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.

Compensação ativa paralela baseada na teoria de potência conservativa

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

Dressagem monitorada por emissão acústica e potência de corte

Para a realização deste experimento, foram utilizados um rebolo de óxido de alumínio instalado em uma retificadora plana, um dispositivo em forma de balança juntamente com o sensor de deslocamento, um sistema de aquisição de sinais e um dressador de ponta única de diamante. O processamento digital dos dados foi obtido com o software Matlab. Nos ensaios, foram aplicados diferentes graus de recobrimento e profundidade de dressagem e comparada a agressividade obtida. A partir dos dados resultantes, os parâmetros RMS, DPO e DPKS mostraram-se bons indicadores para a operação. Também ficou comprovado que para recondicionar e definir novas características para o rebolo é necessária a remoção de 120 um. Do estudo do espectro do dinal de EA, notou-se que não há componentes hormônicas com frequência superior a 200 KHz.

Controle flexível para conversores monofásicos conectados a sistemas elétricos distorcidos de baixa tensão

This paper presents a technique to add flexibility in the control of power electronic converters. The power converter can function as an active power filter, as a local power source interface or perform both functions i. e. mitigate current disturbances and inject power into the grid simultaneously, configuring it as a multifunctional device. The main goal is to extract the full capability of the grid connected power electronic converter to achieve maximum benefits. To achieve this goal, the orthogonal current decomposition of the Conservative Power Theory is used. Each orthogonal current component is weighted by means of different compensation factors (k_i), which are set instantaneously and independently, in any percentage by means of the load performance factors (λ_i), providing an online flexibility in relation to compensation objectives. Finally, to validate the effectiveness and performance the proposed approach, simulations and experimental results are presented.

Conversor analógico digital de 10 bits utilizando arquitetura pipeline e tecnologia CMOS

Pós-graduação em Engenharia Elétrica - FEIS

Contribuições para o estudo de atribuição de responsabilidades em circuitos elétricos de baixa tensão

Pós-graduação em Engenharia Elétrica - FEB

Viabilidade econômica da implantação de compensadores série dinâmicos em redes de distribuição de energia elétrica

Pós-graduação em Engenharia Elétrica - FEIS

Controlador de temperatura para célula de medição de propriedades de líquidos por ultrassom

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Proposta de equipamento de conexão à rede para a utilização da geração de energia solar em consumidores de pequeno e médio porte

Pós-graduação em Engenharia Mecânica - FEG

Análise do acabamento superficial e da potência consumida na usinagem de fresamento frontal e cilíndrico tangencial da madeira de eucalipto

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fabricação e caracterização elétrica de filmes nanoestruturados de derivados do politiofeno

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise estatística de parâmetros elétricos em usinas sucroalcoleiras do centro-oeste paulista

The industry of sugar cane has become an important contributor to the generation of electricity in Brazil. Currently there are 434 sugar and ethanol plants operating in the country, 23% of the total export electricity to the National Integrated System (SIN), the state of São Paulo has 182 plants and 30% of them export energy to the SIN. The objective of this study is to compare parameters of electrical efficiency in the sugar and alcohol industry. For the study, three plants localized in the midwest region of Sao Paulo state with great potential for production and exporting bioenergy were chosen. Five energy analyzers LANDYS + GYR SAGA were used for measure the electrical parameters. The variables studied were energy consumption (C) and power factor (PF). For the statistical analysis it was adopteda randomized block design in a factorial 3 5composed of three companies and five sectors of energy consumption,in which: reception(1), milling (2), boiler (3), supporting activities / juice treatment (4), and distillation (5), totaling 15 treatments. Each group comprised 192 repetitions (48 hours 4 measurements per hour). It was concluded that there is no interest for the plans to fix the FP and reach a value 0.92, which is considered the ideal power factor.This,because the plants generate their own energy and are not penalized. Regarding the energy consumed, all sectors had significant differences. When comparingsector to sector, the plant called USB showed no significant differences in sectors 1 and 3, and the plant USC, in sectors 1 and 4. Considering the production units of this sector and selling power this type of evaluation is essential to perform this analysis, since the analyzed sectors are most important in the production of sugar and ethanol, and analyze and monitor these parameters, use and consumption energy can provide a greater supply of energy to be commercialized.

Análise parâmetros elétricos consumo, fator de carga e demanda de empresas de refino de óleo vegetal

Empresas muitas vezes tem seu consumo de energia elétrica descontrolados por possuírem motores elétricos muitas vezes super-dimensionados, trabalhando em vazio ou em horário de pico. Sendo este tipo de atividade responsável por grande parte do gasto energético da empresa. Existem dois fatores que avaliam o modo de utilização desta energia, denominados fator de potência (fp) e fator de carga (fc), que indicam a eficiência e racionalidade da forma de utilização da energia elétrica, respectivamente. A necessidade de uma avaliação global da utilização da energia, levando em consideração os dois fatores citados, é realizada por especialistas da área energética para a determinação da situação real da empresa. Podendo ser uma tarefa árdua muitas vezes demorada. Para isto é necessária uma análise estatística descritiva dos dados. Este trabalho tem como objetivo realizar esta analise de dados de uma empresa de refino de óleo vegetal.

Metodologia de determinação de funções de pertinência de controla-dores fuzzy para a avaliação energética de empresas de avicultura de postura

The objective of this work is to determine the membership functions for the construction of a fuzzy controller to evaluate the energy situation of the company with respect to load and power factors. The energy assessment of a company is performed by technicians and experts based on the indices of load and power factors, and analysis of the machines used in production processes. This assessment is conducted periodically to detect whether the procedures performed by employees in relation to how of use electricity energy are correct. With a fuzzy controller, this performed can be done by machines. The construction of a fuzzy controller is initially characterized by the definition of input and output variables, and their associated membership functions. We also need to define a method of inference and a processor output. Finally, you need the help of technicians and experts to build a rule base, consisting of answers that provide these professionals in function of characteristics of the input variables. The controller proposed in this paper has as input variables load and power factors, and output the company situation. Their membership functions representing fuzzy sets called by linguistic qualities, as “VERY BAD” and “GOOD”. With the method of inference Mandani and the processor to exit from the Center of Area chosen, the structure of a fuzzy controller is established, simply by the choice by technicians and experts of the field energy to determine a set of rules appropriate for the chosen company. Thus, the interpretation of load and power factors by software comes to meeting the need of creating a single index that indicates an overall basis (rational and efficient) as the energy is being used.

Análise diferencial da potência máxima gerada por um sistema solar fotovoltaico

The Earth receives annually 1,5.1018 kWh of solar energy, which corresponds to 1000 times the world energy consumption in this period. This fact comes out that, besides being responsible for the maintenance of life on Earth, the solar radiation is in an inexhaustible energy source, with an enormous potential for use by systems capture and conversion into another form of energy. In many applications of low power systems that convert light directly into electricity, called photovoltaic advantageously replace other means of production processes, where its distribution is very significant. The determination of the power generated by such a system is of paramount importance for the design energy of its implementation and evaluation of the system itself. This study aims to determine a relationship between the maximum power generated by solar photovoltaic and characteristic parameters of the generator. This relationship allows to evaluate the performance of such a system. For simulations of the developed equations were used 3 photovoltaic modules with an output of 100 Wp each, and data collection was performed during one year by enrolling in addition to meteorological data, solar irradiance incident on the modules.