4 resultados para axisymmetric flows
em Repositório da Produção Científica e Intelectual da Unicamp
Resumo:
This article is part of a study considering the growing importance of the international transit of people, knowledge, and practices in the schooling and professional education processes of some social segments. Considering the public funds made available by the Coordination for the Improvement of Higher Education Personnel - Capes -, the National Council for Scientific and Technological Development - CNPq - and the State of São Paulo Research Foundation - Fapesp - to support researchers' fellowships abroad, aming to improve research and investments on Science and Technology on the context of international exchanges, we have dedicated this article to the preliminary description and analysis of the database of fellows funded abroad by these research agencies from 1970 to 2000. The movement of flows based on the quantitative methodology of the correlation of variables draws the trends of international academic exchange programs in the three research institutions and in the different areas of knowledge, and we intend to analyse them taking into account the scientific and technological development policies adopted by Brazilian State on the period.
Resumo:
In this work the performance of a sugar cane chopped harvester was analysed when fed with two sugar cane mass flows, measuring the invisible losses, which are impossible to measure in the field, harvester sugar cane cleaning efficiency and air velocity on extractors exit. The trial was done under controlled conditions at Copersucar Technology Center in January 2000. The results showed that the flow of sugar cane through the harvester doesn't influence the magnitudes of total invisible losses and raw material cleaning efficiency. The mean air velocity on the primary extractors exit was 12.0 m s-1, and 9.2 m s-1 on the secondary extractor, with a coefficient of variation of 21%, indicating that the poor cleaning performance of the harvester could be related to air velocity difference inside the extractor. Analyzing the data collected in the trials, it was possible to conclude that invisible losses in sugar cane harvester were 10% and the cleaning efficiency was 87%.
Resumo:
Relief influences soil texture variability, since it contributes to the time of exposition of the materials to weathering factors. Our work was carried out in the city of Gavião Peixoto (SP), with the objective of characterizing the spatial variability of texture of a dystrophic Red Latosol cultivated with citrus. The hillside was divided into three segments: top, stocking lean and inferior lean. Soil samples were collected in a grid with regular intervals of 50 m, at the depths of 0.0-0.2 m and 0.6-0.8 m, comprising a total of 332 points in an area of 83.5 ha. The data were submitted to descriptive and geostatistics analyses (semivariogram modeling and kriging maps). The spatial behavior of the texture of oxisols is directly related to the relief forms in this study, which controls the direction of surface and subsurface water flows. The concept of homogeneity of clay distribution in the Oxisol profile is a piece of information that can be adjusted by knowing the spatial pattern of this distribution in different relief forms.
Resumo:
In this paper, space adaptivity is introduced to control the error in the numerical solution of hyperbolic systems of conservation laws. The reference numerical scheme is a new version of the discontinuous Galerkin method, which uses an implicit diffusive term in the direction of the streamlines, for stability purposes. The decision whether to refine or to unrefine the grid in a certain location is taken according to the magnitude of wavelet coefficients, which are indicators of local smoothness of the numerical solution. Numerical solutions of the nonlinear Euler equations illustrate the efficiency of the method. © Springer 2005.