855 resultados para Hybrid woven. Synthetic fibers. Environmental aging. Mechanic properties. fracture characteristics


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Objective of present work was study a influence of environmental and genetic effects over characteristics of milk total production (PL) and lactation duration (DL), from 2572 lactations of 477 Guzerat cows, collected since 1957 to 2002, in Rio de Janeiro State. Environmental effects were analyzed by an statistical model that include male randomized effect, fixed effect of contemporary group, and the (co)variables age of cow (lineal and quadratic) and lactation duration. The contemporary group had significant effect just for PL. Bayesian inference was used to obtain estimatives of genetic parameters over an animal model, in which was included as fixed effect the contemporary group and the covariables age of cow (linear and quadratic). The estimates of heritability and repeatability were 0.36 and 0.75 for PL and 0.29 and 0.36 for DL, respectively. The estimated genetic correlation was 0.97. The heritability estimates for PL and DL were moderate, indicating that it is possible answer to the selection of the characteristics under study. The genetic correlation was high and indicates that selection for increase milk production will be accompanied with increase in lactation duration.

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Impacts on the environment and soil biological activity result in changes in the processes of formation of biogenic and fisiogenic aggregates. Aiming to evaluate the influence on physical and biological genesis of aggregates of Cerrado soils and determine the main environmental factors that determine the characteristics of households in the area of production under integrated crop-livestock (ICL), was developed this study in Farm Cabeceira, Maracaju-MS, in areas of ICL. The areas evaluated were: Savana, pasture/maize, corn/cotton and cotton/soybeans being evaluated during the dry (May/2009) and rainy (March 2010) season. To identify the pathways of aggregation were used morphological patterns, and established three clusters: fisiogenic, biogenic and intermediates. The aggregates were analyzed for exchangeable cations, carbon and aggregate stability, soil was analyzed for the exchangeable cations, particle size fractionation of soil organic matter, oxidizable fractions of total organic carbon, particle size analysis and soil macrofauna. In all areas studied, in the dry season, the highest values were quantified aggregate intermediates, while in the rainy season, in general, no differences were observed aggregates formed by different routes in areas except cotton/soybeans. The aggregates showed positive correlation with biogenic carbon and were found in lesser amounts compared to fisiogenic and intermediates. The different types of aggregates formed, besides having different characteristics morphological also differ as to chemical characteristics.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Agronomia - FEIS

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Diferentes autores concordam que os trabalhadores rurais brasileiros passam por grandes dificuldades relacionadas aos problemas socioambientais e muitas vezes, por não disporem de informações adequadas para o desenvolvimento de suas atividades, são potenciais responsáveis pela depredação do patrimônio natural da área ocupada. Na busca por uma formação diferenciada, o Movimento dos Trabalhadores Sem-Terra (MST) investiu no Curso de Licenciatura Plena em Pedagogia para Educadores (as) da Reforma Agrária, denominado Pedagogia da Terra (CPT), implementado pela Universidade Federal do Pará (UFPA), no período de fevereiro de 2001 a maio de 2005, em parceria com o Instituto Nacional de Colonização e Reforma Agrária (INCRA) e o Programa Nacional de Educação na Reforma Agrária (PRONERA). Esta pesquisa teve os seguintes objetivos: 1) Estudar os princípios que embasam o Curso de Pedagogia da Terra através de documentos referenciais; 2) Averiguar a percepção dos alunos-professores referente à proposta educativa do Curso e 3) Caracterizar a práxis dos egressos em Educação Ambiental. O estudo enveredou pela pesquisa qualitativa na abordagem investigativa - narrativa. Inicialmente realizei pesquisa documental que serviu de base para formulação de uma entrevista semi-estruturada, direcionada a cinco alunos professores do CPT, para tanto, visitei dois assentamento e um acampamento. Para a sistematização e análise, o material foi transcrito literalmente, procurando identificar os temas relevantes e recorrentes, assim como comunalidades e contradições, visando estabelecer categorias de análises. Para aprofundar a questão em foco, busquei a técnica da triangulação de dados e teorias como mais uma forma de interpretação das informações coletadas. Cheguei a conclusão que, a proposta do Curso, apesar de algumas dificuldades, foi bem aceita pelos educandos, sendo avaliado positivamente como um processo rico de aprendizagem e formação que possibilitou a reflexão, a busca da melhoria da qualidade de vida, por meio da inclusão social e do respeito à especificidade da Educação do Campo e a diversidade dos seus sujeitos. Quanto a EA percebo que os alunos-professores têm percepção da importância desta no dia-a-dia da escola e a destacam como: 1) meio para a mudança de mentalidade, como 2) forma de regular a intervenção do homem no ambiente, considerando a intencionalidade desta. Acredito que esta pesquisa contribuiu para revelar a importância de cursos como o CPT em relação ao aprimoramento e a ampliação de conhecimentos em EA, contextualizados em realidades específicas como a vivenciada nos assentamentos/acampamentos paraenses.

