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

Thesis (M. Tech.(Environmental Health)) -- Central University of Technology Free State, 2005 / In developing countries such as South Africa commercial chicken farmers produce the majority of eggs, approximately 5.8kg of eggs per capita per annum. Despite this, many people, especially in rural and marginal-urban areas, still consume eggs produced by backyard systems. Backyard systems are characterised by fragmented and small-scale production units that require minimal management and chickens are often unhoused or poorly housed. In most cases, eggs from backyard systems are laid in nests in poor hygienic condition. Eggs are a cheap, readily available and a good source of animal protein and are consumed by the majority of the people in the community, including the young, the old and people with HIV/AIDS. With little information available regarding the microbiological quality of eggs produced by backyard chickens in Southern Africa, the risks posed by these eggs to consumers are unknown. In this study the microbiological quality of eggs from randomly selected household near Hennenman keeping backyard chickens was determined. The study was done over three seasons which included the cold-dry (May-July), mild-dry (October- February) and the warm-wet (August-September) seasons. The following organisms were isolated: Salmonella spp., Pseudomonas spp., Staphylococcus spp., Escherichia coli and Total Coliforms. Staphylococcus spp. was further characterised to species level. Most of the species were of human origin, with the exception of only two species, S. hyicus and S. lentus, which have previously been associated with chickens. Furthermore, questionnaires were administered to the backyard chicken keepers to assess their knowledge regarding chicken keeping and nest hygiene, the proper method of egg collection and storage, and the preparation of eggs. The decrease of vitamins and Staphylococcus spp. occurring during different preparation methods (scrambling, frying and boiling) was also determined. The results obtained showed that the eggshells were more contaminated than the egg contents. This had been expected as the eggshell is more in contact with the external environment than the egg contents are. Faecal contaminants (Salmonella spp., Escherichia coli and Total Coliforms) were present in both the eggshell and the egg contents during all seasons and this could be attributed to the infrequent cleaning of chicken nests as ascertained from the questionnaires. From the vitamin analysis it was observed that backyard-produced eggs had lower concentrations of vitamins A and E compared to commercially-produced eggs. When determining the best preparation method, causing the most degradation of Staphylococcus spp., while on the other hand preserving vitamins, it was found that scrambling was the best method, followed by the frying and boiling methods respectively.

Thesis (M. Tech.) - Central University of Technology, Free State, 2006 / A multi-threaded, multi-agent image recognition software application called RecMaster has been developed specifically for the purpose of quality control in a production environment. This entails using the system as a monitor to identify invalid objects moving on a conveyor belt and to pass on the relevant information to an attached device, such as a robotic arm, which will remove the invalid object. The main purpose of developing this system was to prove that a desktop computer could run an image recognition system efficiently, without the need for high-end, high-cost, specialised computer hardware. The programme operates by assigning each agent a task in the recognition process and then waiting for resources to become available. Tasks related to edge detection, colour inversion, image binarisation and perimeter determination were assigned to individual agents. Each agent is loaded onto its own processing thread, with some of the agents delegating their subtasks to other processing threads. This enables the application to utilise the available system resources more efficiently. The application is very limited in its scope, as it requires a uniform image background as well as little to no variance in camera zoom levels and object to lens distance. This study focused solely on the development of the application software, and not on the setting up of the actual imaging hardware. The imaging device, on which the system was tested, was a web cam capable of a 640 x 480 resolution. As such, all image capture and processing was done on images with a horizontal resolution of 640 pixels and a vertical resolution of 480 pixels, so as not to distort image quality. The application locates objects on an image feed - which can be in the format of a still image, a video file or a camera feed - and compares these objects to a model of the object that was created previously. The coordinates of the object are calculated and translated into coordinates on the conveyor system. These coordinates are then passed on to an external recipient, such as a robotic arm, via a serial link. The system has been applied to the model of a DVD, and tested against a variety of similar and dissimilar objects to determine its accuracy. The tests were run on both an AMD- and Intel-based desktop computer system, with the results indicating that both systems are capable of efficiently running the application. On average, the AMD-based system tended to be 81% faster at matching objects in still images, and 100% faster at matching objects in moving images. The system made matches within an average time frame of 250 ms, making the process fast enough to be used on an actual conveyor system. On still images, the results showed an 87% success rate for the AMD-based system, and 73% for Intel. For moving images, however, both systems showed a 100% success rate.

