Desenvolvimento de catalisadores sem platina: estudos comparativos da oxidação de metanol em 'PD''RU'/'C' e 'PT''RU'/'C' em meio alcalino

Pós-graduação em Química - IQ

Metabolism of L929 cells after contact with acrylic resins. Part 1: Acrylic denture base resins

The purpose of this study was to evaluate the effectiveness of complementary heat treatment and water storage in reducing cytotoxicity of acrylic resins denture bases used in Brazil by the MTT assay. Material and Methods: First, nine specimens were fabricated from metal matrix in the form of discs with 14 mm in diameter and 1.2 mm of thick. Immediately after making, 24 or 48 hours after storage in distilled water, the samples of heat-polymerized resins were divided into 3 groups (n = 3) according to the type of thermal treatment: Group 1: samples were individually exposed to microwave energy (500 W for 3 minutes); Group 2: samples were immersed in water at 550 C for 60 minutes; Group 3: samples did not receive heat treatment. To prepare the extracts, 3 samples of each group were placed into vials containing 3 mL of culture medium and stored at 37°C for 24 hours. L929 cells were used and the MTT assay was performed to analyze the cellular metabolism. Two-factor analysis of variance was used to detect significant among groups at 5% significance. Results: After statistical analysis, the materials were classified according to the cytotoxic effect: non-cytotoxic, slightly cytotoxic; moderately cytotoxic; and strongly cytotoxic. The results showed that the resins ranged from moderately cytotoxic to non-cytotoxic, but no statistically significant difference among experimental groups. Furthermore, the water storage and thermal treatments reduced the cytotoxicity of the resins. Conclusions: It was concluded that the resins studied are potentially toxic and that treatments can decrease their cytotoxicity.

Avaliação sensorial e influência do tratamento térmico no teor de ácido ascórbico de sorvete de pimenta

In this work were prepared with three ice cream added peppers of different varieties: Capsicum baccatum, Capsicum annuum and Capsicum frutescens. The peppers were first pasteurized and evaluated in relation to the effect of heat treatment on the ascorbic acid content. Results showed that the Capsicum annuum showed higher ascorbic acid content, but the heat treatment resulted in greater loss of biocompounds. The higher retention of ascorbic acid was observed with Capsicum frutescens, which presented lower content of biocompound, but near of the pepper Capsicum annuum. The follow attributes was performed to evaluate the acceptance of ice cream through the sensory attributes: color, aroma, flavor and texture. Analysis of variance showed no significant difference between ice cream formulations at the 5% level of significance with regard to color, aroma and texture. Regarding taste, the samples differed significantly, at 5% significance, and the most preferred was the ice cream made with pepper Capsicum frutescens.

Efeitos do tratamento térmico na obtenção da fase 2223 em amostras de BSCCO com e sem substituição

Pós-graduação em Ciência dos Materiais - FEIS

Influência da adição do nióbio no comportamento mecânico e microestrutural do aço SAE 6150

Pós-graduação em Engenharia Mecânica - FEG

Influência do tratamento térmico de homogeneização na microestrutura de um aço utilizado na fabricação de cilindros de laminação para trabalho a frio

Pós-graduação em Engenharia Mecânica - FEG

Fabricação de membranas fibrosas de compósito PVDF/TIO2 pelo método de fiação por sopro em solução

Pós-graduação em Ciência dos Materiais - FEIS

Aspectos físicos e fisiológicos de sementes de Fimbristylis dicothoma relacionados à germinação e dormência

In the seeds of pioneer plants, the application of treatments for breaking dormancy, and selection by colour and size, are strategies for obtaining seeds of less dormancy and better germination performance. The aim of this study was to evaluate the effect of the physical and physiological aspects of seeds of the tall fringe-rush (Fimbristylis dichotoma) on germination and dormancy. To do this, the seeds were submitted to the following treatments in three studies: (i) control, immersion in H2SO4 (98%, 36N) for 1 minute, immersion in KNO3 (1, 2 and 3%) for 15 minutes, seeding on a substrate moistened with KNO3 (0.2%) and exposure for 5 and 10 hours in a forced air circulation oven at 40 and 70 degrees C; (ii) classification of the seeds by colour (light and dark) and application of the following treatments: control, immersion of the seeds in H2SO4 (98%, 36N) for 1 and 2 minutes, immersion in KNO3 (5% and 10%) for 15 and 30 minutes and seeding on a substrate moistened with KNO3 (0.2%); (iii) classification by size (0.60, 0.50 and 0.40 mm) and germination on a substrate moistened with KNO3 (0.2%) or distilled H2O. The seeds were evaluated by germination test, first count and germination speed index. Moistening the substrate with KNO3 (0.2%), and heat treatment at 40 degrees C for 10 hours improve performance in seeds of the tall fringe-rush. Light-coloured seeds do not display dormancy. Medium-sized seeds of the tall fringe-rush show better performance in terms of percentage and speed of germination.

A flexible lab-on-a-chip for the synthesis and magnetic separation of magnetite decorated with gold nanoparticles

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

Influência de tratamentos termo-mecânicos na estrutura e microestrutura da liga Ti-10%pNi obtida por fusão a arco

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A joint experimental and theoretical study on the electronic structure and photoluminescence properties of Al-2(WO4)(3) powders

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fenton-like processes and adsorption using iron oxide-pillared clay with magnetic properties for organic compound mitigation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Synthesis and characterization of nanostructured TiO2-SnO2 composite

Nanostructured composites based on titanium dioxide have been studied in order to improve optical and photo-catalytic properties, as well as their performance in gas sensors. In this work, titanium and tin dioxides were simultaneously synthesized by the polyol method resulting in TiO2 platelet coated with SnO2 nanoparticles as was observed by scanning electron microscopy. The thermal analysis showed that the combined synthesis promotes more easily the crystallization of the TiO2 rutile phase. The composite obtained after heat treatment at 500 degrees C showed to be formed of almost only rutile phases of both oxides. The optical properties analyzed by UV-Vis spectroscopy showed that the combined oxides have higher absorbance, which reinforces a model found in the literature based on the flow of photo-generated electrons to the conduction band of SnO2 delaying the recombination of charges.

Synthesis and characterization of polyarylacetylene for use in the monolithic vitreous carbon processing

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

Properties of glass-ceramics obtained from crystallization of the SiO2-Al2O3-MgO-Li2O system with addition of ZrO2

This paper presents the study results with glass-ceramics obtained from base glass (MgO-Al2O3- SiO2-Li2O system) with addition of ZrO2 as nucleating agent. The glass was melted at 1650 degrees C for 3 h and at a heating rate of 10 degrees C/min. The molten glass was poured into a graphite mold to obtain monolithic samples and also in water in order to obtain particulate material. Such material was grinded and then pressed by both uniaxial and isostatic pressing methods before being sintered. Both the monolithic and pressed samples were performed under two different conditions of heat treatment so that their nucleation and crystallization occurred. In the first one, the samples were heated to 1100 degrees C with a heating rate of 10 degrees C/min. In the second one, there was an initial heating rate of 10 degrees C/min up to 780 degrees C, which was kept for 5 minutes. After that, the samples were heated to 1100 degrees C at a heating rate of 1 degrees C/min. Microhardness analyses showed that base glass presented values around 7.0 GPa. The glass-ceramics obtained from the powder sintering showed microhardness values lower than those obtained from monolithic samples. The highest hardness values were observed in the samples which were treated with two heating rates, whose values were around 9.2 +/- 0.5 GPa. Moreover, the glass-ceramics which were produced with an only heating rate, presented values around 7.1 +/- 0.2 GPa, very close to those observed in the base glass.