O efeito da intensidade do exercício prévio sobre a cinética do consumo de oxigênio durante a corrida

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Desportos, Programa de Pós-Graduação em Educação Física, Florianópolis, 2014.Abstract : The oxygen uptake (VO2) measured at pulmonary level reflects changes in oxidative metabolism in active tissues. The aim of this study was to compare the effects of two different modes of prior exercise (sustained severe exercise versus intermittent repeated sprints - IRS) on VO2 kinetics parameters during severe intensity running. Thirteen male amateur futsal players (age 22.8 ± 6.1 years; mass 76.0 ± 10.2 kg; height 178.7 ± 6.6 cm; VO2max 58.1 ± 4.5 ml.kg .min-1) performed a maximal incremental running test on the motorized treadmill for the determination of gas exchange threshold (GET) and maximal VO2 (VO2max). In two different days, the subjects completed a 6-min bout of severe exercise (50 % of the difference between the VO2 at LV and VO2max - ? 50) on a treadmill 6 min after: (1) an identical bout of severe exercise (control) and; (2) a protocol of IRS (6 x 40 m; 1 min of passive recovery). Pearson product moment correlations were used to assess the relationships between parameters. Main effects for all variables were determined using one-way repeated-measures analysis of variance. The level of significance was set at p = 0.05. The time constant of VO2 primary component (tp) was not significantly different in all conditions (control = 16.0 ± 6.3 s; prior severe exercise = 14.3 ± 5.4 s; prior IRS = 12.3± 6.2 s). Prior sprint exercise significantly elevated the blood lactate concentration ([La]; ~11 mmol.L-1), VO2 baseline (0.93 L.min-1) and heart rate (HR; 124 bpm) before to the onset of severe exercise. However, both prior severe running and prior IRS exercise significantly increased the absolute primary VO2 amplitude (3.77 L.min-1 and 3.79 L.min-1, respectively), reduced the amplitude of the VO2 slow component (0.26 L.min-1 and 0.21 L.min-1, respectively) and decreased the mean response time (MRT; 28.9 s and 28.0 s, respectively) in the same magnitude during subsequently bouts (p < 0,05). This study showed that different modes and intensities of prior exercise does not alter the primary phase of VO2 kinetics and trigger similar effect on overall VO2 kinetics as well as in the VO2 slow component amplitude in severe domain intensity running

Efeito posterior em dieletricos solidos

Dissertação (mestrado) - Universidade Federal do ParanaResumo: A macro e a micro-estrutura dos materiais dielétricos são sensíveis a sua historia térmica, mecânica e elétrica. Foi estudada, do ponto de vista teórico e experimental, a teoria da resposta dielétrica de Curie-Schweidler-Gross, vista tanto pela abordagem da teoria de circuito como da teoria de campo. O assunto e visto dentro da teoria geral da relaxação dielétrica, particularmente o efeito posterior em materiais dielétricos sólidos. O efeito posterior compreende a descarga interna de dielétricos previamente carregados e sua dependência com o intervalo de tempo de carga e a formação de uma tensão de retorno em dielétricos previamente carregados, e curtocircuitados por um intervalo de tempo finito. São apresentados resultados de ensaios de determinação de curvas de tensão de retorno em capacitores com dielétrico de celulose, polipropileno, mica e poliéster.Abstract: The macro and micro-structure of the dielectric materials are sensitive to their thermal, mechanical and electrical history. The Curie-Schweidler-Gross's dielectric response theory, on both theoretical and experimental standpoint, was studied on the approach of the circuit theory and field theory. The subject is considered with the help of dielectric relaxation general theory, specially, the after-effect on dielectric materials. The after-effect embraces not only the internal discharge of dielectrics with previous charge and its dependence on charging time, but also the build-up of a return voltage in dielectrics with previous charge and short circuited for a finite time. Return voltage curves are given for capacitors with dielectric made of cellulose, polypropylene, mica and polyester

A experiência da linguagem através da poesia

Resumo da Comunicação apresentada na IV Semana de Filosofia da Universidade do Estado da Bahia. O Encontro Acadêmico ocorreu no Departamento de Educação do Campus I da UNEB, na cidade de Salvador, de 14 à 19 de agosto de 2023

