2,203 research outputs found

    Transport: Introduction

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    Space transportation requirements for the NASA baseline scenario for future space missions are discussed. Spacecraft/propulsion technologies required for surface-to-orbit, orbit-to-orbit, and surface (lunar) transportation are addressed

    Half-space theorems for minimal surfaces in Nil_3 and Sol_3

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    We prove some half-space theorems for minimal surfaces in the Heisenberg group Nil_3 and the Lie group Sol_3 endowed with their left-invariant Riemannian metrics. If S is a properly immersed minimal surface in Nil_3 that lies on one side of some entire minimal graph G, then S is the image of G by a vertical translation. If S is a properly immersed minimal surface in Sol_3 that lies on one side of a special plane, then S is another special plane.Comment: 19 pages, 3 figure

    Restructuring the Electric Utility Industry and Its Effect on the Environment

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    The topology, geometry and conformal structure of properly embedded minimal surfaces

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    This paper develops new tools for understanding surfaces with more than one end (and usually, of infinite topology) which properly minimally embed into Euclidean three-space. On such a surface, the set of ends forms a compact Hausdorff space, naturally ordered by the relative heights of the ends in space. One of our main results is that the middle ends of the surface have quadratic area growth, and are thus not limit ends. This implies, for instance, that the surface can have at most two limit ends (at the top and bottom of the ordering), which is a strong topological restriction. There are also restrictions on the asymptotic geometry and conformal structure of such a surface: for example, we prove that if the surface has exactly two limit ends (as do the classical Riemann Staircase examples), then it is recurrent (that is, almost all Brownian paths are dense in the surface, and in particular any positive harmonic function on the surface is constant). These results have played an important role in the proof of several recent advances in the theory, including the uniqueness of the helicoid, the invariance of flux for a coordinate function on a properly immersed minimal surface, and the topological classification of properly embedded minimal surfaces

    Understanding Strikes in Revolutionary Russia

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    Also CSST Working Paper #37.http://deepblue.lib.umich.edu/bitstream/2027.42/51175/1/408.pd

    The Institutionalization of Conflict in the Reform of Schools: A Case Study of Court Implementation of the PARC Decree

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    Symposium: The Sociology of Class Actions NOTE: A printing error labeled this issue Spring 1982, when it should have been labeled Summer 198

    The Institutionalization of Conflict in the Reform of Schools: A Case Study of Court Implementation of the PARC Decree

    Get PDF
    Symposium: The Sociology of Class Actions NOTE: A printing error labeled this issue Spring 1982, when it should have been labeled Summer 198

    Tunable UV Filters

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    This report describes an investigation intended to determine the practical short wavelength limit for Fabry-Perot etalons operating in the far ultraviolet. This portion of the investigation includes a design study of multilayer dielectric reflector coatings that would be required by such an etalon. Results of the study indicate that etalons may be made to operate at wavelengths as short as 121 nm
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