1000 resultados para Falhas de regulação
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Pós-graduação em Engenharia Mecânica - FEIS
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A insuficiência cardíaca (IC) está associada a miopatia dos músculos esqueléticos dos membros, com perda da massa muscular, diminuição na proporção das fibras do tipo I (contração lenta) e aumento na proporção das fibras do tipo II (contração rápida). É provável que alterações na expressão de fatores de transcrição pertencentes à família “basic helix-loop-helix” (bHLH), da qual fazem parte a MyoD, Miogenina, Myf5 e o MRF-4, conhecidos como fatores de regulação miogênica (MRFs), sejam responsáveis pelas mudanças nos tipos de fibras. Enquanto que a Miogenina é expressa em níveis superiores aos da MyoD em músculos lentos, o oposto é verdadeiro para músculos rápidos. Similarmente, a MyoD está associada com a expressão das isoformas de miosina de cadeia pesada rápidas dos tipos IIX e IIB. Estudos in vitro, demonstraram que o TNF-α inibe a expressão de MyoD e miogenina diminuindo a atividade de genes músculo específicos. A ação do TNF-α diminuindo a expressão da MyoD mostra-se mais acentuada quando em associação com o IFN-γ, no entanto, há poucas informações na literatura a respeito do papel desta associação na expressão dos fatores de regulação miogênica, in vitro. Avaliar a expressão dos fatores de regulação miogênica, MyoD, miogenina, Myf5, e MRF-4 em cultura de mioblastos C2C12 submetidos ao TNF-α/IFN-γ. Nossos resultados mostraram um aumentou na expressão dos gene MyoD, Myf5 e miogenina sob tratamento com IFN-γ quando comparado aos grupos controle e TNF-α/IFN-γ. A expressão gênica do MRF-4 na cultura de células não foi detectada em nenhum dos grupos analisados. O GAPDH foi utilizado para normalizar os valores de expressão dos outros genes analisados. O presente estudo demonstrou que o IFN-γ exógeno administrado à culturas de mioblastos... (Resumo completo, clicar acesso eletrônico abaixo)
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This study is about a heating line that uses thermal oil. It is located in a facility that produces interlayers used in cars windshields. A plastic resin is melted and is sent to a matrix called DIE where the interlayers are produced. The DIE needs to receive heat from the circulation of thermal oil in four different regions of its interior, to ensure the correct thickness of the interlayer. The thermal energy is provided by electric heaters and the flow of thermal oil is impelled by four mechanically sealed centrifugal pumps (one per region). The key point of this study is the fact that these four pumps of the system have reported successive failures in the mechanical seals. Apparently, a poorly designed project has burdened the system intermittently. The pumps operation condition is located in a region of low efficiency, according to the characteristic curves. This fact is the source of the noticeable reduced time between failures. Changes in the configuration of the facility and in the number of pumps will be proposed, aiming to achieve higher operational efficiency. The proposals will be mathematically analyzed according to the Hydraulic Institute criteria. At the same time, we will also keep focus on an in-depth study of a heating system structure, starting with a detailed approach for each component and discussion about its real need and economic viability. At the end of this paper it is shown that the gain in efficiency achieved with the new proposed configuration reflects not only in the reduction of maintenance costs, but also a potential improvement in energy efficiency. It is shown that these two aspects are closely related and together form the basis for the design of a reliable and efficient pumping system
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This work presents a study that aims to validate the fatigue analyses developed on finite element commercial software, ANSYS Workbench. It was based on mechanical tests development of traction and hardness, to verify the mechanical properties of material that the shaft was manufactured (ABNT 1045 steel), it was developed bend test, with purpose to prove the confiability degree of computational analyses, obtaining the maximum stress in a work condition determined with 40 [kgf] of load applied, and at the end, was developed the fatigue test to obtain the number of cycles that the transmission shaft can support in a work condition with 8 [kgf] of load applied. The results obtained during the work present, have to be quite satisfactory with the theoretically expected
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The growth and expansion in auto parts market are directly related to the ability of a company to innovate and gain new customers, increasing its portfolio of customers and products. For this purpose the process of prospecting for new business has become a key process in companies seeking this goal, which requires teams and structures dedicated to it. Besides counting on available resources to carry out prospecting, it is necessary to properly manage the process as a whole, whose main result is a business proposal, which may lead to closer relations with the potential client and the activation of a new business. Process failures and difficulties to formulate a commercial proposal lead to documents produced without the quality needed that makes it harder to obtain new business. The objective of this study is to evaluate the process of new businesses quotation in the auto parts industry and indicate opportunities for improving this process. This goal is achieved by mapping the current process, from the diagnosis of problems and the indication of tools that can prevent or minimize the problems diagnosed. The information supporting this study were obtained by the bibliographical research, participant observation of the process, unstructured interviews with some of the involved people in the process and prospecting tools that can improve it. It results the mapping of new business quotation process, the points indicated as failures and difficulties in the process and the appointment of project management tools that can bring improvements to the new business proposals and pointing the moment for your application in the process
