75 resultados para jumps
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
The aim of this study was to analyze the morphophysiological changes of medial gastrocnemius muscle (GM) of Wistar rats underwent to eight weeks of concurrent training (TC). We used fifteen male Wistar rats divided into three groups with five animals each: baseline (LB), control (C) and trained (T). The TC consisted of aerobic endurance training in swimming (TRA) and a forced training (TF) in the same session, three times per week, for eight weeks. There was an increase of 4.4% in the comparison between average cross section area of the GM in animals of groups T (4905,5 ± 77,1µm²) and C (4699,9 ± 78,3 µm²). It is concluded that concurrent training was effective in causing hypertrophy in GM of rats.
Resumo:
The article investigates complex impulsive systems in which the so-called controlling systems jumps effect emerges. In particular, this research includes the correctness of the solution to the impulsive control system and approximation lemmas. A 3D model example is provided which illustrates the relevance of the considered approach to the study of complex impulsive systems.
Resumo:
An excitation force that is not influenced by the system state is said to be an ideal energy source. In real situations, a direct and feedback coupling between the excitation source and the system must always exist at a certain level. This manifestation of the law of conservation of energy is known as the Sommerfeld effect. In the case of obtaining a mathematical model for such a system, additional equations are usually necessary to describe the vibration sources with limited power and its coupling with the mechanical system. In this work, a cantilever beam and a non-ideal DC motor fixed to its free end are analyzed. The motor has an unbalanced mass that provides excitation to the system which is proportional to the current applied to the motor. During the coast up operation of the motor, if the drive power is increased slowly, making the excitation frequency pass through the first natural frequency of the beam, the DC motor speed will remain the same until it suddenly jumps to a much higher value (simultaneously its amplitude jumps to a much lower value) upon exceeding a critical input power. It was found that the Sommerfeld effect depends on some system parameters and the motor operational procedures. These parameters are explored to avoid the resonance capture in the Sommerfeld effect. Numerical simulations and experimental tests are used to help gather insight of this dynamic behavior. (C) 2014 Elsevier Ltd. All rights reserved.
Resumo:
The Post-Activation Potentiation (PAP) offers a proposal to optimize the production of strength and muscular power when performing exercises near maximum to actions previously assessed . The present study aims to show the activation process of postactivation potentiation (PAP) through vertical and plyometric jumps, and explain the user function of these movements. The ratio of post-activation potentiation resulting from plyometric and vertical jumps and explosive strength in the lower limbs aims to improve the potency and maximal strength, proven through studies and protocols detailed here. The results of this research come can be applied both for athletes and for individuals with experience in strength training and jumps (sports like volleyball, basketball and handball). The study was conducted through a literature review, conducted in scientific journals indexed in major databases (PubMed, ISI-Web of Science, SCIELO), books and academic papers (theses and dissertations)
Resumo:
The practice of regular physical activity has been considered a protective factor against the degenerative processes of the body, acting as a promoter of health, especially for risk groups such as obese and resistant groups exercise adherence as among the intellectually disabled (ID) . This study involved the administration of a training protocol and the physical parameters of longitudinal health in a subject about 43 years, intellectually deficient, hypertensive, obese and with a strong predisposition to develop diabetes and heart disease. The main objective of long-term program was to reduce body weight and normalize blood pressure (BP) after the student's physical activity and preferentially interfere with BP values at rest (ie before the daily schedule). The other objective was to improve general physical fitness. The protocol involved four meetings per week lasting one hour, in addition to participation in the program PROEFA (twice a week with sessions of one hour each), totaling 57 sessions spread over five months. The evaluation protocol included in each session the following tests: blood pressure measurements and heart rate, and amount of physical activity recorded via pedometer. Tests applied before and after the training included: anthropometric assessment, agility test, flexibility test, test drive through vertical and horizontal jumps and endurance to the test bench. The mass (kg) and BMI corresponded to the initial values of 127.7 kg and 42.05 kg m-2, and 5 months after 113.2 kg and 37.48 kg m-2, respectively. The waist-hip ratio was close to 1 after the intervention and this value corresponded to 0.98. For the test of agility (shuttle run) was not found improvement in performance. To test the values of the horizontal jump in pre-test were 52 cm and 56 cm post-test, vertical jump has been improved and...(Complete abstract click electronic access below)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
An excitation force that is not influenced by the system's states is said to be an ideal energy source. In real situations, a direct and feedback coupling between the excitation source and the system must always exist. This manifestation of the law of conversation of energy is known as Sommerfeld Effect. In the case of obtaining a mathematical model for such system, additional equations are usually necessary to describe the vibration sources and their coupling with the mechanical system. In this work, a cantilever beam and a non-ideal electric DC motor that is fixed to the beam free end is analyzed. The motor has an unbalanced mass that provides excitation to the system proportional to the current applied to the motor. During the motor's coast up operation, as the excitation frequency gets closer to the beam first natural frequency and if the drive power increases further, the DC motor speed remains constant until it suddenly jumps to a much higher value (simultaneously the vibration amplitude jumps to a much lower value) upon exceeding a critical input power. It was found that the Sommerfeld effect depends on some system parameters and the motor operational procedures. These parameters are explored to avoid the resonance capture in Sommerfeld effect. Numerical simulations and experimental tests are used to help insight this dynamic behavior.
