6,714 research outputs found

    Occupational Status of High School Graduates

    Get PDF
    In recent years there has been a feeling among some educators that the secondary school was failing to equip its graduates with any practical training, either as a preparation for courses of higher learning or for professions. One of the broad purposes of this study was to determine to what degree of the graduates of Fountain High School, Fountain, Colorado, have been able to cope with the economic and social conditions of life

    The Stellar Activity - Rotation Relationship

    Get PDF
    Using a new catalog of 824 solar and late-type stars with X-ray luminosities and rotation periods we have studied the relationship between rotation and stellar activity. From an unbiased subset of this sample the power law slope of the unsaturated regime, LX/LbolRoβL_X/L_{bol}\propto Ro^\beta, is fit as β=2.70±0.13\beta=-2.70\pm0.13. This is inconsistent with the canonical β=2\beta=-2 slope to a confidence of 5σ\sigma and argues for an interface-type dynamo. Super-saturation is observed for the fastest rotators in our sample and its parametric dependencies are explored. Significant correlations are found with both the corotation radius and the excess polar updraft, the latter theory being supported by other observations. We also present a new X-ray population synthesis model of the mature stellar component of our Galaxy and use it to reproduce deep observations of a high Galactic latitude field. The model, XStar, can be used to test models of stellar spin-down and dynamo decay, as well as for estimating stellar X-ray contamination rates for non-stellar studies.Comment: 4 pages, 4 figures. To appear in the proceedings of Cool Stars 17: 17th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, AN 334, 1-2, Eds Klaus Strassmeier and Mercedes Lopez-Morale

    Spin-orbit parameters by the Gelfand-Harter method-a test calculation

    Get PDF
    The spin-orbit parameters for the sextet states of the f5 configuration are computed using the Young-tableau techniques developed by Harter. The conceptual and computational advantages over traditional methods are discussed. © 1977 The American Physical Society

    All-Electron Path Integral Monte Carlo Simulations of Warm Dense Matter: Application to Water and Carbon Plasmas

    Full text link
    We develop an all-electron path integral Monte Carlo (PIMC) method with free-particle nodes for warm dense matter and apply it to water and carbon plasmas. We thereby extend PIMC studies beyond hydrogen and helium to elements with core electrons. PIMC pressures, internal energies, and pair-correlation functions compare well with density functional theory molecular dynamics (DFT-MD) at temperatures of (2.5-7.5)×105\times10^5 K and both methods together form a coherent equation of state (EOS) over a density-temperature range of 3--12 g/cm3^3 and 104^4--109^9 K

    An Algorithm for constructing Hjelmslev planes

    Get PDF
    Projective Hjelmslev planes and Affine Hjelmselv planes are generalisations of projective planes and affine planes. We present an algorithm for constructing a projective Hjelmslev planes and affine Hjelsmelv planes using projective planes, affine planes and orthogonal arrays. We show that all 2-uniform projective Hjelmslev planes, and all 2-uniform affine Hjelsmelv planes can be constructed in this way. As a corollary it is shown that all 2-uniform Affine Hjelmselv planes are sub-geometries of 2-uniform projective Hjelmselv planes.Comment: 15 pages. Algebraic Design Theory and Hadamard matrices, 2014, Springer Proceedings in Mathematics & Statistics 13

    The dynamic dipole polarizabilities of the Li atom and the Be+ ion

    Get PDF
    The dynamic dipole polarizabilities for the Li atom and the Be+ ion in the 2s and 2p states are calculated using the variational method with a Hylleraas basis. The present polarizabilities represent the definitive values in the non-relativistic limit. Corrections due to relativistic effects are also estimated. Analytic representations of the polarizabilities for frequency ranges encompassing the n=3 excitations are presented. The recommended polarizabilities for ^7Li and ^9Be+ were 164.11 \pm 0.03 a.u. and 24.489 \pm 0.004 a.u.

    Calculations of polarizabilities and hyperpolarizabilities for the Be+^+ ion

    Get PDF
    The polarizabilities and hyperpolarizabilities of the Be+^+ ion in the 22S2^2S state and the 22P2^2P state are determined. Calculations are performed using two independent methods: i) variationally determined wave functions using Hylleraas basis set expansions and ii) single electron calculations utilizing a frozen-core Hamiltonian. The first few parameters in the long-range interaction potential between a Be+^+ ion and a H, He, or Li atom, and the leading parameters of the effective potential for the high-LL Rydberg states of beryllium were also computed. All the values reported are the results of calculations close to convergence. Comparisons are made with published results where available.Comment: 18 pp; added details to Sec. I
    corecore