Electric Phenomena
Mostrando 1-12 de 53 artigos, teses e dissertações.
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1. Simulation of Current Pulses and Sound Waves Resulting from Partial Discharges in a Needle-Plane Geometry in Air
Abstract Partial discharges can occur in different types of electric equipment and cause progressive insulation deterioration, so there is interest in monitoring partial discharges for assessing the state of the isolation of an electric system and to predict failures. Techniques to detect partial discharges, such as detecting ultrasonic emission, have been p
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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2. Two methods for solving electrostatic problems with azimuthal symmetry
Abstract The study of electrostatic phenomena is the gateway to the physics described by Classical Electrodynamics. In this paper, we discuss in detail two methods based on the Uniqueness Theorem for solving electrostatic problems with azimuthal symmetry. The first one is the electrostatic potential extension from the axis of symmetry to an arbitrary point.
Rev. Bras. Ensino Fís.. Publicado em: 14/11/2019
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3. Effects of the Photovoltaic Distributed Generation on Electricity Distribution System Voltage - Updated Review
ABSTRACT Concerns about the environment and a growing demand for electricity have led to the intensive search for renewable energy sources. Photovoltaic solar energy, in the form of distributed generation, has shown a very high growth rate to an extent that in some regions it will be adopted on a large scale, thus being responsible for the supply of a signif
Braz. arch. biol. technol.. Publicado em: 22/10/2018
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4. Exposure to 50 Hz electromagnetic field changes the efficiency of the scorpion alpha toxin
AbstractBackground Extremely low-frequency (50 Hz) electromagnetic field (ELF-EMF) is produced by electric power transmission lines and electronic devices of everyday use. Some phenomena are proposed as “first effects” of ELF-EMF: the discrete changes in the membrane potential and the increase of the calcium channel activity as well as the intracellular
J. Venom. Anim. Toxins incl. Trop. Dis. Publicado em: 20/10/2015
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5. Desenvolvimento de um método para levantamento de tecnologias de materiais empregados no trem de força automotivo (powertrain) a partir de patentes / Devolopment of a patent based method for surveying materials technologies used in automotive powertrain
This research approaches the study from patents of technologies for materials used in power train of motor vehicles, to provide additional information in order to support decision making in this universe, especially in the selection of materials and their processing. The powertrain is currently the most important subsystem in a car, being appointed as chief
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 27/05/2012
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6. Estudo das propriedades elétricas de células eletroquímicas emissoras de luz de derivados de polifluoreno / Electric properties study of polymer light-emitting electrochemical cells based on polyfluorene derivatives
Polymer light emitting electrochemical cells, PLECs, are organic electronic devices that have attracted commercial interest because they operate at low voltage and exhibit high performance without the need of specific electrodes such as indium tin oxide (ITO), calcium and others. This feature provides low cost of fabrication and exible devices. The charge in
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 30/11/2011
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7. Influência das variabilidades solar, geomagnética e atmosférica na modulação da intensidade de raios cósmicos / Influence of solar, geomagnetic and atmospheric activities in cosmic ray intensity modulation
Cosmic ray is influenced by solar, geomagnetic and atmospheric phenomena. In this Thesis are presented studies with the cosmic ray data regarded by the CARPET detector, which is installed in the Argentinean Andes, between 2006 and 2008. The variations in the cosmic ray count rate related to rain, temperature, atmospheric pressure and atmospheric electric fie
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 27/05/2011
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8. Desenvolvimento e implementação de um sistema de monitoramento em tempo real da tensão da rede com acesso remoto
Some years ago in Brazil the power quality was related, basically, with interruption of supplied energy and certain special loads of industry. In recent years, however, under controls of the regulating agency ANEEL (Agência Nacional de Energia Elétrica) and with specialists, the power quality area received the due attention and was legislated and acquired
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 05/10/2009
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9. Sistemas eletrônicos em duas dimensões : desordem e resposta dinâmica
In disordered systems the pinning strength on the carriers due to impurities or defects is one of the most important mechanisms that produce insulator behavior. A transition to a metal phase should occur if a driving field is applied to the system. In the last three decades, such transition in two-dimensional systems has attracted much attention in light of
Publicado em: 2009
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10. Fenómenos de relajación interfacial en compuestos epoxi/aluminio
Interfacial dielectric relaxation has been studying in composite materials made with epoxy resin and aluminum. Electric modulus, which has been proposed for the description of systems with relaxation process, presents advantages in comparison to the classic approach of the real and imaginary part of dielectric permittivity. In composite polymer materials, re
Matéria (Rio de Janeiro). Publicado em: 2008-06
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11. Caracterização eletroquímica de colóides magnéticos visando a aplicações nanotecnológicas nanobiotecnológicas
Electric Double Layered Magnetic Fluids (EDL-MF) are stable colloidal dispersions of spinel ferrite type nanoparticles in water medium. The thermodynamic stability is achieved by balancing the van der Waals and magnetic dipolar attractions with the introduction of repulsive electrostatic interactions between particles in order to avoid the agglomeration phen
Publicado em: 2008
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12. Desenvolvimento, caracterizaÃÃo e estudo de permeaÃÃo cutÃnea de diclofenaco de dietilamÃnio em sistemas tÃpicos nanoemulsionados
The nanoemulsions (NE) are transparent, isotropic and thermodynamically stable systems, formed spontaneously under a specific set of experimental conditions from mixtures of water and oil phases stabilized by a surfactant or a mixture of surfactant and cosufactant. Because of their properties, especially the ability to carry lipophilic and hydrophilic drugs
Publicado em: 2008