918 resultados para Extração da sacarose


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The new market, focused on sustainability and other environmental concerns, refers to innovations that seek alternative forms of production. In pulp and paper bleaching alternative reagents are studied, for example, hydrogen peroxide, in partial substitution of chlorine dioxide in order to reduce the formation of organochlorines. In this context, this study examined the burden of hydrogen peroxide (H2O2) on alkaline extraction stage (stage Ep) required for the bleaching of pulp with eucalyptus kraft pulp, pre-oxygen delignified to obtain equivalent brightness at 90 ± 0.5% ISO, as well as its effect on quality of pulp produced. The pulp was bleached by the sequence D(Ep)DP, with the application of factor kappa of 0.14 and varying the concentration of hydrogen peroxide in Ep stage three, five, seven and nine kilograms of reagent per ton of pulp absolutely drought. The final P stage was optimized with the use of six, nine and twelve pounds of hydrogen peroxide per ton of absolutely dry pulp to achieve the required brightness. The quality of the pulp produced was analyzed based on the kappa number, the brightness and the viscosity. The methods were performed according to standards set by the standard TAPPI (Technical Association of the Pulp and Paper Industry). The best result was obtained using the following D0Ep(7)D1P(6), which showed a viscosity of 19.9 cP, 89.6% ISO brightness, consumption of 94.9 kg / t of reagents and reagent costs of US$ 28.15, because it showed better pulp quality for a lower cost compared to the others. It was found that the greater the amount of hydrogen peroxide in alkaline extraction, the lower the kappa number and increased the amount of residual hydrogen peroxide. The higher the charge of hydrogen peroxide in Ep stage, the lower the need for hydrogen peroxide in the final P stage, reducing the cost of bleaching

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The uninterrupted rise in emission of greenhouse gases open way to the use of biofuels, due to politics that focus on fuel safe, clean and renewable. The use of microalgae for biodiesel production has been described as one of the most promising sources of biomass for biofuels. The aim of this study was to evaluate the extraction and lipid profile of the microalgae Dunaliella tertiolecta, Isochrysis galbana and Tetraselsim gracilis. The extractions were performed with solvents chloroform /methanol and petroleum ether. The lipid profile was analyzed by gas chromatography after transesterification.The petroleum ether showed more efficiency in the extraction, the best result obtained was in the microalgae D. tertiolecta with 19.52% of lipid. The lipid profile analysis indicated a biodiesel stable to oxidation and elevated viscosity

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Sucrose esters are biodegradable, non pollutant and safe for health; moreover, they have shown great potential in the pest control. We tested a crude mix of sucrose esters on the survivorship and oviposition of Calacarus heveae Feres (Acari: Eriophyidae) females, an important rubber tree pest mite. The females were collected from rubber leaflets of the GT 1 and RRIM 600 clones. The mites were kept on stock arenas placed in rearing chamber at 28 + 0,1°C, 80 + 10% of relative humidity and 12h of light phase about two weeks before the assays. After this period, the mites were transferred to assay arenas made with leaflets from the same clone of stock arenas. The survivorship of females sprayed with sucrose esters in the concentrations of 1, 2, 3 and 4 g/L and their oviposition effect with 0.5 and 1 g/L were analyzed. The mites sprayed with 4 g/L had about 80% of mortality, while those with 1 g/L around 60%. All mites that died in the treatments with sucrose ester became dark with wrinkled tegument and decreased their body volume, suggesting dehydration. We also observed the efficacy of 1 g/L concentration to decrease the female oviposition in about 50%, in the third day after spraying. No differences were observed in the mortality and oviposition between females kept on both clones.

