11 research outputs found

    Características construtivas de um carneiro hidraúlico com materiais alternativos

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    O objetivo deste trabalho foi avaliar um carneiro hidráulico construído com conexões roscáveis de PVC roscáveis e metálicas e garrafa de polietileno tereftálico (PET). O estudo foi realizado no Laboratório de Hidráulica da Universidade Federal de Lavras, MG. Testaram-se tamanhos de câmaras de ar (0,6 e 2,5L), diâmetros de furos da tampa da garrafa (5, 15 e 25mm), tipos de garrafa plástica (descartável de guaraná e descartável e retornável de refrigerante de cola), e posições da válvula de escape (vertical e horizontal), a diferentes pressões de recalque (48,39 a 483,92kPa), a cada 48,39 kPa. O desnível do reservatório de alimentação ao carneiro hidráulico foi mantido constante a 4,36m. Os resultados indicaram que a combinação de características construtivas que possibilitam melhor rendimento, maior vazão recalcada, menor vazão de alimentação e menor desperdício, foi o uso de garrafa PET descartável ou retornável com capacidade de 0,6L, válvula de escape na horizontal e tamanho de furo de 25mm na tampa da garrafa

    Water storage in wetted strips under irrigated coffee trees with different criteria of irrigation management Armazenamento de água em faixas molhadas sob cafeeiros irrigados com diferentes critérios de manejo de irrigação

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    The increasing demand for water resources accentuates the need to reduce water waste through a more appropriate irrigation management. In the particular case of irrigated coffee planting, which in recent years presented growth with the predominance of drip irrigation, the improvement of drip irrigation management techniques is a necessity. The proper management of drip irrigation depends on the knowledge of the spatial pattern of soil moisture distribution inside the wetted strip formed under the irrigation lines. In this study, grids of 24 tensiometers were used to determine the water storage within the wetted strip formed under drippers, with a 3.78 L h-1 discharge, evenly spaced by 0.4 m, subjected to two different management criteria (fixed irrigation interval and 60 kPa tension). Estimates of storage based on a one-dimensional analysis, that only considers depth variations, were compared with two-dimensional estimates. The results indicate that for high-frequency irrigation the one-dimensional analysis is not appropriate. However, under less frequent irrigation, the two-dimensional analysis is dispensable, being the one-dimensional sufficient for calculating the water volume stored in the wetted strip.<br>A crescente demanda por recursos hídricos acentua a necessidade de redução do desperdício de água através de um manejo mais adequado da irrigação. No caso particular da cafeicultura irrigada, que nos últimos anos apresentou crescimento com predominância da irrigação por gotejamento, o aprimoramento das técnicas de manejo da irrigação por gotejamento é uma necessidade. O manejo adequado do gotejamento depende do conhecimento do padrão espacial de distribuição de umidade no interior da faixa molhada, formada sob as linhas de irrigação. Neste trabalho, foram utilizadas malhas de 24 tensiômetros para determinar o armazenamento de água no interior de faixas molhadas, formadas sob gotejadores, com vazão de 3,78 L h-1, uniformemente espaçados de 40 cm, submetidos a dois critérios distintos de irrigação (turno fixo e tensão de 60 kPa). Estimativas de armazenamento baseadas em análises unidimensionais, considerando apenas variações na profundidade, foram comparadas com estimativas bidimensionais. Os resultados indicam que, com menor turno de irrigação, a análise unidimensional não é adequada. Para maior turno de irrigação, a análise bidimensional é dispensável, sendo a unidimensional suficiente para o cálculo do volume da água armazenada na faixa molhada

    Home-based self-management for sedentary individuals with mild walking disability after stroke: protocol for a randomised pilot study

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    Abstract Background A Phase I study showed that it is feasible to implement a home-based self-management program aimed at increasing physical activity in individuals after stroke with mild walking disability in Brazil. The next step is to test this program against a control group in order to provide a power analysis for a fully-powered Phase III clinical trial. Methods A Phase II pilot randomised clinical trial with concealed allocation, blinded measurement, and intention-to-treat analyses will be carried out. The inclusion criteria will be individuals diagnosed with stroke, in the acute or subacute phase, with mild walking disability, sedentary, and no significant language impairment. The participants will be randomly allocated to the experimental or control group. The experimental group will receive six sessions of a home-based self-management program based on behaviour change techniques through the Social-Cognitive Theory and Control Theory over 11 weeks. The control group will receive one session of education about stroke (regarding the importance of practising physical activity after a stroke) and usual care. A total of 24 participants will be recruited. The primary outcome will be physical activity, measured through steps taken per day by an activity monitor (Actigraph wGT3X-BT, Pensacola, FL, USA). The mean of daily steps will be analysed to compare groups after intervention. Secondary outcomes will be cardiovascular risk (body mass index, waist circumference, and blood pressure), depressive symptoms (Geriatric Depression Scale), walking ability (6-Minute Walk Test and 10-Meter Walk Test), exercise self-efficacy (Self-Efficacy for Exercise scale), social participation (Stroke Impact Scale) and quality of life (EuroQual-5D). Two-way analyses of variance will be implemented for all parametric outcomes, and the Kruskal–Wallis test for non-parametric outcomes will be used to determine the statistical significance of the between-group differences and reported as mean differences between groups (95% CI). All analyses will be conducted intention-to-treat. All outcomes will be measured at baseline (Week 0), post-intervention (Week 12), and follow-up (Week 24). This pilot clinical trial was registered online at Clinical Trials under number NCT05461976 on 4th April 2022. Discussion If beneficial, this Phase II pilot randomised trial will provide data to plan a fully powered future Phase III clinical trial aimed at verifying the efficacy of this program to promote physical activity after stroke. Trial registration Clinical Trials NCT05461976 on 4th April 2022

    Characterisation of microbial attack on archaeological bone

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    As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved
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