939 research outputs found

    On discrete approximations of stable distributions

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    In some fields of applications of stable distributions, especially in economics, it appears, that data have distributions similar to stable in a large region, but do not have such heavy tails. Our aim in this note is to propose several methods of approximation of stable distributions by some discrete distributions, which may have different tail behavior. In a sense the introduced distributions form an alternative to tempered stable distributions that combine Gaussian and stable behavior

    Structural and electromagnetic study of ferromagnetic semiconductor material

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    A detail structural and electrical analysis of a few doubleperovskite (La2CoMnO6, La2FeMnO6) and their perovskite counterpart (LaCoO3, LaCrO3and LaFeO3) have been performed. All the compounds are synthesized by wet chemical route(especially by sol-gel & pyropheric route). From XRD data analysis, the samples are found to be in single phase and stoichiometric. The information about the molecular bonding is obtained from the FTIR spectra. The band gap is calculated from UV-Visible spectra and the sample is characterised whether it is semiconducting and insulating. The morphology of the materials has been studied through FESEM and finally the dielectric spectroscopy has been carried out for all compounds

    Socio-economic inequalities in curative health-seeking for children in Egypt: analysis of the 2008 Demographic and Health Survey.

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    BACKGROUND: The existence and magnitude of socio-economic inequalities in health-seeking behaviours for child curative care in Egypt and mechanisms underlying these associations have not been comprehensively assessed. This study examined whether socio-economic position (SEP) was associated with health-seeking behaviours for diarrhoea and acute respiratory infection (ARI) in children and explored potential mechanisms underlying these associations using mediation analysis. METHODS: Children aged under-five years living with their mothers sampled by the 2008 Egypt Demographic and Health Survey were used to estimate the prevalence of diarrhoea and ARI in the two-week period preceding the survey. If either illness was reported, three dimensions of health-seeking were examined in adjusted mediation models, separately by illness: whether medical care was sought, whether such care was timely (within one day of symptom onset), and whether it was sought from private providers. Latent variables of parental socio-cultural capital and household-level economic capital were the main exposures of interest. RESULTS: In the sample of 10,006 children, 8.4% had diarrhoea and 7.6% had ARI. Care was sought for 62.0% of children with diarrhoea and 78.5% with ARI; two-thirds of care-seeking for both illnesses was timely. More than 7 in 10 children who sought care were taken to private providers. Socio-cultural capital or economic capital were not independently associated with seeking care for either illness. Socio-cultural capital was positively associated with timely care-seeking, and economic capital was positively associated with private provider use in adjusted analyses for both illnesses. CONCLUSIONS: SEP was not a strong determinant of care-seeking for diarrhoea or ARI, but there was a modest positive effect of SEP on timely receipt of care and private provider use. Further research is needed to explore perceptions of illness severity and the availability and quality of care from public and private providers

    Nucleosynthesis in Neutron Stars Crust

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    We address the problem of the origin of heavier and super heavy elements in nature. Believing rapid neutron capture process (r-process) is responsible for synthesis of heavy and super heavy elements in the remnants of supernovae explosions and neutron star crusts under extreme conditions, we developed a computer code in order to understand the formation of elements in extreme astrophysical systems. We carried out Nuclear Statistical equilibrium (NSE) as well as static r-process calculations for a wide range of input parameters

    Current efficiency in the chlorate cell process

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    A mathematical model has been set up for current efficiency in a chlorate cell acting as an ideal electrochemical tubular reactor with a linear increase in hypochlorite concentration from the entrance to the exit. Good agreement was found between the results on current efficiency experimentally obtained under simulated industrial chlorate production conditions and the theoretical values provided by the mathematical model. Ā© 2014 SCS. All rights reserved

    The Phase Diagram of 1-in-3 Satisfiability Problem

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    We study the typical case properties of the 1-in-3 satisfiability problem, the boolean satisfaction problem where a clause is satisfied by exactly one literal, in an enlarged random ensemble parametrized by average connectivity and probability of negation of a variable in a clause. Random 1-in-3 Satisfiability and Exact 3-Cover are special cases of this ensemble. We interpolate between these cases from a region where satisfiability can be typically decided for all connectivities in polynomial time to a region where deciding satisfiability is hard, in some interval of connectivities. We derive several rigorous results in the first region, and develop the one-step--replica-symmetry-breaking cavity analysis in the second one. We discuss the prediction for the transition between the almost surely satisfiable and the almost surely unsatisfiable phase, and other structural properties of the phase diagram, in light of cavity method results.Comment: 30 pages, 12 figure

    Low-temperature UV photoluminescence of ion beam synthesized Si nanoclusters embedded in Si

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    Ultraviolet (UV) photoluminescence (PL) data taken on a double Au implanted Si matrix are reported. This has been studied over a wide temperature range of 28-220 K. At low temperature, the spectrum shows four peaks corresponding to a zero-phonon line (ZP
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