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Liquid-liquid extraction is utilized for purification of biomolecules by Aqueous Biphasic Systems (ABS), since this process does not damage the biotechnological potential of these compounds. In this work, using the free software Scilab®, the fractionated liquid-liquid extraction was studied aiming a lipase (target enzyme) partition in a water + PEG + DEX system. Lisozime was considered as contaminant. As computer simulations has been extensively used when a first estimation of technical feasibility of process is desired, this work demonstred that the system is viable for recovery the 80 % till 90 % the target enzyme, but should be noted that the trial aimed only the fractionation of the enzyme target of a contaminant, not its concentration, which should be done by another process.

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

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Pós-graduação em Engenharia Elétrica - FEIS

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Introduction: Aortic insufficiency (AoI), a volume overload, is characterized by the diastolic reflux of blood from the regurgitating aorta to the left ventricle. This effect results from malfunctioning aortic cusps. The main cause of AoI in developing countries is rheumatic fever, including Brazil, and valvar degeneration in developed countries. There is a strong association between cardiovascular diseases and depression. Selective serotonin reuptake inhibitors (SSRI) are one of the most prescribed antidepressants in the world. Previous studies of our laboratory showed that the utilization of a SSRI, paroxetine, improved cardiac function in rats with sub-chronic AoI and reduced the daily ingestion of hypertonic sodium (NaCl 0,3M). Cardiovascular diseases can determine behavior changes like increase of anxiety, and it is yet unknown if AoI would determine anxiety or anhedonia, incapacity of obtaining pleasure through physical or sensorial experiences. A possible target for SSRI action could be a change in the expression of enzyme isoforms that collaborate in the contractile function of the heart muscle, like the heavy chains of myosine, the sarcoplasmatic reticulum Ca2+/ATPase (SERCA) and its regulator protein, phospholamban (PLB). Objectives: Evaluation of behavior parameters for anxiety and anhedonia state and genic expression of a-myosine, b-myosine, SERCA2a and PLB in the heart tissue of rats with subchronic AoI that received treatment with an SSRI (paroxetine) for 4 weeks. Methods: Surgery to induce AoI was performed on male Wistar rats, anxiety was evaluated by the elevated plus-maze (EPM) and state of anhedonia was tested by ingestion of 2% sucrose solution. After euthanasia the heart tissue was collected and total RNA was extracted to be analyzed by the RT-qPCR method. Results: Heart fractional shortening was preserved in rats with AoI that were treated compared to rats with AoI that were not treated. There was no statistically ...

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Patients are looking for esthetic and functional changes when seeking orthodontic treatment and expect the remaining of a stable occlusion. Occlusion stability is one of the goals of the orthodontist; however, dental relationships changes in long-term can occur leading to a relapse of the treatment. Teeth and shape of arches tend to return to the original form, been the retention phase important after the appliance removal, even after several years of post-treatment. This article approaches a submission of a clinical case of Class II division 1 treated with extraction of premolars analyzing its long-term stability.

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The early malocclusion treatment has increased interest of orthodontic community. Among these is the serial extraction that harmonizes the differences between the amount of dental material and permanent deficiency of supporting bone. The technique is applied in mixed dentition through a predetermined sequence of extractions between deciduous and permanent teeth, in order to reach spontaneous immediately alignment of remaining permanent teeth with a minimum orthodontic mechanics. It will be reported a case where the serial extraction was performed in a growing patient with biprotrusion, Class I malocclusion and severe crowding. All functional and aesthetics goals were reached.

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The correction of a Class III malocclusion in adult patients is one of the major challenges in orthodontics due to facial deformities occurring during the unfavorable growth of this kind of pattern, as well as the treatment options capable of producing facial changes aesthetically acceptable and adequate for today's beauty standards. One acceptable alternative treatment is the removal of a lower incisor. For a Class III correction through a lower incisor extraction a thorough analysis and planning must be carried out by taking into consideration the amount of overjet and overbite, periodontal condition of the teeth and the possibility of obtaining a good dental occlusion with acceptable facial aesthetics. Will be presented two case reports of patients presenting an anteroinferior crowding, Class III malocclusion condition. The treatment through a lower incisor extraction and the reasons why this treatment was adopted will be discussed.