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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

An investigation of the phytochemistry and biological activity of Asparagus laricinus

Fuku, Sandile. Lawrence. January 2014 (has links)
Thesis (D. Tech. (Biomedical Technology)) -- Central University of Technology, Free State, 2014 / Medicinal plants are part of indigenous people‟s cultural heritage, thus since ancient times treatment of various diseases using medicinal plants has been part of human culture. The value of medicinal plants to mankind has been very well proven. It is estimated that 70% to 80% of people worldwide rely mainly on traditional health care systems, especially on herbal medicines (Stanley and Luz, 2003). In many societies the medicinal properties of plants were discovered mostly through trial and error, but use was also influenced by the belief systems of the people involved and often became entangled with religious and mythical practices (Mathias et al., 1996). Besides that, medicinal plants are proving to be rich resources of constituents that can be used in drug development and synthesis. Medicinal plants have been a source of a wide variety of biologically active compounds for many centuries and have been used extensively as crude material or as pure compounds for treating various disease conditions. Between 1% and 10% of plants out of an estimated 250 000 to 500 000 species of plants on earth are used by humans (Boris, 1996). 2 Plants used for medicinal purposes contribute significantly to the development of major medical drugs that are used today. Most common medicines have compounds extracted from plants as their primary active ingredients and many have provided blueprints for synthetic or partially synthesized drugs (Simpson and Ogorzaly, 2001). There has been a major resurgence of interest in traditionally used medicinal plants, with a number of international and local initiatives actively exploring the botanical resources of southern Africa with the intention to screen indigenous plants for pharmacologically active compounds (Gurib-Fakim et al., 2010; Rybicki et al., 2012). South Africa is considered a “hot spot” for biodiversity and more than 22 000 plant species occur within its boundaries. This represents 10% of the world‟s species, although the land surface of South Africa is less than 1% of the earth‟s surface (Coetzee et al., 1999). Plants have also been used by man for various purposes, among others as arrow and dart poisons for hunting, poisons for murder, hallucinogens used for ritualistic purposes, stimulants for endurance and hunger suppression, as well as medicine (Duke et al., 2008; Cragg and Newman, 2005). A derivative of the polyhydroxy diterpenoid ingenol isolated from the sap of Euphorbia peplus (known as “petty spurge” in England or “radium weed” in Australia), which is a potential chemotherapeutic agent for skin cancer, is currently under clinical development by Peplin Biotech for the topical treatment of certain skin cancers (Kedei et al., 2004; Ogbourne et al., 2004). Combretastatin A-4 phosphate, 3 a stilbene derivative from the South African bush willow, Combretum caffrum, acts as an anti-angiogenic agent causing vascular shutdowns in tumors (Newman et al., 2005; Holwell et al., 2002). Further reliance on plants for drug development is demonstrated by the use of galantamine hydrobromide, an alkaloid obtained from the plant Galanthus nivalis used traditionally in Turkey and Bulgaria for the treatment of Alzheimer‟s disease (Howes et al., 2003; Heinrich and Teoh, 2004). The plant chemicals used for the above-mentioned purposes are secondary metabolites, which are derived biosynthetically from plant primary metabolites (e.g. carbohydrates, amino acids and lipids). Secondary metabolites are organic compounds that are exclusively produced by plants and that are not directly involved in the normal growth, development and reproduction of a plant (Firn and Jones, 2003). Yet, they have many functions that are important for the plant‟s long-term health and appearance. Plants, being stationary, have to cope with a number of challenges, including engineering their own pollination and seed dispersal, local variation in the supply of the simple nutrients that they require to synthesize their food and the coexistence of herbivores and pathogens in their immediate environment. Plants have therefore evolved secondary biochemical pathways that allow them to synthesize a spectrum of organic molecules, often in response to specific environmental stimuli, such as herbivore-induced damage, pathogen attacks, or nutrient deprivation (Reymond et al., 2000; Hermsmeier et al., 2001). 4 The biosynthesis of secondary metabolites is derived from the fundamental processes of photosynthesis, glycolysis and the Krebs cycle to afford biosynthetic intermediates which, ultimately, result in the formation of secondary metabolites also known as natural products (Dewick, 2002). It is hypothesized that secondary metabolism utilizes amino acids and the acetate and shikimate pathways to produce “shunt metabolites” (intermediates) that have adopted an alternate biosynthetic route, leading to the biosynthesis of secondary metabolites (Sarker et al., 2006). Modifications in the biosynthetic pathways that produce secondary metabolites are probably due to natural causes (e.g. viruses or environmental changes) or unnatural causes (e.g. chemical or radiation processes) in an effort to adapt or provide longevity for the plant (Sarker et al., 2006). Plants‟ secondary metabolites can be classified into several groups according to their chemical classes, such alkaloids, terpenoids and phenolics (Harbone, 1984; Wink, 2003).
192

