A study on certain factors that may affect the economic viability of backgrounding beef weaner calves on pastures in the Southern Cape area of South Africa
- Authors: Terblanche, Ian
- Date: 2020
- Subjects: Calves -- Weaning -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/47623 , vital:40259
- Description: The backgrounding of beef weaner calves from pastures has the potential to be developed as an intensive beef enterprise that can increase the income of smaller farms, given that these farms have the ability to produce good quality pastures. This study was conducted to verify the inputs that impact on the viability of pasture backgrounding systems in an attempt to provide beef producers with better information for decision making. The scientific research was conducted with the registered Kromme Rhee Bonsmara herd at the Kromme Rhee research farm of the Western Cape Department of Agriculture. The farm is situated at 18º50’E and 33º51’S in the Stellenbosch area and has an altitude of 177 m above sea level. The area is situated in the winter rainfall region of the Western Cape with an annual rainfall of 670 mm. The average summer temperature ranges between 15-35 ºC and winter temperature between 10-17 ºC. The aim of this study was to develop growth curves representing the growth of Bonsmara animals for use by beef producers in predicting future live weight of animals in a pasture backgrounding system. Dry matter (DM) intake was measured at various live weight stages in order to determine whether a prediction model could be established to represent the DM intake of growing Bonsmara cattle on pastures. Results were used as inputs to determine whether backgrounding on pastures was economically viable. Animals were weighed at monthly intervals. Weighings commenced from birth and continued for a period of 797 days, repeated with two production year groups. One group consisted of 18 heifers and 12 bulls that were weighed from birth till an average age of 759 days. The other group consisted of four heifers and seven bulls and was weighed from birth untill an average age of 892 days. Roughage supplementation was done with lucerne hay in periods of pasture shortfalls, while a protein and energy lick were supplied continuously. A feeding trial with 10 weaned heifers and 10 bull calves of the same year group was conducted to determine the average feed intake per individual animal over a thirteen-month period that commenced after weaning. Two groups of five Bonsmara bull calves and two groups of five Bonsmara heifers were grouped according to age and gender. The feed intake of the growing calves was recorded for different live weight categories. The animals received lucerne (Medicago sativa) hay on an ad lib basis, while a concentrate supplement was supplied at 2 kg per animal per day up until live weights of 350 kg for heifers and 380 kg for bulls was achieved. The lucerne based diet was formulated to simulate a diet for growing animals on pasture with additional supplementation. Group feed intake values of the four groups of animals were measured at about 20-day intervals over the trial period of 369 days. The feed waste was dried and weighed back to calculate a waste percentage to be used as a correction factor. The Gompertz growth function was used to develop growth curves for male and female Bonsmara animals. Results indicated a significant difference between the mature weight of males and females (P <0.05). In both year groups the nonlinear Gompertz growth model predicted heavier mature weight for males compared to females. Mature weights of bulls were respectively 44.4% and 68.5% higher than that of heifers over the two year period. Days at maximum growth occurred later for males than for females (P <0.05) and the maturing rate of males and females did not differ significantly. Individual average feed intakes were calculated from the group fed animals over the duration of the rearing period. The data revealed that feed intake for bulls can be predicted by the linear model, DMI= 0.16531 + 0.0235306 x live weight (P ≤0.001; R 2 = 78.25). The feed intake of heifers can be predicted by the linear model, DMI= -1.41991 + 0.0283891 x live weight (P ≤0.001; R 2= 76.25). Analysis of variance detected no difference between the percentage feed intake of heifers (2.46%) and bulls (2.40%), over the experimental period. Prices of different live weight groupings were analysed over seven years to establish whether cyclical price trends can be observed across years and seasonal price trends within years. Within years prices were found to differ between months. For all calf weight groups, the lowest prices occurred in the months of March, April, May, June and July which showed price indices significantly different (P <0.05) from indices of the months of October, November and December when highest prices occurred, confirming seasonality in weaner calf prices. Price indices were developed for use as an input in the economic viability assessment. A brief literature review on the production and quality of four common pastures in the Southern Cape was done to gather information for compiling pasture budgets for use in determining the economic viability of pasture backgrounding. The economic viability of backgrounding on pastures was evaluated on a gross margin level and illustrated for three pasture systems namely irrigated oats as a winter pasture, irrigated lucerne as a spring pasture and dryland P. clandestinum /E. plana /mixed grass also as a low-cost spring pasture. All three pasture systems showed a positive economic viability for the decision parameters used in the illustration. The gross margin of backgrounding on the oats pasture system was more sensitive to a small decrease in the predicted price or the predicted live weight and therefore a riskier option than backgrounding on the other two systems. Outputs from the gross margin analyses were used in partial budgeting to illustrate a robust decision support framework that beef farmers can use for making decisions whether to sell weaners straight after weaning as opposed to selling after a period of backgrounding on pastures. Overall results indicate that backgrounding of calves on pastures has the potential to be a viable beef enterprise on smaller farms in the region. Keywords: beef production; Gompertz growth curves, feed intake; pasture backgrounding; gross margin; partial budgets.
- Full Text:
- Date Issued: 2020
- Authors: Terblanche, Ian
- Date: 2020
- Subjects: Calves -- Weaning -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/47623 , vital:40259
- Description: The backgrounding of beef weaner calves from pastures has the potential to be developed as an intensive beef enterprise that can increase the income of smaller farms, given that these farms have the ability to produce good quality pastures. This study was conducted to verify the inputs that impact on the viability of pasture backgrounding systems in an attempt to provide beef producers with better information for decision making. The scientific research was conducted with the registered Kromme Rhee Bonsmara herd at the Kromme Rhee research farm of the Western Cape Department of Agriculture. The farm is situated at 18º50’E and 33º51’S in the Stellenbosch area and has an altitude of 177 m above sea level. The area is situated in the winter rainfall region of the Western Cape with an annual rainfall of 670 mm. The average summer temperature ranges between 15-35 ºC and winter temperature between 10-17 ºC. The aim of this study was to develop growth curves representing the growth of Bonsmara animals for use by beef producers in predicting future live weight of animals in a pasture backgrounding system. Dry matter (DM) intake was measured at various live weight stages in order to determine whether a prediction model could be established to represent the DM intake of growing Bonsmara cattle on pastures. Results were used as inputs to determine whether backgrounding on pastures was economically viable. Animals were weighed at monthly intervals. Weighings commenced from birth and continued for a period of 797 days, repeated with two production year groups. One group consisted of 18 heifers and 12 bulls that were weighed from birth till an average age of 759 days. The other group consisted of four heifers and seven bulls and was weighed from birth untill an average age of 892 days. Roughage supplementation was done with lucerne hay in periods of pasture shortfalls, while a protein and energy lick were supplied continuously. A feeding trial with 10 weaned heifers and 10 bull calves of the same year group was conducted to determine the average feed intake per individual animal over a thirteen-month period that commenced after weaning. Two groups of five Bonsmara bull calves and two groups of five Bonsmara heifers were grouped according to age and gender. The feed intake of the growing calves was recorded for different live weight categories. The animals received lucerne (Medicago sativa) hay on an ad lib basis, while a concentrate supplement was supplied at 2 kg per animal per day up until live weights of 350 kg for heifers and 380 kg for bulls was achieved. The lucerne based diet was formulated to simulate a diet for growing animals on pasture with additional supplementation. Group feed intake values of the four groups of animals were measured at about 20-day intervals over the trial period of 369 days. The feed waste was dried and weighed back to calculate a waste percentage to be used as a correction factor. The Gompertz growth function was used to develop growth curves for male and female Bonsmara animals. Results indicated a significant difference between the mature weight of males and females (P <0.05). In both year groups the nonlinear Gompertz growth model predicted heavier mature weight for males compared to females. Mature weights of bulls were respectively 44.4% and 68.5% higher than that of heifers over the two year period. Days at maximum growth occurred later for males than for females (P <0.05) and the maturing rate of males and females did not differ significantly. Individual average feed intakes were calculated from the group fed animals over the duration of the rearing period. The data revealed that feed intake for bulls can be predicted by the linear model, DMI= 0.16531 + 0.0235306 x live weight (P ≤0.001; R 2 = 78.25). The feed intake of heifers can be predicted by the linear model, DMI= -1.41991 + 0.0283891 x live weight (P ≤0.001; R 2= 76.25). Analysis of variance detected no difference between the percentage feed intake of heifers (2.46%) and bulls (2.40%), over the experimental period. Prices of different live weight groupings were analysed over seven years to establish whether cyclical price trends can be observed across years and seasonal price trends within years. Within years prices were found to differ between months. For all calf weight groups, the lowest prices occurred in the months of March, April, May, June and July which showed price indices significantly different (P <0.05) from indices of the months of October, November and December when highest prices occurred, confirming seasonality in weaner calf prices. Price indices were developed for use as an input in the economic viability assessment. A brief literature review on the production and quality of four common pastures in the Southern Cape was done to gather information for compiling pasture budgets for use in determining the economic viability of pasture backgrounding. The economic viability of backgrounding on pastures was evaluated on a gross margin level and illustrated for three pasture systems namely irrigated oats as a winter pasture, irrigated lucerne as a spring pasture and dryland P. clandestinum /E. plana /mixed grass also as a low-cost spring pasture. All three pasture systems showed a positive economic viability for the decision parameters used in the illustration. The gross margin of backgrounding on the oats pasture system was more sensitive to a small decrease in the predicted price or the predicted live weight and therefore a riskier option than backgrounding on the other two systems. Outputs from the gross margin analyses were used in partial budgeting to illustrate a robust decision support framework that beef farmers can use for making decisions whether to sell weaners straight after weaning as opposed to selling after a period of backgrounding on pastures. Overall results indicate that backgrounding of calves on pastures has the potential to be a viable beef enterprise on smaller farms in the region. Keywords: beef production; Gompertz growth curves, feed intake; pasture backgrounding; gross margin; partial budgets.
- Full Text:
- Date Issued: 2020
Investigation of the interaction between truck tyre waste rubber particulate and penetration grade and polymer modified bituminous binders
- Authors: Mgangato, Siseko
- Date: 2020
- Subjects: Truck equipment industry
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/48500 , vital:40882
- Description: Recent studies have investigated the waste tyre crumb rubber (TCR)-bitumen interaction by observing the swelling of waste TCR at elevated temperatures. It was found that the waste TCR-bitumen interaction alters the rigidity and shape of TCR, which causes the failure of asphalt mixtures. Consequently, the problem occurs when the waste TCR swells during waste TCR-bitumen interaction from mixing and transportation of the asphalt mixture. Extensive laboratory studies have shown that the rate of absorption of bitumen is correlated with the TCR rubber composition and particle size. However, it is possible that swelling of waste TCR can be prevented or reduced before waste TCR-bitumen interaction by means of pre-treating the rubber crumb as to prevent the alteration of bitumen properties. Therefore, this study seeks to investigate the interaction of truck tyre wastes rubber particulates (WRP)-bitumen with the pretreatment of truck tyre WRP with H2SO4, HNO3 and HCℓ. This treatment was done to make TCR suitable for the dry process asphalt mixtures, where TCR acts as a filler instead of altering bitumen binder properties. The investigation characterized truck tyre WRP-bituminous binder interaction by interacting a single truck tyre WRP with penetration grade (50/70 and 70/100) and industrial polymer modified binders (AE-2 and PolyMod). The interaction through kinetic study revealed that the swelling of truck tyre WRP is either a non-Fickian two-step swelling or anomalous diffusion mechanism of bituminous binders. In addition, the study showed that temperature has an effect on the diffusion, sorption and permeation coefficients; where coefficients increased as the temperature was increased. The characterization of which bituminous binder component was observed by the truck tyre WRP was studied using Fourier Transform Infra-Red Spectroscopy (FTIR), Carbon 13 Nuclear Magnetic Spectroscopy (13C NMR) and Thermalgravimetric Analysis (TGA). The study showed that by analysing the extracted bituminous binder from residual truck tyre WRP after the interaction, Polycyclic Aromatic Hydrocarbons (PAHs) consisting of molecular structure characteristics of bitumen constituent aromatics. So as to restricting the diffusion of bituminous binder into truck tyre WRP, the surface of truck tyre WRP was treated with H2SO4, HNO3 and HCℓ acids from concentrations of 1, 6 and 12 M. The H2SO4 and HCℓ treated WRP showed a change in molecular ii structure, toluene sorption coefficient, surface morphology and thermal characteristics (TGA and DSC). However, changes that were observed with the HNO3 treatment showed that the truck tyre WRP material was in fact being digested by the HNO3 acid. In all the respective acid treatments, the effects were distinct with 12 M acid concentration. This was observed with a decrease in toluene sorption coefficient with increasing acid concentration. From the treatment of the truck tyre WRP with H2SO4, HNO3 and HCℓ acids, the 6 M acid concentration showed desirable characteristics. Interaction of the respective acid treated truck tyre WRP-bituminous binder interaction was carried out following the drainage basket method. In this investigation, the 6 M acid (H2SO4, HNO3 and HCℓ) treated WRP was used and it was found that swelling followed a two-stage and anomalous non-Fickian diffusion patterns. Hence HNO3 absorbed the least binders and this was confirmed by the low sorption coefficients. Although the H2SO4 and HCℓ did not show a significant difference with 50/70 and 70/100 and a significant change with AE-2 and PolyMod binder absorption, the dynamic shear rheometre (DSR) measurements revealed that the residual binders (50/70, 70/100, AE2 and PolyMod) had a higher rutting temperature than respective original binder, where G*/sinδ is ≤ 1 kPa. These binders also had lower fatigue to cracking temperature through analysis of G*sinδ at 5 000 kPa. In addition, the measured phase angle at the respective rutting temperature showed to be between 45 ̊and 90 ̊which suggested that the binders were viscoelastic. Viscoelastic characteristics were therefore assessed using multiple stress creep recovery test (MSCR). The measured MSCR parameters, % recovery and non-recoverable compliance, showed that there was a slight gain in elasticity with 50/70 and 70/100 after the interaction. The AE-2 and PolyMod binders experienced a decrease in elasticity after the interaction. Despite unforeseen outcomes, the treatment of truck tyre WRP with H2SO4, HNO3 and HCℓ acids decreased the swelling phenomenon of truck tyre WRP in a bituminous binder.
