Navegando por Data de Publicação, começando com "2008-06-05"

Filtrar resultados por ano ou mês

Agora exibindo 1 - 2 de 2

Estudo da tenacidade à fratura por meio do método do trabalho essencial de fratura (EWF) da blenda PBT/ABS, reforçada com fibra de vidro
(Universidade Federal de São Carlos, 2008-06-05) Razzino, Carlos do Amaral; Hage Júnior, Elias; https://lattes.cnpq.br/1240692926327687; https://lattes.cnpq.br/2638794744443674
High rubber content acrylonitrile-butadiene-styrene terpolymer (ABS) has been used to tough PBT. As a result, super tough PBT/ABS blends under notched Izod impact have been obtained. However, there has been a significant reduction in the PBT/ABS Young modulus. The development of an optimum stiffness-toughness balance in PBT/ABS blends can be achieved by addition of short glass fibers to the composite blends. The composite performance is strongly dependent on the matrix-fiber interface and consequently the surface treatment of the fiber is a key factor to be considered. In the present work, the effect of two kinds of glass fibers treatment on the mechanical properties of PBT/ABS blends is investigated and the results discussed in terms of the changes of the fiber wettability and interfacial adhesion strength of the fiber to the resin. The processing conditions used to prepare glass fiber reinforced tough PBT/ABS blends were studied to observe the best conditions to maintain the toughness and stiffness of the blend as high as possible. A twin screw extrusion was used to prepare the reinforced PBT/ABS blends. Tensile, impact and essential work of fracture (EWF) testing was carried out to evaluate the mechanical properties for stiffness and toughness of the reinforced blends, respectively. The results have shown a strong dependence of the mechanical properties on the surface treatment of the fibers and these results are corroborated by electron microscopy micrographs that clearly illustrate the changes in the composite fiber/matrix interface in the presence of differences in surface treatments of the fiber. The development of an optimum stiffness-toughness balance in PBT/ABS blends was achieved and EWF has been successfully applied to evaluate the toughness for PBT/ABS blends.
NUPES : protagonista da política para educação superior brasileira? (1989-2005)
(Universidade Federal de São Carlos, 2008-06-05) Grello, Fabíola Bouth; Silva Junior, João dos Reis; https://lattes.cnpq.br/5914699246880638
The aim of this work is to analyze the NUPES academic production, specifically 23 serial researches of Work Documents periodic from 1989 to 2005. The principal objective is to investigate if NUPES academic production was antecipated, in scientific means, to political process and educational laws development process since 90´s decade, keeping in mind Brazilian superior educational official changes. Our specific aim is to identify the concept of scientific publication autonomie of this section, and this concept evolution also. We tried to reflect how political aspirations, vizualazed and projected by NUPES for almost two decades are been incorporeted by educational law arcabouço and based on science and tecnologie Conselho Nacional de Desenvolvimento Científico e Tecnológico-CNPq, analized here by the editais from 2003-2004. The research point out evidences that NUPES proposal Project after 16 years turned them not only a protagonist but na important part of thematic, theorical and methodological field of superior educational reform process. Their researchs, publications, discussions abreviated politics that are incorporate to life by laws, decrees, and measures. The politics point out that the State is suffering a new political orientation, that had been done by NUPES from two decades in BRazil. These orientations focusing on public universities has been materializing under political forms stimulating the management switc, employes hire, its spend, and the new function that demands to the university. All the analysis bring us to a commun place, indicating a academic culture, professor-researcher profile (now a entrepreneur) and flexibility that this politics demands, are changing movements into the university, indicating less scientific autonomie power in academic university space. All this movement bring us to a new State politics, that uses public means to invest in politics direct from productiv section, providing a new knowedlege dimension, not meeting politic and academic time neither social comportament, breaching the three pilars of the university: scientific, financial and didactic autonomy.