4 resultados para scavengers

em Universidade Federal do Rio Grande do Norte(UFRN)


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Recently, it has been a increasing interest in the antioxidative role of natural products to aid the endogenous protective biological systems against the deleterious effects of oxygen (ROS) and nitrogen (RNS) reactive species. Many antioxidant compounds, naturally occurring from plant sources. Natural antioxidants can protect and prevent the human body from oxidative stress and retard the progress of many diseases in which free radical are involved. Several plants used in the folk medicine to treat certain disorders that are accompanied by inflammation and other pharmacological properties have been proved their attributed properties, such antioxidant activity. Turnera ulmifolia Linn. var. elegans (Turneraceae), frequently employed by population as a medicinal plant, demonstrated antioxidant activity by in vitro and in vivo assays, using its leaf hydroethanolic extract (10%) he in vitro DPPH radical-scanvenging activity showed a strong antioxidant activity (86.57% ± 0.14), similar to Carduus marianus and catequine effects. For the in vivo assays, adult female Wistar rats (n=48) with carbon tetrachloride hepatic injury induced (2,5mL/kg i.p.) were used, Six groups or rats were uses (n=8) [G1 = control (1,25 mL/kg i.p. vehicle); G2 = CCl4 (2,5 mL/kg i.p.); G3 = CCl4 + extract 7 days (500 mg/kg p.o.); G4 = CCl4 + Legalon® 7 days (50 mg/kg p.o.), G5 = CCl4 + extract 21 days (500 mg/kg p.o.) e G6 = CCl4 + Legalon® 21 days (50 mg/kg p.o.)]. The hepatic oxidative injury was evaluated through biochemical parameters [alanine amino transferase (ALT), aspartate amino transferase (AST)] histopathological study, while thiobarbituric acid reactive products (TBAR), glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) levels were used to evaluate proantioxidant parameters. The plant extract tested was found effective as hepatoprotective as evidenced by a decreasing in the ALT and AST activities (p<0.001) and TBAR (plasma, p<0.001 and liver, p<0.001). Levels of GSH (blood, p<0.001 and liver, p<0.001) and antioxidant enzymes [CAT erythrocyte (p<0.05) and hepatic (p<0.01); SOD erythrocyte (p<0.001) and hepatic (p<0.001); GPx erythrocyte (p<0.001) and hepatic (p<0.001)] were also significantly increased. Histopathological changes induced by CCl4 were significantly reduced by the extract treatment. The data obtained were comparable to that of Legalon®, a reference hepatoprotective drug. The results showed that T. ulmifolia leaf extract protects against CCl4 induced oxidative damage. Therefore, this effect must be associated to its antioxidant activity, attributed to the phenolic compounds, present in these extract, which can act as free radical scavengers

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One of the concerns of this century is with the handling and the final destination of urban solid waste (RSU), where depending on the form as they will be made use, they can cause diverse problems, they are of ambient or social order, being able to generate the loss of the quality of life and illnesses to the population, of direct or indirect form. The objective of the present work was to diagnosis the environmental partner situation of the Final Destination of the urban solid residues in the District of Guajiru, city of São Gonçalo do Amarante/RN, standing out the partner-economic situation of the scavengers. The research was carried through in the period of March of 2008 the October of 2009, with a methodology developed through analyzes them of documents made available for the state ambient agency, the Air base of Christmas and managing agencies of the city. For collection of the date, it was used directly application of the questionnaire with 20 existing scavengers in points of destination of residues, evaluation of the old place of final destination through the use of the spread sheet of the IQR (Index of Quality of the Residues), developed for the CETESB, identification of the matter dump and photographic register. For effect of treatment of the data, a descriptive analysis with regard to the answers of the interviewed scavengers was carried through. The acquired date, Scale had been according to tabulated and analyzed in Excel 2003, where they had been generated graphical to observe the behavior of the data. The results show that of the twenty interviewed scavengers, 35% possess age between 20 and 30 years; 75% possess incomplete basic education; 60% inhabit in houses of waal or huts (cardboard or wood); 55% do not make use of system of water supply and system of sanitary exhaustion; with regard to income monthly for scavengers, 35% had presented income between R$ 200,00 and R$300,00 and 20% possess income above of R$ 500,00 for possessing another source of income; 80% of the interviewed ones, use some type of equipment of individual protection; In the year of 2009, confirming what it was informed by the State agency of Environment, during the field visit, we evidence that the city of Is Gonçalo do Amarante, currently, destines its residues in Sanitary landfill of São Region Metropolitan of Natal in the District of Massaranduba in the city of Ceará-Mirim, after some interventions of the State Public prosecution service. However, in the district of Guajiru some diggings still exist that today are used as final destination of RCD' s (Residues of Construction and Demolition) of the cities of Natal and São Gonçalo do Amarante, as well as private dumps that are used by scavengers that deviate the final destination (Sanitary landfill) of the residues of the great generators (supermarkets, shopping Center and hotels), with presence of urubus, generating a new ambient problem for the city and the aeroportuária security. Ahead of this scene, the study it suggests viable alternatives for the elimination of the private dumps and for the social situation of the escavengers, aiming at to improve its quality of life and 10 to minimize the ambient impacts caused by the inadequate destination of the solid waste in the community of Guajiru, São Gonçalo do Amarante/RN, being able to contribute so that the public managers carry through action in the handling and the control of the final destination of the urban solid waste

