98 resultados para Oil burners.


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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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The aim of this work was to characterize the yellow melon seeds, hybrid variety, as for their proximate composition, and to evaluate the antioxidant potential of extracts of seed in soybean oil. The extract of melon seeds (EM), obtained by extraction using ethanol: water (95:5), was applied in soybean oil at three different concentrations (500; 750 and 1000 mg kg(-1)) and submitted to Shaal oven method at 60 degrees C for 20 days. Oil samples were evaluated for peroxic a value in periods of five days. The antioxidant activity of the extract was compared to the BHT (butyl-hydroxytoluene) activity. The melon seeds showed a high nutrition value, containing high percentages of lipids (25.2%), proteins (20.1%) and fiber (30.0%). All these treatments retarded lipid oxidation in soybean oil; however the natural extracts were less effective than BHT after 10 days in the oven. The antioxidant activities of different treatments tested in this study followed the order: BHT > EM 1000 mg kg(-1) = EM 750 mg kg(-1) > EM 500 mg kg(-1)> control.

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Por razões econômicas e de proteção à saúde, pesquisas têm sido dirigidas para ampliar a estabilidade dos óleos vegetais. Existe uma tendência para a adição de antioxidantes naturais, em particular, um crescente interesse em ervas e especiarias. Desta forma, os objetivos deste trabalho foram avaliar o potencial antioxidante das oleorresinas de orégano, manjericão e tomilho e seu comportamento ao serem aplicadas ao óleo de soja em diferentes concentrações. Numa primeira etapa foi determinada a atividade antioxidante pelo sistema β-caroteno/ácido linoleico e a quantificação de compostos fenólicos totais. Posteriormente, foram adicionadas ao óleo de soja diferentes concentrações das oleorresinas (500 a 3000 mg.kg-1) e analisado seu potencial antioxidante por meio da estabilidade oxidativa utilizando o Rancimat. A concentração de 3000 mg.kg-1das oleorresinas de orégano e tomilho foi a que apresentou melhor estabilidade oxidativa ao óleo de soja, o que as tornam alternativa natural na conservação de óleos vegetais.

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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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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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Partial pseudoternary phase diagrams were constructed for soy bean oil (SBO)/surfactant/NaCl aqueous solution systems, at 25 degrees C, using the anionic sodium bis(2-ethylhexyl) sulfosuccinate (ACT) and zwiterionic phosphatidylcholine (PC) or mixtures of these surfactants. The isotropic single phase of water-in-oil (W/O) microemulsions (MEs) is shown in the phase diagram and their viscosity reported. ME samples containing small amount of surfactant exhibit slightly higher viscosity than pure SBO, and were used in the solubilization of small water soluble molecules. NaCl enhances the area of the ME phase and MEs with different surfactant composition exhibit different induction time as obtained from tests of oxidative stability, and so are the MEs enriched with ascorbic acid, folic acid and FeSO4, with the latter exhibiting lower stability. The so prepared enriched soy bean oil has potential application in food industry since the surfactants are food grade. (C) 2007 Elsevier B.V. All rights reserved.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Castor oil bean cement (COB) is a new material that has been used as an endodontic sealer, and is a candidate material for direct pulp capping. Objective: The purpose of this study was to evaluate the biocompatibility of a new formulation of COB compared to calcium hydroxide cement (CH) and a control group without any material, in the subcutaneous tissue of rats. Material and Methods: The materials were prepared, packed into polyethylene tubes, and implanted in the rat dorsal subcutaneous tissue. Animals were sacrificed at the 7th and 50th days after implantation. A quantitative analysis of inflammatory cells was performed and data were subjected to ANOVA and Tukey's tests at 5% significance level. Results: Comparing the mean number of inflammatory cells between the two experimental groups (COB and CH) and the control group, statistically significant difference (p=0.0001) was observed at 7 and 50 days. There were no significant differences (p=0.111) between tissue reaction to CH (382 inflammatory cells) and COB (330 inflammatory cells) after 7 days. After 50 days, significantly more inflammatory cells (p=0.02) were observed in the CH group (404 inflammatory cells) than in the COB group (177 inflammatory cells). Conclusions: These results demonstrate that the COB cement induces less inflammatory response within long periods.

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Objective: The purpose of this study was to evaluate the sealing ability of castor oil polymer (COP), mineral trioxide aggregate (MTA) and glass ionomer cement (GIC) as root-end filling materials. Forty-five single-rooted human teeth were cleaned and prepared using a step-back technique. The apical third of each root was resected perpendicularly to the long axis direction. All teeth were obturated with gutta-percha and an endodontic sealer. After, a root-end cavity with 1.25-mm depth was prepared using a diamond bur. The specimens were randomly divided into three experimental groups (n = 15), according to the root-end filling material used: G1) COP; G2) MTA; G3) GIC. The external surfaces of the specimens were covered with epoxy adhesive, except the root-end filling. The teeth were immersed in rhodamine B dye for 24 hours. Then, the roots were sectioned longitudinally and the linear dye penetration at the dentin/material interface was determined using a stereomicroscope. ANOVA and Tukey's tests were used to compare the three groups. The G1 group (COP) presented smaller dye penetration, statistically different than the G2 (MTA) and G3 (GIC) groups (p < 0.05). No statistically significant difference in microleakage was observed between G2 and G3 groups (p > 0.05). The results of this study indicate that the COP presented efficient sealing ability when used as a root-end filling material showing results significantly better than MTA and GIC.