7,474 research outputs found

    LANDSAT language at our reach. First Swedish satellite. Civilization detectors

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    Information on the use of LANDSAT data by Argentina is presented. Details on a Swedish satellite to be completed in 1984 and to be called VIKING are reported. Attempts to contact other civilizations in space by the use of radiotelescopes are discussed

    Multivectorial strategy to interpret a resistive behaviour of loads in smart buildings

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    In Smart buildings, electric loads are affected by an important distortion in the current and voltage waveforms, caused by the increasing proliferation of non linear electronic devices. This paper presents an approach on non sinusoidal power theory based on Geometric Algebra that clearly improves traditional methods in the optimization of apparent power and power factor compensation. An example is included that demonstrates the superiority of this approach compared with traditional methods.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Higher order correction to the neutrino self-energy in a medium and its astrophysical applications

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    We have calculated the 1/M^4 (M the vector boson mass) order correction to the neutrino self-energy in a medium. The possible application of this higher order contribution to the neutrino effective potential is considered in the context of the Early Universe hot plasma and of the cosmological Gamma Ray Burst fireball. We found that, depending on the medium parameters and on the neutrino properties (mixing angle and mass square difference) the resonant oscillation of active to active neutrinos is possible.Comment: 10 pages, revtex style, uses axodraw.sty, 1 figur

    Observability of general linear pairs

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    A Characterization of concave mappings

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    This study focuses on Concave mappings, a class of univalent functions that exhibit a unique property: they map the unit disk onto a domain whose complement is convex. The main objective of this work is to characterize these mappings in terms of the real part of the expression 1+zf′′(z)/f′(z)1 +zf''(z)/f'(z), considering scenarios where the omitted convex domain is either bounded or unbounded. In the case of a bounded convex domain, we investigate the pivotal role played by the Schwarzian derivative and the order of the functions in understanding the behavior and properties of these mappings

    Type Ia Supernova Scenarios and the Hubble Sequence

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    The dependence of the Type Ia supernova (SN Ia) rate on galaxy type is examined for three currently proposed scenarios: merging of a Chandrasekhar--mass CO white dwarf (WD) with a CO WD companion, explosion of a sub--Chandrasekhar mass CO WD induced by accretion of material from a He star companion, and explosion of a sub--Chandrasekhar CO WD in a symbiotic system. The variation of the SNe Ia rate and explosion characteristics with time is derived, and its correlation with parent population age and galaxy redshift is discussed. Among current scenarios, CO + He star systems should be absent from E galaxies. Explosion of CO WDs in symbiotic systems could account for the SNe Ia rate in these galaxies. The same might be true for the CO + CO WD scenario, depending on the value of the common envelope parameter. A testable prediction of the sub--Chandrasekhar WD model is that the average brightness and kinetic energy of the SN Ia events should increase with redshift for a given Hubble type. Also for this scenario, going along the Hubble sequence from E to Sc galaxies SNe Ia events should be brighter on average and should show larger mean velocities of the ejecta. The observational correlations strongly suggest that the characteristics of the SNe Ia explosion are linked to parent population age. The scenario in which WDs with masses below the Chandrasekhar mass explode appears the most promising one to explain the observed variation of the SN Ia rate with galaxy type together with the luminosity--expansion velocity trend.Comment: 16 pages uuencoded compressed Postscript, 2 figures included. ApJ Letters, in pres
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