319 research outputs found

    Soil water distribution for subsurface and surface drip irrigation

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    Devido à falta de estudos sobre o movimento da água quando aplicada abaixo da superfície, realizou-se este trabalho com o objetivo de avaliar a distribuição de água aplicada pelo sistema de gotejamento enterrado e convencional. O experimento de campo foi conduzido na área experimental do Departamento de Engenharia Rural da ESALQ/USP - Piracicaba, SP. Para o estudo, trincheiras foram abertas e instaladas sondas de TDR, dispostas a 0,05; 0,15; 0,25; 0,35 e 0,45 m profundidade, e a 0,05; 0,15; 0,25; 0,35 m comprimento, totalizando 17 sondas por trincheira. Os tratamentos foram baseados na profundidade de aplicação (0,0 e 0,10 m) e vazão aplicada (2 e 4 L h-1): ENT2; ENT4; SUP2 e SUP4. A cada hora era aplicado 1 L de água (total de 10 L), seguida de leituras com o TDR. Medições do disco úmido e saturado foram feitas com régua milimetrada; além disso, estabeleceu-se um volume controle onde foi avaliada a uniformidade de aplicação; assim, foi possível verificar, em relação aos sistemas superficiais, que os sistemas enterrados apresentaram menor área superficial molhada e atingiram maior largura e profundidade; já as maiores concentrações foram obtidas próximas ao ponto de emissão.Studies of sub-surface water movement is an interesting topic in irrigation but, in spite of the its importance, there is little literature. One of the purposes of this study was to contribute to this subject and evaluate the distribution of water applied by both subsurface drip irrigation (SDI) and conventional irrigation. Experiments were conducted at the Department of Rural Engineering (ESALQ/USP), located at Piracicaba, SP. Trenches were opened and 17 three-rod TDR probes were installed, placed at 0.05, 0.15, 0.25, 0.35 and 0.45 m depths, and to 0.05, 0.15, 0.25, 0.35 m intervals. This procedure was repeated using a dripper buried at 0 and 0.10 m for each discharge rate of 2 and 4 L h-1 tested. Wetted soil volume was observed with 1 L of water applications at intervals (total 10 L). The saturated disc around the dripper and the advance of the wetting front on the soil surface were measured with a ruler. Also, a central control volume was established inside the wetted soil volume where the uniformity of application was evaluated. The results suggest that SDI presented smaller wetted soil surface area and it reached larger distance and depth with greater storage of solution adjacent to the dripper

    Metal organic frameworks for selective degradation of amoxicillin in biomedical wastes

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    CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFACEPE - FUNDAÇÃO DE AMPARO À CIÊNCIA E TECNOLOGIA DO ESTADO DE PERNAMBUCOThe accumulation of antibiotics in wastewater has led to the development and spreading of antibiotic resistance in the environment. Amoxicillin (Amox), a beta-lactamic antibiotic, is one of the most frequently consumed antibiotics in the world. We have ap291021272136CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFACEPE - FUNDAÇÃO DE AMPARO À CIÊNCIA E TECNOLOGIA DO ESTADO DE PERNAMBUCOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFACEPE - FUNDAÇÃO DE AMPARO À CIÊNCIA E TECNOLOGIA DO ESTADO DE PERNAMBUCOsem informação23038.004630/2014-35Pronex APQ-0675-1.06/14Pronem APQ-0732-1.06/1

    ADIÇÃO DE APARAS DE PAPEL RECICLÁVEL NA FABRICAÇÃO DE CHAPAS DE MADEIRA AGLOMERADA

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    Neste trabalho, foram analisadas as propriedades físico-mecânicas de chapas aglomeradas produzidas com dois tipos de papel reciclável (papel jornal e offset) e partículas de madeira de Pinus elliottii Engelm. As aparas de papel foram usadas no colchão em dois diferentes formatos (tiras ou moídas) e em diferentes proporções: 0, 20, 40, 60 e 100% do peso seco das partículas. Utilizoaram-se 10% de adesivo à base de tanino-formaldeído na proporção 100:10. O experimento foi estabelecido segundo modelo fatorial, com três repetições. Os testes físico-mecânicos das chapas foram realizados segundo a norma ASTM D1037 (1995). Chapas aglomeradas produzidas tanto pela inclusão de papel jornal quanto offset no formato de tiras apresentaram tendência ao estouro durante a abertura dos pratos da prensa, causado pelo alto teor de umidade do colchão. A inclusão de aparas de papel prejudicaram a maioria das propriedades analisadas, fazendo com que não atendessem aos valores estabelecidos pelas normas DIN 68761 (1)-1961, (3)-1971 e ANSI A 208.1 (1987). A absorção d’água após 24 horas de imersão, a ligação interna e a resistência ao arrancamento de parafusos foram as propriedades mais prejudicadas. De modo geral, o uso de papel jornal se mostrou mais promissor do que o papel offset

