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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.
31

Sustainability studies in recycling post consumer carpet

Subbiah, Valli 25 August 2008 (has links)
This thesis presents some novel techniques to process Post Consumer Carpet waste and provides detailed cost comparisons between setting up and running small-scale decentralized units and large-scale centralized chemical facilities. The techniques presented include: a decentralized underlay manufacturing process which does not distinguish between the types of face fiber, a decentralized facility with twin screw extruder to depolymerize nylon 6 face fiber with a concurrent underlay manufacturing facility, a decentralized pallet production facility, and a centralized facility for chemically depolymerizing nylon 6, and nylon 6,6 with a concurrent underlay manufacturing facility The limiting factors to recycling are the collection of significant volumes of material and effective recycling techniques. This is illustrated in this study. The aim of this study is to enable recyclers to assess their recycling activities using various performance parameters, such as payback period of the venture, mass of carpet recycled, and energy used. Thus, this study aims to shed light on the impact of recycling on current carpet consumption per capita. The results indicate that decentralized facilities located in metropolitan areas with populations of over 2 million people have a lower payback period than the large scale centralized facilities that are sparsely distributed throughout the country. These decentralized facilities are also more efficient in reducing the current carpet consumption per capita. The reduced traveling distance for the post consumer carpet from the collection/disposal site to the processing facility should make a huge impact on energy consumption and the corresponding environmental emissions.
32

Characterization of bioparticulate adhesion to synthetic carpet polymers with atomic force microscopy

Thio, Beng Joo Reginald. January 2008 (has links)
Thesis (Ph.D)--Chemical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: J. Carson Meredith; Committee Member: Amyn Teja; Committee Member: F. Joseph Schork; Committee Member: Lawrence Bottomley; Committee Member: Mark Prausnitz. Part of the SMARTech Electronic Thesis and Dissertation Collection.
33

Flying Carpets from East to West : An Examination on Corporate Social Responsibility within the Indian Carpet Industry

Johansson, Emma January 2012 (has links)
Corporate social responsibility is a concept widely discussed by businesses and has come to describe the relationship between business and society. For some it means the idea o legal responsibility, an ethical behaviour and some equate it with charitable contribution. The World Business Council for Sustainable Development (Hopkins, 2007: 25) defines CSR as follows:   "Corporate Social Responsibility is the continuing commitment by business to contribute to economic development while improving the quality of life of the workforce and their families as well as of the community and society at large."   The relationship is increasingly striving to counteract a variety of problems that are associated with the contemporary globalization, such as violation of human and labour rights along with environmental challenges and is well-mentioned both by academics and businessmen. Within the Indian carpet industry, child labour has become a hot topic due to major scandals on the issues in the 1990s. Though, the meaning of corporate social responsibility is less common. The purpose of this study is to examine the Indian carpet industry’s awareness and use of the international agenda of corporate social responsibility, hence how the carpet export houses approach the responsibility. Also, the purpose is to examine how the carpet weavers are affected by the policies and actions of the export houses.   A field study with an ethnographical approach has been conducted through the use of interviews and observations in the district of Bhadohi, state of Uttar Pradesh in India. The interviewees consisted of workers working with the finishing processes of carpets at two export houses’ factories as well as carpet weavers at the looms in the villages. The findings from the interviews were analyzed through the use of parts of the Sustainable Livelihood Framework and with this approach the weavers’ access to assets is analyzed in relation to the export houses’ applying of the international agenda of CSR, more precise in this study, the UN Global Compact’s principles of CSR. The main findings from this study show that the CSR principles of the UN Global Compact were followed to different extents by the export houses since they are prioritizing some principles before others. The distribution of responsibilities differs depending on the management of the export house, mainly because of how the demands from the buyers and consumers look like. Also, the prioritizing of the export houses has become to affect the weavers’ socio-economic situation and for some the access to assets has increased. Furthermore, the study reveal that corporate social responsibility to a large extent is directed and influenced by the buyers’ and consumers’ (mainly stationed abroad in Western countries) demand. Thereby, through the complex system of sub-contracting, carpet weavers are affected differently since CSR is interpreted and used in various ways that are considered as most “suitable” to the export house.
34