- Full Text:
- Date Issued: 2020
- Authors: Mgangato, Siseko
- Date: 2020
- Subjects: Truck equipment industry
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/48500 , vital:40882
- Description: Recent studies have investigated the waste tyre crumb rubber (TCR)-bitumen interaction by observing the swelling of waste TCR at elevated temperatures. It was found that the waste TCR-bitumen interaction alters the rigidity and shape of TCR, which causes the failure of asphalt mixtures. Consequently, the problem occurs when the waste TCR swells during waste TCR-bitumen interaction from mixing and transportation of the asphalt mixture. Extensive laboratory studies have shown that the rate of absorption of bitumen is correlated with the TCR rubber composition and particle size. However, it is possible that swelling of waste TCR can be prevented or reduced before waste TCR-bitumen interaction by means of pre-treating the rubber crumb as to prevent the alteration of bitumen properties. Therefore, this study seeks to investigate the interaction of truck tyre wastes rubber particulates (WRP)-bitumen with the pretreatment of truck tyre WRP with H2SO4, HNO3 and HCℓ. This treatment was done to make TCR suitable for the dry process asphalt mixtures, where TCR acts as a filler instead of altering bitumen binder properties. The investigation characterized truck tyre WRP-bituminous binder interaction by interacting a single truck tyre WRP with penetration grade (50/70 and 70/100) and industrial polymer modified binders (AE-2 and PolyMod). The interaction through kinetic study revealed that the swelling of truck tyre WRP is either a non-Fickian two-step swelling or anomalous diffusion mechanism of bituminous binders. In addition, the study showed that temperature has an effect on the diffusion, sorption and permeation coefficients; where coefficients increased as the temperature was increased. The characterization of which bituminous binder component was observed by the truck tyre WRP was studied using Fourier Transform Infra-Red Spectroscopy (FTIR), Carbon 13 Nuclear Magnetic Spectroscopy (13C NMR) and Thermalgravimetric Analysis (TGA). The study showed that by analysing the extracted bituminous binder from residual truck tyre WRP after the interaction, Polycyclic Aromatic Hydrocarbons (PAHs) consisting of molecular structure characteristics of bitumen constituent aromatics. So as to restricting the diffusion of bituminous binder into truck tyre WRP, the surface of truck tyre WRP was treated with H2SO4, HNO3 and HCℓ acids from concentrations of 1, 6 and 12 M. The H2SO4 and HCℓ treated WRP showed a change in molecular ii structure, toluene sorption coefficient, surface morphology and thermal characteristics (TGA and DSC). However, changes that were observed with the HNO3 treatment showed that the truck tyre WRP material was in fact being digested by the HNO3 acid. In all the respective acid treatments, the effects were distinct with 12 M acid concentration. This was observed with a decrease in toluene sorption coefficient with increasing acid concentration. From the treatment of the truck tyre WRP with H2SO4, HNO3 and HCℓ acids, the 6 M acid concentration showed desirable characteristics. Interaction of the respective acid treated truck tyre WRP-bituminous binder interaction was carried out following the drainage basket method. In this investigation, the 6 M acid (H2SO4, HNO3 and HCℓ) treated WRP was used and it was found that swelling followed a two-stage and anomalous non-Fickian diffusion patterns. Hence HNO3 absorbed the least binders and this was confirmed by the low sorption coefficients. Although the H2SO4 and HCℓ did not show a significant difference with 50/70 and 70/100 and a significant change with AE-2 and PolyMod binder absorption, the dynamic shear rheometre (DSR) measurements revealed that the residual binders (50/70, 70/100, AE2 and PolyMod) had a higher rutting temperature than respective original binder, where G*/sinδ is ≤ 1 kPa. These binders also had lower fatigue to cracking temperature through analysis of G*sinδ at 5 000 kPa. In addition, the measured phase angle at the respective rutting temperature showed to be between 45 ̊and 90 ̊which suggested that the binders were viscoelastic. Viscoelastic characteristics were therefore assessed using multiple stress creep recovery test (MSCR). The measured MSCR parameters, % recovery and non-recoverable compliance, showed that there was a slight gain in elasticity with 50/70 and 70/100 after the interaction. The AE-2 and PolyMod binders experienced a decrease in elasticity after the interaction. Despite unforeseen outcomes, the treatment of truck tyre WRP with H2SO4, HNO3 and HCℓ acids decreased the swelling phenomenon of truck tyre WRP in a bituminous binder.
- Full Text:
- Date Issued: 2020
The effect of top dressing treatments on stolon weaning and keeping quality on two potato cultivars in the Gamtoos river valley
- Authors: Murray, Roger Benjamin
- Date: 2020
- Subjects: Plants -- Effect of nitrates on
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/48522 , vital:40884
- Description: Potatoes are an important crop in the Eastern Cape, and in South Africa as a whole, as a nutritious staple food. For consumers, they provide a quality, relatively low-priced form of carbohydrate and, for farmers, they are a valuable cash crop. The nutritional requirements of Solanum tuberosum L., in particular its nitrogen (N) needs, during cultivation is an aspect warranting further research. The Eastern Cape is a prime potato-producing region and, as such, is an appropriate and logical choice in terms of a suitable location for the required study. Improper farming practices with regards to improper fertilizer application techniques can adversely affect yields, and excessive application of fertilizer is fundamentally economically unsound, adverse towards the environment and potentially detrimental to the crop. It is therefore imperative that nutrients – and nitrogen in particular – are available to the crop in the correct quantities at the correct time. The objective of this dissertation was to accurately identify the nitrogen fertilizer needs of potatoes – with specific emphasis on whether or not nitrogen affects stolon growth and development. The potato cultivar used in the research trial was Mondial, which is a cultivar well-established in the region. Nitrogen applications needed to be closely monitored with regards to the total seasonal amount of nitrogen applied, the timing of applications and the amount applied at each application. Meaningful data accumulated from this study will help farmers in the area to accurately assess the efficiency of their farming operations. Excessive or insufficient plant nutrition affects tuber bulking and quality. The objective was to accurately identify this “sweet spot” (i.e. the optimal measure and timing) with regards to fertilization, especially nitrogen, while also taking into account various other factors that affect healthy tuber development and stolon formation. The untested assertion that prompted this study was that too much nitrogen adversely affects the number of stolons – and therefore, the number of tubers, since tubers grow from the stolons. It is generally accepted that too little N will adversely affect yields and yield potential will not be achieved, and that too much N will adversely affect yields, incur unnecessary costs and potentially degrade the environment. Optimum nitrogen application quantities were therefore identified, along with points at which deviations from optimum yields occurred. There were 8 distinct treatment combinations – namely: a rate of 150kg/ha, 250kg/ha, 350kg/ha and 450kg/ha – of nitrogen (N) throughout the growing season, administered at 2 different timings (hereafter referred to as the Application Timings). The applications of nitrogen were administered as follows: Application Timing 1 (50% N at planting : 25% N as Topdressing 1 : 25% N as Topdressing 2) and Application Timing 2 (75% N at planting : 12.5% N as Topdressing 1 : 12.5% N as Topdressing 2). The findings suggest that while nitrogen played a role in increasing yield, there was no conclusive evidence to suggest that stolons were weaned by excessive amounts of nitrogen throughout the growing season. The results obtained from statistical analysis showed that, between Application Timing 1 (50%:25%:25%) and Application Timing 2 (75%:12.5%:12.5%), neither split application timing was superior to the other in terms of tuber yield or effect on the average number of stolons when data from all three plantings were combined. In some instances, high stolon numbers were observed in the high N application plots. The highest stolon count in a single data collection in Planting 1 was in the 450kg/ha App. 1 plots in the 3rd data collection. The highest stolon count in a single data collection in Planting 2 was in the 250kg/ha App. 2 plots in the 2nd data collection. The highest stolon count in a single data collection was in the 350kg/ha App. 2 plots in the 3rd data collection. The conjecture that excessive nitrogen causes stolon weaning in potatoes was not supported by the findings of the experiments conducted in the three trial plantings which constituted this research study.
- Full Text:
- Date Issued: 2020
- Authors: Murray, Roger Benjamin
- Date: 2020
- Subjects: Plants -- Effect of nitrates on
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/48522 , vital:40884
- Description: Potatoes are an important crop in the Eastern Cape, and in South Africa as a whole, as a nutritious staple food. For consumers, they provide a quality, relatively low-priced form of carbohydrate and, for farmers, they are a valuable cash crop. The nutritional requirements of Solanum tuberosum L., in particular its nitrogen (N) needs, during cultivation is an aspect warranting further research. The Eastern Cape is a prime potato-producing region and, as such, is an appropriate and logical choice in terms of a suitable location for the required study. Improper farming practices with regards to improper fertilizer application techniques can adversely affect yields, and excessive application of fertilizer is fundamentally economically unsound, adverse towards the environment and potentially detrimental to the crop. It is therefore imperative that nutrients – and nitrogen in particular – are available to the crop in the correct quantities at the correct time. The objective of this dissertation was to accurately identify the nitrogen fertilizer needs of potatoes – with specific emphasis on whether or not nitrogen affects stolon growth and development. The potato cultivar used in the research trial was Mondial, which is a cultivar well-established in the region. Nitrogen applications needed to be closely monitored with regards to the total seasonal amount of nitrogen applied, the timing of applications and the amount applied at each application. Meaningful data accumulated from this study will help farmers in the area to accurately assess the efficiency of their farming operations. Excessive or insufficient plant nutrition affects tuber bulking and quality. The objective was to accurately identify this “sweet spot” (i.e. the optimal measure and timing) with regards to fertilization, especially nitrogen, while also taking into account various other factors that affect healthy tuber development and stolon formation. The untested assertion that prompted this study was that too much nitrogen adversely affects the number of stolons – and therefore, the number of tubers, since tubers grow from the stolons. It is generally accepted that too little N will adversely affect yields and yield potential will not be achieved, and that too much N will adversely affect yields, incur unnecessary costs and potentially degrade the environment. Optimum nitrogen application quantities were therefore identified, along with points at which deviations from optimum yields occurred. There were 8 distinct treatment combinations – namely: a rate of 150kg/ha, 250kg/ha, 350kg/ha and 450kg/ha – of nitrogen (N) throughout the growing season, administered at 2 different timings (hereafter referred to as the Application Timings). The applications of nitrogen were administered as follows: Application Timing 1 (50% N at planting : 25% N as Topdressing 1 : 25% N as Topdressing 2) and Application Timing 2 (75% N at planting : 12.5% N as Topdressing 1 : 12.5% N as Topdressing 2). The findings suggest that while nitrogen played a role in increasing yield, there was no conclusive evidence to suggest that stolons were weaned by excessive amounts of nitrogen throughout the growing season. The results obtained from statistical analysis showed that, between Application Timing 1 (50%:25%:25%) and Application Timing 2 (75%:12.5%:12.5%), neither split application timing was superior to the other in terms of tuber yield or effect on the average number of stolons when data from all three plantings were combined. In some instances, high stolon numbers were observed in the high N application plots. The highest stolon count in a single data collection in Planting 1 was in the 450kg/ha App. 1 plots in the 3rd data collection. The highest stolon count in a single data collection in Planting 2 was in the 250kg/ha App. 2 plots in the 2nd data collection. The highest stolon count in a single data collection was in the 350kg/ha App. 2 plots in the 3rd data collection. The conjecture that excessive nitrogen causes stolon weaning in potatoes was not supported by the findings of the experiments conducted in the three trial plantings which constituted this research study.
