203,889 research outputs found

    The Constitutional Status of Local Government Reapportionment

    Get PDF

    Improved circuit-board interconnectors

    Get PDF
    One component serves three functions, electrical interconnections, thermal control, and mechanical integrity, at same time. Several versions of design: (1) Insulated support plate contains holes; (2) Alternate support plate configuration uses rivets instead of pins; and (3) Another configuration includes leaf-spring contacts instead of pins or rivets

    Life detection

    Get PDF
    Compact automated laboratory unit has 60 independently treatable culture chamber assemblies for metabolic studies of cultured microorganisms on the surface of Mars or other planets

    Simulation of Material Properties Below the Debye Temperature: A Path-Integral Molecular Dynamics Case Study of Quartz

    Full text link
    Classical and path integral molecular dynamics (PIMD) simulations are used to study alpha-quartz and beta-quartz in a large range of temperatures at zero external stress. PIMD account for quantum fluctuations of atomic vibrations, which can modify material properties at temperatures below the Debye temperature. The difference between classical and quantum mechanical results for bond lengths, bond angles, elastic modulii, and some dynamical properties is calculated and comparison to experimental data is done. Only quantum mechanical simulations are able to reflect the correct thermomechanical properties below room temperature. It is discussed in how far classical and PIMD simulations can be helpful in constructing improved potential energy surfaces for silica.Comment: 8 pages, 9 figures, submitted to J. Chem. Phy
    corecore