891 resultados para Intermittent


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The main objective of this study was to analyze the behavior of variables related to swim ability at and above maximal lactate steady state (MLSS), performed at continuous and intermittent conditions in individuals with different aerobic performance levels. Participated of this study male swimmers with ages between 20 to 25 years, specialists in events of 400 m, 800 m and 1500 m and open water swims, with at least 3 years of experience in the modality. The individuals performed a maximal 400-m swim test. After this test, they were divided into two groups, in accordance with the speed attained during 400-m swim test: G1 (higher performance) and G2 (lower performance). For the determination of continuous MLSS (MLSSc), 2 to 4 trials of 30-min were performed. For the determination of the intermittent MLSS (MLSSi) 2 to 4 trials of 30-min (12 repetitions of 2 min 30 s, with 30 s of rest) were performed, in constant speed, with the first trial performed at 102.5% MLSSc. Th technical indexes, stroke rate (FB) and stroke length (CB) were determined in all tests. The SR was calculated trough recordings using the time needed to perform five stroke cycles. The SL was calculated dividing the speed by the SR. There was no significant difference on the antropometric characteristics between groups. The speed at and above MLSSc were significantly higher at G1 (1,23±0,05 e 1,27±0,06, respectively) than G2 (1,10±0,06 e 1,13±0,06, respectively). There was significant change in SL and SR in G2. In the same way, there was significant change in SL and SR only in G2, above MLSSc. Similar to continuous condition, the speeds at and above MLSSi were significantly higher in G1 (1,27±0,05 e 1,30±0,05, respectively) do que no G2 (1,14±0,07 e 1,16±0,07, respectively). There was significant change in SL and SR only in G2. There was significant change in SR and SL in both groups above MLSSi. Thus,...(Complete abstract click electronic access below)

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The ankle sprains represent the most common injuries in sports and basketball. In this sense, the use of ankle bracing and strength capacity analysis of the ankle evertor and invertor muscles, have been suggested as preventive measures and important tools for identifying risk factors associated with ankle sprains. However, questions still persist as to effect of the use ankle bracing on biomechanical variables related to the stability of the ankle. For this reason, this study aims to analyze the effect of the use of ankle bracing on peak torque (PT) of ankle evertor and invertor muscles and on eccentric evertor/concentric invertor torque ratio (EVEECC/INVCON), during the basketball match-play simulation. Ten healthy college basketball players, without mechanics or functional ankle instability performed a laboratory-based protocol representative of work rates observed during basketball match-play, in two different situations, with and without use of ankle bracing. The test was composed of a succession of intermittent physical effort equally distributed in four periods of 10 minutes each, considering the mechanical and physiological demands of a basketball match-play. Prior to the start of the trial (Evaluation 1) and after 2° (Evaluation 2) and 4° (Evaluation 3) periods, the subjects performed five maximal isokinetic concentric and eccentric contractions of ankle invertor and evertor muscles, separated by two minutes rest, at 60 °/s and 120 °/s. After testing for normality of data distribution with the Shapiro-Wilk test, was used the ANOVA repeated measures for two factors and post-hoc Bonferroni test for comparison of variables between assessments. Was adopted p < 0.05. There was no significant difference for PT and EVEECC/INVCON torque ratio between assessments. There was a decrease in PT EVEECC at 60º/s and 120º/s for the ...(Complete abstract click electronic access below)

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The use of heat in parallel with relative low temperatures and applied to several areas of the industry is essential for the main manufacturing processes, like drying, dehydrating, concentration, annealing, production of chemical reactions, and microbiological sterilization. Without neither the heat nor the coming of a great quantity of thermal heat, with high quality, there would not be the “modern society”, with its high standards of living plus its high consumption levels; from services to goods in general. Within an almost absolute way, the heat flows are obtained from vapor systems. Thus, in this work we are going into the operation of a vapor system, composed of two firetube boilers dimensioned to supply vapor for three processes. However, with the transfer of one of the processes to another plant, the system got over-dimensioned. But, taking advantage of this scenario, the two boilers were used to supply vapor to further processes, causing their intermittent usage. Moreover, the operational alternative adopted by the maintenance engineering of the plant for a creating a solution has been presented; both the positive points and negative ones were disclosed, likewise the possibility of improvement points

