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Comparação entre os efeitos da exposição em nível subletal de glifosato e dos herbicidas a base de glifosato Roundup Original® e Roundup Transorb R® sobre girinos de rã-touro
(Universidade Federal de São Carlos, 2012-10-05) Rissoli, Rafael Zanelli; Kalinin, Ana Lúcia; https://lattes.cnpq.br/5493936744279888; https://lattes.cnpq.br/5838813282371566
Glyphosate based herbicides are widely used in agriculture and fishery to control of weeds, being found commonly in water bodies. The Roundup Original® is one of the most used glyphosate-based herbicides that presents in its basic composition isopropylamin glyphosate salt and a surfactant. Many studies suggest that the surfactant is the most lethal compound of Roundup s formulation. Among the Roundup® formulations, Roundup Transorb R® is the most recent. The main goal of this study was to evaluate the possible impacts of exposition to glyphosate (1 ppm), Roundup Original® (1ppm glyphosate acid equivalent e/a.) and Roundup Transorb R® (1ppm e/a) subletal concentrations on bullfrog tadpoles (Lithobates catesbeianus) activity level, cardiorespiratory and histological endpoints. The tadpole s activity level was significantly augmented only by the glyphosate exposition, suggesting that a stressful condition would divert energy from morphogenetic processes. All tested herbicides caused skin morphological alterations like cellular hypertrophy, hypertrophy of epithelium wall and chromatid rupture. The values in Control group were constant until the O2 tension of 40 mmHg suggesting that the critical O2 tension for this species is between 40 and 20mmHg. The exposure to glyphosate caused a significant reduction, possibly due to the observed epidermis hypertrophy, which reduces the O2 uptake. Roundup Transorb R® increased values, suggesting that the composition of inert compounds and surfactants in this formulation influences this parameter. There was no difference between the presented by the Roundup Original® and Control group, which suggests that the possible increase on O2 consumption caused by Roundup exposure was masque by the epidermis hypertrophy. The registered in loco cardiac frequency wasn t altered by the glyphosate and Roundup Original. Glyphosate caused a significant ventricular mass decrease. No difference was observed on Fc, TPT and THR of ventricular strips at sub-physiological stimulation frequencies (0,2 Hz). The Roundup Original® group was the only that presented changes induced by increases in the stimulation frequency, showing Fc increases and THR decreases. It is suggested that this formulation induces the NO production, which promotes cardiac relaxation. However, these increases in Fc and THR acceleration were completely abolished by the addition of adrenaline, suggesting the existence of an antagonistic interaction between the Roundup Original® and adrenaline.
Estudo das propriedades e desempenho mecânico de juntas soldadas por fricção pontual de poli (metacrilato de metila) (PMMA)
(Universidade Federal de São Carlos, 2012-10-05) Oliveira, Pedro Henrique Freiria de; Hage Júnior, Elias; https://lattes.cnpq.br/1240692926327687; https://lattes.cnpq.br/2263046505629088
Polymeric components have been replacing traditional materials such as glass or metals in a wide range of applications due to their advantages, such as optimized specific strength (weight-to-strength ratio), reduced fabrication time and costs, and design flexibility. The increasing use of polymeric materials in engineering requires efficient and environmental friendly fabrication and processing technologies. Initially developed for metals, the Friction Stir Spot Welding (FSSW) is a joining technique with short process cycles, low energy consumption and no need of consumables. Friction Stir Spot Welding has excellent performance in welding of lightweight alloys, showing promising results in thermoplastic welding. This study investigates the relationships between friction stir spot welding parameters (tool rotational speed, plunge rate and dwell time) and weld properties (joint geometry, process temperature, microstructure, lap shear resistance and failure mechanisms) in polymethylmethacrylate (also known as PMMA) single-spot joints. PMMA friction stir spot welds showed similar mechanical performance in comparison to other current welding techniques, with equal or shorter welding cycle times. Differential scanning calorimetry and gel permeation chromatography analysis demonstrated that polymer degradation level in the weld region was negligible. The statistical models proposed for FSSW of PMMA showed good repeatability and reproducibility for the investigated material and welding ranges. Moreover, the feasibility of the Friction Spot Welding (FSpW) a new joining technology developed as a further improvement of the friction stir spot welding was successfully demonstrated in thermoplastic polymers for the first time worldwide. Sound FSpW-single lap joints on PMMA were produced and their properties studied within an exploratory study.
Análise da competitividade da produção agrícola e do processamento da cadeia agroindustrial de suco de laranja concentrado congelado no estado do Paraná
(Universidade Federal de São Carlos, 2012-10-05) Sabes, Jair Júnior Sanches; Souza Filho, Hildo Meirelles de; https://lattes.cnpq.br/6974638747710821
Brazil is the largest producer and exporter of the world market of frozen concentrated orange juice (FCOJ), and the State of São Paulo stands out as the largest producer and exporter of that commodity in Brazil. In recent years, the State of Paraná has increased its production and export of FCOJ. Through the survey of secondary data and interviews with key players, this study identified and evaluated the main critical aspects of the competitiveness of the agri-food chain of FCOJ in Paraná. Through the rapid appraisal method (method of quick research) were possible to evaluate 11 drivers of competitiveness, focusing on the links of agricultural production and processing of that chain. A total of 24 interviews were conducted, using questionnaires and interviews screenplays. It was possible to identify which are the drivers of competitiveness, considered in the context of this research, which are considered favorable, neutral and unfavorable for the competitiveness of the links of agricultural production and processing of the agri-food chain of FCOJ in Paraná. From these analyses it was also possible to verify that none of the drivers of competitiveness, considered in this dissertation, was regarded as very favorable or very unfavorable for the competitiveness of the link of agricultural production of that chain. From these analyses it was also possible to verify that none of the drivers of competitiveness, considered in this dissertation, was regarded as very favorable for the competitiveness of the link of processing of that chain, and only a driver of competitiveness, of the set of drivers considered in this dissertation, was regarded as very unfavorable for the competitiveness of the link of processing. The analyses allowed to point out proposals for public policies and private strategies to enhance the competitiveness. In a general context, it was possible to conclude that the links of agricultural production and processing of the agri-food chain of FCOJ in Paraná have a great potential to continue to expand in Paraná. The citriculture in Paraná has a great potential to expand because it has a good technology, a good production capacity and productivity and a sufficient amount of available agricultural land to extend the exploration of the citriculture in Paraná, in addition, the economic agents that act in the citriculture in Paraná have contracts for the supply of orange to the economic organizations that have manufacturing plants that produce FCOJ in Paraná, so these contracts ensure the sale of the most part of the Paraná s orange production, which is good for the citrus growers who act in Paraná. The processor sector of orange also has a great potential to expand in Paraná because it has agro-industrial technologies of good level and a good production capacity, in addition to be able to expand without great difficulties its manufacturing capacity of FCOJ, moreover, the existence of contracts for orange supply between economic organizations who act in processing and citrus growers in Paraná, secures the supply of oranges, considered of good quality, for the producing plants of FCOJ installed in Paraná.