Incipient motion of boulders in open channel flow

A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering. Johannesburg, 2018The use of boulders to create habitat heterogeneity is important for aquatic diversity, and being able to predict the stability of a boulder that is placed in a river will aid in sizing the boulder. Identifying ways to increase the stability could save costs associated with over design or replacement due to the boulder washing away. Existing research on incipient motion centres on determining threshold conditions for bed material or protruding elements within a bed surface with relation to, among others: shape of particle, size of particle, relative depth of particle to flow depth, and impact of channel slope. The existing research is limited to bed material that is of a similar size and there is no research on the conditions for incipient motion elements that are relatively large compared to the bed material it is resting on. An idealised flume study was performed to identify trends that several factors have on boulder stability, as well as to verify the results obtained from a pivoting analysis model prediction for a spherical boulder. An additional study was performed to obtain drag coefficients that were suitable for use on spherical boulders that were either embedded into the bed material or simply resting on top of the bed material. The results of the drag experiments were varied; only the results for the non-embedded were suitable to integrate into the model predictions while drag coefficients for the embedded boulders need to be taken from previously published results. The results of the flume study provided good confirmation of the model predictions with the average absolute experimental error being 4%. The trends identified in the flume study show that the most effective method in improving a boulder’s stability is to embed it into the bed material with this being more effective than increasing the size of the boulder.MT 201

Paediatric bipolar disorder and the lived experience of parents: a systematic review

Many international studies have been conducted on paediatric bipolar disorder, but few research studies have been conducted on parenting a child diagnosed with bipolar disorder, both on an international and national level. The researcher utilised Bronfenbrenner’s Ecological Systems Theory as the theoretical framework in exploring and describing this research field. The study has been conducted by means of a systematic review and all of the articles included in the review examined some aspect of parenting and paediatric bipolar disorder. The articles were systematically assessed, and six themes emerged which include: paediatric bipolar on the rise; the effects of paediatric bipolar disorder, post-paediatric bipolar disorder; managing paediatric bipolar disorder is a family responsibility; foundations for effective parenting; and supporting parents of a paediatric bipolar patient

Teachers’ beliefs and their intention to use interactive simulations in their classrooms

In this pilot study, we sought to examine the influence of the beliefs of Grade 10 to 12 physical science teachers on their intended and actual usage of interactive simulations (Physics Education Technology, or PhET) in their classrooms. A combination of the Theory of Planned Behaviour, the Technology Acceptance Model and the Innovation Diffusion Theory was used to examine the influence of teachers’ attitudes, subjective norms and perceived behavioural control on their intention to use simulations in their classrooms. Using regression and factor analyses, it was found that beliefs about the perceived usefulness and the pedagogical compatibility of PhET have a significant effect on teachers’ attitude towards the use of the simulations in their classrooms. The expectations of the teachers’ colleagues contribute to the subjective norm of these teachers. The regression and partial correlation result also highlights the importance of teachers’ general technology proficiency. Although we were not able to confirm a direct link between attitudes, subjective norm, perceived behavioural control, and the teachers’ behaviour intention we show the influence of behaviour intention on the actual use of the simulations with an accuracy of 70.83%.Keywords: interactive simulations; PhET project; physics; teacher beliefs;Theory of Planned Behaviou

Monitoring the impact of land reform on quality of life: A South African case study

In 1994, the first democratically elected government of South Africa committed itself to the Reconstruction and Development Programme (RDP), the policy framework through which it was hoped, a broad transformation of South African society could be achieved. The overal

Monitoring the impact of land reform on quality of life : a South African case study.

Accepted for publication by Social Indicators Research 58: 293–312, 2002.This paper outlines the approach that is utilized by the Monitoring and Evaluation directorate of the Department of Land Affairs (DLA) in South Africa in assessing the quality of life for the land Reform beneficiaries. The paper begins with an overview of the three Land Reform programs in South Africa. The paper then moves on to outline the original design for monitoring and evaluating the quality of life for land reform beneficiaries. It then proceeds to detail the current Monitoring and Evaluation design being utilized, highlighting its strengths and weaknesses. The last section discusses some of the findings of the quality of life study undertaken in 1999

Um dos primeiros documentos sobre o Engenho dos Schetz em São Vicente

Contagiado pelo interêsse e pelas esperanças, que entre os historiadores brasileiros levantam o engenho São Jorge dos Erasmos e a documentação da família Schetz, aproveitei uma recente viagem a Bélgica para uma rápida pesquisa nos Archives Généraux du Royau-me em Bruxelas