973 resultados para Bagaço de cana - Purificação


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Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq

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The present study aims to evaluate the potential use of bagasse ash from sugar cane (CBC) as a flux, replacing phyllite and/or feldspar in standard industrial mass production of enameled porcelain, verifying the possibility of the CBC contribute to the overall reduction of the coefficient of thermal expansion of the ceramic mass. To this end, as a result of the research, we characterized the raw material components of the standard mass (clay, phyllite, kaolin, feldspar, quartz and talc) and the residue of BCC, by testing by XRF, XRD, AG, DTA and ATG. Specimens (CDP) were manufactured in the dimensions of 100 mm x 50 mm x 8 mm in uniaxial matrix under compaction pressure of 33 MPa, assembled in batches of 3 units subsequently sintered at temperatures of 1150°C to 1210°C by varying the Rating Scale at 10°C, heating and cooling ramp of 50°C/min and 25°C/min, with levels of 1 min, 3 min, 5 min, 8 min, 10 min, 15 min, 30 min and 60 min. analyzing the results of the physical properties of water absorption (WA), linear firing shrinkage (LFS), dilatometric analysis (DTA), flexural strain (SFT) and SEM of the sintered bodies in order to verify the adequacy of CDP to ISO 13006, ISO 10545, NBR 13816 standards; NBR 13817 and NBR 13818. The study showed that the formulations that best suit the requirements of the standards are:. G4 - which was applied in 10% of replacing the CBC phyllite, sintering temperature 1210 ° C for 10 min and porch, and F3 - with application of 7.5% of CBC to replace the feldspar in the sintering temperatures of 1190°C, 1200°C and 1210°C for 10 min and porch. These formulations showed better performance regarding the formation of primary and secondary mullite, with considerable reduction of cracks and pores, meeting the prerequisites of standards for glazed porcelain. The results shows that the use of the CBC as a flux in the preparation of porcelain mass meets standard parameters for the manufacture of the product, and thereby can reduce environmental impact and the cost of production. Therefore, it is recommended to use this residue in the ceramics industry, due to its industrial, commercial and collaborative viability for sustainability.

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Oral route of administration is considered to be the most comfortable, safe and greater adaptation for patients. But, oral route presents some disadvantages such as drugs bioavailability and side effects on the stomach. Some technologies are studied to soften and/or resolve these problems, such as coating with polymeric films, which are able to protect the pharmaceutical form of the acid stomachic environment and to act in the drug release, and mucoadhesive systems, which allow the pharmaceutical form remains a greater time interval in the intestine, increasing the effectiveness of the drug. Cellulose triacetate (CTA) films were produced from cellulose extracted from sugar cane bagasse. The films were prepared with different morphologies (with and without water, acting as non-solvent) and concentrations (3, 6.5 and 10%) of CTA and characterized using scanning electron microscopy (SEM), water vapor permeability (WVP), puncture resistance (PR), enzymatic digestion (DE), and mucoadhesive force evaluation (MF). Microscopy showed the formation of symmetric and asymmetric morphologies. WVP data showed that more concentrated films have higher values for WVP; moreover, asymmetric films had higher values than symmetric films. PR measurements showed that symmetric membranes are more resistant than asymmetric ones. More concentrated films were also more puncture resistant, except for symmetric membranes with CTA concentrations of 6.5 and 10% that did not show significant differences. All of the films presented large mucoadhesive capacities independent of their morphology and CTA concentration. From the results of WVP and RP, a symmetric filme with 6.5% CTA showed better ability and mechanical resistance, therefore, was selected to serve as coating of gellan gum (GG) particles incorporating ketoprofen (KET), which was confirmed by SEM. The selected film presented low values in measurements of the swelling index (SI) and in a dissolution test (DT). TGA analysis showed that the CTA coating does not influence the thermal stability of the particles and there is no incompatibility evidence between CTA, GG and KET. Coated particles released 100% of the ketoprofen in 24 h, while uncoated particles released the same amount in 4 h. The results of this study highlight the potential of CTA in the development of new controlled oral delivery systems.

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2009

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Cementing operation is one of the most important stages in the oil well drilling processes and has main function to form hydraulic seal between the various permeable zones traversed by the well. However, several problems may occur with the cement sheath, either during primary cementing or during the well production period. Cements low resistance can cause fissures in the cement sheath and compromise the mechanical integrity of the annular, resulting in contamination of groundwater and producing zones. Several researches show that biomass ash, in particular, those generated by the sugarcane industry have pozzolanic activity and can be added in the composition of the cementing slurries in diverse applications, providing improvements in mechanical properties, revenue and cement durability. Due to the importance of a low cost additive that increases the mechanical properties in a well cementing operations, this study aimed to potentiate the use of sugarcane bagasse ash as pozzolanic material, evaluate the mechanisms of action of this one on cement pastes properties and apply this material in systems slurries aimed to cementing a well with 800 m depth and geothermal gradient of 1.7 °F/100 ft, as much primary cementing operations as squeeze. To do this, the ash beneficiation methods were realized through the processes of grinding, sifting and reburning (calcination) and then characterization by X-ray fluorescence, XRD, TG / DTG, specific surface area, particle size distribution by laser diffraction and mass specific. Moreover, the ash pozzolanic activity added to the cement at concentrations of 0%, 20% and 40% BWOC was evaluated by pozzolanic activity index with lime and with Portland cement. The evaluation of the pozzolanic activity by XRD, TG / DTG and compressive strength confirmed the ash reactivity and indicated that the addition of 20% in the composition of cement slurries produces improvement 34% in the mechanical properties of the slurry cured. Cement slurries properties evaluated by rheological measurements, fluid loss, free fluid, slurry sedimentation, thickening time and sonic strength (UCA) were satisfactory and showed the viability of using the sugarcane ash in cement slurries composition for well cementing

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O bagaço de cana-de-açúcar (BCA), possui em sua composição principalmente celulose e hemicelulose que podem ser hidrolisadas para produção de etanol de segunda geração. O objetivo deste trabalho foi verificar se o BCA hidrolisado quimicamente poderia ser utilizado como substrato para a caracterização de enzimas lignocelulolíticas.

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A conversão da celulose e da hemicelulose do bagaço de cana-de-açúcar em bioetanol tem utilizado enzimas comerciais importadas, tornando o processo caro, justificando a busca e a produção de enzimas nacionais. O presente trabalho objetivou caracterizar as proteínas aderidas à fibra do bagaço de cana-de-açúcar (BCA), obtidas do conteúdo ruminal de ovinos Morada Nova, quanto à resistência térmica e à variação de pH.

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2008

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Pós-graduação em Ciências Biológicas (Microbiologia Aplicada) - IBRC

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Química - IBILCE

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)