1000 resultados para Perdas de Velocidade


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

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

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

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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O objetivo do trabalho foi estudar as características morfogenéticas e estruturais do capim-Tanzânia, a produção de forragem, as perdas de nitrogênio (N) por volatilização, reservas orgânicas e a avaliação do sistema radicular sob doses de nitrogênio sob pastejo. O experimento foi instalado na área Fazenda Experimental de Iguatemi da Universidade Estadual de Maringá, no período de março de 2007 a março de 2008. O delineamento experimental utilizado foi de blocos completos ao acaso, com parcelas subdivididas com quatro repetições. Nas parcelas, encontravam-se as doses de N (0, 150, 300 e 450 kg ha-1 de N) e, nas sub-parcelas, as estações do ano. As perdas de N por volatilização foram quantificadas depois da adubação N (1, 2, 3, 6, 9, 12 e 15 dias). As amostragens das raízes foram realizadas nas profundidades de 0-10, 10-20 e 20-40 cm. A aplicação do fertilizante N na pastagem foi parcelada em três aplicações. A produção de massa seca total e de lâmina foliar de forragem respondeu linearmente até 282 kg ha-1 de N na estação do verão. A adubação nitrogenada exerce efeito positivo nas taxas de alongamento e aparecimento foliar, e no número de folhas vivas em plantas de capim-Tanzânia nas estações da primavera e verão. Elevadas adubações nitrogenadas associada a intervalos menores de pastejo promovem uma maior porcentagem de lâmina foliar; no manejo de pastos de capim-Tanzânia sob lotação rotacionada com altura de 70 cm na entrada dos animais para o pastejo e saída com 30 cm de altura do resíduo. A interação entre o nível de adubação e o período depois da aplicação de uréia foi significativa para a variável volatilização acumulada de N-NH3. A aplicação da uréia acarreta perdas percentuais mais elevadas de N nos três primeiros dias após a aplicação. A perda média acumulada de N-NH3 no período para as três estações do ano... (Resumo completo, clicar acesso eletrônico abaixo)

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In Brazil, the practice of Soccer is encouraged very early. It is common remark that parents enroll their sons into soccer schools, promoting the involvement of these children in formal practice. However, there are not many studies that assess the effects of this practice in the physical capacities of children. Thus, the question that guides this study is: children who practice soccer systematically present better development of physical, especially agility, coordination and speed? The objective of this study was to compare the performance in velocity tests, agility and coordination of boys of 10 and 11 years, category dentinho or Sub-11, practitioners of soccer in schools and non practicing. The study included male children, born in 1997 and 1998, formed two groups: group of practitioners of soccer and group of non practicing. To belong to the group of practitioners, the child was regularly engaged for at least 1 year, with 1 hour daily and 2 to 3 times per week. The participants of the group of non practicing were not involved in regular practice of soccer and were paired in weight and stature with participants of the group of practitioners of soccer. Each participant was individually assessed in neutral environment and without foreign interference. For the assessment of the agility, was utilized the (shuttle run) test. The race test 30 meters stopped was employed for the assessment of the speed. The test of fiddling between the cones was employed to measure the coordination. The time spent to perform 1 attempt to each test was used for the comparison between groups. These data were treated, initially, by descriptive statistics (mean and standard deviation) and, subsequently, were compared by means of Anova, for independent samples. The significance level was maintained at 5%. Through analysis of the results the conclusion is that the regular practice ...(Complete abstract click electronic access below)

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This work is initially based in give a solution to a problem consisting of lifting a load in a warehouse focusing specifically on the solution´s project and comparison of the results obtained following the sequence of the book and comparing these results with the finite elements simulation based on the 3D components modeling. Starting from that was realized the project of the worm gear reducer to solve the problem and makes the work easier. The project consisted basically of the study, project itself and simulation by software of a worm gear reducer and projects steps, starting with the initial problem conditions (to lifting a load up to an specific height at a given time) following all the reducer project sequence, starting by the preliminary draft and electric motor selection using iterative process, material selection, worm gear dimensioning, axles, keyways, bearings and coupling. After that was performed the three dimensional modeling of the components using SolidWorks software and simulating these components using Ansys software. The results show the importance of the CAD in terms of improving project development speed and reducing costs with prototypes

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This work aims to make the closed loop control of a three phase induction motor, through the integration of the following equipment: a frequency inverter, the actuator system; a programmable logic controller (PLC), the controller; an encoder, the velocity sensor, used as a feedback monitoring the control variable and the three-phase induction motor, the plant to be controlled. The control is performed using a Proportional - Integrative - Derivative (PID) approach. The PLC has a help instruction, which performs the auto adjustment of the controller, that instruction is used and confronted with other adjustment methods. There are several types of methods adjustments to the PID controllers, where the empirical methods are addressed in this work. The system is deployed at the Interface and Electro Electronic Control laboratory in the Universidade Estadual Paulista Júlio Mesquita Filho, Guaratinguetá, São Paulo, then, in the future, this work becomes an experiment to be conducted in the classroom, allowing undergraduate students to develop a greater affinity to the programs used by the PLC as well as studies of undergraduate and graduate works with the help of assembly made