- Full Text:
- Date Issued: 2020
A bargain that dissolves into a poem unwritten: a critique of bargain retail practices and homemaking through critical design
- Authors: Hawley, Ami Jessica
- Date: 2019
- Subjects: Stores, Retail -- Designs and plans -- South Africa , Interior decoration -- South Africa House furnishings -- South Africa -- 20th century Furniture -- South Africa Store decoration Interior architecture
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/40349 , vital:36146
- Description: Although bargains commonly manifest as loud advertisements and trivial objects, as a moment of exchange they provide a basis to critique economic relations and judgements of taste. This research presents a document study of “bargains” in the context of bargain retail practices and homemaking, illustrated in the case of OK Furniture in South Africa; further situated by Julier’s study of economy and class within design culture, and Bourdieu’s fields of cultural production. The investigation builds to a discussion of the research practice, alluded to in the research project’s title, “A bargain that dissolves into a poem unwritten”. The title is an entry from this practice’s journal that conveys how the everyday experience of a bargain might find a connection to poetry when its exchange is seen as a performance; as a moment or encounter “unwritten”, capable of generating different modes of meaning and sociability. Using critical design strategies, the research practice explores the manifesting discountproduct cultures and retail practices associated with homes as a way to inhabit richer interpersonal relationships and unscripted sociability. This is discussed through four critical design proposals and 26 thought experiments, resulting in Text me when you see this, an online concept store that sells bargains, personal agreements, quality time, conversation and curio: www.textmewhenyouseethis.com. The research explores the limits to a bargain’s economic and emotional exchange by asking What if a bargain represented other forms of sociability, and How else might this mode of exchange look? These questions are used in the critique to model critical design towards both poetic expression and pragmatic embodiment of criticality in the project of reflecting on everyday life and what it might “dissolve into”.
- Full Text:
- Date Issued: 2019
- Authors: Hawley, Ami Jessica
- Date: 2019
- Subjects: Stores, Retail -- Designs and plans -- South Africa , Interior decoration -- South Africa House furnishings -- South Africa -- 20th century Furniture -- South Africa Store decoration Interior architecture
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/40349 , vital:36146
- Description: Although bargains commonly manifest as loud advertisements and trivial objects, as a moment of exchange they provide a basis to critique economic relations and judgements of taste. This research presents a document study of “bargains” in the context of bargain retail practices and homemaking, illustrated in the case of OK Furniture in South Africa; further situated by Julier’s study of economy and class within design culture, and Bourdieu’s fields of cultural production. The investigation builds to a discussion of the research practice, alluded to in the research project’s title, “A bargain that dissolves into a poem unwritten”. The title is an entry from this practice’s journal that conveys how the everyday experience of a bargain might find a connection to poetry when its exchange is seen as a performance; as a moment or encounter “unwritten”, capable of generating different modes of meaning and sociability. Using critical design strategies, the research practice explores the manifesting discountproduct cultures and retail practices associated with homes as a way to inhabit richer interpersonal relationships and unscripted sociability. This is discussed through four critical design proposals and 26 thought experiments, resulting in Text me when you see this, an online concept store that sells bargains, personal agreements, quality time, conversation and curio: www.textmewhenyouseethis.com. The research explores the limits to a bargain’s economic and emotional exchange by asking What if a bargain represented other forms of sociability, and How else might this mode of exchange look? These questions are used in the critique to model critical design towards both poetic expression and pragmatic embodiment of criticality in the project of reflecting on everyday life and what it might “dissolve into”.
- Full Text:
- Date Issued: 2019
A comparison of different strategies to control pests and diseases in Brassica spp. production in the Western Cape
- Van Niekerk, Abraham Johannes
- Authors: Van Niekerk, Abraham Johannes
- Date: 2019
- Subjects: Pesticides , Pests -- Control Agricultural pests , Plant diseases
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/44122 , vital:37113
- Description: Brassica spp. are cultivated all over the world, commercial species include: cabbage, broccoli, kale, kohlrabi and turnip. In this study the focus was on broccoli (Brassica oleracea) production in the Western Cape province of South Africa and its economically important pests and diseases: sugar beet cyst nematode (Heterodera schachtii), diamondback moth (Plutella xylostella), white blister (Albugo candida) and clubroot (Plasmodiophora brassicae), and the different methods to control these pests and diseases. The control methods focused on in this study included a commercial chemical control programme, a biological control programme and a holistic approach. Other factors were bio-fumigation and chemical fumigation and different crop rotation practices including rotation crops versus no rotation crops. The experimental design was a strip split plot design, with different pest and disease management strategies as the main plot treatment and fumigation and rotation treatment combinations arranged in strips across the main plot treatments. The main plot design was a randomized complete block with four programmes (Control, Holistic, Chemical and Biological) replicated four times and laid out in a Randomised Complete Block Design (RCBD). The treatment design of the strip plot factors was a 2x2 factorial with two fumigations (fumigated chemically and fumigated biologically) and two rotations (crop rotated and monoculture) randomly allocated across main plot treatments. Each experimental unit consisted of 40 plants. Plants were evaluated weekly for the incidence of white blister and diamondback moth. Incidences of clubroot and white blister infection of heads of broccoli were recorded 78 days after planting. Baseline soil samples were analysed to establish the soil chemical properties. Post-trial soil samples were also analysed to investigate the effect of the different practices and programmes on the soil chemical properties. Nematodes were extracted pre-trial and post-trial, and the effect of fumigation and crop rotation on plant parasitic nematodes and the nematode population diversity investigated. In the post-trial soil chemical analysis, a significantly higher concentration of Na was recorded for the biological programme when crop rotation was included compared to the no rotation treatment. The concentration of K was also significantly higher in the no rotation compared to the rotation treatment. The nematode results showed very high numbers of bacterial feeders in all the samples. Overall nematode diversity was lacking and showed very few fungal feeders, omnivores and predators. The nematode indices for all of the samples showed that nematodes were highly enriched and unstructured. Of the plant parasitic nematodes, only Heterodera spp. were obtained in the pre-trial analysis, and incidences of these nematodes were lower at the end of the trial. Low numbers of other plant parasitic nematodes viz. Pratylenchus, Paratrichodorus and Tylenchorhynchus were reported for the post-trial analysis of the soil. Because of the low numbers of plant parasitic nematodes, it was not possible to analyse the data statistically. With regard to diamondback moth and the fungal diseases, crop rotation and fumigation did not significantly affect the incidence of white blister and diamondback moth. A significant “days after planting by control programme” interaction was reported for the incidence of white blister on foliage and the incidence of diamondback moth. All three control programmes significantly reduced the incidence of diamondback moth with the chemical programme being significantly more effective than the other two programmes. All three programmes also significantly reduced the incidence of white blister on foliage and the holistic and biological programmes significantly reduced the incidence of white blister on broccoli heads with the holistic programme being significantly more effective than the biological programme. There was no clubroot infection in the trial for any of the treatments. Results of this study showed that it is possible to manage diseases and pests of broccoli using a holistic approach. However, long term trials are needed to confirm the results obtained in this study.
- Full Text:
- Date Issued: 2019
- Authors: Van Niekerk, Abraham Johannes
- Date: 2019
- Subjects: Pesticides , Pests -- Control Agricultural pests , Plant diseases
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/44122 , vital:37113
- Description: Brassica spp. are cultivated all over the world, commercial species include: cabbage, broccoli, kale, kohlrabi and turnip. In this study the focus was on broccoli (Brassica oleracea) production in the Western Cape province of South Africa and its economically important pests and diseases: sugar beet cyst nematode (Heterodera schachtii), diamondback moth (Plutella xylostella), white blister (Albugo candida) and clubroot (Plasmodiophora brassicae), and the different methods to control these pests and diseases. The control methods focused on in this study included a commercial chemical control programme, a biological control programme and a holistic approach. Other factors were bio-fumigation and chemical fumigation and different crop rotation practices including rotation crops versus no rotation crops. The experimental design was a strip split plot design, with different pest and disease management strategies as the main plot treatment and fumigation and rotation treatment combinations arranged in strips across the main plot treatments. The main plot design was a randomized complete block with four programmes (Control, Holistic, Chemical and Biological) replicated four times and laid out in a Randomised Complete Block Design (RCBD). The treatment design of the strip plot factors was a 2x2 factorial with two fumigations (fumigated chemically and fumigated biologically) and two rotations (crop rotated and monoculture) randomly allocated across main plot treatments. Each experimental unit consisted of 40 plants. Plants were evaluated weekly for the incidence of white blister and diamondback moth. Incidences of clubroot and white blister infection of heads of broccoli were recorded 78 days after planting. Baseline soil samples were analysed to establish the soil chemical properties. Post-trial soil samples were also analysed to investigate the effect of the different practices and programmes on the soil chemical properties. Nematodes were extracted pre-trial and post-trial, and the effect of fumigation and crop rotation on plant parasitic nematodes and the nematode population diversity investigated. In the post-trial soil chemical analysis, a significantly higher concentration of Na was recorded for the biological programme when crop rotation was included compared to the no rotation treatment. The concentration of K was also significantly higher in the no rotation compared to the rotation treatment. The nematode results showed very high numbers of bacterial feeders in all the samples. Overall nematode diversity was lacking and showed very few fungal feeders, omnivores and predators. The nematode indices for all of the samples showed that nematodes were highly enriched and unstructured. Of the plant parasitic nematodes, only Heterodera spp. were obtained in the pre-trial analysis, and incidences of these nematodes were lower at the end of the trial. Low numbers of other plant parasitic nematodes viz. Pratylenchus, Paratrichodorus and Tylenchorhynchus were reported for the post-trial analysis of the soil. Because of the low numbers of plant parasitic nematodes, it was not possible to analyse the data statistically. With regard to diamondback moth and the fungal diseases, crop rotation and fumigation did not significantly affect the incidence of white blister and diamondback moth. A significant “days after planting by control programme” interaction was reported for the incidence of white blister on foliage and the incidence of diamondback moth. All three control programmes significantly reduced the incidence of diamondback moth with the chemical programme being significantly more effective than the other two programmes. All three programmes also significantly reduced the incidence of white blister on foliage and the holistic and biological programmes significantly reduced the incidence of white blister on broccoli heads with the holistic programme being significantly more effective than the biological programme. There was no clubroot infection in the trial for any of the treatments. Results of this study showed that it is possible to manage diseases and pests of broccoli using a holistic approach. However, long term trials are needed to confirm the results obtained in this study.
