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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

An experimental study of the activated sludge process under steady state and dynamic conditions

Chu, George Chao-yi January 2010 (has links)
Digitized by Kansas Correctional Industries
2

A database for dismantling of obsolete vessels

Sibal, Pooja. January 2001 (has links)
Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains vii, 86, 1, 26 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 85-86).
3

The kerbside recycling dilemma /

Lim, Boon Hock. January 1998 (has links) (PDF)
Thesis (M. Env. St.)--University of Adelaide, Mawson Graduate Centre for Environmental Studies, 1999. / Includes bibliographical references (leaves 111-121).
4

The viability of salvaging solid waste at dump sites in the Johannesburg Metropolitan Area

Nkosi, Hezekiel S. 23 June 2008 (has links)
With rapid economic growth and urbanization, solid waste generation and management is becoming a major social and environmental issue in Johannesburg. This rapid growth coupled with new consumption patterns has resulted in the over utilisation of natural resources. Consequently, there is more land being used for waste disposal and both pollution and environmental degradation are on the rise. These by-products of economic growth are not compatible with the principles of waste minimisation, which sees reuse and recycling as means for sustainable development. The concept of sustainable development is defined as “the development that meets the needs of the present without compromising the ability of the future generations to meet their own needs” (Johannesburg World Summit on Sustainable Development Report, 2002). Sustainable waste management advocates for the integration of environmental matters with economic and social issues. It is within this sustainable environmental management context that the research work is undertaken to fulfil the principles of sustainable waste management practices. Recycling traditionally involves the recovery of plastics, glass, paper, cardboard, metal and rubber from the waste stream. The recovery of these materials will achieve significant volume reduction, on average according to Lombard (1990) between 30-40 per cent of domestic refuse. But, this should be economically viable and produce marketable goods. This option provides opportunities for salvagers to reclaim recyclable materials to sell and generate an income. Salvaging on landfill sites is strongly discouraged by the Minimum Requirements for Waste Disposal by Landfill (Department of Water Affairs and Forestry, 1998) and by the National Waste Management Strategy (Department of Environmental Affairs and Tourism, 1998) as it interferes with the site operations and places salvagers at a high health and safety risk. The main aim of this mini dissertation is to determine whether or not recovery of recyclable material by salvagers contributes to the reduction of waste quantities to be handled by the landfill sites. The methodology used to obtain data for this research was the questionnaire interview approach where there was an interviewer who asked predefined questions and an interviewee who responded and answered questions as posed. In the discussion of both qualitative and quantitative data analysis, the research followed Dey’s (1993) approach, which seeks to combine different approaches such as the descriptive, classification and connection methodologies to gain a deeper understanding of qualitative data. The research findings are that white paper, clear plastic, newspaper, scrap metal, cardboard boxes and common paper are some of the waste components that are being recovered from landfill sites. But some recyclables are more sought after commodities than the others due to their monetary value and availability, white paper being the most popular and common paper the least popular. The results also illustrate that the recovery percentage does not contribute to a significant reduction in quantities of waste to be disposed at a landfill site, but it does benefits financially the salvagers through the resale of the recovered recyclable commodities. / Dr. L.G.C. Scheepers
5

Analysing the critical design parameters for reuse

Ibbotson, Scott, Mechanical & Manufacturing Engineering, Faculty of Engineering, UNSW January 2006 (has links)
Reuse of components as opposed to material recovery, recycling or disposal has been identified as one of the most efficient EOL strategies for products. The concept behind reuse is that some components and subassemblies have a design life that exceeds the life of the product itself. In order for reuse to be successfully implemented as an EOL strategy, a designer needs to incorporate into a product a philosophy of Design for Reuse (DfRe) at the early design stage. Reliable methods to assess the remaining life of used components based on a products usage life are also required. Furthermore, current industry practices and literature advocate that there is no methodology to decide which parameters need to be redesigned so as to change the life of a selected component to a desired level. The objective of this research is to develop a methodology to assess the reuse potential of product groups based on component failure mechanisms and their associated critical lifetime prediction design parameters. Utilising these clustered groups mathematical models were then developed to establish the useful life of the components for each clustered group. Finally, a means of equating useful life to design life was established and the relationship between, the failure mechanisms, critical lifetime prediction design parameters and design life were represented in graphical format. In order to achieve the proposed objective, Cluster analysis, in particular Group Technology (GT) and Hierarchical clustering were employed to group components with similar failure mechanisms. Following this, multiple linear regression was used to establish mathematical models based on condition monitoring data for each of the clustered groups and their related critical lifetime prediction design parameters. A sensitivity analysis was conducted using the mathematical models, in order to produce graphical relations between the useful life and design parameters of a product. The validity of the suggested methodology was tested on electric motors and a gearbox as both these components have demonstrated great reuse potential. The results demonstrate that the methodology can assist designers in estimating the design life and associated design parameters with great accuracy, and subsequently aiding in a stratagem for reuse.
6

Leftovers a search for the Freegan Ideal

Darrell, Emily. January 2010 (has links)
Thesis (MA)--University of Montana, 2010. / Title from author supplied metadata. Includes bibliographical references.
7

Scrap compiling : using digital technology to manipulate scraps from construction sites in order to create architecture

