Electrical And Electronic Equipment
Mostrando 13-23 de 23 artigos, teses e dissertações.
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13. Obtenção de uma porcelana dielétrica a partir de matérias-primas do Rio Grande do Norte
The dielectric porcelain is usually obtained by mixing various raw materials proportions and is used in the production of electronic equipment for various applications, from capacitors of high and low Power to insulators for low, medium, high and extra high voltage, which are used in distribution lines and transmission of electricity.This work was directed t
Publicado em: 2010
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14. Preparação de vidros boratos dos sistemas 50B2O315PbO(35-x)Li2OxNa2O e 50B2O315PbO(35-x)LiFxNaF e determinação do efeito dos alcalinos mistos / Preparation of borate glasses from 50B2O315PbO(35-x)Li2OxNa2O and 50B2O315PbO(35-x)LiFxNaF systems and the evaluation of the mixed alkali effect
Different alkali glasses have been developed because exhibit a high ionic conductivity and can be used as solid electrolytes in the fabrication of devices such as batteries and chemical sensors. However, a deleterious effect emerges when two alkali ions are present in the same glassy matrix. The phenomenon, named of the mixed alkali effect (MAE), causes a no
Publicado em: 2010
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15. The impact of European environmental requirements for electrical and electronic equipments on Brasil / Os impactos das exigencias ambientais europeias para equipamentos eletroeletronicos sobre o Brasil
The objective of this study is to evaluate the impact of european environmental requirements for electrical and electronic equipment on Brasil. These requirements, that deal with hazardous substances phasing out (RoHS) and post-consume management (WEEE), have afected the firms of electronic sector and environmental goods and services industry in developed co
Publicado em: 2008
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16. Caracterização físico-química de materiais baseados em celulose
Switching cutout devices are electrical circuit breakers which protect electric power distribution webs against lightning discharges. Switching cutout devices main parts are the fuse links in which a fuse element, a special metallic alloy, melts due to the generated heat when struck by electric discharges. When such melting occurs, and the breaker opens, an
Publicado em: 2008
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17. Programmable ac power source used to analyse electronic equipment performance in the electrical power system quality concept / Fonte de tensão ca trifásica programável adequada para testes de equipamentos eletrônicos no contexto da qualidade da energia elétrica
Programmable AC Power Source with Low Harmonic Distortion used to analyse equipment performance when the quality of power supply deviates from the ideal standards is, nowadays, quite imperative. In addition to other applications, this allows for the derivation of distinct load sensitivity and supportability limits as far as power quality is concerned. This w
Publicado em: 2007
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18. Regulador de tensÃo com comutaÃÃo eletrÃnica de taps â anÃlise de operaÃÃo e proteÃÃo das chaves estÃticas
The interconnected operation of large electrical systems and the fast spreading of the electrical sector with an increasing presence of sensitive loads to supply voltage disturbances demanded that the current laws to adapt to consumer needs, for example, to ensure the maintenance of constant voltage levels throughout the feeders of the electrical power distr
Publicado em: 2007
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19. Power electronica control in direct water heater of optimized half cycles. / Controle eletrônico de potência em aquecedores elétricos de passagem por semi ciclos otimizados.
Modern electrical direct water heating (DWH) equipments use electrical resistances built with metal alloys (iron-chrome-aluminum or nickel-chrome) as heating elements. Water temperature control is usually made with water flow control, as well as with resistance tap changing. The simplicity of this approach conflicts with to the lack of flexibility to allow s
Publicado em: 2006
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20. Sistema multicanal de geração e recepção de ondas ultra-sonicas para transdutor matricial linear / Multichannel system for generation and detection of ultrasonic waves with a linear array transducer
Ultrasound in medicine has gone through great evolution in the last few decades and has occupied important position as a tool for therapy and diagnosis. This is due to the ultrasound equipment be of relatively low-cost, ultrasound is a non-ionizing radiation, is a non-invasive imaging method, and the images are created and seen in real time. It is common the
Publicado em: 2006
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21. Development and application of shunt active filters for three-phase four-wire systems / Estudo e aplicação de filtros ativos paralelos para sistemas trifasicos com quatro fios
Electricity power quality has gained increased importance in the past few years. The growing number of power electronicsbased loads has created a preoccupation about harrnonic distortion in electric systems. Electricity power quality is an important issue both for energy utilities and consumers. Harrnonic poIlution may cause severe problems to electricity ut
Publicado em: 2005
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22. Metodologia para avaliação da interferencia eletromagnetica em equipamentos eletromedicos de apoio a procedimentos cirurgicos
The Electromagnetic Interference (EMI) has been appointed as one of the causes of equipment malfunction and hazards occurred in electrosurgical procedures. The identification of source-victim relationships and parameter quantification of these interferences consists in a very important methodology to minimize its undesirable effects. This work focus on the c
Publicado em: 1999
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23. Monitor to characterise electrical noise in alternate current network. / Monitor para caracterização de ruídos em redes de corrente alternada.
Power line disturbances can adversely affect electronic sensitive equipment, particularly microcomputer based systems. In order to register these disturbances a power line monitor has been developed. The developed instrument is microprocessor based using a 80C86-2 as the main CPU. The following electrical disturbances can be monitored: nominal frequency devi
Publicado em: 1992