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Orientador: Rosângela Aparecida de Medeiros Hespanhol / Resumo: O trabalho teve como tema central de análise a dinâmica da cultura de seringueira na Microrregião Geográfica de São José do Rio Preto. Para a consecução do objetivo, fez-se necessário a realização de um resgate histórico que nos ajudou a apreender as relações sociais travadas no âmbito do setor de borracha, as quais foram marcadas até meados da década de 1980 pelos interesses conflitantes entre a elite extrativista amazônica composta por seringalistas e aviadores, de um lado e, a elite industrial do setor pneumático, do outro. Com o aumento do preço da borracha natural a partir de 1973, puxada pelos alta nos preços da borracha sintética devido a crise do setor petrolífero, ocorreu uma maior expansão das plantações de seringueira na região sudeste do país, principalmente no Estado de São Paulo. Assim foi que já no inicio da década de 1990 a produção amazônica representava menos de 50% da produção nacional, perdendo sua posição protagonista como produtora de borracha natural para o Estado de São Paulo. Essa processo redundou no deslocamento do eixo do conflito da região amazônica-sudeste para o interior da região sudeste do país onde os produtores e processadores de borracha natural haviam personificado os interesse da elite extrativista. Com o aprofundamento do processo de industrialização do país a partir da década de 1950, o setor de pneumático foi ganhando envergadura e a partir de então passou a pressionar com mais vigor o Estado que concedeu a permissão para a importação de borracha natural em 1997 com a revogação da Lei de Contingenciamento ao mesmo tempo que promulgou a Lei do Subsídio, a qual apenas em partes compensou a abertura econômica do setor. Constatou-se na referida região a cultura da seringueira sempre se apresentou vantajosa ao produtor... (Resumo completo clicar acesso eletrônico abaixo) / Abstract: The work had as central subject of analysis the dynamics of the culture of rubber tree in the Geographic Microregion of is São José do Rio Preto. For the achievement of the objective, the accomplishment of a historical rescue became necessary that in helped them to apprehend the stopped social relations in the scope of the rubber sector, which had been marked until middle of the decade of 1980 for the conflicting interests between the extrativista elite Amazonian composed for seringalistas and aviators, of a side and, the industrial elite of the pneumatic sector, of the other. With the increase of the price of the natural rubber from 1973, pulled for the high one in the prices of the synthetic rubber which had the crisis of the petroliferous sector, a bigger expansion of the plantations of rubber tree in the Southeastern region of the country occurred, mainly in the State of São Paulo. Thus it was that no longer beginning of the decade of 1990 the Amazonian production represented less than 50% of the national production, losing its position natural rubber protagonist as producing for the State of São Paulo. This process resulted in the displacement of the axle of the conflict of the region Amazonian-Southeast for the interior of the Southeastern region of the country where the natural rubber producers and processors had impersonatied the interest of the extrativista elite. With the deepening of the process of industrialization of the country from the decade of 1950, the tire sector was gaining spread and from now on it started to pressure with more vigor the State that granted the permission for the natural rubber importation in 1997 with the revocation of the Law of Contingenciamento at the same time that it promulgated the Law of the Subsidy... (Complete abstract, click electronic address below) / Mestre

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The study deals with the formulation development and thermorheological properties of crumb rubber/ethylene vinyl acetate (EVA) modified bitumen with the aim of optimizing the amount of crumb rubber and EVA loadings in bitumen based on thermorheological parameters complex shear modulus, phase angle and rutting parameter. In the modified binders EVA offers plastomer properties whereas the crumb rubber confers elasticity to the bitumen. 13.75% crumb rubber and 2.5% EVA loadings based on aging indices gave the best optimized mixture. The thermorheological behaviour of the best optimized mixture was compared to industrial grade EVA (AP-1) and crumb rubber (AR-1) modified bitumen. Improving aging behaviour of the bitumen was evaluated using four antioxidants: carbon black, hydrated lime, Irganox 1010 and Irgafos 168. The least aging indices at 58˚C and 64˚C were obtained from a 1:1:1 Irganox 1010/hydrated lime/carbon black mixture. SARA (saturates, aromatics, resins and asphaltene) analysis gave the chemical background for application of antioxidants to reduce the propensity of short term aging. To further improve the EVA/crumb rubber optimized mixture for workability FT wax (Sasobit®) was assayed at loadings from 0-2.5%. This was done to match the EVA content and maintain the original maximum loading of 2.5% in the optimized mixture. The phase change abilities of FT wax owing to the high latent heat enabled co-crystallization with the EVA with the elastomeric backbone of crumb rubber acting as support material. The energy-sustainability nexus was found to have worked at less than 1% loading of FT wax in the EVA/crumb rubber modified bitumen. Response surface methodology approach to all the sections of work was used to come up with the optimized mixtures based on rheological parameters complex shear modulus, phase angle and rutting parameter at test temperature 64˚C. The interaction chemistry of bitumen, crumb rubber, EVA and FT wax was found to be first and second order in all cases involving individual contributions and co-interaction amongst the factors. Project costing for each section of work (optimizing section, antioxidant section and FT wax section) was conducted involving the raw materials used, equipment used, labour involved and other costs incurred for all the project work.

Quantitative design of extruder dies for rubber compounds and thermoplastics requires a knowledge of the pumping performance of the extruder, for an appropriate extruder-die interaction. The dies are generally formed from a succession of convergent, circular or noncircular ducts with axial varying geometrical dimensions. The design and operation of dies of these types is then a matter of sufficient importance to justify a detailed analysis of the factors involved.

An object of this master thesis is the proposal of variants solving a manufacturing of required part and the selection right technology for single part production of required part from stainless steel 17240 (DIN 1.4301). At the first part of this thesis is briefly reviewed conventional forming and at rest of this thesis is closely reviewed the technology using the elastic tools (rubber, urethane), hydroforming technology and design of proper tool for required part. At the end of this work will be release economics estimation of fine technology and designed tool.

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