    Leucaena leucocephala in ruminant nutrition

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    It is a common situation in extensive ruminant production systems in tropical countries to have low production indicators due to nutrient deficiencies in the diet. An economic alternative to increase animal production is the incorporation of legumes (fodder and fruits) in the diet. This review, presents an analysis of the positive and negative effects of Leucaena leucocephala consumption by ruminants, with particular emphasis on the secondary compound mimosine. Leucaena due to its high nutrient content, rumen by-pass protein supply and its possible effect on the reduction of greenhouse gas (attributed to tannins) has become one of the legumes most commonly used in ruminant feeding practices. However, in countries where leucaena has been introduced, its use is still limited to levels below 30% inclusion in the diet, due to the secondary compound mimosine and its isomers (3,4 and 2,3 DHP), which can induce toxicity, even when animals are inoculated with rumen fluid containing the bacteria Synergistes jonesii reported as responsible for degrading these compounds in the rumen. In the Yucatan Peninsula, Mexico, ruminants consuming leucaena can tolerate more than 50% inclusion in the diet, without having a negative impact on production, attributed intake to mimosine and its isomers. We conclude that in animals not adapted, the intake would be limited to low inclusion levels (less than 30% inclusion in the diet), mainly because of mimosine and its derivatives. The decrease in intake or diet digestibility seem to better explain the reduction in methane production, however, in vivo studies are required to clearly establish the mechanism of action. It has been reported the presence of different bacteria to S. jonessi that would have the ability to degrade mimosine and its derivatives, however, the activity of these bacteria and its effectiveness must be confirmed in vivo

    Effects of Two Intake Levels of \u3cem\u3eLeucaena leucocephala\u3c/em\u3e on Rumen Function of Sheep

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    Ruminant production systems based on grass pastures often produce poor animal performance as expressed by growth or reproductive rates. The nutrient imbalance affecting rumen function is due to their low energy and protein intake. The incorporation of leguminous forages such as Leucaena leucocephala, in the diet of ruminants, can stimulate rumen function by providing protein-rich forage (Barros-Rodriguez et al. 2012). This increases the availability of compounds such as ammonia, amino acids and peptides as well as branched short-chain fatty acids, which are produced as a result of degradation of proteins. These substances promote fibre breakdown by acting as ruminal growth activators for rumen bacteria, especially cellulolytic bacteria (Hoover and Stokes 1991). This study aimed to evaluate the effects of 2 intake levels of L. leucocephala on rumen function of sheep fed Pennisetum purpureum

    Monitoramento da temperatura no interior de chapas aglomeradas durante o processo de prensagem.

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    The objective of the present work was to investigate the behaviour of core and face temperatures of particleboard glued with 8% tannin-formaldehyde adhesive. The boards were manufactured with three replication per treatment, with density of 0,7 g/cm³ and 27 kgf/cm² of pressing specific pressure. Pine flakes (40, 75 and 110 mm long and 0,5 and 1,0 mm thick) and eucalypt particles were used and two pressing temperatures (140 and 180ºC) along with two mat moisture content (17 and 21%) were employed. The curves of temperature rise with pressing time indicated a fast temperature rise during the first 100 seconds of pressing, remaining at a plateau possible after reaching water boiling temperature. The temperature increased again, but on a more gradual form, after the lost mat moisture. It was possible to observe that mat formed by flakes of larger thicknesses showed faster initial temperature rise. The main factor that influenced the temperature behaviour at the board core was the mat moisture content. The higher the mat moisture content, the faster the temperature rise.O objetivo do presente trabalho foi analisar o comportamento da temperatura nas faces e no miolo de chapas de partículas aglomeradas, coladas com 8% de adesivo (base peso seco das partículas) tanino-formaldeído. As chapas foram produzidas com três repetições por tratamento, com massa específica nominal de 0,7 g/cm³ e pressão específica de prensagem de 27 kgf/cm². Os tratamentos basearam-se na utilização de flocos de pinus (Pinus elliottii) e partículas de eucalipto (Eucalytus sp), sendo que os flocos de pinus apresentavam três diferentes comprimentos nominais (40, 75 e 110 mm) e duas espessuras (0,5 e 1,0 mm). Também foram analisados duas temperaturas de prensagem (140 e 180°C) e dois teores de umidade nominal do colchão (17 e 21%). A temperatura no interior dos painéis durante a prensagem foi obtida por meio de fios para termopares tipo K (cromo-alumel). Os gráficos da temperatura em função do tempo de prensagem mostraram uma rápida elevação da temperatura nos primeiros 100 segundos de prensagem, mantendo-se num plateau possivelmente após atingir a temperatura de ebulição da água. A temperatura voltou a aumentar, de forma mais gradual, após a perda de grande parte da umidade do colchão. Observa-se que colchões formados por flocos de maior espessura apresentaram elevação mais rápida de temperatura no miolo. O principal fator que influenciou na velocidade de elevação da temperatura no miolo dos painéis aglomerados foi o teor de umidade do colchão, sendo que quanto maior o teor de umidade, mais rápida foi a elevação da temperatura

    Validation of TerraClass mapping for the Municipality of Paragominas state of Pará

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    This work aims to evaluate the TerraClass mapping for the year 2014, in the municipality of Paragominas, State of Pará. The validation was made by comparing the mapping with the observations found in the field. Images of the Satétile Landsat-8, OLI sensor of the year 2014, path/row 222/062, 222/063, 223/062 and 223/063 were used to aid in the field. Using this data it was possible to analyze the main representative classes in the area, including agriculture, urban area, forest, clean pasture, dirty pasture, reforestation, regeneration with pasture and secondary vegetation. The secondary vegetation presented 2,198.16 km², clean pasture with 3,332.29 km², agriculture with 896.75 km² and the forest occupying 54.21% of the total area of Paragominas. The overall concordance index was 86%, corroborating the reliability of the mapping performed. The average error was 6% and the total value of discordance was of 14%. Concerning the secondary vegetation, pasture, agriculture, urban area and forest classes, they presented concordance higher to 50%, while regeneration with pasture and reforestation presented greater intensity of omission with 40,57% and 76,31% respectively. Inclusion errors were less than 40% for the secondary vegetation, pasture regeneration, clean pasture and dirty pasture classes. The field work was essential to validate and analyze the accuracy of the 2014 TerraClass Project for the studied region, which becomes important for the understanding of the dynamics of land use
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