A clip composition case study of communal wool production in the Eastern Cape, South Africa
- Authors: Dreyer, Susanna Maria
- Date: 2019
- Subjects: Wool industry -- South Africa -- Eastern Cape , Wool -- South Africa -- Eastern Cape Sheep industry -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39480 , vital:35265
- Description: Previous studies conducted on wool production in the communal areas of the Eastern Cape have concluded future research should focus on whether the observed differences in average wool price received between shearing sheds are due to differences in clip preparation (i.e. classing) or differences in the quality of the wool being produced (i.e. genetics).The objective of this study was to establish whether there are indeed geographical differences in the average wool price received by communal wool producers in the Eastern Cape and, if so, whether this difference in earnings is attributable to differences in the quality of wool produced and/or clip preparation. The current research explored eight years of wool production records of communal wool farmers (2009/10 to 2016/17) obtained from BKB, the largest wool broker in South Africa. Statistical analyses included descriptive statistics, analysis of variance, parametric tests (i.e. t-test) and multiple regression analysis. The conclusions drawn from this study are: that there are indeed statistically significant differences in the average wool price received between the different geographic areas of the Eastern Cape communal regions, and that the primary determining factor is wool quality, while clip preparation also plays an important but secondary role. The study identified specific geographic areas where developmental interventions are most critical, with specific emphasis on improving the genetic composition of the wool sheep flocks. Specific strategies are recommended, namely:Removing inferior-quality rams and replacing them with superior-quality rams to prevent any inferior nondescript rams from breeding and producing progeny; Replacing the inferior-quality nondescript ewes in specific areas with superior-quality ewes, and Improving the survival rate of lambs and thereby contributing towards expediting the rate of genetic improvement of the communal wool sheep flocks.
- Full Text:
- Date Issued: 2019
- Authors: Dreyer, Susanna Maria
- Date: 2019
- Subjects: Wool industry -- South Africa -- Eastern Cape , Wool -- South Africa -- Eastern Cape Sheep industry -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39480 , vital:35265
- Description: Previous studies conducted on wool production in the communal areas of the Eastern Cape have concluded future research should focus on whether the observed differences in average wool price received between shearing sheds are due to differences in clip preparation (i.e. classing) or differences in the quality of the wool being produced (i.e. genetics).The objective of this study was to establish whether there are indeed geographical differences in the average wool price received by communal wool producers in the Eastern Cape and, if so, whether this difference in earnings is attributable to differences in the quality of wool produced and/or clip preparation. The current research explored eight years of wool production records of communal wool farmers (2009/10 to 2016/17) obtained from BKB, the largest wool broker in South Africa. Statistical analyses included descriptive statistics, analysis of variance, parametric tests (i.e. t-test) and multiple regression analysis. The conclusions drawn from this study are: that there are indeed statistically significant differences in the average wool price received between the different geographic areas of the Eastern Cape communal regions, and that the primary determining factor is wool quality, while clip preparation also plays an important but secondary role. The study identified specific geographic areas where developmental interventions are most critical, with specific emphasis on improving the genetic composition of the wool sheep flocks. Specific strategies are recommended, namely:Removing inferior-quality rams and replacing them with superior-quality rams to prevent any inferior nondescript rams from breeding and producing progeny; Replacing the inferior-quality nondescript ewes in specific areas with superior-quality ewes, and Improving the survival rate of lambs and thereby contributing towards expediting the rate of genetic improvement of the communal wool sheep flocks.
