362 research outputs found

    Research and development of open-cycle fuel cells Fourth quarterly progress report, period ending Aug. 15, 1965

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    Digital computer program for minimizing weight of fuel cell power systems - prelaunch startup and instrumentation - mathematical model of static moisture removal process - fuel cell mode

    Coryza, Its Causes and Treatment.

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    Research and development of open cycle fuel cells Second quarterly progress report, period ending Feb. 15, 1965

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    Effect of low temperature environment on storage of fuel cell power supply - computer program for fuel cell system parameter optimization - mathematical model of static moisture remova

    ENABLING WARFARE AT THE SPEED OF LIGHT: A COMPARATIVE ANALYSIS OF MULTI-MISSION HIGH ENERGY LASER RADARS

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    This capstone report provides a cost effectiveness analysis of various radar systems capable of guiding the Multi-Mission High Energy Laser (MMHEL) from a Stryker platform. The Army's Rapid Capability and Critical Technologies Office (RCCTO) is developing the MMHEL to provide a Mobile Short-Range Air Defense (MSHORAD) capability to maneuver units. The MMHEL requires a radar to cue the fire control system for target engagement. Past efforts to employ high-energy lasers have relied on large, stationary radars for target acquisition. The reliance on such radars limits a unit's ability to maneuver and results in the laser being employed primarily from a defensive posture. To maximize maneuverability and enable the offensive employment of the MMHEL, the U.S. Army needs an on-platform radar that is compact and inexpensive enough to equip multiple Strykers within a Stryker Brigade Combat Team with the capability to engage targets from a mobile platform. The RCCTO is currently tasked with accelerating efforts to fill this need. The intent of this report is to assist the RCCTO in these efforts by generating a list of viable radar alternatives and conducting a cost effectiveness analysis to produce a recommendation of the most optimal solution. The results indicate that RADA's aCHR radar presents the best value in terms of cost and benefit to the warfighter.http://archive.org/details/enablingwarfarea1094564109Captain, United States ArmyCaptain, United States ArmyMajor, United States ArmyCaptain, United States ArmyCaptain, United States ArmyApproved for public release; distribution is unlimited

    Zeros of the Partition Function and Pseudospinodals in Long-Range Ising Models

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    The relation between the zeros of the partition function and spinodal critical points in Ising models with long-range interactions is investigated. We find the spinodal is associated with the zeros of the partition function in four-dimensional complex temperature/magnetic field space. The zeros approach the real temperature/magnetic field plane as the range of interaction increases.Comment: 20 pages, 9 figures, accepted to PR

    Critical behavior of a fluid in a disordered porous matrix: An Ornstein-Zernike approach

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    Using a liquid-state approach based on Ornstein-Zernike equations, we study the behavior of a fluid inside a porous disordered matrix near the liquid-gas critical point.The results obtained within various standard approximation schemes such as lowest-order γ\gamma-ordering and the mean-spherical approximation suggest that the critical behavior is closely related to that of the random-field Ising model (RFIM).Comment: 10 pages, revtex, to appear in Physical Review Letter

    Clusters and Fluctuations at Mean-Field Critical Points and Spinodals

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    We show that the structure of the fluctuations close to spinodals and mean-field critical points is qualitatively different than the structure close to non-mean-field critical points. This difference has important implications for many areas including the formation of glasses in supercooled liquids. In particular, the divergence of the measured static structure function in near-mean-field systems close to the glass transition is suppressed relative to the mean-field prediction in systems for which a spatial symmetry is broken.Comment: 5 pages, 1 figur

    Avalanches in Breakdown and Fracture Processes

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    We investigate the breakdown of disordered networks under the action of an increasing external---mechanical or electrical---force. We perform a mean-field analysis and estimate scaling exponents for the approach to the instability. By simulating two-dimensional models of electric breakdown and fracture we observe that the breakdown is preceded by avalanche events. The avalanches can be described by scaling laws, and the estimated values of the exponents are consistent with those found in mean-field theory. The breakdown point is characterized by a discontinuity in the macroscopic properties of the material, such as conductivity or elasticity, indicative of a first order transition. The scaling laws suggest an analogy with the behavior expected in spinodal nucleation.Comment: 15 pages, 12 figures, submitted to Phys. Rev. E, corrected typo in authors name, no changes to the pape

    Novel Staufen1 ribonucleoproteins prevent formation of stress granules but favour encapsidation of HIV-1 genomic RNA

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    Human immunodeficiency virus type 1 (HIV-1) Gag selects for and mediates genomic RNA (vRNA) encapsidation into progeny virus particles. The host protein, Staufen1 interacts directly with Gag and is found in ribonucleoprotein (RNP) complexes containing vRNA, which provides evidence that Staufen1 plays a role in vRNA selection and encapsidation. In this work, we show that Staufen1, vRNA and Gag are found in the same RNP complex. These cellular and viral factors also colocalize in cells and constitute novel Staufen1 RNPs (SHRNPs) whose assembly is strictly dependent on HIV-1 expression. SHRNPs are distinct from stress granules and processing bodies, are preferentially formed during oxidative stress and are found to be in equilibrium with translating polysomes. Moreover, SHRNPs are stable, and the association between Staufen1 and vRNA was found to be evident in these and other types of RNPs. We demonstrate that following Staufen1 depletion, apparent supraphysiologic-sized SHRNP foci are formed in the cytoplasm and in which Gag, vRNA and the residual Staufen1 accumulate. The depletion of Staufen1 resulted in reduced Gag levels and deregulated the assembly of newly synthesized virions, which were found to contain several-fold increases in vRNA, Staufen1 and other cellular proteins. This work provides new evidence that Staufen1-containing HIV-1 RNPs preferentially form over other cellular silencing foci and are involved in assembly, localization and encapsidation of vRNA.Fil: Abrahamyan, Levon G.. Davis Jewish General Hospital; CanadáFil: Chatel Chaix, Laurent. Davis Jewish General Hospital; CanadáFil: Ajamian, Lara. Mc Gill University; Canadá. Davis Jewish General Hospital; CanadáFil: Milev, Miroslav P.. Mc Gill University; Canadá. Davis Jewish General Hospital; CanadáFil: Monette, Anne. Mc Gill University; Canadá. Davis Jewish General Hospital; CanadáFil: Clément, Jean François. Davis Jewish General Hospital; CanadáFil: Song, Rujun. Mc Gill University; Canadá. Davis Jewish General Hospital; CanadáFil: Lehmann, Martin. Davis Jewish General Hospital; CanadáFil: DesGroseillers, Luc. University Of Montreal; CanadáFil: Laughrea, Michael. Mc Gill University; Canadá. Davis Jewish General Hospital; CanadáFil: Boccaccio, Graciela Lidia. Fundación Instituto Leloir; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquimicas de Buenos Aires; ArgentinaFil: Mouland, Andrew J.. Mc Gill University; Canadá. Davis Jewish General Hospital; Canad
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