- Full Text:
- Date Issued: 2019
An examination of the visual representation of young white Afrikaner women
- Authors: Jordan, Nicole
- Date: 2019
- Subjects: Photography of women -- South Africa , Photography, Artistic -- South Africa Photography -- South Africa Photography, Artistic -- 21st century Women -- South Africa -- Social conditions
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/39972 , vital:35622
- Description: The purpose of this qualitative research study is to comment on the visual representation of women between the ages of twenty and thirty within white contemporary Afrikaans culture. This will be achieved through an analysis of stereotypes evident in Afrikaner culture. Examples of this include but are not limited to the text and visuals in the Goeie Maniere en Etiket (1981) book by Emsie Schoeman and dated Afrikaans magazine issues by Huisgenoot (Issue XLII, 2 June 1961) and Sarie Marais (Issue 17/19, 30 March 1966). Interviews were conducted with five white young Afrikaner women using a collaborative approach, to gain a better understanding of the influences that cultural and visual stereotypes have on an individual. The research aims to comment on how the emerging post-apartheid generation of young Afrikaner women are responding to the cultural expectations and engaging with their Afrikaner identity in the way they choose to represent themselves through tableau portrait photography. The study is based on a practice-based research method, which encompasses two components: a written output and a practical output. These function as a unity, where the written component guides the development of the practical body of work. The written document provides the foundation and framework in which the practical work functions, creating a conceptual framework that guides the process of collaboration between the visual artist and subject to construct a contemporary visual representation that focuses on how young Afrikaner women react to traditional cultural roles and develop an understanding of self. The study makes use of Gillian Rose’s visual analysis framework as a critical analysis tool to determine the visual representation that emerges from the collaboration between the visual artist and the subject. Ultimately, the aim of this research is to facilitate the potential for the subject to critically engage with visual identity by collaborating with the visual artist. This research presents a unique approach to communicate an evolving post-apartheid identity and has contributed to an understanding of the feminine identity construction of the emerging Afrikaner generation in a democratic South Africa.
- Full Text:
- Date Issued: 2019
- Authors: Jordan, Nicole
- Date: 2019
- Subjects: Photography of women -- South Africa , Photography, Artistic -- South Africa Photography -- South Africa Photography, Artistic -- 21st century Women -- South Africa -- Social conditions
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/39972 , vital:35622
- Description: The purpose of this qualitative research study is to comment on the visual representation of women between the ages of twenty and thirty within white contemporary Afrikaans culture. This will be achieved through an analysis of stereotypes evident in Afrikaner culture. Examples of this include but are not limited to the text and visuals in the Goeie Maniere en Etiket (1981) book by Emsie Schoeman and dated Afrikaans magazine issues by Huisgenoot (Issue XLII, 2 June 1961) and Sarie Marais (Issue 17/19, 30 March 1966). Interviews were conducted with five white young Afrikaner women using a collaborative approach, to gain a better understanding of the influences that cultural and visual stereotypes have on an individual. The research aims to comment on how the emerging post-apartheid generation of young Afrikaner women are responding to the cultural expectations and engaging with their Afrikaner identity in the way they choose to represent themselves through tableau portrait photography. The study is based on a practice-based research method, which encompasses two components: a written output and a practical output. These function as a unity, where the written component guides the development of the practical body of work. The written document provides the foundation and framework in which the practical work functions, creating a conceptual framework that guides the process of collaboration between the visual artist and subject to construct a contemporary visual representation that focuses on how young Afrikaner women react to traditional cultural roles and develop an understanding of self. The study makes use of Gillian Rose’s visual analysis framework as a critical analysis tool to determine the visual representation that emerges from the collaboration between the visual artist and the subject. Ultimately, the aim of this research is to facilitate the potential for the subject to critically engage with visual identity by collaborating with the visual artist. This research presents a unique approach to communicate an evolving post-apartheid identity and has contributed to an understanding of the feminine identity construction of the emerging Afrikaner generation in a democratic South Africa.
- Full Text:
- Date Issued: 2019
An exploration of the materiality of forged steel as medium for visual artists
- Authors: De Lange, Neil
- Date: 2019
- Subjects: Blacksmithing , Art -- 21st century Art -- Sculpture
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/39425 , vital:35245
- Description: This research is an exploration into the materiality of forged steel, and is aimed at the preservation of traditional blacksmith forging techniques and methods by incorporating these methods as added skill set during the making of three dimensional visual art. An investigation into the history of traditional forging (iron works) serves as background aimed at the identification of the various techniques and methods utilized during the processes found in traditional blacksmith forging. The practice of this research consists of three parts: firstly, a textual investigation to establish the basics (note taking- visual journal); secondly, practical exercises to gain a better understanding of the behaviour of various steels by utilizing traditional methods of forging to explore the potential applications for the forge as a tool in service of the visual arts; and lastly, reflection on the process to modify and adapt processes (methods and techniques) to promote further interest in the use of a forge as tool during the making of three-dimensional visual art.
- Full Text:
- Date Issued: 2019
- Authors: De Lange, Neil
- Date: 2019
- Subjects: Blacksmithing , Art -- 21st century Art -- Sculpture
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/39425 , vital:35245
- Description: This research is an exploration into the materiality of forged steel, and is aimed at the preservation of traditional blacksmith forging techniques and methods by incorporating these methods as added skill set during the making of three dimensional visual art. An investigation into the history of traditional forging (iron works) serves as background aimed at the identification of the various techniques and methods utilized during the processes found in traditional blacksmith forging. The practice of this research consists of three parts: firstly, a textual investigation to establish the basics (note taking- visual journal); secondly, practical exercises to gain a better understanding of the behaviour of various steels by utilizing traditional methods of forging to explore the potential applications for the forge as a tool in service of the visual arts; and lastly, reflection on the process to modify and adapt processes (methods and techniques) to promote further interest in the use of a forge as tool during the making of three-dimensional visual art.
- Full Text:
- Date Issued: 2019
Carbon monoxide exposure and respiratory diseases in Wells Estate and Walmer township in Port Elizabeth, South africa
- Authors: Ejesieme, Amarachi
- Date: 2019
- Subjects: Air -- Pollution -- South Africa -- Port Elizabeth , Carbon monoxide , Respiratory organs -- Diseases , Respiratory infections
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/39874 , vital:35496
- Description: To ascertain household exposure to carbon monoxide (CO) and its associations with respiratory diseases in Port Elizabeth, a cross-sectional study was undertaken in Walmer Township and Wells Estate in Port Elizabeth. Ambient and indoor CO levels were measured in each township and compared with national and international air quality guideline. ChromAir® diffusion carbon monoxide badges were used for carbon monoxide measurement. Badges are relatively inexpensive and easy to use and results can be obtained after a 48-hour passive exposure. Exposure to CO was determined by measuring levels in the ambient environment and living rooms of study dwellings. The prevalence of respiratory diseases and symptoms were assessed using the iBhayi study questionnaire. The mean of ambient and indoor CO levels for the total sample was 8.02 (SD 2.43) and 0.68 (SD 1.23) ppm respectively. In this study, 40% of ambient CO measurements exceeded the World Health Organisation (WHO) 8-hour guideline of 8.7 ppm. The Student’s t-test showed that ambient (p = 0.59) and indoor (p = 0.16) CO levels in Walmer Township and Wells Estate were similar. This shows that CO exposure in both townships do not vary significantly. Fever and chills (32%), headache (19%) and runny/blocked nose (19%) were the most prevalent acute respiratory symptoms. The predominant respiratory diseases/conditions were tuberculosis (8.5%) and asthma (5.7%). CO at levels below the WHO 8-hour guidelines was significantly associated with the prevalence of acute respiratory symptoms (AOR = 2.286; 95% CI: 1.220 - 4.283). Ageing emerged as an independent risk factor for high tuberculosis prevalence in the study sites (AOR = 5.837; 95% CI: 1.654 – 20. 596). The study indicated low levels of carbon monoxide exposure in the study areas. From the findings, CO may be associated with an increase in respiratory symptoms in the study population. Increasing community awareness on sources and adverse health effects of CO exposure with improved service delivery will be helpful in reducing the burden of respiratory outcomes in the study sites.
- Full Text:
- Date Issued: 2019
- Authors: Ejesieme, Amarachi
- Date: 2019
- Subjects: Air -- Pollution -- South Africa -- Port Elizabeth , Carbon monoxide , Respiratory organs -- Diseases , Respiratory infections
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/39874 , vital:35496
- Description: To ascertain household exposure to carbon monoxide (CO) and its associations with respiratory diseases in Port Elizabeth, a cross-sectional study was undertaken in Walmer Township and Wells Estate in Port Elizabeth. Ambient and indoor CO levels were measured in each township and compared with national and international air quality guideline. ChromAir® diffusion carbon monoxide badges were used for carbon monoxide measurement. Badges are relatively inexpensive and easy to use and results can be obtained after a 48-hour passive exposure. Exposure to CO was determined by measuring levels in the ambient environment and living rooms of study dwellings. The prevalence of respiratory diseases and symptoms were assessed using the iBhayi study questionnaire. The mean of ambient and indoor CO levels for the total sample was 8.02 (SD 2.43) and 0.68 (SD 1.23) ppm respectively. In this study, 40% of ambient CO measurements exceeded the World Health Organisation (WHO) 8-hour guideline of 8.7 ppm. The Student’s t-test showed that ambient (p = 0.59) and indoor (p = 0.16) CO levels in Walmer Township and Wells Estate were similar. This shows that CO exposure in both townships do not vary significantly. Fever and chills (32%), headache (19%) and runny/blocked nose (19%) were the most prevalent acute respiratory symptoms. The predominant respiratory diseases/conditions were tuberculosis (8.5%) and asthma (5.7%). CO at levels below the WHO 8-hour guidelines was significantly associated with the prevalence of acute respiratory symptoms (AOR = 2.286; 95% CI: 1.220 - 4.283). Ageing emerged as an independent risk factor for high tuberculosis prevalence in the study sites (AOR = 5.837; 95% CI: 1.654 – 20. 596). The study indicated low levels of carbon monoxide exposure in the study areas. From the findings, CO may be associated with an increase in respiratory symptoms in the study population. Increasing community awareness on sources and adverse health effects of CO exposure with improved service delivery will be helpful in reducing the burden of respiratory outcomes in the study sites.
- Full Text:
- Date Issued: 2019
Challenging the aesthetics and functionality of metals in contemporary blacksmithing
- Authors: Lucas, Justin
- Date: 2019
- Subjects: Art metal-work , Blacksmithing Ironwork
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/40533 , vital:36180
- Description: A forge allows the creation of both utilitarian craftwork and artworks. It is difficult to find blacksmiths who are willing to pass on their knowledge, particularly in South Africa where the art of blacksmithing is practised by a small number of individuals who rely on their labour for an income. This dissertation documents the building of a forge and what is needed to practise the art of blacksmithing, sourcing of the materials, and the application of blacksmithing to make pleasing artefacts. The document includes the processes of forge tool-making, providing an avenue for future students to fabricate tools and use the processes for art-making as well as list of suppliers and list of blacksmiths in South Africa.
- Full Text:
- Date Issued: 2019
- Authors: Lucas, Justin
- Date: 2019
- Subjects: Art metal-work , Blacksmithing Ironwork
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/40533 , vital:36180
- Description: A forge allows the creation of both utilitarian craftwork and artworks. It is difficult to find blacksmiths who are willing to pass on their knowledge, particularly in South Africa where the art of blacksmithing is practised by a small number of individuals who rely on their labour for an income. This dissertation documents the building of a forge and what is needed to practise the art of blacksmithing, sourcing of the materials, and the application of blacksmithing to make pleasing artefacts. The document includes the processes of forge tool-making, providing an avenue for future students to fabricate tools and use the processes for art-making as well as list of suppliers and list of blacksmiths in South Africa.
- Full Text:
- Date Issued: 2019
Comparison of consumer perspectives of the natural and commercial synthetic chemical-based mosquito repellent products
- Authors: Ndoyana, Lusanda
- Date: 2019
- Subjects: Insect baits and repellents , Mosquitoes -- Control Consumers -- Attitudes Consumers -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/42902 , vital:36704
- Description: The present study was conducted to determine the perceptions of consumers between the natural mosquito repellent products and the synthetic chemical mosquito repellent products. The perception is that natural mosquito repellent products are more effective than synthetic chemical mosquito repellents based on odour, cost and quality. A comparison of the two products was done in a form of a structured questionnaire where randomly selected participants were given two questionnaires. The participants were asked to provide their perceptions concerning cost, quality and odour. Each participant was also given one formulated natural (green) candle and one synthetic (white) chemical mosquito repellent product. The formulated natural candles contain Oil of Lemon Eucalyptus (OLE) as the active ingredient. OLE is a natural plant-based repellent which is extracted from the leaves and twigs of the lemon-scented gum eucalyptus plant. The results showed that both products were effective in terms of cost, product quality and odour. However, the natural mosquito repellent product was more effective than the synthetic chemical product based on the observed p-value results.
