1000 resultados para Medida de velocidade


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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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The objective of the present study was to compare the effects of a high speed isokinetic training (180°.s-1) and an isometric training (75°) on the maximum rate of force development (RFDmax) measured in the isokinetic and isometric modes. Twenty seven male non active subjects participated of this study (Mean + SD = body mass 78.6 + 14.1 kg; stature 175.1 + 8.9 cm; age 22.6 + 3.8 years). They were randomly divided into three groups: Control (GC); Isokinetic training (GISOC) and; Isometric training (GISOM). The subjects were submitted in different days to the following pre training protocols: 1) Familiarization to the isokinetic dynamometer tests; 2) Five maximum concentric isokinetic contractions of the knee extensors (180°.s-1) to access the maximum concentric torque (TMC) and the concentric RFDmax; 3) Two maximum isometric contractions of the knee extensors (75°) to access the maximum isometric torque (TMI) and the isometric RFDmax. The same tests were repeated after the training period, but without the familiarization session. Eighteen training sessions were performed (3 times per week). The GISOC performed the entire training whit concentric isokinetic contractions whit the speed of 180°.s-1. The GISOM performed the entire training whit isometric contractions whit the angle between the thigh end the leg being 75° (0° = full knee extension). TMI, TMC, concentric RFDmax, isometric RFDmax values of the GC was not different between pre and post training. GISOM increased only the TMI and the GSIOC increased the TMC, concentric RFDmax and isometric RFDmax. Furthermore, the GISOC had a higher percentage increase of the isometric RFDmax than the isokinetic RFDmax. Based on these results, it is possible to conclude that the increase in maximum strength corresponded to the training specificity theory, unlike to the RFDmax. Thus the use of isometric contraction ...(Complete abstract click electronic access below)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The Boron Neutron Capture Therapy (BNCT), based on the 10B(n,α)7Li reaction, represents a promising modality for the treatment of cancers that are resistents to conventional treatments. So, it is necessary to find drugs (boron compounds) with high selectivity for each type of cancer, the neutrons source should be well characterized and the rate of 10B(n,α)7Li reaction should be measured with great accuracy as possible. This study aimed to develop a method for manufacturing thin films of boron, for measure the 10B(n,α)7Li reaction, and analyze the uniformity of the films. Five thin films of boron were manufactured with three different concentrations of boric acid, heated to transform the acid in boron, irradiated with thermic neutrons coupled to CR-39 detectors, in BNCT line at the reactor IEA-R1 IPEN/CNEN, São Paulo. After the irradiation, the detectors were chemically attacked with NaOH to reveal the tracks. The methodology presented is effective because it resulted in deposition of boron as thin film enabling the quantitative analysis of 10B(n,α)7Li reaction. The analysis of the uniformity of density of the induced tracks in CR-39 shows that, in most of the films, there is no uniformity in surface distribution of boron, but when the film is divided, we obtain some uniform sectors

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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

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This study evaluated the effect of physical and chemical activation on the speed of penetration of hydrogen peroxide bleaching agents present in different concentrations through the enamel and dentin. One hundred and twenty bovine incisors were used, which were obtained enamel/dentin discs of the buccal surface, with 6 mm in diameter. The samples were divided into six groups: G1 - Hydrogen Peroxide Gel 20%, G2 - Hydrogen Peroxide Gel 20% with light activation, G3 - Hydrogen Peroxide Gel 20% with Manganese Gluconate; G4 - Hydrogen Peroxide Gel 35%; G5 - Hydrogen Peroxide Gel 35% with the light activation and G6 - Hydrogen Peroxide Gel 35% with Manganese Gluconate. The specimens were placed in a transparent support on which there was a substance sensitive to hydrogen peroxide immediately below and in contact with the specimen. After the procedures for applying the gel for each group, one video camera was positioned and operated to monitor the time of penetration of peroxide in each specimen. The recording ended after changing the color of the fluid revealed in all specimens and times were noted for comparison. ANOVA analysis showed that concentration and type of activation of bleaching gel significantly influenced the diffusion time of hydrogen peroxide (P 0.05). 35% hydrogen peroxide showed the lowest diffusion times compared to the groups with 20% hydrogen peroxide gel. The light activation of hydrogen peroxide decrease significantly the diffusion time compared to chemical activation. The highest diffusion time was obtained with 20% hydrogen peroxide chemically activated. The diffusion time of hydrogen peroxide was dependent on activation and concentration of hydrogen peroxide. The higher concentration of hydrogen peroxide diffused through dental tissues more quickly

