Caracterização de Folhelhos como Rochas Selantes

A capacidade de uma rocha agir como barreira à migração dos hidrocarbonetos é fundamental na configuração de uma trapa. São discutidos os mecanismos que controlam a eficiência da rocha selante em servir como barreira à migração e reter hidrocarbonetos. A pressão capilar medida através de ensaios de injeção de mercúrio em laboratório permite uma correlação com a pressão capilar em que ocorre a invasão do hidrocarboneto através dos poros da rocha selante. Essa pressão capilar pode agir como limitadora da quantidade de hidrocarboneto que pode ser retida abaixo da rocha selante. A partir de determinada espessura da coluna de hidrocarbonetos abaixo do selante a pressão de boiabilidade dos hidrocarbonetos excederia a pressão capilar, passando o selante a constituir então um meio de migração, perdendo sua capacidade de rocha capeadora. Outras formas de limitação de selantes podem ser avaliadas, como a presença de falhas, fraturas e outras heterogeneidades. As rochas com características mais dúcteis tem menor propensão à formação de fraturas, o que lhes confere boas características como selante, pois as fraturas tendem a aumentar a permeabilidade, ocasionando o vazamento de hidrocarbonetos através da rocha selante. A correlação de ensaios de compressão e condições de tensão em subsuperfície, permite predizer situações em que a integridade da rocha selante estaria comprometida. Neste trabalho foram analisadas duas amostras de folhelhos ricos em matéria orgânica das formações Irati e Ponta Grossa na Bacia do Paraná. Os resultados de testes de pressão capilar de injeção de mercúrio e os ensaios de compressão, foram analisados e comparados aos dados texturais e composicionais obtidos a partir da análise de lâminas delgadas, difratometria de raios-X e microscopia eletrônica de varredura. A amostra da Formação Ponta Grossa apresentou boa qualidade tanto em ensaios de pressão capilar quanto de compressão, demonstrando ser um bom selante. A amostra da Formação Irati embora tenha apresentado boas características quanto à pressão capilar, a sua propensão ao fraturamento constitui um fator de risco

RELIABILITY OF KINETIC VARIABLES OF SQUAT JUMPS WITH DIFFERENT STARTING POSITIONS

The aims of the study were to compare dynamic variables (impulse, peak force, peak power and rate of force development) derived from squat jumps starting from self-selected and 90 degree knee angles as well as determining the reliability of these variables in the two conditions. Fourteen male junior volleyball players performed three Squat Jumps on a force platform while starting from each position. Intraclass Correlation Coefficients were calculated and t-tests were used to identify differences between the starting positions. In both conditions, most variables showed ICC coefficients greater than 0.85 and no significant differences between the starting conditions were found. It can be concluded that both conditions lead to reliable dynamic data without significant differences and therefore standardized knee angle is not necessary

A CASE STUDY OF THE KICKING FOOT AND STANCE IN ROUNDHOUSE KICK: CONTROL AND COMBAT SITUATIONS

Once this work is part of a long term study, the aim was to show the preliminary results of the comparison of the kicking foot and stance in the roundhouse kick according to the onset condition (control vs. combat situation). One black belt athlete participated on this study. A motion capture system of 18 cameras (Optitrack© 360Hz) was used for the kinematic data acquisition. In order to obtain the maximum height and speed, execution and movement time of the kicking foot we used one marker. In order to represent the stance positions we used five markers. The preliminary analyses suggest that there are differences between control and combat situations: 1.the maximum height was smaller in combat situation since the athlete prefers to kick in the trunk of the opponent and 2.the stance positions highlight the influence of the movements of the opponent in combat

RELIABILITY OF KINETIC VARIABLES OF SQUAT JUMPS WITH DIFFERENT STARTING POSITIONS AFTER CRITERION BASED FAMILIARIZATION

The aim of this study were the verification of criterion based familiarization by Intraclass Correlation Coefficient (ICC) and Standard Error of Measurement (SEM) and the identification of possible differences of performance and dynamic variables at squat positions with 90o (SJ90 o) and 120o (SJ120 o) of knee angle. Fifteen male junior volleyball players performed three randomly performed jumps with maximal intensity from each squat position. SJ90 o results in lower peak force and higher vertical impulse, impulse duration and time for peak force than SJ120 o. ICC and SEM show that familiarization that consisted of three series of 5 jumps for each squat position with 1 minute of rest between the jumps, is sufficient to ensure adequate test conditions

