Harmonics
Mostrando 25-36 de 106 artigos, teses e dissertações.
-
25. Comparação técnico-econômica entre equipamentos mitigadores de harmônicos e compensadores de energia reativa
Equipamentos mitigadores de harmônicos e compensadores de energia reativa têm sido bastante discutidos e aplicados nos últimos anos com sucesso nas mais variadas instalações comerciais e industriais, fomentados pela eliminação da tarifação por baixo fator de potência e por problemas advindos do aumento significativo de cargas não lineares conectad
Publicado em: 2010
-
26. Aplicação do modelo QUAL2Kw para avaliação da capacidade de assimilação de cargas pontuais no Rio Itapanhaú. / Application of the model QUAL2Kw for assessment of point sources at Itapanhaú River.
The presence of point sources in rivers and streams implicates in downstream impacts that can commit their respective future uses. For this reason, the mathematical modeling comes as a fundamental tool in the evaluation of those discharges in sense to evaluate legal service and to subsidize the licensing of activities to the competent organs. The main object
Publicado em: 2010
-
27. Effects of dust charge variation on electrostatic waves in dusty plasmas with temperature anisotropy
We utilize a kinetic approach to the problem of wave propagation in dusty plasmas, taking into account the variation of the charge of the dust particles due to inelastic collisions with electrons and ions. The components of the dielectric tensor are written in terms of a finite and an infinite series, containing all effects of harmonics and Larmor radius. Th
Brazilian Journal of Physics. Publicado em: 2009-03
-
28. Interferência de harmônicas em equipamentos de medição de energia elétrica. / Harmonic interference in equipment for measurement of eletrical energy.
This work addresses the reliability of energy meters in nonsinusoidal systems, looking for the increase of quality in the electric energy billing. To that purpose, it focuses on a fairer metering and a better relationship between the concessionaire and consumer. The tests were carried through in the laboratories of Eletropaulo, of the Electro-Technology and
Publicado em: 2009
-
29. Estudo comparativo de técnicas de cascateamento de superfícies seletivas em frequência
Este trabalho apresenta uma análise teórica e numérica do cascateamento de superfícies seletivas de frequência, que usa patches retangulares e fractais de Koch triangular como elementos. Para isto, são utilizadas duas técnicas de cascateamento, visando à determinação das características de transmissão e de reflexão. Superfícies seletivas de fre
Publicado em: 2009
-
30. Variability analysis of the monthly average minimum and maximum temperature in Rio Grande do Sul / Análise do comportamento das temperaturas máxima e mínima médias mensais para o estado do Rio Grande do Sul
A study has been done on the minimum and maximum temperature monthly averages in the State of Rio Grande do Sul, between 1918 and 2007. Data have been used collected in 10 meteorological stations spread all over the State territory. In a first stage, it has been verified a tendency of these variables in the months of February, May, August and November, throu
Publicado em: 2009
-
31. Uma Representação de Weierstrass para Superfícies Mínimas em H3 e H2 × R.
The Weierstrass representation of minimal surfaces in R3 and its generalization to Rn shows is a very useful tool in the study of minimal surfaces in these spaces. In this work we want to describe a type Weierstrass representation for immersions simply connected in the group of Heisenberg H3. Using applications harmonics is possible obtain a formula for gene
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 08/08/2008
-
32. A new formulation for the dielectric tensor for magnetized dusty plasmas with variable charge on the dust particles
A kinetic approach to the problem of wave propagation in dusty plasmas, which takes into account the variation of the charge of the dust particles due to inelastic collisions with electrons and ions, is utilized as a starting point for the development of a new formulation, which writes the components of the dielectric tensor in terms of a finite and an infin
Brazilian Journal of Physics. Publicado em: 2008-09
-
33. Modulation of cosmic rays at different cutoff rigidity
The present work deals with the study of first three harmonics of cosmic ray intensity on geo-magnetically quiet days over the period 1981-1993 for Deep River and Inuvik neutron monitoring stations having mid and low cutoff rigidity. The amplitude of first harmonic remains high for Deep River having mid cutoff rigidity as compared to Inuvik neutron monitor h
Brazilian Journal of Physics. Publicado em: 2008-03
-
34. ESTIMAÇÃO DE HARMÔNICOS/INTER-HARMÔNICOS: UMA ABORDAGEM MULTITAXA
This dissertation discusses parameter estimation of harmonics/inter-harmonics of electrical signals under time-varying conditions. Two new suitable approaches for processing this kind of signals are proposed. The first one is based on phase error of DFT (Discrete Fourier Transform) result, occurring due to the frequency deviation of input signal. This method
Publicado em: 2008
-
35. Geração de sinais de RF por mistura de harmonicas de portadoras opticas moduladas em amplificadores opticos a semicondutor / RF signal generation by mixing harmonics of modulated optical carriers in semiconductor optical amplifiers
The gain-crossed properties of semiconductor optical amplifiers are experimentally investigated here. It was observed that optically feed-backed saturated amplifiers could achieve similar performance as that of cascaded amplifiers, offering up to 10 dB gain to two 8-nm-appart modulated optical carriers. Due to saturation the amplifier gain mechanism is alter
Publicado em: 2008
-
36. Diagnóstico sobre a utilização das lâmpadas fluorescentes compactas (LFC) como promotoras de eficiência energética nos sistemas de iluminação no Brasil / Diagnosis about the use of compact fluorescent lamps (CFL) as promoting energy efficiency in lighting systems in Brazil.
O aumento do consumo no Brasil aparte com problemas de abastecimento de energia elétrica na década de 90, durante um período de más condições hidrológicas causou uma preocupação e instou uma pesquisa sobre as formas de redução do consumo. A qualidade de energia não era uma prioridade, cargas não eram tão sensíveis, nem os processos existentes
Publicado em: 2008