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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 Comprehensive Method for the Selection of Sustainable Materials for Building Construction

Zhang, Yuxin 01 May 2012 (has links)
In the design phase of any building industry, appropriate material selection is critical for the entire project. A poor choice of material may affect the quality of the project, lead to high cost during the long term operation and maintenance phases, and even endangering humans and the environment. Since the inception of the United States Green Building Council (USGBC) in 1993, ¡°green¡± buildings have become a hot topic and people have become concerned about how sustainable their buildings are. In order to determine the level of sustainability in buildings, the Leadership in Energy and Environmental Design (LEED) has developed a rating system that has been established now as the common denominator in the industry. However, the LEED rating system simplifies, or even ignores, explicit considerations for Lifecycle Assessment (LCA) in determining the selection of building materials. This lack of explicit consideration for LCA does not permit a full assessment in determining how truly sustainable the chosen materials are. This research analyzes the factors impacting the selection of the green materials and reviews the current standards used in green material. It proposes a more comprehensive rating method for the green material selection illustrating its applicability through a case study analysis based on new WPI Sports and Recreation Center. It is expected that this study would contribute to a better understanding of the sustainable materials selection and can improve help to improving their long term performance in buildings.
2

Guidelines For A Materials Selection Source For Industrial Design Activity: A Survey On The Expectations Of Turkish Designers

Karana, Elvin 01 July 2004 (has links) (PDF)
This thesis focuses on the material selection process in industrial design activity and existing material selection sources particularly used by industrial designers. Therefore, in this study, the knowledge about materials the designers need, and materials selection sources and the methods they use are explored. The aim is, to propose guidelines for a materials selection source basing on the designers&rsquo / needs and expectations from such a guide. The thesis consists of a critical review of the literature on existing materials sources and a field study conducted with 20 industrial designers practicing in Turkey.
3

Sustainable Material Selection:Guiding the Multi-Criteria Process to Design for Sustainable Innovation

Hald, Saga January 2019 (has links)
In the past decades, the world has noticed complex changes in its climate. The resources available now as well as in the future could be said to be analogous to the decreasing circumference of a funnel. The wealthy population with the means to elect what goods they wish to consume are becoming aware of their impact both on nature as well as on the less fortunate people of the planet. As a consequence environmental and human-centered factors are of higher priority than ever before in the decisions made by companies, which in turn will decide the future. This thesis aims to investigate what set of criteria can be seen as most relevant for sustainable material selection at a manufacturing company. To be relevant for the future these design criteria are decided with a base in modern research from the past decade in the field of material selection. The company chosen as a case to study and collaborate with was IKEA Components AB. The research was conducted on-site at the company’s facilities in Älmhult, Småland, as well as at the Blekinge Institute of Technology in Karlskrona, Blekinge. The company vision for the future which IKEA is striving towards is focused on lowering carbon dioxide equivalents, from which a lion share of the emissions is a result of the material they are selecting for their products. Experts within various fields of the chosen company were consulted to gain perspective and knowledge while designing and testing prototypes of a tool to facilitate a sustainable material selection. The metal alloys were analyzed for toxicity based on the percentages of all elements they contained and scored based on chosen sustainability criteria. The plastics were judged on recyclability, renewability, and degradability apart from available numbers for emission factors. After this, the materials were placed in the excel tool which was then tested by engineers and evaluated in semi-structured interviews. Updates were made to make the tool as user-friendly as was possible and new tests were conducted. Overall, the tool was appreciated by the users who tested it and more improvements were planned to finalize the prototype. Results are detailed in the latter part of the report, discussing designs the engineers preferred over others, the current scale of sustainability tools used in the company and how the testers scored the tool. In the discussion, criteria are evaluated based on their multi-criteria compliance with sustainability factors. Drawing conclusions about the subject of sustainability criteria was accomplished by conducting literature studies in material criticality, making use of the methods for sustainable product development taught in the master of science, investigating material toxicity, testing solutions for sustainable material selection at a typical furniture component manufacturing company, receiving feedback from constructors and exploring connections for the selected methods to the principles of sustainability.
4

