998 resultados para Correntes eletricas - Aterramento
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Este trabalho analisa os jornais O Baurú (publicado entre 1906 e 1924), da cidade de Bauru, e O Operário (publicado entre 1909 e 1913), de Sorocaba, com ênfase no período entre 1909 e 1913, para identificar em que medida os dois veículos representavam políticas correntes entre os operários no período (anarquismo, socialismo e anticlericalismo, por exemplo), e faziam parte da experiência comunicacional do início de século XX, na qual segmentos operários e aliados puderam atuar diretamente na produção impressa, visando à organização política de classe
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Therebar of aluminum 1350 AA produced by CBA are used inthe manufacture of wires and cables for electric power transmission, which marketshows increasingly favorableto aluminum due to itslow densityand high electrical conductivity, but to ensure that this materialmeets all specifications of projectsfor electricity transmission, it must have homogeneity in the chemicaland mechanicalproperties.One of the points of improvement in the process of rod production isreducing the high variation of the limitof tensile strengthalong the coils, therefore, this work seeks a better understanding of the factors that significantly influence the mechanical properties of rebar, specifically assessing the influence oftemperatureat the output of the coils, which can cause a recovery effect on the material andif thereare relevantdifferences between the two modes of rebar production: auto and manual.Samples of six coils have been specifically produced forthis study, which weresubsequently subjected to different annealing temperatures for one hour and ten minutes, similar to what occurs in the output of the coil from the machine. The tensile tests showed that aluminum 1350 AA is significantly influenced by temperature, whose behavior was very similar to that presented in the literature. It was found that the phenomenon of recovery occurred more significantly at high temperatures. Through the optical electron microscope Zeiss, 18 surface maps were made with 100x magnification for each sample in different conditions and the images were analyzed using entropy and fractal dimension, aiming to relate the condition of surface hardening on mechanical property of the samples in that condition. The results showed that these methods can be applied, provided they do not have any kind of imperfection on the surface, once they can influence the results. The study concluded that a more efficient cooling is required in ... (Complete abstract click electronic access below)
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The aim of this work was the development a computer code for simulation and analysis of atomic spectra from databases constructed from the literature. There were created four routines that can be useful for spectroscopic studies in the atomic processes of laser isotope separation. In the first routine, Possible Transitions, the program checks the possible electron transitions from an energy level of the atom present in the database considering the selection rules for an electric dipole transition. The second routine, Locator Transitions, checks the possible electronic transitions within a user-specified spectral region. The routine Spectra Simulator creates simulated spectra using the graphical application gnuplot through lorentzian curve and finally, the routine Electronic Temperature determines the temperature of electronic excitation of the atom, thought the Boltzmann Plot Method. To test the reliability of the program there were obtained experimental emission spectra of a hollow cathode discharge of dysprosium and argon as a buffer gas. The hollow cathode discharge has been subjected to different values of operating currents and pressure of inert gas. The spectra obtained were treated with the assistance of program routines developed (Transition Locator and Spectra Simulator) and temperatures electronic excitation of the atoms of dysprosium in the different discharge conditions were calculated (routine Electronic Temperature). The results showed that the electronic excitation temperature of the neutral dysprosium atoms in the hollow cathode discharge increases with increasing current applied to the cathode and also by increasing the gas pressure buffer. The determination coefficients, R2, obtained by the Electronic Temperature routine using the linear adjust of the Boltzmann Plot Method were greater... (Complete abstract click electronic access below)
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O capítulo 1 trará as mais importantes correntes teóricas sobre inflação, desde meados do século XX até o fim deste século. Também será demonstrado o pensamento da corrente Cepalina, mais especificamente os autores brasileiros que escrevem acerca da inflação que era observada no período (década de 1980). Assim, chegaremos a como se é formulado o regime de metas de inflação. Após isso, foi efetuada uma cronologia desde a implementação do plano real no Brasil até a inserção do regime de metas de inflação em 1999. O capítulo 2 tem como seu conteúdo principal abordar a eficácia do regime de metas de inflação. Para isso, trará um modelo estatístico, mostrando e interpretando os resultados obtidos. Após isso, o capítulo trará um panorama geral de como evoluiu o regime de metas de inflação no Brasil nos anos em que o trabalho se situa. Na conclusão, serão trazidos os principais questionamentos do trabalho, bem como as respostas encontradas para este e os eventuais desafios que um aprofundamento maior poderá acarretar