- Full Text:
- Date Issued: 2019
- Authors: Ndoyana, Lusanda
- Date: 2019
- Subjects: Insect baits and repellents , Mosquitoes -- Control Consumers -- Attitudes Consumers -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/42902 , vital:36704
- Description: The present study was conducted to determine the perceptions of consumers between the natural mosquito repellent products and the synthetic chemical mosquito repellent products. The perception is that natural mosquito repellent products are more effective than synthetic chemical mosquito repellents based on odour, cost and quality. A comparison of the two products was done in a form of a structured questionnaire where randomly selected participants were given two questionnaires. The participants were asked to provide their perceptions concerning cost, quality and odour. Each participant was also given one formulated natural (green) candle and one synthetic (white) chemical mosquito repellent product. The formulated natural candles contain Oil of Lemon Eucalyptus (OLE) as the active ingredient. OLE is a natural plant-based repellent which is extracted from the leaves and twigs of the lemon-scented gum eucalyptus plant. The results showed that both products were effective in terms of cost, product quality and odour. However, the natural mosquito repellent product was more effective than the synthetic chemical product based on the observed p-value results.
- Full Text:
- Date Issued: 2019
Development of polypropylene – waste tyre crumbs based tpe's with the aid of vistamaxxtm as a compatibiliser
- Authors: Masele, Siyamtanda
- Date: 2019
- Subjects: Polymers , Polymerization Crumb rubber Rubber
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/42589 , vital:36670
- Description: Polypropylene (PP) is a semi crystalline thermoplastic polymer and one of the most commonly used polyolefins. It is well known for its poor impact resistance; hence, for industries such as the automotive and packaging, reinforced PP is widely used. In general plastic waste disposal is a global crisis raising environmental and human health concerns, with PP being the highest consumed polymer globally; hence a push in the reuse and recycling of PP. Recycled polypropylene has limited uses for industrial applications due to its highly reduced properties owing to the recycling process which inhabits cutting of chains lengths, broadened molecular weight distributions and compromised crystallinity. Several studies have investigated the use of reinforcing fillers and modifiers in order to improve properties of PP. Inorganic materials and minerals such as CaCO3, Mica, Talc and glass fibre are used as fillers to improve mechanical properties (tensile and hardness), but still lacks in improving the impact resistance. Thermoplastic elastomers (TPE) are typically used where elastomer and thermoplastics fail as individual components. This is because they have the benefit of thermoplastic properties at hypo ambient condition and elastomer properties such as good impact and elongation at sub-zero conditions. The study took a route of using PP and waste tyre crumb rubber (CR) material to prepare potentially low-cost waste based TPE’s, which would then inherit both properties of PP and the rubber component. VistamaxxTM 6202 (EPR), a commercial name for ethylene-propylene monomer (EPR), was used as a compatibiliser to improve interaction between PP and CR and to contribute towards the overall improvement of various properties such as mechanical properties. VistamaxxTM has a low glass transition temperature (Tg, = -30 ºC), which is important for low temperature applications such as cold storage; it also has a very high elongation and as a result contributed significantly to the overall properties when used in TPE blends. The study highlighted differences between two TPE compounding formulation pathways; namely master-batch (MB) and design of experiments (DoE). The MB formulations were blends that were prepared by a conventional way of compounding; where a pre-mixed CR/EPR blend, in the ratio of 80(CR):20(EPR), was used to form a master-batch. Results showed that there are some similarities between TPEs prepared in different ways, which suggests that the ultimate properties such as thermal stability are in fact more PP matrix based. Thermal analyses results revealed that when high amount of CR was added to the TPE blends, there was a substantial amount of residue mainly due to inherent carbon black. The degree of crystallinity of the blends decreased with increased amounts of CR irrespective of whether it was the MB or DoE blends. The MB TPE blends demonstrated that hardness is not linked to the amount of the MB nor the crystallinity of blends. Meanwhile, tensile elongation and tensile stress were affected by crystallinity. On the other hand, the impact strength findings showed that the amount of MB in TPE blends reached a threshold at 30%. The DoE based TPE blends demonstrated that the optimum mechanical properties are observed when components of the blends are incorporated individually during compounding. This was observed for impact strength, tensile stress as well as elongation at break. The results showed that the incorporation of EPR should be at least 20% for good impact and elongation properties; however, for tensile and hardness, the PP matrix must be high. The study also showed that, for better mechanical properties it was more suitable to use the blends formulated with DoE, because the master-batch approach limited the improving of the mechanical properties by an addition of up to 30% of both the CR and EPR. The storage modulus as well as the tan delta for both MB and DoE decreased when the elastomeric phases were added on both methods, whereas tan delta Tg values decreased as more of the elastomeric phase was added. Evidence from morphology studies showed that the majority of TPE blends suffer from inadequate distribution and adhesion between PP and elastomer; resulting in poor mechanical properties. Furthermore, a threshold of matrix invasion is observed from 30% and above of CR in the blend, where lack of in capsulated lamps of CR were observed hindering the stress induced crystallization and relaxation of the PP phase. The latter was observed irrespective of the type of blend, which strongly suggests and highlights the limits of blending PP with elastomers. Study demonstrated the ability of VistamaxxTM to be utilized as a binding material for PP and CR and displaying the challenges that might arise when used as a master-batch with crumb rubber.
- Full Text:
- Date Issued: 2019
- Authors: Masele, Siyamtanda
- Date: 2019
- Subjects: Polymers , Polymerization Crumb rubber Rubber
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/42589 , vital:36670
- Description: Polypropylene (PP) is a semi crystalline thermoplastic polymer and one of the most commonly used polyolefins. It is well known for its poor impact resistance; hence, for industries such as the automotive and packaging, reinforced PP is widely used. In general plastic waste disposal is a global crisis raising environmental and human health concerns, with PP being the highest consumed polymer globally; hence a push in the reuse and recycling of PP. Recycled polypropylene has limited uses for industrial applications due to its highly reduced properties owing to the recycling process which inhabits cutting of chains lengths, broadened molecular weight distributions and compromised crystallinity. Several studies have investigated the use of reinforcing fillers and modifiers in order to improve properties of PP. Inorganic materials and minerals such as CaCO3, Mica, Talc and glass fibre are used as fillers to improve mechanical properties (tensile and hardness), but still lacks in improving the impact resistance. Thermoplastic elastomers (TPE) are typically used where elastomer and thermoplastics fail as individual components. This is because they have the benefit of thermoplastic properties at hypo ambient condition and elastomer properties such as good impact and elongation at sub-zero conditions. The study took a route of using PP and waste tyre crumb rubber (CR) material to prepare potentially low-cost waste based TPE’s, which would then inherit both properties of PP and the rubber component. VistamaxxTM 6202 (EPR), a commercial name for ethylene-propylene monomer (EPR), was used as a compatibiliser to improve interaction between PP and CR and to contribute towards the overall improvement of various properties such as mechanical properties. VistamaxxTM has a low glass transition temperature (Tg, = -30 ºC), which is important for low temperature applications such as cold storage; it also has a very high elongation and as a result contributed significantly to the overall properties when used in TPE blends. The study highlighted differences between two TPE compounding formulation pathways; namely master-batch (MB) and design of experiments (DoE). The MB formulations were blends that were prepared by a conventional way of compounding; where a pre-mixed CR/EPR blend, in the ratio of 80(CR):20(EPR), was used to form a master-batch. Results showed that there are some similarities between TPEs prepared in different ways, which suggests that the ultimate properties such as thermal stability are in fact more PP matrix based. Thermal analyses results revealed that when high amount of CR was added to the TPE blends, there was a substantial amount of residue mainly due to inherent carbon black. The degree of crystallinity of the blends decreased with increased amounts of CR irrespective of whether it was the MB or DoE blends. The MB TPE blends demonstrated that hardness is not linked to the amount of the MB nor the crystallinity of blends. Meanwhile, tensile elongation and tensile stress were affected by crystallinity. On the other hand, the impact strength findings showed that the amount of MB in TPE blends reached a threshold at 30%. The DoE based TPE blends demonstrated that the optimum mechanical properties are observed when components of the blends are incorporated individually during compounding. This was observed for impact strength, tensile stress as well as elongation at break. The results showed that the incorporation of EPR should be at least 20% for good impact and elongation properties; however, for tensile and hardness, the PP matrix must be high. The study also showed that, for better mechanical properties it was more suitable to use the blends formulated with DoE, because the master-batch approach limited the improving of the mechanical properties by an addition of up to 30% of both the CR and EPR. The storage modulus as well as the tan delta for both MB and DoE decreased when the elastomeric phases were added on both methods, whereas tan delta Tg values decreased as more of the elastomeric phase was added. Evidence from morphology studies showed that the majority of TPE blends suffer from inadequate distribution and adhesion between PP and elastomer; resulting in poor mechanical properties. Furthermore, a threshold of matrix invasion is observed from 30% and above of CR in the blend, where lack of in capsulated lamps of CR were observed hindering the stress induced crystallization and relaxation of the PP phase. The latter was observed irrespective of the type of blend, which strongly suggests and highlights the limits of blending PP with elastomers. Study demonstrated the ability of VistamaxxTM to be utilized as a binding material for PP and CR and displaying the challenges that might arise when used as a master-batch with crumb rubber.
- Full Text:
- Date Issued: 2019
Experiences of undergraduate diagnostic radiography students regarding assessor feedback during summative clinical assessments
- Authors: Hodgson, Hayley Dianne
- Date: 2019
- Subjects: Medical education , Teacher-student relationships Communication in education Mentoring in education Radiography, Medical -- Digital techniques
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/42296 , vital:36643
- Description: Assessment and feedback are closely interlinked terms. High quality feedback within education and assessment can have a profound influence on learning. Summative clinical assessments and feedback, conducted in clinical training sites, are vital steps in successfully preparing an undergraduate diagnostic radiography student for the desired outcome of a competent, skilled diagnostic radiographer. Feedback has the potential to close the gap between a student’s actual clinical performance and desired clinical performance. Despite the importance of feedback, students across the globe, particularly in the health professions, are dissatisfied with the current feedback systems. Failure to provide effective feedback within the clinical context can be detrimental to patient safety because students have a false impression of their clinical skills and competencies. The aim of the study was to explore and describe the experiences of undergraduate diagnostic radiography students regarding assessor feedback during summative clinical assessments. A qualitative, exploratory, descriptive, and contextual research design was used to gain in-depth knowledge of the experiences of undergraduate diagnostic radiography students regarding assessor feedback during summative clinical assessments. Data were gathered from students by means of semi-structured focus group interviews. Data were transcribed verbatim and coded using Tesch’s eight steps. Two principle themes emerged from the data analysis. Theme 1 unpacked whether an assessor is an ally or foe. Theme 2 focussed on key elements that influence the nature of the feedback process. There were various positive experiences regarding assessor feedback during the summative clinical assessments reported by the participants. However, they were dissatisfied with numerous aspects of assessor feedback during their summative clinical assessments and this subsequently impeded their learning experience. Measures to ensure trustworthiness and ethical research practices governed this research study. Based on the findings, the recommendations include that the higher education institution, clinical supervisors, and radiography students, should utilise feedback as a learning tool for skills development during summative clinical assesssments.