VALIDITY AND RELIABILITY OF THE MICROSOFT KINECT TO OBTAIN THE EXECUTION TIME OF THE TAEKWONDO’S FRONTAL KICK

The aim of this study was to verify the validity and reliability of the Microsoft Kinect® as a tool to analyze the time of the frontal kick of the Taekwondo (ap chagui). The volunteers performed 15 repetitions of this kick while the execution time data was been obtained, simultaneity, by the Microsoft Kinect® and the OptiTrack System (golden pattern). In order to verify the reliability of the durations of the kicks we calculated the Intraclass Correlation Coefficient (ICC3,k) between execution times found for each system. The Pearson Correlation was used to test the concurrent validity. The results of ICC and r Pearson presented in this study indicate that the Microsoft Kinect®, associated with a tracking algorithm, could be a feasible tool to evaluate the execution time of the frontal kick of the Taekwondo (ap-chagui)

Uma comparação durante seis meses da qualidade de vida e estados de humor entre universitários fisicamente ativos e sedentários

A inatividade física tem sido descrita como um dos principais problemas de saúde pública do século XXI. Neste contexto, a atividade física desempenha um papel importante na redução da prevalência de sedentarismo, melhorando a qualidade de vida e a saúde mental dos indivíduos. Objetivo: Este estudo teve como objetivo analisar a influência de seis meses de atividade física (AF) na qualidade de vida (QV) e estados de humor (EH) de adultos jovens. Métodos: Uma amostra de 32 indivíduos completou uma bateria de questionários para avaliar o seu nível de atividade física, qualidade de vida e estados de humor. Eles foram separados em dois grupos: sedentários (n = 15) e fisicamente ativos (n = 17). O International Physical Activity Questionnaire (IPAQ) foi utilizado para avaliar os níveis de AF, o WHO Quality of Life-BREF (WHOQOL_Bref) para QV e a Escala Brasileira de Humor (BRAMS) para os EH. Foi realizada análise fatorial de variância com medidas repetidas e teste post-hoc de Tukey (p ≤ 0,05) para QV e análise inferencial para os EH. Resultados: Escores de QV foram significantemente maiores para o grupo fisicamente ativo nos domí- nios ambiental e social. Da mesma forma, EH apresentaram maiores escores na dimensão Vigor para o grupo fisicamente ativo depois de seis meses, sem contudo, atingir os níveis de significância estatística. Conclusões: Estes resultados sugerem que AF pode influenciar positivamente aspectos na qualidade de vida do indivíduo. Contudo, os dados não evidenciam uma influência significativa da AF nos estados de humorPhysical inactivity has been described as one of the major public health problems of the 21st century. Physical activity plays an important role in reducing the prevalence of sedentarism, improving the quality of life and improving individuals’ mental health. Objective: This study aimed to perform a 6-month comparison of quality of life (QOL) and mood states (MS) between physically active and sedentary college students. Methods: A sample of 32 individuals completed questionnaires to assess their level of physical activity, quality of life and mood states. They were separated into two groups: sedentary (n=15) and physically active (n=17). The International Physical Activity Questionnaire (IPAQ) was used for assessing PA levels, the WHO Quality of Life-BREF for QOL and the Brazilian Mood Scale for MS. We used factorial analysis of variance with repeated measures and post-hoc Tukey test (p ≤ 0.05) for QOL and MS inferential analysis. Results: QOL was significantly higher for the physically active group in Environment and Social Relationships domains. Similarly, MS showed increased scores in Vigor dimension for the physically active group after six months. Conclusions: These results suggest PA can positively influence aspects of an individuals‘ quality of life. However, our data did not show a significant influence of PA on mood state

Network analysis in small-sided and conditioned soccer games: the influence of additional players and playing position

The purpose of this article was to investigate the influence of additional players and playing position on the network properties during 2x4 minutes small-sided and conditioned games (SSCG) in soccer. Eighteen young soccer players (age 16.4±0.7 years), six defenders, six midfielders, and six forwards, voluntarily participated in SSCGs with different task conditions (4vs.3, with an additional player inside the pitch, 3vs.3+2, with two support players at the side of the pitch, and 3vs.3, numerical equality). General (density, total links and clustering coefficient) and individual (degree centrality, degree prestige, and page rank) network properties were analyzed using the SocNetV® software. Results showed higher values of density (F=59.354, p=.001), total links (F=40.951, p=.001), and clustering coefficient (F=21.851, p=.001) during the 4vs.3 SSCG. Besides, midfielders showed higher values of degree centrality than defenders and forwards (F=10.669, p=.001). Midfielders and forwards also showed higher values of degree prestige than defenders (F=5.527, p=.005). These results indicate that both task condition and playing position influence the general and individual network properties during SSCGs. For this reason, it is suggested that both task condition and team composition need to be adjusted to the coaches’ purpose for each training session in order to maximize the possibilities of cooperation among the teammates