136 resultados para vento


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Ciências Biológicas (Zoologia) - IBRC

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Por meio de rica análise do trabalho do ficcionista mineiro Roberto Drummond, Maria Lúcia Outeiro Fernandes busca, neste livro, articular o trabalho do autor de Coca-Cola e guerrilha e O tecedor de vento com vários temas centrais da arte e da cultura contemporâneas. Explicitando os traços presentes na obra do escritor, Fernandes apresenta uma expressiva contribuição ao estudo dos procedimentos formais e posicionamentos ideológicos que permeiam grande parte da produção literária das últimas décadas do século XX, como o ecletismo de estilos, a metaficção historiográfica, o pastiche, a intertextualidade e o hiper-realismo. O deslocamento de fronteiras entre produção erudita e de massas também faz parte do foco da autora. Fernandes discute ainda as possíveis relações entre essas constantes e alguns problemas que emergiram na cultura ocidental principalmente a partir da década de 1960, como a morte da arte, o ocaso das vanguardas, o anti-humanismo, a sociedade do simulacro, a supervalorização da informação, o ceticismo em relação às utopias. São temas que, em Drummond, conduzem ao que a autora chama de perspectivas pós-modernas da ficção.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Each year, there is an increase in pesticide consumption and in its importance of use in the large-scale agricultural production, being fundamental the knowledge of application technology to the activity success. The objective of the present study was to evaluate the influence of working pressure on the drift generated by different spray nozzles, assessed in wind tunnel. The treatments were composed of two spray nozzles AXI 110015 and AXI 11002 with pressure levels of 276 and 414 kPa. The spray solution was composed by water and NaCl at 10%. The applications were conducted at wind speed of 2.0 m s-1, being the drift collected at 5.0; 10.0 and 15.0 m away from the spray boom and at heights of 0.2; 0.4; 0.6; 0.8 e 1.0 m from the tunnel floor. To both spray nozzles, the greatest drift was collected at the smallest distance to the spray-boom and at the lowest height. The AXI 11002 nozzle gave a smaller drift relative to the AXI 110015 nozzle for the two tested pressures and for all the collection points. Regardless of the nozzle, a rise in the working pressure increases the spray drift percentage at all distances in the wind tunnel.

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Environmental monitoring of aquatic systems is an important tool to support policy makers and environmental managers' decisions. Long-term, continuous collection of environmental data is fundamental to the understanding of an aquatic system. This paper aims to present the integrated system for environmental monitoring (SIMA), a long-term temporal series system with a web-based archive for limnological and meteorological data. The following environmental parameters are measured by SIMA: chlorophyll-a (µgL-1), water surface temperature (ºC), water column temperature by a thermistor string (ºC), turbidity (NTU), pH, dissolved oxygen concentration (mg L-1), electric conductivity (µS cm-1), wind speed (ms-1) and direction (º), relative humidity (%), shortwave radiation (Wm-2) and barometric pressure (hPa). The data were collected in a preprogrammed time interval (1 hour) and were transmitted by satellite in quasi-real time for any user within 2500 km of the acquisition point. So far, 11 hydroelectric reservoirs are being monitored with the SIMA buoy. Basic statistics (mean and standard deviation) and an example of the temporal series of some parameters were displayed at a database with web access. However, sensor and satellite problems occurred due to the high data acquisition frequency. Sensors problems occurred due to the environmental characteristics of each aquatic system. Water quality sensors rapidly degrade in acidic waters, rendering the collected data invalid. Data is also rendered invalid when sensors become infested with periphyton. Problems occur with the satellites' reception of system data when satellites pass over the buoy antenna. However, the data transfer at some inland locations was not completed due to the satellite constellation position. Nevertheless, the integrated system of water quality and meteorological parameters is an important tool in understanding the aquatic system dynamic. It can also be used to create hydrodynamics models of the aquatic system to allow for the study of meteorological implications to the water body.

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This paper investigated the influence of the amount of superplasticizer and mineral adding - silica fume and basaltic filer - in plastic shrinkage and cracking of self-compacting concrete (SCC) mortars. Initially analysis was performed of the rheological behavior of cement paste and mortars phases of the compositions of SCC. Then the deformations of mortars were measured by the effect of shrinkage and evaluation of cracking. On plastic shrinkage and cracking, the composition with silica fume showed superior results, independent of wind and superplasticizer content, relative to the composition with addition of basalt filler. However, the composition with silica fume showed superior results only in the tests with imposed ventilation at vertical plastic deformation. The rheological behavior affected directly the plastic shrinkage and cracking at early ages, fact confirmed by the analysis of capillary pressures of mortars tested.