- Full Text:
- Date Issued: 2019
- Authors: Hodgson, Hayley Dianne
- Date: 2019
- Subjects: Medical education , Teacher-student relationships Communication in education Mentoring in education Radiography, Medical -- Digital techniques
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/42296 , vital:36643
- Description: Assessment and feedback are closely interlinked terms. High quality feedback within education and assessment can have a profound influence on learning. Summative clinical assessments and feedback, conducted in clinical training sites, are vital steps in successfully preparing an undergraduate diagnostic radiography student for the desired outcome of a competent, skilled diagnostic radiographer. Feedback has the potential to close the gap between a student’s actual clinical performance and desired clinical performance. Despite the importance of feedback, students across the globe, particularly in the health professions, are dissatisfied with the current feedback systems. Failure to provide effective feedback within the clinical context can be detrimental to patient safety because students have a false impression of their clinical skills and competencies. The aim of the study was to explore and describe the experiences of undergraduate diagnostic radiography students regarding assessor feedback during summative clinical assessments. A qualitative, exploratory, descriptive, and contextual research design was used to gain in-depth knowledge of the experiences of undergraduate diagnostic radiography students regarding assessor feedback during summative clinical assessments. Data were gathered from students by means of semi-structured focus group interviews. Data were transcribed verbatim and coded using Tesch’s eight steps. Two principle themes emerged from the data analysis. Theme 1 unpacked whether an assessor is an ally or foe. Theme 2 focussed on key elements that influence the nature of the feedback process. There were various positive experiences regarding assessor feedback during the summative clinical assessments reported by the participants. However, they were dissatisfied with numerous aspects of assessor feedback during their summative clinical assessments and this subsequently impeded their learning experience. Measures to ensure trustworthiness and ethical research practices governed this research study. Based on the findings, the recommendations include that the higher education institution, clinical supervisors, and radiography students, should utilise feedback as a learning tool for skills development during summative clinical assesssments.
- Full Text:
- Date Issued: 2019
Factors impacting the design of a mobile application for soil management: a case study of the Eastern Cape crops
- Authors: Botha, Stephan
- Date: 2019
- Subjects: Mobile applications -- South Africa -- Eastern Cape , Information technology -- South Africa -- Eastern Cape Soil management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/44907 , vital:38187
- Description: Some of the biggest challenges the global community has to face are the ever-dwindling levels of freshwater resources, the drastic impact of the greenhouse gases on the global climate and the loss of non-renewable fertile soil. South African agriculture contributes a total of 12.7% to the overall South African GDP (gross domestic product). Only a small portion of the South African soil is considered as being able to grow healthy and nutritious crops. The world of information communication technology (ICT) is extremely vast and growing daily with newly created tools, to accommodate the needs of a specific sector, such as agriculture. As the ICT-based agricultural solutions increase and improve, the uptake of these solutions within the South African agricultural sector becomes even smaller. The reasons for the low uptake of mobile soil management solutions for crop-growing farmers are unknown, due to limited research conducted. The identified problem was a lack of understanding of the way mobile technologies can be designed to adequately support farmers to correctly manage their soil to produce the best possible crops. The primary objective of this research study was to identify factors, which may have a significant impact on the design of a mobile soil management application for crop farmers in the Eastern Cape (South Africa). The secondary objectives were as follows: (i) to determine what soil management is and which aspects are required to implement soil management effectively; (ii) to identify possible mobile technologies suitable to act as an effective support structure for a mobile soil management application; and (iii) to identify which user experience guidelines are key for the development of an effective mobile soil management solution and to compile a user experience guideline for an effective mobile soil management solution. Achieving these objectives, resulted in a better understanding of the identified problem. The problem was addressed by conducting a thorough literature review and a case study to better grasp the different aspects of the identified problem. Quantitative data was collected by conducting a user interface evaluation. Qualitative data were also gathered by means of a field test using the mobile soil management application. The field test was done in conjunction with a heuristic evaluation, completed by the participants. Data triangulation was used to compare the results of the gathered data. The results from the data triangulation were used to confirm the factors, which made the most significant impact on the success of the soil management application. These confirmed design factors were used to produce a list of guidelines to improve the design of future mobile ICT soil management applications.
- Full Text:
- Date Issued: 2019
- Authors: Botha, Stephan
- Date: 2019
- Subjects: Mobile applications -- South Africa -- Eastern Cape , Information technology -- South Africa -- Eastern Cape Soil management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/44907 , vital:38187
- Description: Some of the biggest challenges the global community has to face are the ever-dwindling levels of freshwater resources, the drastic impact of the greenhouse gases on the global climate and the loss of non-renewable fertile soil. South African agriculture contributes a total of 12.7% to the overall South African GDP (gross domestic product). Only a small portion of the South African soil is considered as being able to grow healthy and nutritious crops. The world of information communication technology (ICT) is extremely vast and growing daily with newly created tools, to accommodate the needs of a specific sector, such as agriculture. As the ICT-based agricultural solutions increase and improve, the uptake of these solutions within the South African agricultural sector becomes even smaller. The reasons for the low uptake of mobile soil management solutions for crop-growing farmers are unknown, due to limited research conducted. The identified problem was a lack of understanding of the way mobile technologies can be designed to adequately support farmers to correctly manage their soil to produce the best possible crops. The primary objective of this research study was to identify factors, which may have a significant impact on the design of a mobile soil management application for crop farmers in the Eastern Cape (South Africa). The secondary objectives were as follows: (i) to determine what soil management is and which aspects are required to implement soil management effectively; (ii) to identify possible mobile technologies suitable to act as an effective support structure for a mobile soil management application; and (iii) to identify which user experience guidelines are key for the development of an effective mobile soil management solution and to compile a user experience guideline for an effective mobile soil management solution. Achieving these objectives, resulted in a better understanding of the identified problem. The problem was addressed by conducting a thorough literature review and a case study to better grasp the different aspects of the identified problem. Quantitative data was collected by conducting a user interface evaluation. Qualitative data were also gathered by means of a field test using the mobile soil management application. The field test was done in conjunction with a heuristic evaluation, completed by the participants. Data triangulation was used to compare the results of the gathered data. The results from the data triangulation were used to confirm the factors, which made the most significant impact on the success of the soil management application. These confirmed design factors were used to produce a list of guidelines to improve the design of future mobile ICT soil management applications.
- Full Text:
- Date Issued: 2019
Laser welding of thin-walled stainless steel tubing
- Authors: Mabveka, Greystone Graham
- Date: 2019
- Subjects: Laser welding , Welding Mechanical engineering
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/40690 , vital:36223
- Description: Longitudinal butt welds in the motor industry are increasingly being made by laser welding. One of the materials being welded is thin walled type 441 stainless steel tubing. The welding process parameters should however be optimised to give a weld that possesses acceptable properties. In this research, a Yb:YAG laser machine was used to weld a 1.2mm thick tubing. Laser power and welding speed were varied to achieve an optimum weld whose properties compare well with the parent metal. The two parameters were combined such that the heat input was in the range of 7.5 to 25kJ/m. The welds were characterised by the microstructure from the weld, intergranular attack and mechanical properties. It has been shown by microstructure study that grains originated from ‘weld metal/base metal’ interface and elongated towards the weld centreline. A defined line ran through the interface through the thickness of the plate. Smaller grains were noted around the interface in some welds. Susceptibility to intergranular attack tests showed random ditching in the weld metal microstructure which indicated that the weldments produced were acceptable. Mechanical tests of all welds showed a slight increase in micro-hardness in the weld metal. While the base metal had a micro-hardness range of 160 –199HV0.1, it increased to 187 – 242HV0.1 in the fusion zone. An ANOVA regression of tensile test results predicted an expected maximum of 471MPa to occur when a 1000W power is used at a welding speed of 0.06m/s. Fracture morphology of tensile test samples showed that all failures were by overload. This showed that the weld metal still exhibited similar ductility properties with the base metal.
- Full Text:
- Date Issued: 2019
- Authors: Mabveka, Greystone Graham
- Date: 2019
- Subjects: Laser welding , Welding Mechanical engineering
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/40690 , vital:36223
- Description: Longitudinal butt welds in the motor industry are increasingly being made by laser welding. One of the materials being welded is thin walled type 441 stainless steel tubing. The welding process parameters should however be optimised to give a weld that possesses acceptable properties. In this research, a Yb:YAG laser machine was used to weld a 1.2mm thick tubing. Laser power and welding speed were varied to achieve an optimum weld whose properties compare well with the parent metal. The two parameters were combined such that the heat input was in the range of 7.5 to 25kJ/m. The welds were characterised by the microstructure from the weld, intergranular attack and mechanical properties. It has been shown by microstructure study that grains originated from ‘weld metal/base metal’ interface and elongated towards the weld centreline. A defined line ran through the interface through the thickness of the plate. Smaller grains were noted around the interface in some welds. Susceptibility to intergranular attack tests showed random ditching in the weld metal microstructure which indicated that the weldments produced were acceptable. Mechanical tests of all welds showed a slight increase in micro-hardness in the weld metal. While the base metal had a micro-hardness range of 160 –199HV0.1, it increased to 187 – 242HV0.1 in the fusion zone. An ANOVA regression of tensile test results predicted an expected maximum of 471MPa to occur when a 1000W power is used at a welding speed of 0.06m/s. Fracture morphology of tensile test samples showed that all failures were by overload. This showed that the weld metal still exhibited similar ductility properties with the base metal.
- Full Text:
- Date Issued: 2019
Levels of selected heavy metals in garden soil in Walmer Township and Wells Estate, Port Elizabeth
- Ogunfowora, Ebunoluwa Juliana
- Authors: Ogunfowora, Ebunoluwa Juliana
- Date: 2019
- Subjects: Environmental health -- South Africa -- Port Elizabeth , Environmental chemistry Pollution -- Physiological effect
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/42990 , vital:36722
- Description: Heavy metals are naturally occurring elements that have high densities. Heavy metals have been found to have applications in various sectors such as the industrial, domestic, agricultural and medical sectors, thus resulting in environmental pollution which may pose a hazard to human health. Heavy metals such as arsenic, cadmium, manganese, lead and mercury rank among the priority metals that are of public health significance, and they are commonly found in garden soils. In this study, residential garden soils were sampled in dwelling sites in Wells Estate and Walmer Township, and analysed for mercury, cadmium, arsenic, manganese and lead. A cross sectional design was employed in this study. The research was carried out in two phases; the first phase involved soil sample collection, preparation and laboratory work for the determination of heavy metal concentrations. The second phase focused on the social aspect of the study population which included the use of a pre-approved questionnaire and face-to-face interviews for the collection of human health related information at each dwelling site where soil samples were collected. The research protocol was approved by the Health Sciences Faculty Postgraduate Studies Committees (FPGSC) of Nelson Mandela University. Garden soil from residential yards of Wells Estate (near an industrial site, ̴ 2 km) and Walmer Township (further away from the industrial site (̴ 22 km), but relatively close to Port Elizabeth airport, ̴ 2 km) were sampled over a total of six sampling sessions resulting in 100 soil samples. Fifty soil samples were collected in Wells Estate and fifty soil samples in Walmer Township during the month of May 2017. Surface soil samples were collected from the top 2 cm of the soil using a sterile stainless-steel spoon. In addition to the collection of soil samples, a visual inspection of the house was undertaken to collect information about the house characteristics, geographic location (GPS coordinates) and characteristics of the surrounding area. Soil samples were prepared for analysis by grinding and drying followed by heavy metal determination using an X-ray fluorescence (XRF) analyser (Bruker s1 TITAN Analyser, USA). A face-to-face questionnaire was administered to a suitable respondent at each dwelling site to obtain information related to health symptoms such as coughing, fever, chest pains, earache, sore throat, headaches, rapid breathing, sneezing, running/blocked nose, teary watery eyes, cancer, hypertension, heart diseases and mental illness. The mean concentrations of heavy metals were in the order manganese>lead>arsenic for both study sites. In Walmer Township soil samples, the mean concentrations of heavy metals determined were 154.8 mg/kg, 84.4 mg/kg and 5.4 mg/kg for manganese, lead, and arsenic, respectively. Mean concentrations of heavy metals as determined in Wells Estate were 322.2 mg/kg, 11.5 mg/kg, and 3.4 mg/kg for manganese, lead and arsenic, respectively. Manganese concentration across the study sites are below the guideline levels for USA (630 mg/kg) and South African (1500 mg/kg). About 2.0% of the sample exceeded the South African lead guideline level of 230 mg/kg, while 4.1% exceeded European lead level of 400 mg/kg in Walmer Township. Lead levels in Wells Estate were all below the South African, European and United States guideline levels. By contrast, 2.0% of the sample exceeded the South African arsenic guideline level of 48 mg/kg, 2.0% exceeded European arsenic guideline level of 50 mg/kg and 2.0% exceeded USA arsenic guideline level of 11 mg/kg in Walmer Township, while 2.0% exceeded USA arsenic guideline level of 11 mg/kg in Wells Estate. Mann Whitney U test showed statistically significant differences between lead levels (U=1527, p < 0.001) and manganese levels (U=2632, p < 0.001) across study sites. Soil manganese level showed significant association with age of house (crude OR: 0.34, 95% CI: 0.14-0.83, p =0.016). Using data obtained from the questionnaire, a multivariate logistic regression analysis was performed to examine the relationship between soil heavy metals and the various health outcomes. In Walmer Township, manganese showed association with dry cough (OR: 11.35, 95% CI: 1.08-119.20) and sneezing (OR: 11.30, 95% CI: 1.09-116.67). Manganese was also associated with wet cough (OR: 0.19 95% CI: 0.05-0.70), dry cough (OR: 0.22, 95% CI: 0.06-0.83) and watery eye (OR: 4.55, 95% CI: 1.01-20.58) in Wells Estate. Dry cough (OR: 0.31, 95% CI: 0.16-0.64), sneezing (OR: 2.18, 95% CI: 1.06-4.48) and watery eye adjusted (OR: 3.71, 95% CI: 1.63-8.48) were also associated with manganese in the total sample. Confounding factors such as overcrowding (adjusted OR = 2.23; 95% CI: 1.11-4.48) and air pollution (adjusted OR = 2.76; 95% CI:1.39-5.50), predicted wet cough and sneezing, respectively, across the total sample. Heavy metal concentration in most of the study dwellings of Walmer Township and Wells Estate were below the safe limit recommended by United States, European and South Africa soil reference levels. Nevertheless, we found a strong association between manganese and respiratory symptoms such as dry cough and sneezing in Walmer Township, as well as a strong association between manganese and watery eyes in Wells Estate. There was no evidence of associations between heavy metal exposure and gastrointestinal symptoms, chronic diseases and mental illness.
