4,676 research outputs found

    Paper Session III-A - Space Launch Commandos: An Alternate Spproach to how the Military Currently Conducts Space Launch

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    The United States is becoming increasingly dependent on space assets for the conduct of peacetime and wartime military operations. The Gulf War was the first “space-age” war in which space based assets played critical roles in communications, navigation, weather prediction, missile launch detection, and intelligence gathering. Future military actions will all depend heavily on space based assets

    Completeness of Wilson loop functionals on the moduli space of SL(2,C)SL(2,C) and SU(1,1)SU(1,1)-connections

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    The structure of the moduli spaces \M := \A/\G of (all, not just flat) SL(2,C)SL(2,C) and SU(1,1)SU(1,1) connections on a n-manifold is analysed. For any topology on the corresponding spaces \A of all connections which satisfies the weak requirement of compatibility with the affine structure of \A, the moduli space \M is shown to be non-Hausdorff. It is then shown that the Wilson loop functionals --i.e., the traces of holonomies of connections around closed loops-- are complete in the sense that they suffice to separate all separable points of \M. The methods are general enough to allow the underlying n-manifold to be topologically non-trivial and for connections to be defined on non-trivial bundles. The results have implications for canonical quantum general relativity in 4 and 3 dimensions.Comment: Plain TeX, 7 pages, SU-GP-93/4-

    Results for a turbulent system with unbounded viscosities: weak formulations, existence of solutions, boundedness, smoothness'

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    We consider a circulation system arising in turbulence modelling in fluid dynamics with unbounded eddy viscosities. Various notions of weak solutions are considered and compared. We establish existence and regularity results. In particular we study the boundedness of weak solutions. We also establish an existence result for a classical solutio

    VTOL/STOL visual study

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    The development of data bases and real time techniques to improve the realism of sea state, bow and stern wake, and ship motion is addressed. This system was designed for use with the Vertical Motion Simulator to perform basic studies on VTOL/STOL aircraft

    Geometry of Generic Isolated Horizons

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    Geometrical structures intrinsic to non-expanding, weakly isolated and isolated horizons are analyzed and compared with structures which arise in other contexts within general relativity, e.g., at null infinity. In particular, we address in detail the issue of singling out the preferred normals to these horizons required in various applications. This work provides powerful tools to extract invariant, physical information from numerical simulations of the near horizon, strong field geometry. While it complements the previous analysis of laws governing the mechanics of weakly isolated horizons, prior knowledge of those results is not assumed.Comment: 37 pages, REVTeX; Subsections V.B and V.C moved to a new Appenedix to improve the flow of main argument

    From Crystalline to Amorphous Germania Bilayer Films at the Atomic Scale: Preparation and Characterization

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    A new two-dimensional (2D) germanium dioxide film has been prepared. The film consists of interconnected germania tetrahedral units forming a bilayer structure, weakly coupled to the supporting Pt(111) metal-substrate. Density functional theory calculations predict a stable structure of 558-membered rings for germania films, while for silica films 6-membered rings are preferred. By varying the preparation conditions the degree of order in the germania films is tuned. Crystalline, intermediate ordered and purely amorphous film structures are resolved by analysing scanning tunnelling microscopy images

    From Crystalline to Amorphous Germania Bilayer Films at the Atomic Scale: Preparation and Characterization

    Get PDF
    A new two-dimensional (2D) germanium dioxide film has been prepared. The film consists of interconnected germania tetrahedral units forming a bilayer structure, weakly coupled to the supporting Pt(111) metal-substrate. Density functional theory calculations predict a stable structure of 558-membered rings for germania films, while for silica films 6-membered rings are preferred. By varying the preparation conditions the degree of order in the germania films is tuned. Crystalline, intermediate ordered and purely amorphous film structures are resolved by analysing scanning tunnelling microscopy images
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