Soil loss ratio for three green manures

Um experimento sobre perdas de água e solo por erosão foi desenvolvido, durante seis anos agrícolas (1973/74 a 1978/79), no Centro Experimental de Campinas do Instituto Agronômico do estado de São Paulo, Brasil, em um Typic Haplortox, com vistas em avaliar a Razão de Perdas de Solo (RPS) para três leguminosas utilizadas como adubos verdes. As leguminosas estudadas foram a Crotalaria juncea L. (crotalária); Stizolobium aterrinum Piper et Tracy (mucunapreta) e Dolichos lablab L. (labelabe). Para determinar a razão de perdas de solo, foram estabelecidos quatro períodos das culturas isolados de 0-30, 30-60, 60-90 e 60-120 dias após a semeadura e períodos cumulativos de 0-30, 0-60, 0-90 e 0-120 dias após a semeadura. Os resultados obtidos mostraram maior proteção oferecida pela mucuna-preta à erosão, com valores de RPS de 0,28; 0,37; 0,17; e 0,09 para os períodos isolados de 0-30, 30-60; 60-90 e 60-120 dias após a semeadura. O labelabe apresentou, para a mesma situação, os valores de 0,50; 0,45; 0,27 e 0,19; enquanto, para a crotalária, os valores foram de 0,30; 0,42; 0,26 e 0,24. Os resultados mostraram proteção mais efetiva do solo à erosão a partir dos 60 dias após a semeadura, por parte das espécies avaliadas. A mucuna-preta apresentou maior efetividade na proteção do solo, seguida da crotalária, especialmente no primeiro período, e do labelabe, no estádio mais próximo ao florescimento.A field experiment of soil and water losses by erosion was carried out during six consecutive agricultural years (1973/74 to 1978/79) at the Experimental Center of Campinas, Instituto Agronomico of São Paulo, Brazil, in a Typic Haplorthox, to evaluate soil loss ratio (SLR) for three green manures: Crotalaria juncea L., Stizolobium aterrinum Piper et Tracy and Dolichos lablab L. Four cropstage periods were defined as isolated periods (0-30, 30-60, 60-90, and 60-120 days after planting), and as accumulated cropstage period (0-30, 0-60, 0- 90 or 0-120 days after planting). The results showed that Stizolobium aterrinum gave the best cover protection against soil loss, with values of soil loss ratio (SLR) of 0.28, 0.37, 0.17 and 0.19 for cropstage periods of 0-30, 30-60, 60-90 and 60-120 days after planting, respectively. Dolichos lablab showed SLR values of 0.50, 0.45, 0.27 and 0.19 and Crotalaria juncea of 0.30, 0.42, 0.26 and 0.24 for the same cropstage periods, respectively. The results also showed that the cover protection from the three green manures was more effective after 60 days of planting. Stizolobium was the most efficient cover, followed by Crotalaria, mainly in the first cropstage period and Dolichos, during flowering

Changes in VO2 Kinetics After Elevated Baseline Do Not Necessarily Reflect Alterations in Muscle Force Production in Both Sexes

A link between muscle fatigue, decreased efficiency and the slow component of oxygen uptake (VO2sc) has been suggested. However, a cause-effect relationship remains to be elucidated. Although alterations in VO2 kinetics after elevated baseline work rate have previously been reported, to date no study has observed the effect on muscle force production (MFP) behavior considering physiological differences between male and female subjects. This study investigated the effect of elevated baseline work rate on the VO2 kinetics and MFP in 10 male and 10 female healthy subjects. Subjects performed 4 transitions of very-heavy (VH) intensity cycling in a randomized order after unloaded (U-VH) or moderate (M-VH) exercise. Maximal isokinetic efforts (MIE) were performed before and after each condition at two different cadences (60 or 120 rpm). Whereas baseline VO2 and time constant (τ) were significantly higher in M-VH compared to U-VH, the fundamental amplitude and the VO2 slow component (VO2sc) were significantly lower in M-VH (p &lt; 0.05) in both sexes. Blood lactate concentration ([La]) and rate of perceived exertion (RPE) were not influenced by condition or sex (p &gt; 0.05). The MFP post-exercise was not significantly influenced by condition in both sexes and cadences (Δtorque for males: at 60 rpm in U-VH = 13 ± 10 Nm, in M-VH = 13 ± 9 Nm; at 120 rpm in U-VH = 22 ± 14 Nm, in M-VH = 21 ± 12 Nm; for females: at 120 rpm in U-VH = 10 ± 9 Nm, in M-VH = 12 ± 8 Nm; p &gt; 0.05), with the exception that female subjects presented smaller decreases in M-UH at 60 rpm compared to U-VH (11 ± 13 vs. 18 ± 14 Nm, respectively, p &lt; 0.05). There was no correlation between the decrease in torque production and VO2 kinetics parameters (p &gt; 0.05). The alterations in VO2 kinetics which have been suggested to be linked to changes in motor unit recruitment after elevated baseline work rate did not reflect alterations in MFP and fatigue in both sexes