- Full Text:
- Date Issued: 2019
- Authors: Ogunfowora, Ebunoluwa Juliana
- Date: 2019
- Subjects: Environmental health -- South Africa -- Port Elizabeth , Environmental chemistry Pollution -- Physiological effect
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/42990 , vital:36722
- Description: Heavy metals are naturally occurring elements that have high densities. Heavy metals have been found to have applications in various sectors such as the industrial, domestic, agricultural and medical sectors, thus resulting in environmental pollution which may pose a hazard to human health. Heavy metals such as arsenic, cadmium, manganese, lead and mercury rank among the priority metals that are of public health significance, and they are commonly found in garden soils. In this study, residential garden soils were sampled in dwelling sites in Wells Estate and Walmer Township, and analysed for mercury, cadmium, arsenic, manganese and lead. A cross sectional design was employed in this study. The research was carried out in two phases; the first phase involved soil sample collection, preparation and laboratory work for the determination of heavy metal concentrations. The second phase focused on the social aspect of the study population which included the use of a pre-approved questionnaire and face-to-face interviews for the collection of human health related information at each dwelling site where soil samples were collected. The research protocol was approved by the Health Sciences Faculty Postgraduate Studies Committees (FPGSC) of Nelson Mandela University. Garden soil from residential yards of Wells Estate (near an industrial site, ̴ 2 km) and Walmer Township (further away from the industrial site (̴ 22 km), but relatively close to Port Elizabeth airport, ̴ 2 km) were sampled over a total of six sampling sessions resulting in 100 soil samples. Fifty soil samples were collected in Wells Estate and fifty soil samples in Walmer Township during the month of May 2017. Surface soil samples were collected from the top 2 cm of the soil using a sterile stainless-steel spoon. In addition to the collection of soil samples, a visual inspection of the house was undertaken to collect information about the house characteristics, geographic location (GPS coordinates) and characteristics of the surrounding area. Soil samples were prepared for analysis by grinding and drying followed by heavy metal determination using an X-ray fluorescence (XRF) analyser (Bruker s1 TITAN Analyser, USA). A face-to-face questionnaire was administered to a suitable respondent at each dwelling site to obtain information related to health symptoms such as coughing, fever, chest pains, earache, sore throat, headaches, rapid breathing, sneezing, running/blocked nose, teary watery eyes, cancer, hypertension, heart diseases and mental illness. The mean concentrations of heavy metals were in the order manganese>lead>arsenic for both study sites. In Walmer Township soil samples, the mean concentrations of heavy metals determined were 154.8 mg/kg, 84.4 mg/kg and 5.4 mg/kg for manganese, lead, and arsenic, respectively. Mean concentrations of heavy metals as determined in Wells Estate were 322.2 mg/kg, 11.5 mg/kg, and 3.4 mg/kg for manganese, lead and arsenic, respectively. Manganese concentration across the study sites are below the guideline levels for USA (630 mg/kg) and South African (1500 mg/kg). About 2.0% of the sample exceeded the South African lead guideline level of 230 mg/kg, while 4.1% exceeded European lead level of 400 mg/kg in Walmer Township. Lead levels in Wells Estate were all below the South African, European and United States guideline levels. By contrast, 2.0% of the sample exceeded the South African arsenic guideline level of 48 mg/kg, 2.0% exceeded European arsenic guideline level of 50 mg/kg and 2.0% exceeded USA arsenic guideline level of 11 mg/kg in Walmer Township, while 2.0% exceeded USA arsenic guideline level of 11 mg/kg in Wells Estate. Mann Whitney U test showed statistically significant differences between lead levels (U=1527, p < 0.001) and manganese levels (U=2632, p < 0.001) across study sites. Soil manganese level showed significant association with age of house (crude OR: 0.34, 95% CI: 0.14-0.83, p =0.016). Using data obtained from the questionnaire, a multivariate logistic regression analysis was performed to examine the relationship between soil heavy metals and the various health outcomes. In Walmer Township, manganese showed association with dry cough (OR: 11.35, 95% CI: 1.08-119.20) and sneezing (OR: 11.30, 95% CI: 1.09-116.67). Manganese was also associated with wet cough (OR: 0.19 95% CI: 0.05-0.70), dry cough (OR: 0.22, 95% CI: 0.06-0.83) and watery eye (OR: 4.55, 95% CI: 1.01-20.58) in Wells Estate. Dry cough (OR: 0.31, 95% CI: 0.16-0.64), sneezing (OR: 2.18, 95% CI: 1.06-4.48) and watery eye adjusted (OR: 3.71, 95% CI: 1.63-8.48) were also associated with manganese in the total sample. Confounding factors such as overcrowding (adjusted OR = 2.23; 95% CI: 1.11-4.48) and air pollution (adjusted OR = 2.76; 95% CI:1.39-5.50), predicted wet cough and sneezing, respectively, across the total sample. Heavy metal concentration in most of the study dwellings of Walmer Township and Wells Estate were below the safe limit recommended by United States, European and South Africa soil reference levels. Nevertheless, we found a strong association between manganese and respiratory symptoms such as dry cough and sneezing in Walmer Township, as well as a strong association between manganese and watery eyes in Wells Estate. There was no evidence of associations between heavy metal exposure and gastrointestinal symptoms, chronic diseases and mental illness.
- Full Text:
- Date Issued: 2019
Resistance: revealing and exposing the constructions of societal control
- Authors: Vaghmaria, Nishil Rishik
- Date: 2019
- Subjects: Art, Modern -- 21st century -- Research , Aesthetics Artists -- South Africa -- Exhibitions
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/43710 , vital:37035
- Description: This practice based visual arts investigation was triggered by the researcher’s social understandings and personal concern about societal control on the individual, and his resistance to the negative effects of consumerism and capitalism. Through this research project he aims to reveal and expose the workings of those systems of control visually. He pays particular attention to our current global, cultural and socio-political, economic order and the limitations that are imposed on the individual in terms of freedom of choice and expression, and through both the written work and the practical work he aims to influence a revolution of the mind and to encourage critical consciousness and awareness on the part of its audience regarding how individuals are manipulated, distracted and seduced into conformity. As an outcome of his research, and of his intention to act as an agent for socially aware creative practice, he presents a tentative framework for the use of emerging, socially conscious artists and educators. The practical component of this study is focused around the creation and display of graffiti-influenced images in both public and gallery spaces. The researcher makes extensive use of the SI’s subversive artistic technique of Détournement as he engages with the notion of ‘distraction’. This project, with its dual focus on text and on the creation of artworks in both public and gallery spaces, is intended as a contribution to the search for new critical understandings and diagnostic terminologies around social control.
- Full Text:
- Date Issued: 2019
- Authors: Vaghmaria, Nishil Rishik
- Date: 2019
- Subjects: Art, Modern -- 21st century -- Research , Aesthetics Artists -- South Africa -- Exhibitions
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/43710 , vital:37035
- Description: This practice based visual arts investigation was triggered by the researcher’s social understandings and personal concern about societal control on the individual, and his resistance to the negative effects of consumerism and capitalism. Through this research project he aims to reveal and expose the workings of those systems of control visually. He pays particular attention to our current global, cultural and socio-political, economic order and the limitations that are imposed on the individual in terms of freedom of choice and expression, and through both the written work and the practical work he aims to influence a revolution of the mind and to encourage critical consciousness and awareness on the part of its audience regarding how individuals are manipulated, distracted and seduced into conformity. As an outcome of his research, and of his intention to act as an agent for socially aware creative practice, he presents a tentative framework for the use of emerging, socially conscious artists and educators. The practical component of this study is focused around the creation and display of graffiti-influenced images in both public and gallery spaces. The researcher makes extensive use of the SI’s subversive artistic technique of Détournement as he engages with the notion of ‘distraction’. This project, with its dual focus on text and on the creation of artworks in both public and gallery spaces, is intended as a contribution to the search for new critical understandings and diagnostic terminologies around social control.
- Full Text:
- Date Issued: 2019
The aesthetic manifestations of nothingness in contemporary visual arts practice
- Authors: Munnick, Robyn Therése
- Date: 2019
- Subjects: Art -- Research
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/41625 , vital:36546
- Description: The purpose of this dissertation is to explore the notion of nothingness and how it [nothingness] is the conceptual and theoretical foundation for my practice. Furthermore, within this study I explicate how my art uses my mother’s battle with cancer and the subsequent void it created in me as source material for the artistic expression of nothingness. The diagnosis which followed by a physical and emotional absence of the matriarch of my family, led to an emotional trauma that triggered a feeling of nothingness within me. The overarching problem in the study is therefore how this nothingness could be expressed in my art. Nothingness, as a product of expectation, is a notion which refers to where something used to be, should be or is not anymore, and attempts to grasp what is there by not being there. In attempting to express nothingness, the research aimed to build on an exploration of the various materials and modes utilized in order to underpin the research objectives. The primary mode of delivery for my art-making process is painting. However, through strengthening the messages and meaning of the hypothesis of nothingness within my art and research, the use of further modes and materials became pivotal. This involved the use of unconventional contrasting modes within painting such as the cloth doily, thread, tubing, ceramics, food colour, spray paint, PVA, plaster, wooden boxes and fragments thereof. These materials and modes were vital in visualising and aestheticising the conceptual underpinnings of the research. As a result, this strengthened and emancipated my art from the traditional bounds of pure painting. Methods of data gathering took the form of artefacts, document analysis and field notes in the form of photographic journaling. Ultimately my body of work and research validates that the idea of nothingness can be artistically explored.
- Full Text:
- Date Issued: 2019
- Authors: Munnick, Robyn Therése
- Date: 2019
- Subjects: Art -- Research
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/41625 , vital:36546
- Description: The purpose of this dissertation is to explore the notion of nothingness and how it [nothingness] is the conceptual and theoretical foundation for my practice. Furthermore, within this study I explicate how my art uses my mother’s battle with cancer and the subsequent void it created in me as source material for the artistic expression of nothingness. The diagnosis which followed by a physical and emotional absence of the matriarch of my family, led to an emotional trauma that triggered a feeling of nothingness within me. The overarching problem in the study is therefore how this nothingness could be expressed in my art. Nothingness, as a product of expectation, is a notion which refers to where something used to be, should be or is not anymore, and attempts to grasp what is there by not being there. In attempting to express nothingness, the research aimed to build on an exploration of the various materials and modes utilized in order to underpin the research objectives. The primary mode of delivery for my art-making process is painting. However, through strengthening the messages and meaning of the hypothesis of nothingness within my art and research, the use of further modes and materials became pivotal. This involved the use of unconventional contrasting modes within painting such as the cloth doily, thread, tubing, ceramics, food colour, spray paint, PVA, plaster, wooden boxes and fragments thereof. These materials and modes were vital in visualising and aestheticising the conceptual underpinnings of the research. As a result, this strengthened and emancipated my art from the traditional bounds of pure painting. Methods of data gathering took the form of artefacts, document analysis and field notes in the form of photographic journaling. Ultimately my body of work and research validates that the idea of nothingness can be artistically explored.