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This paper is proposed the usage of an Organic Rankine Cycle (ORC) along with waste heat recovery from an inconstant heat source. This method of waste heat recovery with intermittent heat source is part of a technical viability study. This paper also brings up the usage of thermal energy storage as heat source for the ORC. This paper is based on a heat treatment company study in which a natural gas furnace is explored. Data such as mass flow, temperature and specific waste gas heat from this furnace are used through calculations. Calculations are made also based on furnace cycles. This viability study considers a series of working fluids such as ammonia, benzene, R113 and R134a. Results point out that ORC with out thermal storage and using refrigerant fluid ammonia is the best alternative

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The main objective of this study was to analyze the reliability of blood lactate concentration ([La]), oxygen uptake (VO2) and heart rate (FC) in an intermittent protoco, performed at 95%VO2max with passive or active recovery in untrained subjects. Participated of this study, active healthy males with 20 to 25 years, which were doing aerobic exercises witha weekly frequency of 3 sessions at least. The individulas performed, in different days, the following protocols in a cyclergometer: 1) An incremental test until exhaustion to determine maximal oxygen uptake (VO2max) and the intensity at VO2max; b) Two transitions at 95%VO2max for the determination of the VO2 kinetics parameters and; c) Two intermittent tests until exhaustion, with repetitions at 95% IVO2max and with durantion defined as being half of the duration of the slow component. The duration of the recovery was half of the duration of the effort (effort:pause of 2:1). This test was performed with passive (GP) and active recovery (GA). The VO2 and FC were measured continulously in both tests. Blood collections were performed for the determination of the [La]. There was significant correlação in both groups for VO2 (ATIVA - 0.94, PASSIVA - 0.75), [La] (ATIVA - 0.83, PASSIVA - 0.90) and FC (0.93) only for the passive group. Thus, it can be concluded that the cardiorrespiratory and metabolic responses present good realiability in an intermittent exercise with active or passive recovery

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The purpose of this project is to verify whether anaerobic reactors applied to sewage treatment are energetically self-sufficient. This evaluation can be made by balancing the methane produced through the anaerobic transformation stages (hydrolysis, acidogenesis, acetogenesis and methanogenesis) and the reactor energy consumption requirements. The original project included methanogenic activity tests, which could not be performed due to setbacks in the installation of an analytical instrument. Scientific articles about bench- and full-scale anaerobic reactors were investigated instead. An average substrate-to-methane conversion efficiency of 58,2±18,6% was found for the bench-scale reactors and higher efficiencies (89,2%) were found for the cases which had higher Organic Loading Rates (OLRs) values. The average energy output was 0,013 kWh/Lsewage, value unable to meet the energy needs for the reactor operation, considering equipments normally used such as temperature controller. This balance can become positive if few hypotheses are made, for example (i) to eliminate the use of temperature controller (ii) to alter the operation pattern from continuous to intermittent. Based on energy balance assessment of eight bench-scale reactors, it was observed that the implementation of a system for biogas utilization is not energetically feasible. However, interesting results were found for a full-scale sewage treatment plant, ETE Ouro Verde – Foz do Iguaçu, PR, Brazil. Even though its substrate-tomethane conversion efficiency was about 10% only, the energy balance was quite positive, with energy consumption of 68 kWh/month and energy production of 660 kWh/month. This analysis leads us to conclude that energy recovery from full-scale sewage treatment plants should be practiced by other plants

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Osteoarticular diseases are very frequent in small animals, especially dogs. Osteoarthritis is the most common degenerative arthropathy in cats and dogs. It is one of the most important skeletal disease in small animals and it is divided into two broad classes: secondary and genetics. The secondary is originated from situations that can cause joint instability like as trauma, ligament problems and obesity among others. The gene for osteoarthritis comes from hereditary problems such as hip dysplasia, elbow dysplasia and other diseases that can cause articular instability. The hereditary osteoarticular diseases are important only because they can result in the osteoarthritis. It is important to prevent the joint instability and consequently the clinical signs that affect the quality of life of the animals. The most common clinical signs are intermittent claudication, a decrease in performance, reluctance to jump and climb ladders among others. To prevent the clinical signs or mitigate them, the treatments need to be focused on pain control and especially restoration of the affected joint. The treatments most used are the medical and surgery. Anti-inflammatory and analgesics are used in large scale for pain control and to inhibit inflammatory mediators. Furthermore, medical treatment includes weight reduction, physiotherapy and proper nutrition along with anti-inflammatory and analgesics. Surgical treatments are indicated if there is an inadequate response to medical treatment. Physiotherapy is often used in conjunction with other treatments. Besides the reduction of weight is essential and obesity is unacceptable. Cats also suffer from osteoarthritis, but the diagnosis is rarer than in dogs. Usually the cat’s owners relate the reluctance to jump and drop in performance with senility, and when the disease is diagnosed is already in... (Complete abstract click electronic access below)