Quality characteristics of vineyard soil in the conventional and biodynamic cultivation system of chardonnay vinifers

Viticulture, particularly in the production of viniferous varieties, is one of the most present crops in the State of Rio Grande do Sul. Soil indicators can be highlighted attributes linked to organic carbon, which have often been used, to assess soil quality. The objectives here were: a) to evaluate and compare soil quality characteristics of vineyards in the conventional and biodynamic cultivation system of chardonnay vinifers, together with areas of native forest, in the localities where the vineyards exist; b) to estimate the susceptibility to environmental impacts and possible soil degradation processes caused in soil management from cultivation systems and practices. The study was descriptive, exploratory and comparative of quantitative analysis. The sample was 26 vineyards and 19 corresponding native forests about 8 to 10 sub-samples, at a depth of 0 to 20 cm. The results showed an intermediate condition of VBI in relation to VCO and VAT, confirming the tendency of loss of initial soil characteristics from cultivation, but maintaining several attributes in a condition closer to that observed under natural vegetation

Cambios por uso y manejo en suelos de llanuras aluviales en el sur de Brasil

Agricultural land use causes changes in physical and chemical attributes of the soil, due to the management practices employed the productive capacity of the soil can be compromised under different agricultural systems. Thesoils of Porto Alegre are quite diverse reflecting the geology, topography and drainage network of the region, and include lowland soils, like the alluvial plain of the Arroio Dilúvio. This study was carried out in four landscape units (NativeForest, Agroforestry System, Horse Farm and Agricultural Crops), to assess changes in soil characteristics afterdifferent types of land use and management on the plain of the Dilúvio Arroio. We sampled disturbed and undisturbed soil samples for chemical (pH,EC, V, SOM, CEC, Al3+, H+Al) and physical analysis (porosity, microporosity and macroporosity). These chemical and physical attributes of the soils, especially pH, V%, SOM, CEC and Al3+, underwent changes under the different types of land use and management, with significant differences.Most changes were detected in thecropland soils. Multivariate analysis demonstrated the influence of the different types of land use, at the surface, land use and management had the greatest influence, while at depth,theproximity of the areas was the predominant factor.O uso do solo agrícola provoca alterações nos atributos físicos e químicos do solo, devido às práticas de manejo empregadas a capacidade produtiva do solo pode ser comprometida sob diferentes sistemas agrícolas. O município de Porto Alegre apresenta diversidade de solos, topografia e redes de drenagem superficial, em meio a esta diversidade de ambientes é possível encontrar áreas de baixadacomo a planície aluvial do Arroio Dilúvio. Este estudo foi realizado em quatro unidades de paisagem (Mata, Sistema Agroflorestal, Potreiro, Plantas de Lavoura) com o objetivo de avaliar mudanças nas características dos solos após diferentes usos e manejos, na planície do Arroio Diluvio, em Porto Alegre. Para o estudo foram realizadas coletas de amostras deformadas e indeformadas de solo, em profundidades de 0-20 cm e 60-80 cm, para análises químicas (pH, CE, V, MOS, CTC, Al3+, H+Al) e físicas (porosidade,microporosidade e macroporosidade). Os atributos químicos e físicos dos solos sofreram alterações nos diferentes usos e manejos, destacando-se o pH, V%, MOS, CTC e Al3+, com diferenças significativas. O solo da área cultivada com plantas de lavourafoi o solo que apresentou mais alterações. A análise multivariada evidenciou asinfluências para as diferenças entre os tipos de uso do solo, pois em superfície o uso e manejo se mostrouo fator de maior influência, enquanto em profundidade, a proximidadedas áreas foi o fator predominante.El uso de suelos agrícolas provoca cambios en los atributos físicos y químicos del suelo, debido a las prácticas de manejo empleadas la capacidadproductiva del suelo puede verse comprometida bajo diferentes sistemas agrícolas. El municipio de Porto Alegre cuenta con diversidad de suelos, topografía y redes de drenaje superficial, en medio de esta diversidad de ambientes es posibleencontrar zonas de tierras bajas como la llanura aluvial del Arroio Dilúvio. Este estudio se realizó en cuatro unidades de paisaje (Bosque, Sistema Agroforestal, Potrero, Plantas de Cultivo) con el objetivo de evaluar cambios en las características del suelo despuésde diferentes usos y manejos, en la llanura Arroio Diluvio, en Porto Alegre. Para el estudio, se recolectaron muestras de suelo deformado y no perturbado a profundidades de 0-20 cm y 60-80 cm, para análisis químicas (pH, CE, V, MOS, CTC, Al3+, H + Al) y físicos(porosidad, microporosidad y macroporosidad). Los atributos químicos y físicos de los suelos sufrieron cambios en los diferentes usos y manejos, destacando el pH, V%, MOS, CTC y Al3+, con diferencias significativas. El suelo de la zona cultivada conplantas de cultivo fue el suelo que presentó más alteraciones. El análisis multivariado evidenciólas influencias para las diferencias entre los tipos de uso del suelo, ya que en superficie el uso y manejo fue el factor más influyente, mientrasque en profundidad, la proximidad de las áreas fue el factor predominante