Thesis (M. Tech. (Agirculture)) -- Central University of Technology, Free State, 2015

Thesis (M. Tech. (Diagnostic Radiography)) Central University of Technology, Free State, 2014 / Over the past two decades, interventional radiology has been a fast developing field with great advances in technology in the diagnosing and treatment of patients. Interventional radiology procedures are minimally invasive and require little to no hospitalisation time. These procedures are fluoroscopically guided and serial runs are used for documentation, so they have the potential to deliver high doses to patients. Reports about deterministic skin reactions resulting from interventional radiology have become more and more prevalent from the early 1990s. Worldwide concern thus led to legislation for the limitation, justification and optimisation of these doses. Setting of diagnostic reference levels (DRLs) for these procedures is difficult, as they can be complex in nature and are often clinically open-ended. In the case where DRLs were used, they needed to be for a specific locality and had to be refined for the specific circumstances. Patients must be informed of the doses they will be receiving during diagnostic or interventional procedures before consent can be obtained from them. Little information on dose audits was available for South Africa at the time of the study, and it was decided to determine dose ranges at a local level. The research question of this study was: “What radiation doses do patients receive when undergoing vascular, diagnostic and interventional procedures in the interventional suites at a tertiary training hospital in the Free State?” The primary objective was to determine the doses and dose ranges to patients. A secondary objective was to identify specific high dose procedures to individual patients and to the population. A third objective was to investigate the factors influencing these doses. The data of patients who received procedures in two fluoroscopic rooms at the research site were documented over a three-year period. The dose area product (DAP) values were used to calculate skin dose. With the information gathered, dose ranges for frequently performed procedures were determined and specific high dose procedures to individuals and the population identified. Factors influencing the dose were also investigated. This included the relationship of the level of technology, a VI patient’s BMI and practitioners’ level of experience on dose as the research site was a training facility. The results indicated that both diagnostic and interventional procedures have the potential to deliver high doses, as was evident with the isolated occurrences where the response threshold for deterministic effects was exceeded. Most of the locally performed procedures delivered lower or on par radiation dose, compared to values in the literature. Increased BMI values of patients can negatively influence doses received. The level of a practitioner’s experience also plays a vital role in the dose that the patient will receive. Specific recommendations and the implementing of a dose optimisation protocol are proposed to reduce and optimise doses at the research site. This dose optimisation programme will create greater awareness about radiation dose and effects, follow-up procedures and dose reduction methods amongst role-payers. Key words: interventional radiology; limitation, justification and optimisation of radiation dose; deterministic effects; radiation dose awareness

Thesis (M. Tech.) - Central University of Technology, Free State, 2006 / Electron microscopy plays an important role in diagnostic histopathology. When this investigation is anticipated, extra tissue is submitted directly for electron microscopy. However, often it is decided only later in a problematic case to perform this investigation and then the only tissue available is embedded in the routine laboratory’s paraffin block. This tissue has to be retrieved from the wax and this entails using a clearing agent before the rest of the electron microscopy method can be implemented. Traditionally xylene is the agent that is used but has the disadvantage of being extremely toxic. This study compared the morphological effects of a relatively new and non toxic clearing agent, Tissueclear®, with that of xylene. Exposure of tissue to clearing agents for 30 minutes and overnight was performed to assess whether Tissueclear® gave better results in the long term than xylene, in the hope that the laboratory turn around time could be improved and the amount of toxic reagents used in the EM laboratory will be reduced. A second part of the study involved a questionnaire submitted to laboratory staff to assess their knowledge of xylene toxicity. Of the 325 cases submitted for electron microscopy at Universitas Hospital between January 2004 and July 2005, 140 of these had to be retrieved from paraffin wax. Four specimens were prepared from each case. Two were processed in xylene for 30 minutes and overnight and two in Tissueclear® for 30 minutes and overnight. The specimens were evaluated for consistency and resin compaction as well as ultrastructural preservation of the cell membrane, cytoplasmic content and extracellular material. The results showed that Tissueclear® and xylene gave comparable results after 30 minutes and that Tissueclear® was superior after overnight processing. This meant that a specimen submitted for electron microscopy would be processed immediately without waiting for the following morning as was the case with xylene and that the processing time for such a specimen had been shortened from 3 to 2 days. It also meant that the laboratory staff was exposed to one less toxic reagent. The results on the questionnaire showed that there were large areas of ignorance regarding toxicity as well as appropriate safety procedures that need to be followed in the laboratory. It is hoped that this study will improve awareness in this regard and encourage the use of other newer less toxic reagents.

