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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A scenario study on end-of-life tyre management in 2020

Lin, Hong-Mao January 2011 (has links)
With a large amount of tyres being discarded every year, the question of how to manage the end-of-life tyres (ELTs) has become a serious issue. Thus this study identifies different driving forces for this management and the most possible scenarios for the future management of ELTs. The study also compares the business as usual model with a waste hierarchy model to explore the possibilities for optimizing management of ELTs through cascading. This study collects opinions about the driving forces of ELT management from 29 experts working in the area. Important driving forces identified were: price of substitute products, recycled materials’ market, environmental legislation, and technology. This study also surveys 23 experts in the tyre area about the most possible scenarios for ELTs in 2020. One of the more believed in futures was: “Due to increasingly limited fossil fuels and a rise of sustainability awareness, applications for ELTs are growing both in material and energy recycling.” This suggests that a shift toward an equal recycling situation of ELTs among material and energy might be likely to happen by 2020. Based on the most possible scenario for ELTs in 2020, a comparison between waste hierarchy model and business as usual model has been performed. The result shows that the (cascading) waste hierarchy model would likely create more environmental benefits than business as usual model. This is done though the saving and cycling of more materials from energy recovery into material recycling.
2

Estudo e caracterização de compósito de polipropileno e pó de pneu para utilização na indústria automotiva

Lixandrão, Kelly Cristina de Lira January 2017 (has links)
Orientador: Prof. Dr. Fabio Furlan Ferreira / Tese (doutorado) - Universidade Federal do ABC, Programa de Pós-Graduação em Nanociências e Materiais Avançados, 2017. / Em função do constante aumento da populacao e do aumento da producao de veiculos ao longo dos anos, a quantidade de residuos solidos gerados e depositados no meio ambiente cresceu de forma consideravel. O pneu, que e um destes materiais, quando descartado em local inadequado pode provocar serios problemas ambientais e a saude da populacao. Assim no intuito de diminuir sua quantidade enviada ao meio-ambiente e de produzir um ciclo de producao adequado, o po de borracha de pneu foi utilizado como reforco em matriz de polipropileno para ser aplicado no encapsulamento do motor de veiculos comerciais. A sua utilizacao visa assegurar uma reducao do peso da peca e, consequentemente, do veiculo, otimizando seu consumo de combustivel e diminuindo a emissao de poluentes, alem de garantir uma minimizacao da poluicao sonora, atraves da atenuacao do ruido pelo composito. As analises acusticas de perda de transmissao e de ruido externo foram realizadas para verificar se o material atendeu aos limites especificados pelas resolucoes. Analise de difracao de raios X viabilizou a identificacao e a quantificacao das diferentes fases que compoem o material, alem de evidenciar a ocorrencia de polimorfismo. Por calorimetria exploratoria diferencial foi possivel verificar o grau de cristalinidade do material e por termogravimetria foi verificado que a decomposicao termica dos compositos ocorreu em dois estagios: o primeiro na faixa de temperatura entre 300 ¿aC e 400 ¿aC e o segundo entre 400 ¿aC e 500 ¿aC. Ensaios de tracao e flexao demonstraram resultados inferiores aos do polimero virgem; todavia, o ensaio de impacto apresentou valores superiores, em funcao da tenacificacao da matriz termoplastica. / Due to the constant increase in population and the increase in vehicle production over the years, the amount of solid waste generated and deposited in the environment has grown considerably. The tire, which is one of these materials, when discarded in inappropriate locations can cause serious environmental problems and to the health of the population. Thus, in order to reduce the amount sent to the environment and to generate an appropriate production cycle, the tire rubber powder was used as reinforcement in a polypropylene matrix to be applied to the engine encapsulation of commercial vehicles. It is intended to provide a reduction of the weight of the piece and thus the vehicle, optimizing fuel consumption and reducing the emission of pollutants; also it ensures the minimization of noise pollution through the noise attenuation by composite. Acoustic analysis of transmission loss and external noise were carried out to verify whether the material complies with the limits specified by the resolutions. X-ray diffraction analysis enabled the identification and quantification of the different phases that comprise the material, besides evidencing the occurrence of polymorphism. By differential scanning calorimetry it was possible to verify the degree of crystallinity of the material and by thermogravimetry it was verified that the thermal decomposition of the composites occurred in two stages: the first in the temperature range between 300 ¿aC and 400 ¿aC and the second one between 400 ¿aC and 500 ¿aC. Tensile and flexural tests showed lower results than the virgin polymer, however, the impact test had higher values, as a function of thermoplasctic matrix tenacity.

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