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O presente trabalho visa, em meio à crise de identidade que se instaura na Educação Física desde décadas – do seu início oficial em 1851 com a Reforma Couto Ferraz até os dias de hoje onde se fala em Cultura Corporal (de Movimento) – , enquanto área do conhecimento, explorar seu contexto e constituição históricosocial, perpassar por suas principais abordagens, principalmente no que tange à Educação Física Escolar e promover o entendimento da origem da perspectiva cultural, tal qual tem sido veiculada nos principais documentos oficiais que definem a constituição da área e sua práxis. Nesse sentido, aborda-se o contexto higienista/eugenista, onde se buscava uma educação do físico que o prevenisse de doenças e o purifcasse, com profundas influências militares; o contexto nacionalista, na intenção do aperfeiçoamento físico e aprimoramento das funções orgânicas, atrelado às questões de ordem moral e cívica; escolanovista, que proporcionou uma visão não só embasada biologicamente, mas se atentou à fatores psicológicos da criança; o contexto da ditadura militar, fortemente associado ao Esporte e a visibilidade internacional que ele acarretava ao país, inclusive, remetendo à Educação Física ao binômio Educação Física/Esporte; e o contexto que, a partir de década de 80, vem tentando instaurar uma Educação Física mais humana, sem deixar de lado questões relativas à saúde. É a partir dessa última década que o tema será aprofundado, apresentando-se alguns conceitos de “cultura” trazidos e utilizados pelas ciências sociais para, posteriormente, explanar como a Educação Física se apropria de tais conceitos para justificar-se enquanto conteúdo curricular obrigatório, no contexto escolar. Abordar-se-á as principais correntes com seus respectivos autores, referentes à década de 80: desenvolvimentista, por Go Tani; da cultura infantil, com possível aproximação ao construtivismo, por...
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This paper presents a comparative study based on literature and examples in the literature, the two main technologies for the transmission of electricity at high voltage: alternate current transmission and direct current transmission. Inside the direct current transmission will be shown two technologies currently employed, transmission by current source and transmission by voltage source, contributing to a better understanding of them. The ultimate goal is to provide a text for consultation to identify key characteristics that influence the choice of future transmission lines
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The increasing rate of traffic accidents, followed by the high rate of mortality due to these occurrences, favored to the classification of traffic accidents as a public health problem in Brazil. These accidents consume a significant portion of Gross Domestic Product (GDP), especially related to the victims. Considering this scenery with many tragedies and resources being spent only in the end, this paper seeks to examine the influence of federal highways lighting by reducing the number of accidents. Federal Highways sections that received lighting were taken up for study, therefore a survey of statistical data has been raised considering the accidents before and after the route had been illuminated. Taking advantage of the results obtained, an economic analysis has been made considering the amounts consumed by traffic accidents versus the values required for the installation of lighting on highways
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This paper aims to develop a web application for viewing Atmospheric Electrical Discharge, plotting marks on a map, using as base data provided by SIMEPAR. The developed system uses techniques and tools which enable the creation of Web system without requiring the use of plugins or external software, running on virtually all web browsers and platforms. This tool aims to aid meteorologists monitor agile discharges and help society at large to prevent accidents caused by this phenomenon of nature
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The electrical substations have the goal to transmit, distribute and change the characteristics of electrical energy transmission networks of dealers to the end user with a high rate of reliability and continuously. For this it’s necessary to accomplish a gathering of datas from the local dealers where will be installed the substation to make a good electric project. This work has the objective to gather all the contents relatives to electric project of substation that are scattered in the literature, in order to organize and develop a basic guide that presents a methodology to dimension electrical equipments that belong to an industrial substation at 15 kV. In addition to elaborate a basic guide, this work aids to specify electrical equipments installed in the substation, bringing information and comparisons to know and determinate the kind of equipments that will be used, in a correct and coherent way with the national and international rules. Ultimately, after determined, got and specified all the equipments that belongs to an industrial substation, the work mention in global manner how to calculate the dimension of substation physical arrangement, determining all the least and required dimensions of each cubicle
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Through awareness of new trends of consumption of the population with regard to housing, comfort, entertainment, security and sustainability, it was crafted a work that set out to study and develop the concept of home automation and how it will revolutionize the electrical installation projects and energy savings. A pre-wiring project, taking into account, basically, the installed load, is presented as a basis for comparison. The protocols for communication between intelligent devices in an automation environment, used in the work, are the X-10, LonWorks and UPnP. The home network is studied and divided into subsystems, for a better understanding, which are the lighting, audio, video and multimedia system, security, air conditioning and central vacuum system, and the idea of integrated design and system integrator is introduced, showing the change necessity in the design philosophy of electrical installations. The main means of energy savings in an automated home, such as dimerization, master off and smart meters are presented and, finally, it was concluded that there is a need to structure electrical installation projects more comprehensive with regard to home automation, in order to become more efficient and useful to users