- Full Text:
- Date Issued: 2019
A Comparative Study of Bootstrapping Techniques for Inventory Control
- Authors: Frederick, Lauren
- Date: 2020
- Subjects: Computer bootstrapping -- Inventory control
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48335 , vital:40849
- Description: Setting correct inventory levels is an important business consideration in order to minimise inventory investment while at the same time ensuring sufficient inventory levels to meet customer demand. Inventory management has a significant impact on both financial and customer service aspects of a business. Selecting appropriate inventory levels requires that products’ lead time demand be accurately estimated in order to calculate the reorder point. The purpose of this study was to empirically determine whether bootstrapping methods used to estimate the lead time demand distribution and reorder point calculation could match or even outperform a standard parametric approach. The two bootstrapping methods compared in this research included variations of those presented by Bookbinder and Lordahl [1989] and do Rego and de Mesquita [2015]. These were compared to the standard parametric approach common in practice which makes use of the Normal distribution for modelling lead time demand. The three reorder point calculation methods were each incorporated into the inventory policy simulations using data supplied by a South African automotive spare parts business. The simulations covered a period of twelve months and were repeated for multiple service levels ranging from 70 to 99 percent. Results of the simulations were compared at a high level as well as for groups of items identified using segmentation techniques which considered different item demand and lead time characteristics. Key findings were that the Normal approximation method was far superior in terms of the service level metric, while the variation of the Bookbinder and Lordahl [1989] method adopted in this study presented possible cost benefits at lower service levels.
- Full Text:
- Date Issued: 2020
- Authors: Frederick, Lauren
- Date: 2020
- Subjects: Computer bootstrapping -- Inventory control
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48335 , vital:40849
- Description: Setting correct inventory levels is an important business consideration in order to minimise inventory investment while at the same time ensuring sufficient inventory levels to meet customer demand. Inventory management has a significant impact on both financial and customer service aspects of a business. Selecting appropriate inventory levels requires that products’ lead time demand be accurately estimated in order to calculate the reorder point. The purpose of this study was to empirically determine whether bootstrapping methods used to estimate the lead time demand distribution and reorder point calculation could match or even outperform a standard parametric approach. The two bootstrapping methods compared in this research included variations of those presented by Bookbinder and Lordahl [1989] and do Rego and de Mesquita [2015]. These were compared to the standard parametric approach common in practice which makes use of the Normal distribution for modelling lead time demand. The three reorder point calculation methods were each incorporated into the inventory policy simulations using data supplied by a South African automotive spare parts business. The simulations covered a period of twelve months and were repeated for multiple service levels ranging from 70 to 99 percent. Results of the simulations were compared at a high level as well as for groups of items identified using segmentation techniques which considered different item demand and lead time characteristics. Key findings were that the Normal approximation method was far superior in terms of the service level metric, while the variation of the Bookbinder and Lordahl [1989] method adopted in this study presented possible cost benefits at lower service levels.
- Full Text:
- Date Issued: 2020
A comparison of conventional and ultrasonic seams in swimwear
- Authors: Tyalana, Nommiselo
- Date: 2018
- Subjects: Textile finishing , Textile finishing agents Seams (Sewing) Textile fabrics Textile fibers Textile design
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/36727 , vital:34048
- Description: Ultrasonic welding technology is a relatively new technology in apparel construction, this research forms part of a study to assess its effectiveness as a joining technology that can be used in ladies swimwear. The ultimate aim was to determine whether the ultrasonic welding joining technique could be successfully used in assembling ladies swimwear garments, comprising only synthetic fibres, namely polyester/Lycra, polyamide/Lycra, polyamide/Lycra power-net and polyamide/Lycra mesh warp knitted fabrics. These specific swimwear fabrics were selected since they comprise 100% thermoplastic synthetic fibres, considered ideal for ultrasonic welding. This study essentially compares and contrasts the performance of two seam joining techniques: namely conventional sewing and ultrasonic welding, in terms of seam strength, when used in the above mentioned four fabrics. Conventionally sewn and ultrasonically welded seams were produced, straight and curved, in both the wale and course directions of the fabrics. The conventionally sewn seams were produced using two sewing machines; namely an overlocker, also known as a mock safety sewing machine, and a cover seam machines. All conventionally sewn seams were stitched and tested under similar conditions. The ultrasonic welded seams were produced using three different wheels, a Medium Male Knurled pattern wheel, a Staggered Triple Stitch pattern wheel and a Single Stitch pattern wheel. The amplitude and speed of the welding machine, during the ultrasonic seaming, were kept constant, except when welding the polyamide/Lycra power-net and the polyamide/Lycra mesh fabrics when the pressure had to be drastically reduced in order to avoid excessively softened seams. The results of the study are presented in the form of line charts, scatter charts and tables. The ultrasonic welded seams, joined with the Medium Male Knurled wheel, exhibited surface waviness, as opposed to those joined with the Staggered Triple Stitch wheel which were smooth. It was found that, in terms of seam strength, the ultrasonic seams produced with the Single Stitch and Medium Male Knurled pattern wheels out performed those produced with the Staggered Triple Stitch wheels. The polyester/Lycra fabric was found easier to handle during the ultrasonic seaming process than the polyamide/Lycra fabric, although the strength of the ultrasonic seams in the polyester/Lycra fabric did not differ consistently from those of the polyamide/Lycra fabric. It was found that the conventional sewn seams were consistently stronger, and had a better appearance, than the ultrasonic welded seams. Although some promising results were obtained, in terms of the strength of the ultrasonic welded seams, the results overall were far too variable, inconsistent and unsatisfactory for this technique of seaming to be recommended at this stage for any of the swimwear fabrics covered. Further, more in depth, studies are required in order to gain a better understating of the effect of the various ultrasonic seaming parameters, as well as fabric parameters on ultrasonic seam strength and consistency.
