6 resultados para Sustainable development indicators
em Universidade do Minho
Resumo:
Dissertação de mestrado em Construção e Reabilitação Sustentáveis
Resumo:
The increasing environmental concern about waste materials and the necessity of improving the performance of asphalt mixtures prompted the study of incorporating different waste materials in conventional bitumen. The reuse of waste materials can present benefits at an environmental and economic level, and some wastes can be used to improve the pavement performance. Thus, the purpose of this study is to evaluate the incorporation of different waste materials in bitumen, namely waste motor oil and different polymers. In order to accomplish this goal, 10% of waste motor oil and 5% of polymers (high density polyethylene, crumb rubber and styrene-butadiene-styrene) were added to a conventional bitumen and the resulting modified bitumens were characterized through basic and rheological tests. From this work, it can be concluded that the incorporation of different waste materials improve some important properties of the conventional bitumen. Such improvements might indicate a good behaviour at medium/high temperatures and an increase of fatigue and rutting resistance. Therefore, these modified bitumens with waste materials can contribute to a sustainable development of road paving industry due to their performance and environmental advantages.
Resumo:
The employ of vegetal fibers for textiles and composites represents a great potential in economic and social sustainable development. Some Malvaceae species are considered tropical cosmopolitans, such as from Sida genus. Several species of this genus provide excellent textile bast fibers, which are very similar in qualities to the jute textile fiber. The objective of the present study is present the physicochemical characterization of six Brazilian vegetal fibers: Sida rhombifolia L.; Sida carpinifolia L. f.; Sidastrum paniculatum (L.) Fryxell; Sida cordifolia L.; Malvastrum coromandelianum (L.) Gurck; Wissadula subpeltata (Kuntze) R.E.Fries. Respectively the two first species are from Brazilian Atlantic Forest biome and the four remaining from Brazilian Cerrado biome, despite of present in other regions of the planet. The stems of these species were retted in water at 37oC for 20 days. The fibers were tested in order to determine tensile rupture strength, tenacity, elongation, Young’s modulus, cross microscopic structure, Scanning Electronic Microscopy (SEM), regain, combustion, acid, alkali, organic solvent and cellulase effects, pH of the aqueous extract, Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). The obtained values were compared with those from fibers of recognized applicability in the textile industry including hemp. The results are promising in terms of their employment in thermoset and thermoplastic medium resistance composites.
Resumo:
ISSN 19820941
Resumo:
Dissertação de mestrado em Engenharia Industrial (área de especialização em Qualidade, Segurança e Manutenção)
Resumo:
Dissertação de mestrado em Design e Marketing