Process Optimization of Dryers/Tenters in the Textile Industry

Xue, Li 12 July 2004 (has links)
Textile dyeing and finishing industry uses dryers/tenters for drying and heat-setting fabrics. A very large fraction of the heating value of the fuel consumed in the burner ends up as waste in the dryer exhaust. An initial calculation showed that up to 90% of the energy consumed in the tenter is wasted. Therefore, quantifying the energy waste and determining drying characteristics are vitally important to optimizing the tenter and dryer operations. This research developed a portable off-line gas chromatography-based characterization system to assess the excess energy consumption. For low-demanding heat-setting situations, energy savings can be realized quickly. On the other hand, there are demanding situations where fabric drying represents the production bottleneck. The drying rate may be governed either by the rate of heat transport or by the rate of moisture transport. A mathematical model is being developed that incorporates both these processes. The model parameters are being obtained from bench-scale dryer studies in the laboratories. The model will be validated using production scale data. This will enable one to predict optimization dryer operation strategies.
35

Quantification of Bioparticulate Adhesion to Synthetic Carpet Polymers with Atomic Force Microscopy

Thio, Beng Joo Reginald 08 September 2005 (has links)
Atomic force microscopy (AFM) is adapted to the measurement of adhesion forces between indoor-air-pollutant bioparticulates and synthetic carpet fiber materials. This novel technology is used to characterize the adhesion and release of a model bioparticulate, the bacterium E. coli on Nylon. This knowledge will lead to expanded studies of a wider range of biocontaminants, and ultimately to the ability to design carpet and rugs upholstery that reduce the spread of indoor air pollutants. Such an advance would improve life significantly for the 20+ million Americans who suffer from asthma, and countless others who are afflicted with allergies and illness spread via bioparticulates.
36

Surface-initiated Polymerization and Janus Membrane Synthesis from Graphene and Poly(dopamine)

Hafner, Daniel 17 May 2021 (has links)
In dieser Arbeit wurden verschiedene Materialien durch das Pfropfen von Polymerbürsten auf Poly(dopamin) (PDA) und Graphen (G) synthetisiert. Ein besonderes Augenmerk wurde dabei auf sog. strain-engineering von Graphen und Synthese von Janus-Membranen gelegt. Die Kombination aus PDA-Oberflächenchemie und oberflächeninitiierter Cu(0)-vermittelter kontrolliert radikalischer Polymerisation (SI-CuCRP) wurde als robuste und vielseitige Methode zur Synthese von Polymerbürsten etabliert. Dabei können Schichtdicken von einigen hundert Nanometern innerhalb 1 h erreicht werden. Die Zugänglichkeit der Endgruppen bleibt erhalten, was die Synthese von Pentablockcopolymerbürsten ermöglicht. Dies stellt die bis dato höchste Blockzahl für oberflächengebundenes Copolymer dar. Zudem erlaubt die SI-CuCRP eine einfache und hocheffiziente Synthese von Polymerbürsten mit definierten Gradienten und Strukturen sowie die Funktionalisierung von natürlichen Membranen. Im zweiten Teil der Arbeit wurde diese Methode zur Funktionalisierung von Graphen mit Polymerbürsten angewendet. Aufgrund des hohen sterischen Drucks innerhalb der Bürsten, sollte die resultierende chemisch-mechanische Beanspruchung zu einer Deformation des Graphens und einem straintronic-Effekt führen. Die Bewertung und Quantifizierung der chemisch-mechanisch induzierten Belastung ist jedoch problematisch. Vermutlich führt die induzierte mechanische Spannung zum Bruch bzw. Reißen der Graphenschicht, wenn die Pfropfungsdichte und Schichtdicke der Polymerbürsten zunimmt. Diese Annahme wird durch neueste Literatur gestützt. Dennoch wurde eine ganze Reihe von Polymermodifikationen auf Graphen erhalten, um (gerichtete) Faltenbildung verschiedener Größenordnungen zu erzielen. Im Zusammenhang der Materialsynthese wurden sowohl aus PDA als auch aus Graphen Janus-Membranen, sog. Janus polymer carpets, hergestellt. Hierzu wurde entweder sequentieller Transfer freistehender Polymerteppiche oder einseitige, sequentielle Polymerisation auf Graphen genutzt. Auf diesem Weg wurden Janus-Membranen hergestellt, die hydrophob/hydrophil, nicht-sensitiv/T sensitiv oder nicht sensitiv/pH sensitiv sind oder eine Polymerbürsten/Flaschenbürsten-Architektur besitzen. Diese kann allerdings Reihe auf einfache Weise erweitert werden. Alle hergestellten Janus polymer carpets weisen typischerweise eine Größe von ca. 1 cm² auf. Unter Berücksichtigung ihrer Gesamtdicken, die im Bereich von max. einigen hundert Nanometern liegen, betragen die Aspektverhältnisse zwischen 10000 und 100000. In Kombination mit der strukturellen Vielfalt von Polymerbürsten bieten die vorgestellten Methoden einen einzigartigen Weg zu einer ganzen Palette neuartiger 2D-Materialien mit einstellbaren Eigenschaften. Das hervorragende Faltverhalten von strukturierten Janus polymer carpets macht sie besonders interessant für gerichteten Transport und Bewegung oder kontrollierte Verformung.
37

