461 resultados para Monitoramento da integridade estrutural


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The ceramic pigments are colored inorganic substances that during the process of dispersion in the ceramic glazes and subsequent calcination, are stable against physical and chemical attack. Therefore, they are crystalline compounds applied in the ceramic industry for coloring vitreous base. In this study, the Pechini method was used for obtaining the pigment CuCr2O4 with heat treatment at the temperatures of 800, 900 and 1000 ° C. The powder pigments were characterized on their structural, morphological and colorimetric aspects. The thermal analysis conducted on an amorphous precursor in a TG / DTA indicates the weight loss in the entire temperature range investigated, with characteristic exothermic peak of the elimination of the organic composition of the precursor around 300°C. The development of the crystalline phases were investigated by XRD, using a diffractometer with Cu Ka radiation and graphite monochromator, where it was observed the presence of crystalline phases corresponding to Cr2O3 and CuCr2O4.The measurements of the specific surface area of the powders pigments were carried out in an equipment Micromeritcs, model ASAP 2000, using N2 as gas of adsorption/desorption. The colorimetric measurements of the pigments were made in a colorimeter Gretac Macbeth Color-eye spectrophotometer 2180 / 2180UV in CIELAB standards. Based on the obtained results, it can be verified the thermal stability of the powder pigments of green coloration, which enables it as an alternative to the materials currently used in the manufacture of ceramic tiles.

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This paper reports on the effect of the substitution of Fe3+ for Cr3+ ions in the spinel lattice of the powders was investigated. Nickel ferrite powders with a NiFe2-xCrxO4 nominal composition (x = 0.0; 0.5; 1.0 and 1.5 mol of the chromium) were synthesized by combustion reaction using urea as fuel. The powders resulting were characterized by XRD, nitrogen adsorption by BET, SEM and Mössbauer spectroscopy (57Fe Mössbauer spectra). The results show that the substitution of the Fe3+ for Cr3+ions increased the crystalline degree of the phase, reduced the superficial area and consequently increased the particle size. The Mössbauer spectra of the samples also confirm the distribution of the particles size by the magnetic properties. Analyze of the spectra Mössbauer gives an estimate of the superparamagnetic and ferromagnetic particles behavior in each sample for several chromium concentrations.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Genética e Melhoramento Animal - FCAV

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Elucidação dos principais mecanismos técnicos utilizados na formação de Receitas e Despesas Públicas a fim de entender substancialmente a formação de uma apuração fiscal e de que forma influencia na Dívida Pública Federal.Quais teorias dominantes acerca do sistema governamental e da manutenção da Dívida Pública existentes. Apresentação do conceito de Dívida Pública Federal. Discute os principais índices que remuneram os títulos emitidos pelo Governo Federal e como influenciam na decisão dos agentes na composição de sua carteira de títulos e ademais, como toda esta movimentação influencia na Dívida Pública Federal. Busca-se trazer maior luz ao entendimento da formação da Dívida Pública Federal, levando em conta seu período pós-Plano Real até o recente, no governo da presidente Dilma Rousseff

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This study aims to structurally evaluate a support of graphite pastille for the lubrication of railway wheels. The proper lubrication of wheel flanges of the railway extends the life of this component, so it is very important that this occurs lubrication to reduce the costs involved in railway maintenance. To prepar the evaluation structural will be used to International Electrotechnical Comission standard (IEC 61373) establishing which load cases should be applied to this component. The applied loads on the support (accordance with IEC) are random accelerations and accelerations due to shocks, thus simulating the conditions that exist along the route of the train. The structural analyzes are performed by the finite element method, with the aid of the Cosmos software. Thus, it is possible to determine the stresses acting on the support, and so the allowable stresses compared with the standard proposed by the AISC. The stress in the structural analyzes are lower than allowable therefore considered for the configuration presented, unexpected structural problems

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Pós-graduação em Engenharia Mecânica - FEG

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Pós-graduação em Engenharia Civil - FEIS

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This study was conducted to investigate how visually impaired people perform distance estimation tasks by movement and navigation during deprivation of effective perceptual and proprioceptive information. For that they performed the task of walking three distances, being the first and second of 100 meters and the third of 140 meters (triangulation) from a point of origin in open field on a inverted L shaped trajectory and then returning to the origin. The first and second tasks were driven by means of a guide with GPS adapted to the study coordinates, and the third one was freeform with three sessions, the first without perceptual and proprioceptive restrictions, the second without auditory perception, and the third in a wheelchair, without proprioception. The objective of this study was to indicate the differences in distance reproduction in relation to accuracy and investigate the spatial representation of participants in a navigation task, in which there is active movement, but no effective perceptual and proprioceptive information. Results showed that the average participants underestimated distances producing average angles close to the value of 45°. And by means of the "t" students test no significant differences between subjects can be pointed out. To achieve these results we used remote monitoring by GPS and software TrackMaker.

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Governament organizations has as challenge for their governance the requirement ro improve evaluation system that measure the acting of their mediations and profefer for society informations about achievements. The text analyze the challenges and advances of evaluation tools for produce guidelines that could be inserted at context of decision-making from public agents. Thereunto informations must be reliable and real-time, creating vectors of haste for modernization of informational capacity of State as a whole.

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Na reabilitação protética com implantes, a reconstituição das características anatômicas do tecido peri-implantar é fundamental para a obtenção de uma estética ótima. Como os componentes metálicos não transmitem a luz, fazem com que os pacientes com fenótipos gengivais finos apresentem uma coloração escurecida, resultante da limitação estética desses componentes. Pilares cerâmicos (alumina ou zircônia) têm sido utilizados para resolver esse problema, os quais possibilitam a complementação com próteses metal free. A indústria fornece, para alguns sistemas, componentes pré-fabricados cerâmicos a serem personalizados por desgastes e componentes personalizados confeccionados com sistemas CAD/CAM e CAD/MAN. Tendo em vista as limitações de algumas das conexões desses componentes, o objetivo desse estudo é apresentar a técnica laboratorial para confecção de um pilar personalizado cerâmico realizado sobre pilar UCLA de sobrefundição. Concluiu-se que a utilização da cerâmica feldspática proporciona ótima estética, boa transparência, resistência mecânica, baixo custo, melhor capacidade adesiva, com utilização de cimentos resinosos, e, principalmente, técnica de amplo domínio dos laboratórios.

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Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC