998 resultados para Propriedades qualitativas de solucoes
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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This work aims to study the Dual-Phase 600 and 780 steels, which are part of technology development project materials for the automotive industry. It is worth underscoring the antagonistic properties as the Dual-Phase steel assemble, high mechanical strength and elongation due its microstructure, ferrite and martensite. These properties are obtained by a intercritical heat treatment which facilitates the formation of a hardness metastable microstructure shaped plates of low carbon steels. The applicability of Dual Phase steel in the structure of vehicles is huge and its production is already on a commercial scale, so the study and development of this material implies lower cost in automobile manufacturing processes. The dual phase steels DP600 and DP780 underwent tensile, hardness and metallographic analysis to evaluate and comparing its properties. The results indicate that the DP780 steel has higher strength and hardness than the DP600 steel and its microstructure consists of martensite higher fraction which accounts for the higher resistance and hardness. However, the DP600 has higher conformability to DP780 steel
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Pressure vessels are equipments that require a great care because of their high cost and human life risk in case of fail, and its fabrication methods are different for each manufacturer. Normally, pressure vessels and its parts are fabricated by welding, which may change local properties of metals. The head of a pressure vessel is a very important structural component and it is fabricated by welding and mechanical conformation. Because its excellent mechanical properties, de steel A-516 Grade 70 is often used in manufacturing of large pressure vessels that are subjected to high pressure and temperature, but was verified that its mechanical resistance is decreased when submitted to a tension relief heat treatment. By experience it was defined that before mechanical conformation of the head of a large pressure vessel, the steel should be submitted to a stress relief heat treatment in order to facilitate the mechanical conformation, but there is no quantitative analysis to prove this method and study its possible risks. In the present work the steel A-516 Grade 70 demonstrated a decrease of its mechanical resistance when submitted to a stress relief heat treatment, but keeping above the minimum limit defined in the literature. By other side its ductility was substantially increased, being possible to deduce that the stress relief heat treatment before mechanical conformation is a viable e recommended technique, but with reservations. With the data acquired during the fabrication e preparation of the specimen and the result of the tests, it was possible to elaborate a welding procedure that provides the same results obtained in this present work
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Pós-graduação em Química - IQ
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Pós-graduação em Engenharia Civil - FEIS
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Pós-graduação em Química - IQ
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Pós-graduação em Química - IQ
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This article aims to show elements based on historical-cultural psychology, which are reiterative of historically systematized scientific knowledge transmission as condition of human development and essential function of school education. In that way, it points the sign appropriation as decisive mark in the natural psychic basis overcoming towards to culturally established psychophysical properties formation, characterizing the psychism as an interfuncional system answerable for the constitution of the subjective image of objective reality. In the face of such presuppositions, it firms the role of school education in the mentioned image formation, highlighting the qualitative differences resultant of education based to quotidian and spontaneous concepts, as well as scientific ones. It pleads that the defense of sign quality offered to appropriation by school education is the main intersection point between the historical-cultural psychology and the historical-critical pedagogy.
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In this paper we discuss and present the first results gathered from the compilation of a learner corpus comprised of texts written by university students (Language, Literature and Translation Course). We made use of Corpus Linguistics and observations of researchers from the learner’s corpus field, in order to compile and analyze a corpus of argumentative and descriptive texts written in Spanish. Four hundred compositions were collected (about 120 thousand words) from August 2011 to December 2012. The methodology adopted assisted us considerably in maintaining a comprehensive working agenda, taking into consideration students’ needs and using the data collected as subsidy to improve classroom management of content. We also present the difficulties faced during the data gathering and propose procedures do avoid or minimize them.
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Pós-graduação em Ciência dos Materiais - FEIS
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)