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Published Article / Rapid and reliable methods for component development and economic manufacturing layout are today crucial factors for the application of press tooling techniques in mass production of automotive industry components. The use of Finite Element Analysis (FEA) based forming simulation can provide a more detailed insight into the real behaviour of a structure. An LS-DYNA finite element model was developed to analyse the material behaviour during the piercing process of a drainage hole for a shock absorber seat. The simulation is intended to simulate tearing that occurs during the manufacturing stage. Once the current punch produces the observed tearing we can modify the punch to eliminate the problem.

Submitted in partial fulfillment of the requirements for the degree of Masters in Technology: Clinical Technology, Durban University of Technology, 2009. / Exercise assessment, counseling and training are not widely offered to patients with chronic kidney disease. Haemodialysis patient’s participation in exercise and an adequate assessment of exercise effects on haemodialysis outcome are needed so that more interventions can be developed to improve the well being of those patients with chronic kidney disease. Exercise is not routinely advocated in patients with end-stage renal disease receiving maintenance haemodialysis. Lack of widespread awareness of exercise in haemodialysis literature may be contributing to these shortcomings in clinical practice. Purpose of the study This study was aimed to establish the effect of exercise during haemodialysis on pedal oedema and solute removal. This is the first time that such a study was undertaken in dialysis units in South Africa. Methodolgy In a quasi-experimental design, thirty-four end-stage renal failure patients on three times weekly haemodialysis program from Bloemfontein and Newcastle MediClinic Renal Units participation in the study. Ethical approval for the study was obtained from Durban University of Technology Ethics Committee. Seventeen patients were in the intervention group (aged between 25 and 60) and seventeen in the control group (aged between 18 and 60). The intervention group did not exercise for the first three months of the study in order to establish a baseline period. Thereafter, exercising took place from the fourth to the ninth month. Patients pedaled on an exercise cushion for fifteen minutes every hour to achieve a total of sixty minutes of exercise over a four-hour dialysis session. Patients in the control group did not pedal on the exercise cushion during the nine-month study period. Pre and post haemodialysis measurements of creatinine, urea and potassium using the Alkaline Picrate, Urease and Ion Selective Electrode methods respectively were done for each patient monthly over the nine month period. Oedema of the lower limb was evaluated by measuring the right and left ankle circumference, in centimeters before and after dialysis. Urea Kt/V was also measured before and after haemodialysis for each patient over the study period. Results Statistical analysis of results showed a significant 30% reduction in urea levels and a 46% reduction in creatinine levels in the intervention group at the end of the nine month period, a 12% reduction in the potassium levels in the intervention group which was 4% more than the control group. The urea Kt/V in the intervention group showed a 9% greater reduction than the control group. There was a significant improvement in oedema of 45% of the right ankle for the first three months of exercise and thereafter there was a an increase in ankle size in the last three months which was a 13% reduction in oedema compared to baseline. There was a significant improvement in oedema of 60% of the left ankle for the first five months of exercise and thereafter there was an increase in ankle size in the last month which showed a 25% reduction compared to baseline. The reason for the increase in ankle size in both ankles in the last three months in inconclusive and future investigation is recommended. Conclusion The results of this study demonstrated benefits of exercise during haemodialysis on solute removal and oedema perhaps due to the acute increases in blood flow and therefore increasing perfusion of skeletal muscles.

Background and aims: Heart failure (HF) is a life threatening condition and optimal handling is necessary to reduce risk of therapy failure. The aims of this thesis were: (Paper I) to examine whether BNP (B-type natriuretic peptide)-guided HF treatment improves morbidity and mortality when compared with HF therapy implemented by a treating physician at sites experienced in managing patients with HF according to guidelines; (Paper II) to investigate how to define a responder regarding optimal cut-off level of BNP to predict death, need for hospitalisation, and worsening HF and to determine the optimal time to apply the chosen cut-off value; (Paper III) to evaluate how Health-Related Quality of Life (HR-QoL) is influenced by natriuretic peptide guiding and to study how HR-QoL is affected in responders compared to non-responders; (Paper IV) to evaluate the impact of patient age on clinical outcomes, and to evaluate the impact of duration of the HF disease on outcomes and the impact of age and HF duration on BNP concentration. Methods: A randomized, parallel group, multi-centre study was undertaken on 279 patients with HF and who had experienced an episode of worsening HF with increased BNP concentration. The control group (n=132) was treated according to HF guidelines and in the BNP-guided group (n=147) the HF treatment algorithm goal was to reduce BNP concentration to < 150 ng/L in patients < 75 years and <300 ng/L in patients > 75 years (Paper I), and to define the optimal percentage decrease in BNP and at what point during the follow-up to apply the definition (Paper II). To compare the BNP-guided group with the conventional HF treated group (Paper I), and responders and non-responders (Paper II) regarding HR-QoL measured with Short Form 36 (SF-36) at study start and at study end (Paper III) and to evaluate if age or HF duration influenced the HF outcomes and the influence of BNP on age and HF duration (Paper IV). Results: The primary outcome (mortality, hospitalisation and worsening HF) was not improved by BNP-guided HF treatment compared to conventional HF treatment or in any of the secondary outcome variables (Paper I). Applying a BNP decrease of at least 40 percent in week 16 (compared to study start) and/or a BNP<300 ng/L demonstrated the best risk reduction for cardiovascular mortality, by 78 percent and 89 percent respectively for HF mortality (Paper II). The HR-QoL improved in four domains in the BNP-guided group and in the control group in six of eight domains; however there were no significant differences between the groups (Paper III). For responders the within group analysis showed improvement in four domains compared to the non-responders that improved in one domain; however there were no significant differences between the two groups. There were improvements in HR-QoL in all four groups (Paper III). Age did not influence outcome but HF duration did. HF duration was divided into three groups: HF duration less than 1 year (group 1), 1-5 years (group 2) and >5 years (group 3). A 1.65-fold increased risk could be demonstrated in those with HF duration of more than five years compared to patients with short HF duration. The BNP concentration was increased with increased age, and there was a better response regarding BNP decrease in NP-guiding in patients with short HF duration, independent of age (Paper IV). Conclusions: There were no significant differences between BNP-guided HF treatment group and the group with conventional HF treatment as regards mortality, hospitalisation or HR-QoL. The responders to HF treatment showed a significantly better outcome in mortality and hospitalisation compared to non-responders but no significant differences in HR-QoL. The duration of HF might be an important factor to consider in HF treatment by BNP-guiding in the future.