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The tillage comprises on average 25% of the cost of deploying a reed, so this cost reduction measures are desirable since they do not compromise the quality of the operation and longevity of sugarcane. The objective was to evaluate the effect of different tillage systems in Acrustox, correlating soil physical properties and characteristics of sugarcane agroindustrial plant cane and ratoon cane. We used five types of soil tillage, over experimental design in blocks with five replications. The particle size was measured every 0.1 m to 0.4 m depth, through deformed soil samples collected at the end of the first growth cycle of the culture. For other soil physical properties: bulk density, total porosity and water content, assessments were performed at the end of each cycle, collecting soil samples in layers of 0-0.20 to 0.21-0.40 m, in addition to performing the penetration resistance, using a penetrometer impact. The response of sugarcane depending on the types of tillage was determined from the evaluation of productivity per hectare of stem (TCH), sugar (TPH), the values of pol % cane (AP), sugar total recoverable (ATR) and fiber samples collected at harvest stalk of sugarcane plant and ratoon cane. In the tillage studied, there was a change of the physical attributes of the soil, causing reduced productivity in 2009/2010 crop, compared with the 2008/2009 season. In tillage system of furrowing direct lowest result was observed for TCH, especially in 2009/2010 crop, when the difference with conventional tillage was 20.53 Mg ha(-1).

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Products derived from wood or engineered products are becoming interesting alternatives to the replacement of solid wood in various applications, from structural components to the furniture industry and packaging. Among these products, there are panels built by strands, particles and fibers, each one having their particular characteristics and potential of use. Since the different types of panels are produced, waste generation is part of the process, and that more technological it is, it still generates losses of raw materials. Based on the need for rational use of raw materials and using almost full of industrially processed wood, It arises the proposal of this work, which seeks to use waste from the lamination, like pieces of strands, broken strands, strands rough, cracked strands to produce panels with structural characteristics of the OSL panel (Oriented Strand Lumber), LSL (Laminated Strand Lumber) and OSB (Oriented Strand Lumber). Besides the use of waste, this paper seeks an alternative to the use of the adhesive, because the industry uses formaldehyde-based adhesives, which over the press, they emit large amounts of formaldehyde, which is very aggressive to humans and environment. The panels made with polyurethane resin based on castor oil and hot-pressed were characterized by physical and mechanical tests according to specifications of European Standard (EN). High values of tensile strength, elastic modulus and density were found in the results of tests. Adding to stable values of swelling and moisture content, the panel studied adds attractive features to the panel market, especially in the civil construction

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The search for materials with higher properties and characteristics (wear resistance, oxidation, corrosion, etc.) has driven research of various materials. Among the materials that are being studied with such properties and characteristics are super alloys based on nickel which has an important role in the aeronautical, automotive, marine, production of gas turbines and now in space vehicles, rocket engineering , experimental aircraft, nuclear reactors, steam-powered plants, petrochemical and many other applications because besides having all the characteristics and properties mentioned above also have an excellent performance at high temperatures. The super alloy based on nickel studied in this work is the super alloy Pyromet 31v normally used in the manufacture of exhaust valves in common engines and diesel engines of high power by cater requirements such as mechanical strength and corrosion resistance at temperatures of approximately 815 ° C. The objective of this work is to produce results to demonstrate more specific information about the real influence of coatings on cutting tools and cutting fluids in turning and thus promote the optimization of the machining of these alloys. The super alloy Pyromet 31v was processed through turning, being performed with various machining parameters such as cutting speed, feed rate, depth in conditions of Minimum Amount of Fluid (MAF), abundant fluid, cutting tools with coating and without coating in early in his work life and with wear. After turning were obtained several samples of chips and the part generated during the machining process, was measured roughness of the material, subsequently made macrostructural analysis of the tools used order to detect possible wear and microstructural analysis of samples collected being that the latter was used for Optical Microscopy, Scanning Electron Microscopy (SEM) and ... (Complete abstract click electronic access below)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The objective of this study was to develop a new low-calorie symbiotic beverage made from yacon (prebiotic source) and soy extracts, containing probiotic Bifidobacterium animalis ssp. lactis BB-12. The synbiotic beverage was first produced with a range of sucrose concentrations in order to determine ideal sweetness by an acceptance test using a “just-about-right scale”. Sucrose was then replaced by sucralose or aspartame to produce sugar-free beverages. Characteristics including viable cell numbers, physicochemical properties, sensorial characteristics and fructooligosaccharides content were investigated. The ideal sweetness of the beverages with sucrose, aspartame and sucralose were 7.28%, 0.0486% and 0.0167%, respectively. Sucralose exhibited higher scores in acceptance test and was used to replace sucrose in the low-calorie symbiotic beverage. The synbiotic beverage exhibited counts of Bifidobacterium spp. of 108 CFU·mL-1 , sufficient condition to be considered probiotic. The chemical composition of the product was (g/100 g): 2.91 of protein, 1.41 of fat, 2.41 of total carbohydrate; 0.82 of FOS and 148.22 Kj of energy value. The synbiotic beverage developed in this study may be successful in health applications, due to their functional ingredients (soy, probiotic bacteria and yacon prebiotics) that can afford benefits to health or can present disease-preventing properties, beyond their inherent nutritional value. In addition this low-calorie beverage can be consumed by diabetic individuals and people concerned about the ingestion of calories.

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This work includes a study on the stretch zone and the influence of the toughness conditions at fracture in size and appearance. It was done a literature review about material properties, fracture mechanics concepts, definitions and formation of stretch zone, importance of tenacity for structural calculation, methods and standards to measure the toughness of metallic material fracture and presents the method used in microscopy. After the literature review were carried out identification and measurements of stretch zones of proof bodies were made through confocal optical microscopy and then analyzed the results in order to find relationships between the values obtained with the theory