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Os valores encontrados para a viscosidade sanguínea tendem a aparecer com diferenças significativas, de acordo com o sexo, avançar da idade e uso de substâncias. Pelo fato de o sangue ser um fluido não newtoniano, não podemos expressar sua viscosidade em termos absolutos sem que sejam levadas em conta as condições em que a mensuração é feita. Estudos anteriores destacaram a importância esta medida, considerando o efeito da idade, o uso de substâncias, bem como sua relação com Fluxo Sanguíneo Regional Cerebral, o que pode indicar correlação com declínios cognitivos. Entretanto, a prática médica carece ainda de um método simples e clinicamente prático para a verificação desta medida, além de valores de referência. Como passo inicial no sentido de padronizar os procedimentos e condições do processo de medição, avaliamos a quantidade mínima de amostra necessária para a medição da viscosidade sanguínea, utilizando este equipamento. Um total de 20 amostras de sangue foram coletadas de indivíduos saudáveis, entre 18 e 60 anos, em tubos com EDTA, e cada amostra dividida em 9 sub-amostras (de 600μl, 550μl, 500μl, 450μl, 400μl, 350μl, 300μl, 250μl e 200μl), totalizando, portanto, um total de aproximadamente 180 medições. A quantidade de 200 μl apresentou diferenças significativas com relação à primeira medida obtida, quando comparada com todas as demais quantidades (p<0,001), o que indica que com o uso desta quantidade, não é possível obter resultados confiáveis, pois existe alteração nos valores de VS obtidos relacionada à quantidade de material utilizado. Considerando a menor quantidade, bem como, que estivesse dentro da faixa de variação aceitável de 0,2 mPa.s, e a qual não apresentasse diferença significativa quando comparadas às demais (p>0,05), foi verificada a quantidade de 250 μl como a mais eficiente... (Resumo completo, clicar acesso eletrônico abaixo)

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A doença de Parkinson (DP) é uma patologia crônica, degenerativa e progressiva acarretada pela perda de neurônios dopaminérgicos da substância negra (parte compacta), localizada nos núcleos da base. Os comprometimentos na marcha estão entre as principais consequências da DP. Entretanto, pouco se conhece sobre o efeito do estágio da doença na modulação da velocidade do andar. Assim, o objetivo do estudo foi verificar como pacientes em diferentes estágios da DP modulam os parâmetros do andar quando requeridos a andar em máxima velocidade. Os participantes do estudo foram indivíduos com DP idiopática em estágio unilateral (entre 1 e 1,5 na Escala de Hoehn & Yahr) e bilateral (entre 2 e 3 na Escala de Hoehn & Yahr). Inicialmente, os participantes foram submetidos a uma avaliação clínica, realizada por um médico neuropsiquiatra, para verificar o acometimento geral e o estágio da doença. Os dados da avaliação clínica foram utilizados para a distribuição dos participantes entre os dois grupos. Em seguida, os participantes foram convidados a andar sobre uma passarela de 10m de comprimento em duas condições experimentais: Velocidade preferida e velocidade máxima. Somente o grupo bilateral não foi capaz de modular o comprimento da passada na condição de velocidade máxima. Os resultados sugerem que a evolução da DP compromete a capacidade dos pacientes em modular a amplitude de movimentos (comprimento da passada) quando são requeridos a andar em velocidade máxima

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This research presents an investigation on the subject: Quantities and Measurements. The research is dedicated to this subject due to its importance in the school curriculum, and adopts the use of history of mathematics and investigative duties in a manner that will enable the production of knowledge by the student. Following a phenomenological orientation, we conducted field work in a public school in Guaratinguetá, with students from the 6 th grade. The analyze of data of the research, undertaken in accordance with the understanding of the texts FINI (1994), MACHADO (1994), BICUDO (1993, 2000, 2011), understanding how students construct knowledge measures. The data from field work were obtained from images recorded on video, the researcher's field diary and notes of the students. The descriptions of the data, transformed into text, had been detached the strechs most revealing for what it searchs to understand. The understood meaning through the analysis, indicates two categories: measure is to express values and measure is to compare quantities. When interpreting the open categories we understand that the student builds knowledge of measurement making comparisons

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV

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Pós-graduação em Matemática em Rede Nacional - IBILCE

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In this work is studied the fluid dynamic characteristics of sugarcane bagasse for gasification applications and use of syngas in the sugarcane sector. This is an experimental work, which is initially performed the particle size separation of sugarcane bagasse particles, using appropriate equipment. Through the experiment is possible to determine the average diameter of particles pomace typical sugarcane mill. The equipment used for the grading sieve separation assembly consists of several dimensions, arranged vertically and which shows adequate for good separation from the pulp. Later, it makes immediate analysis for the determination of moisture, ash, volatile materials and fixed carbon. The study also determines the gross calorific value and allows analysis of densities of particles of sugar cane bagasse. Also studied the bagasse morphology using electron microscopes, where it was possible to visualize the geometry of the particles of bagasse. The use of Electronic Scanning Microscopy (SEM) provided better understand the morphology and particle size measured by using photography methods. Two methods for determining the sphericity of the particles were also used. The experiments carried out using appropriate standards and specific equations, allowing compare the present results with the values found by several researchers. Subsequently, fluid dynamic simulations were performed for the determination of porosity and minimum fluidization velocity theoretical. It follows that the sphericity and porosity of the bagasse particles influence the minimum fluidization velocity of biomass