Thesis (M. Tech.) - Central University of Technology, Free State, 2007 / Malaria and the mosquito that induces the disease in humans have hounded the military for decades. Malaria represents one of the most important infectious disease threats to deployed military forces. Malaria in soldiers has a serious economic impact, both in terms of lost productivity and treatment cost for the state. A contingent of South African National Defence Force members has been deployed in Burundi since November 2001, as part of a peacekeeping mission. At the time of the study no information was available regarding the prevalence of malaria among military personnel during deployments in Burundi and East Africa. In Africa, the saying is that malaria is the disease of poverty and a cause of poverty. To combat malaria, it is of vital importance that the recommended medication be taken exactly as prescribed and that the course is completed. However, one of the greatest challenges facing the African continent in the present fight against malaria is drug resistance. The discovery of Mefloquine and the subsequent development of suitable drugs, have been intimately associated with military imperatives, contingencies and requirements. Since World War II, the development of Chloroquine-resistant falciparum malaria has driven the search for new drugs. Mefloquine, developed by the Walter Reed Army Institute of Research in the United States, was first shown effective as a prophylaxis and treatment of resistant falciparum malaria in the 1970’s. To obtain data, questionnaires were administered to SANDF soldiers deployed in Burundi, East Africa. The total size of the population under investigation was 336 with a final sample size of 111 respondents. The sample was selected by using simple random sampling. The questionnaire aimed to determine the perception of respondents regarding the malaria threat, their compliance with taking the medication, and their experiencing of possible side-effects which might occur due to the chemoprophylaxis and the prophylactic efficacy of Mefliam®. The fact that, of the 111 people who used Mefliam®, only four presented with any malaria symptoms, is an indicator that Mefliam® is an effective option as an antimalarial drug to be used in East Africa and Burundi. The results of this study will be used by the personnel of the South African National Defence Force (SANDF) and other military forces deployed in East Africa. It is envisaged that the results will be used by military policy- and decision-makers as a control programme and by others involved in the control of malaria. The findings and recommendations should also be of interest to anyone visiting the area.

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

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Political Science, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND DEWEY. / Vita. / Bibliography: leaves 398-409. / by James Allen Cooney. / Ph.D.

This study was designed to examine the relationships between the doctrines of Soviet air power and the changes in aviation capability affected through technological advancement. The Study was limited in scope to those changes in aviation technology which have had large scale application, and were examined from a historical perspective.The study was accomplished by dividing Soviet air power into five distinct segments based on existing Soviet administrative divisions. The divisions are as follows: Frontal Aviation, Strategic Aviation, Military Transport/Commercial Aviation, Air Defense Aviation and Naval Aviation. The growth of each segment and the development of its unique role within the structure of Soviet air power, from its earliest beginnings, was examined historically and analyzed for technologically induced change. When the effects of technological change extended across two or more segments of Soviet air power, each segment was analyzed on an individual basis. While the examination of the question failed to yield a clearly definable direct link between the advancements of Soviet aviation technology and the development of the doctrines of Soviet air power, it did reveal a positive correlation between the expansion of the role of Soviet air power and the advances made in aviation technology. Clearly the ability of the Soviet aviation industry to produce ever more capable aircraft has allowed the various segments of Soviet air power to develop ever more challenging doctrines.