64 research outputs found

    Velocity, Distance and Shoulder Range of Motion in Two Throwing Programs

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    Success in baseball pitching is determined by throwing velocity and accuracy. Strength conditioning, as well as repetitive throwing programs, are used to improve the pitch. Recently, a weighted ball program has been developed and is believed to increase ball velocity with less potential injury. However, there is limited research examining the impact of this program on performance. The purpose of this study was to compare a traditional long toss program versus a weighted ball program. Baseline throwing velocity and distance as well as shoulder range of motion (ROM) were measured in collegiate baseball players. Participants were then randomized to either a six-week-long toss throwing program or weighted ball program. Following training, throwing velocity, distance, and shoulder ROM were measured again. Both training methods significantly improved throwing distance. However, throwing velocity did not change from pre-training measurements. All measurements of shoulder ROM (flexion, abduction, and external rotation) significantly improved in both groups, with abduction showing the greatest improvement in the long toss group. Our results suggest both training programs are beneficial for baseball performance

    CFD STUDIO: AN EDUCATIONAL SOFTWARE FOR CFD ANALYSIS

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    The main goal of this paper is to demonstrate the general characteristics of the educational user-friendly CFD Studio package for CFD teaching. The package was designed for teaching 2D fluid mechanics and heat transfer process, including conduction, coupled conduction/convection, natural and forced convection, external and internal flows, among other phenomena. The finite volume methodology and its related topics can also be taught using the software. Therefore, general aspects of the three main modules, pre-processor, solver and post-processor are discussed aiming to show the generality of the tool. These modules are integrated in the application by a so-called numerical problem project which guide the student through the steps to obtain the solution. To approximate the partial differential equations the finite volume approach is employed using a fully-implicit formulation with the interpolation schemes CDS, UDS and WUDS. Mesh editing and nonorthogonal boundary-fitted mesh generation, using algebraic interpolation and elliptic equations, are important features of the package. Coupled heat transfer problems are handled using the solid-block formulation and the pressure-velocity coupling uses the SIMPLE and SIMPLEC methods with non-staggered grids. To demonstrate the capabilities two fluid flow and heat transfer problem projects are presented

    Bivalve network reveals latitudinal selectivity gradient at the end-Cretaceous mass extinction

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    Biogeographic patterns of survival help constrain the causal factors responsible for mass extinction. To test whether biogeography influenced end-Cretaceous (K-Pg) extinction patterns, we used a network approach to delimit biogeographic units (BUs) above the species level in a global Maastrichtian database of 329 bivalve genera. Geographic range is thought to buffer taxa from extinction, but the number of BUs a taxon occurred in superseded geographic range as an extinction predictor. Geographically, we found a latitudinal selectivity gradient for geographic range in the K-Pg, such that higher latitude BUs had lower extinction than expected given the geographic ranges of the genera, implying that (i) high latitude BUs were more resistant to extinction, (ii) the intensity of the K-Pg kill mechanism declined with distance from the tropics, or (iii) both. Our results highlight the importance of macroecological structure in constraining causal mechanisms of extinction and estimating extinction risk of taxa.Daril A. Vilhena, Elisha B. Harris, Carl T. Bergstrom, Max E. Maliska, Peter D. Ward, Christian A. Sidor, Caroline A. E. Strömberg and Gregory P. Wilso

    Schistosomiasis haematobia in Brazilian patients: clinical and renal functional evaluation with 99mTc-DTPA

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    The present study was carried out at the Army Central Hospital, Rio de Janeiro, Brazil, from September 2000 to December 2001, employing diethylenetriamine penta-acetic acid labeled with technetium-99m (99mTc-DTPA) to evaluate the renal function of nineteen symptomatic patients infected with S. haematobium during a peace mission in Mozambique. Results evidenced that the most frequent clinical manifestations were hematuria (68.4%) and low back pain (68.4%) and 73.7% patients had altered dynamic renal scintigraphy expressed by an increase in the excretory phase independently of the symptoms duration; furthermore, none of them had mechanical obstructive pattern. Schistosoma haematobium glomerulopathy could be considered a pathological finding without correlation with the disease clinical manifestations

    Surface Patterning of Low Carbon Steel via Dc Plasma Nitriding

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    Abstract The surface patterning by plasma nitriding treatment was applied in low carbon steel SAE 1004 and presente

    Métodos de aplicação da simulação computacional em edifícios naturalmente ventilados no clima quente e úmido

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    A ventilação natural é o principal recurso passivo para a obtenção do conforto térmico em climas quentes e úmidos, reduzindo também o consumo energético com condicionamento artificial. Entretanto, arquitetos fazem restrição a seu uso por não haver garantias de solução dos problemas de conforto térmico, quando comparada aos sistemas artificiais. Nesse sentido, decidiu-se investigar formas de prever o comportamento da ventilação natural em edifícios através de ferramentas de simulação computacional, visando apoiar a tomada de decisão no projeto de arquitetura. O objeto de estudo é o edifício pré-fabricado, do tipo galpão, considerado como típico na cidade de Natal, RN. Utilizaram-se um programa de dinâmica de fluidos computacional (CFD) e um de simulação térmica e energética de edificações. O artigo tem como foco a discussão dos procedimentos necessários para viabilizar as análises da ventilação, indicando como o método teve de ser adequado à complexidade de sucessivas abordagens, resultando em simplificações e incertezas de resultados. Para exemplificar a abordagem apresentam-se alguns resultados de simulações. Ao final, as limitações e potencialidades do método são discutidas com base nas características dos códigos de simulações utilizados, das condições de simulação e da representatividade dos modelos
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