910 resultados para Recycling centers


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The neutral hydrolysis reaction of post-consumer poly(ethylene terephthalate) in solid state was studied through the reaction of the polymer with water at the molar ratio 1:91 with autogenous pressure. Two sizes of post-consumer PET flakes and temperatures of 135 °C, 170°C and 205°C with pressures of 4.0 atm, 7.5 atm and 13.5 atm, respectively, were considered. With reaction time equal to 6h, the method reached 99% depolymerization at 205°C, 8.2% at 170 °C and 1.7% at 135°C. The reaction extension was measured by separating the terephthalic acid formed in the process and calculating by gravimetry how much material could still be reacted. Through the viscosimetry of diluted, solutions and the counting of carboxylic end groups in the remaining material from the gravimetric assay, it was possible to suggest that the reaction occurs randomly and in the whole volume of the polymeric particle and not solely on the surface. The terephthalic acid obtained and then purified was characterized by elemental analysis, magnetic nuclear resonance, size and panicle size distribution and spectrophotometry in the visible spectrum, and it was similar to the petrochemical equivalent, with purity recorded in carbon base equal to 99.9%.

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Background. Iron-deficiency anemia currently is the most frequently occurring nutritional disorder worldwide. Previous Brazilian studies have demonstrated that drinking water fortified with iron and ascorbic acid is an adequate vehicle for improving the iron supply for children frequenting day-care centers. Objective. The objective of this study was to clarify the role of ascorbic acid as a vehicle for improving iron intake in children in day-care centers in Brazil. Methods. A six-month study was conducted on 150 children frequenting six day-care centers divided into two groups of three day-care centers by drawing lots: the iron-C group (3 day-care centers, n = 74), which used water fortified with 10 mg elemental iron and 100 mg ascorbic acid per liter, and the comparison group (3 day-care centers, n = 76), which used water containing only 100 mg ascorbic acid per liter. Anthropometric measurements and determinations of capillary hemoglobin were performed at the beginning of the study and after six months of intervention. The food offered at the day-care centers was also analyzed. Results. The fo od offered at the day-care center was found to be deficient in ascorbic acid, poor in heme iron, and adequate in non-heme iron. Supplementation with fortified drinking water resulted in a decrease in the prevalence of anemia and an increase in mean hemoglobin levels associated with height gain in both groups. Conclusions. Fortification of drinking water with iron has previously demonstrated effectiveness in increasing iron supplies. This simple strategy was confirmed in the present study. The present study also demonstrated that for populations receiving an abundant supply of non-heme iron, it is possible to control anemia in a simple, safe, and inexpensive manner by adding ascorbic acid to drinking water. © 2005, The United Nations University.

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The main goal of this work is to demonstrate that the use of recycled material originated from SiC ceramics is viable. These ceramics were produced by commercial starch consolidation process. Before calcination stage, surplus of these materials always appears. This surplus is rich in SiC and starch. Samples were made by material previously milled in automatic mortar and sieved (100 Tyler). Later, 10% of distilled water was added to the material and the mixture was pressed at 40 MPa. In order to characterize the ceramic, three point flexural test were made, according to the ASTM C1161/94 norm. The results were analyzed by Weibull statistical method. Apparent density and porosity measures also were made, according to ASTM C20/87 norm. A verification of the surface was made in the fracture area by the depth from focus method and SEM image analysis. The results showed that the recycling process is fully viable, being a good economic option and reduce possible pollutant effect to the environment.

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The sequential extraction procedure of Zinc and lead performed in a Brazilian soil showed that it presents high pollution potential once over 90% of total lead is present in fractions where the metals can be easily mobilized. The fraction contents are as follow: F1 = 174 and 15 mg kg-1; F2 = 3155 and 9.7 mg kg -1; F3 = 99 and 1.6 mg kg -1; Residual fraction = 38 and 5.5 mg kg -1 for lead and zinc, respectively. The comparison with non contaminated soil only Pb 2+ concentration is above its intervention reference concentration, 900 mg kg -1.

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This paper presents an Advanced Traveler Information System (ATIS) developed on Android platform, which is open source and free. The developed application has as its main objective the free use of a Vehicle-to- Infrastructure (V2I) communication through the wireless network access points available in urban centers. In addition to providing the necessary information for an Intelligent Transportation System (ITS) to a central server, the application also receives the traffic data close to the vehicle. Once obtained this traffic information, the application displays them to the driver in a clear and efficient way, allowing the user to make decisions about his route in real time. The application was tested in a real environment and the results are presented in the article. In conclusion we present the benefits of this application. © 2012 IEEE.

