677 resultados para Subestações elétricas


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Technology always advances and thus the device miniaturization and improved performance, besides multifunctionality, they become extremely necessary. A wave of research on the area tends to grow in number and importance in today's market, it is necessary to search for new materials, new applicability of the existing ones and new processes for increasingly cheaper costs. Dielectric materials are considered a key element in this sector being the main electrical properties its high dielectric constant and low dielectric loss. The Polymeric Precursor Method appears as a good alternative because is a low cost, simple process with controlled stoichiometry. In this method, two steps were performed. In a first step, the precursor solution was decomposed into powders and in a second step the precursor solution was converted in thin films. In this work, was used the polymeric precursor methods to get thin films where they were heat treated and characterized by XRD, SEM and AFM. We have obtained Bi3NbO7 thin films with good homogeneity and uniform distribution of grains were noted. We observed that the best condition to obtain the tetragonal phase is annealing the film at high temperatures for a longer soaking time and with excess of bismuth. Several oxides electrodes were evaluated aiming to obtain textured dielectric thin films

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An experimental study in dogs was accomplished to evaluate impedances at the acupuncture points and the relative false points. According to the physics concepts and the Ohm’ Law, an electrical circuit was set up to determine the impedance. This circuit was introduced into three experiments in anesthetized dogs with needles at selected points. In the first two experiments, was applied an alternating tension with 200Hz frequency in the circuit and, in the last experiment, the frequency was increased to 10kHz, the tensions and electrical currents were measured between every pair of points for the all experiments. The impedances were calculated with the values obtained by experiments. The analysis of impedance values indicated that there is a coherent relation between the results and the applied frequencies in circuit, so just at high frequency condition admits the correct measurement of total impedance, therefore the last experiment gave the result which agreed with the theory, that the impedances at acupuncture points are lower than the impedances at false points

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This paper presents a design and construct the system of data acquisition with wireless transmission of some important parameters like motor temperature, motor rotation and velocity of Unesp Racing´s formula car prototype from Universidade Estadual Paulista, Campus Guaratinguetá. This system development presents a contribution for the electrical technical features adding important points in the competition due car´s electric, in addition, enables preventive maintenance and fine adjustment of the car with the data obtained during training and racing

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This work presents a study about distributed generation using photovoltaic systems in the context of smart grids. The characteristics of a Smart Grid and the several aspects this concept involves - distributed generation among them - are discussed. There are also examples of equipment, like smart meters, and of national and international projects. The specificities of distributed generation and the rules and standards necessary in this sort of installation are talked through with focus in the solar energy generation method. Regarding photovoltaic systems, the working principles of the panels are presented, along with its main electrical characteristics and the technologies available. Finally there is a study concerning the sizing of a distributed generation system that involves photovoltaic panels in a residential plant. An analysis of the costs and return of investment period is made about the specific case in consideration.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Engenharia Elétrica - FEIS

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Pós-graduação em Engenharia Mecânica - FEIS

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Pós-graduação em Engenharia Elétrica - FEIS

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Placing the management of childhood forms considered at risk, we discuss the operation of a welfare institution and its effects on the subjective process. Created to manage the virtues of the poor behavior of children, makes visible to the way technology features disciplinary policies: surveillance is evident of cameras, high walls, electric fences and in the eyes of educators, the penalty stands normalizing practices corrective aimed at standardization bodies, educational meetings are compared to the examination, as they produce dossiers of individual behavior, emphasizing characteristics that are considered dangerous anticipates the administration and production of docile individuals, useful, productive, applying identity models. Following the lines of knowledge and power relations that constitute this space, we used the genealogy in the analysis of discursive practices that cross society in its historical construction, the genealogy allows us to achieve these movements in the consolidation process of the government of life, and also, the deconstruction of hegemonic practices. In an attempt to escape the set, we propose the realization of artistic and cultural activities within a process of collective construction as a strategy of resistance and confrontation with the dominant logic, consolidating practices that favor the enhancement of life in its manifold possibilities.