Limiar de fadiga neuromuscular determinado por diferentes periodos de analise do sinal eletromiografico

Universidade Estadual de Campinas . Faculdade de Educação Física

Sistema de periodização em blocos : efeitos de um modelo de treinamento sobre o desempenho de nadadores velocistas de alto nivel

Universidade Estadual de Campinas . Faculdade de Educação Física

Efeitos de uma periodização de treinamento fisico sobre o desempenho anual de uma equipe de handebol feminino sub-21

Universidade Estadual de Campinas . Faculdade de Educação Física

O efeito posterior duradouro de treinamento (EPDT) das cargas concentradas de força : investigação a partir de ensaio com equipe infanto juvenil e juvenil de voleibol

Universidade Estadual de Campinas. Faculdade de Educação Física

Respostas cardio-respiratorias ao exercicio fisico dinamico em mulheres sedentarias no segundo trimestre de gravidez

Universidade Estadual de Campinas. Faculdade de Educação Física

Futebol : as cargas concentradas de força e a dinamica da alteração das capacidades biomotoras no macrociclo anual de treinamento

Universidade Estadual de Campinas . Faculdade de Educação Física

Salto triplo : o sistema de preparaçao do desportista : da detecção a promoção do talento

Universidade Estadual de Campinas . Faculdade de Educação Física

Remo : cargas concentradas de força e sua relação com a alteração de diferentes indicadores funcionais

Universidade Estadual de Campinas . Faculdade de Educação Física

Basquetebol

Universidade Estadual de Campinas. Faculdade de Educação Física

Aplicação de indentação instrumentada na caracterização mecânica de poliuretana derivada de óleo de mamona

Neste trabalho são investigadas as propriedades mecânicas de poliuretana derivada do óleo de mamona, utilizando a técnica de indentação instrumentada com penetradores de geometrias piramidal e esférica. Foi analisada a influência da forma do penetrador utilizado nos ensaios de indentação instrumentada para se obter valores das propriedades mecânicas de polímero derivado de óleo de mamona. Os penetradores utilizados são de pontas piramidais dos tipos Berkovich e canto de cubo e esférico de raio igual a 150 μm em um Nanoindenter XP TM com cargas aplicadas entre 1 e 200 mN. As penetrações variam de acordo com o formato do penetrador, sendo maiores para pontas agudas. A dureza e o módulo de elasticidade foram determinados, utilizando o método de Oliver e Pharr. Verificou-se que os valores medidos para a dureza são maiores para penetradores mais agudos. Os valores obtidos com a ponta piramidal Berkovich foram de 0,14 GPa para pequenas penetrações e 0,12 GPa para maiores penetrações. Já os valores obtidos com ponta canto de cubo foram 25 a 30% maiores. Isso está relacionado com os volumes das regiões que apresentam deformações plásticas elevadas, no caso de penetradores agudos comparados com os volumes das regiões que sofrem deformações viscoelásticas. A viscosidade aparente determinada, utilizando penetrador esférico em testes de força aplicada constante, é igual a (22 ± 2) × 10(12) Pa.s.

Low and moderate, rather than high intensity strength exercise induces benefit regarding plasma lipid profile

Background: The effects of chronic aerobic exercise upon lipid profile has been previously demonstrated, but few studies showed this effect under resistance exercise conditions. Objective: The aim of this study was to examine the effects of different resistance exercise loads on blood lipids. Methods: Thirty healthy, untrained male volunteers were allocated randomly into four groups based at different percentages of one repetition maximum (1 RM); 50%-1 RM, 75%-1 RM, 90%-1 RM, and 110%-1 RM. The total volume (sets x reps x load) of the exercise was equalized. The lipid profile (Triglycerides [TG], HDL-cholesterol [HDL-c], LDL-cholesterol, and Total cholesterol) was determined at rest and after 1, 24, 48 and 72 h of resistance exercise. Results: The 75%-1 RM group demonstrated greater TG reduction when compared to other groups (p < 0.05). Additionally, the 110%-1 RM group presented an increased TG concentration when compared to 50% and 75% groups (p = 0.01, p = 0.01, respectively). HDL-c concentration was significantly greater after resistance exercise in 50%-1 RM and 75%-1 RM when compared to 110%-1 RM group (p = 0.004 and p = 0.03, respectively). Accordingly, the 50%-1 RM group had greater HDL-c concentration than 110%-1 RM group after 48 h (p = 0.05) and 72 h (p = 0.004), respectively. Finally, The 50% group has showed lesser LDL-c concentration than 110% group after 24 h (p = 0.007). No significant difference was found in Total Cholesterol concentrations. Conclusion: These results indicate that the acute resistance exercise may induce changes in lipid profile in a specific-intensity manner. Overall, low and moderate exercise intensities appear to be promoting more benefits on lipid profile than high intensity. Long term studies should confirm these findings.

