Digitized by Kansas Correctional Industries

M.Sc., Faculty of Science, University of the Witwatersrand, 2011 / There has been a genuine problem with plastic carrier bags (PCBs) pollution since the 1970’s. A literature review revealed that very few scientific studies have been undertaken globally on PCB. The South African Government promulgated regulations to reduce numbers, encourage reuse and recycling of plastic bags in 2003. The regulations introduced a charge for PCBs. This study looked at the handling and disposal of PCB after 2003 in Gauteng Province, South Africa; and looked at the movement of PCB from major retailers and informal traders to consumers and recycling and recovery. The study excluded the manufacturers and distributors of PCB. It began with the retailers and informal traders being the source of PCB and extended to consumers during their grocery shopping in large retail stores and purchases from informal traders. The study also looked at the individual waste collectors operating in landfill sites, residential and industrial areas to establish the level of recycling of PCB. Buyisa-e-Bag (B-e-B) was at the end of the collection of PCB pathway where it was supposed to provide leadership in the recovery of the bags. Semi-structured interviews were used to collate data on recycling approach with specific focus on PCB and understanding of the legislation. A total of one hundred consumers were interviewed in the shopping malls. Consumers did not know much about the regulations hence they could not explain the reason they have to pay for PCB. Ninety one percent of consumers did not reuse bags for shopping and 68% reused PCB at home to store waste before it is disposed of. Eighty informal traders were interviewed: all indicated that they did not charge for PCB. Forty chain supermarkets managers were interviewed from the shopping centres covered by the study. The retailers were affected by the PCB regulations; they reduced the number of grocery packers and increased security to prevent theft. Nevertheless, they complied with the regulations by selling only the thick bags. Twenty landfill and recycling facilities managers formed part of the study. All landfill managers encouraged general waste recycling to prolong lifespan of the site. Fifty individual recyclers were interviewed in the landfill sites, recycling facilities and on the road side while pushing their trolleys. They found it economically impractical to collect PCBs. Awareness of plastic litter has increased and less is visible though this was not measured. Legal compliance with regulations and specifications needed to be actively driven by all the relevant parties. PCBs are fully recyclable; hence more public awareness is required aimed at preventing the contamination of bags which deters re-claimers from collecting them. B-e-B has not met most of the objectives of their formation and has since been placed under administration by DEAT. Inadequate communication and collective bargaining between the key role parties resulted in the delays in getting the recycling projects off the ground. Major retailers complied with the Government regulations. Informal traders and consumers were generally unaware of regulations and consequences of PCB use. Consumers bought new PCB and in most cases, failed to reuse them for shopping. Recycling of PCBs is not carried out effectively as it is not economically worthwhile. This requires further research to explore the potential uses of PCBs at the end of their lifecycle

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Excessive settlement and foundation instability are some of the main problems commonly encountered in fills and embankment structures built on a soft soil of low bearing capacity.The Expanded Polystyrene(EPS)replacement method, by partially or fully replacing the conventional fill material with extremely lightweight EPS geofoam, may solve these problems. In this thesis, experimental and theoretical work have been carried out to investigate the behaviour of EPS under various loading conditions in geotechnical applications and the effectiveness of EPS replacement technique has been studied using numerical models.Several tests were performed for this study and the results of these tests are given / Doctor of Philosophy (PhD)

This thesis examines contemporary cosmetic surgery within a multidisciplinary feminist framework and is particularly interested in anti-ageing cosmetic surgery. It looks at many discursive and concrete examples of cosmetic surgery and casts a net that is inclusive of a wide variety of voices. These discourses are analysed in relation to the idea of ‘makeover culture’. Makeover culture is shown to be an increasingly important part of everyday life that is not confined to – but is particularly evident within – cosmetic surgery. For my purposes ‘makeover culture’ describes the set of cultural logics – the landscapes – in which cosmetic surgery is embedded. In these environments cosmetic surgery is an important part of a socio-cultural paradigm that values endless remaking, improving, renovating, importing and rejuvenating. The thesis’ theoretical cauldron contains cultural studies, media studies, feminist philosophy, actor-network theory, feminist theories of space, and psychoanalysis. I analyse cosmetic surgery as it appears in many media-scapes. The public narratives of some famous ‘extreme practitioners’ of cosmetic surgery are reviewed, as well as the stories of those celebrities who are secretive about cosmetic surgery and aim for a more ‘natural’ look. Also carefully analysed are the cosmetic surgery experiences told to me by more everyday recipients and doctors in interviews. I aim to develop a feminist understanding of contemporary cosmetic surgery that is beyond ideas of agent and victim, that goes further than the rhetoric of ‘just don’t do it’, that sees more similarities than differences between women who choose cosmetic surgery and women who don’t, and that positions the doctor/patient relationship inside a network of technologies and assemblages that includes many actors. The thesis offers suggestions about how people – especially women – may live critically and constructively with cosmetic surgery in all its contradictory, concrete, discursive, and imaginary forms. It acknowledges that there are complex pleasures and desires associated with cosmetic surgery, intertwined with its offensiveness and terrors. / Doctor of Philosophy (PhD)

