Nehemias Curvelo Pereira

Membrane ultrafiltration of crude soybean oil

In the present work, it is evaluated the influence of temperature and transmembrane pressure on the crude soybean oil permeate flux through a ceramic tubular membrane (pore size 0.01 μm) and a polysulphone hollow fiber membrane (pore size 100 KDa). Temperatures and pressures values are 50, 60 and 70°C, 3.0, 4.5 and 6.0 bar, for the ceramic membrane; 50, 60 and 70°C, 0.7 and 1.4 bar, for the polysulphone one. Furthermore, it is also verified some physical properties of the permeate.

Influência do sulfato de condroitina na formação de filmes isolados de polimetacrilato: avaliação do índice de intumescimento e permeabilidade ao vapor d'água

Natural or modified chondroitin sulfate was incorporated in to polymethacrylate to obtain isolated films. The addition of polysaccharide to synthetic polymers occurred at different rates. Isolated films were micro and macroscopically characterized and swelling index and water vapor transmission were determined. Results indicated changed transparency and flexibility, coupled to their dependence on increase in polysaccharide concentration. A similar occurrence was reported in the permeability to water vapor and swelling degree. Films composed of modified chondroitin sulfate, 90:10 concentration, showed hydration levels, permeability and morphological properties which allow them to be applied as excipients in the development of new drug delivery systems.

Generalized drying curves in conductive/convective paper drying

This work presents a study related to conductive/convective drying of paper (cellulose) sheets over heated surfaces, under natural and forced air conditions. The experimental apparatus consists in a metallic box heated by a thermostatic bath containing an upper surface on which the paper samples (about 1 mm thick) are placed. The system is submitted to ambient air under two different conditions: natural convection and forced convection provide by an adjustable blower. The influence of initial paper moisture content, drying (heated surface) temperature and air velocity on drying curves behavior is observed under different drying conditions. Hence, these influence is studied through the proposal of generalized drying curves. Those curves are analyzed individually for each air condition exposed above and for both together. A set of equations to fit them is proposed and discussed.

ANÁLISES FÍSICO-QUÍMICAS DE BIOFILMES DE SULFATO DE CONDROITOINA MODIFICADO

Numerous investigations are dedicated to the research and development of new polymer materials destined for innovation in pharmaceutical forms. The application of these technological resources has allowed the commercialization of new therapeutic systems for modified drug release. This investigation aimed to evaluate the association of modified chondroitin sulfate with an insoluble polymer, Eudragit® RS 30 D, widely available in the pharmaceutical market. Isolated films were prepared by the evaporation process using a Teflon® plate. The aqueous dispersions (4% m/v) of synthetic polymer received the addition of modified chondroitin sulfate at different ratios. The interactions of the polymer chains in the blends were physicochemically characterized by means of Fourier transform infrared spectroscopy, thermal analyses, differential scanning calorimetry, thermogravimetry and scanning electron microscopy combined with hydration and assays in alkaline pH. The results showed appropriate properties of the coating materials for solid oral forms intended for drug deliver in specific environments.

Improvement on the concentrated grape juice physico-chemical characteristics by an enzymatic treatment and Membrane Separation Processes

In this work, the improvement on the concentrated grape juice physico-chemical characteristics by using an enzymatic treatment followed by Membrane Separation Process (MSP) has been investigated. By using Novozym 33095(r) and Ultrazym AFP L(r) enzymes varying three operating parameters, the best result on the grape pulp characteristics was attained for the Novozym 33095(r) performed at 35oC, 15 min. and 50 mgL-1. In micro/ultra filtration processes after enzymatic pretreatment, the best performance of the MSP with high permeate flux value and suitable grape juice characteristics was attained using 0.05 mm membrane pore size, 1 bar pressure and 40 oC treatment temperature. When reverse osmosis process is operated at 40 bar and 40oC, high soluble solid and low turbidity values are attained. An enzymatic treatment along with MSP has shown an alternative and efficient grape juice processing system, being possible to extend to other foods.

Generalization of drying curves in conductive/convective drying of cellulose

The objective of this work is to analyze the possibility of applying the drying curves generalization methodology to the conductive/convective hot plate drying of cellulose. The experiments were carried out at different heated plate temperatures and air velocities over the surface of the samples. This kind of approach is very interesting because it permits comparison of the results of different experiments by reducing them to only one set, which can be divided into two groups: the generalized drying curves and the generalized drying rate curves. The experimental apparatus is an attempt to reproduce the operational conditions of conventional paper dryers (ratio of paper/air movement) and consists of a metallic box heated by a thermostatic bath containing an upper surface on which the cellulose samples are placed. Sample material is short- and long-fiber cellulose sheets, about 1 mm thick, and ambient air was introduced into the system by a adjustable blower under different conditions. Long-fiber cellulose generalized curves were obtained and analyzed first individually and then together with the short-fiber cellulose results from Motta Lima et al. (2000 a,b). Finally, a set of equations to fit the generalized curves obtained was proposed and discussed.

