23 research outputs found

    Dimensional Crossover in the Effective Second Harmonic Generation of Films of Random Dielectrics

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    The effective nonlinear response of films of random composites consisting of a binary composite with nonlinear particles randomly embedded in a linear host is theoretically and numerically studied. A theoretical expression for the effective second harmonic generation susceptibility, incorporating the thickness of the film, is obtained by combining a modified effective-medium approximation with the general expression for the effective second harmonic generation susceptibility in a composite. The validity of the thoretical results is tested against results obtained by numerical simulations on random resistor networks. Numerical results are found to be well described by our theory. The result implies that the effective-medium approximation provides a convenient way for the estimation of the nonlinear response in films of random dielectrics.Comment: 9 pages, 2 figures; accepted for publication in Phys. Rev.

    Lavagem traqueobrônquica por sondagem nasotraqueal em bezerros Tracheobronchial lavage in calves using a nasotracheal technique

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    Avaliou-se a técnica de lavagem traqueobrônquica por sondagem nasotraqueal e caracterizou-se a população celular em 10 bezerros clinicamente sadios. Após a contenção dos animais em decúbito lateral e auxílio de sonda guia, foi introduzida uma sonda de menor diâmetro até a bifurcação da traquéia, para produzir tosse e obter o lavado traqueobrônquico. A média de células totais nas amostras de lavado foi de 133.750 células/ml. À citologia, foram observados na contagem diferencial: 77,2% macrófagos, 14,9% células epiteliais cilíndricas, 6,0% neutrófilos e 1,8% linfócitos. Das células epiteliais cilíndricas, 79,0% eram do tipo ciliadas e 21,0% não-ciliadas. A média de contagem de macrófagos binucleados foi de 78,5 células/lâmina, a de macrófagos trinucleados de 20,5/lâmina e a de células gigantes 28,5/lâmina. Concluiu-se que o método de colheita por sondagem nasotraqueal é eficiente para caracterizar a citologia do lavado traqueobrônquico de bezerros clinicamente sadios.<br>Tracheobronchial lavage through nasotracheal via was performed in 10 clinically health calves. They were maintained in lateral recumbence to perform the procedure. A small tube inserted into a guide tube was introduced until the tracheal bifurcation, producing cough, facilitating the collection of the lavage fluid. The mean number of total cells present in the samples was 133,750 cells/ml. The differential counting was represented by 77.2% of macrophages, 14.9% of cylindrical epithelial cells, 6.0% of neutrophils, 1.8% of lymphocytes. The cylindrical ciliated cells represented 79.0% of the sample and the nonciliated cells represented 21.0%. The mean number of macrophages was 78.5 of binucleated cells, 20.5 of trinucleated cells, and 28.5 of giant cells per smear. The tracheobronchial lavage obtained by this technique was an efficient method to characterize the cytological population of the lungs of clinically health calves
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