Universidade Federal do Pará
Quarta-feira, 30 de Setembro de 2020

Sugestões/Comentários

Quem está Online?

Nós temos 51 visitantes online

Quantos Viram Isto?

Visualizações de Conteúdo : 388240

Home Produções Científicas Produções Científicas-70

ALVAREZ, Román; PAIVA, José Airton C. de. Dielectric relaxations of coal and conductive impurities. Journal of Geophysical Research, v. 84, n. B3, p. 3049-3056. 1979.

RESUMO

Bituminous coal mixed withpyrite and water impurities yields dielectric relaxations of the Davidson-cole type. Measurements were made on mixtures ranging from 100% coal to 50% coal-50% pyrite in the frequency range of  30 Hz to 100 Hz. Wet samples consisted of one of the above mixtures (20 g) plus 1g of water. Mixtures with water and 40-50%pyrite suggest relaxations of the Debye type. Interconnections between pyrite grains dispersed on coal give rise to conducting needles which are in part responsible for the observed dispersions. The mixtures analyzed herein varied in a dc conductivity range of 6 decades, from 10-11 to 10-5 (ohm m)-1, suggesting that various types of coal combined with small amounts of impurities can yield the full, 1-2-decade range of conductivity variation determined for coal elsewhere.

 Texto Completo

 
Banner
Banner
Banner
Banner
Banner
Banner
Banner
Banner
Banner
Qual a sua avaliação para o CEMIG?
 
© 2012 - Instituto de Geociências - Universidade Federal do Pará
Centro de Memórias do Instituto de Geociências
Tel: (91) 3201-7476 • E-mail: cemig@ufpa.br