Artigos científicos, teses e dissertações
Publicados nas melhores instituições de ensino

The knowledge of physical and microphysical properties associated to cloud-ground lightning occurrence is very important for determination of potential forecast parameters of electrical discharges activity. The identification of these parameters could give valuable contribution f...

This work depicts transmission line modeling for lightning strike time domain simulation. It is studied and presented the main mechanisms associated to lightning formation and striking high-voltage transmission lines and wave propagation theory concerned to the hit point. Followi...

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 again...

The occurrence of lightning discharges causes a significant amount of unscheduled supply interruptions in overhead lines of electricity systems, contributing to decrease quality indicators of these systems, even in the case of regions with moderated ground flash density. Focusing...

This work presents a study of geographic influences on the lightning characteristics in Minas Gerais, in the Southeastern Brazil, within an area delimited by 18° to 21° S and 43° to 47° W. The period of study was eight years, from October 1988 to November 1996. The lightning and ...

Electrical fields and current can permeabilize bacterial membranes, allowing for the penetration of naked DNA. Given that the environment is subjected to regular thunderstorms and lightning discharges that induce enormous electrical perturbations, the possibility of natural elect...

This work uses radar images together with data of electrical discharges derived from a lightning localization system taken with a Doppler Meteorological Radar as the input to a Neural Network (NN), in order to stablish the non-linear relationship between the reflectivity in the r...

This work uses radar images together with data of electrical discharges derived from a lightning localization system taken with a Doppler Meteorological Radar as the input to a Neural Network (NN), in order to stablish the non-linear relationship between the reflectivity in the r...

For the first time in Brazil, an electric field antenna for lightning radiation, with 1.25 µs resolution was developed. From thunderstorms over Sao José dos Campos, between February and March of 2003, information of lightning synchronized to GPS time, were simultaneously obtained...

For the first time in Brazil, an electric field antenna for lightning radiation, with 1.25 µs resolution was developed. From thunderstorms over Sao José dos Campos, between February and March of 2003, information of lightning synchronized to GPS time, were simultaneously obtained...

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 ...

The harmful lightning effects on the mankind have motivated several investigations on lightning characteristics in the world and, particularly, in Brazil. Many studies on the geographic, seasonal, topographic and demographic features of lightning have been done using lightning lo...

The characteristics of cloud-to-ground flashes in the southeastern region of Brazil were analyzes for the days of high activity from 1992 to 1994. the data were obtained by a Lightning Positioning and Tracking System (LPATS). The following characteristics of about 450,000 strokes...

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 specifi...

Neste estudo foram analisadas a atividade e as características dos relâmpagos nas regiões de Rondônia e sudeste do Brasil no período de outubro/1999 a março/2000. Os dados de relâmpagos nuvem-solo em Rondônia foram obtidos pelo sistema ‘Brazil Lightning Detection Network (BLDN), ...

The effect of an elevated strike object on the measured current in the top and the bottom of Morro do Cachimbo (MCS) station instrumented tower is modeled, considering a current divisor applied at the tower top, and that the channel current is supplied by the current source locat...

Dados de descargas nuvem-solo (pico de corrente para ambas polaridades e percentual de raios positivos) e a razão entre as descargas intra-nuvens e os raios (IN/NS) foram estudados para o período de 01 de Agosto de 2002 a 12 de fevereiro de 2003 e 01 de Agosto a 25 de Dezembro de...

Dados de descargas nuvem-solo (pico de corrente para ambas polaridades e percentual de raios positivos) e a razão entre as descargas intra-nuvens e os raios (IN/NS) foram estudados para o período de 01 de Agosto de 2002 a 12 de fevereiro de 2003 e 01 de Agosto a 25 de Dezembro de...

Dados de descargas nuvem-solo (pico de corrente para ambas polaridades e percentual de raios positivos) e a razão entre as descargas intra-nuvens e os raios (IN/NS) foram estudados para o período de 01 de Agosto de 2002 a 12 de fevereiro de 2003 e 01 de Agosto a 25 de Dezembro de...

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 anál...

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 str...