158 resultados para Fibras minerais
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Brazil processes much of its fruit by producing natural juices, candy preserves, extracts and pulps; however, almost 60% of their total weight derives from peels, leaves and seeds. As a result, the emphasis lies most strongly on the use of waste, especially waste that is not commonly used by the food industry or by consumers. The use of seeds would increase the viable sources of raw materials, lower operating costs of industries and would promote the development of new food products, since they are our main sources of protein, fat, fiber, functional compounds, vitamins and minerals salts. This paper presents alternatives for the use of pumpkin seeds (Cucurbita sp), which are often underutilized or discarded. It also demonstrates the bioactive and anti-nutritional compounds and their health effects.
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In this work, plasma immersion ion implantation (PIII) treatments of carbon fibers (CFs) were performed in order to induce modifications of chemical and physical properties of the CF surface aimed to improve the performance of thermoplastic composite. The samples to be treated were immersed in nitrogen or air glow discharge plasma and pulsed at −3.0 kV for 2.0, 5.0, 10.0, and 15.0 min. After PIII processing, the specimens were characterized by atomic force microscopy (AFM), scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). After CFs treatments, the CF/Polypropylene (PP) composites were produced by hot pressing method. Surface morphology of as-received CFs exhibited some scratches aligned along the fibers due to the fiber manufacturing process. After both treatments, these features became deeper, and also, a number of small particles nonuniformly distributed on the fiber surface can be observed. These particles are product of CF surface sputtering during the PIII treatment, which removes the epoxy layer that covers as-received samples. AFM analyses of CF samples treated with nitrogen depicted a large increase of the surface roughness (Rrms value approximately six times higher than that of the untreated sample). The increase of the roughness was also observed for samples treated by air PIII. Raman spectra of all samples presented the characteristic D- and G-bands at approximately 1355 and 1582 cm−1, respectively. Analysis of the surface chemical composition provided by the XPS showed that nitrogen and oxygen were incorporated onto the surface. The polar radicals formed on the surface lead to increasing of the CF surface energy. Both the modification of surface roughness and the surface oxidation contributed for the enhancement of CF adhesion to the polymeric matrix. These features were confirmed ... (Complete abstract click electronic access below)
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This graduation work done study of polyamide 6.6/composite carbon fibres, since its processing, characterization of the main properties. Besides the influence of temperature, UV radiation, salt spray and moisture on the mechanical and viscoelastic behavior. To achieve this goal, the first composite was processed from the heat compression molding using known variables of the process and using the empirical method to find the best value for other parameters. The method processing molding was chosen because it common in composites processing in order to evaluate the influence of crystallinity of the properties that influence the mechanical and viscoelastic behavior laminates. From the obtained laminate specimens were evaluated in weathering, such as: in hygrothermal chamber, UV, salt spray and thermal shock. In another step, the effect produced by these constraints were evaluated by optical microscopy, ultrasound, dynamic mechanical analysis and vibration tests. This project was conducted at the Department of Technology and Materials of UNESP in Guaratingueta, where all the equipment and techniques for the implementation of this project met available. After the tests proved the applicability of the composite polyamide 6.6/carbon fibers in aeronautical applications with resistance the main climatic influences
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Pós-graduação em Engenharia Mecânica - FEG
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Pós-graduação em Engenharia Mecânica - FEG
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Pós-graduação em Zootecnia - FCAV
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Pós-graduação em Agronomia (Horticultura) - FCA
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Pós-graduação em Agronomia (Produção Vegetal) - FCAV
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Pós-graduação em Agronomia - FEIS
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Engenharia Mecânica - FEG
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)