45,938 research outputs found

    International data curation education action (IDEA) working group: a report from the second workshop of IDEA

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    The second workshop of the International Data curation Education (IDEA) Working Group was held December 5, 2008, in Edinburgh, Scotland, following the 4th International Digital Curation Conference. This workshop was jointly organized by the UK's Digital Curation Centre (DCC), the US's Institute of Museum and Library Services (IMLS), and the School of Information and Library Science at the University of North Carolina at Chapel Hill (SILS). Nearly forty educators and researchers accepted invitations to attend, with representation from universities, research centers, and funding agencies from Canada, the US, the UK, and Germany

    The evolution of wave correlations in uniformly turbulent, weakly nonlinear systems

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    Evolution of wave correlations in uniformly turbulent, weakly nonlinear system

    On the use of a priori statistics in problems of plasma turbulence

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    Statistical averaging procedure in problems of plasma turbulence involving Vlasov equatio

    Analytical Solutions for the Nonlinear Longitudinal Drift Compression (Expansion) of Intense Charged Particle Beams

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    To achieve high focal spot intensities in heavy ion fusion, the ion beam must be compressed longitudinally by factors of ten to one hundred before it is focused onto the target. The longitudinal compression is achieved by imposing an initial velocity profile tilt on the drifting beam. In this paper, the problem of longitudinal drift compression of intense charged particle beams is solved analytically for the two important cases corresponding to a cold beam, and a pressure-dominated beam, using a one-dimensional warm-fluid model describing the longitudinal beam dynamics

    Development of fiber shields for engine containment

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    Tests were conducted in translational launchers and spin pits to generate empirical data used in the design of a Kevlar shield for containing engine burst debris. Methods are given for modeling the relationship of fragment characteristics to shielding requirements. The change in relative importance of shield mounting provisions as fragment energy is increased is discussed

    Spacecraft attitude sensor

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    A system for sensing the attitude of a spacecraft includes a pair of optical scanners having a relatively narrow field of view rotating about the spacecraft x-y plane. The spacecraft rotates about its z axis at a relatively high angular velocity while one scanner rotates at low velocity, whereby a panoramic sweep of the entire celestial sphere is derived from the scanner. In the alternative, the scanner rotates at a relatively high angular velocity about the x-y plane while the spacecraft rotates at an extremely low rate or at zero angular velocity relative to its z axis to provide a rotating horizon scan. The positions of the scanners about the x-y plane are read out to assist in a determination of attitude. While the satellite is spinning at a relatively high angular velocity, the angular positions of the bodies detected by the scanners are determined relative to the sun by providing a sun detector having a field of view different from the scanners
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