FINITE ELEMENT ANALYSIS OF A TI6AL4V (ELI) MEDICAL IMPLANT PRODUCED THROUGH ADDITIVE MANUFACTURING

Published ThesisMedical implants created by Ti6Al4V (ELI) through Additive Manufacturing (AM) processes have a very positive impact on the quality of life of patients who have undergone skeletal reconstructive surgery. The effectiveness of medical implant design for AM processes would be significantly improved if finite element analysis (FEA) could be established as an accepted design tool. This study is aimed at validating FEA as a tool for predicting the strain distribution in a Ti6Al4V (ELI) medical implant produced through a selective laser melting (SLM) process by comparing the FEA results with strain gauge measurements. The approach followed was to demonstrate the correlation between an FEA model and strain gauge measurements performed on a human mandibular implant. For the design of the mandibular implant the geometrical data of an adult human mandible obtained from a computer tomography (CT) scan was transferred to a computer-aided design (CAD) software package. A CAD model based on this data, which was suitable for experimental validation, was used for FEA when subjected to typical static mastication load condition. Through this FEA simulation the distribution of strain in the implant under basic functional condition was determined. Using the same CAD model, an implant was manufactured through SLM and strain gauges were mounted on the implant at locations corresponding to the areas of significant strain as determined on the FEA model. The results obtained from both FEA and strain gauge measurements were compared and a correlation within a deviation of less than 10% for most of the measurements was obtained. Requirements for achieving this level of correlation were determined. It was concluded that FEA is indeed a powerful tool for improving the effectiveness of design for AM of medical implants

Climate Change: Towards Compensating Africa for Economic Growth and Development by Industrialized Countries

On one hand, anthropogenic climate change is real and affecting the world economy in general and Africa in particular. On the other hand, the policy of climate change adaptation as the solution to the problem of climate change is seriously unsuccessful in Africa. Even though climate change is affecting the whole world, Africa is the most vulnerable continent that is economically affected. This is due to a variety of interconnected consequences of climate change such as droughts, floods, desertification, diseases and poor agricultural system including other unknown factors. This article focuses on challenges facing the implementation of climate change adaptation policy in Africa. The implementation of the policy of mitigation of greenhouse gas emissions will not be discussed. The aim of the article is to investigate the underlying implications of climate change adaptation policy that hamper smooth growth and development of the African economy. To achieve this aim, the theoretical research method will be utilized. This article concludes that Africa cannot afford to adapt to climate change because of its extreme poverty and will remain economically poor and suffer the consequences of climate change if industrialized countries are reluctant to compensate it. Therefore, the article argues that industrialized countries have a moral duty to compensate Africa for the harm they have caused through industrialization. The compensation will boost the African economy that is necessary for climate change adaptation.&nbsp

Inflation and economic growth nexus in the Southern African Development Community : a panel data investigation

