not included in the calibration solution. The calibrated model shows 20 mm improvement over the uncalibrated model predictions over the same period. A comparison of the DZDs calculated from GPS measurements over a month period with calibrated and uncalibrated ZHD model predictions shows 15 mm average improvement. C1 Hong Kong Polytech Univ, Dept Land Surveying & Geoinformat, Kowloon, Hong Kong. USN Observ, Earth Orientat Dept, Washington, DC 20392 USA. RP Liu, Y (reprint author), Hong Kong Polytech Univ, Dept Land Surveying & Geoinformat, Kowloon, Hong Kong. NR 16 TC 3 Z9 4 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD JAN-FEB PY 2000 VL 35 IS 1 BP 133 EP 140 DI 10.1029/1999RS900100 PG 8 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA 281LF UT WOS:000085161000012 ER PT S AU Kassim, NE Lazio, TJW Erickson, WC Crane, PC Perley, RA Hicks, B AF Kassim, NE Lazio, TJW Erickson, WC Crane, PC Perley, RA Hicks, B BE Butcher, HR TI The Low-Frequency Array (LOFAR): Opening a new window on the Universe SO RADIO TELESCOPES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Radio Telescopes CY MAR 27-30, 2000 CL MUNICH, GERMANY SP SPIE, European SO Observ, DFM Engn Inc DE cosmology : observations; galaxies : clusters : general; instrumentation : interferometers; interstellar medium : structure; radio continuum : general; Sun : radio radiation ID EXTREME-ULTRAVIOLET EMISSION; COSMIC-RAY ELECTRONS; COMA-CLUSTER; MASS EJECTIONS; HIGH-REDSHIFT; RADIO-SOURCES; GALAXIES; POPULATION; EVOLUTION; PULSAR AB The first, serendipitous, radio-astronomical observations by K. Jansky were at decametric wavelengths. However, after the initial pioneering work, long-wavelength radio astronomy was largely abandoned in the quest for higher angular resolution because ionospheric structure was thought to limit interferometric imaging to short (< 5 km) baselines. The long-wavelength (LW, 2-20 m or 15-150 MHz) portion of the electromagnetic spectrum thus remains poorly explored. The NRL-NRAO 74 MHz observing system on the Very Large Array has demonstrated that; self-calibration techniques can remove ionospheric distortions over arbitrarily long baselines. We describe the scientific justification and initial technical design of the Low Frequency Array (LOFAR)-a fully electronic, broad-band antenna array operating in the 15-150 MHz range with a collecting area of 1 km(2) at 15 MHz. The longest baselines may be 500 km, providing an angular resolution of 10 " at 15 MHz and 1 " at 150 MHz. The combination of large collecting area and high angular resolution will enable LOFAR to produce images with sensitivities of order 1 mJy at 15 MHz and 300 mu Jy at 150 MHz. As such LOFAR will represent an improvement of 2-3 orders of magnitude in resolution and sensitivity over the state of the art. A key operational goal of LOFAR will be solar observations-both passive imaging and radar imaging. In the latter mode LOFAR will serve as the receiver for bi-static observations of the Sun, with particular emphasis on the imaging of coronal mass ejections. LOFAR will serve as an astrophysical laboratory to study the origin, spectrum, and distribution of the Galactic cosmic ray electron gas and as an instrument to probe the high-redshift Universe. C1 USN, Res Lab, Washington, DC 20375 USA. RP Lazio, TJW (reprint author), USN, Res Lab, Code 7213, Washington, DC 20375 USA. NR 47 TC 12 Z9 12 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3640-2 J9 P SOC PHOTO-OPT INS PY 2000 VL 4015 BP 328 EP 340 DI 10.1117/12.390454 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ70J UT WOS:000089219700034 ER PT B AU Kusterbeck, AW Gauger, PR Charles, PT AF Kusterbeck, AW Gauger, PR Charles, PT BE Stopa, PJ Bartoszcze, MA TI Environmental applications of the NRL flow immunosensor SO RAPID METHODS FOR ANALYSIS OF BIOLOGICAL MATERIALS IN THE ENVIRONMENT SE NATO ADVANCED SCIENCE INSTITUTE SERIES, SUB-SERIES 1: DISARMAMENT TECHNOLOGIES LA English DT Proceedings Paper CT NATO Advanced Research Workshop on rapid Methods for Monitoring the Environment for Biological Hazards CY MAY 19-22, 1997 CL WARSAW, POLAND SP NATO Sci Comm, Polish Minist Def, USA European Res Off, US Edgewood Chem & Biol Ctr AB An antibody-based biosensor developed at the Naval Research Laboratory (NRL) is being tested at several United States Environmental Protection Agency (USEPA) remediation sites to examine the utility of the technology for monitoring explosives levels in groundwater and soil. Using antibodies as the recognition element and fluorescently labeled explosive analogs as reporters of binding events, the biosensor can detect contamination at the sub-parts per billion level in under two minutes. A portable version of the device, known as the FAST 2000, has been engineered by Research International, Woodinville, WA, for convenient use in rapid on-site evaluation and characterization of contaminated areas. Alternatively, the device can be used to follow cleanup progress on a routine basis or to monitor air samples for the presence of explosives or other small-molecular-weight contaminants. C1 USN, Res Lab, Ctr Biomol Sci & Engn, Biosensors & Biomat Lab, Washington, DC 20375 USA. RP Kusterbeck, AW (reprint author), USN, Res Lab, Ctr Biomol Sci & Engn, Biosensors & Biomat Lab, Code 6910,4555 Overlook Ave SW, Washington, DC 20375 USA. NR 6 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6304-3 J9 NATO SCI S 1 DISARM PY 2000 VL 30 BP 79 EP 85 PG 7 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA BR43T UT WOS:000166415300007 ER PT S AU Linde, G AF Linde, G GP IEEE IEEE TI Use of wideband waveforms for target recognition with surveillance radars SO RECORD OF THE IEEE 2000 INTERNATIONAL RADAR CONFERENCE SE Radar Conference LA English DT Proceedings Paper CT 2000 IEEE Radar Conference CY MAY 07-12, 2000 CL ALEXANDRIA, VA SP Natl Capital Area Council, IEEE, Aerosp & Electr Syst Soc, Radar Syst Panel, Inst Elect Engineers, ITT Gilfillan, Lockheed Martin, Northrop Grumman, Raytheon Co, SAIC, Syst & Electr Inc C1 USN, Res Lab, Washington, DC 20375 USA. RP Linde, G (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 2 TC 1 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1097-5764 BN 0-7803-5776-0 J9 RADAR CONF PY 2000 BP 128 EP 133 DI 10.1109/RADAR.2000.851817 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BQ62Y UT WOS:000089015800025 ER PT S AU Scholnik, DP Coleman, JO AF Scholnik, DP Coleman, JO GP IEEE IEEE TI Optimal design of wideband array patterns SO RECORD OF THE IEEE 2000 INTERNATIONAL RADAR CONFERENCE SE Radar Conference LA English DT Proceedings Paper CT 2000 IEEE Radar Conference CY MAY 07-12, 2000 CL ALEXANDRIA, VA SP Natl Capital Area Council, IEEE, Aerosp & Electr Syst Soc, Radar Syst Panel, Inst Elect Engineers, ITT Gilfillan, Lockheed Martin, Northrop Grumman, Raytheon Co, SAIC, Syst & Electr Inc AB In radar systems, wideband array patterns are typically nothing but patterns designed in the conventional narrowband way and then time-delay steered. It is increasingly common to use digital filters to approximate the needed delays. We suggest, however, that approximating time delays is an inefficient use of the valuable resource represented by these filters and propose instead that their responses be jointly optimized to meet specifications on the array pattern as a function of angle and frequency. This frees the angle-dependence and frequency-dependence of the array function from the fixed relationship implied by time delay steering and allows tremendous design flexibility, and it improves the tradeoff between filter length and ultimate array performance. C1 USN, Res Lab, Div Radar, Washington, DC 20375 USA. RP Scholnik, DP (reprint author), USN, Res Lab, Div Radar, Washington, DC 20375 USA. NR 10 TC 6 Z9 6 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1097-5764 BN 0-7803-5776-0 J9 RADAR CONF PY 2000 BP 172 EP 177 DI 10.1109/RADAR.2000.851825 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BQ62Y UT WOS:000089015800033 ER PT S AU Gray, JE Foster, GJ AF Gray, JE Foster, GJ GP IEEE IEEE TI An alternative method to using plant noise as a means of selecting filter gains in a complex tracking environment SO RECORD OF THE IEEE 2000 INTERNATIONAL RADAR CONFERENCE SE IEEE Radar Conference LA English DT Proceedings Paper CT 2000 IEEE Radar Conference CY MAY 07-12, 2000 CL ALEXANDRIA, VA SP Natl Capital Area Council, IEEE, Aerosp & Electr Syst Soc, Radar Syst Panel, Inst Elect Engineers, ITT Gilfillan, Lockheed Martin, Northrop Grumman, Raytheon Co, SAIC, Syst & Electr Inc DE Kalman filter; plant noise model; bias minimization.; complex tracking environment AB In this paper, we develop a methodology for comparing filter gain selection for several different filter coefficient relationships. When designing tracking Alters, an important issue is the selection of the of the Alter gains. The steady state solution of the Kalman filter leads to different filter coefficient relationships depending on what one assumes for the process noise model. Three commonly used relationships are the Benedict-Bordner relationship, the Kalata relationship, and the continuous white noise relationship. However, an analytic method for comparing these different relationships is needed. We develop a common methodology for comparing filter performance based upon cost functions in this note and then discuss how the comparison might be used. C1 USN, Ctr Surface Warfare, Combat Syst Dept, Dahlgren Div, Dahlgren, VA 22448 USA. RP Gray, JE (reprint author), USN, Ctr Surface Warfare, Combat Syst Dept, Dahlgren Div, Code N92, Dahlgren, VA 22448 USA. EM jgray@nswc.navy.mil; gfoster@nswc.navy.mil NR 11 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1097-5764 BN 0-7803-5776-0 J9 IEEE RAD CONF PY 2000 BP 278 EP 283 DI 10.1109/RADAR.2000.851846 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BQ62Y UT WOS:000089015800054 ER PT S AU Chen, VC Lipps, R AF Chen, VC Lipps, R GP IEEE IEEE TI ISAR imaging of small craft with roll, pitch and yaw analysis SO RECORD OF THE IEEE 2000 INTERNATIONAL RADAR CONFERENCE SE IEEE Radar Conference LA English DT Proceedings Paper CT 2000 IEEE Radar Conference CY MAY 07-12, 2000 CL ALEXANDRIA, VA SP Natl Capital Area Council, IEEE, Aerosp & Electr Syst Soc, Radar Syst Panel, Inst Elect Engineers, ITT Gilfillan, Lockheed Martin, Northrop Grumman, Raytheon Co, SAIC, Syst & Electr Inc ID RADAR AB In this paper, we analyze the effect of roll, pitch and yaw rotations on inverse synthetic aperture radar (ISAR) imaging of small craft. An ideal ISAR image of a target with regular motion can be derived from the image projection plane and the radar line-of-sight (LOS) unit vector. Roll, pitch and yaw rotations can induce time-varying Doppler shifts that can be analyzed through the rotation matrix and the effective rotation vector. We use a commercial small craft ISAR data accompanied with roll, pitch and yaw data collected by Trimble's Tans Vector system with 4 GPS antennas to study the effect of rotational motion on ISAR imaging. For a target with regular motion, perturbations of roll and pitch motions may make image blurring if conventional motion compensation is used. In this case, advanced imaging algorithms, such as polar reformatting algorithm, that compensate the perturbations may improve the image. C1 USN, Res Lab, Div Radar, Washington, DC 20375 USA. RP Chen, VC (reprint author), USN, Res Lab, Div Radar, Washington, DC 20375 USA. NR 6 TC 7 Z9 8 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1097-5764 BN 0-7803-5776-0 J9 IEEE RAD CONF PY 2000 BP 493 EP 498 DI 10.1109/RADAR.2000.851883 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BQ62Y UT WOS:000089015800091 ER PT S AU Gray, JE AF Gray, JE GP IEEE IEEE TI Applications of the solution to the Rayleigh problem SO RECORD OF THE IEEE 2000 INTERNATIONAL RADAR CONFERENCE SE Radar Conference LA English DT Proceedings Paper CT 2000 IEEE Radar Conference CY MAY 07-12, 2000 CL ALEXANDRIA, VA SP Natl Capital Area Council, IEEE, Aerosp & Electr Syst Soc, Radar Syst Panel, Inst Elect Engineers, ITT Gilfillan, Lockheed Martin, Northrop Grumman, Raytheon Co, SAIC, Syst & Electr Inc DE Rayleigh Problem; coordinate transformations of random variables; superposition of RV's AB In this note, the formalism to determine the probability density function (PDF) resulting from a coordinate transformation applied to an arbitrary PDF is developed. The results are applied to the coordinate transformation used in target tracking, specifically the transformation from spherical to Cartesian coordinates. This result is then applied to the specific example of a Gaussian random variable transformed by sine and cosine coordinate transformations. A brief discussion is then made of multi-dimensional transformations. C1 USN, Ctr Surface Warfare, Dahlgren Div, Combat Syst Dept, Dahlgren, VA 22448 USA. RP Gray, JE (reprint author), USN, Ctr Surface Warfare, Dahlgren Div, Combat Syst Dept, Code N92, Dahlgren, VA 22448 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1097-5764 BN 0-7803-5776-0 J9 RADAR CONF PY 2000 BP 527 EP 532 DI 10.1109/RADAR.2000.851889 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BQ62Y UT WOS:000089015800097 ER PT S AU Foreman, TL Wilson, SG AF Foreman, TL Wilson, SG GP IEEE IEEE TI Multiple pulse detection in distributed Rayleigh clutter SO RECORD OF THE IEEE 2000 INTERNATIONAL RADAR CONFERENCE SE Radar Conference LA English DT Proceedings Paper CT 2000 IEEE Radar Conference CY MAY 07-12, 2000 CL ALEXANDRIA, VA SP Natl Capital Area Council, IEEE, Aerosp & Electr Syst Soc, Radar Syst Panel, Inst Elect Engineers, ITT Gilfillan, Lockheed Martin, Northrop Grumman, Raytheon Co, SAIC, Syst & Electr Inc ID RADAR AB This paper studies the Neyman-Pearson discrete-time detector for multiple pulse phase/amplitude coded radar signals in the presence of spatially-white distributed Rayleigh clutter. The detector is shown to be an inner-product computer (not the usual correlator), followed by an envelope detector. In other words, the optimum detector for the distributed clutter case is not a moving target detector (MTD) plus matched filter. Interesting properties are presented, namely extremely low range time sidelobes in the ambiguity diagram and the concept of oversampling. Oversampling allows one to substantially improve clutter rejection for situations of high clutter to noise ratio. Finally, the performance of the optimum detector is compared to that of the correlator plus MTD demonstrating the potential performance improvement of the optimum detector. C1 USN, Ctr Surface Warfare, Dahlgren Div, Dahlgren, VA 22448 USA. RP Foreman, TL (reprint author), USN, Ctr Surface Warfare, Dahlgren Div, Dahlgren, VA 22448 USA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1097-5764 BN 0-7803-5776-0 J9 RADAR CONF PY 2000 BP 637 EP 642 DI 10.1109/RADAR.2000.851908 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BQ62Y UT WOS:000089015800116 ER PT S AU Park, JS Sandhu, R Ghanta, S AF Park, JS Sandhu, R Ghanta, S BE Atluri, V Hale, J TI RBAC on the Web by secure cookies SO RESEARCH ADVANCES IN DATABASE AND INFORMATION SYSTEMS SECURITY SE International Federation for Information Processing LA English DT Proceedings Paper CT 13th Annual Working Conference on Database Security CY JUL 25-28, 1999 CL SEATTLE, WA SP Off Naval Res, Int Federat Informat Processing, TC 11, Int Federat Informat Processing, WG 11 3 DE cookies; role-based access control; Web security AB Current approaches to access control on Web servers do not scale to enterprise-wide systems, since they are mostly based on individual users. Therefore, we were motivated by the need to manage and enforce the strong access control technology of RBAC in large-scale Web environments. Cookies can be used to support RBAC on the Web, holding users' role information. However, it is insecure to store and transmit sensitive information in cookies. Cookies are stored and transmitted in clear text, which is readable and easily forged. In this paper, we describe an implementation of Pole-Based Access Control with role hierarchies on the Web by secure cookies. Since a user's role information is contained in a set of secure cookies and transmitted to the corresponding Web servers, these servers can trust the role information in the cookies after cookie-verification procedures and use it for role-based access control. In our implementation, we used CGI scripts and PGP (Pretty Good Privacy) to provide security services to secure cookies. The approach is transparent to users and applicable to existing Web servers and browsers. C1 USN, Res Lab, Ctr High Assurance Comp Syst, Washington, DC 20375 USA. RP USN, Res Lab, Ctr High Assurance Comp Syst, Washington, DC 20375 USA. EM jpark@list.gmu.edu; sandhu@isse.gmu.edu; sghanta@list.gmu.edu RI Sandhu, Ravi/C-6031-2009 NR 21 TC 4 Z9 4 U1 0 U2 0 PU KLUWER ACADEMIC PUBLISHERS PI NORWELL PA 101 PHILIP DRIVE, ASSINIPPI PARK, NORWELL, MA 02061 USA SN 1571-5736 BN 0-7923-7848-2 J9 INT FED INFO PROC PY 2000 VL 43 BP 49 EP 62 PG 14 WC Computer Science, Information Systems; Computer Science, Theory & Methods SC Computer Science GA BR81R UT WOS:000167659100004 ER PT S AU Kang, MH Froscher, JN Eppinger, BJ Moskowitz, IS AF Kang, MH Froscher, JN Eppinger, BJ Moskowitz, IS BE Atluri, V Hale, J TI A strategy for an MLS workflow management system SO RESEARCH ADVANCES IN DATABASE AND INFORMATION SYSTEMS SECURITY SE INTERNATIONAL FEDERATION FOR INFORMATION PROCESSING LA English DT Proceedings Paper CT 13th Annual Working Conference on Database Security CY JUL 25-28, 1999 CL SEATTLE, WA SP Off Naval Res, Int Federat Informat Processing, TC 11, Int Federat Informat Processing, WG 11 3 DE multilevel security; workflow management systems AB Current DoD information systems need to support many different missions through cooperation with different organizations and allies. In todays fast paced and dynamic environment, it is almost impossible to design and implement a different information system for each mission. Therefore, DoD needs MLS work-flow management systems (WFMS) to enable globally distributed users and existing applications to cooperate across classification domains to achieve mission critical goals. An MLS WFMS that allows users to program multilevel mission logic, securely coordinate widely distributed tasks, and monitor the progress of the workflow across classification domains is required. In this paper, we present requirements for MLS workflow and a strategy for implementing it, especially the method for decomposing an MLS workflow into multiple single-level workflows. C1 USN, Res Lab, Washington, DC 20375 USA. RP Kang, MH (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBLISHERS PI NORWELL PA 101 PHILIP DRIVE, ASSINIPPI PARK, NORWELL, MA 02061 USA SN 1571-5736 BN 0-7923-7848-2 J9 INT FED INFO PROC PY 2000 VL 43 BP 161 EP 174 PG 14 WC Computer Science, Information Systems; Computer Science, Theory & Methods SC Computer Science GA BR81R UT WOS:000167659100011 ER PT S AU Bashkansky, M Duncan, MD Reintjes, J AF Bashkansky, M Duncan, MD Reintjes, J BE Thompson, DO Chimenti, DE TI Detection of near-surface microscopic defects in ceramics and other materials using optical coherence tomography SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 19A AND 19B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 26th Annual Review of Progress in Quantitative Nondestructive Evaluation CY JUL 25-30, 1999 CL MONTREAL, CANADA SP Iowa State Univ, Ctr NDE, Ind Mat Inst, Natl Res Council Canada, US DOE, Ames Lab, Amer Soc Nondestruct Testing, NASA, Natl Inst Stand & Technol, Fed Aviat Adm, Natl Sci Fdn Ind, Univ Cooperat Res Ctr C1 USN, Res Lab, Washington, DC 20375 USA. RP Bashkansky, M (reprint author), USN, Res Lab, Code 5614,4555 Overlook Ave SW, Washington, DC 20375 USA. NR 5 TC 0 Z9 0 U1 3 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-930-0 J9 AIP CONF PROC PY 2000 VL 509 BP 1517 EP 1523 PG 7 WC Acoustics; Engineering, Electrical & Electronic; Materials Science, Characterization & Testing; Physics, Applied SC Acoustics; Engineering; Materials Science; Physics GA BQ87X UT WOS:000089913700195 ER PT S AU Simmonds, KE Mignogna, RB Batra, NK AF Simmonds, KE Mignogna, RB Batra, NK BE Thompson, DO Chimenti, DE TI Ultrasonic method for monitoring corrosion damage in petroleum metal storage tanks using spectral tracking SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 19A AND 19B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 26th Annual Review of Progress in Quantitative Nondestructive Evaluation CY JUL 25-30, 1999 CL MONTREAL, CANADA SP Iowa State Univ, Ctr NDE, Ind Mat Inst, Natl Res Council Canada, US DOE, Ames Lab, Amer Soc Nondestruct Testing, NASA, Natl Inst Stand & Technol, Fed Aviat Adm, Natl Sci Fdn Ind, Univ Cooperat Res Ctr C1 USN, Res Lab, Multifunct Mat Branch, Washington, DC 20375 USA. RP Simmonds, KE (reprint author), USN, Res Lab, Multifunct Mat Branch, Code 6352, Washington, DC 20375 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-930-0 J9 AIP CONF PROC PY 2000 VL 509 BP 1809 EP 1816 PG 8 WC Acoustics; Engineering, Electrical & Electronic; Materials Science, Characterization & Testing; Physics, Applied SC Acoustics; Engineering; Materials Science; Physics GA BQ87X UT WOS:000089913700232 ER PT J AU Spence, SE Stoudt, DC Swanson, NL Parks, AD Peterkin, FE AF Spence, SE Stoudt, DC Swanson, NL Parks, AD Peterkin, FE TI A method for balancing the paths of a two-photon interferometer SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID 2 PHOTONS; INTERFERENCE; TIME AB We present and demonstrate a method for balancing the two paths of a two-photon interferometer of the Hong-Ou-Mandel (HOM) variety. This method removes the difficulties of balancing the paths in this type of interferometer where a type-I crystal is used for the generation of the entangled photon pairs. Using this method we show that we are consistently able to balance the similar to 2000 mm path lengths in our HOM interferometer on average to within similar to 60 mu m. (C) 2000 American Institute of Physics. [S0034-6748(00)01101-1]. C1 USN, Ctr Surface Warfare, Syst Res & Technol Dept, Quantum Proc Grp, Dahlgren, VA 22448 USA. RP Spence, SE (reprint author), USN, Ctr Surface Warfare, Syst Res & Technol Dept, Quantum Proc Grp, Dahlgren, VA 22448 USA. NR 7 TC 2 Z9 2 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JAN PY 2000 VL 71 IS 1 BP 23 EP 26 DI 10.1063/1.1150154 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 278PY UT WOS:000084999200007 ER PT S AU Fahroo, F Ross, IM AF Fahroo, F Ross, IM BE Junkins, JL Alfriend, KT Howell, KC TI A spectral patching method for direct trajectory optimization SO RICHARD H BATTIN ASTRODYNAMICS SYMPOSIUM SE Advances in the Astronautical Sciences LA English DT Proceedings Paper CT Richard H Battin Astrodynamics Symposium CY MAR 19-21, 2000 CL TEXAX A&M UNIV, COLLEGE STN, TX SP Amer Astronaut Soc, Texas Eng Expt Stn, Aerosp Engn Dept HO TEXAX A&M UNIV ID DIFFERENTIAL INCLUSION; COLLOCATION AB A new direct method for trajectory optimization is presented in this paper, This method is based on using global orthogonal polynomials instead of the traditional spline-integration method to discretize the dynamical constraints. The states and controls are approximated by interpolating polynomials with unknown coefficients as the values of the functions at the collocation points. The collocation points are the Legendre-Gauss-Lobatto points which provide the smallest error in interpolation in the least-squares sense. They also provide an expression for the Lagrange interpolating polynomials used as trial functions in terms of Legendre polynomials. In order to achieve a greater freedom in the distribution of the collocation points, we present a patching method wherein the time domain may be arbitrarily divided into a few sub-intervals. The state equations over these subintervals are discretized by the spectral collocation method. Then, the solutions on these subintervals are "patched" by a continuity condition. In this patching method, by judiciously combining the ideas of the traditional collocation methods with global spectral methods, we achieve advantages of both methods while using neither. The results for the so-called Moon-Landing problem show that the spectral patching method works well for just two subintervals. C1 USN, Postgrad Sch, Dept Math, Monterey, CA 93943 USA. RP Fahroo, F (reprint author), USN, Postgrad Sch, Dept Math, Code Ma-Ff, Monterey, CA 93943 USA. EM ffahroo@nps.navy.mil; imross@nps.navy.mil NR 19 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-472-9 J9 ADV ASTRONAUT SCI PY 2000 VL 106 BP 353 EP 369 PG 17 WC Engineering, Aerospace SC Engineering GA BR01H UT WOS:000165335700018 ER PT B AU Nguyen, TN DeBolt, C Nguyen, TB AF Nguyen, TN DeBolt, C Nguyen, TB BE Stone, WC TI Using a swarm of autonomous robots for UXO clearance, the BUGS project SO ROBOTICS 2000, PROCEEDINGS LA English DT Proceedings Paper CT 4th International Conference and Exposition/Demonstration on Robotics for Challenging Situations and Environments CY FEB 27-MAR 02, 2000 CL ALBUQUERQUE, NM SP Amer Soc Civil Engineers, Aerosp Div, Amer Astronaut Soc, NASA, Sandia Natl Labs, Natl Space Soc, Int Assoc Automat & Robot Construct, Univ New Mexico, Dept Civil Engn, Space Daily, Spacenews Com AB The objective of the Basic UXO Gathering System (BUGS) is to develop, test, evaluate, and demonstrate the use of multiple small robots in neutralizing unexploded ordnance in contaminated land areas. We are studying control methodologies and working on multiple autonomous robots to perform a practical and useful UXO (Unexploded Ordnance) clearance mission, It is important to select a multiple-robotic system approach that is reliable, economical, and robust enough to operate in an unknown environment. This paper addresses the completed milestones at NAVEODTECHDIV, in building multiple small, robust and inexpensive robot systems to neutralize UXO area. C1 USN, EOD Technol Div, Indian Head, MD 20640 USA. RP Nguyen, TN (reprint author), USN, EOD Technol Div, 2008 Stump Neck Rd, Indian Head, MD 20640 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CIVIL ENGINEERS PI NEW YORK PA UNITED ENGINEERING CENTER, 345 E 47TH ST, NEW YORK, NY 10017-2398 USA BN 0-7844-0476-3 PY 2000 BP 353 EP 359 PG 7 WC Automation & Control Systems; Engineering, Civil SC Automation & Control Systems; Engineering GA BQ36E UT WOS:000088122200047 ER PT J AU Berdal, BP Mehl, R Haaheim, H Loksa, M Grunow, R Burans, J Morgan, C Meyer, H AF Berdal, BP Mehl, R Haaheim, H Loksa, M Grunow, R Burans, J Morgan, C Meyer, H TI Field detection of Francisella tularensis SO SCANDINAVIAN JOURNAL OF INFECTIOUS DISEASES LA English DT Article ID ANTIBODIES; TULAREMIA AB A field investigation was undertaken following an outbreak of water-borne tularemia in Northern Norway. Francisella tularensis bacterial cellular components were analysed by rapid immunochromatography (RI)-testing, enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR), Water from 1 reservoir, fed from a rapid stream, tested negative, From another reservoir, 2 of a chain of 3 wells tested negative. The third well, at the end of the chain, contained lemming (Lemmus lemmus) carcasses and gave ample proof of F. tularensis contamination, We concluded that the origin of the outbreak was dead, infective lemming carcasses in the water sources, For the various sampling materials, the RI-test proved itself particularly handy and versatile, compared with the ELISA and the PCR. C1 Armed Forces Med Serv, Inst Microbiol, Oslo, Norway. Natl Publ Hlth Inst, Oslo, Norway. Univ Tromso Hosp, Dept Microbiol, N-9012 Tromso, Norway. Salangen Vet Dist, Tromso, Norway. German Armed Forces Med Acad, Inst Microbiol, Munich, Germany. USN, Med Res Inst, Bethesda, MD USA. RP Meyer, H (reprint author), Sanitatsakad Bundeswehr, Inst Mikrobiol, Neuherbergstr 11, D-80937 Munich, Germany. NR 12 TC 45 Z9 49 U1 0 U2 11 PU TAYLOR & FRANCIS AS PI OSLO PA CORT ADELERSGT 17, PO BOX 2562, SOLLI, 0202 OSLO, NORWAY SN 0036-5548 J9 SCAND J INFECT DIS JI Scand. J. Infect. Dis. PY 2000 VL 32 IS 3 BP 287 EP 291 PG 5 WC Infectious Diseases SC Infectious Diseases GA 325VA UT WOS:000087696100011 PM 10879600 ER PT B AU Tag, PM Bankert, RL Hadjimichael, M Kuciauskas, AP Thompson, WT Richardson, KL AF Tag, PM Bankert, RL Hadjimichael, M Kuciauskas, AP Thompson, WT Richardson, KL GP AMS AMS TI Applying knowledge discovery from databases (KDD) to combined satellite and high resolution numerical model data SO SECOND CONFERENCE ON ARTIFICIAL INTELLIGENCE LA English DT Proceedings Paper CT 2nd Conference on Artificial Intelligence CY FEB 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc ID PREDICTION; VISIBILITY; SYSTEM C1 USN, Res Lab, Monterey, CA 93943 USA. RP Tag, PM (reprint author), USN, Res Lab, 7 Grace Hopper Ave, Monterey, CA 93943 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2000 BP 78 EP 83 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Meteorology & Atmospheric Sciences SC Computer Science; Meteorology & Atmospheric Sciences GA BS02Y UT WOS:000168377900016 ER PT B AU Schulze, KG Shelby, RN Treacy, DJ Wintersgill, MC AF Schulze, KG Shelby, RN Treacy, DJ Wintersgill, MC BE Chambers, JA TI Andes: A coached learning environment for classical Newtonian physics SO SELECTED PAPERS FROM THE 11TH INTERNATIONAL CONFERENCE ON COLLEGE TEACHING AND LEARNING LA English DT Proceedings Paper CT 11th International Conference on College Teaching and Learning CY 2000 CL FLORIDA COMMUNITY COLL, JACKSONVILLE, FL HO FLORIDA COMMUNITY COLL C1 USN Acad, Annapolis, MD 21402 USA. NR 8 TC 0 Z9 0 U1 1 U2 1 PU FLORIDA COMM COLL JACKSONVILLECTR ADV TEACHING & LEARNING PI JACKSONVILLE PA 501 W STATE ST, JACKSONVILLE, FL 32202 USA PY 2000 BP 151 EP 162 PG 12 WC Education & Educational Research SC Education & Educational Research GA BQ29D UT WOS:000087839200018 ER PT B AU Schneidewind, NF AF Schneidewind, NF GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Investigation of logistic regression as a discriminant of software quality SO SEVENTH INTERNATIONAL SOFTWARE METRICS SYMPOSIUM - METRICS 2001, PROCEEDINGS LA English DT Proceedings Paper CT 7th International Software Metrics Symposium CY APR 04-06, 2001 CL LONDON, ENGLAND SP IEEE Comp Soc, Tech Council Software Engn DE software quality prediction; logistic regression functions; Boolean discriminant functions AB We investigated the possibility that Logistic Regression Functions (LRFs) when used in combination with Boolean Discriminant functions (BDFs), which we had previously developed, would improve the quality classification ability of BDFs when used alone. This was the case; when the union of a BDF and LRF was used to classify quality, the predicative accuracy of quality and inspection cost was improved over that of using either function alone for the Space Shuttle. Also, the LRFs proved useful for ranking the quality of modules in a build. The significance of these results is that very high quality classification accuracy (1.25% error) can be obtained while reducing the inspection cost incurred in achieving high quality. This is particularly important for safety critical systems. Because the methods are general and not particular to the Shuttle, they could be applied to other domains. A key parr of the LRF development was a method for identifying the critical value (i.e. threshold) that could discriminate between high and low quality and at the same rime constrain the cost of inspection to a reasonable value. C1 USN, Postgrad Sch, Monterey, CA 93940 USA. RP USN, Postgrad Sch, Monterey, CA 93940 USA. EM nschneicl@nps.navy.mil NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-1043-4; 0-7695-1044-2 PY 2000 BP 328 EP 337 DI 10.1109/METRIC.2001.915540 PG 10 WC Computer Science, Software Engineering SC Computer Science GA BS02Z UT WOS:000168378300032 ER PT J AU Wardlaw, AB Luton, JA AF Wardlaw, AB Luton, JA TI Fluid-structure interaction mechanisms for close-in explosions SO SHOCK AND VIBRATION LA English DT Article AB This paper examines fluid-structure interaction for close-in internal and external underwater explosions. The resulting flow field is impacted by the interaction between the reflected explosion shock and the explosion bubble. This shook reflects off the bubble as an expansion that reduces the pressure level between the bubble and the target, inducing cavitation and its subsequent collapse that reloads the target. Computational examples of several close-in interaction cases are presented to document the occurrence of these mechanisms. By comparing deformable and rigid body simulations, it is shown that cavitation collapse can occur solely from the shock-bubble interaction without the benefit of target deformation. Addition of a deforming target lowers the flow field pressure, facilitates cavitation and cavitation collapse, as well as reducing the impulse of the initial shock loading. C1 USN, Ctr Surface Warfare, Indian Head Div, Warhead Dynam Div, Indian Head, MD 20640 USA. RP Wardlaw, AB (reprint author), USN, Ctr Surface Warfare, Indian Head Div, Warhead Dynam Div, Code 420,101 Strauss Ave, Indian Head, MD 20640 USA. NR 12 TC 52 Z9 53 U1 4 U2 40 PU IOS PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 1070-9622 J9 SHOCK VIB JI Shock Vib. PY 2000 VL 7 IS 5 BP 265 EP 275 PG 11 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 395VR UT WOS:000166602400001 ER PT S AU Jones, HD Zerilli, FJ Holt, WH Mock, W Miller, PJ Lindfors, AJ AF Jones, HD Zerilli, FJ Holt, WH Mock, W Miller, PJ Lindfors, AJ BE Furnish, MD Chhabildas, LC Hixson, RS TI Equation of state for porous mixtures SO SHOCK COMPRESSION OF CONDENSED MATTER-1999, PTS 1 AND 2 SE AIP Conference Proceedings LA English DT Proceedings Paper CT 11th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUN 27-JUL 02, 1999 CL SNOWBIRD, UT SP Amer Phys Soc Top Grp AB An equation of state for porous mixtures is described based on the mixing properties of the Gibbs potential. For a mixture, neglecting surface energy, the Gibbs potential is simply the sum of the Gibbs potentials of the components. Nitrogen is added to account for porosity, with the mole number proportional to the porosity. The Gibbs potential for fluid species is calculated by means of a perturbation theory originated by Weeks, Chandler, and Anderson. A semi-empirical Debye-Gruneisen equation of state with a Murnaghan form for the zero degree isotherm is used to describe solids. Due to the complexity of the Weeks-Chandler-Anderson fluid equation of state, the possibility of using an ideal gas representation for nitrogen was investigated. A very good match to the shock Hugoniot for porous copper results from this approach. The model is also used to calculate the Hugoniot for an AI-TEFLON mixture and compared to data obtained by Miller and Lindfors and by Holt and Mock. C1 Naval Surface Warfare Ctr Indian Head, Energet Mat Res & Technol Dept, Indian Head, MD 20604 USA. USN, Ctr Surface Warfare, Dahlgren Div, Dahlgren, VA 22448 USA. USN, Ctr Weap, Detonat Sci Sect, China Lake, CA 93555 USA. RP Jones, HD (reprint author), Naval Surface Warfare Ctr Indian Head, Energet Mat Res & Technol Dept, Indian Head, MD 20604 USA. EM fzerill@darkstar2.ih.navy.mil; wholt@nswc.navy.mil; millerpj@navair.navy.mil NR 9 TC 3 Z9 3 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-923-8 J9 AIP CONF PROC PY 2000 VL 505 BP 137 EP 140 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BQ23D UT WOS:000087647600029 ER PT S AU White, A Zerilli, FJ Jones, HD AF White, A Zerilli, FJ Jones, HD BE Furnish, MD Chhabildas, LC Hixson, RS TI An ab initio method for estimating equation of state parameters SO SHOCK COMPRESSION OF CONDENSED MATTER-1999, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUN 27-JUL 02, 1999 CL SNOWBIRD, UT SP Amer Phys Soc Top Grp ID COMPRESSION; NITROGEN AB This paper describes an ab initio method for estimating intermolecular potential parameters required for equations of state. The intermolecular potentials are thermodynamically averaged over the Euler angles of the system as proposed by Ree to give a spherical average at that intermolecular distance. An alternative treatment using the multipole moments of the angular dependent potentials is also described. The results obtained in a detonation state calculation for the explosive FEFO agree well with those measured in experiments. C1 USN, Surface Warfare Ctr, Energet Mat Res & Technol Dept, Indian Head Div, Indian Head, MD 20640 USA. RP White, A (reprint author), USN, Surface Warfare Ctr, Energet Mat Res & Technol Dept, Indian Head Div, Indian Head, MD 20640 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-923-8 J9 AIP CONF PROC PY 2000 VL 505 BP 165 EP 168 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BQ23D UT WOS:000087647600036 ER PT S AU Elert, ML Swanson, DR White, CT AF Elert, ML Swanson, DR White, CT BE Furnish, MD Chhabildas, LC Hixson, RS TI Molecular dynamics simulation of shock-induced chemistry in acetylene SO SHOCK COMPRESSION OF CONDENSED MATTER-1999, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUN 27-JUL 02, 1999 CL SNOWBIRD, UT SP Amer Phys Soc Top Grp ID DETONATION; ATMOSPHERES; DIAMOND; HYDROCARBONS; JUPITER; OZONE AB Many experimental studies have demonstrated the existence of shock- induced chemical reactions in organic materials. Some of this work was motivated by the possible cosmo-chemical significance of shock- induced synthesis resulting from meteor bombardment of planetary atmospheres. In most cases, fundamental reaction mechanisms and kinetics, and threshold conditions for reaction initiation, remain poorly understood. Using a recently developed reactive empirical bond order (REBO) potential for hydrocarbons, we have carried out molecular dynamics simulations of shocked condensed-phase acetylene to investigate the resulting shock-induced chemistry at an atomistic level. C1 USN Acad, Dept Chem, Annapolis, MD 21402 USA. RP Elert, ML (reprint author), USN Acad, Dept Chem, Annapolis, MD 21402 USA. NR 21 TC 2 Z9 2 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-923-8 J9 AIP CONF PROC PY 2000 VL 505 BP 283 EP 286 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BQ23D UT WOS:000087647600063 ER PT S AU Swanson, DR Elert, ML White, CT AF Swanson, DR Elert, ML White, CT BE Furnish, MD Chhabildas, LC Hixson, RS TI Detonation Hugoniots produced by piston-driven simulations SO SHOCK COMPRESSION OF CONDENSED MATTER-1999, PTS 1 AND 2 SE AIP Conference Proceedings LA English DT Proceedings Paper CT 11th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUN 27-JUL 02, 1999 CL SNOWBIRD, UT SP Amer Phys Soc Top Grp ID MOLECULAR-DYNAMICS AB We have previously introduced a model of an energetic diatomic molecular solid based on reactive empirical bond order (REBO) potentials. This model is capable of supporting a detonation in two and three dimensions. When the range of the REBO potential is varied, a wide variety of properties are exhibited, including a split shock wave and a dissociative phase transition. We present simulations with the boundary conditions behind the detonation front maintained by a constant velocity piston. Detonation Hugoniots are derived from these calculations and analyzed using continuum theory. C1 USN, Res Lab, Washington, DC 20375 USA. RP Swanson, DR (reprint author), USN, Res Lab, Washington, DC 20375 USA. EM dswanson4@unl.edu; elert@nadn.navy.mil; white@alchemy.nrl.navy.mil NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-923-8 J9 AIP CONF PROC PY 2000 VL 505 BP 385 EP 388 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BQ23D UT WOS:000087647600087 ER PT S AU Holt, WH Wilson, LT Mock, W Simpson, B AF Holt, WH Wilson, LT Mock, W Simpson, B BE Furnish, MD Chhabildas, LC Hixson, RS TI Dynamic properties of a shock loaded tungsten composite SO SHOCK COMPRESSION OF CONDENSED MATTER-1999, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUN 27-JUL 02, 1999 CL SNOWBIRD, UT SP Amer Phys Soc Top Grp AB Disks of a 90% tungsten, 9% nickel, 1% cobalt composite have been shock loaded in momentum trapping assemblies using a 40 mm bore gas gun, and recovered in water bags. The specimen disks were 30.5 mm in diameter and 7.2 mm thick. The larger-diameter impactor disks had the same composition. Impact speeds for the three experiments were 0.073, 0.148, and 0.405 km/sec, respectively. The specimen disks were shocked and recovered without fracture only for the two lower impact speeds. Portions of the recovered material for these experiments were machined into specimens for Hopkinson bar measurements. These measurements indicated minor differences in the constitutive response of the shocked and "as received" material. C1 USN, Ctr Surface Warfare, Dahlgren Div, Dahlgren, VA 22448 USA. RP Holt, WH (reprint author), USN, Ctr Surface Warfare, Dahlgren Div, Dahlgren, VA 22448 USA. NR 2 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-923-8 J9 AIP CONF PROC PY 2000 VL 505 BP 459 EP 462 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BQ23D UT WOS:000087647600105 ER PT S AU Zerilli, FJ Armstrong, RW AF Zerilli, FJ Armstrong, RW BE Furnish, MD Chhabildas, LC Hixson, RS TI Application of Eyring's thermal activation theory to constitutive equations for polymers SO SHOCK COMPRESSION OF CONDENSED MATTER-1999, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUN 27-JUL 02, 1999 CL SNOWBIRD, UT SP Amer Phys Soc Top Grp AB The application of a constitutive model based on the thermal activation theory of Eyring to the yield stress of polymethylmethacrylate at various temperatures and strain rates, as measured by Bauwens-Crowet, shows that the yield stress may reasonably well be described by a thermal activation equation in which the volume of activation is inversely proportional to the yield stress. It is found that, to obtain an accurate model, the dependence of the cold (T = 0 K) yield stress on the shear modulus must be taken into account. C1 USN, Ctr Surface Warfare, Indian Head Div, Energet Mat Res & Technol Dept, Indian Head, MD 20640 USA. RP Zerilli, FJ (reprint author), USN, Ctr Surface Warfare, Indian Head Div, Energet Mat Res & Technol Dept, Indian Head, MD 20640 USA. NR 8 TC 3 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-923-8 J9 AIP CONF PROC PY 2000 VL 505 BP 531 EP 534 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BQ23D UT WOS:000087647600122 ER PT S AU Guirguis, RH AF Guirguis, RH BE Furnish, MD Chhabildas, LC Hixson, RS TI Ignition due to macroscopic shear SO SHOCK COMPRESSION OF CONDENSED MATTER-1999, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUN 27-JUL 02, 1999 CL SNOWBIRD, UT SP Amer Phys Soc Top Grp AB The energy dissipated by macroscopic shear when a thin explosive sample is squeezed between two parallel planes is quantified for a variety of boundary conditions and constitutive models. The viscous fluid model predicts the localization of energy dissipation near the edges, where ignition is usually observed. C1 USN, Ctr Surface Warfare, Indian Head, MD 20640 USA. RP Guirguis, RH (reprint author), USN, Ctr Surface Warfare, Indian Head, MD 20640 USA. NR 4 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-923-8 J9 AIP CONF PROC PY 2000 VL 505 BP 647 EP 650 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BQ23D UT WOS:000087647600149 ER PT S AU John, HJ Alamo, MF AF John, HJ Alamo, MF BE Furnish, MD Chhabildas, LC Hixson, RS TI High-strain rate testing of HMX-based explosive SO SHOCK COMPRESSION OF CONDENSED MATTER-1999, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUN 27-JUL 02, 1999 CL SNOWBIRD, UT SP Amer Phys Soc Top Grp AB A split Hopkinson pressure bar (SHPB) was used to measure the mechanical behavior of Navy explosive PBXC-129 (a high-solids-loaded explosive material) with strain rates up to similar to 3500 s(-1). The PBXC-129's high-strain response is typical of other explosive and propellant behavior. At higher strain rates, the PBXC-129 shows significant stiffening with a possible reaction. Stress-strain curves and material properties for PBXC-129 are presented in this paper. C1 USN, Air Warfare Ctr, Weapons Div, China Lake, CA 93555 USA. RP John, HJ (reprint author), USN, Air Warfare Ctr, Weapons Div, 1 Adm Circle,Code 478400D, China Lake, CA 93555 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-923-8 J9 AIP CONF PROC PY 2000 VL 505 BP 679 EP 682 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BQ23D UT WOS:000087647600157 ER PT S AU Sharma, J Coffey, CS Armstrong, RW Elban, WL Lanzerotti, MYD AF Sharma, J Coffey, CS Armstrong, RW Elban, WL Lanzerotti, MYD BE Furnish, MD Chhabildas, LC Hixson, RS TI Nanostructure of porosity (and entrapped solvent effects) in laboratory-grown crystals of RDX as revealed by an AFM SO SHOCK COMPRESSION OF CONDENSED MATTER-1999, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUN 27-JUL 02, 1999 CL SNOWBIRD, UT SP Amer Phys Soc Top Grp AB Internal porosity within laboratory-grown crystals of RDX has been investigated with an atomic force microscope (AFM) in extension of previous work [1]]. The crystals were cleaved along {001} planes so as to provide cross-sections of the defects. The pores showed up as nano-caverns, ranging in size from 10 nm to a few microns, with very complicated shapes and tentacle-like arms. They were only 5-200 nm deep, and were seen in various orientations. The complex shapes seem to arise from anisotropic local crystal growth and from thermal influences with associated redistribution of solvent and solute. RDX crystals, grown in an ultracentrifuge were also investigated. They did not show any bubbles or solvent inclusions. Both kinds of crystals studied, frequently showed one molecule high terraces running over distances of microns. These seem to have been left by edge dislocations which have egressed out of the crystals altogether. C1 USN, Ctr Surface Warfare, Carderock Div, Bethesda, MD 20817 USA. RP Sharma, J (reprint author), USN, Ctr Surface Warfare, Carderock Div, Bethesda, MD 20817 USA. NR 6 TC 4 Z9 4 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-923-8 J9 AIP CONF PROC PY 2000 VL 505 BP 719 EP 722 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BQ23D UT WOS:000087647600167 ER PT S AU Davis, JJ Woody, DL Miller, PJ AF Davis, JJ Woody, DL Miller, PJ BE Furnish, MD Chhabildas, LC Hixson, RS TI Shock and impact initiation of a porous incendiary material SO SHOCK COMPRESSION OF CONDENSED MATTER-1999, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUN 27-JUL 02, 1999 CL SNOWBIRD, UT SP Amer Phys Soc Top Grp AB In order to better understand the deformation - initiation process, experiments have been performed in which an energetic composition containing KClO4 and Al/Mg was impact tested via gas gun at velocities ranging from 0.33 - 0.98 mm/mu s at two densities: 84 and 70% TMD. An investigation of the importance of sample thickness was conducted with the 84% TMD samples. These tests used the observation of visible light emission as indication of reaction. This series of experiments complements a prior series in which PVDF pressure gauges were used to determine reaction threshold as well as the inert Hugoniot for this material. As expected, the light method determined a lower initiation threshold than the gauge work. C1 USN, Ctr Weap, Air Warfare Ctr, Engn Sci Div, China Lake, CA 93555 USA. RP Davis, JJ (reprint author), USN, Ctr Weap, Air Warfare Ctr, Engn Sci Div, China Lake, CA 93555 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-923-8 J9 AIP CONF PROC PY 2000 VL 505 BP 771 EP 774 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BQ23D UT WOS:000087647600179 ER PT S AU Sutherland, GT Burns, J AF Sutherland, GT Burns, J BE Furnish, MD Chhabildas, LC Hixson, RS TI Explosive response model evaluation using the explosive H6 SO SHOCK COMPRESSION OF CONDENSED MATTER-1999, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUN 27-JUL 02, 1999 CL SNOWBIRD, UT SP Amer Phys Soc Top Grp AB Reactive rate model parameters for a two term Lee Tarver [simplified ignition and growth (SIG)] model were obtained for the explosive H6 from modified gap test data. These model was used to perform simulations of the underwater sensitivity test (UST) using the CTH hydrocode. Reaction was predicted in the simulations for the same water gaps that reaction was observed in the UST. The expansions observed for the UST samples were not simulated correctly, and this is attributed to the density equilibrium conditions imposed between unreacted and reacted components in CTH for the Lee-Tarver model. C1 USN, Ctr Surface Warfare, Indian Head Div, Indian Head, MD 20640 USA. RP Sutherland, GT (reprint author), USN, Ctr Surface Warfare, Indian Head Div, Indian Head, MD 20640 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-923-8 J9 AIP CONF PROC PY 2000 VL 505 BP 805 EP 808 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BQ23D UT WOS:000087647600187 ER PT S AU Doherty, RM Forbes, JW Lawrence, GW Deiter, JS Baker, RN Ashwell, KD Sutherland, GT AF Doherty, RM Forbes, JW Lawrence, GW Deiter, JS Baker, RN Ashwell, KD Sutherland, GT BE Furnish, MD Chhabildas, LC Hixson, RS TI Detonation velocity of melt-cast ADN and ADN/nano-diamond cylinders SO SHOCK COMPRESSION OF CONDENSED MATTER-1999, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUN 27-JUL 02, 1999 CL SNOWBIRD, UT SP Amer Phys Soc Top Grp AB Detonation velocities of confined cylinders of melt-cast ADN/ZnO (99.5/0.5 by weight), ADN/nano-diamond/ZnO (92.4/7.2/0.4), ADN/AN/ZnO (95.5/4.0/0.5) and ADN/AN/ZnO/nano-diamond (88.0/4.5/0.5/7.0) have been measured using a streak camera. Velocities ranging between 3.9 and 4.5 mm/mu s were obtained for 1.3 cm diameter samples confined by steel and a 2.5 cm diameter ADN/AN/ZnO cylinder. In one of the samples the detonation was failing as it proceeded through the charge. For the other shots reported, the shock velocities appeared to be steady through the last half of the charge, though the lengths were too short for any definitive statement about the failure diameter to be made. C1 USN, Ctr Surface Warfare, Indian Head, MD 20640 USA. RP Doherty, RM (reprint author), USN, Ctr Surface Warfare, Indian Head, MD 20640 USA. NR 6 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-923-8 J9 AIP CONF PROC PY 2000 VL 505 BP 833 EP 836 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BQ23D UT WOS:000087647600194 ER PT S AU Peiris, SM Pangilinan, GI Russell, TP AF Peiris, SM Pangilinan, GI Russell, TP BE Furnish, MD Chhabildas, LC Hixson, RS TI The laser-induced decomposition of TATB at static high pressure SO SHOCK COMPRESSION OF CONDENSED MATTER-1999, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUN 27-JUL 02, 1999 CL SNOWBIRD, UT SP Amer Phys Soc Top Grp ID ENERGETIC MATERIALS AB The laser-induced decomposition of 1,3,5-triaminino 2,4,6-trinitro benzene (TATB) at static high-pressures to 2.0 GPa are investigated. Time-resolved UV-visible absorption is obtained with microsecond temporal resolution in the spectral range 270-800 nm. The observed absorbance band of TATE centered at 370nm, and its decrease in intensity upon laser-initiation, is used to investigate the rate of reaction of TATE. At higher pressure, the rate of decomposition increases, while the induction time to reaction remains about 1.5 mu s. C1 USN, Res Lab, Div Chem, Washington, DC 20375 USA. RP Peiris, SM (reprint author), USN, Res Lab, Div Chem, Code 6112, Washington, DC 20375 USA. NR 14 TC 2 Z9 2 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-923-8 J9 AIP CONF PROC PY 2000 VL 505 BP 849 EP 852 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BQ23D UT WOS:000087647600198 ER PT S AU Parker, LJ Ladouceur, HD Russell, TP AF Parker, LJ Ladouceur, HD Russell, TP BE Furnish, MD Chhabildas, LC Hixson, RS TI Teflon and Teflon/A1 (nanocrystalline) decomposition chemistry at high pressures SO SHOCK COMPRESSION OF CONDENSED MATTER-1999, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUN 27-JUL 02, 1999 CL SNOWBIRD, UT SP Amer Phys Soc Top Grp AB Teflon (polytetrafluoroethylene) and Teflon/Al mixtures were studied to develop a fundamental understanding of the decomposition reactions and combustion processes of metal/polymer composites under extreme conditions. Our goal was to determine the role of pressure and laser fluence on Teflon and Teflon/Al reaction mechanisms and their global reaction rates. High-pressure time-resolved absorption spectroscopy was employed to investigate the reaction mechanisms and global reaction rates. Absorption spectra (400-700 nm) were collected at a maximum temporal resolution of 1.25 mu s, during and up to 90 mu s after the heating pulse. The pressure dependence and the effect of Al composition on decomposition will be reported. Preliminary models to explain the heterogeneous combustion process of these materials will be discussed. C1 USN, Res Lab, Div Chem, Washington, DC 20375 USA. RP Parker, LJ (reprint author), USN, Res Lab, Div Chem, Code 6112, Washington, DC 20375 USA. NR 10 TC 21 Z9 21 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-923-8 J9 AIP CONF PROC PY 2000 VL 505 BP 941 EP 944 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BQ23D UT WOS:000087647600220 ER PT S AU Peiris, SM Pangilinan, GI Russell, TP AF Peiris, SM Pangilinan, GI Russell, TP BE Furnish, MD Chhabildas, LC Hixson, RS TI Structural changes in ammonimum perchlorate under compression to 5 GPa SO SHOCK COMPRESSION OF CONDENSED MATTER-1999, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUN 27-JUL 02, 1999 CL SNOWBIRD, UT SP Amer Phys Soc Top Grp ID SINGLE-CRYSTAL; CELL AB The effect of pressure to 5.5 GPa on the structure of ammonium perchlorate (AP, NH,CIO,) was investigated at room temperature. X-ray diffraction studies and high-resolution Raman spectra reveal two phase transitions, one at about 1.5 GPa and another at 3.3 GPa. The phase at 1.5 GPa is indicated by new diffraction peaks and a discontinuity in the pressure-induced shifts of certain Raman frequencies, and is most likely a molecular change in AP. The high-pressure structure, above 3.3 GPa, is characterized by an entirely different diffraction pattern and two new Raman modes, and is a new structure with possibly hexagonal or tetragonal symmetry. The isothermal compression of AP was used to obtain isothermal equation-of-state parameters for the ambient-pressure phase to 1.5 GPa. C1 USN, Res Lab, Div Chem, Washington, DC 20375 USA. RP Peiris, SM (reprint author), USN, Res Lab, Div Chem, Code 6112, Washington, DC 20375 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-923-8 J9 AIP CONF PROC PY 2000 VL 505 BP 955 EP 958 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BQ23D UT WOS:000087647600223 ER PT S AU Zakraysek, AJ Sutherland, GT Sandusky, HD Strange, D AF Zakraysek, AJ Sutherland, GT Sandusky, HD Strange, D BE Furnish, MD Chhabildas, LC Hixson, RS TI A new gun facility dedicated to performing shock physics and terminal ballistics experiments SO SHOCK COMPRESSION OF CONDENSED MATTER-1999, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUN 27-JUL 02, 1999 CL SNOWBIRD, UT SP Amer Phys Soc Top Grp AB A new building has been constructed to house various powder and single-stage and two-stage gas guns at the Naval Surface Warfare Center, Indian Head Division. Guns previously located at the Naval Research Laboratory and the former White Oak Site of the Naval Surface Warfare Center have been relocated here. Most of the guns are mounted on moveable pedestals to allow them to be shot into various chambers. The facility includes a concrete blast chamber, a target chamber/catch tank for flyer plate experiments, and a target chamber outfitted for terminal ballistics measurements. This paper will discuss the capabilities of this new facility. C1 USN, Ctr Surface Warfare, Indian Head Div, Indian Head, MD 20640 USA. RP Zakraysek, AJ (reprint author), USN, Ctr Surface Warfare, Indian Head Div, Indian Head, MD 20640 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-923-8 J9 AIP CONF PROC PY 2000 VL 505 BP 1091 EP 1094 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BQ23D UT WOS:000087647600253 ER PT S AU Watson, GA Rice, TR Alouani, AT AF Watson, GA Rice, TR Alouani, AT BE Kadar, I TI An IMM architecture for track fusion SO SIGNAL PROCESSING, SENSOR FUSION, AND TARGET RECOGNITION IX SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Signal Processing, Sensor Fusion, and Target Recognition IX CY APR 24-26, 2000 CL ORLANDO, FL SP SPIE DE track fusion; IMM algorithm; Kalman filter; asynchronous; optimal; feedback AB A numeric solution for the fusion of multiple tracks produced from an arbitrary number of asynchronous measurements has been recently developed. This track fusion solution is a weighted sum of the values associated with the previous fused estimate and the multiple individual estimates. This Optimal Asynchronous Track Fusion Algorithm (OATFA) has properties that are identical to the Kalman filter. However, the deficiencies of the Kalman filter when tracking maneuvering targets are also exhibited by the OATFA but can be overcome with the use of the Interacting Multiple Model (IMM) algorithm. Consequently, it should be possible to replace the Kalman filter commonly employed in a conventional IMM algorithm with the OATFA to form the IMM-OATFA. The IMM-OATFA will be developed and simulation results will be used to compare its performance with a conventional IMM tracker. C1 USN, Ctr Surface Warfare, Dahlgren Div, Syst Res & Technol Dept,Digital Syst Branch, Dahlgren, VA 22448 USA. RP Watson, GA (reprint author), USN, Ctr Surface Warfare, Dahlgren Div, Syst Res & Technol Dept,Digital Syst Branch, Code B32, Dahlgren, VA 22448 USA. NR 9 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3678-X J9 P SOC PHOTO-OPT INS PY 2000 VL 4052 BP 2 EP 13 DI 10.1117/12.395057 PG 12 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Engineering, Electrical & Electronic SC Automation & Control Systems; Computer Science; Engineering GA BR51K UT WOS:000166690400001 ER PT S AU Smith, JF Rhyne, RD AF Smith, JF Rhyne, RD BE Kadar, I TI Fuzzy logic based resource allocation for isolated and multiple platforms SO SIGNAL PROCESSING, SENSOR FUSION, AND TARGET RECOGNITION IX SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Signal Processing, Sensor Fusion, and Target Recognition IX CY APR 24-26, 2000 CL ORLANDO, FL SP SPIE DE fuzzy logic; genetic algorithms; expert systems; distributed AI algorithms ID MULTISENSOR ASSOCIATION ALGORITHM AB Modern naval battle forces generally include many different platforms each with its own sensors, radar, ESM, and communications. The sharing of information measured by local sensors via communication links across the battle group should allow for optimal or near optimal decisions. The survival of the battle group or members of the group depends on the automatic real-time allocation of various resources. A fuzzy logic algorithm has been developed that automatically allocates electronic attack (EA) resources in real-time. The particular approach to fuzzy logic that is used is the fuzzy decision tree, a generalization of the standard artificial intelligence technique of decision trees. The controller must be able to make decisions based on rules provided by experts. The fuzzy logic approach allows the direct incorporation of expertise forming a fuzzy linguistic description, i.e., a formal representation of the system in terms of fuzzy if-then rules. Genetic algorithm based optimization is conducted to determine the form of the membership functions for the fuzzy root concepts. The isolated platform and multiple platform resource manager models are discussed as well as the underlying multi-platform communication model. The resource manager is shown to exhibit excellent performance under many demanding scenarios. C1 USN, Res Lab, Washington, DC 20375 USA. RP Smith, JF (reprint author), USN, Res Lab, Code 5741, Washington, DC 20375 USA. NR 15 TC 4 Z9 4 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3678-X J9 P SOC PHOTO-OPT INS PY 2000 VL 4052 BP 36 EP 47 DI 10.1117/12.395092 PG 12 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Engineering, Electrical & Electronic SC Automation & Control Systems; Computer Science; Engineering GA BR51K UT WOS:000166690400004 ER PT S AU Lynch, RS Willett, PK AF Lynch, RS Willett, PK BE Kadar, I TI Class-specific feature selection based on uniform dirichlet priors SO SIGNAL PROCESSING, SENSOR FUSION, AND TARGET RECOGNITION IX SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Signal Processing, Sensor Fusion, and Target Recognition IX CY APR 24-26, 2000 CL ORLANDO, FL SP SPIE DE Bayesian; discrete observations; multinomial; dimensionality reduction ID PERFORMANCE AB In this paper, the Bayesian Data Reduction Algorithm (BDRA) is applied to reducing the dimensionality of a data set that contains class-specific features. The BDRA uses the probability of error, conditioned on the training data, and a "greedy" approach (similar to a backward sequential feature search) for reducing irrelevant features from the data. Here, the BDRA is shown to be an effective means of selecting binary valued class-specific features, where the remaining non-class-specific features are irrelevant to correct classification. In fact, performance results reveal that when using a small number of training data relative to feature dimensionality (and when class-specific features exist for each class), the BDRA outperforms the appropriate class-specific classifier. C1 USN, Ctr Underwater Syst, Signal Proc Branch, Newport, RI 02840 USA. RP Lynch, RS (reprint author), USN, Ctr Underwater Syst, Signal Proc Branch, Code 8212, Newport, RI 02840 USA. OI Willett, Peter/0000-0001-8443-5586 NR 16 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3678-X J9 P SOC PHOTO-OPT INS PY 2000 VL 4052 BP 94 EP 101 PG 8 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Engineering, Electrical & Electronic SC Automation & Control Systems; Computer Science; Engineering GA BR51K UT WOS:000166690400010 ER PT S AU Rowland, LB Dunne, GT Freitas, JA AF Rowland, LB Dunne, GT Freitas, JA BE Carter, CH Devaty, RP Rohrer, GS TI Initial results on thick 4H-SiC epitaxial layers grown using vapor phase epitaxy SO SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT International Conference on Silicon Carbide and Related Materials CY OCT 10-15, 1999 CL RES TRIANGLE PK, NORTH CAROLINA SP NASA, Glenn Res Ctr, USAF, Res Lab, mat & Mfg Directoirate, USN, Off Res, Def Res & Engn, Cree Inc, Charles & Colvard Inc, ABB Semicond, Sterling Semicond Inc, ATMI Inc, Epigress AB, Aixtron AG, Northrop Grumman, Siemens AG, EMCORE Inc, GE, Corp R & D, Litton Airton, II-VI Inc DE epitaxy; tantalum carbide ID SILICON-CARBIDE AB Epitaxial layers of 4H-SiC of up to 120 micron thickness have been grown by vapor phase epitaxy using a tantalum carbide-coated susceptor surrounded by graphite foam. Background doping levels due to N and Al impurities were in the low 10(15) cm(-3) range. The electrical and optical properties of these layers are comparable to those grown using conventional vapor phase epitaxy. C1 Sterling Semicond Inc, Sterling, VA 20166 USA. USN, Res Lab, Washington, DC 20375 USA. RP Rowland, LB (reprint author), Sterling Semicond Inc, 22660 Execut Dr,Suite 101, Sterling, VA 20166 USA. RI Rowland, Larry/C-4487-2008 NR 5 TC 3 Z9 3 U1 0 U2 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2000 VL 338-3 BP 161 EP 164 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Materials Science GA BR27W UT WOS:000165996700038 ER PT S AU Saks, NS Mani, SS Agarwal, AK Hegde, VS AF Saks, NS Mani, SS Agarwal, AK Hegde, VS BE Carter, CH Devaty, RP Rohrer, GS TI Hall mobility of the electron inversion layer in 6H-SiC MOSFETs SO SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT International Conference on Silicon Carbide and Related Materials CY OCT 10-15, 1999 CL RES TRIANGLE PK, NORTH CAROLINA SP NASA, Glenn Res Ctr, USAF, Res Lab, mat & Mfg Directoirate, USN, Off Res, Def Res & Engn, Cree Inc, Charles & Colvard Inc, ABB Semicond, Sterling Semicond Inc, ATMI Inc, Epigress AB, Aixtron AG, Northrop Grumman, Siemens AG, EMCORE Inc, GE, Corp R & D, Litton Airton, II-VI Inc DE charge-sheet model; Hall effect; interface trap; inversion layer; mobility; MOS AB Electron mobility and free carrier density have been measured in 6H-SiC MOS inversion layers using the Hall effect to study unexpectedly low transconductance in SiC MOSFETs. We find that the Hall mobility can be much larger than the effective mobility extracted from transconductance data. In addition, the actual free electron density is found to be smaller than predicted by the charge-sheet model, which is caused by substantial electron trapping at the SiC/SiO2 interface. C1 USN, Res Lab, Washington, DC 20375 USA. Northrop Grumman Corp, Pittsburgh, PA USA. RP Saks, NS (reprint author), USN, Res Lab, Code 6813, Washington, DC 20375 USA. NR 11 TC 17 Z9 17 U1 0 U2 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2000 VL 338-3 BP 737 EP 740 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Materials Science GA BR27W UT WOS:000165996700179 ER PT S AU Tucker, JB Handy, EM Rao, MV Holland, OW Papanicolaou, N Jones, KA AF Tucker, JB Handy, EM Rao, MV Holland, OW Papanicolaou, N Jones, KA BE Carter, CH Devaty, RP Rohrer, GS TI Characteristics of n-p junction diodes made by double-implantations into SiC SO SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT International Conference on Silicon Carbide and Related Materials CY OCT 10-15, 1999 CL RES TRIANGLE PK, NORTH CAROLINA SP NASA, Glenn Res Ctr, USAF, Res Lab, mat & Mfg Directoirate, USN, Off Res, Def Res & Engn, Cree Inc, Charles & Colvard Inc, ABB Semicond, Sterling Semicond Inc, ATMI Inc, Epigress AB, Aixtron AG, Northrop Grumman, Siemens AG, EMCORE Inc, GE, Corp R & D, Litton Airton, II-VI Inc DE annealing; diode; doping; ion-implantation AB Empirical formulae for range statistics of acceptor ions Al+ and B+ in the energy range 50 keV to 4 MeV were developed by fitting the data obtained from the analysis of secondary ion mass spectrometry (SIMS) depth profiles of single energy ion implants. Double implantation technology consisting of deep-range acceptor followed by shallow-range donor implantation was used to fabricate n-p junction diodes in 4H-SIC. Either Al or B was used as the acceptor species and N as the donor species with all implants performed at 700 degreesC and annealed at 1650 degreesC with an AIN encapsulant. The diodes were characterized for their current-voltage (I-V) and capacitance-voltage (C-V) behavior over the temperature range 25 degreesC to 400 degreesC. C1 George Mason Univ, Dept Elect & Comp Engn, Fairfax, VA 22030 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. USN, Res Lab, Washington, DC 20375 USA. USA, Res Lab, SEDD, Adelphi, MD 20783 USA. RP Tucker, JB (reprint author), George Mason Univ, Dept Elect & Comp Engn, Fairfax, VA 22030 USA. NR 4 TC 5 Z9 5 U1 0 U2 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2000 VL 338-3 BP 925 EP 928 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Materials Science GA BR27W UT WOS:000165996700224 ER PT S AU Vassilevski, KV Zekentes, K Constantinidis, G Papanicolaou, N Nikitina, IP Babanin, AI AF Vassilevski, KV Zekentes, K Constantinidis, G Papanicolaou, N Nikitina, IP Babanin, AI BE Carter, CH Devaty, RP Rohrer, GS TI Structural and morphological characterization of Al/Ti-based ohmic contacts on p-type 4H-SiC annealed under various conditions SO SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT International Conference on Silicon Carbide and Related Materials CY OCT 10-15, 1999 CL RES TRIANGLE PK, NORTH CAROLINA SP NASA, Glenn Res Ctr, USAF, Res Lab, mat & Mfg Directoirate, USN, Off Res, Def Res & Engn, Cree Inc, Charles & Colvard Inc, ABB Semicond, Sterling Semicond Inc, ATMI Inc, Epigress AB, Aixtron AG, Northrop Grumman, Siemens AG, EMCORE Inc, GE, Corp R & D, Litton Airton, II-VI Inc DE 4H-SiC; annealing; depth profiling; ohmic contacts; p-type AB Structural and morphological characterization of Al/Ti-based contacts to p-type 4H-SiC was performed. Ohmic contacts with low specific contact resistance (similar to 10(-4)Omega .cm(2)) were obtained when cap layers have been used while were completely oxide-free when the annealing was performed under high vacuum conditions the contacts. It was found that use of Ti and Ni in the contact metallizations led to the formation of Ni2Si/TiC duplex coatings at high temperature annealing. C1 Fdn Res & Technol Hellas, GR-71110 Iraklion, Greece. USN, Res Lab, Washington, DC 20375 USA. Ioffe Inst, RU-194021 St Petersburg, Russia. RP Vassilevski, KV (reprint author), Fdn Res & Technol Hellas, POB 1527, GR-71110 Iraklion, Greece. RI Zekentes, Konstantinos/A-2498-2014; Konstantinidis, George/A-1719-2014 OI Konstantinidis, George/0000-0002-1072-9618 NR 7 TC 10 Z9 10 U1 1 U2 1 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2000 VL 338-3 BP 1017 EP 1020 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Materials Science GA BR27W UT WOS:000165996700247 ER PT S AU Saks, NS Mani, SS Agarwal, AK AF Saks, NS Mani, SS Agarwal, AK BE Carter, CH Devaty, RP Rohrer, GS TI Interface trap profiles near the band edges in 6H-SiC MOSFETs SO SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT International Conference on Silicon Carbide and Related Materials CY OCT 10-15, 1999 CL RES TRIANGLE PK, NORTH CAROLINA SP NASA, Glenn Res Ctr, USAF, Res Lab, mat & Mfg Directoirate, USN, Off Res, Def Res & Engn, Cree Inc, Charles & Colvard Inc, ABB Semicond, Sterling Semicond Inc, ATMI Inc, Epigress AB, Aixtron AG, Northrop Grumman, Siemens AG, EMCORE Inc, GE, Corp R & D, Litton Airton, II-VI Inc DE capacitance-voltage measurements; interface trap; interface trap profiles; MOS AB The interface trap density Dit(E) has been profiled versus energy in the bandgap for 6H-SiC MOS devices. A modified "low-frequency" capacitance-voltage technique is presented which allows trap densities to be independently profiled close to the conduction and valence band edges. Results show that Dit(E) is much higher close to both band edges than the average (midgap) value. These results show that the low transconductance typically reported for n-channel 6H-SiC MOSFETs is caused by trapping of inversion layer electrons at the SiC/SiO2 interface. C1 USN, Res Lab, Washington, DC 20375 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Cree Res Inc, Durham, NC 27703 USA. RP Saks, NS (reprint author), USN, Res Lab, Code 6877, Washington, DC 20375 USA. NR 9 TC 3 Z9 3 U1 0 U2 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2000 VL 338-3 BP 1113 EP 1116 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Materials Science GA BR27W UT WOS:000165996700271 ER PT S AU Agarwal, AK Saks, NS Mani, SS Hegde, VS Sanger, PA AF Agarwal, AK Saks, NS Mani, SS Hegde, VS Sanger, PA BE Carter, CH Devaty, RP Rohrer, GS TI Investigation of lateral RESURF, 6H-SiC MOSFETs SO SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT International Conference on Silicon Carbide and Related Materials CY OCT 10-15, 1999 CL RES TRIANGLE PK, NORTH CAROLINA SP NASA, Glenn Res Ctr, USAF, Res Lab, mat & Mfg Directoirate, USN, Off Res, Def Res & Engn, Cree Inc, Charles & Colvard Inc, ABB Semicond, Sterling Semicond Inc, ATMI Inc, Epigress AB, Aixtron AG, Northrop Grumman, Siemens AG, EMCORE Inc, GE, Corp R & D, Litton Airton, II-VI Inc DE interface trap; LDMOS; mobility; power MOSFETs; RESURF ID VOLTAGE AB We report on theoretical and experimental investigations of 600 V, lateral RESURF, 6H-SiC MOSFETs. The 2 dimensional device simulations show that the breakdown voltage of this class of devices is limited by the peak electric field in the oxide, which should be kept below 3 MV/cm for long-term reliability. The devices made on 6H-SiC substrates show 600 V breakdown, which was limited by the breakdown of the gate oxide. In order to reduce the electric field in the gate oxide, we show that it is necessary to reduce the doping of the lateral drift layer. This results in excessive specific on-resistance, which is dominated by the resistance of the drift layer. The inversion layer electron mobility of 50-60 cm(2)/V(.)s was obtained on experimental devices. Large area devices (560 mum x 1700 mum) had a specific on-resistance of 57 mohm(.)cm(2). C1 Cree Res Inc, Durham, NC 27703 USA. USN, Res Lab, Washington, DC 20375 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Northrop Grumman, Pittsburgh, PA 15235 USA. RP Agarwal, AK (reprint author), Cree Res Inc, 4600 Silicon Dr, Durham, NC 27703 USA. NR 8 TC 6 Z9 6 U1 0 U2 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2000 VL 338-3 BP 1307 EP 1310 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Materials Science GA BR27W UT WOS:000165996700318 ER PT S AU Yang, Y Bellitto, VJ Thoms, BD Koleske, DD Wickenden, AE Henry, RL AF Yang, Y Bellitto, VJ Thoms, BD Koleske, DD Wickenden, AE Henry, RL BE Carter, CH Devaty, RP Rohrer, GS TI Adsorption and desorption of hydrogen on Ga-rich GaN(0001) SO SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT International Conference on Silicon Carbide and Related Materials CY OCT 10-15, 1999 CL RES TRIANGLE PK, NORTH CAROLINA SP NASA, Glenn Res Ctr, USAF, Res Lab, mat & Mfg Directoirate, USN, Off Res, Def Res & Engn, Cree Inc, Charles & Colvard Inc, ABB Semicond, Sterling Semicond Inc, ATMI Inc, Epigress AB, Aixtron AG, Northrop Grumman, Siemens AG, EMCORE Inc, GE, Corp R & D, Litton Airton, II-VI Inc DE deuterium; HREELS; TPD ID COMPENSATION AB Hydrogen adsorption and desorption from GaN(0001) was studied using high resolution electron energy loss spectroscopy HREELS), energy loss spectroscopy ELS), low energy electron diffraction (LEED), Auger electron spectroscopy (AES), and temperature programmed desorption (TPD). HREELS loss peaks produced by atomic hydrogen were observed at 2580, 3280, and 3980 cm (-1) and are attributed to Ga-H bonds. Heating the surface to 380 degreesC completely removes the absorbate vibrational peaks. TPD confirms that the disappearance of GaH feature in HREEL spectra is due to recombinative desorption of hydrogen. Overall, this work demonstrates that the recombinative desorption of hydrogen from surface Ga sites occurs over the range of 250 to 500 degreesC. C1 Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. USN, Res Lab, Lab Adv Mat Synth, Washington, DC 20375 USA. RP Thoms, BD (reprint author), Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. NR 10 TC 1 Z9 1 U1 3 U2 5 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2000 VL 338-3 BP 1533 EP 1536 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Materials Science GA BR27W UT WOS:000165996700372 ER PT S AU Bellitto, VJ Thoms, BD Koleske, DD Wickenden, AE Henry, RL AF Bellitto, VJ Thoms, BD Koleske, DD Wickenden, AE Henry, RL BE Carter, CH Devaty, RP Rohrer, GS TI Extremely efficient electron stimulated desorption of hydrogen from GaN(0001) SO SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT International Conference on Silicon Carbide and Related Materials CY OCT 10-15, 1999 CL RES TRIANGLE PK, NORTH CAROLINA SP NASA, Glenn Res Ctr, USAF, Res Lab, mat & Mfg Directoirate, USN, Off Res, Def Res & Engn, Cree Inc, Charles & Colvard Inc, ABB Semicond, Sterling Semicond Inc, ATMI Inc, Epigress AB, Aixtron AG, Northrop Grumman, Siemens AG, EMCORE Inc, GE, Corp R & D, Litton Airton, II-VI Inc DE electron energy loss spectroscopy; electron stimulated desorption; hydrogen ID WURTZITE GAN; SURFACE; H/GAN(0001) AB Electron-stimulated desorption (ESD) of hydrogen from GaN(0001) has been observed and characterized using electron-energy-loss spectroscopy. Saturation exposure to atomic hydrogen produces a decrease in the intensity of energy loss peaks at 3.5 and 6.6 eV and an increase in the intensity of loss peaks at 11.7 and 18 eV. Bombardment with 90 eV electrons produces a reversal of the hydrogen-induced changes at 3.5, 6.6, and 11.7 eV. The increased intensity at 18 eV is almost unchanged by electron exposure. We conclude that the reversal of changes at 3.5, 6.6, and 11.7 eV is due to electron-stimulated desorption of hydrogen from Ga sites while the loss peak at 18 eV may be due to bulk hydrogen and not affected by 90 eV electrons. Cross sections for removal of H and D are found to be 2 x 10(-17) and 7 x 10(-18) cm(2), respectively. The large cross section and small isotope effect for ESD of hydrogen from GaN indicates the participation of a long-lived excited electronic state. C1 Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. USN, Res Lab, Lab Adv Mat Synth, Washington, DC 20375 USA. RP Thoms, BD (reprint author), Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. NR 16 TC 0 Z9 0 U1 0 U2 1 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2000 VL 338-3 BP 1537 EP 1540 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Materials Science GA BR27W UT WOS:000165996700373 ER PT S AU Thoms, BD Bellitto, VJ Yang, Y Koleske, DD Wickenden, AE Henry, RL AF Thoms, BD Bellitto, VJ Yang, Y Koleske, DD Wickenden, AE Henry, RL BE Carter, CH Devaty, RP Rohrer, GS TI The reaction of oxygen with GaN(0001) SO SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT International Conference on Silicon Carbide and Related Materials CY OCT 10-15, 1999 CL RES TRIANGLE PK, NORTH CAROLINA SP NASA, Glenn Res Ctr, USAF, Res Lab, mat & Mfg Directoirate, USN, Off Res, Def Res & Engn, Cree Inc, Charles & Colvard Inc, ABB Semicond, Sterling Semicond Inc, ATMI Inc, Epigress AB, Aixtron AG, Northrop Grumman, Siemens AG, EMCORE Inc, GE, Corp R & D, Litton Airton, II-VI Inc DE adsorption; energy loss spectroscopy; surface ID GALLIUM NITRIDE; GAN; H/GAN(0001); OXIDE AB The interaction of oxygen with GaN(0001) at room temperature is investigated using low energy electron diffraction (LEED), Auger electron spectroscopy (AES), electron energy loss spectroscopy (ELS), and high resolution electron energy loss spectroscopy (HREELS). Both ELS and HREELS are consistent with reaction of oxygen with surface Ga. LEED shows no surface reconstruction produced by oxygen adsorption. AES reveals a plateau in adsorbed oxygen coverage above similar to 200 L of exposure to molecular oxygen (1 L = 10(-6) Torr*s). However, ELS continues to show changes in surface electronic structure to similar to 1000 L of O-2. C1 Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. USN, Res Lab, Lab Adv Mat Synth, Washington, DC 20375 USA. RP Thoms, BD (reprint author), Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. NR 13 TC 0 Z9 0 U1 0 U2 2 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2000 VL 338-3 BP 1541 EP 1544 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Materials Science GA BR27W UT WOS:000165996700374 ER PT J AU Wu, C AF Wu, C TI Intelligent computer-aided simulation, design and improvement of heat pumps SO SIMULATION LA English DT Article DE intelligent software; vapor cycle; heat pump; design; Rankine vapor cycle AB The Rankine vapor cycle plays a very important role in heat pumps. Vapor heat pump cycle design is long and tedious. It is very necessary to obtain the cycle performance, including compressor work, heat added, turbine work, cooling load, and coefficient of performance, quickly and accurately. This paper describes the use of an intelligent computer-aided software in simulation, design and possible refinements of vapor heat pumps. Historical evolution and several differently arranged Rankine heat pump cycles are demonstrated. Objectives for improvements, constraints, and, consequently, design, which cannot be easily accomplished using conventional methods, are emphasized. Using the software increases engineers' interest and design ability in the vapor heat pump cycle. C1 USN Acad, Dept Mech Engn, Annapolis, MD 21402 USA. RP Wu, C (reprint author), USN Acad, Dept Mech Engn, Annapolis, MD 21402 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SIMULATION COUNCILS INC PI SAN DIEGO PA PO BOX 17900, SAN DIEGO, CA 92117 USA SN 0037-5497 J9 SIMULATION JI Simulation PD JAN PY 2000 VL 74 IS 1 BP 18 EP 27 DI 10.1177/003754970007400103 PG 10 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA 275NF UT WOS:000084825700003 ER PT S AU Bordetsky, A AF Bordetsky, A BE Horais, BJ Twiggs, RJ TI Celestial data routing network SO SMALL PAYLOADS IN SPACE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Small Payloads in Space CY AUG 03-04, 2000 CL SAN DIEGO, CA SP SPIE DE pico satellite network; collaborative multipoint communications; cooperating satellite based agents AB Imagine that information processing human-machine network is threatened in a particular part of the world. Suppose that an anticipated threat of physical attacks could lead to disruption of telecommunications network management infrastructure and access capabilities for small geographically distributed groups engaged in collaborative operations. Suppose that small groups of astronauts are exploring the solar planet and need to quickly configure orbital information network to support their collaborative work and local communications. The critical need in both scenarios would be a set of low-cost means of small team celestial networking. To the geographically distributed mobile collaborating groups such means would allow to maintain collaborative multipoint work, set up orbital local area network, and provide orbital intranet communications. This would be accomplished by dynamically assembling the network enabling infrastructure of the small satellite based router, satellite based Codec, and set of satellite based intelligent management agents. Cooperating single function pico satellites, acting as agents and personal switching devices together would represent self-organizing intelligent orbital network of cooperating mobile management nodes. Cooperative behavior of the pico satellite based agents would be achieved by comprising a small orbital artificial neural network capable of learning and restructuring the networking resources in response to the anticipated threat. C1 USN, Postgrad Sch, Monterey, CA 93940 USA. RP Bordetsky, A (reprint author), USN, Postgrad Sch, Monterey, CA 93940 USA. NR 16 TC 0 Z9 0 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3781-6 J9 P SOC PHOTO-OPT INS PY 2000 VL 4136 BP 87 EP 97 DI 10.1117/12.406647 PG 11 WC Engineering, Aerospace SC Engineering GA BR62D UT WOS:000166963700011 ER PT S AU Goddu, G McDowell, D Bingham, B AF Goddu, G McDowell, D Bingham, B BE Jacobs, JH TI Adaptive control of radiated noise from a cylindrical shell using active fiber composite actuators SO SMART STRUCTURES AND MATERIAL 2000: INDUSTRIAL AND COMMERCIAL APPLICATIONS OF SMART STRUCTURES TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2000 Conference CY MAR 05-09, 2000 CL NEWPORT BEACH, CA SP SPIE, Soc Exptl Mech, Amer Soc Mech Engn, BFGoodrich, Def Adv Res Projects Agcy, USA Res Off, USAF Res Lab, Ceram Soc Japan, Intelligent Mat Forum, Japan DE active fiber composites; active vibration control; adaptive control; filtered-x LMS; piezoelectric ID ALGORITHM; VIBRATION; SOUND AB This paper describes the application of Active Fiber Composite actuators, a hybrid piezoelectric device, to the reduction of acoustic radiation from a cylindrical shell by active control methods. Active Fiber Composites were developed to provide a mechanically robust method for large-area, orthotropic actuation and sensing in active structures. The actuation layer is formed by small diameter piezoelectric fibers that are unidirectionally aligned and imbedded in a resin matrix system. By the nature of its structure, an Active Fiber Composite actuator allows use of the primary piezoelectric effect in the plane of the composite. A cylindrical shell testbed is used for this experiment due to the predominance of this structure, and the resulting general interest, within the field of underwater acoustics. To control acoustic radiation from the cylindrical shell, the Active Fiber Composite actuators, placed at optimal locations determined using numerical models, are used to generate a strain field that counteracts the strain associated with acoustically efficient shell motions. Using an end-mounted accelerometer as the error measurement, an adaptive LMS algorithm is used to minimize the error signal in real-time. Experimental are supplied to validate both the device and the methodology in a complex, real-world environment. C1 USN, Undersea Warfare Ctr, Newport, RI 02840 USA. RP Goddu, G (reprint author), USN, Undersea Warfare Ctr, Newport, RI 02840 USA. NR 11 TC 1 Z9 1 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3609-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 3991 BP 95 EP 102 DI 10.1117/12.388150 PG 8 WC Engineering, Aerospace; Engineering, Industrial; Engineering, Mechanical; Materials Science, Multidisciplinary; Optics SC Engineering; Materials Science; Optics GA BQ59X UT WOS:000088917900011 ER PT S AU Wu, CCM Lewis, D Park, SEE AF Wu, CCM Lewis, D Park, SEE BE Jacobs, JH TI High authority telescoping actuators with single crystal piezoelectric materials SO SMART STRUCTURES AND MATERIAL 2000: INDUSTRIAL AND COMMERCIAL APPLICATIONS OF SMART STRUCTURES TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2000 Conference CY MAR 05-09, 2000 CL NEWPORT BEACH, CA SP SPIE, Soc Exptl Mech, Amer Soc Mech Engn, BFGoodrich, Def Adv Res Projects Agcy, USA Res Off, USAF Res Lab, Ceram Soc Japan, Intelligent Mat Forum, Japan DE actuators; telescoping; piezoelectric single crystals; compact; high displacement; high authority; solid state amplification AB The displacement output of the telescoping actuators, as developed in the Naval Research Laboratory(1,2), depend on the material properties. Recently developed relaxer ferroelectric materials, with compositions near the morphotropic phase boundary and in single crystal forms, show high strain output capability and high coupling coefficients. These materials, when designed into devices, would provide high performance, in terms of displacement output, and high transduction efficiency. We have utilized one of these single crystal materials, namely, lead zinc niobate-lead titanate, PZN-PT, for the construction of the NRL telescoping actuators. The evaluation of the piezoelectric performance of these single crystal-based telescoping actuators showed much higher displacement outputs than that for the ones previously made with polycrystalline PZT ceramics. C1 USN, Res Lab, Washington, DC 20375 USA. RP Wu, CCM (reprint author), USN, Res Lab, Code 6354, Washington, DC 20375 USA. NR 5 TC 3 Z9 3 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3609-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 3991 BP 304 EP 311 DI 10.1117/12.388172 PG 8 WC Engineering, Aerospace; Engineering, Industrial; Engineering, Mechanical; Materials Science, Multidisciplinary; Optics SC Engineering; Materials Science; Optics GA BQ59X UT WOS:000088917900032 ER PT S AU Corsaro, RD AF Corsaro, RD BE Lynch, CS TI Light weight polymeric sound generator SO SMART STRUCTURES AND MATERIALS 2000 - ACTIVE MATERIALS: BEHAVIOR AND MECHANICS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2000 Conference CY MAR 05-09, 2000 CL NEWPORT BEACH, CA SP SPIE, Soc Exptl Mech, Amer Soc Mech Engn, BFGoodrich, Def Adv Res Projects Agcy, USA Res Off, USAF Res Lab, Ceram Soc Japan, Intelligent Mat Forum, Japan DE sound generator; loudspeaker; PVDF; aerospace AB A very low-mass sound generator with wide frequency bandwidth is described. It is constructed of four layers of PVDF film configured as a dual bi-laminate bender. The top and bottom bi-laminates are separately formed in a pre-curved press to form a rippled geometry. These two laminates are then attached back-to-back, and flat cover plates are applied. When a voltage is applied, the forced bending of these bi-laminates will generate a net thickness change of the package. Results obtained are shown to be in agreement with the predictions of the numerical model. While the measured displacement is small (i.e. 10 microns at 300 V drive), useful sound pressure levels can be produced from devices with reasonably large surface areas. These devices are expected to find principal use in aerospace applications, where mass is of crucial importance. C1 USN, Res Lab, Washington, DC 20375 USA. RP Corsaro, RD (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3610-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 3992 BP 656 EP 660 DI 10.1117/12.388252 PG 5 WC Materials Science, Ceramics; Mechanics; Materials Science, Composites; Physics, Applied SC Materials Science; Mechanics; Physics GA BQ59Y UT WOS:000088918100063 ER PT S AU Chang, CC LeBlanc, M Vohra, S AF Chang, CC LeBlanc, M Vohra, S BE Claus, RO Spillman, WB TI Investigation of transverse stress measurements by using embedded fiber Bragg grating sensors subjected to host Poisson's effect SO SMART STRUCTURES AND MATERIALS 2000: SENSORY PHENOMENA AND MEASUREMENT INSTRUMENTATION FOR SMART STRUCTURES AND MATERIALS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2000 Conference CY MAR 05-09, 2000 CL NEWPORT BEACH, CA SP SPIE, Soc Exptl Mech, Amer Soc Mech Engn, BFGoodrich, Def Adv Res Projects Agcy, USA Res Off, USAF Res Lab, Ceram Soc Japan, Intelligent Mat Forum, Japan DE birefringence; Poisson's effect; fiber Bragg grating; shear-lag model; strain transfer; micro-mechanics ID STRAIN-TEMPERATURE MODELS; LOAD AB In many situations, it is desirable to measure the load acting in a specific direction by measuring the strain induced by Poisson effects in a direction perpendicular to the load direction. For this to be possible, a fixed relationship between the strains in both directions must be known. This can be useful, for example, when the geometry is such that there is not sufficient room to locate a strain gauge parallel to the load direction but a gauge can be placed in a transverse plane. In this paper, we investigate the use of a fiber Bragg grating in such an arrangement with the fiber embedded within the host material. The investigation is done by theoretical, numerical and experimental approaches and we concentrate on two aspects: (a) the non-uniform. strain transfer, particular in axial strains, due to shear-lag effects, and (a) the effect of induced birefringence in the optical fiber due to a load cross to its axis. The results of these approaches indicate that the strains of an embedded fiber sensor subjected to transverse loads are dependent on the location of the embedded sensor and the material properties of the host material. The results also show that when the Young's modulus of the host material is much less than the modulus of the embedded sensor, the Bragg spectrum broadening due to induced birefringence is not significant. However, a lower host Young's modulus also results in longer sections on non-uniform axial strain near the ingress and egress sections of the optical fiber. These two factors must be balanced if we desire to use conventional methods of Bragg grating interrogation that measure only the central wavelength of the Bragg grating's spectrum. In the case investigated (Host Young's modulus of 4.83 GPa) full strain build-up requires similar to 4mm of fiber length at each end. Likewise, the transverse stress coupling into the fiber modifies its wavelength-shift-to-axial-strain-coefficient by about 6%. C1 USN, Res Lab, Washington, DC 20375 USA. RP Chang, CC (reprint author), USN, Res Lab, Code 5673,4555 Overlook Ave, Washington, DC 20375 USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3604-6 J9 P SOC PHOTO-OPT INS PY 2000 VL 3986 BP 472 EP 479 DI 10.1117/12.388138 PG 8 WC Materials Science, Composites; Optics SC Materials Science; Optics GA BQ59A UT WOS:000088899600051 ER PT S AU Chang, CC Johnson, G Vohra, S Althouse, B AF Chang, CC Johnson, G Vohra, S Althouse, B BE Claus, RO Spillman, WB TI Development of fiber Bragg grating based soil pressure transducer for measuring pavement response SO SMART STRUCTURES AND MATERIALS 2000: SENSORY PHENOMENA AND MEASUREMENT INSTRUMENTATION FOR SMART STRUCTURES AND MATERIALS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2000 Conference CY MAR 05-09, 2000 CL NEWPORT BEACH, CA SP SPIE, Soc Exptl Mech, Amer Soc Mech Engn, BFGoodrich, Def Adv Res Projects Agcy, USA Res Off, USAF Res Lab, Ceram Soc Japan, Intelligent Mat Forum, Japan DE soil pressure; fiber Bragg grating; diaphragm; spectral broadening; Boussinesq equation AB A soil pressure transducer by using fiber Bragg grating (FBG) sensors associated with a circular diaphragm is developed. The FBG based transducers can be used for pavement performance study and weigh-in-motion measurement. We consider three methods of bonding the FBG to the diaphragm: (i) radially, (ii) radially, inside a glass capillary, and (iii) circumferentially. The investigation of strain-gradient induced spectral broadening in FBG-based transducers is conducted since spectral broadening can have adverse effects on the sensor interrogations. We derive analytical closed form results for describing measurand-induced strain gradients in circular geometry transducers, which allow us to experimentally demonstrate novel FBG bonding approaches that eliminate spectral broadening;. In addition, Bragg spectral broadening analysis using T-matrix calculation is also conducted to validate some of the experimental results. Two prototypes of soil pressure transducers are field tested at the Cold Region Research Engineering Laboratory (CRREL). The buried pressure transducers are impact-tested by use of a Falling-Weight-Deflectometer (FWD), and detected by NRL-developed FBG interrogation device. Lastly, we use the Boussinesq equation to verify the soil stress measured by the buried transducers. C1 USN, Res Lab, Fiber Opt Smart Struct Grp, Washington, DC 20375 USA. RP Chang, CC (reprint author), USN, Res Lab, Fiber Opt Smart Struct Grp, Code 5673, Washington, DC 20375 USA. NR 7 TC 0 Z9 0 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3604-6 J9 P SOC PHOTO-OPT INS PY 2000 VL 3986 BP 480 EP 488 DI 10.1117/12.388139 PG 9 WC Materials Science, Composites; Optics SC Materials Science; Optics GA BQ59A UT WOS:000088899600052 ER PT S AU Lynch, RS Willett, PK AF Lynch, RS Willett, PK GP IEEE IEEE TI Adaptive Bayesian classification using noninformative Dirichlet priors SO SMC 2000 CONFERENCE PROCEEDINGS: 2000 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN & CYBERNETICS, VOL 1-5 SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Systems, Man and Cybernetics CY OCT 08-11, 2000 CL NASHVILLE, TN SP IEEE Inc, Syst Man & Cybernet Soc DE uniform priors; discrete data; optimal quantization complexity; mislabeled training data ID RECOGNITION AB In this paper, a model is developed to illustrate the effect that adapting correctly labeled training data with possibly incorrectly labeled data has on classification performance. The model is based on a previously developed model for mislabeled training data that uses the uniform Dirichlet distribution as a noninformative prior on the symbol probabilities of each class. Two versions of the model are developed under different a priori mislabeling assumptions for the data. In the first case, the probability of mislabeling is fixed and known, and in the second, the mislabeling is marginalized out given it is a priori uniformly distributed from zero to one half. A formula for the average probability of error is used to illustrate results that are plotted as a function of the quantization complexity, and for varying numbers of adapted-mislabeled data. In general, it is shown that even for severe mislabeling performance improves as more data are adapted to the training set. C1 USN, Undersea Warfare Ctr, Newport, RI 02841 USA. RP Lynch, RS (reprint author), USN, Undersea Warfare Ctr, Newport, RI 02841 USA. OI Willett, Peter/0000-0001-8443-5586 NR 10 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1062-922X BN 0-7803-6583-6 J9 IEEE SYS MAN CYBERN PY 2000 BP 2812 EP 2815 PG 4 WC Computer Science, Cybernetics; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BR32T UT WOS:000166106900489 ER PT S AU Fitz-Gerald, JM Chrisey, DB Piqu, A Auyeung, RCY Mohdi, R Young, HD Wu, HD Lakeou, S Chung, R AF Fitz-Gerald, JM Chrisey, DB Piqu, A Auyeung, RCY Mohdi, R Young, HD Wu, HD Lakeou, S Chung, R BE Danforth, SC Dimos, D Prinz, FB TI Matrix assisted pulsed laser evaporation direct write (MAPLE DW): A new method to rapidly prototype active and passive electronic circuit elements SO SOLID FREEFORM AND ADDITIVE FABRICATION-2000 SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Solid Freeform and Additive Fabrication CY APR 24-26, 2000 CL SAN FRANCISCO, CA SP Mat Res Soc, Off Naval Res, Sandia Natl Lab ID METAL-DEPOSITION; FILMS AB We demonstrate a novel laser-based approach to perform rapid prototyping of active and passive circuit elements caned MAPLE DW. This technique is similar in its implementation to laser induced forward transfer (LIFT), but different in terms of the fundamental transfer mechanism and materials used. In MAPLE DW, a focused pulsed laser beam interacts with a composite material on a laser transparent support transferring the composite material to the acceptor substrate. This process enables the formation of adherent and uniform coatings at room temperature and atmospheric pressure with minimal post-deposition modification required, i.e., less than or equal to 400 degreesC thermal processing. The firing of the laser and the work piece (substrate) motion is computer automated and synchronized using software designs from an electromagnetic modeling program validating that this technique is fully CAD/CAM compatible. The final properties of the deposited materials depend on the deposition conditions and the materials used, but when optimized, the properties are competitive with other thick film techniques such as screen-printing. Specific electrical results for conductors are < 5X the resistivity of bulk Ag, for BaTiO3/TiO2 composite capacitors the k can be tuned between 4 and 100 and losses are < 1-4%, and for polymer thick film resistors the compositions cover 4 orders of magnitude in sheet resistivity. The surface profiles and fracture cross-section micrographs of the materials and devices deposited show that they are very uniform, densely packed and have minimum resolutions of similar to 10 mum. A discussion of how these results were obtained, the materials used, and methods to improve them will be given. C1 USN, Res Lab, Washington, DC 20375 USA. RP Fitz-Gerald, JM (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 14 TC 6 Z9 6 U1 0 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-533-1 J9 MATER RES SOC SYMP P PY 2000 VL 625 BP 99 EP 110 PG 4 WC Engineering, Manufacturing; Materials Science, Ceramics; Materials Science, Composites SC Engineering; Materials Science GA BR97P UT WOS:000168248000013 ER PT J AU Alcalde, AM Marques, GE Weber, G Reinecke, TL AF Alcalde, AM Marques, GE Weber, G Reinecke, TL TI Electron-acoustic-phonon scattering rates in II-VI quantum dots: contribution of the macroscopic deformation potential SO SOLID STATE COMMUNICATIONS LA English DT Article DE nanostructures; semiconductors; phonons; electron-phonon interactions ID FREQUENCY RAMAN-SCATTERING; RELAXATION; ABSORPTION; VIBRATIONS; GLASS AB The electron-acoustic-phonon scattering process in spherical II-VI quantum dots is discussed. The quantized acoustic modes are described in terms of Lamb's classical theory for the oscillations of a continuous sphere. The longitudinal spheroidal modes are included owing to their dominant contribution to the acoustic-phonon deformation potential (DP) scattering. We considered two mechanisms for the interaction between electrons and acoustic modes: microscopic DP, and macroscopic acoustic deformation, also called the ripple mechanism (RM). We also discuss the influence of the glass matrix on the electron-phonon coupling, which is particularly important for the RM. Our calculations show that the macroscopic deformation scattering rates become dominant by more than an order of magnitude, for a small dot radius. In general, the total scattering rate depends substantially on the choice of the mechanical boundary conditions and on the acoustic properties of the glass matrix. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Fed Sao Carlos, Dept Fis, BR-13565905 Sao Carlos, SP, Brazil. Univ Sao Francisco, Ctr Ciencias Exatas & Tecnol, BR-13251900 Itatiba, SP, Brazil. USN, Res Lab, Washington, DC 20375 USA. RP Alcalde, AM (reprint author), Univ Fed Sao Carlos, Dept Fis, BR-13565905 Sao Carlos, SP, Brazil. RI Weber, Gerald/A-8669-2010; Alcalde, Augusto/J-5856-2014; Marques, Gilmar Eugenio/G-3528-2015 OI Weber, Gerald/0000-0002-2935-1571; Alcalde, Augusto/0000-0002-3806-0661; Marques, Gilmar Eugenio/0000-0002-8608-6508 NR 15 TC 15 Z9 15 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PY 2000 VL 116 IS 5 BP 247 EP 252 DI 10.1016/S0038-1098(00)00323-9 PG 6 WC Physics, Condensed Matter SC Physics GA 361WU UT WOS:000089747900003 ER PT J AU Zhang, Y Iqbal, Z Vijayalakshmi, S Qadri, S Grebel, H AF Zhang, Y Iqbal, Z Vijayalakshmi, S Qadri, S Grebel, H TI Formation of hexagonal-wurtzite germanium by pulsed laser ablation SO SOLID STATE COMMUNICATIONS LA English DT Article DE thin films; laser processing; crystal structure and symmetry ID SILICON PHASE AB A stable phase of relatively large hexagonal-wurtzite germanium (lonsdaleite) crystals (up to 10 mu m) was formed when germanium was directly deposited at low pressure using pulsed ultraviolet laser ablation. Films were grown on various substrates at room temperature from a single crystal, cubic germanium target. Crystallites of the hexagonal-wurtzite phase of germanium were clearly identified using selected area electron diffraction. Further characterizations of the films were made using X-ray diffraction and confocal scanning micro-Raman spectroscopy. (C) 2000 Published by Elsevier Science Ltd. C1 New Jersey Inst Technol, Dept Elect & Comp Engn, Nonlinear Nanostruct Lab, Newark, NJ 07102 USA. Honeywell, Corp Technol, Morristown, NJ 07962 USA. USN, Res Lab, Washington, DC 20375 USA. RP Grebel, H (reprint author), New Jersey Inst Technol, Dept Elect & Comp Engn, Nonlinear Nanostruct Lab, Newark, NJ 07102 USA. NR 9 TC 10 Z9 10 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PY 2000 VL 115 IS 12 BP 657 EP 660 DI 10.1016/S0038-1098(00)00259-3 PG 4 WC Physics, Condensed Matter SC Physics GA 344UT UT WOS:000088778400005 ER PT J AU Sjostedt, E Nordstrom, L Singh, DJ AF Sjostedt, E Nordstrom, L Singh, DJ TI An alternative way of linearizing the augmented plane-wave method SO SOLID STATE COMMUNICATIONS LA English DT Article DE surfaces and interfaces; electronic band structure ID MOLECULES; CORE AB A new basis set for a full potential treatment of crystal electronic structures is presented and compared to that of the well-known linearized augmented plane-wave (LAPW) method. The basis set consists of energy-independent augmented planewave functions combined with local orbitals. Each basis function is continuous over the whole unit cell but it may have a discontinuous slope at the muffin-tin boundaries, i.e. at the surfaces of atomic centered, non-overlapping spheres. This alternative way to linearize the augmented plane-wave method is shown to reproduce the accurate results of the LAPW method, but using a smaller basis set size. The reduction in number of basis functions is most significant for open structures. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Uppsala Univ, Dept Phys, Condensed Matter Theory Grp, S-75121 Uppsala, Sweden. USN, Res Lab, Complex Syst Theory Branch, Washington, DC 20375 USA. RP Sjostedt, E (reprint author), Uppsala Univ, Dept Phys, Condensed Matter Theory Grp, S-75121 Uppsala, Sweden. RI Singh, David/I-2416-2012 NR 17 TC 593 Z9 598 U1 2 U2 17 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 EI 1879-2766 J9 SOLID STATE COMMUN JI Solid State Commun. PY 2000 VL 114 IS 1 BP 15 EP 20 DI 10.1016/S0038-1098(99)00577-3 PG 6 WC Physics, Condensed Matter SC Physics GA 291PD UT WOS:000085744500004 ER PT J AU Hoffman, DM Meyer, BK Ekimov, AI Merkulov, IA Efros, AL Rosen, M Couino, G Gacoin, T Boilot, JP AF Hoffman, DM Meyer, BK Ekimov, AI Merkulov, IA Efros, AL Rosen, M Couino, G Gacoin, T Boilot, JP TI Giant internal magnetic fields in Mn doped nanocrystal quantum dots SO SOLID STATE COMMUNICATIONS LA English DT Article DE nanostructures; impurities in semiconductors; optical properties; spin dynamics; electron paramagnetic resonance ID EXCHANGE INTERACTION; HOLE; ZNS AB We observed a giant splitting of exciton spin sublevels in CdS nanocrystals, each doped on the average by one Mn ion. The splitting, which exists in zero external magnetic field, is caused by the gigantic internal magnetic field of the Mn ion and results from the enhancement of the short range spin-spin interactions in nanocrystal quantum dots. The splitting is seen in the strong magnetic circular dichroism of the CdS band edge transitions. The magnitude of the observed band edge splitting is in good agreement with a theoretical calculation of the effective magnetic field. (C) 2000 Published by Elsevier Science Ltd. All rights reserved. C1 AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia. Univ Giessen, Inst Phys 1, D-35392 Giessen, Germany. USN, Res Lab, Nanostruct Opt Sect, Washington, DC 20375 USA. Ecole Polytech, Phys Mat Condensee Lab, F-91128 Palaiseau, France. RP Ekimov, AI (reprint author), AF Ioffe Phys Tech Inst, Politekhnicheskaya 26, St Petersburg 194021, Russia. RI gacoin, Thierry/D-7574-2013 NR 16 TC 116 Z9 117 U1 2 U2 35 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PY 2000 VL 114 IS 10 BP 547 EP 550 DI 10.1016/S0038-1098(00)00089-2 PG 4 WC Physics, Condensed Matter SC Physics GA 310PY UT WOS:000086837600009 ER PT J AU Stallworth, PE Guillemoles, JH Flowers, J Vedel, J Greenbaum, SG AF Stallworth, PE Guillemoles, JH Flowers, J Vedel, J Greenbaum, SG TI NMR studies of CuInS2 and CuInSe2 crystals grown by the Bridgman method SO SOLID STATE COMMUNICATIONS LA English DT Article DE semiconductors; crystal growth; point defects; nuclear resonances ID NUCLEAR MAGNETIC-RESONANCE; SEMICONDUCTORS AB Bridgman-grown polycrystalline CuInS2 and CuInSe2 containing 2 at.