Återanvändning av textilt restmaterial / Recycling of textile waste materials

Englund, Angelica, Palm Samuelsson, Jessica, Tanemar, Olivia January 2013 (has links)
Detta arbete handlar om vad ett väletablerat företag skulle kunna göra med sitt restmaterial. Vi vet att det idag finns en mängd företag som jobbar för att minska sitt restmaterial och här presenteras förslag på vad man kan göra med det som ändå uppkommer. I arbetet presenterar vi först hur vi gått till väga för att samla in vår information, alltså hur vår forskning gjorts. Då arbetets syfte utgår ifrån Kasthall Mattor & Golv AB, har vi valt att presentera fakta kring företaget och hur deras syn ser ut på miljöarbete idag. För att förstå hur ett ökat miljöarbete påverkar ett företag har vi valt att fördjupa oss i CSR, Cradle to cradle, materialfakta och avfallshantering. Med hjälp av detta vill vi att läsaren lättare skall kunna följa vara tankar då förslagen presenteras samt diskuteras. I diskussionen analyseras detta sedan vidare med våra egna funderingar. Det tas också upp vad vi tycker om de olika förslagen och vilka fördelar respektive nackdelar vi ser att de har. I slutsatsen knyter vi samman arbetet med våra slutgiltiga tankar.This paper is about what a well-established company could do with their waste materials. We are aware of that today there are many companies working to reduce its waste materials and this paper presents suggestions for what to do with it. Firstly we present how we proceeded to gather our information. The purpose is based on Kasthall Mattor & Golv AB ́s waste problem and we have chosen to present the facts about the company and how they work with environmental questions today. To understand how an increased environmental work impacts a company we have chosen to immerse ourselves in CSR, Cradle to cradle, material facts, and waste management. Using this, we want to help the reader follow our thoughts when the proposals are presented and discussed. In the discussion we further analyze this with our own thoughts. It also looks at what we think about the various proposals and what advantages and disadvantages we find. In the conclusion we summarize the paper with our thoughts. / Program: Textil produktutveckling med entreprenörs- och affärsinriktning
38

Rigidité quasi-symétrique, tapis de Julia et le débarquement de dynamique resp. paramètres rayons / Quasisymmetric rigidity, carpet Julia sets and the landing of dynamic resp. parameter rays