Severe plastic deformation (SPD) has been used over the past few decades for producing submicron grain (SMG) structures in range of metals and alloys. Equal channel angular pressing (ECAP) is a useful process for producing these types of structures whereby the material is deformed to very high plastic strains by passing a billet several times through the ECAP die. This process has an added advantage maintaining the initial dimensions of the billet. SMG materials produced by ECAP and related routes are useful as they usually exhibit excellent properties including high strength and hardness, and excellent superplastic formability: these and other properties make SMG materials useful for industrial and aerospace applications. In this thesis, a binary aluminium alloy containing a very low concentration of scandium (0.1 wt. %) Sc alloy was investigated and compared with higher Sc-containing alloys. The material was deformed by ECAP in the solution treated condition to an equivalent von Mises strain of 9.2 then pre-aged at 250 0C to generate a submicron grained material containing a relatively uniform dispersion of nanosized Al3Sc dispersiods. The thermal stability of this pre-aged microstructure was investigated by annealing at temperatures up to 450 0C resulted in continuous grain coarsening by the process of continuous recrystallization whereby the initial microstructure evolves gradually with no marked change in the grain size distribution, texture and grain boundary character. However, extended annealing (> 1h) at 4500 C resulted in discontinuous grain coarsening (often termed recrystallization) whereby a few grains grow rapidly to eventually produce a coarse-grained final microstructure. Throughout annealing, there was a good correlation between the dispersion parameter, (f/d) where f and d is the volume fraction and the mean diameter of Al3Sc particles in the alloy, respectively, and both the mean grain size (D ) and D /D max where max D is the maximum grain diameter observed in the microstructure. The grain structure was found to undergo moderate coarsening at the high f/d-values but converted to a coarsegrained structure for f/d ~<0.5/μm, and this change occurred when the mean grain diameter was ~ 3-4μm. Hence, the critical value of the dispersion parameter for the transition from continuous to discontinuous coarsening falls between the theoretical value for submicron grain size alloys (f/d ~ 1.5/μm) and the value found for conventionally-deformed alloys (f/d ~ 0.1/μm). This behaviour is the result of the alloy no longer being ultra-fine grained at the onset of discontinuous coarsening.

<p>Full thickness wounds, such as deep burns, need restoration of both the dermal and epidermal layers of the skin. In normal wound healing, re-epithelialization occurs by migration and proliferation of keratinocytes from the wound edges and by differentiation of stem cells from remaining hair follicles. Restoration of dermis occurs by influx of growth factors secreted by macrophages, platelets, and fibroblasts; by fibroblast proliferation and subsequent synthesis and remodeling of collagenous dermal matrix. In the case of full-thickness acute burn injuries and chronic wounds (e.g. pressure ulcers, venous ulcers and diabetic foot ulcers), these processes are defective. With the principles of tissue engineering in mind (to correct, improve and maintain tissues and their functions), researchers have developed promising materials and methods to make it possible to restore either the dermal (Integra^® DRT, Alloderm^®) or the epidermal layer (split thickness skin grafts (STSG), cultured epithelial autografts (CEA), autologous keratinocytes in single cell suspension). It is now well established that superior results are obtained if both dermal and epidermal components are combined, for example in a bilayered skin equivalent.<strong> </strong>Apligraf^®is recommended for use on venous ulcers and is the only bilayered living skin equivalent currently approved by the FDA. Studies on different factors affecting the wound healing capacity as well as techniques in use provide valuable information for further development.</p><p>In this licentiate thesis, we evaluated different transplantation techniques for delivering cultured human keratinocytes in single cell suspension, a measure becoming more frequently used in addition to STSG and CEA for restoring the epidermal layer of the skin. We found that the pressure device, commonly used to spray cell suspension onto the wound with pressures as high as 200 kPa, killed around 0% of the cells. In comparison, an ordinary syringe with the attachment of a spray nozzle showed almost 90% viable cells post transplantation and provided an equally good distribution of the cell suspension.</p><p>We also studied different silver containing dressings regarding silver accumulation in human skin. In addition, we graded the re-epithelialization to evaluate whether the dressings caused any delay in the wound healing process. We found that the silver dressings tested, with few exceptions, caused dermal accumulation of silver, primarily aggregated around blood vessels. We could also show that most of the dressings had negative effect on the re-epithelialization.</p><p>For the restoration of the dermal layer of the skin, Integra^® DRT functions as a scaffold for guided tissue regeneration of the dermis. We had the possibility to study a case of necrotizing fasciitis were the treatment consisted of the use of Integra^® DTR together with sub-atmospheric pressure (after initial surgical debridement) and later transplantation of split thickness skin grafts. This measure proved to be safe as well as giving satisfactory pliable and aesthetically acceptable result.</p>

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Thesis (M.S. in materials science and engineering)--Washington State University, May 2007. / Includes bibliographical references.