Voltage Regulation
Mostrando 25-36 de 352 artigos, teses e dissertações.
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25. Projeto de um retificador trifásico regenerativo com elevado fator de potência e controle em coordenadas dq0 implementado no DSP TMS320F2812
This work presents the design of a regenerative three-phase switching rectifier with high power factor and control in dq0 coordinates implemented on DSP TMS320F2812 of Texas InstrumentsTM. The controls have used the Clark and Park transformations and the bilinear equation of Tustin, so that the design of the digitals controllers, carried through on the frequ
Publicado em: 2006
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26. CONTROLE DE ACELERAÇÃO DE UMA MÁQUINA DE VIBRAÇÃO ELETRODINÂMICA / ACCELERATION CONTROL OF AN ELECTRODYNAMIC VIBRATION MACHINE
This work presents the development of a novel digital acceleration controller for sinusoidal vibration tests using switching-mode AC power source (ACPS) fed electrodynamic vibration machines. The proposed scheme is based on the interaction of two control loops: one for the shaker s acceleration regulation and another for the ACPS output voltage control. A ro
Publicado em: 2005
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27. Design, development and implementation of a solid-state pulse modulator for high-power pulse transmitters / Projeto, desenvolvimento e construção de um modulador de pulso estado-solido para transmissores pulsados de alta potencia
This work describes the development of a modular line-type solid-state pulse modulator topology to be applied in magnetron pulsed power radar transmitters, commonly found on tracking, weather and air traffic management radars. This research includes the design, development and assembling of a pulsed modulator for the Barreira do Inferno Launching Center (CLB
Publicado em: 2005
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28. Gender differences in vascular expression of endothelin and ET A/ET B receptors, but not in calcium handling mechanisms, in deoxycorticosterone acetate-salt hypertension
We determined if the increased vascular responsiveness to endothelin-1 (ET-1) observed in male, but not in female, DOCA-salt rats is associated with differential vascular mRNA expression of ET-1 and/or ET A/ET B receptors or with functional differences in Ca2+ handling mechanisms by vascular myocytes. Uninephrectomized male and female Wistar rats received DO
Brazilian Journal of Medical and Biological Research. Publicado em: 2002-09
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29. Sintese e aplicações de indutancias negativas
This doctorate dissertation presents methods for emulating negative inductance, as well as their applications and stability analysis. Such non-natural behavior is analyzed based on mathematical modeling, circuit simulations and experimental results. Previously presented synthesis methods, the VAPAR and the BVI are described, and a new strategy, called SDR is
Publicado em: 2002
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30. Convergent regulation of skeletal muscle Ca2+ channels by dystrophin, the actin cytoskeleton, and cAMP-dependent protein kinase
The skeletal muscle L-type Ca2+ channel (CaV1.1), which is responsible for initiating muscle contraction, is regulated by phosphorylation by cAMP-dependent protein kinase (PKA) in a voltage-dependent manner that requires direct physical association between the channel and the kinase mediated through A-kinase anchoring proteins (AKAPs). The role of the actin
National Academy of Sciences.
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31. Enhancement of calcium current during digitalis inotrophy in mammalian heart: positive feed-back regulation by intracellular calcium?
1. Effects of digitalis compounds on slow inward Ca current Isi) and contractile force were examined in ferret ventricular muscle (single sucrose-gap voltage clamp) and calf Purkinje fibres (two micro-electrode voltage clamp).
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32. Ultrasteep voltage dependence in a membrane channel.
A mechanism for regulating voltage-gated channels is presented. The treatment amplifies the effect of the applied membrane potential resulting in a dramatic increase in the channel's voltage dependence. Addition of a large polyvalent anion to the medium bathing a phospholipid bilayer containing the voltage-dependent channel from the mitochondrial outer membr
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33. Two types of anion channel currents in guard cells with distinct voltage regulation
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34. A voltage-gated ion channel expressed specifically in spermatozoa
Calcium ions play a primary role in the regulation of sperm cell behavior. We report finding a voltage-gated ion channel (CatSper2) that is expressed in male germ cells but not in other cells. The putative channel contains 6 transmembrane segments, making it more similar to the voltage-gated potassium channels, but the ion selectivity pore domain sequence re
The National Academy of Sciences.
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35. Differential beta-adrenergic regulation and phenotypic modulation of voltage-gated calcium currents in rat aortic myocytes.
1. We studied the beta-adrenergic regulation of voltage-gated Ca2+ channel currents using the whole-cell patch-clamp technique (18-22 degrees C) in freshly isolated and in cultured (1-20 days) rat aortic vascular smooth muscle cells (VSMCs). These currents include a transient low-voltage-activated (LVA) current and two L-type-related high-voltage-activated c
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36. Voltage-dependent gating characteristics of the K+ channel KAT1 depend on the N and C termini
We studied how the C and N termini of the plant K+ channel KAT1 influence the voltage-dependent gating behavior by generating C- and N-terminal deletion mutants. Functional expression was observed only when C-terminal deletions were downstream of the putative cyclic nucleotide binding site. Treatments of oocytes expressing KAT1 channels with anticytoskeletal
The National Academy of Sciences of the USA.