% excess S and Se, respectively, were investigated by Cu-63 and In-115 NMR. Cu-63 lineshapes were obtained at 79.83 MHz within the temperature range of 123 < T < 473 K, Line-shapes from both samples are similar and are typically broadened by first-order electric quadrupolar interactions with average coupling constant magnitudes of 0.54 MHz; whereas, the central transition reveals broadening due to chemical shift anisotropy. Temperature dependent motional narrowing of the copper line is observed with CuInSe2; the associated diffusion coefficient is 3 x 10(-13) cm(2)/s at 473 K. The dependence of the paramagnetic shift with temperature suggests a complex form of magnetic ordering between unpaired spins. (C) 2000 Published by Elsevier Science Ltd. All rights reserved. C1 USN Acad, Dept Phys, Annapolis, MD 21402 USA. Ecole Natl Super Chim Paris, Lab Electrochim & Chim Analyt, F-75231 Paris 05, France. CUNY Medgar Evers Coll, Dept Phys Sci & Comp Sci, Brooklyn, NY 11225 USA. CUNY Hunter Coll, Dept Phys, New York, NY 10021 USA. RP Stallworth, PE (reprint author), USN Acad, Dept Phys, Annapolis, MD 21402 USA. RI Guillemoles, JF/I-5166-2013; OI Guillemoles, Jean-Francois/0000-0003-0114-8624 NR 22 TC 8 Z9 9 U1 0 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PY 2000 VL 113 IS 9 BP 527 EP 532 DI 10.1016/S0038-1098(99)00533-5 PG 6 WC Physics, Condensed Matter SC Physics GA 279JF UT WOS:000085040100010 ER PT J AU Morris, CE AF Morris, CE TI The economics of World War II: Six great powers in international comparison SO SOUTHERN ECONOMIC JOURNAL LA English DT Book Review C1 USN Acad, Annapolis, MD 21402 USA. RP Morris, CE (reprint author), USN Acad, Annapolis, MD 21402 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU UNIV NORTH CAROLINA PI CHAPEL HILL PA SOUTHERN ECONOMIC JOURNAL, CHAPEL HILL, NC 27514 USA SN 0038-4038 J9 SOUTHERN ECON J JI South. Econ. J. PD JAN PY 2000 VL 66 IS 3 BP 808 EP 810 DI 10.2307/1061444 PG 3 WC Economics SC Business & Economics GA 275ZE UT WOS:000084849900024 ER PT J AU Brough, AS Stewart, F Zachowski, S AF Brough, AS Stewart, F Zachowski, S TI Rapid onset of stupor SO SOUTHERN MEDICAL JOURNAL LA English DT Article ID CATATONIA; LORAZEPAM AB Catatonia is a syndrome with many causes that can be difficult to diagnose. In this report, we describe a case of rapid onset of stupor and loss of consciousness, subsequent evaluation, and treatment of catatonia in an HIV-positive man. C1 USN, Dept Psychiat, Med Ctr, Portsmouth, VA USA. RP Brough, AS (reprint author), Sewells Point Clin Aviat Med, 1721 Taussig Blvd, Norfolk, VA 23511 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU SOUTHERN MEDICAL ASSN PI BIRMINGHAM PA 35 LAKESHORE DR PO BOX 190088, BIRMINGHAM, AL 35219 USA SN 0038-4348 J9 SOUTHERN MED J JI South.Med.J. PD JAN PY 2000 VL 93 IS 1 BP 70 EP 71 PG 2 WC Medicine, General & Internal SC General & Internal Medicine GA 275XM UT WOS:000084845500014 PM 10653071 ER PT J AU Blum, J AF Blum, J TI Laboratory experiments on preplanetary dust aggregation SO SPACE SCIENCE REVIEWS LA English DT Review DE laboratory experiments; preplanetery dust aggregation; planetesimal formation ID SOLAR NEBULA; BROWNIAN-MOTION; SURFACE-ENERGY; COAGULATION; PARTICLES; CONTACT; ADHESION; SOLIDS AB For a better understanding of the processes which lead to the formation of planetesimals in the early solar nebula, we performed an extensive series of laboratory experiments. We find that the capture velocities in collisions between spherical grains are more than one order of magnitude higher than predicted by Chokshi et al (1993). In contrast, irregular grains have no capture threshold and can be better described by a sticking probability which is typically a few 10%, even for velocities exceeding 10 m/s. However, adhesion forces between spherical, micron-sized particles match the theoretical predictions very well, although contact areas and deformations are of the order of inter-atomic distances only. Aggregation experiments in rarefied turbulent gases reveal the fractal nature of dust aggregates. Mass distribution functions are bell-shaped. Similar behaviour can be found in aggregation experiments with sedimenting particles. Experiments on collision-induced aggregate compaction and fragmentation match the numerical simulations by Dominik and Tielens (1997) very well if revised experimental values of the break-up energy (from our impact experiments) and the rolling-friction force (from our AFM measurements on particle chains) are used. C1 Univ Jena, Inst Astrophys, D-07745 Jena, Germany. Univ Jena, Univ Sternwarte, D-07745 Jena, Germany. RP USN, Div Space Sci, Res Lab, 4555 Overlook Ave SW, Washington, DC 20375 USA. EM jblum@ssd5.nrl.navy.mil RI Blum, Jurgen/B-5590-2011 OI Blum, Jurgen/0000-0003-1531-737X NR 20 TC 13 Z9 13 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 EI 1572-9672 J9 SPACE SCI REV JI Space Sci. Rev. PY 2000 VL 92 IS 1-2 BP 265 EP 278 DI 10.1023/A:1005251414391 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 357HP UT WOS:000089492700018 ER PT S AU Adams, J Bashindzhagyan, G Chilingarian, A Drury, L Egorov, N Golubkov, S Korotkova, N Panasyuk, M Podorozhnyi, D Procqureur, J Roganova, T Saavedra, O Sidorov, A Simon, M Sveshnikova, L Thompson, A Turundaevsky, A Yashin, I AF Adams, J Bashindzhagyan, G Chilingarian, A Drury, L Egorov, N Golubkov, S Korotkova, N Panasyuk, M Podorozhnyi, D Procqureur, J Roganova, T Saavedra, O Sidorov, A Simon, M Sveshnikova, L Thompson, A Turundaevsky, A Yashin, I BE ElGenk, MS TI Particle energy determination device for the International Space Station using a new approach to cosmic ray spectral measurements (TUS-M mission) SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2000) CY JAN 30-FEB 03, 2000 CL ALBUQUERQUE, NM SP Boeing Co, Lockheed Martin Corp, NASA, US DOE, Sandia Natl Lab, Los Almos Natl Lab, Amer Astronaut Soc, Amer Inst Chem Engineers, Div Heat Transfer & Energy Convers, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer inst Aeronaut & Astronaut, Local Sect, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Div Nucl Engn, Amer Soc Mech Engineers, Div Heat Transfer, Inst Elect & Electr Engineers Inc, Nucl & Plasma Sci Soc, Int Astronaut Federat, NASA, Natl Space Grant Coll & Fellowship Program, New Mexico Space grant Consortium AB A new approach to the measurement of high energy cosmic ray nuclei (E>10(11) eV) is proposed. The method is based on measuring the primary particle energy by determining the angular distribution of secondaries produced in a target layer. The proposed technique can be used over a wide range of energies (10(11) - 10(16) eV) and gives an energy resolution of 60% or better. This approach is being utilized to design a new advanced instrument (KLEM) for future space station and satellite cosmic ray experiments. Due to its light weight and large aperture the newly developed instrument will allow a dramatically increased exposure factor and will enable the directly measured energy range in cosmic ray research to be extended up to and beyond 10(16) eV. A reduced scale version of this new instrument (project TUS-M) has already been accepted for exposure in the Russian Segment of the International Space Station. The essence of the TUS-M project is to test and confirm the new technique under fright conditions. During a one-year test exposure TUS-M will be able to measure the energy spectra of primary particles up to 10(14) eV. The full scale instrument, with a three-year exposure has the capacity to address the "knee" problem with a data base including at least 25 particles with E>10(16) eV. C1 USN, Res Lab, Washington, DC 20375 USA. RP Adams, J (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Roganova, Tatiana/E-2118-2012; chilingarian, ashot/B-1901-2014; Drury, Luke/B-1916-2017 OI Roganova, Tatiana/0000-0002-6645-7543; chilingarian, ashot/0000-0002-2018-9715; Drury, Luke/0000-0002-9257-2270 NR 12 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-919-X J9 AIP CONF PROC PY 2000 VL 504 BP 175 EP 180 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BP88C UT WOS:000086475500028 ER PT S AU Seago, JH Davis, MA Clement, AE AF Seago, JH Davis, MA Clement, AE BE Kluever, CA Neta, B Hall, CD Hanson, JM TI Precision of a multi-satellite trajectory database estimated from satellite laser ranging SO SPACEFLIGHT MECHANICS 2000, VOL 105, PTS I AND II SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA 10th Space Flight Mechanics Meeting CY JAN 23-26, 2000 CL CLEARWATER, FL SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut ID SPACE SURVEILLANCE SYSTEM; ORBIT DETERMINATION; TRACKING DATA; TOPEX/POSEIDON; CALIBRATION AB Orbital ephemerides based on Satellite Laser Ranging are being utilized as a tool to validate and diagnose problems in orbit determination software systems and satellite observatories. Several criteria are examined to design a quick-look ephemeris database with suitable precision to accomplish the specific task of calibrating satellite-observing radars. Reference orbit accuracy requirements for radar calibration should specify both the accuracy requirement and the tolerance level for unintentionally accepting low quality orbits (type II errors). By fixing the type II risk tolerance to be a very low percentage of total orbits, internal quality indicators are assessed to determine their ability to qualify orbits that conform to expected performance levels. The accuracy of select satellites in the historical database is estimated against reference trajectories provided by the Center for Space Research. C1 USN, Res Lab, Electro Opt Technol Sect, Washington, DC 20375 USA. RP Seago, JH (reprint author), USN, Res Lab, Electro Opt Technol Sect, Code 8123,4555 Overlook Ave SW, Washington, DC 20375 USA. NR 34 TC 5 Z9 5 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-470-2 J9 ADV ASTRONAUT SCI PY 2000 VL 105 BP 1235 EP 1253 PN 1&2 PG 19 WC Engineering, Aerospace SC Engineering GA BQ99H UT WOS:000165304900074 ER PT S AU Boers, J Coffey, S Barnds, WJ Johns, D Davis, M Seago, J AF Boers, J Coffey, S Barnds, WJ Johns, D Davis, M Seago, J BE Kluever, CA Neta, B Hall, CD Hanson, JM TI Accuracy assessment of the Naval Space Command special perturbations cataloging system SO SPACEFLIGHT MECHANICS 2000, VOL 105, PTS I AND II SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA 10th Space Flight Mechanics Meeting CY JAN 23-26, 2000 CL CLEARWATER, FL SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB The Naval Space Command passed Initial Operational Capability for a special perturbations catalog on July 7, 1999, Centered around a numerical integrator for orbit propagation, this system has the inherent capability to produce significantly more accurate orbits than the general perturbations method employed for decades by the Air Force and Naval Space Commands. This paper quantifies the improved orbit determination accuracy of the Navy System. C1 USN, Space Command, Dahlgren, VA 22448 USA. RP Boers, J (reprint author), USN, Space Command, Dahlgren, VA 22448 USA. NR 3 TC 6 Z9 6 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-470-2 J9 ADV ASTRONAUT SCI PY 2000 VL 105 BP 1291 EP 1304 PN 1&2 PG 14 WC Engineering, Aerospace SC Engineering GA BQ99H UT WOS:000165304900077 ER PT S AU Yan, H Fahroo, F Ross, IM AF Yan, H Fahroo, F Ross, IM BE Kluever, CA Neta, B Hall, CD Hanson, JM TI Accuracy and optimality of direct transcription methods SO SPACEFLIGHT MECHANICS 2000, VOL 105, PTS I AND II SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA 10th Space Flight Mechanics Meeting CY JAN 23-26, 2000 CL CLEARWATER, FL SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut ID DIRECT OPTIMIZATION; RIGID SPACECRAFT; TRAJECTORIES; COLLOCATION AB Direct transcription methods transcribe an optimal control problem into a finite-dimensional parameter optimization problem, which is then solved by a nonlinear programming (NLP) solver. While these methods enjoy a relatively wide radius of convergence, it is well known that the accuracy of the solution is often questionable when compared to indirect methods. In this paper we identify additional issues and demonstrate them numerically. We show that two different NLP solvers yield very different results; in fact, the solutions obtained from the MATLAB Optimization Toolbox can often be incorrect. The same problem may be solvable by one transcription technique and not by another. The convergence of the NLP iteration and that of the discretization are two distinct issues. Contrary to the impression given in the literature, we show that the direct solutions are highly dependent on the transcription methods, the choice of the nodes, NLP solvers, initial guesses and on the number of the NLP variables. As part of this analysis, we show that the minimum-time rest-to-rest reorientation of a symmetric rigid spacecraft has multiple solutions while the direct solutions for the solar-sail orbit-transfer problem are unsatisfactory for the control variable. C1 USN, Postgrad Sch, Dept Math, Monterey, CA 93943 USA. RP Yan, H (reprint author), USN, Postgrad Sch, Dept Math, Code Ma Ff, Monterey, CA 93943 USA. NR 24 TC 5 Z9 5 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-470-2 J9 ADV ASTRONAUT SCI PY 2000 VL 105 BP 1613 EP 1630 PN 1&2 PG 18 WC Engineering, Aerospace SC Engineering GA BQ99H UT WOS:000165304900095 ER PT S AU Lanzagorta, M Kuo, E AF Lanzagorta, M Kuo, E BE Merritt, JO Benton, SA Woods, AJ Bolas, MT TI RAGE visualization for special forces operations SO STEREOSCOPIC DISPLAYS AND VIRTUAL REALITY SYSTEMS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Stereoscopic Displays and Virtual Reality Systems VII CY JAN 24-27, 2000 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, SPIE AB The Responsive Advanced Graphical Environment (RAGE) system is a collaborative virtual environment which is being developed at the Naval Research Laboratory specifically for planning, training and situation awareness. It consists of the CAVE(TM)-like device known as the GROTTO (Graphical Room for Observation, Training and Tactical Orientation) and a virtual workbench. The system offers many important capabilities for hostage rescue scenarios. First, it avoids the need to create physical mockups of rooms and buildings, instead computer models are generated. Second, it is possible to explore alternative scenarios to experiment with different tactical operations. Third, the system can be linked with other software modules such as simulators and analysis tools, and has the capability to dynamically change the environment as new intelligence information is received. This system has three potential applications. First, it can be used as a device far the training of Special Forces. Second, it can be used to study important military operations. Finally, it can be used as a command and control device used in real-time as the rescue operation is being carried out. We show some these capabilities by reproducing one famous special forces hostage rescue operation. C1 USN, Res Lab, Washington, DC USA. RP Lanzagorta, M (reprint author), USN, Res Lab, 4555 Overlook Ave SW, Washington, DC USA. NR 11 TC 0 Z9 0 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3575-9 J9 P SOC PHOTO-OPT INS PY 2000 VL 3957 BP 380 EP 388 DI 10.1117/12.384464 PG 9 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic; Optics; Imaging Science & Photographic Technology SC Computer Science; Engineering; Optics; Imaging Science & Photographic Technology GA BQ35Z UT WOS:000088119500042 ER PT S AU Lanzagorta, M Rosenberg, R Kuo, E AF Lanzagorta, M Rosenberg, R Kuo, E BE Merritt, JO Benton, SA Woods, AJ Bolas, MT TI VR scientific visualization in an immersive room SO STEREOSCOPIC DISPLAYS AND VIRTUAL REALITY SYSTEMS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Stereoscopic Displays and Virtual Reality Systems VII CY JAN 24-27, 2000 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, SPIE AB This paper describes the efforts being carried out at the Naval Research Laboratory (NRL) towards VR Scientific Visualization. We are exploring scientific visualization in an immersive virtual environment: the NRL's CAVE-like device known as the GROTTO. Our main effort has been towards the development of software that eases the transition between desktop visualization and VR visualization. It has been our intention to develop visualization tools that can be applied in a wide range of scientific areas without spending excessive time in software development. The advantages of such software are clear. The scientists do not have to be expert programmers, nor need they make a large investment of time to visualize scientific information in a Virtual Environment. As a result of this effort, we were able to port a considerable number of applications to the GROTTO in a short period of time. These projects cover a wide range of scientific areas and include chemistry, fluid dynamics, space physics and materials sciences. We describe the major technical hurdles we have addressed for interactive visualization of real data sets for real users. Finally we comment on the advantages that immersive systems like the GROTTO offer to the scientific community. C1 USN, Res Lab, Washington, DC 20375 USA. RP Lanzagorta, M (reprint author), USN, Res Lab, 4555 Overlook Ave SW, Washington, DC 20375 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3575-9 J9 P SOC PHOTO-OPT INS PY 2000 VL 3957 BP 433 EP 443 DI 10.1117/12.384471 PG 11 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic; Optics; Imaging Science & Photographic Technology SC Computer Science; Engineering; Optics; Imaging Science & Photographic Technology GA BQ35Z UT WOS:000088119500048 ER PT S AU Katz, RA Quazi, AH AF Katz, RA Quazi, AH BE Broomhead, DS Luchinskaya, EA McClintock, PVE Mullin, T TI Dynamical evolution of sonar signal propagation SO STOCHASTIC AND CHAOTIC DYNAMICS IN THE LAKES SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference on Stochastic and Chaotic Dynamics in the Lakes CY AUG, 1999 CL AMBLESIDE, ENGLAND AB Sonar signal propagation is traditionally modeled as a linear stochastic process. This research is aimed at modeling acoustic signal propagation dynamics de terministically using the analysis tools of Nonlinear Dynamics/Chaos Theory. This near paradigm is demonstrated by simulating a linear frequency modulated (LFM) signal and a nonlinear variation of it. The representative LFM signal simulates a re alistic active source component. The nonlinear variant simulates the received echo response, that includes interactions between source, propagation channel and target. A discriminator called the differential radius (DR) is applied to the two types of simulated acoustic time series for distinguishing between the linear and nonlinear dynamics, respectively. C1 USN, Undersea Warfare Ctr, Newport, RI 02841 USA. RP Katz, RA (reprint author), USN, Undersea Warfare Ctr, 1176 Howell St, Newport, RI 02841 USA. EM katzra@npt.nuwc.navy.mil NR 9 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-915-7 J9 AIP CONF PROC PY 2000 VL 502 BP 624 EP 629 PG 6 WC Mathematics, Applied; Physics, Multidisciplinary SC Mathematics; Physics GA BP75Z UT WOS:000086079200087 ER PT B AU Howarth, TR Tressler, JF Bucaro, JA Horner, CG Robbins, WE AF Howarth, TR Tressler, JF Bucaro, JA Horner, CG Robbins, WE BE Ferguson, NS Wolfe, HF Ferman, MA Rizzi, SA TI Acoustic actuator blanket for interior sound control SO STRUCTURAL DYNAMICS: RECENT ADVANCES, VOLS 1 & 2, PROCEEDINGS LA English DT Proceedings Paper CT 7th International Conference on Recent Advances in Structural Dynamics CY JUL 24-27, 2000 CL UNIV SOUTHAMPTON, INST SOUND & VIBRAT RES, SOUTHAMPTON, ENGLAND SP USAF, European Off Aerosp Res & Dev, UASF, Res Lab, Wright Patterson AFB, Parks Coll,Engn & Aviat, St Louis Univ, NASA, Langley Res Ctr, Struct Acoust Branch HO UNIV SOUTHAMPTON, INST SOUND & VIBRAT RES AB The Naval Research Laboratory (NRL) is currently developing techniques for the active noise control quieting of interior spaces. The conceptual approach to this effort: is to develop an acoustic blanket that may be mounted either on the structure boundaries or hung from the wall in the interior free space. One of the most difficult aspects of this concept is the actuator subsystem. This particular component is the key to the system in that large displacement and acoustic output are required while maintaining lightweight and flexibility. These two needs are difficult to obtain as they are inconsistent with present technology capabilities. In an effort to accomplish these goals, NRL designed the actuator subsystem using the numerical analysis code PZFlex(R). Upon satisfaction of the initial system actuator requirements, NRL worked with NASA's Langley Research Center (LaRC) to fabricate prototype blanket shells. This has required advanced fixturing and the use of an autoclave for formation of the specified actuator bubbles into the desired blanket configuration. After the actuator blanket shell was fabricated at LaRC, NRL then installed piezoelectric ceramic drivers into the shell. Both individual acoustic bubble shapes and a 30-cm by 30-cm section with four acoustic bubbles were evaluated for displacement using laser Doppler vibrometry(LDV). These same prototypes were also evaluated for acoustic sound pressure output using free field measurement techniques. This paper will discuss each of these steps as well as the direction for the find blanket configuration. C1 USN, Res Lab, Washington, DC 20375 USA. RP Howarth, TR (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INST SOUND VIBRATION RESEARCH PI SOUTHAMPTON PA THE UNIVERSITY, SOUTHAMPTON S09 5NH, ENGLAND BN 0-85432-721-5 PY 2000 BP 727 EP 730 PG 4 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BR55R UT WOS:000166796300055 ER PT S AU Gaudett, M Tregoning, R Focht, E Zhang, XJ Aylor, D AF Gaudett, M Tregoning, R Focht, E Zhang, XJ Aylor, D BE Toor, PM TI Laboratory techniques for service history estimations of high strength fastener failures SO STRUCTURAL INTEGRITY OF FASTENERS, VOL 2 SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT 2nd Symposium on Structural Integrity of Fasteners CY MAY 19, 1999 CL SEATTLE, WA SP Amer Soc Testing & Mat DE IN625; K-500; high strength fastener materials; failure analysis; environmentally assisted cracking; fatigue ID NICKEL AB Two fastener failures have been analyzed to determine both failure mode and service loading history. The analyses were conducted through careful fractographic investigation and laboratory simulation to assess the integrity of the assembly design and to evaluate the role of unintended environmental effects in these failures. The first case involves Monel K-500 bolts that failed due to fatigue loading, terminated by overload fracture. The fatigue mode was intergranular (IG) at initiation, and then transitioned to classical transgranular fatigue prior to overload failure. Intergranular cracking in Monel K-500 is usually associated with environmentally assisted cracking (EAC). However, simulated service testing of several bolts under both fatigue and slow strain rate loading revealed that IG fatigue cracking could occur at low applied Delta K in air. Transgranular fatigue is associated with higher Delta K levels. Therefore, EAC was not the root cause of these failures. The second case examines the fatigue failure of several IN625 studs. The stud stresses are estimated from fatigue striation measurements using a representative fatigue crack growth behavior and driving force equation. The inferred applied stress is greater than the material yield strength, which is indicative of a basic deficiency in the original joint design. Laboratory testing verifies the relative accuracy of this stress estimation method for both simple and complex loading histories. The accuracy can be most significantly improved through fatigue crack growth testing of the actual failed material under relevant service conditions. C1 USN, Ctr Surface Warfare, Carderock Div, Bethesda, MD 20817 USA. RP Gaudett, M (reprint author), USN, Ctr Surface Warfare, Carderock Div, Bethesda, MD 20817 USA. NR 23 TC 1 Z9 1 U1 0 U2 0 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 0-8031-2863-0 J9 AM SOC TEST MATER PY 2000 VL 1391 BP 16 EP 35 DI 10.1520/STP13522S PG 20 WC Mechanics; Materials Science, Characterization & Testing SC Mechanics; Materials Science GA BQ72A UT WOS:000089259700002 ER PT S AU McNelley, TR Perez-Prado, MT AF McNelley, TR Perez-Prado, MT BE Berbon, PB Berbon, MZ Sakuma, T Langdon, TG TI Computer simulation of grain boundary character in a superplastic aluminum alloy SO SUPERPLASTICITY-CURRENT STATUS AND FUTURE POTENTIAL SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Superplasticity-Current Status and Future Potential held at the 1999 MRS Fall Meeting CY NOV 29-DEC 01, 1999 CL BOSTON, MA SP Mat Res Soc, USA, Off Res, Lawrence Livermore Natl Lab ID ROLLING TEXTURES; DEFORMATION; RECRYSTALLIZATION; MICROSTRUCTURES; EVOLUTION; COPPER AB High-angle grain boundaries are generally deemed necessary for superplasticity in metals. Ln polycrystalline materials the grain boundary character must be described in terms of a probability distribution rather than by a single parameter, and little has been reported on the relationship between this distribution and fine-grain superplasticity. For aluminum alloys that exhibit continuous recrystallization the results of computer-aided electron backscatter diffraction analysis have shown that bimodal grain boundary disorientation distributions are present in as-processed material and persist during subsequent annealing. Such distributions may be simulated by computer methods based on a model of the microstructure which assumes that deformation banding occurs during deformation processing. High-angle boundaries (greater than or equal to 30 degrees) develop in association with deformation banding while boundaries of lower disorientation (<30 degrees) develop by dislocation reaction within the bands. Improved understanding of the grain boundary types associated with various microstructural transformation mechanisms will aid the design of processes to produce superplastic microstructures. C1 USN, Postgrad Sch, Dept Mech Engn, Monterey, CA 93943 USA. RP McNelley, TR (reprint author), USN, Postgrad Sch, Dept Mech Engn, 700 Dyer Rd, Monterey, CA 93943 USA. RI Perez-Prado, Maria Teresa/M-2050-2014 OI Perez-Prado, Maria Teresa/0000-0003-0758-2851 NR 27 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-509-9 J9 MATER RES SOC SYMP P PY 2000 VL 601 BP 3 EP 14 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BQ35C UT WOS:000088094300001 ER PT S AU Schuler, J Howard, JG Warren, P Scribner, D Klein, R Satyshur, M Kruer, M AF Schuler, J Howard, JG Warren, P Scribner, D Klein, R Satyshur, M Kruer, M BE Watkins, WR Clement, D Reynolds, WR TI Multi-band E/O color fusion with consideration of noise and registration SO TARGETS AND BACKGROUNDS VI: CHARACTERIZATION, VISUALIZATION, AND THE DETECTION PROCESS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Targets and Backgrounds VI: Characterization, Visualization, and the Detection Process CY APR 24-26, 2000 CL ORLANDO, FL SP SPIE DE image fusion; sensor fusion; color fusion; image registration; image noise AB Sensor fusion of up to three disparate imagers can readily be achieved by assigning each component video stream to a separate channel any standard RGB color monitor such as with television or personal computer systems. Provided the component imagery is pixel registered, such a straightforward systems can provide improved object-background separation, yielding quantifiable human-factors performance improvement compared to viewing monochrome imagery of a single sensor. Consideration is given to appropriate dynamic range management of the available color gamut, and appropriate color saturation in the presence of imager noise. C1 USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. RP Schuler, J (reprint author), USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. NR 15 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3655-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4029 BP 32 EP 40 DI 10.1117/12.392552 PG 9 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BR65Y UT WOS:000167102500004 ER PT S AU Howard, JG Warren, P Klein, R Schuler, J Satyshur, M Scribner, D Kruer, M AF Howard, JG Warren, P Klein, R Schuler, J Satyshur, M Scribner, D Kruer, M BE Watkins, WR Clement, D Reynolds, WR TI Real-time color fusion of E/O sensors with PC-based COTS hardware SO TARGETS AND BACKGROUNDS VI: CHARACTERIZATION, VISUALIZATION, AND THE DETECTION PROCESS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Targets and Backgrounds VI: Characterization, Visualization, and the Detection Process CY APR 24-26, 2000 CL ORLANDO, FL SP SPIE DE color fusion; color night vision; sensor fusion; image registration; human visualization AB Increases in the power of personal computers and the availability of infrared focal plane array cameras allows new options in the development of a real-time color fusion system for human visualization. This paper describes on-going development of an inexpensive, real-time PC-based infrared color visualization system. The hardware used in the system is all COTS, making it relatively inexpensive to maintain and modify. It consists of a dual Pentium II PC, with fast digital storage, and up to five PCI frame-grabber cards. The frame-grabber cards allow data to be collected from RS-170 (analog) or RS-422 (digital) cameras. Software allows the system configuration to be changed on the fly, so cameras can be swapped at will and new cameras can be added to the system in a matter of minutes. The software running on the system reads up to five separate images from the frame-grabber cards. These images are then digitally registered using a rubber-sheeting algorithm to reshape and shift the images. The registered data, from two or three cameras, is men processed by the selected fusion algorithm to produce a color-fused image, which is then displayed in real-time. The real-time capability of this system allows interactive laboratory testing of issues such as band selection, fusion algorithm optimization, and visualization trade-offs. C1 USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. RP Howard, JG (reprint author), USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. NR 4 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3655-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4029 BP 41 EP 48 DI 10.1117/12.392554 PG 8 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BR65Y UT WOS:000167102500005 ER PT B AU Nada, N Luqi, L Shing, M Rine, D Damiani, E Tuwaim, S AF Nada, N Luqi, L Shing, M Rine, D Damiani, E Tuwaim, S BE Li, QY Firesmith, D Riehle, R Pour, G Meyer, B TI Software reuse technology practices and assessment tool-kit SO TECHNOLOGY OF OBJECT-ORIENTED LANGUAGES AND SYSTEMS - TOOLS 34, PROCEEDINGS LA English DT Proceedings Paper CT 34th International Conference on Technology of Object-Oriented Languages and Systems (TOOLS 34) CY JUL 30-AUG 04, 2000 CL SANTA BARBARA, CA SP Microsoft, CMP, Borders Bookstores, Software Council So Calif, PCAI Magazine, Interact Software Engn DE knowledge-base; case-based reasoning systems; intelligent tutoring; distance learning; learning environments; web-based training systems AB This paper focuses on a CBS module of Knowledge-Based Tutoring System for Software Reuse Practices. The paper presents a public CBS using a validated Software Reuse Reference Model (SRRM). A CBS-SRRM allows the software engineer to improve reuse practice by being tutored with selected course material based on the user profile. This material is combined with actual practice-based knowledge derived from different case studies from software development organizations' reuse practices. A CBS-SRRM provides software engineers with a way to be tutored using positive lessons learned by other organizations. Our research focuses on achieving more effective means for software development organizations to find alternative educational (training) solutions to problems in software reuse practices. C1 USN, Postgrad Sch, Dept Comp Sci, Monterey, CA 93943 USA. RP Nada, N (reprint author), USN, Postgrad Sch, Dept Comp Sci, Monterey, CA 93943 USA. OI damiani, ernesto/0000-0002-9557-6496 NR 37 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-0775-1 PY 2000 BP 307 EP 316 DI 10.1109/TOOLS.2000.868981 PG 10 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BQ83F UT WOS:000089736600028 ER PT B AU Luqi Berzins, V Shing, M Riehle, R Nogueira, J AF Luqi Berzins, V Shing, M Riehle, R Nogueira, J BE Li, QY Firesmith, D Riehle, R Pour, G Meyer, B TI Evolutionary Computer Aided Prototyping System (CAPS) SO TECHNOLOGY OF OBJECT-ORIENTED LANGUAGES AND SYSTEMS - TOOLS 34, PROCEEDINGS LA English DT Proceedings Paper CT 34th International Conference on Technology of Object-Oriented Languages and Systems (TOOLS 34) CY JUL 30-AUG 04, 2000 CL SANTA BARBARA, CA SP Microsoft, CMP, Borders Bookstores, Software Council So Calif, PCAI Magazine, Interact Software Engn AB This paper describes a distributed development environment, CAPS (Computer-Aided Prototyping System), to support rapid prototyping and automatic generation of source code based on designer specifications in an evolutionary software development process. The CAPS system uses a fifth-generation prototyping language to model the communication structure, timing constraints, I/O control, and data buffering that comprise the requirements for an embedded software system. The language supports the specification of hard real-time systems with reusable components from domain specific component libraries. CAPS has been used successfully as a research tool in prototyping large real-time control systems (e.g. the command-and-control station, cruise missile flight control system, missile defense systems) and demonstrated its capability to support the development of large complex embedded software. C1 USN, Postgrad Sch, Dept Comp Sci, Monterey, CA 93943 USA. RP Luqi (reprint author), USN, Postgrad Sch, Dept Comp Sci, Monterey, CA 93943 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-0775-1 PY 2000 BP 363 EP 372 PG 10 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BQ83F UT WOS:000089736600033 ER PT J AU Collins, MM Tang, T Slack, R Sintasath, D Hartzman, RJ Ng, J Hurley, CK AF Collins, MM Tang, T Slack, R Sintasath, D Hartzman, RJ Ng, J Hurley, CK TI The relative frequencies of HLA-DRB1*01 alleles in the major US populations SO TISSUE ANTIGENS LA English DT Article DE HLA; HLA-DRB1*01; allele frequency; SSOP typing; DR1 ID MARROW TRANSPLANTATION; HLA-A; DONOR; REGISTRY AB The frequencies of alleles in the HLA-DRB1*01 family were determined in each of five US populations from a database of 82,979 individuals. Individuals typed as DR1 (or DRB1*01) comprised between 7.6%-21.3% of the individuals in each population group. Fifty-nine DR1 individuals were randomly selected from each group and subjected to high-resolution DNA typing by polymerase chain reaction using sequence-specific oligonucleotide probes. DRB1*0101 was the most common allele in the Caucasian, Asian/Pacific Islander, and Native American groups while the DRB1*0102 allele was found in the majority of African Americans and Hispanics. DRB1*0103 was present at a similar frequency in all populations. DRB1*0104, DRB1*0105, and DRB1*0106 alleles were not observed. C1 Georgetown Univ, Med Ctr, Dept Microbiol & Immunol, Washington, DC 20007 USA. Georgetown Univ, Med Ctr, Dept Pediat, Washington, DC 20007 USA. Georgetown Univ, Med Ctr, Dept Biostat, Washington, DC 20007 USA. USN, Med Res Ctr, Bethesda, MD 20084 USA. RP Hurley, CK (reprint author), Georgetown Univ, Med Ctr, Dept Microbiol & Immunol, E404 Res Bldg,3970 Reservoir Rd NW, Washington, DC 20007 USA. NR 17 TC 18 Z9 18 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0001-2815 J9 TISSUE ANTIGENS JI Tissue Antigens PD JAN PY 2000 VL 55 IS 1 BP 48 EP 52 DI 10.1034/j.1399-0039.2000.550108.x PG 5 WC Cell Biology; Immunology; Pathology SC Cell Biology; Immunology; Pathology GA 280DV UT WOS:000085087700008 PM 10703608 ER PT J AU Lin, YS Hoyer, RJ Tang, TF Ng, J Hartzman, RJ Hurley, CK AF Lin, YS Hoyer, RJ Tang, TF Ng, J Hartzman, RJ Hurley, CK TI Detection of four novel alleles: DRB1*1130, DRB1*13072, DRB1*1315 and DRB1*1331 SO TISSUE ANTIGENS LA English DT Article DE class II; SSOP; direct DNA sequencing; DRB1 alleles; DRB3 alleles; gene conversion; human leukocyte antigen (HLA) ID POLYMERASE CHAIN-REACTION; OLIGONUCLEOTIDE PROBES; SEQUENCE; DNA; IDENTIFICATION; REGION; HLA AB Four new DR52-associated DRB1 alleles are described. One al lele, DRB1*1130, is a hybrid between a DRB3*02 allele and a DRB1*11011 allele. The other alleles, DRB1*13072, DRB1*1315, and DR131*1331, are simple reshufflings of known polymorphic motifs. C1 Georgetown Univ, Med Ctr, Dept Microbiol & Immunol, Washington, DC 20007 USA. Georgetown Univ, Med Ctr, Dept Pediat, Washington, DC 20007 USA. USN, Med Res Ctr, Bethesda, MD 20084 USA. RP Hurley, CK (reprint author), Georgetown Univ, Med Ctr, Dept Microbiol & Immunol, E404 Res Bldg,3970 Reservoir Rd NW, Washington, DC 20007 USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0001-2815 J9 TISSUE ANTIGENS JI Tissue Antigens PD JAN PY 2000 VL 55 IS 1 BP 92 EP 96 DI 10.1034/j.1399-0039.2000.550121.x PG 5 WC Cell Biology; Immunology; Pathology SC Cell Biology; Immunology; Pathology GA 280DV UT WOS:000085087700021 PM 10703621 ER PT S AU Bharadwaj, R Sims, S AF Bharadwaj, R Sims, S BE Graf, S Schwartzbach, M TI Salsa: Combining constraint solvers with BDDs for automatic invariant checking SO TOOLS AND ALGORITHMS FOR THE CONSTRUCTION AND ANALYSIS OF SYSTEMS SE Lecture Notes in Computer Science LA English DT Article; Proceedings Paper CT 6th International Conference on Tools and Algorithms for the Construction and Analysis of Systems at the European Conference on Theory and Practice of Software CY MAR 25-APR 02, 2000 CL TECH UNIV BERLIN, BERLIN, GERMANY SP Tech Univ Berlin, Inst Commun & Software Technol, European Assoc Programming Languages & Syst, European Assoc Theoret Comp Sci, European Assoc Software Dev Sci, European Commiss 5th Framework Programme HO TECH UNIV BERLIN ID SPECIFICATIONS; REQUIREMENTS; VERIFICATION; TOOLSET; LOGIC AB Salsa is an invariant checker for specifications in SAL (the SCR Abstract Language). To establish a formula as an invariant without any user guidance, Salsa carries out an induction proof that utilizes tightly integrated decision procedures, currently a combination of BDD algorithms and a constraint solver for integer linear arithmetic, for discharging the verification conditions. The user interface of Salsa is de signed to mimic the interfaces of model checkers; i.e., given a formula and a system description, Salsa either establishes the formula as an invariant of the system (but returns no proof) or provides a counterexample. In either case, the algorithm will terminate. Unlike model checkers, Salsa returns a state pair as a counterexample and not an execution sequence. Also, due to the incompleteness of induction, users must validate the counterexamples. The use of induction enables Salsa to combat the state explosion problem that plagues model checkers - it can handle specifications whose state spaces are too large for model checkers to analyze. Also, unlike general purpose theorem provers, Salsa concentrates on a single task and gains efficiency by employing a set of optimized heuristics. C1 USN, Res Lab, Ctr High Assurance Comp Syst, Washington, DC 20375 USA. RP USN, Res Lab, Ctr High Assurance Comp Syst, Washington, DC 20375 USA. EM ramesh@itd.nrl.navy.mil; sims@reactive-systems.com NR 34 TC 6 Z9 6 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-67282-6 J9 LECT NOTES COMPUT SC PY 2000 VL 1785 BP 378 EP 394 PG 17 WC Computer Science, Theory & Methods SC Computer Science GA BR01L UT WOS:000165369300026 ER PT S AU Ray, JR AF Ray, JR BE Rummel, R Drewes, H Bosch, W Hornik, H TI Towards an integrated global reference system: Geodesy as a utility SO TOWARDS AN INTEGRATED GLOBAL GEODETIC OBSERVING SYSTEM (IGGOS) SE INTERNATIONAL ASSOCIATION OF GEODESY SYMPOSIA LA English DT Proceedings Paper CT International Symposium on Towards an Integrated Global Geodetic Observing System (IGGOS) CY OCT 05-09, 1998 CL BAVARIAN ACAD SCI, MUNICH, GERMANY SP Int Assoc Geodesy HO BAVARIAN ACAD SCI AB The global reference system provides a framework that allows users to determine geocentric coordinates with a precision of 1 cm or better. The overall accuracy of the system is probably similar to5 mm in long-term position and about 1 to 2 mm/yr in rates. This is similar to the 1 -day precision of the best measurement systems, an indication that systematic errors dominate over random observational noise in the long term. Nonetheless, the current system satisfies the requirements of all but the most demanding users and it continues to improve. This achievement, combined with the relatively easy and cost-effective access provided by GPS, is transforming the global reference system from a research tool into a geodetic utility. The trend is likely to continue and perhaps accelerate. The IAG is uniquely suited to promote and guide this development in such a way as to ensure the highest standards of user service are met while protecting the interests of scientific researchers. However, doing so will require new organizational structures to link the observing techniques and to provide improved user interfaces and services. C1 USN Observ, Earth Orientat Dept, Washington, DC 20392 USA. RP Ray, JR (reprint author), USN Observ, Earth Orientat Dept, 3450 Massachusetts Av NW, Washington, DC 20392 USA. RI Symposia, IAG/K-2857-2012 NR 0 TC 3 Z9 3 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0939-9585 BN 3-540-67079-3 J9 IAG SYMP PY 2000 VL 120 BP 19 EP 21 PG 3 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BR53D UT WOS:000166722100004 ER PT B AU McNelley, TR AF McNelley, TR BE Mishra, RS Semiatin, SL Suryanarayana, C Thadhani, NN Lowe, TC TI The application of EBSD methods to evaluate grain boundary character of fine-grain pure aluminum SO ULTRAFINE GRAINED MATERIALS LA English DT Proceedings Paper CT Symposium on Ultrafine Grained Materials at the 2000TMS Annual Meeting CY MAR 12-16, 2000 CL NASHVILLE, TN SP Minerals Met & Mat Soc, MPMD Div ID AL-MG ALLOY; SUPERPLASTICITY; EVOLUTION; SIZE; MICROSTRUCTURES; MICROTEXTURE; DEFORMATION; REFINEMENT AB Ultra-fine grain sizes may be achieved by severe plastic deformation utilizing equal-channel angular (ECA) pressing. Grain sizes of similar to 1.0 mu m have been reported for pure aluminum processed by repetitive ECA pressing and submicron grain sizes have been attained in aluminum-magnesium alloys. However the grain boundary characteristics developed in materials processed by the various repetitive ECA pressing routes remain to be fully assessed. Measurement of grain-to-grain misorientations by use of recently developed computer-aided electron backscatter diffraction (EBSD) analysis methods enables the evaluation of grain boundary character in severely deformed materials. A background on EBSD analysis and its application to examination of the evolution of the grain-to-grain misorientation and microtexture during repetitive ECA pressing of pure aluminum is provided. C1 USN, Postgrad Sch, Dept Engn Mech, Monterey, CA 93943 USA. RP McNelley, TR (reprint author), USN, Postgrad Sch, Dept Engn Mech, Monterey, CA 93943 USA. NR 33 TC 2 Z9 2 U1 0 U2 1 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-472-0 PY 2000 BP 185 EP 194 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BQ57P UT WOS:000088805300018 ER PT S AU Jaynes, TG AF Jaynes, TG BE Carapezza, EM Hintz, TM TI Development of an aeronautical Inmarsat D+ terminal SO UNATTENDED GROUND SENSOR TECHNOLOGIES AND APPLICATIONS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Unattended Ground Sensor Technologies and Applications II CY APR 26, 2000 CL ORLANDO, FL SP SPIE DE satellite; communications; Inmarsat; D; tracking; GPS AB Inmarsat D+ service is a short messaging service that offers advantages allowing for a small transceiver design. SkyWave Mobile, Inc. was contracted to miniaturize their first generation D+ transceiver, the DMR-200, to produce a 20 cubic inch device. This device, designated the DMR-400, incorporates an Inmarsat D+ transceiver, GPS receiver, antennas, I/O lines, and advanced power management into a 14 cubic inch unit. The DMR-400 has received Inmarsat land-mobile certification and will soon enter an aeronautical approval phase packaged in a radome housing. The first step in the aeronautical certification phase was the design of a radome and mounting kit for external mounting on an aircraft fuselage. This housing also incorporates a heating element to extend the operational temperature range to -55 degreesC. The assembled unit will soon begin DO-160 testing to be followed by Doppler correction testing, FAA flight-testing, and Inmarsat Aeronautical testing. The key to the entire process is the successful implementation of Doppler compensation based on the GPS data. The expectation is an FAA and Inmarsat aeronautical certified unit. C1 USN, Ctr Surface Warfare, Dahlgren Div, Dahlgren, VA 22448 USA. RP Jaynes, TG (reprint author), USN, Ctr Surface Warfare, Dahlgren Div, Code T43,17320 Dahlgren Rd, Dahlgren, VA 22448 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3666-6 J9 P SOC PHOTO-OPT INS PY 2000 VL 4040 BP 191 EP 198 DI 10.1117/12.392566 PG 8 WC Remote Sensing SC Remote Sensing GA BR35M UT WOS:000166174300021 ER PT S AU Schultz, AC Grefenstette, JJ AF Schultz, AC Grefenstette, JJ BE Gerhart, GR Gunderson, RW Shoemaker, CM TI Continuous and embedded learning in autonomous vehicles: Adapting to sensor failures SO UNMANNED GROUND VEHICLE TECHNOLOGY II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Unmanned Ground Vehicle Technology II CY APR 24-25, 2000 CL ORLANDO, FL SP SPIE DE Robotics; Learning; Genetic Algorithms; adaptation; Evolutionary Algorithms AB This project describes an approach to creating autonomous systems that can continue to learn throughout their lives, that is, to be adaptive to changes in the environment and in their own capabilities. Evolutionary learning methods have been found to be useful in several areas in the development of autonomous vehicles. In our research, evolutionary algorithms are used to explore alternative robot behaviors within a simulation model as a way of reducing the overall knowledge engineering effort. The learned behaviors are then tested in the actual robot and the results compared. Initial research demonstrated the ability to learn reasonable complex robot behaviors such as herding, and navigation and collision avoidance using this offline learning approach. In this work, the vehicle is always exploring different strategies via an internal simulation model; the simulation, in turn, is changing over time to better match the world. This model, which we call Continuous and Embedded Learning (also referred to as Anytime Learning), is a general approach to continuous learning in a changing environment. The agent's learning module continuously tests new strategies against a simulation model of the task environment, and dynamically updates the knowledge base used by the agent on the basis of the results. The execution module controls the agent's interaction with the environment, and includes a monitor that can dynamically modify the simulation model based on its observations of the environment. When the simulation model is modified, the learning process continues on the modified model. The learning system is assumed to operate indefinitely, and the execution system uses the results of learning as they become available. Early experimental studies demonstrate a robot that can learn to adapt to failures in its sonar sensors. C1 USN, Res Lab, Intelligent Syst Sect, Washington, DC 20375 USA. RP Schultz, AC (reprint author), USN, Res Lab, Intelligent Syst Sect, Washington, DC 20375 USA. NR 16 TC 6 Z9 6 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3650-X J9 P SOC PHOTO-OPT INS PY 2000 VL 4024 BP 55 EP 62 DI 10.1117/12.391649 PG 8 WC Engineering, Aerospace SC Engineering GA BQ62J UT WOS:000088995200007 ER PT S AU DeBolt, CK Aviles, JD DeLeon, JD Nguyen, TB Nguyen, TN AF DeBolt, CK Aviles, JD DeLeon, JD Nguyen, TB Nguyen, TN BE Gerhart, GR Gunderson, RW Shoemaker, CM TI Development of a simple, autonomous system of small robots to clear unexploded submunition ordnance SO UNMANNED GROUND VEHICLE TECHNOLOGY II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Unmanned Ground Vehicle Technology II CY APR 24-25, 2000 CL ORLANDO, FL SP SPIE DE UXO; autonomy; robots; UGV; control AB The Naval Explosive Ordnance Disposal Technology Division (NAVEODTECHDIV) has had an active program for several years for the development of technologies required to realize an autonomous system of small robots to clear an area of unexploded submunitions. The focus thus far has been on the technology elements themselves, with an emphasis on autonomous electronic control and processing. NAVEODTECHDIV is now developing demonstration systems to prove the feasibility of this application. At this stage, the systems are used in relatively benign terrain, and the targets are inert, not live munitions. However, this is adequate to show possibilities, and allow for experimentation before a full-scale development effort is initiated. C1 USN, Explos Ordnance Disposal Technol Div, Indian Head, MD 20640 USA. RP Nguyen, TN (reprint author), USN, Explos Ordnance Disposal Technol Div, Indian Head, MD 20640 USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3650-X J9 P SOC PHOTO-OPT INS PY 2000 VL 4024 BP 253 EP 262 DI 10.1117/12.391635 PG 10 WC Engineering, Aerospace SC Engineering GA BQ62J UT WOS:000088995200026 ER PT S AU Perzanowski, D Schultz, AC Adams, W Marsh, E AF Perzanowski, D Schultz, AC Adams, W Marsh, E BE Gerhart, GR Gunderson, RW Shoemaker, CM TI Using a natural language and gesture interface for unmanned vehicles SO UNMANNED GROUND VEHICLE TECHNOLOGY II SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Unmanned Ground Vehicle Technology II CY APR 24-25, 2000 CL ORLANDO, FL SP SPIE DE adjustable autonomy; gesture; goal tracking; mixed-initiative; natural language interface; robotics AB Unmanned vehicles, such as mobile robots, must exhibit adjustable autonomy. They must be able to be self-sufficient when the situation warrants; however, as they interact with each other and with humans, they must exhibit an ability to dynamically adjust their independence or dependence as co-operative agents attempting to achieve some goal. This is what we mean by adjustable autonomy. We have been investigating various modes of communication that enhance a robot's capability to work interactively with other robots and with humans. Specifically, we have been investigating how natural language and gesture can provide a user-friendly interface to mobile robots. We have extended this initial work to include semantic and pragmatic procedures that allow humans and robots to act co-operatively, based on whether or not goals have been achieved by the various agents in the interaction. By processing commands that are either spoken or initiated by clicking buttons on a Personal Digital Assistant and by gesturing either naturally or symbolically, we are tracking the various goals in the interaction, the agent involved in the interaction, and whether or not the goal has been achieved. The various agents involved in achieving the goals are each aware of their own and others' goals and what goals have been stated or accomplished so that eventually any member of the group, be it a robot or a human, if necessary, can interact with the other members to achieve the stated goals of a mission. C1 USN, Res Lab, Ctr Appl Res Artificial Intelligence, Washington, DC 20375 USA. RP USN, Res Lab, Ctr Appl Res Artificial Intelligence, Code 5512, Washington, DC 20375 USA. EM dennisp@aic.nrl.navy.mil NR 9 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3650-X J9 PROC SPIE PY 2000 VL 4024 BP 341 EP 347 DI 10.1117/12.391644 PG 7 WC Engineering, Aerospace SC Engineering GA BQ62J UT WOS:000088995200034 ER PT S AU Gillespie, DT AF Gillespie, DT BE Abbott, D Kish, LB TI Non-Markovian stochastic processes SO UNSOLVED PROBLEMS OF NOISE AND FLUCTUATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 2nd International Conference on Unsolved Problems of Noise and Fluctuations (UPoN 99) CY JUL 12-15, 1999 CL ADELAIDE, AUSTRALIA SP IEEE Electron Devoces Soc, Inst Phys, US Off Naval Res, USAF Res Labs, Ctr Biomed Engn, Adelaide, Natl Inst Theoret Phys, Dept Ind Sci & Resources Australia, Defence Sci & Technol Org, Inst Engineers, Australia ID QUANTUM-MECHANICS CANNOT; DYNAMICS; DRIVEN; STATE; NOISE AB New perspectives on non-Markovian stochastic process theory are provided by recent work on the question of whether quantum mechanical measurement statistics can be modeled as a self-consistent stochastic process. C1 USN, Air Warfare Ctr, Computat Sci Div 4t4400D, China Lake, CA 93555 USA. RP Gillespie, DT (reprint author), USN, Air Warfare Ctr, Computat Sci Div 4t4400D, China Lake, CA 93555 USA. NR 24 TC 2 Z9 2 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-826-6 J9 AIP CONF PROC PY 2000 VL 511 BP 49 EP 56 PG 8 WC Physics, Applied SC Physics GA BP98J UT WOS:000086805200005 ER PT S AU Pattabiraman, N Matthews, JH Ward, KB Mantile-Selvaggi, G Miele, L Mukherjee, AB AF Pattabiraman, N Matthews, JH Ward, KB Mantile-Selvaggi, G Miele, L Mukherjee, AB BE Mukherjee, AB Chilton, BS TI Crystal structure analysis of recombinant human uteroglobin and molecular modeling of ligand binding SO UTEROGLOBIN/CLARA CELL PROTEIN FAMILY SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Article; Proceedings Paper CT Conference on Uteroglobin/Calra Cell Protein Family CY APR 14-16, 2000 CL BETHESDA, MARYLAND SP NICHHD, NHLBI, New York Acad Sci ID IMMUNOGLOBULIN-A NEPHROPATHY; CELL 10-KDA PROTEIN; PHOSPHOLIPASE-A2 ACTIVITY; SECONDARY STRUCTURE; RABBIT UTEROGLOBIN; GENE-EXPRESSION; KDA PROTEIN; PROGESTERONE; REFINEMENT; RESOLUTION AB Uteroglobin, a steroid-inducible, cytokine-like, secreted protein with immunomodulatory properties, has been reported to bind progesterone, polychlorinated biphenyls (PCB), and retinol. Structural studies may delineate whether binding of ligands is a likely physiological function of human uteroglobin (hUG). We report a refined crystal structure of uncomplexed recombinant hUG (rhUG) at 2.5-Angstrom, resolution and the results of our molecular modeling studies of ligand binding to the central hydrophobic cavity of rhUG. The crystal structure of rhUG is very similar to that of reported crystal structures of uteroglobins. Using molecular modeling techniques, the three ligands-PCB, progesterone, and retinol-were docked into the hydrophobic cavity of the dimer structure of rhUG. We undocked the progesterone ligand by pulling the ligand from the cavity into the solvent From our modeling and undocking studies of progesterone, it is clear that these types of hydrophobic ligands could slip into the cavity between helix-3 and helix-3' of the dimer instead of between helix-1 and helix-4 of the monomer, as proposed earlier. Our results suggest that at least one of the physiological functions of UG is to bind to hydrophobic ligands, such as progesterone and retinol. C1 USN, Res Lab, Struct Matter Lab, Washington, DC 20375 USA. NICHHD, Sect Dev Genet, Heritable Disorders Branch, NIH, Bethesda, MD 20892 USA. RP Pattabiraman, N (reprint author), NCI, Adv Biomed Comp Ctr, SAIC, 430 Miller Dr, Frederick, MD 21702 USA. NR 48 TC 18 Z9 19 U1 0 U2 2 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-293-2 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 2000 VL 923 BP 113 EP 127 PG 15 WC Biochemistry & Molecular Biology; Multidisciplinary Sciences SC Biochemistry & Molecular Biology; Science & Technology - Other Topics GA BT10P UT WOS:000171966400009 PM 11193750 ER PT S AU Rosenberg, R Lanzagorta, M Chtchelkanova, A Khokhlov, A AF Rosenberg, R Lanzagorta, M Chtchelkanova, A Khokhlov, A BE Erbacher, RF Chen, PC Roberts, JC Wittenbrink, CM TI Parallel visualization of large data sets SO VISUAL DATA EXPLORATION AND ANALYSIS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 7th Meeting on Visual Data Exploration and Analysis CY JAN 24-26, 2000 CL SAN JOSE, CA SP SPIE, Soc Imaging & Technol ID REFINEMENT; OCTREE AB In this paper we describe our efforts towards the parallel visualization of large data sets. We describe the Fully Threaded Tree (FTT) structure developed at NRL to tackle the problem of massive parallel calculations using adaptive mesh refinement methods. All operations with FTT are performed in parallel and require only a small memory overhead. The FTT can be viewed as a data compression scheme that dramatically improves the performance of standard finite difference algorithms by performing calculations on the compressed data in situ. Because of the tremendous benefits of this type of data structure, it is of great interest to develop visualization algorithms that are native to the FTT. Using the FTT library, we convert the FTT data structure to an unstructured data set and discuss applications to both scatter dot visualization and parallel ray-tracing. The latter technique gives a good indication of the performance and scalability of the FTT algorithm for ray-tracing. We then discuss conversion of the FTT data structure for virtual reality visualization in an immersive room. Our results are presented using an example of a numerical calculation of a detonation in a rectangular cavity using from 1 to 2 million cells. C1 USN, Res Lab, Washington, DC 20375 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3578-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 3960 BP 135 EP 143 DI 10.1117/12.378889 PG 9 WC Computer Science, Software Engineering SC Computer Science GA BP87X UT WOS:000086471500014 ER PT S AU Schuler, JM Scribner, DA Kruer, MR AF Schuler, JM Scribner, DA Kruer, MR BE Park, SK Rahman, Z TI Alias reduction and resolution enhancement by a temporal accumulation of registered data from focal plane array sensors SO VISUAL INFORMATION PROCESSING IX SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Visual Information Processing IX CY APR 25, 2000 CL ORLANDO, FL SP SPIE DE super resolution; image reconstruction; super sampling; alias reduction; resolution enhancement ID OPTICAL-FLOW; VIDEO SEQUENCES; IMAGE AB The size and dimensions of a focal plane array do not necessarily limit the achievable resolution of a digital imaging camera if such a camera can make repeated exposures of a scene where all such exposures differ by some perspective transformation. This paper outlines a generalized reconstruction approach that does not depend on controlled micro dithering of the camera, nor requires the set of exposures to maintain a strictly uniform translation. C1 USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. RP Schuler, JM (reprint author), USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. NR 18 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3667-4 J9 P SOC PHOTO-OPT INS PY 2000 VL 4041 BP 94 EP 102 DI 10.1117/12.390473 PG 9 WC Computer Science, Information Systems; Optics SC Computer Science; Optics GA BQ62M UT WOS:000088996200011 ER PT S AU Swan, JE Lanzagorta, M Maxwell, D Kuo, E Uhlmann, J Anderson, W Shyu, HJ Smith, W AF Swan, JE Lanzagorta, M Maxwell, D Kuo, E Uhlmann, J Anderson, W Shyu, HJ Smith, W GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI A computational steering system for studying microwave interactions with missile bodies SO VISUALIZATION 2000, PROCEEDINGS SE IEEE CONFERENCE ON VISUALIZATION LA English DT Proceedings Paper CT IEEE Visualization Conference CY OCT 08-13, 2000 CL SALT LAKE CITY, UT SP IEEE Comp Soc, Tech Comm Visualizat & Graph, ACM SIGGRAPH DE modeling and simulation; scientific visualization; computational steering; inverse steering; virtual reality ID NONSTANDARD FINITE-DIFFERENCES AB This paper describes a computer modeling and simulation system that supports computational steering, which is an effort to make the typical simulation workflow more efficient. Our system provides an interface that allows scientists to perform all of the steps in the simulation process in parallel and online. It uses a standard network flow visualization package, which has been extended to display graphical output in an immersive virtual environment such as a CAVE. Our system allows scientists to interactively manipulate simulation parameters and observe the results. It also supports inverse steering, where the user specifies the desired simulation result, and the system searches for the simulation parameters that achieve this result. Taken together, these capabilities allow scientists to more efficiently and effectively understand model behavior, as well as to search through simulation parameter space. This paper is also a case study of applying our system to the problem of simulating microwave interactions with missile bodies. Because these interactions are difficult to study experimentally, and have important effects on missile electronics, there is a strong desire to develop and validate simulation models of this phenomena. C1 USN, Res Lab, Virtual Real Lab, Washington, DC 20375 USA. RP Swan, JE (reprint author), USN, Res Lab, Virtual Real Lab, Code 5580,4555 Overlook Ave SW, Washington, DC 20375 USA. NR 10 TC 3 Z9 3 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA SN 1070-2385 BN 0-7803-6478-3 J9 IEEE VISUAL PY 2000 BP 441 EP 444 DI 10.1109/VISUAL.2000.885727 PG 4 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BR26T UT WOS:000165971600055 ER PT S AU Jones, DL Allen, RJ Basart, JP Bastian, T Blume, WH Bougeret, JL Dennison, BK Desch, MD Dwarakanath, KS Erickson, WC Farrell, W Finley, DG Gopalswamy, N Howard, RE Kaiser, ML Kassim, NE Kuiper, TBH MacDowall, RJ Mahoney, MJ Perley, RA Preston, RA Reiner, MJ Rodriguez, P Stone, RG Unwin, SC Weiler, KW Woan, G Woo, R AF Jones, DL Allen, RJ Basart, JP Bastian, T Blume, WH Bougeret, JL Dennison, BK Desch, MD Dwarakanath, KS Erickson, WC Farrell, W Finley, DG Gopalswamy, N Howard, RE Kaiser, ML Kassim, NE Kuiper, TBH MacDowall, RJ Mahoney, MJ Perley, RA Preston, RA Reiner, MJ Rodriguez, P Stone, RG Unwin, SC Weiler, KW Woan, G Woo, R BE Hirabayashi, H Preston, RA Gurvits, LI TI The ALFA medium explorer mission SO VSOP RESULTS AND THE FUTURE OF SPACE VLBI SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT E1 3 Symposium of COSPAR Scientific Commission E held at the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP Comm Space Res AB The frequency range below a few tens of MHz is unexplored with high angular resolution due to the opacity of Earth's ionosphere. An interferometer array in space providing arcminute angular resolution images at frequencies of a few MHz would allow a wide range of problems in solar, planetary, galactic, and extragalactic astronomy to be attacked. These include the evolution of solar radio emissions associated with shocks driven by coronal mass ejections and searches for coherent radio emission from supernova remnants and relativistic jets, in addition, it is likely that unexpected objects or emission processes will be discovered by such an instrument, as has always happened when high resolution astronomical observations first become possible in a new region of the electromagnetic spectrum. The Astronomical Low Frequency Array (ALFA) mission will consist of 16 identical small satellites forming an aperture synthesis array. The satellites will cover the surface of a spherical region approximate to 100 km in diameter, thus providing good aperture plane coverage in all directions simultaneously. The array will operate in two modes: 1) "snapshot" imaging of strong, rapidly changing sources such as solar radio bursts and 2) long-term aperture synthesis observations for maximum sensitivity, high dynamic range imaging, in both cases a large number of array elements is needed. (C) 2000 COSPAR. Published by Elsevier Science Ltd. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Iowa State Univ, Ames, IA 50011 USA. Observ Paris, Meudon, France. Natl Radio Astron Observ, Socorro, NM 87801 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Raman Res Inst, Bangalore 560080, Karnataka, India. Univ Maryland, College Pk, MD 20742 USA. Univ Tasmania, Hobart, Tas, Australia. USN, Res Lab, Washington, DC 20375 USA. Univ Glasgow, Glasgow, Lanark, Scotland. RP Jones, DL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI MacDowall, Robert/D-2773-2012; Gopalswamy, Nat/D-3659-2012; Dwarakanath, K /D-4876-2012; Astronomy & Astrophysics Group, Raman Res Institute/D-4046-2012; Farrell, William/I-4865-2013 NR 0 TC 10 Z9 10 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2000 VL 26 IS 4 BP 743 EP 746 DI 10.1016/S0273-1177(99)01204-1 PG 4 WC Engineering, Aerospace SC Engineering GA BQ23F UT WOS:000087679700034 ER PT S AU Fiedler, R Jansen, R AF Fiedler, R Jansen, R BE Szu, HH Vetterli, M Campbell, WJ Buss, JR TI Adventures in SAR processing SO WAVELET APPLICATIONS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Wavelet Applications VII CY APR 26-28, 2000 CL ORLANDO, FL SP SPIE DE synthetic aperture radar; SAR; time-frequency analysis; signal processing; non-stationary processes; stationary processes; image artifacts; moving targets; sub-aperture processing AB The image formation process associated with coherent imaging sensors is particularly sensitive to and is often corrupted by non-stationary processes. In the case of synthetic aperture radar (SAR), non-stationary processes result from motion within the scene, variable radar cross section, multi-path, topographic variations, sensor anomalies, and deficiencies in the image formation processing chain. Conversely, stationary processes result in image signatures that appear literal to the eye, e.g., urban infrastructure, vegetation, and natural terrain. In analyzing SAR signal history two objectives unfold. One is to obtain a well-focussed image devoid of distortions and non-literal artifacts. The second objective is the detection and value-added exploitation of the non-stationary signatures. Note that the roles of signal and clutter are reversed for these two objectives. The notion that joint time-frequency (JTF) techniques may prove useful in accomplishing these objectives has spurred limited investigations into the field of coherent radar imaging systems. This paper addresses SAR image formation processing, the complex response function for a point source, and SAR JTF image formation implementations. Each of these topics is described within the context of applying JTF processing to all aspects of SAR image formation and analysis. C1 USN, Res Lab, Washington, DC 20375 USA. RP Fiedler, R (reprint author), USN, Res Lab, Code 7260, Washington, DC 20375 USA. NR 7 TC 4 Z9 4 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3682-8 J9 P SOC PHOTO-OPT INS PY 2000 VL 4056 BP 186 EP 196 DI 10.1117/12.381680 PG 11 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BQ40G UT WOS:000088256200016 ER PT S AU Chen, VC Lipps, R AF Chen, VC Lipps, R BE Szu, HH Vetterli, M Campbell, WJ Buss, JR TI Time-frequency signatures of micro-Doppler phenomenon for feature extraction SO WAVELET APPLICATIONS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Wavelet Applications VII CY APR 26-28, 2000 CL ORLANDO, FL SP SPIE DE time-frequency analysis; micro-Doppler; feature extraction AB In this paper, we introduce the concept of micro-Doppler phenomenon. Micro-Doppler induced by mechanical vibrating or rotating of structures in a target is potentially useful for detection, classification and recognition of targets, While the Doppler frequency due to target body is constant, the micro-Doppler due to vibrating or rotating structures of a target is a function of the dwell time. This time-varying Doppler signature in the time-frequency domain may provide further information for target detection, classification and recognition. C1 USN, Res Lab, Div Radar, Washington, DC 20375 USA. RP Chen, VC (reprint author), USN, Res Lab, Div Radar, Washington, DC 20375 USA. NR 8 TC 31 Z9 32 U1 1 U2 5 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3682-8 J9 P SOC PHOTO-OPT INS PY 2000 VL 4056 BP 220 EP 226 DI 10.1117/12.381683 PG 7 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BQ40G UT WOS:000088256200019 ER PT S AU Breaux, N Szu, H AF Breaux, N Szu, H BE Szu, HH Vetterli, M Campbell, WJ Buss, JR TI Real world analysis of electromagnetic pulses using adaptive Wavelet Transforms SO WAVELET APPLICATIONS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Wavelet Applications VII CY APR 26-28, 2000 CL ORLANDO, FL SP SPIE DE adaptive wavelet transform; continuous wavelet transform; Morlet wavelet; signal analysis AB The Fourier Transform (FT) is often used to analyze transient and non-stationary signals even when such signals are not periodic in nature. We demonstrate how an adaptive Wavelet Transform (WT) can bring out signal details that the traditional FT cannot, as first shown by Szu et al. in 1992 (Ref. 1). The magnitude plot of the complex Morlet wavelet shows the evolution of the signal's energy in both time and frequency, while the phase plot pinpoints signal discontinuities at various scales. This information can be used to build a compact model and approximate representation of signals characterized by pulses. We are able to infer (not shown here) the physics of devices that generate EM pulses. C1 USN, Ctr Surface Warfare, Dahlgren, VA 22448 USA. RP Breaux, N (reprint author), USN, Ctr Surface Warfare, Dahlgren, VA 22448 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3682-8 J9 P SOC PHOTO-OPT INS PY 2000 VL 4056 BP 258 EP 266 DI 10.1117/12.381689 PG 9 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BQ40G UT WOS:000088256200023 ER PT S AU Jump, A Sherlock, B AF Jump, A Sherlock, B BE Szu, HH Vetterli, M Campbell, WJ Buss, JR TI Wavelets of arbitrary order of regularity SO WAVELET APPLICATIONS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Wavelet Applications VII CY APR 26-28, 2000 CL ORLANDO, FL SP SPIE DE orthonormal wavelets; regularity; perfect reconstruction ID ORTHONORMAL WAVELETS AB This research deals with finite length, perfect reconstruction two-channel orthonormal wavelet filters. For these filters, the coefficients of the filter of maximum order of regularity are unique and are known. Previous research has also developed a parameterization to generate the coefficients of all filters of order of regularity one. The current research presents a parametrization for the generation of the coefficients of these filters with order of regularity between one and the maximum possible. C1 USN, Ctr Surface Warfare, Dahlgren, VA 22448 USA. RP Jump, A (reprint author), USN, Ctr Surface Warfare, 17320 Dahlgren Rd, Dahlgren, VA 22448 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3682-8 J9 P SOC PHOTO-OPT INS PY 2000 VL 4056 BP 394 EP 405 DI 10.1117/12.381700 PG 12 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BQ40G UT WOS:000088256200036 ER PT J AU Wahl, KJ Dunn, DN Singer, IL AF Wahl, KJ Dunn, DN Singer, IL TI Effects of ion implantation on microstructure, endurance and wear behavior of IBAD MoS2 SO WEAR LA English DT Article DE wear; molybdenum disulphide; MoS2; solid lubrication; ion irradiation ID BEAM-ASSISTED DEPOSITION; IMPROVED TRIBOLOGICAL PROPERTIES; X-RAY-DIFFRACTION; FILMS; COATINGS; LIFE; CERAMICS; ENHANCEMENT; BOMBARDMENT; SAPPHIRE AB Thin MoS2 coatings were prepared on steel and Si substrates via ion-beam assisted deposition using conditions known to produce dense, basal oriented microstructures. After deposition, the coated substrates were irradiated with 180 keV Ar2+ ions at doses of 1 X 10(15) 1 X 10(16), and 5 X 10(16) ions/cm(2). Microstructures of as-deposited and ion irradiated MoS2 coatings were examined using X-ray diffraction, high resolution transmission electron microscopy, and micro-Raman spectroscopy. Friction, wear and endurance were examined under both unidirectional and reciprocating sliding conditions in dry air. The lowest ion irradiation dose altered the initial microstructure, producing basal oriented, nearly defect-free crystalline domains of MoS2 in an amorphous matrix; at the highest dose the coatings were nearly amorphous, but the remaining MoS2 showed mixed orientation. Ion irradiation of the MoS2 coatings did not significantly modify the friction behavior, and only at the highest dose was the endurance altered, decreasing by more than 75%. Two changes in wear behavior were observed in the highest dosed coatings: (1) accelerated wear of the coating and (2) elimination of solid lubricant reservoirs. Destruction of the solid lubricant replenishment process resulted in premature failure of the highest dosed coating. (C) 2000 Published by Elsevier Science S.A. C1 USN, Res Lab, Tribol Sect, Washington, DC 20375 USA. Univ Virginia, Dept Mat Sci & Engn, Charlottesville, VA 22903 USA. RP Wahl, KJ (reprint author), USN, Res Lab, Tribol Sect, Code 6176, Washington, DC 20375 USA. OI Wahl, Kathryn/0000-0001-8163-6964 NR 48 TC 31 Z9 32 U1 0 U2 17 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD JAN PY 2000 VL 237 IS 1 BP 1 EP 11 DI 10.1016/S0043-1648(99)00316-6 PG 11 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 288NM UT WOS:000085569200001 ER PT J AU Carr, LE Elsberry, RL AF Carr, LE Elsberry, RL TI Dynamical tropical cyclone track forecast errors. Part I: Tropical region error sources SO WEATHER AND FORECASTING LA English DT Article ID PREDICTION SYSTEM AB All highly erroneous (>300 n mi or 555 km at 72 h) Navy Operational Global Atmospheric Prediction System (NOGAPS) and U. S. Navy version of the Geophysical Fluid Dynamics Laboratory model (GFDN) tropical cyclone track forecasts in the western North Pacific during 1997 are examined. Responsible error mechanisms are described by conceptual models that are all related to known tropical cyclone motion processes that are being misrepresented in the dynamical models. Error mechanisms that predominantly occur while the tropical cyclone is still in the Tropics are described in this paper, and those errors that are more related to midlatitude circulations are addressed in a companion paper. Of the 69 NOGAPS large- error cases, 39 were attributed to excessive direct cyclone interaction (E- DCI), 12 cases of excessive ridge modification by the tropical cyclone (E- RMT), and 10 cases of excessive reverse trough formation (E- RTF). Of the 50 GFDN large- error cases, 31 were E- DCI, and only two E- RMT and two E- RTF cases were found, but 9 cases involving a single cyclone were attributed to excessive tropical cyclone size (E- TCS). Characteristics and symptoms in the forecast tracks and model fields that accompany these frequently occurring error mechanisms are documented and illustrative case studies are presented. When a sudden deviation from previous track guidance or a track outlier from the other dynamical model guidance appears, the forecaster should diagnose whether this is an error, or is indicative of a real track change. If the conceptual models of large- error mechanisms proposed from this retrospective study can be applied in real time, track forecasting will be improved. C1 USN, Postgrad Sch, Dept Meteorol, Monterey, CA 93943 USA. RP Carr, LE (reprint author), USN, Postgrad Sch, Dept Meteorol, Code MR-Cr,589 Dyer Rd,Room 254, Monterey, CA 93943 USA. NR 12 TC 26 Z9 27 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PY 2000 VL 15 IS 6 BP 641 EP 661 DI 10.1175/1520-0434(2000)015<0641:DTCTFE>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 385EH UT WOS:000165989300001 ER PT J AU Carr, LE Elsberry, RL AF Carr, LE Elsberry, RL TI Dynamical tropical cyclone track forecast errors. Part II: Midlatitude circulation influences SO WEATHER AND FORECASTING LA English DT Article AB All highly erroneous (>300 n mi or 555 km at 72 h) Navy Operational Global Atmospheric Prediction System (NOGAPS) and U. S. Navy version of the Geophysical Fluid Dynamics Laboratory model (GFDN) tropical cyclone track forecasts in the western North Pacific during 1997 are examined. Error mechanisms that are more related to midlatitude circulations are described in this paper and those errors that predominantly occur while the tropical cyclone (TC) is still in the Tropics are addressed in a companion paper. Responsible error mechanisms are described by conceptual models that are all related to known tropical cyclone motion processes that are being misrepresented in the dynamical models. As in the companion paper, characteristics and symptoms in the forecast tracks and model fields that accompany these frequently recurring error mechanisms are documented and illustrative case studies are presented. Whereas 21 GFDN forecasts were degraded by an improper prediction of a midlatitude system evolution, only seven NOGAPS track forecasts had 72- h errors exceeding 300 n mi. The NOGAPS model is more prone to excessive responses to vertical shear, and a useful indicator is that the 500- mb circulation of the TC becomes noticeably displaced downshear of the low- level center in the 48- 72- h forecast fields. Both the NOGAPS and GFDN forecasts are degraded by the baroclinic cyclone interaction, and none of the five dynamical models provided consistently accurate or time- consistent TC track forecasts in these situations. These midlatitude cases are more difficult than the tropical errors to diagnose as multiple error sources may be present. When a sudden deviation from previous track guidance or a track outlier from the other dynamical model guidance appears, the forecaster should diagnose whether this is an error, or is indicative of a real track change. If the conceptual models of large- error mechanisms proposed from this retrospective study can be applied in real time, track forecasting will be improved. C1 USN, Postgrad Sch, Dept Meteorol, Monterey, CA 93943 USA. RP Carr, LE (reprint author), USN, Postgrad Sch, Dept Meteorol, Code MR-Cr,Room 254,589 Dyer Rd, Monterey, CA 93943 USA. NR 4 TC 21 Z9 22 U1 1 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PY 2000 VL 15 IS 6 BP 662 EP 681 DI 10.1175/1520-0434(2000)015<0662:DTCTFE>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 385EH UT WOS:000165989300002 ER PT J AU Sikora, TD Friedman, KS Pichel, WG Clemente-Colon, P AF Sikora, TD Friedman, KS Pichel, WG Clemente-Colon, P TI Synthetic aperture radar as a tool for investigating polar mesoscale cyclones SO WEATHER AND FORECASTING LA English DT Article ID ATMOSPHERIC BOUNDARY-LAYER; SEA-SURFACE; IMAGERY; FEATURES; WAVES; GULF; LOWS AB Polar mesoscale cyclones are intense vortices that form in cold, marine air masses poleward of major jet streams and frontal zones. Synthetic aperture radar (SAR) should be considered as a potential tool for the study of polar mesoscale cyclones because of its ability to remotely sense, at least qualitatively, the high- resolution near- surface wind field independent of daylight and atmospheric conditions. Four case studies demonstrating this ability are presented. SAR imagery from the Canadian Space Agency's RADARSAT are compared to corresponding infrared imagery, surface analyses, and upper- air analyses. In three of the four case studies, it is argued that the addition of SAR imagery to the process of generating a manual surface analysis would have led to a better product. Moreover, it is demonstrated that the SAR imagery reveals a host of marine- meteorological phenomena in the vicinity of the polar mesoscale cyclones including atmospheric gravity waves, roll vortices, and cellular convection. Because of the high- resolution attributes of SAR imagery, SAR shows promise to aid the forecaster and researcher in the study of marine- meteorological phenomena such as polar mesoscale cyclones. C1 USN Acad, Dept Oceanog, Annapolis, MD 21402 USA. Caelum Res Corp, Camp Springs, MD USA. NOAA, Natl Environm Satellite Data & Informat Serv, Camp Springs, MD USA. RP Sikora, TD (reprint author), USN Acad, Dept Oceanog, 572M Holloway Rd, Annapolis, MD 21402 USA. RI Clemente-Colon, Pablo/F-5581-2010; Pichel, William/F-5619-2010 OI Pichel, William/0000-0001-6332-0149 NR 37 TC 18 Z9 18 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PY 2000 VL 15 IS 6 BP 745 EP 758 DI 10.1175/1520-0434(2000)015<0745:SARAAT>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 385EH UT WOS:000165989300007 ER PT J AU Lee, TF AF Lee, TF TI Nighttime observation of sheared tropical cyclones using GOES 3.9-mu m data SO WEATHER AND FORECASTING LA English DT Article ID IMAGERY; RESOLUTION; SURFACE; TRMM; FOG AB This note discusses a Geostationary Operational Environmental Satellite product that can reveal the low clouds associated with tropical cyclones at night. It is based on a pixel- by- pixel difference of the longwave (10.8 mum) and shortwave (3.9 mum) brightness temperature fields. This product is compared with daytime visible images from the same satellite and passive microwave images from the Tropical Rainfall Measuring Mission Microwave Imager and the Defense Meteorological Satellite Program Special Sensor Microwave/ Imager. Implications for weather analysis and forecasting are discussed for weak and shearing systems. C1 USN, Res Lab, Monterey, CA 93943 USA. RP Lee, TF (reprint author), USN, Res Lab, 7 Grace Hopper Ave, Monterey, CA 93943 USA. NR 12 TC 2 Z9 2 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PY 2000 VL 15 IS 6 BP 759 EP 766 DI 10.1175/1520-0434(2000)015<0759:NOOSTC>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 385EH UT WOS:000165989300008 ER PT J AU Rippey, W Gilsinn, J Flitter, L AF Rippey, W Gilsinn, J Flitter, L TI Networking of welding applications: A Tutorial - Knowing the basics behind network technology will help users of welding equipment identify where networks may be most beneficial SO WELDING JOURNAL LA English DT Article C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. USN, Ctr Surface Warfare, Carderock Div, W Bethesda, MD USA. RP Rippey, W (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER WELDING SOC PI MIAMI PA PO BOX 351040, MIAMI, FL 33135 USA SN 0043-2296 J9 WELD J JI Weld. J. PD JAN PY 2000 VL 79 IS 1 BP 49 EP 53 PG 5 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 271JU UT WOS:000084591100010 ER PT B AU Rolison, DR AF Rolison, DR GP NRC NRC NRC TI Title IX for women in academic chemistry: Isn't a millennium of affirmative action for white men sufficient? SO WOMEN IN THE CHEMICAL WORKFORCE LA English DT Proceedings Paper CT Roundtable Workshop on Women in the Chemical Workforce CY MAY, 2000 CL NATL ACAD SCI, WASHINGTON, D.C. HO NATL ACAD SCI ID SCIENCE C1 USN, Res Lab, Washington, DC 20375 USA. NR 24 TC 5 Z9 5 U1 0 U2 0 PU NATL ACADEMIES PRESS PI WASHINGTON PA 2101 CONSTITUTION AVE, WASHINGTON, DC 20418 USA BN 0-309-07293-X PY 2000 BP 74 EP 93 PG 20 WC Industrial Relations & Labor; Women's Studies SC Business & Economics; Women's Studies GA BV32X UT WOS:000178611300006 ER PT S AU Fritz, GG Wood, KS Van Vechten, D Gyulamiryan, AL Kuzanyan, AS Giordano, NJ Jacobs, TM Wu, HD Horwitz, JS Gulian, AM AF Fritz, GG Wood, KS Van Vechten, D Gyulamiryan, AL Kuzanyan, AS Giordano, NJ Jacobs, TM Wu, HD Horwitz, JS Gulian, AM BE Flanagan, KA Siegmund, OHW TI Thermoelectric single-photon detectors for X-ray/UV radiation SO X-RAY AND GAMMA-RAY INSTRUMENTATION FOR ASTRONOMY XI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Instrumentation for Astronomy IX CY AUG 02-04, 2000 CL SAN DIEGO, CA SP SPIE DE imaging microcalorimeter; energy resolution; thermoelectric sensors; hexaborates AB A feasibility study of megapixel microcalorimeter arrays, based on thermoelectric energy to voltage conversion and digital superconducting readout, is presented. The design concept originated from the philosophy of employing the simplest principles at the single-pixel level to enable large arrays without sacrificing energy resolution, fast operation speed, and quantum efficiency. Initial experimental tests confirm the basic predictions of theory, and show no major obstacle in achieving the desired characteristics. C1 USN, Res Lab, Washington, DC 20375 USA. RP Fritz, GG (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 16 TC 6 Z9 6 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3785-9 J9 P SOC PHOTO-OPT INS PY 2000 VL 4140 BP 459 EP 469 DI 10.1117/12.409144 PG 11 WC Astronomy & Astrophysics; Instruments & Instrumentation SC Astronomy & Astrophysics; Instruments & Instrumentation GA BR53H UT WOS:000166723400047 ER PT S AU Seely, JF AF Seely, JF BE Hoover, RB Walker, ABC TI Multilayer grating for the Extreme Ultraviolet Spectrometer (EIS) SO X-RAY OPTICS, INSTRUMENTS, AND MISSIONS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray Optics, Instruments, and Missions IV CY JUL 30-31, 2000 CL SAN DIEGO, CA SP SPIE DE multilayers; extreme ultraviolet; diffraction grating; grating efficiency ID WAVELENGTH REGION; X-RAY; EFFICIENCY AB The design of the multilayer coatings and multilayer grating for the EIS spectrometer is presented. The grating substrate has a rectangular laminar groove profile with 4200 grooves/mm and a 58 Angstrom groove depth. The grating and mirror have two multilayer coatings, each covering half of the areas of the grating and minor, and with high reflectance in the two wavelength regions 170-210 Angstrom and 250-290 Angstrom. The reflectance of the multilayer coating and the efficiency of the multilayer grating were calculated using computer codes that were validated by comparison to reflectance and efficiency measurements performed using synchrotron radiation. The sensitivities of the calculated reflectance and grating efficiency to surface microroughness, layer interdiffusion, layer nonuniformity, illumination angle, grating groove variations, hydrocarbon contamination, and oxide buildup were analyzed. C1 USN, Res Lab, Div Space Sci, Washington, DC 20375 USA. RP Seely, JF (reprint author), USN, Res Lab, Div Space Sci, Washington, DC 20375 USA. NR 5 TC 11 Z9 11 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3783-2 J9 P SOC PHOTO-OPT INS PY 2000 VL 4138 BP 174 EP 181 DI 10.1117/12.407557 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Engineering; Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BR62F UT WOS:000166964200020 ER PT J AU Russell, LM Seinfeld, JH Flagan, RC Ferek, RJ Hegg, DA Hobbs, PV Wobrock, W Flossmann, AI O'Dowd, CD Nielsen, KE Durkee, PA AF Russell, LM Seinfeld, JH Flagan, RC Ferek, RJ Hegg, DA Hobbs, PV Wobrock, W Flossmann, AI O'Dowd, CD Nielsen, KE Durkee, PA TI Aerosol dynamics in ship tracks SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CHARACTERIZATION EXPERIMENT ACE-1; CLOUD CONDENSATION NUCLEI; MARINE BOUNDARY-LAYER; PACIFIC-OCEAN; STRATOCUMULUS; MODEL; SULFUR; SIZE; NUCLEATION; PARTICLES AB Ship tracks are a natural laboratory to isolate the effect of anthropogenic aerosol emissions on cloud properties. The Monterey Area Ship Tracks (MAST) experiment in the Pacific Ocean west of Monterey, California, in June 1994, provides an unprecedented data set for evaluating our understanding of the formation and persistence of the anomalous cloud features that characterize ship tracks. The data set includes conditions in which the marine boundary layer is both clean and continentally influenced. Two case studies during the MAST experiment are examined with a detailed aerosol microphysical model that considers an external mixture of independent particle populations. The model allows tracking individual particles through condensational and coagulational growth to identify the source of cloud condensation nuclei (CCN). In addition, a cloud microphysics model was employed to study specific effects of precipitation. Predictions and observations reveal important differences between clean (particle concentrations below 150 cm(-3)) and continentally influenced (particle concentrations above 400 cm(-3)) background conditions: in the continentally influenced conditions there is a smaller change in the cloud effective radius, drop number and liquid water content in the ship track relative to the background than in the clean marine case. Predictions of changes in cloud droplet number concentrations and effective radii are consistent with observations although there is significant uncertainty in the absolute concentrations due to a lack of measurements of the plume dilution. Gas-to-particle conversion of sulfur species produced by the combustion of ship fuel is predicted to be important in supplying soluble aerosol mass to combustion-generated particles, so as to render them available as CCN. Studies of the impact of these changes on the cloud's potential to precipitate concluded that more complex dynamical processes must be represented to allow sufficiently long drop activations for drizzle droplets to form. C1 Princeton Univ, Dept Chem Engn, Princeton, NJ 08544 USA. CALTECH, Dept Chem Engn, Pasadena, CA 91125 USA. USN, Res Off, Arlington, VA USA. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. Univ Clermont Ferrand, Dept Atmospher Phys, Clermont Ferrand, France. Univ Sunderland, Sch Environm, Sch Marine & Atmopsher Sci, Durham, England. USN, Postgrad Sch, Dept Meteorol, Monterey, CA 93943 USA. RP Russell, LM (reprint author), Princeton Univ, Dept Chem Engn, A317 Engn Quadrangle, Princeton, NJ 08544 USA. EM lrussell@princeton.edu; seinfeld@cco.caltech.edu; flagan@cco.caltech.edu; ferekr@onr.navy.mil; deanhegg@atmos.washington.edu; phobbs@atmos.washington.edu; flossman@opgc.univ-bpclermont.fr; colin.odowd@cmas.demon.co.uk; kenielsen@nps.navy.mil; durkee@nps.navy.mil OI Flossmann, Andrea/0000-0002-4484-6425 NR 38 TC 22 Z9 22 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 27 PY 1999 VL 104 IS D24 BP 31077 EP 31095 DI 10.1029/1999JD900985 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 273DQ UT WOS:000084692900014 ER PT J AU Tutein, AB Stuart, SJ Harrison, JA AF Tutein, AB Stuart, SJ Harrison, JA TI Indentation analysis of linear-chain hydrocarbon monolayers anchored to diamond SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ATOMIC-FORCE MICROSCOPY; SELF-ASSEMBLED MONOLAYERS; MOLECULAR-DYNAMICS SIMULATIONS; FRICTIONAL-PROPERTIES; LENGTH DEPENDENCE; CARBON NANOTUBES; AU(111); SURFACE; PHASE; COMPRESSION AB Classical molecular dynamics simulations are used to examine the indentation of monolayers composed of linear hydrocarbon chains with 8, 13, or 22 carbon atoms that are chemically bound (or anchored) to a diamond (111) substrate. Indentation is accomplished using both a flexible and rigid single-wall, capped [10,10] nanotube as the tip. Regardless of the nanotube used, the simulations show that indentation of the hydrocarbon monolayers causes a disruption of the original ordering of the monolayer, pinning of selected hydrocarbon chains beneath the tube, and the formation of gauche defects within the monolayer. Because nanotubes are stiff along their axial direction, the flexible nanotube is distorted only slightly by its interaction with the softer monolayers. However, interaction with the hard diamond substrate causes the tube to buckle. Severe indents with a rigid nanotube tip result in rupture of chemical bonds within the hydrocarbon monolayer. C1 USN Acad, Dept Chem, Annapolis, MD 21402 USA. Clemson Univ, Dept Chem, Clemson, SC 29634 USA. RP Harrison, JA (reprint author), USN Acad, Dept Chem, Annapolis, MD 21402 USA. RI Stuart, Steven/H-1111-2012 NR 52 TC 63 Z9 63 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD DEC 23 PY 1999 VL 103 IS 51 BP 11357 EP 11365 DI 10.1021/jp992687j PG 9 WC Chemistry, Physical SC Chemistry GA 271NY UT WOS:000084601400018 ER PT J AU Buzin, AI Godovsky, YK Makarova, NN Fang, J Wang, X Knobler, CM AF Buzin, AI Godovsky, YK Makarova, NN Fang, J Wang, X Knobler, CM TI Stepwise collapse of monolayers of cyclolinear poly(organosiloxane)s at the air/water interface: A Brewster-angle microscopy and scanning force microscopy study SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID AIR-WATER-INTERFACE; PHASE-TRANSITIONS; LIPID MONOLAYERS; LIQUID-CRYSTALS; THIN-FILMS; SURFACE; BEHAVIOR; POLYMER; POLY(DIETHYLSILOXANE); TENSION AB We report studies of the collapse of monolayers of cyclolinear poly(organosiloxane)s that consist of six-membered rings joined by oxygen bridges and that contain two phenyl groups per monomer unit. Surface pressure-area isotherms show that these films undergo a stepwise collapse. The organization within the films has been examined at different stages of the collapse process by Brewster-angle microscopy. Films transferred to mica by the Langmuir-Blodgett technique have been imaged by scanning force microscopy. Five fractions of an atactic polymer with molecular weights (M-W) ranging from 8900 to 85 000 and one trans-tactic polymer (M-W = 8100) have been investigated. Bilayers of the fractions with the highest M-W's appear in the form of islands but the bilayers in the other samples have the form of ribbons 50-250 nm wide. C1 Russian Acad Sci, Inst Synthet Polymer Mat, Moscow 117393, Russia. LY Karpov Phys Chem Res Inst, Moscow 103064, Russia. Russian Acad Sci, AN Nesmeyanov Organoelement Cpds Inst, Moscow 117813, Russia. USN, Res Lab, Ctr Biomol Sci & Engn, Washington, DC 20375 USA. Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. RP Knobler, CM (reprint author), Russian Acad Sci, Inst Synthet Polymer Mat, 70 Profsoyuznaya, Moscow 117393, Russia. RI Buzin, Alexander/H-5482-2011 NR 44 TC 25 Z9 25 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD DEC 23 PY 1999 VL 103 IS 51 BP 11372 EP 11381 DI 10.1021/jp992708+ PG 10 WC Chemistry, Physical SC Chemistry GA 271NY UT WOS:000084601400020 ER PT J AU Rice, JK Fearnley, IM Barker, PD AF Rice, JK Fearnley, IM Barker, PD TI Coupled oxidation of heme covalently attached to cytochrome b(562) yields a novel biliprotein SO BIOCHEMISTRY LA English DT Article ID BIS-METHIONINE LIGATION; REACTION REGIOSPECIFICITY; ELECTRONIC CONTROL; ACTIVE-SITE; OXYGENASE; IRON; BIOSYNTHESIS; PHYCOBILINS; CONVERSION; CATABOLISM AB A variant of Escherichia coli cytochrome b(562) with covalently attached heme can be converted to a biliverdin-containing protein in two distinct stages by coupled oxidation and acid hydrolysis. The first stage of coupled oxidation yields a stable verdoheme-containing protein. This verdoheme protein is unusual in three respects. First, the verdoheme group is covalently bound to the protein through a c-type thioether linkage. Second, the oxidation stops at the verdoheme stage, and finally, this is the first report of verdoheme generated from a heme protein with exclusive methionine ligation to the heme iron. In addition, the oxidation process does not require denaturation of the protein. The product has been characterized by optical spectroscopy, ESI mass spectrometry, and H-1 NMR. The NMR data show that the predominant product is the result of oxidation at the alpha-meso carbon. A collective evaluation of data on the topic suggests that the electronic structure of the heme, not protein steric effects, is the main factor in controlling the regiospecificity of the oxidation site. In the second stage of conversion to a biliprotein, we demonstrate that the verdoheme ring can be opened by treatment with aqueous formic acid to give alpha-biliverdin covalently attached to the folded protein. This product, a protein-bound linear tetrapyrrole as characterized by optical spectroscopy and mass spectrometry, is an example of a phycobilin chromophore that has not been observed previously. C1 MRC Ctr, Ctr Prot Engn, Cambridge CB2 2QH, England. MRC Ctr, Mol Biol Lab, Cambridge CB2 2QH, England. USN, Res Lab, Washington, DC 20375 USA. RP Barker, PD (reprint author), MRC Ctr, Ctr Prot Engn, Hills Rd, Cambridge CB2 2QH, England. NR 35 TC 23 Z9 24 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD DEC 21 PY 1999 VL 38 IS 51 BP 16847 EP 16856 DI 10.1021/bi990880y PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 270YC UT WOS:000084563900016 PM 10606518 ER PT J AU Price, GL AF Price, GL TI On the classification of binary shifts of finite commutant index SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE conjugacy class; subfactor index ID TYPE-II1 FACTORS AB We provide a complete classification up to conjugacy of the binary shifts of finite commutant index on the hyperfinite II1 factor. There is a natural correspondence between the conjugacy classes of these shifts and polynomials over GF(2) satisfying a certain duality condition. C1 USN Acad, Dept Math 9E, Annapolis, MD 21402 USA. RP Price, GL (reprint author), USN Acad, Dept Math 9E, Annapolis, MD 21402 USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD DEC 21 PY 1999 VL 96 IS 26 BP 14700 EP 14705 DI 10.1073/pnas.96.26.14700 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 267TM UT WOS:000084375400009 PM 10611276 ER PT J AU Klein, PB Freitas, JA Binari, SC Wickenden, AE AF Klein, PB Freitas, JA Binari, SC Wickenden, AE TI Observation of deep traps responsible for current collapse in GaN metal-semiconductor field-effect transistors SO APPLIED PHYSICS LETTERS LA English DT Article ID PERSISTENT PHOTOCONDUCTIVITY AB Deep traps responsible for current collapse phenomena in GaN metal-semiconductor field-effect transistors have been detected using a spectroscopic technique that employs the optical reversibility of current collapse to determine the photoionization spectra of the traps involved. In the n-channel device investigated, the two electron traps observed were found to be very deep and strongly coupled to the lattice. Photoionization thresholds for these traps were determined at 1.8 and at 2.85 eV. Both also appear to be the same traps recently associated with persistent photoconductivity effects in GaN. (C) 1999 American Institute of Physics. [S0003-6951(99)04351-X]. C1 USN, Res Lab, Washington, DC 20375 USA. RP Klein, PB (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 16 TC 104 Z9 105 U1 0 U2 15 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 20 PY 1999 VL 75 IS 25 BP 4016 EP 4018 DI 10.1063/1.125523 PG 3 WC Physics, Applied SC Physics GA 265KG UT WOS:000084242700038 ER PT J AU Kaufman, MJ Wolfire, MG Hollenbach, DJ Luhman, ML AF Kaufman, MJ Wolfire, MG Hollenbach, DJ Luhman, ML TI Far-infrared and submillimeter emission from Galactic and extragalactic photodissociation regions SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : ISM; infrared : ISM : lines and bands; infrared : ISM : continuum; ISM : atoms; ISM : molecules; submillimeter ID POLYCYCLIC AROMATIC-HYDROCARBONS; FINE-STRUCTURE TRANSITIONS; PHOTON-DOMINATED REGIONS; 1-0 LINE EMISSION; INTERSTELLAR-MEDIUM; MOLECULAR CLOUDS; STAR-FORMATION; MAGELLANIC CLOUDS; 158 MICRON; C-II AB Photodissociation region (PDR) models are computed over a wide range of physical conditions, from those appropriate to giant molecular clouds illuminated by the interstellar radiation field to the conditions experienced by circumstellar disks very close to hot massive stars. These models use the most up-to-date values of atomic and molecular data, the most current chemical rate coefficients, and the newest grain photoelectric heating rates, which include treatments of small grains and large molecules. In addition, we examine the effects of metallicity and cloud extinction on the predicted line intensities. Results are presented for PDR models with densities over the range n = 10(1)-10(7) cm(-3) and for incident far-ultraviolet radiation fields over the range G(0) = 10(-0.5)-10(6.5) (where G(0) is the far-ultravioliet [FUV] flux in units of the local interstellar value), for metallicities Z = 1 and 0.1 times the local Galactic value, and for a range of PDR cloud sizes. We present line strength and/or line ratio plots for a variety of useful PDR diagnostics: [C II] 158 mu m, [O I] 63 mu m and 145 mu m, [C I] 370 mu m and 609 mu m, CO J = 1-0, J = 2-1, J = 3-2, J = 6-5, and J = 15-14, as well as the strength of the far-infrared continuum. These plots will be useful for the interpretation of Galactic and extragalactic far-infrared and submillimeter spectra observable with the Infrared Space Observatory (ISO), the Stratospheric Observatory for Infrared Astronomy, the Submillimeter Wave Astronomy Satellite, the Far Infrared and Submillimeter Telescope, and other orbital and suborbital platforms. As examples, we apply our results to ISO and ground-based observations of M82, NGC 278, and the Large Magellanic Cloud. Our comparison of the conditions in M82 and NGC 278 show that both the gas density and FUV flux are enhanced in the starburst nucleus of M82 compared with those in the normal spiral NGC 278. We model the high [C II]/CO ratio observed in the 30 Doradus region of the LMC and find that it can be explained either by lowering the average extinction through molecular clouds or by enhancing the density contrast between the atomic layers of PDRs and the CO-emitting cloud cores. The ratio L[CO]/M[H-2] implied by the low extinction model gives cloud masses too high for gravitational stability. We therefore rule out low-extinction clouds as an explanation for the high [C II]/CO ratio and instead appeal to density contrast in A(V) = 10 clouds. C1 San Jose State Univ, Dept Phys, San Jose, CA 95192 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. RP Kaufman, MJ (reprint author), San Jose State Univ, Dept Phys, San Jose, CA 95192 USA. NR 78 TC 396 Z9 396 U1 1 U2 7 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 1999 VL 527 IS 2 BP 795 EP 813 DI 10.1086/308102 PN 1 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 270XD UT WOS:000084561700027 ER PT J AU Kassim, NE Lazio, TJW AF Kassim, NE Lazio, TJW TI Upper limits on the continuum emission from Geminga at 74 and 326 MHz SO ASTROPHYSICAL JOURNAL LA English DT Article DE pulsars : individual (Geminga); radio continuum : stars ID GAMMA-RAY SOURCES; RADIO PULSAR; SCINTILLATION AB We report a search for radio continuum emission from the gamma-ray pulsar Geminga. We have used the VLA to image the location of the optical counterpart of Geminga at 74 and 326 MHz. We detect no radio counterpart. We derive upper limits to the pulse-averaged flux density of Geminga, taking diffractive scintillation into account. We find that diffractive scintillation is probably quenched at 74 MHz and does not influence our upper limit, S < 56 mJy (2 sigma), but that a 95% confidence level at 326 MHz is S < 5 mJy. Owing to uncertainties on the other low-frequency detections and the possibility of intrinsic variability or extrinsic variability (refractive interstellar scintillation) or both, our nondetections are nominally consistent with these previous detections. C1 USN, Res Lab, Washington, DC 20375 USA. RP Kassim, NE (reprint author), USN, Res Lab, Code 7213, Washington, DC 20375 USA. NR 31 TC 10 Z9 10 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 1999 VL 527 IS 2 BP L101 EP L104 DI 10.1086/312406 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 270XE UT WOS:000084561800008 ER PT J AU Bayer, M Gutbrod, T Forchel, A Reinecke, TL Knipp, P Werner, R Reithmaier, JP AF Bayer, M Gutbrod, T Forchel, A Reinecke, TL Knipp, P Werner, R Reithmaier, JP TI Optical demonstration of a crystal band structure formation SO PHYSICAL REVIEW LETTERS LA English DT Article ID PERIODIC DIELECTRIC STRUCTURES; NEAR-INFRARED WAVELENGTHS; SPONTANEOUS EMISSION; PHOTONIC CRYSTALS; QUANTUM BOXES; WAVE-GUIDES; MODES; TRANSMISSION; MICROCAVITY; PROPAGATION AB The optical modes of chains of coupled micron sized semiconductor cavities have been studied using photoluminescence spectroscopy and detailed calculations. With an increasing number of cavities, the chains exhibit photon band gaps at several Brillouin zone boundaries. The sizes of the band Sops are shown to depend on the coupling between the microcavities and also on the order of the Brillouin zone involved. C1 Univ Wurzburg, D-97074 Wurzburg, Germany. USN, Res Lab, Washington, DC 20375 USA. Christopher Newport Univ, Newport News, VA 23606 USA. RP Bayer, M (reprint author), Univ Wurzburg, Hubland, D-97074 Wurzburg, Germany. RI Reithmaier, Johann/G-8171-2012; OI Reithmaier, Johann/0000-0002-1974-8292; Forchel, Alfred/0000-0002-9377-9935 NR 27 TC 67 Z9 68 U1 0 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 20 PY 1999 VL 83 IS 25 BP 5374 EP 5377 DI 10.1103/PhysRevLett.83.5374 PG 4 WC Physics, Multidisciplinary SC Physics GA 266LH UT WOS:000084301100048 ER PT J AU Le Sage, GP Cowan, TE Fiorito, RB Rule, DW AF Le Sage, G. P. Cowan, T. E. Fiorito, R. B. Rule, D. W. TI Transverse phase space mapping of relativistic electron beams using optical transition radiation SO PHYSICAL REVIEW SPECIAL TOPICS-ACCELERATORS AND BEAMS LA English DT Article AB Optical transition radiation (OTR) has proven to be a versatile and effective diagnostic for measuring the profile, divergence, and emittance of relativistic electron beams with a wide range of parameters. Diagnosis of the divergence of modern high brightness beams is especially well suited to OTR interference (OTRI) techniques, where multiple dielectric or metal foils are used to generate a spatially coherent interference pattern. Theoretical analysis of measured OTR and OTRI patterns allows precise measurement of electron beam emittance characteristics. Here we describe an extension of this technique to allow mapping of divergence characteristics as a function of transverse coordinates within a measured beam. We present the first experimental analysis of the transverse phase space of an electron beam using all optical techniques. Comparing an optically masked portion of the beam to the entire beam, we measure different angular spread and average direction of the particles. Direct measurement of the phase-space ellipse tilt angle has been demonstrated using this optical masking technique. C1 [Le Sage, G. P.; Cowan, T. E.] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. [Fiorito, R. B.] Catholic Univ Amer, Washington, DC 20064 USA. [Rule, D. W.] Naval Surface Warfare Ctr, Carderock Div, West Bethesda, MD 20817 USA. RP Le Sage, GP (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Cowan, Thomas/A-8713-2011 OI Cowan, Thomas/0000-0002-5845-000X FU U.S. Department of Energy by the Lawrence Livermore National Laboratory [W-7405-Eng-48] FX We would like to acknowledge the expert assistance of G. G. Anderson, R. P. Hall, and W. S. Patterson in fielding these experiments. This work was performed under the auspices of the U.S. Department of Energy by the Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48. NR 6 TC 8 Z9 8 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-4402 J9 PHYS REV SPEC TOP-AC JI Phys. Rev. Spec. Top.