Zeng, Jinsong 13 May 2015 (has links)
Cette thèse est constituée de cinq parties distinctes. La première partie est consacrée au problème de rigidité quasi-symétrique associé à un nouveau modèle de tapis de Sierpinski, qui ne sont pas quasi-symétriquement équivalent aux tapis de Sierpinski usuels. La seconde partie est une discussion portant sur la géométrie quasi-symétrique des ensembles de tapis de Julia, incluant en outre le quasi-cercle uniforme, ainsi que certaines propriétés de séparation uniforme. Lors de la troisième partie, nous déterminerons une condition permettant de savoir quand deux rayons externes d'un polynôme tendent vers un même point. Comme application, nous montrerons également la monotonie de l'entropie associée à une famille de polynômes quadratiques. La quatrième partie est inspirée du travail récent de Cui Guizhen et Tan Lei. En utilisant des outils classiques (module d'anneau et chirurgie quasi-conforme), nous étudierons la convergence de certains rayons en campagne locus espace des paramètres. Enfin, la dernière partie pore sur la famille des transformations de renormalisations générées. Plus précisément, cette partie abordera la connexité de ces ensembles de Julia, et le lieu de confinement dans l'espace des paramètres, ainsi que la formule asymptotique de la dimension d'Hausdorff des ensembles de Julia. / The thesis consists of five parts. The first part is concerned with the quasisymmetric rigidity of a new Sierpinski carpet, which are not quasis-ymmetrically equivalent to the standard Sierpinski carpets. The second part discusses the quasisymmetrically geometry of the carpet Julia sets, including the uniformly quasicircle and uniformly separated properties. The third part is to determine when two external rays of a polynomial land at the same point. As an application, we also show the monotonicity of core-entropy on a family of quadratic polynomials. In the fourth part, following Cui and Tan's work, we use the classic tools modulus of annulus and quasi-conformal surgery to study the landing of some parameter rays in shift locus parameter space. The last part discusses a family of generated renormal-ization transformations. Specifically, it is on the connec-tivity of its Julia sets and the non-escaping locus in its parameter space, the asymptotic formula of the Hausdorff dimention of the Julia sets.
39

Ozone Interaction with Indoor Building Materials and HVAC Filters

Abbass, Omed Akber 16 August 2017 (has links)
As modern life develops, humans spend most of their time inside buildings. Understanding the effects of different building materials that exist indoors on indoor air quality is crucial to ensure comfort, health, and productivity of building occupants. Indoor air quality (IAQ) is an important field of building science that focuses on studying the existence of different compounds indoors. These compounds include: airborne particles such as dust, volatile organic compounds (VOCs) such as carbonyls, reactive gases such as radon, ozone and others. Ozone is a strong oxidant gas that has adverse effects on human health, and is highly reactive with building materials that exist indoors. This reaction may reduce its concentration indoors, but may produce other by-products that could be more harmful for human health than ozone itself. In this dissertation, ozone reaction with different building materials is investigated in four studies. The first includes studying the effect of indoor carpet fiber type on ozone removal and carbonyl emissions. This study provides valuable data and knowledge about the importance of selecting carpet type and its effect on indoor environment. In the second study, different indoor plants were tested to evaluate their ability to remove ozone. The results from this study show wide variation between plants tested on ozone removal. Also, the ability of plants as ozone removal agent changes as light levels change. The third part studies ozone removal efficiency of HVAC filters previously installed in air handling units located on green and white membrane roofs of a commercial building. Detailed filter surface analysis using scanning electron microscope (SEM) was performed to understand the nature of deposits on these filters. The reason for differences in ozone removal efficiency of two filters in comparison with new filter is also discussed. The fourth study investigated ozone removal and carbonyl emissions from three different VOC content indoor latex paints. The outcomes from this research show that zero VOC latex paint has the most ozone effective removal capacity and this paint is the least carbonyl emitter. The research presented in this dissertation adds new data, valuable knowledge, and expands the understanding of the importance of selecting indoor materials to raise indoor air quality and make the buildings' indoor environment healthier and safer.
40

Evaluation of Fuel Saving for an Airline

Berglund, Tobias January 2008 (has links)
<p>A study of which methods and measures that can be used to reduce fuel consumption and harmful discharges in an airline.</p><p>The study begins with an investigation containing calculations of the differences between estimated fuel consumption calculated by a computer program called Skytrack and actual fuel consumption. Results from this study allows synchronization between actual consumption with calculated consumption. In addition to this methods and configurations to reduce weight and thus weight onboard aircrafts e.g. carpet exchange, lightweight trolleys and water reduction has been created and analysed.</p><p>To bring the thesis to an end, the author has investigated other methods and configurations which TUIfly Nordic is implementing for fuel conservation.</p><p>The thesis results in several conceivable areas for fuel conservation with calculated savings of 830 000 EUR which for the moment is implemented in TUIFly Nordic.</p>

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