Avaliação in situ da capacidade remineralizadora de selantes que contenham fosfato de cálcio amorfo e/ou fluoreto

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ethanolysis optimisation of Jupati (Raphia taedigera Mart.) oil to biodiesel using response surface methodology

In this work, the transesterification of jupati (Raphia taedigera Mart.) oil using ethanol and acid catalyst was examined. The production of biodiesel was performed using a central composite design (CCD). A range of values for catalyst concentration (1 to 4.21%), temperature (70-80 °C), and the molar ratio of alcohol to oil (6:1-13.83:1) were tested, and ester content, viscosity, and yield were the response variables. The synthesis process was optimised using response surface methodology (RSM), resulting in the following optimal conditions for the production of jupati ethyl esters: a catalyst concentration of 3.85% at 80 °C and an alcohol-to-oil molar ratio of 10:1.

Obtenção dos parâmetros e estudo cinético da hidrólise ácida dos resíduos florestais de eucalipto

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

Análise do escoamento turbulento por um queimador industrial a gás utilizando dinâmica dos fluidos computacional

Pós-graduação em Engenharia Mecânica - FEG

Otimização do cultivo de Lasiodiplodia theobromae para obtenção de EPS e caracterização física e química dos polissacarídeos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação de suportes para a imobilização de Zymomonas mobilis CCT 4494 visando à produção de etanol e levana

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Numerical modeling of flow through an industrial burner orifice

This paper presents numerical modeling of a turbulent natural gas flow through a non-premixed industrial burner of a slab reheating furnace. The furnace is equipped with diffusion side swirl burners capable of utilizing natural gas or coke oven gas alternatively through the same nozzles. The study is focused on one of the burners of the preheating zone. Computational Fluid Dynamics simulation has been used to predict the burner orifice turbulent flow. Flow rate and pressure at burner upstream were validated by experimental measurements. The outcomes of the numerical modeling are analyzed for the different turbulence models in terms of pressure drop, velocity profiles, and orifice discharge coefficient. The standard, RNG, and Realizable k-epsilon models and Reynolds Stress Model (RSM) have been used. The main purpose of the numerical investigation is to determine the turbulence model that more consistently reproduces the experimental results of the flow through an industrial non-premixed burner orifice. The comparisons between simulations indicate that all the models tested satisfactorily and represent the experimental conditions. However, the Realizable k-epsilon model seems to be the most appropriate turbulence model, since it provides results that are quite similar to the RSM and RNG k-epsilon models, requiring only slightly more computational power than the standard k-epsilon model. (C) 2014 Elsevier Ltd. All rights reserved.

Modelagem e otimização por metodologia de superfícies de resposta: um estudo em arames de aço SAE 9254 para molas automobilísticas

Pós-graduação em Engenharia Mecânica - FEG

Sucrose utilization by Zymomonas mobilis: Levan production optimization using submerged fermentation

Levan is an extracellular polysaccharide (EPS), constituted by linked fructose units β (2,6), obtained by transfructosilation reaction during fermentation of microorganisms in a sucrose rich culture medium. The bacterial levan production is a good alternative of fructose source, besides having certain functional characteristics in the human body, such as a hypocholesterolemic and an anticarcinogenic agent. In the food industry, the levan can be used to fix colors and flavors, as well as to thickening and stabilizing agent in foods. This work aimed to analyze the kinetic parameters for levan production by Zymomonas mobilis CCT 4494, using submerged fermentation. The response surface methodology (RSM), was utilized to predict the optimization of medium for exopolymer production and the independent variables studied were: initial pH, incubation temperature, sucrose, KCl, K2SO4, MgSO4 and CaCl2. It was observed that the bacterium Z. mobilis CCT 4494 well adapted in medium containing high concentrations of sucrose.

Chicken fat and inorganic nitrogen source for lipase production by Fusarium sp. (Gibberella fujikuroi complex)

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

Estudo do comportamento reológico de sucos combinados de frutas vermelhas

The aim of this work was to evaluate the rheological behavior of combined juices of strawberry, blackberry and raspberry in two different temperatures of interest in industrial processes in the food industry, using rheological analyses on non-oscillatory regime and the Response Surface Methodology (RSM). The rheological data were fitted by the Casson model. All samples of combined juices of ref fruits showed a Newtonian behavior and the rheological parameters yield stress (Kc) and plastic viscosity of Casson (Koc) had a decrease in its values with the temperature increase. By the analysis of the ternary diagrams it is evident that the raspberry juice effectively contributed to the higher values of yield stress and plastic viscosity of Casson in both temperatures studied.

The effects of land use and soil management on the physical properties of an Oxisol in Southeast Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of high hydrostatic pressure on ascorbic acid, phenolic compounds and antioxidant activity of pera rio orange juice

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

Purification, characterization and structural determination of chitinases produced by Moniliophthora perniciosa

The enzyme chitinase from Moniliophthora perniciosa the causative agent of the witches' broom disease in Theobroma cacao, was partially purified with ammonium sulfate and filtration by Sephacryl S-200 using sodium phosphate as an extraction buffer. Response surface methodology (RSM) was used to determine the optimum pH and temperature conditions. Four different isoenzymes were obtained: ChitMp I, ChitMp II, ChitMp III and ChitMp IV. ChitMp I had an optimum temperature at 44-73ºC and an optimum pH at 7.0-8.4. ChitMp II had an optimum temperature at 45-73ºC and an optimum pH at 7.0-8.4. ChitMp III had an optimum temperature at 54-67ºC and an optimum pH at 7.3-8.8. ChitMp IV had an optimum temperature at 60ºC and an optimum pH at 7.0. For the computational biology, the primary sequence was determined in silico from the database of the Genome/Proteome Project of M. perniciosa, yielding a sequence with 564 bp and 188 amino acids that was used for the three-dimensional design in a comparative modeling methodology. The generated models were submitted to validation using Procheck 3.0 and ANOLEA. The model proposed for the chitinase was subjected to a dynamic analysis over a 1 ns interval, resulting in a model with 91.7% of the residues occupying favorable places on the Ramachandran plot and an RMS of 2.68.

A swirler stabilized combustion chamber for a micro-gas turbine fuelled with natural gas

Micro-gas turbines are a good alternative for on-site power generation, since their operation is very reliable. The possibility of operating with various fuels increases versatility and, as a result, the usage of these devices. Focusing on a performance improvement of a tri-fuel low-cost micro-gas turbine, this work presents investigations of the inner flow of its combustion chamber. The aim of this analysis was the characterization of the flame structure by the temperature field of the chamber inner flow. The chamber was fuelled with natural gas. In the current chamber, a swirler and a reversed flow configuration were utilized to provide flame stabilization. The inner flow investigations were done with numerical analysis, which were compared to experimental data. The analysis of the inner flow was done with numerical simulations, which used the RSM turbulence model. A β-PDF equilibrium model was adopted to account for the turbulent combustion process. Different models of heat transfer were compared. Thermal radiation and specially heat conduction in the liner walls played significant roles on results.