Transport Theory
Mostrando 13-24 de 171 artigos, teses e dissertações.
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13. Processamento de sinais de descargas parciais em tempo real com base em wavelets e seleção de coeficientes adaptativa espacialmente
On-line partial discharge (PD) analysis is a highly pursued feature due to the economy related to scheduled shutdowns, disassembling and transport. Nevertheless, on-site PD measurements are frequently limited by interferences found in high-voltage facilities, a situation that imposes the continued development of PD signal processing methods. In the last year
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 04/11/2011
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14. Análise das variáveis de entrada de uma rede neural usando teste de correlação e análise de correlação canônica / Analysis of input variables of an artificial neural network using bivariate correlation and canonical correlation
The monitoring of variables and diagnosis of sensor fault in nuclear power plants or processes industries is very important because an early diagnosis allows the correction of the fault and, like this, do not cause the production interruption, improving operators security and its not provoking economics losses. The objective of this work is, in the whole of
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 21/09/2011
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15. Desenvolvimento de um método espectronodal livre de erros de truncamento espacial para problemas adjuntos de transporte de partículas neutras monoenergéticas na formulação de ordenadas discretas em geometria unidimensional / Development of a spectral nodal method free from spatial truncation error for one-speed neutral particle adjoint transport problems in the discrete ordinater formulations in slab geometry
Um método numérico nodal livre de erros de truncamento espacial é desenvolvido para problemas adjuntos de transporte de partículas neutras monoenergéticas em geometria unidimensional com fonte fixa na formulação de ordenadas discretas (SN). As incógnitas no método são os fluxos angulares adjuntos médios nos nodos e os fluxos angulares adjuntos nas
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 19/09/2011
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16. âAplicaÃÃo da Teoria Fuzzy em um Modelo Bidimensional de Transporte de Massa, para Estudar o Risco Fuzzy em Rios Urbanos, Sujeitos a LanÃamentos de Agentes Poluentesâ. / Application of Fuzzy Theory in Two-Dimensional Mass Transport Model to study the Fuzzy Risk in Urban Rivers, Subject to Release of pollutants
A modelagem matemÃtica tem se tornado uma importante ferramenta para quantificar a qualidade de Ãgua nos mais diversos sistemas hÃdricos. Estas formulaÃÃes se tornaram mais frequentes a partir dos anos 60 com os avanÃos dos mÃtodos numÃricos e dos computadores digitais. Atualmente, como os problemas de qualidade de Ãgua se tornaram mais crÃticos, a
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/07/2011
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17. Estudos em adsorÃÃo de gÃs natural: armazenamento, transporte e purificaÃÃo / Studies of Natural Gas Adsorption: Storage, Transport and Purification
The use of vessels filled with activated carbon to store and transport natural gas (NG) at moderate pressures (about 3.5 MPa) and ambient temperature (about 298 K) has been studied as a potential alternative to compressed natural gas storage at high pressures (ca. 20 MPa). The present study provides an experimental investigation of charge and discharge cycle
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 23/02/2011
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18. Comparison of computed amplitudes of magnetoresistance in spin-valve structures with wafer probe measurements
A code has been developed based on the semi-classical theory of giant magnetoresistance of Camley and Barnas [l]. It computes the sheet conductance and magnetoresistance of spin-valve structures. The input parameters are phenomenological transport parameters (mean-free paths and reflection/transmission coefficients at interfaces). These parameters are fairly
Publicado em: 2011
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19. Simulações de sensores de gás nanoscópicos baseados em nanotubos de carbono: estrutura eletrônica e transporte de elétrons / Computational simulations of nanoscopic gas sensors based on carbon nanotubes: electronic structure and electronic transport
Since their discovery by S. Iijima in 1991, carbon nanotubes have been considered as one of the most promising nanostructured materials for the development of new nanoscopic electronic devices. Due to its high surface area to volume ratio, this material stands out as a candidate for possible gas sensoring applications. In this thesis, we have studied, by mea
Publicado em: 2011
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20. Análise dos fatores determinantes da internacionalização e desempenho financeiro das empresas brasileiras de capital aberto: a contribuição da visão baseada em recursos (RBV)
Brazil has a significant number of enterprises in all business segments such as: car-industry, market share, consumer goods, electric-electronics, energy, construction, digital industry, mining, paper and cellulose, farming, chemistry, petrochemistry, fabric industry, transport and so on. As we know, all of these companies are inserted into the capital marke
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 14/06/2010
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21. Construção do conceito de medição por meio de uma estratégia pedagógica baseada no modelo didático de formulação de perguntas
The didactic laboratory is of addition importance in Physics learning since it contributes to relate theory and practice. However, studies tell that many students demonstrate difficulty in understanding the experimental activities for if they find in the Punctual Paradigm and, therefore, they carry problematic representations to the they come across the acco
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 30/04/2010
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22. The role of nonequilibrium thermo-mechanical statistics in modern technologies and industrial processes: an overview
The nowadays notable development of all the modern technology, fundamental for the progress and well being of world society, imposes a great deal of stress in the realm of basic Physics, more precisely on Thermo-Statistics. We do face situations in electronics and optoelectronics involving physical-chemical systems far-removed-from equilibrium, where ultrafa
Brazilian Journal of Physics. Publicado em: 2010-03
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23. Aspectos eletrônicos e estruturais do grafeno e derivados:: um estudo teórico-experimental
In this work we study the electronic and structural properties of graphene and graphene based materials by means of experimental and theoretical techniques. By means of ab-initio calculations using the Density Funcional Theory (DFT), we study the effect of pressure on graphene multi-layers. We look for an explanation for experimental results on the charge in
Publicado em: 2010
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24. Development of an Acquisition System and Data Analysis for Measurements of Electron Transport Parameters in Gases / Desenvolvimento de sistema de aquisição e tratamento de dados para medidas de parâmetros de transporte de elétrons em gases
This thesis describes a pulsed Townsend experiment whose purpose was to obtain experimentally the transport parameters of electron in gases, particularly nitrogen and isobutane, within a range of reduced electric field between 130 Td and 210 Td. The transport parameters obtained were the average speed of center of mass of the electron cloud, the ionization r
Publicado em: 2010