202 resultados para extração ácida
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Persistent Organic Pollutants (POPs) are chemical substances extraordinarily toxic and persistent in the environment. Due to these properties, POPs are targets of the Stockholm Convention which aims to provide means to eliminate production and use by encouraging the reduction and, where possible, eliminating the release of these contaminants to the environment. One of the articles of this _Convention aims to assess the basal levels of such substances in the environment to monitor both the reduction of release to the environment, and to assess human exposure, using analyzes of milk and air for example. Although efforts to control POPs production and release to the environment have been made, data about their levels in Brazil are still scarce, mainly in the atmosphere or indoor environment. Considering the permanence of people inside its house, this study presents a method for POP extraction from XAD-2 sorbent employed in indoor air sampling, with identification and quantification by GC-ECD. GC-ECD linear range of the studied analytes, congeners of polychlorinated biphenyls (PCB) (28, 52, 101, 118, 138, 153 and 180), DDTs and their metabolites (DDDs, DDEs) and endosullan (isomers c - and 13 - and metabolite endosulfan sulfate) ranged between 0.5 and 16.0 ng mL-I with r2 > 0.967. The method developing consist of selecting the extraction solvent system by agitation (90 rpm, 1 hour) with n-hexan,e (2 mL) or n-hexane:acetone (1:1, v/v) (2 mL), concentration the extract with a gentle N2 stream, and evaluation of breakthrough with passage or air through the fortified XAD-2 cartridge before extraction, employing a low volume air suction pump (Pump Model 224 universal-PCXR8; 5-5000 mL min-1, SKC Inc., Eighty Four, PA, USA), Calibrator Dry-Cal DC-Lite (BIOS, Butler, NJ, USA)). Two fortification levels were employed, 15 and 30 ng. After selecting n-hexane as extraction solvent, with accuracy and precision ranging...
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The identification of Salmonella spp. in food samples by microbiological diagnosis is time consuming, with approximately five different stages, requiring about 120 hours until the final result. The utilization of the polymerase chain reaction technique (PCR) can reduce this time, but substances present in samples may affect the reaction. The present work aimed to compare DNA extraction by thermic treatment and by the use of cetyltrimethil ammonium bromide (CTAB), in products originated from poultry houses corresponding to raw material (meat meal) and experimentally contaminated drag swabs. Materials obtained from the extractions were submitted to PCR, utilizing a pair of initiator oligonucleotides for amplification of Sdf 1 gene fragments. Comparing the methods of extraction, it was observed that when CTAB was employed, SE was detected in 70% of meat meal and in 80% of drag swabs, while the thermic treatment method yielded positive results in 20% of meat meal and in 40% of drag swabs. SE was detected under both methods utilized for DNA extraction, but the use of CTAB detected a greater number of positive samples, compared with thermal treatment.
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The biomass resulting from processing sugarcane bagasse has been considered a source of cellulose with the potential production of bio-fuels. This lignocellulose can be processed into ethanol since is hydrolyzed by chemical processes (acids) or biotechnology (enzymes) which generate sugars suit for fermentation. This study had the objective to utilize physical and chemical pre-treatment processes for prehydrolysis of sugarcane bagasse. The experimental treatment was adjusted at a factor of 4 X 2, by the combination of pre-hydrolysis timing (15, 30, 45 and 60 minutes) and sulfuric acid concentrations (7.0% and 9.0%) which was incubated at a temperature of 121° C in an autoclave. The treatment data was subjected to analysis of the variance and averages which were compared using the Tukey test with a probability of 5%. The results obtained showed that through pretreatment acid applied on the lignocellulose material, there was a significant break from the substrate fibers like cellulose, hemicellulose and lignin.
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The international energy situation indicates to the depletion of oil reserves in the short term. Brazil, considering its potential, has sought through public policy, encourage the study of alternative forms of energy. Many of these forms are based on sub-products and agricultural products, especially the ethanol industry for fuel purposes. Another alternative of vegetable origin, most recently discussed, would be the production of fuel oil called biodiesel. The study aimed to extract and measure the pulp oil production of macaúba palm [Acrocomia aculeata (Jacq) Lodd. ex Mart], collected in Botucatu (SP). In addition, the qualitative analysis of the pulp and almond oil are determined. The results showed low productivity in oils, compared to the reported for macauba natural populations of Minas Gerais. The qualitative analysis of the macauba pulp shows to be rich in long chain fatty acids, while the almond have significant amounts of lauric acid.
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Ananas erectifolius (curaua) is a fibrous vegetable that can be found in North and Central West regions of Brazil. It is a bromeliaceae family plant which physico-chemical features provides great potential in the automobilistic industry as a source of fibers. As commonly described in other bromeliaceae species, it contains significant levels of bromelain, of high commercial value and wide range of aplications in food, pharmaceutical and cosmetic industry. In this paper, experimental tests were performed to evaluate the extraction of the proteolytic enzymes of the Ananas erectifolius under different pH and temperature conditions to determine in which ones the enzymatic activity would be the maximum for later purification of the bromelain. The two commercially available curaua varieties (white and purple) were used in the experiments and the results showed the same optimal pH of 8,5 for both varieties and different temperatures of 30ºC for the white one, and 10ºC, 20ºC and 35ºC for the purple one.
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This study aimed to technically and economically evaluate the Forwarder performance in the first cutting wood extraction from a Eucalyptus grandis plantation. Technical analysis included a movement and timing study by continuous method, and the productivity was determined using the extracted wood volume in cubic meters. Economical analysis included operational costs parameters and wood extraction cost. Results referred to the effective operational performance. Loading and unloading activities responded for more than ¾ of the total time of effective Forwarder operational cycle. Operational costs were influenced by maintenance and repair costs. The estimated cost of extraction was US$ 0.97 per cubic meter.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)