Thesis (M. Tech.) -- Central University of Technology, Free State, 2009 / Contradictory results are reported regarding the value of external representations such as dynamic and static visuals in a learning environment (Lowe 1999; Hanzen, Narayanan & Hegarty 2002; Weiss, Knowlton and Morrison 2002; Bodemar, Ploetzner, Feuerlein & Spada 2004; Bodemar & Ploetzner 2004; Moreno & Valdez 2005; Höffler & Loetner 2007). Some of the recent findings indicate little or no significant differences between static and dynamic visuals. This study looks at studies that used a variety of external representations to facilitate different learning tasks. A ―two journal article‖ format was adopted for Chapter 2 and 3 respectively. The first article, i.e. Chapter 2, is a review of the literature and provides a theoretical background to the research topic. Chapter 2 reviews theories and empirical studies regarding learning with text, dynamic and static visuals, and examines the conditions under which external representations facilitate learning. Subjects‘ prior knowledge, the content of the instructional material and the testing method are but some of the variables that can determine if graphic medium can increase a subject‘s comprehension and if such comprehension can be accurately measured. Chapter 2 also presents a model that suggests how dynamic and static visuals can be used in a learning environment. The second article, i.e. Chapter 3, presents an animation for a specific learning task in order to test the hypothesis that this external representation may improve the comprehension of a linear scientific process. Tertiary students (N = 61) participated in a pre-test and post-test experimental study during which they were exposed to 4 treatment variables: text (T), video and text (VT), illustration and text (IT), and animation and text (AT). It was hypothesised that the group who received the animation and text treatment would comprehend the linear process better than the control group (text only) and the other two groups (text and illustration; text and video). The question that was asked to explore this comparison therefore was: Can animation be used to improve comprehension of instructional text? The results indicate that no significant differences in achievement existed among the treatment groups. The results of the study show that dynamic visuals with text can have essentially the same effect on students' understanding of a particular process as static visual with text. It is further acknowledged that the subjects‘ prior knowledge, the content of the instructional material and the testing method are but some of the variables that can determine if an external representation can increase a subject‘s comprehension and if such comprehension can be accurately measured.

Thesis (D. Tech.) - Central University of Technology, Free State, 2009

Thesis (M. Ed.) - Central University of Technology, Free State, 2007

Thesis (M. Tech.) - Central University of Technology, Free State, 2006 / Women Education managers are still in the minority in primary schools in Bloemfontein, despite the many changes education has undergone in recent years. It is against this background that the researcher found it imperative to investigate the problems women education managers might experience in carrying out their managerial duties and responsibilities. The study further sought to investigate the training needs of women education managers. On the basis of the perceptions held by educators, findings of research studies and the little South African literature that exists, the research questions crystallise as follows: What managerial problems do women education managers experience in carrying out their managerial duties? Do women education managers experience problems other than managerial problems in carrying out their duties? What training do they require? The purpose of this investigation was to gain an insight into the problems women education managers in primary schools in Bloemfontein experience in carrying out their managerial duties. The literature review provided a focus as the framework on which this study is based. In order to collect factual information about the managerial problems women education managers in primary schools in Bloemfontein encounter, questionnaires were distributed amongst the target group. Women education managers experience problems in performing their managerial duties. These problems include delegation, finance management, human resource management, planning, formulation of objectives, policy formulation, decision making, problem solving and allocation of time. There are some factors other than managerial competence and leadership style that have an influence on the way women education managers perform their duties. These factors include workplace discrimination, sexual harassment, negative attitudes towards women, emotional influences, promotion myths, lack of self-confidence, lack of support, role models and positive reinforcement, cultural socialization as well as allocation of duties. Other organisational factors women experience include: difficulty to cope with the demands of the post, too much workload, human relations, division of work in the department and when acting as principal when he/she is absent. Based on the findings of the study, it is imperative that relevant training programmes that would address the particular needs of women education managers in primary schools in Bloemfontein, be developed. These training programmes should address the various areas of management which are problematic to women education managers. As education managers, women should seize every opportunity to leave behind the gender discrimination which is still prevalent in the sphere of education and commit themselves to undergo management training to successfully execute their managerial duties. As education managers, women also need training in various organisational issues in which they experience problems. These problems also have an influence on the way women execute their managerial duties. Recommendations for the study: By providing women education managers with the necessary managerial skills, the different areas of management in which women experience problems can be eradicated. They will have to undergo relevant training. Workshops and in-service training sessions need to be conducted to address the managerial areas in which women education managers experience problems. The findings of this study are not representative of the Free State province and further research needs to be conducted in the entire province or even all over South Africa.