Visualising animal hard tissues

O'Connor, Sonia A., Sparrow, Thomas, Holland, Andrew D., Kershaw, Rachael, Brown, Emma, Janaway, Robert C., Ugail, Hassan, Wilson, Andrew S. 19 August 2022 (has links)
No / This chapter summarises AHRC/EPSRC Science and Heritage Programme-funded research to develop a digital resource to disseminate knowledge of the identification of osseous and keratinous animal hard tissues. The choice of materials in the manufacture of individual artefacts or classes of objects can make a major contribution to understanding their cultural significance and questions of provenance or authenticity. This resource builds on understanding gained through a Fellowship to O’Connor in developing, evaluating and validating identification criteria for these materials in raw, worked and decayed states. The resource concentrates on the non-destructive visual methods of particular relevance to the examination of artworks, historic and archaeological artefacts. The chapter highlights the potential of various visualisation methods and digital technologies to capture and combine 2D images and 3D models and guide the viewer through the multi-scalar visual cues of each material to a reliable identification. By accessing a range of collections, the project has produced a comprehensive and accessible resource, disseminating these findings more widely than could be achieved by a physical reference collection. This resource supports the identification of cultural heritage objects for conservation scientists and heritage professionals and informs the fight against the illegal hunting and trafficking of rare and endangered species. / VAHT was funded through an AHRC-EPSRC Science and Heritage Programme Research Development Award (AH/K006169/1) that developed directly from Sonia O'Connor's AHRC/EPSRC Science & Heritage Programme Fellowship (AH/H032150/1)—Cultural Materials Worked in Skeletal Hard Tissues (COWISHT).
5

Performance des bétons autoplaçants développés pour la préfabrication d'éléments de ponts précontraints / Performance-based specifications of self-consolidating concrete designated for precast/prestressed bridge girder applications

Long, Wu Jian January 2008 (has links)
In the precast construction market, the competitive situation is significantly affected by price, cost, productivity, and quality factors. Since self-consolidating concrete (SCC) was first introduced to the concrete industry in the late 1980s, it has been used worldwide in variety of applications. Despite the documented technical and economic advantages of SCC in precast, prestressed applications, the use of SCC has been limited in some countries due to some technical uncertainties of such innovative material. To explore some unsolved issues related to SCC and to contribute to a wider acceptance of SCC in precast, prestressed applications, this study was undertaken to assess the effect of mixture proportioning and material characteristics on the performance of SCC and recommend performance-based specifications for use of SCC in the precast, prestressed applications. The thesis presents an experimental program that contains four parts: (1) a parametric study to evaluate the influence of binder type, w/cm, coarse aggregate type, and coarse aggregate nominal size on the modulus of elasticity and compressive strength developments; (2) a parametric study to evaluate the effect of mixture proportioning and material characteristics on fresh and hardened properties of SCC; (3) a fractional factorial design to identify the relative significance of primary mixture parameters and their coupled effects on SCC properties; and (4) a field validation using full-scale AASHTO Type II girders cast to investigate constructability, material properties, and structural performance (the latter part was carried out by the research team of Professor Denis Mitchell at McGill University). Based on the experimental test results, SCC exhibits similar compressive strength and modulus of elasticity to that of conventional high-performance concrete (HPC) of normal slump consistency. SCC and HPC mixtures made of a given binder type exhibit similar autogenous shrinkage. However, SCC exhibits up to 30% and 20% higher drying shrinkage and creep, respectively, at 300 days compared to HPC made with similar w/cm but different paste volume. The results of the experiment program show that among the investigated material constituents and mix design parameters, the w/cm has the most significant effect on mechanical and visco-elastic properties. The binder content, binder type, and sand-to-total aggregate ratio (S/A) also have considerable effect on those properties. The thickening-type viscosity modifying admixture (VMA) content (0 to 150 ml/100 kg CM) does not significantly affect mechanical and visco-elastic properties. Based on the findings, some mixture parameters regarding the overall performance of SCC designated for precast and prestressed applications can be recommended: SCC made with relatively low w/cm (such as 0.34 vs. 0.40) should be selected to ensure desirable compressive strength, modulus of elasticity (MOE), flexural strength, as well as less drying shrinkage and creep; the use of crushed aggregate with 12.5 mm MSA is suggested since it provides better mechanical properties of SCC compared to gravel; the use of low S/A (such as 0.46 vs. 0.54) to secure adequate mechanical and visco-elastic properties is recommended; the use of thickening-type VMA can help to secure robustness and stability of the concrete in the case of SCC proportioned with moderate and relatively high w/cm; and the use of Type MS cement can lead to lower creep and shrinkage than Type HE cement and 20% Class F fly ash. However, SCC mixtures made with Type HE cement and 20% Class F fly ash can result in better workability and mechanical properties. Therefore, it is recommended to use Type HE cement and 20% Class F fly ash and reduce binder content (such as 440 kg/m[exposant 3] vs. 500 kg/m[exposant 3]) to assure better overall performance of SCC. Validation on full-scale AASHTO-Type II girders using two HPC and two SCC mixtures show that girders casting with SCC can be successfully carried out without segregation and blocking for the selected optimized mixtures. The surface quality of the girders cast with SCC is quite satisfactory and of greater uniformity than girders cast with HPC. Both HPC and SCC mixtures develop similar autogenous shrinkage for mixtures made with similar w/cm. Again, the two evaluated SCC mixtures develop about 20% greater drying shrinkage than comparable HPC mixtures. Modifications of existing models to assess mechanical and visco-elastic properties of SCC used in the precast, prestressed applications are proposed. Based on the comparisons of various code provisions, the ACI 209 and CEB-FIP codes with suggested material coefficients can be recommended to estimate compressive strength. The modified AASHTO 2007 model can be used for predicting the elastic modulus and flexural strength. The AASHTO 2004 and 2007 models with suggested material coefficients can be used to estimate drying shrinkage and creep, respectively. The CEB-FIP 90 code model can be used to predict both drying shrinkage and creep. Finally, the modified Tazawa and Miyazawa 1997 model with material modifications can be used to estimate autogenous shrinkage of SCC.
6

Elaboração de fichas técnicas de materiais visando o design de órteses de membros superiores e inferiores

Danckwardt, Frances January 2016 (has links)
Este trabalho tem por objetivo principal a elaboração de fichas técnicas de materiais utilizados na fabricação de órteses de membro superior e inferior. Para a escolha dos materiais a serem elencados e caracterizados, selecionou-se as instituições de apoio ao deficiente da área metropolitana de Porto Alegre, RS. As selecionadas para a pesquisa foram a Associação de Assistência à Criança com Deficiência (AACD) e Associação Canoense de Deficientes Físicos (ACADEF). A metodologia abordou a listagem e seleção, e as etapas seguintes se deram a partir da organização dos materiais em grandes grupos: materiais poliméricos, materiais metálicos, materiais naturais e fibras. Assim agrupados, seguiu-se a caracterização e a análise dos materiais por meio de microscopia eletrônica de varredura (MEV), espectroscopia por energia dispersiva (EDS), espectroscopia no infravermelho por transformada de Fourier (FT-IR), espectrometria de fluorescência de raios-X e ensaio de tração e compressão. Os resultados práticos e as pesquisas em materiais bibliográficos e bancos de dados como o Granta Design permitiram a elaboração das fichas técnicas de cada material, apresentando as características gerais, propriedades físicas, mecânicas e químicas e aplicação. Essas fichas têm finalidade multidisciplinar, buscando auxiliar profissionais que trabalham no processo de fabricação destas órteses, como fisioterapeutas, terapeutas ocupacionais, técnicos de oficina, designers e projetistas, permitindo acesso direto e praticidade na fabricação destes produtos. / The main objective of this study is to develop technical sheets of materials utilized in the manufacturing of superior and inferior limb orthoses. Institutions that support disabled persons in the metropolitan area of Porto Alegre, RS, were selectioned in order to decide which materials were to be listed and characterized. The Association of Assistance for Children with Disability (AACD) and the Canoense Association of persons with Physical Disability (ACADEF) were selected for this research. Methods included listing and selection, and the following steps were conducted through the categorization of materials into large groups: polymeric materials, metal materials, natural materials and fibers. Thus grouped, the study continued with the characterization and analysis of materials through scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), X-ray fluorescence spectrometry and tension and compression testing. Practical results and research in bibliographical material and databases such as Granta Design enabled the development of technical sheets for each material, presenting general characteristics, physical, mechanical and chemical properties and application. Such sheets have multidisciplinary purposes, seeking to assist health professionals who work in the manufacturing process of these orthoses, such as physiotherapists, occupational therapists, workshop technicians, designers and drafters, allowing for direct access and convenience in the manufacturing of these products.
7

Engenharia e design : contribuição ao estudo da seleção de materiais no projeto de produto com foco nas características intangíveis / Engineering and design: contribution to the study of materials selection in product design with focus on the intangible characteristics