-Accel. Beams PD DEC 20 PY 1999 VL 2 IS 12 AR 122802 PG 7 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA V38AX UT WOS:000209317400001 ER PT J AU Gindulyte, A Massa, L Huang, LL Karle, J AF Gindulyte, A Massa, L Huang, LL Karle, J TI Ab initio study of unimolecular decomposition of nitroethylene SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID AMINE SENSITIZATION; NITROMETHANE; MECHANISM; DISSOCIATION AB Four distinct pathways of unimolecular decomposition of nitroethylene, the C-NO2 bond breaking, nitroto-nitrite rearrangement, 1,2-elimination reaction and 1,1-elimination reaction, have been computationally investigated with ab initio, MP2, MP4, and G2 methods as well as with DFT methods, The nitro-to-nitrite rearrangement and 1,2-elimination reaction ate found to give the lowest energy decomposition pathways for this molecule, about 15 kcal/mol lower than the cleavage of the nitro group. C1 USN, Res Lab, Struct Matter Lab, Washington, DC 20375 USA. CUNY Hunter Coll, Dept Chem, New York, NY 10021 USA. CUNY, Grad Sch, New York, NY 10036 USA. Geocenters Inc, Ft Washington, MD 20744 USA. RP Karle, J (reprint author), USN, Res Lab, Struct Matter Lab, Washington, DC 20375 USA. NR 26 TC 33 Z9 33 U1 2 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD DEC 16 PY 1999 VL 103 IS 50 BP 11040 EP 11044 DI 10.1021/jp991793i PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 268PP UT WOS:000084425000050 ER PT J AU Gindulyte, A Massa, L Huang, LL Karle, J AF Gindulyte, A Massa, L Huang, LL Karle, J TI Proposed mechanism of 1,1-diamino-dinitroethylene decomposition: A density functional theory study SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID CONDENSED-PHASE DECOMPOSITION; AB-INITIO; THERMAL-DECOMPOSITION; ENERGETIC MATERIALS; RDX; 1,3,5-TRINITROHEXAHYDRO-S-TRIAZINE AB We have investigated the heretofore unknown unimolecular decomposition pathway of the explosive molecule diaminodinitroethylene (DADNE). With the use of DFT methods, whose accuracy has been calibrated by means of ab initio calculations (MP2, MP4, G2) on a simpler but related molecule, nitroethylene, we have been able to characterize the entire decomposition reaction pathway. Importantly, we find that the reaction is initiated by a nitro-to-nitrite rearrangement with a calculated energy barrier of magnitude 59.1 kcal/mol obtained by use of B3LYP (59.7 kcal/mol B3P86) which is very close to the experimental activation energy of 58 kcal/mol. We have been able to characterize every step in the decomposition reaction path leading to fragments NO, HONO, CO, NH2, and HNC. These may interact to yield final stable products, CO, N-2, H2O with an energy release that on average is adequate to initiate two additional DADNE molecular decompositions, and thus, sustain a chain reaction. The structural parameters we have calculated for DADNE are consistent with the known experimental crystallographic structure, and also with previous theoretical calculations. Additionally, we have obtained the structural parameters of the initial transition state, as well as each subsequent step along the decomposition pathway. Thus we consider the unimolecular decomposition of DADNE to be well characterized. C1 USN, Res Lab, Struct Matter Lab, Washington, DC 20375 USA. CUNY Hunter Coll, Dept Chem, New York, NY 10021 USA. CUNY, Grad Sch, New York, NY 10036 USA. Geocenters Inc, Ft Washington, MD 20744 USA. RP Karle, J (reprint author), USN, Res Lab, Struct Matter Lab, Washington, DC 20375 USA. NR 27 TC 92 Z9 95 U1 1 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD DEC 16 PY 1999 VL 103 IS 50 BP 11045 EP 11051 DI 10.1021/jp991794a PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 268PP UT WOS:000084425000051 ER PT J AU Reames, DV Ng, CK Tylka, AJ AF Reames, DV Ng, CK Tylka, AJ TI Energy-dependent ionization states of shock-accelerated particles in the solar corona SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MEAN IONIC CHARGE; FAST HEAVY-IONS; PLASMA; NUCLEON AB We examine the range of possible energy dependence of the ionization states of ions that are shock-accelerated from the ambient plasma of the solar corona. If acceleration begins in a region of moderate density, sufficiently low in the corona, ions above similar to 0.1 MeV/amu approach an equilibrium charge state that depends primarily upon their speed and only weakly on the plasma temperature. We suggest that the large variations of the charge states with energy for ions such as Si and Fe observed in the 1997 November 6 event are consistent with stripping in moderately dense coronal plasma during shock acceleration. In the large solar-particle events studied previously, acceleration occurs sufficiently high in the corona that even Fe ions up to 600 MeV/amu are not stripped of electrons. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. RP Reames, DV (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. RI Tylka, Allan/G-9592-2014 NR 30 TC 48 Z9 48 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 15 PY 1999 VL 26 IS 24 BP 3585 EP 3588 DI 10.1029/1999GL003656 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 271JQ UT WOS:000084590800002 ER PT J AU Ngai, KL Yamamuro, O AF Ngai, KL Yamamuro, O TI Thermodynamic fragility and kinetic fragility in supercooling liquids: A missing link in molecular liquids SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GLASS-FORMING LIQUIDS; CONFIGURATIONAL ENTROPY; DIELECTRIC-RELAXATION; DYNAMICS; CRYSTALLIZATION; 3-BROMOPENTANE; TEMPERATURE; TERPHENYL; TOLUENE; TIME AB Ito, Moynihan, and Angell [Nature 398, 492 (1999)] compared the kinetic and thermodynamic measures of a glassformer's "fragility." For the liquids they considered which include molecular, covalent, and ionic substances, thermodynamic fragility and kinetic fragility follow the same order, suggesting that the thermodynamic data alone may be sufficient to determine the kinetic fragility of a liquid. Here we restrict the comparison to a large number of molecular glass-forming liquids, and find breakdowns of the proposed correlation. The absence of an immediate connection between thermodynamic and kinetic fragilities at least in molecular liquids may be due to the effect of kinetic factors and cooperative many-body molecular dynamics. The development of a relation between them requires taking into consideration the cooperative many-body molecular dynamics. The latter governs, in conjunction with thermodynamics, the kinetics of glass-forming liquids, and thus is the missing link between the two. (C) 1999 American Institute of Physics. [S0021-9606(99)70547-7]. C1 USN, Res Lab, Washington, DC 20375 USA. Osaka Univ, Grad Sch Sci, Dept Chem, Toyonaka, Osaka 560, Japan. Osaka Univ, Grad Sch Sci, Microcalorimetry Res Ctr, Toyonaka, Osaka 560, Japan. RP Ngai, KL (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 24 TC 73 Z9 74 U1 0 U2 17 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 15 PY 1999 VL 111 IS 23 BP 10403 EP 10406 DI 10.1063/1.480394 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 260AY UT WOS:000083927200001 ER PT J AU Fonda, RW Jones, HN AF Fonda, RW Jones, HN TI Microstructure, crystallography, and shape memory effect in equiatomic NbRu SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT International Conference on Martensitic Transformations CY DEC 07-11, 1998 CL SAN CARLOS BARILO, ARGENTINA SP Fdn Antorchas, Consejo Nacl Invest Cient Tecnicas, Inst Invest Cient & Tecnicas Fuerzas Armadas DE shape memory effect; microstructure; crystallography; equiatomic NbRu; high temperature shape memory effect ID TARU AB The microstructure and crystallography of equiatomic NbRu were examined by transmission electron microscopy (TEM) and electron diffraction. This alloy exhibits a highly twinned microstructure identical to that in the similar TaRu system. Electron diffraction demonstrates that, like TaRu, the room-temperature crystal structure of NbRu is not orthorhombic as had been previously reported, but is instead monoclinic. The transformation which forms this monoclinic structure produces a high concentration of antiphase domain boundaries and some delta-domain boundaries within the twinned microstructure. The shape memory effect in NbRu was demonstrated by reheating bent samples to above the high-temperature tetragonal-to-cubic transformation temperature and observing the decrease in bend angle. Initial tests demonstrate a strain recovery of 4% at the tensile surface. (C) 1999 Elsevier Science S.A. All rights reserved. C1 USN, Res Lab, Div Mat Sci & Technol, Washington, DC 20375 USA. RP Fonda, RW (reprint author), USN, Res Lab, Div Mat Sci & Technol, Code 6324, Washington, DC 20375 USA. EM fonda@anvil.nrl.navy.mil NR 17 TC 36 Z9 36 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD DEC 15 PY 1999 VL 273 SI SI BP 275 EP 279 DI 10.1016/S0921-5093(99)00354-8 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 270WP UT WOS:000084560400036 ER PT J AU Oran, ES Khokhlov, AM AF Oran, ES Khokhlov, AM TI Deflagrations, hot spots, and the transition to detonation SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article DE shock-flame interactions; deflagration-to-detonation transition; hot spots; turbulent flames; explosions ID INITIATION; FLAMES AB A series of multidimensional numerical simulations were used to investigate how, through a series of shock-flame interactions, a turbulent flame may suddenly evolve into a detonation, the process of deflagration-to-detonation transition (DDT). The reactive Navier-Stokes equations were solved on an adaptive mesh that resolved selected features of the flow including the structure of the laminar flame. The chemical and thermophysical models used reproduced the flame and detonation properties of acetylene in air over a range of temperatures and pressures. The interactions of an incident shock with the initially laminar flame led to the formation of secondary shocks, rarefactions, and contact surfaces that continued to distort the flame surface, eventually creating a turbulent flame brush. Pressure fluctuations, generated by shock-flame interactions in the flame brush, were the seeds for hot spots in unreacted material. The simulations showed that these hot spots underwent transition to a detonation when the gradients in induction time in the hot spot allowed the formation of spontaneous waves. An unsuccessful explosion in hot spots formed a shock with a flame left behind it. As the strength of the initial incident shock was increased, the location of DDT shifted from outside the flame brush to inside the flame brush. The main features of the simulated DDT process show trends similar to those observed in experiments. C1 USN, Computat Phys & Fluid Dynam Lab, Res Lab, LCP&FD, Washington, DC 20375 USA. RP USN, Computat Phys & Fluid Dynam Lab, Res Lab, LCP&FD, Code 6404, Washington, DC 20375 USA. NR 22 TC 23 Z9 25 U1 1 U2 5 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-503X EI 1471-2962 J9 PHILOS T R SOC A JI Philos. Trans. R. Soc. A-Math. Phys. Eng. Sci. PD DEC 15 PY 1999 VL 357 IS 1764 BP 3539 EP 3551 DI 10.1098/rsta.1999.0508 PG 13 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 279LY UT WOS:000085046300005 ER PT J AU Nishikawa, H Stahlbush, RE Stathis, JH AF Nishikawa, H Stahlbush, RE Stathis, JH TI Oxygen-deficient centers and excess Si in buried oxide using photoluminescence spectroscopy SO PHYSICAL REVIEW B LA English DT Article ID SIMOX STRUCTURES; ION-IMPLANTATION; SILICON; ELECTRON; SIO2-FILMS; DEFECTS; LUMINESCENCE; EXCITATION; LAYERS; HOLE AB Defects in buried oxide (BOX) in Si prepared from the separation by implantation of oxygen (SIMOX) technique under various preparation conditions such as doses of oxygen [(0.39-1.9)X 10(18) cm(-2)] and anneal temperatures (1310-1350 degrees C) were investigated by a photoluminescence technique using synchrotron radiation as a light source. Under excitation at 5.0 eV at room temperature, all the SIMOX BOX samples typically exhibit a broad photoluminescence (PL) band in the range of 2-3 eV, which can be deconvoluted into three Gaussian components at 3.1, 2.6-2.8, and 2.4 eV. The 3.1- and 2.6-2.8-eV bands have lifetimes of about 2-45 ns, while the 2.4-eV band has a much longer lifetime. In addition, some high-dose SIMOX BOX's prepared with multiple oxygen implant steps show a 4.4-eV PL band with a lifetime of about 4 ns associated with a form of oxygen-deficient centers (ODC's) called ODC(II) in a-SiO2, which were suppressed by a supplemental oxygen implantation. The behavior of the short-lived 2-3-eV PL components was sensitive to the oxygen doses and anneal temperatures, and conditions that tended to increase the 2-3-eV PL tended to decrease the 4.4-eV band. Etchback experiments of the BOX layer show that the defects responsible for the 2-3-eV band were located at the BOX close to the superficial Si/BOX interface, while those for the 4.4-eV band exist throughout the whole BOX layer. Comparison with high-temperature oxide grown on Si at 1350 degrees C suggests that the postimplantation, high-temperature anneal results in the generation of defects responsible for the short-lived 2-3-eV bands. Based on the similarities with the PL bands in Si clusters in SiO2, we conclude that the 2-3-eV bands in the BOX's are associated with Si clusters in SiO2. [S0163-1829(99)03247-6]. C1 Tokyo Metropolitan Univ, Dept Elect Engn, Tokyo 1920397, Japan. USN, Res Lab, Washington, DC 20375 USA. IBM Corp, Thomas J Watson Res Ctr, Yorktown Heights, NY 10598 USA. RP Nishikawa, H (reprint author), Tokyo Metropolitan Univ, Dept Elect Engn, 1-1 Minami Osawa, Tokyo 1920397, Japan. OI Stathis, James/0000-0001-8340-2475 NR 27 TC 37 Z9 37 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD DEC 15 PY 1999 VL 60 IS 23 BP 15910 EP 15918 DI 10.1103/PhysRevB.60.15910 PG 9 WC Physics, Condensed Matter SC Physics GA 272BZ UT WOS:000084631800077 ER PT J AU Singh, DJ Blaha, P Schwarz, K Mazin, II AF Singh, DJ Blaha, P Schwarz, K Mazin, II TI Electronic structure and heavy-fermion behavior in LiV2O4 SO PHYSICAL REVIEW B LA English DT Article ID SYSTEMS AB First principles density functional calculations of the electronic and magnetic properties of spinel-structure LiV2O4 have been performed using the full potential linearized augmented plane-wave method. The calculations show that the electronic structure near the Fermi energy consists of a manifold of 12 bands derived from V t(2g) states, weakly hybridized with O p states. While the total width of this active manifold is approximately 2 eV, it may be roughly decomposed into two groups: high velocity bands and flatter bands, although these mix in density functional calculations. The flat bands, which an the more atomiclike, lead to a high density of states and magnetic instability of local moment character. The value of the on-site exchange energy is sensitive to the exact exchange correlation parametrization used in the calculations, but is much larger than the interaction between neighboring spins, reflecting the weak coupling of the magnetic system with the high velocity bands. A scenario for the observed heavy-fermion behavior is discussed, in which conduction electrons in the dispersive bands are weakly scattered by local moments associated with strongly correlated electrons in the heavy bands. This is analogous to that in conventional Kondo-type heavy fermions, but is unusual in that both the local moments and conduction electrons come from the same d manifold. [S0163-1829(99)00548-2]. C1 USN, Res Lab, Washington, DC 20375 USA. Tech Univ Vienna, Inst Phys & Theoret Chem, A-1060 Vienna, Austria. RP Singh, DJ (reprint author), USN, Res Lab, Code 6391, Washington, DC 20375 USA. RI Mazin, Igor/B-6576-2008; Blaha, Peter/F-2847-2010; Singh, David/I-2416-2012 NR 20 TC 48 Z9 48 U1 0 U2 6 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD DEC 15 PY 1999 VL 60 IS 24 BP 16359 EP 16363 DI 10.1103/PhysRevB.60.16359 PG 5 WC Physics, Condensed Matter SC Physics GA 274XX UT WOS:000084791300027 ER PT J AU Marangolo, M Bellin, C Loupias, G Rabii, S Erwin, SC Buslaps, T AF Marangolo, M Bellin, C Loupias, G Rabii, S Erwin, SC Buslaps, T TI Experimental and theoretical study of electron momentum density of A(n)C(60) (n=3,4) and comparison to pristine C-60 SO PHYSICAL REVIEW B LA English DT Article ID LITHIUM-INTERCALATED GRAPHITE; COMPTON-SCATTERING; PROFILES; CRYSTALS AB Compton profile measurements on KnC60 (n=3 and 4), CsRb2C60, Rb4C60, and C-60 powders have been carried out using inelastically scattered photons. We compare the experimental Compton profile difference (CPD) of KnC60 (n = 3,4) and that of C-60 with the corresponding calculated results, obtained from ab initio self-consistent field calculations of the energy band structure. This permits us to isolate the contribution of the distortion of the C60 orbitals for each compound and to compare them, as a function of alkali intercalation. For all the samples we have obtained an overall agreement between theory and experiment. Nevertheless, in the case of K4C60, the comparison between the calculated and measured CPD's widths is not satisfactory. The calculated width is larger than the experimental results. Furthermore, similar measurements performed on heavy ions intercalated compounds (Rb4C60 and Rb2CsC60) show clearly that CPD depends on the number of ions and not on their nature. We put forward two possible hypotheses in order to explain the mismatch between theoretical and experimental CPD's of K4C60: (1) The orientations of C-60 molecules in these compounds vary with n and they are not taken in account by calculations. (2) Jahn-Teller effect for the negatively charged C-60 molecule in the solid. [S0163-1829(99)12447-0]. C1 Univ Paris 06, Lab Mineral Cristallog Paris, F-75252 Paris 05, France. Univ Paris 07, CNRS, URA 7590, F-75252 Paris 05, France. Univ Penn, Dept Elect Engn, Philadelphia, PA 19104 USA. NRL, Complex Syst Theory Branch, Washington, DC 20375 USA. European Synchrotron Radiat Facil, F-38043 Grenoble, France. Univ Paris Sud, Lab Utilisat Rayonnement Electromagnet, F-91405 Orsay, France. RP Marangolo, M (reprint author), Univ Paris 06, Lab Mineral Cristallog Paris, Case 115,4 Pl Jussieu, F-75252 Paris 05, France. RI Erwin, Steven/B-1850-2009 NR 32 TC 2 Z9 2 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD DEC 15 PY 1999 VL 60 IS 24 BP 17084 EP 17090 DI 10.1103/PhysRevB.60.17084 PG 7 WC Physics, Condensed Matter SC Physics GA 274XX UT WOS:000084791300110 ER PT J AU Nindos, A Kundu, MR White, SM Gary, DE Shibasaki, K Dere, KP AF Nindos, A Kundu, MR White, SM Gary, DE Shibasaki, K Dere, KP TI Microwave and extreme ultraviolet observations of solar polar regions SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : corona; Sun : radio radiation; Sun : UV radiation ID TRANSIENT BRIGHTENINGS; IMAGING TELESCOPE; CORONAL HOLES; SOHO; SUN; EIT; PLUMES; CAP AB The poles of the Sun are brighter than the rest of the quiet Sun's emission in a limited range of radio frequencies from 17 GHz to 87 GHz. We have studied microwave images of the quiet Sun made with the Nobeyama radioheliograph at 17 GHz. They show,that the so-called polar-cap brightening consists of two components: a diffuse component of 1500 K excess brightness and patchy compact sources with localized excess brightness of about 3500 K. We test the reality of the compact sources using the maximum entropy method deconvolution. The total flux and the number of compact polar sources as well as the north-south extent of the diffuse polar emission are larger in the pole that is closest to the Earth. We compared the microwave polar emission with nearly simultaneous SOHO EIT images taken in the lines of He II. at 304 Angstrom and Fe XII at 195 Angstrom. No one-to-one correlation between the compact radio sources and the bright EUV features was found: most of the radio emission arises between the plumes visible to EIT. The boundaries of the polar-cap brightenings did not match exactly the boundaries of the coronal holes as seen in either the Fe XII 195 Angstrom images or the He II 304 Angstrom images. The temporal variations of the compact microwave sources did not correspond to any significant changes in EUV emission. On the other hand, most He II 304 Angstrom changing features were associated with the diffuse polar microwave emission, which was practically constant. Our data suggest that the origin of the polar brightening is not coronal; it seems that the bulk of the patchy radio emission comes from heights below the 80,000 K layer. C1 Univ Maryland, Dept Astron, College Pk, MD 20742 USA. New Jersey Inst Technol, Dept Phys, Newark, NJ 07102 USA. Nobeyama Radio Observ, Minamisa Ku, Nagano 38413, Japan. USN, Res Lab, Washington, DC 20375 USA. RP Nindos, A (reprint author), Univ Maryland, Dept Astron, College Pk, MD 20742 USA. OI Gary, Dale/0000-0003-2520-8396 NR 31 TC 30 Z9 31 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 1999 VL 527 IS 1 BP 415 EP 425 DI 10.1086/308072 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265EA UT WOS:000084227300037 ER PT J AU Doschek, GA AF Doschek, GA TI The electron temperature and fine structure of soft X-ray solar flares SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : flares; Sun : X-rays; gamma rays ID EMISSION MEASURE; BRIGHT KNOTS; YOHKOH; SPECTRA; TELESCOPE; CALCIUM; RATIOS; PLASMA; LOOPS; TOPS AB I discuss the determination of the electron temperature of soft X-ray solar flares using data obtained from the iron-line Bragg Crystal Spectrometer (BCS) and Soft X-ray Telescope (SXT) instruments on the Yohkoh spacecraft. I find that there is a substantial difference in the derived temperatures obtained from the two instruments, with the highest temperatures obtained from the BCS. However, in some regions of certain flares, the SXT temperatures equal the temperatures expected from the iron-line spectra. These hot regions are almost always considerably weaker in intensity than the brightest regions in the SXT flare images. I discuss the relationship of the SXT hot regions to the brightest regions in the flare and show that, at least in some cases, the hot SXT regions appear to be related to the hard X-ray flare component. I also show that the temperature data from the two instruments can be reconciled by concluding that flare loops that appear to be single loops are actually collections of loops with different temperatures on arcsecond or less spatial scales. This result was obtained indirectly by Doschek, Strong, & Tsuneta in 1995 from an analysis of SXT flare images and is substantiated so far by flare images from TRACE. The appearance of a soft X-ray flare depends critically on the electron temperature response of the imaging instrumentation. C1 USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. RP Doschek, GA (reprint author), USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. NR 28 TC 19 Z9 20 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 1999 VL 527 IS 1 BP 426 EP 434 DI 10.1086/308070 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265EA UT WOS:000084227300038 ER PT J AU Laming, JM Feldman, U AF Laming, JM Feldman, U TI Relationships among the intensities of Li-, Be-, and Na-like resonance lines in collisionally ionized astrophysical plasmas (10(5) <= T-e <= 10(7) K) SO ASTROPHYSICAL JOURNAL LA English DT Article DE line : formation; plasmas; stars : coronae; Sun : abundances; Sun : corona ID STELLAR CORONAL ABUNDANCES; SUPERNOVA REMNANT; SNR 1987A; X-RAY; SOLAR; SPECTROMETER; IONIZATION; EMISSION; EXCITATION; PROCYON AB The strongest lines emitted from optically thin collisionally ionized astrophysical plasmas are usually those of the Li-, Be-, and Na-like sequences. When numerous other weaker lines are also measurable in the spectrum, the derivation of relative element abundances is reasonably straightforward. However, for many sources only the strongest lines will be observed, so here we explore under what conditions it may be possible to determine relative element abundances in this case. We find that several temperature regions exist in which the ratios of these strong lines can be fairly insensitive to temperature. We discuss applications to solar/stellar coronae, the interstellar medium, and SN 1987A. Additionally under certain conditions in the solar corona ratios of Li-like line intensities to those of He II are found to allow relatively straightforward determinations of the He abundance. C1 SFA Inc, Largo, MD 20774 USA. USN, Res Lab, Washington, DC 20375 USA. RP Laming, JM (reprint author), SFA Inc, Largo, MD 20774 USA. NR 44 TC 14 Z9 14 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 1999 VL 527 IS 1 BP 461 EP 469 DI 10.1086/308064 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 265EA UT WOS:000084227300041 ER PT J AU Ranganathan, D Haridas, V Sundari, CS Balasubramanian, D Madhusudanan, KP Roy, R Karle, IL AF Ranganathan, D Haridas, V Sundari, CS Balasubramanian, D Madhusudanan, KP Roy, R Karle, IL TI Design, synthesis, crystal structure, and host-guest properties of polymethylene-bridged cystine-based cyclobisamides: A facile entry into hydrogen-bonded peptide nanotubes SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID NANOSCALE TUBULAR ENSEMBLES; TRANSMEMBRANE ION CHANNELS; FLUORESCENCE; MEMBRANES; PYRENE; DIFFUSION; ZEOLITE AB A general design strategy for the synthesis of cystine-based peptide nanotubes is described. The design essentially involves closing of the polymethylene chains with cystine diOMe. The cystine-based nanotubes are constructed by the self-assembly of a simple cyclobisamide building block, a key structural feature of which is the presence of two amide groups at almost opposite poles of the ring. A large variety of cyclobisamides with the general structure cyclo(-CO-(CH2)(n)-CO-Cyst-) have been prepared by a single-step procedure involving the condensation of 1,omega-alkane dicarbonyl dichloride [(CH2)(n)(COCl)(2), n = 2, 3,..., 10, 20] with cystine diOMe providing macrocyclic bisamides with ring size varying from 14 to 30 members. Single-crystal X-ray studies with four members (n = 4, 6, 8, and 10, respectively) have shown that the polymethylene-bridged cystine-based cyclobisamides possess the intrinsic property of self-assembling into highly ordered parallel arrays of solid-state nanotubes. The hydrogen-bonded cystine tubes are hollow and open ended and extend to infinity. The interior of the tubes is totally hydrophobic. As a result, the polymethylene-bridged peptide tubes (a) are able to enhance the solubility of highly lipophilic compounds in water, as demonstrated here, with pyrene and perylene polycyclic arenes, (b) are able to bind to fluorescent probe dyes such as Nile Red, and (c) can even induce an ordered secondary structure in linear peptides as shown here with the 26-residue bee-venom peptide melittin, in the 30-membered cystine tubule. Crystallographic parameters are (C14H22N2O6S2, P2(1)2(1)2) a = 16.489(1) Angstrom, b = 23.049(1) Angstrom, c = 4.864(1) Angstrom; (C16H26N2O6S2, P2(1)2(1)2) a = 19.171(2) Angstrom, b = 21.116(2) Angstrom, c = 5.0045(4) Angstrom; (C18H30N2O6S2 , P2(1)2(1)2(1)) a = 5.022(1) Angstrom, b = 17.725(3) Angstrom, c = 25.596(2) Angstrom; and (C20H34N2O6S2, C2) a = 40.698(15) Angstrom, b = 5.083(3) Angstrom, c 12.105(5) Angstrom, beta = 99.66(3)degrees. C1 Indian Inst Chem Technol, Discovery Lab, Hyderabad 500007, Andhra Pradesh, India. LV Prasad Eye Inst, Eye Res Fdn, Hyderabad 500034, Andhra Pradesh, India. Ctr Cellular & Mol Biol, Hyderabad 500007, Andhra Pradesh, India. Cent Drug Res Inst, Lucknow 226001, Uttar Pradesh, India. USN, Res Lab, Struct Matter Lab, Washington, DC 20375 USA. RP Ranganathan, D (reprint author), Indian Inst Chem Technol, Discovery Lab, Hyderabad 500007, Andhra Pradesh, India. RI V, haridas/K-2992-2012 NR 36 TC 35 Z9 36 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3263 J9 J ORG CHEM JI J. Org. Chem. PD DEC 10 PY 1999 VL 64 IS 25 BP 9230 EP 9240 DI 10.1021/jo991378m PG 11 WC Chemistry, Organic SC Chemistry GA 265XC UT WOS:000084270600037 ER PT J AU Azoulay, B Wasserman, E Brown, HC Castro, G Thackray, A Roy, R Olah, GA Pavlath, AE Bovenschulte, RD Lilley, D Massie, SP Raber, DJ Price, DB Walter, PHL Pearce, EM Hamamoto, R AF Azoulay, B Wasserman, E Brown, HC Castro, G Thackray, A Roy, R Olah, GA Pavlath, AE Bovenschulte, RD Lilley, D Massie, SP Raber, DJ Price, DB Walter, PHL Pearce, EM Hamamoto, R TI Millennial musings SO CHEMICAL & ENGINEERING NEWS LA English DT Editorial Material C1 Elf Atochem N Amer, Philadelphia, PA 19103 USA. Purdue Univ, W Lafayette, IN 47907 USA. San Jose State Univ, Coll Sci, San Jose, CA 95192 USA. Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. Univ So Calif, Loker Hydrocarbon Res Inst, Los Angeles, CA 90089 USA. USDA, Western Reg Res Ctr, Washington, DC 20250 USA. Amer Chem Soc, Publicat Div, Washington, DC 20036 USA. USN Acad, Annapolis, MD 21402 USA. Natl Res Council, Board Chem Sci & Technol, Washington, DC 20418 USA. BF Goodrich Co, Performance Mat, Akron, OH 44333 USA. Petrochem Corp Singapore, Singapore, Singapore. RP Azoulay, B (reprint author), Elf Atochem N Amer, Philadelphia, PA 19103 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0009-2347 J9 CHEM ENG NEWS JI Chem. Eng. News PD DEC 6 PY 1999 VL 77 IS 49 BP 118 EP + PG 6 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 262KC UT WOS:000084065300064 ER PT J AU Ngai, KL AF Ngai, KL TI Alternative explanation of the difference between translational diffusion and rotational diffusion in supercooled liquids SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID GLASS-FORMING LIQUIDS; MOLECULAR-DYNAMICS SIMULATION; PHOTON-CORRELATION SPECTROSCOPY; NUCLEAR-SPIN RELAXATION; MISCIBLE POLYMER BLENDS; COUPLING MODEL ANALYSIS; LOCAL SEGMENTAL MOTION; SHORT-TIME DYNAMICS; AMORPHOUS POLYMERS; VISCOELASTIC PROPERTIES AB We offer an alternative explanation of the breakdown of Debye-Stokes-Einstein and Stokes-Einstein relations observed as enhanced translational diffusion compared with rotational diffusion of probe molecules in supercooled liquids and polymers close to the glass transition temperature. By showing that the breakdowns of Debye-Stokes-Einstein and Stokes-Einstein relations in glass-forming liquids are special cases of a more general phenomenon, it becomes clear that a more general explanation than spatially heterogeneous dynamics is needed. In the framework of the coupling model, the explanation is based on the fact that different dynamic variables mu weigh the intermolecular cooperativity differently and have different coupling parameters (i.e., degrees of intermolecular cooperativity), n(mu), which enter into the stretch exponents of their correlation functions, [mu(0)mu(t)] = exp[-(t/tau(mu))(1-n mu)], represented in the Kohlrausch form. In some of the applications we made, the values of n(mu)'s are known from experiment and the difference between them is absolutely clear. The explanation of the difference between the tau(mu)'s and their temperature dependencies then becomes quantitative, requiring no adjustable parameter (Ngai, K. L.; Mashimo, S.; Fytas, G. Macromolecules 1988, 21, 3030). An exception is the present explanation of the breakdown of Stokes-Einstein relation where experimental technique has not yet been developed to determine the microscopic correlation function and, hence, the coupling parameter of translational diffusion. The explanation from the coupling model is based on the assumption that the known coupling parameter of rotational diffusion is larger than that of translational diffusion, which has been justified on theoretical grounds and can be falsified experimentally when the latter becomes known in the future. The effect depends on the degree of probe participation in the cooperative dynamics with the host molecules characterized by the ratio, tau(c)/tau(alpha), of the probe rotational relaxation time tau(c) to the alpha-relaxation time of the neat host tau(alpha). The observed variation in the magnitude of the enhanced translation with the size of the probes in supercooled liquids and polymers is explained. In the process, we have established a correlation between the enhanced translation and tau(c)/tau(alpha) as well as a correlation between the Kohlrausch exponent beta of the rotation correlation function and tau(c)/tau(alpha). These two correlations when combined give rise to the correlation between enhanced translational diffusion and (1-beta) established earlier by Ediger and co-workers. The present explanation of enhanced translational diffusion can also explain the recent findings of (a) a parallel enhancement of dielectric relaxation in supercooled liquids by Chang and Sillescu and (b) a breakdown of. the Debye-Stokes-Einstein relation of deploarized light scattering data of diglycidyl ether of bisphenol A by Comet et al. On the other hand, the spatially heterogeneous dynamics explanation of enhanced translation no longer can explain these results. C1 USN, Res Lab, Washington, DC 20375 USA. Tokyo Inst Technol, Fac Sci, Tokyo 1528551, Japan. RP Ngai, KL (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 87 TC 89 Z9 89 U1 0 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD DEC 2 PY 1999 VL 103 IS 48 BP 10684 EP 10694 DI 10.1021/jp990554s PG 11 WC Chemistry, Physical SC Chemistry GA 263EZ UT WOS:000084113300020 ER PT J AU Lai, JCS Platzer, MF AF Lai, JCS Platzer, MF TI Jet characteristics of a plunging airfoil SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 36th Aerospace Sciences Meeting CY JAN 12-15, 1998 CL RENO, NEVADA SP Amer Inst Aeronaut & Astronaut ID OSCILLATING AIRFOIL; FOILS; PROPULSION; WAKE AB Water tunnel tests of a NACA 0012 airfoil that was oscillated sinusoidally in plunge are described. The flowfield downstream of the airfoil was explored by dye flow visualization and single component laser Doppler velocimetry (LDV) measurements for a range of freestream speeds, frequencies, and amplitudes of oscillation. The dye visualizations show that the vortex patterns generated by the plunging airfoil change from drag-producing wake flows to thrust-producing jet flows as soon as the ratio of maximum plunge velocity to freestream speed, i.e., the nondimensional plunge velocity, exceeds approximately 0.4. The LDV measurements show that the nondimensional plunge velocity is the appropriate parameter to collapse the maximum streamwise velocity data covering a nondimensional plunge velocity range from 0.18 to 9.3. The maximum streamwise velocity at a given streamwise distance downstream starts to exceed the freestream speed as soon as the nondimensional plunge velocity exceeds 0.25, Furthermore, this maximum jet velocity has been shown to be a linear function of the nondimensional plunge velocity. C1 USN, Postgrad Sch, Dept Aeronaut & Astronaut, Monterey, CA 93943 USA. RP Lai, JCS (reprint author), USN, Postgrad Sch, Dept Aeronaut & Astronaut, Monterey, CA 93943 USA. OI Lai, Joseph/0000-0002-8946-9993 NR 26 TC 119 Z9 121 U1 3 U2 17 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 1999 VL 37 IS 12 BP 1529 EP 1537 DI 10.2514/2.641 PG 9 WC Engineering, Aerospace SC Engineering GA 263JB UT WOS:000084120600001 ER PT J AU Skelton, HG Smith, KJ AF Skelton, HG Smith, KJ TI Infiltrative glomus tumor arising from a benign glomus tumor - A distinctive immunohistochemical pattern in the infiltrative component SO AMERICAN JOURNAL OF DERMATOPATHOLOGY LA English DT Article DE glomus tumor; immunohistochemistry; CD34 ID DENDRITIC CELLS AB Malignant glomus tumors (MGT) are rare. Although metastatic MGT has been reported, most MGT have only been locally aggressive, some with multiple local recurrences. We report an additional case of an infiltrative glomus tumor. In addition to the pattern of immunohistochemical staining for alpha-smooth muscle actin (SM-actin) previously described, we performed immunohistochemical stains for Ki-67 and CD34. The infiltrative component of the glomus tumor showed variably decreased staining with SM-actin and occasional tumor cells showed nuclear staining with Ki-67. CD34 staining occurred in stromal cells forming the pseudocapsule in the benign component of this tumor and in other benign glomus tumors. The infiltrative component showed increased CD34 stromal cells. Although Ki-67 staining showed only an occasional proliferative cell, the immunohistochemical staining pattern of CD34 and SM-actin raise the possibility that the infiltrative component of this tumor may have differences in the degree of differentiation from the circumscribed part and that local factors could support its spread from a conventional benign glomus tumor. C1 USN, Natl Naval Med Ctr, Dept Dermatol & Pathol, Bethesda, MD 20889 USA. Lab Corp Amer, Herndon, VA USA. RP Smith, KJ (reprint author), USN, Natl Naval Med Ctr, Dept Dermatol & Pathol, 8901 Wisconsin Ave, Bethesda, MD 20889 USA. NR 17 TC 17 Z9 18 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0193-1091 J9 AM J DERMATOPATH JI Am. J. Dermatopathol. PD DEC PY 1999 VL 21 IS 6 BP 562 EP 566 DI 10.1097/00000372-199912000-00011 PG 5 WC Dermatology SC Dermatology GA 263UF UT WOS:000084143100011 PM 10608251 ER PT J AU Luban, M Luscombe, JH AF Luban, M Luscombe, JH TI Equilibrium time correlation functions and the dynamics of fluctuations SO AMERICAN JOURNAL OF PHYSICS LA English DT Article ID DIFFUSION AB Equilibrium time correlation functions are of great importance because they probe the equilibrium dynamical response to external perturbations. We discuss the properties of time correlation functions for several systems that are simple enough to illustrate the calculational steps involved. The discussion underscores the need for avoiding language which misleadingly suggests that thermal equilibrium is associated with a quiescent or moribund state of the system. (C) 1999 American Association of Physics Teachers. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. USN, Postgrad Sch, Dept Phys, Monterey, CA 93943 USA. RP Luban, M (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 37 TC 8 Z9 8 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD DEC PY 1999 VL 67 IS 12 BP 1161 EP 1169 DI 10.1119/1.19102 PG 9 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA 261RW UT WOS:000084023600023 ER PT J AU Shlesinger, MF Klafter, J Zumofen, G AF Shlesinger, MF Klafter, J Zumofen, G TI Above, below and beyond Brownian motion SO AMERICAN JOURNAL OF PHYSICS LA English DT Article ID RANDOM-WALKS; DIFFUSION; TRANSPORT; TIME AB Brownian motion represents simple diffusion random walk processes. More complex random walk processes also can occur when probability distributions describing the random jump distances and times have infinite moments. We explore the manner in which these distributions can arise and how they underlie various scaling laws that play an important role in both random and deterministic systems. (C) 1999 American Association of Physics Teachers. C1 Off Naval Res, Div Phys Sci, Arlington, VA 22217 USA. Tel Aviv Univ, Sch Chem, IL-69978 Tel Aviv, Israel. ETH Zentrum, Phys Chem Lab, CH-8092 Zurich, Switzerland. RP Shlesinger, MF (reprint author), Off Naval Res, Div Phys Sci, Arlington, VA 22217 USA. NR 20 TC 52 Z9 52 U1 0 U2 11 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD DEC PY 1999 VL 67 IS 12 BP 1253 EP 1259 DI 10.1119/1.19112 PG 7 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA 261RW UT WOS:000084023600033 ER PT J AU Evans, L Collins, GE Shaffer, RE Michelet, V Winkler, JD AF Evans, L Collins, GE Shaffer, RE Michelet, V Winkler, JD TI Selective metals determination with a photoreversible spirobenzopyran SO ANALYTICAL CHEMISTRY LA English DT Article ID MULTIVARIATE CALIBRATION; ION-TRANSPORT; CROWN-ETHERS; SENSOR; SPECTROPHOTOMETRY; BINDING; ARRAY AB The photoreversible metal-ion complexation behavior of nitroquinolinospiropyranindoline (NQSP) was studied in combination with the selective identification of six different transition-metal ions, Zn2+, Co2+, Hg2+, Cu2+, Cd2+, and Ni2+, in single- and binary-component mixtures via partial least squares discriminant (PLSD) analysis. The plasticizer, dicapryl phthalate, was chosen as the support medium for this study on the basis of (1) its enhancement of the photoreversibility and hypsochromic shifts seen in metal complexation and (2) its potential application to supported liquid membranes for eventual sensor applications. Complexation of divalent transition-metal ions by NQSP in dicapryl phthalate produced variable hypsochromic shifts in the absorption spectra (30-60 nm), requiring chemometric techniques in order to overcome the spectral overlaps. PLSD analysis was used to build classification analysis models to differentiate between the six divalent transition-metal ions. The feasibility of performing mixture analysis was studied using the concept of net analyte signal prior to experimental verification. Single- and binary-component mixtures of metals were identified with 100 and 97.4% accuracy, respectively, which included no false positives in either the training or prediction sets. C1 USN, Res Lab, Div Chem, Washington, DC 20375 USA. Univ Penn, Dept Chem, Philadelphia, PA 19104 USA. RP Collins, GE (reprint author), USN, Res Lab, Div Chem, Code 6116, Washington, DC 20375 USA. RI MICHELET, Veronique/A-5601-2009; Shaffer, Ronald/I-2134-2012 NR 28 TC 51 Z9 52 U1 1 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD DEC 1 PY 1999 VL 71 IS 23 BP 5322 EP 5327 DI 10.1021/ac990755s PG 6 WC Chemistry, Analytical SC Chemistry GA 260YW UT WOS:000083981900017 PM 21662730 ER PT J AU Vijayendran, RA Ligler, FS Leckband, DE AF Vijayendran, RA Ligler, FS Leckband, DE TI A computational reaction-diffusion model for the analysis of transport-limited kinetics SO ANALYTICAL CHEMISTRY LA English DT Article ID FIBER OPTIC PROBES; MASS-TRANSPORT; EVANESCENT-WAVE; BIOSENSOR; BINDING; ANTIBODIES AB Optical, evanescent wave biosensors have become popular tools for quantitatively characterizing the kinetic properties of biomolecular interactions. Analyzing data from biosensor experiments, however, is often complicated when mass-transfer influences the detection kinetics. We present a computational, transport-kinetic model that can be used to analyze transport-limited biosensor data. This model describes a typical biosensor experiment in which a soluble analyte diffuses through a flow chamber and binds to a receptor immobilized on the transducer surface. Analyte transport in the flow chamber is described by the diffusion equation while the kinetics of analyte-surface association and dissociation are captured by a reactive boundary condition at the sensor surface. Numerical integration of the model equations and nonlinear least-squares fitting are used to compare model kinetic data to experimental results and generate estimates for the rate constants that describe analyte detection. To demonstrate the feasibility of this model, we use it to analyze data collected for the binding of fluorescently labeled trinitrobenzene to immobilized monoclonal anti-TNT antibodies, A successful analysis of this antigen-antibody interaction is presented for data collected with a fluorescence-based fiber-optic immunoassay, The results of this analysis are compared with the results obtained with existing methods for analyzing diffusion-limited kinetic data. C1 Univ Illinois, Dept Chem Engn, Urbana, IL 61801 USA. Univ Illinois, Ctr Biophys & Computat Biol, Urbana, IL 61801 USA. USN, Res Lab, Ctr Biomol Sci & Engn, Washington, DC 20375 USA. RP Leckband, DE (reprint author), Univ Illinois, Dept Chem Engn, Urbana, IL 61801 USA. NR 14 TC 66 Z9 71 U1 0 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD DEC 1 PY 1999 VL 71 IS 23 BP 5405 EP 5412 DI 10.1021/ac990672b PG 8 WC Chemistry, Analytical SC Chemistry GA 260YW UT WOS:000083981900030 PM 21662737 ER PT J AU Kim, H Horwitz, JS Pique, A Gilmore, CM Chrisey, DB AF Kim, H Horwitz, JS Pique, A Gilmore, CM Chrisey, DB TI Electrical and optical properties of indium tin oxide thin films grown by pulsed laser deposition SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Article; Proceedings Paper CT 5th International Conference on Laser Ablation COLA'99 CY JUL 19-23, 1999 CL GOTTINGEN, GERMANY AB Indium tin oxide (ITO) thin films (200-400 nm in thickness) have been grown by pulsed laser deposition (PLD) on glass substrates without a post-deposition anneal. The electrical and optical properties of these films have been investigated as a function of substrate temperature and oxygen partial pressure during deposition. Films were deposited at substrate temperatures ranging from room temperature to 300 degrees C in O-2 partial pressures ranging from 0.1 to 100 mTorr. For 300 nm thick ITO films grown at room temperature in oxygen pressure of 10 mTorr, the electrical conductivity was 2.6 x 10(-3) Omega(-1) cm(-1) and the average optical transmittance was 83% in the visible range (400-700 nm). For 300 nm thick ITO films deposited at 300 degrees C in 10 mTorr of oxygen, the conductivity was 5.2 x 10(-3) Omega(-1) cm(-1) and the average transmittance in the visible range was 87%. Atomic force microscopy (AFM) measurements showed that the RMS surface roughness for the ITO films grown at room temperature was similar to 7 Angstrom, which is the lowest reported value for the ITO films grown by any film growth technique at room temperature. C1 George Washington Univ, Inst Mat Sci, Washington, DC 20052 USA. USN, Res Lab, Washington, DC 20375 USA. RP Kim, H (reprint author), George Washington Univ, Inst Mat Sci, Washington, DC 20052 USA. NR 12 TC 42 Z9 43 U1 2 U2 19 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0947-8396 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD DEC PY 1999 VL 69 SU S BP S447 EP S450 DI 10.1007/s003390051435 PG 4 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 287WV UT WOS:000085530400091 ER PT J AU Pique, A Chrisey, DB Auyeung, RCY Fitz-Gerald, J Wu, HD McGill, RA Lakeou, S Wu, PK Nguyen, V Duignan, M AF Pique, A Chrisey, DB Auyeung, RCY Fitz-Gerald, J Wu, HD McGill, RA Lakeou, S Wu, PK Nguyen, V Duignan, M TI A novel laser transfer process for direct writing of electronic and sensor materials SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Article; Proceedings Paper CT 5th International Conference on Laser Ablation COLA'99 CY JUL 19-23, 1999 CL GOTTINGEN, GERMANY ID CHEMICAL SENSORS; NOSE AB MAPLE direct write (MAPLE DW) is a new laser-based direct-write technique which combines the basic approach employed in laser-induced forward transfer (LIFT) with the unique advantages of matrix-assisted pulsed-laser evaporation (MAPLE). MAPLE DW utilizes an optically transparent substrate coated on one side with a matrix consisting of the material toe transferred mixed with a polymer or organic binder. As in LIFT, the laser is focused through the transparent substrate onto the matrix. When a laser pulse strikes the matrix, the binder decomposes and aids the transfer of the material of interest to an acceptor substrate placed parallel to the matrix surface. MAPLE DW is a maskless deposition process which operates in air and at room temperature. Powders of Ag, BaTiO3, SrTiO3, and Y3Fe5O12 with average diameters of 1 mu m were transferred onto the surfaces of alumina, glass, silicon, and printed circuit board substrates. Parallel-plate and interdigitated capacitors and flat inductors were produced by MAPLE DW over Rogers RO4003 substrates. MAPLE DW was also used to transfer polymer composites for the fabrication of gas sensor chemoresistors. One such composite chemoresistor fabricated with polyepichlorohydrin/graphite was used to detect organic vapors with a sensitivity of parts per million. C1 USN, Res Lab, Washington, DC 20375 USA. SFA Inc, Largo, MD USA. Univ Dist Columbia, Washington, DC USA. So Oregon Univ, Ashland, OR USA. Geocenters Inc, Ft Washington, MD 20744 USA. Potomac Photon Inc, Lanham, MD USA. RP Pique, A (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 10 TC 116 Z9 117 U1 6 U2 46 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0947-8396 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD DEC PY 1999 VL 69 SU S BP S279 EP S284 DI 10.1007/s003390051400 PG 6 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 287WV UT WOS:000085530400056 ER PT J AU Chusuei, CC Morris, RE Schreifels, JA AF Chusuei, CC Morris, RE Schreifels, JA TI Decomposition products of N,N '-disalicylidene-1,2-propanediamine adsorbed on 304 stainless steel SO APPLIED SURFACE SCIENCE LA English DT Article DE TPD; temperature programmed desorption; thermal desorption; CTPD; contour TPD; surface chemistry; jet fuel; MDA; metal deactivators ID SCHIFF-BASE COMPLEXES; THERMAL-STABILITY; EPOXIDATION; OLEFINS; ADSORPTION; IRON(III); CATALYST; ETHYLENE; SURFACE; CU(100) AB The compound, N,N'-disalicylidene-1,2-propanediamine, is commonly added to jet fuels to counteract the catalysis of thermally induced autoxidation by certain dissolved metals. The behavior of the metal deactivator additive (MDA) in thermally stressed jet fuel has raised questions on whether it decomposes after coming into contact with hot metal surfaces within the aircraft fuel system. Temperature programmed desorption (TPD) was performed to detect decomposition products of MDA on the 304SS surface. A method of scanning a relatively large mass range during desorption was developed to acquire S-dimensional contour TPD (CTPD) plots of adsorbed species on the surface. Compounds with molecular masses of 107, 133, 232 and 290 were detected and their structures proposed. Conventional TPD spectra of selected molecular masses were then taken as a function of exposure. Mechanistic pathways for decomposition of MDA and formation of new compounds on the surfaces are proposed. (C) 1999 Elsevier Science B.V. All rights reserved. C1 George Mason Univ, Dept Chem, Fairfax, VA 22030 USA. USN, Res Lab, Div Chem, Washington, DC 20375 USA. RP Schreifels, JA (reprint author), George Mason Univ, Dept Chem, Fairfax, VA 22030 USA. NR 33 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD DEC PY 1999 VL 153 IS 1 BP 23 EP 34 DI 10.1016/S0169-4332(99)00336-0 PG 12 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 269UN UT WOS:000084496100004 ER PT J AU Eyre, DP AF Eyre, DP TI Death so noble: Memory, meaning and the first world war. SO ARMED FORCES & SOCIETY LA English DT Book Review C1 USN, Postgrad Sch, Washington, DC 20350 USA. RP Eyre, DP (reprint author), USN, Postgrad Sch, Washington, DC 20350 USA. NR 1 TC 0 Z9 0 U1 0 U2 2 PU TRANSACTION PERIOD CONSORTIUM PI PISCATAWAY PA DEPT 4010, RUTGERS UNIV, 35 BERRUE CIRCLE, PISCATAWAY, NJ 08854-8042 USA SN 0095-327X J9 ARMED FORCES SOC JI Armed Forces Soc. PD WIN PY 1999 VL 25 IS 2 BP 340 EP 344 DI 10.1177/0095327X9902500212 PG 5 WC Political Science; Sociology SC Government & Law; Sociology GA 187FW UT WOS:000079777000012 ER PT J AU Boley, D Gini, M Gross, R Han, EH Hastings, K Karypis, G Kumar, V Mobasher, B Moore, J AF Boley, D Gini, M Gross, R Han, EH Hastings, K Karypis, G Kumar, V Mobasher, B Moore, J TI Document categorization and query generation on the World Wide Web using WebACE SO ARTIFICIAL INTELLIGENCE REVIEW LA English DT Article DE clustering; divisive partitioning; graph partitioning; principal component analysis; web documents ID INFORMATION AB We present WebACE, an agent for exploring and categorizing documents on the World Wide Web based on a user profile. The heart of the agent is an unsupervised categorization of a set of documents, combined with a process for generating new queries that is used to search for new related documents and for filtering the resulting documents to extract the ones most closely related to the starting set. The document categories are not given a priori. We present the overall architecture and describe two novel algorithms which provide significant improvement over Hierarchical Agglomeration Clustering and AutoClass algorithms and form the basis for the query generation and search component of the agent. We report on the results of our experiments comparing these new algorithms with more traditional clustering algorithms and we show that our algorithms are fast and sacalable. C1 Univ Minnesota, Dept Comp Sci & Engn, Minneapolis, MN 55455 USA. Silicone Graph Inc, Eagan, MN USA. Univ Minnesota, Dept Comp Sci, Minneapolis, MN 55455 USA. USN, Washington, DC 20350 USA. Depaul Univ, Ctr Web Data Min E Commerce, Chicago, IL 60604 USA. Minneapolis Star Tribune, Minneapolis, MN USA. RP Boley, D (reprint author), Univ Minnesota, Dept Comp Sci & Engn, Minneapolis, MN 55455 USA. OI Gini, Maria/0000-0001-8841-1055 NR 36 TC 58 Z9 59 U1 1 U2 9 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0269-2821 J9 ARTIF INTELL REV JI Artif. Intell. Rev. PD DEC PY 1999 VL 13 IS 5-6 BP 365 EP 391 DI 10.1023/A:1006592405320 PG 27 WC Computer Science, Artificial Intelligence SC Computer Science GA 317YH UT WOS:000087254300003 ER PT J AU Whiting, AB Hau, GKT Irwin, M AF Whiting, AB Hau, GKT Irwin, M TI A new Local Group galaxy in Cetus SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : distances and redshifts; galaxies : dwarf; Local Group ID DWARF SPHEROIDAL GALAXY; LUMINOSITY FUNCTION; VELOCITY; MAPS; M31 AB We report the discovery of a previously uncataloged Local Group galaxy in the constellation Cetus. Faintly visible on UKST survey plates, it has a smooth, diffuse appearance and appears to be a dwarf spheroidal of type dE3.5. A color-magnitude diagram in V, V-I shows a clear giant branch but no sign of recent star formation. From the position of the tip of the giant branch, we derive a reddening-corrected distance modulus of 24.45 +/- 0.15 and a metallicity of - 1.9 +/- 0.2. With an implied heliocentric distance of 775 +/- 50 kpc, and a corresponding Local Group barycentric distance of 615 kpc, the Cetus dwarf lies well within the boundaries of the Local Group, and although it currently lacks a radial velocity measurement, it is undoubtedly a member of the Local Group. The nearest Local Group galaxies are WLM and IC 1613 at angular separations of 7 degrees.3 and 16 degrees.3 and roughly 175 and 230 kpc total distance, respectively. Although the Cetus dwarf is unlikely to be directly associated with any other Local Group galaxy, it does lie in the general direction of the extension of the Local Group toward the Sculptor Group. C1 USN Acad, Dept Phys, Annapolis, MD 21402 USA. Catholic Univ Chile, Fac Fis & Astron, Santiago 22, Chile. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. RP Whiting, AB (reprint author), USN Acad, Dept Phys, Annapolis, MD 21402 USA. NR 36 TC 55 Z9 55 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD DEC PY 1999 VL 118 IS 6 BP 2767 EP 2774 DI 10.1086/301142 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 274KY UT WOS:000084766100016 ER PT J AU Nordgren, TE Germain, ME Benson, JA Mozurkewich, D Sudol, JJ Elias, NM Hajian, AR White, NM Hutter, DJ Johnston, KJ Gauss, FS Armstrong, JT Pauls, TA Rickard, LJ AF Nordgren, TE Germain, ME Benson, JA Mozurkewich, D Sudol, JJ Elias, NM Hajian, AR White, NM Hutter, DJ Johnston, KJ Gauss, FS Armstrong, JT Pauls, TA Rickard, LJ TI Stellar angular diameters of late-type giants and supergiants measured with the navy prototype optical interferometer SO ASTRONOMICAL JOURNAL LA English DT Article DE stars : fundamental parameters techniques : interferometric ID LIMB-DARKENING COEFFICIENTS; EFFECTIVE TEMPERATURES; STARS; CATALOG AB We have measured the angular diameters of 50 F, G, K, and M giant and supergiant stars using the Navy Prototype Optical Interferometer at wavelengths between 649 and 850 nm and using three baselines with lengths up to 37.5 m. Uniform-disk diameters, obtained from fits to the visibility amplitude, were transformed to limb-darkened diameters through the use of limb-darkening coefficients for plane-parallel stellar atmosphere models. These limb-darkened diameters are compared with those measured with the Mark III optical interferometer and with those computed by the infrared flux method. Sources of random and systematic error in the observations are discussed. C1 USN Observ, NPOI, Flagstaff, AZ USA. USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. Univ Wyoming, Dept Phys & Astron, Laramie, WY 82076 USA. USN Observ, Astrometry Dept, Washington, DC 20392 USA. Lowell Observ, Flagstaff, AZ 86001 USA. RP Nordgren, TE (reprint author), USN Observ, NPOI, POB 1149, Flagstaff, AZ USA. NR 19 TC 74 Z9 74 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD DEC PY 1999 VL 118 IS 6 BP 3032 EP 3038 DI 10.1086/301114 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 274KY UT WOS:000084766100036 ER PT J AU Fan, XH Strauss, MA Gunn, JE Lupton, RH Carilli, CL Rupen, MP Schmidt, GD Moustakas, LA Davis, M Annis, J Bahcall, NA Brinkmann, J Brunner, RJ Csabai, I Doi, M Fukugita, M Heckman, TM Hennessy, GS Hindsley, RB Ivezic, Z Knapp, GR Lamb, DQ Munn, JA Pauls, AG Pier, JR Rockosi, CM Schneider, DP Szalay, AS Tucker, DL York, DG AF Fan, XH Strauss, MA Gunn, JE Lupton, RH Carilli, CL Rupen, MP Schmidt, GD Moustakas, LA Davis, M Annis, J Bahcall, NA Brinkmann, J Brunner, RJ Csabai, I Doi, M Fukugita, M Heckman, TM Hennessy, GS Hindsley, RB Ivezic, Z Knapp, GR Lamb, DQ Munn, JA Pauls, AG Pier, JR Rockosi, CM Schneider, DP Szalay, AS Tucker, DL York, DG TI The discovery of a high-redshift quasar without emission lines from Sloan Digital Sky Survey commissioning data SO ASTROPHYSICAL JOURNAL LA English DT Article DE quasars : individual (SDSS 1533-00); radio continuum : galaxies; X-rays : galaxies ID BL LACERTAE OBJECTS; SPECTROPHOTOMETRY; EVOLUTION AB We report observations of a luminous unresolved object at redshift z = 4.62, with a featureless optical spectrum redward of the Ly alpha forest region, discovered from Sloan Digital Sky Survey commissioning data. The redshift is determined by the onset of the Ly alpha forest at lambda similar to 6800 Angstrom and a Lyman limit system at lambda = 5120 Angstrom. A strong Ly alpha absorption system with weak metal absorption lines at z = 4.58 is also identified in the spectrum. The object has a continuum absolute magnitude of -26.6 at 1450 Angstrom in the rest frame (h(0) = 0.5, q(0) = 0.5) and therefore cannot be an ordinary galaxy. It shows no radio emission (the 3 sigma upper limit of its flux at 6 cm is 60 mu Jy), indicating a radio-to-optical flux ratio at least as small as that of the radio-weakest BL Lacertae objects known. It is also not linearly polarized to a 3 sigma upper limit of 4% in the observed I band. Therefore, it is either the most distant BL Lac object known to date, with very weak radio emission, or a new type of unbeamed quasar, whose broad emission line region is very weak or absent. C1 Princeton Univ Observ, Princeton, NJ 08544 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Univ Oxford, Dept Astrophys, Oxford OX1 3RH, England. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Apache Point Observ, Sunspot, NM 88349 USA. Johns Hopkins Univ, Henry A Rowland Dept Phys & Astron, Baltimore, MD 21218 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. Eotvos Lorand Univ, Dept Phys Complex Syst, H-1117 Budapest, Hungary. Univ Tokyo, Dept Astron, Tokyo 1130033, Japan. Univ Tokyo, Inst Cosm Ray Res, Tokyo 1888502, Japan. USN Observ, Washington, DC 20392 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. USN Observ, Flagstaff Stn, Flagstaff, AZ 86002 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Univ Tokyo, Res Ctr Early Universe, Tokyo 1130033, Japan. RP Fan, XH (reprint author), Princeton Univ Observ, Peyton Hall, Princeton, NJ 08544 USA. RI Csabai, Istvan/F-2455-2012 NR 26 TC 73 Z9 73 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 1999 VL 526 IS 2 BP L57 EP L60 DI 10.1086/312382 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 263GG UT WOS:000084116600001 ER PT J AU Wiegmann, DA Shappell, SA AF Wiegmann, DA Shappell, SA TI Human error and crew resource management failures in Naval aviation mishaps: A review of US Naval Safety Center data, 1990-96 SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Review DE crew resource management; accident investigation; military aviation AB The present study examined the role of human error and crew-resource management (CRM) failures in U.S. Naval aviation mishaps. All tactical jet (TACAIR) and rotary wing Class A flight mishaps between fiscal years 1990-1996 were reviewed. Results indicated that over 75% of both TACAIR and rotary wing mishaps were attributable, at least in part, to some form of human error of which 70% were associated with aircrew human factors. Of these aircrew-related mishaps, approximately 56% involved at least one CRM failure. These percentages are very similar to those observed prior to the implementation of aircrew coordination training (ACT) in the fleet, suggesting that the initial benefits of the program have not persisted and that CRM failures continue to plague Naval aviation. Closer examination of these CRM-related mishaps suggest that the type of flight operations (preflight, routine, emergency) do play a role in the etiology of CRM failures. A larger percentage of CRM failures occurred during non-routine or extremis flight situations when TACAIR mishaps were considered. In contrast, a larger percentage of rotary wing CRM mishaps involved failures that occurred during routine flight operations. These findings illustrate the complex etiology of CRM failures within Naval aviation and support the need for ACT programs tailored to the unique problems faced by specific communities in the fleet. C1 USN, Safety Ctr, Norfolk, VA USA. RP Shappell, SA (reprint author), Civil Aeromed Inst, AAM-510,POB 25082, Oklahoma City, OK 73125 USA. NR 8 TC 22 Z9 25 U1 1 U2 8 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD DEC PY 1999 VL 70 IS 12 BP 1147 EP 1151 PG 5 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 258VF UT WOS:000083859300001 PM 10596766 ER PT J AU Gallimore, JJ Brannon, NG Patterson, FR Nalepka, JP AF Gallimore, JJ Brannon, NG Patterson, FR Nalepka, JP TI Effects of FOV and aircraft bank on pilot head movement and reversal errors during simulated flight SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article DE helmet-mounted displays; spatial orientation; field of view; opto-kinetic cervical reflex; head movements; control reversal errors ID AVIATION SPATIAL ORIENTATION; POSITION; REFLEX AB Background: Recent studies have shown that while flying under Visual meteorological conditions (VMC) pilots tilt their head to keep the horizon stabilized on their fovea. This reflex, referred to as Opto-Kinetic Cervical Reflex (OKCR), may improve spatial awareness by establishing the horizon retinal image as a stabilized primary visual-spatial cue. Since the limited field of View (FOV) provided by helmet-mounted displays (HMDs) significantly decreases visual stimuli, the purpose of this research was to determine how reduced FOV affects head movements. Hypotheses: As FOV is decreased, there will be a significant reduction in OKCR-induced head movement. Reduced FOV will also increase control reversal errors. Methods: Twelve pilots completed simulated flight tasks in a stationary dome. Head tilt, pitch, and yaw were examined as a function of aircraft bank and FOV(40 degrees, 60 degrees and 100 degrees circular). The number of control reversal errors was analyzed to investigate signs of spatial disorientation. Results:During VMC manuevers pilots exhibited significant OKCR; however there were no significant differences among the three levels of FOV. FOV significantly affected head pitch movements under both VMC and instrument meteorological conditions (IMC). Pilots yawed their heads in the direction of aircraft bank under VMC. Pilots committed 22 reversal errors out of 72 trials (30.55%). The magnitude of the error was largest for the 40 degrees FOV condition. Conclusions: Pilots exhibit the OKCR under all tested levels of FOV and also make head yaw movements in order to keep the way point in sight during banking maneuvers. Pilots demonstrated stick reversal errors when transitioning from following a lead aircraft under both VMC and IMC conditions. C1 Wright State Univ, Dept Biomed & Human Factors Engn, Russ Engn Ctr 207, Dayton, OH 45435 USA. USN, Aerosp Med Res Lab, Pensacola, FL USA. USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Gallimore, JJ (reprint author), Wright State Univ, Dept Biomed & Human Factors Engn, Russ Engn Ctr 207, Dayton, OH 45435 USA. NR 9 TC 9 Z9 9 U1 0 U2 1 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD DEC PY 1999 VL 70 IS 12 BP 1152 EP 1160 PG 9 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 258VF UT WOS:000083859300002 PM 10596767 ER PT J AU Sims, JR Tibbles, PM Jackman, RP AF Sims, JR Tibbles, PM Jackman, RP TI A descriptive analysis of asthma in the US Navy Submarine Force. SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article DE asthma; occupational exposure; closed-environment ID GENERAL-POPULATION; METHACHOLINE; CHALLENGE; MORTALITY AB Background: The U.S. Navy Submarine Force offers a unique opportunity to study asthma because of the relative socioeconomic and physical homogeneity of the population and the closed environment occupational exposure. Currently, asthma is disqualifying from submarine service, which results in a significant loss of experienced personnel. Methods: We performed a retrospective analysis of 119 U.S. Navy submariner disqualification packages for asthma between 1989-1993. Results:We found a 0.16% annual period prevalence of asthma in the active duty Enlisted Atlantic Fled Submarine Force. Two groups of asthma disqualifications were identified with a significant increase above their proportional representation in the fleet: enlisted personnel (p < 0.01) and submarine recruits (p < 0.0001). The proportion of African-American personnel also had a tendency reward increased asthma disqualification (p < 0.08). There were no differences in prevalence of asthma between crews of ballistic missile submarines or fast attack submarines. Asthma risk factors reported in the civilian literature (childhood history of asthma, family history of asthma and non-drug allergies) were highly represented in our study (41%, 46% and 68% of submariners, respectively). Most disqualified submariners had "mild" asthma based on the diagnostic work-up. The methacholine challenge test appeared to carry a disproportionate diagnostic weight despite its low specificity. Conclusion: Although the period prevalence of asthma is low in the U.S. Navy Submarine Force, submariners disqualified for asthma have similar historical and ethnic risk factors as the civilian population. C1 USN, Submarine Med Res Lab, Submarine Base New London, Groton, CT 06349 USA. RP Sims, JR (reprint author), USN, Submarine Med Res Lab, Submarine Base New London, Box 900, Groton, CT 06349 USA. NR 21 TC 4 Z9 4 U1 1 U2 1 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD DEC PY 1999 VL 70 IS 12 BP 1214 EP 1218 PG 5 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 258VF UT WOS:000083859300013 PM 10596778 ER PT J AU Cras, JJ Rowe-Taitt, CA Nivens, DA Ligler, FS AF Cras, JJ Rowe-Taitt, CA Nivens, DA Ligler, FS TI Comparison of chemical cleaning methods of glass in preparation for silanization SO BIOSENSORS & BIOELECTRONICS LA English DT Article DE cleaning methods; glass surface; soda lime; (3-mercaptopropyl)silane; silanization ID SILICA SURFACES; AQUEOUS KOH; MONOLAYERS; IMMOBILIZATION; FABRICATION; ADSORPTION AB The uniform deposition of a silane monolayer upon glass has been shown to require small amounts of water along with hydroxyl groups in an isolated or geminal configuration on the substrate surface. In order to expose these groups, organic compounds at the surface must be removed. We present a qualitative evaluation of eight chemical methods commonly used to clean glass microscope slides in preparation for silanization. Mean contact angle of deionized water was measured before covalent attachment of (3-mercaptopropyl)triethoxysilane to assess the efficacy of each procedure. Contact angles were also measured after silanization as a means of determining the uniformity and reproducibility of the silane monolayer. The results indicate that a 1:1 methanol/HCl wash followed by a bath in concentrated H2SO4 removes surface contaminants most effectively and allows for a very even silanization of the glass surface. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Georgetown Univ, Washington, DC 20057 USA. USN, Res Lab, Ctr Biomol Sci & Engn, Washington, DC 20375 USA. RP Ligler, FS (reprint author), Georgetown Univ, Washington, DC 20057 USA. RI Delehanty, James/F-7454-2012 NR 29 TC 208 Z9 219 U1 12 U2 114 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0956-5663 J9 BIOSENS BIOELECTRON JI Biosens. Bioelectron. PD DEC PY 1999 VL 14 IS 8-9 BP 683 EP 688 DI 10.1016/S0956-5663(99)00043-3 PG 6 WC Biophysics; Biotechnology & Applied Microbiology; Chemistry, Analytical; Electrochemistry; Nanoscience & Nanotechnology SC Biophysics; Biotechnology & Applied Microbiology; Chemistry; Electrochemistry; Science & Technology - Other Topics GA 265UU UT WOS:000084264800003 ER PT J AU Hough, SE Lees, JM Monastero, F AF Hough, SE Lees, JM Monastero, F TI Attenuation and source properties at the Coso geothermal area, California SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID EMPIRICAL GREENS-FUNCTION; SOUTHERN-CALIFORNIA; SOURCE PARAMETERS; EARTHQUAKE; WAVES; MICROSEISMICITY; AFTERSHOCKS; SPECTRA; STRESS; REGION AB We use a multiple-empirical Green's function method to determine source properties of small (M - 0.4 to 1.3) earthquakes and P- and S-wave attenuation at the Coso Geothermal Field, California. Source properties of a previously identified set of clustered events from the Coso geothermal region are first analyzed using an empirical Green's function (EGF) method. Stress-drop values of at least 0.5-1 MPa are inferred for all of the events; in many cases, the corner frequency is outside the usable bandwidth, and the stress drop can only be constrained as being higher than 3 MPa. P- and S-wave stress-drop estimates are identical to the resolution limits of the data. These results are indistinguishable from numerous EGF studies of M 2-5 earthquakes, suggesting a similarity in rupture processes that extends to events that are both tiny and induced, providing further support for Byerlee's Law. Whole-path Q estimates for P and S waves are determined using the multiple-empirical Green's function (MEGF) method of Hough (1997), whereby spectra from clusters of colocated events ata given station are inverted for a single attenuation parameter, kappa, with source parameters constrained from EGF analysis. The kappa estimates, which we infer to be resolved to within 0.01 sec or better, exhibit almost as much scatter as a function of hypocentral distance as do values from previous single-spectrum studies for which much higher uncertainties in individual kappa estimates are expected. The variability in kappa estimates determined here therefore suggests real lateral variability in Q structure. Although the ray-path coverage is too sparse to yield a complete three-dimensional attenuation tomographic image, we invert the inferred kappa value for three-dimensional structure using a damped least-squares method, and the results do reveal significant lateral variability in Q structure. The inferred attenuation variability corresponds to the heat-flow variations within the geothermal region. A central lowe region corresponds well with the central high-heat flow region; additional detailed structure is also suggested. C1 US Geol Survey, Pasadena, CA 91106 USA. Yale Univ, New Haven, CT USA. USN, Geothermal Program, China Lake, CA USA. RP Hough, SE (reprint author), US Geol Survey, Pasadena, CA 91106 USA. NR 33 TC 28 Z9 33 U1 0 U2 2 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 USA SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD DEC PY 1999 VL 89 IS 6 BP 1606 EP 1619 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 276PP UT WOS:000084886800016 ER PT J AU Khokhlov, AM Oran, ES AF Khokhlov, AM Oran, ES TI Numerical simulation of detonation initiation in a flame brush: The role of hot spots SO COMBUSTION AND FLAME LA English DT Article ID DEFLAGRATION; TRANSITION; DYNAMICS AB This is the final paper in a series describing numerical simulations of deflagration-to-detonation transition (DDT) fur conditions similar to reflected shock-tube experiments in an acetylene-air mixture (100 Torr, 298 K). In the experiments and calculations, the interaction of a shock wave and an expanding flame front leads to the rapid creation of a turbulent flame brush and, for sufficiently high Mach numbers of the incident shock, to the subsequent transition to a detonation. The two-dimensional reactive Navier-Stokes equations, including the effects of viscosity, thermal conduction, molecular diffusion, and chemical reaction, are solved on a high-resolution adapting mesh. Shock-flame interactions, through the Richtmyer-Meshkov instability, create and maintain a highly turbulent flame brush and are responsible for injecting unburned material into the region of burned material. Hot spots are created by pressure fluctuations and shocks generated In the flame brush. At relatively law Mach numbers, hot spots that transition to detonation are created outside of the flame brush. For higher Mach numbers, such hot spots are created in pockets of unreacted material inside the flame brush. La both cases, the hot spots give rise to detonations by the gradient mechanism, in which a gradient in induction time leads to a supersonic spontaneous wave that later becomes a detonation. (C) 1999 by The Combustion Institute. C1 USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. RP Khokhlov, AM (reprint author), USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. EM ajk@lcp.nrl.navy.mil NR 23 TC 50 Z9 60 U1 0 U2 13 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0010-2180 EI 1556-2921 J9 COMBUST FLAME JI Combust. Flame PD DEC PY 1999 VL 119 IS 4 BP 400 EP 416 DI 10.1016/S0010-2180(99)00058-9 PG 17 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 251AN UT WOS:000083422600002 ER PT J AU Prasad, K Li, CP Kailasanath, K Ndubizu, C Ananth, R Tatem, PA AF Prasad, K Li, CP Kailasanath, K Ndubizu, C Ananth, R Tatem, PA TI Numerical modelling of methanol liquid pool fires SO COMBUSTION THEORY AND MODELLING LA English DT Article ID FLAMES; FUELS AB The focus of this paper is on numerical modelling of methanal liquid pool fires. A mathematical model is first developed to describe the evaporation and burning of a two-dimensional or axisymmetric pool containing pure liquid methanol. Then, the complete set of unsteady, compressible Navier-Stokes equations for reactive hows are solved in the gas phase to describe the convection of the fuel gases away from the pool surface, diffusion of the gases into the surrounding air and the oxidation of the fuel into product species. Heat transfer into the liquid pool and the metal container through conduction, convection and radiation are modelled by solving a modified form of the energy equation. Clausius-Clapeyron relationships are invoked to model the evaporation rate of a two-dimensional pool of pure liquid methanol. The governing equations along with appropriate boundary and interface conditions are solved using the flux corrected transport algorithm. Numerical results exhibit a dame structure that compares well with experimental observations. Temperature: profiles and burning rates were found to compare favourably with experimental data from single- and three-compartment laboratory burners. The model predicts a puffing frequency of approximately 12 Hz for a 1 cm diameter methanol pool in the absence of any air co-flow. It is also observed that increasing the air co-flow velocity helps in stabilizing the diffusion flame, by pushing the vortical structures away from the flame region. C1 USN, Res Lab, Computat Phys & Fluid Dynam Lab, Ctr React Flow & Dynam Syst, Washington, DC 20375 USA. USN, Res Lab, Navy Technol Crtr Safety & Survivabil, Div Chem, Washington, DC 20375 USA. RP USN, Res Lab, Computat Phys & Fluid Dynam Lab, Ctr React Flow & Dynam Syst, Code 6410,4555 Overlook Ave, Washington, DC 20375 USA. EM prasad@lcp.nrl.navy.mil NR 41 TC 22 Z9 24 U1 0 U2 5 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 1364-7830 EI 1741-3559 J9 COMBUST THEOR MODEL JI Combust. Theory Model. PD DEC PY 1999 VL 3 IS 4 BP 743 EP 768 DI 10.1088/1364-7830/3/4/308 PG 26 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Mathematics, Interdisciplinary Applications SC Thermodynamics; Energy & Fuels; Engineering; Mathematics GA 277JX UT WOS:000084931400008 ER PT J AU Devereaux, A Amundson, D AF Devereaux, A Amundson, D TI Antibacterial effect of perflubron: Time for bugs to sink or swim SO CRITICAL CARE MEDICINE LA English DT Editorial Material DE liquid ventilation; perflubron; positive end-expiratory pressure ID PARTIAL LIQUID VENTILATION; NEUTROPHIL C1 USN, Med Ctr, San Diego, CA 92152 USA. RP Devereaux, A (reprint author), USN, Med Ctr, San Diego, CA 92152 USA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0090-3493 J9 CRIT CARE MED JI Crit. Care Med. PD DEC PY 1999 VL 27 IS 12 BP 2838 EP 2839 DI 10.1097/00003246-199912000-00045 PG 2 WC Critical Care Medicine SC General & Internal Medicine GA 270EZ UT WOS:000084523600045 PM 10628642 ER PT J AU Sageman, WS AF Sageman, WS TI Thoracic bioimpedance: A work in progress SO CRITICAL CARE MEDICINE LA English DT Letter C1 USN, Med Ctr, San Diego, CA 92152 USA. RP Sageman, WS (reprint author), USN, Med Ctr, San Diego, CA 92152 USA. NR 3 TC 1 Z9 1 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0090-3493 J9 CRIT CARE MED JI Crit. Care Med. PD DEC PY 1999 VL 27 IS 12 BP 2848 EP 2849 DI 10.1097/00003246-199912000-00053 PG 2 WC Critical Care Medicine SC General & Internal Medicine GA 270EZ UT WOS:000084523600053 PM 10628650 ER PT J AU Witucki, PJ Bell, SJ AF Witucki, PJ Bell, SJ TI Comparison of three new technology pulse oximeters during recovery from extreme exercise in adult males SO CRITICAL CARE MEDICINE LA English DT Meeting Abstract C1 USN, Special Warefare Ctr, San Diego, CA 92152 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0090-3493 J9 CRIT CARE MED JI Crit. Care Med. PD DEC PY 1999 VL 27 IS 12 SU S MA 224 BP A87 EP A87 DI 10.1097/00003246-199912001-00224 PG 1 WC Critical Care Medicine SC General & Internal Medicine GA 276RX UT WOS:000084892100224 ER PT J AU Coffin, RB Cifuentes, LA AF Coffin, RB Cifuentes, LA TI Stable isotope analysis of carbon cycling in the Perdido Estuary, Florida SO ESTUARIES LA English DT Article ID MARINE-BACTERIA; ORGANIC-MATTER; NITROGEN; GULF; FRACTIONATION; DYNAMICS; MEXICO; BAY AB Stable carbon isotope (delta(13)C) analysis was used in the Perdido Estuary, Florida U.S. to determine the predominant carbon source that supports the bacterial assemblage. Stable carbon isotope values were measured in the suspended particulate matter (SPM), dissolved organic and inorganic matter, and bacteria. Stable nitrogen isotope (delta(15)N) ratios were measured in SPM and nitrate to assist in understanding carbon cycling through the estuary. Analyses were conducted on samples from riverine, coastal, and anthropogenic sources and compared with samples from the bay. Stable isotope ratio analysis was coupled with estimates of mixing of riverine and coastal waters into the bay. Preliminary observation of the delta(13)C data indicates that terrestrial organic matter is the primary carbon source that is assimilated by bacteria in the ecosystem. Stable isotope data from carbon and nitrogen pools in combination with analysis of estuarine current velocities indicates that primary production is an important factor in the carbon cycle. This study demonstrates the importance of stable isotope analysis of multiple carbon and nitrogen pools to assess sources and cycling of organic matter. C1 USN, Res Lab, Environm Qual Sci Sect, Washington, DC 20375 USA. Texas A&M Univ, Dept Oceanog, College Stn, TX 77842 USA. US EPA, Gulf Breeze Environm Res Lab, Gulf Breeze, FL 32561 USA. RP Coffin, RB (reprint author), USN, Res Lab, Environm Qual Sci Sect, 4555 Overlook Dr SW, Washington, DC 20375 USA. NR 33 TC 42 Z9 42 U1 2 U2 11 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 USA SN 0160-8347 J9 ESTUARIES JI Estuaries PD DEC PY 1999 VL 22 IS 4 BP 917 EP 926 DI 10.2307/1353071 PG 10 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 280LR UT WOS:000085104700008 ER PT J AU Sanchez, GI Carucci, DJ Sacci, J Resau, JH Rogers, WO Kumar, N Hoffman, SL AF Sanchez, GI Carucci, DJ Sacci, J Resau, JH Rogers, WO Kumar, N Hoffman, SL TI Plasmodium yoelii: Cloning and characterization of the gene encoding for the mitochondrial heat shock protein 60 SO EXPERIMENTAL PARASITOLOGY LA English DT Article DE Plasmodium yoelii; Plasmodium falciparum; protozoa; malaria; heat shock protein; chaperonin 60; polymerase chain reaction; circumsporozoite protein; apical membrane antigen-1; Plasmodium; mitochondrial chaperonin ID MALARIA PARASITES; MOLECULAR CHARACTERIZATION; FALCIPARUM; EXPRESSION; FAMILY; STAGE; LOCALIZATION; CHAPERONES; BERGHEI; BIOLOGY AB Heat shock proteins are a highly conserved group of proteins required for the correct folding, transport, and degradation of other proteins in vivo. The Hsp70, Hsp90, and Hsp60 families are among the most widely studied families. Hsp60 is found in eubacteria, mitochondria, and chloroplasts, where, in cooperation with Hsp10, it participates in protein folding and translocation of proteins to the organelles. We have cloned and characterized the Hsp60 gene of Plasmodium yoelii (PyHsp60). PyHsp60 is a single-copy gene, located on chromosome 9, 10, or 11. The PyHsp60 cDNA sequence showed an open reading frame of 1737 nucleotides that codes for a polypeptide of 579 amino acids, with 93% amino acid identity to Plasmodium falciparum Hsp60 (PfHsp60). Cloning and sequencing of a genomic PCP clone showed the presence of a 201-bp intron, located 141 bp downstream of the ATG codon. A single, heat-inducible, 2.3-kb transcript was detected in Northern blots of RNA isolated from blood stage parasites. Mouse antisera raised against a DNA vaccine vector that expresses PyHsp60 recognized sporozoites and liver- and blood-stage parasites by indirect fluorescent antibody test (IFAT). By Western blot, these antisera reacted with the mycobacterial Hsp65 and recognized a protein of approximately 65 kDa in P. yoelii sporozoites and P. falciparum blood stages. These results show that PyHsp60 and PfHsp60 genes are homologous and that of the PyHsp60 gene encodes a heat-inducible, intracellular protein that is expressed in several of the developmental stages of P. yoelii. (C) 1999 Academic Press. C1 Johns Hopkins Univ, Sch Hyg & Publ Hlth, Dept Mol Microbiol & Immunol, Baltimore, MD 21205 USA. USN, Med Res Ctr, Malaria Program, Rockville, MD 20852 USA. Univ Maryland, Dept Microbiol & Immunol, Baltimore, MD 21201 USA. NCI, Frederick Canc Res & Dev Ctr, ABL Basic Res Program, Frederick, MD 21702 USA. RP Sanchez, GI (reprint author), Johns Hopkins Univ, Sch Hyg & Publ Hlth, Dept Mol Microbiol & Immunol, 615 N Wolfe St, Baltimore, MD 21205 USA. OI Sanchez, Gloria Ines/0000-0001-5992-0475 FU NIAID NIH HHS [AI31589] NR 33 TC 14 Z9 17 U1 0 U2 3 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0014-4894 J9 EXP PARASITOL JI Exp. Parasitol. PD DEC PY 1999 VL 93 IS 4 BP 181 EP 190 DI 10.1006/expr.1999.4455 PG 10 WC Parasitology SC Parasitology GA 262AE UT WOS:000084042900001 PM 10600443 ER PT J AU Leondires, MP Escalpes, M Segars, JH Scott, RT Miller, BT AF Leondires, MP Escalpes, M Segars, JH Scott, RT Miller, BT TI Microdose follicular phase gonadotropin-releasing hormone agonists (GnRH-a) compared with luteal phase GnRH-a for ovarian stimulation at in vitro fertilization SO FERTILITY AND STERILITY LA English DT Article; Proceedings Paper CT 53rd Annual Meeting for the American-Society-for-Reproductive-Medicine CY OCT 18-23, 1997 CL CINCINNATI, OHIO SP Amer Soc Reprod Med DE microdose GnRH-a; in vitro fertilization; cost efficiency ID INVITRO FERTILIZATION; OVULATION INDUCTION; LEUPROLIDE ACETATE; OOCYTE RETRIEVAL; SUPPRESSION; PROTOCOL; FLARE; HYPERSTIMULATION; RESPONSIVENESS; FECUNDITY AB Objective: To compare an ovarian stimulation protocol using microdose follicular phase GnRH agonist (GnRH-a) and oral contraceptive (OC) pills to a luteal phase CnRH-a protocol. Design: Retrospective analysis. Setting: University affiliated IVF program. Patient(s): One hundred seventy patients who underwent IVF and ET in 1996. Intervention(s): Patients were assigned to either a midluteal start of leuprolide acetate (LA) 1 mg/d, reduced to 0.5 mg/d after addition of gonadotropins (LUT), or OC pills until cycle day 0 followed by 20 mu g of LA every 12 hours on cycle day 3 with addition of gonadotropins on cycle day 5 (MICRO). Main Outcome Measure(s): Number of FSH ampules, days of stimulation, peak E-2, and number of oocytes retrieved. Result(s): There were no statistically significant differences in the main outcome measures between the two groups using an age-matched ANOVA. Clinical pregnancy rate per cycle start was not statistically different (LUT = 54%, and MICRO = 37%). The cancellation rate was significantly higher in the MICRO group (22.5% vs. 8.2%). Conclusion(s): Given the higher cancellation rate in the microdose group, a randomized clinical trial is required to determine the possible benefit of a lower dose of GnRN-a in patients with normal ovarian function. ((C)1999 by American Society for Reproductive Medicine.). C1 USN, Dept Obstet & Gynecol, Natl Med Ctr, Gaithersburg, MD 20899 USA. Wayne State Univ, NICHHD, NIH, Detroit, MI USA. Reprod Med Associates New Jersey, Morristown, NJ USA. Wayne State Univ, Dept Obstet & Gynecol, Detroit, MI USA. RP Miller, BT (reprint author), USN, Dept Obstet & Gynecol, Natl Med Ctr, 8901 Wisconsin Ave, Gaithersburg, MD 20899 USA. NR 21 TC 41 Z9 41 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0015-0282 J9 FERTIL STERIL JI Fertil. Steril. PD DEC PY 1999 VL 72 IS 6 BP 1018 EP 1023 DI 10.1016/S0015-0282(99)00423-9 PG 6 WC Obstetrics & Gynecology; Reproductive Biology SC Obstetrics & Gynecology; Reproductive Biology GA 259QL UT WOS:000083904500012 PM 10593374 ER PT J AU Slinker, SP Fedder, JA Hughes, WJ Lyon, JG AF Slinker, SP Fedder, JA Hughes, WJ Lyon, JG TI Response of the ionosphere to a density pulse in the solar wind: simulation of traveling convection vortices SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; GLOBAL NUMERICAL-SIMULATION; TWIN-VORTICES; MAGNETOSPHERE; MODEL AB We show the response of the Earth's magnetosphere and ionosphere to a density pulse in the solar wind using a global 3D MHD simulation model. Flow vortices are generated in the ionosphere and they exhibit many properties similar to those observed during impulsive traveling convection vortices. Two oppositely rotating flow vortices are formed at about 70 degrees magnetic latitude near noon. They separate and move down the morning and evening flanks, greatly weakening as they pass the terminator. Meanwhile a second pair of flow vortices appears at noon at a slightly higher latitude and with opposite flow directions than the first pair. The second pair follows the first and also fades as it reaches the nightside. The results are interpreted as a hydromagnetic wave propagating in the inhomogeneous magnetosphere plasma. C1 USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. George Mason Univ, Fairfax, VA 22030 USA. Boston Univ, Ctr Space Phys, Boston, MA 02215 USA. Dartmouth Coll, Hanover, NH 03755 USA. RP Slinker, SP (reprint author), USN, Res Lab, Div Plasma Phys, Code 6794, Washington, DC 20375 USA. NR 16 TC 56 Z9 56 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1999 VL 26 IS 23 BP 3549 EP 3552 DI 10.1029/1999GL010688 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 261LN UT WOS:000084010800032 ER PT J AU Krebs, WK McCarley, JS Bryant, EV AF Krebs, WK McCarley, JS Bryant, EV TI Effects of mission rehearsal simulation on air-to-ground target acquisition SO HUMAN FACTORS LA English DT Article ID ROTATION; DESIGN AB Traditionally military aviators have prepared for air-to-ground bombing missions with maps and aerial photographs of their targets. Mission rehearsal systems augment these media by allowing pilots to view simulated ingress to their target, as seen from the cockpit perspective. In the present experiment we assessed the benefits of mission rehearsal with a task requiring observers to view recorded approaches to target objects and to detect the target objects as quickly as possible. Results indicated that premission simulations allowed observers to detect target objects at greater stand-off ranges than did study with maps and aerial photographs alone. Actual or potential applications of this research include the deployment of a mission rehearsal system to assist aviators' mission planning. C1 USN, Postgrad Sch, Dept Operat Res, Monterey, CA 93943 USA. RP Krebs, WK (reprint author), USN, Postgrad Sch, Dept Operat Res, 1411 Cunningham Rd, Monterey, CA 93943 USA. NR 16 TC 10 Z9 10 U1 0 U2 0 PU HUMAN FACTORS SOC PI SANTA MONICA PA BOX 1369, SANTA MONICA, CA 90406 USA SN 0018-7208 J9 HUM FACTORS JI Hum. Factors PD DEC PY 1999 VL 41 IS 4 BP 553 EP 558 DI 10.1518/001872099779656725 PG 6 WC Behavioral Sciences; Engineering, Industrial; Ergonomics; Psychology, Applied; Psychology SC Behavioral Sciences; Engineering; Psychology GA 302EN UT WOS:000086352900004 PM 10774126 ER PT J AU Hurst, P Kub, F Khoury, JM AF Hurst, P Kub, F Khoury, JM TI Special issue on the 1999 ISSCC analog sensor and communication circuits SO IEEE JOURNAL OF SOLID-STATE CIRCUITS LA English DT Editorial Material C1 Univ Calif Davis, Davis, CA 95616 USA. USN, Res Lab, Washington, DC 20375 USA. Lucent Technol, Philadelphia, PA 18104 USA. RP Hurst, P (reprint author), Univ Calif Davis, Davis, CA 95616 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9200 J9 IEEE J SOLID-ST CIRC JI IEEE J. Solid-State Circuit PD DEC PY 1999 VL 34 IS 12 BP 1688 EP 1690 DI 10.1109/JSSC.1999.808893 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 266ZV UT WOS:000084330900001 ER PT J AU Posey, R Vohra, ST AF Posey, R Vohra, ST TI An eight-channel fiber-optic Bragg grating and stimulated Brillouin sensor system for simultaneous temperature and strain measurements SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article DE Brillouin scattering; fiber Bragg gratings; fiberoptic sensing ID SCATTERING AB An eight channel fiber-optic sensor has been developed to simultaneously measure the strain and temperature independently using fiber Bragg gratings and stimulated Brillouin scattering, The temperature and strain resolution is approximately 1.5 degrees C and 20 mu epsilon, and the spatial resolution for sensing Brillouin scattering is 5 m. C1 USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. RP Posey, R (reprint author), USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. NR 8 TC 11 Z9 11 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD DEC PY 1999 VL 11 IS 12 BP 1641 EP 1643 DI 10.1109/68.806873 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 263AL UT WOS:000084100400039 ER PT J AU Burns, WK Howerton, MM Moeller, RP AF Burns, WK Howerton, MM Moeller, RP TI Broad-band unamplified optical link with RF gain using a LiNbO3 modulator SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article DE integrated optics; LiNbO3 optical modulators; optical links ID PERFORMANCE AB A reflection traveling-wave LiNbO3 modulator is used to demonstrate unamplified link gain to 550 MHz, taking advantage of its low-drive voltage (0.5 V V-pi) at low frequencies, and high optical powers. 7.5 dB of gain is achieved at 50 MHz with an optical power of 188 mW and 8.5 mA of detector current. Noise figure of the 50-MHz link is 11 dB and spur-free dynamic range is 114 dB.Hz(2/3). A model for gain is presented, which shows good agreement with experimental results. C1 USN, Res Lab, Washington, DC 20375 USA. SFA Inc, Largo, MD 20774 USA. RP Burns, WK (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 10 TC 11 Z9 11 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD DEC PY 1999 VL 11 IS 12 BP 1656 EP 1658 DI 10.1109/68.806878 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 263AL UT WOS:000084100400044 ER PT J AU Dennis, ML Kaechele, WI Goldberg, L Carruthers, TF Duling, IN AF Dennis, ML Kaechele, WI Goldberg, L Carruthers, TF Duling, IN TI Wavelength-division-multiplexed 4 x 10 Gb/s adiabatic soliton transmission over 235 km SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article DE optical solitons; optical transmission; solitons; wavelength-division multiplexing ID SINGLE-CHANNEL TRANSMISSION; UNREPEATERED TRANSMISSION; WDM TRANSMISSION; FIBER; AMPLIFIERS; 1.55-MU-M; DISTANCE AB We demonstrate four-channel error-free repeaterless transmission using adiabatic propagation of optical solitons. We show that channel-to-channel cross phase modulation does not degrade system performance for as many as eight transmitted WDM channels. No stimulated Brillouin scattering threshold is observed up to launched powers of 29 dBm per channel. C1 USN, Res Lab, Adv Lightwave Appl Sect, Washington, DC 20375 USA. RP Dennis, ML (reprint author), USN, Res Lab, Adv Lightwave Appl Sect, Washington, DC 20375 USA. NR 13 TC 2 Z9 2 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD DEC PY 1999 VL 11 IS 12 BP 1680 EP 1682 DI 10.1109/68.806886 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 263AL UT WOS:000084100400052 ER PT J AU Creusere, CD AF Creusere, CD TI Fast embedded compression for video SO IEEE TRANSACTIONS ON IMAGE PROCESSING LA English DT Letter DE embedded compression; EZW; high speed; image compression; low complexity; video compression; wavelet compression ID WAVELET AB An embedded coding algorithm creates a compressed bit stream that can be truncated to produce reduced resolution versions of the original image, Unfortunately, such algorithms are relatively slow. In this work, we introduce two new concepts in an effort to address this problem: adaptive embedding and cache-based zerotree processing. C1 USN, Warfare Ctr, China Lake, CA 93555 USA. RP Creusere, CD (reprint author), USN, Warfare Ctr, China Lake, CA 93555 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1057-7149 J9 IEEE T IMAGE PROCESS JI IEEE Trans. Image Process. PD DEC PY 1999 VL 8 IS 12 BP 1811 EP 1816 DI 10.1109/83.806626 PG 6 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 261VP UT WOS:000084031200014 PM 18267457 ER PT J AU Musseau, O Torres, A Campbell, AB Knudson, AR Buchner, S Fischer, B Schlogl, M Briand, P AF Musseau, O Torres, A Campbell, AB Knudson, AR Buchner, S Fischer, B Schlogl, M Briand, P TI Medium-energy heavy-ion single-event-burnout imaging of power MOSFET's SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 IEEE Nuclear and Space Radiation Effects Conference (NSREC 99) CY JUL 12-16, 1999 CL NORFOLK, VIRGINIA SP IEEE Nuclear & Plasma Sci Soc, Raduat Effects Comm, Def Threat Redyct Agcy, Sandia Natl Lab, NASA Goddard Space Flight Ctr, Jet Propuls Lab, Air Force Res Lab ID UPSETS; SEB AB We present the first experimental determination of the SEE sensitive area in a power MOSFET irradiated with a high-LET heavy-ion microbeam. We used a spectroscopy technique to perform coincident measurements of the charge collected in both source and drain junctions together, with a non-destructive technique (current limitation). The resulting charge collection images are related to the physical structure of the individual cells. These experimental data reveal the complex 3-dimensional behavior of a real structure, which can not easily be simulated using available tools. As the drain voltage is increased, the onset of burnout is reached, characterized by a sudden change in the charge collection image. "Hot spots" are observed where the collected charge reaches its maximum value. Those spots, due to burnout triggering events, correspond to areas where the silicon is degraded through thermal effects along a single ion track. This direct observation of SEE sensitive areas as applications for, either device hardening, by modifying doping profiles or layout of the cells, or for code calibration and device simulation. C1 CEA DAM DIF, Bruyeres Le Chatel, France. USN, Res Lab, Washington, DC 20375 USA. SFA, Landover, MD USA. GSI, Darmstadt, Germany. ST Microelect, Rennes, France. RP Musseau, O (reprint author), CEA DAM DIF, Bruyeres Le Chatel, France. NR 14 TC 4 Z9 6 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1999 VL 46 IS 6 BP 1415 EP 1420 DI 10.1109/23.819101 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 279RG UT WOS:000085058500015 ER PT J AU Buchner, S Tran, L Mann, J Turflinger, T McMorrow, D Campbell, A Dozier, C AF Buchner, S Tran, L Mann, J Turflinger, T McMorrow, D Campbell, A Dozier, C TI Single-event effects in resolver-to-digital converters SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 IEEE Nuclear and Space Radiation Effects Conference (NSREC 99) CY JUL 12-16, 1999 CL NORFOLK, VIRGINIA SP IEEE Nuclear & Plasma Sci Soc, Raduat Effects Comm, Def Threat Redyct Agcy, Sandia Natl Lab, NASA Goddard Space Flight Ctr, Jet Propuls Lab, Air Force Res Lab AB Single-event effects (SEE's) in two resolver-to-digital converters (RDC's) have been studied using heavy ions and pulsed laser light. The important role of the pulsed laser in establishing single-event upset (SEU) and single-event latchup (SEL) levels prior to accelerator testing is described, as is its role in evaluating the test software and hardware and in gaining a better understanding of the origins of the SEE's. Results from pulsed-laser testing are in quantitative agreement with those from heavy-ion testing: the RDC-19220 is sensitive to both SEU's and SEL's whereas the AD2S80 is less sensitive to SEU's and immune to SEL. C1 USN, Res Lab, Washington, DC 20375 USA. SFA Inc, Largo, MD 20774 USA. NSWC, Crane, IN 47401 USA. RP Buchner, S (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 5 TC 12 Z9 12 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1999 VL 46 IS 6 BP 1445 EP 1452 DI 10.1109/23.819106 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 279RG UT WOS:000085058500020 ER PT J AU Xapsos, MA Summers, GP Barth, JL Stassinopoulos, EG Burke, EA AF Xapsos, MA Summers, GP Barth, JL Stassinopoulos, EG Burke, EA TI Probability model for worst case solar proton event fluences SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 IEEE Nuclear and Space Radiation Effects Conference (NSREC 99) CY JUL 12-16, 1999 CL NORFOLK, VIRGINIA SP IEEE Nuclear & Plasma Sci Soc, Raduat Effects Comm, Def Threat Redyct Agcy, Sandia Natl Lab, NASA Goddard Space Flight Ctr, Jet Propuls Lab, Air Force Res Lab AB A predictive model of worst case solar proton event fluences is presented. It allows the expected worst case eve nt fluence to be calculated for a given confidence level and fbr periods of time corresponding to space missions. The proton energy range is from > 1 to > 300 MeV, so that the model is useful for a variety of radiation effects applications. For each proton energy threshold, the maximum entropy principle is used to select the initial distribution of solar proton event fluences. This turns out to be a truncated power law, i.e., a power law for smaller event fluences that smoothly approaches zero at a maximum fluence. The strong agreement of the distribution with satellite data for the last three solar cycles indicates this description captures the essential features of a solar proton event fluence distribution. Extreme value theory is then applied to the initial distribution of events to obtain the model of worst case fluences. C1 USN, Res Lab, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Xapsos, MA (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 18 TC 35 Z9 35 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1999 VL 46 IS 6 BP 1481 EP 1485 DI 10.1109/23.819111 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 279RG UT WOS:000085058500025 ER PT J AU Dyer, CS Comber, C Truscott, PR Sanderson, C Underwood, C Oldfield, M Campbell, A Buchner, S Meehan, T AF Dyer, CS Comber, C Truscott, PR Sanderson, C Underwood, C Oldfield, M Campbell, A Buchner, S Meehan, T TI Microdosimetry code simulation of charge-deposition spectra, single-event upsets and multiple-bit upsets SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 IEEE Nuclear and Space Radiation Effects Conference (NSREC 99) CY JUL 12-16, 1999 CL NORFOLK, VIRGINIA SP IEEE Nuclear & Plasma Sci Soc, Raduat Effects Comm, Def Threat Redyct Agcy, Sandia Natl Lab, NASA Goddard Space Flight Ctr, Jet Propuls Lab, Air Force Res Lab ID SEU RATES; PROTON; SATELLITE; ANGLE AB An ion microdosimetry extension to the Monte Carlo High Energy Transport Code (HETC) has been developed to allow tracking of all the reaction products and has been applied to model charge-deposition spectra in pin diodes caused by atmospheric neutron spectra, as well as upsets in DRAMs from ground and space irradiation by protons. These cases cover sensitive zone sizes ranging from hundreds of microns to sub-micron. Angular distributions of both incident particles and reaction products are found to be important, particularly for the prediction of multiple-bit upsets in devices of small feature size. C1 DERA, Dept Space, Farnborough GU14 0LX, Hants, England. EDS Def Ltd, Fleet, Hants, England. Univ Surrey, Surrey Space Ctr, Guildford, Surrey, England. USN, Res Lab, Radiat Effects Branch, Washington, DC 20375 USA. USN, Res Lab, SFA Radiat Effects Branch, Washington, DC 20375 USA. USN, Res Lab, Navy Ctr Space Technol, Washington, DC 20375 USA. RP Dyer, CS (reprint author), DERA, Dept Space, A8 Bldg, Farnborough GU14 0LX, Hants, England. NR 17 TC 23 Z9 23 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1999 VL 46 IS 6 BP 1486 EP 1493 DI 10.1109/23.819112 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 279RG UT WOS:000085058500026 ER PT J AU Messenger, SR Burke, EA Summers, GP Xapsos, MA Walters, RJ Jackson, EM Weaver, BD AF Messenger, SR Burke, EA Summers, GP Xapsos, MA Walters, RJ Jackson, EM Weaver, BD TI Nonionizing energy loss (NIEL) for heavy ions SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 IEEE Nuclear and Space Radiation Effects Conference (NSREC 99) CY JUL 12-16, 1999 CL NORFOLK, VIRGINIA SP IEEE Nuclear & Plasma Sci Soc, Raduat Effects Comm, Def Threat Redyct Agcy, Sandia Natl Lab, NASA Goddard Space Flight Ctr, Jet Propuls Lab, Air Force Res Lab ID INDUCED DISPLACEMENT DAMAGE; TEMPERATURE; RADIATION AB The concept of nonionizing energy loss (NIEL) has been found useful for characterizing displacement damage effects in materials and devices. Published tabulations, however, are limited with respect to target materials, particle types and energies. In this paper we show how the NIEL database can be significantly expanded to include heavy ions in the coulombic limit by using the Monte Carlo code SRIM. The methodology used to extract NIEL from SRIM is described This greatly adds to the number of materials and incident particles for which the NIEL concept can be applied. To show that values so derived are consistent with previous calculations, we compare alpha particle NIEL for GaAs derived from SRIM with a direct analytical calculation. The SRIM code is limited in that only coulombic interactions are considered. General rules of thumb are also described which permit prediction of NIEL for any target material over a large energy range. Tabulated values of NIEL for alpha particles incident on Si, GaAs and InP are presented. C1 SFA Inc, Largo, MD 20774 USA. Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA. USN, Res Lab, Washington, DC 20375 USA. RP Messenger, SR (reprint author), SFA Inc, Largo, MD 20774 USA. NR 18 TC 114 Z9 116 U1 1 U2 12 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1999 VL 46 IS 6 BP 1595 EP 1602 DI 10.1109/23.819126 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 279RG UT WOS:000085058500040 ER PT J AU Titus, JL Emily, D Krieg, JF Turflinger, T Pease, RL Campbell, A AF Titus, JL Emily, D Krieg, JF Turflinger, T Pease, RL Campbell, A TI Enhanced low dose rate sensitivity (ELDRS) of linear circuits in a space environment SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 IEEE Nuclear and Space Radiation Effects Conference (NSREC 99) CY JUL 12-16, 1999 CL NORFOLK, VIRGINIA SP IEEE Nuclear & Plasma Sci Soc, Raduat Effects Comm, Def Threat Redyct Agcy, Sandia Natl Lab, NASA Goddard Space Flight Ctr, Jet Propuls Lab, Air Force Res Lab AB To investigate the ELDRS effect in a real space environment, an experiment was designed, launched, and placed in a highly elliptical orbit in November 1997. After its deployment, the electrical responses of several bipolar transistors and linear circuits have been and continue to be recorded once during every 12-hour orbit. System dosimeters are monitored to establish an average accumulated dose per orbit. With this information, the electrical parameter data are correlated with the dosimetry data to determine the total dose response of each device. This paper updates information on the ELDRS experiment through May 14, 1999. As of this date, the experiment has been in flight for a period of 18 months and has accumulated an approximate dose of 18 krd(Si). For comparison,devices, specifically linear circuits with the same date code, were irradiated using Co-60 sources, herein defined as ground-based tests. The ground-based tests are used to evaluate two hardness assurance tests, a room temperature irradiation at 10 mrd(Si)/s and an elevated temperature irradiation at 100 degrees C and 10 rd(Si)/s and to evaluate the ELDRS response. To that end, irradiations were performed at room temperature, approximately 22 degrees C, at fixed dose rates of 100, 1, and 0.01 rd(Si)/s and at elevated temperature, approximately 100 degrees C, at a fixed dose rate of 10 rd(Si)/s. Currently, irradiations are being performed at room temperature at a fixed dose rate of 0.001 rd(Si)/s. Comparing the ground-based data to the flight data clearly demonstrates that enhanced parametric degradation has occurred in the flight parts. The two hardness assurance screens predicted ELDRS but the design margin for the elevated temperature test may not be adequate. C1 USN, Ctr Surface Warfare, Crane, IN 47522 USA. RLP Res, Albuquerque, NM 87122 USA. USN, Res Lab, Washington, DC 20375 USA. RP Titus, JL (reprint author), USN, Ctr Surface Warfare, 300 Hwy 361, Crane, IN 47522 USA. NR 11 TC 13 Z9 21 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1999 VL 46 IS 6 BP 1608 EP 1615 DI 10.1109/23.819128 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 279RG UT WOS:000085058500042 ER PT J AU Banerjee, G Niu, G Cressler, JD Clark, SD Palmer, MJ Ahlgren, DC AF Banerjee, G Niu, G Cressler, JD Clark, SD Palmer, MJ Ahlgren, DC TI Anomalous dose rate effects in gamma irradiated SiGe heterojunction bipolar transistors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 IEEE Nuclear and Space Radiation Effects Conference (NSREC 99) CY JUL 12-16, 1999 CL NORFOLK, VIRGINIA SP IEEE Nuclear & Plasma Sci Soc, Raduat Effects Comm, Def Threat Redyct Agcy, Sandia Natl Lab, NASA Goddard Space Flight Ctr, Jet Propuls Lab, Air Force Res Lab ID HARDNESS ASSURANCE; GAIN DEGRADATION; RADIATION AB Low dose rate (LDR) cobalt-60 (0.1 rad(Si)/s) gamma irradiated Silicon Germanium (SiGe) Heterojunction Bipolar Transistors (HBTs) were studied. Comparisons were made with devices irradiated with 300 rad(Si)/s gamma radiation to verify if LDR radiation is a serious radiation hardness assurance (RHA) issue. Almost no LDR, degradation was observed in this technology up to 50 krad(Si). The assumption of the presence of two competing mechanisms is justified by experimental results. At low total dose (less than or equal to 20 krad), an anomalous base current decrease was observed which is attributed to self-annealing of deep-level traps to shallower levels. An increase in base current at larger total doses is attributed to radiation induced generation-recombination (G/R) center generation. Experiments on gate-assisted lateral PNP transistors and 2D numerical simulations using MEDICI were used to confirm these assertions. C1 Auburn Univ, Dept Elect Engn, Alabama Microelect Sci & Technol Ctr, Auburn, AL 36849 USA. USN, Ctr Surface Warfare, Crane, IN 47522 USA. IBM Microelect, Hopewell Junction, NY 12533 USA. RP Banerjee, G (reprint author), Auburn Univ, Dept Elect Engn, Alabama Microelect Sci & Technol Ctr, 200 Broun Hall, Auburn, AL 36849 USA. NR 18 TC 18 Z9 20 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1999 VL 46 IS 6 BP 1620 EP 1626 DI 10.1109/23.819130 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 279RG UT WOS:000085058500044 ER PT J AU Titus, JL Wheatley, CF Wheatley, TH Levinson, WA Burton, DI Barth, JL Reed, RA LaBel, KA Howard, JW VanTyne, KM AF Titus, JL Wheatley, CF Wheatley, TH Levinson, WA Burton, DI Barth, JL Reed, RA LaBel, KA Howard, JW VanTyne, KM TI Prediction of early lethal SEGR failures of VDMOSFETs for commercial space systems SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 IEEE Nuclear and Space Radiation Effects Conference (NSREC 99) CY JUL 12-16, 1999 CL NORFOLK, VIRGINIA SP IEEE Nuclear & Plasma Sci Soc, Raduat Effects Comm, Def Threat Redyct Agcy, Sandia Natl Lab, NASA Goddard Space Flight Ctr, Jet Propuls Lab, Air Force Res Lab ID EVENT-GATE-RUPTURE; VERTICAL POWER MOSFETS; CROSS-SECTION; EXPRESSION AB Quantitative risk assessments are presented for two radiation-hardened MOSFETs (Harris FSL11A0 and FRL11A0) using an extracted expression, integral flux curves representing different conditions, and experimentally-determined signature curves taken at different ion impact angles. The effectiveness of certain parameters including the selected orbit, spacecraft shielding thickness, drain and gate biases, device hardness, and time of exposure are discussed. Failures are studied using normalized Monte Carlo simulations validated by statistical methods. These validated Monte Carlo simulations are then used to extract and present an extracted expression. The concept of a lethal ion rate is discussed. Single event gate rupture (SEGR) failure thresholds at different ion impact angles are measured and reported on the Harris FSL11A0 and FRL11A0 (radiation-hardened vertical MOSFETs having similar layouts but with different SEGR sensitivities). Integral flux curves are presented for various orbits and conditions. Predictions of very early failures are performed using the extracted expression, the integral flux curves, and the new signature curves. Based upon these predictions, the influence of selected parameters are evaluated. C1 USN, Ctr Surface Warfare, Crane, IN 47522 USA. Harris Semicond Inc, Palm Bay, FL 32905 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA J&T, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Titus, JL (reprint author), USN, Ctr Surface Warfare, 300 Hwy 361, Crane, IN 47522 USA. NR 17 TC 14 Z9 14 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1999 VL 46 IS 6 BP 1640 EP 1651 DI 10.1109/23.819133 PN 1 PG 12 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 279RG UT WOS:000085058500047 ER PT J AU Xapsos, MA Summers, GP Jackson, EM AF Xapsos, MA Summers, GP Jackson, EM TI Enhanced total ionizing dose tolerance of bulk CMOS transistors fabricated for ultra-low power applications SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 IEEE Nuclear and Space Radiation Effects Conference (NSREC 99) CY JUL 12-16, 1999 CL NORFOLK, VIRGINIA SP IEEE Nuclear & Plasma Sci Soc, Raduat Effects Comm, Def Threat Redyct Agcy, Sandia Natl Lab, NASA Goddard Space Flight Ctr, Jet Propuls Lab, Air Force Res Lab ID RADIATION AB The first radiation tests of transistors fabricated in a commercial bulk CMOS process designed for ultra-low power applications in space are presented and analyzed. The predominant failure mode of bulk CMOS, i.e., radiation-induced parasitic leakage currents in n-channel transistors, is greatly suppressed by the use of low threshold voltage devices and by the application of backbias used to optimize their performance. With 2 volts of backbias applied, the transistors tested here show no degradation up to a dose of 200 krad(Si). C1 USN, Res Lab, Washington, DC 20375 USA. SFA Inc, Largo, MD 20774 USA. RP Xapsos, MA (reprint author), USN, Res Lab, Code 6825, Washington, DC 20375 USA. NR 9 TC 10 Z9 10 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1999 VL 46 IS 6 BP 1697 EP 1701 DI 10.1109/23.819141 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 279RG UT WOS:000085058500055 ER PT J AU Zhang, SM Niu, GF Cressler, JD Clark, SD Ahlgren, DC AF Zhang, SM Niu, GF Cressler, JD Clark, SD Ahlgren, DC TI The effects of proton irradiation on the RF performance of SiGeHBTs SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 IEEE Nuclear and Space Radiation Effects Conference (NSREC 99) CY JUL 12-16, 1999 CL NORFOLK, VIRGINIA SP IEEE Nuclear & Plasma Sci Soc, Raduat Effects Comm, Def Threat Redyct Agcy, Sandia Natl Lab, NASA Goddard Space Flight Ctr, Jet Propuls Lab, Air Force Res Lab ID IONIZING-RADIATION; DEGRADATION; TECHNOLOGY; TOLERANCE AB The effects of proton irradiation on the RF performance of SiGe Heterojunction Bipolar Transistors (HBTs) are reported in this paper. Frequency response and broadband noise properties are investigated in SiGe HBTs for proton fluences up to 5x10(13) p/cm(2). The current gain in the radio frequency (RF) bias region and the cutoff frequency (f(T)) show little degradation at even extreme proton fluence (realistic space fluences are 1-5x10(11) p/cm(2)). The slight degradation of NFmin is due to the irradiation-induced increase in the total emitter and base resistance. The associated available gain GA,assoc at noise matching is 20.2 dB at f=2 GHz and I-C=2.6 mA for a proton fluence of 5x10(13) p/cm(2). These results suggest that space-borne RF circuit applications of SiGe HBTs should be robust to proton irradiation. C1 Auburn Univ, Dept Elect & Comp Engn, Alabama Microelect Sci & Technol Ctr, Auburn, AL 36849 USA. USN, Ctr Surface Warfare, Crane, IN 47522 USA. IBM Microelect, Hopewell Junction, NY 12533 USA. RP Zhang, SM (reprint author), Auburn Univ, Dept Elect & Comp Engn, Alabama Microelect Sci & Technol Ctr, 200 Broun Hall, Auburn, AL 36849 USA. NR 16 TC 19 Z9 21 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1999 VL 46 IS 6 BP 1716 EP 1721 DI 10.1109/23.819144 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 279RG UT WOS:000085058500058 ER PT J AU Liu, ST Balster, S Sinha, S Jenkins, WC AF Liu, ST Balster, S Sinha, S Jenkins, WC TI Worst case total dose radiation response of 0.35 mu m SOICMOSFETs SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 IEEE Nuclear and Space Radiation Effects Conference (NSREC 99) CY JUL 12-16, 1999 CL NORFOLK, VIRGINIA SP IEEE Nuclear & Plasma Sci Soc, Raduat Effects Comm, Def Threat Redyct Agcy, Sandia Natl Lab, NASA Goddard Space Flight Ctr, Jet Propuls Lab, Air Force Res Lab ID SIMOX AB Through experimental results and analysis by TSUPREM4/MEDICI simulations, the worst ease back gate total dose bias condition is established for body tied SOI NMOSFETs. Utilizing the worst-case bias condition, a recently proposed model that describes the back n-channel threshold voltage shift as a function of total dose, TSUPREM4/MEDICI simulations, and circuit level SPICE simulations, a methodology to model post-rad standby current is developed and presented. This methodology requires the extraction of fundamental starting material/material preparation constants, and then can be utilized to examine post-rad stand-by current at the device and circuit level as function of total dose. Good agreement between experimental results and simulations is demonstrated. C1 Honeywell Inc, Solid State Elect Ctr, Plymouth, MN 55441 USA. USN, Res Lab, Washington, DC 20375 USA. RP Liu, ST (reprint author), Honeywell Inc, Solid State Elect Ctr, Plymouth, MN 55441 USA. NR 12 TC 38 Z9 43 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1999 VL 46 IS 6 BP 1817 EP 1823 DI 10.1109/23.819159 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 279RG UT WOS:000085058500073 ER PT J AU Liu, ST Fechner, P Balster, S Dougal, G Sinha, S Chen, H Shaw, G Yue, J Jenkins, WC Hughes, HL AF Liu, ST Fechner, P Balster, S Dougal, G Sinha, S Chen, H Shaw, G Yue, J Jenkins, WC Hughes, HL TI A 5 nm nitrided gate oxide for 0.25 mu m SOICMOS technologies SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 IEEE Nuclear and Space Radiation Effects Conference (NSREC 99) CY JUL 12-16, 1999 CL NORFOLK, VIRGINIA SP IEEE Nuclear & Plasma Sci Soc, Raduat Effects Comm, Def Threat Redyct Agcy, Sandia Natl Lab, NASA Goddard Space Flight Ctr, Jet Propuls Lab, Air Force Res Lab AB Hot carrier lifetime, gate oxide integrity, and radiation response of a 5 nm nitrided gate oxide were evaluated for 0.25 mu m SOI CMOS devices intended for use in 2.5V applications and high radiation environments. The devices were fabricated in a new SOI substrate called UNIBOND-170. It is found that the DC hot electron lifetime of the devices exceed 10 years at the operating voltage. Good gate oxide integrity and radiation hardening up to 1Mrad are shown to make this technology promising for radiation-hard ULSI applications. C1 Honeywell Inc, Solid State Elect Ctr, Plymouth, MN 55441 USA. USN, Res Lab, Washington, DC 20375 USA. RP Liu, ST (reprint author), Honeywell Inc, Solid State Elect Ctr, Plymouth, MN 55441 USA. NR 17 TC 8 Z9 9 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1999 VL 46 IS 6 BP 1824 EP 1829 DI 10.1109/23.819160 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 279RG UT WOS:000085058500074 ER PT J AU Niu, G Mathew, SJ Banerjee, G Cressler, JD Clark, SD Palmer, MJ Subbanna, S AF Niu, G Mathew, SJ Banerjee, G Cressler, JD Clark, SD Palmer, MJ Subbanna, S TI Total dose effects on the shallow-trench isolation leakage current characteristics in a 0.35 mu m SiGeBiCMOS technology SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 IEEE Nuclear and Space Radiation Effects Conference (NSREC 99) CY JUL 12-16, 1999 CL NORFOLK, VIRGINIA SP IEEE Nuclear & Plasma Sci Soc, Raduat Effects Comm, Def Threat Redyct Agcy, Sandia Natl Lab, NASA Goddard Space Flight Ctr, Jet Propuls Lab, Air Force Res Lab ID INTERFACE AB The effects of gamma irradiation on the Shallow-Trench Isolation (STI) leakage currents in a SiGe BiCMOS technology are investigated for the first time, and shown to be strongly dependent on the irradiation gate bias and operating substrate bias. A positive irradiation gate bias significantly enhances the STI leakage, suggesting a strong field assisted nature of the charge buildup process in the STI. Numerical simulations also suggest the existence of fixed positive charges deep in the bulk along the STI/Si interface. A negative substrate bias, however, effectively suppresses the STI leakage, and can be used to eliminate the leakage produced by the charges deep in the bulk under irradiation. C1 Auburn Univ, Dept Elect & Comp Engn, Alabama Microelect Sci & Technol Ctr, Auburn, AL 36849 USA. USN, Ctr Surface Warfare, Crane, IN 47522 USA. IBM Microelect, Hopewell Junction, NY 12533 USA. RP Niu, G (reprint author), Auburn Univ, Dept Elect & Comp Engn, Alabama Microelect Sci & Technol Ctr, 200 Broun Hall, Auburn, AL 36849 USA. NR 10 TC 33 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 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1999 VL 46 IS 6 BP 1841 EP 1847 DI 10.1109/23.819163 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 279RG UT WOS:000085058500077 ER PT J AU Mathew, SJ Niu, G Clark, SD Cressler, JD Palmer, MJ Dubbelday, WB AF Mathew, SJ Niu, G Clark, SD Cressler, JD Palmer, MJ Dubbelday, WB TI Radiation-induced back-channel leakage in SiGeCMOS on silicon-on-sapphire (SOS) technology SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 IEEE Nuclear and Space Radiation Effects Conference (NSREC 99) CY JUL 12-16, 1999 CL NORFOLK, VIRGINIA SP IEEE Nuclear & Plasma Sci Soc, Raduat Effects Comm, Def Threat Redyct Agcy, Sandia Natl Lab, NASA Goddard Space Flight Ctr, Jet Propuls Lab, Air Force Res Lab ID CMOS AB We report the first results of a high-energy gamma irradiation experiment on SiGe CMOS on silicon-on-sapphire (SOS) technology. In contrast to bulk Si CMOS, with increasing total dose the pFET's develop a significant off-state leakage, while the nFET's show a reduction in the leakage, which we attribute to negative charge trapping at the back Si-sapphire interface. Both the Si and SiGe pFET's showed the enhancement in leakage, suggesting that the leakage mechanism was not related to the SiGe channel. When the devices were cooled to liquid-nitrogen temperature, the leakage disappears completely, suggesting that the trapping mechanism is strongly temperature dependent. C1 Auburn Univ, Dept Elect & Comp Engn, Alabama Microelect Sci & Technol Ctr, Auburn, AL 36849 USA. USN, Ctr Surface Warfare, Crane, IN 47522 USA. SPAWAR Syst Ctr, San Diego, CA 92152 USA. RP Cressler, JD (reprint author), Auburn Univ, Dept Elect & Comp Engn, Alabama Microelect Sci & Technol Ctr, 200 Broun Hall, Auburn, AL 36849 USA. NR 14 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1999 VL 46 IS 6 BP 1848 EP 1853 DI 10.1109/23.819164 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 279RG UT WOS:000085058500078 ER PT J AU Runkle, P Carin, L Couchman, T Yoder, TJ Bucaro, JA AF Runkle, P Carin, L Couchman, T Yoder, TJ Bucaro, JA TI Multiaspect target identification with wave-based matched pursuits and continuous hidden Markov models SO IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE LA English DT Article DE hidden Markov model; matched pursuits; classification ID SPEECH RECOGNITION; SHELL AB Multiaspect target identification is effected by fusing the features extracted from multiple scattered waveforms; these waveforms are characteristic of viewing the target from a sequence of distinct orientations. Classification is performed in the maximum-likelihood sense, which we show. under reasonable assumptions, can be implemented via a hidden Markov model (HMM). We utilize a continuous-HMM paradigm and compare its performance to its discrete counterpart. The feature parsing is performed via wave-based matched pursuits. Algorithm performance is assessed by considering measured acoustic scattering data from five similar submerged elastic targets. C1 Duke Univ, Dept Elect & Comp Engn, Durham, NC 27708 USA. USN, Res Lab, Washington, DC 20375 USA. SFA Inc, Largo, MD 20785 USA. RP Runkle, P (reprint author), Duke Univ, Dept Elect & Comp Engn, Box 90291, Durham, NC 27708 USA. EM lcarin@ee.duke.edu NR 20 TC 32 Z9 33 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0162-8828 EI 1939-3539 J9 IEEE T PATTERN ANAL JI IEEE Trans. Pattern Anal. Mach. Intell. PD DEC PY 1999 VL 21 IS 12 BP 1371 EP 1378 DI 10.1109/34.817415 PG 8 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 275PG UT WOS:000084828100010 ER PT J AU Bagenstoss, PM AF Bagenstoss, PM TI Class-specific feature sets in classification SO IEEE TRANSACTIONS ON SIGNAL PROCESSING LA English DT Article DE classification; class-specific features; sufficiency ID STATISTICAL PATTERN-RECOGNITION AB In this correspondence, we present a new approach to the design of probabilistic classifiers that circumvents the dimensionality problem. Rather than working with a common high-dimensional feature set, the classifier is written in terms of likelihood ratios with respect to a common class using sufficient statistics chosen specifically for each class. C1 USN, Undersea Warfare Ctr, Newport, RI 02841 USA. RP Bagenstoss, PM (reprint author), USN, Undersea Warfare Ctr, Newport, RI 02841 USA. NR 17 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 USA SN 1053-587X J9 IEEE T SIGNAL PROCES JI IEEE Trans. Signal Process. PD DEC PY 1999 VL 47 IS 12 BP 3428 EP 3432 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA 261CX UT WOS:000083991800028 ER PT J AU Pecora, LM Carroll, TL AF Pecora, LM Carroll, TL TI Master stability functions for synchronized coupled systems SO INTERNATIONAL JOURNAL OF BIFURCATION AND CHAOS LA English DT Article ID CHAOTIC SYSTEMS; OSCILLATOR-SYSTEMS; ORBITS AB We show that many coupled oscillator array configurations considered in the literature can be put into a simple form so that determining the stability of the synchronous state can be done by a master stability function which solves, once and for all, the problem of synchronous stability for many couplings of that oscillator. C1 USN, Res Lab, Washington, DC 20375 USA. RP Pecora, LM (reprint author), USN, Res Lab, Code 6343, Washington, DC 20375 USA. OI Carroll, Thomas/0000-0002-2371-2049 NR 27 TC 10 Z9 10 U1 1 U2 24 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-1274 J9 INT J BIFURCAT CHAOS JI Int. J. Bifurcation Chaos PD DEC PY 1999 VL 9 IS 12 BP 2315 EP 2320 DI 10.1142/S0218127499001814 PG 6 WC Mathematics, Interdisciplinary Applications; Multidisciplinary Sciences SC Mathematics; Science & Technology - Other Topics GA 276GW UT WOS:000084870400011 ER PT J AU Dickinson, DL Wilson, LT AF Dickinson, DL Wilson, LT TI The impact of long rods into spaced-plate arrays SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING LA English DT Article; Proceedings Paper CT 6th Symposium on Hypervelocity Impact (HVIS 98) CY NOV 17-19, 1998 CL HUNTSVILLE, ALABAMA SP Army Res Lab, Army Res Off, Ernst Mach Inst, European Res Off, Lawrence Livermore Natl Lab, NASA Marshall Space Flight Ctr, Sandia Natl Lab, Univ Alabama, Huntsville, US Army Aviat & Missile Command AB The penetration equations of the FATEPEN2 engineering code have been updated to include behavior of large length-to-diameter ratio rods into spaced plate arrays. The changes were validated with light-gas gun experiments conducted at the Naval Research Laboratory to determine the effects of pitch and yaw on long-rod penetration. These experiments were modeled using the CTH hydrocode to simulate rod impact and interaction with the plate army. Numerical and experimental data for three tests were compared directly, and the discrepancies were analyzed. The analysis led to the conclusion that problem resolution is critical to the success of the calculations. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 USN, Ctr Surface Warfare, Dahlgren Div, Dahlgren, VA 22448 USA. RP Dickinson, DL (reprint author), USN, Ctr Surface Warfare, Dahlgren Div, Dahlgren, VA 22448 USA. NR 6 TC 0 Z9 0 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0734-743X J9 INT J IMPACT ENG JI Int. J. Impact Eng. PD DEC PY 1999 VL 23 IS 1 BP 193 EP 204 DI 10.1016/S0734-743X(99)00072-X PN 1 PG 12 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA 270EB UT WOS:000084521500019 ER PT J AU Nebolsine, PE Humer, ND Harmon, NF Baker, JR AF Nebolsine, PE Humer, ND Harmon, NF Baker, JR TI Statistical analysis of NRL 1964-1969 hypervelocity rod-plate impact data and comparison to recent data SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING LA English DT Article; Proceedings Paper CT 6th Symposium on Hypervelocity Impact (HVIS 98) CY NOV 17-19, 1998 CL HUNTSVILLE, ALABAMA SP Army Res Lab, Army Res Off, Ernst Mach Inst, European Res Off, Lawrence Livermore Natl Lab, NASA Marshall Space Flight Ctr, Sandia Natl Lab, Univ Alabama, Huntsville, US Army Aviat & Missile Command AB The previously reported Naval Research Laboratory hypervelocity rod-plate impact database was studied to derive the statistical variation that could be assigned to measurements of rod erosion for various impact conditions and impacting materials. The database covers impacts of 3.175 mm diameter rods having diameter-to-length ratios of 10 at velocities between 2.6 and 6.1 km/s upon targets whose thickness varied from 0.0355 to 6.5 rod diameters. Seven different projectile materials and 10 different target materials as well as alloys of aluminum and steel were tested. Of the 275 individual impacts reported, 157 were selected for statistical analysis. It was found that all of the data were normally distributed with a mean of 0.966 and standard deviation of 7.6% of the mean when the individual experimental measurements of rod erosion were normalized to predicted values calculated for the same impact conditions using the semi-empirical equation reported by Baker. Using this normalization, recent data from a multiple plate impact experiment was found to lie well within the uncertainty band. Subsets of the data are discussed. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Phys Sci Inc, Andover, MA 01810 USA. USN, Res Lab, Washington, DC 20375 USA. RP Nebolsine, PE (reprint author), Phys Sci Inc, 20 New England Business Ctr, Andover, MA 01810 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0734-743X J9 INT J IMPACT ENG JI Int. J. Impact Eng. PD DEC PY 1999 VL 23 IS 1 BP 639 EP 649 DI 10.1016/S0734-743X(99)00110-4 PN 2 PG 11 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA 270ED UT WOS:000084521700013 ER PT J AU Cebrowski, AK AF Cebrowski, AK TI Infrastructure vulnerability SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Letter C1 USN, War Coll, Newport, RI 02840 USA. RP Cebrowski, AK (reprint author), USN, War Coll, Newport, RI 02840 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD WIN PY 1999 VL 15 IS 2 BP 12 EP 12 PG 1 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA 158CF UT WOS:000078097900010 ER PT J AU Mendelsohn, J AF Mendelsohn, J TI Atomic audit: The costs and consequences of US nuclear weapons since 1940 SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Book Review C1 USN Acad, Annapolis, MD 21402 USA. RP Mendelsohn, J (reprint author), USN Acad, Annapolis, MD 21402 USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD WIN PY 1999 VL 15 IS 2 BP 92 EP 95 PG 4 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA 158CF UT WOS:000078097900043 ER PT J AU Brady, RF Bonafede, SJ Schmidt, DL AF Brady, RF Bonafede, SJ Schmidt, DL TI Self-assembled water-borne fluoropolymer coatings for marine fouling resistance SO JOCCA-SURFACE COATINGS INTERNATIONAL LA English DT Article ID ADHESION AB Fluoropolymer coatings were prepared by crosslinking a polymeric perfluoroalkyl surfactant with a poly[(2-isopropenyl-2-(oxozoline)]. Marine organisms adhered to these coatings with significantly less strength then to PTFE and other fluoropolymer films. This performance is attributed to a surface of close-packed and oriented trifluoromethyl-terminated groups which resists diffusion and rearrangement leading potentially to infiltration of marine adhesives. C1 USN, Res Lab, Div Chem, Washington, DC 20375 USA. Dow Chem Co, C&NB R&D Designed Prod & Devices, Midland, MI 48674 USA. RP Brady, RF (reprint author), USN, Res Lab, Div Chem, Code 6123,4555 Overlook Ave, Washington, DC 20375 USA. NR 18 TC 15 Z9 15 U1 0 U2 2 PU OIL COLOUR CHEM ASSN PI MIDDLESEX PA PRIORY HOUSE-967 HARROW RD WEMBLEY, MIDDLESEX, ENGLAND HA0 2SF SN 1356-0751 J9 JOCCA-SURF COAT INT JI JOCCA-Surf. Coat. Int. PD DEC PY 1999 VL 82 IS 12 BP 582 EP 585 PG 4 WC Chemistry, Applied; Engineering, Chemical; Materials Science, Coatings & Films SC Chemistry; Engineering; Materials Science GA 273AG UT WOS:000084683200008 ER PT J AU Rao, MV Berry, AK Do, TQ Ridgway, MC Chi, PH Waterman, J AF Rao, MV Berry, AK Do, TQ Ridgway, MC Chi, PH Waterman, J TI S and Si ion implantation in GaSb grown on GaAs SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID GALLIUM ANTIMONIDE; BEHAVIOR; DAMAGE AB Single and multiple energy S and Si ion implantations were performed at room temperature (RT) and 200 degrees C into GaSb epitaxial layers grown on semi-insulating GaAs substrates. The implanted material was annealed with a Si3N4 cap at 400-600 degrees C for 5 min. Secondary ion mass spectrometry measurements indicated the thermal stability of the Si and S implants even for 600 degrees C annealing. Appreciable donor electrical activations of Si and S were obtained only for 200 degrees C implantation for annealing temperatures greater than or equal to 500 degrees C. For S implantation the calculated substitutional activation is similar to 50%. Rutherford backscattering/channeling measurements indicated a lattice quality that is close to the virgin level for samples annealed at 600 degrees C. N-type conduction was not observed in GaSb bulk material implanted at either RT or 200 degrees C. (C) 1999 American Institute of Physics. [S0021-8979(99)03723-8]. C1 George Mason Univ, Dept Elect & Comp Engn, Fairfax, VA 22030 USA. Australian Natl Univ, Dept Elect Mat Engn, Canberra, ACT 2601, Australia. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. USN, Res Lab, Washington, DC 20375 USA. RP Rao, MV (reprint author), George Mason Univ, Dept Elect & Comp Engn, Fairfax, VA 22030 USA. RI Ridgway, Mark/D-9626-2011 OI Ridgway, Mark/0000-0002-0642-0108 NR 10 TC 3 Z9 3 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 1 PY 1999 VL 86 IS 11 BP 6068 EP 6071 DI 10.1063/1.371655 PG 4 WC Physics, Applied SC Physics GA 256ML UT WOS:000083729000021 ER PT J AU Kim, H Gilmore, CM Pique, A Horwitz, JS Mattoussi, H Murata, H Kafafi, ZH Chrisey, DB AF Kim, H Gilmore, CM Pique, A Horwitz, JS Mattoussi, H Murata, H Kafafi, ZH Chrisey, DB TI Electrical, optical, and structural properties of indium-tin-oxide thin films for organic light-emitting devices SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID DOPED IN2O3 FILMS; TRANSPARENT CONDUCTORS; FABRICATION; EVAPORATION; DEPOSITION AB High-quality indium-tin-oxide (ITO) thin films (200-850 nm) have been grown by pulsed laser deposition (PLD) on glass substrates without a postdeposition annealing treatment. The structural, electrical, and optical properties of these films have been investigated as a function of target composition, substrate deposition temperature, background gas pressure, and film thickness. Films were deposited from various target compositions ranging from 0 to 15 wt % of SnO2 content. The optimum target composition for high conductivity was 5 wt % SnO2+95 wt % In2O3. Films were deposited at substrate temperatures ranging from room temperature to 300 degrees C in O-2 partial pressures ranging from 1 to 100 mTorr. Films were deposited using a KrF excimer laser (248 nm, 30 ns full width at half maximum) at a fluence of 2 J/cm(2). For a 150-nm-thick ITO film grown at room temperature in an oxygen pressure of 10 mTorr, the resistivity was 4 x 10(-4) Omega cm and the average transmission in the visible range (400-700 nm) was 85%. For a 170-nm-thick ITO film deposited at 300 degrees C in 10 mTorr of oxygen, the resistivity was 2 x 10(-4) Ohm cm and the average transmission in the visible range was 92%. The Hall mobility and carrier density for a 150-nm-thick film deposited at 300 degrees C were 27 cm(2)/V s and 1.4 x 10(21) cm(-3), respectively. A reduction in the refractive index for ITO films can be achieved by raising the electron density in the films, which can be obtained by increasing the concentration of Sn dopants in the targets and/or increasing deposition temperature. Atomic force microscopy measurements of these ITO films indicated that their root-mean-square surface roughness (similar to 5 Angstrom) was superior to that of commercially available sputter deposited ITO films (similar to 40 Angstrom). The PLD ITO films were used to fabricate organic light-emitting diodes. From these structures the electroluminescence was measured and an external quantum efficiency of 1.5% was calculated. (C) 1999 American Institute of Physics. [S0021-8979(99)04223-1]. C1 George Washington Univ, Sch Engn & Appl Sci, Washington, DC 20052 USA. Naval Res Lab, Washington, DC 20375 USA. RP Kim, H (reprint author), George Washington Univ, Sch Engn & Appl Sci, 725 23rd St NW, Washington, DC 20052 USA. EM hskim@ccf.nrl.navy.mil RI Murata, Hideyuki/J-8453-2012 OI Murata, Hideyuki/0000-0001-8248-9652 NR 39 TC 659 Z9 665 U1 44 U2 367 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 1 PY 1999 VL 86 IS 11 BP 6451 EP 6461 DI 10.1063/1.371708 PG 11 WC Physics, Applied SC Physics GA 256ML UT WOS:000083729000082 ER PT J AU Borges, CF Peters, CS AF Borges, CF Peters, CS TI Computing approximate stationary distributions for discrete Markov processes with banded infinitesimal generators SO JOURNAL OF APPLIED PROBABILITY LA English DT Article DE homogeneous complement; singular value decomposition ID CHAINS AB We develop an algorithm for computing approximations to the stationary distribution of a discrete birth-and-death process, provided that the infinitesimal generator is a banded matrix. We begin by computing stationary distributions for processes whose infinitesimal generators are Hessenberg. Our derivation in this special case is different from the classical case but it leads to the same result. We then show how to extend these ideas to processes where the infinitesimal generator is banded (or half-banded) and to quasi-birth-death processes. Finally, we give an example of the application of this method to a nearly completely decomposable Markov chain to demonstrate the general applicability of the technique. C1 USN, Postgrad Sch, Monterey, CA 93943 USA. Gen Elect Co, Niskayuna, NY 12309 USA. RP Borges, CF (reprint author), USN, Postgrad Sch, Code MA-BC, Monterey, CA 93943 USA. RI Borges, Carlos/E-3157-2010 NR 8 TC 0 Z9 0 U1 0 U2 2 PU APPLIED PROBABILITY TRUST PI SHEFFIELD PA THE UNIVERSITY, SCHOOL MATHEMATICS STATISTICS, SHEFFIELD S3 7RH, ENGLAND SN 0021-9002 J9 J APPL PROBAB JI J. Appl. Probab. PD DEC PY 1999 VL 36 IS 4 BP 1086 EP 1100 PG 15 WC Statistics & Probability SC Mathematics GA 291EZ UT WOS:000085722300012 ER PT J AU Copper, CL Koubek, E AF Copper, CL Koubek, E TI An experiment to demonstrate how a catalyst affects the rate of a reaction SO JOURNAL OF CHEMICAL EDUCATION LA English DT Article C1 USN Acad, Dept Chem, Annapolis, MD 21402 USA. RP Copper, CL (reprint author), USN Acad, Dept Chem, Annapolis, MD 21402 USA. NR 9 TC 1 Z9 1 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9584 J9 J CHEM EDUC JI J. Chem. Educ. PD DEC PY 1999 VL 76 IS 12 BP 1714 EP 1715 PG 2 WC Chemistry, Multidisciplinary; Education, Scientific Disciplines SC Chemistry; Education & Educational Research GA 256HJ UT WOS:000083719600041 ER PT J AU Gomba, FJ AF Gomba, FJ TI A comment on molecular geometry SO JOURNAL OF CHEMICAL EDUCATION LA English DT Article C1 USN Acad, Dept Chem, Annapolis, MD 21402 USA. RP Gomba, FJ (reprint author), USN Acad, Dept Chem, Annapolis, MD 21402 USA. NR 8 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9584 J9 J CHEM EDUC JI J. Chem. Educ. PD DEC PY 1999 VL 76 IS 12 BP 1732 EP 1734 PG 3 WC Chemistry, Multidisciplinary; Education, Scientific Disciplines SC Chemistry; Education & Educational Research GA 256HJ UT WOS:000083719600047 ER PT J AU Dlugosz, LJ Hocter, WJ Kaiser, KS Knoke, JD Heller, JM Hamid, NA Reed, RJ Kendler, KS Gray, GC AF Dlugosz, LJ Hocter, WJ Kaiser, KS Knoke, JD Heller, JM Hamid, NA Reed, RJ Kendler, KS Gray, GC TI Risk factors for mental disorder hospitalization after the Persian Gulf War: US Armed Forces, June 1, 1991-September 30, 1993 SO JOURNAL OF CLINICAL EPIDEMIOLOGY LA English DT Article DE mental disorders; Persian Gulf syndrome; incidence studies; hospitalization; combat disorders; medical records ID VIETNAM VETERANS; PSYCHIATRIC-DISORDERS; STRESS DISORDER; HEALTH; EPIDEMIOLOGY; EXPERIENCE; SERVICE; COMBAT; BLACK; PTSD AB Effects of Persian Gulf War (August 2, 1990-luly 31, 1991) and Gulf War occupation on post-War hospitalization risk were evaluated through Cox proportional hazards modeling. Active-duty men (n = 1,775,236) and women (n = 209,760) in the Army, Air Force, Navy, and Marine Corps had 30,539 initial postwar hospitalizations for mental disorders between June 1, 1991 and September 30, 1993. Principal diagnoses in the Defense Manpower Data Center hospitalization database were grouped into 10 categories of ICD-9-CM codes. Gulf War service was associated with significantly greater risk for acute reactions to stress and lower risk for personality disorders and adjustment reactions among men. Personnel who served in ground war support occupations (men and women) were at greater risk for postwar drug-related disorders. Men who served in ground war combat occupations were at higher risk for alcohol-related disorders. Longitudinal studies of health, hospitalization, and exposure beginning at recruitment are needed to better understand how exposure to combat affects the mental health of military personnel. (C) 1999 Elsevier Science Inc. C1 USN, Hlth Res Ctr, Emerging Illness Div, Dept Hlth Sci & Epidemiol, San Diego, CA 92186 USA. USN, Med Ctr, Dept Psychiat, San Diego, CA 92152 USA. USA, Ctr Hlth Promot & Prevent Med, Aberdeen Proving Ground, MD USA. Virginia Commonwealth Univ, Med Coll Virginia, Richmond, VA 23298 USA. RP Gray, GC (reprint author), USN, Hlth Res Ctr, Emerging Illness Div, Dept Hlth Sci & Epidemiol, POB 85122, San Diego, CA 92186 USA. NR 41 TC 30 Z9 30 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0895-4356 J9 J CLIN EPIDEMIOL JI J. Clin. Epidemiol. PD DEC PY 1999 VL 52 IS 12 BP 1267 EP 1278 DI 10.1016/S0895-4356(99)00131-6 PG 12 WC Health Care Sciences & Services; Public, Environmental & Occupational Health SC Health Care Sciences & Services; Public, Environmental & Occupational Health GA 258AZ UT WOS:000083817000018 PM 10580791 ER PT J AU Shad, JA Lee, YR AF Shad, JA Lee, YR TI Separation of an overtube from the bite block during treatment of food impaction SO JOURNAL OF CLINICAL GASTROENTEROLOGY LA English DT Letter ID ENDOSCOPY; LIGATION C1 USN, Med Ctr, Dept Internal Med, Div Gastroenterol, San Diego, CA 92152 USA. USN, Med Ctr, Dept Clin Invest, San Diego, CA 92152 USA. RP Shad, JA (reprint author), USN, Med Ctr, Dept Internal Med, Div Gastroenterol, San Diego, CA 92152 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0192-0790 J9 J CLIN GASTROENTEROL JI J. Clin. Gastroenterol. PD DEC PY 1999 VL 29 IS 4 BP 345 EP 346 DI 10.1097/00004836-199912000-00011 PG 2 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA 260YN UT WOS:000083981200013 PM 10599640 ER PT J AU Widjaja, S Cohen, S Brady, WE O'Reilly, K Susanto Wibowo, A Cahyono Graham, RR Porter, KR AF Widjaja, S Cohen, S Brady, WE O'Reilly, K Susanto Wibowo, A Cahyono Graham, RR Porter, KR TI Evaluation of a rapid assay for detection of Chlamydia trachomatis infections in outpatient clinics in South Kalimantan, Indonesia SO JOURNAL OF CLINICAL MICROBIOLOGY LA English DT Article ID LIGASE CHAIN-REACTION AB A multicenter cross-sectional survey was conducted comparing a commercially available chlamydial optical immunoassay (OIA) to the chlamydial ligase chain reaction (LCR). Endocervical samples from 415 outpatients visiting clinics from three hospitals in South Kalimantan, Indonesia, were evaluated. Relative to the LCR, the overall sensitivity and specificity of the OLA were 31.6 and 98.9%, respectively. The sensitivity of the OIA varied among the three hospital laboratories, ranging from 20 to 50%, The OIA performance was slightly lower on samples from patients attending dermatovenereology clinics than on samples from nondermatovenereology clinic patients. The results indicate that the OIA did not perform well compared to LCR. C1 USN, Med Res Unit 2, Virus Res Program, Unit 8132, APO, AP 96520 USA. MotherCare, Jakarta, Indonesia. Ulin Prov Hosp, Kalimantan, Indonesia. Banjar Baru Dist Hosp, Kalimantan, Indonesia. Kandangan Dist Hosp, Kalimantan, Indonesia. MotherCare, Washington, DC USA. World Hlth Org, Div Reprod Tract, Geneva, Switzerland. RP Porter, KR (reprint author), USN, Med Res Unit 2, Virus Res Program, Unit 8132, APO, AP 96520 USA. RI Porter, Kevin/A-8027-2011 NR 10 TC 6 Z9 6 U1 0 U2 0 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0095-1137 J9 J CLIN MICROBIOL JI J. Clin. Microbiol. PD DEC PY 1999 VL 37 IS 12 BP 4183 EP 4185 PG 3 WC Microbiology SC Microbiology GA 259CY UT WOS:000083877400075 PM 10565960 ER PT J AU Pederson, MR Laouini, N AF Pederson, MR Laouini, N TI Properties of the TDAE molecule within density-functional theory SO JOURNAL OF CLUSTER SCIENCE LA English DT Article; Proceedings Paper CT 7th Annual Workshop of the Consortium for Nanostructured Materials CY OCT 29-31, 1998 CL RICHMOND, VA DE TDAE-C-60 cluster; density-functional theory; magnetism ID ELECTRONIC-STRUCTURE; PRESSURE-DEPENDENCE; RAMAN-SCATTERING; C-60; TDAE-C-60; CLUSTERS; FERROMAGNETISM; CRYSTAL; K3C60 AB Density-functional-based methodologies have been used to calculate the geometric, electronic, and vibrational properties of the TDAE molecule. The molecule has a low first-ionization energy but, in contrast to alkali atoms, releases the electron without appreciably changing the effective molecular size. In addition to ionization energies and geometries we present the vibrational spectrum of the molecule and determine the infrared (IR) and Raman intensities as well. A discussion of some of the energetics that impact the ionicity and subsequent magnetism of TDAE-C-60 is presented. Further, we identify one Raman active mode, at 1682 cm(-1), which is particularly interesting since it may be used to probe the TDAE charge state experimentally. C1 USN, Res Lab, Washington, DC 20375 USA. Max Planck Inst Festkorperforsch, D-70569 Stuttgart 80, Germany. RP USN, Res Lab, Washington, DC 20375 USA. NR 40 TC 4 Z9 4 U1 0 U2 1 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1040-7278 EI 1572-8862 J9 J CLUST SCI JI J. Clust. Sci. PD DEC PY 1999 VL 10 IS 4 BP 557 EP 571 DI 10.1023/A:1021961209684 PG 15 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 256AE UT WOS:000083701700008 ER PT J AU Fatemi, M AF Fatemi, M TI Refinement of high-resolution X-ray diffraction data in characterizing epitaxial layers and multiple-quantum wells by the peak separation technique SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE X-rays; epitaxy; refinement ID STRAIN AB The process of determining the strain and composition in epitaxial layers by the X-ray rocking curve technique involves the measurement of peak separations between the substrate and the epilayer for specific reflections. The resulting interplanar spacings are combined and solved for the in-plane and perpendicular lattice parameters and hence for the strain. However, lattice parameters computed from different combinations of reflections often differ by amounts as large as several hundred parts per million, whereas much smaller errors of near ten parts per million are expected. This leads to an ambiguity in separating discrepancies from true experimental errors. To remove this ambiguity, a simple, analytical, and versatile method is proposed, which forces the X-ray reflection equations towards internal consistency by making small adjustments to each measurement. A least-squares version of the method is described, and applied to several common systems of interest, although any other assumed relationship among the adjustments may also be utilized. The concepts of inconsistency and experimental error are distinguished, and an index of consistency is defined. This definition does not absolve the requirement of repeated measurements for determining the experimental error, but gives a quantitative gauge of fit among individual measurements from various diffracting planes. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 USN, Res Lab, Div Elect Sci & Technol, Washington, DC 20375 USA. RP Fatemi, M (reprint author), USN, Res Lab, Div Elect Sci & Technol, Code 6856, Washington, DC 20375 USA. NR 9 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD DEC PY 1999 VL 207 IS 3 BP 188 EP 199 DI 10.1016/S0022-0248(99)00370-X PG 12 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 258LZ UT WOS:000083841800004 ER PT J AU Gaskill, DK Glembocki, OJ Holm, RT Giordana, A AF Gaskill, DK Glembocki, OJ Holm, RT Giordana, A TI Growth and photoreflectance characterization of GaAs impact ionization avalanche transit time diodes SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT 3rd Conference on Rapid Thermal Processing CY MAR, 1999 CL SAN DIEGO, CALIFORNIA SP TMS EPDMD DE organometallic vapor phase epitaxy; IMPATT diode; photoreflectance ID FRANZ-KELDYSH OSCILLATIONS AB The organometallic vapor phase epitaxial growth of GaAs double-drift Read impact ionization avalanche transit time diodes where the p-type layers were doped with carbon is described. Ka-band oscillation testing yielded average performance of 3.5 W with 16% efficiency for pulse lengths > 1 mu s and 10.5 W with 13% efficiency for pulse lengths < 1 mu s; these RF performances are similar to conventionally grown vapor phase epitaxy IMPATTs where the p-type dopant was zinc. Photoreflectance spectra obtained from diode structures were found to be dominated by the electric field in the avalanche region and hence are sensitive to the amount of charge in the doping spikes that determine the electric field in that region. C1 USN, Res Lab, Washington, DC 20375 USA. RP Gaskill, DK (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 15 TC 3 Z9 3 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD DEC PY 1999 VL 28 IS 12 BP 1424 EP 1427 DI 10.1007/s11664-999-0134-7 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 268ZB UT WOS:000084449600019 ER PT J AU Slinker, SP Fedder, JA Emery, BA Baker, KB Lummerzheim, D Lyon, JG Rich, FJ AF Slinker, SP Fedder, JA Emery, BA Baker, KB Lummerzheim, D Lyon, JG Rich, FJ TI Comparison of global MHD simulations with AMIE simulations for the events of May 19-20, 1996 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; LATITUDE ELECTRIC POTENTIALS; IONOSPHERIC ELECTRODYNAMICS; NUMERICAL-SIMULATION; EARTHS MAGNETOSPHERE; CIRCULATION MODEL; GRAND CHALLENGE; ENERGY; CONDUCTANCES; CONVECTION AB Using WIND-measured solar wind data, we have simulated the magnetosphere for the time between 1200 UT May 19 and 0200 UT May 20, 1996, with a three-dimensional MHD model. This time period has been chosen as an International Solar-Terrestrial Physics/Global Geospace Science event for community study, and there is a large set of data with which to compare. In this paper we will compare the simulation predictions with results from the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) analysis. We show comparisons for the convection, the auroral precipitation, the ionospheric conductances, the field-aligned currents, and the Joule heating distribution. The results concentrate on four time periods when the two DMSP spacecraft, F12 and F13, and the POLAR spacecraft were passing over the northern (summer) polar region. The comparisons show excellent agreement with the F13 electric field measurements. The ionospheric convection patterns agree well. between the simulation and the AMIE analysis with the cross polar potential drop somewhat higher in the MHD model. The auroral electron precipitation energy flux from the MHD model is too low, particularly in the late morning, when compared with the POLAR UVI data because of the lack of electron drift physics in the model. We show how the MHD auroral input can be improved by adjusting the parameters in the auroral precipitation model. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. George Mason Univ, Inst Computat Sci & Informat, Fairfax, VA 22030 USA. Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD USA. Univ Alaska, Inst Geophys, Hanover, NH USA. USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA USA. RP Slinker, SP (reprint author), Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. NR 35 TC 41 Z9 41 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1999 VL 104 IS A12 BP 28379 EP 28395 DI 10.1029/1999JA900403 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 266UN UT WOS:000084318800034 ER PT J AU Burns, WK Howerton, MM Moeller, RP Krahenbuhl, R McElhanon, RW Greenblatt, AS AF Burns, WK Howerton, MM Moeller, RP Krahenbuhl, R McElhanon, RW Greenblatt, AS TI Low drive voltage, broad-band LiNbO3 modulators with and without etched ridges SO JOURNAL OF LIGHTWAVE TECHNOLOGY LA English DT Article DE electrooptics; fiber optics; integrated optics; lithium niobate; modulators; optical communications; optical modulators; traveling wave optical modulators ID TI-LINBO3 OPTICAL MODULATOR; GHZ AB Frequency dependent drive voltage is reported in velocity matched, packaged, Mach-Zehnder interferometers, made on Z-cut, Y-propagating LiNbO3, with and without etched ridges. Drive voltages of similar to 7 V at 40 GHz are demonstrated, with the etched ridge device showing a 1/2-1 V advantage. Microwave modeling allowed the extraction of the effects of dispersion in material properties, occurring near the acoustic resonance, on bandwidth and drive voltage. C1 USN, Res Lab, Washington, DC 20375 USA. SFA Inc, Largo, MD 20774 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. RP Burns, WK (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 14 TC 46 Z9 46 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0733-8724 J9 J LIGHTWAVE TECHNOL JI J. Lightwave Technol. PD DEC PY 1999 VL 17 IS 12 BP 2551 EP 2555 DI 10.1109/50.809676 PG 5 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA 268LZ UT WOS:000084419000016 ER PT J AU Kendziora, C Pelloquin, D Villard, G AF Kendziora, C Pelloquin, D Villard, G TI Polarized electronic Raman scattering studies of underdoped and overdoped high-T-c superconductors SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article; Proceedings Paper CT International Conference on Physics and Chemistry of Molecular and Oxide Superconductors (MOS-99) CY JUL 28-AUG 02, 1999 CL ROYAL INST TECHNOL, STOCKHOLM, SWEDEN SP Royal Inst Technol, Royal Swedish Acad Sci, Swedish Nat Sci, Engn Sci Res Councils, SAS, Gran Gustafsson Fdn, City of Stockholm HO ROYAL INST TECHNOL ID SINGLE-CRYSTALS; PSEUDOGAP; SPECTRA; GAP; BI2SR2CACU2O8+DELTA; FLUCTUATIONS; EVOLUTION AB We report on polarized Raman scattering from high-T, superconductors in the Bi2Sr2 CaCu2 O8+delta (Bi2212) and HgBa2 CuO4+delta (Hg1201) classes, with an emphasis on the effect of superconductivity on the low frequency electronic continuum. The Hg-based materials confirm earlier observations from Bi2212 that the superconducting energy gap 2 Delta peak is not present in underdoped samples, while its Raman shift is maximum in B-1g symmetry at optimal doping, and decreases dramatically with overdoping. These similarities despite the different numbers of bands crossing the Fermi surface argues against a multiple-band explanation for the anomalous doping dependence of the gap. We also discuss an anomalous B-1g feature observed at 600 cm(-1) in Y underdoped Bi2212. This "pseudogap-like" feature has several properties which suggest it is of electronic - rather than phononic - origin. C1 USN, Res Lab, Washington, DC 20375 USA. ISMRA Univ Caen, Lab CRISMAT, CNRS, UMR 6508, F-14050 Caen, France. RP USN, Res Lab, Code 6333, Washington, DC 20375 USA. NR 17 TC 3 Z9 3 U1 0 U2 0 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2291 EI 1573-7357 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD DEC PY 1999 VL 117 IS 5-6 BP 1007 EP 1011 DI 10.1023/A:1022505819394 PG 5 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 269PK UT WOS:000084486600002 ER PT J AU Kortright, JB Awschalom, DD Stohr, J Bader, SD Idzerda, YU Parkin, SSP Schuller, IK Siegmann, HC AF Kortright, JB Awschalom, DD Stohr, J Bader, SD Idzerda, YU Parkin, SSP Schuller, IK Siegmann, HC TI Research frontiers in magnetic materials at soft X-ray synchrotron radiation facilities SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Review DE magnetic films; synchrotron radiation; electron spectroscopy; X-ray spectroscopy; X-ray scattering; microscopy ID QUANTUM-WELL STATES; CORE-LEVEL PHOTOEMISSION; SUPERCONDUCTING TRANSITION-TEMPERATURE; NANOMETER-SCALE MAGNETS; SPIN-DENSITY-WAVE; GD-Y SUPERLATTICE; CIRCULAR-DICHROISM; GIANT MAGNETORESISTANCE; PHOTOELECTRON DIFFRACTION; ENHANCED MAGNETORESISTANCE AB Current and anticipated future research frontiers in magnetism and magnetic materials are discussed from a perspective of soft X-ray synchrotron utilization. Topics covered include dimensionality (including effects of spatial dimensions and differing time scales), magneto-electronics, structure/property relationships, and exploratory materials, with an emphasis on challenges that limit the understanding and advancement of these areas. Many soft X-ray spectroscopies can be used to study magnetism associated with transition and rare earth metals with element- and chemical-state specificity and large cross-sections associated with dipole transitions from p --> d and d --> f states. Established electron spectroscopies, including spin-resolved techniques, yield near-surface sensitivity in conjunction with linear and circular magnetic dichroism. Emerging photon-based scattering and Faraday and Kerr magneto-optical measurements can be used beyond the near-surface region and in applied magnetic fields. Microscopies based on either electron or photon spectroscopies to image the magnetization at 50 nm resolution are also emerging, as are time-resolved measurements that utilize the natural time structure of synchrotron sources. Examples of research using these techniques to impact our fundamental understanding of magnetism and magnetic materials are given, as are future opportunities. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. IBM Corp, Almaden Res Ctr, San Jose, CA 95120 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. USN, Res Lab, Washington, DC 20375 USA. Univ Calif San Diego, Phys Dept 0319, La Jolla, CA 92093 USA. Swiss Fed Inst Technol, CH-8093 Zurich, Switzerland. RP Kortright, JB (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. EM jbkortright@lbl.gov RI Parkin, Stuart/D-2521-2012; Bader, Samuel/A-2995-2013 NR 190 TC 153 Z9 154 U1 9 U2 60 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD DEC PY 1999 VL 207 IS 1-3 BP 7 EP 44 DI 10.1016/S0304-8853(99)00485-0 PG 38 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 257MQ UT WOS:000083786000002 ER PT J AU Lee, SK Das, BN Harris, VG AF Lee, SK Das, BN Harris, VG TI Magnetic structure of single crystal Tb2Fe14B SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE rare earth iron boron compounds; single crystals; polarized light microscopy; magnetic domains; domain wall energy; domain wall thickness; magnetic anisotropy constant ID MAGNETOSTRICTION; ND2FE14B; DOMAINS AB The magnetic structure of a single crystal Tb2Fe14B sample, grown by the Czochralski process, was studied using polarized light microscopy with a xenon light source. The domain wall energy, domain wall thickness, and critical single domain particle size were calculated from measurements of equilibrium domain widths in thin crystals. The calculated values were compared with previous results from other permanent magnetic compounds. The changes in domain wall energy, gamma, in RE2Fe14B (RE = rare earth elements) single crystals are proportional to changes in magnetic anisotropy constant, K-1. The changes in domain wall thickness, delta, in these single crystals, on the other hand, are inversely proportional to changes in K-1. Both of these trends are in agreement with the continuum model (D.J. Craik, Contemp. Phys. 11 (1970) 65). (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 USN, Res Lab, Washington, DC 20375 USA. Geocenters Inc, Ft Washington, MD 20744 USA. Emory Univ, Atlanta, GA 30322 USA. RP Das, BN (reprint author), USN, Res Lab, Code 6342, Washington, DC 20375 USA. RI Harris, Vincent/A-8337-2009 NR 19 TC 5 Z9 6 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD DEC PY 1999 VL 207 IS 1-3 BP 137 EP 145 DI 10.1016/S0304-8853(99)00519-3 PG 9 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 257MQ UT WOS:000083786000012 ER PT J AU Murday, JS AF Murday, James S. TI Science and technology of nanostructures in the Department of Defense SO JOURNAL OF NANOPARTICLE RESEARCH LA English DT Article DE nanostructured materials; nanoelectronics; nanobiotechnology; defense applications; survey AB The United States Department of Defense maintains a research and development program in nanostructures with special attention to miniaturization of information technology devices, nanostructured materials, and nanobiotechnology for detection of biological agents. This article provides a brief guide to those DoD funding officers and research scientists actively interested in nanostructures. C1 USN, Code 6100, Res Lab, Washington, DC 20375 USA. RP Murday, JS (reprint author), USN, Code 6100, Res Lab, Washington, DC 20375 USA. EM murday@ccf.nrl.navy.mil NR 18 TC 7 Z9 7 U1 1 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1388-0764 J9 J NANOPART RES JI J. Nanopart. Res. PD DEC PY 1999 VL 1 IS 4 BP 501 EP 505 DI 10.1023/A:1010032706804 PG 5 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Chemistry; Science & Technology - Other Topics; Materials Science GA V19IV UT WOS:000208067000009 ER PT J AU Mahmood, MF Qadri, SB AF Mahmood, MF Qadri, SB TI Modeling propagation of chirped solitons in an elliptically low birefringent single-mode optical fiber SO JOURNAL OF NONLINEAR OPTICAL PHYSICS & MATERIALS LA English DT Article ID PULSE-PROPAGATION; KERR MEDIUM; INSTABILITIES; STABILITY; DYNAMICS AB An analytical description is presented, for the first time, to describe propagation dynamics of chirped solitons in an elliptically low birefringent optical fiber within the framework of a model described by coupled nonlinear Schroedinger equations. Using nonlinear Schroedinger solitons as trial functions in an averaged Lagrangian formulation, a set of ordinary differential equations (ODEs) are derived for various soliton parameters. These ODEs describe chirped soliton dynamics and give a criterion for nonlinear coupling of polarized pulses to form a bound state corresponding to a phase mismatch. C1 Howard Univ, Dept Elect Engn, Washington, DC 20059 USA. USN, Res Lab, Washington, DC 20375 USA. RP Mahmood, MF (reprint author), Howard Univ, Dept Elect Engn, Washington, DC 20059 USA. NR 14 TC 16 Z9 16 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-1991 J9 J NONLINEAR OPT PHYS JI J. Nonlinear Opt. Phys. Mater. PD DEC PY 1999 VL 8 IS 4 BP 469 EP 475 DI 10.1142/S0218863599000345 PG 7 WC Optics; Physics, Applied SC Optics; Physics GA 283QX UT WOS:000085287400004 ER PT J AU Bucca, D Keller, TM AF Bucca, D Keller, TM TI Oxidation-resistant thermosets derived from thermal copolymerization of acetylenic monomers containing boron and silicon SO JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY LA English DT Article DE ethynyl-substituted monomers; inorganic monomers; preceramic monomers; high-performance thermosets; synthesis; thermal analysis AB Polymerization of acetylenic monomers containing silicon and boron produces materials that are resistant to oxidation at elevated temperature. In addition to homopolymerization, these inorganic-organic hybrid monomers can be copolymerized with an otherwise all carbon containing system. Inorganic elements incorporated by this method enhance the thermooxidative stability of the copolymer. This stability is a function of the amount of boron in the final product. We show that a thermoset containing an initial 5% by weight of boron can be charred to a material that when heated in air at 1000 degrees C loses less than 10% of its mass. (C) 1999 John Wiley & Sons, Inc. C1 USN, Res Lab, Div Chem, Mat Chem Branch, Washington, DC 20375 USA. RP Keller, TM (reprint author), USN, Res Lab, Div Chem, Mat Chem Branch, Code 6127, Washington, DC 20375 USA. NR 11 TC 13 Z9 13 U1 1 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-624X J9 J POLYM SCI POL CHEM JI J. Polym. Sci. Pol. Chem. PD DEC 1 PY 1999 VL 37 IS 23 BP 4356 EP 4359 DI 10.1002/(SICI)1099-0518(19991201)37:23<4356::AID-POLA12>3.0.CO;2-3 PG 4 WC Polymer Science SC Polymer Science GA 255RP UT WOS:000083684200012 ER PT J AU Mahnken, TG AF Mahnken, TG TI Uncovering foreign military innovation SO JOURNAL OF STRATEGIC STUDIES LA English DT Article AB An analysis of US assessments of Germany's development of armored warfare illustrates the problems that intelligence agencies face as they attempt to understand military innovation. The covert nature of German Army's tank research in the years immediately following World War I limited the number of indicators of Berlin's interest in armored warfare. Similarly, the United States possessed at best a fragmentary picture of German experimentation with armor. By the outbreak of World War II, however, US military attaches had nonetheless developed an accurate understanding of German concepts of armored warfare. If the United States is to avoid strategic surprise in the future, it must cultivate intelligence sources and employ considerably different methods from those of the Cold War. C1 USN, War Coll, Newport, RI 02840 USA. Georgetown Univ, Natl Secur Studies Program, Washington, DC 20057 USA. RP Mahnken, TG (reprint author), USN, War Coll, Newport, RI 02840 USA. NR 68 TC 7 Z9 7 U1 3 U2 9 PU FRANK CASS CO LTD PI ESSEX PA NEWBURY HOUSE, 900 EASTERN AVE, NEWBURY PARK, ILFORD, ESSEX IG2 7HH, ENGLAND SN 0140-2390 J9 J STRATEGIC STUD JI J. Strateg. Stud. PD DEC PY 1999 VL 22 IS 4 BP 26 EP 54 DI 10.1080/01402399908437768 PG 29 WC International Relations; Political Science SC International Relations; Government & Law GA 300VX UT WOS:000086274800002 ER PT J AU Sarkani, S Michaelov, G Kihl, DP Beach, JE AF Sarkani, S Michaelov, G Kihl, DP Beach, JE TI Stochastic fatigue damage accumulation of FRP laminates and joints SO JOURNAL OF STRUCTURAL ENGINEERING-ASCE LA English DT Article ID MODEL; LIFE AB Results are presented from a study on fatigue damage accumulation in fiber-reinforced plastic coupons and joints. The main objective of the study is to investigate the effectiveness of the Palmgren-Miner linear damage accumulation model in predicting the fatigue lives of FRP structures under stochastic loading histories. The coupon specimens used in the study are configured four ways: with the laminate laid up in two loading directions (0/90 degrees and +/-45 degrees), and with the load transferred by two types of bearing (passive and active). The joint specimens considered represent bonded, bolted, and bonded-bolted butt-strap configurations. The results of the constant-amplitude fatigue tests are fitted to two types of S-N curve models: power-law and exponential. Variable-amplitude fatigue tests using narrow-band stochastic stress histories with various root-mean-square stresses are carried out. Rayleigh approximation formulas corresponding to both types of S-N curves are used to predict the fatigue lives based on the S-N curve and loading parameters. The analytical fatigue life predictions are compared with the experimental results. It is shown that the analytical predictions may overestimate or underestimate the actual fatigue lives, depending on the specimen configuration and the root-mean-square stress level. C1 George Washington Univ, Sch Engn & Appl Sci, Washington, DC 20052 USA. USN, Ctr Surface Warfare, Struct & Compos Dept, Carderock Div, W Bethesda, MD 20817 USA. RP Sarkani, S (reprint author), George Washington Univ, Sch Engn & Appl Sci, Washington, DC 20052 USA. NR 14 TC 12 Z9 14 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 0733-9445 J9 J STRUCT ENG-ASCE JI J. Struct. Eng.-ASCE PD DEC PY 1999 VL 125 IS 12 BP 1423 EP 1431 DI 10.1061/(ASCE)0733-9445(1999)125:12(1423) PG 9 WC Construction & Building Technology; Engineering, Civil SC Construction & Building Technology; Engineering GA 255PX UT WOS:000083679600009 ER PT J AU Maidanik, G Becker, KJ AF Maidanik, G Becker, KJ TI Characterization of multiple-sprung masses for wideband noise control SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID SATELLITE HARMONIC-OSCILLATORS; FUZZY AB The-design of a wide frequency band neutralizer, vibration absorber and/or structural fuzzy, in the form of multiple-sprung masses, is extensively reported in the open literature. The action of the device is reported in terms of the joint point impedance of the sprung masses. This joint impedance is merely the sum over the impedances of the individual sprung: masses at the common point to which the device is to be attached to a master structure. The normalized frequency bandwidth of a device composed of a single-sprung mass is proportional to the loss factor of that sprung mass. To increase this bandwidth, a device composed of more than one sprung mass, with distributed resonance frequencies, is utilized. To keep suppressed: the undulations in the joint impedance of a set composed of a multiplicity of sprung masses, the loss factors are rendered larger than the normalized separations between adjacent antiresonance frequencies. This modal overlap condition, together with consideration of weight, are central to the design of the device. The analysis of the device is enriched by considering two distinct distributions of resonance frequencies for each set of sprung masses. Moreover, the ranges and parameters which specify that device are limited to reasonably moderate values; e.g., the useful frequency bandwidth of a given device is limited to one-third of its center frequency and the number of sprung masses in a device is restricted not to exceed one-score. In a set employing the first resonance frequency distribution, as the number of sprung masses is initially increased, an increase in the bandwidth is accompanied by an increase in the level of the joint impedance. As the number of sprung masses is further increased, the bandwidth and the level of the joint impedance become saturated. In a set incorporating the second resonance frequency distribution, an ongoing increase in the bandwidth, as the number of sprung masses increases, is accompanied by an ongoing decrease in the level of the joint impedance. The examination of these and other characteristics in the:joint impedance of the sprung masses is provided by data obtained in computer experiments performed on a few selected sets of. sprung masses. (C) 1999 Acoustical Society of America. [S0001-4966(99)00812-7]. C1 USN, Ctr Surface Warfare, Carderock Div DTMB, W Bethesda, MD 20817 USA. RP Maidanik, G (reprint author), USN, Ctr Surface Warfare, Carderock Div DTMB, 9500 MacArthur Blvd, W Bethesda, MD 20817 USA. NR 18 TC 7 Z9 7 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD DEC PY 1999 VL 106 IS 6 BP 3109 EP 3118 DI 10.1121/1.428164 PG 10 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 266YW UT WOS:000084328700009 ER PT J AU Maidanik, G Becker, KJ AF Maidanik, G Becker, KJ TI Criteria for designing multiple-sprung masses for wideband noise control SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID SATELLITE HARMONIC-OSCILLATORS; FUZZY AB In a companion paper the characterization of a multiple-sprung masses design for wideband noise control is presented. The characterization is largely conducted in terms of the point impedance of a set-of sprung masses. The sprung masses in the set. are collectively acting at a point. Tn that companion paper the dependencies of the joint impedance on the number of sprung masses, the modal overlap factors, the total mass, and the resonance frequency distribution are of particular interest. In the present paper this characterization of a set of sprung masses is utilized to define a number of design criteria that determine the potential viability of the set as a noise control device. In the final analysis, the device must be assessed in an-ill situ setting. In that setting the device is tested in terms of the overall gain. The determination of the overall gain requires, in addition to the joint impedance of the device, the impedance of the hosting master structure at the point of attachment. (The device is meant to control the noise in the master structure.) It is argued that although the overall gain is the final judge, the potential viability? of a device may be a useful critique of the intended performance of the device. In this vein,a viability and a criterion of promise are defined to assist with the design processes of this noise:control device. In assessing the viability and in satisfying the criterion of promise, the desired characteristics in a set of sprung masses can be judicially selected. (C) 1999 Acoustical Society of America. [S0001-4966(99)00912-1]. C1 USN, Ctr Surface Warfare, Carderock Div DTMB, W Bethesda, MD 20817 USA. RP Maidanik, G (reprint author), USN, Ctr Surface Warfare, Carderock Div DTMB, 9500 MacArthur Blvd, W Bethesda, MD 20817 USA. NR 18 TC 11 Z9 11 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD DEC PY 1999 VL 106 IS 6 BP 3119 EP 3127 DI 10.1121/1.428165 PG 9 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 266YW UT WOS:000084328700010 ER PT J AU Smith, KB AF Smith, KB TI A three-dimensional propagation algorithm using finite azimuthal aperture SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID DEPENDENT BENCHMARK PROBLEMS; PARABOLIC EQUATION; APPROXIMATION; WEDGE AB The use of three-dimensional (3-D) propagation models is becoming increasingly common in current underwater acoustics applications. Such models typically treat the propagation as a function of range, depth, and bearing, consistent with previous multibearing two-dimensional (N X 2-D) models. However, to obtain accurate 3-D solutions at long,ranges, many bearings must be computed in order to maintain the necessary cross-range resolution between bearings. In this paper, a 3-D parabolic equation (PE) model is developed with a marching algorithm based on the split-step Fourier technique in both depth and azimuthal bearing. The algorithm includes a scheme to compute the solution for only a finite azimuthal aperture rather than the full 360 degrees of bearing. The success of this algorithm allows for increased cross-range resolution at long range without increasing the number of bearings needed in the calculation. Results of-this technique are compared to results from a suggested benchmark case. [S0001-4966(99)02712-5]. C1 USN, Postgrad Sch, Dept Phys, Monterey, CA 93943 USA. RP Smith, KB (reprint author), USN, Postgrad Sch, Dept Phys, Monterey, CA 93943 USA. NR 23 TC 26 Z9 26 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD DEC PY 1999 VL 106 IS 6 BP 3231 EP 3239 DI 10.1121/1.428177 PG 9 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 266YW UT WOS:000084328700022 ER PT J AU Yoo, K Yang, TC AF Yoo, K Yang, TC TI Broadband source localization in shallow water in the presence of internal waves SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID BAND SOURCE LOCALIZATION; MATCHED-FIELD; PARABOLIC EQUATION; VERTICAL ARRAY; PROPAGATION; RANGE; BOTTOM; GUIDE AB Source localization is a challenging problem in a time-varying random shallow-water environment In the presence of internal waves. The short correlation time of the acoustic field (a couple of minutes) makes it difficult to adjust the replica field in response to the environmental changes. Also, mode couplings induced by the internal waves are random and not predictable. In this paper, the effect of mode coupling on source localization in the presence of Garrett-Munk and solitary internal waves is investigated. It is found that mode coupling affects: practically all modes in shallow water. Random-mode coupling reduces the matched-field correlation. To improve source localization, a broadband matched-beam processing algorithm is proposed to suppress the noncoherent coupled-mode contributions. It is shown that this technique significantly improves the localization performance over conventional matched-field processing. [50001-4966(99)03112-4]. C1 USN, Res Lab, Washington, DC 20375 USA. RP Yoo, K (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 36 TC 18 Z9 24 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD DEC PY 1999 VL 106 IS 6 BP 3255 EP 3269 DI 10.1121/1.428179 PG 15 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 266YW UT WOS:000084328700024 ER PT J AU Piquette, JC Forsythe, SE AF Piquette, JC Forsythe, SE TI One-dimensional phenomenological model of hysteresis. I. Development of the model SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID MAGNESIUM NIOBATE PMN AB A one-dimensional phenomenological model of hysteresis is presented. The model is suitable for application both to electrostrictive materials, such as lead magnesium niobate (PMN), and to magnetostrictive materials, such as Terfenol D. The concepts of ''inflation,'' ''field space,'' and the "reference ellipse" are introduced as suitable mechanisms for transforming measured hysteretic data into corresponding anhysteretic versions. An anhysteretic model is then fitted (in the least-squares sense) to the transformed data. By applying the inverse transforms to the fitted anhysteretic model, a hysteretic model is deduced. Good agreement with the original (hysteretic) data-is seen. It is shown that, when a sample is driven by:a monofrequency electric field, the area of the polarization vs electric-field hysteresis loop is independent of-all harmonics in the polarization but. the first. A principle useful for understanding the shapes assumed by P-E and M-H hysteresis loops in general is described. [S0001-4966(99)03712-1]. C1 USN, Undersea Warfare Ctr, Newport, RI 02841 USA. RP Piquette, JC (reprint author), USN, Undersea Warfare Ctr, Code 2161,1176 Howell St, Newport, RI 02841 USA. NR 12 TC 9 Z9 9 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD DEC PY 1999 VL 106 IS 6 BP 3317 EP 3327 DI 10.1121/1.428185 PG 11 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 266YW UT WOS:000084328700031 ER PT J AU Piquette, JC Forsythe, SE AF Piquette, JC Forsythe, SE TI One-dimensional phenomenological model of hysteresis. II. Applications SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB model of hysteresis is applied to determine material response to multifrequency drives, and to the output control problem. Although as presented in Paper I the model is based on a monofrequency sinusoidal drive, it can readily be generalized. The generalization is based upon the fact, at least for quasistatic drives, that the shape of the hysteresis loop is independent of the shape of the drive waveform used to produce it provided that the drive is characterized by only one wave amplitude. The material response to a given arbitrarily shaped drive can be determined if the drive is first subdivided into single-amplitude regimes or epochs. Each such regime then has associated with it a unique hysteresis loop, which can be determined from the model. Each theoretical loop is generated using a monofrequency sinusoidal drive whose amplitude is equal to the single amplitude contained within the corresponding drive epoch. The material response is then determined by correlating the level of the given drive field (and the sign of its time derivative) with that of the sinusoidal drive used to generate the associated theoretical loop. The response to the arbitrary drive is taken to be equal to the response to the sinusoidal drive at the corresponding drive level and correspondingly signed time derivative. This process is capable of inversion. Thus, not only can the material response be determined for a drive of arbitrary waveshape, but also the drive waveshape required to produce a desired output trajectory can be determined. The procedure is illustrated by determining the drive necessary to produce a monofrequency sinusoidal magnetization response from a biased, prestressed sample of Terfenol D driven at high-amplitude magnetic field. [S0001-4966(99)03812-6]. C1 USN, Undersea Warfare Ctr, Newport, RI 02841 USA. RP Piquette, JC (reprint author), USN, Undersea Warfare Ctr, Code 2161,1176 Howell St, Newport, RI 02841 USA. NR 10 TC 4 Z9 4 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD DEC PY 1999 VL 106 IS 6 BP 3328 EP 3334 DI 10.1121/1.428186 PG 7 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 266YW UT WOS:000084328700032 ER PT J AU Gionar, YR Rusmiarto, S Susapto, D Bangs, MJ AF Gionar, YR Rusmiarto, S Susapto, D Bangs, MJ TI Use of a funnel trap for collecting immature Aedes aegypti and copepods from deep wells in Yogyakarta, Indonesia SO JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION LA English DT Article DE Aedes aegypti; Copepoda; funnel trap; wells; mosquito surveillance; Indonesia ID MESOCYCLOPS-ASPERICORNIS; VILLAGE AB During the course of a "dry" season dengue vector survey, indoor and outdoor household wells were sampled for the possible presence of immature mosquitoes and copepods. With a simple floating funnel trap, Aedes aegypti immature stages were captured in over 33% of the sampled wells (n = 93) during a 24-h trapping period per well. Average number of larvae tall instars) per positive well was 8.8 (range 1-63). Positive wells varied in depth from 2.7 to 14.7 m (8.8-48.2 ft), with a mean of 7.9 +/-SE 0.5 m in well rim to water surface. Only 4 wells (4.3%) contained Culex quinquefasciatus larvae. Only I of 31 infested wells contained both species. Aedes albopictus was not detected in any of the wells. Cyclopoid copepods were captured in 15% of the wells. No significant difference was found between positive and negative wells with regard to the physical characteristics (inside diameter, distance to water level! or the depth and volume of water held at the time of sampling. A significant association was found between wells positive for larvae and numbers of other positive containers in the vicinity of the wells, In general, wells containing copepods had fewer larvae present in the trap, possibly indicating some level of natural population regulation of Ae. aegypti occurring in the well; however this association was not significant. Preliminary results indicate that a ells in Yogyakarta serve as important permanent habitats for Ae. aegypti, especially during the dry season. C1 USN, Med Res Unit 2, Dept Entomol, APO, AP 96520 USA. RP Gionar, YR (reprint author), USN, Med Res Unit 2, Dept Entomol, Box 3, APO, AP 96520 USA. NR 20 TC 9 Z9 9 U1 0 U2 4 PU AMER MOSQUITO CONTROL ASSN INC PI LAKE CHARLES PA 2200 E PRIEN LAKE RD, LAKE CHARLES, LA 70601 USA SN 8756-971X J9 J AM MOSQUITO CONTR JI J. Am. Mosq. Control Assoc. PD DEC PY 1999 VL 15 IS 4 BP 576 EP 580 PG 5 WC Entomology SC Entomology GA 265KP UT WOS:000084243700021 PM 10612624 ER PT J AU Yu, SY Brodrick, CW Ryan, MP Scully, JR AF Yu, SY Brodrick, CW Ryan, MP Scully, JR TI Effects of Nb and Zr alloying additions on the activation behavior of Ti in hydrochloric acid SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID ANODIC OXIDE-FILMS; CORROSION BEHAVIOR; CHLORIDE SOLUTIONS; PASSIVE BEHAVIOR; HCL SOLUTION; TITANIUM; DISSOLUTION; CR; ELECTROCHEMISTRY; SPECTROSCOPY AB The activation behaviors of air-passivated commercially pure Ti, Ti-50 wt % Zr, and Ti-45 wt % Nb were investigated in hydrochloric acid (HCl) ranging from 0.1 to 10 M, and temperatures ranging from 13 to 52 degrees C. in situ electrochemical impedance spectroscopy and X-ray adsorption studies in 5 M HCl confirmed: (i) oxide dissolution occurred uniformly and (ii) rapid drops in open-circuit potential (OCP) corresponded with the exposure of the underlying metal to solution. Activation energies varied from 56.5 +/- 8, and 62.9 +/- 5, to 103 +/- 6.2 kJ/mol for Ti, Ti-45% Nb, and Ti-50% Zr, respectively. Activation energies, low dissolution rates (<10-7 mol/m(2) s or 10(-3) nm/s) and dependency of the log of the oxide dissolution rate on the log of hydrogen ion activity ranging from 0.4-0.6 suggest that cleavage of metal cation-oxide bonds occurs by a rate-determining ion transfer step involving protonation of O-2 in oxides by one H+ ion to form free OH-. (C) 1999 The Electrochemical Society. S0013-4651(98)11-107-2. All rights reserved. C1 Univ Virginia, Ctr Electrochem Sci & Engn, Charlottesville, VA 22903 USA. Brookhaven Natl Lab, Dept Appl Sci, Div Mat Sci, Upton, NY 11973 USA. RP Yu, SY (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 48 TC 53 Z9 56 U1 6 U2 14 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD DEC PY 1999 VL 146 IS 12 BP 4429 EP 4438 DI 10.1149/1.1392655 PG 10 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 265PE UT WOS:000084251900017 ER PT J AU Elson, JM Tran, P AF Elson, JM Tran, P TI R-matrix propagator with perfectly matched layers for the study of integrated optical components SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID ELECTROMAGNETIC-WAVES; PHOTONIC MEDIA; DIFFRACTION; ABSORPTION; DISPERSION; GRATINGS AB The perfectly matched layer boundary conditions are incorporated into the R-matrix propagator method to achieve an extended capability for the modeling of integrated optical devices. As examples, with this technique we calculate the free-space coupling of a Gaussian beam into a planar waveguide, both with and without surface roughness on the waveguide surface. (C) 1999 Optical Society of America [S0740-3232(99)00112-X]. C1 USN, Air Warfare Ctr, Weapons Div, Computat Sci Div,Res Dept, China Lake, CA 93555 USA. RP Elson, JM (reprint author), USN, Air Warfare Ctr, Weapons Div, Computat Sci Div,Res Dept, China Lake, CA 93555 USA. NR 9 TC 6 Z9 6 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD DEC PY 1999 VL 16 IS 12 BP 2983 EP 2989 DI 10.1364/JOSAA.16.002983 PG 7 WC Optics SC Optics GA 347WH UT WOS:000088951800019 ER PT J AU Fedderly, JJ Lee, GF Lee, JD Hartmann, B Dusek, K Somvarsky, J Smrckova, M AF Fedderly, JJ Lee, GF Lee, JD Hartmann, B Dusek, K Somvarsky, J Smrckova, M TI Multifunctional polyurethane network structures SO MACROMOLECULAR SYMPOSIA LA English DT Article AB A series of thirteen polyurethanes were synthesized using blends of monofunctional, difunctional, and trifunctional poly(propylene oxides) reacted with 4,4'-diphenylmethane diisocyanate in a stoichiometric ratio. Experimental measurements were made of glass transition temperature, sol fraction, and dynamic mechanical properties. Computer simulations based on the theory of branching processes were made on the same systems. The glass transition temperature was correlated with the number average functionality of the components. Dynamic mechanical data was fitted to the Havriliak-Negami model. A correlation was demonstrated between the measured rubbery modulus and the concentration of elastically active network chains. C1 USN, Ctr Surface Warfare, Carderock Div, W Bethesda, MD 20817 USA. Acad Sci Czech Republ, Inst Macromol Chem, Prague 16006 6, Czech Republic. RP Fedderly, JJ (reprint author), USN, Ctr Surface Warfare, Carderock Div, 9500 MacArthur Blvd, W Bethesda, MD 20817 USA. RI Dusek, Karel /I-5692-2014; Duskova-Smrckova, Miroslava/I-5530-2014 NR 7 TC 6 Z9 6 U1 1 U2 1 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 1022-1360 J9 MACROMOL SYMP JI Macromol. Symp. PD DEC PY 1999 VL 148 BP 1 EP 14 DI 10.1002/masy.19991480103 PG 14 WC Polymer Science SC Polymer Science GA 288LZ UT WOS:000085565400002 ER PT J AU Garroway, AN AF Garroway, Allen N. TI Solid state NMR, MRI and Sir Peter Mansfield: (1) from broad lines to narrow and back again; and (2) a highly tenuous link to landmine detection SO MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE LA English DT Article AB The contributions of Sir Peter Mansfield to MRI are rooted in solid state NMR. I summarize some of the important contributions of Sir Peter to that field, provide a glimpse of the state of the art in multiple-pulse line-narrowing in the early 1970s, and indicate how the earliest MRI efforts at Nottingham flowed from solid state NMR. These line-narrowing methods, providing control over the Hamiltonian governing the dynamics of nuclear spins, continue to evolve and to find new uses. I indicate how some methods and ideas from solid state NMR of the 1970s are at present applied to the detection of explosives in landmines by nuclear quadrupole resonance (NQR). (C) 1999 Elsevier Science B.V. All rights reserved. C1 USN, Res Lab, Div Chem, Washington, DC 20375 USA. RP Garroway, AN (reprint author), USN, Res Lab, Div Chem, Code 6122, Washington, DC 20375 USA. EM garroway@nrl.navy.mil FU US Federal Aviation Administration; Office of Special Technology (US Department of Defense); US Defense Advanced Research Projects Agency FX It is a great pleasure to formally acknowledge my very warm and fruitful connections with Sir Peter Mansfield and his colleagues at the MRI Centre and Nottingham Physics Department over the past quarter century. Work on explosives detection at the US Naval Research Laboratory has been sponsored by the US Federal Aviation Administration, the Office of Special Technology (US Department of Defense) and the US Defense Advanced Research Projects Agency. NR 19 TC 3 Z9 3 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0968-5243 J9 MAGN RESON MATER PHY JI Magn. Reson. Mat. Phys. Biol. Med. PD DEC PY 1999 VL 9 IS 3 BP 103 EP 108 PG 6 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA V20KL UT WOS:000208138800003 PM 10628681 ER PT J AU Romero, MJ Walters, RJ Araujo, D Garcia, R AF Romero, MJ Walters, RJ Araujo, D Garcia, R TI Failure analysis of heavily proton irradiated p(+)-n InGaP solar cells by EBIC and cathodoluminescence SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 4th International Workshop on Expert Evaluation and Control of Compound Semiconductor Materials and Technologies (EXMATEC 98) CY JUN 22-24, 1998 CL UNIV WALES, CARDIFF, WALES SP Univ Wales, Appl Soild State Chem Grp Royal Soc Chem, British Assoc Crystal Growth, Wafer Technol Ltd, I E M Technol Ltd, Chell Instruments Ltd, Bede Sci Instruments Ltd, US Army European Res Off HO UNIV WALES DE heavy proton irradiation; electron-beam-induced-current (EBIC); cathodoluminescence (CL); InGaP solar cells; device failure ID GROWTH TEMPERATURE; V/III RATIO; GAINP AB In this paper the effects of heavy proton irradiation on single-junction (SJ) p(+)-n InGaP solar cells are investigated by means of electron-beam-induced-current (EBIC) and cathodoluminescence (CL). A hole diffusion length reduction from 0.3 to 0.02 mu m after 1 x 10(14) protons/cm(2) irradiation is estimated from EBIC measurements. Such degradation is attributed mainly to IE3 point defects as evidenced by the temperature dependence of the CL intensity. The electronic activity of such defects is shown to be reduced after thermal treatment. Indeed an enhancement of the light emission is observed after electron bombardment only on InGaP while no recovery is observed on the GaAs substrate. Such results illustrate the potential of EBIC/CL in device failure analysis as they are non-destructive techniques. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Univ Cadiz, Fac Ciencias, Dept Ciencia Mat & IM & QI, E-11510 Puerto Real, Cadiz, Spain. USN, Res Lab, Washington, DC 20375 USA. RP Romero, MJ (reprint author), Univ Cadiz, Fac Ciencias, Dept Ciencia Mat & IM & QI, Aptdo 40, E-11510 Puerto Real, Cadiz, Spain. OI Garcia Roja, Rafael/0000-0003-2867-7016 NR 15 TC 0 Z9 0 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD DEC 1 PY 1999 VL 66 IS 1-3 BP 189 EP 193 DI 10.1016/S0921-5107(99)00096-3 PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 265QM UT WOS:000084254900039 ER PT J AU de Hoop, M Fishman, L AF de Hoop, M Fishman, L TI Wave splitting and inverse problems SO MATHEMATICS AND COMPUTERS IN SIMULATION LA English DT Editorial Material C1 Colorado Sch Mines, Dept Math & Comp Sci, Ctr Wave Phenomena, Golden, CO 80401 USA. USN, Res Lab, Stennis Space Ctr, MS 39529 USA. Univ New Orleans, Dept Phys, New Orleans, LA 70148 USA. RP de Hoop, M (reprint author), Colorado Sch Mines, Dept Math & Comp Sci, Ctr Wave Phenomena, Golden, CO 80401 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4754 J9 MATH COMPUT SIMULAT JI Math. Comput. Simul. PD DEC 1 PY 1999 VL 50 IS 5-6 BP 373 EP 375 PG 3 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA 258GK UT WOS:000083830100001 ER PT J AU Almeida, SA Trone, DW Leone, DM Shaffer, RA Patheal, SL Long, K AF Almeida, SA Trone, DW Leone, DM Shaffer, RA Patheal, SL Long, K TI Gender differences in musculoskeletal injury rates: a function of symptom reporting? SO MEDICINE AND SCIENCE IN SPORTS AND EXERCISE LA English DT Article DE exercise; physical conditioning; training; US Marine Corps recruits; active surveillance ID LOWER-EXTREMITY INJURIES; OVERUSE INJURIES; EXERCISE; RUNNERS; SPORTS; RISKS; HYPOTHESES; HEALTH AB Purpose: This study determined gender differences in voluntary reporting of lower extremity musculoskeletal injuries among U.S. Marine Corps (USMC) recruits, and it examined the association between these differences and the higher injury rates typically found among women trainees. Methods: Subjects were 176 male and 241 female enlisted USMC recruits who were followed prospectively through 11 wk (men) and 12 wk (women) of boot camp training. Reported injuries were measured by medical record reviews. Unreported injuries were determined by a questionnaire and a medical examination administered at the completion of training. Results: Among female recruits the most commonly reported injuries were patellofemoral syndrome (10.0% of subjects), ankle sprain (9.1%), and iliotibial band syndrome (5.8%); the most common unreported injuries were patellofemoral syndrome (2.1%), metatarsalgia(1.7%), and unspecified knee pain (1.7%). Among male recruits iliotibial band syndrome (4.0% of subjects), ankle sprain (2.8%), and Achilles tendinitis/bursitis (2.8%) were the most frequently reported injuries: shin splints (4.6%). iliotibial band syndrome (4.0%), and ankle sprain (2.8%) were the most common unreported diagnoses. Female recruits were more likely to have a reported injury than male recruits (44.0%) vs 25.6%, relative risk (RR) = 1.72, 95% confidence interval (CT) 1.29-2.30), but they were less Likely to have an unreported injury (11.6% vs 23.9% RR = 0.49, 95% CI 0.31-0.75). When both reported and unreported injuries were measured, total injury rates were high for both sexes (53.5% women, 45.5% men, RR = 1.18, 95% CI 0.96-1.44), but the difference between the rates was not statistically significant. Conclusions: Our results indicate that the higher injury rates often found in female military trainees may be explained by gender differences in symptom reporting. C1 USN, Dept Hlth Sci & Epidemiol, Hlth Res Ctr, San Diego, CA 92152 USA. RP Almeida, SA (reprint author), USN, Dept Hlth Sci & Epidemiol, Hlth Res Ctr, San Diego, CA 92152 USA. NR 33 TC 66 Z9 68 U1 3 U2 9 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0195-9131 J9 MED SCI SPORT EXER JI Med. Sci. Sports Exerc. PD DEC PY 1999 VL 31 IS 12 BP 1807 EP 1812 DI 10.1097/00005768-199912000-00017 PG 6 WC Sport Sciences SC Sport Sciences GA 265MC UT WOS:000084247100017 PM 10613432 ER PT J AU Amundson, DA Gubler, KD Parrish, JS AF Amundson, DA Gubler, KD Parrish, JS TI Subject: ARDS treatment challenged SO MILITARY MEDICINE LA English DT Letter C1 USN, Med Ctr, San Diego, CA 92152 USA. RP Amundson, DA (reprint author), USN, Med Ctr, San Diego, CA 92152 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ASSN MILITARY SURG US PI BETHESDA PA 9320 OLD GEORGETOWN RD, BETHESDA, MD 20814 USA SN 0026-4075 J9 MIL MED JI Milit. Med. PD DEC PY 1999 VL 164 IS 12 BP II EP II PG 1 WC Medicine, General & Internal SC General & Internal Medicine GA 266QF UT WOS:000084310100001 PM 10628151 ER PT J AU Lall, R Holmes, EK Brinkmyer, KR Johnson, WB Yatko, BR AF Lall, R Holmes, EK Brinkmyer, KR Johnson, WB Yatko, BR TI Personality characteristics of future military leaders SO MILITARY MEDICINE LA English DT Article ID NAVY AB Relatively little is known about the personality characteristics of military personnel, particularly those who are most successful in military careers. This study evaluated the personality characteristics of 530 third-year midshipmen at the U.S. Naval Academy. Participants completed the Hogan Personality Inventory and a demographic questionnaire. Class ranking data were also obtained as an indicator of success at the Naval Academy. The results indicated that compared with national norms, midshipmen scored somewhat higher on scales of ambition, sociability, intellectance, and school success and lower on scales of adjustment, likability, and prudence. Ambition, prudence, intellectance, and school success were each significantly positively correlated with class standing. The implications of these findings for understanding personality correlates of success in military leadership are discussed. C1 USN Acad, Dept Leadership Eth & Law, Annapolis, MD 21402 USA. RP Lall, R (reprint author), USN Acad, Dept Leadership Eth & Law, Annapolis, MD 21402 USA. NR 21 TC 4 Z9 4 U1 1 U2 4 PU ASSOC MILITARY SURG US PI BETHESDA PA 9320 OLD GEORGETOWN RD, BETHESDA, MD 20814 USA SN 0026-4075 EI 1930-613X J9 MIL MED JI Milit. Med. PD DEC PY 1999 VL 164 IS 12 BP 906 EP 910 PG 5 WC Medicine, General & Internal SC General & Internal Medicine GA 266QF UT WOS:000084310100018 ER PT J AU Abdel-Hamid, TK Sengupta, K Swett, C AF Abdel-Hamid, TK Sengupta, K Swett, C TI The impact of goals on software project management: An experimental investigation SO MIS QUARTERLY LA English DT Article DE goals; software project management; software cost; software quality ID TASK-PERFORMANCE; DECISION-MAKING; ENVIRONMENTS; INFORMATION; PERSPECTIVE; JUDGMENT; FEEDBACK AB Over the last three decades, a significant stream of research in organizational behavior has established the importance of goals in regulating human behavior. The precise degree of association between goals and action, however, remains an empirical question since people may, for example, make errors and/or lack the ability to attain their goals. This may be particularly true in dynamically complex task environments, such as the management of software development. To date, goal setting research in the software engineering field has emphasized the development of tools to identify, structure, and measure software development goals. In contrast, there has been little microempirical analysis of how goals affect managerial decision behavior. The current study attempts to address this research problem. It investigated the impact of different project goals on software project planning and resource allocation decisions and, in turn, on project performance. The research question was explored through a role-playing project simulation game in which subjects played the role of software project managers. Two multigoal structures were tested, one for cost/schedule and the other quality/schedule. The cost/schedule group opted for smaller cost adjustments and was more willing to extend the project completion time. The quality/schedule group, on the other hand, acquired a larger staff level in the later stages of the project and allocated a higher percentage of the larger staff level to quality assurance. A cost/schedule goal led to lower cost, while a quality/schedule goal led to higher quality. These findings suggest that given specific software project goals, managers do make planning and resource allocation choices in such a way that will meet those goals. The implications of the results for project management practice and research are discussed. C1 USN, Postgrad Sch, Dept Syst Management, Monterey, CA 93943 USA. RP Abdel-Hamid, TK (reprint author), USN, Postgrad Sch, Dept Syst Management, Monterey, CA 93943 USA. NR 56 TC 42 Z9 43 U1 2 U2 26 PU SOC INFORM MANAGE-MIS RES CENT PI MINNEAPOLIS PA UNIV MINNESOTA-SCH MANAGEMENT 271 19TH AVE SOUTH, MINNEAPOLIS, MN 55455 USA SN 0276-7783 J9 MIS QUART JI MIS Q. PD DEC PY 1999 VL 23 IS 4 BP 531 EP 555 DI 10.2307/249488 PG 25 WC Computer Science, Information Systems; Information Science & Library Science; Management SC Computer Science; Information Science & Library Science; Business & Economics GA 308EK UT WOS:000086697400004 ER PT J AU Singer, IL AF Singer, IL TI Amontons' rules of friction formulated 300 years ago SO MRS BULLETIN LA English DT Article C1 USN, Res Lab, Washington, DC 20375 USA. RP Singer, IL (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 4 TC 0 Z9 0 U1 1 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0883-7694 J9 MRS BULL JI MRS Bull. PD DEC PY 1999 VL 24 IS 12 BP 52 EP 52 PG 1 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 266XB UT WOS:000084324600025 ER PT J AU Dawson, DA Sugano, H McCarron, RM Hallenbeck, JM Spatz, M AF Dawson, DA Sugano, H McCarron, RM Hallenbeck, JM Spatz, M TI Endothelin receptor antagonist preserves microvascular perfusion and reduces ischemic brain damage following permanent focal ischemia SO NEUROCHEMICAL RESEARCH LA English DT Article DE endothelin-1; cerebral ischemia; microvascular perfusion; ET-1 receptor antagonist; spontaneously hypertensive rat ID CEREBRAL-ARTERY OCCLUSION; GLOBAL-ISCHEMIA; BLOOD-FLOW; IN-VITRO; RAT; VASOSPASM; HYPOPERFUSION; PHARMACOLOGY; INFARCTION; MODEL AB Synthesis and release of the potent vasoconstrictor peptide endothelin-1 (ET-1) increases following cerebral ischemia and has previously been shown to mediate the delayed hypoperfusion associated with transient global ischemia. In this study we assessed the impact of ET-1 on perfusion and infarct volume in a focal model of cerebral ischemia by use of the selective ETA receptor antagonist Ro 61-1790 (affinity for ETA receptor 1000 fold greater than ETB receptor). Control rats subjected to permanent middle cerebral artery occlusion (MCAO) showed extensive reductions in microvascular perfusion 4 h post-MCAO that were significantly attenuated by Ro 61-1790 pretreatment (10 mg/kg, i.v.). Ro 61-1790 concomitantly and significantly reduced the ischemic lesion volume in the same animals. This effect was maintained 24 h post-MCAO providing that the animals received additional i.v. injections of 5 mg/kg Ro 61-1790 at 5 h and 8 h after MCAO. These findings demonstrate that ETA receptor antagonism partially preserves tissue perfusion following focal ischemia and that this effect is associated with significant neuroprotection. The results also support the hypothesis that vasoactive mediators, and ET-1 in particular, are important contributors to the pathogenesis of cerebral ischemic injury. C1 NINDS, Stroke Branch, NIH, Bethesda, MD 20892 USA. USN, Resuscitat Med Dept, Med Res Ctr, Gaithersburg, MD 20899 USA. RP Spatz, M (reprint author), NINDS, Stroke Branch, NIH, 36 Convent Dr,MSC 4128, Bethesda, MD 20892 USA. NR 33 TC 51 Z9 52 U1 1 U2 2 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0364-3190 J9 NEUROCHEM RES JI Neurochem. Res. PD DEC PY 1999 VL 24 IS 12 BP 1499 EP 1505 DI 10.1023/A:1021139713026 PG 7 WC Biochemistry & Molecular Biology; Neurosciences SC Biochemistry & Molecular Biology; Neurosciences & Neurology GA 258DH UT WOS:000083822500001 PM 10591398 ER PT J AU Abzug, R Webb, NJ AF Abzug, R Webb, NJ TI Relationships between nonprofit and for-profit organizations: A stakeholder perspective SO NONPROFIT AND VOLUNTARY SECTOR QUARTERLY LA English DT Article; Proceedings Paper CT Annual ARNOVA Conference CY NOV 05-07, 1998 CL SEATTLE, WASHINGTON SP Assoc Res Nonprofit Org & Voluntary Act AB The purpose of this article is to provide a new more comprehensive stakeholder theory of the relationships between nonprofit,far-profit, and government sectors. This theory combines aspects of neoclassical economics and principal-agency theory to complement the traditional notions that these organizations either compete or exist in a vacuum relative to one another. The article discusses nonprofit organizations that are employee groups (unions and professional associations), shareholders (institutional investors including pension funds and endowments), community and other interest groups, government contractors, competitors, consumers, and suppliers. By viewing these organizations as agents relative to a principal for-profit (or government) organization, it is possible to hypothesize about relationships and behaviors between organizations of different sectors of the economy. This new perspective allows a better understanding of the many relationships observed in the nonprofit sector and of a much greater range of nonprofit stakeholders than is currently possible given existing theory. C1 New Sch Univ, Milano Grad Sch Management & Urban Policy, Nonprofit Management Program, New York, NY USA. USN, Postgrad Sch, Def Resources Management Inst, Washington, DC USA. RP Abzug, R (reprint author), New Sch Univ, Milano Grad Sch Management & Urban Policy, Nonprofit Management Program, New York, NY USA. NR 34 TC 23 Z9 27 U1 0 U2 2 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 0899-7640 J9 NONPROF VOLUNT SEC Q JI Nonprofit Volunt. Sect. Q. PD DEC PY 1999 VL 28 IS 4 BP 416 EP 431 DI 10.1177/0899764099284003 PG 16 WC Social Issues SC Social Issues GA 262YN UT WOS:000084096000003 ER PT J AU Earle, MD Steele, KE Wang, DWC AF Earle, MD Steele, KE Wang, DWC TI Use of advanced directional wave spectra analysis methods SO OCEAN ENGINEERING LA English DT Article DE buoys; wave data; wave spectra ID PITCH AB Frequency-dependent cross-spectral parameters for pitch-roll buoy data and parameters that describe directional wave spectra based on a directional Fourier series are developed by the National Data Buoy Center (NDBC) and other organizations that collect wave data. The World Meteorological Organization (WMO) specifies wave data product formats in its Wave Observation (FM 65 WAVEOB) code. Other organizations, such as the US Army Corps of Engineers Field Wave Caging Program (FWGP), have similar specifications. A directional Fourier series has poor directional resolution compared with advanced methods such as those based on maximum likelihood and maximum entropy. Transformations are developed for applying the advanced methods and working with directional wave information stored in the WMO's FM 65 WAVEOB code, the FWGP's Wave Data Analysis Standard (WDAS) format, and similar codes and formats. Using the transformations, a directional Fourier series expansion method, a Maximum Likelihood Method (MLM), and a Maximum Entropy Method (MEM) are each applied to 115 sets of NDBC directional wave data. The MEM and MLM provide better directional resolution, but the MEM produces artificial double peaks, There are considerable differences for the three used methods. The developed transformation equations enable wave data users to apply the method that best suits their applications. