4,474 research outputs found

    Digital video display system

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    System displays image data in real time on 120,000-element raster scan with 2, 4, or 8 shades of grey. Designed for displaying planetary range Doppler data, system can be used for X-Y plotting, displaying alphanumerics, and providing image animation

    One vertex spin-foams with the Dipole Cosmology boundary

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    We find all the spin-foams contributing in the first order of the vertex expansion to the transition amplitude of the Bianchi-Rovelli-Vidotto Dipole Cosmology model. Our algorithm is general and provides spin-foams of arbitrarily given, fixed: boundary and, respectively, a number of internal vertices. We use the recently introduced Operator Spin-Network Diagrams framework.Comment: 23 pages, 30 figure

    The Gibbs paradox, Black hole entropy and the thermodynamics of isolated horizons

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    This letter presents a new, solely thermodynamical argument for considering the states of the quantum isolated horizon of a black hole as distinguishable. We claim that only if the states are distinguishable, the thermodynamic entropy is an extensive quantity and can be well-defined. To show this, we make a comparison with a classical ideal gas system whose statistical description makes only sense if an additional 1/N!-factor is included in the state counting in order to cure the Gibbs paradox. The case of the statistical description of a quantum isolated horizon is elaborated, to make the claim evident.Comment: 8 pages, closest to the published version; taken from the author's diploma thesi

    The kernel and the injectivity of the EPRL map

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    In this paper we prove injectivity of the EPRL map for |\gamma|<1, filling the gap of our previous paper.Comment: 17 pages, 3 figure

    Response of selected plant and insect species to simulated solid rocket exhaust mixtures and to exhaust components from solid rocket fuels

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    The effects of solid rocket fuel (SRF) exhaust on selected plant and and insect species in the Merritt Island, Florida area was investigated in order to determine if the exhaust clouds generated by shuttle launches would adversely affect the native, plants of the Merritt Island Wildlife Refuge, the citrus production, or the beekeeping industry of the island. Conditions were simulated in greenhouse exposure chambers and field chambers constructed to model the ideal continuous stirred tank reactor. A plant exposure system was developed for dispensing and monitoring the two major chemicals in SRF exhaust, HCl and Al203, and for dispensing and monitoring SRF exhaust (controlled fuel burns). Plants native to Merritt Island, Florida were grown and used as test species. Dose-response relationships were determined for short term exposure of selected plant species to HCl, Al203, and mixtures of the two to SRF exhaust

    Biological description of Old Plantation Flats Deep Trough, a proposed dredged material disposal site: Interim report

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    The Old Plantation Trough site biological community was surveyed August 29-30, 1978. Bottom profiles were completed September 9, 1978. An Interim Report containing the procedures, list of stations, hydrographic data, bottom profiles, and species list was prepared and filed October 3, 1978. This report contains tables of numbers and weights of fish and invertebrates collected during the August 1978 survey and thus concludes the report on the Summer Survey

    Biological description of Old Plantation Flats Deep Trough, a proposed dredged material disposal site: Interim report

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    The Old Plantation Deep Trough sampling area in the Virginia portion of the Chesapeake Bay began at the latitudes of the southwestern end of the Cherrystone Inlet channel near Old Plantation Flats (approximately 37°13.S\u27N) and extended north to the latitude of Church Neck at Hungars Creek (approximately 37°25.S\u27N) (see attached Figure 1: Disposal Area 2 and area to the north). Twenty-one stations, one-quarter mile square grid, were occupied on August 29 and 30, 1978 (Table 1 and accompanying Charts). Seven stations were sampled with a lined, 30-foot semiballoon otter trawl, seven sampled with a 48-inch wide crab dredge, and seven were sampled with both gears (Table 1)

    Black hole entropy from an SU(2)-invariant formulation of Type I isolated horizons

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    A detailed analysis of the spherically symmetric isolated horizon system is performed in terms of the connection formulation of general relativity. The system is shown to admit a manifestly SU(2) invariant formulation where the (effective) horizon degrees of freedom are described by an SU(2) Chern-Simons theory. This leads to a more transparent description of the quantum theory in the context of loop quantum gravity and modifications of the form of the horizon entropy.Comment: 30 pages, 1 figur

    Generic isolated horizons in loop quantum gravity

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    Isolated horizons model equilibrium states of classical black holes. A detailed quantization, starting from a classical phase space restricted to spherically symmetric horizons, exists in the literature and has since been extended to axisymmetry. This paper extends the quantum theory to horizons of arbitrary shape. Surprisingly, the Hilbert space obtained by quantizing the full phase space of \textit{all} generic horizons with a fixed area is identical to that originally found in spherical symmetry. The entropy of a large horizon remains one quarter its area, with the Barbero-Immirzi parameter retaining its value from symmetric analyses. These results suggest a reinterpretation of the intrinsic quantum geometry of the horizon surface.Comment: 13 page
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