Experimentos químicos para melhor aplicação do currículo oficial do Estado de São Paulo

O presente trabalho relata o desenvolvimento e os resultados do projeto do programa Núcleos de ensino da UNESP que visou promover mecanismos didático-pedagógicos para o ensino de química da rede pública de São José do Rio Preto. Utilizou-se como material de referência os Cadernos do professor, implementado pelo novo Currículo Oficial do Estado de São Paulo. A metodologia utilizada foi da investigação-ação, na perspectiva da ação-reflexão-ação. O projeto foi desenvolvido na forma de um curso de capacitação com aulas teóricas e práticas semanais aos professores PEB II pertencentes à Diretoria de Ensino de São José do Rio Preto. As aulas foram desenvolvidas por meio de exposições dialogadas, da leitura e interpretação de textos relacionados ao tema da aula e da realização de experimentos. A avaliação constou da elaboração de relatórios, da socialização dos resultados dos experimentos, da participação nas aulas e de uma avaliação final com questões dissertativas referentes aos conteúdos teóricos e dos experimentos desenvolvidos. A realização deste projeto colaborou com o sistema formativo dos professores, auxiliando-os no uso dos Cadernos do professor e aluno, o curso foi avaliado como muito bom por 90% dos participantes. Somente uma formação que leve o professor a comprometer-se com sua prática é capaz de dar uma resposta positiva à escola. Com comprometimento e autonomia, é possível levar a mudanças na prática dos professores e na constituição do profissional colaborador, ético, leitor e escritor, conseqüentemente, reflexivo e crítico. As escolas necessitam de profissionais que indagam, refletem e investigam continuamente sua prática

HYGROSCOPIC PROPERTIES OF ORANGE PULP AND PEEL

This contribution addresses the hygroscopic properties of orange pulp and peel (OPP), an agro-industrial by-product used for pectinase and phytase production by solid-state fermentation (SSF). Experiments were carried out using the static gravimetric method and the modified Halsey model best fitted to the experimental data. Bates and Watts curvature measurements, Box parameter bias estimation and residual analysis were performed in order to validate the model and the estimated parameters. Desorption experiments were also carried out and the results showed that drying took place even at high air relative humidity. The results presented are fundamental for water transfer modeling in SSF in fixed bed bioreactors.Practical ApplicationsThe current work addresses the hygroscopic properties of OPP, a solid waste rich in pectin, which can be used as substrate in SSF for the synthesis of pectinases and phytases. Thermal sorption isotherms (TSI) and water desorption kinetics (WDK) were investigated, both of the key information required for the fermentation process, either on simulation or in the laboratory. Usually, the moisture content of the solid phase in SSF is far above its moisture equilibrium content, and since the microbial metabolism is strongly affected by the moisture content, knowledge of TSI and WDK are mandatory. Experimental information was gathered and TSI nonlinear models were applied and special care was taken for the parameter estimation, applying specific tools to assess nonlinearity problems. The work therefore possesses significant new information, particularly interesting for engineers dealing with design and scaling-up of SSF bioreactors and with nonlinear regression estimation.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Structural properties of beds packed with agro-industrial solid by-products applicable for solid-state fermentation: Experimental data and effects on process performance

The knowledge of structural properties of beds packed with particles from agro-industrial solid wastes is important for modeling and simulation of heat and mass transfer in solid-state fermentation (SSF) in packed-bed bioreactors. This paper addresses the experimental determination of particle and bulk densities (rho(part) and rho(bulk)) and porosities (epsilon) of beds packed with sugar cane bagasse (SCB), wheat bran (WB) and orange pulp and peel (OPP) and with mixtures of them. The effects of moisture content (MC) and packing technique on structural properties were evaluated. Microscopic analysis of cell-size was performed and the porosity along the fermentation was determined, as well as the endoglucanase yields for different proportions of a medium composed by SCB/WB. Results showed that MC affects significantly rho(part), rho(bulk) and epsilon. For OPP and WB, epsilon ranged from 0.4 to 0.7, depending on MC, and for SCB from 0.7 to 0.9, depending on MC and packing technique. For the composed media SCB:OPP:WB (1:2:2, weight) and SCB:WB (7:3), epsilon values were similar to the ones obtained for SCB. The growth of the fungi Myceliophthora thermophila I-1D3b and Trichoderma reesei QM9414 did not affect epsilon of the medium composed by SCB:WB. A comprehensive discussion on how the structural properties of solid matrices affect the performance of SSF processes was done, considering both operational aspects and bioproducts yields. (C) 2014 Elsevier B.V. All rights reserved.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP