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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

Análise do uso das fibras do pseudocaule da bananeira em misturas asfálticas SMA.

COSTA, Laiana Ferreira da. 27 July 2018 (has links)
Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-07-27T12:43:49Z No. of bitstreams: 1 LAIANA FERREIRA DA COSTA - DISSERTAÇÃO (PPGECA) 2017.pdf: 4381777 bytes, checksum: 6345f1966848f073e490738bd0fdb149 (MD5) / Made available in DSpace on 2018-07-27T12:43:49Z (GMT). No. of bitstreams: 1 LAIANA FERREIRA DA COSTA - DISSERTAÇÃO (PPGECA) 2017.pdf: 4381777 bytes, checksum: 6345f1966848f073e490738bd0fdb149 (MD5) Previous issue date: 2017-04-25 / CNPq / A Stone Matrix Asphalt (SMA) é uma mistura asfáltica que otimiza o contato grão a grão devido a sua alta porcentagem de agregado graúdo, elevando a resistência ao cisalhamento do revestimento e consequentemente o desempenho estrutural deste. Fibras sintéticas e ligantes asfálticos modificados por polímero são, geralmente, utilizados para evitar o escorrimento devido ao alto teor de ligante empregado nesse tipo de mistura. O agronegócio da banana, de grande importância para a economia brasileira e nordestina, é um dos grandes geradores de rejeitos pós-colheita, destacando-se o pseudocaule da planta de onde pode ser extraída fibras consideradas de boa qualidade para a aplicação nos mais diversos fins. A presente pesquisa tem por objetivo analisar a viabilidade da incorporação da fibra do pseudocaule da bananeira do tipo Pacovan (variedade mais produzida no país, principalmente no Nordeste) em misturas asfálticas do tipo SMA e avaliar a influência do comprimento dessas fibras no desempenho da mistura. Para isso foram realizados testes de escorrimento tanto para identificar o teor ideal de fibra de bananeira para a diminuição do escorrimento do ligante quanto para avaliar a influência do comprimento da fibra nesse parâmetro. Posteriormente, com o uso do teor ótimo da fibra obtido, foram realizados ensaios para determinar as propriedades mecânicas da mistura (estabilidade Marshall, Lottman modificado, resistência a tração, cântabro, módulo de resiliência, fadiga à tensão controlada, módulo dinâmico e flow number) variando o comprimento desta. Em geral, os resultados indicaram que a fibra do pseudocaule da bananeira do tipo Pacovan pode ser uma alternativa viável para SMA, tanto pela capacidade de controle do escorrimento quanto pelas melhorias proporcionadas nas propriedades mecânicas da mistura, sendo o comprimento de 20mm aquele que propiciou melhor desempenho da SMA em todos os aspectos supracitados. / Stone Matrix Asphalt (SMA) is an asphalt mixture that optimizes stone-to-stone contact due to its large coarse aggregate fraction, increasing the shear strength of the pavement surface layer and consequently its structural performance. Synthetic fibers and polymer modified asphalt binders are generally used to prevent draindown due to high contents of binder employed in this type of mixture. The agribusiness of banana, which has a great importance in the Brazilian and Northeastern economies, is one of the major generators of post-harvest rejects, highlighting the false stem of the plant from which can be extracted fibers considered of good quality for application in diverse purposes. The aim of the present research was to analyze the feasibility of incorporating Pacovan banana false stem fiber (cultivar most produced in the country, mainly in the Northeast region) in SMA mixtures and evaluate the influence of these fibers length on the performance of the mixture. For this purpose, draindown tests were performed to identify the ideal banana fiber content in order to decrease binder draindown and evaluate the influence of fiber length on this parameter. Afterwards, tests were performed to determine the mechanical properties of the binder (stability Marshall, modified Lottman, tensile strength, Cantabro, resilience modulus, controlled stress fatigue, dynamic modulus and flow number) using the optimal fiber content obtained and varying the length of the fiber. In general, the results indicated that the fiber from the false stem of Pacovan banana plant may be a viable alternative for SMA, both for the stabilizing capacity of draindown and for improvements in the mechanical properties of the mixture. The length of 20mm provided the best performance of SMA.
2

Non-wood fibers for strength enhancement of paper : Mixing softwood pulp with abaca, sisal and banana fibers

Rinaldo, Emilia January 2020 (has links)
The aim with this master thesis was to investigate the potential of using non-wood fibers to enhance the paper strength. Abaca, sisal and banana fibers were added to conventional bleached chemical softwood pulp. The effect of refining was investigated, both as co-refining and as separate refining. The fiber properties were determined with a Fiber Tester and the drainage resistance was determined with Schopper-Riegler. Density, tensile index, tear index and burst index were determined on paper sheets made in a Rapid-Köthen sheet former. The results showed that abaca had longer fiber length than softwood, while sisal had slightly shorter fiber length compared with softwood. Sheet density was lowered with addition of all three fiber types, while the drainage resistance was increased for the same. It was also observed that the tensile index increased with additions of abaca, while additions of sisal and banana fibers gave lower tensile indexes. The same trend was observed for the tear index and burst index. Refining gave higher values of the drainage resistance, density, tensile index and burst index. However, the tear index was affected differently depending on the fiber type and fiber blend. For sisal and banana fibers, the tear index was first increased at lower refining degrees and were thereafter decreased with further refining. When studying abaca and softwood, a declining trend was observed over the entire refining interval. The conclusion was that addition of abaca fibers increased all investigated strength properties. Sisal and banana fibers gave higher values of the tear strength, when exposed to mild refining.
3

Textila material av bananavfall : En undersökning om för- och nackdelar för bananavfall som textiltmaterial i modebranschen. / Textile material of banana waste : A review study in regards to the advantages and disadvantages for banana waste as textile material within the fashion industry.

Hamp, Cajsa, Nilsson, Emelie January 2020 (has links)
Denna studie undersöker för- och nackdelar med textilier gjorda av bananavfall applicerat inom modebranschen. Studien granskas ur ett miljöperspektiv med ett fokus utifrån mål 12: Hållbarkonsumtion och produktion från de Globala målen. De Globala målen är en del avhandlingsplanen Agenda 2030 som är uppsatt av United Nation Development Program, där det eftersträvas att fram till och med år 2030 ha uppnått en mer hållbar värld. Vidare kommer bananfiberns egenskaper att granskas ur ett teoretiskt perspektiv för att se om detta är ett lämpligt val inom modebranschen. Studien ger också en inblick i hur modebranschen i Sverige förhåller sig till textilt material av bananavfall. Studien utgör en viktig del för att sprida kunskap om bananfiberns för- och nackdelar medmöjligheter att ge bättre förutsättningar till modeindustrin att kunna använda en hållbar fiber. Studiens resultat visar att det finns möjligheter för att detta ska kunna uppnås i framtiden sett ur ett hållbarhetsperspektiv, samt utifrån bananfiberns egenskaper. / This thesis examines the advantages and disadvantages regarding textiles made out of bananawaste within the fashion industry. An environmental perspective is applied based on goal 12:Responsible consumption and production from the Sustainable Development Goals (SDGs).SDGs is a part of the 2030 Agenda set by United Nation Development Programs, which aims tocreate a better world by 2030. Furthermore, the characteristics of the banana fiber and itsadequacy for the fashion industry will be theoretically examined. An aspect regarding thematerial from the fashion industries point of view will also be processed. Only swedishcompanies are included in the thesis.The thesis constitutes an important part for disseminate knowledge regarding the advantages anddisadvantages of the banana fiber. This with an expectation to provide better conditions withinthe fashion industry using a more sustainable fiber. Based on the results of the thesis, theopportunities to achieve this in the future are significant, due to the fact that both an sustainableperspective and the characteristics of the banana fiber shows a positive outcome. Furthermore,the thesis indicates a split result regarding the fashion companies point of view in the matter.

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