Atmospheric Discharges
Mostrando 1-12 de 25 artigos, teses e dissertações.
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1. Sodium Chloride Crystallization by Electric Discharge in Brine
Electrical discharges in liquids are currently used to synthesize nanoparticles. The plasma-liquid interaction is complex, where parameters such as electric field, ion charges and other species present are important. In order to understand the mechanism of crystallization, mother liquor (saturated solution of NaCl, MgCl2 and KCl) was used to study the effect
Mat. Res.. Publicado em: 06/07/2017
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2. Sistema especialista para seleção otimizada de dispositivos de proteção de transformadores frente às descargas atmosféricas / Expert system for optimized selection of transformer protection devices against atmospheric discharges
O objetivo deste trabalho consiste em apresentar o projeto de um sistema especialista que visa auxiliar nos procedimentos envolvidos com a especificação de pára-raios de óxido de zinco para proteção de transformadores frente às descargas atmosféricas, bem como permitir que a análise do comportamento dos surtos de tensão de origem atmosférica que i
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 03/08/2011
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3. Quasi-neutrality and local thermodynamical equilibrium in atmospheric presure arc discharges
The atmospheric pressure Tungsten Inert Gas (TIG) arc plasma in argon is studied combining results from emission spectroscopy temperature maps with composition data and transport parameters available from literature. Two arc currents are considered and maps are obtained for the Debye number, the number of particle in the Debye sphere, which shows values of t
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2009-09
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4. Contribuições ao estudo comparativo dos efeitos de descargas atmosféricas em sistemas compostos por cabos aéreos e subterrâneos a seco e a óleo
By means of computing simulations, it is presented in this work a comparative study of the effects of electromagnetic transients proceeding from indirect and direct atmospheric discharges in mixed-transmission lines, which consist of aerial and underground parts with oil and dry type isolation. The developed and implemented model in the ATP computing environ
Publicado em: 2009
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5. The impact of urbanization on the distribution of lightning induced voltages on overhead lines / O impacto do aumento da urbanização nos niveis das tensões induzidas por descargas atmosfericas nas proximidades de linhas de transmissão
Some of the worst damage caused by lightning is indirect, that is, it is caused by electromagnetic fields radiated from this kind of natural phenomenon resulting in electromagnetic compatibility problems or in challenges for designers of surge protection systems and shields against these interferences. This work considers one of these indirect effects, induc
Publicado em: 2009
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6. Sensor para medição do campo eletrico / Sensor of field mill measurement
Este trabalho apresenta a elaboração e a construção de um sensor utilizado na detecção de intensidade de campo elétrico e consequentemente de descargas atmosféricas. O sensor de diâmetro igual a 10 cm é constituído por uma placa girante composta por quatro aletas, que tem seu movimento de rotação controlado por um mini motor de 12000 rpm, e uma
Publicado em: 2009
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7. 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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8. Avaliação de custos decorrentes de descargas atmosféricas em sistemas de distribuição de energia / Evaluation of the costs arising from atmospheric discharges in power distribution systems.
As descargas atmosféricas sempre foram tratadas como acontecimentos fortuitos e de força maior, inerentes à vontade do homem. Contudo, mudanças significativas a esse respeito ocorreram recentemente na legislação brasileira, no Código Civil e na norma ABNT NBR 5410: 2004 (Instalações Elétricas de Baixa Tensão). Além disso, em 29 de abril de 2004 f
Publicado em: 2007
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9. Hidrocarbonetos policíclicos aromáticos no meio ambiente: diferenciação de fontes em sedimentos e metabólitos em bile de peixes
Many studies on environmental ecosystems quality related to polycyclic aromatic hydrocarbons (PAH) have been carried out routinely due to their ubiquotus presence worldwide and to their potential toxicity after its biotransformation. PAH may be introduced into the environmet by natural and anthropogenic processes from direct runoff and discharges and indirec
Publicado em: 2007
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10. ESTUDO PARA O DESENVOLVIMENTO DE UM PREVISOR DE DESCARGAS ELÉTRICAS ATMOSFÉRICAS APLICADO À REGIÃO COSTEIRA DO ESTADO DO RIO DE JANEIRO
The atmospheric dynamics evidently is very complex. There are many macro and micron scales processes and meteorological variables involved in the atmospheric physicalphenomena. The storms with electrical discharges are distinguished, among these phenomena, by the damage consequences to the human beings, directly or indirectly. Many researchers have pursued t
Publicado em: 2005
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11. Análise das características dos relâmpagos na região sudeste do Brasil / Lightning characteristics in southeastern Brazil
The first climatological studies of cloud-to-ground (CG) lightning flashes characteristics in Brazil were published at the middle of 90. However, at that time, the lightning detection network used to be composed by only a few sensors, which restricted the analyses to some specific regions. In the beginning of this decade, new studies were published using lig
Publicado em: 2005
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12. 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