- Full Text:
- Date Issued: 2019
The aesthetic manifestations of nothingness in contemporary visual arts practice
- Authors: Munnick, Robyn Therése
- Date: 2019
- Subjects: Art, Modern -- 21st century , Aesthetics , Visual perception , Art -- Philosophy
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/41636 , vital:36550
- Description: The purpose of this dissertation is to explore the notion of nothingness and how it [nothingness] is the conceptual and theoretical foundation for my practice. Furthermore, within this study I explicate how my art uses my mother’s battle with cancer and the subsequent void it created in me as source material for the artistic expression of nothingness. The diagnosis which followed by a physical and emotional absence of the matriarch of my family, led to an emotional trauma that triggered a feeling of nothingness within me. The overarching problem in the study is therefore how this nothingness could be expressed in my art. Nothingness, as a product of expectation, is a notion which refers to where something used to be, should be or is not anymore, and attempts to grasp what is there by not being there. In attempting to express nothingness, the research aimed to build on an exploration of the various materials and modes utilized in order to underpin the research objectives. The primary mode of delivery for my art-making process is painting. However, through strengthening the messages and meaning of the hypothesis of nothingness within my art and research, the use of further modes and materials became pivotal. This involved the use of unconventional contrasting modes within painting such as the cloth doily, thread, tubing, ceramics, food colour, spray paint, PVA, plaster, wooden boxes and fragments thereof. These materials and modes were vital in visualising and aestheticising the conceptual underpinnings of the research. As a result, this strengthened and emancipated my art from the traditional bounds of pure painting. Methods of data gathering took the form of artefacts, document analysis and field notes in the form of photographic journaling. Ultimately my body of work and research validates that the idea of nothingness can be artistically explored.
- Full Text:
- Date Issued: 2019
- Authors: Munnick, Robyn Therése
- Date: 2019
- Subjects: Art, Modern -- 21st century , Aesthetics , Visual perception , Art -- Philosophy
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/41636 , vital:36550
- Description: The purpose of this dissertation is to explore the notion of nothingness and how it [nothingness] is the conceptual and theoretical foundation for my practice. Furthermore, within this study I explicate how my art uses my mother’s battle with cancer and the subsequent void it created in me as source material for the artistic expression of nothingness. The diagnosis which followed by a physical and emotional absence of the matriarch of my family, led to an emotional trauma that triggered a feeling of nothingness within me. The overarching problem in the study is therefore how this nothingness could be expressed in my art. Nothingness, as a product of expectation, is a notion which refers to where something used to be, should be or is not anymore, and attempts to grasp what is there by not being there. In attempting to express nothingness, the research aimed to build on an exploration of the various materials and modes utilized in order to underpin the research objectives. The primary mode of delivery for my art-making process is painting. However, through strengthening the messages and meaning of the hypothesis of nothingness within my art and research, the use of further modes and materials became pivotal. This involved the use of unconventional contrasting modes within painting such as the cloth doily, thread, tubing, ceramics, food colour, spray paint, PVA, plaster, wooden boxes and fragments thereof. These materials and modes were vital in visualising and aestheticising the conceptual underpinnings of the research. As a result, this strengthened and emancipated my art from the traditional bounds of pure painting. Methods of data gathering took the form of artefacts, document analysis and field notes in the form of photographic journaling. Ultimately my body of work and research validates that the idea of nothingness can be artistically explored.
- Full Text:
- Date Issued: 2019
Top-soil water retention in organic and conventional farming systems in South Africa’s Southern Cape
- Authors: Eckert, Catherine Jessica
- Date: 2019
- Subjects: Water harvesting , Soil moisture conservation Organic farming Sustainable agriculture
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/39885 , vital:35500
- Description: With the world’s growing population and limited natural resources, there is a need to produce more food using less inputs. A major limiting factor to meeting the agricultural production needs of the growing population is fresh water. Water is a critical resource in agriculture and may be more of a limiting factor than other crop growth requirements in some areas. Furthermore, water availability is being impacted by climate change and competition from other industries. Methods of improving crop water use efficiency through conservation of water and the enhancement of crop growth need to be employed to meet the growing demand sustainably. The purpose of the research was to assess the differences in soil water status between organically farmed crops with a grass mulch and conventionally farmed crops without mulch, with a view to making more efficient use of the water resource. This research was conducted at the Mandela long term organic farming systems research trial site at Nelson Mandela University, George campus in the southern Cape, South Africa. It is part of a larger research project (the Mandela Trials) in which various researchers have been involved in different aspects of this trial including agronomy, microbiology and pest and disease control. This research took place over two seasons, namely, 2016-2017 season and 2017-2018 season. The soil water content (SWC) of organic and conventional plots were measured using fixed capacitance probes that recorded continuous data, every half hour, at depths of 10, 30 and 50 cm. A handheld theta probe was also used to measure the SWC in the top 6 cm of the soil at 7 to14 day intervals. The organic treatment had a significantly higher SWC than the conventional treatment over the two seasons in which this research was conducted. In addition, soil carbon was significantly higher in the organic treatment, than the conventional. Organic farming methods preserve and promote an increase in soil organic matter, thus improving the soil structure and increasing the soil’s water holding capacity. From this research, it is concluded that organic farming practices can be used to help conserve SWC, keeping it available to crops for longer and helping farmers make more efficient use of this scarce resource. This is especially relevant for low rainfall areas which are affected by water shortages. The improved SWC availability should be coupled with good agronomic practices to increase productive water losses and the conversion of water to yields, thus increasing water use efficiency. In addition, adding organic matter to the soil will improve resilience of the soil and help sequester carbon and thus help in mitigating climate change.
- Full Text:
- Date Issued: 2019
Top-soil water retention in organic and conventional farming systems in South Africa’s Southern Cape
- Authors: Eckert, Catherine Jessica
- Date: 2019
- Subjects: Water harvesting , Soil moisture conservation Organic farming Sustainable agriculture
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/39885 , vital:35500
- Description: With the world’s growing population and limited natural resources, there is a need to produce more food using less inputs. A major limiting factor to meeting the agricultural production needs of the growing population is fresh water. Water is a critical resource in agriculture and may be more of a limiting factor than other crop growth requirements in some areas. Furthermore, water availability is being impacted by climate change and competition from other industries. Methods of improving crop water use efficiency through conservation of water and the enhancement of crop growth need to be employed to meet the growing demand sustainably. The purpose of the research was to assess the differences in soil water status between organically farmed crops with a grass mulch and conventionally farmed crops without mulch, with a view to making more efficient use of the water resource. This research was conducted at the Mandela long term organic farming systems research trial site at Nelson Mandela University, George campus in the southern Cape, South Africa. It is part of a larger research project (the Mandela Trials) in which various researchers have been involved in different aspects of this trial including agronomy, microbiology and pest and disease control. This research took place over two seasons, namely, 2016-2017 season and 2017-2018 season. The soil water content (SWC) of organic and conventional plots were measured using fixed capacitance probes that recorded continuous data, every half hour, at depths of 10, 30 and 50 cm. A handheld theta probe was also used to measure the SWC in the top 6 cm of the soil at 7 to14 day intervals. The organic treatment had a significantly higher SWC than the conventional treatment over the two seasons in which this research was conducted. In addition, soil carbon was significantly higher in the organic treatment, than the conventional. Organic farming methods preserve and promote an increase in soil organic matter, thus improving the soil structure and increasing the soil’s water holding capacity. From this research, it is concluded that organic farming practices can be used to help conserve SWC, keeping it available to crops for longer and helping farmers make more efficient use of this scarce resource. This is especially relevant for low rainfall areas which are affected by water shortages. The improved SWC availability should be coupled with good agronomic practices to increase productive water losses and the conversion of water to yields, thus increasing water use efficiency. In addition, adding organic matter to the soil will improve resilience of the soil and help sequester carbon and thus help in mitigating climate change.
- Full Text:
- Date Issued: 2019
An evaluation of the role of cost management control systems on organisational performance in public enterprises in Namibia: a case study of the Namibia airports company
- Authors: Shindobo, Teopolina
- Date: 2018
- Subjects: Cost accounting , Activity-based costing , Performance standards -- Namibia -- Evaluation , Organizational effectiveness -- Namibia
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/35785 , vital:33812
- Description: The primary goal of this study was to evaluate the role of cost management control systems (CMCS) on organisational performance of public enterprises in Namibia, using Namibia Airports Company (NAC) as a case study organisation. NAC uses the activity based costing (ABC) management control system and is still making losses, the auditor General have recommended that there is a need to evaluate the CMCS used by the NAC and their expenditure. In pursuing the primary objective of the study, four secondary objectives were therefore developed. The first objective was concerned with evaluating the purpose of the CMCSs in organisational decision making process. The second objective was concerned with analysing the effect of CMCSs on organisational performance in public enterprises. This was also achieved through a comprehensive review of literature. The third objective dealt with the design of a suitable methodology. The last objective was concerned with conclusions and recommendations of the study. The study followed a quantitative research methodology and a total of 100 questionnaires were self-administered to the respondents. Sixty-five questionnaires were returned with usable responses and were captured for analysis. Statistical analysis was applied in order to meet the requirements of research methodology as well as record and analyse the research findings. The study used descriptive statistics, reliability statistics, factor analysis and one way variance analysis (ANOVAs). Factor analysis was performed on the elements used to measure the impacts of CMCSs on the organisational performance of the Namibia Airports Company. Four key impacts of CMCSs were identified in this study. ANOVAs were employed as a way of determining significant differences between groups with regard to the factors that were identified. The finding of the study revealed that, the level of employee involvement in cost management activities is relatively weak at Namibia Airports Company despite a higher frequency of using the CMCSs. There is a significant effect on financial performance of the organisation as a result of employing CMCSs. The significant impacts of CMCSs on the organisational performance of the Namibia Airports Company include opportunities for improving financial performance management, efficiency in service delivery, and strategic decisions.
- Full Text:
- Date Issued: 2018
- Authors: Shindobo, Teopolina
- Date: 2018
- Subjects: Cost accounting , Activity-based costing , Performance standards -- Namibia -- Evaluation , Organizational effectiveness -- Namibia
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/35785 , vital:33812
- Description: The primary goal of this study was to evaluate the role of cost management control systems (CMCS) on organisational performance of public enterprises in Namibia, using Namibia Airports Company (NAC) as a case study organisation. NAC uses the activity based costing (ABC) management control system and is still making losses, the auditor General have recommended that there is a need to evaluate the CMCS used by the NAC and their expenditure. In pursuing the primary objective of the study, four secondary objectives were therefore developed. The first objective was concerned with evaluating the purpose of the CMCSs in organisational decision making process. The second objective was concerned with analysing the effect of CMCSs on organisational performance in public enterprises. This was also achieved through a comprehensive review of literature. The third objective dealt with the design of a suitable methodology. The last objective was concerned with conclusions and recommendations of the study. The study followed a quantitative research methodology and a total of 100 questionnaires were self-administered to the respondents. Sixty-five questionnaires were returned with usable responses and were captured for analysis. Statistical analysis was applied in order to meet the requirements of research methodology as well as record and analyse the research findings. The study used descriptive statistics, reliability statistics, factor analysis and one way variance analysis (ANOVAs). Factor analysis was performed on the elements used to measure the impacts of CMCSs on the organisational performance of the Namibia Airports Company. Four key impacts of CMCSs were identified in this study. ANOVAs were employed as a way of determining significant differences between groups with regard to the factors that were identified. The finding of the study revealed that, the level of employee involvement in cost management activities is relatively weak at Namibia Airports Company despite a higher frequency of using the CMCSs. There is a significant effect on financial performance of the organisation as a result of employing CMCSs. The significant impacts of CMCSs on the organisational performance of the Namibia Airports Company include opportunities for improving financial performance management, efficiency in service delivery, and strategic decisions.
- Full Text:
- Date Issued: 2018