299 resultados para microestrutura do dicionário
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Pós-graduação em Engenharia Mecânica - FEB
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Pós-graduação em Engenharia Civil - FEIS
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This work will address the study of fatigue conditions with constant load in an alloy of aluminum analysis 7475 - T761, so we can better understand the conditions of the aircrafts which contain this alloy in their structures. A literature review, which was discussed the concepts of fracture mechanics, fatigue, aeronautical components, chemical analysis of aluminum alloys, fatigue problems that appears in the aircrafts, metallographic analysis, and testing of optical microscopy tensile, fatigue and microhardness, surface analysis (MEV) study of the chemical composition of the alloy in question, the main causes of crashes, was performed, completing the work, analysis of data from tensile test, hardness and fatigue together with the interpretation of images of optical microscopy and scanning electron was taken. The data indicated the high mechanical strength of the alloy, along with its microstructure indicating elongated grains and high surface contour, which shows such resistance by hindering the movement of dislocations. The grooves are clearly shown in the MEV images as well as the classic with increased fatigue loading and subsequent reduction of the number of cycles to rupture behavior shown in the graphs. Therefore we observed the optimal behavior is supported by the league when subjected to fatigue loadings
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Aluminum alloys have shown great potential for the automotive industry, especially aluminum alloys 6xxx series. This category has good mechanical strength and excellent corrosion resistance, important for the areas of construction and transport. The automotive industry has always shown great interest in the study of fatigue behavior, because structural components are subjected to cyclic and vibration loads, generating cracks and fracturing. The mechanical response depends on the material properties, applications, surface condition and microstructure. In this work was study the fatigue behavior of high cycle of machined bodies (not polished) and the effect of roughness on the fatigue life for three aluminum alloys of 6xxx series: AA6005, AA6351 and AA606, all in the T6 condition . S / N curves were made from fatigue tests in rotating bending (R = -1). The influence of roughness was studied by measuring the roughness of each specimen. Was compare the fatigue behavior of polished specimen and not polished specimens. The fractured surfaces of samples were observed by MEV, and it was observed that most of nucleation sites for fatigue crack is initiated below the surface
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Pós-graduação em Engenharia Mecânica - FEIS
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Este trabalho tem como objetivo observar a presença de palavras de origem inglesa em dicionários do Português Brasileiro relacionando este fato com a atual identificação do brasileiro com a cultura norteamericana – como consequência da importância dos EUA no cenário mundial nas últimas décadas. Neste estudo, notou-se que as palavras estrangeiras passam por um período de observação pelos lexicógrafos antes de serem finalmente inseridas em importantes obras de referência da língua portuguesa. Observou-se também que, quando inseridas nos dicionários, as palavras inglesas são encontradas em diferentes tipos de verbetes: alguns trazem transcrição fonética, por exemplo, outros não. Além disso, muitos verbetes não indicam se a palavra ainda pode ser considerada “estrangeira” à língua portuguesa ou se já se encontra aportuguesada. Dessa forma, podemos concluir que não há um padrão de entrada para palavras estrangeiras em dicionários do Português Brasileiro e que vem sendo uma tarefa difícil para os lexicógrafos encontrar um modelo de verbete que melhor atenda as necessidades das pessoas. Por fim, esta pesquisa comprovou que fatores extralinguísticos e culturais são importantes para que se decida se uma palavra estrangeira deve ou não estar presente em um dicionário do Português Brasileiro.
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This paper aims at offering an overview of the different functionalist approaches in all their programmes, by verifying which functionalist premises would be relevant in each case. This may be a way to elucidate the differentiated approach of certain themes and of certain objects of analysis, and especially, to contribute to a better account of certain relations between each proposal and others realms of knowledge.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Pós-graduação em Engenharia Mecânica - FEB
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Engenharia Mecânica - FEIS
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This paper aims at rescuing some critical appraisals found in the high school anthology Autores Contemporâneos (1931), by the critic, philologist and writer João Ribeiro, one of the main Brazilian intellectual representatives of the first decades of the twentieth century. João Ribeiro, along with Coelho Neto and, Laudelino Freire, among others, took part in of the panel which compiled, in 1921, the Dicionário da Academia Brasileira de Letras. Therefore, we find the analytical process João Ribeiro, their theoretical observations, concepts and dilemmas which are appointed by him in literary history and criticism of the early twentieth century.
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The purpose of this study was to evaluate the macroscopy and microstructure of a double setting alpha-tricalcium phosphate bone cement sphere provided with interconnection channels (alpha-TCP-i), as well as the integration of the implant with the rabbits' orbital tissue, through macroscopic analysis and histopathology. The external and internal surfaces of the alpha-TCP-i were evaluated macroscopically and by electron microscopy. Twelve New Zealand rabbits received 12mm implants of alpha-TCP-i following enucleation of the left eye. The clinical assessment was undertaken daily during the first 15 days, followed by fortnightly assessment until the end of the study period. For the morphological analysis, exenteration was performed in 3 animals per experimental period (15, 45, 90 and 180 days). The external and internal surfaces of the implant appeared solid, smooth and compact, with six channels which interconnected centrally. The micro-architecture was characterized by the formation of columns of hexagonal crystals. No signs of infection, exposure, dehiscence of sutures or extrusion of the implant were noted in any of the animals during the entire period of the study. The morphological evaluation demonstrated the presence of a thin capsule around the implant, from whence appeared fibro-vascular projections, which penetrated it through the interconnecting channels. In the first days after the insertion of the implant, an intense inflammatory reaction was noted. At 180 days, however, there were no signs of inflammation. The alpha-tricalcium phosphate cement implant was well tolerated in this rabbit model and appeared to be relatively inert with some fibrovascular ingrowth through the large channels.
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Pós-graduação em Odontologia Restauradora - ICT