4,304 research outputs found

    Dengue epidemic in Belém, Pará, Brazil, 1996-97.

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    We describe clinical and epidemiologic findings during the first epidemic of dengue fever in Belém, Pará State, Brazil, in 1996-97. Of 40,237 serum samples, 17,440 (43%) were positive for dengue by virus isolation or serologic testing. No hemorrhagic cases or deaths were reported. Mycobacterium tuberculosi

    Ultrasonic pulse technique for evaluation of mechanical damage in processed coffee beans.

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    The knowledge of the physical characteristics of the coffee bean allows the transition from the conventional storage model in bags to the silo storage, and as an indirect measure of the improvement and conservation of the quality of the stored grain. The elastic modulus allows comparisons on the strength of material. The variations of this occur due to its chemical composition, microstructures and material defects, being able to be used as indicator of the physical integrity of the grain. The ultrasonic pulse technique is an alternative to obtain the elastic modulus in a simple and non-destructive way. In this context, it was proposed the development of a non-destructive methodology that will perform the quality evaluation by determining the elastic modulus of the coffee beans. For this purpose, a reference silo was constructed, reproducing the storage conditions, and the elastic modulus values were determined. The values obtained by the Stress Wave Timer apparatus are between 2.54 and 4.23 MPa, with a maximum load of 8.32 kN, and a calculated vertical pressure of 1,526 kPa. To evaluate the impact of the storage conditions and the loads applied during the non-destructive test, laboratory tests applied in seeds were performed, and the tetrazolium test was the only one able to differentiate the samples. It was concluded that Stress Wave Timer was able to determine the elastic modulus values for the coffee bean mass and could be used as an indicative of the quality.Título em português: Técnica de pulso ultrassônico para avaliação de danos mecânicos em grãos de café beneficiados

    Pesos e rendimentos da carcaça de bovinos Nelore Mocho selecionados para maciez.

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    A falta de padronização e de qualidade das carcaças ofertadas faz com que a carne bovina brasileira receba baixas remunerações, além da limitada expansão para novos mercados. Dessa forma, objetivou-se avaliar as características de peso ao abate, peso da carcaça e seus rendimentos de 68 bovinos machos da raça Nelore Mocho, inteiros, oriundos de uma população segregante para maciez da carne. Os animais foram abatidos ao apresentarem 5 mm de espessura de gordura e/ou 500 kg de peso vivo. Antes do embarque para o frigorifico, os animais foram pesados para obtenção do peso ao abate. Ao final da linha de abate, as meias carcaças foram pesagens individuais para obtenção do peso de carcaça quente e carcaça fria após resfriamento por 24 horas em câmara. O rendimento de carcaça foi obtido em porcentagem do peso da carcaça quente, em relação ao peso vivo ao abate. Cálculo similar foi realizado para rendimento de carcaça fria. Amostras desse músculo foram maturadas por sete dias para mensuração da força de cisalhamento (FC) por meio do aparelho de Warner-Bratzler shear force (WBSF). Foram, então, definidos dois grupos: baixo WBSF (FC≤3,5 kgf) e alto WBSF (FC>3,5 kgf). As médias foram comparadas por meio do teste Duncan a 5% de significância. Não foram observadas diferenças estatisticamente entre os grupos de baixo e alto WBSF, para peso ao abate, peso da carcaça e seus rendimentos. A seleção para a maciez da carne em bovinos Nelore Mocho não afetou as demais características de carcaça. Abstract: Although Brazil exports only 18% of its beef production, the lack of standardization and carcass quality has limited expansion into new markets. Therefore, we aimed to evaluate the characteristics of slaughter weight, carcass weight and dressing percentage of 68 intact male Polled Nelore (OB brand) cattle derived from a population segregating for meat tenderness. The animals were slaughtered with 5 mm of fat thickness and/or 500 kg live weight (LW). After slaughter, half carcasses were weighed and chilled at 0 to 2 °C for 24 hours, then re-weighed and measurements taken of pH, rib eye area (REA) and back fat (BF) at the 12th rib. Samples of the L. dorsi muscle were removed and aged for seven days for measurement of Warner - Bratzler Shear Force (WBSF). Two groups were then defined based on WBSF: low WBSF (≤ 3.5 kg) and high WBSF (> 3.5 kg). Hot (HDP) and cold (CDP) carcass dressing % were obtained as the percentages of hot (HCW, immediately following slaughter) and cold (CCW, after 24 hours at 0 to 2 °C) carcass weights in relation to live weight (LW) at slaughter. No differences were observed between Low and High WBSF groups with regard to LW, HCW, CCW HDP or CDP. Selection for meat tenderness in Polled Nellore should not affect carcass characteristics

    Forces on a boiling bubble in a developing boundary layer, in microgravity with g-jitter and in terrestrial conditions

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    Terrestrial and microgravity flow boiling experiments were carried out with the same test rig, comprising a locally heated artificial cavity in the center of a channel near the frontal edge of an intrusive glass bubble generator. Bubble shapes were in microgravity generally not far from those of truncated spheres,which permitted the computation of inertial lift and drag from potential flow theory for truncated spheres approximating the actual shape. For these bubbles, inertial lift is counteracted by drag and both forces are of the same order of magnitude as g-jitter. A generalization of the Laplace equation is found which applies to a deforming bubble attached to a plane wall and yields the pressure difference between the hydrostatic pressures in the bubble and at the wall, p. A fully independent way to determine the overpressure p is given by a second Euler-Lagrange equation. Relative differences have been found to be about 5% for both terrestrial and microgravity bubbles. A way is found to determine the sum of the two counteracting major force contributions on a bubble in the direction normal to the wall from a single directly measurable quantity. Good agreement with expectation values for terrestrial bubbles was obtained with the difference in radii of curvature averaged over the liquid-vapor interface, (1/R2 − 1/R1), multiplied with the surface tension coefficient, σ. The new analysis methods of force components presented also permit the accounting for a surface tension gradient along the liquid-vapor interface. No such gradients were found for the present measurements

    Desempenho de cultivares de sorgo sacarino para a produção de etanol sob diferentes densidades de plantas.

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