497 resultados para polpa Kraft


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Pós-graduação em Zootecnia - FCAV

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

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Industrial activity is growing at an increasingly rapid accelerated bringing impacts not very consistent with the preservation of the environment, since it uses its resources to meet its countless demands, making the sources begin to become increasingly scarce. Therefore, this paper proposes the use of waste a furniture industry for the production of panels for the interior decoration. Were used to manufacture them, two different types of materials, where such, the Kraft paper is more efficient for the underpinnings of these panels. Regarding the type of glue used, the contact yielded better results. The initial conditions for the development of such a proposal were based on existing laws for solid waste as well as proposals for environmental agencies

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Mesenchymal stem cells (MSCs) are adult multipotent cells with fibroblastoid morphology and adherent to plastic. Furthermore, they can be obtained from different sources. Besides bone marrow, these cells are taken from umbilical cord blood, umbilical vein, saphenous vein, peripheral blood, arteries, liver and fetal pancreas, placenta, dental pulp and adipose tissue. MSCs derived from adipose tissue are important because of the abundant number of cells that can be obtained from this tissue, easy access and little discomfort to the patient. This study compared two techniques for obtaining MSCs from adipose tissue: mechanical dissociation (MD) and enzymatic digestion (ED). We also analyzed the inter-species cross-reactions using commercial monoclonal antibodies directed against surface antigens of stem cells from different species: mouse, horse, rabbit, monkey and human. We found that MD technique is favorable in relation to ED within 15 days of culture, and ED is more efficient in the first days of culture. The data also showed that MD causes less damage to cellular DNA. About inter-species cross-reactions, the monoclonal antibody A69 directed against stem cells from rabbits, which can be used in veterinary medicine, particularly in research involving horses

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This paper concerns about the durability of new material in construction. It is noteworthy the fact that increases increasingly searching for alternative materials that do not depend only of natural resources and at the same time be an alternative for reuse of industrial waste. Since the construction materials have a long life and a high cost of civil works and maintenance, it is crucial to estimate the behavior of a new product. Thus , this work discuss the durability of mixed mortar lining , made with waste from the process Kraft pulp production , known as dregs and grits , in partial replacement of sand. Tests were conducted to simulate conditions as adverse environments of constant heat and fire, with the aim of analyzing the behavior of mortar mixed matched the behavior of standard mortar

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The deslignification with oxygen, also denominated pre-O2, consists in a whitening stage, which consists of accomplishing an oxidation of the lignin, and remove it with the alkali, providing a larger earnings in the bleaching of the pulp. The pre-O2 is a process already very established, where a significant part of the cellulose of whitened short fiber produced nowadays suffers deslignification for this method. The conditions of work of this stage contemplate directly in the results of the deslignification level, in the physical, optical and mechanics properties of the pulp, and consequently of the paper, because this is important to know their effects fully. The main variables related to the control of this process are respectively: pressure and oxygen load, alkaline load, consistence, time and temperature, being this last variable was the study focus in this work. The objective of the work was to analyze the effect of the variation of the temperature in the oxygen whitening along every bleaching process of the pulp, refine and in the optical, physics and mechanics properties of the paper. The development of the work was based in four temperature levels (90, 95, 100 and 105°C) combined to two whitening sequences (OD0(E+P)D1P and OAHTD0(E+P)D1P). The results obtained in the oxygen deslignification stage indicated that the elevation of the temperature contemplated in increases of the whiteness, deslignification efficiency and in the viscosity loss allied to the reduction of the selectivity of the process. In the remaining of the whitening, the sequence that included the acid hydrolysis presented values slightly inferior of whiteness, kappa number, viscosity and yield in relation to the other sequence when compared with the samples of same temperatures. Already the physical tests showed that the sequence with acid stage amplifies the values of capillary... (Complete abstract click electronic access below)