The aim of the thesis is to examine the relationship between inflation and economic growth using the Southern African Development Community (SADC) as a case study. The motivation emanates not only because of the lack of studies analysing this relationship in the SADC region, but also due to the fact that this relationship may differ from the one that exists in developed countries due to the level of economic development and prudent macroeconomic policies being practised in the latter (Sarel, 1996). The relationship may differ because the vast majority of developed countries have established independent central banks with a clear mandate to keep inflation levels within a specific range (adopted an inflation targeting framework). However, in most developing countries, central banks do not have a clear inflation targeting monetary policy framework, for instance, in the SADC region, only South Africa has adopted an inflation targeting monetary policy framework. High inflation episodes are known to contribute to macroeconomic instability, therefore policy makers find it important to understand the kind of the relationship that exists between inflation and economic growth in order to develop and implement sound macroeconomic policies. Therefore, inflation is viewed to be one of the basic indicators of macroeconomic stability; hence it is an indicator of the ability of the government to manage the economy. High levels of inflation may be indicative of a lack of sound governance by the monetary authority of a country. In addition, it is a sign of government that has lost control of its finances (Fischer,1993). The thesis addresses issues of nonlinearities in the inflation-growth nexus by endogenously estimating the threshold level of inflation below which inflation may have no, or positive, impact on economic growth, or above which inflation may be detrimental to economic growth. It also assesses the effects of a shock to inflation in South Africa, being the largest economy in the region, on inflation and economic growth of the rest of the region. First, different panel data methodologies; Fixed Effects (FE), Difference Generalised Method of Moments (DIF-GMM), System Generalised Method of Moments (SYSGMM), and Seemingly Unrelated Regression (SUR) estimators are used in order to examine the relationship between inflation and economic growth in the region. Second, Panel Smooth Transition Regression (PSTR) methodology is utilised to examine the nonlinearities in the inflation-growth nexus. In particular, the threshold level of inflation is endogenously estimated and the smoothness of the transition from a low to a high inflation regime in the region is also estimated1. Thirdly, the effects of South African inflation on the inflation and economic growth in the rest of the region are assessed using impulse-response functions derived from estimating a Panel Vector Autoregression (PVAR) model. Overall, the study deals with problems which are normally encountered when using cross-country data such as endogeneity, heterogeneity and cross-sectional dependence. The main findings of the study are that inflation and economic growth in the region are negatively related, as is also the case in other regions of the world as depicted by the empirical literature (Fischer, 1993 and De Gregorio, 1993). Therefore, in terms of the inflation-growth link, the SADC region is not different from all the other regions around the globe. Secondly, the threshold level of inflation in the region is estimated at 18.9 per cent, which is in line with the findings of authors like Drukker et al. (2005), Mignon and Villavicencio (2011), and Ibarra and Trupkin (2011), who found a threshold level of 19.2 per cent, 19.6 per cent, and 19.1 per cent for developing countries. However, this threshold level marginally exceeds that of Khan and Senhadji (2001), Schiavo and Vaona (2007), Moshiri and Sepehri (2009) and Espinoza et al. (2010), which studies report threshold values between 10 and 12 per cent for developing countries. The empirical results also reveal that shocks to South African inflation have significant economic impact on inflation, openness, investment and economic growth in the rest of the SADC region. In particular, more interestingly, South African inflation is found to have a negative and statistically significant impact on economic growth in the region for up to about 12 years after the shock, after which, it becomes insignificant. The contribution of the thesis to the literature is that, firstly, this looks into the inflation-growth relationship in the context of Africa, in particular the SADC region; as such an investigation or research has not been conducted before. Secondly, the research takes advantage of panel data methodologies so as to provide more robust estimates and confront the potential bias emanating from problems such as endogeneity, heterogeneity and cross-country dependence that may have affected previous empirical work on inflation-growth nexus. This is believed to provide more informative estimates on the inflation-growth link, and therefore deepens our knowledge of the region.Thesis (PhD)--University of Pretoria, 2012.Economicsunrestricte

Challenging vision in visual arts in the South African sociocultural context

This conceptual article is anchored on critical phenomenology to challenge the monopolisation of visual arts by the sense of vision, thus depriving visually impaired people of aesthetic value beyond ordinary cognitive faculties. In this study, we discuss the forms of painting, drawing and sculpting defined as Visual Arts referring to appreciation only by vision; thus, excluding the visually impaired as unable to appreciate or create by sight. This exclusiveness has dominated and directed art aesthetics and ethics, allowing aesthetic criteria research projects and educational curricula to be established and, conventionally, maintain their static existence unchallenged. Furthermore, vision exclusiveness limits creative thinking and artistic inspiration. This article demonstrates the need and importance of broadening students’ artistic conceptualisation of inclusiveness in Visual Arts by exploring three fields of humanities education, i.e., academic, educational and sociocultural. The article challenges established stereotypes by introducing innovative approaches and opening alternative channels of creative and critical thinking in higher art education. From a sociocultural viewpoint in the South African context, the analysis questions the validity of certain firmly rooted stereotypical concepts about art values and standards by encountering the visually unimpeded and impaired. While the research broadens students’ artistic conceptualisation of inclusiveness in Visual Arts, it simultaneously promotes the concept of hephapreneurship (hepha+preneurship), a neologism inspired by the Greek god, Hephaestus, protector of arts and crafts, himself handicapped. The term does not draw attention to the inabilities of persons with visual impairment, but their creative abilities through encouragement and motivation. By direct and open exposure to the problem, the research promotes the importance of arts education as a challenging platform for interaction between two, by definition, opposed realities

