Elementos de manutenção de transformadores de potência

The intended purpose of this paper is to present the main commissioning tests for power transformers and the most used techniques in industrial segment, it is also discussed your results and consequences in the equipment’s normal operation. Also in this text, it is given specific information concerning a maintenance plan compatible to power transformers, with elements of preventive and predictive maintenance, exposing essential components, tests and the regulations current, showing how analyze and interpreted the results from this maintenance resources. Also in this paper is submitted the economic impact of damage to transformers and how the correct maintenance method can minimize them. The objective of this text is demonstrate the importance of the equipment and the benefits of proper maintenance, much of in financial terms as in electric system reliability

Planejamento de reativos em sistemas elétricos de potência multi-área através de modelos estocásticos

Pós-graduação em Engenharia Elétrica - FEIS

Efeitos biológicos do laser de baixa potência sobre o cultivo de células-tronco mesenquimais provenientes do tecido adiposo e da medula óssea de cães

Pós-graduação em Medicina Veterinária - FMVZ

De uma cultura política à Teologia da Liberação: as cartas do cárcere de Frei Betto e a ditadura civil-militar no Brasil

Pós-graduação em História - FCLAS

A lei e a força no regime militar brasileiro: da proscrição da frente ampla à edição do Ato Institucional n. 5

This article analyses the Brazilian political process in the period between the beginning of the government of general Arthur da Costa e Silva in March 15, 1967 and the edition of the Institutional Act No. 5 (December 13, 1968). Through the analysis of the key moments in this context, seeks to qualify the actions of the main political players in terms of their goals and strategies and assess the impact that they had on the production of authoritarian legislation.

Vozes de trabalhadores na ditadura civil-militar: ensaios sobre literatura, memória e testemunho

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A vigilância sem farda: a espionagem interna na ditadura civil militar através do DEOPS

Pós-graduação em História - FCHS

A potência do cyborg no agenciamento de modos de subjetivação pós-identitários: conexões parciais entre arte, psicologia e gênero

In line with a psychology more attached to the becoming [devenir] rather than tothe essence, the goal of this paper is to ground the importance of understandingsubjectivity as a process, mainly when regarding our current discussions aboutidentity and gender. After that, we do some linkage between art and psychology. Forus, art is understood as a powerfulmanner to encourage modes of subjectivation thathave difference as an inherited relation. Lastly, we draw our attention upon somefragments of the contemporaneous artist, Mathew Barney's work-of-art (specially,Cremaster), to see how it runs through the binaries of gender boundaries andlaunches post-identity lines of subjectivation.

Estudo do ultrassom de potência no pré-tratamento do material lignocelulósico de resíduos da bananeira

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Determinação das melhores condições de hidrólise física com ultrassom de potência em resíduos de amendoim

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Resposta de fibroblastos da gengiva de pacientes jovens e idosos e efeito da laserterapia de baixa potência e de fator de crescimento sobre estas células

Pós-graduação em Reabilitação Oral - FOAR

Aplicação da teoria de potência conservativa para monitoramento do comportamento do motor de indução trifásico sob distúrbios de qualidade de energia

Pós-graduação em Engenharia Elétrica - FEB

Avaliação da potência anaeróbia antes e após o período competitivo ematletas profissionais de futebol

The aim of this study was to examine changes on anaerobic power after competitive period in professional soccer players. Twenty five male was evaluated before (PRE) and after (POS) competitive period. To assess anaerobic power was used running based on anaerobic sprint test (RAST), which were determined the maximum power (MAXP), medium power (MEDP), minimum power (MINP) and fatigue index (FI). The test was performed in the first (PRE) and the last (POS) training session of competitive period, wich lasted 20 weeks. There were no significant difference (p>0,05) in POS condition compared to PRE condition on MAXP (10,70 ± 0,95 vs 10,83 ± 0,87), MINP (8,48 ± 0,92 vs 8,28 ± 0,76), MEDP (9,52 ± 0,83 vs 9,41 ± 0,61) and FI (22,73 ± 7,48 vs 25,53 ± 8,79). There was no significant change on anaerobic power after a competitive period wich lasted 20 weeks in professional soccer players.

Retificador entrelaçado com elevado fator de potência para operação de um veículo trólebus alimentado por redes em CA Ou CC

This paper presents the development and the main results for an interleaved boost rectifier operating as a special input power stage for a trolleybus type vehicle, allowing its feeding by alternate current (AC) or direct current (DC) distribution power systems. When feeding with two wires (single phase) alternate current distribution system, the converter accomplish active power factor correction, providing a relatively sinusoidal current with low total harmonic distortion (THD) and fully complying with IEC 61000-3-4 standards. In addition, a management control system promotes the required automatic operation changes for the proposed rectifier when the vehicle is changing from the DC distribution power system to the AC distribution power system and vice-versa, keeping its original electrical DC system characteristics for the adjustable speed driver sub-system. The main experimental results for a prototype rated at 150kW are presented, considering its application for a trolleybus with DC adjustable speed driver, demonstrating the proposed converter benefits and the possibility of AC feeding system for trolleybus type vehicle.