2,242 research outputs found

    Method of fabricating a photovoltaic module of a substantially transparent construction

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    A method characterized by the steps of positioning a plurality of uniformly dimensioned photovoltaic cells in registered relation with a plurality of openings formed in a planar tool is disclosed. The method allows acess to the P contact surface of each of the cells. The steps of the method are: (1) connecting the N contact surface of alternate cells to the P contact surface of the cells interposed therebetween, (2) removing therefrom residue of solder flux, (3) applying to the N contact surfaces of the cells a transparent adhesive, (4) placing a common transparent cover plate in engaged relation with the adhesive, (5) placing a film over the circular openings for hermetically sealing the openings, and (6) establishing a vacuum between the film and the cover plate

    A preface to Gutstein Generalized: A Philosophical Debate

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    The National Council of Teachers of Mathematics (NCTM) has taken a very firm stand on the issue of equity in mathematics education. Not only is equity incorporated in the Curriculum and Evaluation Standards for School Mathematics (1989) and Principles and Standards for School Mathematics (2000), equity is the first plank of NCTM’s legislative platform

    MATH 691.01: Research Methods in Mathematics Education

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    STS Flight Experiments Database

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    In response to a request of the Space Station Task Force, a data base has been developed, utilizing experiment definitions from all NASA Centers, with emphasis on candidate STS flight experiments that relate to the development and operation of initial and growth versions of a Space Station. Experiments are also included for Shuttle enhancement, for servicing and operations of advanced vehicles such as OMV and OTV, for generic technology such as large structures, control and pointing, heat rejection, for life sciences and for physical sciences and applications. Criteria for selection activity are defined

    Topology Change in (2+1)-Dimensional Gravity

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    In (2+1)-dimensional general relativity, the path integral for a manifold MM can be expressed in terms of a topological invariant, the Ray-Singer torsion of a flat bundle over MM. For some manifolds, this makes an explicit computation of transition amplitudes possible. In this paper, we evaluate the amplitude for a simple topology-changing process. We show that certain amplitudes for spatial topology change are nonvanishing---in fact, they can be infrared divergent---but that they are infinitely suppressed relative to similar topology-preserving amplitudes.Comment: 19 pages of text plus 4 pages of figures, LaTeX (using epsf), UCD-11-9

    Analytic Torsion on Hyperbolic Manifolds and the Semiclassical Approximation for Chern-Simons Theory

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    The invariant integration method for Chern-Simons theory for gauge group SU(2) and manifold \Gamma\H^3 is verified in the semiclassical approximation. The semiclassical limit for the partition function associated with a connected sum of hyperbolic 3-manifolds is presented. We discuss briefly L^2 - analytical and topological torsions of a manifold with boundary.Comment: 12 pages, LaTeX fil

    Vocational Agriculture Forestry Lesson 1: How are Trees Useful to Us

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    Retardation of Particle Evaporation from Excited Nuclear Systems Due to Thermal Expansion

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    Particle evaporation rates from excited nuclear systems at equilibrium matter density are studied within the Harmonic-Interaction Fermi Gas Model (HIFGM) combined with Weisskopf's detailed balance approach. It is found that thermal expansion of a hot nucleus, as described quantitatively by HIFGM, leads to a significant retardation of particle emission, greatly extending the validity of Weisskopf's approach. The decay of such highly excited nuclei is strongly influenced by surface instabilities
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