178,989 research outputs found

    Constrained Molecular Dynamics Simulations of Atomic Ground-States

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    Constrained molecular dynamics(CoMD) model, previously introduced for nuclear dynamics, has been extended to the atomic structure and collision calculations. Quantum effects corresponding to the Pauli and Heisenberg principle are enforced by constraints, in a parameter-free way. Our calculations for small atomic system, H, He, Li, Be, F reproduce the ground-state binding energies within 3%, compared with the results of quantum mechanical Hartree-Fock calculations.Comment: 3 pages, 2 figure

    Persistent Problems in Medical Care

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    Fossil Glasses Produced by Impact of Meteorites, Asteroids and Possibly Comets with the Planet Earth

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    In recent times one of the most intriguing mysteries of geology bas been the occurrence of aerodynamically-shaped glasses on five continents of the earth. These glasses under discussion are obviously not of fulgurite origin. Recent research indicates that these glasses known as tektites are ~he result of meteorite, asteroid, or possibly comet impact. Impact glasses, in general, differ from volcanic glasses in that they are lower in water content, have lower gallium and germanium contents, and are not necessarily in magmatically unstable continental areas

    Analysis of F and G subdwarfs. 3 - An abundance analysis of the subdwarf mu Cassiopeia

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    Model atmospheric abundance analysis of subdwarf micron Cassiopeia constellatio

    Hazard's Toll: The Costs of Inaction at the Salton Sea

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    The objective of this report is to estimate the costs of inaction - defined as the absence of any large-scale revitalization or air quality management project - at the Salton Sea, to provide decision-makers and the general public with information for deciding on a path forward

    Analytical fuel property effects, small combustors, phase 1

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    The effects of nonstandard aviation fuels on a typical small gas turbine combustor was analyzed. The T700/CT7 engine family was chosen as being representative of the class of aircraft power plants desired. Fuel properties, as specified by NASA, are characterized by low hydrogen content and high aromatics levels. Higher than normal smoke output and flame radiation intensity for the current T700 combustor which serves as a baseline were anticipated. It is, therefore, predicted that out of specification smoke visibility and higher than normal shell temperatures will exist when using NASA ERBS fuels with a consequence of severe reduction in cyclic life. Three new designs are proposed to compensate for the deficiencies expected with the existing design. They have emerged as the best of the eight originally proposed redesigns or combinations thereof. After the five choices that were originally made by NASA on the basis of competing performance factors, General Electric narrowed the field to the three proposed
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