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

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Efficient implementation of recycling networks requires appropriate logistical structures for managing the reverse flow of materials from users to producers. The steel sheet distributor studied had established a protocol for scrap recovery with the steel plant and its customers. The company invested in producing containers, hiring a specialized labor force and in purchasing trucks for container transportation to implement the logistics network for recycling. That network interconnected the company with two kinds of customers: the ones returning scrap and the ones who preferred to continue business-as-usual. The logistical network was analyzed using emergy synthesis, and the data obtained were used to evaluate and compare the system's environmental costs and benefits from the perspective of the distributor and the steel plant operator. The use of emergy ternary diagrams provided a way to assess recycle strategies to compare the relative economic and environmental benefits of the logistical network implemented. The minimum quantity of scrap that the distributor must recover to improve environmental benefits was determined allowing decision on whether it is worth keeping the system running. The new assessment method proposed also may help policy-makers to create strategies to reward or incentive users of reverse logistics, and help to establish regulations, by decreasing taxes or stimulating innovation, for effectively implement the National Policy on Solid Waste. (C) 2013 Elsevier Ltd. All rights reserved.

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

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OBJECTIVE: To evaluate treatment of Brazilian patients with gestational trophoblastic disease (GTD).STUDY DESIGN: A retrospective cohort study with analysis of medical reports performed in 10 Brazilian referral centers from January 2000 to December 2011.RESULTS: Of 5,250 patients 3 died (0.06%) at the time of uterine evacuation. Spontaneous remission of GTD (group G1) was observed in 4,103 cases, and 1,144 (21.8%) progressed to gestational trophoblastic neoplasia (GTN) (G2). In G1 2,716 (66.2%) had complete hydatidiform mole (HM) and 1,210, partial HM (29.5%); 3,772 patients (92.7%) recovered as noted in December 2012. In G2, of 1,118 patients treated, initial histopathological results of previous gestation were complete HM (77.5% [n = 886]), partial HM (8.8% [n = 100]), and choriocarcinoma (8.0% [n = 92]); 930 (81.3%) were low-risk, 200 (17.5%) were high-risk GTN, and 14 had placental site trophoblastic tumor (PSTT) (1.2%); cure was achieved in 1,078 cases (96.4%), but 26 patients (2.3%) died (4 low-risk [0.4%], 19 high-risk [9.5%], and 3 PSTT [21.4%]).CONCLUSION: The highest death rates were due to high-risk GTN and PSTT. Patients with molar pregnancy should be referred to a referral center for an early diagnosis and prompt treatment of GTN in order to reduce the morbidity and mortality found in advanced stages.

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Introduction: childhood obesity is a major public health problem, affecting children even at early ages. Objective: to assess the impact of dietary intervention and relatively simple physical activity on the nutritional state of preschoolers. Method: this was an intervention study in public daycare centers targeting children from 2 to 4 years of age, in the State of São Paulo. The sample consisted of 9 daycare centers covering 578 children, with 264 children in the intervention group (IG) and 314 in the comparison group (CG). Intervention was focused on modifications in diet and physical activity, avoiding overloading the routine of daycare centers, for duration of one year. A zBMI score > 1 (zBMI) and < 2 was considered risk of being overweight, and > 2 zBMI was considered excess weight (overweight and obese). Analysis was done by frequency calculations, comparisons of proportions by χ2, mean comparisons by t-student and calculations according to Pearson’s correlation coefficient. Results: IG showed an inverse correlation between the initial zBMI of the children and the difference with the zBMI at the end of the intervention (rP = -0.39, p <0.0001). The mean difference of zBMI of the overweight children in IG between the beginning and the end of the study period was negative (-0.46 z score), indicating weight reduction, while the children in the CG was positive (+0. 17 z score) (p = 0.0037). Conclusion: intervention in diet and physical activity in overweight preschool children in daycare centers could have a favorable impact on the evolution of their nutritional state.

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A good catheter implantation technique is important to allow effective peritoneal access function and long-term technique survival. Studies regarding results obtained by nephrologists in comparison with different techniques have been limited. The aim of this study was to investigate the rate of early catheter-related complications and catheter survival in two Brazilian centers, according to two different percutaneous methods of catheter implantation performed by nephrologist team. Adult incident patients recruited from January 2006 to July 2013 having undergone first peritoneal dialysis (PD) catheter implantation were included in the analysis. Mechanical and infectious early complication rates were defined as time to the first event occurring up to 3 months. Four hundred and forty-five consecutive Tenckhoff catheters were implanted by nephrologist team percutaneously after antibiotic prophylaxis in an operating room: trocar was used in 349 (78.4 %) and Seldinger technique (ST) in 99 (21.6 %). The ST was significantly associated with a lower rate of leak (16.3 vs 3 %, p = 0.03) and outflow failure due to tip catheter migration (22.6 vs 10.1 %, p = 0.04), while early infectious complication rates were similar between the two groups (p = 0.59). Long-term catheter survival was higher in Seldinger group (log-rank, p = 0.031). By Cox multivariate analysis, adjusted for age, sex, and diabetes, the ST remained independently associated with better catheter survival [HR 0.681 (0.462-0.910), p = 0.04]. As conclusion, our experience showed better PD outcomes with the ST than trocar method of catheter implantation by nephrologist.