Piriyaprakob, Nutthawut January 2006 (has links)
This project is inspired by two facts that occur on an everyday basis in much of the world. First, it is obvious that many persons and organizations in many developing nations are paying large amounts of money for large-scale architecture projects, including skyscrapers, museums, and airport, subway, and train terminals. It is often the case that as the mega-buildings are built, many useful materials—structural steel, wood, reinforcing rods, sheets of corrugated steel, and concrete among them--are wasted, even though they could be utilized in smaller projects. The second fact is that digital technology is playing a more important role in the daily life of many people and professionals. The development of such technologies also influences the ways in which buildings are created. Many types of software programs now facilitate the standard and non-standard workings of architecture offices worldwide, starting with design, moving through fabrication, and culminating with assembly.It is suggested that we can reuse the scraps from huge construction projects to provide much needed small buildings in the developing world (such as houses or small commercial structures) by using new digital technologies. As the technology becomes available, many architects will be able to adapt and utilize all types of raw materials in the most efficient ways possible while minimizing the amount of waste taken to landfill sites.To advance these ideas, the author worked as an intern at Morphosis and visited the offices of Gehry Partners and Greg Lynn Form (all in Los Angeles), and Sharpies Holden Pasquarelli Architects (SHoP) in New York; these firms are among the most influential offices in the world, both in regards to the buildings they design and the digital technologies with which they work. Rule-based design was studied to better understand the logic of computation. Simultaneously, several experimental projects were designed and built.The knowledge gained from these studies, experiences, and experiments can give us confidence that new technology can help architects and designers organize the complexity of unique scraps for use in the construction of buildings or building components.However, problems were revealed that are in need of attention. For example, the machines that are typically used for digital fabrication procedures today, such as the laser cutter and CNC router, do not provide the best support for this work because they are not intended to be used with scraps and the price of the machine is relatively high.It is hoped that this project can be a small first step for other architects to understand the possibility and the logic of digital technology within the realm of building construction waste. If studied and understood, the new technology can be a very powerful tool to utilize the leftover material in the most efficient way. / Department of Architecture
8

Re-use of containers for post-disaster housing

Ali, Aquil Ahmed. January 1975 (has links)
No description available.
9

Analysing the critical design parameters for reuse

Ibbotson, Scott, Mechanical & Manufacturing Engineering, Faculty of Engineering, UNSW January 2006 (has links)
Reuse of components as opposed to material recovery, recycling or disposal has been identified as one of the most efficient EOL strategies for products. The concept behind reuse is that some components and subassemblies have a design life that exceeds the life of the product itself. In order for reuse to be successfully implemented as an EOL strategy, a designer needs to incorporate into a product a philosophy of Design for Reuse (DfRe) at the early design stage. Reliable methods to assess the remaining life of used components based on a products usage life are also required. Furthermore, current industry practices and literature advocate that there is no methodology to decide which parameters need to be redesigned so as to change the life of a selected component to a desired level. The objective of this research is to develop a methodology to assess the reuse potential of product groups based on component failure mechanisms and their associated critical lifetime prediction design parameters. Utilising these clustered groups mathematical models were then developed to establish the useful life of the components for each clustered group. Finally, a means of equating useful life to design life was established and the relationship between, the failure mechanisms, critical lifetime prediction design parameters and design life were represented in graphical format. In order to achieve the proposed objective, Cluster analysis, in particular Group Technology (GT) and Hierarchical clustering were employed to group components with similar failure mechanisms. Following this, multiple linear regression was used to establish mathematical models based on condition monitoring data for each of the clustered groups and their related critical lifetime prediction design parameters. A sensitivity analysis was conducted using the mathematical models, in order to produce graphical relations between the useful life and design parameters of a product. The validity of the suggested methodology was tested on electric motors and a gearbox as both these components have demonstrated great reuse potential. The results demonstrate that the methodology can assist designers in estimating the design life and associated design parameters with great accuracy, and subsequently aiding in a stratagem for reuse.
10

Analysing the critical design parameters for reuse

Ibbotson, Scott, Mechanical & Manufacturing Engineering, Faculty of Engineering, UNSW January 2006 (has links)
Reuse of components as opposed to material recovery, recycling or disposal has been identified as one of the most efficient EOL strategies for products. The concept behind reuse is that some components and subassemblies have a design life that exceeds the life of the product itself. In order for reuse to be successfully implemented as an EOL strategy, a designer needs to incorporate into a product a philosophy of Design for Reuse (DfRe) at the early design stage. Reliable methods to assess the remaining life of used components based on a products usage life are also required. Furthermore, current industry practices and literature advocate that there is no methodology to decide which parameters need to be redesigned so as to change the life of a selected component to a desired level. The objective of this research is to develop a methodology to assess the reuse potential of product groups based on component failure mechanisms and their associated critical lifetime prediction design parameters. Utilising these clustered groups mathematical models were then developed to establish the useful life of the components for each clustered group. Finally, a means of equating useful life to design life was established and the relationship between, the failure mechanisms, critical lifetime prediction design parameters and design life were represented in graphical format. In order to achieve the proposed objective, Cluster analysis, in particular Group Technology (GT) and Hierarchical clustering were employed to group components with similar failure mechanisms. Following this, multiple linear regression was used to establish mathematical models based on condition monitoring data for each of the clustered groups and their related critical lifetime prediction design parameters. A sensitivity analysis was conducted using the mathematical models, in order to produce graphical relations between the useful life and design parameters of a product. The validity of the suggested methodology was tested on electric motors and a gearbox as both these components have demonstrated great reuse potential. The results demonstrate that the methodology can assist designers in estimating the design life and associated design parameters with great accuracy, and subsequently aiding in a stratagem for reuse.

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