Thesis (D. Tech. (Biomedical Technology)) -- Central University of Technology, Free State, 2015 / This study reviewed national and international literature to develop an audit-feedback instrument (AFI) to monitor adherence of South African oral health care facilities with compliance to infection prevention and control precautions. In a multi-phased literature search, existing infection prevention and control recommendations, guidelines and audit-feedback instruments were reviewed and broadened to include “dental audit tools”, as well as audit tools from other health care disciplines. Audit-feedback instruments were scrutinised for user friendliness, the use of simple language, electronic calculations and feedback possibilities. A new South African AFI was proposed, considering the differences between public and private oral health care facilities and also the diversity of training levels of oral health care personnel employed. Eleven focus areas supporting all aspects of infection prevention and control in oral health care facilities, including administrative controls; personnel protection controls; environmental- and work controls; surface contamination management; equipment maintenance, service or repair; air- and waterline management; personal protective equipment usage; personal and hand hygiene practices; sterilisation practices; safe sharps handling and waste management were included. The AFI was tested in a sample of 50 oral health care facilities. None of the participating facilities demonstrated 100% compliance. Personal- and hand hygiene practices and waste management performed the best, at respectively 75% and 63%, while administrative controls and air- and waterline management scored the lowest mean values; 31% and 36% respectively The general lack of compliance with infection prevention and control precautions in the participating oral health care facilities clearly poses a safety hazard to both patients and oral health care workers. Results indicate that adherence of South African oral health care facilities with compliance to infection prevention and control precautions need to be improved. The AFI should go a long way towards improving safety and the high expectations about providing quality infection prevention and control outcomes in oral health care.

Thesis (M. Tech. (Biomedical Technology)) -- Central University of Technology, 2014 / The rising costs of health care, the outbreak of drug resistant organisms, health depleting lifestyles and the risky side effects of currently used drugs are world-wide problems. This has led to the search for novel drugs and drug leads. Traditional healers and other individuals across the globe possess unlimited knowledge on the healing powers of different plants that has been passed on through generations. This knowledge together with scientific investigations can lead to the eradication of most of the diseases either by treatment or prevention. Aloe ferox Mill. is one of the plants that have gained a lot of interest from the pharmaceutical industry. The plant has over 80 documented medicinal uses. These include treatment of impotence and infertility, sexually transmitted infections, arthritis, hypertension, leukaemia, bacterial and fungal infections. It is also known as a blood purifier, widely used as a laxative and anti- inflammatory agent. More research is required to discover more about A. ferox and its benefits to health as well as to investigate its potential for the development of novel drugs. The current study was focused at investigating the anti- cancer, anti- microbial antidiabetic, cytotoxic activities and phytochemical composition of leaf extracts of A. ferox. Three cancer cell lines namely: breast (MCF7), colon (HCT116) and prostate (PC3) cancer cell lines were used to investigate the anticancer activity of the extracts using the Sulforhodamine B (SRB) method. To determine the anti- diabetic activity of the plant extracts the C2C12 and Chang cell in- vitro models of glucose uptake were used. The micro- dilution technique was IV used to evaluate the antibacterial and antifungal activity of the extract. The safety of these extracts against normal human foetal lung fibroblasts (W138), Chang and C2C12 cells was done by through the SRB and the MTT methods. To determine the phytochemical profile of A. ferox the DPPH radical scavenging and the Folin Ciocalteu methods were used to test the antioxidant activity and the total phenolic content of the different extracts respectively. Different methods were used to determine the presence of phytochemicals such as steroids, saponins, alkaloids, carbohydrates and flavonoids. LCMS was also done to detect the elemental composition of the plant extracts. According to the CSIR criteria A. ferox was inactive against the cancer cell lines used. It however exhibited antioxidant activity even at low concentrations, with an EC50 of 0.865 ± 0.783. The methanol extract showed more phenolic content than the dichloromethane and aqueous extracts at a concentration of 5mg/ml. It is believed that the antioxidant activity correlates with the phenolic content and quality of the phenols present in the plant and more assays have to be done to prove this hypothesis. Other phytochemicals found in the extract included saponins, steroids, alkaloids as well as flavonoids. Both the methanol and aqueous extracts of A. ferox caused a significant increase in glucose uptake by C2C12 cells but caused a slightly decreased uptake by the Chang cells. The plant extracts inhibited the growth of Staphylococcus epidermidis, Streptococcus pneumonia, Escherichia coli and Candida albicans at a concentration of 15mg/ml extract. Candida tropicalis and Escherichia faecalis were resistant to A. ferox extracts. Finally the extracts showed no toxic activity against the normal foetal lung fibroblasts, Chang and C2C12 cells validating the safety of this plant for human use. V The results in conjunction with literature findings show A. ferox to be a promising source of drugs and therapeutic agents. Due to the fact that traditional healers already rely on it as treatment for different ailments, it is important that the safety of the plant for use has been validated though other studies and clinical trial still need to be done to fully confirm this. All the information gathered also showed this plant to be of great benefit against major health problems, responsible for millions of deaths each year such as cancer, cardiovascular and inflammatory diseases, and diabetes. There is however still a great need for more investigation to be done on this plant against a vast majority of organisms and diseases so as to fully benefit from it.

Thesis (M. Tech.) - Central University of Technology, Free State, 2006 / Occupational noise affects industries in many countries around the world, and there is strong evidence from previous research linking it to noise-induced hearing loss (NIHL). More than 30 million workers in the United States of America alone were exposed to hazardous noise at the workplace before 1998. In South Africa, workers are not supposed to be exposed to a noise rating limit at or above 85dB(A). Abattoir employees are subjected to high noise levels when compared to the occupational noise rating limit of 85dB(A). Noise is generated from various mechanised and manual processes and activities in the abattoir during the slaughter of different animal species. Noise sources include conveyers, circular saws, air conditioners and pumps, pneumatic and other mechanical equipment. The aim of this study was to characterise noise exposure in different grades of abattoirs during the slaughter of cattle and sheep. The grading of abattoirs was previously done according to Grade A-E. Grade A-C is now referred to as high throughput abattoirs while Grade D and E are referred to as low throughput abattoirs. Personal and environmental noise exposure levels of workers in Grade A, C and D abattoirs in the Free State were therefore investigated. Noise measurements were done in accordance with the methods stipulated in the South African National Standards (SANS) Code of Practice 10083. Environmental and personal sampling were conducted with a calibrated Type 1 Quest integrated sound level meter (ISLM) and a Quest noise dosimeter respectively. Calibration was checked before and after taking measurements to ensure reliability and validity of results. The average noise exposure level in the high throughput abattoirs was above the recommended standard of 85dB(A). In the low throughput abattoirs the noise exposure levels were below this level. There were no statistically significant differences between the noise exposure levels during the slaughter of different species (P>0.05), or between Grade A and Grade C (P>0.05). There was a statistically significant difference (P<0.05) however between Grade A and Grade D noise exposure levels. The results indicate that workers in Grade A and C abattoirs are exposed to unacceptable noise levels. Further research is recommended to include all categories of abattoirs and to determine the impact of noise exposure on the worker’s hearing in order to develop strategies to protect employees from the effects of excessive exposure to noise.

Thesis (M.Tech.) - Central University of Technology, Free State, 2007 / The latest technological trend worldwide, is automation. Reducing human labour and introducing robots to do the work is a pure business decision. The reason for automating a plant can be some, or all, of the following: Improve productivity Reduce labour and equipment costs Reduce product damage System reliability can be monitored Improves plant safety When the automation process is started, Automatic Guided Vehicles (AGVs) will be one of the first commodities that can be used. The reason for this is that they are so versatile. They can be programmed to follow specific paths when moving material from one point to another and the biggest advantage of all is that they can operate for twenty four hours a day. Automatic Guided Vehicles are developed for many different applications and therefore many different types of AGVs are available. All AGVs are equipped with sensors so that they are able to “see” what is happening around them. Since the AGV must be able to function without any human help or control, it must be able to navigate through the work environment. In this study a remote control car was converted to an AGV and thorough research was done on the different types of sensors that can be used to make the AGV more intelligent when it comes to navigating in an unknown environment.

Thesis (M.Tech.) - Central University of Technology, Free State, 2006 / The ultimate goal regarding this research was to make an intelligent learning machine, thus a new method had to be developed. This was to be made possible by creating a programme that generates another programme. By constantly changing the generated programme to improve itself, the machines are given the ability to adapt to there surroundings and, thus, learn from experience. This generated programme had to perform a specific task. For this experiment the programme was generated for a simulated PIC microcontroller aboard a simulated robot. The goal was to get the robot as close to a specific position inside a simulated maze as possible. The robot therefore had to show the ability to avoid obstacles, although only the distance to the destination was given as an indication of how well the generated programme was performing. The programme performed experiments by randomly changing a number of instructions in the current generated programme. The generated programme was evaluated by simulating the reactions of the robot. If the change to the generated programme resulted in getting the robot closer to the destination, then the changed generated programme was kept for future use. If the change resulted in a less desired reaction, then the newly generated programme was removed and the unchanged programme was kept for future use. This process was repeated for a total of one hundred thousand times before the generated program was considered valid. Because there was a very slim chance that the instruction chosen will be advantageous to the programme, it will take many changes to get the desired instruction and, thus, the desired result. After each change an evaluation was made through simulation. The amount of necessary changes to the programme is greatly reduced by giving seemingly desirable instructions a higher chance of being chosen than the other seemingly unsatisfactory instructions. Due to the extensive use of the random function in this experiment, the results differ from one another. To overcome this barrier, many individual programmes had to be generated by simulating and changing an instruction in the generated programme a hundred thousand times. This method was compared against Genetic Algorithms, which were used to generate a programme for the same simulated robot. The new method made the robot adapt much faster to its surroundings than the Genetic Algorithms. A physical robot, similar to the virtual one, was build to prove that the programmes generated could be used on a physical robot. There were quite a number of differences between the generated programmes and the way in which a human would generally construct the programme. Therefore, this method not only gives programmers a new perspective, but could also possibly do what human programmers have not been able to achieve in the past.

Thesis (M. Tech.) - Central University of Technology, Free State, 2007