501 resultados para Materiais cerâmicos : Microestrutura


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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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 de Produção - FEG

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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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Pós-graduação em Serviço Social - FCHS

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Levando em conta o modelo de desenvolvimento vigente, consideramos o momento atual, de crise ambiental, como fruto do estabelecimento de uma postura antropocêntrica frente à natureza. Assim, a EA vem sendo apontada como uma das possibilidades de mudança deste cenário. A EA que propomos se apoia em três dimensões, estabelecidas por Carvalho (1989), com especial enfoque na dimensão valorativa. Dentre os recursos potencialmente relevantes para o desenvolvimento da EA, destacamos o cinema ficcional e documentário. Possuidor de uma linguagem própria, o cinema pode e deve ser utilizado, visto que sua presença na sociedade atual é intensa. Dentre as inúmeras qualidades que este recurso possui, consideramos que ele apresenta imenso poder de atrair a atenção dos alunos, uma vez que possui por si só técnicas únicas para tal finalidade. O uso do cinema em sala de aula, entretanto, exige alguns cuidados e preparativos por parte de quem se propõe a utilizá-lo com este fim, ou corre-se o risco de recair em um uso corriqueiro, a fins de entretenimento, e portanto sem qualquer finalidade educativa. As perguntas que permeiam o presente trabalho são: este assunto tem sido abordado em teses e dissertações voltadas a pesquisas envolvendo a EA? Se sim, quais fundamentações teóricas abarcam, e o que está sendo levando em consideração para sua execução? Que aspectos significativos têm sido apontados sobre esses recursos, que podem subsidiar os trabalhos de EA? Para a coleta das teses de interesse, recorreremos ao banco de dissertações e teses de educação ambiental desenvolvido pelo projeto de pesquisa interinstitucional denominado Educação ambiental no Brasil: análise da produção acadêmica (teses e dissertações) - EArte. Verificamos que, apesar de muitos trabalhos apontarem o uso de filmes em suas pesquisas, este uso ainda é feito de maneira superficial e é tido apenas como mais um recurso de apoio. Existe uma...

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This study aims to evaluate the corrosion resistance of Ti-30Ta alloy when subjected to different strain rates. Samples of the alloy Ti-30Ta were obtained from the melting of pure elements in the arc furnace in inert atmosphere (argon gas). Then, the samples were subjected to a thermal treatment and to cold worked to obtain bars. After forging, the samples were machined in accordance with ASTME9-09 standard for carried out compression tests. To microstructural characterization, samples were sectioned longitudinal and transversally and embedded in resin. After, the wet sanding and polishing were performed, followed by a chemical attack, in order to study the microstructure under an optical microscope. Microhardness was measured on the samples that were subjected to microstructural characterization by using microhardness tester. Phases were evaluated by x-rays diffraction. Corrosion tests were carried out to evaluate the influence of deformation on the corrosion resistance. Results show that microstructure was not influenced by deformation

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Having in mind that petroleum's history presents a huge growth, the exploration and production areas have been receiving lots of investments, in order to attend the increasing demand for gas and petroleum. Looking through that scenario, new technologies have been evolving in favor of discovering new natural petroleum deposits and act with effectiveness in truly deep waters without giving up the worldwide best operational security practices. The use of rigid pipes in marine installations have been rising quickly and, thanks to this reality, the many storage and pipe launching forms became study objects and are getting improved. The analysis of steel API X70 characteristics, proving that they are suitable for use in pipes developed to transport gas and petroleum is the theme of this presentation. A tensile test was conducted to determine the base metal's mechanical properties, draining's tension, traction's resistance, elasticity's modulus and maximum tension. An aspect that is concerning too is the metallographic analysis, in order to determine the studied iron's microstructure. Results of analyzes showed that the steel has high resistance, with good capacity for deformation and well defined yield point, concluding suitable for the application in question

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One of the existing business models is the family business. This paper deals with the structure of family businesses. With the purpose to analyzing the input and output processes of goods, and management behavior in decision-making, looking for the professionalization of the family business administration. This paper is a case study in a construction materials shop, with an applied research due to their nature, according to his purpose takes the characteristic of exploratory research, using interviews, observation and analysis of company data. During the analysis of processes in the company were noted some shortcomings. Given this fact, made the comparison with the theories found, proposals were generated improvements to be accomplished within the company structure

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A large number of metal alloys are used in Dentistry for the manufacture of fixed and removable dentures. In the oral cavity, these structures are exposed to a chemically aggressive medium, like saliva and mechanical efforts, like mastication. In addition, acidic solutions containing fluoride ions are also frequently used in dental treatments to prevent dental plates and decays development. In this context, it was considered important to investigate the influence that a fourth element could exert when added to the ternary alloy Ni-Cr-Mo, largely used in Brazil. Therefore, electrochemical tests were done to evaluate the resistance to corrosion of quaternary alloy 65Ni-25Cr-5Mo-5Ta and 65Ni-25Cr-5Mo-5W in NaF solution 0,08mol / L, pH = 4.7. For greater understanding the microstructure and morphology of alloys were studied, through metallographic analysis, using optics microscopy and electron microscopy scanning. For the electrochemical tests were applied techniques traditionally used in corrosion researches, such as: potential measures in open circuit (OCP) and cyclic polarization (CP). It was found that both quaternary alloys showed very similar results. Comparing these quaternary alloys with the ternary 65Ni-25Cr-10Mo, it was found that the quaternary alloys exhibit greater resistance to corrosion, in other words, less passivation current density than the ternary alloy, showing that it is advantageous to add a fourth element in the alloy

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This work is part of several research related to the plan of design and construction of a sustainable house. The previous researches focused on sustainable materials and it have shown that ceramic material are more interesting to improve the thermal comfort and the reduction of fees and prices of the house, making possible to construct popular home, mainly clay bricks, that have high thermal inertia and low costs, besides the fact that it is easy to find the raw materials in nature and process them. However, a major issue in using clay bricks is that it uses too many energy to be processed during the sintering (burning), a crucial part of the process that assures mechanical resistance. Alternative materials are being proposed by the researchers, as the clay bricks without the sintering mixed with Portland cement, assuring the proper resistance to the brick. Raw materials of cement, however, also need to be thermally processed in rotary kilns, in a process called clinckerization. This research was proposed for comparing the energy used by the two types of bricks and other objectives, in order to determinate which one uses less thermal energy. The intention was to compare the energy used during the sintering of regular clay bricks and the unfired bricks with 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% and 100% of Portland cement. The paper also investigated and compared the use of electrical and thermal energy of all the bricks to identify how important were the thermal stages (sintering or clinkerization) relatively to the total energy spent. At last, a resumed analysis was performed to identify the possible health damages of the many life cycles of the bricks. The conclusion was that unfired bricks with less than 40% of cement use less thermal energy to be processed. In addition, their carbon dioxides emissions were less dangerous to ... (Complete abastract click electronic access below)