168 research outputs found

    Static quantities of the W boson in the SU_L(3) X U_X(1) model with right-handed neutrinos

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    The static electromagnetic properties of the WW boson, Δκ\Delta \kappa and ΔQ\Delta Q, are calculated in the SU_L(3)} \times U_X(1) model with right-handed neutrinos. The new contributions from this model arise from the gauge and scalar sectors. In the gauge sector there is a new contribution from a complex neutral gauge boson Y0Y^0 and a singly-charged gauge boson Y±Y^\pm. The mass of these gauge bosons, called bileptons, is expected to be in the range of a few hundreds of GeV according to the current bounds from experimental data. If the bilepton masses are of the order of 200 GeV, the size of their contribution is similar to that obtained in other weakly coupled theories. However the contributions to both ΔQ\Delta Q and Δκ\Delta \kappa are negligible for very heavy or degenerate bileptons. As for the scalar sector, an scenario is examined in which the contribution to the WW form factors is identical to that of a two-Higgs-doublet model. It is found that this sector would not give large corrections to Δκ\Delta \kappa and ΔQ\Delta Q.Comment: New material included. Final version to apppear in Physical Review

    Uso De Extensores Flexíveis Na Derriça Em Lavouras De Café De Primeira Safra

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    The coffee harvest of the first crop can be benefited by the use of rubber extenders at the end of the stems. This because their malleable constitution acquires oscillatory motion increasing the stem contact area with the fruits. However, the coffee varieties have big morphological and physiological differences that can influence the mechanical harvesting. This study had a goal to test two of coffee harvesters (conventional and adapted to the harvest of the first crop plantations) in the absence and presence of rubber extenders in two cultivars (Catuaí Vermelho IAC 144 and Tupi IAC 1669-33). The design was randomized blocks in five plants per plot. Evaluated the amount of fallen coffee, remaining harvested, picked and operational defoliation. Evaluated the amount of fallen coffee, remaining harvested and operational defoliation. There was obtained that the use of rubber extenders increases the amount of coffee collected in 16.6%. The first crop coffee harvest should be made with harvester adapted to this situation. The Cultivar Tupi IAC 1669-33 has high difficulty to be mechanically harvested the first crop, should be taken with two mechanized operations. © 2016, Editora UFLA. All rights reserved.11218719

    Comparação de dois testes de neutralização, utilizados no diagnóstico sorológico do vesiculovírus Piry

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    A serological survey of Piry was undertaken of the sera of inhabitants of Catolância - Bahia State, Brazil. Serum results obtained by a vesiculovirus neutralization test of C6/36 cells read by ELISA are compared with those obtained by the classic technique, carried out on newbom mice. The agreement between the results was as high as 98.7% of the 204 sera tested and the neutralization test of C6/36 cells was chosen as the most suitable technique for the sero-survey testing.Realizou-se inquérito sorológico para pesquisar anticorpos neutralizantes contra o vesiculovírus Piry, na cidade de Catolândia-Bahia-Brasil. Duas técnicas de vírus-neutralização foram comparadas em cultura das células C6/36, com revelação pelo método imunoenzimático ( TN-C6/36) e em camundongos recém-nascidos (TN-camundongos), que é considerada a prova maior. Em 204 soros, dos 1 .274 colhidos, a concordância das duas técnicas foi de 98,7% (K= 0,9853). Com este resultado do TN-C6/36, que também é mais exeqüível, decidiu-se desenvolver o estudo soro-epidemiológico do vesiculovírus Piry, em Catolândia, baseado nesta nova técnica

    The decay Z -> neutrino antineutrino photon in the Standard Model

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    A complete study of the one-loop induced decay Z -> neutrino antineutrino photon is presented within the framework of the Standard Model. The advantages of using a nonlinear gauge are stressed. We have found that the main contributions come from the electric dipole and the magnetic dipole transitions of the Z gauge boson and the neutrino, respectively. We obtain a branching ratio B=7.16E-10, which is about four orders of magnitude smaller than the bound recentely obtained by the L3 collaboration and thus it leaves open a window to search for new physics effects in single-photon decays of the Z boson.Comment: REVTEX,15 pp, 5 eps figures, Approved for publication in Physical Review

    Determinação dos elementos-traço (Zn, Co e Ni) em sedimentos da Plataforma Continental Amazônica sob influência da descarga do rio Amazonas

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    Determination of trace elements (Zn, Co and Ni) in sediments at the Amazon Continental Shelf on influence of the Amazon River discharge This research was developed at Amazon Continental Shelf (ACS) between the Orange Cape (Amapá State) and the Maguari Cape (Pará State), to determine the levels of zinc, cobalt and nickel in the superficial sediments identifying its inputs and outputs. The rate of these metallic elements in the sediments decreases following Zn> Ni> Co. The concentrations of total metals in the surface sediments range from Zn = 52.8-159.5; Ni = 21.7-47.4 and Co = 14.3-48.8 (mg.kg-1). The levels of trace elements observed in the sediments at ACS are of natural occurrence. Pollution sources of metallic elements were not observed
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