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This thesis looks into the examination of polymer composite wreckage from the perspective of the aircraft accident investigator. It develops an understanding of the process of wreckage examination as well as identifying the potential for visual and macroscopic interpretation of polymer composite aircraft wreckage. The in-field examination of aircraft wreckage, and subsequent interpretations of material failures, can be a significant part of an aircraft accident investigation. As the use of composite materials in aircraft construction increases, the understanding of how macroscopic failure characteristics of composite materials may aid the field investigator is becoming of increasing importance. The first phase of this research project was to explore how investigation practitioners conduct wreckage examinations. Four accident investigation case studies were examined. The analysis of the case studies provided a framework of the wreckage examination process. Subsequently, a literature survey was conducted to establish the current level of knowledge on the visual and macroscopic interpretation of polymer composite failures. Relevant literature was identified and a compendium of visual and macroscopic characteristics was created. Two full-scale polymer composite wing structures were loaded statically, in an upward bending direction, until each wing structure fractured and separated. The wing structures were subsequently examined for the existence of failure characteristics. The examination revealed that whilst characteristics were present, the fragmentation of the structure destroyed valuable evidence. A hypothetical accident scenario utilising the fractured wing structures was developed, which UK government accident investigators subsequently investigated. This provided refinement to the investigative framework and suggested further guidance on the interpretation of polymer composite failures by accident investigators.

published_or_final_version / abstract / Statistics / Doctoral / Doctor of Philosophy

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<p>Entrepreneurial failure, in this thesis defined as bankruptcy, is an area within the entrepreneurship research where little or no emphasis has been placed. By combining entrepreneurial failure and learning, it is possible to provide a more balanced view as well as point to the fact that a bankruptcy does not necessarily have to be of negative nature as valuable learning outcomes might be gained. The purpose of this thesis was thus to explore the learning outcomes and its implications from an individual entrepreneur’s failure.</p><p>A qualitative approach, in the form of a case study, was taken. Seven semi-structured face-to-face interviews were performed to gather primary data which was analyzed. Three research questions helped to fulfill the task, by covering the pragmatic and psychosocial responses, the personal and professional learning outcomes and also the ways that these learning outcomes are used and applied.</p><p>The respondents reacted to the bankruptcy by blaming external factors, such as the environment, the strategy/structure or the available resources. Through deeper analysis, we found that the entrepreneurs themselves had a clear impact on the bankruptcy. The fact that most of the entrepreneurs rather blamed factors out of their control, than realizing their own involvement, can constitute a barrier for constructive reflection on the failure, which ultimately forms the basis for learning.</p><p>Most of the learning outcomes, seen from a personal and professional perspective, were classified as corrective. That is; they involved improvement of professional skills and not the personal life. Further, the respondents also showed insight in terms of reforming and intrinsic learning. While the corrective learning outcomes were firm specific, the intrinsic ones were more focused on personal insight. Further, the reforming learning outcomes pointed to issues that had a big impact on both the personal and professional lives of the entrepreneurs. The unproportionally low number of cursory learning outcomes indicate that opportunities of learning from a bankruptcy exist and are large both in terms of personal and professional aspects.</p><p>Lastly, the majority of the entrepreneurs make use of their learning since they have passed the double loop in Argyris and Schön’s (1996) Single and Double loop learning model. This indicates that an entrepreneurial failure is an important experience and the learning out-comes that can be drawn from it is applied in the entrepreneurs’ daily life in the form of new firms and projects, consultancy firms or even in new ways of living. The conclusions drawn in this section point to the importance of realizing that a failure is not always negative. By this, we suggest that through conscious and honest reflection, a failed entrepreneur can gain insights that could not possibly be gained without going trough a setback.</p>