Estudo das propriedades mecânicas do concreto com adição de cinza de casca de arroz

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of inulin and oligofructose on the physicochemical, microbiological and sensory characteristics of symbiotic dairy beverages

The aim of this study was to verify the effect of inulin and oligofructose on the physicochemical, microbiological and sensory characteristics of symbiotic dairy beverages. Four formulations were made: 1) a control (C); 2) a sample with added Lactobacillus paracasei (P); 3) a sample with added L. paracasei and inulin (PI); and 4) a sample with added L. paracasei and oligofructose (PO). The probiotic population, pH, and acidity of the products were evaluated once a week for 21 days while refrigerated (5 +/- 1 degrees C). Possible contaminating microorganisms (coliforms, E. coli, and Salmonella spp.) were investigated after three days of storage. Sensorial acceptance and purchase intention were evaluated seven days after manufacture. Dairy beverages presented with L. paracasei populations above 8.50 log CFU/mL during the whole storage period. Significantly (p<0.05) lower pH values were observed in P and PI, and higher acidity values were found in all formulations throughout storage. The dairy beverages were considered to be a promising matrix for the probiotic microorganism L. paracasei. The prebiotic additions (inulin and oligofructose) did not interfere with the overall acceptance and intention to purchase the beverages.

alpha-SiAlON-SiC composites obtained by gas-pressure sintering and hot-pressing

The objective of this work was the obtaining in situ of alpha-SiAlON-SiC composite, using an alternative rare-earth oxide mixture, RE2O3, as sintering additive, by two different sintering processes. As sintering additive, 20 vol.% of AlN-RE2O3 in a molar ratio of 90: 10 was mixed to the alpha-Si3N4 powder. In the Si3N4-AlN-RE2O3 powder mixture, 0, 10, 15 and 20wt.% of SiC were added. The powder batches were milled, dried and compacted by cold isostatic pressing. Two different sintering processes were used: gas-pressure sintering at 1950 degrees C for 1 h under 1.5 MPa of N-2 atmosphere, or uniaxial hot-pressing at 1750 degrees C, for 30 min under pressure of 20 MPa. The sintered samples were characterized by X-ray diffraction, scanning electron microscopy and mechanical properties. XRD patterns indicate only alpha-SiAlON (alpha') and beta-SiC as crystalline phases. It was observed that the SiC addition did not influence the alpha-SiAlON formation, although the growth of elongated alpha'-grains is substantially decreased. The hot-pressed composites presented better mechanical properties, exhibiting fracture toughness of 5 MPa m(1/2) and hardness around 21.5 GPa. (c) 2007 Elsevier B.V. All rights reserved.

Análise da sustentabilidade ambiental de um cultivo de ostras em um estuário tropical

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo da influência da cinza de casca de arroz e da cal nas propriedades do solo-cimento auto-adensável

Pós-graduação em Engenharia Civil - FEIS

Determinação de fósforo em biodiesel utilizando eletrodo quimicamente modificado com nanopartículas de ferro

Once petroleum is na exhaustible source of energy, alternative fuels are having more prominence. A much discussed option for replacing fossil fuels is the use of biofuels derived from oils or fats, especially biodiesel. The biodiesel preparation is through a reaction named transesterification, a reaction of triglycerides with a short chain alcohol with a catalyst, producing a mixture of fatty acid esters and glycerol. According to ANP (National Petroleum Agency) specifications, biodiesel can have contaminants due to the catalyst or oil used on its synthesis, such as phosphorus, wich can damage the catalytic converter and cause significant increase in the particles emission. This project aims to develop na alternative method using chemically modified electrodes with iron nanoparticles for determination of phosphorus in biodiesel. For the formation of the iron nanoparticles film on the surface of a glassy carbon electrode, was used a iron sulfate solution. The film was formed after 10 successive cycles, with a scanning speed of 50 mV s-1 and a potential range of -0,9 to -1,25 V. To reduce possible oxides on the surface and activate the electrode, it has been subjected to a cathodic polarization with a potential of -1,25 V for 15 minutes in a sodium hydroxide solution. In cyclic voltammograms obtained in the study of the speed of scanning, there is an increase in the intensity of the anodic and cathodic current peaks. The cathodic peak current varied linearly with the square root of scan rate, showing that the electrode is controlled by diffusion. After successive additions of phosphate there is a linear variation in the current peak in the concentration range of 1,0 x 10-7 a 1,0 x 10-6 mol L-1. To determine if the concentration of phosphorus in real sample, the method of adding standard was used by adding aliquots of phosphate ions in the solution containing soy biodiesel extracted with ....

Características estruturais de aerogéis hidrofílicos e hidrofóbicos de sílica modificados com Dodecil Sulfato de Sódio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Spatial and temporal quality of water in the Itupararanga Reservoir, Alto Sorocaba basin (SP), Brazil

Considering the great importance of the Itupararanga Reservoir, Upper Alto Sorocaba basin/SP, this study aimed to report the variations of some parameters of water quality in the spatial and temporal gradients in this multipurpose res- ervoir. The eutrophication of this reservoir was checked using the Carlson Index Modified and the results indicate that the surface water were classified as eutrophic and mesotrophic in wet and dry periods, being characterized the better quality of water in wet period. In the vertical gradient the results showed a stratiphication in all parameters analyzed, except for the electrical conductivity, with good correlation between total phosphorous and chlorophyll-a, indicating that eutrophication of the reservoir changes the conditions of algal growth, mainly in its initial area. Immediate inter- ventions are needed, which must be directed to planning of land use, domestic effluents treatment, taking to an inte- grated management of this important watershed located in the São Paulo State.

Goma de soja na alimentação de frangos de corte: digestibilidade e desempenho

Pós-graduação em Ciência e Tecnologia Animal - FEIS

Níveis de fósforo em dietas para Zebrafish Danio rerio

Pós-graduação em Zootecnia - FMVZ

Effect of nitrogen and application ways of a plant biostimulant on different wheat genotypes contrasting in stature

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

Obtenção de amido resistente por intercruzamento e por tratamento hidrotérmico, e sua incorporação em bolos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estimativa da irradiação solar global pelo método de Angstrom-Prescott e técnicas de aprendizado de máquinas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aditivo alternativo, associado ou não ao antimicrobiano, na dieta de leitões recém-desmamados

Pós-graduação em Ciência e Tecnologia Animal - FEIS