Electric Breakdown
Mostrando 1-12 de 23 artigos, teses e dissertações.
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1. A Finite-Difference Time-Domain Formulation for Modeling Air Ionization Breakdown Streamers
Abstract A numerical model based on the finite-difference time-domain (FDTD) method is developed for calculating discharge currents and fields produced due air ionization between two electrodes. Electric conductivity σ of the ionized channel between two electrodes is calculated using non-linear equations, i.e., σ is obtained using functions of time. The fu
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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2. Lightning Protection Design for Small Riverboats Using the FDTD Method
Abstract The Amazon region has high lightning occurrence rates, with many lightning hot spots. Different rivers cross the Amazon rainforests and the people that live there use these rivers as roads to go from one place to another. Every year, lightning deaths are reported in the Brazilian Amazon region. In 2018, a lightning discharge struck a small riverboat
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-06
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3. Contrastive Research on Electrical Contact Performance for Contact Materials of Cu-SnO2 and Cu-ZnO2 Alloys
Herein, SnO2- and ZnO2-doped (1.5 wt.%) composite Cu powder was prepared by mechanical alloying (MA) respectively, and both the contact materials of oxide-doped Cu alloys were subsequently obtained by canned hot-pressing powder sintering with hot extrusion combined. Scanning electron microscopy (SEM), laser scanning confocal microscopy (LSCM) and self-design
Mat. Res.. Publicado em: 25/04/2019
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4. Influência da estrutura da vegetação de um fragmento florestal nas características físicas e químicas da água e no funcionamento do ecossistema de um córrego rural
Riparian ecosystems are being rapidly degraded due to deforestation for conversion of natural areas to agriculture, pasture, and urban development. In rural areas, riparian forest remnants can be very important for biodiversity conservation and for the maintenance and improvement of water physical and chemical characteristics as the deforested stream passes
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 18/05/2012
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5. Desenvolvimento de uma metodologia robusta e eficiente para fluxo de carga da continuação otimo multiobjetivo / Development of a robust and efficient methodology for the multiobjective optimal continuation load flow
O objetivo deste trabalho de pesquisa é desenvolver uma metodologia robusta e eficiente para o fluxo de carga da continuação ótimo multiobjetivo. O fluxo de carga da continuação se presta à obtenção de um contínuo de pontos de operação da rede para carga e geração variáveis e a determinação do máximo carregamento do sistema. A associação
Publicado em: 2010
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6. Privatization and organization breakdown of the workforce / Privatização, desestruturação organizacional e da força de trabalho: o caso de uma empresa de energia
Este trabalho tem como objetivo caracterizar o processo de privatização, como parte do projeto da reestruturação produtiva e de reforma do Estado, no contexto da crise do setor energético brasileiro nos anos 90. Para isto, é tomado, como caso exemplar, uma empresa do setor elétrico, para investigação das implicações ocorridas para a organização
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 06/05/2008
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7. Caracterización eléctrica de películas delgadas de Al2O3 depositadas sobre GaAs por la técnica de rocío pirolítico
Electrical characteristics of thin films of aluminum oxide prepared by spray pyrolysis were studied. The films were prepared from solution onto single crystal GaAs (100) substrates at temperatures from 300°C to 600°C. The electrical characteristics of these films as a function of the substrate temperature were determined from the capacitance and current ve
Matéria (Rio de Janeiro). Publicado em: 2008-03
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8. Anomalous effects of two gap superconductivity in MgB2
In this paper a brief overview of anomalous behavior resulting from the two-gap superconductivity in MgB2 is given. We focus on two characteristic effects: an anomalous enhancement of the upper critical field by nonmagnetic impurities and nonequilibrium interband phase textures which appear as a result of interband breakdown caused by electric field. Both ef
Brazilian Journal of Physics. Publicado em: 2003-12
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9. Desenvolvimento e avaliaÃÃo de um escudo polimÃrico para minimizar a quebra de isoladores de vidro por vandalismo em linhas de transmissÃo
Electrical insulators are largely employed in the hot lines to isolate the electricity conductors from the earth and suppor them at the towers. Nowadays, there are several kinds of isolatores for such application. Particularly, the glass insulators are largely employed in Brazil, and it is known to have a long useful life, able to reach more than 40 years. F
Publicado em: 2003
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10. Técnica do Pulso Eletroacústico para medidas de Perfis de Carga Espacial em Dielétricos / Electro-acoustic Pulse to Measure Space Charge Profile in Dielectric Materials
It is described the implementation of the electroacustic pulse technique, PEA, for the determination of space charge profiles in dielectrics. The method is based on the acoustic signal generated by the application of a voltage pulse with short duration on the sample. The acoustic signal generated by pulse is detected by using a piezoelectric transducer coupl
Publicado em: 1999
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11. Studies in films of Poly(terephtalate of ethylene) re-covered with conducting Polyaniline. / Estudos em filmes de Poli (tereftalato de etileno) recoberto com polianilina condutora.
Composites with conductive properties have been proposed as materiais in which different physical properties of polymers are combined. In this work a composite consisting of surface layers of polyaniline, PANI, deposited on films of poly(ethylene terephtalate), PET, were prepared. In order to deposit the PANI the PET film were immersed in the solution in whi
Publicado em: 1998
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12. Efeitos do atordoamento eletrico, da estimulação eletrica e da desossa a quente na qualidade da carne do peito (Musculo Pectoralis major) de frango
The objective of this study was to investigate the effect s of the electrical stunning, stimulation and hot deboning on the quality of broiler breast meat. In the first stage the effect of electrical stunning on the quality of broiler breast meat using 20, 40, 80 and 100V at 60Hz and also high frequencies such as 200, 350, 500 and 1000Hz, as determined. The
Publicado em: 1995