Results 11 to 20 of about 106 (100)

Influência de dopantes doadores na degradação do varistor à base de SnO2 e o efeito do oxigênio pós-degradação nfluence of donor dopants on the degradation of SnO2 -based varistors and the effect of the oxygen post-degradation

Cerâmica, 2006
A degradação elétrica de varistores à base de SnO2 foi estudada e verificou-se que na temperatura de 220 ºC ocorreu a degradação do material. Suas características foram recuperadas quando tratadas em atmosfera de O2, o que mostra que esta atmosfera é ...
M. M. Oliveira, J. H. G. Rangel, V. C. de Sousa, E. R. Leite, E. Longo, P. R. Bueno, J. A. Varela   +6 more
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Electrical and microstructural properties of microwave sintered SnO2-based varistors Propriedades elétricas e microestruturais de varistores à base de SnO2 sinterizados por microondas

Cerâmica, 2012
An investigation was made of the microstructural and electrical properties of SnO2-based varistors microwave sintered at 1200 ºC, applying a heating rate of 120 ºC/min and treatment times of 10, 20, 30, 40, 50 and 60 min.
P. S. Furtado, M. M. Oliveira, J. S. Vasconcelos, J. H. G. Rangel, E. Longo, V. C de Sousa   +5 more
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A formação e o estágio atual do grupo de materiais cerâmicos (GPMC) da UEPG

Cerâmica, 1999
Dentro da área de materiais, a Universidade Estadual de Ponta Grossa possui um Centro Interdisciplinar de Pesquisas em Materiais, do qual o grupo de materiais cerâmicos faz parte.
S. A. Pianaro, S. R. M. Antunes, A. J. Zara, A. C. Antunes   +3 more
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Desenvolvimento de varistores à base de SnO2 para aplicação em redes de alta tensão Development of SnO2-based varistors for high voltage application

Cerâmica, 2006
Varistores à base de SnO2 foram preparados pelo processo convencional de mistura de óxidos. As amostras foram sinterizadas a 1250 °C por 2 h. Os difratogramas obtidos por difração de raios X e as análises por microscopia eletrônica de varredura ...
M. M. Oliveira, J. H. G. Rangel, V. C. de Sousa, E. R. Leite, E. Longo, P. R. Bueno, J. A. Varela   +6 more
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Control of Varistor Voltage by Grain-size Control of Bi-added ZnO Varistors

IOP Conference Series: Materials Science and Engineering, 2011
Relationship between the grain size of ZnO and the amounts of Bi and Sb for Bi-Ba-Sb-Co-Mn-added ZnO was investigated. The amount of Bi at which the grain size of ZnO became the maximum shifted to the notably larger one by adding small amount of Sb such as 0.01 mol%.
Fukumori, Ai, Kubota, Atsuko, Sato, Yuuki, Yoshikado, Shinzo   +3 more
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Control microestructural en varistores cerámicos basados en el sistema ZnO-Bi₂O₃-Sb₂O₃ dopados con TiO₂

Boletín de la Sociedad Española de Cerámica y Vidrio, 2012
Typically Titanium oxide is added to the formulation of Bi2O3-doped ZnO based varistors to enhance the growth of ZnO grains, thus allowing their application in low voltage devices. However its incorporation to formulation based on the ZnOBi2O3-Sb2O3 (ZBS
Fernández-Hevia, D., Reyes, Y., Gallego, B., Cruz, A. M., Peiteado, M.   +4 more
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Estudio comparativo de dos métodos de síntesis para la obtención de polvos cerámicos de ZnO - Pr₂O₃ - CoO

Boletín de la Sociedad Española de Cerámica y Vidrio, 2004
Zinc oxide containing rare earth metal and Cobalt oxide are utilized as raw material to make varistors. Some of systems were found to exhibit non-ohmic current-voltaje characteristics and they are applicable not only for low voltaje devices but also for ...
Rodríguez-Páez, J. E., Caballero, A. C., Villegas, M., Cruz, A. M., Ávila, H.   +4 more
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Estudio de la región rica en Bi₂O₃ en el sistema binario ZnO-Bi₂O₃

Boletín de la Sociedad Española de Cerámica y Vidrio, 2004
Ceramic materials based in the ZnO- Bi2O3 system have their principal application as varistors. The binary system ZnO-Bi2O3 is specially relevant to the formation of the microstructure responsable of the varistor behaviour.
Caballero, A. C., Fernández, J. F., Peiteado, M., de la Rubia, M. A.   +3 more
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The mathematics of varistors

European Journal of Applied Mathematics, 2016
A three-dimensional model of the varistor device is proposed. The thermal and electric conductivity of the material are taken to depend, in addition to the electric potential, on the temperature. Two theorems of existence and uniqueness of solutions for the boundary-value problem which determine the potential and the temperature inside the device are ...
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Thermodynamic study of the rich-Bi₂O₃ region of the Bi₂O₃-ZnO system

Boletín de la Sociedad Española de Cerámica y Vidrio, 2006
Precise knowledge of the Bi2O3-ZnO system is fundamental to control the functional microstructure of ZnO-based varistors. Also the potential applications of materials based on ZnO and Bi2O3 as dielectric materials in the high frequency range have renewed
de la Rubia, M. A., Serena, S., Serena, S., Serena, S., Caballero, A. C., Caballero, A., de la Rubia, M. A., Caballero, A. C., de la Rubia, M. A., Caballero, A. C., Caballero, A., Caballero, A.   +11 more
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