Modeling box - jenkins applied a prediction of wind speed in the regions of the brazilian northeast for the fins of wind generation

In the present work, a study was carried out to predict monthly average wind speed in regions of the Brazilian Northeast. For this purpose, the Box - Jenkins modeling methodology was applied to the 10 m high wind speed data from January 2010 to December 2013. The forecast in all study locations was for the year 2014 through of the SARIMA model, which predominated in practically all regions, that is, an indication that the ideal forecast model must necessarily be introduced to the seasonal component. The prediction was efficient in some regions, for example, in Aracaju it was possible to find a MAPE error of 4.66%. In the localities of Aracaju and Salvador it is possible to identify that the predicted series tend to have similar behavior to the observed series regarding the similarity of maximum and minimum wind speed. This work could be used as a wind speed prediction tool to study and advance wind generation in several regions, providing decision makers with local wind exploitation, since it will be possible to estimate the wind regime in the future

Thigh Ischemia-Reperfusion Model Does Not Accelerate Pulmonary VO2 Kinetics at High Intensity Cycling Exercise

Background: We aimed to investigate the effect of a priming ischemia-reperfusion (IR) model on the kinetics of pulmonary oxygen uptake (VO2) and cardiopulmonary parameters after high-intensity exercise. Our primary outcome was the overall VO2 kinetics and secondary outcomes were heart rate (HR) and O2 pulse kinetics. We hypothesized that the IR model would accelerate VO2 and cardiopulmonary kinetics during the exercise.Methods: 10 recreationally active men (25.7 ± 4.7 years; 79.3 ± 10.8 kg; 177 ± 5 cm; 44.5 ± 6.2 mL kg−1 min−1) performed a maximal incremental ramp test and four constant load sessions at the midpoint between ventilatory threshold and VO2 max on separate days: two without IR (CON) and two with IR (IR). The IR model consisted of a thigh bi-lateral occlusion for 15 min at a pressure of 250 mmHg, followed by 3 min off, before high-intensity exercise bouts.Results: There were no significant differences for any VO2 kinetics parameters (VO2 base 1.08 ± 0.08 vs. 1.12 ± 0.06 L min−1; P = 0.30; τ = 50.1 ± 7.0 vs. 47.9 ± 6.4 s; P = 0.47), as well as for HR (MRT180s 67.3 ± 6.0 vs. 71.3 ± 6.1 s; P = 0.54) and O2 pulse kinetics (MRT180s 40.9 ± 3.9 vs. 48.2 ± 5.6 s; P = 0.31) between IR and CON conditions, respectively.Conclusion: We concluded that the priming IR model used in this study had no influence on VO2, HR, and O2 pulse kinetics during high-intensity cycling exercise