974 resultados para rocket motors
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This work presents a proposal to replace thetraditional system of traction electric car that usesone electric motor and a mechanical differential, by two electric motors of lower power, controlled byelectronic control low cost. The proposed control isopen loop and uses the technique of Pulse WidthModulation (PWM), discrete and synchronizedaiming to reduce the generation of harmonics. The implementation of two smaller motor one on each wheel-drive distributes the weight of the vehicle, improving the heat exchange of the windings,beyond enable the power components supporting a current of 50% predicted for only one motor . The solution adopted for being open-loop, has a similar behavior to the mechanical differential, where theeffort imposed by the trajectory makes the velocity distribution between the wheels be appropriate tovehicle trajectory
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In the industries of wood processing (sawmills), where timber is sawn in equipment such as band saws, circular saws, trowel, thicknessers, among others, that mechanically transform this resource and use of electric motors, which are not unusually poorly scaled working or overloaded, often a factor that is not found in these industries and has fundamental importance in the production process is energy efficiency that is achieved by both technological innovation and through all the practices and policies that aim to lower energy consumption, lowering energy costs and increasing the amount of energy offered no change in generation. For both during the design of an electrical installation, both overall and in various sectors of the installation, investigations are necessary, considerations and uses of variables and factors that put into practice the theme of energy efficiency. Therefore, in this paper, these factors were calculated and analyzed for a wood processing industry (sawmill) in the municipality of Taquarivaí - SP, namely: active power, power factor, demand factor and load factor. Where they were small in relation to the literature, these events that occur when devices are connected at the same time and due to the conditions of processing the wood, where the engines have large variations in electricity consumption during the unfolding of the same, due to efforts with the load and idle moments between each machining operation in the equipment
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The search for better performance and competitive advantage in the current market scenario has made organizations keep their focus on quality planning and the use of effective techniques aimed at continuous improvement and optimization of processes and resources. The situation is not different for the painting process in the automotive industry, which has a significant amount of variables and influential external factors. This work, developed at General Motors in São José dos Campos, aims to analyze the feasibility of changing the painting process of the pickup S10 railings in the Antracite color located in the main line to the another line located in a Painting Repair Booth at the plant and, therefore, to study the possibility about reducing the window of cure for Antracite’s enamel by using Design of Experiments’ techniques. Applying this method is possible to find the best arrangement among studied factors of Painting Repair Booth that are, in this case, the Temperature, in Celsius degrees, and Skid’s Steps, in seconds, and it’s also possible to get their behavior according to quality requirements specified by GM rules for the Brightness and Paint Adhesion on the part. As a result, it can conclude that is possible to paint the S10 Antracite railings in the painting process’ line of Painting Repair Booth, and with the new configuration obtained by the Design of Experiments for the process variables, there are significant gains related to the parts’ quality, costs reduction and the optimization of production capacity, much in the main line as in the line of the Painting Repair Booth
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This work aims the design and analysis of a thrust frame system for a liquid fuel rocket engine. The project was developed following the design requirements established by the Division of Space Propulsion of the Institute of Aeronautics and Space. The layout of the structure was developed with the aid of a software of 3D modeling and static and dynamic analysis were performed by using a finite element package. The results of the analyzes helped in defining the layout of the structure which met all design requirements. The safety factor and the mass achieved were comfortably low, which may be useful in the future because the liquid fuel rocket engine is still in development
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A launching rocket and its payload are submitted to strong acoustic loads in some moments of its flight like lift off, during transonic flight and in the instant of maximum dynamic pressure. These loads could affect the payload and other rocket internal equipment. It must be taken into account that in the higher stages, where delicate control equipment and the payload are placed, the acoustic excitations are dominant. The knowledge of the acoustic loads is of great importance in order to provide estimated loads for the design phase, define intensity level to specify qualification and acceptation acoustic tests to which subsystems and elements of the launcher and its payload shall be submitted and to design an acoustic … (Complete abstract click electronic access below)
Proposta de uma metodologia de rebobinamento para converter motor de indução trifásico em monofásico
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This paper proposes the conversion of a three-phase induction motor into single phase through rewinding its stator. It presents a methodology to calculate this rewinding process considering the constructive parameters of the, such as number of slots and number of poles, for instance. The operating principles of DC motors are highlighted to introduce the logic involved in the calculation of lap and wave windings. The construction of the stator three-phase induction motor generally uses the lap winding, which is also used in single phase to perform the conversion. The rewinding process is widely used for reconstruction of industrial and residential electric motors that have suffered damage or present flaws with use. Therefore, many three-phase electric motors that are discarded or disposed of could be recovered by the method described in this work for a purpose that contributes to energy efficiency or simply saving resources in single-phase uses
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Pós-graduação em Agronomia (Ciência do Solo) - FCAV
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Pós-graduação em Engenharia Elétrica - FEIS
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The Brazilian automotive industry has undergone profound changes during the 90’s decade, as a consequence of the market opening up through the liberation of automobile imports. The exposure of the Brazilian domestic market to competition with imported products of high quality and lower prices indicated the need for significant changes in those auto industries operating in this country, with the intention of making them competitive. To achieve these objectives management and production concepts were adopted, such as: the just-in-time philosophy; lean manufacturing; outsourcing; reengineering and increasing the rate of automation in both production and management systems. These changes helped to increase productivity and, in turn, reduced the level of employment in the sector, especially in activities where the required qualification levels were low. Despite this modernization, the Brazilian companies have committed themselves to meet the specific needs of the Brazilian market. The objective of this paper is to analyze and present manufacturing strategies from six manufacturers of automotive vehicles: Toyota in Japan, Fiat in Italy, Volkswagen in Brazil and Germany and General Motors in the U.S. and Brazil. The predominant method of research was from reviewing relevant literature, whereas the empirical data was analyzed qualitatively. The article seeks to identify the manufacturing strategies adopted by manufacturers located in the above countries, electing one automotive manufacturer to represent each country. The research demonstrated that the processes for production of automobiles in four plants located in, the U.S. (GM); Italy (Fiat); Japan (Toyota) and Germany (VW) are similar to those adopted in Brazilian industrial plants of the same companies (GM and VW), with differences of operations only in the business strategies adopted by each of them.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Myosins are molecular motors associated with the actin cytoskeleton that participate in the mechanisms of cellular motility. During the development of the nervous system, migration of nerve cells to specific sites, extension of growth cones, and axonal transport are dramatic manifestations of cellular motility. We demonstrate, via immunoblots, the expression of myosin Va during early stages of embryonic development in chicks, extending from the blastocyst period to the beginning of the fetal period. The expression of myosin Va in specific regions and cellular structures of the nervous system during these early stages was determined by immunocytochemistry using a polyclonal antibody. Whole mounts of chick embryos at 24-30-h stages showed intense immunoreactivity of the neural tube in formation along its full extent. Cross-sections at these stages of development showed strong labeling in neuroepithelial cells at the basal and apical regions of the neural tube wall. Embryos at more advanced periods of development (48h and 72 h) showed distinctive immunolabeling of neuroepithelial cells, neuroblasts and their cytoplasmic extensions in the mantle layer of the stratified neural tube wall, and neuroblasts and their cytoplasmic extensions in the internal wall of the optic cup, as well as a striking labeling of cells in the apparent nuclei of cranial nerves and budding fibers. These immunolocalization studies indicate temporal and site-specific expression of myosin Va during chick embryo development, suggesting that myosin Va expression is related to recruitment for specific cellular tasks.
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Pós-graduação em Engenharia Elétrica - 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 - FEG
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Pós-graduação em Engenharia Elétrica - FEIS