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The competitiveness in the industrial sector is increasingly fierce. In this context, the quality of maintenance is often neglected due to the sense of urgency that arises in these companies. Thus, it becomes increasingly necessary to use tools of Reliability Centered Maintenance to assist in managing maintenance effectively and efficiently, and directing resources .This study aims to evaluate the use of the fault tree to identify critical paths in the maintenance sector in an industry. The proposal is uses the tools of Reliability Centered Maintenance (MCC) for the collection, disposal and prioritizing causes problems in the transport industry. The study has its focus on the theoretical foundation of problem solving methods and techniques to identify the root causes, using the fault tree
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In recent years, increasing demand for energy has led to studies to increase the amount of electricity produced. Due to this fact, more and more boilers are becoming important sources of electricity generation. To raise the efficiency of energy generated in the boilers is necessary to raise the steam pressure and temperature to values previously unimaginable. The use of more resistant materials and maintenance practices and most appropriate operation made it possible. The objective of this study is to test the main types of failure in a chemical recovery boiler, in particular due to fatigue in the superheater, because it is a component subjected to high temperatures and thus more subject to different failures. In this manner this study aims to reduce the incidence of unscheduled maintenance shutdowns, increasing the operation time under appropriate conditions. Modeling performed in this study, the failure did not occur, because we considered only the mechanical stress. Under normal conditions, mechanical stress in combination with thermal stresses can cause cracks in the tubes due to cyclical stresses, leading to fatigue failure
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Pós-graduação em Fisioterapia - FCT
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Enfermagem (mestrado profissional) - FMB
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Pós-graduação em Engenharia Elétrica - FEIS
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This article presents a reflection on the historical aspects and legislation on Distance Learning (DL). For this, a bibliographic and documentary research was performed with the goal of raising the necessary notes for discussion. The text begins with the characterization of the current society, the Information Society, which supports the modern distance education, which uses information and communication technologies (ICTs) to establish the process of learning teaching. Five stages of the EAD are identified. Later, the Brazilian legislation concerning the DL is punctuated, starting with the passage by Article 80 of the Guidelines and Bases Law-LBD (Law 9394/96) along with the critical analysis of Decree 5,622/05. Finally, in the final considerations is discussed the negative image that the DL carries by the Brazilian population and obstacles in the existing rules that hinder the democratization of access to education that aims DL.
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Our main concern was to investigate the forms and rationalities implicit in the social regulation/autonomy of the management processes of learning, historically established in the 1971 through 2002 educational reforms, via assessment guidelines of school performance in the state of São Paulo. We used a socio-historical approach, relying on speeches and official documents as our primary source and on studies and research work about teacher assessment and performance as secondary sources. As central categories we considered continuity and rupture in the patterns and mechanisms of social regulation/autonomy of educational work. The results help to clarify how educational policies, instituted in contexts of social reproduction/transformation, influence the management of educational processes within the school.
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Temperature is certainly one of the major factors that affect biochemical and physiological processes. So, the investigation of how animals regulate body temperature (Tb) and respond to changes in ambient temperature is indispensable. There are five thermal states defined up to date that include euthermy, hypo and hyperthermia (forced fall and increase of Tb, respectively), fever and anapyrexia (regulated increase and fall of Tb, respectively). In this review, we present some classic and recent data about thermoregulatory mechanisms involved in those thermal states with special attention directed to anapyrexia, a phenomenon that has attracted the interest of researchers due to its potential therapeutic benefits.