The role of aerobic fitness on session rating of perceived exertion in futsal players

Purpose: The aim of this study was to verify the influence of aerobic fitness (VO(2)max) on internal training loads, as measured by the session rating of perceived exertion (session-RPE) method. Methods: Nine male professional outfield futsal players were monitored for 4 wk of the in-season period with regards to the weekly accumulated session-RPE, while participating in the same training sessions. Single-session-RPE was obtained from the product of a 10-point RPE scale and the duration of exercise. Maximal oxygen consumption was determined during an incremental treadmill test. Results: The average training load throughout the 4 wk period varied between 2,876 and 5,035 arbitrary units. Technical-tactical sessions were the predominant source of loading. There was a significant correlation between VO(2)max (59.6 +/- 2.5 mL.kg(-1).min(-1)) and overall training load accumulated over the total period (r = -0.75). Conclusions: The VO(2)max plays a key role in determining the magnitude of an individual's perceived exertion during futsal training sessions.

EVALUATING VIBRATIONS ON A SMALL-SCALE MODEL OF A TIMBER FOOTBRIDGE

In Brazil, the study of pedestrian-induced vibration on footbridges has been undertaken since the early 1990s, for concrete and steel footbridges. However, there are no recorded studies of this kind for timber footbridges. Brazilian code ABNT NBR 7190 (1997) gives design requirements only for static loads in the case of timber footbridges, without considering the serviceability limit state from pedestrian-induced vibrations. The aim of this work is to perform a theoretical dynamic, numerical and experimental analysis on simply-supported timber footbridges, by using a small-scale model developed from a 24 m span and 2 m width timber footbridge, with two main timber beams. Span and width were scaled down (1:4) to 6 m e 0.5 in, respectively. Among the conclusions reached herein, it is emphasized that the Euler-Bernoulli beam theory is suitable for calculating the vertical and lateral first natural frequencies in simply-supported timber footbridges; however, special attention should be given to the evaluation of lateral bending stiffness, as it leads to conservative values.

Risk optimization of a steel frame communications tower subject to tornado winds

The structural engineering community in Brazil faces new challenges with the recent occurrence of high intensity tornados. Satellite surveillance data shows that the area covering the south-east of Brazil, Uruguay and some of Argentina is one of the world most tornado-prone areas, second only to the infamous tornado alley in central United States. The design of structures subject to tornado winds is a typical example of decision making in the presence of uncertainty. Structural design involves finding a good balance between the competing goals of safety and economy. This paper presents a methodology to find the optimum balance between these goals in the presence of uncertainty. In this paper, reliability-based risk optimization is used to find the optimal safety coefficient that minimizes the total expected cost of a steel frame communications tower, subject to extreme storm and tornado wind loads. The technique is not new, but it is applied to a practical problem of increasing interest to Brazilian structural engineers. The problem is formulated in the partial safety factor format used in current design codes, with all additional partial factor introduced to serve as optimization variable. The expected cost of failure (or risk) is defined as the product of a. limit state exceedance probability by a limit state exceedance cost. These costs include costs of repairing, rebuilding, and paying compensation for injury and loss of life. The total expected failure cost is the sum of individual expected costs over all failure modes. The steel frame communications, tower subject of this study has become very common in Brazil due to increasing mobile phone coverage. The study shows that optimum reliability is strongly dependent on the cost (or consequences) of failure. Since failure consequences depend oil actual tower location, it turn,,; out that different optimum designs should be used in different locations. Failure consequences are also different for the different parties involved in the design, construction and operation of the tower. Hence, it is important that risk is well understood by the parties involved, so that proper contracts call be made. The investigation shows that when non-structural terms dominate design costs (e.g, in residential or office buildings) it is not too costly to over-design; this observation is in agreement with the observed practice for non-optimized structural systems. In this situation, is much easier to loose money by under-design. When by under-design. When structural material cost is a significant part of design cost (e.g. concrete dam or bridge), one is likely to lose significantmoney by over-design. In this situation, a cost-risk-benefit optimization analysis is highly recommended. Finally, the study also shows that under time-varying loads like tornados, the optimum reliability is strongly dependent on the selected design life.

Load Ratio Estimation Through Striation Height and Spacing Analysis of an Aerospace Al Alloy 7475-T7351

It is well known that striation spacing may be related to the crack growth rate, da/dN, through Paris equation, as well as the maximum and minimum loads under service loading conditions. These loads define the load ratio, R, and are considered impossible to be evaluated from the inter-spacing striations analysis. In this way, this study discusses the methodology proposed by Furukawa to evaluate the maximum and minimum loads based on the experimental fact that the relative height of a striation, H, and the striation spacing, s, are strongly influenced by the load ratio, R. Fatigue tests in C(T) specimens were conducted on SAE 7475-T7351 Al alloy plates at room temperature and the results showed a straightforward correlation between the parameters H, s, and R. Measurements of striation height, H, were performed using scanning electron microscopy and field emission gun (FEG) after sectioning the specimen at a large inclined angle to amplify the height of the striations. The results showed that for increasing R the values of H/s tend to increase. Striation height, striation spacing, and load ratio correlations were obtained, which allows one to estimate service loadings from fatigue fracture surface survey.