Detecting Internet visual plagiarism in higher education photography with Google™ Search by Image : proposed upload methods and system evaluation

Van Heerden, Leanri. January 2014 (has links)
Thesis (M. Tech. (Design and Studio Art)) - Central University of Technology, Free State, 2014 / The Information Age has presented those in the discipline of photography with very many advantages. Digital photographers enjoy all the perquisites of convenience while still producing high-quality images. Lecturers find themselves the authorities of increasingly archaic knowledge in a perpetual race to keep up with technology. When inspiration becomes imitation and visual plagiarism occurs, lecturers may find themselves at a loss for taking action as content-based image retrieval systems, like Google™ Search by Image (SBI), have not yet been systematically tested for the detection of visual plagiarism. Currently there exists no efficacious method available to photography lecturers in higher education for detecting visual plagiarism. As such, the aim of this study is to ascertain the most effective uploading methods and precision of the Google™ SBI system which lecturers can use to establish a systematic workflow that will combat visual plagiarism in photography programmes. Images were selected from the Google™ Images database by means of random sampling and uploaded to Google™ SBI to determine if the system can match the images to their Internet source. Each of the images received a black and white conversion, a contrast adjustment and a hue shift to ascertain whether the system can also match altered images. Composite images were compiled to establish whether the system can detect images from the salient feature. Results were recorded and the precision values calculated to determine the system’s success rate and accuracy. The results were favourable and 93.25% of the adjusted images retrieved results with a precision value of 0.96. The composite images had a success rate of 80% when uploaded intact with no dissections and a perfect precision value of 1.00. Google™ SBI can successfully be used by the photography lecturer as a functional visual plagiarism detection system to match images unethically appropriated by students from the Internet.
193

DEVELOPING AN INTEGRATED HUMAN RESOURCE DEVELOPMENT PLAN FOR OFFICE-BASED EDUCATORS IN THE FREE STATE PROVICE

Kgati, Edward. Mokoakoa. January 2013 (has links)
Thesis (PhD. (Education )) - Central University of Technology, Free State, 2013 / Human Resource Development is receiving increased attention as organizations seek performance gains from their workforces during challenging economic times, as well as a measure of compliance with the Skills Development Levies Acts (1998 & 1999) and the subsequent National Skills Development Strategy (NSDS). Organisations are facing increasing pressure to demonstrate how well they perform and to provide plans for their future improvement. The Free State Department of Basic Education (FSDoBE) is one public sector organisation which has embarked on aligning its human resource development strategies with the current developments as they present themselves in the labour market and as per NSDS requirements. In this research study, the construct of an integrated human resource development plan is challenged mainly along two lines: how office-based educators’ training needs assist to determine the model of an integrated HRD plan; and how the impact of the developed integrated HRD plan will assist with the heightened job performance of office-based educators. The effectiveness of job performance by office-based educators will consequently serve as a route to improved learner results in schools. The delivery of quality education and training is one of the most important endeavours for the restoration of the culture of teaching and learning. The human resource development of office-based educators is therefore seen as an essential part for promoting the delivery of education and improving learners’ performance in schools. An essential part of developing an integrated HRD plan for office-based educators is typically with performance management process, which is the tool the FSDoBE has to use to meet its overall goals, and is directly dependent upon the ability of office-based educators to perform effectively in the management and delivery of services to schools. In order to successfully develop an integrated HRD plan, the literature overview on human resource development and performance management was presented. xvii Human resource development plans have been studied and implemented in various organizations, but not adequately explored in the FSDoBE to surface possible specific performance challenges. This study addresses this performance gaps by introducing an integrated HRD plan from the perspectives of various job ranks of office-based educators. It identifies gaps in the perceptions of office-based educators concerning performance management as conducted through the appraisal tool for office-based educators, the Performance Management and Development system (PMDS), and identifies steps in the development of an integrated HRD plan, concluding with lessons for practice. The data gathered through the literature study, questionnaires and interviews assisted the researcher to analyse and interpret the data and come up with the findings and conclude on the model of an integrated HRD plan for office-based educators. The questionnaires were administered to 60 office-based educators across their ranks (SESs, DCESs and CESs) and all 60 questionnaires were returned. The questionnaires and interviews were administered in the three education districts. The interviews were conducted to supplement the questionnaire data in order to gather rich responses from the participants. The data from corresponding questionnaire questions and interview questions was grouped together to correspond with the key research questions so as to provide the rich data as required by the research study. The key findings were that office-based educators have the desire to play a significant role in their job performance and that they need empowerment, resources and leadership to guide them in their daily duties. The analysis and interpretation of the data gathered further assisted the researcher to develop an integrated HRD plan as presented in Table 7.1 and as stated by the title of this research. The evidence of the narrative incidents with office-based educators suggest that the development of an integrated HRD plan will provide a useful research tool for those wishing to study the design and use of HRD plans in the future, as it gives a xviii holistic overview to be taken in the process and makes the development of an integrated plan a feasible task for the researcher. According to the model of the proposed integrated HRD plan, it requires a new way of thinking and interacting amongst district sections, and it should be regarded as a step forward to improved office-based educators’ development and subsequent influence on school-based educators’ knowledge and skills, and for improved learner performance in the schools.
194

The development of sensory products to stimulate children with learning problems (LP)

Burger, Yolandi 11 1900 (has links)
Thesis (M. Tech.) - Central University of Technology, Free State, 2009 / Children with Learning Problems (LP) are mostly identified in the primary grades. Early intervention is desirable to remediate LP. One strategy is to use visual aids as a cue during an intervention strategy. A visual aid can be tactile and can appeal to the child’s senses, such as hearing and touch. Three main cornerstones which influence Sensory Product Development (SPD) were identified. These are design factors such as illustrations, colour, and book themes, the senses of the children and supporting factors which include therapeutic practices and cultural sensitivity. It is envisaged that if these three cornerstones are integrated into a sensory product such as a book, that it will be able to stimulate a child with LP through play, touch and sound. The aim of the study is the development of a qualitative tool that can be used to asses sensory products and the development of a sensory product that are tested for the specific target group. The sensory product was designed according to the guidelines that were identified in a literature review. This qualitative tool includes the various cornerstones and serves as a checklist that teachers and therapists can use to evaluate a sensory product to establish its suitability for a child with LP. The second article in this study recorded the responses from children with LP towards the sensory product and recommendations for the improvement of the sensory product.
195

A framework to position the somatology profession in South Africa

Vosloo, Marlé. January 1900 (has links)
Thesis (M. Tech.) -- Central University of Technology, Free State, [2009] / Somatologists in South Africa no longer only practice beauty technology. They receive highly skilled training in the well being of the whole body, thus a more holistic approach is emphasized. Currently, stakeholders in the field of somatology are facing a number of challenges, which could impact greatly on the profession. The question of recurriculation, in order to align the training provided for somatologists with the new Higher Education Qualification Framework (HEQF) and the possible registration of the profession with a statutory body, are some of the challenges posed to the profession. In order to position the somatology profession favourably in South Africa, it was thus necessary to explore the current status of the profession through input from all stakeholders in the industry and to develop a possible framework. The objective of the study was firstly to obtain quantitative information from stakeholders in the field of somatology on matters related to their professional training, employment, recurriculation, referral trends to and from medical professionals and registration of the profession. Secondly, to obtain quantitative information from other medical professionals regarding referrals to somatologists and thirdly, to develop a possible framework that could facilitate the positioning of somatology more favourably as a profession in South Africa. Data were collected by means of two separate questionnaires, one sent to stakeholders in the somatology field and the other to medical professionals specializing in the fields of dermatology, plastic surgery and oncology. The results indicated that the stakeholders in the somatology field were satisfied with the current training provided by registered IX private providers and Universities of Technology. Job satisfaction was experienced by most, however, the hours and days worked could be improved. The need for short courses, as a means of staying in touch with the latest developments in the somatology industry, was identified. Currently, there exists a referral trend between somatologists and medical professionals, however, the frequency of referrals could be improved. The need for the somatology profession to register with a statutory body was identified by both somatologists and medical professionals. Two possible frameworks, with regards to the training provided for somatologists and the registration of the profession, were compiled based on the feedback obtained in the study, in order to position the profession somatology more favourably in South Africa.
196

Waste handling practices in the South African high-throughput poultry abattoirs

Molapo, Ntahli Ashley January 2009 (has links)
Thesis (M. Tech.) - Central University of Technology, Free State, 2009 / The production of poultry meat at abattoirs implies a tremendous amount of organic matter that requires environmentally and biologically safe disposal or utilisation. As a result, waste management is a concern in poultry abattoirs worldwide. Problems with proper storage, handling, management and utilisation of by-products have come to the forefront in planning, establishing and operating of poultry abattoirs. The rationale for this study centres on the need for the review of poultry abattoir waste management practices, by-product production and environmental implication at South African high-throughput abattoirs. The need for this review stems from the rapid growth of the poultry industry over the past ten years. The industry has responded to this growing demand with larger and faster processing lines and more employees. This has led to the generation of high loads of waste material associated with negative environmental impacts. Poultry waste is of great concern as it plays a major role in environmental affairs over and above the present crisis with waste in South Africa, especially in rural and peri-urban areas. The primary objectives of the study were to identify the existing waste management practices in relation to the sources, type of waste material generated, and the methods of handling (collection, storage and disposal) as well as to ascertain whether there is any in-house treatment methods practised. In addition, to identify any environmental impacts resulting from waste management practices. To obtain data, site visits were conducted countrywide and abattoir personnel were interviewed through a questionnaire, in detail about the operation and waste management practices of their respective abattoirs. Their experiences in the industry regarding waste management were determined as well. From a total of thirty-four registered and operating high-throughput poultry abattoirs, twenty-six (76.4%) were visited. Huge amounts of wastes are generated at South Africa high-throughput poultry abattoirs, and these amongst others includes blood, feathers, feet, intestines, trimmed meat off-cuts, faecal matter, condemned chickens and waste-water. Waste handling practices varies according to abattoir preferences. Different collection facilities are used for different types of waste, 50 - 750_ containers and blood troughs are used for blood (table 4.5), crates, wheelie bins, conveyors, black rubbish bags for feathers (table 4.6). Waste is either stored at the dirty area of the abattoir or in an open space next to the abattoir under strict supervision prior to disposal or by-product processing. Since not all abattoirs dispose off generated waste, some abattoirs have by-products processing facilities either on site or outside abattoir premises. Examples of by-products produced (table 4.3) include poultry (carcass) meal, feather meal, poultry oil and blood meal. Disposal methods used differs from burial, rendering, land application, municipal landfill, collection by farmers (animal feeding), burning, composting depending on waste type. It should however be noted that some of disposal method used are not legally approved in South Africa although legally permitted in other international countries as per literature review. Three environmental implications were identified by the respondents included in the study (table 4.14) and these included air pollution, water pollution and land/soil pollution. Recommendations are made to encourage the safe disposal of abattoir waste, minimisation of environmental implications and to limit the methods of disposal to those that are internationally permitted and suggested.
197

A study of the effects of warm ischaemic times on harvested homografts

Bester, Dreyer 03 1900 (has links)
Thesis (M. Tech.) -- Central University of Technology, Free State, 2009
198

The influence of nest keeping and preparation methods on the microbiota associated with backyard chicken eggs

Moalusi, Boitumelo M. January 2005 (has links)
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.
199

A feasibility study on the use of agent-based image recognition on a desktop computer for the purpose of quality control in a production environment

Haskins, Bertram Peter January 2006 (has links)
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.
200

Protein accretion and its effects on growth rate and testicular traits of Kolbroek boars

Netshirovha, Thivhilaheli Richard January 2015 (has links)
Thesis (M. Tech. (Agirculture)) -- Central University of Technology, Free State, 2015

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