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The air-assisted ground spray is fairly widespread. However, due to the unpredictable weather conditions, the operational efficiency is impaired by stops on grounds of low humidity and high temperatures. The aim of this work was to assess an air humidification method and evaluate its impact on temperature and air humidity for the air curtain of the air-assisted sprayer. With respect to relative air humidity, it has increased in 6.59%, being the maximum change when inserting 1.92 L min-1. So, it is concluded that the pipeline humidification might significantly reduce temperature and enhance air humidity. The treatments performed in this study consisted of a varied flow of a humidity device, related to weather conditions. Temperature and relative air humidity were measured at 1.0 m height from right to left of middle point of the machine, corresponding to the end of the spray boom, in the middle and end of right spray boom. The readings were also performed at three different distances from the end of the pipeline and at 0.25 and 0.50 m from that to the soil. The results show that 0.48 L min-1 in the humidification system has promoted a better efficiency in reducing air-temperature, on average 2.52 ºC when compared to the non-humidified one.

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Pós-graduação em Engenharia Elétrica - FEIS

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Pós-graduação em Engenharia Elétrica - FEIS

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Nos últimos anos, têm se notado a grande preocupação com relação às condições climáticas do planeta e suas implicações. As discussões sobre as mudanças climáticas têm se tornado cada vez mais relevantes à medida que as adversidades climáticas têm implicações diretas na sociedade. Neste contexto, o objetivo deste trabalho foi identificar e avaliar episódios atmosféricos severos ocorridos no Estado de São Paulo no ano de 2005, elaborando posteriormente o estudo de caso do tornado ocorrido na cidade de Indaiatuba (SP). No levantamento sobre o evento atmosférico levou-se em conta a condição atmosférica que o originaram, além dos impactos ambientais e sócio-econômicos do fenômeno na sua região de abrangência. Para isso foram realizados levantamentos bibliográficos mais completos possíveis sobre o assunto, utilizando revistas credenciadas em âmbito nacional ou internacional. Logo após esta etapa foram coletados os dados de estações meteorológicas e dados atmosféricos como vento, temperatura, pressão disponibilizados pelo (NCEP) National Centers for Environmental Prediction. Estes dados atmosféricos disponibilizados pelo (NCEP) foram avaliados e analisados para a caracterização do episódio atmosférico e o cruzamento de informações por meio dos (SIGs) Sistema de Informação Geográfica, referentes à dinâmica atmosférica e topografia. A interpretação de todos os dados gerados relacionados e suas implicações no contexto ambiental e sócio-econômico está organizada em forma de uma síntese na redação final.

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O processo de urbanização é bastante expressivo na modificação do clima na escala local, pois as formas materiais assumidas pela cidade, bem como as atividades que nela se desenvolvem, provocam anomalias nos elementos do clima como a temperatura, umidade relativa do ar, direção e velocidade do vento. Destes, a temperatura tem se destacado nos estudos sobre o clima urbano, pois as características da área urbana promovem seu aumento tanto no ar quanto nos alvos da superfície. Nesse sentido, este estudo objetivou detectar as anomalias térmicas intraurbanas e suas magnitudes, relacionando-as com os tipos de uso e ocupação da superfície do solo no município de Presidente Prudente-SP. Para tanto, foram realizadas análises das diferenças térmicas e higrométricas entre o urbano e o rural em dias representativos do inverno e do verão, e a verificação da temperatura da superfície através do sensoriamento remoto no infravermelho termal. Os resultados apresentaram que os tipos de tempo, assim como as características da superfície foram responsáveis pelas maiores ou menores diferenças entre a área urbana e a rural, o que demonstra a importância de se adequar o planejamento urbano às características do ambiente local

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In engineering, for correct designing the structural components required for cyclical stresses, it is necessary to determine a limit of resistance to fatigue, which is the maximum amplitude of the applied tension under which the fatigue failure does not occurs after a certain number cycles. The marine environment is hostile, not only by the high pressure, corrosion, but also by low temperatures. Petrol Production units, composed of the risers (pipelines connecting the oil well to the ship), are dimensioned to remain installed for periods of 20 up to 30 years, and must therefore be prepared to support various efforts, such as tidal, wind currents and everything that is related. This paper focuses on a study on the fatigue behavior of microalloyed steel, API 5L Grade X70, used to transport oil and gas by pipelines. For analysis, we obtained the curves S-N (stress vs. number of cycles) using laboratory data collected from cylindrical longitudinal and transverse specimens used in axial fatigue test in accordance with ASTM E466. The tensile tests and microhardness were performed to characterize the mechanical properties of the samples, and it was found that the values meet the specifications of the standard API 5L. To characterize microstructurally the material, it was also made a metallographic analysis of the steel under study, and the origin of the fatigue crack was investigated with the support of a scanning electron microscope (SEM).

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The present work intends to study some fluid dynamic and heat transfer aspects of a solar chimney, aiming at a preliminary design of a facility. Some definitions and concepts of this system are presented. The simulation was performed based on a theoretical model validated with measurements of a prototype in Manzanares, Spain. Using the same theoretical model and some considerations, dimensions on a small scale are applied, making the model more interesting from its constructive aspect. The results show the behavior of the air velocity inside the chimney and illustrate some values of two preselected turbines. This technology looks promising in Brazilian territory due to high levels of solar radiation