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Phenolic compounds represent one of the main groups of secondary metabolites. Due to their chemical diversity, they have a variety of functions in plants, such as protection against ultraviolet radiation, herbivores and pathogens, and attraction of pollinators or dispersers of fruits and seeds. For human, the phenolic compounds are used like food colorings and flavors and, due to their pharmacological properties, mainly to antioxidant activity, they are associated with several health benefits, such as delay senility, prevention and therapy of cardiovascular diseases and of some cancers. The grapes are considered one of the main source of phenolic compounds and the fruit and its products are consumed in Brazil and worldwide. Considering the phenolic compounds diversity and their different distribution in the grape parts, this work had like aims the extraction, identification and quantification of the main classes of phenolic compounds of 10 grape varieties. The content of total phenols, flavanols and anthocyanins were determined, respectively, according to the Folin-Ciocalteu, DMACA and comparison of pH spectrophotometric methods. The content of total phenols varied from 142.75 + 1.86 to 483.39 + 5.90 mg.L-1 in the peel and from 86.50 + 0.54 to 146.32 + 9.97 mg.L-1 in the pulp. The amount of total flavanols varied from 3.68 + 0.03 to 6.92 + 0.26 mg.L-1 in the peel and from 0.90 + 0.00 to 1.36 + 0.00 mg.L-1 in the pulp. The content of total anthocyanins varied from 7.00 + 0.99 to 406.56 + 39.50 mg.L-1 in the peel and from 2.88 + 0.28 to 46.36 + 1.89 mg.L-1 in the pulp. The phenolic compounds concentration was higher in the peel than in the pulp. The total phenols and anthocyanins varied a lot while the total flavanols were more constant. The flavanols represent the smaller portion of phenolic compounds

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A xilana, o segundo principal componente da parede celular vegetal, pertence ao grupo das hemiceluloses, sendo composta por diferentes carboidratos, principalmente xilose e arabinose. Na natureza, devido a sua heterogeneidade estrutural, este complexo polissacarídeo é completamente hidrolisado pela ação sinergística de diferentes enzimas, incluindo xilanases e β-xilosidases, responsáveis pela degradação da sua cadeia principal e outras enzimas chamadas auxiliares ou desramificantes, importantes para remoção dos grupos laterais. Dentre estas últimas, destacam-se as α-L-arabinofuranosidases, enzimas responsáveis pela remoção de resíduos L-arabinofuranosil do polímero. As arabinofuranosidases podem ser produzidas por micro-organismos, como bactérias e fungos, sendo essencialmente enzimas extracelulares. Fungos, especialmente os de solo e madeira, têm sido utilizados para produção de enzimas xilanolíticas, sendo particularmente interessantes do ponto de vista industrial, pelo fato de secretarem suas enzimas diretamente no meio em que se encontram não necessitando de ruptura celular para a liberação das mesmas. Além disso, apresentam níveis de produção mais elevados que os obtidos em culturas bacterianas ou de leveduras. A crescente preocupação com a escassez dos recursos naturais e com a degradação ambiental tem levado à busca por tecnologias mais eficientes, mais competitivas e menos poluentes. Atualmente, muitos processos industriais empregam enzimas microbianas, apresentando inúmeras vantagens em relação às técnicas convencionais. As α-L-arabinofuranosidases podem ser utilizadas individualmente ou em combinação com outras enzimas, representando uma ferramenta promissora para aplicação em diversos processos biotecnológicos como no branqueamento da polpa celulósica, na síntese de oligossacarídeos, na produção de etanol de segunda geração, ou ainda...(Resumo completo, clicar acesso eletrônico abaixo)

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The alimentary act of three species of frugivorous bats of the genus Artibeus: A. lituratus, A. fimbriatus and A. planirostris, in a total of nine individuals, was studied by observations in field and captivity, during the months of May to September of 2008. With the objective to caracterize the form of consumption of two tipes of fruits (soft and consistent) and it relates with the dentary structure of this bats, the alimentary act was film and analysed later. It had little variation between the species. The fruits had been consumed in similar way, being that statistics analisis had demonstrated that consistent fruits had received more lateral bytes than the soft fruits. The dentary analisis shown that the posterior teeth (pre-molar and molar) present important characteristcs to triturate pieces of more consistent fruits and the incisors serve to scrape the pulp of the soft fruits. This study it served to describe the form of feeding of frugivorous bats, that little is explained in the studies of alimentary behavior

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)