Faller, Roberto da Rosa January 2009 (has links)
Nos anos recentes, evidenciou-se o destaque de outros aspectos dos produtos além dos ligados ao bom funcionamento e usabilidade. Estudos nesse âmbito trouxeram à tona a importância da relação emocional envolvida na interação indivíduo-objeto. Intermediando essa relação estão os materiais, elementos capazes de transferir parte de sua personalidade aos produtos por meio de suas características tangíveis e intangíveis. O estudo dos aspectos técnicos dos materiais é amplamente apoiado por diferentes programas computacionais, livros e pesquisas científicas. Já seus aspectos ligados à subjetividade não encontram suporte semelhante. Assim, os métodos de Seleção de Materiais e as fontes de pesquisa existentes mostram-se incapazes de dar o suporte exigido pelo projeto de produtos com foco no usuário. Dessa forma, o presente trabalho apresenta contribuições ao processo de Seleção de Materiais em Design de Produto, destinadas a capacitar os projetos na incorporação de aspectos emocionais. É proposto, então, um modelo de elucidação das emoções, que demonstra e relaciona as variáveis envolvidas durante a interação indivíduo-objeto; são apresentadas duas pesquisas de campo que visam levantar atributos verbais utilizados na descrição de produtos e materiais e é proposto, por fim, um método de Seleção de Materiais que dê suporte a busca de características intangíveis. / In the last years, several aspects related to product features other than good operation and usefulness have been discussed. Studies regarding this topic enlighten the importance of user-product emotional interaction. Materials work as a link in this relation, as they may transfer part of its personality to the products through its tangible and intangible characteristics. The study of the material's technical aspects is widely supported by a large number of softwares, books and scientific researches. However, their aspects appealing to subjectivity do not share the same support. Therefore, the existing methods of material selection and sources of research do not provide the support demanded by user-focused projects. Thus, this paper presents contributions to the Material Selection process in Product Design, aiming to the incorporation of emotional aspects in such projects. It is proposed an emotion elucidation model, that presents and links the variables involved during the interaction individual-object. This work consists of two field researches aiming to raise verbal attributes used to descript products and materials, and a method of material selection that supports searching for intangible characteristics.
8

Further Development of a Docking Station : Redesign of MagniLink S Docking Station at LVI Low Vision International

Johansson, Tim, Nilsson, Pontus January 2015 (has links)
The purpose of this work is to evaluate how a docking station can be more future proof, environmentally friendly and satisfy the customers’ needs more. The docking station in focus of this project is owned by LVI, and used with one of their cameras MagniLink S. When comparing the results of the new docking station and the current docking station, the new docking station is more future proof, environmentally friendly and satisfies the customers’ needs more. In the end it is established that following steps should be followed during the development of a docking station: -          Make sure that the cables are reliably fastened into the docking station and that the connectors can handle the docking force. -          Design to use more material with lower environmental impact and ensure that the material fulfils the product requirements and objectives. Use as small amount of material as possible. -          Prioritize the customers’ expressed and unexpressed needs as one of the highest priorities during the development process.
9

Integration of material circularity in product design / Intégration de la circularité des matériaux en conception

Dwek, Mauricio 12 December 2017 (has links)
Au cours des dernières décennies, de nombreux outils ont été développés pour comprendre et gérer les cycles anthropiques des matériaux, avec différentes approches. Chacune considère les flux de matière dans la société de différentes manières et chacune possède ses bases de données respectives alimentant leurs utilisations. Il ne semble toutefois pas y avoir de bases communes pour la communication entre les activités de conception et les activités de bouclage, ainsi que leurs parties prenantes respectives, ce qui entrave les échanges d'informations nécessaires à une bonne gestion des produits mis au rebut (et de leurs matériaux). Cette thèse apporte ainsi deux contributions originales à la conception circulaire de produits: un outil pour l'intégration de la circularité des matériaux dans la conception de produits et un cadre pour caractériser les réseaux de bouclage de matériaux. L'outil est composé d'un indicateur multicritères de la valeur circulaire des matériaux utilisé dans la méthode de conception pour la circularité des matériaux (Design for Material Circularity method). Le cadre s'appuie sur une analyse documentaire approfondie, enrichie par des entretiens avec des experts de l'industrie, et sert de base à la collecte de données et à la capitalisation des connaissances sur les filières de bouclage. Les filières de recyclage en boucle ouverte de huit matériaux, appartenant aux trois principales catégories de matériaux, sont caractérisées grâce à ce cadre (acier, aluminium, cuivre, métaux précieux, métaux de spécialité, terres rares, plastiques et verre). Deux études de cas détaillent le déploiement de ces contributions. La première porte sur le choix optimal du matériau et du scénario de fin de vie pour une bouteille de 1,5 litre. La deuxième vise à identifier les points chauds (hotspots) de circularité des matériaux et les scénarios de fin de vie idéaux pour un bloc-batterie véhiculaire au lithium. / In the last decades, many tools have been developed to understand and manage the anthropogenic cycles of materials, with different approaches. Each handles the material flows in society in different ways and each possesses its respective databases that fuel their uses. Yet there seems to be no common ground of communication between design activities and cycling activities, as well as their respective stakeholders, which hinders the information exchanges required for a proper management of discarded products (and their materials). This thesis provides two original contributions to circular product design: a tool for the integration of material circularity in product design and a framework to characterize material cycling networks. The tool is composed of a multi-criteria indicator for circular material value that is used in the Design for Material Circularity method. The framework is based on an extensive literature review enhanced by industry experts’ interviews and provides a basis for data collection and knowledge capitalization on cycling activities. The open-loop recycling networks of eight materials, from the three main material classes, are characterized using this framework (steel, aluminium, copper, precious metals, specialty metals, rare earth elements, plastics and glass). Two case studies detail the deployment of these contributions. The first focuses on the optimal choice of material and end-of-life scenario for a 1,5-litre bottle container. The second is aimed at identifying material circularity hotspots and ideal end-of-life scenarios for a vehicular lithium-ion battery pack.
10

