Dielectric Breakdown
Mostrando 1-12 de 12 artigos, teses e dissertações.
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1. 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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2. Blindagem balÃstica de compÃsito polimÃrico contra o vandalismo e proteÃÃo UV para cadeias de isoladores de vidro em linhas de transmissÃo
The aim of this study was to induce the UV absorption of soda-lime silica glasses by gamma irradiation, as well as to select and evaluate the mechanical and electrical properties and also the microstructure of the polycarbonate (PC), with and without heat treatment, and the glass fiber reinforced epoxy composite, to make a prototype for transmission lines co
Publicado em: 2008
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3. CARACTERIZAÇÃO DE ATUADORES BASEADOS EM MÚSCULOS ARTIFICIAIS POLIMÉRICOS POR EFEITO CAPACITIVO / CHARACTERIZATION OF ACTUATORS BASED ON POLYMERIC ARTIFICIAL MUSCLES WITH CAPACITIVE EFFECT
It is well known the needs of finding new technologies for robotic systems actuations, with the same efficiency of the natural muscles. The common actuators have better agility and force when compared to natural muscles, but the dimensions and weight are bigger and for that the demand of energy necessary for the actuation is higher. Smaller and cheaper robot
Publicado em: 2007
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4. Estudo de camadas dielétricas para aplicação em capacitores MOS. / Study of dielectric layers for MOS capacitors.
Silicon oxynitride films obtained by the PECVD technique from N2O+SiH4+He gaseous mixtures, at 320°C, with different deposition pressure and RF power were studied intending to improve the interface quality with Si, decreasing the effective charge density and the interface state density in order to utilize them in MOS semiconductor devices. The results showe
Publicado em: 2007
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5. Fabricação e caracterização de óxidos de porta MOS ultrafinos crescidos sobre superfícies planas e com degraus empregando processos convencional e pirogênico. / Fabrication and characterization of ultrathin MOS gate oxides grown onto flat and stepped surfaces using conventional and pirogenic processes.
Neste trabalho, investigou-se capacitores MOS fabricados sobre superfícies irregulares contendo formas retangulares periódicas com 100 nm de altura, obtidas a partir de corrosão por plasma localizadas. Os óxidos de porta com 4,5 nm de espessura foram crescidos em ambientes ultrapuros de O2 ou pirogênico a fim de comparar a uniformidade de cobertura sobr
Publicado em: 2006
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6. Effect of air-oxygen and argon-oxygen mixtures on dielectric barrier discharge decomposition of toluene
One alternative application in the decomposition and destruction of volatile organic compounds (VOCs) by a silent plasma dielectric barrier discharge (DBD) has been successfully accomplished. For this purpose, we have designed and constructed two pairs of cells, of rectangular and circular geometries, 333.96 cm³ each cell, and a similar second pair of 62.25
Brazilian Journal of Physics. Publicado em: 2004-12
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7. Current distribution in fused electrical networks
Electrical networks provide a natural model to study transport processes such us dielectric breakdown and metal insulator transition in disordered inhomogeneous conductors. We present a calculation for current distribution on an infinite hyper-cubic network due to an external applied current. This is used to compute, analytically, the redistribution of curre
Brazilian Journal of Physics. Publicado em: 2003-06
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8. 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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9. 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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10. Flutuações de composição em um elastomero dieletrico processado por extrusão
Dielectric polymer materials, such as the elastomers based on poly(ethylene/propylene/1,4-hexadiene), also called EPDM or ethylene-propylene rubbers, are normally used for the electric insulation of hiqh voltage cables. The dielectric strength of these materiaIs is one of the most significant properties for the evaluation of their performance, as a function
Publicado em: 1988
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11. Considerações sobre a ruptura dieletrica em gases sob ação de um campo de laser intenso
Gas breakdown, steady-state maintenance and continuous generation of low-temperature plasma and propagation of the plasma fronts are important subjects of past and current research on laser induced gas discharges. This Thesis is concerned with some aspects of the laser induced dielectric breakdown in a gas. We have specifically addressed the question of the
Publicado em: 1985
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12. Theory of electroporation of planar bilayer membranes: predictions of the aqueous area, change in capacitance, and pore-pore separation.
A large increase in the transmembrane voltage, U(t), of a fluid bilayer membrane is believed to result in the occurrence of temporary aqueous pathways ("pores") across the membrane. The number, size, and evolution dynamics of these pores are expected to be crucial to the transport of water-soluble species ranging from small ions to macromolecules such as pro