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Brazil is a major world producer and exporter of agricultural products like soybeans, sugar, coffee, orange and tobacoo. However, the action of phytopathogenic fungi has been one of the largest challenges encountered in the field as they are responsible for approximately 25 to 50 per cent of losses in crops of fruits and vegetables. The presence of these pathogens is always a problem, because the damage on the tissues and organs promote lesions which decreses growth vegetation and often leads the individual (host) to death. Therefore, it is crucial to understand the process of spreading of these pathogens in the field to develop strategies which prevent the epidemics caused by them. In this study, the dispersal of fungi phytopathogenic in the field was modeled using the automata cellular formalism. The growth rate of infected plants population was measured by the radius of gyration and the influence of host different susceptibility degrees into the disease spread was assessed. The spatial anisotropy related to the plant-to-plant space and the system’s response to distinct seasonal patterns were also evaluated. The results obtained by a mean field model (spatially implicit models) emphasized the importance of the spatial structure on the spreading process, and dispersal patterns obtained by simulation (using a cellular automata) were in agreement with thse observed in data. All computational implementation was held in language Cl

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Disorders in gait are identified in Parkinson’s disease patients. As a result, the capacity of walking independently and the interaction with the environment can be impairment. So, the auditory cues have been utilized as a non-pharmacological treatment to improve the locomotor impairment of the PD patients. However, these effects were observed in the regular lands and it’s not known the effects of auditory cues in gait during avoidance obstacles that could be more threaten for these patients. Yet, few studies in the literature compare the Parkinson’s disease patients with the older adults during the locomotor tasks and obstacle avoidance in association with the effects of auditory cues. The aim of the study is to compare the effects of the auditory cues in the gait and during obstacle avoidance in PD patients and older adults. 30 subjects distributed in two groups (Group 1 - 15, Parkinson’s disease patients; Group 2 - 15, healthy older adults) are going to participate of this study. After the participation approval, the assessment of clinical condition will be done by a physician. So, to investigate the locomotor pattern, it will be done a kinematic analysis. The experimental task is to walk on 8 m pathway and 18 trials will be done (6 for the free gait and 12 for adaptive gait). For the adaptive gait, two different obstacle heights will be manipulated: high obstacle (HO) and low obstacle (LO). In order to verify possible differences between the groups and the experimental condition, multivariance tests will be used with a significance level of 0.05. MANOVA revealed effect of condition and task. Thus, with DA, we observed an increase in cadence and reduced single support and stride length. When the tasks were compared, it was observed that the LO task, subjects had lower velocity and stride length... 9Complete abstract click electronic access below)

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Existente desde os Jogos Olímpicos da Grécia Antiga, as corridas de velocidade ocupam espaço de destaque dentre as provas do atletismo. Em particular, os 100 metros rasos masculino é a prova cujas particularidades merecem ser investigadas, sobretudo em função das inúmeras alterações ocorridas ao longo dos anos. Por exemplo, a princípio, a corrida de velocidade era disputada nos Jogos Olímpicos da Grécia Antiga, com o nome de stádion ou dromo e com um percurso de 192,27 metros. Com a decadência e a extinção dos Jogos Olímpicos, a corrida de velocidade deixou de ser disputada, retornando em 1896, com o renascimento dos Jogos Olímpicos da Era Moderna. Entretanto, dentre as modificações nas provas do atletismo, as corridas de velocidade passaram a ser de 100 e 400 metros rasos, o bloco de partida passou a ser obrigatório etc. O objetivo desta pesquisa consiste em averiguar as principais modificações ocorridas na prova dos 100 metros rasos masculino, desde a sua origem até os dias atuais. Esta pesquisa, de caráter histórico-bibliográfico, tem a finalidade de resgatar a história da prova dos 100 metros rasos com base na história dos Jogos Olímpicos, verificando as alterações em suas regras básicas, em sua composição e técnicas específicas, a fim de reunir subsídios para o seu ensino em aulas de Educação Física. Com esta pesquisa, esperamos contribuir não apenas com o resgate da história desta ocorridas na prova dos 100 metros rasos masculino, desde a sua origem até os dias atuais. Esta pesquisa, de caráter histórico-bibliográfico, tem a finalidade de resgatar a história da prova dos 100 metros rasos com base na história dos Jogos Olímpicos, verificando as alterações em suas regras básicas, em sua composição e técnicas específicas, a fim de reunir subsídios para o seu ensino em aulas de Educação Física. Com esta pesquisa, esperamos... (Resumo completo, clicar acesso eletrônico abaixo)

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Due to the rapid development of some species such as pine and eucalyptus and a growing demand for raw materials, timber, there was a need for detailed studies to better use and higher quality in products derived from wood. In order to contribute to to better utilization of wood ,this study aims to analyze the quality of the wood surface after machining Corymbia citrodora around, with varying feed rates (40, 70, 100 mm/mim), shear rate (1.88, 2.19, 2.51 m/s) and with the use of inserts for turning new and used (cemented carbide). 18 were used bodies and each body was made three different assays for each test were a total of 54 tests three replicates. This study will also addres the analysis of power consumption for each of the tests. With the results obtained through experiments, including the surface roughness of parts and power consumption for each test, we try to evaluate the power consumption in machining with the variations in cutting speed and feed, with two tools carbide

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This work presents a proposal to replace thetraditional system of traction electric car that usesone electric motor and a mechanical differential, by two electric motors of lower power, controlled byelectronic control low cost. The proposed control isopen loop and uses the technique of Pulse WidthModulation (PWM), discrete and synchronizedaiming to reduce the generation of harmonics. The implementation of two smaller motor one on each wheel-drive distributes the weight of the vehicle, improving the heat exchange of the windings,beyond enable the power components supporting a current of 50% predicted for only one motor . The solution adopted for being open-loop, has a similar behavior to the mechanical differential, where theeffort imposed by the trajectory makes the velocity distribution between the wheels be appropriate tovehicle trajectory