Navegando por Autor "VERMA, Om Prakash"

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Acesso aberto (Open Access)
Estudo de geração de campo uniforme para modelagem eletromagnética
(1998-03) CHAVES NETO, Antonio Maia de Jesus; VERMA, Om Prakash
In order to study the electromagnetic prospecting problems in geophysics through analog modelling, the full scale conditions are represented in the laboratory at a reduced scale according to the theory of similitude. Therefore, to investigate the problems of VLF, AFMAG and MT techniques, it is necessary to create a uniform field in the experimental set up. The systems studied generating uniform fields are a circular coil, a Helmholtz coil system, a solenoid, a rectangular coil, a plane of currents and a two parallel planes of currents. The percentage deviation maps were presented for all the systems studied here. A comparative study of these systems shows that the solenoid is the most efficient way to create an uniform field followed by a Helmholtz coil system. Nevertheless, the field created within a solenoid is a closed space where it is difficult to place models in order to carry out the experiments. Therefore, it is recommended the use of a Helmholtz coil system because it provides sufficient open space on an uniform field that facilitates the experiments.
Acesso aberto (Open Access)
Resistividade e polarização induzida (IP): modelagem analógica
(2006-03) GALLAS, José Domingos Faraco; VERMA, Om Prakash
The aim of this study is to develop an analogical modeling methodology for IP and resistivity. Simple geometrical cylindrical and tabular shapes were built using standard cement, quartzitic sand and graphite. The experiment was carried out with various amounts of graphite in order to measure the IP response for different model geometries. The results are discussed in terms of IP response as a function of geometry, graphite content, depth and strike of the models.