Contribuição ao ecodesign (DfE) a partir de propriedades de blendas PC/PMMA em sucessivos ciclos de processamento: estudo de caso de óculos oriundos de apreensão da Receita Federal do Brasil

Vidales, Lúcia Torres January 2013 (has links)
Devido às crescentes exigências da sociedade, das legislações ambientais e do próprio meio ambiente pela sua preservação, é imprescindível a tomada de providências, especialmente no que tange ao projeto de produto (Design de Produto). Nesta fase, deve ser possível prever o desempenho do produto e de seus materiais em todo o ciclo de vida, desde a produção até os processos de reaproveitamento, reciclagem e descarte final. Para que essa previsão seja possível, são necessários dados de propriedades dos materiais, viabilizando a seleção destes conforme a finalidade a que se destinam. O presente trabalho se deteve, assim, aos estudos relacionados ao Ecodesign, especificamente ao Design para Reciclagem, de óculos oriundos de apreensão pela Receita Federal do Brasil. O objetivo foi propiciar subsídios técnicos para gerar soluções viáveis para um encaminhamento adequado desses resíduos provenientes de apreensão. Como possibilidade para reciclagem, foi sugerida a produção de blendas com os polímeros constituintes dos óculos, policarbonato (PC) e polimetilmetacrilato (PMMA). As blendas e os polímeros puros, tanto de material virgem quanto provenientes dos óculos, foram caracterizados via espectroscopia de infravermelho por transformada de Fourier (FTIR), análise termogravimétrica (TGA), ensaios de tração e de impacto, inspeção visual e testes de chama e de solubilidade. Os dados obtidos foram, então, comparados para o decorrer de quatro ciclos de processamento, entre as diferentes composições e para o material virgem e dos óculos, proporcionando noções a respeito das tendências no comportamento das propriedades dos materiais reciclados. As blendas consideradas total ou parcialmente miscíveis via calorimetria diferencial exploratória (DSC) foram 90PC10PMMA, 80PC20PMMA e 70PC30PMMA (composições mássicas). / Increasing demands from society, environmental legislation, and environment itself make it imperative that we take actions concerning product design. In this phase, one should be able to predict product and materials performance in all of the product's life cycle, from its production up to reuse, recycling and final disposal. In order to make this prediction possible, one needs data about materials properties. These data enable material selection in accordance to their usage. This work consists in a study related to Ecodesign and, more specifically, Design for Recycling, of counterfeit glasses apprehended by Brazilian internal revenue service (Receita Federal). Its goal is providing a technical basis and presenting viable solutions for an adequate disposal of these residues after apprehension. This dissertation suggests the production of blends with the polymers that constitute the glasses, namely PC and PMMA, as a possibility to carry out recycling. The blends, as well as the polymers in their pure state, either from virgin material or from the counterfeit glasses, were characterized with Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), tension and impact tests, and visual inspection, as well as with flame and solubility tests. The data thus obtained was compared along four processing cycles regarding the different compositions, yielding valuable information about trends in the behavior of the recycled materials' properties. The blends considered miscible or partially miscible by means of differential scanning calorimetry (DSC) were 90PC10PMMA, 80PC20PMMA e 70PC30PMMA (mass fractions).

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