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Neptune Sci Inc, Reston, VA 20191 USA. Natl Data Buoy Ctr, Stennis Space Ctr, MS 39529 USA. USN, Res Lab, Stennis Space Ctr, MS 39529 USA. RP Earle, MD (reprint author), Neptune Sci Inc, 12310 Pinecrest Rd,Suite 203, Reston, VA 20191 USA. NR 11 TC 14 Z9 14 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0029-8018 J9 OCEAN ENG JI Ocean Eng. PD DEC PY 1999 VL 26 IS 12 BP 1421 EP 1434 DI 10.1016/S0029-8018(99)00010-4 PG 14 WC Engineering, Marine; Engineering, Civil; Engineering, Ocean; Oceanography SC Engineering; Oceanography GA 221WN UT WOS:000081750300008 ER PT J AU Lancaster, DG Richter, D Curl, RF Tittel, FK Goldberg, I Koplow, J AF Lancaster, DG Richter, D Curl, RF Tittel, FK Goldberg, I Koplow, J TI High-power continuous-wave mid-infrared radiation generated by difference frequency mixing of diode-laser-seeded fiber amplifiers and its application to dual-beam spectroscopy SO OPTICS LETTERS LA English DT Article ID SPECTROMETER; WAVELENGTH AB We report the generation of up to 0.7 mW of narrow-linewidth (<60-MHz) radiation at 3.3 mu m by difference frequency mixing of a Nd:YAG-seeded 1.6-W Yb fiber amplifier and a 1.5-mu m diode-laser-seeded 0.6-W Er/Yb fiber amplifier in periodically poled LiNbO3. A conversion efficiency of 0.09%/W (0.47 mW W-2 cm(-1)) was achieved. A room-air CH4 spectrum acquired with a compact 80-m multipass cell and a dual-beam spectroscopic configuration indicates an absorption sensitivity of +/-2.8 x 10(-6) (+/-1 sigma), corresponding to a subparts-in-10(9) (ppb) CH4 sensitivity (0.8 ppb). (C) 1999 Optical Society of America. C1 Rice Univ, Rice Quantum Inst, Houston, TX 77005 USA. USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. RP Lancaster, DG (reprint author), Rice Univ, Rice Quantum Inst, Houston, TX 77005 USA. RI Lancaster, David/J-4215-2016 OI Lancaster, David/0000-0002-1299-8600 NR 12 TC 20 Z9 20 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD DEC 1 PY 1999 VL 24 IS 23 BP 1744 EP 1746 DI 10.1364/OL.24.001744 PG 3 WC Optics SC Optics GA 260PW UT WOS:000083959900030 PM 11543188 ER PT J AU Greinwald, JH Bauman, NM AF Greinwald, JH Bauman, NM TI Larsen's syndrome SO OTOLARYNGOLOGY-HEAD AND NECK SURGERY LA English DT Article C1 Univ Iowa, Coll Med, Dept Otolaryngol Head & Neck Surg, Iowa City, IA USA. RP Greinwald, JH (reprint author), USN, Med Ctr Portsmouth, Dept Otolaryngol Head & Neck Surg, Portsmouth, VA 23708 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 USA SN 0194-5998 J9 OTOLARYNG HEAD NECK JI Otolaryngol. Head Neck Surg. PD DEC PY 1999 VL 121 IS 6 BP 845 EP 845 DI 10.1053/hn.1999.v121.a97362 PG 1 WC Otorhinolaryngology; Surgery SC Otorhinolaryngology; Surgery GA 262MX UT WOS:000084072000037 PM 10580256 ER PT J AU Hill, JM AF Hill, JM TI The ethnopsychology of in-law feud and the remaking of group identity in 'Beowulf': The cases of Hengest and Ingeld SO PHILOLOGICAL QUARTERLY LA English DT Article C1 USN Acad, Annapolis, MD 21402 USA. RP Hill, JM (reprint author), USN Acad, Annapolis, MD 21402 USA. NR 30 TC 3 Z9 3 U1 0 U2 0 PU UNIV IOWA PI IOWA CITY PA ENGLISH PHILOSOPHY BLDG DEPT PUBLICATIONS LOU EICHLER, IOWA CITY, IA 52242 USA SN 0031-7977 J9 PHILOLOGICAL QUART JI Philol. Q. PD WIN-SPR PY 1999 VL 78 IS 1-2 BP 97 EP 123 PG 27 WC Language & Linguistics; Literature SC Linguistics; Literature GA 353ZX UT WOS:000089306300005 ER PT J AU Glaser, ER Kennedy, TA Freitas, JA Shanabrook, BV Wickenden, AE Koleske, DD Henry, RL Obloh, H AF Glaser, ER Kennedy, TA Freitas, JA Shanabrook, BV Wickenden, AE Koleske, DD Henry, RL Obloh, H TI Optically detected magnetic resonance of shallow donor - shallow acceptor and deep (2.8-3.2 eV) recombination from Mg-doped GaN SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 20th International Conference on Defects in Semiconductors (ICDS-20) CY JUL 26-30, 1999 CL BERKELEY, CA SP Air Force Off Sci Res, Amer Xtal Technol Inc, Appl Mat Inc, Bell Labs Lucent Technol, Hewlett Packard Lab, IBM, Intel Corp, Lawrence Berkeley Natl Lab, Off Naval Res, Sula Technol, Xeeox Palo Alto Res Ctr DE gallium nitride; Mg doping; photoluminescence; magnetic resonance ID PHOTOLUMINESCENCE; LUMINESCENCE; MOVPE; BANDS AB Comprehensive photoluminescence (PL) and optically detected magnetic resonance (ODMR) experiments have been performed on a set of GaN epitaxial layers doped with Mg from 2.5 x 10(18) to 5.0 x 10(19) cm(-3). Strong shallow donor-shallow acceptor recombination at 3.27 eV is observed from the lowest-doped sample while broad emission bands at 2.8 and 3.2 eV were found from the more heavily doped films. ODMR at 24 GHz on these bands reveals evidence for effective-mass shallow donors and Mg-related accepters with unique g-tensors, including the first observation of the resonance parameters (g(parallel to) = 2.113(4) and g(perpendicular to) = 1.970(5)) associated with Mg shallow accepters in GaN. (C) 1999 Elsevier Science B.V. All rights reserved. C1 USN, Res Lab, Washington, DC 20375 USA. Fraunhofer Inst Angew Festkorperphys, D-79108 Freiburg, Germany. RP Glaser, ER (reprint author), USN, Res Lab, Washington, DC 20375 USA. EM glaser@bloch.nrl.navy.mil NR 21 TC 17 Z9 17 U1 2 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD DEC PY 1999 VL 273-4 BP 58 EP 62 DI 10.1016/S0921-4526(99)00406-8 PG 5 WC Physics, Condensed Matter SC Physics GA 268ZX UT WOS:000084452200012 ER PT J AU Glaser, ER Kennedy, TA Bennett, BR Shanabrook, BV Hemstreet, LA Bayerl, MW Brandt, MS AF Glaser, ER Kennedy, TA Bennett, BR Shanabrook, BV Hemstreet, LA Bayerl, MW Brandt, MS TI Optical and magnetic resonance studies of As-impurities in AlSb: from isoelectronic point defects to planes SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 20th International Conference on Defects in Semiconductors (ICDS-20) CY JUL 26-30, 1999 CL BERKELEY, CA SP Air Force Off Sci Res, Amer Xtal Technol Inc, Appl Mat Inc, Bell Labs Lucent Technol, Hewlett Packard Lab, IBM, Intel Corp, Lawrence Berkeley Natl Lab, Off Naval Res, Sula Technol, Xeeox Palo Alto Res Ctr DE aluminum antimonide; arsenic impurities; photoluminescence; magnetic resonance ID QUANTUM-WELLS; PHOTOLUMINESCENCE; EXCITONS AB Strong photoluminescence (PL) has been observed and assigned to excitons from superlattices (SL) composed of fractional or single planes of As atoms separated by 8-49 monolayers (ML) of AlSb, from a single As-impurity sheet embedded in AlSb, and from AlSb layers uniformly doped with As. The emission ( similar to 1.40-1.62 eV) from the SLs exhibits a weak dependence on period but a strong dependence on the amount of As in the plane. From optically detected magnetic resonance, the g-values and strength of the exchange interaction indicate that the SL recombination involves an exciton whose electron is strongly localized at the As-planes and whose hole is excluded to the AlSb layers. This assignment is supported by ab initio total energy calculations of the electronic band structure. Similar PL was found from the sample with a single As-impurity sheet. A PL band at 1.606 eV from the As-doped AlSb layer is ascribed to recombination of excitons bound to As-impurities that substitute isoelectronically on the Sb sites. (C) 1999 Elsevier Science B.V. All rights reserved. C1 USN, Res Lab, Washington, DC 20375 USA. Tech Univ Munich, Walter Schottky Inst, D-85748 Garching, Germany. RP Glaser, ER (reprint author), USN, Res Lab, Washington, DC 20375 USA. EM glaser@bloch.nrl.navy.mil RI Bennett, Brian/A-8850-2008; Brandt, Martin/C-5151-2017 OI Bennett, Brian/0000-0002-2437-4213; NR 15 TC 0 Z9 0 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD DEC PY 1999 VL 273-4 BP 811 EP 814 DI 10.1016/S0921-4526(99)00510-4 PG 4 WC Physics, Condensed Matter SC Physics GA 268ZX UT WOS:000084452200192 ER PT J AU Rajagopal, AK AF Rajagopal, AK TI Quantum entanglement and the maximum-entropy states from the Jaynes principle SO PHYSICAL REVIEW A LA English DT Article ID INFORMATION AB We show that the Jaynes principle is indeed a proper inference scheme when applied to compound systems and will correctly produce the entangled maximum entropy states compatible with appropriate data. This is shown in a particular example considered recently by Horodecki et al. [Phys. Rev. A 59, 1799 (1999)], by including the dispersion of the entanglement along with its mean value as constraints and an application of the uncertainty principle. We also construct a "thermodynamiclike" description of the entanglement arising out of the maximum entropy principle. [S1050-2947(99)00512-0]. C1 USN, Res Lab, Washington, DC 20375 USA. RP Rajagopal, AK (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 15 TC 15 Z9 15 U1 0 U2 1 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 DEC PY 1999 VL 60 IS 6 BP 4338 EP 4340 DI 10.1103/PhysRevA.60.4338 PG 3 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 263WJ UT WOS:000084148000023 ER PT J AU Jackson, K Briley, A Grossman, S Porezag, DV Pederson, MR AF Jackson, K Briley, A Grossman, S Porezag, DV Pederson, MR TI Raman-active modes of a-GeSe2 and a-GeS2: A first-principles study SO PHYSICAL REVIEW B LA English DT Article ID INITIO MOLECULAR-DYNAMICS; BROKEN CHEMICAL ORDER; GLASSY GESE2; INTENSITIES; SCATTERING; ORIGIN AB We have used a recently developed computational technique based on density-functional theory to study the Raman-active modes of amorphous GeSe2 and GeS2. Vibrational modes and the associated Raman activities for three cluster building blocks of the glasses are calculated directly from first principles. The positions of the calculated symmetric-stretch modes in the cluster models ape in excellent agreement with sharp features in the observed spectra. Moreover, simulated spectra based on the cluster results are in good agreement with experiment, accounting for all the observed features in the bond-stretch region of the spectra. The cluster results suggest a new interpretation for the 250 cm(-1) mode appearing in the spectra of Ge-rich samples in the GexS1-x family. [S0163-1829(99)51846-8]. C1 Cent Michigan Univ, Dept Phys, Mt Pleasant, MI 48859 USA. USN, Res Lab, Ctr Mat Simulat, Washington, DC 20375 USA. RP Cent Michigan Univ, Dept Phys, Mt Pleasant, MI 48859 USA. OI Jackson, Koblar/0000-0002-5342-7978 NR 28 TC 109 Z9 109 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD DEC 1 PY 1999 VL 60 IS 22 BP R14985 EP R14989 DI 10.1103/PhysRevB.60.R14985 PG 5 WC Physics, Condensed Matter SC Physics GA 272BX UT WOS:000084631600001 ER PT J AU Blank, M Danly, BG Levush, B Calame, JP Nguyen, K Pershing, D Petillo, J Hargreaves, TA True, RB Theiss, AJ Good, GR Felch, K James, BG Borchard, P Cahalan, P Chu, TS Jory, H Lawson, WG Antonsen, TM AF Blank, M Danly, BG Levush, B Calame, JP Nguyen, K Pershing, D Petillo, J Hargreaves, TA True, RB Theiss, AJ Good, GR Felch, K James, BG Borchard, P Cahalan, P Chu, TS Jory, H Lawson, WG Antonsen, TM TI Demonstration of a 10 kW average power 94 GHz gyroklystron amplifier SO PHYSICS OF PLASMAS LA English DT Article ID 2ND-HARMONIC GYROKLYSTRON; BAND GYROKLYSTRON; GYRO-AMPLIFIERS; DESIGN; AMPLIFICATION; PERFORMANCE; 2-CAVITY AB The experimental demonstration of a high average power W-band (75-110 GHz) gyroklystron amplifier is reported. The gyroklystron has produced 118 AW peak output power and 29.5% electronic efficiency in the TE011 mode using a 66.7 kV, 6 A electron beam at 0.2% rf duty factor. At this operating point, the instantaneous full width at half-maximum (FWHM) bandwidth is 600 MHz. At 11% rf duty factor, the gyroklystron has produced up to 10.1 kW average power at 33% electronic efficiency with a 66 kV, 4.15 A electron beam. This represents world record performance for an amplifier at this frequency. At the 10.1 kW average power operating point, the FWHM bandwidth is 420 MHz. At higher magnetic fields and lower beam voltages, larger bandwidths can be achieved at the expense of peak and average output power. (C) 1999 American Institute of Physics. [S1070-664X(99)00712-0]. C1 USN, Res Lab, Vacuum Elect Branch, Washington, DC 20375 USA. Litton Syst Inc, Electron Devices Div, San Carlos, CA 94070 USA. Commun & Power Ind, Microwave Power Prod Div, Palo Alto, CA 94303 USA. Univ Maryland, College Pk, MD 20742 USA. KN Res, Silver Spring, MD 20906 USA. Mission Res Corp, Newington, VA 22122 USA. Sci Applicat Int Corp, Burlington, MA 01803 USA. RP Blank, M (reprint author), USN, Res Lab, Vacuum Elect Branch, Washington, DC 20375 USA. RI Antonsen, Thomas/D-8791-2017 OI Antonsen, Thomas/0000-0002-2362-2430 NR 25 TC 27 Z9 29 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD DEC PY 1999 VL 6 IS 12 BP 4405 EP 4409 DI 10.1063/1.873726 PG 5 WC Physics, Fluids & Plasmas SC Physics GA 255TH UT WOS:000083685900001 ER PT J AU Darken, RP Allard, T Achille, LB AF Darken, RP Allard, T Achille, LB TI Spatial orientation and wayfinding in large-scale virtual spaces II - Introduction SO PRESENCE-TELEOPERATORS AND VIRTUAL ENVIRONMENTS LA English DT Editorial Material C1 USN, Dept Comp Sci, Postgrad Sch, Monterey, CA 93943 USA. Off Naval Res, Cognit & Neural Sci & Technol Div, Washington, DC USA. USN, Crewstn Technol Lab, Air Warfare Ctr, Div Aircraft, Washington, DC USA. RP Darken, RP (reprint author), USN, Dept Comp Sci, Postgrad Sch, Monterey, CA 93943 USA. NR 16 TC 13 Z9 13 U1 0 U2 3 PU M I T PRESS PI CAMBRIDGE PA FIVE CAMBRIDGE CENTER, CAMBRIDGE, MA 02142 USA SN 1054-7460 J9 PRESENCE-TELEOP VIRT JI Presence-Teleoper. Virtual Env. PD DEC PY 1999 VL 8 IS 6 BP III EP VI DI 10.1162/pres.1999.8.6.iii PG 4 WC Computer Science, Cybernetics; Computer Science, Software Engineering SC Computer Science GA 276FD UT WOS:000084864200001 ER PT J AU Templeman, JN Denbrook, PS Sibert, LE AF Templeman, JN Denbrook, PS Sibert, LE TI Virtual locomotion: Walking in place through virtual environments SO PRESENCE-TELEOPERATORS AND VIRTUAL ENVIRONMENTS LA English DT Article ID TRAVEL AB This paper presents both an analysis of requirements for user control over simulated locomotion and a new control technique designed to meet these requirements. The goal is to allow the user to move through virtual environments in as similar a manner as possible to walking through the real world. We approach this problem by examining the interrelationships between motion control and the other actions people use to act, sense, and react to their environment. If the interactions between control actions and sensory feedback can be made comparable to those of actions in the real world, then there is hope for constructing an effective new technique. Candidate solutions are reviewed once the analysis is developed. This analysis leads to a promising new design for a sensor-based virtual locomotion called Gaiter. The new control allows users to direct their movement through virtual environments by stepping in place. The movement of a person's legs is sensed, and in-place walking is treated as a gesture indicating the user intends to take a virtual step. More specifically, the movement of the user's legs determines the direction, extent, and timing of their movement through virtual environments. Tying virtual locomotion to leg motion allows a person to step in any direction and control the stride length and cadence of his virtual steps. The user can walk straight, turn in place, and turn while advancing. Motion is expressed in a body-centric coordinate system similar to that of actual stepping. The system can discriminate between gestural and actual steps, so both types of steps can be intermixed. C1 USN, Res Lab, Washington, DC 20375 USA. RP Templeman, JN (reprint author), USN, Res Lab, Code 5513, Washington, DC 20375 USA. EM templeman@itd.nrl.navy.mil NR 27 TC 51 Z9 52 U1 0 U2 2 PU MIT PRESS PI CAMBRIDGE PA 55 HAYWARD STREET, CAMBRIDGE, MA 02142 USA SN 1054-7460 J9 PRESENCE-TELEOP VIRT JI Presence-Teleoper. Virtual Env. PD DEC PY 1999 VL 8 IS 6 BP 598 EP 617 DI 10.1162/105474699566512 PG 20 WC Computer Science, Cybernetics; Computer Science, Software Engineering SC Computer Science GA 276FD UT WOS:000084864200003 ER PT J AU Mathur, VK Lewandowski, AC Guardala, NA Price, JL AF Mathur, VK Lewandowski, AC Guardala, NA Price, JL TI High dose measurements using thermoluminescence of CaSO4 : Dy SO RADIATION MEASUREMENTS LA English DT Article AB Thermoluminescence dosimetry has been very successful in monitoring the personnel level doses due to high sensitivity and reusability. However, these dosimeters saturate at high doses involved in radiation processing. Present investigations show that the range of high dose measurements can be increased by an order of magnitude by increasing the concentration of dysprosium in CaSO4:Dy. A further increase in high dose measurements is possible by considering the ratio of two high temperature peaks. As the ratio of two peaks is an intrinsic property of the material, it is expected that the initial calibration of these dosimeters may not be required. This may be advantageous at very high doses where calibration of the dosimeters is quite problematic. Use of thermoluminescence peaks higher than 300 degrees C also make this technique appropriate for high dose measurements at high temperatures. Published by Elsevier Science Ltd. C1 USN, Ctr Surface Warfare, Carderock Div, Bethesda, MD 20817 USA. RP Mathur, VK (reprint author), USN, Ctr Surface Warfare, Carderock Div, 9500 MacArthur Blvd, Bethesda, MD 20817 USA. NR 7 TC 14 Z9 14 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1350-4487 J9 RADIAT MEAS JI Radiat. Meas. PD DEC PY 1999 VL 30 IS 6 BP 735 EP 738 DI 10.1016/S1350-4487(99)00244-9 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 260ZU UT WOS:000083984000006 ER PT J AU Agrawal, BN Treanor, KE AF Agrawal, BN Treanor, KE TI Shape control of a beam using piezoelectric actuators SO SMART MATERIALS & STRUCTURES LA English DT Article AB This paper presents the analytical and experimental results on optimal placement of piezoceramic actuators for shape control of beam structures. The objective is to determine the optimum piezoceramic actuator locations and voltages to minimize the error between the desired shape and the achieved shape. The analytical model for predicting beam deformation due to a piezoelectric actuator is based on the Euler-Bernoulli model. The cost function has fifth-order polynomials in the actuator locations and second-order polynomials in actuator voltages. This difference resulted in difficulty in simultaneous optimization of actuator locations and voltages. Using embedded Nader and Mead simplex algorithms to separately optimize actuator locations and voltages was found to produce reliable results, converging to the same optimum solution for a variety of initial conditions. Experimental results show that the analytical model provides a reasonable prediction of actuator performance at low input voltage, but does not account for the nonlinear behavior of the piezoceramic and effects of hysteresis. C1 USN, Postgrad Sch, Spacecraft Res & Design Ctr, Monterey, CA 93943 USA. NR 5 TC 57 Z9 58 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0964-1726 J9 SMART MATER STRUCT JI Smart Mater. Struct. PD DEC PY 1999 VL 8 IS 6 BP 729 EP 739 DI 10.1088/0964-1726/8/6/303 PG 11 WC Instruments & Instrumentation; Materials Science, Multidisciplinary SC Instruments & Instrumentation; Materials Science GA 270VM UT WOS:000084557900004 ER PT J AU Friebele, EJ Askins, CG Bosse, AB Kersey, AD Patrick, HJ Pogue, WR Putnam, MA Simon, WR Tasker, FA Vincent, WS Vohra, ST AF Friebele, EJ Askins, CG Bosse, AB Kersey, AD Patrick, HJ Pogue, WR Putnam, MA Simon, WR Tasker, FA Vincent, WS Vohra, ST TI Optical fiber sensors for spacecraft applications SO SMART MATERIALS & STRUCTURES LA English DT Article ID BRAGG GRATING ARRAYS; SUBSPACE TRACKING; STRAIN-SENSOR; IDENTIFICATION; PERFORMANCE; MECHANICS; ALGORITHM; SYSTEMS; DRAW C1 USN, Res Lab, Washington, DC 20375 USA. NR 41 TC 69 Z9 71 U1 2 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0964-1726 J9 SMART MATER STRUCT JI Smart Mater. Struct. PD DEC PY 1999 VL 8 IS 6 BP 813 EP 838 DI 10.1088/0964-1726/8/6/310 PG 26 WC Instruments & Instrumentation; Materials Science, Multidisciplinary SC Instruments & Instrumentation; Materials Science GA 270VM UT WOS:000084557900011 ER PT J AU Delannee, C Aulanier, G AF Delannee, C Aulanier, G TI Cme associated with transequatorial loops and a bald patch flare SO SOLAR PHYSICS LA English DT Article ID CORONAL MASS EJECTIONS; CURRENT-SHEET FORMATION; MAGNETIC-FIELD; SOLAR-FLARES; ACTIVE REGIONS; CONFIGURATIONS; ORIGIN; RECONNECTION; TOPOLOGY; COMPLEX AB We study a flare which occurred on 3 November 1997 at 10:31 UT in the vicinity of a parasitic polarity of AR 8100. Using SOHO/EIT 195 Angstrom observations, we identify the brightening of thin transequatorial loops connecting AR 8100 and AR 8102, and dimmings located between the two active regions. Difference images highlight the presence of a loop-like structure rooted near the flare location usually called an EIT wave. The coronal magnetic field derived from potential extrapolations from a SOHO/MDI magnetogram shows that the topology is complex near the parasitic polarity. There, a 'bald patch' (defined as the locations where the magnetic field is tangent to the photosphere) is present. We conclude that the flare was a 'bald patch flare'. Moreover, the extrapolation confirms that there is a large coronal volume filled with transequatorial field lines interconnecting AR 8100 and AR 8102, and overlaying the bald patch. We show that the dimmings are located at the footpoints of these large field lines, which can be also related to the thin bright loops observed during the flare. As this event was related to a coronal mass ejection (CME) observed by SOHO/LASCO, we propose that the observed dimmings are due to a decrease in plasma density during the opening of the transequatorial loops connecting both ARs. We propose a scenario where these large field lines are in fact pushed up by the opening of low-lying sheared field lines forming the bald patch. We finally discuss how the fast opening of these field lines can produce the brightening near the footpoints of the separatrix, observed as an 'EIT wave'. C1 NASA, Goddard Space Flight Ctr, SOHO EAF, Greenbelt, MD 20771 USA. Univ Paris 11, IAS, F-91405 Orsay, France. USN, Res Lab, Washington, DC 20375 USA. George Mason Univ, CSI, Fairfax, VA 22030 USA. RP NASA, Goddard Space Flight Ctr, SOHO EAF, Mail Code 6823,Bldg 26,Room G-1, Greenbelt, MD 20771 USA. NR 58 TC 177 Z9 180 U1 1 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 EI 1573-093X J9 SOL PHYS JI Sol. Phys. PD DEC PY 1999 VL 190 IS 1-2 BP 107 EP 129 DI 10.1023/A:1005249416605 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 316RP UT WOS:000087182100008 ER PT J AU Handy, BN Tarbell, TD Wolfson, CJ Korendyke, CM Vourlidas, A AF Handy, BN Tarbell, TD Wolfson, CJ Korendyke, CM Vourlidas, A TI Calibrated HI Lyman alpha observations with TRACE SO SOLAR PHYSICS LA English DT Article ID TRANSITION REGION; CORONAL EXPLORER AB Since shortly after launch in April 1998, the Transition Region and Coronal Explorer (TRACE) observatory has amassed a collection of H I L alpha (1216 Angstrom) observations of the Sun that have been not only of high spatial and temporal resolution, but also span a duration in time never before achieved. The L alpha images produced by TRACE are, however, composed of not only the desired line emission, but also local ultraviolet continuum and longer wavelength contamination. This contamination has frustrated attempts to interpret TRACE observations in H I L alpha. The Very Advanced Ultraviolet Telescope (VAULT) sounding rocket payload was launched from White Sands Missile range 7 May 1999 at 20:00 UT. The VAULT telescope for this flight was a dedicated H I L alpha imaging spectroheliograph. We use TRACE observations in the 1216 Angstrom and 1600 Angstrom channels along with observations from the VAULT flight to develop a method for removing UV continuum and longer wavelength contamination from TRACE L alpha images. C1 Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. Lockheed Martin Palo Alto Adv Technolk Ctr, Palo Alto, CA 94303 USA. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. RP Handy, BN (reprint author), Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. RI Vourlidas, Angelos/C-8231-2009 OI Vourlidas, Angelos/0000-0002-8164-5948 NR 9 TC 20 Z9 20 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD DEC PY 1999 VL 190 IS 1-2 BP 351 EP 361 DI 10.1023/A:1005257618422 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 316RP UT WOS:000087182100022 ER PT J AU Hourani, LL Warrack, G Coben, PA AF Hourani, LL Warrack, G Coben, PA TI A demographic analysis of suicide among US navy personnel SO SUICIDE AND LIFE-THREATENING BEHAVIOR LA English DT Article; Proceedings Paper CT Annual Meeting of the American-Psychological-Association CY AUG 09-12, 1996 CL TORONTO, CANADA SP Amer Psychol Assoc ID UNITED-STATES-ARMY; MORTALITY; MILITARY; UNEMPLOYMENT; DEATH AB Age-, sex-, race-, and employment-adjusted standardized mortality ratios (SMRs) were calculated for sailors committing suicide between 1990 and 1996 and compared with adjusted SMRs for civilians. Cluster analyses were conducted on annual rates from 1983 through 1995 to examine differences between comparison groups across time and location. Results showed fewer than expected suicides for Caucasian and African American males and a somewhat higher than expected suicide rate among other ethnic group males and among Caucasian women. The suicide rate showed an increase during the study period, with some evidence toward a clustering effect in time and space. C1 USN, Hlth Res Ctr, Dept Epidemiol & Hlth Scih, Div Hlth Sci, San Diego, CA 92186 USA. RP Hourani, LL (reprint author), USN, Hlth Res Ctr, Dept Epidemiol & Hlth Scih, Div Hlth Sci, POB 85122, San Diego, CA 92186 USA. NR 40 TC 18 Z9 19 U1 0 U2 0 PU GUILFORD PUBLICATIONS INC PI NEW YORK PA 72 SPRING STREET, NEW YORK, NY 10012 USA SN 0363-0234 J9 SUICIDE LIFE-THREAT JI Suicide Life-Threat. Behav. PD WIN PY 1999 VL 29 IS 4 BP 365 EP 375 PG 11 WC Psychiatry; Psychology, Multidisciplinary SC Psychiatry; Psychology GA 271UC UT WOS:000084611000008 PM 10636330 ER PT J AU Kostoff, RN Geisler, E AF Kostoff, RN Geisler, E TI Strategic management and implementation of textual data mining in government organizations SO TECHNOLOGY ANALYSIS & STRATEGIC MANAGEMENT LA English DT Article AB This paper focuses on the strategic role and the implementation of textual data mining (IDM) in government organizations, with special emphasis on TDM to support the management of science and technology (S&T). It begins by defining TDM, and discussing the strategic management process in federal government organisations and the role of IDM as an integral part of this process. The paper then proceeds to describe some of the uses and applications of TDM. The results of a demonstration program by the US Office of Naval Research shorer some potential benefits from TDM: (1) integration of national and multi-national S&T databases; (2) supporting strategic decisions on the direction and funding of government S & T; and (3) creation of usable S&T databases to support strategic decisions in other areas of government. Implications of the demonstration program relative to larger scale implementation of TDM are discussed. The paper ends with a description of the principles and requirements of higher quality TDM studies. C1 Off Naval Res, Arlington, VA 22217 USA. IIT, Stuart Grad Sch Business, Chicago, IL 60661 USA. RP Off Naval Res, 800 N Quincy St, Arlington, VA 22217 USA. EM kostofr@onr.navy.mil; geisler@is.netcom.com NR 62 TC 15 Z9 15 U1 3 U2 7 PU ROUTLEDGE JOURNALS, TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXFORDSHIRE, ENGLAND SN 0953-7325 EI 1465-3990 J9 TECHNOL ANAL STRATEG JI Technol. Anal. Strateg. Manage. PD DEC PY 1999 VL 11 IS 4 BP 493 EP 525 PG 33 WC Management; Multidisciplinary Sciences SC Business & Economics; Science & Technology - Other Topics GA 267GR UT WOS:000084350200001 ER PT J AU Butler, FK Bove, AA AF Butler, FK Bove, AA TI Infraorbital hypesthesia after maxillary sinus barotrauma SO UNDERSEA & HYPERBARIC MEDICINE LA English DT Article DE barotrauma; neuropathy; traumatic neuropathy; paresthesias; diving disorders ID DECOMPRESSION-SICKNESS; NEUROPATHY AB We report a case of a diver who suffered an episode of maxillary sinus barotrauma that presented with decreased sensation over the cutaneous distribution of the infraorbital nerve after an ascent which produced facial pain and crepitus. This case illustrates a potential confusion between a decompression sickness etiology and a barotraumatic etiology for the observed sensory deficit The clinical features of this case were most consistent with a barotraumatic etiology for the findings noted. The anatomy of the trigeminal nerve and previous reports of cranial nerve deficits following barotrauma are reviewed. C1 USN, Special Warfare Command Detachment, Pensacola, FL 32508 USA. Temple Univ, Sch Med, Philadelphia, PA 19122 USA. RP Butler, FK (reprint author), USN, Special Warfare Command Detachment, Pensacola, FL 32508 USA. NR 13 TC 13 Z9 13 U1 0 U2 1 PU UNDERSEA & HYPERBARIC MEDICAL SOC INC PI KENSINGTON PA 10531 METROPOLITAN AVE, KENSINGTON, MD 20895 USA SN 1066-2936 J9 UNDERSEA HYPERBAR M JI Undersea Hyperb. Med. PD WIN PY 1999 VL 26 IS 4 BP 257 EP 259 PG 3 WC Marine & Freshwater Biology; Medicine, Research & Experimental SC Marine & Freshwater Biology; Research & Experimental Medicine GA 273TZ UT WOS:000084724800009 PM 10642073 ER PT J AU Steevens, CC Russell, KL Knafelc, ME Smith, PF Hopkins, EW Clark, JB AF Steevens, CC Russell, KL Knafelc, ME Smith, PF Hopkins, EW Clark, JB TI Noise-induced neurologic disturbances in divers exposed to intense water-borne sound: two case reports SO UNDERSEA & HYPERBARIC MEDICINE LA English DT Article DE water-borne sound; neurologic disturbances; diving; noise ID FLUID-PERCUSSION MODEL; BRAIN INJURY AB Divers may be exposed to intense noise underwater. Two cases of neurologic disturbances during experimental exposures to 15 min of continuous underwater sound are described. Sound exposure in the first case consisted of a warble tone with center frequency of 240 Hz and a sound pressure level of 160 dB re 1 mu Pa. Symptoms during exposure consisted of somnolence, lightheadedness, and an inability to concentrate. No apparent effect on hearing was noted. In the second case, a center frequency of 1,000 Hz at 181 dB was used. Lightheadedness, inability to concentrate, agitation, and head vibrations were noted during the exposure. The diver also exhibited a temporary auditory threshold shift of 19.2 dB. In both cases, overt symptoms resolved within 30 min alter exposure, but both divers reported recurrent symptoms days to weeks after the exposures. Medical histories and examinations, assessment of dive profiles, and breathing gas analysis failed to support a source other than the sound exposures to account for the symptoms observed. Potential mechanisms for the described symptoms are discussed. C1 USN, Submarine Med Res Lab, Groton, CT 06340 USA. USN, Expt Diving Unit, Panama City, FL USA. USN, Aerosp Med Res Lab, Pensacola, FL USA. RP Steevens, CC (reprint author), USN, Submarine Med Res Lab, Groton, CT 06340 USA. OI Clark, Jonathan/0000-0002-1162-1238 NR 18 TC 16 Z9 16 U1 0 U2 5 PU UNDERSEA & HYPERBARIC MEDICAL SOC INC PI KENSINGTON PA 10531 METROPOLITAN AVE, KENSINGTON, MD 20895 USA SN 1066-2936 J9 UNDERSEA HYPERBAR M JI Undersea Hyperb. Med. PD WIN PY 1999 VL 26 IS 4 BP 261 EP 265 PG 5 WC Marine & Freshwater Biology; Medicine, Research & Experimental SC Marine & Freshwater Biology; Research & Experimental Medicine GA 273TZ UT WOS:000084724800010 PM 10642074 ER PT J AU Ohring, S Lugt, HJ AF Ohring, S Lugt, HJ TI Numerical simulation of a time-dependent 3-D GMA weld pool due to a moving arc SO WELDING JOURNAL LA English DT Article DE gas metal arc welding; modeling; weld pool; numerical techniques; fluid flow; heat transfer; mushy zone ID FLUID-FLOW; METAL TRANSFER; HEAT-TRANSFER AB A transient three-dimensional GMA weld pool was simulated numerically. The addition of molten material was modeled by an impacting liquid metal spray on the weld pool, with evaporation and latent heat absorption for boiling being computed at the weld pool surface. Realistic are power and current were applied, i.e., values of more than 10,000 W and 300 A. The mushy zone and the development of reinforcement without specific assumptions were included. The numerical technique consisted of a finite-difference, boundary fitted coordinate scheme to conveniently compute the nonlinear surface conditions, along with the use of an artificial compressibility method for enforcing incompressibility of the flow field. A numerical solution was presented for a finite workpiece of stainless steel 304. Results included flow and temperature fields, force estimates for various segments of the weld pool and surface geometry. Results were compared with available experimental data. C1 USN, Ctr Surface Warfare, Caderock Div, Bethesda, MD 20084 USA. RP Ohring, S (reprint author), USN, Ctr Surface Warfare, Caderock Div, Bethesda, MD 20084 USA. NR 21 TC 10 Z9 10 U1 0 U2 1 PU AMER WELDING SOC PI MIAMI PA PO BOX 351040, MIAMI, FL 33135 USA SN 0043-2296 J9 WELD J JI Weld. J. PD DEC PY 1999 VL 78 IS 12 BP 416S EP 424S PG 9 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 260DR UT WOS:000083934700013 ER PT J AU Reed, JM Gray, EM Lewis, D Oring, LW Coleman, R Burr, T Luscomb, P AF Reed, JM Gray, EM Lewis, D Oring, LW Coleman, R Burr, T Luscomb, P TI Growth patterns of Hawaiian Stilt chicks SO WILSON BULLETIN LA English DT Article ID BIRDS; RATES; ADAPTATION; HIMANTOPUS; WEIGHT AB We studied chick growth and plumage patterns in the endangered Hawaiian Stilt (Himantopus mexicanus knudseni). Body mass of captive chicks closely fit a Gompertz growth curve, revealing a growth coefficient (K) of 0.065 day(-1) and point of inflection (T) of 17 days. When chicks fledged about 28 days after hatching, they weighed only 60% of adult body mass; at 42 d, birds still were only 75% of adult mass; culmen, tarsus, and wing chord at hedging also were less than adult size. This trend of continued growth to adult size after fledging is typical for most shorebirds. After hatching, captive chicks grew more rapidly than wild chicks, probably because of an unlimited food supply. We found no evidence for adverse effects of weather on the growth of wild chicks. As with other shorebirds, the tarsus started relatively long, with culmen and then wing chord growing more rapidly in later development. Tarsal and wing chord growth were sigmoidal, whereas culmen growth was linear. We describe plumage characteristics of weekly age classes of chicks to help researchers age birds in the wild. C1 Univ Nevada, Biol Resources Res Ctr, Reno, NV 89557 USA. Univ Nevada, Reno, NV 89512 USA. US Fish & Wildlife Serv, Portland, OR 97232 USA. USN, Facil Engn Command, SW Div, San Diego, CA 92132 USA. RP Reed, JM (reprint author), Tufts Univ, Dept Biol, Medford, MA 02155 USA. NR 28 TC 9 Z9 9 U1 0 U2 8 PU WILSON ORNITHOLOGICAL SOC PI ANN ARBOR PA MUSEUM OF ZOOLOGY UNIV MICHIGAN, ANN ARBOR, MI 48109 USA SN 0043-5643 J9 WILSON BULL JI Wilson Bull. PD DEC PY 1999 VL 111 IS 4 BP 478 EP 487 PG 10 WC Ornithology SC Zoology GA 267KK UT WOS:000084357000004 ER PT J AU Johnston, E Bullock, S Uilk, J Gatenholm, P Wynne, KJ AF Johnston, E Bullock, S Uilk, J Gatenholm, P Wynne, KJ TI Networks from alpha,omega-dihydroxypoly(dimethylsiloxane) and (tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane: Surface microstructures and surface characterization SO MACROMOLECULES LA English DT Article ID INORGANIC HYBRID MATERIALS; DYNAMIC CONTACT ANGLES; BLOCK-COPOLYMERS; SIDE-CHAINS; POLYMERS; POLY(DIMETHYLSILOXANE); POLYDIMETHYLSILOXANE; BEHAVIOR; PROPERTY; ESCA AB The dibutyltin diacetate-catalyzed reaction of (tridecafluoro-1,1,2, 2-tetrahydrooctyl)triethoxysilane (FTEOS) with dihydroxy-terminated poly(dimethylsiloxane), HO(Me2SiO)(n)H, has been used to prepare surface-modified siloxane networks. Surface characterization of these elastomers was carried out with electron spectroscopy for chemical analysis (ESCA) and optical and atomic force microscopy (AFM). Surface phase separation occurs as a function of FTEOS concentration. For example, FTEOS-6x compositions (where 6x is the initial SiOEt/SiOH ratio) exhibited micron scale "islands" of fluorinated siliceous phase (FSP) surrounded by a siloxane-rich "sea". In FTEOS-12x, the FSP formed a continuous layer on the elastomeric network. Differing dynamic contact angle (DCA) analysis protocols with water as the interrogating fluid showed that water contamination affects force vs distance curve (fdc) data on samples up to FTEOS-10Ox. Intrinsic wetting behavior is reproduced only with a protocol where clean mater is used for each DCA cycle. For FTEOS-12x, an FSP monodomain exists characterized by high theta(adv) (135-6 degrees) and low theta(rec) (55-56 degrees), similar to previously reported values for fluoroalkyl side chain polymers. Long-term testing showed that the coatings undergo slow chemical degradation by water, with the rate depending on composition. FTEOS-12x is chemically stable in water due to the continuous FSP overlayer. C1 Off Naval Res, Div Phys Sci 331, Arlington, VA 22217 USA. USN, Res Lab, Mat Chem Branch, Washington, DC 20375 USA. Virginia Polytech Inst, Dept Chem, Blacksburg, VA 24061 USA. George Mason Univ, Fairfax, VA 22030 USA. Chalmers Univ Technol, Dept Polymer Technol, S-41296 Gothenburg, Sweden. RP Wynne, KJ (reprint author), Off Naval Res, Div Phys Sci 331, Arlington, VA 22217 USA. NR 37 TC 46 Z9 47 U1 2 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD NOV 30 PY 1999 VL 32 IS 24 BP 8173 EP 8182 DI 10.1021/ma990628y PG 10 WC Polymer Science SC Polymer Science GA 261QL UT WOS:000084020000031 ER PT J AU Yamauchi, B AF Yamauchi, B TI Decentralized coordination for multirobot exploration SO ROBOTICS AND AUTONOMOUS SYSTEMS LA English DT Article DE mobile robots; exploration; map-building; multiagent coordination; multirobot teams ID MOBILE ROBOTS; LOCALIZATION AB In order for multiple robots to explore an unknown environment, they need a strategy for cooperation. We propose a strategy where robots share perceptual information but maintain separate maps. These robots make independent decisions about where to explore using frontier-based exploration. This allows each robot to use the information from other robots while retaining the capability to explore independently. As a result, the multirobot team is robust to the loss of communications or the loss of individual robots. We have implemented this system on real robots and have demonstrated that they can explore and map indoor environments effectively. (C) 1999 Elsevier Science B.V. All rights reserved. C1 USN, Res Lab, Navy Ctr Appl Res Artificial Intelligence, Washington, DC 20375 USA. RP IS Robot, Twin City Off Ctr, Suite 6,22 McGrath Highway, Somerville, MA 02143 USA. EM yamauchi@isr.com NR 11 TC 37 Z9 40 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8890 EI 1872-793X J9 ROBOT AUTON SYST JI Robot. Auton. Syst. PD NOV 30 PY 1999 VL 29 IS 2-3 BP 111 EP 118 DI 10.1016/S0921-8890(99)00046-9 PG 8 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Robotics SC Automation & Control Systems; Computer Science; Robotics GA 278DD UT WOS:000084971900002 ER PT J AU Kirk, AD Jacobson, LM Heisey, DM Radke, NF Pirsch, JD Sollinger, HW AF Kirk, AD Jacobson, LM Heisey, DM Radke, NF Pirsch, JD Sollinger, HW TI Clinically stable human renal allografts contain histological and RNA-based findings that correlate with deteriorating graft function SO TRANSPLANTATION LA English DT Article; Proceedings Paper CT 23rd Annual Meeting of the American-Society-of-Transplant-Surgeons CY MAY 10-16, 1997 CL CHICAGO, ILLINOIS SP Amer Soc Transplant Surgeons ID POLYMERASE CHAIN-REACTION; CYTOKINE MESSENGER-RNA; CYCLOSPORINE; REJECTION; TRANSCRIPTION; LYMPHOCYTES; RECIPIENTS; THERAPY AB Background. Chronic rejection (CR) remains idiopathic, difficult to prospectively identify, and once detected, unresponsive to increased immunosuppression. We hypothesized that clinically stable human renal allografts have ongoing evidence of injury and immune activity, and that this correlates with the worsening of allograft function characteristic of CR. Methods. The allografts of 40 stable renal allograft recipients were biopsied 25 years after transplantation, Biopsies were processed for histology and RNA extraction. RNA was evaluated by semi-quantitative RT-polymerase chain reaction for CD3 gamma mRNA (a marker of T cell receptor turnover), and mRNA from cytokine genes previously shown to be transcribed during acute rejection tumor necrosis factor-alpha isterferon-gamma, interleukin- (IL) 1 beta, IL-2, IL-4, IL-6, and IL-8. Clinical parameters including urine protein and glomerular filtration rate were measured the day of biopsy. Findings were then compared with clinical outcome to establish associations between subclinical inflammation and graft dysfunction. Allograft function was measured again 2-3 years after biopsy and correlated with findings at the time of biopsy. Results. Cytokine transcripts and histological evidence of injury were detected in more than two-thirds of stable grafts. The degree of the lymphocytic in filtrate correlated with the degree of proteinuria (P=0.034) and histological fibrosis (P=0.005). Similarly, the degree of intragraft CD3 gamma transcription correlated with increasing proteinuria (P=0.043), IL-6 and IL-8 transcripts were also correlated with evidence of graft injury. After 2 years, those biopsies originally found to have evidence of fibrosis, tubular atrophy, or CD3 gamma transcription had worsening graft function as determined by creatinine and glomerular filtration rate. Conclusions, These data demonstrate that significant injury and immune activity can be detected in patients who are stable on clinical grounds. Undetected subclinical graft injury may be a cause of chronic allograft rejection. C1 USN, Med Res Ctr, Immune Cell Biol Program, Bethesda, MD 20889 USA. Univ Wisconsin, Sch Med, Div Transplantat, Madison, WI 53792 USA. RP Kirk, AD (reprint author), USN, Med Res Ctr, Immune Cell Biol Program, Bldg 17,Room 235,8901 Wisconsin Ave, Bethesda, MD 20889 USA. RI Kirk, Allan/B-6905-2012 NR 23 TC 48 Z9 50 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0041-1337 J9 TRANSPLANTATION JI Transplantation PD NOV 27 PY 1999 VL 68 IS 10 BP 1578 EP 1582 DI 10.1097/00007890-199911270-00024 PG 5 WC Immunology; Surgery; Transplantation SC Immunology; Surgery; Transplantation GA 261GV UT WOS:000084002200024 PM 10589958 ER PT J AU Mangan, MA Kral, MV Spanos, G AF Mangan, MA Kral, MV Spanos, G TI Correlation between the crystallography and morphology of proeutectoid Widmanstatten cementite precipitates SO ACTA MATERIALIA LA English DT Article DE Widmanstatten cementite; scanning electron microscopy (SEM); crystallography; phase transformations; microstructure ID ORIENTATION RELATIONSHIP; AUSTENITE; PLATES; STEEL AB Electron backscatter diffraction was used in conjunction with deep etching to examine the relationship between the crystallography and three-dimensional morphology of cementite precipitates in an Fe-1.34 wt% C-13.1 wt% Mn steel. Orientation relationships (ORs) between more than 200 proeutectoid Widmanstatten cementite precipitates and the surrounding austenite were determined to be on or very near either the well-known Pitsch OR or the Farooque-Edmonds OR. Scanning electron microscopy of the same specimens after deep etching was used to determine the three-dimensional morphology of each of the precipitates for which an OR was determined. These precipitates could be identified as either monolithic plates or conglomerates of laths. Results show that monolithic plates consistently exhibit the Pitsch OR and conglomerates of laths have the Farooque-Edmonds OR, indicating that the precipitate morphologies are dictated by their orientation relationships. Published by Elsevier Science Ltd on behalf of Acta Metallurgica Inc. C1 USN, Res Lab, Phys Met Branch, Washington, DC 20375 USA. Univ Canterbury, Dept Mech Engn, Christchurch 1, New Zealand. RP Spanos, G (reprint author), USN, Res Lab, Phys Met Branch, Washington, DC 20375 USA. RI Kral, Milo/C-2904-2009 NR 30 TC 22 Z9 22 U1 2 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD NOV 26 PY 1999 VL 47 IS 17 BP 4263 EP 4274 DI 10.1016/S1359-6454(99)00323-7 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 263XQ UT WOS:000084150900003 ER PT J AU Murata, H Merritt, CD Inada, H Shirota, Y Kafafi, ZH AF Murata, H Merritt, CD Inada, H Shirota, Y Kafafi, ZH TI Molecular organic light-emitting diodes with temperature-independent quantum efficiency and improved thermal durability SO APPLIED PHYSICS LETTERS LA English DT Article ID HOLE-TRANSPORT MATERIAL; ELECTROLUMINESCENT DEVICES; STARBURST MOLECULE; LAYER AB We demonstrate efficient and thermally stable molecular light-emitting diodes based on a multilayered structure that consists of two hole transport layers with high glass-transition temperatures, and an emitting layer doped with a highly fluorescent dye. Stable device operation was achieved up to 90 degrees C. By using an emitting layer doped with a highly fluorescent dye, the electroluminescence quantum efficiency reaches 2.2% and does not decrease with increasing temperature in contrast to a device with an undoped emitting layer. The luminous efficiency at 100 cd/m(2) increases from 4.6 lm/W at room temperature to 7.5 lm/W at 90 degrees C. The half-decay time of the initial luminance (similar to 800 cd/m(2)) of the devices is 3200 h (room temperature) and 200 h (80 degrees C) at constant dc current (10 mA/cm(2)). (C) 1999 American Institute of Physics. [S0003-6951(99)01747-7]. C1 USN, Res Lab, Washington, DC 20375 USA. Osaka Univ, Dept Appl Chem, Suita, Osaka 565, Japan. SFA Inc, Largo, MD 20774 USA. RP Murata, H (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Murata, Hideyuki/J-8453-2012 OI Murata, Hideyuki/0000-0001-8248-9652 NR 17 TC 43 Z9 43 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 22 PY 1999 VL 75 IS 21 BP 3252 EP 3254 DI 10.1063/1.125315 PG 3 WC Physics, Applied SC Physics GA 256MA UT WOS:000083728000004 ER PT J AU Stadler, S Idzerda, YU Chen, Z Ogale, SB Venkatesan, T AF Stadler, S Idzerda, YU Chen, Z Ogale, SB Venkatesan, T TI The magnetism of a buried La0.7Sr0.3MnO3 interface SO APPLIED PHYSICS LETTERS LA English DT Article ID RAY-ABSORPTION-SPECTROSCOPY; THIN-FILMS; GIANT MAGNETORESISTANCE; OXYGEN DIFFUSION; SINGLE-CRYSTALS; DEVICES AB Using x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) techniques, we have investigated the electronic structure and magnetic properties of La0.7Sr0.3MnO3 (LSMO) as a function of YBa2Cu3O7-delta (YBCO) cap layer thickness. The Mn L-2,L-3 XAS and XMCD data clearly show that the magnetic properties and electronic structure of the LSMO are adversely affected by the YBCO overlayer caused by cation displacement/exchange that effectively reduces the concentration of the La atoms in the LSMO near the YBCO/LSMO interface. (C) 1999 American Institute of Physics. [S0003-6951(99)03746-8]. C1 USN, Res Lab, Mat Phys Branch, Washington, DC 20375 USA. Univ Maryland, Ctr Superconduct Res, Dept Phys, College Pk, MD 20742 USA. RP Stadler, S (reprint author), Brookhaven Natl Lab, NSLS Bldg 725A-U4B, Upton, NY 11973 USA. RI Venkatesan, Thirumalai/E-1667-2013 NR 30 TC 36 Z9 37 U1 4 U2 29 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 22 PY 1999 VL 75 IS 21 BP 3384 EP 3386 DI 10.1063/1.125359 PG 3 WC Physics, Applied SC Physics GA 256MA UT WOS:000083728000048 ER PT J AU Roland, CM Santangelo, PG Plazek, DJ Bernatz, KM AF Roland, CM Santangelo, PG Plazek, DJ Bernatz, KM TI Creep of selenium near the glass temperature SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SEGMENTAL RELAXATION; INTERMOLECULAR COOPERATIVITY; DIELECTRIC-RELAXATION; AMORPHOUS SELENIUM; PLASTIC CRYSTALS; ENERGY LANDSCAPE; FRAGILE LIQUIDS; FORMING LIQUIDS; BRIEF CRITIQUE; POLYMERS AB Creep experiments were carried out on amorphous selenium (Se) at temperatures in the vicinity of the glass temperature. The recoverable compliance lacks a plateau, indicating Se chains are too short to form an entanglement network. The measured compliance function was thermorheological complex, even after subtraction of the glassy level and normalizing by the steady state compliance. The temperature dependence determined from the viscosity was in accord with previous viscosity data, although weaker than the near-Arrhenius dependence deduced from the stress relaxation of Se. Based on a comparison to other, small-molecule glass-formers, the dynamic fragility calculated from the viscosity was larger than expected from Se's thermodynamic fragility (i.e., steepness of the normalized Kauzmann curve). In contrast, although polypropylene (PP) is substantially more dynamically fragile than Se, PP is less thermodynamic fragile. Thus, when compared to either small-molecule liquids or polymers, Se exhibits a disconnect between dynamic and thermodynamic measures of fragility. (C) 1999 American Institute of Physics. [S0021-9606(99)50144-X]. C1 USN, Res Lab, Div Chem, Washington, DC 20375 USA. Univ Pittsburgh, Dept Mat Sci & Engn, Pittsburgh, PA 15261 USA. RP Roland, CM (reprint author), USN, Res Lab, Div Chem, Code 6120, Washington, DC 20375 USA. NR 66 TC 15 Z9 15 U1 0 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 22 PY 1999 VL 111 IS 20 BP 9337 EP 9342 DI 10.1063/1.479846 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 253PX UT WOS:000083565900028 ER PT J AU Terry, RE Davis, J Deeney, C Velikovich, AL AF Terry, RE Davis, J Deeney, C Velikovich, AL TI Current switching and mass interpenetration offer enhanced power from nested-array Z pinches SO PHYSICAL REVIEW LETTERS LA English DT Article ID X-RAY POWER AB Nested-array Z pinches are concentric, two layer wire assemblies-an exterior (driver) layer and an interior (target) layer. On the 20-MA Z accelerator they produce record-high x-ray power, 40% over a single array, but the mechanism of power enhancement remains unclear. The observed kinematics of the nested arrays is best described by a model that allows the drive mass to penetrate the target mass. At assembly the load filament's mutual inductance requires current to switch rapidly from the drive to the target array. C1 USN, Radiat Hydrodynam Branch, Div Plasma Phys, Res Lab, Washington, DC 20375 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Terry, RE (reprint author), USN, Radiat Hydrodynam Branch, Div Plasma Phys, Res Lab, Washington, DC 20375 USA. RI Velikovich, Alexander/B-1113-2009 NR 14 TC 30 Z9 31 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 22 PY 1999 VL 83 IS 21 BP 4305 EP 4308 DI 10.1103/PhysRevLett.83.4305 PG 4 WC Physics, Multidisciplinary SC Physics GA 256UV UT WOS:000083745600021 ER PT J AU Haltrin, VI AF Haltrin, VI TI Chlorophyll-based model of seawater optical properties SO APPLIED OPTICS LA English DT Article ID INELASTIC-SCATTERING; OCEANIC OPTICS; ABSORPTION; WATER; MATTER; COLOR AB A one-parameter model of the inherent optical properties of biologically stable waters is proposed. The model is based on the results of in situ measurements of inherent optical properties that have been conducted at different seas and oceans by a number of researchers. The results of these investigations are processed to force this model to agree satisfactorily with an established regression model that, connects the color index with the chlorophyll concentration. The model couples two concentrations of colored dissolved organic matter (concentrations of humic and fulvic acids) and two concentrations of suspended scattering particles (concentrations of terrigenic and biogenic particles) with the chlorophyll concentration. As a result, this model expresses all inherent properties of seawater by a single parameter; the concentration of chlorophyll. OCIS codes: 010.000, 010.160, 010.200, 060.210, 060.220, 290.150. C1 USN, Res Lab, Ocean Sci Branch, Stennis Space Ctr, MS 39529 USA. RP USN, Res Lab, Ocean Sci Branch, Code 7331, Stennis Space Ctr, MS 39529 USA. EM haltrin@nrlssc.navy.mil NR 31 TC 42 Z9 44 U1 0 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD NOV 20 PY 1999 VL 38 IS 33 BP 6826 EP 6832 DI 10.1364/AO.38.006826 PG 7 WC Optics SC Optics GA 256UC UT WOS:000083743900004 PM 18324222 ER PT J AU Wolff, MT Wood, KS Imamura, JN Middleditch, J Steiman-Cameron, TY AF Wolff, MT Wood, KS Imamura, JN Middleditch, J Steiman-Cameron, TY TI X-ray and optical observations of BL Hydri SO ASTROPHYSICAL JOURNAL LA English DT Article DE novae, cataclysmic variables; radiation mechanisms : nonthermal stars : individual (BL Hydri); white dwarfs; X-rays : stars ID QUASI-PERIODIC OSCILLATIONS; MAGNETIC WHITE-DWARFS; RADIATIVE SHOCKS; TIMING EXPLORER; AM-HER; EMISSION; HYI; POLARIMETRY; PERFORMANCE; SEARCH AB We acquired hard X-ray and unfiltered optical photometric data of the AM Herculis system BL Hydri. The X-ray data were obtained using the Proportional Counter Array detector of the Rossi X-Ray Timing Explorer satellite on 1997 October 17. The optical data were obtained using the 1.5 m telescope of the Cerro Tololo Inter-American Observatory on 1997 September 24. At the time of our observations, BL Hyi was in an unusual high-luminosity state with average visual magnitude m(v) approximate to 14.4 and orbital phase-averaged 2-10 keV X-ray flux approximate to 1.5 x 10(-11) ergs cm(-2) s(-1), roughly 50% larger than had been seen previously. The X-ray light curves suggested that two accretion poles were active. The primary X-ray emission region was extended, covering similar to 45 degrees in longitude on the white dwarf, while the secondary X-ray emission region was consistent with a point source with flux similar to 33% that of the primary region. The X-ray spectra were well fitted by absorbed bremsstrahlung with Gaussian emission-line models; and absorbed power law with Gaussian emission-line models. For the thermal models, the X-ray spectra were consistent with kT(X) approximate to 11 keV and an emission line at E approximate to 6.7-6.8 keV with equivalent width EW = 0.86-1.2 keV. The absorbed power-law models had slope alpha approximate to 2.1 and an emission line at E = 6.7-6.8 keV with EW = 1.1-1.5 keV. The optical data showed, 2.7% +/- 0.2% rms quasi-periodic oscillations (QPOs) over the frequency range 0.2-0.8 Hz modulated strongly on the orbital period suggesting that the QPOs were connected with the dominant accretion hot spot. We did not did corresponding QPOs in the X-ray emission for an upper limit of 20% rms. There were no detections of other short-period QPOs or coherent features in either the optical or the X-ray data. The X-ray and optical data were consistent with a radiative shock model. Based primarily on the X-ray continuum and line spectrum, we infer that the mass of the white dwarf in the BL Hyi system is 0.3-0.7 M., depending on the relative cyclotron and hard X-ray luminosities. C1 USN, Res Lab, Washington, DC 20375 USA. Univ Oregon, Dept Phys, Eugene, OR 97403 USA. Univ Oregon, Inst Theoret Sci, Eugene, OR 97403 USA. Univ Calif Los Alamos Natl Lab, Comp Informat & Commun Div, Los Alamos, NM 87545 USA. Indiana Univ, Dept Astron, Bloomington, IN 47405 USA. RP Wolff, MT (reprint author), USN, Res Lab, Code 7621-9, Washington, DC 20375 USA. NR 30 TC 16 Z9 16 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 1999 VL 526 IS 1 BP 435 EP 444 DI 10.1086/307982 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258XA UT WOS:000083863900037 ER PT J AU Winebarger, AR Emslie, AG Warren, HP AF Winebarger, AR Emslie, AG Warren, HP TI Analyzing the energetics of explosive events observed by SUMER on SOHO SO ASTROPHYSICAL JOURNAL LA English DT Article DE sun : activity; sun : transition region; sun : UV radiation ID SOLAR TRANSITION REGION; MAGNETIC RECONNECTION; FLARES; SPECTROMETER; TELESCOPE; EMISSION; CORONA; JETS; SUN AB The SUMER spectrometer on SOHO has obtained numerous observations of optically thin chromosphere-corona transition-region line profiles with high spatial, spectral, and temporal resolution. Many of these profiles exhibit asymmetries and broadenings associated with impulsive mass motions (explosive events) in the solar atmosphere. We present here a new method of analyzing non-Gaussian line profiles to calculate the distribution of fluid velocities and hence the associated energy flux. We illustrate this method through a preliminary analysis of explosive event line profiles observed by SUMER. We derive the magnitudes of the energy fluxes directed both toward and away from the observer, and their ("net flux") differences. We also identify and quantify the various components of each (i.e., kinetic, thermal and nonthermal enthalpy, and the high-energy component associated with the skewed tail of the distribution). The global energy contribution of explosive events to the solar atmosphere is then estimated under two different "grouping" assumptions. This preliminary analysis reveals an average net upward energy flux over the entire Sun of 10(4)-10(5) ergs cm(-2) s(-1), up to an order of magnitude larger than previous estimates based on characteristic velocities of the fluid. Furthermore, the global estimate for the separate upward- and downward-directed energy fluxes is 10(5)-10(6) ergs cm(-2) s(-1), which is comparable to the energy flux required for heating of the quiet corona and indicates that explosive events may indeed have significant implications for the energy balance of the chromosphere and corona. C1 Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Winebarger, AR (reprint author), Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. NR 23 TC 11 Z9 12 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 1999 VL 526 IS 1 BP 471 EP 477 DI 10.1086/307966 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 258XA UT WOS:000083863900041 ER PT J AU Bartlett, B Valdisera, JM Russell, JN AF Bartlett, B Valdisera, JM Russell, JN TI A comparison of the surface chemistry of phenyl cyanate and phenol on Al(111) SO SURFACE SCIENCE LA English DT Article DE adhesion; aluminum; aromatics; phenol; phenyl cyanate; surface chemical reaction; thermal desorption spectroscopy; X-ray photoelectron spectroscopy ID NI(110); DECOMPOSITION; ORIENTATION; ADSORPTION; KINETICS; COVERAGE; BENZENE; MO(110); ANILINE AB The surface chemistry of phenyl cyanate and phenol on Al(111) was investigated by temperature-programmed desorption and X-ray photoelectron spectroscopy between 100 and 800 K. Chemisorption of the initial monolayer occurred via cleavage of the O-CN bond for phenyl cyanate and the O-H bond for phenol. A surface phenoxide species was formed for both cases that decomposed further to yield a chemisorbed phenyl group. Ultimately, benzene and hydrogen were observed as desorption products. Carbide and oxide remained on the surface as decomposition products for both molecules, while a nitride species also remained after phenyl cyanate decomposition. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 USN, Res Lab, Funct Mat Sect, Washington, DC 20375 USA. RP Russell, JN (reprint author), USN, Res Lab, Funct Mat Sect, Code 6125, Washington, DC 20375 USA. RI Russell, John/A-3621-2009 NR 20 TC 19 Z9 19 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD NOV 20 PY 1999 VL 442 IS 2 BP 265 EP 276 DI 10.1016/S0039-6028(99)00926-7 PG 12 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 258LE UT WOS:000083840000019 ER PT J AU Bellitto, VJ Yang, Y Thoms, BD Koleske, DD Wickenden, AE Henry, RL AF Bellitto, VJ Yang, Y Thoms, BD Koleske, DD Wickenden, AE Henry, RL TI Desorption of hydrogen from GaN(0001) observed by HREELS and ELS SO SURFACE SCIENCE LA English DT Letter DE desorption; gallium nitride; HREELS; hydrogen ID MOLECULAR-BEAM-EPITAXY; ELECTRONIC-PROPERTIES; GAAS(110) SURFACES; GALLIUM NITRIDE; GAN SURFACES; DECOMPOSITION; COMPENSATION; GROWTH; H-2 AB The bare and hydrogenated GaN(0001) surfaces were characterized using high resolution electron energy loss spectroscopy (HREELS), electron energy loss spectroscopy (ELS), Auger electron spectroscopy (AES) and low energy electron diffraction (LEED). AES and LEED show that the GaN surface is clean but faceted. Changes in the surface electronic structure are characterized using ELS. Exposure to atomic hydrogen produces a merging of the double peak centered near 20 eV and a leveling of the region from 10 to 15 eV. These hydrogen-induced changes begin to decrease after briefly heating to 260 degrees C and are completely reversed after heating to 380 degrees C. Atomic hydrogen exposure produces HREELS loss peaks at 2580, 3280 and 3980 cm(-1) due to combinations of the Ga-H stretching vibration at 1880 cm(-1) and Fuchs-Kliewer phonons. Briefly heating to 260 degrees C or above produces a decrease in the intensity of Ga-H vibrations. Heating to 380 degrees C results in a complete disappearance of adsorbate vibrational peaks. Observation of desorbing molecular hydrogen by mass spectrometry confirms that the disappearance of Ga-H features in HREEL and ELS spectra is due to recombinative desorption of hydrogen. Overall this work demonstrates desorption of hydrogen from surface Ga sites between 250 and 450 degrees C. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. USN, Res Lab, Div Elect Sci & Technol, Lab Adv Mat Synth, Washington, DC 20375 USA. RP Thoms, BD (reprint author), Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. RI Schaff, William/B-5839-2009 NR 25 TC 15 Z9 15 U1 2 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD NOV 20 PY 1999 VL 442 IS 2 BP L1019 EP L1023 DI 10.1016/S0039-6028(99)00973-5 PG 5 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 258LE UT WOS:000083840000005 ER PT J AU Thompson, CA Mowrey, RC Russell, TP AF Thompson, CA Mowrey, RC Russell, TP TI Experimental and computational studies of the structure and vibrational spectra of azetidine derivatives SO JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM LA English DT Article DE harmonic vibrational frequency; azetidine; molecular motion; nitroso-DNAZ ID MOLECULAR-ORBITAL METHODS; GAUSSIAN-TYPE BASIS; ELECTRON-DIFFRACTION; ORGANIC-MOLECULES; 4-MEMBERED RINGS; 1,3,3-TRINITROAZETIDINE; ABINITIO; GAS; CONFORMATION; SPECTROSCOPY AB The IR spectra of 3,3-dinitroazetidine (DNAZ), 1-nitroso-3,3-dinitroazetidine (nitroso-DNAZ), and azetidine in solid argon matrices were measured. In addition, the structures and harmonic vibrational frequencies of these molecules were theoretically evaluated using three electronic structure methods: restricted Hartree-Fock and the B3LYP and BP86 density functional methods. The computed geometries are compared with the experimental measurements. The computed vibrational frequencies are used to determine the types of molecular motion associated with each of the observed experimental bands. Comparison with the experimental spectra provides important information about the ability of these computational methods to describe the vibrational modes in these highly polar strained ring compounds. (C) 1999 Elsevier Science B.V. All rights reserved. C1 USN, Res Lab, Div Chem, Washington, DC 20375 USA. RP Russell, TP (reprint author), USN, Res Lab, Div Chem, Code 6100,4555 Overlook Ave SW, Washington, DC 20375 USA. NR 27 TC 4 Z9 4 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-1280 J9 J MOL STRUC-THEOCHEM JI Theochem-J. Mol. Struct. PD NOV 19 PY 1999 VL 491 BP 67 EP 80 DI 10.1016/S0166-1280(99)00078-0 PG 14 WC Chemistry, Physical SC Chemistry GA 253EQ UT WOS:000083544000008 ER PT J AU Eckermann, SD Preusse, P AF Eckermann, SD Preusse, P TI Global measurements of stratospheric mountain waves from space SO SCIENCE LA English DT Article ID ATMOSPHERIC GRAVITY-WAVES; LEE WAVES; LIDAR OBSERVATIONS; MIDDLE ATMOSPHERE; OZONE DEPLETION; TURBULENCE; VARIANCE; WIND; TEMPERATURES; PROPAGATION AB Temperatures acquired by the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) during shuttle mission STS-66 have provided measurements of stratospheric mountain waves from space. Large-amplitude, Long-wavelength mountain waves at heights of 15 to 30 kilometers above the southern Andes Mountains were observed and characterized, with vigorous wave breaking inferred above 30 kilometers. Mountain waves also occurred throughout the stratosphere (15 to 45 kilometers) over a broad mountainous region of central Eurasia. The global distribution of mountain wave activity accords well with predictions from a mountain wave model. The findings demonstrate that satellites can provide the global data needed to improve mountain wave parameterizations and hence global climate and forecast models. C1 USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. Berg Univ Gesamthsch Wuppertal, Dept Phys, D-42097 Wuppertal, Germany. RP Eckermann, SD (reprint author), USN, Res Lab, EO Hulburt Ctr Space Res, Code 7641-2, Washington, DC 20375 USA. RI Preusse, Peter/A-1193-2013 OI Preusse, Peter/0000-0002-8997-4965 NR 50 TC 168 Z9 170 U1 2 U2 8 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD NOV 19 PY 1999 VL 286 IS 5444 BP 1534 EP 1537 DI 10.1126/science.286.5444.1534 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 257DZ UT WOS:000083768300049 ER PT J AU Xiao, C Wu, J Yang, L Yee, AF Xie, L Gidley, D Ngai, KL Rizos, AK AF Xiao, C Wu, J Yang, L Yee, AF Xie, L Gidley, D Ngai, KL Rizos, AK TI Positronium annihilation lifetime and dynamic mechanical studies of gamma-relaxation in BPA-PC and TMBPA-PC plasticized by TOP SO MACROMOLECULES LA English DT Article ID DISSOLVED POLYCARBONATES; LOCAL MOTION; SPIN RELAXATION; NEUTRON-SCATTERING; PHENYLENE MOTION; MIXTURES; GLASSY; POLYMERS; ANTIPLASTICIZATION; MODEL AB Positronium annihilation lifetime spectroscopy (PALS) was employed to study the structure and dynamic properties of glassy BPA-PC and TMBPA-PC containing tris(2-ethylhexyl) phosphate (TOP) as diluent molecules. For BPA-PC/TOP blends, the results showed that the total hole volume fraction is insensitive to the addition of TOP up to 10 wt % but increases at higher TOP concentration. However, in the case of TMBPA-PC/TOP blends, a different trend was observed. The total hole volume fraction decreases monotonically with TOP concentration up to 15% and thereafter increases slightly from 15 to 20%. Dynamic mechanical relaxation was also used to monitor the dynamics of the blends. This part of the work was motivated by a prediction of the coupling model (made before the experimental measurement was carried out) that addition of TOP should have opposite effects on the gamma-relaxation times of BPA-PC and TMBPA-PC. Indeed, it was found by dynamic mechanical measurement at constant frequency that, while the gamma-relaxation peak temperature of BPA-PC was shifted to higher temperature with addition of TOP, the opposite effect was found in TMBPA-PC. The gamma-relaxation peak temperature of TMBPA-PC was shifted to lower temperatures upon addition of TOP with little change in the width of the peak as predicted by the coupling model. The predictions of the coupling model and the dynamic mechanical results are supported by (1) dielectric relaxation measurements of the gamma-relaxation performed on the same TMBPA-PC/TOP blends by Rites and co-workers [accompanying paper] and also (2) the phosphorus-31 nuclear magnetic resonance data on diluent dynamics in the same BPA-PC/TOP and the TMBPA-PC/TOP blends obtained by Bergquist et al. [accompanying paper], which is shown by them to be also consistent with the lattice model for diluent dynamics. C1 USN, Res Lab, Washington, DC 20375 USA. Univ Michigan, Dept Mat Sci & Engn, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Univ Crete, Dept Chem, Heraklion, Crete, Greece. FORTH, Heraklion, Crete, Greece. RP Ngai, KL (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Yee, Albert/E-5398-2010; Rizos, Apostolos/F-6807-2011 OI Yee, Albert/0000-0002-5762-6042; NR 41 TC 25 Z9 26 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD NOV 16 PY 1999 VL 32 IS 23 BP 7913 EP 7920 DI 10.1021/ma980203w PG 8 WC Polymer Science SC Polymer Science GA 257HB UT WOS:000083775500026 ER PT J AU Rizos, AK Petihakis, L Ngai, KL Wu, JH Yee, AF AF Rizos, AK Petihakis, L Ngai, KL Wu, JH Yee, AF TI A dielectric relaxation study of the gamma-relaxation in tetramethylbisphenol A polycarbonate plasticized by tris(2-ethylhexyl) phosphate SO MACROMOLECULES LA English DT Article ID BISPHENOL-A POLYCARBONATE; DISSOLVED POLYCARBONATES; SECONDARY RELAXATION; MOLECULAR MOTIONS; PHENYLENE MOTION; DYNAMICS; GLASSY; POLYMERS; NMR AB Dielectric relaxation spectroscopy (DR) was employed to study the dynamics of glassy tetramethylbisphenol A polycarbonate (TMBPA-PC) containing various amounts of tris(2-ethylhexyl) phosphate (TOP) added as diluent molecules. The present data confirm that the gamma-relaxation dynamics, at constant frequency, shift to lower temperatures with increasing TOP content, an effect observed for the first time by dynamic mechanical measurements. This behavior of the gamma-relaxation in TMBPA-PC plasticized by TOP is to be contrasted with that in bisphenol A polycarbonate (BPA-PC) plasticized by TOP. In the latter case, the gamma-relaxation dynamics, at constant frequency, shift to higher temperatures with addition of TOP. These opposite trends of the gamma-relaxation dynamics in two similar polycarbonates are surprising. However, the results can be rationalized by the coupling model. C1 USN, Res Lab, Washington, DC 20375 USA. Univ Crete, Dept Chem, GR-71409 Iraklion, Greece. Fdn Res & Technol Hellas, GR-71409 Iraklion, Greece. Univ Michigan, Dept Mat Sci & Engn, Ann Arbor, MI 48109 USA. RP Ngai, KL (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Yee, Albert/E-5398-2010; Rizos, Apostolos/F-6807-2011 OI Yee, Albert/0000-0002-5762-6042; NR 31 TC 16 Z9 16 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD NOV 16 PY 1999 VL 32 IS 23 BP 7921 EP 7924 DI 10.1021/ma980204o PG 4 WC Polymer Science SC Polymer Science GA 257HB UT WOS:000083775500027 ER PT J AU Koleske, DD Twigg, ME Wickenden, AE Henry, RL Gorman, RJ Freitas, JA Fatemi, M AF Koleske, DD Twigg, ME Wickenden, AE Henry, RL Gorman, RJ Freitas, JA Fatemi, M TI Properties of Si-doped GaN films grown using multiple AlN interlayers SO APPLIED PHYSICS LETTERS LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; THREADING DISLOCATIONS; SAPPHIRE AB Electrical, optical, and structural properties of Si-doped GaN films grown on multiple AlN interlayers (IL) sandwiched between high-temperature (HT) GaN are presented. We show that as the number of AlN IL/HT GaN layers increases, the electron mobility increases in the top Si-doped GaN layer, showing a near doubling from 440 to 725 cm(2) V-1 s(-1). Cross-sectional transmission electron microscopy images reveal a significant reduction in the screw dislocation density for GaN films grown on the AlN IL/HT GaN layers. The symmetric and off-axis x-ray linewidths increase as the number of AlN IL/HT GaN layers increase, indicating a greater relative misalignment of the adjacent HT GaN layers. Photoluminescence spectra of undoped and Si-doped GaN films on the multiple AlN IL/HT GaN layers have small yellow-band intensity. Analysis based on a single-donor/single-acceptor model for the electrical conduction suggests that the improved electron mobility is the result of a reduced acceptor concentration in the top GaN film and that this acceptor may possibly be associated with threading screw dislocations in GaN. [S0003-6951(99)04546-5]. C1 USN, Res Lab, Div Elect Sci & Technol, Washington, DC 20375 USA. RP USN, Res Lab, Div Elect Sci & Technol, Code 6800, Washington, DC 20375 USA. EM koleske@estd.nrl.navy.mil NR 17 TC 24 Z9 25 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 15 PY 1999 VL 75 IS 20 BP 3141 EP 3143 DI 10.1063/1.125257 PG 3 WC Physics, Applied SC Physics GA 254NV UT WOS:000083619800031 ER PT J AU Rosler, ES Chute, J Hoffman, R AF Rosler, ES Chute, J Hoffman, R TI Direct examination ob the competitive engraftment potential of various human stem cell sources in a triple HLA-mismatched scid-hu bone model. SO BLOOD LA English DT Meeting Abstract C1 Univ Illinois, Chicago, IL USA. USN, Med Res Inst, Bethesda, MD USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC HEMATOLOGY PI WASHINGTON PA 1200 19TH ST, NW, STE 300, WASHINGTON, DC 20036-2422 USA SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1999 VL 94 IS 10 SU 1 MA 127 BP 32A EP 32A PN 1 PG 1 WC Hematology SC Hematology GA 257PH UT WOS:000083790300176 ER PT J AU Rosler, ES Brandt, JE Chute, J Hoffman, R AF Rosler, ES Brandt, JE Chute, J Hoffman, R TI Competitive engraftment potential of primary and ex vivo expanded cord blood CD34+cells in a triple HLA-mismatched SCID-hu bone model. SO BLOOD LA English DT Meeting Abstract C1 Univ Illinois, Chicago, IL USA. USN, Med Res Inst, Bethesda, MD USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC HEMATOLOGY PI WASHINGTON PA 1200 19TH ST, NW, STE 300, WASHINGTON, DC 20036-2422 USA SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1999 VL 94 IS 10 SU 1 MA 3120 BP 706A EP 706A PN 1 PG 1 WC Hematology SC Hematology GA 257PH UT WOS:000083790303169 ER PT J AU Loschialpo, P Forester, DW Schelleng, J AF Loschialpo, P Forester, DW Schelleng, J TI Anomalous transmission through near unit index contrast dielectric photonic crystals SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID BAND-GAP STRUCTURES; TRANSMITTANCE; LATTICES; FINITE; ARRAYS AB We present calculations that reveal a limitation for devices that demand photonic crystals with very narrow band gaps. The opaque regions of the transmission spectra through finite length crystals may be substantially broader than the band gap of the corresponding infinite crystals. This is a consequence of the crystals' near unit dielectric index contrast. The opaque spectral width decreases gradually with increasing thickness. Many hundreds of layers may be needed to obtain a transmission null which approaches the width of the band gap for the infinite crystal. The analysis is done for two configurations of interest for optical applications due to their relative ease of manufacturer. The first is a two-dimensional triangular array of dielectric rods for which finite difference time domain simulations are done to determine the transmission spectra. The second is a one-dimensional dielectric stack for which transmission is analytically calculated. (C) 1999 American Institute of Physics. [S0021-8979(99)08722-8]. C1 USN, Res Lab, Washington, DC 20375 USA. SFA Inc, Largo, MD 20774 USA. RP Loschialpo, P (reprint author), USN, Res Lab, Code 5050, Washington, DC 20375 USA. NR 18 TC 6 Z9 6 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD NOV 15 PY 1999 VL 86 IS 10 BP 5342 EP 5347 DI 10.1063/1.371530 PG 6 WC Physics, Applied SC Physics GA 251GH UT WOS:000083435900003 ER PT J AU Schlaf, R Merritt, CD Crisafulli, LA Kafafi, ZH AF Schlaf, R Merritt, CD Crisafulli, LA Kafafi, ZH TI Organic semiconductor interfaces: Discrimination between charging and band bending related shifts in frontier orbital line-up measurements with photoemission spectroscopy SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ENERGY-LEVEL ALIGNMENT; X-RAY; UV PHOTOEMISSION; DEVICES AB Gaq(3) is a promising luminescent organic semiconductor for applications in organic light emitting diodes. The frontier orbital alignment at the tris (8-hydroxyquinolinato) gallium (Gaq(3))/Pt organic Schottky contact was determined by combined x-ray and ultraviolet photoemission spectroscopy (XPS, UPS) measurements. A Gaq(3) thin film was deposited in several steps on a previously Ar+ sputtered pure Pt foil. After each growth step, the sample was characterized by XPS and UPS. The combination of XPS and UPS measurements allows the precise evaluation of the interface dipole independent from the simultaneously occurring band bending at the interface and charging artifacts. The measurements show that the Pt/Gaq(3) interface has a strong dipole of 0.71 eV indicating the transfer of negative charge from Gaq(3) to Pt. Due to the large work function difference between Pt and Gaq(3), strong band bending occurred. At Gaq(3) coverages higher than 128 Angstrom strong charging shifts occurred in the overlayer related emission lines which were identified by measuring the high binding energy cutoff (secondary edge) of both the XP and UP spectra. Due to the several magnitudes difference between the x-ray and ultraviolet source photon intensities, differences between the high binding energy cutoff positions of both measurements allow to pinpoint charging shifts with high sensitivity. In order to investigate the possible influence of radiation damage to the Gaq(3) film, a single growth step control film of Gaq(3) of the same thickness as in the multi-step orbital line-up procedure was deposited. The comparison of XPS peak intensities and positions suggest that no significant chemical alteration occurred during the photoemission spectroscopy measurements of the multi-step deposition experiment. However, the doping level of the layer may have changed due to the radiation exposure during the measurements. (C) 1999 American Institute of Physics. [S0021-8979(99)01422-X]. C1 USN, Res Lab, Washington, DC 20375 USA. RP Schlaf, R (reprint author), SUNY Binghamton, Dept Phys, Binghamton, NY 13902 USA. NR 24 TC 58 Z9 60 U1 2 U2 17 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD NOV 15 PY 1999 VL 86 IS 10 BP 5678 EP 5686 DI 10.1063/1.371578 PG 9 WC Physics, Applied SC Physics GA 251GH UT WOS:000083435900053 ER PT J AU Geltmacher, AB Matic, P Everett, RK AF Geltmacher, AB Matic, P Everett, RK TI Integrated experimental-computational characterization of TIMETAL 21S SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE TIMETAL 21S; constitutive parameters; stress-strain response; specimen geometry; localization; finite element modeling AB Accurate material constitutive parameters are important for the finite element simulation of processing, and component and structural loading. Simulations have shown that standard mechanical testing and data reduction practices can produce material property uncertainties of the order of the desired manufacturing tolerances for future components. The present study refines an integrated experimental-computational constitutive response characterization methodology that yields more accurate finite element simulations. Contrary to the previous data reduction techniques, where the goal was to produce a single uniform stress state, the new methodology seeks to generate a wide range of multiaxial stress states and then deconvolve the material response from the specimen behavior through simulation. This methodology extracts the constitutive response from experimental load-displacement test data and specimen shape evolution by constructing the material input curve from finite element simulations of the test specimen. This research includes the development of a novel test specimen to supplement the ASTM E8 specimen design, which exhibits variations in the position of strain localization along the gage length and generates a limited range of multiaxial stress states induced in the material undergoing testing. The novel specimen design examined in the present study uses a single through-thickness hole to generate the multiaxial stress and strain states. This has the added benefit of more nearly matching the stress states in actual structural components. (C) 1999 Elsevier Science S.A. All rights reserved. C1 USN, Res Lab, Multifunct Mat Branch, Washington, DC 20375 USA. RP Geltmacher, AB (reprint author), USN, Res Lab, Multifunct Mat Branch, Code 6352,4555 Overlook Ave SW, Washington, DC 20375 USA. OI Everett, Richard/0000-0002-6725-9442 NR 11 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD NOV 15 PY 1999 VL 272 IS 1 BP 99 EP 113 DI 10.1016/S0921-5093(99)00545-6 PG 15 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 255AU UT WOS:000083648000015 ER PT J AU Yang, MJ Yang, CH Bennett, BR AF Yang, MJ Yang, CH Bennett, BR TI Magnetocapacitance and far-infrared photoconductivity in GaSb/InAs composite quantum wells SO PHYSICAL REVIEW B LA English DT Article ID NEGATIVE MAGNETORESISTANCE; ALSB/INAS HEMTS; HOLE GAS; HETEROSTRUCTURES; HYBRIDIZATION; SUPERLATTICES; RESONANCE; DETECTOR; LASERS AB Magnetocapacitance-voltage measurements are performed in hybridized composite quantum wells at 4.2 K, In the quantum Hall regime, the capacitance reveals a series of oscillations resulting from the spin-resolved Landau levels. It is found that the capacitance signal is determined by the filling factor that is the difference between the electron and hole filling factors. A fan chart is generated in order to determine the Fermi level position relative to the electron and hole subbands at different gate voltages. When the Fermi level resides in the middle of the hybridization gap, far infrared photo signals have been detected with photon energy ranging from 1.4 to 5.3 meV. The hybridization gap is determined to be 3 meV. [S0163-1829(99)50544-4]. C1 USN, Res Lab, Washington, DC 20375 USA. RP Yang, MJ (reprint author), USN, Res Lab, Washington, DC 20375 USA. EM yang@bloch.nrl.navy.mil RI Bennett, Brian/A-8850-2008 OI Bennett, Brian/0000-0002-2437-4213 NR 35 TC 11 Z9 11 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1999 VL 60 IS 20 BP 13958 EP 13961 PG 4 WC Physics, Condensed Matter SC Physics GA 261NP UT WOS:000084015500005 ER PT J AU Porezag, D Pederson, MR Liu, AY AF Porezag, D Pederson, MR Liu, AY TI Importance of nonlinear core corrections for density-functional based pseudopotential calculations SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE CALCULATIONS; GENERALIZED GRADIENT APPROXIMATION; TOTAL-ENERGY CALCULATIONS; ATOMIC ORBITALS METHOD; MOLECULAR-DYNAMICS; LINEAR COMBINATION; ALL-ELECTRON; SOLIDS; SYSTEMS; DIAMOND AB We have investigated the importance of nonlinear core corrections (NLCC) for accurate density-functional based pseudopotential (PSP) calculations. The quality of the PSP approach is assessed by comparing it to accurate all-electron calculations. it is found that a correct description of spin-polarized states requires the NLCC, even for first-row atoms. This is essential for simulations on magnetic systems and reaction processes that involve radicals. The NLCC is also essential for a realistic description of elements with mon long-range core states such as alkali atoms. We propose a functional form for the partial NLCC, which is feasible in plane-wave calculations and suggest a scheme for choosing the default cutoff radius. [S0163-1829(99)02043-3]. C1 USN, Ctr Computat Mat Sci, Res Lab, Washington, DC 20375 USA. Georgetown Univ, Dept Phys, Washington, DC 20057 USA. RP USN, Ctr Computat Mat Sci, Res Lab, Washington, DC 20375 USA. RI Liu, Amy/E-2266-2015 OI Liu, Amy/0000-0002-2011-1854 NR 40 TC 44 Z9 44 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1999 VL 60 IS 20 BP 14132 EP 14139 DI 10.1103/PhysRevB.60.14132 PG 8 WC Physics, Condensed Matter SC Physics GA 261NP UT WOS:000084015500034 ER PT J AU Vurgaftman, I Meyer, JR AF Vurgaftman, I Meyer, JR TI TE- and TM-polarized roughness-assisted free-carrier absorption in quantum wells at midinfrared and terahertz wavelengths SO PHYSICAL REVIEW B LA English DT Article ID OPTICAL PHONON-SCATTERING; CONDUCTION-BAND; ELECTRON; SUPERLATTICES; TEMPERATURE; LASER; PERFORMANCE; TRANSITION; TRANSPORT; SILICON AB A free-carrier absorption mechanism, in which a photon transition is accompanied by an elastic interface-roughness scattering event, is considered for a few representative quantum well structures. Interface-roughness scattering determines the low-temperature mobility in undoped narrow quantum wells such as those used in infrared lasers. It is found that in spite of the contribution due to scattering to higher subbands, the absorption coefficient for TE-polarized light remains appreciably less than the semiclassical value at shorter wavelengths. The implications of these results for the recently proposed interband far-infrared and terahertz lasers based on "W" antimonide structures are discussed. In the case of roughness-assisted absorption of TM-polarized light, transitions forbidden by symmetry and exclusion arguments become allowed. However, the largest second-order contribution relative to first-order intersubband absorption tends to occur at wavelengths where the total absorption coefficient is rather small. [S0163-1829(99)10143-7]. C1 USN, Res Lab, Washington, DC 20375 USA. RP Vurgaftman, I (reprint author), USN, Res Lab, Code 5613, Washington, DC 20375 USA. NR 41 TC 24 Z9 24 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1999 VL 60 IS 20 BP 14294 EP 14301 DI 10.1103/PhysRevB.60.14294 PG 8 WC Physics, Condensed Matter SC Physics GA 261NP UT WOS:000084015500054 ER PT J AU Steeds, JW Gilmore, A Charles, S Heard, P Howarth, B Butler, JE AF Steeds, JW Gilmore, A Charles, S Heard, P Howarth, B Butler, JE TI Use of novel methods for the investigation of the boron distribution in CVD diamond SO ACTA MATERIALIA LA English DT Article; Proceedings Paper CT Acta Materialia Workshop on Materials Science and Mechanics of Interfaces CY OCT 25-30, 1998 CL LA JOLLA, CALIFORNIA DE diamond; boron; SIMS; micro-Raman spectroscopy; photoluminescence spectroscopy ID CHEMICAL-VAPOR-DEPOSITION; FILMS; OXYGEN AB Previous work on boron-doped CVD diamond films has indicated inhomogeneity of boron distribution. A variety of methods has been used to investigate the nature of these inhomogeneities. The methods used include electron irradiation in a transmission electron microscope followed by helium cooled microscopic photoluminescence studies, imaging SIMS and micro-Raman imaging. A number of sharp B-related photoluminescence lines has been identified and found to vary considerably from one location to another. This evidence of inhomogeneity is confirmed by B mapping using imaging SIMS and micro-Raman microscopy. (C) 1999 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Bristol, Dept Phys, Bristol BS8 1TL, Avon, England. Univ Bristol, Ctr Interface Anal, Bristol BS8 1TL, Avon, England. USN, Res Lab, Washington, DC 20375 USA. RP Steeds, JW (reprint author), Univ Bristol, Dept Phys, Bristol BS8 1TL, Avon, England. RI Butler, James/B-7965-2008; Heard, Peter/C-2155-2008 OI Butler, James/0000-0002-4794-7176; Heard, Peter/0000-0002-8926-4680 NR 23 TC 14 Z9 14 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD NOV 12 PY 1999 VL 47 IS 15-16 BP 4025 EP 4030 DI 10.1016/S1359-6454(99)00262-1 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 262JN UT WOS:000084063800010 ER PT J AU Ishii, KJ Weiss, WR Klinman, DM AF Ishii, KJ Weiss, WR Klinman, DM TI Prevention of neonatal tolerance by a plasmid encoding granulocyte-macrophage colony stimulating factor SO VACCINE LA English DT Article DE DNA vaccine; tolerance; GM-CSF ID HEPATITIS-B VIRUS; LIGAND-TREATED MICE; MALARIA DNA VACCINE; IMMUNE-RESPONSES; DENDRITIC CELLS; CIRCUMSPOROZOITE PROTEIN; ANTIBODY-RESPONSE; COSTIMULATORY MOLECULES; GENETIC IMMUNIZATION; IN-VIVO AB A plasmid DNA vaccine encoding the circumsporozoite protein of malaria (pCSP) induces protective immunity in adult mice but persistent tolerance when administered to neonates. In an effort to improve antigen presenting cell (APC) function in newborns, we co-administered pCSP with a plasmid encoding granulocyte-macrophage colony stimulating factor (pGMCSF). This combination of plasmids prevented the development of neonatal tolerance, instead eliciting a primary IgG anti-CSP immune response. Mice primed as neonates and boosted as adults mounted anamnestic responses characterized by high serum antibody titers, cytotoxic T-cell activity and antigen-specific interferon gamma (IFN gamma) production. Neonatal administration of pGMCSF accelerated the maturation of local dendritic cells, suggesting that APC function plays a key role in determining whether tolerance or immunity results from neonatal exposure to antigen. Published by Elsevier Science Ltd. C1 US FDA, Ctr Biol Evaluat & Res, Retroviral Immunol Sect, Div Viral Prod, Bethesda, MD 20892 USA. USN, Med Res Ctr, Malaria Program, Bethesda, MD 20889 USA. RP Klinman, DM (reprint author), US FDA, Ctr Biol Evaluat & Res, Retroviral Immunol Sect, Div Viral Prod, Bldg 29A Room 3 D 10, Bethesda, MD 20892 USA. RI Ishii, Ken/B-1685-2012 OI Ishii, Ken/0000-0002-6728-3872 NR 45 TC 20 Z9 21 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0264-410X J9 VACCINE JI Vaccine PD NOV 12 PY 1999 VL 18 IS 7-8 BP 703 EP 710 DI 10.1016/S0264-410X(99)00267-4 PG 8 WC Immunology; Medicine, Research & Experimental SC Immunology; Research & Experimental Medicine GA 256NP UT WOS:000083731800018 PM 10547430 ER PT J AU Frenk, CS White, SDM Bode, P Bond, JR Bryan, GL Cen, R Couchman, HMP Evrard, AE Gnedin, N Jenkins, A Khokhlov, AM Klypin, A Navarro, JF Norman, ML Ostriker, JP Owen, JM Pearce, FR Pen, UL Steinmetz, M Thomas, PA Villumsen, JV Wadsley, JW Warrren, MS Xu, G Yepes, G AF Frenk, CS White, SDM Bode, P Bond, JR Bryan, GL Cen, R Couchman, HMP Evrard, AE Gnedin, N Jenkins, A Khokhlov, AM Klypin, A Navarro, JF Norman, ML Ostriker, JP Owen, JM Pearce, FR Pen, UL Steinmetz, M Thomas, PA Villumsen, JV Wadsley, JW Warrren, MS Xu, G Yepes, G TI The Santa Barbara cluster comparison project: A comparison of cosmological hydrodynamics solutions SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : theory; dark matter; galaxies : clusters : general; large-scale structure of universe; X-rays : galaxies ID SMOOTHED PARTICLE HYDRODYNAMICS; X-RAY-CLUSTERS; FLUX-CORRECTED TRANSPORT; HIGH-RESOLUTION; GALAXY CLUSTERS; GAS-DYNAMICS; N-BODY; UNIVERSE; SIMULATION; ALGORITHM AB We have simulated the formation of an X-ray cluster in a cold dark matter universe using 12 different codes. The codes span the range of numerical techniques and implementations currently in use, including smoothed particle hydrodynamics (SPH) and grid methods with fixed, deformable, or multilevel meshes. The goal of this comparison is to assess the reliability of cosmological gasdynamical simulations of clusters in the simplest astrophysically relevant case, that in which the gas is assumed to be nonradiative. We compare images of the cluster at different epochs, global properties such as mass, temperature and X-ray luminosity, and radial profiles of various dynamical and thermodynamical quantities. On the whole, the agreement among the various simulations is gratifying, although a number of discrepancies exist. Agreement is best for properties of the dark matter and worst for the total X-ray luminosity. Even in this case, simulations that adequately resolve the core radius of the gas distribution predict total X-ray luminosities that agree to within a factor of 2. Other quantities are reproduced to much higher accuracy. For example, the temperature and gas mass fraction within the virial radius agree to within about 10%, and the ratio of specific dark matter kinetic to gas thermal energies agree to within about 5%. Various factors, including differences in the internal timing of the simulations, contribute to the spread in calculated cluster properties. Based on the overall consistency of results, we discuss a number of general properties of the cluster we have modeled. C1 Univ Durham, Dept Phys, Durham DH1 3LE, England. Max Planck Inst Astrophys, D-85740 Garching, Germany. Univ Penn, Dept Phys & Astron, Philadelphia, PA 19104 USA. Univ Toronto, Canadian Inst Theoret Astrophys, Toronto, ON M5S 3H8, Canada. Univ Toronto, Dept Astron, Toronto, ON M5S 3H8, Canada. MIT, Dept Phys, Cambridge, MA 02139 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Univ Western Ontario, Dept Phys & Astron, London, ON N6A 3K7, Canada. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. New Mexico State Univ, Dept Astron, Las Cruces, NM 88001 USA. Univ Victoria, Dept Phys & Astron, Victoria, BC V8W 2P6, Canada. Univ Illinois, NCSA, Lab Computat Astrophys, Urbana, IL 61801 USA. Univ Illinois, Dept Astron, Urbana, IL 61801 USA. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Univ Sussex, Brighton BN1 9QH, E Sussex, England. Univ Calif Santa Cruz, Board Studies Astron & Astrophys, Santa Cruz, CA 95064 USA. Univ Autonoma Madrid, Dept Fis Teor 100 11, E-28049 Madrid, Spain. RP Univ Durham, Dept Phys, Durham DH1 3LE, England. RI Pearce, Frazer/H-1503-2012; OI Warren, Michael/0000-0002-1218-7904; Evrard, August/0000-0002-4876-956X; Yepes, Gustavo/0000-0001-5031-7936 NR 56 TC 344 Z9 346 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD NOV 10 PY 1999 VL 525 IS 2 BP 554 EP 582 DI 10.1086/307908 PN 1 PG 29 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 257HP UT WOS:000083776700002 ER PT J AU Johnson, TJ Wilson, CR Chao, BF AF Johnson, TJ Wilson, CR Chao, BF TI Oceanic angular momentum variability estimated from the Parallel Ocean Climate Model, 1988-1998 SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID POLAR MOTION; CIRCULATION MODEL; EARTH; ROTATION; FLUCTUATIONS; ORIENTATION; EXCITATION; SIGNALS; LENGTH AB This paper describes the use of a global numerical model of the oceans to estimate variations in both the equatorial and axial components of angular momentum resulting from oceanic mass redistribution and circulation. The Parallel Ocean Climate Model, driven by daily wind fields and monthly heat fluxes from the European Gentle for Medium-Range Weather Forecasts for 1988-1998, provides insight into variations in the transport and exchange of angular momentum, a quantity which is essentially conserved within the Earth system. Exchange of angular momentum between the oceans and tl-Le solid Earth should be manifest as changes in the Earth's rotation (both polar motion and length of day), and it is possible to compare predicted Earth rotation changes with actual geodetic observations. Using an inverted barometer assumption for oceans, the numerical model predictions of rotation change agree in sign and magnitude and are significantly correlated with observed polar motion and length of day variations after subtracting the dominant atmospheric contributions. The correlation has a seasonal variation which suggests that the role of the oceans in the excitation polar motion is more important during the Northern Hemisphere summer. Our results indicate that the oceans, to a different extent, account for a significant part of the nonatmospheric angular momentum budget for the Earth, and its fluid envelopes on interannual to submonthly timescales. C1 Univ Texas, Dept Geol Sci, Ctr Space Res, Austin, TX USA. NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Greenbelt, MD 20771 USA. NASA Headquarters, Washington, DC USA. RP Johnson, TJ (reprint author), USN Observ, Earth Orientat Dept, Washington, DC 20392 USA. EM tj@CasA.usno.navy.mil RI Chao, Benjamin Fong/N-6156-2013 NR 36 TC 52 Z9 54 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD NOV 10 PY 1999 VL 104 IS B11 BP 25183 EP 25195 DI 10.1029/1999JB900231 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 255DE UT WOS:000083653600002 ER PT J AU Bakaltcheva, IB Ligler, FS Patterson, CH Shriver-Lake, LC AF Bakaltcheva, IB Ligler, FS Patterson, CH Shriver-Lake, LC TI Multi-analyte explosive detection using a fiber optic biosensor SO ANALYTICA CHIMICA ACTA LA English DT Article; Proceedings Paper CT Immunochemistry Summit VII/3rd Workshop on Biosensors and Biological Techniques in Environmental Analysis CY DEC 01-03, 1998 CL LAS VEGAS, NEVADA SP US EPA, Natl Exposure Res Lab, Int Assoc Environm Analyt Chem DE fiber optic; biosensor; immunosensor; deoxycholic acid; TNT; RDX ID EVANESCENT-WAVE; TNT; ASSAY; WATER AB A fiber optic immunosensor has been developed for simultaneous detection of the most common explosives, 2,4,6, trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). It employs a competitive immunoassay on the antibody-coated fiber optic probes, in which a fluorescent antigen competes with free antigen of unknown concentration for binding sites on the fiber surface. To achieve dual explosive detection, two alpha-TNT fiber probes and two alpha-RDX fiber probes are connected in series. The sample is mixed with fluorescent analogs, Cy5-ethylenediamine-trinitrobenzene (Cy5-EDA-TNB) and Cy5-ethylenediamine-RDX hapten (Cy5-EDA-RDH). Inhibition of the maximum signal in the presence of the sample is proportional to the concentration of the explosive. The detection limits for the multi-analyte assays are equivalent (6 ng/ml for both TNT and RDX) to those of the individual assays (5 ng/ml for both TNT and RDX). The standard curves for TNT and RDX represent a Linear relationship between percent signal inhibition and the natural logarithm of analyte concentration in the multi-analyte format, as well as in single analyte assays, thus allowing a simple and precise method of quantification. There is minimal cross-reactivity for the two antigens in the multi-analyte immunosensor, so it is also an effective means in analyzing samples containing mixtures of RDX and TM: (C) 1999 Elsevier Science B.V. All rights reserved. C1 USN, Res Lab, Ctr Biomol Sci & Engn, Washington, DC 20375 USA. Geocenters Inc, Rockville, MD 20852 USA. RP Shriver-Lake, LC (reprint author), USN, Res Lab, Ctr Biomol Sci & Engn, Code 6910, Washington, DC 20375 USA. NR 20 TC 53 Z9 57 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0003-2670 J9 ANAL CHIM ACTA JI Anal. Chim. Acta PD NOV 8 PY 1999 VL 399 IS 1-2 BP 13 EP 20 DI 10.1016/S0003-2670(99)00571-1 PG 8 WC Chemistry, Analytical SC Chemistry GA 251VM UT WOS:000083467100003 ER PT J AU Felix, CL Bewley, WW Vurgaftman, I Olafsen, LJ Stokes, DW Meyer, JR Yang, MJ AF Felix, CL Bewley, WW Vurgaftman, I Olafsen, LJ Stokes, DW Meyer, JR Yang, MJ TI High-efficiency midinfrared "W" laser with optical pumping injection cavity SO APPLIED PHYSICS LETTERS LA English DT Article ID QUANTUM-WELL LASERS AB We describe an optical pumping injection cavity (OPIC) edge-emitting laser which employs GaSb/AlAsSb distributed Bragg reflectors above and below the type-II "W" active region to form an etalon for the pump beam. A pulsed W-OPIC laser emitting at 3.1-3.4 mu m displays an incident threshold pump intensity of only 8 kW/cm(2) at 300 K, and incident power conversion efficiencies per facet of 9% at 77 K and 4% at 275 K. (C) 1999 American Institute of Physics. [S0003-6951(99)00545-8]. C1 USN, Res Lab, Washington, DC 20375 USA. RP Felix, CL (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Olafsen, Linda/G-4996-2013 NR 18 TC 31 Z9 31 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 8 PY 1999 VL 75 IS 19 BP 2876 EP 2878 DI 10.1063/1.125176 PG 3 WC Physics, Applied SC Physics GA 252CV UT WOS:000083483900002 ER PT J AU Bonadeo, NH Lenihan, AS Chen, G Guest, JR Steel, DG Gammon, D Katzer, DS Park, D AF Bonadeo, NH Lenihan, AS Chen, G Guest, JR Steel, DG Gammon, D Katzer, DS Park, D TI Single quantum dot states measured by optical modulation spectroscopy SO APPLIED PHYSICS LETTERS LA English DT Article ID PHOTOREFLECTANCE; EXCITONS; GAAS; PHOTOLUMINESCENCE; MICROSTRUCTURES; DEPENDENCE; ABSORPTION; LINEWIDTHS; MECHANISMS; SPECTRA AB Using optical modulation spectroscopy, we report the direct observation of absorption lines from excitons localized in GaAs single quantum dot potentials. The data provide a measurement of the linewidth, resonance energy, and oscillator strength of the transitions, and show that states which decay primarily by nonradiative processes can be directly probed using this technique. The experiments establish this technique for the characterization of single quantum dot transitions, thereby complementing luminescence studies. (C) 1999 American Institute of Physics. [S0003-6951(99)00939-0]. C1 Univ Michigan, Harrison M Randall Lab Phys, Ann Arbor, MI 48109 USA. Univ Michigan, Ctr Ultrafast Opt Sci, Ann Arbor, MI 48109 USA. USN, Res Lab, Washington, DC 20375 USA. RP Bonadeo, NH (reprint author), Univ Michigan, Harrison M Randall Lab Phys, Ann Arbor, MI 48109 USA. RI Guest, Jeffrey/B-2715-2009; Katzer, D. Scott/N-7841-2013 OI Guest, Jeffrey/0000-0002-9756-8801; NR 27 TC 9 Z9 9 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 8 PY 1999 VL 75 IS 19 BP 2933 EP 2935 DI 10.1063/1.125177 PG 3 WC Physics, Applied SC Physics GA 252CV UT WOS:000083483900021 ER PT J AU Oliver, FW Seifu, D Hoffman, E Chrisey, DB Horwitz, JS Dorsey, PC AF Oliver, FW Seifu, D Hoffman, E Chrisey, DB Horwitz, JS Dorsey, PC TI Transmission Mossbauer spectroscopy on pulsed-laser-deposited thick Fe and Ni-Zn ferrite films SO APPLIED PHYSICS LETTERS LA English DT Article AB Mossbauer spectroscopy with Fe-57 is used to characterize pulsed-laser-deposited (PLD) Ni0.6Zny-Fe2O4 films is demonstrated. Mossbauer spectra were recorded as a function of film thickness (3-16 mu m) for films deposited in background O-2 pressures of 50 and 200 mTorr, and for a zinc concentration of y = 0.72. A spectrum was also recorded for y = 0.4 deposited in a background pressure of 200 mTorr. The site occupancy was determined for the tetrahedral (A) and octahedral (B) sites. Results obtained here show that the effect of increasing the Zn is to shift Fe(tet) to Fe(oct). When compared with previous Mossbauer measurements on the bulk NiZn ferrites, the ferrite films give spectra of similar quality with no visible evidence of clustering or multiple phases present. The same linewidth was found for a PLD processed Fe film and a Mossbauer standard 70-mu m-thick alpha-Fe enriched foil. The Fe film had a magnetic hyperfine field of 334 kOe and no evidence of the presence of any iron oxides. Good spectra may be obtained by selecting substrates with low mass and low atomic number. We were successful in obtaining measurable Mossbauer spectra for films deposited on 0.5-mm-thick MgO, sapphire, and alumina substrates whereas films deposited on Si, GaAs, and cubic zirconia substrates did not give good spectra. (C) 1999 American Institute of Physics. [S0003-6951(99)04345-4]. C1 Morgan State Univ, Baltimore, MD 21251 USA. USN, Res Lab, Washington, DC 20375 USA. RP Oliver, FW (reprint author), Morgan State Univ, Baltimore, MD 21251 USA. NR 14 TC 9 Z9 9 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 8 PY 1999 VL 75 IS 19 BP 2993 EP 2995 DI 10.1063/1.125212 PG 3 WC Physics, Applied SC Physics GA 252CV UT WOS:000083483900041 ER PT J AU Zhang, ML Miao, MS Van Doren, VE Ladik, JJ Mintmire, JW AF Zhang, ML Miao, MS Van Doren, VE Ladik, JJ Mintmire, JW TI Calculation of the total energy per unit cell and of the band structures of the five nucleotide base stacks using the local-density approximation SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELECTRONIC-STRUCTURE; POLYMERS; CONFORMATION; SYSTEMS; POLYACETYLENE; POLYETHYLENE AB All-electron first-principles total energy electronic structure calculations were carried out for single chains of four nucleotide base stacks (composed of adenine, thymine, guanine, and cytosine, respectively) in the DNA B conformation (3.36 Angstrom stacking distance and 36 degrees screw angle theta) using the local-density approximation (LDA) within a helical band structure approach. A uracil stack was also computed in the DNA B conformation and compared with the results obtained for the four DNA base stacks. The total energies per unit cell as a function of the stacking distance (at fixed screw angle theta = 36 degrees) and of the screw angle (at d = 3.36 Angstrom) show in most cases rather good agreement with the experiment. As expected with LDA calculations, the band gaps were underestimated by nearly 50% compared to experimentally suggested values. Finally, some suggestions are given for the improvement of the band structures of the nucleotide base stacks. (C) 1999 American Institute of Physics. [S0021-9606(99)30342-1]. C1 Univ Antwerp, Dept Phys, B-2020 Antwerp, Belgium. Univ Erlangen Nurnberg, Natl Fdn Canc res, Theoret Chem & Lab, D-91058 Erlangen, Germany. USN, Res Lab, Div Chem, Washington, DC 20375 USA. RP Zhang, ML (reprint author), Univ Antwerp, Dept Phys, Groenenbergenlaan 171, B-2020 Antwerp, Belgium. OI Mintmire, John/0000-0002-6551-0349 NR 28 TC 17 Z9 17 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 8 PY 1999 VL 111 IS 18 BP 8696 EP 8700 DI 10.1063/1.480209 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 249RB UT WOS:000083345100051 ER PT J AU Wagenhofer, M Erickson-Natishan, M Armstrong, RW Zerilli, FJ AF Wagenhofer, M Erickson-Natishan, M Armstrong, RW Zerilli, FJ TI Influences of strain rate and grain size on yield and serrated flow in commercial Al-Mg alloy 5086 SO SCRIPTA MATERIALIA LA English DT Article DE aluminum alloy; constitutive equations; Portevin-LeChatelier effects; grain boundaries; thermally activated processes ID DEPENDENCE; STEEL C1 Univ Maryland, Dept Mech Engn, College Pk, MD 20742 USA. USN, Ctr Surface Warfare, Indian Head Div, Indian Head, MD 20640 USA. RP Wagenhofer, M (reprint author), Univ Maryland, Dept Mech Engn, College Pk, MD 20742 USA. NR 28 TC 57 Z9 58 U1 2 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD NOV 5 PY 1999 VL 41 IS 11 BP 1177 EP 1184 DI 10.1016/S1359-6462(99)00265-1 PG 8 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 257RK UT WOS:000083795400006 ER PT J AU Joyner, D AF Joyner, D TI A correspondence for the supercuspidal representations of (SL2(F))over-bar, F p-adic SO ARCHIV DER MATHEMATIK LA English DT Article AB Following D. Manderscheid, we describe the supercuspidal representations of the n-fold metaplectic cover <(SL2(F))over bar>, where F is a p-adic field with (p, 2n) = 1. We prove a ''Frobenius formula" for the character of a supercuspidal representation of <(SL2(F))over bar>. Using this formula, we obtain a character relation between corresponding supercuspidal representations of <(SL2(F))over bar> and of SL2(F) in the case n = 2. C1 USN Acad, Dept Math, Annapolis, MD 21402 USA. RP Joyner, D (reprint author), USN Acad, Dept Math, Chouvenet Hall, Annapolis, MD 21402 USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU BIRKHAUSER VERLAG AG PI BASEL PA VIADUKSTRASSE 40-44, PO BOX 133, CH-4010 BASEL, SWITZERLAND SN 0003-889X J9 ARCH MATH JI Arch. Math. PD NOV 2 PY 1999 VL 73 IS 5 BP 332 EP 340 DI 10.1007/s000130050406 PG 9 WC Mathematics SC Mathematics GA 262GK UT WOS:000084057400003 ER PT J AU Knollmann, BC Knollmann, BEC Weissman, NJ Jones, LR Morad, M AF Knollmann, BC Knollmann, BEC Weissman, NJ Jones, LR Morad, M TI Electrophysiological remodeling in hypertrophic and failing hearts of calsequestrin overexpressing mice SO CIRCULATION LA English DT Meeting Abstract C1 Georgetown Univ, Washington, DC USA. USN, Med Ctr, Bethesda, MD 20814 USA. Krannert Inst, Indianapolis, IN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0009-7322 J9 CIRCULATION JI Circulation PD NOV 2 PY 1999 VL 100 IS 18 SU S MA 2237 BP 425 EP 425 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA 250YD UT WOS:000083417102234 ER PT J AU Sageman, WS Riffenburgh, RH AF Sageman, WS Riffenburgh, RH TI Equivalence of thoracic bioimpedance and thermodilution-derived cardiac index measurements in past cardiopulmonary bypass sugery patients SO CIRCULATION LA English DT Meeting Abstract C1 USN, Ctr Med, San Diego, CA 92152 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0009-7322 J9 CIRCULATION JI Circulation PD NOV 2 PY 1999 VL 100 IS 18 SU S MA 3041 BP 577 EP 577 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA 250YD UT WOS:000083417103037 ER PT J AU Lansky, AJ Danchenko, A Silva, J Culp, D Dandreo, K Desai, KJ Chen, XH Ramee, SR AF Lansky, AJ Danchenko, A Silva, J Culp, D Dandreo, K Desai, KJ Chen, XH Ramee, SR TI Clinical implications of non Q-Wave myocardial infarction in thrombus containing lesions. Results from the VEGAS II randomized clinical trial and thrombolysis exclusion registry. SO CIRCULATION LA English DT Meeting Abstract C1 Washington Hosp Ctr, Washington, DC 20010 USA. USN, Med Ctr, Bethesda, MD 20084 USA. Alton Ochsner Med Fdn & Ochsner Clin, New Orleans, LA 70121 USA. Beth Israel Deaconess Med Ctr, Boston, MA USA. Ochsner Fdn Hosp, New Orleans, LA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0009-7322 J9 CIRCULATION JI Circulation PD NOV 2 PY 1999 VL 100 IS 18 SU S MA 4274 BP 810 EP 810 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA 250YD UT WOS:000083417104266 ER PT J AU Lim, AAT Karakla, DW Watkins, DV AF Lim, AAT Karakla, DW Watkins, DV TI Osteoradionecrosis of the cervical vertebrae and occipital bone: A case report and brief review of the literature SO AMERICAN JOURNAL OF OTOLARYNGOLOGY LA English DT Article ID MANAGEMENT AB Osteoradionecrosis (ORN) is a common complication of radiation therapy. We present the first case reported in the literature of ORN involving the first and second cervical vertebrae and occipital bone in a patient who was treated with surgery and radiation therapy 9 years prior for a TxN3M0 squamous cell carcinoma of the left neck arising from an unknown primary origin. A brief review of the pathophysiology and treatment of this pathological process is also presented. Although the mandible is the most commonly affected site in the head and neck, ORN may develop in an unusual location without any preceding trauma and display an insidious but rapidly progressive course. The pathophysiology of ORN is believed to be a complex metabolic and homeostatic deficiency created by radiation-induced cellular injury and fibrosis, which is characterized by the formation of hypoxic, hypovascular, and hypocellular tissue. The irradiated bone loses its capability to increase the metabolic requirements and nutrient supply required to replace normal collagen and cellular components lost through routine wear. This results in tissue breakdown and the formation of a chronic nonhealing wound. Infection plays only a contaminant role, with trauma being a possible initiating factor. Diagnosis of ORN begins with a complete physical examination, including fiberoptic examination and biopsy of any suspicious lesion to eliminate the possibility of recurrent tumor. Treatment of ORN commonly requires the debridement of necrotic bone and hyperbaric oxygen therapy. The head and neck surgeon must possess a high degree of suspicion to promptly diagnose ORN and initiate early treatment. Because of similarities in clinical presentation, the most important step in the initial management of suspected ORN is to eliminate the possibility of tumor recurrence or a new primary. C1 USN, Ctr Med, Dept Otolaryngol Head & Neck Surg, Portsmouth, VA 23708 USA. RP Lim, AAT (reprint author), USN, Ctr Med, Dept Otolaryngol Head & Neck Surg, Portsmouth, VA 23708 USA. NR 9 TC 20 Z9 21 U1 0 U2 3 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0196-0709 J9 AM J OTOLARYNG JI Am. J. Otolaryngol. PD NOV-DEC PY 1999 VL 20 IS 6 BP 408 EP 411 PG 4 WC Otorhinolaryngology SC Otorhinolaryngology GA 257GX UT WOS:000083775100010 PM 10609488 ER PT J AU Denardo, B Earwood, J Sazonova, V AF Denardo, B Earwood, J Sazonova, V TI Experiments with electrical resistive networks SO AMERICAN JOURNAL OF PHYSICS LA English DT Article ID FIBONACCI SEQUENCE; POLYGONS AB Theoretical problems involving equivalent resistances of large or infinite networks of resistors have received substantial attention. We consider two actual networks. In the first, the resistance is measured across one end of a ladder whose number of loops is incremented until the precision of the multimeter is exceeded. In the second, resistances are measured across nodes near the center of a 12 by 12 square grid of resistors. These experiments are useful in the introductory physics laboratory as interesting examples of equivalent resistance, and can be added to a standard Ohm's law experiment. The square grid apparatus also can be employed for lecture demonstrations. In addition, this apparatus offers approximate experimental confirmation of complicated theoretical calculations for the equivalent resistance between two nonadjacent nodes of an infinite square grid. These experimental results are verified numerically. (C) 1999 American Association of Physics Teachers. C1 USN, Postgrad Sch, Dept Phys, Monterey, CA 93943 USA. Univ Mississippi, Dept Phys & Astron, University, MS 38677 USA. RP Denardo, B (reprint author), USN, Postgrad Sch, Dept Phys, Monterey, CA 93943 USA. NR 23 TC 4 Z9 4 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD NOV PY 1999 VL 67 IS 11 BP 981 EP 986 DI 10.1119/1.19176 PG 6 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA 251CH UT WOS:000083426700008 ER PT J AU Larraza, A AF Larraza, A TI A demonstration apparatus for an acoustic analog to the Casimir effect SO AMERICAN JOURNAL OF PHYSICS LA English DT Article ID RADIATION PRESSURE; FORCE C1 USN, Postgrad Sch, Dept Phys, Monterey, CA 93943 USA. RP Larraza, A (reprint author), USN, Postgrad Sch, Dept Phys, Monterey, CA 93943 USA. NR 7 TC 10 Z9 10 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD NOV PY 1999 VL 67 IS 11 BP 1028 EP 1030 DI 10.1119/1.19166 PG 3 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA 251CH UT WOS:000083426700017 ER PT J AU Brook, I Frazier, EH AF Brook, I Frazier, EH TI Microbiology of subphrenic abscesses: A 14-year experience SO AMERICAN SURGEON LA English DT Article ID ANAEROBIC-BACTERIA; BACTEROIDES AB The objective of the review was to study the aerobic and anaerobic microbiology of subphrenic abscesses in relation with predisposing conditions. A retrospective review of clinical and laboratory data of 52 patients treated between 1974 and 1988 was conducted. Forty-three (83%) patients developed the abscesses after an operative procedure. These included 11 patients after colonic, 9 patients after gastric or duodenal, 7 patients after abdominal trauma, 7 patients after biliary, and 6 patients after appendix surgery. A total of 194 organisms (3.7 isolates/specimen), 83 aerobic (1.6/specimen), and 111 anaerobes (2.1/specimen) were recovered. Aerobic bacteria only were recovered in 7 (13%) abscesses, anaerobic bacteria only in 11 (21%), and mixed aerobic aid anaerobic bacteria in 34 (65%). Polymicrobial infection was present in 47 (90%). The predominant aerobic isolates were Escherichia coli (28 isolates), Enterococcus group D(9), and Staphylococcus aureus (9). The predominant anaerobes were Peptostreptococcus species (33 isolates), Bacteroides fragilis group (25), Clostridium species (13), and Prevotella species (6). The number of isolates/site varied. The number of anaerobic bacteria/site outnumbered or was equal to the number of aerobic or facultatives in all instances, except in abscesses after biliary surgery. Their number/site was especially hi gh in abscesses after appendectomy, and the number of aerobic and anaerobic bacteria was the lowest after gastric or duodenal surgery. S. aureus predominated after gastric, duodenal and posttrauma surgery; B. fragilis predominated after colonic, appendix, and postabdominal trauma surgery; Enterococcus group D predominated after biliary surgery; Fusobacterium and Prevotella species predominated after gastric or duodenal surgery; and Clostridium species predominated after colonic or appendix surgery. These data highlight the polymicrobial aerobic-anaerobic nature of subphrenic abscesses and their correlation with predisposing surgery. C1 USN Hosp, Dept Pediat & Infect Dis, Bethesda, MD 20814 USA. RP Brook, I (reprint author), POB 70412, Bethesda, MD 20814 USA. NR 24 TC 14 Z9 16 U1 0 U2 1 PU SOUTHEASTERN SURGICAL CONGRESS PI ATLANTA PA 141 WEST WIEUCA RD, STE B100, ATLANTA, GA 30342 USA SN 0003-1348 J9 AM SURGEON JI Am. Surg. PD NOV PY 1999 VL 65 IS 11 BP 1049 EP 1053 PG 5 WC Surgery SC Surgery GA 250LU UT WOS:000083390500011 PM 10551755 ER PT J AU Pancrazio, JJ Whelan, JP Borkholder, DA Ma, W Stenger, DA AF Pancrazio, JJ Whelan, JP Borkholder, DA Ma, W Stenger, DA TI Development and application of cell-based biosensors SO ANNALS OF BIOMEDICAL ENGINEERING LA English DT Review DE antibody; environmental monitoring; functional assay; chemical warfare; extracellular potential; impedance; microelectrode; patterning; stem cells ID EMBRYONIC STEM-CELLS; COPLANAR MOLECULAR ASSEMBLIES; NUCLEIC-ACID HYBRIDIZATION; PATCH-CLAMP DETECTION; OPTIC-BASED BIOSENSOR; OF-THE-ART; IN-VITRO; HIPPOCAMPAL-NEURONS; SYNAPSE FORMATION; MAMMALIAN-CELLS AB Biosensors incorporate a biological sensing element that converts a change in an immediate environment to signals conducive for processing. Biosensors have been implemented for a number of applications ranging from environmental pollutant detection to defense monitoring. Biosensors have two intriguing characteristics: (1) they have a naturally evolved selectivity to biological or biologically active analytes; and (2) biosensors have the capacity to respond to analytes in a physiologically relevant manner. In this paper, molecular biosensors, based on antibodies, enzymes, ion channels, or nucleic acids, are briefly reviewed. Moreover, cell-based biosensors are reviewed and discussed. Cell-based biosensors have been implemented using microorganism, particularly for environmental monitoring of pollutants. Biosensors incorporating mammalian cells have a distinct advantage of responding in a manner that can offer insight into the physiological effect of an analyte. Several approaches for transduction of cellular signals are discussed; these approaches include measures of cell metabolism, impedance, intracellular potentials, and extracellular potentials. Among these approaches, networks of excitable cells cultured on microelectrode arrays are uniquely poised to provide rapid, functional classification of an analyte and ultimately constitute a potentially effective cell-based biosensor technology. Three challenges that constitute barriers to increased cell-based biosensor applications are presented: analytical methods, reproducibility, and cell sources. Possible future solutions to these challenges are discussed. (C) 1999 Biomedical Engineering Society. [S0090-6964(99)01406-X]. C1 USN, Res Lab, Ctr Biomol Sci & Engn, Washington, DC 20375 USA. Alexeter Sci, Chicago, IL USA. Cepheid Corp, Sunnyvale, CA USA. RP Pancrazio, JJ (reprint author), USN, Res Lab, Ctr Biomol Sci & Engn, Code 6910, Washington, DC 20375 USA. RI Pancrazio, Joseph/M-3206-2015 OI Pancrazio, Joseph/0000-0001-8276-3690 NR 157 TC 270 Z9 278 U1 8 U2 118 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0090-6964 J9 ANN BIOMED ENG JI Ann. Biomed. Eng. PD NOV-DEC PY 1999 VL 27 IS 6 BP 697 EP 711 DI 10.1114/1.225 PG 15 WC Engineering, Biomedical SC Engineering GA 270CQ UT WOS:000084518200001 PM 10625143 ER PT J AU Tandy, TK Bottomy, DP AF Tandy, TK Bottomy, DP TI Wellens' syndrome - Reply SO ANNALS OF EMERGENCY MEDICINE LA English DT Letter C1 USN, Med Ctr, Dept Emergency Med, Portsmouth, VA 23708 USA. RP Tandy, TK (reprint author), USN, Med Ctr, Dept Emergency Med, Portsmouth, VA 23708 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 USA SN 0196-0644 J9 ANN EMERG MED JI Ann. Emerg. Med. PD NOV PY 1999 VL 34 IS 5 BP 685 EP 685 PG 1 WC Emergency Medicine SC Emergency Medicine GA 250JA UT WOS:000083384200024 ER PT J AU Ly, LN Luong, P AF Ly, LN Luong, P TI Numerical multi-block grids in coastal ocean circulation modeling SO APPLIED MATHEMATICAL MODELLING LA English DT Article ID EQUATION AB In coastal ocean modeling, one desires to capture the evolution and interaction of multi-scales of physical phenomena in a complicated physical domain. With limited computer resources, an appropriate choice of the numerical grid has a key role in determining the quality of the solution of a numerical coastal ocean model. Traditionally, single-block rectangular grids have been most commonly used in coastal ocean modeling for their simplicity. An effective coastal ocean model represents the dynamics of the coastal ocean flow on a numerical grid, including the effects of complicated features such as coastlines, bottom topography (submarine canyons, seamounts, narrow straits), and multi-scale physical phenomena. These problems require a model grid system more efficient than a traditional single-block rectangular grid. The model grids must give better resolution of coastlines and boundary conditions, multi-scale physical phenomenon, and save computer resources. These grids can also easily increase horizontal resolution in a subregion of the model domain without increasing computer expense with high resolution over the entire domain. The multi-block numerical generation grid technique is used in developing a coastal ocean system applied to the Mediterranean Sea (MED) with complicated coastlines, bottom topography and multi-scale physical features. The MED coastal ocean system consists of the MED model based on the Princeton Ocean Model, numerical grid generation routines, and a grid package which allows the model to be coupled with model grids. The traditional, nine-block orthogonal grid, and eight-block curvilinear nearly orthogonal coastline-following grid are used in the study. The numerical solutions with the three grids are compared in term of effectiveness. The numerical simulations show some MED basic physical features. (C) 1999 Elsevier Science Inc. All rights reserved. C1 USN, Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA. Univ Texas, WES DoD HPC MSRC, Vicksburg, MS 39180 USA. RP Ly, LN (reprint author), USN, Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA. NR 27 TC 5 Z9 5 U1 0 U2 4 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0307-904X J9 APPL MATH MODEL JI Appl. Math. Model. PD NOV PY 1999 VL 23 IS 11 BP 865 EP 879 DI 10.1016/S0307-904X(99)00011-6 PG 15 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications; Mechanics SC Engineering; Mathematics; Mechanics GA 243XU UT WOS:000083023400004 ER PT J AU Kowalski, MP Barbee, TW Heidemann, KF Gursky, H Rife, JC Hunter, WR Fritz, GG Cruddace, RG AF Kowalski, MP Barbee, TW Heidemann, KF Gursky, H Rife, JC Hunter, WR Fritz, GG Cruddace, RG TI Efficiency calibration of the first multilayer-coated holographic ion-etched flight grating for a sounding rocket high-resolution spectrometer SO APPLIED OPTICS LA English DT Article ID WAVELENGTH REGION; CRYSTAL MONOCHROMATOR; PERFORMANCE AB We have fabricated the four flight gratings for a sounding rocket high-resolution spectrometer using a holographic ion-etching technique. The gratings are spherical (4000-mm radius of curvature), large (160 mm x 90 mm), and have a laminar groove profile of high density (3600 grooves/mm). They have been coated with a high-reflectance multilayer of Mo/Si. Using an atomic force microscope, we examined the surface characteristics of the first grating before and after multilayer coating. The average roughness is approximately 3 Angstrom rms after coating. Using synchrotron radiation, we completed an efficiency calibration map over the wavelength range 225-245 Angstrom. At an angle of incidence of 5 degrees and a wavelength of 234 Angstrom, the average efficiency in the first inside order is 10.4 +/- 0.5%, and the derived groove efficiency is 34.8 +/- 1.6%. These values exceed all previously published results for a high-density grating. (C) 1999 Optical Society of America. OCIS codes: 050.1950, 120.6200, 120.6660, 260.7200, 310.1620, 350.1260. C1 USN, Res Lab, Washington, DC 20375 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Carl Zeiss, D-73446 Oberkochen, Germany. SFA Inc, Largo, MD 20774 USA. RP Kowalski, MP (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 14 TC 21 Z9 21 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD NOV 1 PY 1999 VL 38 IS 31 BP 6487 EP 6493 DI 10.1364/AO.38.006487 PG 7 WC Optics SC Optics GA 253LF UT WOS:000083557500003 PM 18324179 ER PT J AU Shibuya, TY Wei, WZ Zormeier, M Ensley, J Sakr, W Mathog, RH Meleca, RJ Yoo, G June, CH Levine, B Lum, LG AF Shibuya, TY Wei, WZ Zormeier, M Ensley, J Sakr, W Mathog, RH Meleca, RJ Yoo, G June, CH Levine, B Lum, LG TI Anti-CD3/anti-CD28 monoclonal antibody-coated suture enhances the immune response of patients with head and neck squamous cell carcinoma SO ARCHIVES OF OTOLARYNGOLOGY-HEAD & NECK SURGERY LA English DT Article ID CD28 RECEPTOR FAMILIES; T-CELLS; TUMOR-IMMUNITY; LYMPH-NODES; PATHWAY; B7; COSTIMULATION; PROLIFERATION; STIMULATION; ACTIVATION AB Objective: To test whether anti-CD3/anti-CD28 (alpha CD3/alpha CD28) monoclonal antibodies could be coated on surgical suture and used to enhance T-cell immune function in patients with advanced-stage head and neck squamous cell carcinoma (HNSCC). Design: alpha CD3/alpha CD28 monoclonal antibodies at varying concentrations and ratios were coated on surgical sutures and tested on peripheral blood mononuclear cells from normal donors to identify the optimal stimulating condition. Immune-enhancing properties of alpha CD3/alpha CD28 monoclonal antibody suture were tested on peripheral blood mononuclear cells and regional lymph node mononuclear cells isolated from patients with advanced HNSCC and on normal donor peripheral blood mononuclear cells. Proliferation, T-cell phenotype, and cytokines were measured during 8-day in vitro stimulation with alpha CD3/alpha CD28 suture and compared with alpha CD3/alpha CD28-coated tissue culture plastic, a previously recognized carrier. Results: Optimal stimulation was observed with mono-filament nylon incubated with alpha CD3/alpha CD28, 2 mu g/mL, at a 1:1 ratio for 18 hours at 37 degrees C. Strong proliferation of peripheral blood mononuclear cells and lymph node mononuclear cells in patients with HNSCC was induced by alpha CD3/alpha CD28 suture. There was no difference in maximal proliferation between alpha CD3/alpha CD28 plastic and suture. On day 6 after alpha CD3/alpha CD28 suture stimulation, T-cell subpopulations expressing CD3, CD4, CD8, CD28, and CD45RO were enhanced. Suture stimulation significantly enhanced interleukin 2 secretion when compared with plastic stimulation (P = .01). Both alpha CD3/alpha CD28 suture and plastic stimulated interferon gamma secretion. Conclusions: To our knowledge, this study is the first to report the modification of surgical suture to create an immunomodulant. alpha CD3/alpha CD28-coated suture expanded T cells from patients with HNSCC and induced a T(H)1 immune response, which may be a useful therapeutic tool in the treatment of HNSCC and other diseases. C1 Wayne State Univ, Dept Otolaryngol Head & Neck Surg, Sch Med, Detroit, MI 48201 USA. Wayne State Univ, Dept Immunol Microbiol, Sch Med, Detroit, MI 48201 USA. Wayne State Univ, Dept Pathol, Sch Med, Detroit, MI 48201 USA. Karmanos Canc Inst, Detroit, MI USA. USN, Med Res Inst, Bethesda, MD USA. St Lukes Med Ctr, Immunotherapy Res & Treatment Inst, Milwaukee, WI USA. RP Shibuya, TY (reprint author), Wayne State Univ, Dept Otolaryngol Head & Neck Surg, Sch Med, 5-E UHC 540 E Canfield, Detroit, MI 48201 USA. RI Levine, Bruce/D-1688-2009 FU NIDCD NIH HHS [T32DC00026] NR 23 TC 13 Z9 13 U1 0 U2 1 PU AMER MEDICAL ASSOC PI CHICAGO PA 515 N STATE ST, CHICAGO, IL 60610 USA SN 0886-4470 J9 ARCH OTOLARYNGOL JI Arch. Otolaryngol. Head Neck Surg. PD NOV PY 1999 VL 125 IS 11 BP 1229 EP 1234 PG 6 WC Otorhinolaryngology; Surgery SC Otorhinolaryngology; Surgery GA 252UB UT WOS:000083519700007 PM 10555694 ER PT J AU Reed, DS Balick, B Hajian, AR Klayton, TL Giovanardi, S Casertano, S Panagia, N Terzian, Y AF Reed, DS Balick, B Hajian, AR Klayton, TL Giovanardi, S Casertano, S Panagia, N Terzian, Y TI Hubble Space Telescope measurements of the expansion of NGC 6543: Parallax distance and nebular evolution SO ASTRONOMICAL JOURNAL LA English DT Article DE astrometry; planetary nebulae : individual (NGC 6543) ID PLANETARY-NEBULAE; PROPER MOTIONS; CENTRAL STARS; ETA-CARINAE; NGC-6572 AB The optical expansion parallax of NGC 6543 has been detected and measured using two epochs of Hubble Space Telescope images separated by a time baseline of only 3 years. We have utilized three separate methods of deriving the angular expansion of bright fiducials, with excellent agreement in the results. We combine our angular expansion estimates with spectroscopically obtained expansion velocities to derive a distance to NGC 6543 of 1001 +/- 269 pc. The deduced kinematic age of the inner bright core of the nebula is 1039 +/- 259 yr; however, the kinematic age of the polar caps that surround the core is larger-perhaps the result of deceleration or earlier mass ejection. The morphology and expansion patterns of NGC 6543 provide insight into a complex history of axisymmetric, interacting stellar mass ejections. C1 Univ Washington, Dept Astron, Seattle, WA 98150 USA. USN Observ, Washington, DC 20392 USA. Univ Bologna, Dipartimento Astron, I-40127 Bologna, Italy. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Cornell Univ, Natl Astron & Ionosphere Ctr, Ithaca, NY 14853 USA. RP Reed, DS (reprint author), Univ Washington, Dept Astron, Box 351580, Seattle, WA 98150 USA. NR 27 TC 57 Z9 57 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD NOV PY 1999 VL 118 IS 5 BP 2430 EP 2441 DI 10.1086/301091 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 264LB UT WOS:000084182800038 ER PT J AU Stone, RC Pier, JR Monet, DG AF Stone, RC Pier, JR Monet, DG TI Improved astrometric calibration regions along the celestial equator SO ASTRONOMICAL JOURNAL LA English DT Article DE astrometry; stars : general ID PHOTOMETRIC STANDARD STARS; REFERENCE-FRAME; REFRACTION; CATALOG; SYSTEM AB We present improved and highly accurate International Celestial Reference System (ICRS) equatorial positions for 1,268,732 stars in 16 astrometric calibration regions located around the celestial equator. Each region is about 7.degrees 6 x 3.degrees 2 in area (similar to 24.3 deg(2)), contains a large number of stars (18,767 to 263,810), has stellar densities ranging from 765 to 10,772 stars deg(-2), covers a wide range in magnitude (9.5 < R < 17.8, or equivalently 10.0 < V < 18.3), and is complete to magnitude R similar to 17.2 (V similar to 17.7). All of the observations were taken in 1994-1998 (mean epoch similar to J1996.0) with the Flagstaff Astrometric Scanning Transit Telescope. Furthermore, each region was observed many times with overlapped CCD strip scans, and these data were reduced to star positions using differential reductions. The reference-star positions were taken from the ACT catalog of accurate star positions and proper motions. The star positions presented herein are typically accurate to +/-26 mas (+/-12 mas precision) in both right ascension and declination, except for the faintest stars, whose errors are about 2 times larger. Similarly, magnitudes were determined for the astrometric calibration stars using standard photometric reductions, and accuracies of +/-18 mmag (+/-10 mmag precisions) were achieved (about +/-46 mmag for the faintest stars). There is little variation among the individual astrometric calibration regions in terms of the positional and photometric accuracies achieved. In addition, the positions and magnitudes presented in this paper supersede those given in 1997 by Stone, insofar as they are considerably more accurate, are rigorously placed in the ICRS, include many more stars in the low Galactic regions, and have had accurate proper motions computed for them as well. The proper motions are accurate to about +/-6 mas yr(-1) and should maintain the accuracy of the positions for many years to come. Concerning possible applications, the positions and magnitudes of the stars in the astrometric calibration regions can be used to calibrate single and mosaicked CCD detectors, as well as to optimize techniques for reducing star measures on astrographic plates to star positions and magnitudes. As a consequence, the positions, proper motions, and magnitudes put forth in this paper are made available to interested users. C1 USN Observ, Flagstaff Stn, Flagstaff, AZ 86002 USA. RP Stone, RC (reprint author), USN Observ, Flagstaff Stn, POB 1149, Flagstaff, AZ 86002 USA. NR 23 TC 35 Z9 35 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD NOV PY 1999 VL 118 IS 5 BP 2488 EP 2502 DI 10.1086/301099 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 264LB UT WOS:000084182800044 ER PT J AU Zacharias, N Zacharias, MI AF Zacharias, N Zacharias, MI TI The twin astrographic catalog on the Hipparcos system SO ASTRONOMICAL JOURNAL LA English DT Article DE astrometry; catalogs; techniques : photometric AB The Twin Astrographic Catalog (TAC) is an astrometric, photographic catalog covering most of the sky between declinations +90 degrees and -18 degrees to an average limiting magnitude of about V = 11 and B=12. This release 2 is based on the same 4912 plates as release 1, which were taken with the US Naval Observatory Twin Astrograph (blue and yellow lens) between 1977 and 1986. The Hipparcos Catalogue has been used for a new plate-by-plate, rigorous reduction. A significant improvement over the release 1 version of the data was achieved. With an average precision of 48 to 120 mas per coordinate, depending on magnitude, and a higher star density than the Tycho Catalogue, the TAC is a significant catalog for proper-motion determination. This release 2 of the TAC contains high-quality positions of 705,099 stars, supplemented by photographic photometry (B and V) for most of these stars. Astrometric reduction and catalog construction details are discussed and the final product is described, which is available from the US Naval Observatory. C1 USN Observ, Washington, DC 20392 USA. Univ Space Res Assoc, Washington, DC USA. RP Zacharias, N (reprint author), USN Observ, 3450 Massachusetts Ave NW, Washington, DC 20392 USA. NR 12 TC 21 Z9 21 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD NOV PY 1999 VL 118 IS 5 BP 2503 EP 2510 DI 10.1086/301098 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 264LB UT WOS:000084182800045 ER PT J AU Zacharias, N Zacharias, MI Hall, DM Johnston, KJ de Vegt, C Winter, L AF Zacharias, N Zacharias, MI Hall, DM Johnston, KJ de Vegt, C Winter, L TI Accurate optical positions of extragalactic radio reference frame sources SO ASTRONOMICAL JOURNAL LA English DT Article DE astrometry; catalogs; reference systems; quasars : general ID HIPPARCOS-CATALOG; SYSTEM AB Optical positions on the 50 mas level in the Hipparcos system have been obtained for 327 extragalactic, radio reference frame sources for both hemispheres from a 2-step procedure. Positions of secondary reference stars in the 10 less than or equal to V less than or equal to 14 magnitude range were obtained from photographic plates taken at the Hamburg astrograph (Northern Hemisphere) and the US Naval Observatory astrograph at Black Birch (Southern Hemisphere) using Hipparcos stars for astrometric plate solutions. Positions of the optical counterparts of compact, extragalactic, radio reference frame sources were then obtained from CCD direct imaging at the KPNO and CTIO 0.9 m telescopes, using the secondary reference star positions and correcting for field distortions. Several previously unknown counterparts could be identified, and several previously suspected identifications turned out to be empty fields. CCD images are available on the World Wide Web to serve as finding charts. A comparison between the optical and radio positions reveals systematic offsets of 10 to 40 mas per coordinate as a function of the observing run. Corrections for Galactic rotation and solar motion have been attempted because of a lack of individual proper motions for the secondary reference stars. Neither 0.9 m telescope is an astrometric instrument, and limitations are clearly seen in remaining systematic errors. Orientation angles between the radio system and our optical data are zero within an accuracy of 4 mas (standard error). A significant reduction of the systematic errors will be achieved with new wide-held CCD imaging currently been taken in parallel to new 0.9 m observations, to provide more secondary reference star positions with higher precision at a common epoch, which will allow extended modeling of the mapping properties of 0.9 m observations. C1 USN Observ, Washington, DC 20392 USA. Univ Hamburg, D-21029 Hamburg, Germany. Univ Space Res Assoc, Washington, DC USA. RP Zacharias, N (reprint author), USN Observ, 3450 Massachusetts Ave NW, Washington, DC 20392 USA. NR 29 TC 21 Z9 21 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 EI 1538-3881 J9 ASTRON J JI Astron. J. PD NOV PY 1999 VL 118 IS 5 BP 2511 EP 2525 DI 10.1086/301083 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 264LB UT WOS:000084182800046 ER PT J AU Piner, BG Unwin, SC Wehrle, AE Edwards, PG Fey, AL Kingham, KA AF Piner, BG Unwin, SC Wehrle, AE Edwards, PG Fey, AL Kingham, KA TI VSOP and ground-based VLBI imaging of the TeV blazar Markarian 421 at multiple epochs SO ASTROPHYSICAL JOURNAL LA English DT Article DE BL Lacertae objects : individual (Markarian 421); galaxies : active; galaxies : jets; radiation mechanisms : nonthermal; radio continuum : galaxies techniques : interferometric ID ACTIVE GALACTIC NUCLEI; LACERTAE OBJECT MARKARIAN-421; RADIO REFERENCE FRAME; GAMMA-RAY EMISSION; SELF-COMPTON MODEL; BL-LACERTAE; X-RAY; MILLIARCSECOND STRUCTURE; GALAXY MARKARIAN-421; SUPERLUMINAL MOTION AB We present 30 VLBI images of the TeV blazer Markarian 421 (1101 + 384) at 15 epochs spanning the time range 1994-1997 and at six different frequencies from 2.3 to 43 GHz. The imaged observations include a high-resolution 5 GHz VLBI Space Observatory Programme (VSOP) observation with the HALCA satellite on 1997 November 14; full-track Very Long Base Array (VLBA) observations from 1994 April, 1996 November, and 1997 May at frequencies between 5 and 43 GHz; six epochs of VLBA snapshot observations at frequencies between 2 and 15 GHz from Radio Reference Frame studies; and five geodetic VLBI observations at 2 and 8 GHz from the archive of the Washington VLBI Correlator Facility located at the US Naval Observatory. The dense time coverage of the images allows us to track components unambiguously in the parsec-scale jet over the observed time range. We measure the speeds of three inner jet components located between 0.5 and 5 mas from the core (0.3-3 pc projected linear distance) to be 0.19 +/- 0.27c, 0.30 +/- 0.07c, and -0.07 +/- 0.07c (H-0 = 65 km s(-1) Mpc(-1)). If the sole 43 GHz image is excluded, all measured speeds are consistent with no motion. These speeds differ from tentative superluminal speeds measured by Zhang & Baath from three epochs of data from the early 1980s. Possible interpretations of these subluminal speeds in terms of the high Doppler factor demanded by the TeV variability of this source are discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Jet Prop Lab, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. USN Observ, Earth Orientat Dept, Washington, DC 20392 USA. RP Piner, BG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 71 TC 44 Z9 45 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 1 PY 1999 VL 525 IS 1 BP 176 EP 190 DI 10.1086/307905 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 251MR UT WOS:000083449900014 ER PT J AU Farahmand, K Kaufman, JW AF Farahmand, K Kaufman, JW TI Nasal heat probe to measure nasal cavity heat and water vapor transport SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Editorial Material C1 Texas A&M Univ, Dept Mech & Ind Engn, Kingsville, TX 78363 USA. USN, Air Warfare Ctr, Div Aircraft, Crew Syst Dept, Patuxent River, MD 20670 USA. RP Farahmand, K (reprint author), Texas A&M Univ, Dept Mech & Ind Engn, Kingsville, TX 78363 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD NOV PY 1999 VL 70 IS 11 BP 1139 EP 1139 PG 1 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 251KP UT WOS:000083445100015 PM 10608614 ER PT J AU Singh, A Lvov, Y Qadri, SB AF Singh, A Lvov, Y Qadri, SB TI Formation of supramolecular assemblies by complementary association of octadecyloxy tartaric acid and bispyridyls SO CHEMISTRY OF MATERIALS LA English DT Article ID MOLECULAR-RECOGNITION; HYDROGEN-BONDS; COMPONENTS; STABILIZATION; COMPLEXATION; POLYAMIDE; INDUCTION; CHEMISTRY; PHASE AB Formation properties of molecular assemblies from chiral amphiphile, 2,3-dioctadecyloxy-L-tartaric acid (1) are studied. Organization of 1 was achieved by self-complementary association, as well as with the aid of 2,2' and 4,4' bispyridyl components (2 and 3, respectively). Thermally induced formation of molecular assemblies in the solid state is reported. The results show that by modifying the geometry and angle of headgroup interaction one can control the microscopic morphologies, adding thus another facet to the design and manipulation of supramolecular polymers and liquid crystals. Amphiphile 1 produced ordered birefringent smectic texture in the solid state when heated to 90 degrees C; mixtures of 1 with 2 produced helices and needles, and 1 with 3 produced birefringent; fan-shaped crystalline textures. X-ray diffraction data showed two motifs in observed reflections: smectic layer ordering as well as lang-range in-plane ordering. An order parameter of 1000 Angstrom in in-plane reflection indicated the existence of helices. Optical microscopic results confirmed the X-ray findings. The results suggest that microscopic features of the molecular assemblies can be modulated by involving a bifunctional molecular director (2 or 3) capable of hydrogen bonding with amphiphiles. C1 USN, Res Lab, Ctr Biomol Sci & Engn, Washington, DC 20375 USA. RP Singh, A (reprint author), USN, Res Lab, Ctr Biomol Sci & Engn, Code 6930, Washington, DC 20375 USA. RI Lvov, Yuri/E-7633-2012 NR 19 TC 14 Z9 15 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD NOV PY 1999 VL 11 IS 11 BP 3196 EP 3200 DI 10.1021/cm990421j PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 257HG UT WOS:000083776000031 ER PT J AU Federico, PA AF Federico, PA TI Hypermedia environments and adaptive instruction SO COMPUTERS IN HUMAN BEHAVIOR LA English DT Review DE hypermedia environments; adaptive instruction ID APTITUDE-TREATMENT INTERACTIONS; LEARNER CONTROL; INFORMATION-RETRIEVAL; HYPERTEXT; NAVIGATION; KNOWLEDGE; PATTERNS; STRATEGIES; DESIGN; TEXT AB The relevant professional literature is reviewed and discussed regarding the following salient issues: (I) hypermedia environments enable learner control; (2) this is reflected in individuals' navigational paths through network-based subject matter; (3) these student tracks can be captured in log fries; and (4) this information can be used by artificially intelligent tutors to implement adaptive instruction. Assuming (1) most schools, colleges, universities, and corporations will eventually offer distributed students network-based instruction for particular refresher preparation and certain core courses, and (2) adaptive intelligent tutors are crucial components of course management systems, recommendations for research, development, and evaluation, extracted from the discussion, are made to appropriate sponsors, academic administrators, faculty members, training managers, and instructional developers, interested in realizing on-line learning. Published by Elsevier Science Ltd. C1 USN, Postgrad Sch, Inst Defense Educ & Anal, Monterey, CA 93943 USA. RP Federico, PA (reprint author), USN, Postgrad Sch, Inst Defense Educ & Anal, Criscuolo Hall,101 North St, Monterey, CA 93943 USA. NR 126 TC 23 Z9 23 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0747-5632 J9 COMPUT HUM BEHAV JI Comput. Hum. Behav. PD NOV PY 1999 VL 15 IS 6 BP 653 EP 692 DI 10.1016/S0747-5632(99)00044-8 PG 40 WC Psychology, Multidisciplinary; Psychology, Experimental SC Psychology GA 245YT UT WOS:000083136800001 ER PT J AU Natishan, PM Jones-Meehan, J Loeb, GI Little, BJ Ray, R Beard, M AF Natishan, PM Jones-Meehan, J Loeb, GI Little, BJ Ray, R Beard, M TI Corrosion behavior of some transition metals and 4340 steel metals exposed to sulfate-reducing bacteria SO CORROSION LA English DT Article DE chromium; environmental scanning electron; microscopy; microbiologically influenced corrosion; molybdenum; niobium; sulfate-reducing bacteria; steel; tantalum; tungsten; type 4340 steel; zirconium ID MICROBIOLOGICALLY INFLUENCED CORROSION AB Microbial colonization of metals (zirconium chromium, niobium tantalum, molybdenum, tungsten, and type 4340 steel [UNS G43400]) and susceptibility of these metals to microbiologically influenced corrosion by sulfate-reducing bacteria was investigated Environmental scanning electron microscopy characterization after 12 months and 21 months showed patchy biofilms on all metals except tungsten. Weight loss after 24 months for zirconium and niobium were either nonexistent or negligible, indicating that these metals did not experience MIC under the test conditions. C1 American Univ, Washington, DC 20016 USA. Naval Res Lab, Stennis Space Ctr, MS USA. Naval Surface Warfare Ctr, Carderock Div, W Bethesda, MD USA. Naval Res Lab, Washington, DC 20375 USA. RP Natishan, PM (reprint author), Naval Res Lab, Code 6134,Bldg 3,Room 272, Washington, DC 20375 USA. NR 18 TC 0 Z9 1 U1 0 U2 4 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 USA SN 0010-9312 J9 CORROSION JI Corrosion PD NOV PY 1999 VL 55 IS 11 BP 1062 EP 1068 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 260XZ UT WOS:000083979900007 ER PT J AU Corwin, HL Gettinger, A Rodriguez, RM Pearl, RG Gubler, KD Enny, G Colton, T Corwin, MJ AF Corwin, HL Gettinger, A Rodriguez, RM Pearl, RG Gubler, KD Enny, G Colton, T Corwin, MJ TI Efficacy of recombinant human erythropoietin in the critically ill patient: A randomized, double-blind, placebo-controlled trial SO CRITICAL CARE MEDICINE LA English DT Article DE erythropoietin; anemia; blood transfusion; transfusion medicine; blood substitutes; critical care; intensive care unit ID BLOOD-TRANSFUSION; COSTS AB Objective: To determine whether the administration of recombinant human erythropoietin (rHuEPO) to critically ill patients in the intensive care unit (ICU) would reduce the number of red blood cell (RBC) transfusions required. Design: A prospective, randomized, double-blind, placebo-controlled, multicenter trial. Setting: ICUs at three academic tertiary care medical centers. Patients: A total of 160 patients who were admitted to the ICU and met the eligibility criteria were enrolled in the study (80 into the rHuEPO group; 80 into the placebo group). Interventions: Patients were randomized to receive either rHuEPO or placebo. The study drug (300 units/kg of rHuEPO or placebo) was administered by subcutaneous injection beginning ICU day 3 and continuing daily for a total of 5 days (until ICU day 7). The subsequent dosing schedule was every other day to achieve a hematocrit (Hct) concentration of >38%, The study drug was given for a minimum of 2 wks or until ICU discharge (for subjects with ICU lengths of stay >2 wks) up to a total of 6 wks (42 days) postrandomization. Measurements and Main Results: The cumulative number of units of RBCs transfused was significantly less in the rHuEPO group than in the placebo group (p < .002, Kolmogorov-Smirnov test). The rHuEPO group was transfused with a total of 166 units of RBCs vs. 305 units of RBCs transfused in the placebo group. The final Hct concentration of the rHuEPO patients was significantly greater than the final Hct concentration of placebo patients (35.1 +/- 5.6 vs. 31.6 +/- 4.1; p < .01, respectively). A total of 45% of patients in the rHuEPO group received a blood transfusion between days 8 and 42 or died before study day 42 compared with 55% of patients in the placebo group (relative risk, 0.8; 95% confidence interval, 0.6, 1,1), There were no significant differences between the two groups either in mortality or in the frequency of adverse events. Conclusions: The administration of rHuEPO to critically ill patients is effective in raising their Hct concentrations and in reducing the total number of units of RBCs they require. C1 Dartmouth Hitchcock Med Ctr, Dept Crit Care Med, Lebanon, NH 03766 USA. Dartmouth Hitchcock Med Ctr, Dept Anesthesiol, Lebanon, NH 03766 USA. Stanford Univ, Dept Anesthesiol, Stanford, CA 94305 USA. USN, Med Ctr, San Diego, CA 92152 USA. Ortho Biotech, Raritan, NJ USA. Boston Univ, Sch Publ Hlth, Boston, MA USA. RP Corwin, HL (reprint author), Dartmouth Hitchcock Med Ctr, Dept Crit Care Med, Lebanon, NH 03766 USA. NR 16 TC 219 Z9 228 U1 0 U2 3 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0090-3493 J9 CRIT CARE MED JI Crit. Care Med. PD NOV PY 1999 VL 27 IS 11 BP 2346 EP 2350 DI 10.1097/00003246-199911000-00004 PG 5 WC Critical Care Medicine SC General & Internal Medicine GA 258AA UT WOS:000083814800003 PM 10579246 ER PT J AU Nissen, ME AF Nissen, ME TI Knowledge-based knowledge management in the reengineering domain SO DECISION SUPPORT SYSTEMS LA English DT Article DE expert systems; knowledge management; knowledge systems; reengineering AB A fundamental problem with knowledge management is the information technology (IT) employed to enable knowledge work appears to target data and information, as opposed to knowledge itself. In contrast, knowledge-based systems (KBS) maintain an explicit and direct focus on knowledge. The research described in this article is focused on innovating knowledge management through KBS technology. We refer to this KBS-enabled transformation of knowledge work as knowledge-based knowledge management. Drawing from the recent literature, we identify a number of key activities associated with knowledge management to establish a set of requirements for knowledge management support. We match these requirements with textbook capabilities of intelligent systems and use this analysis to evaluate KOPeR, a KBS employed to automate and support knowledge management in the reengineering domain. We find KOPeR possesses the capabilities required for knowledge management support. And its field application, as part of a major reengineering engagement, reveals four important knowledge effects enabled by this KBS. From this study, we also find KOPeR to be effective in its automation and support of key knowledge management activities. And through its successful use and knowledge effects in this study, we conclude that KBS can be developed and employed for effective knowledge management support. Published by Elsevier Science B.V. C1 USN, Postgrad Sch, Monterey, CA 93943 USA. RP Nissen, ME (reprint author), USN, Postgrad Sch, 555 Dyer Rd,Code SM-Ni, Monterey, CA 93943 USA. NR 62 TC 21 Z9 21 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-9236 J9 DECIS SUPPORT SYST JI Decis. Support Syst. PD NOV PY 1999 VL 27 IS 1-2 BP 47 EP 65 DI 10.1016/S0167-9236(99)00036-6 PG 19 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Operations Research & Management Science SC Computer Science; Operations Research & Management Science GA 268CL UT WOS:000084396700004 ER PT J AU Ross, EV Yashar, SS Naseef, GS Barnette, DJ Skrobal, M Grevelink, J Anderson, RR AF Ross, EV Yashar, SS Naseef, GS Barnette, DJ Skrobal, M Grevelink, J Anderson, RR TI A pilot study of in vivo immediate tissue contraction with CO2 skin laser resurfacing in a live farm pig SO DERMATOLOGIC SURGERY LA English DT Article ID HIGH-ENERGY; IN-VITRO; CO2-LASER; SHRINKAGE; RHYTIDES; COLLAGEN AB BACKGROUND. It has been suggested that tissue ablation, collagen shrinkage, and new collagen deposition contribute to the clinical outcome of laser skin resurfacing. OBJECTIVE. TO Study the effects of fluence and pass number on thermal damage and tissue shrinkage, eve performed experiments in an in vivo farm pig model. METHODS. A CO2 laser was used to treat the flank skin of a farm pig. There were nine treatment sites based on number of passes and fluence per pass. Wound surface areas were measured pretreatment and immediately posttreatment. Biopsies were performed immediately after irradiation. RESULTS. Surface area measurements showed that immediate contraction tended to increase with increasing fluence and pass number up to a maximum of approximately 38% shrinkage, after which the percent contraction remained constant. Thermal damage increased with pass number for low and moderate fluence groups; however, in high fluence groups the thermal damage remained constant with an increasing number of passes. CONCLUSIONS. Our results suggest that CO2 laser resurfacing produces immediate tissue contraction and residual thermal damage that is saturable for multiple passes and high fluences. For small fluences, however, there is an almost linear increase in thermal damage and shrinkage with an increasing number of passes. C1 Massachusetts Gen Hosp, Dept Dermatol, Wellman Labs Photomed, Boston, MA 02114 USA. Naval Med Ctr San Diego, Dept Dermatol, San Diego, CA USA. RP Ross, EV (reprint author), USN Hosp, Box 324,34800 Bob Wilson Dr, San Diego, CA 92134 USA. NR 20 TC 20 Z9 20 U1 0 U2 0 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 1076-0512 J9 DERMATOL SURG JI Dermatol. Surg. PD NOV PY 1999 VL 25 IS 11 BP 851 EP 856 DI 10.1046/j.1524-4725.1999.99091.x PG 6 WC Dermatology; Surgery SC Dermatology; Surgery GA 253FA UT WOS:000083544900007 PM 10594596 ER PT J AU McNeill, KM Hendrix, RM Lindner, JL Benton, FR Monteith, SC Tuchscherer, MA Gray, GC Gaydos, JC AF McNeill, KM Hendrix, RM Lindner, JL Benton, FR Monteith, SC Tuchscherer, MA Gray, GC Gaydos, JC TI Large, persistent epidemic of adenovirus type 4-associated acute respiratory disease in US army trainees SO EMERGING INFECTIOUS DISEASES LA English DT Article AB In May 1997, a large, persistent epidemic of adenovirus type 4-associated acute respiratory disease began at Fort Jackson, South Carolina, the largest army basic training center. The epidemic lasted until December and declined when vaccine administration resumed. More than 1,000 male and female trainees were hospitalized; 66.1% of those hospitalized had an adenovirus type 4 isolate. C1 Dwight David Eisenhower Army Med Ctr, Ft Gordon, GA USA. Univ S Carolina, Sch Med, Columbia, SC USA. Moncrief Army Community Hosp, Ft Jackson, SC USA. Naval Hlth Res Ctr, San Diego, CA USA. US Dept Def, Global Emerging Infect Syst, Washington, DC 20305 USA. RP McNeill, KM (reprint author), Catawba Hlth Dist, POB 817, Lancaster, SC 29721 USA. NR 6 TC 52 Z9 53 U1 0 U2 1 PU CENTER DISEASE CONTROL PI ATLANTA PA ATLANTA, GA 30333 USA SN 1080-6040 J9 EMERG INFECT DIS JI Emerg. Infect. Dis PD NOV-DEC PY 1999 VL 5 IS 6 BP 798 EP 801 PG 4 WC Immunology; Infectious Diseases SC Immunology; Infectious Diseases GA 268HK UT WOS:000084408100009 PM 10603214 ER PT J AU Zhang, D Lee, V Friedel, J Keyser, R AF Zhang, D Lee, V Friedel, J Keyser, R TI ANDES: a phased-array antenna diagnostic expert system SO EXPERT SYSTEMS WITH APPLICATIONS LA English DT Article DE phased-array antenna; diagnostic expert system; knowledge acquisition; rule base; CLIPS AB The Antenna Repair Facility at McClellan Air Force Base, which has been responsible for the repair and maintenance of US Air Force antennas and radars over several decades, now faces the challenge of transferring their many years of expertise in antenna repair and maintenance from their closing base to an acquiring base. This is being done with the requirement of maintaining the in-house expertise and production levels, while manpower decreases. To meet the challenge, an expert system called ANDES is being developed to help diagnose electronically steered phased-array satellite ground station antennas at McClellan AFB and the acquiring base. This paper discusses the key issues in the design and development of ANDES and focuses on its use as a tool to help human engineers improve the antenna diagnostic process. The ANDES' experience indicates that during the times of downsizing, streamlining and restructuring, expert systems offer a viable and sometimes pivotal means to preserve expertise from a closing facility and also can be used as a training tool by an acquiring facility. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Calif State Univ Sacramento, Dept Comp Sci, Sacramento, CA 95819 USA. USN, PMO, SPL, Mt View, CA 94039 USA. LHHDEC, SM ALC, Near Field Test Range, McClellan AFB, CA 95652 USA. RP Zhang, D (reprint author), Calif State Univ Sacramento, Dept Comp Sci, Sacramento, CA 95819 USA. NR 17 TC 0 Z9 0 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0957-4174 J9 EXPERT SYST APPL JI Expert Syst. Appl. PD NOV PY 1999 VL 17 IS 4 BP 327 EP 352 DI 10.1016/S0957-4174(99)00044-5 PG 26 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Operations Research & Management Science SC Computer Science; Engineering; Operations Research & Management Science GA 256WZ UT WOS:000083750600008 ER PT J AU Gottuk, DT Peatross, MJ Farley, JP Williams, FW AF Gottuk, DT Peatross, MJ Farley, JP Williams, FW TI The development and mitigation of backdraft: a real-scale shipboard study SO FIRE SAFETY JOURNAL LA English DT Article DE backdraft; compartment fire; water spray; fuel mass fraction; ventilation AB This paper presents the results of a real-scale experimental test series to study the development and mitigation of backdrafts. Experiments consisted of creating backdrafts onboard a US Navy test ship, ex-USS SHADWELL. This study has shown that the key parameter for backdraft development is the fuel mass fraction. The results show that the critical fuel mass fraction, Y-f, required for the development of diesel fuel backdraft is 0.16 for fully vitiated conditions. The effects of varying adjacent room boundaries and ventilation conditions are discussed. In general, the intensity of a backdraft is more dependent on the adjacent boundaries than on the ventilation conditions. The injection of water spray into the fire compartment was shown to be an effective mitigating tactic that was able to completely suppress backdrafts primarily by means of diluting the atmosphere and reducing the fuel mass fraction, rather than by a thermal mechanism of cooling. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Hughes Associates Inc, Baltimore, MD 21227 USA. USN, Res Lab, Washington, DC 20375 USA. RP Gottuk, DT (reprint author), Hughes Associates Inc, Baltimore, MD 21227 USA. NR 11 TC 28 Z9 35 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0379-7112 J9 FIRE SAFETY J JI Fire Saf. J. PD NOV PY 1999 VL 33 IS 4 BP 261 EP 282 DI 10.1016/S0379-7112(99)00033-8 PG 22 WC Engineering, Civil; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 255GH UT WOS:000083660800002 ER PT J AU Blotter, RH Connolly, E Wasan, A Chapman, MW AF Blotter, RH Connolly, E Wasan, A Chapman, MW TI Acute complications in the operative treatment of isolated ankle fractures in patients with diabetes mellitus SO FOOT & ANKLE INTERNATIONAL LA English DT Article AB Using a computer database, we conducted a retrospective review of all ankle fractures treated at our institution from March 1985 to October 1996. Twenty-one patients with diabetes mellitus and isolated ankle fractures that were treated operatively met all inclusion criteria. Seven had insulin-dependent diabetes, and 14 had non-insulin-dependent diabetes. A randomly selected control group of 46 patients without diabetes who also underwent operative treatment of ankle fractures during this same time period were matched for age, sex, and fracture severity. The complication rate was 43% with 13 complications in nine patients with diabetes. There were seven (15.5%) complications in the control group, Complications in the diabetic group included seven infections (five deep, two superficial) and three losses of fixation. The complications were more severe in our diabetic population, requiring seven additional procedures including two below-knee amputations; a third patient refused an amputation. No additional procedures were required in our control group. All complications in our control group resolved with treatment. The relative risk for postoperative complications in patients with diabetes who sustained ankle fractures that were treated operatively was 2.76 times greater than the control group's (95% confidence interval, 1.57-3.97). C1 USN Hosp, FPO, AP 96350 USA. Univ Calif Davis, Dept Orthopaed Surg, Sacramento, CA 95817 USA. Orthopaed & Rheumatol Assoc, Moline, IL USA. RP Blotter, RH (reprint author), USN Hosp, PSC 475 Box 1672, FPO, AP 96350 USA. NR 7 TC 57 Z9 57 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 1071-1007 J9 FOOT ANKLE INT JI Foot Ankle Int. PD NOV PY 1999 VL 20 IS 11 BP 687 EP 694 PG 8 WC Orthopedics SC Orthopedics GA 256MH UT WOS:000083728700003 PM 10582843 ER PT J AU Mushrush, GW Beal, EJ Hardy, DR Hughes, JR AF Mushrush, GW Beal, EJ Hardy, DR Hughes, JR TI Nitrogen compound distribution in middle distillate fuels derived from petroleum, oil shale, and tar sand sources SO FUEL PROCESSING TECHNOLOGY LA English DT Article DE nitrogen compound; distillate fuels; tar sand sources ID SEDIMENT FORMATION; STORAGE STABILITY; MODEL; 2,5-DIMETHYLPYRROLE AB Nitrogen compounds present in crude sources constitute serious problems both for producers and consumers. For producers, these compounds are responsible for poisoning catalysts during the refining processes. For consumers, these compounds are responsible for the degradation observed in fuels during storage and handling. The quality of petroleum, as measured by degrees API gravity, continues to decrease in quality. This, coupled with the inevitable use of other crude sources, if used in quantity will further decrease the stability of middle distillate fuels. In this article we present our method for the separation and quantitation of the slate of nitrogen compounds present in middle distillate fuels derived from petroleum, oil shale and tar sand sources. Results from our laboratory indicate that of all of the nitrogen compounds present in middle distillate fuels, the indole type structure is the most deleterious. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 USN, Res Lab, Mat Chem Branch, Fuels Sect, Washington, DC 20375 USA. George Mason Univ, Dept Chem, Fairfax, VA 22030 USA. Geo Ctr, Ft Washington, MD 20749 USA. RP Mushrush, GW (reprint author), USN, Res Lab, Mat Chem Branch, Fuels Sect, Code 6121,4555 Overlook Ave SW, Washington, DC 20375 USA. NR 15 TC 46 Z9 47 U1 4 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD NOV PY 1999 VL 61 IS 3 BP 197 EP 210 DI 10.1016/S0378-3820(99)00056-9 PG 14 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA 266DK UT WOS:000084285200002 ER PT J AU Capps, M Watsen, K Zyda, M AF Capps, M Watsen, K Zyda, M TI Cyberspace and mock apple pie - A vision of the future of graphics and virtual environments SO IEEE COMPUTER GRAPHICS AND APPLICATIONS LA English DT Article C1 USN, Postgrad Sch, San Diego, CA 92132 USA. RP Capps, M (reprint author), USN, Postgrad Sch, San Diego, CA 92132 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0272-1716 J9 IEEE COMPUT GRAPH JI IEEE Comput. Graph. Appl. PD NOV-DEC PY 1999 VL 19 IS 6 BP 8 EP 11 DI 10.1109/38.799712 PG 4 WC Computer Science, Software Engineering SC Computer Science GA 248CD UT WOS:000083257000002 ER PT J AU Astheimer, P Rosenblum, L AF Astheimer, P Rosenblum, L TI A business view of virtual reality SO IEEE COMPUTER GRAPHICS AND APPLICATIONS LA English DT Article C1 Siemens AG, ZT IF IK, Corp Res & Dev, Innovat Field Informat & Commun, D-81735 Munich, Germany. USN, Adv Informat Technol Branch, Div Informat Technol, Res Lab, Washington, DC 20375 USA. RP Astheimer, P (reprint author), Siemens AG, ZT IF IK, Corp Res & Dev, Innovat Field Informat & Commun, D-81735 Munich, Germany. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0272-1716 J9 IEEE COMPUT GRAPH JI IEEE Comput. Graph. Appl. PD NOV-DEC PY 1999 VL 19 IS 6 BP 28 EP 29 DI 10.1109/MCG.1999.799735 PG 2 WC Computer Science, Software Engineering SC Computer Science GA 248CD UT WOS:000083257000005 ER PT J AU Gabbard, JL Hix, D Swan, JE AF Gabbard, JL Hix, D Swan, JE TI User-centered design and evaluation of virtual environments SO IEEE COMPUTER GRAPHICS AND APPLICATIONS LA English DT Article C1 VPST, Blacksburg, VA 24060 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. USN, Virtual Real Lab, Res Lab, San Diego, CA USA. RP VPST, 2000 Kraft Dr,Suite 2600, Blacksburg, VA 24060 USA. EM jgabbard@vpst.org NR 12 TC 87 Z9 88 U1 1 U2 6 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0272-1716 EI 1558-1756 J9 IEEE COMPUT GRAPH JI IEEE Comput. Graph. Appl. PD NOV-DEC PY 1999 VL 19 IS 6 BP 51 EP 59 DI 10.1109/38.799740 PG 9 WC Computer Science, Software Engineering SC Computer Science GA 248CD UT WOS:000083257000009 ER PT J AU Bewley, WW Felix, CL Aifer, EH Stokes, DW Vurgaftman, I Olafsen, LJ Meyer, JR Yang, MJ Lee, H AF Bewley, WW Felix, CL Aifer, EH Stokes, DW Vurgaftman, I Olafsen, LJ Meyer, JR Yang, MJ Lee, H TI Thermal characterization of diamond-pressure-bond heat sinking for optically pumped mid-infrared lasers SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article DE CW lasers; laser thermal factors; mid-infrared lasers; quantum-well lasers; semiconductor lasers ID QUANTUM-WELL LASERS; CW OUTPUT; II W; POWER; SOLDER AB The heat sinking properties of optically pumped semiconductor lasers mounted by the diamond-pressure-bonding (DPB) technique have been evaluated quantitatively. This method combines epi-side-down mounting with minimal processing and top optical access via pumping through the diamond. By correlating the pump-intensity variation of the emission wavelength with its temperature variation, specific thermal resistances have been determined for DPB-mounted type-II "W" lasers operating in the mid-infrared. Values less than or equal to 2.0 K.cm(2)/kW were obtained for all temperatures in the range 140-220 K. C1 USN, Res Lab, Washington, DC 20375 USA. Sarnoff Corp, Princeton, NJ 08543 USA. RP Bewley, WW (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Olafsen, Linda/G-4996-2013 NR 14 TC 25 Z9 25 U1 2 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD NOV PY 1999 VL 35 IS 11 BP 1597 EP 1601 DI 10.1109/3.798081 PG 5 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 250UJ UT WOS:000083406300004 ER PT J AU Goltsov, A Morozov, A Suckewer, S Elton, R Feldman, U Krushelnick, K Jones, T Moore, C Seely, J Sprangle, P Ting, A Zigler, A AF Goltsov, A Morozov, A Suckewer, S Elton, R Feldman, U Krushelnick, K Jones, T Moore, C Seely, J Sprangle, P Ting, A Zigler, A TI Is efficiency of gain generation in Li III 13.5-nm laser with 0.25-mu m subpicosecond pulses the same as with 1 mu m? SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Article DE lasers; optical propagation; X-ray applications; X-ray lasers; X-ray lithography; X-ray spectroscopy ID X-RAY LASER; DISCHARGE AB The main goal of this paper is to present experimental results on comparison of lasing efficiency for Li III 13.5 nm (2-1 transition) line in LIF microcapillary plasmas using 0.25 and 1 mu m subpicosecond pumping lasers, A formula for soft X-ray laser efficiency calculation is presented and used for such comparisons. The results for discharge created preplasma in L = 4 mm and L = 14 mm microcapillaries are also presented and compared with the results for laser created preplasma. C1 IV Kurchatov Atom Energy Inst, Troitsk 142092, Russia. Princeton Univ, Dept Mech & Aerosp Engn, Princeton, NJ 08544 USA. Univ Maryland, College Pk, MD 20742 USA. USN, Res Lab, Washington, DC 20375 USA. Univ London Imperial Coll Sci Technol & Med, London, England. Icarus Res Inc, Bethesda, MD USA. Hebrew Univ Jerusalem, Jerusalem, Israel. RP Goltsov, A (reprint author), IV Kurchatov Atom Energy Inst, Troitsk 142092, Russia. RI zigler, arie/C-2667-2012 NR 15 TC 24 Z9 24 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1077-260X J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD NOV-DEC PY 1999 VL 5 IS 6 BP 1453 EP 1459 DI 10.1109/2944.814984 PG 7 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 274HQ UT WOS:000084760700005 ER PT J AU Birtcher, CR Balanis, CA DeCarlo, D AF Birtcher, CR Balanis, CA DeCarlo, D TI Rotor-blade modulation on antenna amplitude pattern and polarization: Predictions and measurements SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article DE measurements; predictions; radiation patterns; rotor blade modulation ID ELECTROMAGNETIC-WAVE SCATTERING; METAL FAN BLADES; DIFFRACTION; SPECTRA AB The rotation of lift- and thrust-generating airfoils causes a periodic variation in aircraft communication signals. This effect is called rotor-blade modulation (RBM). The RBM on the radiation characteristics of helicopter-mounted antennas are predicted using the uniform theory of diffraction (UTD) and the finite-difference time-domain (FDTD) method and are compared with scale model measurements and full-scale in-flight measurements, In addition, the effects of electric field polarization on RBM are studied using the FDTD. C1 Arizona State Univ, Dept Elect Engn, Ctr Telecommun Res, Tempe, AZ 85287 USA. USN, Warfare Ctr, Div Aircraft, RF Sensors Branch 4555, Patuxent River, MD 20670 USA. RP Birtcher, CR (reprint author), Arizona State Univ, Dept Elect Engn, Ctr Telecommun Res, Tempe, AZ 85287 USA. NR 15 TC 9 Z9 10 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD NOV PY 1999 VL 41 IS 4 BP 384 EP 393 DI 10.1109/15.809828 PN 1 PG 10 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 266RX UT WOS:000084314800015 ER PT J AU Schneidewind, NF AF Schneidewind, NF TI Measuring and evaluating maintenance process using reliability, risk, and test metrics SO IEEE TRANSACTIONS ON SOFTWARE ENGINEERING LA English DT Article DE maintenance process stability; product and process integration; reliability risk ID SOFTWARE AB In analyzing the stability of a maintenance process, it is important that it not be treated in isolation from the reliability and risk of deploying the software that result from applying the process. Furthermore, we need to consider the efficiency of the test effort that is a part of the process and a determinate of reliability and risk of deployment. The relationship between product quality and process capability and maturity has been recognized as a major issue in software engineering based on the premise that improvements in process will lead to higher quality products. To this end, we have been investigating an important facet of process capability-stability-as defined and evaluated by trend, change, and shape metrics, across releases and within a release. Our integration of product and process measurement serves the dual purpose of using metrics to assess and predict reliability and risk and to evaluate process stability. We use the NASA Space Shuttle flight software to illustrate our approach. C1 USN, Postgrad Sch, Comp & Informat Sci & Operat Div, Monterey, CA 93943 USA. RP USN, Postgrad Sch, Comp & Informat Sci & Operat Div, Monterey, CA 93943 USA. EM nschneid@nps.navy.mil NR 20 TC 15 Z9 16 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0098-5589 EI 1939-3520 J9 IEEE T SOFTWARE ENG JI IEEE Trans. Softw. Eng. PD NOV-DEC PY 1999 VL 25 IS 6 BP 769 EP 781 DI 10.1109/32.824387 PG 13 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 286DE UT WOS:000085427700005 ER PT J AU Charoenvit, Y Majam, VF Corradin, G Sacci, JB Wang, RB Doolan, DL Jones, TR Abot, E Patarroyo, ME Guzman, F Hoffman, SL AF Charoenvit, Y Majam, VF Corradin, G Sacci, JB Wang, RB Doolan, DL Jones, TR Abot, E Patarroyo, ME Guzman, F Hoffman, SL TI CD4(+) T-cell- and gamma interferon-dependent protection against murine malaria by immunization with linear synthetic peptides from a Plasmodium yoelii 17-kilodalton hepatocyte erythrocyte protein SO INFECTION AND IMMUNITY LA English DT Article ID SPOROZOITE SURFACE PROTEIN-2; MONOCLONAL-ANTIBODIES; CIRCUMSPOROZOITE PROTEIN; ANTIGEN; VACCINES; INDUCTION; IMMUNITY; CLONES; STAGE; MICE AB Most work on protective immunity against the pre-erythrocytic stages of malaria has focused on induction of antibodies that prevent sporozoite invasion of hepatocytes, and CD8(+) T-cell responses that eliminate infected hepatocytes. We recently reported that immunization of A/J mice with an 18-amino-acid synthetic linear peptide from Plasmodium yoelii sporozoite surface protein 2 (SSP2) in TiterMax adjuvant induces sterile protection that is dependent on CD4(+) T cells and gamma interferon (IFN-gamma). We now report that immunization of inbred A/J mice and outbred CD1 mice with each of two linear synthetic peptides from the 17-kDa P. yoelii hepatocyte erythrocyte protein (HEP17) in the same adjuvant also induces protection against sporozoite challenge that is dependent on CD4(+) T cells and IFN-gamma. The SSP2 peptide and the two HEP17 peptides are recognized by B cells as well as T cells, and the protection induced by these peptides appears to be directed against the infected hepatocytes, In contrast to the peptide-induced protection, immunization of eight different strains of mice with radiation-attenuated sporozoites induces protection that is absolutely dependent on CD8(+) T cells. Data represented here demonstrate that CD4(+) T-cell-dependent protection fan be induced by immunization with linear synthetic peptides. These studies therefore provide the foundation for an approach to pre-erythrocytic-stage malaria vaccine development, based on the induction of protective CD4(+) T-cell responses, which mill complement efforts to induce protective antibody and CD8(+) T-cell responses. C1 USN, Malaria Program, Med Res Ctr, Bethesda, MD 20814 USA. Univ Lausanne, Inst Biochem, CH-1066 Epalinges, Switzerland. Univ Maryland, Sch Med, Dept Microbiol & Immunol, Baltimore, MD 21201 USA. World Hlth Org, Pan Amer Hlth Org, Reg Off, Washington, DC 20037 USA. Univ Nacl Colombia, Hosp San Juan de Dios, Inst Immunol, Bogota, Colombia. Henry M Jackson Fdn, Rockville, MD 20852 USA. RP Charoenvit, Y (reprint author), USN, Malaria Program, Med Res Ctr, 12300 Washington Ave, Rockville, MD 20852 USA. RI Doolan, Denise/F-1969-2015 NR 32 TC 43 Z9 43 U1 0 U2 1 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0019-9567 J9 INFECT IMMUN JI Infect. Immun. PD NOV PY 1999 VL 67 IS 11 BP 5604 EP 5614 PG 11 WC Immunology; Infectious Diseases SC Immunology; Infectious Diseases GA 249QD UT WOS:000083343000009 PM 10531206 ER PT J AU Lee, LH Burg, E Baqar, S Bourgeois, AL Burr, DH Ewing, CP Trust, TJ Guerry, P AF Lee, LH Burg, E Baqar, S Bourgeois, AL Burr, DH Ewing, CP Trust, TJ Guerry, P TI Evaluation of a truncated recombinant flagellin subunit vaccine against Campylobacter jejuni SO INFECTION AND IMMUNITY LA English DT Article ID COLI VC167 FLAGELLIN; POSTTRANSLATIONAL MODIFICATION; INTESTINAL COLONIZATION; TRAVELERS DIARRHEA; ANTIGENS; MOTILITY; IDENTIFICATION; PATHOGENESIS; INFECTION; PROTEINS AB A recombinant protein comprising the maltose-binding protein (MBP) of Escherichia coli fused to amino acids 5 to 337 of the FlaA flagellin of Campylobacter coli VC167 was evaluated for immunogenicity and protective efficacy against challenge by a heterologous strain of campylobacter, Campylobacter jejuni 81-176, in two murine models. The sequence of the flaA gene of strain 81-176 revealed a predicted protein which was 98.1% similar to that of VC167 FlaA over the region expressed in the fusion protein. Mice were immunized intranasally with two doses of 3 to 50 mu g of MBP-FlaA, given 8 days apart, with or without 5 mu g of the mutant E. coli heat-labile enterotoxin (LTR192G) as a mucosal adjuvant, The full range of MBP-FlaA doses were effective in eliciting antigen-specific serum immunoglobulin G (IgG) responses, and these responses were enhanced by adjuvant use, except in the highest dosing group. Stimulation of FlaA-specific intestinal secretory IgA (sIgA) responses required immunization with higher doses of MBP-FlaA (greater than or equal to 25 mu g) or coadministration of lower doses with the adjuvant, When vaccinated mice were challenged intranasally 26 days after immunization, the best protection was seen in animals given 50 mu g of MBP-FlaA plus LTR192G. The protective efficacies of this dose against disease symptoms and intestinal colonization were 81.1 and 84%, respectively. When mice which had been immunized with 50 mu g of MBP-FlaA plus LTR192G intranasally were challenged orally with 8 x 10(10), 8 x 10(9), or 8 x 10(8) cells of strain 81-176, the protective efficacies against intestinal colonization at 7 days postinfection were 71.4, 71.4, and 100%, respectively. C1 Natl Naval Med Ctr, Naval Med Res Ctr, Enter Dis Program, Gaithersburg, MD 20889 USA. US FDA, Beltsville, MD 20708 USA. Univ Victoria, Dept Biochem & Microbiol, Victoria, BC V8W 3P6, Canada. RP Guerry, P (reprint author), Natl Naval Med Ctr, Naval Med Res Ctr, Enter Dis Program, 8901 Wisconsin Ave, Gaithersburg, MD 20889 USA. RI Guerry, Patricia/A-8024-2011 NR 45 TC 59 Z9 64 U1 0 U2 1 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0019-9567 J9 INFECT IMMUN JI Infect. Immun. PD NOV PY 1999 VL 67 IS 11 BP 5799 EP 5805 PG 7 WC Immunology; Infectious Diseases SC Immunology; Infectious Diseases GA 249QD UT WOS:000083343000034 PM 10531231 ER PT J AU Carroll, TL Johnson, GA Pecora, LM Mar, DJ AF Carroll, TL Johnson, GA Pecora, LM Mar, DJ TI Parameter-insensitive and narrow-band synchronization of chaotic circuits SO INTERNATIONAL JOURNAL OF BIFURCATION AND CHAOS LA English DT Article; Proceedings Paper CT International Workshop on Synchronization, Pattern Formation, and Spatio-Temporal Chaos in Coupled Chaotic Oscillators CY JUN 07-10, 1998 CL SANTIAGO COMPOSTE, SPAIN SP Univ Santiago Compostela, Nonlinear Phys Grp ID OPTIMAL PERIODIC-ORBITS; SYSTEMS; SIGNALS; OSCILLATORS; HYPERCHAOS AB There have been many proposals to use chaotic signals for communications. There are many practical problems with transmitting chaotic signals, however: transmitter and receiver must match, and chaotic signals are affected by phase or amplitude distortion and additive noise. We describe ways to reduce the parameter sensitivity of chaotic synchronization and reduce the bandwidth of chaotic signals. C1 USN, Res Lab, Washington, DC 20375 USA. Boston Univ, Dept Biomed Engn, Boston, MA 02215 USA. RP USN, Res Lab, Washington, DC 20375 USA. OI Carroll, Thomas/0000-0002-2371-2049 NR 28 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-1274 EI 1793-6551 J9 INT J BIFURCAT CHAOS JI Int. J. Bifurcation Chaos PD NOV PY 1999 VL 9 IS 11 BP 2189 EP 2196 DI 10.1142/S0218127499001619 PG 8 WC Mathematics, Interdisciplinary Applications; Multidisciplinary Sciences SC Mathematics; Science & Technology - Other Topics GA 276DB UT WOS:000084859400007 ER PT J AU Holtz, RL Sadananda, K Imam, MA AF Holtz, RL Sadananda, K Imam, MA TI Fatigue thresholds of Ni-Ti alloy near the shape memory transition temperature SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article; Proceedings Paper CT Engineering Foundation Conference on Fatigue Damage of Structural Materials II CY SEP 07-11, 1998 CL HYANNIS, MASSACHUSETTS SP Engn Fdn, USN, USAF DE fatigue crack threshold; load ratio effect; K-max threshold; fundamental threshold curve; crack closure; nickel-titanium alloy; shape-memory alloy ID CRACK CLOSURE AB The fatigue thresholds of nickel-titanium alloy with martensite start temperature of 80 degrees C were measured in air from room temperature to 150 degrees C and load ratios of 0.1 to 0.9. The Delta K versus K-max fundamental threshold curves are characteristic of ductile metals at all temperatures tested and are consistent with the existence of two threshold parameters, Delta K-th* and K-max,K-th*, for cyclic and maximum stress intensity, respectively. Delta K-th* increases linearly with temperature, while K-max,K-th*, exhibits a transition between 80 and 100 degrees C, decreasing by half as a function of temperature. Compliance curves suggest the existence of crack closure in the stable martensite regime below 100 degrees C, but little or no crack closure in the stress-induced martensite regime above 100 degrees C up to 150 degrees C. The results suggest that both crack closure and the existence of an intrinsic fundamental threshold curve with both Delta K and K-max thresholds as a function of load ratio are necessary to fully account for R dependence of Delta K-th. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 USN, Res Lab, Div Mat Sci & Technol, Washington, DC 20375 USA. RP Holtz, RL (reprint author), USN, Res Lab, Div Mat Sci & Technol, Code 6323, Washington, DC 20375 USA. NR 21 TC 28 Z9 28 U1 1 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD NOV PY 1999 VL 21 SU S BP S137 EP S145 PG 9 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 263MN UT WOS:000084128600015 ER PT J AU Sadananda, K Vasudevan, AK Holtz, RL Lee, EU AF Sadananda, K Vasudevan, AK Holtz, RL Lee, EU TI Analysis of overload effects and related phenomena SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article; Proceedings Paper CT Engineering Foundation Conference on Fatigue Damage of Structural Materials II CY SEP 07-11, 1998 CL HYANNIS, MASSACHUSETTS SP Engn Fdn, USN, USAF DE fatigue; threshold; K-max; overload; crack closure; residual stress ID FATIGUE-CRACK-GROWTH; BEHAVIOR; ALLOY AB Overloads and underloads perturb steady state fatigue crack growth conditions and affect the growth rates by retarding or accelerating the growth. Clear understanding of these transient effects is important for the reliable life prediction of a component subjected to random loads. The overload effects have predominately been attributed to either plasticity induced crack closure behind the crack tip, residual stresses ahead of the crack tip, or a combination of both. These effects are critically examined in the context of the Unified Approach proposed by the authors. Recent experimental and analytical evaluation of crack closure has confirmed its negligible contribution to crack growth and has demonstrated that changes in the stresses ahead of the crack tip are more important than closure behind the crack tip. It is shown that the overload effects and other transient effects arise due to perturbation of the stresses ahead of the crack tip, and these can be accounted for by the two parametric approach emphasized in the unified theory. It is shown that related phenomena including the role of K-max the existence of propagation threshold K-pr, and effects of overloads on K-pr and K-max etc, are all accounted for by the Unified Approach. (C) 1999 Published by Elsevier Science Ltd. All rights reserved. C1 USN, Res Lab, Div Mat Sci & Technol, Washington, DC 20375 USA. Off Naval Res, Arlington, VA 22217 USA. USN, Air Warfare Ctr, Div Aircraft, Patuxent River, MD 20670 USA. RP Sadananda, K (reprint author), USN, Res Lab, Div Mat Sci & Technol, Washington, DC 20375 USA. NR 37 TC 79 Z9 81 U1 1 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD NOV PY 1999 VL 21 SU S BP S233 EP S246 PG 14 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 263MN UT WOS:000084128600025 ER PT J AU Stanzl-Tschegg, SE Plasser, O Tschegg, EK Vasudevan, AK AF Stanzl-Tschegg, SE Plasser, O Tschegg, EK Vasudevan, AK TI Influence of microstructure and load ratio on fatigue threshold behavior in 7075 aluminum alloy SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article; Proceedings Paper CT Engineering Foundation Conference on Fatigue Damage of Structural Materials II CY SEP 07-11, 1998 CL HYANNIS, MASSACHUSETTS SP Engn Fdn, USN, USAF DE fatigue crack growth thresholds; K-max; Delta K-th; high-strength aluminum alloys; microstructure; slip mode; load ratio; crack closure ID CRACK-GROWTH-BEHAVIOR; CLOSURE; PROPAGATION AB The influence of microstructure and load ratio on fatigue crack propagation in the near-threshold regime has been investigated on the 7075-aluminum alloy. The alloy heat treatment was varied to give underaged and overaged microstructures with approximately the same yield strength properties. Crack growth measurements were performed at constant load ratios between R=-1 and +0.8 in ambient air. The influence of load ratio is discussed in terms of deformation slip, crack branching and fracture mode. Vacuum data from the literature are compared with the current air results. For both environmental conditions, it was observed that the crack growth and threshold properties of the underaged alloy were better than the overaged alloy. The overall fatigue behavior is discussed in terms of the two parameter concept namely Delta K and K-max. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Agr Sci, Inst Met & Phys, A-1180 Vienna, Austria. Vienna Tech Univ, Inst Appl & Tech Phys, A-1040 Vienna, Austria. USN, Res Lab, Off Naval Res, Arlington, VA 22217 USA. RP Stanzl-Tschegg, SE (reprint author), Univ Agr Sci, Inst Met & Phys, Turkenschanzstr 18, A-1180 Vienna, Austria. NR 32 TC 14 Z9 15 U1 0 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD NOV PY 1999 VL 21 SU S BP S255 EP S262 PG 8 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 263MN UT WOS:000084128600027 ER PT J AU Vasudevan, AK Sadananda, K AF Vasudevan, AK Sadananda, K TI Application of unified fatigue damage approach to compression-tension region SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article; Proceedings Paper CT Engineering Foundation Conference on Fatigue Damage of Structural Materials II CY SEP 07-11, 1998 CL HYANNIS, MASSACHUSETTS SP Engn Fdn, USN, USAF DE fatigue crack growth; load ratio; mechanism; microstructure; environment; Delta K; K-max; steel; aluminum alloys; nickel alloys; titanium ID CRACK GROWTH-BEHAVIOR; GRAPHITE CAST IRONS; STRESS-RATIO; THRESHOLD CONDITION; MEAN STRESS; CLOSURE; RANGE; MODEL; PROPAGATION; COMPOSITES AB A Unified Approach to fatigue crack growth developed earlier is extended to include the fatigue behavior over the entire load ratio (R) regime, from compression-tension to tension-tension. This approach provides a self consistent description of cyclic damage using the two loading parameters, Delta K and K-max, applicable over the entire crack growth regime. Crack growth behavior in the R>0 regime has been classified into five distinct classes. This classification is extended here to include the negative R-ratio region. When compression loads are included with the tension cycle, each classification is further divided into three additional subsets, reflecting a characteristic change in crack growth mechanisms. The current overall classification provides a methodology for understanding the combined effects of tension and compression loads on crack tip forces and their effect on material crack growth resistance. Like wise the role of environmental effect will also be altered in the presence of compressive forces. (C) 1999 Published by Elsevier Science Ltd. All rights reserved. C1 USN, Res Lab, Washington, DC USA. Off Naval Res, Arlington, VA 22217 USA. RP Sadananda, K (reprint author), USN, Res Lab, Code 6323, Washington, DC USA. NR 42 TC 26 Z9 26 U1 2 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD NOV PY 1999 VL 21 SU S BP S263 EP S273 PG 11 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 263MN UT WOS:000084128600028 ER PT J AU Vasudevan, AK Cammett, JT Nicholas, T Jata, KV AF Vasudevan, AK Cammett, JT Nicholas, T Jata, KV TI Fatigue damage in structural materials II - 7-11 September 1998 - Hyannis, Massachusetts, USA - Foreword SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Editorial Material C1 Off Naval Res, Arlington, VA 22217 USA. USN, Aviat Depot, Arlington, VA USA. USAF, Res Lab, Arlington, VA USA. RP Vasudevan, AK (reprint author), Off Naval Res, Arlington, VA 22217 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD NOV PY 1999 VL 21 SU S BP SV EP SV PG 1 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 263MN UT WOS:000084128600001 ER PT J AU Singh, BK Singh, AK Pandey, CS Srivastava, ON AF Singh, BK Singh, AK Pandey, CS Srivastava, ON TI Investigation on synthesis, characterization and hydrogenation behaviour of hydrogen storage material: Fe1-xZrxTi1.3 (x=0.2) SO INTERNATIONAL JOURNAL OF HYDROGEN ENERGY LA English DT Article ID KINETICS AB The present study is aimed at investigations on the structural and microstructural characterization and hydrogenation behaviour of Zr substituted Fe1-xZrxTi1.3 (x = 0.2) alloys. This storage alloy has been synthesized using R.F.induction melting under an argon atmosphere in a previously outgassed graphite crucible. The structural characterization (XRD) has revealed that the as-synthesized sample is multiphasic in nature and embodies the phases FeTi, Fe2Ti, FeTi2 and Ti. Microstructural evaluations (SEM) exhibited the presence of interfaces and cracking. The P-C isotherm was determined and it showed the storage capacity of similar to 1.20 wt.% at 200 degrees C. The activation as well as desorption kinetics (75% desorption of H-2 in 6 min) were found to be better for Zr-substituted alloy (Fe0.8Zr0.2Ti1.3) as compared to FeTi1.3. The improved activation and desorption kinetics are thought to be due to presence of several interfaces e.g. Fe(Zr)Ti/Fe(Zr)Ti-2, Fe(Zr)Ti/{Fe(Zr)}(2)Ti and volume expansion induced cracking of Ti. (C) 1999 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved. C1 Banaras Hindu Univ, Dept Phys, Varanasi 221005, Uttar Pradesh, India. USN, Res Lab, Washington, DC USA. RP Srivastava, ON (reprint author), Banaras Hindu Univ, Dept Phys, Varanasi 221005, Uttar Pradesh, India. NR 10 TC 5 Z9 5 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-3199 J9 INT J HYDROGEN ENERG JI Int. J. Hydrog. Energy PD NOV PY 1999 VL 24 IS 11 BP 1077 EP 1082 DI 10.1016/S0360-3199(98)00145-1 PG 6 WC Chemistry, Physical; Electrochemistry; Energy & Fuels SC Chemistry; Electrochemistry; Energy & Fuels GA 246KA UT WOS:000083161900005 ER PT J AU Stokes, DW Olafsen, LJ Bewley, WW Vurgaftman, I Felix, CL Aifer, EH Meyer, JR Yang, MJ AF Stokes, DW Olafsen, LJ Bewley, WW Vurgaftman, I Felix, CL Aifer, EH Meyer, JR Yang, MJ TI Type-II quantum-well "W" lasers emitting at lambda=5.4-7.3 mu m SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID INTERBAND CASCADE; PERFORMANCE AB A series of optically pumped type-II quantum-well "W" lasers with wavelengths ranging from 5.4 to 7.3 mu m operated at temperatures up to at least 220 K for pulsed operation. The peak output power at 80 K was 1.1 W/facet for a device emitting at lambda=7.0 mu m. Internal losses were characterized for the temperature range between 40 and 190 K. Auger coefficients determined from an analysis of the threshold pump intensities were found to be suppressed by up to an order of magnitude compared to type-I III-V semiconductors with the same energy gaps. (C) 1999 American Institute of Physics. [S0021-8979(99)05121-X]. C1 USN, Res Lab, Washington, DC 20375 USA. RP Stokes, DW (reprint author), USN, Res Lab, Code 5613, Washington, DC 20375 USA. RI Olafsen, Linda/G-4996-2013 NR 20 TC 26 Z9 26 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD NOV 1 PY 1999 VL 86 IS 9 BP 4729 EP 4733 DI 10.1063/1.371436 PG 5 WC Physics, Applied SC Physics GA 246XA UT WOS:000083189100002 ER PT J AU Vurgaftman, I Meyer, JR Ram-Mohan, LR AF Vurgaftman, I Meyer, JR Ram-Mohan, LR TI High-speed spin-polarized intersubband lasers SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MODULATION BANDWIDTH; CASCADE LASER; QUANTUM-WELLS; SUPERLATTICES; DEVICES; RESONANCE AB Spin-polarized intersubband lasers based on optically pumped type-II antimonide quantum wells in a magnetic field are proposed. Complete discretization of the electron energy spectrum is predicted to extend the electron lifetime considerably. Continuous-wave room-temperature operation is projected for both interband and intersubband pumping configurations lasing at lambda=16-24 mu m. Furthermore, the parasitic capacitances associated with electrical injection are eliminated, and the large differential gain and fast intrinsic time scale should give modulation bandwidths in excess of 100 GHz. (C) 1999 American Institute of Physics. [S0021- 8979(99)07021-8]. C1 USN, Res Lab, Washington, DC 20375 USA. Worcester Polytech Inst, Worcester, MA 01609 USA. RP Vurgaftman, I (reprint author), USN, Res Lab, Code 5613, Washington, DC 20375 USA. RI Ram-Mohan, Ramdas/C-5167-2012 NR 27 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD NOV 1 PY 1999 VL 86 IS 9 BP 4734 EP 4739 DI 10.1063/1.371437 PG 6 WC Physics, Applied SC Physics GA 246XA UT WOS:000083189100003 ER PT J AU Buot, FA Krowne, CM AF Buot, FA Krowne, CM TI Double-barrier THz source based on electrical excitation of electrons and holes SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID RESONANT-TUNNELING STRUCTURES; CURRENT BISTABILITY; QUANTUM TRANSPORT; DEVICES; OSCILLATIONS; SEMICONDUCTORS; SIMULATION; HYSTERESIS; SYSTEMS AB A detailed dynamical analysis of an all solid-state THz source is given. This is based on the polarization-induced autonomous oscillation in resonant tunneling heterostructure with staggered band-gap alignment. The physical model consists of the following processes: (a) Generation by Zener tunneling of holes trapped in the barrier and electrons drifting in the depletion layer of the drain, whose rate decreases with the polarization between the barrier and quantum well. (b) Stimulated generation of barrier-well polarization. (c) Nonradiative decay of barrier-well polarization through barrier-hole recombination and quantum-well electron discharge. It is shown that a limit cycle oscillation of the barrier-well polarization and trapped-hole charge in the barrier can occur which induce THz oscillations in the resonant tunneling current across the device. The time-averaged results agree with the measured current-voltage characteristic of AlGaSb/InAs/AlGaSb staggered band-gap double-barrier structure. In particular, the measured smaller current offset at forward bias compared to that of reverse bias in the current-voltage hysteresis loop is predicted by our physical model and limit cycle analysis. Thus, we have experimental evidence indicating the correctness of our approach and the promising potential of this device as a novel all solid-state THz source. (C) 1999 American Institute of Physics. [S0021-8979(99)07221-7]. C1 USN, Res Lab, Washington, DC 20375 USA. RP Buot, FA (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 24 TC 7 Z9 7 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD NOV 1 PY 1999 VL 86 IS 9 BP 5215 EP 5231 DI 10.1063/1.371503 PG 17 WC Physics, Applied SC Physics GA 246XA UT WOS:000083189100074 ER PT J AU Levine, ER Lueck, RG AF Levine, ER Lueck, RG TI Turbulence measurement from an autonomous underwater vehicle SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article; Proceedings Paper CT Workshop on Microstructure Sensors CY OCT 23-25, 1996 CL MT HOOD, OREGON ID HEAT-FLUX; MICROSTRUCTURE MEASUREMENTS; DISSIPATION MEASUREMENTS; STRATIFIED FLUID; SEA-SURFACE; SUBMARINE; THERMOCLINE; TEMPERATURE; INTERFACE; DECAY AB Horizontal profiles of the microstructure of velocity and temperature were obtained with a large autonomous underwater vehicle (AUV) using two piezoelectric shear probes, an FF07 thermistor, and three orthogonal accelerometers mounted on a sting at the forward end of the vehicle. A winter field trial in Narragansett Bay provided a run in the midwater pycnocline at 8-m depth that contained a thermal front, an ascending profile to 3-m depth, and a run in the weakly stratified surface layer at this depth. Although shear spectra were strongly contaminated by narrowband vibrations produced by the motor and actuators, this contamination was highly coherent with the measured acceleration and was removed with standard signal processing techniques. The corrected spectra agreed well with the Nasmyth universal spectrum for wavenumbers up to 40 cpm. The estimated rate of dissipation of kinetic energy varied from 0.8 to 250 X 10(-8) W kg(-1) and was consistent with the rate of production of turbulence by surface wind forcing and bottom stress. C1 USN, Undersea Warfare Ctr Div, Dept Navy, Newport, RI 02841 USA. Univ Victoria, Ctr Earth & Ocean Res, Victoria, BC V8W 2Y2, Canada. RP Levine, ER (reprint author), USN, Undersea Warfare Ctr Div, Dept Navy, 1178 Howell St, Newport, RI 02841 USA. NR 38 TC 39 Z9 40 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD NOV PY 1999 VL 16 IS 11 BP 1533 EP 1544 DI 10.1175/1520-0426(1999)016<1533:TMFAAU>2.0.CO;2 PN 1 PG 12 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 258VG UT WOS:000083859400009 ER PT J AU Hwang, PA AF Hwang, PA TI Microstructure of ocean surface roughness: A study of spatial measurement and laboratory investigation of modulation analysis SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article; Proceedings Paper CT Workshop on Microstructure Sensors CY OCT 23-25, 1996 CL MT HOOD, OREGON ID WAVE-NUMBER SPECTRA; LASER SLOPE GAUGE; SHORT WATER-WAVES; WIND-WAVES; RADAR AB This paper describes a technique to measure the spatial structure of short capillary-gravity waves on the water surface. The method is based on optical refraction of a single laser beam crossing the air-water interface to derive the surface slope information. By quickly scanning the laser beam, the spatial and temporal evolution of the surface undulation can be studied in great detail. The spatial measurement of the surface fluctuation also allows direct computation of the wavenumber spectra in the capillary-gravity wave regime. This approach avoids the difficulty of resolving the Doppler frequency shift encountered in the processing of high-frequency spectra derived from a single-point sensor. The modulation of short waves by the orbital velocity of surface long waves is analyzed from the distribution of the wavenumber spectra of short waves along the phase of long waves. Key parameters determining the modulation magnitude are identified to be the slope of wavenumber spectra in the neighborhood of the modulated wave component, the ratio of the group and phase velocities of the modulated wave component, the dimensionless relaxation parameter, and the resonance parameter. Quantitative results on these parameters are obtained from the experimental data. C1 USN, Res Lab, Div Oceanog, Stennis Space Ctr, MS 39529 USA. RP Hwang, PA (reprint author), USN, Res Lab, Div Oceanog, Code 7332, Stennis Space Ctr, MS 39529 USA. NR 31 TC 7 Z9 7 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD NOV PY 1999 VL 16 IS 11 BP 1619 EP 1629 DI 10.1175/1520-0426(1999)016<1619:MOOSRA>2.0.CO;2 PN 1 PG 11 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 258VG UT WOS:000083859400015 ER PT J AU Wesson, J Saunders, KD Bricker, B Perkins, H AF Wesson, J Saunders, KD Bricker, B Perkins, H TI A miniature fluorometer for oceanographic applications SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article; Proceedings Paper CT Workshop on Microstructure Sensors CY OCT 23-25, 1996 CL MT HOOD, OREGON ID FLUORESCENCE; CHLOROPHYLL AB A fluorometer intended for ocean measurements of dye patches achieves small size, law power consumption, and high sensitivity. Its performance is reported using fluorescein sodium as the fluorescent agent, although the principle is applicable to any dye that fluoresces at a wavelength sufficiently different from the excitation wavelength. An implementation in the Naval Research Laboratory's advanced microstructure profiler is described in detail, and results from static calibration and dynamic response tests are given. C1 USN, Res Lab, Stennis Space Ctr, MS 39529 USA. Planning Syst Inc, Slidell, LA USA. RP Perkins, H (reprint author), USN, Res Lab, Code 7332, Stennis Space Ctr, MS 39529 USA. NR 4 TC 3 Z9 3 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD NOV PY 1999 VL 16 IS 11 BP 1630 EP 1634 DI 10.1175/1520-0426(1999)016<1630:AMFFOA>2.0.CO;2 PN 1 PG 5 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 258VG UT WOS:000083859400016 ER PT J AU Ready, WJ Turbini, LJ Nickel, R Fischer, J AF Ready, WJ Turbini, LJ Nickel, R Fischer, J TI A novel test circuit for automatically detecting electrochemical migration and conductive anodic filament formation SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT 128th TMS Annual Meeting CY FEB 28-MAR 04, 1999 CL SAN DIEGO, CALIFORNIA SP Min, Met & Mat Soc DE conductive anodic filament formation (CAF) electrochemical migration (ECM); surface insulation resistance (SIR); reliability; dendrite AB The rapid growth of the global electronics manufacture environment has brought about the onset of a variety of new, untested materials and processing chemicals. The interactions between substrates and processing chemicals that can occur during manufacture, storage and use must be assessed in order to determine long-term reliability. Surface insulation resistance (SIR) testing is a standard industry technique used to assess the interactions between processing chemicals (e.g., soldering fluxes) and substrates. SIR test method conditions vary in terms of the temperature and the humidity used to accelerate the normal failure modes. Typically, a 45 to 50 volt bias is applied to an interdigitated comb pattern, and periodic SIR measurements are made using a 100 volt test. Pass/fail criteria based solely on SIR electrical values, (e.g., 100 M Ohm) however are inadequate. Often the electrical measurement fails to reveal the presence of surface dendrites due to contaminants related to processing chemicals. This failure occurs because the dendrite burns out between electrical readings when the circuit continues to be biased at 50 volts. A new "linear test circuit" has been developed to overcome this deficiency. The circuit uses an operational amplifier to detect the formation of a surface dendrite between electrodes on the comb pattern. When the dendrite shorts the circuit, voltage to the comb pattern is removed. Thus, the presence of the dendrite is captured electrically, and the dendrite is preserved for further analysis. This paper will present the circuit used and data showing its' effectiveness at detecting both surface dendrites and subsurface conductive anodic filament formation. C1 Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30322 USA. USN, Air Warfare Ctr, China Lake, CA USA. RP Ready, WJ (reprint author), Georgia Inst Technol, Sch Mat Sci & Engn, 778 Atlantic Dr, Atlanta, GA 30322 USA. NR 13 TC 12 Z9 12 U1 1 U2 5 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD NOV PY 1999 VL 28 IS 11 BP 1158 EP 1163 DI 10.1007/s11664-999-0151-6 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 255DH UT WOS:000083653900004 ER PT J AU Jensen, SA Walker, TL Hutter, JW Nicoll, BK AF Jensen, SA Walker, TL Hutter, JW Nicoll, BK TI Comparison of the cleaning efficacy of passive sonic activation and passive ultrasonic activation after hand instrumentation in molar root canals SO JOURNAL OF ENDODONTICS LA English DT Article ID STEP-BACK; DEBRIDEMENT; INVITRO AB The purpose of this study was to compare the cleaning-efficacy of passive ultrasonic activation with that of passive sonic activation after hand instrumentation. Sixty curved molar canals were hand-instrumented to size 35 and divided into three groups. Group 1 received no further treatment. Group received 3 min of passive sonic activation,Group 3 received 3 min of passive ultrasonic activation. The roots were split and photomicrographs (x20) were made of the apical 6 mm of canal. transparent grid was placed over projected images, and the total number of squares covering the apical 6 mm of canal space and the number: of squares containing debris were counted,:a debris score was calculated for each specimen by dividing the number of squares with debris by the total number of squares. The mean debris scores were 31.6% for hand instrumentation only, 15.1% for the sonic group, and 16.7% for the ultrasonic group, The debris scores for the sonic and ultrasonic activation groups were significantly lower than that for the hand instrumentation only group (p < 0.01); however, there was no significant difference between the sonic and ultrasonic activation groups. Passive sonics after hand instrumentation produces a cleaner canal than hand instrumentation alone and is comparable with that of passive ultrasonics. C1 USN, Sch Dent, Endodont Dept, Bethesda, MD 20889 USA. Great Lakes Naval Training Ctr, Great Lakes, IL USA. Boston Univ, Goldman Sch Dent Med, Adv Specialty Educ Program Endodont, Boston, MA USA. RP Jensen, SA (reprint author), USN, Sch Dent, Endodont Dept, 8901 Wisconsin Ave, Bethesda, MD 20889 USA. NR 19 TC 46 Z9 53 U1 1 U2 4 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0099-2399 J9 J ENDODONT JI J. Endod. PD NOV PY 1999 VL 25 IS 11 BP 735 EP 738 DI 10.1016/S0099-2399(99)80120-4 PG 4 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 252VV UT WOS:000083523700009 PM 10726540 ER PT J AU Sheeley, NR Walters, JH Wang, YM Howard, RA AF Sheeley, NR Walters, JH Wang, YM Howard, RA TI Continuous tracking of coronal outflows: Two kinds of coronal mass ejections SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY SHOCKS; LASCO OBSERVATIONS; JANUARY 6-11; II BURSTS; EARTH; ASSOCIATIONS; TRANSIENTS; SPEEDS; EVENTS; ORIGIN AB We have developed a new technique for tracking white-light coronal intensity features and have used this technique to construct continuous height/time maps of coronal ejecta as they move outward through the 2-30 R(s) field of view of the Large-Angle Spectrometric Coronagraph (LASCO) on the Solar and Heliospheric Observatory (SOHO) spacecraft. Displayed as gray-scale images, these height/time maps provide continuous histories of the motions along selected radial paths in the corona and reveal a variety of accelerating and decelerating features, including two principal types of coronal mass ejections (CMEs): (1) Gradual CMEs, apparently formed when prominences and their cavities rise up from below coronal streamers: When seen broadside, these events acquire balloon-like shapes containing central cares, and their leading edges accelerate gradually to speeds in the range 400-600 km/s before leaving the 2-30 R(s) field of view. The cores fall behind with speeds in the range 300-400 km/s. Seen along the line of sight, these events appear as smooth halos around the occulting disk, consistent with head-on views of optically thin bubbles stretched out from the Sun. At the relatively larger radial distances seen from this "head-on" perspective, gradually accelerating CMEs fade out sooner and seem to reach a constant speed more quickly than when seen broadside. Some suitably directed gradual CMEs are associated with interplanetary shocks and geomagnetic storms. (2) Impulsive CMEs, often associated with flares and Moreton waves on the visible disk: When seen broadside, these CMEs move uniformly across the 2-30 R(s) held of view with speeds typically in excess of 750 km/s. At the relatively larger radial distances seen from a head-on perspective, impulsive events tend to have a more ragged structure than the gradual CMEs and show clear evidence of deceleration, sometimes reducing their speeds from 1000 to 500 km/s in 1 hour. Such decelerations are too large to represent ballistic motions in the Sun's gravitational field but might be caused by shock waves, sweeping up material far from the Sun. C1 USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. RP Sheeley, NR (reprint author), USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. EM sheeley@spruce.nrl.navy.mil NR 56 TC 345 Z9 350 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD NOV 1 PY 1999 VL 104 IS A11 BP 24739 EP 24767 DI 10.1029/1999JA900308 PG 29 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 250XC UT WOS:000083414700014 ER PT J AU Saur, J Neubauer, FM Strobel, DF Summers, ME AF Saur, J Neubauer, FM Strobel, DF Summers, ME TI Three-dimensional plasma simulation of Io's interaction with the Io plasma torus: Asymmetric plasma flow SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID WAVE CURRENT SYSTEM; GALILEO MAGNETOMETER; JOVIAN MAGNETOSPHERE; MHD SIMULATION; CROSS-SECTIONS; PAST IO; ATMOSPHERE; JUPITER; SO2; VOYAGER-1 AB A three-dimensional, stationary, two-fluid plasma model for electrons and one ion species was developed to understand the local interaction of Io's atmosphere with the Io plasma torus and the formation of Io's ionosphere. Our model calculates, self-consistently, the plasma density, the velocity and the temperatures of the ions and electrons, and the electric field for a given neutral atmosphere and imposed Io plasma torus conditions but assumes for the magnetic field the constant homogeneous Jovian field. With only photoionization in a pure SO2 atmosphere it is impossible to correctly model the plasma measurements by the Galileo spacecraft. With collisional ionization and photoionization the observations can be successfully modeled when the neutral atmospheric column density is N-col = 6 x 10(20) m(-2) and the atmospheric scale height is H = 100 km. The energy reservoir of the Io plasma torus provides via electron heat conduction the necessary thermal energy for the maintenance of the collisional ionization process and thus the formation of Io's ionosphere. Anisotropic conductivity is shown numerically as well as analytically to be essential to understand the convection patterns and current systems across Io. The electric field is very greatly reduced, because the ionospheric conductances far exceed the Alfven conductance Sigma(A), and also strongly twisted owing to the Hall effect. We find that the electric field is twisted by an analytic angle tan Theta(twist) = Sigma(2)/(Sigma(1) + 2 Sigma(A)) from the anti-Jupiter direction toward the direction of corotation for constant values of the Pedersen and Hall conductances Sigma(1) and Sigma(2) within a circle encompassing Io's ionosphere. Because the electron velocity is approximately equal to the E x B drift velocity, the electron flow trajectories are twisted by the same angle toward Jupiter, with E and B the electric and magnetic fields, respectively. Since Sigma(1) similar to Sigma(2), the electron how is strongly asymmetric during convection across Io, and the magnitude of this effect is directly due to the Hall conductivity. In contrast, the ions are diverted slightly away from Jupiter when passing Io. Large electric currents flow in Io's ionosphere owing to these substantially different flow patterns for electrons and ions, and our calculations predict that a total electric current of 5 million A was carried in each Alfven wing during the Galileo flyby. We also find a total Joule heating rate dissipated in Io's ionosphere of P = 4.2 x 10(11) W. C1 Univ Cologne, Inst Geophys & Meteorol, D-50923 Cologne, Germany. Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA. USN, Res Lab, EO Hulburt Ctr Space Res, Div Space Sci, Washington, DC 20375 USA. RP Saur, J (reprint author), Univ Cologne, Inst Geophys & Meteorol, Albertus Magnus Pl, D-50923 Cologne, Germany. NR 63 TC 83 Z9 83 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD NOV 1 PY 1999 VL 104 IS A11 BP 25105 EP 25126 DI 10.1029/1999JA900304 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 250XC UT WOS:000083414700041 ER PT J AU Walker, DN Fernsler, RF Amatucci, WE Duncan, D Keskinen, MJ AF Walker, DN Fernsler, RF Amatucci, WE Duncan, D Keskinen, MJ TI Magnetic field and electrode geometry effects on vehicle discharging by neutral gas release SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID IONOSPHERE; VOLTAGE; PAYLOAD; PLASMA AB In earlier work we quantified the effect of the Mach number of neutral gas release and neutral gas species on minimum breakdown potential in ionospheric-like plasmas. The theoretical basis of this work incorporates the Townsend breakdown criterion to the ambient plasma to characterize the discharge. The results of a model based on this theory provide good agreement with the results of experiments in a variety of gases performed in the large Space Physics Simulation Chamber (SPSC) at the Naval Research Laboratory. The experiments in the SPSC used a 10 cm x 10 cm aluminum cylinder which contained a neutral gas release valve and variable Mach number nozzles. The cylinder was charged to high negative potential before neutral gas was released, causing breakdown to the ambient plasma for sufficient valve plenum pressure. We have recently incorporated both electrode geometry design changes and an external magnetic field produced by a permanent magnet in an effort to lower the breakdown voltage required. We have preliminary results which suggest that both an extended smaller cylinder and an external magnetic field can significantly lower the potentials required for breakdown. We are in the process of verifying these results by adding an adjustable constant magnetic field both perpendicular and parallel to the gas release direction. C1 USN, Res Lab, Div Plasma Phys, Charged Particle Phys Branch, Washington, DC 20375 USA. Sachs Freeman Associates Inc, Landover, MD 20785 USA. RP Walker, DN (reprint author), USN, Res Lab, Div Plasma Phys, Charged Particle Phys Branch, Code 6755,4555 Overlook Dr SW, Washington, DC 20375 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD NOV 1 PY 1999 VL 104 IS A11 BP 25159 EP 25165 DI 10.1029/1999JA900328 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 250XC UT WOS:000083414700046 ER PT J AU Tycko, R Berger, AE AF Tycko, R Berger, AE TI Dual processing of two-dimensional exchange data in magic angle spinning NMR of solids SO JOURNAL OF MAGNETIC RESONANCE LA English DT Article DE solid state NMR; molecular structure; molecular dynamics; two-dimensional spectroscopy; magic angle spinning ID STATE NMR; ROTATING SOLIDS; SPECTROSCOPY; PEPTIDE AB We discuss procedures for processing data in rotor-synchronized two-dimensional magic angle spinning (2D MAS) NMR exchange measurements for both structural and dynamical studies. We show, both mathematically and experimentally, that there are two distinct data processing procedures that lead to 2D MAS exchange spectra with purely absorptive crosspeaks. One procedure is that described previously by Hagemeyer, Schmidt-Rohr, and Spiess (HSS), The other procedure is related, but different, and leads to crosspeak intensities given by the formulae of Herzfeld, Roberts, acid Griffin (HRG), In 2D MAS exchange experiments on doubly C-13-labeled L-alanylglycylglycine, we demonstrate that the HSS and HRG crosspeak intensities can be extracted separately from the same data set and contain independent information. Processing and analysis of 2D MAS exchange data with both the HSS and the HRG procedures may enhance utilization of the information content of 2D MAS exchange measurements. C1 NIDDKD, Chem Phys Lab, NIH, Bethesda, MD 20892 USA. USN, Ctr Surface Warfare, Dahlgren, VA 22448 USA. RP Tycko, R (reprint author), NIDDKD, Chem Phys Lab, NIH, Bldg 5,Room 112, Bethesda, MD 20892 USA. NR 16 TC 17 Z9 17 U1 0 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1090-7807 J9 J MAGN RESON JI J. Magn. Reson. PD NOV PY 1999 VL 141 IS 1 BP 141 EP 147 DI 10.1006/jmre.1999.1877 PG 7 WC Biochemical Research Methods; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Biochemistry & Molecular Biology; Physics; Spectroscopy GA 254XH UT WOS:000083639100015 PM 10527751 ER PT J AU Tan, Q Xu, Z Viehland, D AF Tan, Q Xu, Z Viehland, D TI Effect of substituents with different valences on antiferroelectric stability of antiferroelectric lead zirconate ceramics SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID TITANATE; INCOMMENSURATION AB The effect of lower valent substituents on the stability of the antiferroelectric phase of lead zirconate was studied by dielectric spectroscopy, Sawyer-Tower polarization methods, and electron diffraction techniques. The stability of an intermediate ferroelectric phase region was found to be enhanced with increasing lower valent substitution concentration. The influences of substituents of different ionic size and valence on the stabilization of the intermediate ferroelectric phase were differentiated. Ln general, lower valent substituents, such as K+ and Fe3+ affected antiferroelectric phase stability more significantly than higher valent ones. C1 Johnson Matthey Elect, Spokane, WA 99216 USA. Univ Illinois, Dept Mat Sci & Engn, Urbana, IL 61801 USA. USN, Undersea Warfare Ctr, Newport, RI 02841 USA. RP Tan, Q (reprint author), Johnson Matthey Elect, 15128 E Euclid Ave, Spokane, WA 99216 USA. OI XU, Zhengkui/0000-0002-7465-8513 NR 22 TC 12 Z9 12 U1 4 U2 7 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD NOV PY 1999 VL 14 IS 11 BP 4251 EP 4258 DI 10.1557/JMR.1999.0576 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA 257FC UT WOS:000083771000021 ER PT J AU Gad, AM Farid, HA Ramzy, RRM Riad, MB Presley, SM Cope, SE Hassan, MM Hassan, AN AF Gad, AM Farid, HA Ramzy, RRM Riad, MB Presley, SM Cope, SE Hassan, MM Hassan, AN TI Host feeding of mosquitoes (Diptera : Culicidae) associated with the recurrence of Rift Valley fever in Egypt SO JOURNAL OF MEDICAL ENTOMOLOGY LA English DT Article DE mosquito; blood meal; Rift Valley fever; Egypt ID CULEX-PIPIENS; VIRUS; PATTERNS; GOVERNORATE; TRANSMISSION; KENYA AB In 1993, Rift Valley fever (RVF) virus reappeared in Egypt. We determined the prevalence and feeding patterns of mosquitoes in 5 villages where the virus was active. Of 10 species recovered, Aedes caspius (Pallas), Culex pipiens L., Cx. antennatus (Becker), and Cx, perexiguus Theobald constituted 99% of >35,000 mosquitoes captured in dry ice-baited CDC light traps. Ae. caspius was most prevalent, except at Nag' El Hagar where it was replaced by Cx. perexiguus. Cx. pipiens ranked 2nd, except at Nag' El Ghuneimiya, where it was replaced by Cx. antennatus. Most blood meals analyzed by an enzyme-linked immunosorbent assay reacted to greater than or equal to 1 antiserum. Cx. pipiens was mainly anthropophagic, and therefore may have been the main vector of RVF virus among humans. Ae. caspius feeds were chiefly from humans, bovines, and equines. Cx. antennatus and Cx. perexiguus fed generally on bovines. Mixed blood meals from humans and RVF virus susceptible animals were identified in the predominant mosquitoes. Prevalence and host selection, as well as predicted probability for a blood meal being interrupted, indicated that AE. caspius may have served as a bridge vector between humans and bovines in 4 of the villages. Cx. perexiguus may have played this role at Nag' El Hagar. Because potential vectors are abundant, susceptible domestic animals are associated closely with humans, and surveillance of imported livestock is not systematic, we conclude that RVF virus sporadically will recur in Egypt. C1 Marine Corps Combat Dev Command, Training Programs Br C 464, Quantico, VA 22134 USA. Ain Shams Univ, Res & Training Ctr Vectors Dis, Cairo, Egypt. USN, Med Res Unit 3, Cairo, Egypt. RP Gad, AM (reprint author), Marine Corps Combat Dev Command, Training Programs Br C 464, 3300 Russell Rd, Quantico, VA 22134 USA. NR 28 TC 16 Z9 20 U1 0 U2 1 PU ENTOMOL SOC AMER PI LANHAM PA 9301 ANNAPOLIS RD, LANHAM, MD 20706 USA SN 0022-2585 J9 J MED ENTOMOL JI J. Med. Entomol. PD NOV PY 1999 VL 36 IS 6 BP 709 EP 714 PG 6 WC Entomology; Veterinary Sciences SC Entomology; Veterinary Sciences GA 256HE UT WOS:000083719200011 PM 10593070 ER PT J AU Griscom, DL Merzbacher, CI Weeks, RA Zuhr, RA AF Griscom, DL Merzbacher, CI Weeks, RA Zuhr, RA TI Electron spin resonance studies of defect centers induced in a high-level nuclear waste glass simulant by gamma-irradiation and ion-implantation SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID PARAMAGNETIC DEFECTS; HIGH-PURITY; SPECTROSCOPY; A-SIO2 AB Samples of an iron-free soda-lime boro-aluminosilicate high-level nuclear waste (HLW) glass simulant were implantated with 160-keV protons or He+ ions or irradiated by Co-60 gamma-rays. Electron spin resonance (ESR) spectra were recorded before and after implantation or irradiation and after postirradiation isochronal anneals to 550 degrees C. The most numerous paramagnetic states in the unannealed samples following gamma-irradiation were boron-oxygen hole centers and Ti3+ trapped-electron centers, The most numerous paramagnetic states in the as-implanted samples were peroxy radicals (PORs), Annealing of the gamma-irradiated samples at temperatures >300 degrees C caused recombination of the trapped electrons and holes, revealing an underlying POR spectrum which annealed in stages at similar to 400 degrees C and 550 degrees C, similar to the annealing of PORs in the He+-implanted sample. For equivalent depositions of ionizing energy, the initial FOR concentration in the He+-implanted sample was similar to 100 times that in the gamma-irradiated sample and at least 10 times larger than the (unmeasurable) number of PORs in the proton-implanted sample. Since TRIM calculations indicate that 160-keV protons deliver twice the ionizing dose of He+ ions of the same energy but displace only 1/10 as many atoms, it is evident that the PORs induced by He+ implantation result from displacements of oxygens in elastic collision cascades. The absence of trapped electrons and holes in the implanted samples is ascribed to annealing during irradiation associated with the fraction of the implantation energy deposited as heat. One of the fundamental defects to be expected in HLW glasses containing alpha-particle emitters is therefore the FOR. Several distinct families of radiation-induced PORs are unambiguously identified in our samples by computer line-shape simulations constrained by the Kanzig-Cohen g-value formulae. Possible reasons for the non-observation of PORs in similarly-irradiated glasses containing several wt% Fe2O3 are proposed. (C) 1999 Elsevier Science B.V. All rights reserved. C1 USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Griscom, DL (reprint author), USN, Res Lab, Div Opt Sci, Code 5675,4555 Overlook Ave SW, Washington, DC 20375 USA. NR 51 TC 18 Z9 18 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD NOV PY 1999 VL 258 IS 1-3 BP 34 EP 47 DI 10.1016/S0022-3093(99)00557-8 PG 14 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 251ZA UT WOS:000083475200005 ER PT J AU Chao, WH Askew, EW Roberts, DE Wood, SM Perkins, JB AF Chao, WH Askew, EW Roberts, DE Wood, SM Perkins, JB TI Oxidative stress in humans during work at moderate altitude SO JOURNAL OF NUTRITION LA English DT Article DE oxidative stress; indicators of oxidative stress; antioxidants; breath pentane; exercise; altitude; cold; military rations; humans ID FREE-RADICALS; PHYSICAL PERFORMANCE; EXERCISE; DAMAGE; ANTIOXIDANTS; ASSAY AB Increased oxidative stress has been associated with work at high altitude; however, it is not known whether oxidative stress is a significant problem at moderate altitudes. The oxidative stress indicators, breath pentane (BP), 8-hydroxydeoxyguanosine (8-OHdG), oxygen radical absorption capacity (ORAC), 4-hydroxynonenal (4-HNE), malondialdehyde (MDA), and lipid peroxides (LPO) were measured in breath, blood and urine samples of U.S. Marines engaged in moderate altitude (similar to 3000 m) cold weather field training. The test subjects were divided into a placebo and four antioxidant supplement groups (n = 15/group) and received the following supplements for 28 d: 1) vitamin E, 440 alpha-tocopherol equivalents (alpha-TE); 2) vitamin A, 2000 retinol equivalents (RE) of beta-carotene; 3) vitamin C, 500 mg ascorbic acid; 4) a mixture of 440 alpha-TE, 2000 RE of beta-carotene, 500 mg ascorbic acid, 100 mu g selenium and 30 mg zinc daily. Strenuous work (similar to 23 MJ/d) in cold weather at moderate altitude was accompanied by increases in several indicators of oxidative stress that were not effectively controlled by conventional antioxidant supplements. The group receiving the antioxidant mixture exhibited lower BP (P < 0.05) compared with those receiving single antioxidant supplements; however, not all markers of oxidative stress responded like BP. Because these markers did not respond in the same manner, it is important to include markers from more than one source to assess the effect of supplemental dietary antioxidants. C1 Univ Utah, Div Foods & Nutr, Salt Lake City, UT 84112 USA. USN, Hlth Res Ctr, Dept Human Performance, San Diego, CA 92152 USA. Abbott Labs, Ross Prod Div, Columbus, OH 43219 USA. DataChem Labs Inc, Salt Lake City, UT 84123 USA. RP Askew, EW (reprint author), Univ Utah, Div Foods & Nutr, Salt Lake City, UT 84112 USA. NR 28 TC 54 Z9 57 U1 1 U2 5 PU AMER INST NUTRITION PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0022-3166 J9 J NUTR JI J. Nutr. PD NOV PY 1999 VL 129 IS 11 BP 2009 EP 2012 PG 4 WC Nutrition & Dietetics SC Nutrition & Dietetics GA 251YA UT WOS:000083472900013 PM 10539777 ER PT J AU Ernst, GP Kawaguchi, J Saliba, E AF Ernst, GP Kawaguchi, J Saliba, E TI Effect of patellar taping on knee kinetics of patients with patellofemoral pain syndrome SO JOURNAL OF ORTHOPAEDIC & SPORTS PHYSICAL THERAPY LA English DT Article DE lower-extremity kinetics; patellar taping; patellofemoral pain ID COMPRESSION SYNDROME; VASTUS LATERALIS; MANAGEMENT; DISORDERS; EXTENSION; POSITION; EXERCISE; TRACKING; HEIGHT; BRACE AB Study Design: Single-group repeated measures examining patients with patellofemoral pain syndrome. Objective: To examine the effect of McConnell patellar taping on single-leg vertical jump height and knee extensor moment and power during a Vertical jump and lateral step-up. Background: Patellar taping is used by clinicians in an attempt to maximize knee extensor function during sporting activities and rehabilitation of patients with patellofemoral pain syndrome. No studies have examined the effect of patellar taping on Vertical jump height and knee extensor moment and power during a maximal vertical jump or lateral step-up. Methods and Measures: Fourteen women (24.4 +/- 5.8 years) with unilateral patellofemoral pain performed a single-leg Vertical jump and lateral step-up during 4 knee conditions: patellar tape, placebo tape, no tape, and the uninvolved knee. Maximal knee extensor moment, knee power, and vertical jump height were measured for each condition using a force platform and motion analysis system. Results: Analyses of variance and post hoc analyses revealed a main effect for knee condition. The patellar tape condition resulted in a greater knee extensor moment (1.57 +/- 0.32 N.m/kg) and power (3.47 +/- 0.67 W/kg) than did the no-tape (1.31 +/- 0.39 N.m/kg and 2.79 +/- 1.27 W/kg) and placebo tape (1.33 +/- 0.30 N.m/kg and 2.70 +/- 0.99 W/kg) conditions. Additional analyses showed that the vertical-jump height was significantly greater in the uninvolved lower extremity (25.69 +/- 2.66 cm) compared with the patellar tape (23.33 +/- 4.22 cm), placebo tape (23.08 +/- 4.20 cm), and no-tape (23.45 +/- 4.54 cm) conditions. The patellar tape condition did not show a different vertical jump height than the placebo or no-tape conditions. Conclusions: These results suggest that patellar taping compared with no tape may improve the knee extensor moment and power during weight-bearing activities such as the lateral step-up exercise and the Vertical jump. C1 USN, Med Serv Corp, Ft Sam Houston, TX USA. USA, Baylor Univ, Program Phys Therapy, Ft Sam Houston, TX USA. Univ Virginia, Charlottesville, VA USA. RP Ernst, GP (reprint author), 182 Artillery Post, Ft Sam Houston, TX 78234 USA. NR 37 TC 52 Z9 53 U1 0 U2 9 PU J O S P T, ALLIANCE GROUP COMMUNICATIONS PI LAWRENCE PA 810 EAST 10TH ST, PO BOX 1897, LAWRENCE, KS 66044-8897 USA SN 0190-6011 J9 J ORTHOP SPORT PHYS JI J. Orthop. Sports Phys. Ther. PD NOV PY 1999 VL 29 IS 11 BP 661 EP 667 PG 7 WC Orthopedics; Rehabilitation; Sport Sciences SC Orthopedics; Rehabilitation; Sport Sciences GA 254GP UT WOS:000083603800006 PM 10575643 ER PT J AU Maheswaran, M Ali, S Siegel, HJ Hensgen, D Freund, RF AF Maheswaran, M Ali, S Siegel, HJ Hensgen, D Freund, RF TI Dynamic mapping of a class of independent tasks onto heterogeneous computing systems SO JOURNAL OF PARALLEL AND DISTRIBUTED COMPUTING LA English DT Article DE batch mode mapping; dynamic mapping; mapping heuristics; mete-task mapping; immediate mode mapping AB Dynamic mapping (matching and scheduling) heuristics For a class of independent tasks using heterogeneous distributed computing systems are studied. Two types of mapping heuristics are considered, immediate mode and batch mode heuristics. Three new heuristics, one for batch mode and two for immediate mode, are introduced as part of this research. Simulation studies art: performed to compare these heuristics with some existing ones. In total five immediate mode heuristics and three batch mode heuristics are examined. The immediate mode dynamic heuristics consider, to varying degrees and in different ways: task affinity for different machines and machine ready times. The batch mode dynamic heuristics consider these Factors, as well as aging of tasks waiting to execute. The simulation results reveal that the choice of which dynamic mapping heuristic to use in a given heterogeneous environment depends on parameters such as (a) the structure of the heterogeneity among tasks and machines and (b) the arrival rate of the tasks. (C) 1999 Academic Press. C1 Univ Manitoba, Dept Comp Sci, Winnipeg, MB R3T 2N2, Canada. Purdue Univ, Sch Elect & Comp Engn, W Lafayette, IN 47907 USA. USN, Postgrad Sch, Dept Comp Sci, Monterey, CA 93940 USA. NOEMIX Inc, San Diego, CA 92101 USA. RP Maheswaran, M (reprint author), Univ Manitoba, Dept Comp Sci, Winnipeg, MB R3T 2N2, Canada. EM maheswar@cs.umanitoba.ca; alis@ecn.purdue.edu; hj@ecn.purdue.edu; hensgen@cs.nps.navy.mil; rffreund@home.com NR 27 TC 281 Z9 302 U1 3 U2 10 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0743-7315 J9 J PARALLEL DISTR COM JI J. Parallel Distrib. Comput. PD NOV PY 1999 VL 59 IS 2 BP 107 EP 131 DI 10.1006/jpdc.1999.1581 PG 25 WC Computer Science, Theory & Methods SC Computer Science GA 257GT UT WOS:000083774700002 ER PT J AU Brain, JH Paul, BF Assad, DA AF Brain, JH Paul, BF Assad, DA TI Periodontal plastic surgery in a dystrophic epidermolysis bullosa patient: Review and case report SO JOURNAL OF PERIODONTOLOGY LA English DT Article DE epidermolysis bullosa dystrophica; periodontal diseases/surgery; periodontal diseases/therapy ID ANESTHETIC MANAGEMENT AB Epidermolysis bullosa (EB) is a group of genetic disorders in which patients frequently present with fragile skin and mucosal surfaces that blister following minor trauma; 23 subtypes have been recognized, but their precise pathogenesis and etiology remain obscure, There is no treatment for EB, only palliative therapy. Oral bullae are the most common oral finding and affect all surfaces, Patients with EB present a unique challenge in terms of periodontal therapy. The following article reviews this disorder and describes the complications encountered when providing periodontal plastic surgery to a patient exhibiting this condition. A 36-year-old female with dystrophic EB presented for treatment of a 3 mm recession area with minimal attached gingiva on the facial of #24 and 25. Oral evaluation revealed multiple ulcers. The treatment consisted of a subepithelial connective tissue graft in conjunction with a coronally positioned flap and buccal frenectomy. Most of the epithelium associated with the surgical area and buccal vestibule sloughed. During the postoperative course, the frenum had regenerated at a more coronal level and was applying tension on the gingival tissues. It appeared that a connective tissue union had formed between the de-epithelialized surface of the facial flap and the buccal mucosa of the vestibule. A second frenectomy was performed, and a clear acrylic stent was fabricated to prevent the union of the connective tissue of the facial flap to the buccal mucosa. The stent prevented the fusion of both connective tissue layers and allowed time for epithelium migration. C1 USN, Sch Dent, Dept Periodont, Bethesda, MD 20814 USA. RP Brain, JH (reprint author), 20242 Waters Row Terr, Germantown, MD 20874 USA. NR 14 TC 11 Z9 12 U1 0 U2 1 PU AMER ACAD PERIODONTOLOGY PI CHICAGO PA 737 NORTH MICHIGAN AVENUE, SUITE 800, CHICAGO, IL 60611-2690 USA SN 0022-3492 J9 J PERIODONTOL JI J. Periodont. PD NOV PY 1999 VL 70 IS 11 BP 1392 EP 1396 DI 10.1902/jop.1999.70.11.1392 PG 5 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 259JB UT WOS:000083889800017 PM 10588504 ER PT J AU Chu, PC Edmons, NL Fan, CW AF Chu, PC Edmons, NL Fan, CW TI Dynamical mechanisms for the South China Sea seasonal circulation and thermohaline variabilities SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID MODEL; OCEAN AB The seasonal ocean circulation and the seasonal thermal structure in the South China Sea (SCS) were studied numerically using the Princeton Ocean Model (POM) with 20-km horizontal resolution and 23 sigma levels conforming to a realistic bottom topography. A 16-month control run was performed using climatological monthly mean wind stresses, restoring-type surface salt and heat, and observational oceanic inflow/outflow at the open boundaries. The seasonally averaged effects of isolated forcing terms are presented and analyzed from the following experiments: 1) nonlinear dynamic effects removed, 2) wind effects removed, and 3) open boundary inflow/outflow set to zero. This procedure allowed analysis of the contribution of individual parameters to the general hydrology and specific features of the SCS: for example, coastal jets, mesoscale topographic gyres, and countercurrents. The results show that the POM model has the capability of simulating seasonal variations of the SCS circulation and thermohaline structure. The simulated SCS surface circulation is generally anticyclonic (cyclonic) during the summer (winter) monsoon period with a strong western boundary current, a mean maximum speed of 0.5 m s(-1) (0.95 m s(-1)), a mean volume transport of 5.5 Sv (10.6 Sv) (Sv = 10(6) m(3) s(-1)), and extending to a depth of around 200 m (500 m). During summer, the western boundary current splits and partially leaves the coast; the bifurcation point is at 14 degrees N in May and shifts south to 10 degrees N in July. A mesoscale eddy on the Sunda shelf (Natuna Island eddy) was also simulated. This eddy is cyclonic (anticyclonic) with maximum swirl velocity of 0.6 m s(-1) at the peak of the winter (summer) monsoon. The simulated thermohaline structure for summer and winter are nearly horizontal from east to west except at the coastal regions. Coastal upwelling and downwelling are also simulated: localized lifting (descending) of the isotherms and isohalines during summer (winter) at the west boundary. The simulation is reasonable when compared to the observations. Sensitivity experiments were designed to investigate the driving mechanisms. Nonlinearity is shown to be important to the transport of baroclinic eddy features, but otherwise insignificant. Transport from lateral boundaries is of considerable importance to summer circulation and thermal structure, with lesser effect on winter monsoon hydrology. In general, seasonal circulation patterns and upwelling phenomena are determined and forced by the wind, while the lateral boundary forcing plays a secondary role in determining the magnitude of the circulation velocities. C1 USN, Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA. RP Chu, PC (reprint author), USN, Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA. NR 23 TC 103 Z9 112 U1 1 U2 20 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD NOV PY 1999 VL 29 IS 11 BP 2971 EP 2989 DI 10.1175/1520-0485(1999)029<2971:DMFTSC>2.0.CO;2 PG 19 WC Oceanography SC Oceanography GA 258ZA UT WOS:000083868500014 ER PT J AU Froimowitz, M Gordon, DJ Moussa, A Haidar, RM George, C AF Froimowitz, M Gordon, DJ Moussa, A Haidar, RM George, C TI Stochastic conformational search of brefeldin A and experimental structures SO JOURNAL OF PHYSICAL ORGANIC CHEMISTRY LA English DT Article DE ab initio; brefeldin A; breflate; crystallography; conformation; energy minimization; MM3-92; stochastic search ID CROWN-ETHERS AB The macrocyclic lactone brefeldin A was used as a test molecule for the MM3-92 Stochastic Search conformational searching algorithm. A number of low energy conformers were found and I:! of these were also subjected to ab initio energy minimization using the 3-21G* and 6-31G* basis sets with the Spartan 5.0 package. There was reasonable agreement between the MM3-92 and ab initio results in that almost all of the conformers found bu the former were also stable low energy conformers with the latter. The structure of breflate, an ester analog of brefeldin. was also determined by X-ray crystallography. There was very good agreement between experimental structures for the compound and the lowest energy conformer determined by the ab initio methods. This was also among the lowest conformers found by MM3-92. Despite some imperfections in the MM3-92 force field, the Stochastic Search method was a powerful method for determining molecular conformation. Copyright (C) 1999 John Wiley & Sons, Ltd. C1 Pharm Eco Labs, Lexington, MA 02421 USA. USN, Struct Matter Lab, Res Lab, Washington, DC 20375 USA. RP Froimowitz, M (reprint author), Pharm Eco Labs, 128 Spring St, Lexington, MA 02421 USA. NR 22 TC 2 Z9 2 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0894-3230 J9 J PHYS ORG CHEM JI J. Phys. Org. Chem. PD NOV PY 1999 VL 12 IS 11 BP 858 EP 864 DI 10.1002/(SICI)1099-1395(199911)12:11<858::AID-POC205>3.3.CO;2-E PG 7 WC Chemistry, Organic; Chemistry, Physical SC Chemistry GA 272QC UT WOS:000084661600007 ER PT J AU Atwood, AI Boggs, TL Curran, PO Parr, TP Hanson-Parr, DM Price, CF Wiknich, J AF Atwood, AI Boggs, TL Curran, PO Parr, TP Hanson-Parr, DM Price, CF Wiknich, J TI Burning rate of solid propellant ingredients, Part 1: Pressure and initial temperature effects SO JOURNAL OF PROPULSION AND POWER LA English DT Article AB Burning rate data are presented with respect to initial temperature and pressure for three compounds that are currently used in propellant and explosive formulations. The dependence of burning rate on initial temperature and pressure is presented for ammonium perchlorate (AP), HMX, and RDX, Data for ingredients being considered for advanced propellants, such as CL-20, ammonium dinitramide (ADN), and hydrazinium nitroformate (HNF) are also presented and compared to the more traditional compounds. These ingredients are all capable of self-deflagration, and their behavior often controls the behavior of the propellants in which they are the main ingredients. C1 USN, Air Warfare Ctr, Dept Res, Weap Div, China Lake, CA 93555 USA. Sverdrup Technol Inc, Syst Engn T&E Dept, Ridgecrest, CA 93555 USA. RP Atwood, AI (reprint author), USN, Air Warfare Ctr, Dept Res, Weap Div, Code 4T4310D, China Lake, CA 93555 USA. NR 17 TC 68 Z9 83 U1 2 U2 13 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD NOV-DEC PY 1999 VL 15 IS 6 BP 740 EP 747 DI 10.2514/2.5522 PG 8 WC Engineering, Aerospace SC Engineering GA 262XU UT WOS:000084094200003 ER PT J AU Atwood, AI Boggs, TL Curran, PO Parr, TP Hanson-Parr, DM Price, CF Wiknich, J AF Atwood, AI Boggs, TL Curran, PO Parr, TP Hanson-Parr, DM Price, CF Wiknich, J TI Burning rate of solid propellant ingredients, Part 2: Determination of burning rate temperature sensitivity SO JOURNAL OF PROPULSION AND POWER LA English DT Article AB Once the burning rate as a function of initial temperature has been measured for a particular material, it is often desirable to report its burning rate temperature sensitivity as a single value that can then be used in other applications. A few of the obstacles encountered when making the determination of burning rate temperature sensitivity, sigma(p), are examined. Burning rate temperature sensitivity was evaluated for the neat ingredients AP, HMX, RDX, ADN, CL-20, and HNF. C1 USN, Air Warfare Ctr, Dept Res, China Lake, CA 93555 USA. USN, Air Warfare Ctr, Engn Sci Div, Dept Res, China Lake, CA 93555 USA. USN, Air Warfare Ctr, Weap Div, Dept Res, China Lake, CA 93555 USA. Sverdrup Technol Inc, Syst Engn T&E Dept, Ridgecrest, CA 93555 USA. RP Atwood, AI (reprint author), USN, Air Warfare Ctr, Dept Res, Code 4T4310D, China Lake, CA 93555 USA. NR 6 TC 26 Z9 29 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD NOV-DEC PY 1999 VL 15 IS 6 BP 748 EP 752 DI 10.2514/2.5523 PG 5 WC Engineering, Aerospace SC Engineering GA 262XU UT WOS:000084094200004 ER PT J AU Louwers, J Gadiot, GMHJL Brewster, MQ Son, SF Parr, T Hanson-Parr, D AF Louwers, J Gadiot, GMHJL Brewster, MQ Son, SF Parr, T Hanson-Parr, D TI Steady-state hydrazinium nitroformate (HNF) combustion modeling SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID PROPELLANTS AB Two simplified modeling approaches are used to model the combustion of hydrazinium nitroformate (HNF), N2H5. C(NO2)(3). The condensed phase is treated by high-activation-energy asymptotics. The gas phase is treated by two limit cases: the classical high-activation-energy approximation and the recently introduced low-activation-energy approach. This results in simplification of the gas-phase energy equation, making an (approximate) analytical solution possible. The results of both models are compared with experimental results of HNF combustion. It is shown that the low-activation-energy approach yields better agreement with experimental observations, for example, regression rate and temperature sensitivity, than the high-activation-energy approach. C1 TNO, Prins Maurits Lab, Res Grp Rocket Technol, NL-2280 AA Rijswijk, Netherlands. Univ Illinois, Dept Mech & Ind Engn, Urbana, IL 61801 USA. USN, Air Warfare Ctr, Dept Res, Weap Div, China Lake, CA 93555 USA. RP Louwers, J (reprint author), TNO, Prins Maurits Lab, Res Grp Rocket Technol, POB 45, NL-2280 AA Rijswijk, Netherlands. OI Son, Steven/0000-0001-7498-2922 NR 25 TC 9 Z9 10 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD NOV-DEC PY 1999 VL 15 IS 6 BP 772 EP 777 DI 10.2514/2.5495 PG 6 WC Engineering, Aerospace SC Engineering GA 262XU UT WOS:000084094200008 ER PT J AU Kitchenham, BA Travassos, GH von Mayrhauser, A Niessink, F Schneidewind, NF Singer, J Takada, S Vehvilainen, R Yang, HJ AF Kitchenham, BA Travassos, GH von Mayrhauser, A Niessink, F Schneidewind, NF Singer, J Takada, S Vehvilainen, R Yang, HJ TI Towards an ontology of software maintenance SO JOURNAL OF SOFTWARE MAINTENANCE-RESEARCH AND PRACTICE LA English DT Article DE empirical research; maintenance factors; maintenance scenarios; evolutionary maintenance; independent maintenance groups; maintenance ontology AB We suggest that empirical studies of maintenance are difficult to understand unless the context of the study is fully defined. We developed a preliminary ontology to identify a number of factors that influence maintenance. The purpose of the ontology is to identify factors that would affect the results of empirical studies, We present the ontology in the form of a UML model. Using the maintenance factors included in the ontology, we define two common maintenance scenarios and consider the industrial issues associated with them. Copyright (C) 1999 John Wiley & Sons, Ltd. C1 Univ Keele, Dept Comp Sci, Keele ST5 5BG, Staffs, England. Univ Maryland, COPPE, UFRJ, BR, College Pk, MD 20742 USA. Univ Maryland, DCS, ESEG, College Pk, MD 20742 USA. Colorado State Univ, Dept Comp Sci, Ft Collins, CO 80523 USA. Free Univ Amsterdam, Fac Sci, Div Math & Comp Sci, NL-1081 HV Amsterdam, Netherlands. USN, Postgrad Sch, Pebble Beach, CA USA. Natl Res Council Canada, Inst Informat Technol, Ottawa, ON K1A 0R6, Canada. Keio Univ, Fac Sci & Technol, Dept Informat & Comp Sci, Kohoku Ku, Yokohama, Kanagawa 2238522, Japan. DPM Consulting Oy, Tuusula 04320, Finland. De Montfort Univ, Dept Comp Sci, Leicester LE1 9BH, Leics, England. RP Kitchenham, BA (reprint author), Univ Keele, Dept Comp Sci, Keele ST5 5BG, Staffs, England. RI Travassos, Guilherme/G-2842-2012; OI Travassos, Guilherme/0000-0002-4258-0424; Kitchenham, Barbara/0000-0002-6134-8460 NR 17 TC 80 Z9 82 U1 0 U2 6 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1040-550X J9 J SOFTW MAINT-RES PR JI J. Softw. Maint.-Res. Pract. PD NOV-DEC PY 1999 VL 11 IS 6 BP 365 EP 389 DI 10.1002/(SICI)1096-908X(199911/12)11:6<365::AID-SMR200>3.0.CO;2-W PG 25 WC Computer Science, Software Engineering SC Computer Science GA 274FL UT WOS:000084753000001 ER PT J AU Makris, NC Chia, CS Fialkowski, LT AF Makris, NC Chia, CS Fialkowski, LT TI The bi-azimuthal scattering distribution of an abyssal hill SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID MID-ATLANTIC RIDGE; OCEAN CRUST; REVERBERATION; BACKSCATTER; INTENSITY AB High-resolution bistatic images of a typical abyssal hill on the western flank of the Mid-Atlantic Ridge, are made with a low-frequency towed-array system operating remotely at 1/2 convergence zone (similar to 33.3 km) stand-off. Comparison with modeled images, generated from high-resolution supporting bathymetry sampled at 5-m intervals, roughly the;wavelength scale, reveals that steep scarps return the strongest echoes because they project the largest area along the acoustic path from the source to receiver. Prominent returns deterministically image scarp morphology when the cross-range axis of the system's resolution footprint runs along the scarp axis. Statistical fluctuations inherent in the scattered field prevent the system from distinguishing; smaller-scale anomalies on the scarps, such as canyons and gullies (similar to 100-200 m scale), that would otherwise be resolvable in range, in certain bistatic geometries. The mean bi-azimuthal scattering distributions of the two major scarps on the abyssal hill are identical and have strengths equal to the constant -17 dB +/- 8 dB. This suggests that long-range reverberation from prominent geomorphological features of the world's mid-ocean ridges can be adequately modeled as Lambertian with-albedo pi/10(1.7), given supporting bathymetry sampled with sufficient frequency to resolve the projected area of these features. (C) 1999 Acoustical Society of America. [S0001-4966(99)01911-6]. C1 MIT, Cambridge, MA 02139 USA. USN, Res Lab, Washington, DC 20375 USA. RP Makris, NC (reprint author), MIT, 77 Massachusetts Ave, Cambridge, MA 02139 USA. NR 31 TC 11 Z9 11 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD NOV PY 1999 VL 106 IS 5 BP 2491 EP 2512 DI 10.1121/1.428138 PG 22 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 257MN UT WOS:000083785800017 ER PT J AU Collins, MD AF Collins, MD TI Wave-number sampling at short range SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID PARABOLIC EQUATION METHOD; SELF-STARTER; APPROXIMATIONS; PROPAGATION AB Spectral solutions can be obtained efficiently at long ranges by using a quadrature scheme that involves perturbing the integration contour off the Peal line [F. B. Jensen et al., Computational Ocean Acoustics (American Institute of Physics, New York, 1994), pp. 231-240]. The efficiency of this implementation of the spectral solution is investigated for short-range problems. Examples are presented to illustrate that the self-starter [J. Acoust. Sec. Am. 92, 2059-2074 (1992)] is about ten times faster at ranges on the order of ten wavelengths. The accuracy of the spectral solution and the self-starter are directly related to the accuracy of rational approximations. The rational function associated with the spectral solution is based on the numerical evaluation of the spectral integral. The rational function associated with the self-starter is based on the analytic evaluation of the spectral integral. The relationship between these approaches is analogous to the relationship between the finite-difference and split step Padi [J. Acoust. Sec, Am. 93, 1736-1742 (1993)] solutions of the parabolic equation. [S0001-4966(99)06211-6]. C1 USN, Res Lab, Washington, DC 20375 USA. RP Collins, MD (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD NOV PY 1999 VL 106 IS 5 BP 2535 EP 2539 DI 10.1121/1.428085 PG 5 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 257MN UT WOS:000083785800020 ER PT J AU Morse, SF Marston, PL AF Morse, SF Marston, PL TI Meridional ray contributions to scattering by tilted cylindrical shells above the coincidence frequency: ray theory and computations SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID TONE BURSTS; BACKSCATTERING ENHANCEMENTS; SPHERICAL-SHELL; WAVE; WATER; AMPLITUDES AB High-frequency scattering enhancements from a submerged infinite cylindrical shell are studied by means of partial wave series (PWS) calculations and a ray approximation. For certain oblique angles of incidence it is possible to launch a generalized leaky Lamb wave which propagates strictly in the axial direction on the shell. This meridional leaky wave radiates with a locally flat wavefront curvature and produces large far-field amplitudes over a range of tilt angles. When combined with a reflection from a discontinuity in the shell, this process can give rise to large backscattering enhancements at large tilt angles for thick finite cylindrical shells [S. F. Morse ed nl., J. Acoust, Sec. Am. 103, 785-794 (1998)] and is present in sonar images. A convolution formulation ray theory for the far-field meridional ray amplitude is compared with the exact PWS solution in the region where enhancements are observed for both the a(0) and s(0) Lamb waves. The ray theory correctly predicts both the peak enhancement amplitude and the general shape of the enhancement curve. (C) 1999 Acoustical Society of America. [S0001-4966(99)04511-7]. C1 Washington State Univ, Dept Phys, Pullman, WA 99164 USA. RP Morse, SF (reprint author), USN, Res Lab, Code 7136,4555 Overlook Ave SW, Washington, DC 20375 USA. NR 21 TC 16 Z9 16 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD NOV PY 1999 VL 106 IS 5 BP 2595 EP 2600 DI 10.1121/1.428091 PG 6 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 257MN UT WOS:000083785800027 ER PT J AU Parlette, E Smith, KJ Germain, M Rolfe, A Skelton, H AF Parlette, E Smith, KJ Germain, M Rolfe, A Skelton, H TI Accelerated growth of dermatofibrosarcoma protuberans during pregnancy SO JOURNAL OF THE AMERICAN ACADEMY OF DERMATOLOGY LA English DT Article ID SPINDLE-CELL LIPOMA; NERVE SHEATH TUMORS; PERIPHERAL-NERVE; SOFT-TISSUE; CHROMOSOME-22; DIAGNOSIS; ANGIOMYOFIBROBLASTOMA; PERINEURIOMA; POPULATION; SEQUENCES AB Dermatofibrosarcoma protuberans (DFSPs) are uncommon skin tumors that have a high incidence of local recurrence even with wide surgical margin, but DFSPs rarely metastasize. Previous reports have suggested that DFSPs may enlarge more rapidly during pregnancy. We report 3 additional cases of DFSPs that showed accelerated growth during pregnancy. Immunohistochemical stains for CD34, S-100 protein, factor XIIIa, and estrogen and progesterone receptors were performed on biopsy specimens. The tumors in all 3 patients, and 4 additional DFSPs from 2 male and 2 female subjects, showed expression of progesterone receptor. As with many other stromal neoplasms, DFSPs appear to express low levels of hormone receptors, which may be one factor that accounts for their accelerated growth during pregnancy. C1 USN, Natl Med Ctr, Dept Dermatol, Bethesda, MD 20889 USA. USN, Natl Med Ctr, Dept Pathol, Bethesda, MD 20889 USA. Lab Corp Amer, Herndon, VA USA. RP Smith, KJ (reprint author), USN, Natl Med Ctr, Dept Dermatol, 8901 Wisconsin Ave, Bethesda, MD 20889 USA. NR 32 TC 17 Z9 19 U1 0 U2 1 PU MOSBY-ELSEVIER PI NEW YORK PA 360 PARK AVENUE SOUTH, NEW YORK, NY 10010-1710 USA SN 0190-9622 J9 J AM ACAD DERMATOL JI J. Am. Acad. Dermatol. PD NOV PY 1999 VL 41 IS 5 BP 778 EP 783 PN 1 PG 6 WC Dermatology SC Dermatology GA 249VH UT WOS:000083353600020 ER PT J AU Hoang-Xuan, T Steger, JW AF Hoang-Xuan, T Steger, JW TI Adult-onset angiofibroma and multiple endocrine neoplasia type I SO JOURNAL OF THE AMERICAN ACADEMY OF DERMATOLOGY LA English DT Article; Proceedings Paper CT 55th Annual Meeting of the American-Academy-of-Dermatology CY MAR 21-26, 1997 CL SAN FRANCISCO, CALIFORNIA SP Amer Acad Dermatol AB Multiple endocrine neoplasia type 1 (MEN 1) predisposes affected persons to neoplasms of the parathyroid glands, the endocrine pancreas, the anterior pituitary, and the duodenum. We report the first case of adult-onset multiple angiofibromas of the central face associated with MEN 1. Seven siblings also developed adult-onset, angiofibromas, none with evidence of tuberous sclerosis. Basic fibroblast growth factor (BFGF) is elevated in many patients with MEN 1 and may play a pathogenetic role. C1 USN, Med Ctr, Dept Dermatol, San Diego, CA 92152 USA. USN, Med Ctr, Dept Clin Res, San Diego, CA 92152 USA. RP Hoang-Xuan, T (reprint author), USN, Med Ctr, Dept Clin Invest, 34800 Bob Wilson Dr,Suite 5, San Diego, CA 92134 USA. NR 12 TC 5 Z9 5 U1 0 U2 0 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 USA SN 0190-9622 J9 J AM ACAD DERMATOL JI J. Am. Acad. Dermatol. PD NOV PY 1999 VL 41 IS 5 SU S BP 890 EP 892 DI 10.1016/S0190-9622(99)70353-1 PN 2 PG 3 WC Dermatology SC Dermatology GA 250WL UT WOS:000083412200024 PM 10534680 ER PT J AU Wang, XH Li, GF Hong, J Pappert, SA AF Wang, XH Li, GF Hong, J Pappert, SA TI Spatiotemporal dynamics and high-frequency self-pulsations in two-section distributed feedback lasers SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID WELL DFB LASERS; GENERATION; GHZ AB Ne present a traveling-wave large-signal simulation of the spatiotemporal dynamics of two-section distributed feedback lasers, emphasizing the self-pulsation phenomenon. For index-coupled lasers, self-pulsation is a result of the interaction of two modes, each spatially confined primarily to one section. For partially gain-coupled lasers, self-pulsation is a result of the interaction of two modes, one that is spatially confined primarily to one section and another that belongs to both sections. The self-pulsation frequency-tuning range and the modulation index of partially gain-coupled lasers are found to be substantially larger than those of index-coupled lasers. Experimentally, self-pulsation with a frequency-tuning range from 20 to 60 GHz in two-section partially gain-coupled distributed-feedback; lasers has been characterized in the electrical domain. The noise of self-pulsation was reduced experimentally by optical feedback. (C) 1999 Optical Society of America [S0740-3224(99)01811-1]. C1 Univ Cent Florida, CREOL, Sch Opt, Orlando, FL 32816 USA. Nortel Networks, Adv Technol Lab, Ottawa, ON K1Y 4H7, Canada. USN, Space & Naval Warfare Syst Ctr, SSCSD Div 895, San Diego, CA 92152 USA. RP Wang, XH (reprint author), Univ Cent Florida, CREOL, Sch Opt, 400 Cent Florida Blvd, Orlando, FL 32816 USA. NR 15 TC 18 Z9 19 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD NOV PY 1999 VL 16 IS 11 BP 2030 EP 2039 DI 10.1364/JOSAB.16.002030 PG 10 WC Optics SC Optics GA 252TV UT WOS:000083519100025 ER PT J AU Hellberg, CS Pickett, WE Boyer, LL Stokes, HT Mehl, MJ AF Hellberg, CS Pickett, WE Boyer, LL Stokes, HT Mehl, MJ TI Ab initio calculation of spin gap behavior in CaV4O9 SO JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN LA English DT Letter DE CaV4O9; spin gap; density functional theory; superexchange; magnetic susceptibility ID ATOMIC DEFORMATION MODEL; HEISENBERG-MODEL; SYSTEM CAV4O9; EXPANSIONS; LATTICE; STATES AB Second neighbor dominated exchange coupling in CaV4O9 has been obtained from ab initio density functional (DF) calculations. A DF-based self-consistent atomic deformation model reveals that the nearest neighbor coupling is small due to strong cancellation among the various superexchange processes. Exact diagonalization of the predicted Heisenberg model yields spin-gap behavior in good agreement with experiment. The model is refined by fitting to the experimental susceptibility. The resulting model agrees very well with the experimental susceptibility and triplet dispersion. C1 USN, Res Lab, Ctr Computat Mat Sci, Washington, DC 20375 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Brigham Young Univ, Dept Phys & Astron, Provo, UT 84602 USA. RP Hellberg, CS (reprint author), USN, Res Lab, Ctr Computat Mat Sci, Washington, DC 20375 USA. RI Hellberg, C. Stephen/E-5391-2010; Mehl, Michael/H-8814-2016 NR 25 TC 18 Z9 18 U1 0 U2 5 PU PHYSICAL SOCIETY JAPAN PI TOKYO PA KIKAI-SHINKO BUILDING, 3-5-8 SHIBA-KOEN, MINATO-KU, TOKYO, 105, JAPAN SN 0031-9015 J9 J PHYS SOC JPN JI J. Phys. Soc. Jpn. PD NOV PY 1999 VL 68 IS 11 BP 3489 EP 3492 DI 10.1143/JPSJ.68.3489 PG 4 WC Physics, Multidisciplinary SC Physics GA 259HU UT WOS:000083889100006 ER PT J AU Park, YD Temple, D Jung, KB Kumar, D Holloway, PH Pearton, SJ AF Park, YD Temple, D Jung, KB Kumar, D Holloway, PH Pearton, SJ TI Fabrication and magneto-transport and SQUID measurements of submicron spin-valve structures SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID GIANT MAGNETORESISTANCE AB Submicron Ni0.8Fe0.2/Cu/Co spin valves and Co/Cu pseudo spin valves with widths ranging from 200 to 0.5 mu m have been realized by direct deposition and liftoff. The resulting configurations were structurally characterized by atomic force microscope and cross-sectional transmission electron microscopy. Transport and magnetic properties of arrays of these spin-valve structures were studied using superconducting quantum interference device magnetometry. Magnetic measurements carried out on several spin-valve structures showed that both coercivity and field at which maximum magnetoresistance (MR) occurs increase with decrease in widths of the spin valves; Comparison of the results obtained from the magnetometry and transport measurements indicated the existence of an offset between the coercive field and field of maximum MR. Resistance versus temperature measurements for varying linewidth show a minimal shift in peak temperature, indicating that processing effects are minimal. (C) 1999 American Vacuum Society. [S0734-211X(99)00806-9]. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Microelect Ctr N Carolina, Res Triangle Pk, NC 27709 USA. RP Park, YD (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Park, Yun/A-9559-2008 OI Park, Yun/0000-0001-7699-0432 NR 16 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 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD NOV-DEC PY 1999 VL 17 IS 6 BP 2471 EP 2475 DI 10.1116/1.591114 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 266CJ UT WOS:000084282800013 ER PT J AU Bermudez, VM AF Bermudez, VM TI Low-energy electron-beam effects on poly(methyl methacrylate) resist films SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID THIN-FILMS; RESONANCE SPECTRA; SPECTROSCOPY; LITHOGRAPHY; RADIATION AB The effects of low-energy electron irradiation (10-50 eV, up to similar to 2 x 10(17) e cm(-2)) on thin films of poly(methyl methacrylate) (PMMA), deposited on air-exposed Al, have been studied in situ as a function of temperature (similar to 200-300 K) using polarization-modulated infrared reflection absorption spectroscopy. Near 300 K damage is seen in the form of a loss of material, as shown by a decrease in the intensity of the entire PMMA spectrum. At low temperature, in addition to damage, evidence is seen for a radiation-induced change in chain configuration leading to an increased interaction between ester groups and the Al surface. This configuration is unstable and is removed by annealing to similar to 300 K. [S0734-211X(99)01706-0]. C1 USN, Res Lab, Div Elect Sci & Technol, Washington, DC 20375 USA. RP Bermudez, VM (reprint author), USN, Res Lab, Div Elect Sci & Technol, Washington, DC 20375 USA. NR 24 TC 14 Z9 14 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD NOV-DEC PY 1999 VL 17 IS 6 BP 2512 EP 2518 DI 10.1116/1.591134 PG 7 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 266CJ UT WOS:000084282800019 ER PT J AU Zhang, D Luqi AF Zhang, D Luqi TI Approximate declarative semantics for rule base anomalies SO KNOWLEDGE-BASED SYSTEMS LA English DT Article DE knowledge base anomalies; inconsistency; redundancy; circularity; incompleteness; knowledge base verification ID KNOWLEDGE-BASED SYSTEMS; EXPERT SYSTEMS; PETRI NETS; VERIFICATION; VALIDATION; FRAMEWORK; TOOL AB Despite the fact that there has been a surge of publications in verification and validation of knowledge-based systems and expert systems in the past decade, there are still gaps in the study of verification and validation (V&V) of expert systems, not the least of which is the lack of appropriate semantics for expert system programming languages. Without a semantics, it is hard to formally define and analyze knowledge base anomalies such as inconsistency and redundancy, and it is hard to assess the effectiveness of V&V tools, methods and techniques that have been developed or proposed. In this paper, we develop an approximate declarative semantics for rule-based knowledge bases and provide a formal definition and analysis of knowledge base inconsistency, redundancy, circularity and incompleteness in terms of theories in the first order predicate logic. In the paper, we offer classifications of commonly found cases of inconsistency, redundancy, circularity and incompleteness. Finally, general guidelines on how to remedy knowledge base anomalies are given. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Calif State Univ Sacramento, Dept Comp Sci, Sacramento, CA 95819 USA. USN, Postgrad Sch, Dept Comp Sci, Monterey, CA 93943 USA. RP Zhang, D (reprint author), Calif State Univ Sacramento, Dept Comp Sci, Sacramento, CA 95819 USA. NR 50 TC 12 Z9 12 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0950-7051 J9 KNOWL-BASED SYST JI Knowledge-Based Syst. PD NOV PY 1999 VL 12 IS 7 BP 341 EP 353 DI 10.1016/S0950-7051(99)00032-5 PG 13 WC Computer Science, Artificial Intelligence SC Computer Science GA 256XR UT WOS:000083752200002 ER PT J AU Ngai, KL AF Ngai, KL TI An improved theory of polymer dynamics in solution: Probe diffusion and viscosity SO MACROMOLECULAR SYMPOSIA LA English DT Article ID CONCENTRATED COLLOIDAL SUSPENSIONS; COUPLING MODEL ANALYSIS; WATER AB A more complete coupling/scaling theory of polymer dynamics in solution is presented and applied to explain several anomalous properties of probe diffusion and viscosity. Similar properties are found in totally physically and chemically different systems. These similarities strongly support the need of a general approach to these problems as given here. C1 USN, Res Lab, Washington, DC 20375 USA. RP Ngai, KL (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 18 TC 3 Z9 3 U1 0 U2 0 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 1022-1360 J9 MACROMOL SYMP JI Macromol. Symp. PD NOV PY 1999 VL 146 BP 117 EP 123 DI 10.1002/masy.19991460117 PG 7 WC Polymer Science SC Polymer Science GA 288CM UT WOS:000085544300016 ER PT J AU Reynolds, CA AF Reynolds, CA TI A comparison of analysis and forecast correction techniques: Impact of negative dissipation SO MONTHLY WEATHER REVIEW LA English DT Article ID SINGULAR VECTORS; OPTIMAL PERTURBATIONS; INITIAL CONDITIONS; KALMAN SMOOTHER; ANALYSIS-ERROR; PREDICTABILITY; SENSITIVITY; ASSIMILATION; PREDICTION AB The impact of negative dissipation on posttime analysis and forecast correction techniques is examined in a simplified context. The experiments are conducted using a three-level quasigeostrophic model (with a nonsingular tangent propagator matrix) under a perfect-model assumption. Corrections to the initial analysis errors are obtained by operating on the forecast error with (i) the full inverse of the forward tangent propagator, (ii) an inverse composed of a subset of the first leading singular vectors (pseudoinverse), and (iii) the tangent equations with a negative time step (backward integration). When the forecast error is known exactly, using negative dissipation during the full-inverse or backward-integration calculation results in an analysis-error estimate that projects too weakly onto the leading singular vectors and too strongly onto the decaying singular vectors. These discrepancies are small for weak dissipation but increase as the dissipation strength is increased. When the forecast error is known inexactly, negative dissipation provides a beneficial damping of the backward-in-time growth of uncertainties present in the forecast error. This damping effect is found to be due to a fairly uniform change in the singular values, not changes in the singular vectors. However, even for very strong negative dissipation, the uncertainty in the forecast error still grows during the full inverse or backward integration. Therefore. the analysis error estimate will still be dominated by the trailing singular vectors, which represent the decaying part of the initial error. This is in contrast to the pseudoinverse technique, which, like the adjoint sensitivity, is dominated by the fastest growing part of the initial error and is therefore relatively insensitive to the analysis uncertainty contained within the forecast error. Thus, while full-inverse and backward-integration calculations may provide an analysis perturbation that results in a significantly improved forecast, the analysis error estimate is accurate only when the forecast error is known exactly (i.e., perfect model experiments), regardless of the sign of the dissipation. These results hold for both global and regional forecast errors. C1 USN, Res Lab, Monterey, CA 93943 USA. RP Reynolds, CA (reprint author), USN, Res Lab, 7 Grace Hopper Ave, Monterey, CA 93943 USA. OI Reynolds, Carolyn/0000-0003-4690-4171 NR 27 TC 2 Z9 2 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD NOV PY 1999 VL 127 IS 11 BP 2576 EP 2596 DI 10.1175/1520-0493(1999)127<2576:ACOAAF>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 250TG UT WOS:000083403800004 ER PT J AU Pearson, DH Edelstein, AS AF Pearson, DH Edelstein, AS TI Threshold behavior in the formation of nanoscale silicon particles prepared by sputtering SO NANOSTRUCTURED MATERIALS LA English DT Article ID GAS-EVAPORATED SI; FINE PARTICLES; DEPOSITION; POWDERS; GROWTH; CU AB DC magnetron sputtering of silicon was carried out at 175 watts in argon gas at pressures from 100 mtorr to 900 mtorr. Sputter deposits were collected on an array of transmission electron microscopy (TEM) grids placed between the sputter source and a cold-finger located 10.5 cm above the sputter source. The resulting deposits were analyzed by TEM, and the morphologies were found to include granular films, well-defined particles 5-13 nm in diameter, and transition morphologies between that of particles and granular films. The resulting morphology map, as a function of sputtering pressure and TEM-grid location, indicated that particles were mon likely to form at higher pressures and locations farther from the source. In addition, results obtained by varying the cold-finger temperature and the sputter-source/cold-finger distance indicated that the temperature of the cold-finger can play a significant role in particle formation at small sputter-source/cold-finger separations. Deposits with granular-film morphologies were amorphous under most conditions. However, deposits containing particles exhibited the diamond-cubic crystalline phase under some conditions as well as the amorphous phase. Published by Elsevier Science Ltd. C1 USN, Res Lab, Washington, DC 20375 USA. RP Pearson, DH (reprint author), USN, Res Lab, Code 6342,4555 Overlook Ave SW, Washington, DC 20375 USA. NR 28 TC 6 Z9 6 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PD NOV PY 1999 VL 11 IS 8 BP 1111 EP 1122 DI 10.1016/S0965-9773(99)00401-8 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA 316AF UT WOS:000087144600017 ER PT J AU Lai, ZW Jing, JP Aston, C Clarke, V Apodaca, J Dimalanta, ET Carucci, DJ Gardner, MJ Mishra, B Anantharaman, TS Paxia, S Hoffman, SL Venter, JC Huff, EJ Schwartz, DC AF Lai, ZW Jing, JP Aston, C Clarke, V Apodaca, J Dimalanta, ET Carucci, DJ Gardner, MJ Mishra, B Anantharaman, TS Paxia, S Hoffman, SL Venter, JC Huff, EJ Schwartz, DC TI A shotgun optical map of the entire Plasmodium falciparum genome SO NATURE GENETICS LA English DT Article ID DNA-MOLECULES; GEL-ELECTROPHORESIS; MALARIA; SEPARATION C1 WM Keck Lab Biomol Imaging, Dept Chem, New York, NY USA. NYU, Dept Chem, Dept Comp Sci, Courant Inst Math Sci, New York, NY 10003 USA. USN, Med Res Ctr, Malaria Program, Rockville, MD USA. Inst Genom Res, Rockville, MD USA. RP Univ Wisconsin, Ctr Biotechnol, Dept Chem, Madison, WI 53705 USA. EM schwad01@mcrcr.med.nyu.edu FU NCI NIH HHS [R01CA 79063-1]; NHGRI NIH HHS [2 RO1 HG00225-01-09] NR 30 TC 59 Z9 60 U1 2 U2 6 PU NATURE PUBLISHING GROUP PI NEW YORK PA 75 VARICK ST, 9TH FLR, NEW YORK, NY 10013-1917 USA SN 1061-4036 EI 1546-1718 J9 NAT GENET JI Nature Genet. PD NOV PY 1999 VL 23 IS 3 BP 309 EP 313 DI 10.1038/15484 PG 5 WC Genetics & Heredity SC Genetics & Heredity GA 257QC UT WOS:000083792200019 PM 10610179 ER PT J AU Gherman, RB Goodwin, TM Leung, B Byrne, JD Hethumumi, R Montoro, M AF Gherman, RB Goodwin, TM Leung, B Byrne, JD Hethumumi, R Montoro, M TI Incidence, clinical characteristics, and timing of objectively diagnosed venous thromboembolism during pregnancy SO OBSTETRICS AND GYNECOLOGY LA English DT Article; Proceedings Paper CT 46th Annual Clinical Meeting of the American-College-of-Obstetricians-and-Gynecologists CY MAY 09-13, 1998 CL NEW ORLEANS, LOUISIANA SP Amer Coll Obstetricians & Gynecologists ID DEEP-VEIN THROMBOSIS; MATERNAL MORTALITY; UNITED-STATES; GENERATION; DISEASE AB Objective: To estimate the incidence, timing, and associated clinical characteristics of objectively diagnosed pregnancy-associated venous thromboembolism. Methods: We retrospectively reviewed venous thromboembolism cases (deep venous thrombosis and pulmonary embolism) that occurred between 1978 and 1996. Study inclusion criteria required the objective diagnosis with either Doppler ultrasound, venography, impedance plethysmography, pulmonary angiography, ventilation-perfusion scanning, or computed tomography or magnetic resonance imaging, Results: Among 268,525 deliveries there were 165 (0.06%) episodes of venous thromboembolism (one per 1627 births). There were 127 cases of deep venous thrombosis and 38 cases of pulmonary embolism, Only 14% (23 of 165 patients) had a history of venous thromboembolism. Most cases of deep venous thrombosis were in the left leg (104 of 127, 81.9%), with nearly three quarters of them (94 of 127, 74.8%) occurring during the antepartum period. Among cases of antepartum deep venous thrombosis, half were detected before 15 weeks' gestation (47 of 95, 49.5%), and only 28 eases occurred after 20 weeks (P < .001), Most of the pulmonary embolisms occurred in the postpartum period (23 of 38, 60.5%) and were strongly associated with cesarean delivery (19 of 36,470 compared with four of 232,032, P < .001). Conclusion: The incidence of venous thromboembolism during pregnancy is lower than has been previously described. Most cases occurred in the antepartum period, with the risk of deep venous thrombosis appearing to begin even before the second trimester. (C) 1999 by The American College of Obstetricians and Gynecologists. C1 Univ So Calif, Sch Med, Dept Obstet & Gynecol, Div Maternal Fetal Med, Los Angeles, CA 90033 USA. USN, Med Ctr, Div Maternal Fetal Med, Dept Obstet & Gynecol, Portsmouth, VA USA. RP Gherman, RB (reprint author), USN Hosp, Dept Obstet & Gynecol, 620 John Paul Jones Circle, Portsmouth, VA 23708 USA. NR 22 TC 161 Z9 171 U1 2 U2 3 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0029-7844 J9 OBSTET GYNECOL JI Obstet. Gynecol. PD NOV PY 1999 VL 94 IS 5 BP 730 EP 734 DI 10.1016/S0029-7844(99)00426-3 PN 1 PG 5 WC Obstetrics & Gynecology SC Obstetrics & Gynecology GA 249CW UT WOS:000083316100017 PM 10546719 ER PT J AU Rodriguez, M Harrison, TA Nowacki, MR Saltzman, AK AF Rodriguez, M Harrison, TA Nowacki, MR Saltzman, AK TI Luteoma of pregnancy presenting with massive ascites and markedly elevated CA 125 SO OBSTETRICS AND GYNECOLOGY LA English DT Article C1 USN, Med Ctr, Dept Obstet & Gynecol, San Diego, CA 92152 USA. USN, Med Ctr, Dept Pathol, San Diego, CA 92152 USA. RP Rodriguez, M (reprint author), USN, Med Ctr, Dept Obstet & Gynecol, San Diego, CA 92152 USA. NR 4 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0029-7844 J9 OBSTET GYNECOL JI Obstet. Gynecol. PD NOV PY 1999 VL 94 IS 5 SU S BP 854 EP 854 DI 10.1016/S0029-7844(99)00246-X PN 2 PG 1 WC Obstetrics & Gynecology SC Obstetrics & Gynecology GA 249YU UT WOS:000083361700032 PM 10546765 ER PT J AU Forsnes, EV Derrough, KR O'Donoghue, M AF Forsnes, EV Derrough, KR O'Donoghue, M TI A mitotically active myoma in Rokitansky-Kuster-Hauser syndrome SO OBSTETRICS AND GYNECOLOGY LA English DT Article C1 Naval Hosp, Dept Obstet & Gynecol, Camp Lejeune, NC 28547 USA. Naval Hosp, Dept Pathol, Camp Lejeune, NC 28547 USA. RP Forsnes, EV (reprint author), Naval Hosp, Dept Obstet & Gynecol, Camp Lejeune, Camp Lejeune, NC 28547 USA. NR 4 TC 4 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0029-7844 J9 OBSTET GYNECOL JI Obstet. Gynecol. PD NOV PY 1999 VL 94 IS 5 SU S BP 862 EP 862 DI 10.1016/S0029-7844(99)00290-2 PN 2 PG 1 WC Obstetrics & Gynecology SC Obstetrics & Gynecology GA 249YU UT WOS:000083361700040 PM 10546773 ER PT J AU Morton, DP Wood, RK AF Morton, DP Wood, RK TI Restricted-recourse bounds for stochastic linear programming SO OPERATIONS RESEARCH LA English DT Article ID UNCERTAINTY; NETWORK; EXPECTATION; MODEL; APPROXIMATION; DECOMPOSITION; OPTIMIZATION; AGGREGATION; ASSET AB We consider the problem of bounding the expected value of a linear program (LP) containing random coefficients, with applications to solving two-stage stochastic programs. An upper bound for minimizations is derived from a restriction of an equivalent, penalty-based formulation of the primal stochastic LP, and a lower bound is obtained from a restriction of a reformulation of the dual. Our "restricted-recourse bounds" are more general and more easily computed than most other bounds because random coefficients may appear anywhere in the LP, neither independence nor boundedness of the coefficients is needed, and the bound is computed by solving a single LP or nonlinear program. Analytical examples demonstrate that the new bounds can be stronger than complementary Jensen bounds. (An upper bound is "complementary" to a lower bound, and vice versa). In computational work, we apply the bounds to a two-stage stochastic program for semiconductor manufacturing with uncertain demand and production rates. C1 Univ Texas, Grad Program Operat Res, Austin, TX 78712 USA. USN, Postgrad Sch, Dept Operat Res, Monterey, CA 93943 USA. RP Morton, DP (reprint author), Univ Texas, Grad Program Operat Res, Austin, TX 78712 USA. RI Morton, David/K-2388-2014; OI Wood, Kevin/0000-0002-0311-8712 NR 62 TC 11 Z9 11 U1 0 U2 2 PU INST OPERATIONS RESEARCH MANAGEMENT SCIENCES PI LINTHICUM HTS PA 901 ELKRIDGE LANDING RD, STE 400, LINTHICUM HTS, MD 21090-2909 USA SN 0030-364X J9 OPER RES JI Oper. Res. PD NOV-DEC PY 1999 VL 47 IS 6 BP 943 EP 956 DI 10.1287/opre.47.6.943 PG 14 WC Management; Operations Research & Management Science SC Business & Economics; Operations Research & Management Science GA 286BJ UT WOS:000085423500014 ER PT J AU Poggi, MM Thomas, BE Johnstone, PAS AF Poggi, MM Thomas, BE Johnstone, PAS TI Excision and radiotherapy for heterotopic ossification of the elbow SO ORTHOPEDICS LA English DT Article ID HIGH-RISK PATIENTS; RANDOMIZED TRIAL; PREVENTION; TUMORS AB Radiotherapy has a well-defined role in prophylaxis of recurrent heterotopic ossification of the hip, but has been described infrequently in other situations. This article reports the use of excision and low-dose external beam radiotherapy in three patients with heterotopic ossification of the elbow treated between February 1995 and September 1996. Radiotherapy was delivered in a single fraction of 7-8 Cy within 48 hours post-operatively using opposed anteroposterior portals. After a median follow-up of 10.5 months, all three patients demonstrated a significant increase in range of motion without any evidence of recurrence. These results indicate adjuvant postexcision radiotherapy may be used for prophylaxis of recurrent heterotopic ossification of the elbow. C1 USN, Med Ctr, Dept Clin Res, San Diego, CA 92134 USA. RP Poggi, MM (reprint author), USN, Med Ctr, Dept Clin Res, 34800 Bob Wilson Dr, San Diego, CA 92134 USA. NR 21 TC 9 Z9 9 U1 0 U2 0 PU SLACK INC PI THOROFARE PA 6900 GROVE RD, THOROFARE, NJ 08086 USA SN 0147-7447 J9 ORTHOPEDICS JI Orthopedics PD NOV PY 1999 VL 22 IS 11 BP 1059 EP 1061 PG 3 WC Orthopedics SC Orthopedics GA 258DD UT WOS:000083822100006 PM 10580824 ER PT J AU Hurst, DS Gordon, BR Fornadley, JA Hunsaker, DH AF Hurst, DS Gordon, BR Fornadley, JA Hunsaker, DH TI Safety of home-based and office allergy immunotherapy: A multicenter prospective study SO OTOLARYNGOLOGY-HEAD AND NECK SURGERY LA English DT Article; Proceedings Paper CT 101st Annual Meeting of the American-Academy-of-Otolaryngology-Head-and-Neck-Surgery CY SEP 07-10, 1997 CL SAN FRANCISCO, CALIFORNIA SP Amer Acad Otolaryngol Head & Neck Surg ID SYSTEMIC REACTIONS; PREMEDICATION; TRANSFUSION; ANAPHYLAXIS; PREVENTION; FATALITIES; MORBIDITY; MORTALITY; EXTRACTS AB During a 1-year period, 27 otolaryngic allergy practices recorded all systemic reactions to immunotherapy resulting from 635,600 patient visits and 1,144,000 injections, Sixty percent of injections were given at home. Major systemic reactions were observed after 0.005% of Injections. There were no hospitalizations or deaths. Eighty-seven percent of major reactions began within 20 minutes of injection. Frequently observed risk factors for major reactions were buildup phase of immunotherapy, active asthma, and first injection from a treatment vial. Home and office injections had similar rates of total systemic reactions, but home-based immunotherapy had far fewer major reactions. Home-based immunotherapy was found to be safe. The methods and precautions used to treat patients with this degree of safety are specified and discussed. C1 Cape Cod Hosp, Dept Otolaryngol, Hyannis, MA 02601 USA. Tufts Univ, Dept Otolaryngol, Medford, MA 02155 USA. Univ Uppsala, Dept Immunol, S-75105 Uppsala, Sweden. Harvard Univ, Dept Otol & Laryngol, Cambridge, MA 02138 USA. Penn State Univ, Dept Surg, University Pk, PA 16802 USA. USN, Med Ctr, San Diego, CA 92152 USA. RP Gordon, BR (reprint author), Cape Cod Hosp, Dept Otolaryngol, 20 Gleason St, Hyannis, MA 02601 USA. NR 38 TC 27 Z9 29 U1 0 U2 0 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 USA SN 0194-5998 J9 OTOLARYNG HEAD NECK JI Otolaryngol. Head Neck Surg. PD NOV PY 1999 VL 121 IS 5 BP 553 EP 561 DI 10.1016/S0194-5998(99)70055-0 PG 9 WC Otorhinolaryngology; Surgery SC Otorhinolaryngology; Surgery GA 252JG UT WOS:000083497900009 PM 10547469 ER PT J AU McCoskey, S Kao, CH AF McCoskey, S Kao, CH TI Testing the stability of a production function with urbanization as a shift factor SO OXFORD BULLETIN OF ECONOMICS AND STATISTICS LA English DT Article ID ECONOMIC-DEVELOPMENT; COINTEGRATION; GROWTH AB Urban economists have long sought to explain the relationship between urbanization levels and output. In this paper we revisit this question and test the long-run stability of a production function including urbanization using non-stationary panel data techniques. Our results show that a long-run relationship between urbanization, output per worker and capital per worker cannot be rejected for either our sample of 30 developing countries or our sample of 22 developed countries. We do find, however, that the sign and magnitude of the impact of urbanization varies considerably across the countries. In addition, we estimate the long-run average effects on GDPW of urbanization and capital. These results offer new insights and potential for dynamic urban models rather than the simple cross-section approach. C1 USN Acad, Dept Econ, Annapolis, MD 21402 USA. Syracuse Univ, Syracuse, NY 13244 USA. RP McCoskey, S (reprint author), USN Acad, Dept Econ, 121 Blake Rd, Annapolis, MD 21402 USA. EM mccoskey@nadn.navy.mil NR 25 TC 24 Z9 24 U1 2 U2 7 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0305-9049 EI 1468-0084 J9 OXFORD B ECON STAT JI Oxf. Bull. Econ. Stat. PD NOV PY 1999 VL 61 SI SI BP 671 EP 690 DI 10.1111/1468-0084.61.s1.15 PG 20 WC Economics; Social Sciences, Mathematical Methods; Statistics & Probability SC Business & Economics; Mathematical Methods In Social Sciences; Mathematics GA 269XX UT WOS:000084503700004 ER PT J AU McCoskey, S Kao, CH AF McCoskey, S Kao, CH TI Testing the stability of a production function with urbanization as a shift factor SO OXFORD BULLETIN OF ECONOMICS AND STATISTICS LA English DT Article ID ECONOMIC-DEVELOPMENT; COINTEGRATION; GROWTH AB Urban economists have long sought to explain the relationship between urbanization levels and output. In this paper we revisit this question and test the long-run stability of a production function including urbanization using non-stationary panel data techniques. Our results show that a long-run relationship between urbanization, output per worker and capital per worker cannot be rejected for either our sample of 30 developing countries or our sample of 22 developed countries. We do find, however, that the sign and magnitude of the impact of urbanization varies considerably across the countries. In addition, we estimate the long-run average effects on GDPW of urbanization and capital. These results offer new insights and potential for dynamic urban models rather than the simple cross-section approach. C1 USN Acad, Dept Econ, Annapolis, MD 21402 USA. Syracuse Univ, Syracuse, NY USA. RP McCoskey, S (reprint author), USN Acad, Dept Econ, 121 Blake Rd, Annapolis, MD 21402 USA. EM mccoskey@nadn.navy.mil NR 25 TC 24 Z9 24 U1 2 U2 7 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0305-9049 EI 1468-0084 J9 OXFORD B ECON STAT JI Oxf. Bull. Econ. Stat. PD NOV PY 1999 VL 61 IS 4 SU S BP 671 EP 690 DI 10.1111/1468-0084.61.s1.15 PG 20 WC Economics; Social Sciences, Mathematical Methods; Statistics & Probability SC Business & Economics; Mathematical Methods In Social Sciences; Mathematics GA 269JG UT WOS:000084472600004 ER PT J AU Allen, PB Feldman, JL Fabian, J Wooten, F AF Allen, PB Feldman, JL Fabian, J Wooten, F TI Diffusons, locons and propagons: character of atomic vibrations in amorphous Si SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article; Proceedings Paper CT 7th International Workshop on Disordered Systems CY MAR, 1999 CL MOLVENO, ITALY SP Univ Trento, Dipartimento Fis, Grp Nazl Struttura Mat ID THERMAL-CONDUCTIVITY; MOLECULAR-DYNAMICS; VITREOUS SILICA; COMPUTER-SIMULATION; DISORDERED-SYSTEMS; RAMAN-SCATTERING; THIN-FILMS; GLASSES; STATES; SOLIDS AB Numerical studies of amorphous Si show that the lowest 4% of vibrational modes are plane wave like ('propagons') and the highest 3% of modes are localized ('locons'). The rest are neither plane wave like nor localized. We call them 'diffusons'. Since diffusons are by far the most numerous, we try to characterize them by calculating such properties as the wave-vector and polarization (which do not seem to be useful), 'phase quotient' (a measure of the change of vibrational phase between first-neighbour atoms), spatial polarization memory and diffusivity. Localized states are characterized by finding decay lengths, inverse participation ratios and coordination numbers of the participating atoms. C1 SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. USN, Res Lab, Washington, DC 20375 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Univ Calif Davis, Dept Appl Sci, Davis, CA 95916 USA. RP Allen, PB (reprint author), SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. RI Allen, Philip/A-4366-2008; Fabian, Jaroslav/K-1700-2013 OI Fabian, Jaroslav/0000-0002-3009-4525 NR 65 TC 123 Z9 124 U1 2 U2 29 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD NOV-DEC PY 1999 VL 79 IS 11-12 BP 1715 EP 1731 DI 10.1080/13642819908223054 PG 17 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA 260LZ UT WOS:000083953300002 ER PT J AU Ngai, KL AF Ngai, KL TI Breakdown of Debye-Stokes-Einstein and Stokes-Einstein relations in glass-forming liquids: an explanation from the coupling model SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article; Proceedings Paper CT 7th International Workshop on Disordered Systems CY MAR, 1999 CL MOLVENO, ITALY SP Univ Trento, Dipartimento Fis, Grp Nazl Struttura Mat ID ENHANCED TRANSLATIONAL DIFFUSION; MOLECULAR-DYNAMICS SIMULATION; SUPERCOOLED O-TERPHENYL; NUCLEAR-SPIN RELAXATION; CONDUCTIVITY-RELAXATION; NEUTRON-SCATTERING; DIELECTRIC-RELAXATION; ROTATIONAL DIFFUSION; AMORPHOUS POLYMERS; ALPHA-RELAXATION AB The breakdown of Debye-Stokes-Einstein and Stokes-Einstein relations in glass-forming liquids is shown to be a special case of a more general phenomenon. A general explanation is given in the framework of the coupling model, which is based on the fact that different dynamic variables may have different coupling parameters entering into the stretch exponents of their Kohlrausch correlation functions. In most of the applications, the explanation requires no adjustable parameter. An exception is the explanation of the breakdown of a Stokes-Einstein relation where an experimental technique has not yet been developed to determine the coupling parameter of translational diffusion. We can explain also the breakdown of the Debye-Stokes-Einstein relation of depolarized light scattering data of the liquid diglycidyl ether of bisphenol-A. This breakdown occurs at high temperatures due to a reduction of the light scattering relaxation rate as compared with the shear stress relaxation rate. This behaviour is entirely opposite to the breakdown of the Stokes-Einstein relation of other glass-forming liquids, which occurs at low temperatures due an enhancement of translational diffusion over rotational diffusion or shear stress relaxation rate. C1 USN, Res Lab, Washington, DC 20375 USA. RP Ngai, KL (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 44 TC 13 Z9 13 U1 0 U2 5 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD NOV-DEC PY 1999 VL 79 IS 11-12 BP 1783 EP 1797 DI 10.1080/13642819908223061 PG 15 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA 260LZ UT WOS:000083953300009 ER PT J AU Rodina, AV Dietrich, M Goldner, A Eckey, L Efros, AL Rosen, M Hoffmann, A Meyer, BK AF Rodina, AV Dietrich, M Goldner, A Eckey, L Efros, AL Rosen, M Hoffmann, A Meyer, BK TI Exciton energy structure in wurtzite GaN SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT 3rd International Conference on Nitride Semiconductors (ICNS 99) CY JUL 04-09, 1999 CL MONTPELLIER, FRANCE ID SPLITTINGS AB Results of theoretical and experimental magneto-optical studies of free excitons in wurtzite GaN are presented. The direct photoluminescence from free exciton states of high-quality GaN epilayers was studied by polarization-dependent magneto-optical measurements in magnetic fields up to 15 T. Zeeman splittings and diamagnetic shifts of the n = 1 and n = 2 slates of the A exciton were observed for magnetic fields parallel and perpendicular to the hexagonal axis. The experimental data are described by a theory of the exciton energy structure in hexagonal semiconductors with wurtzite symmetry in the framework of the quasi-cubic approximation. C1 Russian Acad Sci, AF Ioffe Physicotech Inst, St Petersburg, Russia. Tech Univ Berlin, Inst Solid State Phys, D-10623 Berlin, Germany. USN, Res Lab, Washington, DC 20375 USA. Univ Giessen, Inst Phys 1, D-35392 Giessen, Germany. RP Rodina, AV (reprint author), Russian Acad Sci, AF Ioffe Physicotech Inst, Polytekhnicheskaya 26, St Petersburg, Russia. NR 20 TC 7 Z9 7 U1 1 U2 5 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD NOV PY 1999 VL 216 IS 1 BP 21 EP 26 DI 10.1002/(SICI)1521-3951(199911)216:1<21::AID-PSSB21>3.3.CO;2-J PG 6 WC Physics, Condensed Matter SC Physics GA 264QX UT WOS:000084193900006 ER PT J AU Bayerl, MW Brandt, MS Glaser, ER Wickenden, AE Koleske, DD Henry, RL Stutzmann, M AF Bayerl, MW Brandt, MS Glaser, ER Wickenden, AE Koleske, DD Henry, RL Stutzmann, M TI The origin of red luminescence from Mg-doped GaN SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT 3rd International Conference on Nitride Semiconductors (ICNS 99) CY JUL 04-09, 1999 CL MONTPELLIER, FRANCE ID CHEMICAL-VAPOR-DEPOSITION; LIGHT-EMITTING-DIODES; MAGNETIC-RESONANCE AB In addition to broad photoluminescence (PL) bands at 3.2 and 2.8 eV, Mg-doped GaN also exhibits a characteristic red PL band centered around 1.75 eV. Using optically detected magnetic resonance (ODMR), a deep defect with an isotropic g-value of 2.001 and a linewidth of 5 mT is found to be responsible for the red luminescence. Various shallow and deep donors are also found to participate in this radiative transition. The results are compared to the ODMR of n-type GaN. C1 Tech Univ Munich, Walter Schottky Inst, D-85748 Garching, Germany. USN, Res Lab, Washington, DC 20375 USA. RP Bayerl, MW (reprint author), Tech Univ Munich, Walter Schottky Inst, Coulombwall, D-85748 Garching, Germany. RI Stutzmann, Martin/B-1480-2012; Brandt, Martin/C-5151-2017; OI Stutzmann, Martin/0000-0002-0068-3505 NR 14 TC 11 Z9 11 U1 0 U2 5 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD NOV PY 1999 VL 216 IS 1 BP 547 EP 550 DI 10.1002/(SICI)1521-3951(199911)216:1<547::AID-PSSB547>3.0.CO;2-8 PG 4 WC Physics, Condensed Matter SC Physics GA 264QX UT WOS:000084193900105 ER PT J AU Abe, S Rajagopal, AK AF Abe, S Rajagopal, AK TI Quantum entanglement inferred by the principle of maximum nonadditive entropy SO PHYSICAL REVIEW A LA English DT Article ID BELL INEQUALITIES; MIXED STATES; THERMODYNAMICS; TELEPORTATION AB The problem of quantum-state inference and the concept of quantum entanglement are studied using a nonadditive measure in the form of the Tsallis entropy indexed by the positive parameter q. The maximum entropy principle associated with this entropy along with its thermodynamic interpretation are discussed in detail for the Einstein-Podolsky-Rosen pair of two spin-1/2 particles. Given the data on the Bell-Clauser-Horne-Shimony-Holt observable, the analytic expression is presented for the inferred quantum entangled state. It is shown that for q > 1, indicating the subadditive feature of the Tsallis entropy, the entangled region is small and enlarges as one goes into the superadditive regime where q < 1. It is also shown that quantum entanglement can be quantified by the generalized (Kullback-Leibler) relative entropy. [S1050-2947(99)01111-7]. C1 Nihon Univ, Coll Sci & Technol, Funabashi, Chiba 2748501, Japan. USN, Res Lab, Washington, DC 20375 USA. RP Abe, S (reprint author), Nihon Univ, Coll Sci & Technol, Funabashi, Chiba 2748501, Japan. NR 29 TC 63 Z9 65 U1 1 U2 4 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 NOV PY 1999 VL 60 IS 5 BP 3461 EP 3466 DI 10.1103/PhysRevA.60.3461 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 257ED UT WOS:000083768800024 ER PT J AU Lin-Chung, PJ Rajagopal, AK AF Lin-Chung, PJ Rajagopal, AK TI Theory of thermopower in disordered mixed crystals: Application to Si-Ge systems SO PHYSICAL REVIEW B LA English DT Article ID CONVERSION EFFICIENCY; ALLOYS; SUPERLATTICES; SCATTERING; METALS AB A Green's-function theory of thermoelectric power in disordered mixed crystals is presented. This theory incorporates features of (a) disorder, (b) band structure, (c) relevant dielectric function, and (d) electron-phonon interaction. By formulating the theory in coordinate space, besides subsuming previous work on metals and alloys as special cases, the inclusion of disorder effects based on coherent potential approximation has been incorporated into this scheme. This formulation gives the concentration and band occupancy dependence of thermopower. Thus it provides a possibility for investigating other disordered mixed systems which may be tailored to yield larger values of thermoelectric figure of merit. As an illustration of this formalism, numerical estimations of the contributions due to disorder and electron-phonon effects to the thermopower in a two-band model of Si-Ge mixed crystal system are given at room temperature. [S0163-1829(99)00441-5]. C1 USN, Res Lab, Washington, DC 20375 USA. RP Lin-Chung, PJ (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 45 TC 2 Z9 2 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1999 VL 60 IS 17 BP 12033 EP 12044 DI 10.1103/PhysRevB.60.12033 PG 12 WC Physics, Condensed Matter SC Physics GA 257XU UT WOS:000083808700039 ER PT J AU Carroll, TL AF Carroll, TL TI Using unstable periodic orbits to overcome distortion in chaotic signals SO PHYSICAL REVIEW E LA English DT Article ID SYNCHRONIZATION; SYSTEMS; CIRCUITS AB Proposals to use chaos for communications have been hindered by the fact that broadband chaotic signals are distorted by narrow band or frequency dependent communications channels. I show in this paper how the unstable periodic orbits from a chaotic attractor may be used to estimate the parameters of a filter that has acted on a signal from that attractor and estimate the chaotic signal, even when additive noise larger than the chaotic signal is present. [S1063-651X(99)13111-8]. C1 USN, Res Lab, Washington, DC 20375 USA. RP Carroll, TL (reprint author), USN, Res Lab, Code 6345, Washington, DC 20375 USA. OI Carroll, Thomas/0000-0002-2371-2049 NR 26 TC 1 Z9 2 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD NOV PY 1999 VL 60 IS 5 BP 5469 EP 5473 DI 10.1103/PhysRevE.60.5469 PN A PG 5 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 258ZZ UT WOS:000083870700063 PM 11970420 ER PT J AU Xu, JL Selinger, RLB Selinger, JV Ratna, BR Shashidhar, R AF Xu, JL Selinger, RLB Selinger, JV Ratna, BR Shashidhar, R TI Monte Carlo simulation of smectic liquid crystals and the electroclinic effect: The role of molecular shape SO PHYSICAL REVIEW E LA English DT Article ID MODEL; BEHAVIOR; PHYSICS; FIELD AB Using Monte Carlo simulation methods, we explore the role of molecular shape in the phase behavior of liquid crystals and the electroclinic effect. We study a "bent-rod" mesogen shaped like the letter Z, composed of seven soft spheres bonded rigidly together with no intramolecular degrees of freedom. For strongly angled molecules, we find that steric repulsion alone provides the driving force for a smectic-C phase, even without intermolecular dipole-dipole interactions. For weakly angled (nearly rodlike) molecules, we find a stable smectic-A (SmA) phase and a strong electroclinic effect with a saturation tilt angle of about 19 degrees. In the SmA phase we find evidence of vortexlike point defects. We also observe a field-induced nematic-smectic phase transition. [S1063-651X(99)02111-X]. C1 Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. USN, Res Lab, Ctr Biomol Sci & Engn, Washington, DC 20375 USA. RP Selinger, RLB (reprint author), Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. RI Selinger, Jonathan/D-1445-2010; OI Selinger, Jonathan/0000-0002-4982-2457; Selinger, Robin/0000-0002-6519-9685 NR 25 TC 28 Z9 28 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD NOV PY 1999 VL 60 IS 5 BP 5584 EP 5590 DI 10.1103/PhysRevE.60.5584 PN A PG 7 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 258ZZ UT WOS:000083870700078 PM 11970435 ER PT J AU Kafafi, ZH Murata, H Picciolo, LC Mattoussi, H Merritt, CD Iizumi, Y Kido, J AF Kafafi, ZH Murata, H Picciolo, LC Mattoussi, H Merritt, CD Iizumi, Y Kido, J TI Electroluminescent properties of functional pi-electron molecular systems SO PURE AND APPLIED CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Symposium on Functional Dyes - Science and Technology of Functional pi-Electron Systems CY MAY 31-JUN 04, 1999 CL OSAKA, JAPAN SP Int Union Pure & Appl Chem, Kinki Chem Soc Japan ID LIGHT-EMITTING-DIODES; PHOTOLUMINESCENCE QUANTUM YIELD; THIN-FILMS; DURABILITY; DEVICES; RUBRENE AB Molecules with delocalized pi-electrons possess attractive electroluminescent properties, and have been recently incorporated as the active emissive layers in organic light-emitting devices. In particular, electroluminescent molecular composites using a highly fluorescent guest, with/without carrier trapping properties, and a host with dual luminescent and carrier transport properties are the focus of this study. Devices based on these luminescent functional pi-electron molecular systems exhibited high electroluminescence quantum efficiency, and good thermal and temporal stability, with ease of color tunability. The paper discusses the mechanisms of light-emission that lead to superior performance in these molecular devices. Efficient Forster energy transfer from the host to the guest molecules, and direct carrier recombination at the highly fluorescent guest molecules are proposed as the two mechanisms responsible for high efficiency. C1 USN, Res Lab, Washington, DC 20375 USA. Yamagata Univ, Grad Sch Engn, Yonezawa, Yamagata 992, Japan. RP Kafafi, ZH (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI KIDO, Junji/H-3049-2012; Murata, Hideyuki/J-8453-2012 OI Murata, Hideyuki/0000-0001-8248-9652 NR 23 TC 11 Z9 12 U1 0 U2 1 PU INT UNION PURE APPLIED CHEMISTRY PI RES TRIANGLE PK PA 104 TW ALEXANDER DR, PO BOX 13757, RES TRIANGLE PK, NC 27709-3757 USA SN 0033-4545 J9 PURE APPL CHEM JI Pure Appl. Chem. PD NOV PY 1999 VL 71 IS 11 BP 2085 EP 2094 DI 10.1351/pac199971112085 PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA 334RU UT WOS:000088200100011 ER PT J AU Bobak, JP Ruf, CS AF Bobak, JP Ruf, CS TI A new model for the structure function of integrated water vapor in turbulence SO RADIO SCIENCE LA English DT Article ID REFRACTIVE-INDEX; WET TROPOSPHERE; BOUNDARY-LAYER; FLUCTUATIONS; SCALE; GHZ AB Turbulent fluctuation of integrated water vapor in the troposphere is one of the major noise sources in radio interferometry. Processed integrated water Vapor estimates from microwave radiometers colocated with interferometers have been used to set bounds on this uncertainty. The bound has been in the form of a calculated structure function, which is a measure of temporal or spatial decorrelation of fluctuations. In this paper a new model is presented for the estimation of the structure function in the absence of radiometer measurements. Using this model, the structure function can be estimated using measurements or estimates of a limited number of meteorological parameters. These parameters include boundary layer depth, surface heat and humidity fluxes, entrainment humidity flux, average virtual potential temperature in the boundary layer, and geostrophic wind speed. These parameters can be found or estimated from radiosonde and surface eddy correlation system data. The model is based on a framework of turbulence meteorology and provides excellent agreement when compared with state-of-the-art atmospheric turbulence simulations. Results of preliminary comparisons with ground truth show some excellent agreement, as well as some problems. The performance of the new model exceeds that of one current model. C1 Penn State Univ, Dept Elect Engn, University Pk, PA 16802 USA. RP Bobak, JP (reprint author), USN, Res Lab, Remote Sensing Phys Branch, 4555 Overlook Ave SW, Washington, DC 20375 USA. RI Ruf, Christopher/I-9463-2012 NR 27 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD NOV-DEC PY 1999 VL 34 IS 6 BP 1461 EP 1473 DI 10.1029/1999RS900097 PG 13 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA 258EC UT WOS:000083824300010 ER PT J AU Balzaretti, NM Gonzalez, EJ Piermarini, GJ Russell, TP AF Balzaretti, NM Gonzalez, EJ Piermarini, GJ Russell, TP TI Resistance heating of the gasket in a gem-anvil high pressure cell SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID NANOSIZE PARTICLES; X-RAY; IRON; FABRICATION AB Resistance heating of the gasket strip in a gem-anvil high pressure cell was successful in obtaining sample temperatures up to 1100 degrees C, under pressures up to 4.0 GPa. The heating capabilities, as well as the mechanical and chemical stability, of several different gasket strips (two Ni-based alloys, Ta, Pt/Rh, and a Re/Mo alloy) with different design shapes, and two different single-crystal anvil materials (diamond and cubic zirconia) were investigated. Two gasket-strip designs were found to provide optimum uniform heating conditions while decreasing the required current needed to achieve 1100 degrees C. Two anvil systems were investigated to reduce the temperature increase of the pressure cell body. Cubic zirconia anvils reduced the cell-body temperature to 100 degrees C at sample temperatures up to 1100 degrees C. However, zirconia anvils often failed during heating and almost always failed during cooling. Diamond anvils with cubic zirconia mounting plates also permitted temperatures up to 1100 degrees C to be reached without anvil failure. However, the cell-body temperature increased to 300 degrees C. A sealed vacuum-type chamber was employed to eliminate the problem with gasket and anvil oxidation. The optimized operating parameters reported here provide a routine method for high temperature-high pressure studies. The method was used to densify and sinter nanosize amorphous silicon nitride and gamma-alumina powders at high temperatures and high pressures. [S0034-6748(99)03610-2]. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. USN, Res Lab, Washington, DC 20375 USA. UFRGS, Inst Fis, Porto Alegre, RS, Brazil. RP Balzaretti, NM (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Balzaretti, Naira/L-3417-2014 OI Balzaretti, Naira/0000-0003-2797-8618 NR 22 TC 4 Z9 4 U1 1 U2 10 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD NOV PY 1999 VL 70 IS 11 BP 4316 EP 4323 DI 10.1063/1.1150095 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 251NQ UT WOS:000083452100032 ER PT J AU Ramirez, DA Janiesch, RE AF Ramirez, DA Janiesch, RE TI Coordinated test and training for undersea warfare at AUTEC SO SEA TECHNOLOGY LA English DT Article C1 Atlantic Undersea Test & Evaluat Ctr Detachment, W Palm Beach, FL USA. USN, Undersea Warfare Ctr, Div Newport, Engn Test & Evaluat Dept, Newport, RI USA. RP Ramirez, DA (reprint author), Atlantic Undersea Test & Evaluat Ctr Detachment, W Palm Beach, FL USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU COMPASS PUBL INC PI ARLINGTON PA SUITE 1000 1117 N 19 ST, ARLINGTON, VA 22209 USA SN 0093-3651 J9 SEA TECHNOL JI Sea Technol. PD NOV PY 1999 VL 40 IS 11 BP 31 EP 36 PG 6 WC Engineering, Ocean SC Engineering GA 260FT UT WOS:000083939400004 ER PT J AU Shad, JA Chinn, CG Brann, OS AF Shad, JA Chinn, CG Brann, OS TI Acute hepatitis after ingestion of herbs SO SOUTHERN MEDICAL JOURNAL LA English DT Article ID TOXIC HEPATITIS; CHAPARRAL LEAF; HEPATOTOXICITY; REMEDIES; MEDICINE; PRODUCT AB Herbal preparations are marketed as natural and safe alternatives to conventional medicines for the prevention and treatment of a variety of ailments. However, consumers may not be fully aware of their potential side effects. We report two cases of acute hepatitis after the ingestion of herbal preparations. One of the mixtures included chaparral and bee pollen; the other was pure bee pollen. Chaparral has been reported to have similar effects in other patients, but we found no reports of acute hepatitis: from bee pollen. We discuss chaparral and several other hepatotoxic herbs and review the literature. Our case reports remind primary care physicians to ask their patients about herbal use and discuss their potential toxicities. C1 USN, Med Ctr, Dept Clin Invest, USNR,MC, San Diego, CA 92134 USA. USN, Med Ctr, Dept Internal Med, Div Gastroenterol, San Diego, CA 92134 USA. RP Shad, JA (reprint author), USN, Med Ctr, Dept Clin Invest, USNR,MC, 34800 Bob Wilson Dr,Suite 5, San Diego, CA 92134 USA. NR 24 TC 18 Z9 19 U1 0 U2 1 PU SOUTHERN MEDICAL ASSN PI BIRMINGHAM PA 35 LAKESHORE DR PO BOX 190088, BIRMINGHAM, AL 35219 USA SN 0038-4348 J9 SOUTHERN MED J JI South.Med.J. PD NOV PY 1999 VL 92 IS 11 BP 1095 EP 1097 DI 10.1097/00007611-199911000-00011 PG 3 WC Medicine, General & Internal SC General & Internal Medicine GA 259ZT UT WOS:000083924400011 PM 10586838 ER PT J AU Booth, JC Vale, LR Ono, RH Claassen, JH AF Booth, JC Vale, LR Ono, RH Claassen, JH TI Predicting nonlinear effects in superconducting microwave transmission lines from mutual inductance measurements SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article; Proceedings Paper CT International Superconductive Electronics Conference CY JUN 21-25, 1999 CL BERKELEY, CALIFORNIA ID INTERMODULATION AB We demonstrate the use of a new experimental technique based on mutual inductance measurements to quantitatively predict nonlinear effects in microwave devices fabricated from high-temperature superconductor (HTS) materials. The mutual inductance measurements yield the current dependence of the penetration depth lambda(J) in unpatterned HTS thin films. This information is used to calculate third-harmonic generation in coplanar waveguide (CPW) transmission lines and compares very well with actual measurements of CPW transmission lines of variable dimensions fabricated from YBa2Cu3O7-delta thin film samples. The mutual inductance measurements should prove extremely valuable as a screening technique for microwave applications of HTS materials that require very low nonlinear response. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. USN, Res Lab, Washington, DC 20375 USA. RP Booth, JC (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD NOV PY 1999 VL 12 IS 11 BP 711 EP 713 DI 10.1088/0953-2048/12/11/306 PG 3 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 260KH UT WOS:000083948400006 ER PT J AU Claassen, JH Booth, JC Beall, JA Vale, LR Rudman, DA Ono, RH AF Claassen, JH Booth, JC Beall, JA Vale, LR Rudman, DA Ono, RH TI Comparison of microwave and mutual inductance measurements of the inductive nonlinearity of HTS thin films SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article; Proceedings Paper CT International Superconductive Electronics Conference CY JUN 21-25, 1999 CL BERKELEY, CALIFORNIA AB A quadratic dependence of penetration depth on supercurrent density may be observed both by an inductive measurement on unpatterned films and by a microwave measurement of third-harmonic generation in coplanar waveguide. Results for the two methods are compared for a series of YBCO films. We find good agreement between the two measurements. C1 USN, Res Lab, Washington, DC 20375 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Claassen, JH (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 8 TC 7 Z9 7 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD NOV PY 1999 VL 12 IS 11 BP 714 EP 716 DI 10.1088/0953-2048/12/11/307 PG 3 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 260KH UT WOS:000083948400007 ER PT J AU Pique, A McGill, RA Chrisey, DB Leonhardt, D Mslna, TE Spargo, BJ Callahan, JH Vachet, RW Chung, R Bucaro, MA AF Pique, A McGill, RA Chrisey, DB Leonhardt, D Mslna, TE Spargo, BJ Callahan, JH Vachet, RW Chung, R Bucaro, MA TI Growth of organic thin films by the matrix assisted pulsed laser evaporation (MAPLE) technique SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 26th International Conference on Metallurgical Coating and Thin Films CY APR 12-15, 1999 CL SAN DIEGO, CALIFORNIA SP Div Amer Vacuum Soc, Vacuum Metallurgy & Thin Films DE polymer thin films; organic thin films; chemical sensors; matrix assisted pulsed laser evaporation ID CHEMICAL SENSORS; ABLATION; POLYMERS; NM AB A novel variation of conventional pulsed laser evaporation, known as matrix assisted pulsed laser evaporation, or MAPLE, has been successfully used to deposit highly uniform thin films of a variety of organic materials including a number of polymers. The MAPLE technique is carried out in a vacuum chamber and involves directing a pulsed laser beam (lambda = 193 or 248 nm: fluence = 0.01 to 0.5 J/cm(2)) onto a frozen target (100-200 K) consisting of a solute polymeric or organic compound dissolved in a solvent matrix. The laser beam evaporates the surface layers of the target, with both solvent and solute molecules being released into the chamber. The volatile solvent is pumped away, whereas the polymer/organic molecules coat the substrate. Thin uniform films (< 50 nm) Of various materials, such as functionalized polysiloxanes and carbohydrates, have been deposited on Si(lll)and NaCl substrates. The films prepared using this method have been examined by optical microscopy, scanning electron microscopy, atomic force microscopy, Fourier transform infrared spectroscopy and electrospray mass spectrometry. Careful control of the processing conditions allowed the complex polymer/organic molecules to be transferred to the substrate as uniform films without any significant chemical modification. Using MAPLE, large or small regions within a substrate can be discretely coated with submonolayer thickness control. The use of MAPLE films for chemical sensor applications has been investigated and the potential of this technique for producing high quality thin films of other organic compounds will be discussed. (C) 1999 Elsevier Science S.A. All rights reserved. C1 USN, Res Lab, Washington, DC 20375 USA. Geocenters Inc, Ft Washington, MD 20744 USA. RP Pique, A (reprint author), USN, Res Lab, Washington, DC 20375 USA. EM pique@nrl.navy.mil NR 18 TC 134 Z9 135 U1 2 U2 21 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD NOV PY 1999 VL 355 BP 536 EP 541 DI 10.1016/S0257-8972(99)00376-X PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 269WP UT WOS:000084500800093 ER PT J AU Gue, KR AF Gue, KR TI The effects of trailer scheduling on the layout of freight terminals SO TRANSPORTATION SCIENCE LA English DT Article AB Supervisors in a less-than-truckload freight terminal establish material flows inside the terminal by assigning incoming trailers to open doors. A common scheduling strategy is to look ahead into the queue of incoming trailers and assign them to doors to minimize worker travel. We develop a model of the resulting material flows and use it to construct Layouts that exploit this type of scheduling policy. Based on data from a test site, our results suggest that look-ahead scheduling alone can reduce labor costs due to travel by 15-20% compared to a first-come-first-served policy. Layouts constructed with the material flow model provide further savings of 3-30% in labor cost due to travel, depending on the mix of freight on incoming trailers and the length of the queue of trailers from which the supervisor makes assignments. C1 USN, Postgrad Sch, Dept Syst Management, Monterey, CA 93943 USA. RP Gue, KR (reprint author), USN, Postgrad Sch, Dept Syst Management, Monterey, CA 93943 USA. NR 6 TC 75 Z9 77 U1 1 U2 3 PU INST OPERATIONS RESEARCH MANAGEMENT SCIENCES PI LINTHICUM HTS PA 901 ELKRIDGE LANDING RD, STE 400, LINTHICUM HTS, MD 21090-2909 USA SN 0041-1655 J9 TRANSPORT SCI JI Transp. Sci. PD NOV PY 1999 VL 33 IS 4 BP 419 EP 428 DI 10.1287/trsc.33.4.419 PG 10 WC Operations Research & Management Science; Transportation; Transportation Science & Technology SC Operations Research & Management Science; Transportation GA 257WT UT WOS:000083806000007 ER PT J AU Gagne, PJ Martinez, JM AF Gagne, PJ Martinez, JM TI Treatment of upper-extremity phlegmasia cerulea dolens with intra-arterial thrombolysis - A case report SO VASCULAR SURGERY LA English DT Article ID VENOUS GANGRENE; CAERULEA DOLENS AB Upper-extremity deep vein thrombosis is a common iatrogenic complication in patients who have had central venous catheters, and is usually associated with mild symptoms. This report is of a 57-year-old craftsman who developed phlegmasia cerulea dolens of his left upper extremity 16 hours after removal of an ipsilateral subclavian vein catheter. The extremity was tensely edematous, hand was mottled, and tips of the digits were cyanotic. Arterial Doppler signals were normal. Fourteen hours of extremity elevation and heparin anticoagulation resulted in no clinical improvement. Duplex ultrasonography and venography showed diffuse thrombosis of the veins of the arm and forearm, but patent axillary and subclavian veins. Due to the severity of the edema and evidence of vascular compromise, an infusion catheter, introduced through the right common femoral artery, was positioned in the left brachial artery and an intra-arterial urokinase infusion of the left upper extremity initiated. Within 12 hours, the patient's left upper extremity improved notably. Ninety-three hours later, the urokinase infusion was stopped and the left upper extremity appeared normal. Follow-up duplex ultrasonography documented no residual thrombus in the deep veins of the left arm and forearm. Six months later, the patient has no residual disability, extremity edema, or limitations in function. An extensive review of the English literature identified no previous reports of intra-arterial thrombolysis for upper-extremity phlegmasia cerulea dolens. This case is discussed and pertinent literature reviewed. C1 USN, Med Ctr, Div Vasc Surg, Portsmouth, VA USA. RP Gagne, PJ (reprint author), Univ Vasc Associates, 530 1st Ave,Suite 6F, New York, NY 10016 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU WESTMINSTER PUBL INC PI GLEN HEAD PA 708 GLEN COVE AVE, GLEN HEAD, NY 11545 USA SN 0042-2835 J9 VASCULAR SURG JI Vasc. Surg. PD NOV-DEC PY 1999 VL 33 IS 6 BP 633 EP 639 DI 10.1177/153857449903300608 PG 7 WC Surgery; Peripheral Vascular Disease SC Surgery; Cardiovascular System & Cardiology GA 256DH UT WOS:000083710300008 ER PT J AU Georgiou, IT Corless, MJ Bajaj, AK AF Georgiou, IT Corless, MJ Bajaj, AK TI Dynamics of nonlinear structures with multiple equilibria: A singular perturbation-invariant manifold approach SO ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND PHYSIK LA English DT Article DE nonlinear structural dynamics; singular perturbations; slow invariant manifold ID OSCILLATOR AB This work analyzes the motions of a stiff linear oscillator coupled to a soft nonlinear oscillator and subject to a forcing term. This system is a representative of a large class of structural dynamical systems with stiff and soft substructures and with multiple equilibrium states. Using the methodology of singular perturbations and the theory of invariant manifolds, we describe globally (in time) the motions in a finite neighborhood of the origin in phase space. It is shown that, every motion of the system depends on a slowly varying component and a component which rapidly decays with time. The long term behavior of the system is, thus, described by a lower order slow system, which is the restriction of the system to an invariant manifold that contains ail the slow motions of the system. For slow periodic forcing, the slow manifold is periodic. The dynamics of the slow system on the invariant manifold, as well as the effects of the singular perturbation parameter on the validity of the slow manifold approximation are also explored. C1 USN, Res Lab, Special Project Nonlinear Sci, Washington, DC 20375 USA. Purdue Univ, Sch Mech Engn, W Lafayette, IN 47907 USA. Purdue Univ, Sch Aeronaut & Astronaut, W Lafayette, IN 47907 USA. RP Georgiou, IT (reprint author), USN, Res Lab, Special Project Nonlinear Sci, Code 6700-3, Washington, DC 20375 USA. RI Corless, Martin/F-2299-2011 NR 17 TC 6 Z9 6 U1 0 U2 0 PU BIRKHAUSER VERLAG AG PI BASEL PA VIADUKSTRASSE 40-44, PO BOX 133, CH-4010 BASEL, SWITZERLAND SN 0044-2275 J9 Z ANGEW MATH PHYS JI Z. Angew. Math. Phys. PD NOV PY 1999 VL 50 IS 6 BP 892 EP 924 DI 10.1007/s000330050185 PG 33 WC Mathematics, Applied SC Mathematics GA 270TV UT WOS:000084553100003 ER PT J AU Todd, MD Johnson, GA Chang, CC AF Todd, MD Johnson, GA Chang, CC TI Passive, light intensity-independent interferometric method for fibre Bragg grating interrogation SO ELECTRONICS LETTERS LA English DT Article ID SENSORS AB The authors describe a passive technique for sensing the strain-induced wavelength shift of a fibre Bragg grating (FBG) using a Mach-Zehnder interferometer that utilises a 3 x 3 coupler. Laboratory data show that a resolution of similar to 10n epsilon/root Hz RMS is achievable with inherent insensitivity to sourer intensity variations. C1 USN, Res Lab, Washington, DC 20375 USA. RP Todd, MD (reprint author), USN, Res Lab, Code 5670, Washington, DC 20375 USA. NR 5 TC 36 Z9 36 U1 0 U2 3 PU INST ENGINEERING TECHNOLOGY-IET PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD OCT 28 PY 1999 VL 35 IS 22 BP 1970 EP 1971 DI 10.1049/el:19991328 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA 316NA UT WOS:000087172500057 ER PT J AU Fromm, MD Bevilacqua, RM Hornstein, J Shettle, E Hoppel, K Lumpe, JD AF Fromm, MD Bevilacqua, RM Hornstein, J Shettle, E Hoppel, K Lumpe, JD TI An analysis of Polar Ozone and Aerosol Measurement (POAM) II Arctic polar stratospheric cloud observations, 1993-1996 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID VORTEX CONDITIONS; WINTER; DEPLETION; HNO3; MLS; TEMPERATURES; JANUARY; NORWAY; EASOE AB The Polar Ozone and Aerosol Measurement (POAM) II instrument made numerous observations of polar stratospheric clouds (PSCs) in the northern hemisphere winters of 1993/1994 through 1995/1996. An updated POAM II PSC detection algorithm, described herein, is applied to POAM II 1060 nm aerosol extinction profiles to distinguish PSCs from noncloud measurements. The impact of the updated algorithm on previously published Antarctic PSC statistics is discussed. Operating sporadically in the 1993/1994 PSC season (defined as November through April), but continuously in the following two winters, POAM II made approximately 340 PSC profile measurements. We analyze the POAM II PSC observations with respect to polar vortex location, temperature, longitude, time, and altitude. Daily PSC probability (defined as the number of PSC profiles inside the polar vortex relative to the number of all profiles located inside the vortex) exceeds 60% during the most intense PSC episodes. There is considerable year-to-year variability in PSC probability, preferred location, and timing of onset and final appearance. The POAM II data also reveal interannual differences in the seasonal change of PSC altitude. Certain observations of opaque clouds are used to infer Type II PSCs. The pattern of observed PSCs is discussed with respect to recent studies of Arctic ozone loss. C1 Computat Phys Inc, Fairfax, VA 22031 USA. USN, Res Lab, Washington, DC 20375 USA. RP Fromm, MD (reprint author), Computat Phys Inc, 2750 Prosper Ave,Suite 600, Fairfax, VA 22031 USA. EM fromm@poama.nrl.navy.mil RI Fromm, Michael/F-4639-2010 NR 37 TC 39 Z9 39 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 27 PY 1999 VL 104 IS D20 BP 24341 EP 24357 DI 10.1029/1999JD900273 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 249KN UT WOS:000083332400009 ER PT J AU Watts, DM Porter, KR Putvatana, P Vasquez, B Calampa, C Hayes, CG Halstead, SB AF Watts, DM Porter, KR Putvatana, P Vasquez, B Calampa, C Hayes, CG Halstead, SB TI Failure of secondary infection with American genotype dengue 2 to cause dengue haemorrhagic fever SO LANCET LA English DT Article ID HEMORRHAGIC-FEVER; SHOCK SYNDROME; MOLECULAR EVOLUTION; TYPE-2 VIRUS; RISK-FACTORS; IDENTIFICATION; NUCLEOTIDE; ANTIBODIES; EPIDEMIC; THAILAND AB Background Population-based epidemiological studies have shown that infection with dengue type 2 (DEN-2) virus in individuals previously infected with a different serotype of the virus is a major risk factor for dengue haemorrhagic fever and dengue shock syndrome. However, the western hemisphere was spared epidemics of these two syndromes, until the introduction of a southeast Asian DEN-2 genotype. Possibly American DEN-2 genotype strains lacked properties necessary to cause severe disease. We report on a major epidemic of DEN-2 in Peru in 1995, about 5 years after an epidemic of DEN-1 in the same population. Methods In Iquitos, a city of 344 686 inhabitants in Peru, cases of dengue fever were studied prospectively from 1990. Acute phase of illness serum samples from patients were tested for virus in C6/36 cells, and virus isolates were identified by immunofluorescence. Isolates of dengue 2 virus obtained from patients during an outbreak of mild febrile illness in 1995 were sequenced to determine the genotype. Serological analysis of paired samples from the patients was done with an IgM capture ELISA and an indirect IgG ELISA. In addition, serum samples collected annually between 1993 and 1996 from a large cohort of students were tested for dengue IgG antibody by an ELISA. Serum samples from a random sample of 129 students from this cohort were tested for dengue neutralising antibodies to quantify the serotype specific infection rates. Findings Among the 129 students (aged 7-20 years in 1993) who had serum samples available before and after the epidemic, 78 (60.5%) had a secondary DEN-2 virus infection. By extrapolation, 49 266 of the 81 479 children (aged 5-14 years) in Iquitos would have experienced such infections. From previous studies, between 887 and 10 247 cases of dengue haemorrhagic fever and dengue shock syndrome would have been expected. No cases were found. DEN-2 isolates were of the American genotype. Interpretation This prospective study shows that secondary infection by the American DEN-2 genotype did not cause dengue haemorrhagic fever and dengue shock syndrome. C1 USN, Med Res Ctr Detachment, AMEMB NAMRID, Unit 3800, Bethesda, MD USA. Peruvian Navy, Ctr Med Naval, Bellavista, Callao, Peru. Loreto Reg Minist Hlth, Iquitos, Loreto, Peru. Off Naval Res, Arlington, VA 22217 USA. RP Watts, DM (reprint author), USN, Med Res Ctr, Detachment AMEMB NAMRID, Unit 3800, APO, AA 34031 USA. RI Porter, Kevin/A-8027-2011 NR 34 TC 183 Z9 195 U1 0 U2 11 PU LANCET LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 0140-6736 J9 LANCET JI Lancet PD OCT 23 PY 1999 VL 354 IS 9188 BP 1431 EP 1434 DI 10.1016/S0140-6736(99)04015-5 PG 4 WC Medicine, General & Internal SC General & Internal Medicine GA 248LY UT WOS:000083277400013 PM 10543670 ER PT J AU Owrutsky, JC Baronavski, AP AF Owrutsky, JC Baronavski, AP TI Ultrafast photodissociation studies of acetyl cyanide and acetic acid and unimolecular decomposition rates of the acetyl radical products SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID 193 NM; STEPWISE DISSOCIATION; IONIZATION-POTENTIALS; EXCITED-STATES; ALPHA-CLEAVAGE; ACETONE; CHLORIDE; DYNAMICS; SPECTROSCOPY; PHOTOLYSIS AB Unimolecular decomposition rates for acetyl radical following the photodissociation of acetyl cyanide and acetic acid near 193 nm have been studied using ultrafast mass-resolved photoionization spectroscopy. In both cases, the parent decays with an instrumentally limited lifetime, while the acetyl radical behaves in a manner consistent with an RRKM mechanism, in contrast to our previous results on acetone. It is necessary to convolute the population distribution with the microcanonical RRKM rates in order to achieve this agreement. We have also undertaken an ab initio study of the excited states of acetyl cyanide to clarify the assignments of these states. The state excited at 193 nm arises from a pi -->pi* transition with a calculated transition velocity dipole moment oriented at an angle of 57 degrees with respect to the C-C=N bond, resulting in an anisotropy parameter of -0.22. This is in reasonable agreement with the previous data of North [J. Phys. Chem. A 101, 9224 (1997)]. The apparent RRKM behavior of the acetyl radical formed by the photodissociation of acetic acid and acetyl cyanide indicates that acetyl radical produced by the photodissociation of acetone at 193 nm may exhibit "extrinsic non-RRKM" effects, i.e., dynamic bottlenecks or mode specific effects. (C) 1999 American Institute of Physics. [S0021-9606(99)01440-3]. C1 USN, Res Lab, Div Chem, Washington, DC 20375 USA. RP Owrutsky, JC (reprint author), USN, Res Lab, Div Chem, Code 6111, Washington, DC 20375 USA. RI Owrutsky, Jeffrey/K-7649-2012 NR 53 TC 43 Z9 43 U1 0 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 22 PY 1999 VL 111 IS 16 BP 7329 EP 7336 DI 10.1063/1.480056 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 244LG UT WOS:000083052100018 ER PT J AU Gierlinski, M Zdziarski, AA Poutanen, J Coppi, PS Ebisawa, K Johnson, WN AF Gierlinski, M Zdziarski, AA Poutanen, J Coppi, PS Ebisawa, K Johnson, WN TI Radiation mechanisms and geometry of Cygnus X-1 in the soft state SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE accretion, accretion discs; radiation mechanisms : non-thermal; stars : individual : Cygnus X-1; gamma-rays : observations; gamma-rays : theory; X-rays : stars ID ACTIVE GALACTIC NUCLEI; X-RAY-EMISSION; ACCRETION DISKS; BLACK-HOLE; HDE 226868; CROSS-SECTIONS; PAIR PLASMAS; MASS; ABSORPTION; SPECTRUM AB We present X-ray/gamma-ray spectra of Cyg X-1 observed during the transition from the hard to the soft state and in the soft state by ASCA, RXTE and CGRO/OSSE in 1996 May and June. The spectra consist of a dominant soft component below similar to 2keV and a power-law-like continuum extending to at least similar to 800 keV. We interpret them as emission from an optically thick, cold accretion disc and from an optically thin, non-thermal corona above the disc, A fraction f greater than or similar to 0.5 of total available power is dissipated in the corona, We model the soft component by multicolour blackbody disc emission taking into account the torque-free inner-boundary condition. If the disc extends down to the minimum stable orbit, the ASCA/RXTE data yield the most probable black hole mass of M-X approximate to 10 M-circle dot and an accretion rate, (M) over dot approximate to 0.5L(E)/c(2), locating Cyg X-l in the soft state in the upper part of the stable, gas-pressure-dominated, accretion-disc solution branch. The spectrum of the corona is well modelled by repeated Compton scattering of seed photons from the disc off electrons with a hybrid, thermal/non-thermal distribution. The electron distribution can be characterized by a Maxwellian with an equilibrium temperature of kT(e) similar to 30-50 keV, a Thomson optical depth of tau similar to 0.3 and a quasi-power-law tail, The compactness of the corona is 2 less than or similar to l(h) less than or similar to 7, and a presence of a significant population of electron-positron pairs is ruled out, We find strong signatures of Compton reflection from a cold and ionized medium, presumably an accretion disc, with an apparent reflector solid angle, Omega/2 pi similar to 0.5-0.7. The reflected continuum is accompanied by a broad iron K alpha line. C1 Jagiellonian Univ, Astron Observ, PL-30244 Krakow, Poland. N Copernicus Astron Ctr, PL-00716 Warsaw, Poland. Stockholm Observ, SE-13336 Saltsjobaden, Sweden. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Washington, DC USA. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. Yale Univ, Dept Astron, New Haven, CT 06511 USA. RP Gierlinski, M (reprint author), Jagiellonian Univ, Astron Observ, Orla 171, PL-30244 Krakow, Poland. RI Johnson, Neil/G-3309-2014; Poutanen, Juri/H-6651-2016; OI Poutanen, Juri/0000-0002-0983-0049; Gierlinski, Marek/0000-0001-9149-3514 NR 87 TC 319 Z9 322 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD OCT 21 PY 1999 VL 309 IS 2 BP 496 EP 512 DI 10.1046/j.1365-8711.1999.02875.x PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 251VK UT WOS:000083466900025 ER PT J AU Kroeger, RA Johnson, WN Kurfess, JD Phlips, BF AF Kroeger, RA Johnson, WN Kurfess, JD Phlips, BF TI Gamma ray polarimetry using a position sensitive germanium detector SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th International Conference on Solid State Detectors CY DEC 04-06, 1998 CL NARA, JAPAN SP Crest, Japan Sci & Technol Corp DE gamma-ray; polarimetry; germanium detector; Compton ID SPECTROSCOPY AB Imaging gamma-ray detectors make sensitive polarimeters in the Compton energy regime by measuring the scatter direction of gamma rays. The principle is to capitalize on the angular dependence of the Compton scattering cross section to polarized gamma rays and measure the distribution of scatter directions within the detector. This technique is effective in a double-sided germanium detector between roughly 50 keV and 1 MeV. This paper reviews device characteristics important to the optimization of a Compton polarimeter, and summarizes measurements we have made using a device with a 5 x 5 cm active area, 1 cm thickness, and strip-electrodes on a 2 mm pitch. (C) 1999 Elsevier Science B.V. All rights reserved. C1 USN, Res Lab, Washington, DC 20375 USA. Univ Space Res Assoc, Columbia, MD 21044 USA. RP Kroeger, RA (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Johnson, Neil/G-3309-2014 NR 10 TC 17 Z9 17 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 21 PY 1999 VL 436 IS 1-2 BP 165 EP 169 DI 10.1016/S0168-9002(99)00615-4 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 241TD UT WOS:000082897900025 ER PT J AU McKeown, W AF McKeown, W TI Frequency dependence in a liquid's complex refractive index measured with infrared spectroradiometry SO APPLIED OPTICS LA English DT Article ID TEMPERATURE; WATER; SKIN AB A laboratory measurement of wavelength dependence in the real n(lambda) and the imaginary k(lambda) parts of a liquid's complex refractive index is presented. A known heat flow through the liquid-gas interface is generated while a high-resolution infrared radiance spectrum is taken simultaneously. Wavelength variations of the absorption coefficient allow the emerging radiation to sense subsurface temperature gradients. This technique is valid only at intervals at which the absorption coefficient is sufficiently low to allow subsurface temperatures to be measured. Knowledge of a liquid's thermal conductivity, specific heat, and light transmission spaed is required. Measurement error depends on radiance measurement error and the minimization of atmospheric parameters. C1 USN, Remote Sensing Applicat Branch, Res Lab, Stennis Space Ctr, MS 39529 USA. RP McKeown, W (reprint author), USN, Remote Sensing Applicat Branch, Res Lab, Code 7340, Stennis Space Ctr, MS 39529 USA. EM mckeown@nrlssc.navy.mil NR 9 TC 0 Z9 0 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD OCT 20 PY 1999 VL 38 IS 30 BP 6439 EP 6446 DI 10.1364/AO.38.006439 PG 8 WC Optics SC Optics GA 249BA UT WOS:000083311200029 PM 18324174 ER PT J AU Harris, HC Dahn, CC Vrba, FJ Henden, AA Liebert, J Schmidt, GD Reid, IN AF Harris, HC Dahn, CC Vrba, FJ Henden, AA Liebert, J Schmidt, GD Reid, IN TI A very low luminosity, very cool, DC white dwarf SO ASTROPHYSICAL JOURNAL LA English DT Article DE polarization; stars : fundamental parameters; stars : individual (LHS 3250); white dwarfs ID DOUBLE-DEGENERATE; HELIUM; STARS; EVOLUTION; ENVELOPES; DISCOVERY AB The star LHS 3250 is found to be a white dwarf at a distance of 30 pc. Its absolute magnitudes (M-v = 15.72, M-bol = 16.2) put it among the least luminous white dwarfs known. Its optical spectrum shows no features, indicating that it has a DC classification, and it shows no detectable polarization, indicating that it does not have a very strong magnetic field. However, its broadband colors show it to have a unique spectral energy distribution, and it stands out from all other stars in BVI and other broadband photometric surveys. We discuss these properties and conclude that LHS 3250 must be an extremely cool white dwarf with strong collision-induced absorption at red-infrared wavelengths from molecular hydrogen, in accord with models for very cool white dwarf atmospheres. If so, it is the first such star known and the first star to provide observational evidence supporting these models. It suggests that other very cool white dwarfs, both halo white dwarfs and the oldest disk white dwarfs, also may have colors affected by similar absorption. The atmospheric composition of LHS 3250 is not known, and therefore its temperature is poorly determined. It is likely to be a helium-core star with a mass 0.3 < hi < 0.45 M. and a product of mass transfer in a close binary system. However, until its temperature is better known, its mass and age remain uncertain. C1 USN Observ, Flagstaff, AZ 86002 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. CALTECH, Palomar Observ, Pasadena, CA 91125 USA. RP Harris, HC (reprint author), USN Observ, POB 1149, Flagstaff, AZ 86002 USA. NR 39 TC 66 Z9 66 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 1999 VL 524 IS 2 BP 1000 EP 1007 DI 10.1086/307856 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 245YB UT WOS:000083135300040 ER PT J AU Sterling, AC Pike, CD Mason, HE Watanabe, T Antiochos, SK AF Sterling, AC Pike, CD Mason, HE Watanabe, T Antiochos, SK TI Variation of thermal structure with height of a solar Active Region derived from SOHO CDS and YOHKOH BCS observations SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : corona; Sun : UV radiation; Sun : X-rays, gamma rays ID CORONAL DIAGNOSTIC SPECTROMETER; BRAGG CRYSTAL SPECTROMETER; X-RAY-EMISSION; TEMPERATURE STRUCTURE; SPECTRA; FLARES; LINES; LOOPS; XUV AB We present observations of NOAA solar Active Region 7999 when it was near the west solar limb on 1996 December 2 and 3, using data from the Coronal Diagnostic Spectrometer (CDS) experiment on the SOHO satellite. Ratios of intensities of 2 MK material (as observed in CDS Fe XVI images) to 1 MK material (from CDS Mg IX images) indicate that there is a drop in the ratio of the hotter to the cooler material with height in the region, up to an altitude of about 10(5) km. At low altitudes the relative amount of 2 MK emission measure to 1 MK emission measure ranges from 8 to 10, while the ratio is minimum near 105 km, ranging from 1.3 to 3.5. The decrease with height of the CDS ratio qualitatively resembles the decrease in S XV election temperature with height (measurable up to approximate to 85,000 km) in the same active region obtained from the Bragg crystal spectrometer instrument on Yohkah. The CDS images indicate that the highest S XV temperatures and largest CDS ratios correspond to regions of microflares, and somewhat lower S XV temperatures and CDS ratios correspond to diffuse regions. Above 10(5) km, the trend of the CDS ratios changes, either increasing or remaining approximately constant with height. At these altitudes the CDS images show faint, large-scale diffuse structures. C1 Computat Phys Inc, Fairfax, VA 22031 USA. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. Rutherford Appleton Lab, Dept Space Sci, Didcot OX11 0QX, Oxon, England. Univ Cambridge, Dept Appl Math & Theoret Phys, Cambridge CB3 9EW, England. Natl Astron Observ, Mitaka, Tokyo 181, Japan. RP Inst Space & Astronaut Sci, Yoshinodai 3-1-1, Kanagawa 2298510, Japan. EM asterling@solar.stanford.edu; cdp@ast.star.rl.ac.uk; H.E.Mason@damtp.cam.ac.uk; watanabe@uvlab.mtk.nao.ac.jp; spiro@zeus.nrl.navy.mil RI Antiochos, Spiro/D-4668-2012 OI Antiochos, Spiro/0000-0003-0176-4312 NR 38 TC 9 Z9 9 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 1999 VL 524 IS 2 BP 1096 EP 1104 DI 10.1086/307820 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 245YB UT WOS:000083135300047 ER PT J AU Khokhlov, AM Hoflich, PA Oran, ES Wheeler, JC Wang, L Chtchelkanova, AY AF Khokhlov, AM Hoflich, PA Oran, ES Wheeler, JC Wang, L Chtchelkanova, AY TI Jet-induced explosions of core collapse supernovae SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; ISM : jets and outflows; pulsars : general; supernovae : general; supernovae : individual (SN 1998bw) ID GAMMA-RAY BURSTS; 25 APRIL 1998; MECHANISM; POLARIMETRY; CONVECTION; SN-1987A; EMISSION; STAR AB We numerically studied the explosion of a supernova caused by supersonic jets present in its center. The jets are assumed to be generated by a magnetorotational mechanism when a stellar core collapses into a neutron star. We simulated the process of the jet propagation through the star, jet breakthrough, and the ejection of the supernova envelope by the lateral shocks generated during jet propagation. The end result of the interaction is a highly nonspherical supernova explosion with two high-velocity jets of material moving in polar directions and slower moving, oblate, highly distorted ejecta containing most of the supernova material. The jet-induced explosion is entirely due to the action of the jets on the surrounding star and does not depend on neutrino transport or reacceleration of a stalled shock. The jet mechanism can explain the observed high polarization of Types Ib, Ic, and IIsupernovae, pulsar kicks, very high velocity material observed in supernova remnants, indications that radioactive material was carried to the hydrogen-rich layers in SN 1987A, and other observations that are very difficult or impossible to explain by the neutrino energy deposition mechanism. The breakout of the jet from a compact, hydrogen-deficient core may account for the gamma-ray burst and radio outburst associated with SN 1998bw/ GRB 980425. C1 USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. Univ Texas, Dept Astron, Austin, TX 78712 USA. Berkeley Res Associates Inc, Springfield, VA USA. RP Khokhlov, AM (reprint author), USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. NR 30 TC 170 Z9 170 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 1999 VL 524 IS 2 BP L107 EP L110 DI 10.1086/312305 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 245YM UT WOS:000083136300008 ER PT J AU Schaefer, BE Snyder, JA Hernandez, J Roscherr, B Deng, M Ellman, N Bailyn, C Rengstorf, A Smith, D Levine, A Barthelmy, S Butterworth, P Hurley, K Cline, T Meegan, C Kouveliotou, C Kippen, RM Park, HS Williams, GG Porrata, R Bionta, R Hartmann, D Band, D Frail, D Kulkarni, S Bloom, J Djorgovski, S Sadava, D Chaffee, F Harris, F Abad, C Adams, B Andrews, P Baltay, C Bongiovanni, A Briceno, C Bruzual, G Coppi, P Della Prugna, F Dubuc, A Emmet, W Ferrin, I Fuenmayor, F Gebhard, M Herrera, D Honeycutt, K Magris, G Mateu, J Muffson, S Musser, J Naranjo, O Oemler, A Pacheco, R Paredes, G Rengel, M Romero, L Rosenzweig, P Sabbey, C Sanchez, G Sanchez, G Schenner, H Shin, J Sinnott, J Sofia, S Stock, J Suarez, J Telleria, D Vicente, B Vieira, K Vivas, K AF Schaefer, BE Snyder, JA Hernandez, J Roscherr, B Deng, M Ellman, N Bailyn, C Rengstorf, A Smith, D Levine, A Barthelmy, S Butterworth, P Hurley, K Cline, T Meegan, C Kouveliotou, C Kippen, RM Park, HS Williams, GG Porrata, R Bionta, R Hartmann, D Band, D Frail, D Kulkarni, S Bloom, J Djorgovski, S Sadava, D Chaffee, F Harris, F Abad, C Adams, B Andrews, P Baltay, C Bongiovanni, A Briceno, C Bruzual, G Coppi, P Della Prugna, F Dubuc, A Emmet, W Ferrin, I Fuenmayor, F Gebhard, M Herrera, D Honeycutt, K Magris, G Mateu, J Muffson, S Musser, J Naranjo, O Oemler, A Pacheco, R Paredes, G Rengel, M Romero, L Rosenzweig, P Sabbey, C Sanchez, G Sanchez, G Schenner, H Shin, J Sinnott, J Sofia, S Stock, J Suarez, J Telleria, D Vicente, B Vieira, K Vivas, K TI Discovery of the optical transient of GRB 990308 SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts ID GAMMA-RAY BURSTS; 28 FEBRUARY 1997; EMISSION; GRB-970508; EVOLUTION; GALAXIES AB The optical transient of the faint gamma-ray burst GRB 990308 was detected by the QUEST camera on the Venezuelan 1 m Schmidt telescope starting 3.28 hr after the burst. Our photometry gives V = 18.32 +/- 0.07, R = 18.14 +/- 0.06, B = 18.65 +/- 0.23, and R = 18.22 +/- 0.05 for times ranging from 3.28 to 3.47 hr after the burst. The colors correspond to a spectral slope of close to f(v) proportional to nu(1/3). Within the standard synchrotron fireball model, this requires that the external medium be less dense than 10(4) cm(-3), the electrons contain more than 20% of the shock energy, and the magnetic field energy be less than 24% of the energy in the electrons for normal interstellar or circumstellar densities. We also report upper limits of V> 12.0 at 132 s (with LOTIS), V > 13.4 from 132 to 1029 s (with LOTIS), V>15.3 at 28.2 minutes (with Super-LOTIS), and a 8.5 GHz flux of less than 114 mu Jy at 110 days (with the Very Large Array). Wisconsin-Indiana-Yale-NOAO 3.5 m and Keck 10 m telescopes reveal this location to be empty of any host galaxy to R > 25.7 and K> 23.3. The lack of a host galaxy likely implies that it is either substantially subluminous or more distant than a redshift of similar to 1.2. C1 Yale Univ, Dept Phys, New Haven, CT 06520 USA. Yale Univ, Dept Astron, New Haven, CT 06520 USA. CIDA, Merida 5101, Venezuela. Univ Los Andes, Dept Fis, Merida 5101, Venezuela. Indiana Univ, Dept Astron, Bloomington, IN 47405 USA. MIT, Dept Phys, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Clemson Univ, Dept Phys & Astron, Kinard Lab, Clemson, SC 29634 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. WM Keck Observ, Kamuela, HI 96743 USA. USN Observ, Flagstaff, AZ 86002 USA. Cent Univ Venezuela, Dept Fis, Caracas 1042, Venezuela. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. RP Schaefer, BE (reprint author), Yale Univ, Dept Phys, POB 208121, New Haven, CT 06520 USA. RI Barthelmy, Scott/D-2943-2012; Bongiovanni, Angel/J-6176-2012 NR 33 TC 24 Z9 25 U1 3 U2 5 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 1999 VL 524 IS 2 BP L103 EP L106 DI 10.1086/312318 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 245YM UT WOS:000083136300007 ER PT J AU Tsias, A Wirth, M Carslaw, KS Biele, J Mehrtens, H Reichardt, J Wedekind, C Weiss, V Renger, W Neuber, R von Zahn, U Stein, B Santacesaria, V Stefanutti, L Fierli, F Bacmeister, J Peter, T AF Tsias, A Wirth, M Carslaw, KS Biele, J Mehrtens, H Reichardt, J Wedekind, C Weiss, V Renger, W Neuber, R von Zahn, U Stein, B Santacesaria, V Stefanutti, L Fierli, F Bacmeister, J Peter, T TI Aircraft lidar observations of an enhanced type Ia polar stratospheric clouds during APE-POLECAT SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OZONE DEPLETION; GROWTH; TEMPERATURES; PARTICLES; DROPLETS; VORTEX AB Polar stratospheric clouds (PSCs) which do not fit into the standard type Ia/Ib scheme were measured by the airborne lidar OLEX (Ozone Lidar Experiment) on board the Deutsches Zentrum fur Luft- und Raumfhart (DLR) Falcon during the Airborne Polar Experiment and Polar stratospheric clouds, Leewaves, Chemistry Aerosol and Transport (APE-POLECAT) campaign. In contrast, the standard classification is satisfied by almost all observations for four winters at Ny Alesund, Spitsbergen, which is one of the most comprehensive data sets of ground station lidar measurements presently available. The cloud observed by the Falcon south of Spitsbergen on December 31, 1996, was a 400-km long type I cloud with backscatter ratio S = 2.5 and aerosol depolarization delta(A) 15%, which is clearly distinct from the Ny Alesund 4 year record. Using a combination of microphysical and optical modeling, we investigate the possible evolution of this cloud assuming either in situ freezing of ternary HNO3/H2SO4/H2O droplets as nitric acid trihydrate, or the formation of the clouds in mountain waves over the east coast of Greenland, as suggested by a mountain wave model. Best agreement with the observations was obtained by assuming mountain-wave-induced cloud formation, which yields nitric acid trihydrate particles with much higher total mass than achieved by assuming synoptic-scale freezing. Our analysis suggests that this rare type of PSC, which we term type Ia-enh, is characterized by nitric acid hydrate particles rather close to thermodynamic equilibrium, while the more common type Ia PSCs appear to contain much less mass than representative of equilibrium. C1 Max Planck Inst Chem, D-55020 Mainz, Germany. Alfred Wegener Inst, D-14473 Potsdam, Germany. DLR Oberpfaffenhofen, D-82334 Wessling, Germany. Inst Atmospharenphys, D-18225 Kuhlungsborn, Germany. GKSS Forschungszentrum Geesthacht GmbH, D-2054 Geesthacht, Germany. Free Univ Berlin, Inst Expt Phys, D-14195 Berlin, Germany. CNR, IROE, I-50127 Florence, Italy. CNRS, Serv Aeron, UPMC, IPSL, F-91371 Verrieres Le Buisson, France. USN, Res Lab, Washington, DC 20375 USA. RP Tsias, A (reprint author), Max Planck Inst Chem, Postfach 3060, D-55020 Mainz, Germany. EM tsias@mpch-mainz.mpg.de; Martin.Wirth@dlr.de; carslaw@lec.leeds.ac.uk; jbiele@awi-potsdam.de; mehrtens@iap-kborn.de; jens.reichardt@gkss.de; wede@physik.fu-berlin.de; Volker.Weiss@dlr.de; Wolfgang.Renger@dlr.de; neuber@awi-potsdam.de; Fed-erico.Fierli@aerov.jussieu.fr; julio@ismap5.nrl.navy.mil RI Carslaw, Ken/C-8514-2009; Neuber, Roland/B-4923-2014; OI Carslaw, Ken/0000-0002-6800-154X; Neuber, Roland/0000-0001-7382-7832; Fierli, Federico/0000-0001-9975-2883 NR 24 TC 53 Z9 53 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 20 PY 1999 VL 104 IS D19 BP 23961 EP 23969 DI 10.1029/1998JD100055 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 246WT UT WOS:000083188400025 ER PT J AU Ngai, KL AF Ngai, KL TI Correlation between beta-relaxation and alpha-relaxation in the family of poly(n-butyl methacrylate-stat-styrene) random copolymers SO MACROMOLECULES LA English DT Article ID DYNAMIC GLASS-TRANSITION; SECONDARY RELAXATIONS; DIELECTRIC-RELAXATION; MULTIDIMENSIONAL NMR; COOPERATIVITY ONSET; AMORPHOUS POLYMERS; FORMING MATERIALS; COUPLING MODEL; METHACRYLATE); TIME AB Previously a rough correlation between the logarithm of the most probable secondary beta-relaxation time at the glass temperature T-g, log[tau(beta)(T-g)], and the Kohlrausch-Williams-Watts (KWW) exponent, (1 - n), of the primary alpha-relaxation correlation function exp[-(t/tau(alpha))(1-n)] was found when examining a whole host of chemically different glass-forming materials including amorphous homopolymers, small molecule van der Waal liquids, plastic crystals, and inorganic compounds. This rough correlation is expected from the exact correlation between the logarithm of the primitive relaxation time of the coupling model at the glass temperature T-g, log[tau(o)(T-g)], and (1 - n) and from the similarity between the P-relaxation and the primitive relaxation, both being free from intermolecular cooperativity. This correlation holds only when n in the KWW exponent (1 - n) can be identified with the coupling parameter n(alpha) of the alpha-relaxation in the coupling model. Now, this correlation is examined on a series of poly(n-butyl methacrylate-stat-styrene) copolymers with styrene contents ranging from 0 to 66 mol % utilizing the dielectric relaxation data of Kahle et al. [Macromolecules 1997, 30, 7214]. For the present extension, the KWW function fails to fit the dielectric data due to the presence of concentration fluctuations in the random copolymer. Instead, the most probable coupling parameter (n) over cap(alpha) of the n-butyl methacrylate component in the copolymers is obtained indirectly through the steepness of the temperature dependences of the most probable alpha-relaxation time. A good correlation between log[tau(beta)(T-g)] and (n) over cap(alpha) is found to bold in this series of copolymers as well as in the poly(n-alkyl methacrylates). Moreover, the orders of magnitude of tau(beta)(T-g) and tau(o)(T-g) are not far apart, supporting the similarity between the beta-relaxation and the primitive relaxation. C1 USN, Res Lab, Washington, DC 20375 USA. RP Ngai, KL (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 32 TC 36 Z9 36 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 19 PY 1999 VL 32 IS 21 BP 7140 EP 7146 DI 10.1021/ma990284b PG 7 WC Polymer Science SC Polymer Science GA 247LR UT WOS:000083222700037 ER PT J AU Bussmann, K Prinz, GA Cheng, SF Wang, D AF Bussmann, K Prinz, GA Cheng, SF Wang, D TI Switching of vertical giant magnetoresistance devices by current through the device SO APPLIED PHYSICS LETTERS LA English DT Article ID MULTILAYERS AB Experiments are reported that demonstrate current-perpendicular-to-the-plane giant magnetoresistance devices can be switched repeatably between the high- and low-resistance states by passing current vertically through the structure. The lithographically patterned devices, having diameters in the range of 0.3-0.7 mu m, operate at room temperature and exhibit distinctly separate switching of the soft and hard layers. Designs for magnetoelectronic random access memory can utilize this scheme for storing and reading information. (C) 1999 American Institute of Physics. [S0003-6951(99)04642-2]. C1 USN, Res Lab, Washington, DC 20375 USA. Nonvolatile Elect Inc, Eden Prairie, MN 55344 USA. RP Bussmann, K (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 11 TC 94 Z9 95 U1 1 U2 12 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 18 PY 1999 VL 75 IS 16 BP 2476 EP 2478 DI 10.1063/1.125053 PG 3 WC Physics, Applied SC Physics GA 245LU UT WOS:000083111100045 ER PT J AU Hsu, DSY Gray, HF AF Hsu, DSY Gray, HF TI A low-voltage, low-capacitance, vertical ruthenium-lithium-ruthenium sandwich layer thin-film-edge dispenser field emitter electron source SO APPLIED PHYSICS LETTERS LA English DT Article ID SIDEWALL LITHOGRAPHY; FABRICATION; DEPOSITION; PERFORMANCE; EMISSION; CATHODES; ARRAYS AB A low-voltage, low-capacitance, field emitter array (FEA) electron source has been developed for applications such as field emitter displays, high-voltage switches, and high frequency power amplifiers. The FEA cell has a horizontal gate and a vertical edge emitter made by sandwiching a low-work-function lithium dispenser thin film between two ruthenium films. We measured a low turn-on voltage (several nanoamps at 27 V) and high collected current (16 mu A at 62 V) from 1 to 3 cells. Based on chemical beam deposition, the fabrication method allows all the FEA cell dimensions to be independently adjustable. Our FEA has many potential advantages in performance such as low capacitance, low voltage, high transconductance, high current, and resistance to oxidation and to erosion by back-ion bombardment. Furthermore, much lower manufacturing cost should result from the significantly fewer processing steps. [S0003-6951(99)03942-X]. C1 USN, Res Lab, Div Chem, Washington, DC 20375 USA. USN, Res Lab, Div Elect Sci & Technol, Washington, DC 20375 USA. RP Hsu, DSY (reprint author), USN, Res Lab, Div Chem, Washington, DC 20375 USA. NR 15 TC 6 Z9 6 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 18 PY 1999 VL 75 IS 16 BP 2497 EP 2499 DI 10.1063/1.125060 PG 3 WC Physics, Applied SC Physics GA 245LU UT WOS:000083111100052 ER PT J AU Heim, LO Blum, J Preuss, M Butt, HJ AF Heim, LO Blum, J Preuss, M Butt, HJ TI Adhesion and friction forces between spherical micrometer-sized particles SO PHYSICAL REVIEW LETTERS LA English DT Article ID SURFACE FORCES; CONTACT DEFORMATIONS; MICROSCOPE; SPHERES; ENERGY; SOLIDS; ELECTROLYTE AB An experimental setup, based on the principles of atomic force microscopy (AFM), was used to measure directly the adhesion and rolling-friction forces between individual silica microspheres of radii between 0.5 and 2.5 mu m. It showed that the linear dependence of the pull-off force on the particle radius is still valid for micron-sized particles. Rolling-friction forces between silica microspheres were measured for the first time by combining AFM methods and optical microscopy: They are similar to 100 times lower than the corresponding adhesion forces. C1 Univ Jena, Inst Astrophys, D-07745 Jena, Germany. Univ Jena, Univ Sternwarte, D-07745 Jena, Germany. Univ Mainz, Inst Phys Chem, D-55099 Mainz, Germany. RP Blum, J (reprint author), USN, Res Lab, Div Space Sci, 4555 Overlook Av SW, Washington, DC 20375 USA. RI Blum, Jurgen/B-5590-2011; Butt, Hans-Jurgen/C-4811-2011 OI Blum, Jurgen/0000-0003-1531-737X; NR 33 TC 220 Z9 221 U1 7 U2 74 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 18 PY 1999 VL 83 IS 16 BP 3328 EP 3331 DI 10.1103/PhysRevLett.83.3328 PG 4 WC Physics, Multidisciplinary SC Physics GA 245XH UT WOS:000083133200057 ER PT J AU Wasserman, TH Petroni, GR Millard, FE Chung, CT Barcos, M Johnson, JL Canellos, GP Peterson, BA AF Wasserman, TH Petroni, GR Millard, FE Chung, CT Barcos, M Johnson, JL Canellos, GP Peterson, BA TI Sequential chemotherapy (etoposide, vinblastine, and doxorubicin) and subtotal lymph node radiation for patients with localized Hodgkin disease and unfavorable prognostic features - A phase II Cancer and Leukemia Group B study (9051) SO CANCER LA English DT Article DE Hodgkin disease; chemotherapy; combined modality therapy; Cancer and Leukemia Group B ID COMBINED-MODALITY; CLINICAL STAGES; IRRADIATION; MOPP; ABVD; RISK AB BACKGROUND. The aim of this study was to evaluate a regimen of sequential chemotherapy and radiotherapy for patients with Hodgkin disease. METHODS. The Cancer and Leukemia Group B conducted a Phase II study of three cycles of etoposide, vinblastine, and doxorubicin (EVA) chemotherapy followed by subtotal lymph node radiation for patients with localized Hodgkin disease and unfavorable prognostic features. Fifty-nine patients were enrolled in the study. Fifty-three patients met all study eligibility criteria; 48 of them (91%) had medias tinal disease and 29 (55%) had bulky mediastinal disease. RESULTS. A complete response (CR) occurred in 35 of the patients (66%). Of all patients who had CR, 26% had the CR after the chemotherapy and before the radiation, and 74% after the chemotherapy and radiation. Twenty percent of the patients who had CR experienced disease progression; in these patients, the progression was outside the radiotherapy field in the lung and involved widespread disease. CONCLUSIONS. EVA offers a nonbleomycin-containing alternative for patients in whom preexisting pulmonary disease may be exacerbated by bleomycin and radiation therapy. EVA, as given in this study tin three cycles), was insufficient chemotherapy for patients who had disease in areas outside the radiation fields (occult disease). (C) 1999 American Cancer Society. C1 Washington Univ, Barnes Jewish Hosp, Dept Radiat Oncol, St Louis, MO 63110 USA. Univ Virginia, Sch Med, Dept Hlth Evaluat Sci, Div Biostat & Epidemiol, Charlottesville, VA 22908 USA. USN, Med Ctr, Div Hematol Oncol, San Diego, CA 92152 USA. SUNY Hlth Sci Ctr, Dept Radiat Oncol, Syracuse, NY 13210 USA. Roswell Pk Canc Inst, Div Pathol, Buffalo, NY USA. CALGB, Ctr Stat, Durham, NC USA. Dana Farber Canc Inst, Boston, MA 02115 USA. Univ Minnesota, Div Oncol, Mason Canc Ctr, Minneapolis, MN 55455 USA. RP Wasserman, TH (reprint author), Washington Univ, Barnes Jewish Hosp, Dept Radiat Oncol, St Louis, MO 63110 USA. FU NCI NIH HHS [CA21060, CA59518, CA32291] NR 17 TC 11 Z9 11 U1 0 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0008-543X J9 CANCER JI Cancer PD OCT 15 PY 1999 VL 86 IS 8 BP 1590 EP 1595 DI 10.1002/(SICI)1097-0142(19991015)86:8<1590::AID-CNCR29>3.0.CO;2-4 PG 6 WC Oncology SC Oncology GA 245WJ UT WOS:000083130900029 PM 10526290 ER PT J AU Mattoussi, H Radzilowski, LH Dabbousi, BO Fogg, DE Schrock, RR Thomas, EL Rubner, MF Bawendi, MG AF Mattoussi, H Radzilowski, LH Dabbousi, BO Fogg, DE Schrock, RR Thomas, EL Rubner, MF Bawendi, MG TI Composite thin films of CdSe nanocrystals and a surface passivating/electron transporting block copolymer: Correlations between film microstructure by transmission electron microscopy and electroluminescence SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID LIGHT-EMITTING-DIODES; DOT-POLYMER COMPOSITES; P-PHENYLENE-VINYLENE; SEMICONDUCTING POLYMER; QUANTUM DOTS; POLYELECTROLYTE SOLUTIONS; POLY(PHENYLENE VINYLENE); FABRICATION; DEVICES; CATHODOLUMINESCENCE AB We present a microscopic characterization of composite thin films made of CdSe semiconductor nanocrystals (quantum dots) dispersed in a polynorbornene-based block copolymer with surface-passivating and electron transport functionalities. We used two types of nanocrystals, CdSe with pure organic capping groups ("bare") and CdSe-ZnS core-shell nanocrystals, also capped on the outer surface with organic groups. The composite thin films are incorporated in heterostructure light emitting devices where they serve as both the electron transport layer and the emissive layer. A thin layer of self-assembled poly (phenylene vinylene) (PPV) is used as the hole transport layer. We used transmission electron microscopy (TEM) to examine the film structure in plan view and in cross section. The TEM analysis uncovered distinct and complex differences between the microstructures of thin films containing bare and ZnS overcoated nanocrystals. We found a strong correlation between the composite film microstructure and the corresponding electroluminescence (EL) spectra as well as the device performance. For example, the presence of phase separation at low concentration and nanocrystal migration to the surface in films with ZnS overcoated particles, result in a large PPV contribution to the EL spectra. At higher concentrations, particles form connecting paths between the interfaces, resulting in spectra dominated by nanocrystal emission, but with a higher efficiency for bare particles. (C) 1999 American Institute of Physics. [S0021-8979(99)02320-8]. C1 MIT, Ctr Mat Sci & Engn, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. MIT, Ctr Mat Sci & Engn, Dept Chem, Cambridge, MA 02139 USA. RP Mattoussi, H (reprint author), USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. RI Fogg, Deryn/P-1992-2014 OI Fogg, Deryn/0000-0002-4528-1139 NR 41 TC 90 Z9 92 U1 1 U2 17 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 15 PY 1999 VL 86 IS 8 BP 4390 EP 4399 DI 10.1063/1.371376 PG 10 WC Physics, Applied SC Physics GA 240TB UT WOS:000082840300048 ER PT J AU Fontanella, JJ AF Fontanella, JJ TI Pressure and temperature variation of the electrical conductivity of poly(propylene glycol) containing LiCF3SO3 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LISCN/DIMETHYLFORMAMIDE/POLY(PROPYLENE OXIDE) SYSTEM; GLASS-TRANSITION TEMPERATURE; POLYMER ELECTROLYTES; IONIC-CONDUCTIVITY; STRUCTURAL RELAXATIONS; COPOLYMER NETWORKS; PHOTON-CORRELATION; COMPLEX IMPEDANCE; FORMING LIQUIDS; VISCOSITY AB Complex impedance and differential scanning calorimetry (DSC) studies have been carried out on poly(propylene glycol) with average molecular weight 1025 (PPG) and PPG containing LiCF3SO3. The impedance studies were made at frequencies from about 1 mHz to 100 MHz at pressures up to 0.3 GPa (3 kbar) over the temperature range 215-365 K. Both the impedance and DSC studies were carried out in vacuum or at atmospheric pressure over a temperature range of about 100-375 K. As a consequence, the impedance studies overlap the DSC glass transition temperature. The inadequacy of the widely used Vogel-Tammann-Fulcher or Williams-Landel-Ferry equations to describe the temperature variation of the vacuum electrical conductivity data is discussed. It is shown that the Bendler-Shlesinger formalism is a better representation of the data, particularly in the region close to the glass transition. The first pressure derivative of the electrical conductivity, and hence apparent activation volume, decreases strongly as temperature increases. In addition, the activation volumes are larger for the low molecular weight liquids than the values reported previously for related, high molecular weight rubbery electrolytes. Next, there appears to be an exponential relationship between the activation volume and the electrical conductivity. Finally, the pressure variation of the electrical conductance exhibits negative curvature which shows that the activation volume increases as pressure increases. A qualitative explanation of each of these results concerning the relationship between conductivity, temperature, and pressure is given in terms of free volume. However, whether free volume can provide a quantitative explanation remains to be determined. (C) 1999 American Institute of Physics. [S0021-9606(99)50339-5]. C1 USN Acad, Dept Phys, Annapolis, MD 21402 USA. RP Fontanella, JJ (reprint author), USN Acad, Dept Phys, Annapolis, MD 21402 USA. NR 61 TC 41 Z9 41 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 15 PY 1999 VL 111 IS 15 BP 7103 EP 7109 DI 10.1063/1.480002 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 244LB UT WOS:000083051600050 ER PT J AU Morey, SL Shriver, JF O'Brien, JJ AF Morey, SL Shriver, JF O'Brien, JJ TI The effects of Halmahera on the Indonesian throughflow SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID INDO-PACIFIC THROUGHFLOW; INDIAN OCEANS; WORLD OCEAN; THERMOCLINE; FLOW; MODEL; WATER; SEAS AB The pathways of the Pacific to Indian Ocean throughflow and the relative contributions of North Pacific (NP) and South Pacific (SP) water to the throughflow are examined using the Navy Layered Ocean Model. The roles of Halmahera Island in directing flow along the pathways and determining the composition of the throughflow are also studied. The global ocean simulations use a horizontal resolution of up to 1/4 degrees between like variables and have a vertical resolution ranging from one and a half layer reduced gravity to six active layers with realistic bottom topography. hll of the simulations are forced by the Hellerman and Rosenstein [1983] monthly wind stress climatology. The predominant throughflow pathway consists of NP water traveling through the Celebes Sea, Makassar Strait, Flores Sea, and to the Indian Ocean through the Timer, Savu, and Lombok Straits. Model results show that the island of Halmahera is responsible for preventing a flow of SP water into the Celebes Sea and for diverting some SP water southward through the Seram and Bands Seas. The island impacts the lower thermocline and intermediate water pathways throughout the entire year and affects the surface layer during the boreal spring through fall. To estimate the relative contributions of the NP and SP surface water to the throughflow, Lagrangian drifters are advected backward in time from near the exit to the throughflow region to their respective sources. By tracking these buoys, it is found that the presence of Halmahera changes the throughflow composition in the surface layer from similar to 69% NP and 31% SP to 92% NP and 8% SP. Halmahera does not change the composition of the throughflow in the undercurrent layer, which is fed by the NP, or in the lower thermocline and intermediate water layers, which are fed by water from the SP. C1 Florida State Univ, Ctr Ocean Atmosphere Predict Studies, Tallahassee, FL 32306 USA. USN, Res Lab, Stennis Space Ctr, MS 39529 USA. RP Morey, SL (reprint author), Florida State Univ, Ctr Ocean Atmosphere Predict Studies, RM Johnson Bldg,Suite 200,2035 E Paul Dirac Dr, Tallahassee, FL 32306 USA. OI Morey, Steven/0000-0002-6585-1688 NR 28 TC 29 Z9 29 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD OCT 15 PY 1999 VL 104 IS C10 BP 23281 EP 23296 DI 10.1029/1999JC900195 PG 16 WC Oceanography SC Oceanography GA 246KT UT WOS:000083163500001 ER PT J AU Keen, TR Glenn, SM AF Keen, TR Glenn, SM TI Shallow water currents during hurricane Andrew SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID TEXAS-LOUISIANA SHELF; NEAR-INERTIAL OSCILLATIONS; OCEAN CURRENT RESPONSE; TROPICAL STORM DELIA; CONTINENTAL-SHELF; MODEL; CYCLONES; SURGE; TURBULENCE; TRANSIENT AB Oceanographic measurements are used in combination with a numerical model to examine the influence of stratification on shallow water currents during the directly forced stage of a tropical cyclone (Hurricane Andrew) on the continental shelf. The following stratification-dependent coastal processes are examined: (1) turbulent mixing, (2) coastally trapped waves, (3) near-inertial oscillations, and (4) upwelling and downwelling. Turbulent mixing was strong within 1 R-w (radius of maximum winds) of the storm track, and stratification was nearly destroyed. Turbulent mixing was weak at distances greater than 2 R-w. The dominant coastal wave was a barotropic Kelvin wave generated as the storm surge relaxed after landfall. Baroclinic near-inertial oscillations were dominant at the shelf break and occurred along with a barotropic response on the middle shelf Downwelling-favorable flow developed east of the track prior to the storm peak, and upwelling-favorable flow evolved west of the track as the eye crossed the shelf. The idealized storm flow was modified by local barotropic and baroclinic pressure gradients on the shelf. Ocean circulation during Hurricane Andrew was hindcast using both stratified and unstratified three-dimensional numerical models. For areas within 1 R-w of the storm track, the unstratified model matched the observed currents better than the stratified model, partly because of errors in the initial stratification. At distances greater than 2 R-w the influence of stratification increases, and the unstratified model does not reproduce the observed upwelling-favorable flow. C1 USN, Res Lab, Div Oceanog, Stennis Space Ctr, MS 39529 USA. Rutgers State Univ, Inst Marine & Coastal Sci, New Brunswick, NJ 08903 USA. RP Keen, TR (reprint author), USN, Res Lab, Div Oceanog, Stennis Space Ctr, MS 39529 USA. NR 38 TC 10 Z9 10 U1 2 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD OCT 15 PY 1999 VL 104 IS C10 BP 23443 EP 23458 DI 10.1029/1999JC900180 PG 16 WC Oceanography SC Oceanography GA 246KT UT WOS:000083163500012 ER PT J AU Sica, L AF Sica, L TI Bell's inequalities - I: An explanation for their experimental violation SO OPTICS COMMUNICATIONS LA English DT Article DE Bell's inequality; hidden variables AB Derivations of two Bell's inequalities are given in a form appropriate to the interpretation of experimental data for explicit determination of all the correlations. They are arithmetic identities independent of statistical reasoning and thus cannot be violated by data that meets the conditions for their validity. Two experimentally performable procedures are described to meet these conditions. Once such data are acquired, it follows that the measured correlations cannot all equal a negative cosine of angular differences. The relation between this finding and the predictions of quantum mechanics is discussed in a companion paper. Published by Elsevier Science B.V. C1 USN, Res Lab, Washington, DC 20375 USA. RP Sica, L (reprint author), USN, Res Lab, Code 5630, Washington, DC 20375 USA. NR 12 TC 25 Z9 25 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD OCT 15 PY 1999 VL 170 IS 1-3 BP 55 EP 60 DI 10.1016/S0030-4018(99)00417-4 PG 6 WC Optics SC Optics GA 247ZV UT WOS:000083251600009 ER PT J AU Sica, L AF Sica, L TI Bell's inequalities - II: Logical loophole in their interpretation SO OPTICS COMMUNICATIONS LA English DT Article DE Bell's inequality; hidden variables AB Assumed data streams from a delayed choice gedanken experiment must satisfy a Bell's identity independently of locality assumptions. The violation of Bell's inequality by assumed correlations of identical form among these data streams implies that they cannot all result from statistically equivalent variables of a homogeneous process. This is consistent with both the requirements of arithmetic and distinctions between commuting and noncommuting observables in quantum mechanics. Neglect of these distinctions implies a logical loophole in the conventional interpretation of Bell's inequalities. Published by Elsevier Science B.V. C1 USN, Res Lab, Washington, DC 20375 USA. RP Sica, L (reprint author), USN, Res Lab, Code 5630, Washington, DC 20375 USA. NR 17 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD OCT 15 PY 1999 VL 170 IS 1-3 BP 61 EP 66 DI 10.1016/S0030-4018(99)00418-6 PG 6 WC Optics SC Optics GA 247ZV UT WOS:000083251600010 ER PT J AU Fermann, ME Galvanauskas, A Stock, ML Wong, KK Harter, D Goldberg, L AF Fermann, ME Galvanauskas, A Stock, ML Wong, KK Harter, D Goldberg, L TI Ultrawide tunable Er soliton fiber laser amplified in Yb-doped fiber SO OPTICS LETTERS LA English DT Article ID SELF-FREQUENCY SHIFT AB A Raman-shifted and frequency-doubled high-power Er-fiber soliton laser for seeding an Efficient high-power Yb fiber femtosecond amplifier is demonstrated. The Raman-shifted and frequency-doubled Er-soliton laser is tunable from 1.00 to 1.070 mu m and produces bandwidth-limited 24-pJ pulses at a repetition rate of 50 MHz with a FWHM pulse width of 170 fs at 1.040 mu m. The Yb3+ amplifier has a slope efficiency of 52% and generates 3-ps linearly chirped pulses with an average power of 0.8 W at 1.05 mu m. after pulse compression, 74-fs bandwidth-limited pulses with an average power of 0.4 W and a pulse energy of 8 nJ are generated. (C) 1999 Optical Society of America OCIS codes: 060.7140, 060.4370, 060.2320, 320.7090, 320.7140, 140.3510. C1 IMRA Amer Inc, Ann Arbor, MI 48105 USA. USN, Res Lab, Washington, DC 20375 USA. RP Fermann, ME (reprint author), IMRA Amer Inc, 1044 Woodbridge Ave, Ann Arbor, MI 48105 USA. NR 14 TC 47 Z9 52 U1 1 U2 8 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD OCT 15 PY 1999 VL 24 IS 20 BP 1428 EP 1430 DI 10.1364/OL.24.001428 PG 3 WC Optics SC Optics GA 245FY UT WOS:000083096600016 PM 18079824 ER PT J AU Walck, SN Reinecke, TL Bayer, M Gutbrod, T Reithmaier, JP Forchel, A AF Walck, SN Reinecke, TL Bayer, M Gutbrod, T Reithmaier, JP Forchel, A TI Magnetic-field dependence of the exciton-photon coupling in structured photonic cavities SO PHYSICAL REVIEW B LA English DT Article ID SEMICONDUCTOR QUANTUM MICROCAVITY; WELLS; ENHANCEMENT; DOTS AB The dependence of the exciton-photon interaction, which is given by the Rabi-splitting, has been studied by magnetophotoluminescence and by detailed calculations in three-dimensionally structured photonic microcavities. The Rabi splittings corresponding to several distinct confined photon modes have been observed. They are found to increase monotonically with increasing magnetic field, independent of the confined photon state involved. Numerical calculations show that the increase arises from the enhancement of the exciton oscillator strength with increasing magnetic field. [S0163-1829(99)05639-8]. C1 USN, Res Lab, Washington, DC 20375 USA. Univ Wurzburg, D-97074 Wurzburg, Germany. RP Walck, SN (reprint author), Univ Rochester, Inst Opt, Rochester, NY 14627 USA. RI Reithmaier, Johann/G-8171-2012; OI Reithmaier, Johann/0000-0002-1974-8292; Forchel, Alfred/0000-0002-9377-9935 NR 17 TC 2 Z9 2 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1999 VL 60 IS 15 BP 10695 EP 10698 DI 10.1103/PhysRevB.60.10695 PG 4 WC Physics, Condensed Matter SC Physics GA 251CT UT WOS:000083427600035 ER PT J AU Jimenez, VM Lassaletta, G Fernandez, A Espinos, JP Yubero, F Gonzalez-Elipe, AR Soriano, L Sanz, JM Papaconstantopoulos, DA AF Jimenez, VM Lassaletta, G Fernandez, A Espinos, JP Yubero, F Gonzalez-Elipe, AR Soriano, L Sanz, JM Papaconstantopoulos, DA TI Resonant photoemission characterization of SnO SO PHYSICAL REVIEW B LA English DT Article ID ELECTRON-ENERGY-LOSS; TIN OXIDES; ROOM-TEMPERATURE; HIGH-RESOLUTION; CROSS-SECTIONS; LOSS SPECTRA; METAL-OXIDE; GAS SENSORS; SPECTROSCOPY; FILMS AB A thick layer of SnO, equivalent in its electronic properties to the bulk material, has been investigated by means of resonant photoemission and the mathematical method of factor analysis. This study has shown that O2p, Sn5s, and Sn5p partial density of states are the main contributions to the valence band of this material. The distribution through the valence band of these partial contributions has been determined by spectral subtraction and factor analysis of the resonance photoemission spectra, as well as by band structure calculation. The resonance behavior (i.e., change in intensity with the photon energy) of these three contributions has been analyzed. The Sn5p levels present a typical Fano-like behavior with a minimum intensity at about 28 eV and a maximum at 40 eV. The Sn5s partial density distribution also depicts a change in intensity as a function of the photon energy with a minimum situated at 35 eV and a maximum at 55 eV. Tentatively, this behavior has been linked to the existence of a broad absorption feature detected by electron energy loss spectroscopy and constant final state spectra, both depicting a broad maximum at about 50 eV. [S0163-1829(99)07339-7]. C1 Univ Sevilla, CSIC, Inst Ciencia Mat Sevilla, Seville 41092, Spain. Dept Quim Inorgan, Seville 41092, Spain. Univ Autonoma Madrid, Dept Fis Aplicada, Fac Ciencias C XII, E-28049 Madrid, Spain. USN, Res Lab, Complex Syst Theory Branch, Washington, DC 20375 USA. RP Gonzalez-Elipe, AR (reprint author), Univ Sevilla, CSIC, Inst Ciencia Mat Sevilla, Ave Americo Vespucio S-N, Seville 41092, Spain. EM Agustin@cica.es RI Soriano, Leonardo/A-7664-2011; Sanz, Jose /L-7941-2013; Fernandez, Asuncion/M-3286-2014; ESPINOS, JUAN PEDRO/C-2156-2015; Gonzalez-Elipe, Agustin R/C-7419-2015; Yubero, Francisco/E-7171-2015 OI Soriano, Leonardo/0000-0001-5715-376X; Sanz, Jose /0000-0002-0069-9208; Fernandez, Asuncion/0000-0002-7487-7054; ESPINOS, JUAN PEDRO/0000-0002-3053-0841; Gonzalez-Elipe, Agustin R/0000-0002-6417-1437; Yubero, Francisco/0000-0001-5107-9490 NR 39 TC 20 Z9 21 U1 0 U2 7 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1999 VL 60 IS 15 BP 11171 EP 11179 DI 10.1103/PhysRevB.60.11171 PG 9 WC Physics, Condensed Matter SC Physics GA 251CT UT WOS:000083427600104 ER PT J AU Laming, JM AF Laming, JM TI Neutrino induced waves in degenerate electron plasmas: a mechanism in supernovae or gamma ray bursts? SO NEW ASTRONOMY LA English DT Article DE supernovae : general; gamma rays : bursts; plasmas; instabilities; dense matter ID MAGNETIC-FIELD; PULSAR; COLLAPSE; EXPLOSIONS; CONVECTION; RADIATION AB We consider a process related to the inverse of photon/plasmon decay to neutrino-antineutrino pairs; the stimulated emission of photons and plasmons by the intense flux of neutrinos and antineutrinos present during the neutrino burst of a core collapse supernova. We find physically insignificant emission and plasma heating unless a magnetic field is present, with strength >10(15) G. For plasma electron temperatures similar to 1 MeV, a population of waves enhanced over thermal levels in the postshock plasma is also required. The magnetic field is consistent with recent theory and observations concerning highly magnetic pulsars, known as magnetars. The status of this field is briefly reviewed, and the possibility that this instability might also apply to models of gamma ray bursts is also explored. (C) 1999 Elsevier Science B.V. All rights reserved. C1 USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. RP USN, Res Lab, EO Hulburt Ctr Space Res, Code 7674L, Washington, DC 20375 USA. EM jlaming@ssd5.nrl.navy.mil NR 43 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1384-1076 EI 1384-1092 J9 NEW ASTRON JI New Astron. PD OCT 13 PY 1999 VL 4 IS 5 BP 389 EP 403 DI 10.1016/S1384-1076(99)00036-6 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 254JW UT WOS:000083609000001 ER PT J AU Tsai, TE Taunay, T Friebele, EJ AF Tsai, TE Taunay, T Friebele, EJ TI Stress-dependent growth kinetics of ultraviolet-induced refractive index change and defect centers in highly Ge-doped SiO2 core fibers SO APPLIED PHYSICS LETTERS LA English DT Article ID OPTICAL FIBERS; BRAGG GRATINGS; GERMANOSILICATE FIBERS; GE-SIO2 FIBERS; EXCIMER-LASER; PHOTOSENSITIVITY AB The evolution of the index change of type-IIa gratings observed in 28 mol % Ge-SiO2 core fibers with 1.8 mu m core diameter under various strains was measured from the optical spectra, and the induced defects at high and low strains were studied with electron spin resonance. Data will be presented to show that the index modulation (Delta n(mod)) of type-IIa gratings is likely associated with Ge E-' centers. (C) 1999 American Institute of Physics. [S0003-6951(99)04141-8]. C1 USN, Res Lab, Washington, DC 20375 USA. Virginia Polytech Inst & State Univ, Fiber & Electroopt Res Ctr, Blacksburg, VA 24061 USA. RP Tsai, TE (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 13 TC 3 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 11 PY 1999 VL 75 IS 15 BP 2178 EP 2180 DI 10.1063/1.124957 PG 3 WC Physics, Applied SC Physics GA 244KK UT WOS:000083050200006 ER PT J AU Briggs, MS Band, DL Kippen, RM Preece, RD Kouveliotou, C van Paradijs, J Share, GH Murphy, RJ Matz, SM Connors, A Winkler, C McConnell, ML Ryan, JM Williams, OR Young, CA Dingus, B Catelli, JR Wijers, RAMJ AF Briggs, MS Band, DL Kippen, RM Preece, RD Kouveliotou, C van Paradijs, J Share, GH Murphy, RJ Matz, SM Connors, A Winkler, C McConnell, ML Ryan, JM Williams, OR Young, CA Dingus, B Catelli, JR Wijers, RAMJ TI Observations of GRB 990123 by the Compton Gamma Ray Observatory SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; X-rays : bursts ID BATSE OBSERVATIONS; BURST SPECTRA; OPTICAL COUNTERPART; AFTERGLOW; EMISSION; CONSTRAINTS; EVOLUTION; REDSHIFT AB GRB 990123 was the first burst from which simultaneous optical, X-ray, and gamma-ray emission was detected; its afterglow has been followed by an extensive set of radio, optical, and X-ray observations. We have studied the gamma-ray burst itself as observed by the Compton Gamma Ray Observatory detectors. We find that gamma-ray fluxes are not correlated with the simultaneous optical observations and that the gamma-ray spectra cannot be extrapolated simply to the optical fluxes. The burst is well fitted by the standard four-parameter GRB function, with the exception that excess emission compared with this function is observed below similar to 15 keV during some time intervals. The burst is characterized by the typical hard-to-soft and hardness-intensity correlation spectral evolution patterns. The energy of the peak of the upsilon f(upsilon) spectrum, E-p, reaches an unusually high value during the first intensity spike, 1470 +/- 110 keV, and then falls to similar to 300 keV during the tail of the burst. The high-energy spectrum above similar to 1 MeV is consistent with a power law with a photon index of about -3. By fluence, GRB 990123 is brighter than all but 0.4% of the GRBs observed with BATSE, clearly placing it on the - 3/2 power-law portion of the intensity distribution. However, the redshift measured for the afterglow is inconsistent with the Euclidean interpretation of the - 3/2 power law. Using the redshift value of greater than or equal to 1.61 and assuming isotropic emission, the gamma-ray energy exceeds 10(54) ergs. C1 Univ Alabama, Huntsville, AL 35812 USA. Univ Calif San Diego, Ctr Astrophys & Space Sci 0424, La Jolla, CA 92093 USA. Univ Space Res Assoc, Huntsville, AL 35800 USA. Univ Amsterdam, Amsterdam, Netherlands. NRL, Washington, DC 20375 USA. Northwestern Univ, Evanston, IL 60208 USA. Wellesley Coll, Wellesley, MA USA. Estec, ESA, Dept Space Sci, Div Astrophys, Noordwijk, Netherlands. Univ New Hampshire, Durham, NH 03824 USA. Univ Utah, Salt Lake City, UT 84102 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. RP Briggs, MS (reprint author), Univ Alabama, Huntsville, AL 35812 USA. OI Preece, Robert/0000-0003-1626-7335; Dingus, Brenda/0000-0001-8451-7450 NR 60 TC 101 Z9 105 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 1999 VL 524 IS 1 BP 82 EP 91 DI 10.1086/307808 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 242TK UT WOS:000082957600008 ER PT J AU Hurley, K Li, P Boer, M Cline, T Fishman, GJ Meegan, C Kouveliotou, C Greiner, J Laros, J Luginbuhl, C Vrba, F Murakami, T Pedersen, H van Paradijs, J AF Hurley, K Li, P Boer, M Cline, T Fishman, GJ Meegan, C Kouveliotou, C Greiner, J Laros, J Luginbuhl, C Vrba, F Murakami, T Pedersen, H van Paradijs, J TI A ROSAT deep survey of four small gamma-ray burst error boxes SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : distances and redshifts; gamma rays : bursts; X-rays : galaxies ID ARRIVAL TIME LOCALIZATIONS; NEUTRON STAR MODELS; CONSTRAINTS; IDENTIFICATION; COUNTERPART; GALAXIES; REDSHIFT; ULYSSES; ORIGIN AB We have used the ROSAT High Resolution Imager to search for quiescent X-ray counterparts to four gamma-ray bursts (GRBs) which were localized to small (less than or equal to 10 arcmin(2)) error boxes with the Interplanetary Network. The observations took: place years after the bursts, and the effective exposure times for each target varied from similar to 16 to 23 ks. We have not found any X-ray sources inside any of the error boxes. The 0.1-2.4 keV 3 sigma flux upper limits range from around 5 x 10(-14) to 6 x 10(-13) ergs cm(-2) s(-1) depending on the burst and the assumed shape of the quiescent spectrum. Pie consider four types of X-ray-emitting galaxies (normal, active galactic nucleus, faint, and star forming) and use the flux upper limits to constrain their redshifts. We then use the GRB fluences to constrain the total energies of the bursts. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Ctr Etud Spatiale Rayonnements, F-31029 Toulouse, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Huntsville, AL 35812 USA. MPE, D-85740 Garching, Germany. Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. USN Observ, Flagstaff Stn, Flagstaff, AZ 86002 USA. Inst Space & Astronaut Sci, Kanagawa 229, Japan. Copenhagen Univ Observ, DK-1350 Copenhagen, Denmark. Univ Alabama, Huntsville, AL 35899 USA. RP Hurley, K (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. OI Boer, Michel/0000-0001-9157-4349 NR 38 TC 1 Z9 1 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 1999 VL 524 IS 1 BP 92 EP 97 DI 10.1086/307812 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 242TK UT WOS:000082957600009 ER PT J AU Strickman, MS Harding, AK de Jager, OC AF Strickman, MS Harding, AK de Jager, OC TI A Rossi X-Ray Timing Explorer observation of the vela pulsar: Filling in the X-ray gap SO ASTROPHYSICAL JOURNAL LA English DT Article DE pulsars : individual (Vela pulsar); X-rays : stars ID EMISSION AB We have detected pulsed emission from the Vela pulsar at 2-30 keV during a 93 ks observation with the Rossi X-Ray Timing Explorer (RXTE). The RXTE pulse profile shows two peaks, which are roughly in phase with the EGRET peaks, but does not show any significant interpeak emission. The phase of peak 2 is energy dependent, moving to higher phase with increasing energy in the RXTE band, in phase alignment with the second optical pulse in the lowest energy band (2-8 keV) and in phase alignment with the second EGRET pulse in the highest energy band (16-30 keV). The average pulse spectrum joins smoothly to the high-energy spectrum of OSSE, COMPTEL, and EGRET, although the spectrum of peak 1 is significantly harder than that of peak 2. A break or turnover in the spectrum around 50 keV, previously suggested by OSSE data, is now clearly defined. The RXTE spectrum falls several orders of magnitude below the ROSAT emission in the 0.1-2 keV band, suggesting a thermal origin for the ROSAT pulse. C1 USN, Res Lab, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Potchefstroom Univ Christian Higher Educ, ZA-2520 Potchefstroom, South Africa. RP USN, Res Lab, Washington, DC 20375 USA. EM strickman@osse.nrl.navy.mil RI Harding, Alice/D-3160-2012 NR 18 TC 28 Z9 28 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 1999 VL 524 IS 1 BP 373 EP 378 DI 10.1086/307802 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 242TK UT WOS:000082957600028 ER PT J AU Chen, LG Ni, N Wu, C Sun, FR AF Chen, LG Ni, N Wu, C Sun, FR TI Performance analysis of a closed regenerated brayton heat pump with internal irreversibilities SO INTERNATIONAL JOURNAL OF ENERGY RESEARCH LA English DT Article DE Brayton heat pump; irreversibilities ID FINITE-TIME THERMODYNAMICS; POWER-PLANTS; EFFICIENCY; ENGINE AB This paper analyses the performance of a real heat pump plant via methods of entropy generation minimization or finite-time thermodynamics. The analytical relations between heating load and pressure ratio, and between coefficient of performance (COP) and pressure ratio of real closed regenerated Brayton heat pump cycles coupled to constant- and variable-temperature heat reservoirs are derived. In the analysis, the irreversibilities include heat transfer-irreversible losses in the hot- and cold-side heat exchangers and the regenerator, the non-isentropic expansion and compression losses in the compressor and expander, and the pressure drop loss in the pipe and system. The optimal performance characteristics of the cycle may be obtained by optimizing the distribution of heat conductances or heat transfer surface areas among the two heat exchangers and the regenerator, and the matching between working fluid and the heat reservoirs. The influence of the effectiveness of regenerator, the effectiveness of hot- and cold-side heat exchangers, the efficiencies of the expander and compressor, the pressure recovery coefficient and the temperature of the heat reservoirs on the heating load and COP of the cycle are illustrated by numerical examples. Published in 1999 by John Wiley & Sons, Ltd. C1 USN Acad, Dept Mech Engn, Annapolis, MD 21402 USA. RP Wu, C (reprint author), USN Acad, Dept Mech Engn, 121 Blake Rd, Annapolis, MD 21402 USA. NR 21 TC 21 Z9 21 U1 2 U2 3 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0363-907X J9 INT J ENERG RES JI Int. J. Energy Res. PD OCT 10 PY 1999 VL 23 IS 12 BP 1039 EP 1050 DI 10.1002/(SICI)1099-114X(19991010)23:12<1039::AID-ER539>3.0.CO;2-6 PG 12 WC Energy & Fuels; Nuclear Science & Technology SC Energy & Fuels; Nuclear Science & Technology GA 246VG UT WOS:000083185000003 ER PT J AU Agassi, D Cohen, JR AF Agassi, D Cohen, JR TI Superconductor strip response to a normally incident magnetic field SO PHYSICA C LA English DT Article DE superconductor strip; normally incident; magnetic field ID FLUX-PENETRATION; FLAT SUPERCONDUCTORS; THIN-FILMS; CURRENTS; BARRIER; LOSSES AB The response of an infinitely long superconductor strip in its virgin state to a normally incident magnetic field is calculated. The non-divergent, analytic expressions for the screening current and magnetic field apply for a strip of arbitrary width and thickness. For a high aspect-ratio strip, the calculated surface induction and screening current spatial distribution compares well with the corresponding expressions obtained from the commonly employed (canonical) expression, provided the evaluation point is not close to the strip edges. The new expression predicts for the total screening-current a value which exceeds that obtained from the canonical expression by a factor of 5-8 and is highly peaked at the strip edges. (C) 1999 Elsevier Science B.V. All rights reserved. C1 USN, Ctr Surface Warfare, Carderock Div, W Bethesda, MD 20817 USA. RP Agassi, D (reprint author), USN, Ctr Surface Warfare, Carderock Div, Code 682,9500 MacArthur Blvd, W Bethesda, MD 20817 USA. NR 30 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT 10 PY 1999 VL 323 IS 3-4 BP 94 EP 106 DI 10.1016/S0921-4534(99)00398-6 PG 13 WC Physics, Applied SC Physics GA 250DZ UT WOS:000083374900002 ER PT J AU Bressanini, D Reynolds, PJ AF Bressanini, D Reynolds, PJ TI Spatial-partitioning-based acceleration for variational Monte Carlo SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID BODY WAVE-FUNCTIONS; METROPOLIS METHOD; OPTIMIZATION; SIMULATIONS; ATOMS; RENORMALIZATION; POTENTIALS; DYNAMICS; FERMION AB The problem of inherently differing time scales of core and valence electrons in Monte Carlo (MC) simulations is circumvented in a straightforward and intuitive manner. By appropriately subdividing into equivalent subspaces the high-dimensional (many-electron) space in which Monte Carlo integration is done, it is possible to choose completely independent and appropriate sampling times for each "electron." This approach trivially satisfies detailed balance. The partitioning of space is applicable to both variational and Green's function MC. Such a partitioning, however, only provides a significant computational advantage in variational MC. Using this approach we were able to have inner electrons move with reasonably large steps and yet avoid excessive rejection, while outer electrons were moved great distances in few steps. The net result is a large decrease in the sampling autocorrelation time, and a corresponding increase in convergence rate. Results of several standard algorithms are compared with the present acceleration algorithm for the atoms Be and Ne, and the molecule Li-2. (C) 1999 American Institute of Physics. [S0021-9606(99)50838-6]. C1 Off Naval Res, Div Phys Sci, Arlington, VA 22217 USA. Univ Insubria, Dipartimento Sci Chim Fis & Matemat, I-22100 Como, Italy. Georgetown Univ, Dept Phys, Washington, DC 20057 USA. RP Reynolds, PJ (reprint author), Off Naval Res, Div Phys Sci, Arlington, VA 22217 USA. NR 34 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 8 PY 1999 VL 111 IS 14 BP 6180 EP 6189 DI 10.1063/1.479922 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 240TM UT WOS:000082841300006 ER PT J AU Ekstrom, CR AF Ekstrom, CR TI The quantum beat - The physical principles of atomic clocks SO SCIENCE LA English DT Book Review C1 USN Observ, Directorate Time, Washington, DC 20392 USA. RP Ekstrom, CR (reprint author), USN Observ, Directorate Time, 3450 Massachusetts Ave NW, Washington, DC 20392 USA. NR 3 TC 0 Z9 0 U1 2 U2 2 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 OCT 8 PY 1999 VL 286 IS 5438 BP 248 EP 248 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 243YE UT WOS:000083024400030 ER PT J AU Brodine, SK Shaffer, RA Starkey, MJ Tasker, SA Gilcrest, JL Louder, MK Barile, A VanCott, TC Vahey, MT McCutchan, FE Birx, DL Richman, DD Mascola, JR AF Brodine, SK Shaffer, RA Starkey, MJ Tasker, SA Gilcrest, JL Louder, MK Barile, A VanCott, TC Vahey, MT McCutchan, FE Birx, DL Richman, DD Mascola, JR TI Drug resistance patterns, genetic subtypes, clinical features, and risk factors in military personnel with HIV-1 seroconversion SO ANNALS OF INTERNAL MEDICINE LA English DT Article DE epidemiology, molecular; drug resistance, microbial; human immunodeficiency virus; human immunodeficiency virus infections; anti-HIV agents ID TYPE-1 SUBTYPE; UNITED-STATES; VIRUS; SENSITIVITY; PREVALENCE; INFECTION; DIVERSITY; COMMUNITY; THERAPY; PLASMA AB Background: Regular testing of military personnel identifies early HIV infection; this identification provides a sentinel cohort in which to describe the evolving molecular epidemiology of HIV-1 transmission. Objective: To describe the prevalence and epidemiologic correlates associated with the acquisition of non-subtype B and drug-resistant HIV infections. Design: Cross-sectional study. Setting: Military referral hospital. Patients: 95 military personnel with HIV-1 seroconversion. Measurements: Self-reported questionnaire, CD4 cell counts, plasma HIV-1 RNA levels, and nucleic acid sequence analysis for drug-resistant mutations and HIV-1 genetic subtype. Results: 95 patients were enrolled between February 1997 and February 1998. The likely geographic location of HIV-1 acquisition was overseas in 8% of patients, the United States in 68%, and either overseas or the United States in 24%. Seven patients (7.4%) had subtype E infection; the remainder had subtype B infection. Eight of 31 (26%) treatment-naive patients had mutations in the reverse transcriptase or protease gene associated with drug resistance. Conclusions: The percentage of HIV-1 non-subtype B infection and antiretroviral drug-resistant mutations was relatively high in U.S. military personnel with recently acquired HIV-1 infection. C1 San Diego State Univ, Coll Hlth & Human Serv, Grad Sch Publ Hlth, San Diego, CA 92182 USA. Naval Hlth Res Ctr, Div Clin Epidemiol, San Diego, CA 92186 USA. Naval Hlth Res Ctr, San Diego, CA 92152 USA. Naval Med Ctr, San Diego, CA 92134 USA. Henry M Jackson Fdn Advancement Mil Med, Rockville, MD USA. Walter Reed Army Inst Res, Div Retrovirol, Rockville, MD 20850 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. RP Brodine, SK (reprint author), San Diego State Univ, Coll Hlth & Human Serv, Grad Sch Publ Hlth, 5500 Campanile Dr, San Diego, CA 92182 USA. FU NIAID NIH HHS [AI 27670, AI 36214, AI 38858] NR 20 TC 90 Z9 91 U1 0 U2 0 PU AMER COLL PHYSICIANS PI PHILADELPHIA PA INDEPENDENCE MALL WEST 6TH AND RACE ST, PHILADELPHIA, PA 19106-1572 USA SN 0003-4819 J9 ANN INTERN MED JI Ann. Intern. Med. PD OCT 5 PY 1999 VL 131 IS 7 BP 502 EP + PG 6 WC Medicine, General & Internal SC General & Internal Medicine GA 243VU UT WOS:000083018800003 PM 10507958 ER PT J AU Goodman, C Emmons, W Newton, J AF Goodman, C Emmons, W Newton, J TI Misdiagnosis of HIV infection SO ANNALS OF INTERNAL MEDICINE LA English DT Letter C1 Naval Med Ctr Portsmouth, Portsmouth, VA 23708 USA. RP Goodman, C (reprint author), Naval Med Ctr Portsmouth, Portsmouth, VA 23708 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER COLL PHYSICIANS PI PHILADELPHIA PA INDEPENDENCE MALL WEST 6TH AND RACE ST, PHILADELPHIA, PA 19106-1572 USA SN 0003-4819 J9 ANN INTERN MED JI Ann. Intern. Med. PD OCT 5 PY 1999 VL 131 IS 7 BP 547 EP 547 PG 1 WC Medicine, General & Internal SC General & Internal Medicine GA 243VU UT WOS:000083018800027 PM 10507979 ER PT J AU Saxton, PC Moran, AL Rutledge, SK AF Saxton, PC Moran, AL Rutledge, SK TI Emissivity measurement comparison SO AMERICAN CERAMIC SOCIETY BULLETIN LA English DT Article AB Emissivity measurements generated by two different methods were compared for selected candidate materials. The system used by NASA Glenn Research Center is a useful tool for rapid screening of candidate emitter materials. C1 USN Acad, Annapolis, MD 21402 USA. NASA, Glenn Res Ctr, Cleveland, OH USA. RP Saxton, PC (reprint author), USN Acad, Annapolis, MD 21402 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7812 J9 AM CERAM SOC BULL JI Am. Ceram. Soc. Bull. PD OCT PY 1999 VL 78 IS 10 BP 55 EP 58 PG 4 WC Materials Science, Ceramics SC Materials Science GA 291WR UT WOS:000085762800005 ER PT J AU Stillwell, P AF Stillwell, P TI The USS Essex and the birth of the American Navy SO AMERICAN HISTORY LA English DT Book Review C1 USN Acad, Annapolis, MD 21402 USA. RP Stillwell, P (reprint author), USN Acad, Annapolis, MD 21402 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU COWLES HISTORY GROUP PI HARRISBURG PA 6405 FLANK DR, HARRISBURG, PA 17112-2753 USA SN 1076-8866 J9 AM HIST JI Am. Hist. PD OCT PY 1999 VL 34 IS 4 BP 66 EP 67 PG 2 WC History SC History GA 225EM UT WOS:000081945500024 ER PT J AU Coyle, WJ Sedlack, RE Nemec, R Peterson, R Duntemann, T Murphy, M Lawson, JM AF Coyle, WJ Sedlack, RE Nemec, R Peterson, R Duntemann, T Murphy, M Lawson, JM TI Eradication of Helicobacter pylori normalizes elevated mucosal levels of epidermal growth factor and its receptor SO AMERICAN JOURNAL OF GASTROENTEROLOGY LA English DT Article ID GASTRIC-CANCER; DUODENAL-ULCER; REGULATORY PEPTIDES; BARRETTS-ESOPHAGUS; LUMINAL RELEASE; BINDING ASSAY; EXPRESSION; INFECTION; CARCINOMA; JUICE AB OBJECTIVE: Helicobacter pylori (H. pylori) infection has been linked to gastric cancer. The factors that promote carcinogenesis remain unknown. Epidermal growth factor (EGF) has been shown to be a potent epithelial mitogen and oncoprotein when sustained over expression occurs. Our aim was to compare gastric mucosal levels of EGF and its receptor (EGFR) among controls, H. pylori-infected subjects, and subjects following H. pylori eradication using quantitative flow cytometric analysis. METHODS: Patients referred for evaluation of dyspepsia underwent EGD and six antral biopsies were performed (two each for rapid urease testing (RUT), histopathology, and how cytometry). Controls were those found to be H. pylori negative while subjects had confirmed infection. The study patients were treated, then had repeat EGD with biopsies. RESULTS: There were 17 controls and 28 cases. Mean EGF and EGFR values were 2.69 and 2.46 for controls and 4.67 and 4.64 for subjects. Subjects' mean EGF was 73% higher (p =.035) and EGFR was 88% higher (p = 0.029) than controls. After treatment, the subjects' mean values declined 55% (p = 0.0001) for EGF and 40% (p = 0.002) for EGFR. Three subjects had persistent infection and showed no change in their EGF/EGFR levels. No difference was found among factor levels with respect to endoscopic findings. CONCLUSIONS: Both EGF and EGFR from gastric antral biopsies are increased nearly 2-fold in infection with H. pylori. Infection eradication reduces levels of both factors to those of controls. One major pathogenic mechanism for gastric mucosal hyperproliferation and possibly carcinogenesis related to H. pylori may be the over expression of EGF and increased receptor density of ECFR on gastric mucosal cells. (C) 1999 by Am. Cell. of Gastroenterology. C1 USN, Med Ctr Portsmouth, Dept Gastroenterol, Portsmouth, VA 23708 USA. RP Coyle, WJ (reprint author), USN, Med Ctr Portsmouth, Dept Gastroenterol, 62 John Paul Jones Circle, Portsmouth, VA 23708 USA. OI Sedlack, Robert/0000-0002-6216-1710 NR 38 TC 32 Z9 35 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0002-9270 J9 AM J GASTROENTEROL JI Am. J. Gastroenterol. PD OCT PY 1999 VL 94 IS 10 BP 2885 EP 2889 PG 5 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA 243DD UT WOS:000082981000017 PM 10520838 ER PT J AU Otterson, GA Modi, S Nguyen, K Coxon, AB Kaye, FJ AF Otterson, GA Modi, S Nguyen, K Coxon, AB Kaye, FJ TI Temperature-sensitive RB mutations linked to incomplete penetrance of familial retinoblastoma in 12 families SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Article ID GERM-LINE MUTATIONS; HEREDITARY RETINOBLASTOMA; SPONTANEOUS REGRESSION; MILD EXPRESSION; GENE; PROTEIN; CANCER; PHENOTYPE; RETINOMA; PRODUCT AB The tumor-suppressor activity of the retinoblastoma protein (RB) is encoded within a protein-binding ("pocket") domain that is targeted for mutations in all cases of familial retinoblastoma and in many common adult cancers. Although familial retinoblastoma is a paradigm for a highly penetrant, recessive model of tumorigenesis, the molecular basis for the phenotype of incomplete penetrance of familial retinoblastoma is undefined. We studied the RE pocket-binding properties of three independent, mutant RE alleles that are present in the germline of 12 kindreds with the phenotype of incomplete penetrance of familial retinoblastoma. Each arises from alterations of single codons within the RE pocket domain (designated "Delta 480," "661W," or "712R"). Under the same conditions, we studied the properties of wild-type (WT) RE, an RE point mutant isolated from a lung carcinoma sample (706F) and an adjacent, in vitro-generated point mutant (707W). The Delta 480, 661W, and 712R mutants lack pocket protein-binding activity in vitro but retain the WT ability to undergo cyclin-mediated phosphorylation in vivo. Each of the low-penetrant RE mutants exhibits marked enhancement of pocket protein binding when the cells are grown at reduced temperature. In contrast, in this temperature range, no change in binding activity is seen with WT RE, the 706F mutant, or the 707W mutant. We have demonstrated that many families with incomplete penetrance of familial retinoblastoma carry unstable, mutant RE alleles with temperature-sensitive pocket protein-binding activity. The variable frequency for tumor development in these families may result from reversible fluctuations in a threshold level of RE pocket-binding activity. C1 NCI, Div Clin Sci, Med Branch, Dept Genet, Bethesda, MD 20892 USA. Natl Naval Med Ctr, Bethesda, MD USA. RP Kaye, FJ (reprint author), Naval Hosp, Bldg 8-Room 5101, Bethesda, MD 20889 USA. RI kaye, frederic/E-2437-2011 NR 33 TC 24 Z9 25 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1999 VL 65 IS 4 BP 1040 EP 1046 DI 10.1086/302581 PG 7 WC Genetics & Heredity SC Genetics & Heredity GA 241XW UT WOS:000082910000012 PM 10486322 ER PT J AU Holmboe, ES Meehan, TP Radford, MJ Wang, Y Marciniak, TA Krumholz, HM AF Holmboe, ES Meehan, TP Radford, MJ Wang, Y Marciniak, TA Krumholz, HM TI Use of critical pathways to improve the care of patients with acute myocardial infarction SO AMERICAN JOURNAL OF MEDICINE LA English DT Article ID COOPERATIVE CARDIOVASCULAR PROJECT; PRACTICE GUIDELINES; MEDICARE PATIENTS; SURGERY; EXPERIENCE; COST; STAY AB PURPOSE: While critical pathways have become a popular strategy to improve the quality of care, their effectiveness is not well defined. The objective of this study was to investigate the effect of a critical pathway on processes of care and outcomes for Medicare patients admitted with acute myocardial infarction. SUBJECTS AND METHODS: A retrospective cross-sectional and longitudinal cohort study was made of Medicare patients aged 65 years and older hospitalized at 32 nonfederal Connecticut hospitals with a principal diagnosis of myocardial infarction during two periods: lune 1, 1992, to February 28, 1993, and August 1, 1995, to November 30, 1995. The main endpoints of the cross-sectional analyses for the 1995 cohort were the proportion of patients without contraindications who received evidence-based medical therapies, length of stay, and 30-day mortality. Hospitals with specific critical pathways for patients with myocardial infarction were compared with hospitals without critical pathways. The main endpoints of the longitudinal analyses were change between 1992-93 and 1995 in the proportion of patients receiving evidence-based medical therapies, length of stay, and 30-day mortality. RESULTS: Ten hospitals developed critical pathways between 1992-93 and 1995, Eighteen of 22 nonpathway hospitals employed some combination of standard orders, multidisciplinary teams. or physician champions. Patients admitted to hospitals with critical pathways did not have greater use of aspirin within the first day, during hospitalization, or at discharge; beta-blockers within the first day or at discharge; reperfusion therapy; or use of angiotensin-converting enzyme inhibitors at discharge in 1995. The mean (+/- SD) length of stay in 1995 was not significantly different between pathway (7.8 +/- 4.6 days) versus nonpathway hospitals (8.0 +/- 4.2 days), and the change in length of stay between 1992-93 and 1995 was 2.2 days for pathway hospitals and 2.3 days for nonpathway hospitals. Patients admitted to critical pathway hospitals had lower 30-day mortality in 1995 (8.6% versus 11.6% for nonpathway hospitals, P = 0.10) and in 1992-93 (12.6% versus 13.8%, P = 0.39), but the differences were not statistically significant. CONCLUSIONS: Hospitals that instituted critical pathways did not have increased use of proven medical therapies, shorter lengths of stay, or reductions in mortality compared with other hospitals that commonly used alternative approaches to quality improvement among Medicare patients with myocardial infarction. (C) 1999 by Excerpta Medica, Inc. C1 Yale Univ, Sch Med, Robert Wood Johnson Clin Scholars Program, New Haven, CT USA. Yale Univ, Sch Med, Dept Epidemiol & Publ Hlth, Sect Chron Dis Epidemiol, New Haven, CT USA. Yale New Haven Hosp, Ctr Outcomes Res & Evaluat, New Haven, CT 06504 USA. Connecticut Peer Review Org, Middletown, CT USA. US Hlth Care Financing Adm, Bethesda, MD USA. Univ Connecticut, Sch Med, Dept Med, Div Cardiol, Farmington, CT USA. RP Holmboe, ES (reprint author), USN, Natl Med Ctr, Div Gen Internal Med, 8901 Wisconsin Ave, Bethesda, MD 20889 USA. FU PHS HHS [500-96-P549] NR 17 TC 31 Z9 32 U1 0 U2 0 PU EXCERPTA MEDICA INC PI NEW YORK PA 245 WEST 17TH STREET, NEW YORK, NY 10011 USA SN 0002-9343 J9 AM J MED JI Am. J. Med. PD OCT PY 1999 VL 107 IS 4 BP 324 EP 331 DI 10.1016/S0002-9343(99)00239-9 PG 8 WC Medicine, General & Internal SC General & Internal Medicine GA 246QY UT WOS:000083177100004 PM 10527033 ER PT J AU DiGiovanni, C AF DiGiovanni, C TI Domestic terrorism with chemical or biological agents: Psychiatric aspects SO AMERICAN JOURNAL OF PSYCHIATRY LA English DT Article ID ORGANOPHOSPHATE PESTICIDES; LONGITUDINAL PERSPECTIVE; CRISIS SUPPORT; MENTAL-HEALTH; MASS HYSTERIA; DISASTER; INCIDENT; EPIDEMIC; WARFARE; SARIN AB Objective: This article highlights the mental health consequences of a domestic terrorist incident involving chemical or biological weapons. Method: The author reviews the literature on the neuropsychiatric effects of selected chemical and biological weapon agents, on the psychological sequelae of mass disasters, and on approaches to crisis intervention. Results: Disturbances of behavior, affect, and cognition can result directly from the pharmacological actions of some chemical and biological weapon agents. In addition, an incident involving these agents can have considerable psychological effects on individuals and the community. In either case, some disorders are acute and others are prolonged or delayed in onset. Effective therapeutic intervention involves a broad range of clinical, social, and administrative actions. Conclusions: Psychiatrists have an important role in the management of a chemical or biological terrorist incident and, along with their other medical colleagues, should train and prepare for it. C1 USN, Natl Med Ctr, Dept Neurol, Bethesda, MD 20889 USA. RP DiGiovanni, C (reprint author), USN, Natl Med Ctr, Dept Neurol, Box 137, Bethesda, MD 20889 USA. EM cdig@july.dgsys.com NR 59 TC 49 Z9 50 U1 4 U2 10 PU AMER PSYCHIATRIC PUBLISHING, INC PI ARLINGTON PA 1000 WILSON BOULEVARD, STE 1825, ARLINGTON, VA 22209-3901 USA SN 0002-953X J9 AM J PSYCHIAT JI Am. J. Psychiat. PD OCT PY 1999 VL 156 IS 10 BP 1500 EP 1505 PG 6 WC Psychiatry SC Psychiatry GA 241RN UT WOS:000082896500006 PM 10518158 ER PT J AU Shaffer, RE Rose-Pehrsson, SL AF Shaffer, RE Rose-Pehrsson, SL TI Improved probabilistic neural network algorithm for chemical sensor array pattern recognition SO ANALYTICAL CHEMISTRY LA English DT Article ID ARTIFICIAL VISION; DISCRIMINATION; IDENTIFICATION; POWER; SEEDS AB An improved probabilistic neural network (IPNN) algorithm for use in chemical sensor array pattern recognition applications is described. The IPNN is based on a modified probabilistic neural network (PNN) with three innovations designed to reduce the computational and memory requirements, to speed training, and to decrease the false alarm rate. The utility of this new approach is illustrated with the use of four data sets extracted from simulated and laboratory-collected surface acoustic wave sensor array data. A competitive learning strategy, based on a learning vector quantization neural network, is shown to reduce the storage and computation requirements, The IPNN hidden layer requires only a fraction of the storage space of a conventional PNN. A simple distance-based calculation is reported to approximate the optimal kernel width of a PNN. This calculation is found to decrease the training time and requires no user input. A general procedure for selecting the optimal rejection threshold for a PNN-based algorithm using Monte Carlo simulations is also demonstrated. This outlier rejection strategy is implemented for an IPNN classifier and found to reject ambiguous patterns, thereby decreasing the potential for false alarms. C1 USN, Res Lab, Div Chem, Washington, DC 20375 USA. RP Shaffer, RE (reprint author), USN, Res Lab, Div Chem, Code 6116,4555 Overlook Ave SW, Washington, DC 20375 USA. EM shaffer@ccf.nrl.navy.mil RI Shaffer, Ronald/I-2134-2012 NR 28 TC 29 Z9 30 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD OCT 1 PY 1999 VL 71 IS 19 BP 4263 EP 4271 DI 10.1021/ac990238+ PG 9 WC Chemistry, Analytical SC Chemistry GA 241RM UT WOS:000082896400033 PM 21662855 ER PT J AU Dominguez, E Eslinger, MR McCord, SV AF Dominguez, E Eslinger, MR McCord, SV TI Postoperative (pressure) alopecia: Report of a case after elective cosmetic surgery SO ANESTHESIA AND ANALGESIA LA English DT Article ID CARDIAC-SURGERY C1 USN, Med Ctr, Dept Anesthesiol, Portsmouth, VA 23708 USA. RP Dominguez, E (reprint author), USN, Med Ctr, Dept Anesthesiol, 620 John Paul Jones Circle, Portsmouth, VA 23708 USA. NR 9 TC 9 Z9 10 U1 1 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0003-2999 J9 ANESTH ANALG JI Anesth. Analg. PD OCT PY 1999 VL 89 IS 4 BP 1062 EP 1063 DI 10.1097/00000539-199910000-00046 PG 2 WC Anesthesiology SC Anesthesiology GA 240LP UT WOS:000082827700047 PM 10512292 ER PT J AU Dominguez, E AF Dominguez, E TI Carbon dioxide monitoring during deep conscious sedation using nasopharyngeal airways SO ANESTHESIOLOGY LA English DT Letter ID NASAL C1 USN, Med Ctr, Dept Anesthesiol, Portsmouth, VA 23708 USA. RP Dominguez, E (reprint author), USN, Med Ctr, Dept Anesthesiol, Portsmouth, VA 23708 USA. NR 3 TC 2 Z9 2 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0003-3022 J9 ANESTHESIOLOGY JI Anesthesiology PD OCT PY 1999 VL 91 IS 4 BP 1177 EP 1178 DI 10.1097/00000542-199910000-00042 PG 2 WC Anesthesiology SC Anesthesiology GA 241PR UT WOS:000082892200038 PM 10519524 ER PT J AU Novarini, JC Keiffer, RS AF Novarini, JC Keiffer, RS TI Impulse response of a density contrast wedge: practical implementation and some aspects of its diffracted component SO APPLIED ACOUSTICS LA English DT Article DE wedge diffraction; penetrable wedge; impulse response ID ASSEMBLAGE AB Davis and Scharstein have recently derived a complete solution for the impulse response of a density contrast wedge (Davis AMJ, Scharstein RW, J. Acoust. Sec. Am, 1997, 101, 2821-1835). However, the general solution given as a sum of residues, reduces to a closed form only for a discrete set of wedge angles. To circumvent this limitation and make the solution available for arbitrary angles, the explicit form for the residues is provided and the numerical implementation of the solution is discussed. The solution is then applied to the analysis of the diffracted field and physical aspects are analyzed. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Planning Syst Inc, Long Beach, MS 39560 USA. RP Keiffer, RS (reprint author), USN, Res Lab, Code 7181, Stennis Space Ctr, MS 39529 USA. NR 5 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0003-682X J9 APPL ACOUST JI Appl. Acoust. PD OCT PY 1999 VL 58 IS 2 BP 195 EP 210 DI 10.1016/S0003-682X(98)00054-1 PG 16 WC Acoustics SC Acoustics GA 187YP UT WOS:000079816700007 ER PT J AU Driggers, RG Kruer, M Scribner, D Warren, P Leachtenauer, J AF Driggers, RG Kruer, M Scribner, D Warren, P Leachtenauer, J TI Sensor performance conversions for infrared target acquisition and intelligence-surveillance-reconnaissance imaging sensors SO APPLIED OPTICS LA English DT Article ID QUALITY EQUATION AB Target acquisition infrared imaging sensors are characterized by their minimum resolvable temperature parameter that is translated to the probability of identification (Pid) performance estimate for a given target. Intelligence-surveillance-reconnaissance (ISR) sensors are characterized by the general image quality equation to give a national imagery interpretability rating scale (NIIRS) performance estimate. Sensors, such as those on Predator and Global Hawk, will soon be used for both ISR and target acquisition purposes. We present a performance conversion that includes both sensor resolution and sensitivity. We also provide the first empirical results to our knowledge ever to be presented that relate NIIRS and Pid for a given set of targets. (C) 1999 Optical Society of America. C1 USN, Res Lab, Sci & Technol Reserve Detachment 206, Washington, DC 20373 USA. USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. ERIM Int, Arlington, VA 22209 USA. RP Driggers, RG (reprint author), USN, Res Lab, Sci & Technol Reserve Detachment 206, 2701 S Capital St SW, Washington, DC 20373 USA. NR 7 TC 2 Z9 4 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD OCT 1 PY 1999 VL 38 IS 28 BP 5936 EP 5943 DI 10.1364/AO.38.005936 PG 8 WC Optics SC Optics GA 244YV UT WOS:000083079100004 PM 18324111 ER PT J AU Marvel, KB Boboltz, DA AF Marvel, KB Boboltz, DA TI Observations of water masers associated with the proto-planetary nebula candidate IRAS 19296+2227 SO ASTRONOMICAL JOURNAL LA English DT Article DE circumstellar matter; stars : AGB and post-AGB; stars : winds, outflows ID OH MASERS; W3(OH) AB We present the first very long baseline interferometric observations of the 6(16)-5(23), 22 GHz H2O maser emission associated with a proto-planetary nebula candidate. We obtained three epochs of observation of the water masers associated with IRAS 19296+2227, using the Very Long Baseline Array, operated by the National Radio Astronomy Observatory. These observations show that the water masers are distributed over a 50 mas arclike structure covering a limited velocity range of similar to 9 km s(-1). The masers most likely reside in an asymptotic giant branch-like circumstellar shell, although we cannot rule out the possibility that they lie in a shocked region. Over the 40 days spanning the epochs of observation, we have measured an error-weighted average proper motion of 6.16 +/- 1.32 km s(-1), indicating that the masers are not in a high-velocity outflow. C1 Amer Astron Soc, Washington, DC 20009 USA. USN Observ, Washington, DC 20392 USA. RP Marvel, KB (reprint author), Amer Astron Soc, Suite 400,2000 Florida Ave NW, Washington, DC 20009 USA. OI Marvel, Kevin/0000-0002-3972-8790 NR 15 TC 8 Z9 8 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD OCT PY 1999 VL 118 IS 4 BP 1791 EP 1797 DI 10.1086/301027 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 251CR UT WOS:000083427500028 ER PT J AU Young, PR Klimchuk, JA Mason, HE AF Young, PR Klimchuk, JA Mason, HE TI Temperature and density in a polar plume - measurements from CDS/SOHO SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE sun : UV radiation; sun : abundances; sun : solar wind ID CORONAL DIAGNOSTIC SPECTROMETER; SPECTROSCOPIC DIAGNOSTICS; EMISSION-LINES; ACTIVE-REGION; SOLAR; ABUNDANCES; SOHO; HOLES; SUMER; SUN AB A detailed analysis of a particularly intense polar plume observed on the 25th of October, 1996, by the Coronal Diagnostic Spectrometer (CDS) on board the Solar and Heliospheric Observatory (SOHO) is presented. Above the limb, emission measure distributions derived for both the plume and a section of coronal hole background are found to be sharply peaked at approximately 1.0-1.1 million degrees in both regions. The temperature rises with height in the background, but no evidence is found for a rising temperature in the plume. The density of the background is approximately 10(8) electrons/cm(3) and falls with height. In the plume the density is between 3.8 and 9.5 x 10(8) electrons/cm(3), and exhibits no decrease with height up to 70 000 km. The plume base is visible on the solar surface and shows a strong brightening lying directly below the main body of the plume. This brightening has a temperature of 2 000 000 K, and a density of 2.5-5.6 x 10(9) electrons/cm(3). Images from lines formed at different temperatures suggest that the morphology of the base is consistent with an emerged bipole in a region of unipolar magnetic flux. A measurement of the Mg/Ne relative abundance is made: at two transition region brightenings at the base of the plume. An enhancement of only 1.5 is found over the photospheric value. Considerations of the geometry of both the high temperature brightening at the base of the plume and the off-limb section give filling factors of 0.5 and 1.0, respectively. C1 Univ Cambridge, Dept Appl Math & Theoret Phys, Cambridge CB2 1TN, England. USN, Res Lab, Washington, DC 20375 USA. RP Young, PR (reprint author), Univ Cambridge, Dept Appl Math & Theoret Phys, Cambridge CB2 1TN, England. EM P.R.Young@damtp.cam.ac.ul RI Klimchuk, James/D-1041-2012 OI Klimchuk, James/0000-0003-2255-0305 NR 39 TC 45 Z9 46 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 OCT PY 1999 VL 350 IS 1 BP 286 EP 301 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 248QZ UT WOS:000083288000028 ER PT J AU Milne, PA The, LS Leising, MD AF Milne, PA The, LS Leising, MD TI Positron escape from type Ia supernovae SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE gamma rays : observations; gamma rays : theory; supernovae : general ID LIGHT CURVES; HUBBLE CONSTANT; NEBULAR SPECTRA; ANALYTIC SOLUTIONS; DETONATION MODELS; WHITE-DWARF; SN 1991T; X-RAY; BRIGHTNESS; SN-1991T AB We generate bolometric light curves for a variety of Type Ia supernova models at late times, simulating gamma-ray and positron transport for various assumptions about the magnetic field and ionization of the ejecta. These calculated light curve shapes are compared with light curves of specific supernovae for which there have been adequate late observations. The selection of models is generally not based upon the ability to fit the late observations, but rather because the model has been demonstrated by other authors to approximate the spectra and early light curves of that specific SN. From these comparisons we draw two conclusions: whether a suggested model is an acceptable approximation of a particular event, and, given that it is, the magnetic field characteristics and degree of ionization that are most consistent with the observed light curve shape. For the 10 SNe included in this study, five strongly suggest (56)Co positron escape as would be permitted by a weak or radially combed magnetic field. Of the remaining five SNe, none clearly show the upturned light curve expected for positron trapping in a strong, tangled magnetic field. Chandrasekhar mass models can explain normally luminous, slightly subluminous, and superluminous supernova light curves; sub-Chandrasekhar mass models have difficulties with subluminous SNe. An estimate of the galactic positron production rate from Type Ia SNe is compared with gamma-ray observations of Galactic 511 keV annihilation radiation. Additionally, we emphasize the importance of correctly treating the positron transport for calculations of spectra, or any properties, of Type Ia SNe at late epochs (greater than or equal to 200 days). C1 USN, Res Lab, Washington, DC 20375 USA. Clemson Univ, Dept Phys & Astron, Clemson, SC 29634 USA. RP Milne, PA (reprint author), USN, Res Lab, Code 7650, Washington, DC 20375 USA. NR 99 TC 74 Z9 74 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD OCT PY 1999 VL 124 IS 2 BP 503 EP 526 DI 10.1086/313262 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 255TN UT WOS:000083686400006 ER PT J AU Montgomery, HE AF Montgomery, HE TI One-electron wavefunctions: variational perturbation theory SO CHEMICAL PHYSICS LETTERS LA English DT Article AB The ground-state wavefunction of H-2(+) is calculated using variational perturbation theory. The accuracy of the wavefunction is demonstrated by comparing calculated energies and expectation values with the corresponding exact values. Extrapolation of the ratios of the perturbation energies and of the expectation value coefficients is used to study the asymptotic behavior of the perturbation expansions. (C) 1999 Elsevier Science B.V. All rights reserved. C1 USN, Undersea Warfare Ctr, NUWC 01, Newport, RI 02891 USA. RP Montgomery, HE (reprint author), 664 Richmond Rd, Lancaster, KY 40444 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD OCT 1 PY 1999 VL 311 IS 5 BP 367 EP 371 DI 10.1016/S0009-2614(99)00894-5 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 244VR UT WOS:000083071900005 ER PT J AU DeSisto, WJ Cukauskas, EJ Rappoli, BJ Culbertson, JC Claassen, JH AF DeSisto, WJ Cukauskas, EJ Rappoli, BJ Culbertson, JC Claassen, JH TI Metal-organic chemical vapor deposition of La2CuO4+x thin films with gas phase composition control SO CHEMICAL VAPOR DEPOSITION LA English DT Article DE MOCVD; composition control; superconductor ID ELECTROCHEMICAL OXIDATION; TEMPERATURE; PRECURSORS; GROWTH; BARIUM; MOCVD AB Composition-controlled metal-organic chemical vapor deposition of La2CuO4 thin films using ultraviolet absorption sensors to provide incoming precursor flux control is reported. These sensors provide a more flexible and sensitive alternative to ultrasonic sensors. The films were c-axis oriented and semiconducting as grown on LaAlO3 substrates. Chemical oxidization at room temperature in a sodium hypobromite solution resulted in an expansion of the c-axis lattice parameter and the conversion of the semiconducting film into a superconductor with a zero-resistance transition temperature of 32 K. C1 USN, Res Lab, Washington, DC 20375 USA. RP DeSisto, WJ (reprint author), USN, Res Lab, Code 6861, Washington, DC 20375 USA. NR 16 TC 4 Z9 4 U1 2 U2 2 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0948-1907 J9 CHEM VAPOR DEPOS JI Chem. Vapor Depos. PD OCT PY 1999 VL 5 IS 5 BP 233 EP 236 DI 10.1002/(SICI)1521-3862(199910)5:5<233::AID-CVDE233>3.0.CO;2-9 PG 4 WC Electrochemistry; Materials Science, Coatings & Films; Physics, Condensed Matter SC Electrochemistry; Materials Science; Physics GA 244NX UT WOS:000083058600006 ER PT J AU Leventis, N Elder, IA Rolison, DR Anderson, ML Merzbacher, CI AF Leventis, N Elder, IA Rolison, DR Anderson, ML Merzbacher, CI TI Durable modification of silica aerogel monoliths with fluorescent 2,7-diazapyrenium moieties. Sensing oxygen near the speed of open-air diffusion SO CHEMISTRY OF MATERIALS LA English DT Article ID SOL-GEL PROCESS; THERMAL-STABILITY; CHEMICAL SENSORS; FILMS; CHROMOPHORES; NETWORKS; ELECTRODES; BIOSENSORS; REDUCTION; PLATFORMS AB Silica sol-gels were covalently modified with N-(3-trimethoxysilylpropyl)-2,7-diazapyrenium bromide (DAP). Luminescent aerogels are created in which none of the fluorophore leaches from the gels during either the washing or supercritical drying necessary to prepare DAP-modified aerogels, The bulk density (0.17 g/cm(3)), N-2-adsorption surface area (870 m(2)/g), and thermogravimetric and scanning electron micrographic characteristics of the dye-modified aerogels remain identical to those of the unmodified silica aerogels, The bulk concentration of the dye in the aerogels was 16.6 mM; at these loadings the aerogels demonstrate bulk photoluminescence. As based on the mesoporous surface area, the surface coverage of the dye is 7-8% of a monolayer. The absorption, emission, and O-2-quenching characteristics of the diazapyrenium dye in the aerogels parallel those obtained in alcoholic (rather than aqueous) solution, which further indicates that the dopant molecules are Isolated from each other and that they see an environment with a similar to OH polarity, Time-resolved emission studies indicate that all DAP moieties reside in a single type of microenvironment. Emission quenching of similar to 1-cm-diameter monoliths of DAP-silica aerogel is complete in <15 s, which compares very favorably with the best response times for pyrene guests in micrometer-thick xerogel films. The apparent diffusion coefficient of O-2 or Ar in the DAP-aerogel monoliths was estimated at greater than or equal to 0.01.-0.02 cm(2)/s, which is only 10x less than the unimpeded diffusion coefficient of Ar in air. C1 Univ Missouri, Dept Chem, Rolla, MO 65409 USA. USN, Res Lab, Surface Chem Branch, Washington, DC 20375 USA. USN, Res Lab, Opt Tech Branch, Washington, DC 20375 USA. RP Leventis, N (reprint author), Univ Missouri, Dept Chem, Rolla, MO 65409 USA. NR 56 TC 104 Z9 106 U1 2 U2 25 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD OCT PY 1999 VL 11 IS 10 BP 2837 EP 2845 DI 10.1021/cm9901966 PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 248DY UT WOS:000083261100029 ER PT J AU Halstead, SB O'Rourke, EJ AF Halstead, SB O'Rourke, EJ TI Resuscitation of patients with dengue hemorrhagic fever/dengue shock syndrome - Editorial response SO CLINICAL INFECTIOUS DISEASES LA English DT Editorial Material ID TOXICITY; FLUIDS C1 Off Naval Res, Div Med Sci & Technol, Arlington, VA 22217 USA. Boston Childrens Hosp, Div Infect Dis, Boston, MA USA. RP Halstead, SB (reprint author), 5824 Edson Lane, N Bethesda, MD 20852 USA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 1058-4838 J9 CLIN INFECT DIS JI Clin. Infect. Dis. PD OCT PY 1999 VL 29 IS 4 BP 795 EP 796 DI 10.1086/520436 PG 2 WC Immunology; Infectious Diseases; Microbiology SC Immunology; Infectious Diseases; Microbiology GA 248RQ UT WOS:000083289500017 PM 10589890 ER PT J AU Minshew, PT Schraml, FV Flemming, DJ Silverman, ED AF Minshew, PT Schraml, FV Flemming, DJ Silverman, ED TI Atypical presentation of Paget's disease on bone scintigraphy SO CLINICAL NUCLEAR MEDICINE LA English DT Article DE ankylosing spondylitis; Paget's disease C1 Natl Naval Med Ctr, Div Nucl Med, Dept Radiol, Gaithersburg, MD 20899 USA. Natl Naval Med Ctr, Div Diagnost Radiol, Dept Radiol, Gaithersburg, MD 20899 USA. Uniformed Serv Univ Hlth Sci, Bethesda, MD 20814 USA. RP Schraml, FV (reprint author), Natl Naval Med Ctr, Div Nucl Med, Dept Radiol, Gaithersburg, MD 20899 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0363-9762 J9 CLIN NUCL MED JI Clin. Nucl. Med. PD OCT PY 1999 VL 24 IS 10 BP 820 EP 822 DI 10.1097/00003072-199910000-00027 PG 3 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 238HC UT WOS:000082704000027 ER PT J AU Hyams, KC AF Hyams, KC TI Gulf War Syndrome: potential role of infectious diseases SO CURRENT OPINION IN INFECTIOUS DISEASES LA English DT Review ID OPERATION-DESERT-STORM; PERSIAN-GULF; BIRTH-DEFECTS; US VETERANS; SHIELD; TROOPS; MORTALITY; CHILDREN; HEALTH AB Following the 1991 war with Iraq, some US, British, and Canadian Veterans began experiencing diverse symptoms, which have been characterized as a possible 'Gulf War Syndrome'. Although veterans have been found to have a variety of illnesses, neither the existence nor etiology of a unique syndrome has been confirmed. In this review of current literature, the potential for infectious diseases to cause health problems nearly a decade after the Gulf War is evaluated. Curr Opin Infect Dis 12:439-443. (C) 1999 Lippincott Williams & Wilkins. C1 USN, Div Epidemiol, Med Res Ctr, Bethesda, MD 20084 USA. RP Hyams, KC (reprint author), USN, Med Res Ctr, 12300 Washington Ave, Rockville, MD 20852 USA. NR 50 TC 30 Z9 30 U1 1 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0951-7375 J9 CURR OPIN INFECT DIS JI Curr. Opin. Infect. Dis. PD OCT PY 1999 VL 12 IS 5 BP 439 EP 443 PG 5 WC Infectious Diseases SC Infectious Diseases GA 260EW UT WOS:000083937400005 PM 17035809 ER PT J AU Steeds, JW Davis, TJ Charles, SJ Hayes, JM Butler, JE AF Steeds, JW Davis, TJ Charles, SJ Hayes, JM Butler, JE TI 3H luminescence in electron-irradiated diamond samples and its relationship to self-interstitials SO DIAMOND AND RELATED MATERIALS LA English DT Article DE diamond; electron irradiation; 3H luminescence; self-interstitials ID DEFECTS AB 3H luminescence has been induced in a wide variety of rather pure natural and chemical vapour deposited diamond samples by electron irradiation in an ion-free 300 kV transmission electron microscope, with subsequent annealing in some cases. A few of the irradiations were performed with samples cooled by liquid helium. Subsequent luminescence studies were performed by microscopic photoluminescence spectroscopy at liquid-helium temperatures. The results lead to the conclusion that 3H luminescence arises from the single, isolated, [100] split self-interstitial in diamond. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Univ Bristol, Dept Phys, Bristol BS8 1TL, Avon, England. USN, Res Lab, Washington, DC 20375 USA. RP Steeds, JW (reprint author), Univ Bristol, Dept Phys, Bristol BS8 1TL, Avon, England. RI Butler, James/B-7965-2008 OI Butler, James/0000-0002-4794-7176 NR 12 TC 42 Z9 43 U1 0 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-9635 J9 DIAM RELAT MATER JI Diam. Relat. Mat. PD OCT PY 1999 VL 8 IS 10 BP 1847 EP 1852 DI 10.1016/S0925-9635(99)00144-2 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA 236AW UT WOS:000082576900005 ER PT J AU Bowman, WR Mehay, SL AF Bowman, WR Mehay, SL TI Graduate education and employee performance: evidence from military personnel SO ECONOMICS OF EDUCATION REVIEW LA English DT Article DE graduate education; internal labor markets; bivariate probit model; promotion probabilities ID JOB-PERFORMANCE; EARNINGS PROFILES; PRODUCTIVITY; FIRM; MARKET; WAGES AB Few studies have examined the relationship between on-the-job productivity and graduate education using single-firm data. This paper studies the effect of graduate education on job performance using a unique micro-database consisting of military officers. Supervisor ratings and promotion probabilities are examined for professional and technical officers in the US Navy, a hierarchical organization with an internal labor market and up-or-out promotion policies. Single-stage estimates indicate that, among those eligible to be considered for promotion to grade 4, the up-or-out point, those with any graduate degree are more likely to be promoted. The effect is especially pronounced for those who receive a degree via the Navy's sponsored, full-time program. However, when instruments that are uncorrelated with promotion are used to predict graduate degree status, the results suggest that a sizeable portion of the relationship between graduate education and promotion is due to unobserved attributes that lead some people to attend (or to be selected for) graduate school and to be more promotable. The selection-corrected estimates of the promotion effect of graduate education are reduced by between 40 and 50%. [JEL I21, J24] (C) 1999 Elsevier Science Ltd. All rights reserved. C1 USN, Postgrad Sch, Dept Syst Management, Monterey, CA 93943 USA. USN Acad, Dept Econ, Annapolis, MD 21402 USA. RP Mehay, SL (reprint author), USN, Postgrad Sch, Dept Syst Management, Monterey, CA 93943 USA. NR 25 TC 1 Z9 1 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0272-7757 J9 ECON EDUC REV JI Econ. Educ. Rev. PD OCT PY 1999 VL 18 IS 4 BP 453 EP 463 DI 10.1016/S0272-7757(99)00014-X PG 11 WC Economics; Education & Educational Research SC Business & Economics; Education & Educational Research GA 220PP UT WOS:000081674600005 ER PT J AU Prasad, K Li, CP Kailasanath, K AF Prasad, K Li, CP Kailasanath, K TI Simulation of water mist suppression of small scale methanol liquid pool fires SO FIRE SAFETY JOURNAL LA English DT Article ID FLUX-CORRECTED TRANSPORT; SECTIONAL APPROACH; FUEL SPRAYS; DROPLET; VAPORIZATION; COMBUSTION; FLAMES AB The focus of this paper is on numerical modeling of methanol liquid pool fires and the suppression of these fires using water mist. A mathematical model is first developed to describe the evaporation and burning of liquid methanol. The complete set of unsteady, compressible Navier-Stokes equations are solved along with an Eulerian sectional water mist model. Heat transfer into the liquid pool and the metal container through conduction, convection and radiation are modeled by solving a modified form of the energy equation. Clausius-Clapeyron relationships are invoked to model the evaporation rate of a two-dimensional pool of pure liquid methanol. The interaction of water mist with pulsating fires stabilized above a liquid methanol pool and steady fires stabilized by a strong co-flowing air jet are simulated. Time-dependent heat release/absorption profiles indicate the location where the water droplets evaporate and absorb energy. The relative contribution of the various suppression mechanisms such as oxygen dilution, radiation and thermal cooling is investigated. Parametric studies are performed to determine the effect of mist density, injection velocity and droplet diameter on entrainment and suppression of pool fires, These results are reported in terms of reduction in peak temperature, effect on burning rate and changes in overall heat release rate. Numerical simulations indicate that small droplet diameters exhibit smaller characteristic time for decrease of relative velocity with respect to the gas phase, and therefore entrain more rapidly into the diffusion flame than larger droplet. Hence for the co-flow injection case, smaller diameter droplets produce maximum flame suppression for a fixed amount of water mist. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. Sci Applicat Int Corp, Mclean, VA 22102 USA. RP USN, Res Lab, Computat Phys & Fluid Dynam Lab, 4555 Overlook Ave,Code 6410, Washington, DC 20375 USA. EM prasad@lcp.nrl.navy.mil NR 35 TC 33 Z9 35 U1 1 U2 13 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0379-7112 EI 1873-7226 J9 FIRE SAFETY J JI Fire Saf. J. PD OCT PY 1999 VL 33 IS 3 BP 185 EP 212 DI 10.1016/S0379-7112(99)00028-4 PG 28 WC Engineering, Civil; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 250ZB UT WOS:000083419200003 ER PT J AU Gaquin, A AF Gaquin, A TI Languages in the minority in France and in the new Europe SO FRENCH REVIEW LA French DT Article C1 USN Acad, Annapolis, MD 21402 USA. RP Gaquin, A (reprint author), USN Acad, Annapolis, MD 21402 USA. NR 27 TC 3 Z9 3 U1 0 U2 0 PU AMER ASSN TEACH FRENCH PI CHAMPAIGN PA 57 EAST ARMORY AVE, CHAMPAIGN, IL 61820 USA SN 0016-111X J9 FR REV JI Fr. Rev. PD OCT PY 1999 VL 73 IS 1 BP 94 EP 107 PG 14 WC Literature, Romance SC Literature GA 244HW UT WOS:000083046600009 ER PT J AU Rashid, A Koteish, AK Cortez-Pinto, H Wang, XT Yang, SQ Coyle, W Guggino, S Diehl, AME AF Rashid, A Koteish, AK Cortez-Pinto, H Wang, XT Yang, SQ Coyle, W Guggino, S Diehl, AME TI Subcellular localization of uncoupling protein (UCP)2 and evidence for increased UCP2 expression in nonalcoholic steatohepatitis. SO HEPATOLOGY LA English DT Meeting Abstract C1 Johns Hopkins Univ, Baltimore, MD USA. Hosp Univ Santa Mario, Lisbon, Portugal. Natl Naval Med Ctr, Portsmouth, VA USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0270-9139 J9 HEPATOLOGY JI Hepatology PD OCT PY 1999 VL 30 IS 4 SU S MA 980 BP 405A EP 405A PN 2 PG 1 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA 239XE UT WOS:000082794700979 ER PT J AU Yu, H Wang, LJ Flippen-Anderson, JL Tian, XR Coop, A Rice, KC AF Yu, H Wang, LJ Flippen-Anderson, JL Tian, XR Coop, A Rice, KC TI Synthesis of a novel 7,14 beta-ethano-bridged opiate SO HETEROCYCLES LA English DT Article AB A novel 7,14 beta-ethano-bridged opiate (1) was prepared from the known 14-alkenylcodeinone (3) in two steps. Selective reduction of the enone double bond of 3 followed by ozonolysis led to an aldehyde intermediate, which was cyclized in situ through an intramolecular aldol condensation to give the rigid hexacyclic derivative (1). C1 NIDDKD, Med Chem Lab, Bethesda, MD 20892 USA. USN, Res Lab, Washington, DC 20375 USA. RP Rice, KC (reprint author), NIDDKD, Med Chem Lab, Bldg 8,Room B1-23, Bethesda, MD 20892 USA. NR 5 TC 3 Z9 3 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0385-5414 J9 HETEROCYCLES JI Heterocycles PD OCT 1 PY 1999 VL 51 IS 10 BP 2343 EP 2347 PG 5 WC Chemistry, Organic SC Chemistry GA 248AP UT WOS:000083253400006 ER EF