Life orientation teacher training needs in career guidance at rural high schools

The inclusion of career guidance in the life orientation (LO) curriculum has posed a number of challenges for LO teachers in South Africa. LO teachers seem to experience confusion, feelings of incompetence, and insufficient training that points to a need for training and professional development. The purpose of this article is to explore the training needs of LO teachers in teaching career guidance at rural high schools in the Lephalale Municipality of the Waterberg District. A qualitative research approach was followed in this study. This study was a small investigation in which non-probability purposive sampling was used to select 2 secondary schools and 1 LO teacher per selected school. Face-to-face, semi-structured interviews were used to elicit responses from a purposefully selected sample of 2 Further Education and Training (FET) LO teachers at 2 rural high schools in the Lephalale Municipality. FET LO teacher training needs in teaching career guidance emerged as a major theme and is discussed in this article.Keywords: career guidance; FET phase; Life Orientation; life orientation teacher; rural high schools; training need

In-school transition challenges among primary school learners with autism spectrum disorders in South Africa: Parents and teachers' perspectives

Successful school transition is a basis for career development and eventual overall adult educational and socio-economic outcomes. Transitioning through primary school grades is a combination of relative academic and social skills acquired in each grade and forms the basis for subsequent academic and social success at ensuing educational pursuit and adult independent life. Evidence indicates that learners with autism spectrum disorder (ASD) and their families experience limiting challenges in their school transition at different levels. There is a gap in the literature as to the specific factors that constitute school transition difficulties in primary school learners with ASD in the area of study. The purpose of this study was to investigate challenges that learners with ASD face as they transition through school grades. The study adopted a phenomenological design with 12 participants (6 parents and 6 teachers). Two focus group discussions were held to collect data analysed using inductive thematic analysis. The results revealed three main themes, which included poor academic achievement and skills development, social and economic challenges as well as behavioural problems. The findings of the study suggest an increased need for home-school collaboration during the early stages and throughout the school years for the effective transition of learners with ASD. Thus, providing learners with ASD and their families with academic, emotional and behavioural intervention and support can help learners with autism to develop personal resources that will encourage their educational success

Utilising counselling services by law enforcement : an exploratory case study

Abstract: Mounted Police Services (females = 42.5 %; constables = 57.5 %, age range 21 to 50+). The officers completed the Workplace Counselling Service Utilisation survey on their perceptions of the relevance and accessibility of counselling services by their workstation. Descriptive analysis results indicate the officers to perceive the value of workplace counselling for chronic health conditions and general well-being as well as for mental health support. The officers perceived their workplace counselling services inaccessible due to lack of privacy, as well as risks for stigmatisation for languishing health and poorer career prospects. Workplace counselling for law enforcement would be serviceable with infrastructure for privacy and confidentiality

Mainstreaming disability in education beyond 2015

This article presents an exemplary case study of an Independent Business Owner (IBO) from multiple case studies on narratives of differently abled persons. The aim of this article is to illustrate mainstreaming disability through an exemplary case of the IBO. The article is informed by the imperatives of critical theory to understand mainstreaming disability. I examine mainstreaming disability in reference to inclusive education and sustainable development via hephapreneurship (later described in the text). The purposively selected sample of the study was (n=18) participants. The argument forwarded suggests hephapreneurship as one way of mainstreaming disability. Data were collected through interviews, observations and informal conversations. Results indicate the need to unlock entrepreneurial capacities of persons with disabilities such that they may contribute to sustainable development. The study concludes by showing that the participation of independent business owners in sustainable development activities could serve as an anchor for mainstreaming disability beyond 2015.http://www.sajournalofeducation.co.za/hb201

The Paradox of Foreign Aid: Lesotho as a Case Study of the Impact of Foreign Aid on the Growth of Africa

The purpose of the paper is to determine the key institutional factors that could make Foreign Aid more effective on the economic growth of Lesotho