APLICAÇÃO DE PROCESSOS DE COAGULAÇÃO/FLOCULAÇÃO E ELETROCOAGULAÇÃO PARA O TRATAMENTO DE EFLUENTE TEXTIL

RESUMO O objetivo deste trabalho foi a aplicacao dos processos de tratamentos por coagulacao/floculacao, utilizando tres diferentes coagulante/floculante: tanino, policloreto de aluminio e sulfato de aluminio, e o processo de eletrocoagulacao, para o tratamento de efluentes liquidos de uma lavanderia textil. Para o processo de coagulacao/floculacao, foi realizado inicialmente um estudo para determinar a melhor dosagem dos coagulantes em relacao ao efluente, em seguida o melhor pH inicial para cada dosagem estabelecida, nestas condicoes foram verificadas as percentagens de remocoes de DQO, cor aparente e turbidez para cada coagulante. Para o tratamento de eletrocoagulacao, foi utilizando um reator de escala laboratorial, do tipo batelada, com eletrodos de aluminio, capacidade de 4 litros e densidade de corrente de 1,51mAm -2 . O efluente textil apresentou, apos os processos de tratamentos avaliados, caracteristicas fisico-quimicas dentro dos limites de despejo em corpos hidricos receptores impostos pelo CONAMA.

TRATAMENTO E CARACTERIZAÇÃO FÍSICO-QUÍMICA DO ÓLEO DE FRITURA E SEBO BOVINO PARA DESENVOLVIMENTO DE BLENDAS LÍQUIDAS CAPAZES DE SEREM DESTINADAS PARA PRODUÇÃO DE BIODIESEL ETÍLICO.

RESUMO: Devido ao crescente interesse por novas fontes energeticas, o biodiesel tem ganhado grande destaque dentre as fontes de energia limpa. Esse biocombustivel pode ser produzido tanto com oleos de origem vegetal como de origem animal; duas materias prima que tem ganhado a atencao de pesquisadores e a utilizacao do sebo bovino e oleo de fritura (coccao). Estes produtos sao considerados residuos pela sociedade e em grande parte sao descartados, o que gera um grande problema para a natureza. Porem se isoladas possuem algumas desvantagens, juntas podem ser de grande beneficio. Por isso a ideia de melhorar estas caracteristicas indesejadas utilizaremos a producao de blendas. A mistura dos dois componentes pode resultar em uma materia-prima com baixo custo de producao, associado a um baixo custo de tratamento, barateando a producao de biodiesel associado a qualidade do mesmo. Este trabalho baseia se na producao de blendas de sebo mais coccao no estado liquido e assim encontrar uma materia-prima ideal e viavel para producao de um biocombustivel de qualidade. Palavras-chave : Residuos. Blendas. Residuos.

Avaliação do efeito do polieletrólito aniônico na clarificação do extrato aquoso de Stevia rebaudiana

The clarification is an important stage in the process of sweeteners for obtaining the stevioside. In this work, it was used the anionic polyelectrolyte (BETZDEARBORNTMF11) for decantation of the raw extract suspension, which possesses dark color, and it was evaluated its sweats application. The used extract was obtained in first stage from selected plants and modified genetically, in the Nucleus of Studies in Natural Products of the Universidade Estadual de Maringa (UEM), which maintains a line of denominated research Project Stevia and its plant pilot works in partnership with the private initiative. The rehearsals were accomplished in apparel Jar Test divided in two stages, either distinguished in dosage of the polymer and in the use of the supernatant or of the total suspension after treatment with calcium oxide, which accomplished the adjustment of the pH. Absorbances were read in 420 (color) and 670hm (turbidity) and, it was calculated the color removal percentage and the decantation speed. The best results in the stage 1 was when it was applied low amounts of anionic polyelectrolyte and the use of supernatant was 72.2 and 97.0% for color removal in 420hm and 670hm and the decantation speed was of 0.72cm/min. At stage 2, when it was used a risen amount of the polyelectrolyte and the total suspension, the best results obtained for color removal were of 70.5% in 420hm, and 85.6% in 670hm and decantation speed was of 0.71cm/min.