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With the growth of the demand on electric energy in the last decades, the urban distribution and transmission systems have experienced a bigger necessity to improve on the substations, the automation procedures and techniques on the operation maneuvers of such systems, in a sense that better attends the quality levels, availability, continuity and operational reliability. In this way, the objective of the present paper is to perform a study of protection and control on an electrical industrial system involving the procedures of digitizing and maneuvers automatism utilizing operational techniques and other pertinent information used in a typical high-voltage Industrial Electrical System. Analysis were made on short-circuits to specify the main components of the 138 [kV] substation, in addition, there were used digital MiCOM relays to make the protection of the present elements. With that, a program was developed to allow the user to monitor the condition of circuit-breakers through a supervision screen being able to simulate some kinds of faults, as well as observing the characteristics of each device. This way, the importance of having a fast and reliable system that ensures the equipment’s protection and the industrial process continuity due to faults on the electrical system is noticeable. It’s important to highlight that all this digitizing was mainly favored by the development of digital technology on the last years, mainly on microelectronics, also with the appearance of supervision gadgets allowing the development of complex systems in supervision and electric energy control
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The present work aims to prepare a study of selectivity and coordination in an isolated electrical system with the aid of computer software PTW (Power Tools for Windows). Based on appropriate protection standards, on equipment data and the survey of the curves of “time versus current” (Time Current Curve – TCC), may be defined protection settings to leave the system selective, coordinated and properly protected. Definitions of adjustments are made taking into account the data of, so called, thermal curves of the equipment, which take into account the rated current and the supportability of short-circuit current of the equipment and cables involved in the installation in question. For that we use the tools provided by the PTW in which an industrial electrical circuit is simulated, presenting and discussing the results. With that validates the software PTW, taking it as a great tool helper implementation the coordination and selectivity study
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STRATIGRAPHIC SUCCESSION OF ALAGOAS STAGE ON SERRA DO TONÃ, TUCANO BASIN (BAHIA). Located in northeast of Bahia, serra do Tonã is a NS elongated plateau that standsout in the flattened relief of Tucano Basin. The stratigraphic succession belongs to the Aptian post-rift sequence of this basin. Based on facies analysis, vertical stratigraphic profiles and satelite images interpretation, three stacked stratigraphic units were recognized: (1) lower carbonate unit, composed by laminated limestones and breccias, 5 m thick, correlated with Camadas Batateira of Arripe Basin; (2) intermediate siliciclastic unit, 100m thick and made of sandstones exhibiting finning upward cycles, overlaid by mudstones and sandstones wich sedimentary structures suggest action of tidal currents and (3) upper carbonate unit, composed by laminated limestones, 2-10 m thick, related with Santana Formation, that record lacustrine environment with possible marine influence. Paleocurrent analysis indicates proviniance from north and paleoflows towards south, similar to the Aptian fluvial facies of Araripe Basin, showing that both basins integrated the same continental paleodrainage
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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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Together with the increase of environmental degradation in the past few decades, the environmental education (EE) has emerged and grown all around the world. It is worrying the frequent assigning of stereotypes to the animals and the cases of disrespect to them. For these matters it was studied the presence and importance attributed to animals in the annals of six editions of an event of great significance in the field of Environmental Education, the meetings Pesquisa em Educação Ambiental (EPEAs). The animals were chosen for deserving more attention in the preservationist context, besides allowing the use of a great extent of activities in EE, regarding scholar and non-scholar organizations. The articles that presented descriptors related to animals in the title, keywords or abstract were analyzed in depth and characteristics such as segmentation of the studied population, locations where jobs tend to be performed, prevailing aspects and didactic material production, among others, were investigated and compared. It was also verified which current trends on Environmental Education currents are more frequently presented in the EPEAs articles, in order to map the Environmental Education in Brazil in the past few years, using as a basis an important theoretical framework in the area. Through the use of descriptors it was possible to define the articles that would be analyzed in depth, which is less than 6% of the total work published and represents that, until the sixth edition, the EPEAs have a minor amount of works concerning animal matters. In many of these articles animals were superficially worked, which demonstrates the necessity of approaches not only involving more the animals, but also addressing the complex environmental matter. Several trends were identified in various EE currents, coexisting and also conflicting in the field of Brazilian Environmental Education. It was observed, in several cases, two or more trend currents in the ...