Resumo:
We study the phase transition from a dx2-y2 to a dx2-y2+dxy superconductor using the tight-binding model of two-dimensional cuprates. As the temperature is lowered past the critical temperature Tc, first a dx2-y2 superconducting phase is created. With further reduction of temperature, the dx2-y2+dxy phase is created at temperature T=Tc1. We study the temperature dependencies of the order parameter, specific heat, and spin susceptibility in these mixed-angular-momentum states on a square lattice and on a lattice with orthorhombic distortion. The above-mentioned phase transitions are identified by two jumps in specific heat at Tc and Tc1. ©1999 The American Physical Society.
Resumo:
The composite SmBa2Cu3O7-delta (Sm-123), obtained by the substitution of the ion Y for Sm in the very well known and studied YBa2Cu3O7-delta (Y-123), is potentially attractive for better understanding superconductivity mechanisms and for its applications as electronic devices. Sm-123 samples show higher critical temperatures than Y-123 ones do and a larger solubility of Sm in Ba-Cu-O solvent, which makes their growth process faster. When oxygen is present interstitially, it strongly affects the physical properties of the material. The dynamics of oxygen can be investigated by anelastic spectroscopy measurements, a powerful technique for the precise determination of the oscillation frequency and the internal friction when atomic jumps are possible. Anelastic spectroscopy allows determining the elasticity modulus (related to the oscillation frequency) and the elastic energy loss (related to the internal friction) as a function of the temperature. The sample was also investigated by X-ray diffraction (XRD), scanning electronic microscopy (SEM), and electric resistivity. The results obtained show a thermally activated relaxation structure composed by at least 3 relaxation processes. These processes may be attributed to the jumps of oxygen atoms present of the Cu-O plane in the orthorhombic phase.
Resumo:
The goal of the present study was to investigate possible differences towards strenght recovery measured by different methods and running economy (RE), after one session of downhill running (DR), in order to induce muscle damage (MD). Our hypothesis is that the strenght recovery measured by jumps is more alike RE markers, due to the measures' specificity. Ten male subjects, ages 18 to 30, apparently healthy, without any experience with strenght training at least 6 months before the tests took place in this study. After going to the lab twice (to familiarize themselves with the protocols, and determine their maximum oxygen consumption/running speeds), they went to the lab five times in the following week, in order to collect all the variables before, immediately after, and 24, 48, 72 and 96 hours in. The variables obtained were: stride frequency (SF), stride lenght (SL), oxygen volume (VO2), carbon dioxide volume (VCO2), ventilation (VE), lactate blood concentration ([Lac]), isometric peak torque (IPT), subjective pain perception (SPP), effort perception (EP), medial-portion circumference (CIR), knee movement extent (EXT), torque development rate (TDR), counter movement jump and squat jump height (HCM and HS), strenght development rate of both jumps (SDCM and SDS), and maximum soil strenght reaction (SRCM and SRS). Changes over time in all variables were verified by one way variancy analysis. Differences between the strenght measures were verified by two way variancy analysis. When significant effects were verified, Tuckey's post-hoc were applied. The significancy level taken on this study was p < 0,05. Of all indirect muscle damage markers, IPT, SPP and TDR were the only ones in which ocurred significant changes. We couldn't find the moments where this happened for TDR with the post-hoc used. On RE markers, VO2, [Lac] and VE suffered significant effects over time. About the jumps variables, only SDCM and HCM presented significant...
Resumo:
The temperature dependencies of specific heat and spin susceptibility of a coupled dx2-y2 + idxy superconductor in the presence of a weak dxy component are investigated in the tight-binding model (1) on square lattice and (2) on a lattice with orthorhombic distortion. As the temperature is lowered past the critical temperature Tc, first a less ordered dx2-y2 superconductor is created, which changes to a more ordered dx2-y2 + idxy superconductor at Tcl(< Tc). This manifests in two second order phase transitions identified by two jumps in specific heat at Tc and Tc1. The temperature dependencies of the superconducting observables exhibit a change from power-law to exponential behavior as temperature is lowered below Tc1 and confirm the new phase transition. © 1998 Published by Elsevier Science B.V. All rights reserved.
Resumo:
The aim of the present study were: 1) To verify the relationship of vertical, horizontal and sextuple jumps with agility and velocity of 5, 10 and 25 m; 2) To verify the capacity of these jumps to predict the agility and 5, 10 and 25 m velocity performance in children. Twenty eight boys (9.47 ± 0.64 years) and thirty girls (9.69 ± 0.70 years) were evaluated. The correlation values between agility and velocity on 5, 10 and 25 m velocity were, respectively, r = 0.63, 0.51, 0.44 and 0.64 with vertical jump, r = 0.68, 0.62, 0.28 and 0.62 with sextuple jump, and r = 0.60, 0.50, 0.26 and 0.57 with horizontal jump. The vertical and sextuple jumps were able to predict the agility and 25 m velocity performance (p < 0.05). Furthermore, they demonstrated capacity to predict 5 and 10 m velocity, respectively (p < 0.05). The vertical and sextuple jump tests may be used for assessment and control of training with children practicing activities that require agility and velocity, since both jumps predicted the agility and velocity performance, which did not occur with the horizontal jump.
Resumo:
Pós-graduação em Bases Gerais da Cirurgia - FMB