568 resultados para SMA connector
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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A aplicação das ligas com memória de forma (shape memory alloys – SMA) têm se mostrado como uma alternativa promissora no controle de vibração de máquinas e estruturas, devido principalmente aos fenômenos de memória de forma e pseudoelástico que elas apresentam. Do mesmo modo, tais ligas proporcionam grandes forças de recuperação e capacidade de amortecimento quando comparadas aos materiais tradicionais. Na literatura científica encontra-se um grande número de trabalhos que tratam da aplicação das SMA no controle de vibração em estruturas. Contudo, a aplicação desse tipo de material em máquinas rotativas ainda é um assunto pouco abordado. Nesse sentido, busca-se explorar numericamente o comportamento de atuadores baseados em ligas com memória de forma para o controle de vibração em máquinas rotativas. Na primeira análise deste trabalho um rotor tipo Jeffcott com luvas SMA em um dos mancais é utilizado. São empregadas diferentes espessuras de luvas nos estados martensítico e austenítico e as variações em termos de amplitude e frequência são então comparadas. Posteriormente, dois diferentes sistemas rotativos com dois discos e molas SMA aplicadas em um e dois mancais são estudados sob configurações variadas. As molas foram posicionadas externamente aos mancais e a temperatura de operação desses componentes é ajustada de acordo com a necessidade do controle de vibração. Além disso, foi utilizado um código computacional para a representação do comportamento termomecânico de molas SMA assim como um programa baseado no Método de Elementos Finitos (MEF) para a simulação do comportamento dinâmico dos rotores. Os resultados das análises numéricas demonstram que as SMA são eficientes no controle de vibração de sistemas rotativos devido obterem-se reduções significativas das amplitudes de deslocamento, modificações nas velocidades críticas, supressão de movimentos indesejáveis e controle das órbitas de precessão.
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Pós-graduação em Bases Gerais da Cirurgia - FMB
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The process of environmental impact assessment (EIA), in the extent of previous environmental studies, has as one of its functions to provide subsidies to the actions of environmental managment of enterprises. However, the proper estructuring of programs that allows to support this managment does not often occurs. This research sought as one of its objectives to evaluate in which extent the process of EIA can be a subsidie for the EMS, providing basic elements of this system. In addition, more specifically, the research had as one of its objetives the development of subsidies for the implantation of an Environmental Managment System (EMS), based on the model of ISO 14001 (2004), for a sewage treatment plant yet to be constructed in the city of President Venceslau / SP. In order to achieve theses objetives, a discussion was held based on the evaluation of environmental studies available in the library of Cetesb / SMA. Still, for the elaboration of subsidies for the EMS of the treatment plant, the research was focused on the structuring of environmental management program, based on the information contained in its Preliminary Environmental Report (PER). The research had as one of its products, the development of subsidies for the planning and control of the environmental aspects and impacts and for the environmental program of the enterprise, based on the use of environmental indicators. It was concluded, based on the results that, in general, the previous environmental studies analyzed showed little emphasis on the phase of development of structured environmental programs that offer guidelines to achieve the desired results for the environmental performance of the company.
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The growing concern over deforestation of native forests from Brazil to the marketing of wood in various sectors had made greater attention from lawmakers. In this context, did the reforestation, which came into existence to meet the demand for forest raw material. This paper attempts to make a survey, focusing on the interplay between small and medium producers, consumers of forest products and reforestation associations. For this, we conducted a survey of legislation at the federal and state since the emergence, evolution and current context for understanding the legal basis on the subject. In addition, literature reviews have been made seeking to direct the concepts and importance of reforestation, reforestation, forest plantations and productive use of the species Eucalyptus sp for the supply of forest raw material. Approach was also sought on the structure of the system of reforestation of the state of Sao Paulo and their assignments. We also present an in loco study of Chairman Wenceslas municipality in order to analyze the participation of the municipality in the reforest the region of Pontal Paranapanema and actions of regulatory agencies. As a result presents a survey of consumers of timber enterprises in the municipality of President Wenceslas based on the resolution SMA No. 082/2008, which describes the characteristics of these companies and their fields of activity
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This study proposes, based on Halliday (1985) and Raible (1992, 2001), that the interpropositional patterns of assim are distributed in continuum, which is set among the representative usages of different types of interdependency, starting from the examples of domination relations of parataxis up to the examples of hypotatics, passing through the ones that are between the poles of the continuum. We will exemplify this paperwork starting from the functioning of the phrase assim que, describing its syntactic and semantic behavior in the selected corpus and in an evidence analysis of the linguistic changing process through grammaticalization, which infers its functioning as a secular connector in order to indicate its position held by this pattern in the continuum.
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The aim of this research study was to evaluate the structural behaviour of the wood and concrete composite system for bridge decks with emphasis on the metal shear connectors. Experimental tests were performed on composite specimens and wood and concrete beams with a metallic connector system in an X position, using CS100900-type screws. All specimens and beams were submitted to static loads until failure in order to obtain the strength and stiffness of the connection system. The experimental results for the stiffness of the beams were compared with the analytical results obtained through the Mohler model, presenting good equivalence for service loads. The experimental results obtained demonstrate that the most significant damage in composite systems occurred in the connectors' areas.
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The objective of this research is to present a study on a relationship between the local head loss in connection of emitters in pipes with different diameters used in drip irrigation, with the online geometry of the emitter connectors, that allows an easy quantification of such head loss regarding of the size of the connectors. The experiment was carried out according to the Reynolds Numbers at a turbulent flow interval, obtained by the variation of the pipe outflow at a constant temperature of water. The results indicated that the friction factor of the Darcy-Weisbach equation can be estimated by the Blasius equation with the coefficients b = 0.300 and m = 0.25, for the above mentioned pipes. The head losses produced by the connections of the emitters, in relation to the pipe without emitter, was of 62%. A relationship between the kinetic load coefficient (K) and the index of blockage (IO) provoked by the online connector is presented by an algebraic equation which shows a coefficient of adjustment of approximately 96%.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Engenharia Mecânica - FEG
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Fundação de Apoio à Pesquisa do Estado de São Paulo (FAPESP)