234 resultados para Instalações eletricas
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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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Leaking of hydrocarbon in fuel underground storage tanks constitute object of concern for urban environmental management, because therefore they provoke damages to the physical, biological and socioeconomic environment. Though laws that regulate this essential activity exist, aiming at to prevent contamination with hydrocarbon, we observe that this still happens. This fact evidences that the selection of places for installation of gas stations has not considered the characteristics of the natural environment, implying in more critical consequences associated to the leaking. The objective of this work is to elaborate a chart applied to the gas stations in Rio Claro/SP. The determination of the Index of Environmental Sensitivity for elaboration of such chart was carried through breaking the selection of factors of Environmental Sensitivity of physical, biological and socioeconomic environment. The balance of these factors was given by means of Ad hoc consultation. The crossing of the information was carried through using the method of overlapping of overlays. The result is a chart that shows us areas with classes of high, middle and low Environmental Sensitivity. One gives credit that this type of material can be used as criterion in the selection of adjusted areas for installations of new gas stations and management of the already installed gas stations. The diagnosis of the current situation of the gas stations in the area and recommendations had also been elaborated.
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In hospitals, health professionals may face different situations and problems. By following them, it is remarkable that one of the difficulties is related to the support provided by the facilities to carry out their work. This also affects the quality of treatment offered to patients. One of the points of improvement that could be studied is hospital beds. The Fawler's simplest hospital bed type, used in most Brazilian public hospitals, is designed with an ergonomic average height that offers a default position for analysis and treatment of patients. There is no possibility of adjusting the height of those beds, and hence there is a limitation in this regard since that height is fixed, but the physical structures of the workers and patients may vary widely and there may be a conflict when there are people too large or small involved in this process. Beyond that, studies by experts show that beds with height adjustment decreases the muscular effort and improve the movement quality of the spine of nursing staff, reducing the force on certain vertebrae and also the ergonomic risk. Of course, patient comfort is also affected accordingly. As the beds made with height adjustment are very expensive, this study aims to design a device to adapt the not adjustable beds. The project must be viable from an economic and mechanic standpoint, being able to adapt both old and new simplest Fawler hospital bed models, since their dimensions are similar. The final result shows that it is possible to adapt such beds using the designed concept at a viable cost. Furthermore, this concept could be applied in other bed types or objects that have hollow feet
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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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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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This study aimed to develop a computer program which systematizes the structural shielding design calculation in diagnostic radiology facilities. For this purpose methodology of the National Council of Radiation Protection and Measurements (NCRP 147[5]) was used. By comparative statistics studies, it was verified if reference parameters values suggested by the US publication correspond to the average national values. The World Wide Web was chosen because of its characteristics as a powerful mean of communication, especially in terms of the wide variety of useful resources and easy access. To compare the reference values of some parameters proposed by NCRP 147 to Brazilian average, studies about the normalized workload per patient, performance of X-ray tube and primary air kerma, unshielded, at one meter from the focal point of the X-ray tube were made. Through this research, relative differences were found. In workload values this differences reached up to 50% in mammography compared to those presented by the NCRP 147; in X-ray tube performance the percentage differences reached 69% in dental radiology, and air kerma results amounted 31% in fluoroscopy. This demonstrates the importance of validation of international protocols to local realities
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This work presents an intervention at the Guaratinguetá Railway Station and its surroundings, including this area in the urban context, at this moment isolated of the activities and citizen attentions, offering new activities on this commercial area. The selected area finds itself in a state of neglect and forgetfulness from the urban relations. Located between the periphery of the commercial center and the Paraiba do Sul River, the correlation is tension between the advancement of shops, the railway line, and the natural barrier of the Paraiba River. On the context of these limits, the railroad and the river stand as barriers for the center expansion and the flows that connect the old part of the town with the new part, which is growing and is called “post-city river”. These barriers have relegating properties around them to isolation, despite being located in the center. The area choice and this intervention seeks to break this isolation and the barrier flow, linking areas of opposite sides to form a leak through the barrier of the railway line. The pedestrian flow is prioritized in the project, this flow will be attracted by the program offered and by the new created areas, increasing the space utilization by users and breaking the isolation of urban activities. And entering the area in the context of life of city residents. The attraction of these new flows will be through the implementation of a Cultural Center, supplying a lack of city by spaces that offer this type of activity. Its implementation aims to attract and modify the activities of these spaces and the surrounding areas, one side facing the commercial center, and another facing the river, linking this two sides at the same time that this link provides the expansion of distance traveled and known
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Pós-graduação em Engenharia Mecânica - FEG
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Pós-graduação em Artes - IA
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Pós-graduação em Medicina Veterinária - FCAV
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The gas turbine (GT) is known to have: low cost of capital over the amount of energy, high flexibility, high reliability, short delivery time, commissioning and commercial operation at the beginning and quick departure. The gas turbine is also recognized for its superior environmental performance, manifested in air pollution containment and reducing greenhouse gases (Mahi, 1994). Gas turbines in simple cycle mode (SC) have long been used by utilities to limited power generation peak. In addition, manufacturing facilities use gas turbines for power generation units on site, often in combination with the process of heat production, such as hot water and steam process. In recent years, the performance of industrial gas turbines has been improved due to significant investments in research and development, in terms of fuel to electricity conversion efficiency, plant capacity, availability and reliability. The greater availability of energy resources such as natural gas (NG), the significant reduction of capital costs and the introduction of advanced cycles, have also been a success factor for the increased use of gas turbines to load applications base (Poulikas, 2004). Open Cycle Gas Turbine with a greater degree of heat to the atmosphere may alternatively be used to produce additional electricity using a steam cycle, or to compose a cogeneration process. The combined cycle (CC) uses the heat from the gas turbine exhaust gas to increase the power output and increase the overall efficiency of more than 50% second (Najjar, 2001). The initial discovery of these cycles in the commercial power generation market was possible due to the development of the gas turbine. Only from the 1970s that gas turbine inlet temperature and therefore the exhaust gas temperature was sufficiently high to allow a better efficiency in the combined cycle ... (Complete Abstract click electronic access below)
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Distribution networks are formed by long lines that carry electricity substations to homes and industries. These lines have associated impedance and depending on operating conditions of the network these impedances may vary. This paper provides a detailed analysis of the effects observed in studies of voltage drop, short circuit and electrical losses, when considered the drivers sequence impedances used in primary distribution network at different temperatures. Therefore, it is initially presented a calculation methodology and details the factors that influence the final values. The methodology presented tackles in a practical way the main factors that directly or indirectly influence the values of the impedances as an emblematic example and will be properly dealt with throughout the paper is the effect of temperature on the values of the sequence impedances. More specifically is dealt with the case of XLPE cables protected, by having a higher maximum operating temperature than the operating temperature of the network. The effects observed in the power flow generated when considering the impedance values at both temperatures were analyzed. The impedance drivers tend to increase with increasing temperature. Thus the impedance of the conductor XLPE protected will tend to be greater for the maximum operating temperature for which the operating temperature of the network, resulting in greater voltage drop and higher electrical losses
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Pós-graduação em Engenharia Elétrica - FEIS