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This project aimed to analyze the feasibility of the methane yield associated to the anaerobic digestion of brewery residues, checking whether the energetic balance of the system is favorable. The methane yield efficiency was calculated for the parameters of two papers that treated solids with a particle-size <1mm. Theses solids are not degraded in conventional treatment systems. Calculations were based in the reactions of anaerobic degradation of the macromolecules that compose brewery residues, considering the theoretical production and the effective production of methane. The results were 50.44% and 52.86%. Regarding to the energy balance of the anaerobic treatment, we noted the high influence of the selection and operating regime of electrical equipment over the potential energy. The best situation, in which the energetic self-sufficiency was reached, was observed when using the mixer under an intermittent regime (1min/h), without employing the heating recirculator, for the maximum organic loading of 4.0 gVS/L.day (days 248-258). In this case, the system would generate an amount of energy equal to 0.0356 kWh/day, able to overcome the energy required by the equipment in about 6.5 times. Moreover, we also noted the interference of the application of different solid loadings in the reactors, once the application of the higher organic load generated 5 times more energy than the application of the smaller one

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The objective of this study was to compare the power corresponding to maximal lactate steady state determined through continuous (MLSSC) and intermittent protocol with active recovery (MLSSI). Ten trained male cyclists (25 ± 4 yr, 72.5 ± 10.6 kg, 178.5 ± 4.0 cm), performed the following tests on different days on a cycle ergometer: (1) incremental test in order to determine the anaerobic threshold (AT) and maximal power (Pmax); (2) two to five constant workload tests to determine MLSSC, and; 3) two to three constant workload tests to determine MLSSI, consisting on 8 x 4 minutes bouts interspersed by two minutes of active recovery at 50% Pmax (i.e., 46 min of exercise protocol). MLSS intensity was defined as the highest workload at which blood lactate concentration did not increase by more than 1 mM between minutes 10 and 30 of the constant workload. The workload corresponding to MLSSC (273.2 ± 21.4 W) was significantly lower than that corresponding to MLSSI (300.5 ± 23.9 W). With base on these data, it can be verified that the intermittent exercise mode utilized in this study, allows an increase of 10% approximately, in the exercise intensity corresponding to MLSS.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Due to concerns about rational use of energy, several alternative technologies of power generation appeared, including the conversion of solar energy into electrical energy by photovoltaic panels. In low-income households, the refrigerator represents considerable impact on the electric bill, since it requires constant power given its use in food preservation. It is possible to reduce this share, with the use of an alternative energy source. This work presents a timed switching electronic system, which allows commercial equipment that is not affected by short interruptions in the power supply to use a photovoltaic panel as a source of alternative energy, which usually do not provide energy continuously. Switching is made automatically in case of low incidence of sunlight, and without any form of energy storage. Between each switching, there is a dead time without power supply, therefore preventing the use of synchronizers circuits between the photovoltaic panel and the public power grid. A circuit containing a 80C31 microcontroller is used to control the system’s switching. The photovoltaic panel’s voltage inverter is in H bridge configuration, and is also controlled by the microcontroller through Pulse Width Modulation, which makes use of preprogrammed tables to generate the control signals of the power transistors. Through the use of software simulations, the proposed system was tested, which is capable of supplying intermittent single-phase loads. The simulations indicates that the project developed in this paper can be assembled into a prototype and be tested under real operating conditions, as long as the scaling of components, the characteristics of the photovoltaic panel to be used, and the project involved load are taken into account

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Pós-graduação em Bases Gerais da Cirurgia - FMB

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)