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This dissertation conducted in the years 2011 and 2012, an analysis of cooperatives waste pickers in the city of Natal, Rio Grande do Norte, aiming to identify improvements to be implemented to assist the management of waste from the municipality as well as to improve the living conditions of the workers who perform the selective collection, the environmental perspective. This analysis was performed by means of an investigation of the reality in which they live cooperatives and their local representation, using also the law. The research is characterized as a case study of an applied nature, documentary, consultations with the institutions related to the issue of solid waste in the national and local levels; exploratory and descriptive, the main methodological tools technical visits and structured interviews. From these methods was possible to obtain data regarding the organization of cooperatives, environmental perception of the collector of recyclable materials, among other issues. For the analysis of data matrices were used to include comments and method GUT, from which it was possible to identify numerous difficulties faced by recycling cooperatives, and develop proposals for possible improvements in various aspects of their operation, such as infrastructure and production process , which can improve both the waste management and the quality of life of workers involved in the selective collection system city

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Natural gas, although basically composed by light hydrocarbons, also presents contaminant gases in its composition, such as CO2 (carbon dioxide) and H2S (hydrogen sulfide). The H2S, which commonly occurs in oil and gas exploration and production activities, causes damages in oil and natural gas pipelines. Consequently, the removal of hydrogen sulfide gas will result in an important reduction in operating costs. Also, it is essential to consider the better quality of the oil to be processed in the refinery, thus resulting in benefits in economic, environmental and social areas. All this facts demonstrate the need for the development and improvement in hydrogen sulfide scavengers. Currently, the oil industry uses several processes for hydrogen sulfide removal from natural gas. However, these processes produce amine derivatives which can cause damage in distillation towers, can cause clogging of pipelines by formation of insoluble precipitates, and also produce residues with great environmental impact. Therefore, it is of great importance the obtaining of a stable system, in inorganic or organic reaction media, able to remove hydrogen sulfide without formation of by-products that can affect the quality and cost of natural gas processing, transport, and distribution steps. Seeking the study, evaluation and modeling of mass transfer and kinetics of hydrogen removal, in this study it was used an absorption column packed with Raschig rings, where the natural gas, with H2S as contaminant, passed through an aqueous solution of inorganic compounds as stagnant liquid, being this contaminant gas absorbed by the liquid phase. This absorption column was coupled with a H2S detection system, with interface with a computer. The data and the model equations were solved by the least squares method, modified by Levemberg-Marquardt. In this study, in addition to the water, it were used the following solutions: sodium hydroxide, potassium permanganate, ferric chloride, copper sulfate, zinc chloride, potassium chromate, and manganese sulfate, all at low concentrations (»10 ppm). These solutions were used looking for the evaluation of the interference between absorption physical and chemical parameters, or even to get a better mass transfer coefficient, as in mixing reactors and absorption columns operating in counterflow. In this context, the evaluation of H2S removal arises as a valuable procedure for the treatment of natural gas and destination of process by-products. The study of the obtained absorption curves makes possible to determine the mass transfer predominant stage in the involved processes, the mass transfer volumetric coefficients, and the equilibrium concentrations. It was also performed a kinetic study. The obtained results showed that the H2S removal kinetics is greater for NaOH. Considering that the study was performed at low concentrations of chemical reagents, it was possible to check the effect of secondary reactions in the other chemicals, especially in the case of KMnO4, which shows that your by-product, MnO2, acts in H2S absorption process. In addition, CuSO4 and FeCl3 also demonstrated to have good efficiency in H2S removal