246 resultados para Derivados de petróleo


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Os solos derivados de rochas serpentinizadas ou serpentinitos constituem um grupo especial de solos em toda superfície terrestre. de caráter ultramáfico, ou seja, rochas com mais de 70 % de minerais máficos (ferromagnesianos), os serpentinitos apresentam uma mineralogia pobre em sílica e escassa em Al, sendo, no entanto, muito enriquecida em Mg. São poucos os estudos sobre a morfologia, mineralogia, gênese e classificação dos solos desenvolvidos de tais rochas. em ambiente tropical úmido no sudoeste de Minas Gerais, na zona do greenstone belt do Morro de Ferro, em superfícies geomórficas jovens, três perfis de solos representativos dessa paisagem sobre rochas serpentinizadas foram caracterizados por meio de descrições macro e micromorfológicas, análises granulométricas, químicas e por mineralogia de raios X das frações argila e silte. Complementarmente, para acompanhamento da alteração geoquímica dos horizontes do solo, foram feitas microanálises das seções delgadas por EDRX. Os solos foram classificados como Chernossolo Háplico Férrico típico, Cambissolo Háplico eutroférrico léptico e Neossolo Regolítico eutrófico típico e, embora situados num clima que favorece o rápido intemperismo, do ponto de vista morfológico e mineralógico, mostraram-se similares aos solos derivados de rochas serpentinizadas das regiões subtropicais e temperada. No processo de formação de solo, a evolução da trama segue a seguinte seqüência: alteração da rocha ® trama frâgmica ® trama porfírica com cavidades ® trama porfírica aberta por coalescência de cavidades. O processo de argiluviação é evidente e se dá em dois estádios distintos: argiluviação primária, que ocorre nas fendas e cavidades que se formam por alteração de rocha, e argiluviação secundária, verificada na porosidade mais aberta e evoluída da coalescência das cavidades. Os solos apresentam mineralogia pouco comum para solos tropicais, com presença de minerais primários de fácil decomposição até mesmo na fração argila, com destaque para o talco, clorita trioctaedral e ocorrência limitada de tremolita, sendo esta última abundante na fração silte. Óxidos de Fe, caulinita e os interestratificados de clorita-esmectita e de clorita-vermiculita completam a assembléia mineralógica. A tendência de evolução é para B textural ou para B nítico com mineralogia 1:1 e alto conteúdo de óxidos de Fe. Nas fases iniciais de alteração, os alteromorfos já apresentam composição química similar aos agregados do solo, com forte perda de Mg, Ca e Si e acúmulo relativo de Al e Fe. Nas três situações estudadas, ocorreu um rejuvenescimento superficial por erosão diferencial, que acumulou material grosseiro e removeu os finos, contribuindo para o incremento da relação textural.

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

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The effects of inclusion of whole yeast, autolyzed yeast and yeast cell wall on hematological parameters and gut villus perimeter were evaluated in juvenile Nile tilapia, after 80 experimental days. Isoproteic (32.0% DP) and isoenergetic (3200 kcal DE kg -1) practical diets were supplemented with three levels of whole yeast or autolyzed yeast (1.0, 2.0 and 3.0%) and three levels of yeast cell wall (0.1, 0.2 and 0.3%), plus a control diet (with no test microingredients). Red blood cell count, hemoglobin concentration, total plasmatic protein, hematocrit percentage, mean corpuscular volume, mean corpuscular hemoglobin concentration and gut villus perimeter were evaluated. Variations on hematological parameters in animals fed diets with whole yeast; autolyzed yeast and yeast cell wall were observed to be within normal ranges for this species. There was significant influence (p<0.05) of different levels of yeast and derivatives on intestinal villus perimeter. Results showed that experimental period and proposed levels of whole yeast, autolyzed yeast and yeast cell wall do not provide undesirable alterations on standard hematological parameters to Nile tilapia and can be safely used to compound diets for this species. Results also showed that supplement of yeast cell wall provide higher intestinal villus perimeter.

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Microwaves have been used in organic synthesis, since 1986, and have proved advantageous in several respects: the possibility of higher yields, greater selectivity and less thermal decomposition. Phthalimide and its derivatives constitute an important class of compounds for use in synthetic organic chemistry; in medicinal chemistry, it is considered an important biophore, acting as a pharmacophoric structural subunit for the synthesis of a number of compounds with different pharmacological uses, such as against sickle-cell disease. The purpose of the work reported here was to develop an alternative method for the synthesis of phthalimide derivatives by exploiting the condensation of phthalic anhydride with amino groups under microwave radiation. The results showed that phthalimide derivatives were obtained in shorter reaction times (5-10 min) and higher yields (60-89%) than by with conventional heating (reflux), demonstrating the potential use of microwaves in the synthesis of this class of molecules.

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The patulin, (4hydroxy-4furo[3,2-c]pyran(6H)-1), is a thermal resistent mycotoxin produced by several species of fungi are common in plants, mainly in derivatives and apples. Studies on the toxicity in animals have shown that mycotoxin has character teratogenic, and carcinogenic in mice immunotoxic. Its biosynthesis is well understood involving a series of reactions of condensation and oxiredução, many catalyzed by enzymes. The danger of contamination of food with patulin, warning about the need for a more rigorous control. Recent research aimed their removal and degradation as well as increase the sensitivity of the tests, making them faster and at less cost. The removal of patulin of food is made with composite adsorbents, with inconvenience to diminish the quality of the product by adsorbs other components desirable. The degradation is made with sulfur compounds, which are not allowed in food in many countries, and the growth of yeasts, such as the production of cider. Many yeasts have resistance against patulin and produce compounds capable degrade it. Here, we reviewed research on patulin with emphasis on its influence in food industry, incidence of patulin in apple juice and other foods, maximum permissible concentrations, health effects, biosynthesis, removal, degradation and most widely used methods for its detection and quantification.

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The Petrobras produced green petroleum coke (GPC) is a carbon rich fuel, virtually ash-free, with low sulfur content, and is a fuel suitable to replace metallurgical coke in blast furnaces. The GPC was tested in a pulverized coal injection simulator built in the Volta Redonda research center. It presented a low burning efficiency due to low volatile material content and high substitution rate by the carbon content. The tests were carried out in blast furnaces with ≤ 50% Petrobras GPC in the coal blends. The injected coal/CVP mixtures produced no negative side effects in the blast furnace grinding systems, pneumatic conveying, or operating process. The mixture burning process inside the blast furnace showed a decrease in fuel consumption, with a significant reduction in metallurgical coke consumption. The industrial-scale tests of the GPC mixtures did not reach the 70% maximum for lack of the GPC feedstock, which is necessary to continue with standard coal mixtures.

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The residues generation is a quite serious problem in several industrial areas and also in the lumbering area. The search for the elimination or reduction of the volume of generated residues is endless, however limited, resulting in the search for a proper destination or better use, instead of simply burning it. A lot of uses and services are commonly proposed, but with low aggregated value to the residue. This work shows the usage viability of different discarded residues and wood composites in the production of an electric guitar. Cupiúba, ipê and jatobá residues have been used besides wood composites of pinus. The residues and wood composites have shown appropriate resistance, surfacing quality and design terms, and could be used to substitute the traditionally wood used in the production of the instrument as well as in other products of similar characteristics and with larger aggregated value.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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

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Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC

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

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)