21,264 research outputs found

    Coherent State Path Integrals in the Weyl Representation

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    We construct a representation of the coherent state path integral using the Weyl symbol of the Hamiltonian operator. This representation is very different from the usual path integral forms suggested by Klauder and Skagerstan in \cite{Klau85}, which involve the normal or the antinormal ordering of the Hamiltonian. These different representations, although equivalent quantum mechanically, lead to different semiclassical limits. We show that the semiclassical limit of the coherent state propagator in Weyl representation is involves classical trajectories that are independent on the coherent states width. This propagator is also free from the phase corrections found in \cite{Bar01} for the two Klauder forms and provides an explicit connection between the Wigner and the Husimi representations of the evolution operator.Comment: 23 page

    Tecnologia para biodegradação da casca de coco sem gerar outros resíduos.

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    bitstream/CPATC/19770/1/f_07_2007.pdfExiste o documento impresso

    Deformation method for generalized Abelian Higgs-Chern-Simons models

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    We present an extension of the deformation method applied to self-dual solutions of generalized Abelian Higgs-Chern-Simons models. Starting from a model defined by a potential V(ϕ)V(| \phi |) and a non-canonical kinetic term ω(ϕ)Dμϕ2\omega(| \phi |) | D_{\mu}\phi |^2 whose analytical domain wall solutions are known, we show that this method allows to obtain an uncountable number of new analytical solutions of new models defined by other functions V~\widetilde{V} and ω~\widetilde{\omega}. We present some examples of deformation functions leading to new families of models and their associated analytic solutions.Comment: 6 pages, 10 figure

    Tecnologia para produção orgância de cenoura consorciada com alface em Sergipe.

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    bitstream/CPATC/19935/1/ct-50.pd

    Extreme thermopower anisotropy and interchain transport in the quasi-one-dimensional metal Li(0.9)Mo(6)O(17)

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    Thermopower and electrical resistivity measurements transverse to the conducting chains of the quasi-one-dimensional metal Li(0.9)Mo(6)O(17) are reported in the temperature range 5 K = 400 K the interchain transport is determined by thermal excitation of charge carriers from a valence band ~ 0.14 eV below the Fermi level, giving rise to a large, p-type thermopower that coincides with a small, n-type thermopower along the chains. This dichotomy -- semiconductor-like in one direction and metallic in a mutually perpendicular direction -- gives rise to substantial transverse thermoelectric (TE) effects and a transverse TE figure of merit among the largest known for a single compound.Comment: PRL in press, manuscript (5pp, 4 Fig.'s) and Supplementary Material (3pp, 3 Fig.'s

    Tecnologia para biodegradação da casca de coco seco e de outros resíduos do coqueiro.

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    bitstream/item/158629/1/ct-46.pd

    Gravitational waves in the generalized Chaplygin gas model

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    The consequences of taking the generalized Chaplygin gas as the dark energy constituent of the Universe on the gravitational waves are studied and the spectrum obtained from this model, for the flat case, is analyzed. Besides its importance for the study of the primordial Universe, the gravitational waves represent an additional perspective (besides the CMB temperature and polarization anisotropies) to evaluate the consistence of the different dark energy models and establish better constraints to their parameters. The analysis presented here takes this fact into consideration to open one more perspective of verification of the generalized Chapligin gas model applicability. Nine particular cases are compared: one where no dark energy is present; two that simulate the Λ\Lambda-CDM model; two where the gas acts like the traditional Chaplygin gas; and four where the dark energy is the generalized Chaplygin gas. The different spectra permit to distinguish the Λ\Lambda-CDM and the Chaplygin gas scenarios.Comment: Latex file, 9 pages, 11 figures eps forma

    Evolução e perfil distributivo das aplicações do Fundo Constitucional de Financiamento do Norte (FNO) na pecuária leiteira paraense no período 2000-2009.

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    O crédito rural é uma política importante para viabilizar o desenvolvimento regional, pois propicia aos produtores recursos para custeio, investimento e comercialização, contribuindo para o fortalecimento das cadeias produtivas. O crescimento da demanda por produtos lácteos tem realçado a necessidade de medidas visando ampliar a produção leiteira em todo o país. Nos últimos anos os estados da Região Norte têm exibido um importante crescimento nessa atividade. No estado do Pará, um importante instrumento de apoio tem sido os recursos de crédito rural do Fundo Constitucional de Financiamento do Norte (FNO). Este trabalho analisou a evolução e o perfil distributivo das aplicações do FNO na pecuária leiteira paraense no período 2000-2009. Neste período foram alocados R519,2milho~esnaatividade,distribuıˊdosentre119municıˊpios.Essasaplicac\co~escresceramaumataxade10,61 519,2 milhões na atividade, distribuídos entre 119 municípios. Essas aplicações cresceram a uma taxa de 10,61% ao ano, correspondendo a uma aplicação média de R 52 milhões por ano
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