- Full Text:
- Date Issued: 2018
- Authors: Tyalana, Nommiselo
- Date: 2018
- Subjects: Textile finishing , Textile finishing agents Seams (Sewing) Textile fabrics Textile fibers Textile design
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/36727 , vital:34048
- Description: Ultrasonic welding technology is a relatively new technology in apparel construction, this research forms part of a study to assess its effectiveness as a joining technology that can be used in ladies swimwear. The ultimate aim was to determine whether the ultrasonic welding joining technique could be successfully used in assembling ladies swimwear garments, comprising only synthetic fibres, namely polyester/Lycra, polyamide/Lycra, polyamide/Lycra power-net and polyamide/Lycra mesh warp knitted fabrics. These specific swimwear fabrics were selected since they comprise 100% thermoplastic synthetic fibres, considered ideal for ultrasonic welding. This study essentially compares and contrasts the performance of two seam joining techniques: namely conventional sewing and ultrasonic welding, in terms of seam strength, when used in the above mentioned four fabrics. Conventionally sewn and ultrasonically welded seams were produced, straight and curved, in both the wale and course directions of the fabrics. The conventionally sewn seams were produced using two sewing machines; namely an overlocker, also known as a mock safety sewing machine, and a cover seam machines. All conventionally sewn seams were stitched and tested under similar conditions. The ultrasonic welded seams were produced using three different wheels, a Medium Male Knurled pattern wheel, a Staggered Triple Stitch pattern wheel and a Single Stitch pattern wheel. The amplitude and speed of the welding machine, during the ultrasonic seaming, were kept constant, except when welding the polyamide/Lycra power-net and the polyamide/Lycra mesh fabrics when the pressure had to be drastically reduced in order to avoid excessively softened seams. The results of the study are presented in the form of line charts, scatter charts and tables. The ultrasonic welded seams, joined with the Medium Male Knurled wheel, exhibited surface waviness, as opposed to those joined with the Staggered Triple Stitch wheel which were smooth. It was found that, in terms of seam strength, the ultrasonic seams produced with the Single Stitch and Medium Male Knurled pattern wheels out performed those produced with the Staggered Triple Stitch wheels. The polyester/Lycra fabric was found easier to handle during the ultrasonic seaming process than the polyamide/Lycra fabric, although the strength of the ultrasonic seams in the polyester/Lycra fabric did not differ consistently from those of the polyamide/Lycra fabric. It was found that the conventional sewn seams were consistently stronger, and had a better appearance, than the ultrasonic welded seams. Although some promising results were obtained, in terms of the strength of the ultrasonic welded seams, the results overall were far too variable, inconsistent and unsatisfactory for this technique of seaming to be recommended at this stage for any of the swimwear fabrics covered. Further, more in depth, studies are required in order to gain a better understating of the effect of the various ultrasonic seaming parameters, as well as fabric parameters on ultrasonic seam strength and consistency.
- Full Text:
- Date Issued: 2018
A congestion aware ant colony optimisation-based routing and wavelength assignment algorithm for transparent flexi-grid optical burst switched networks
- Authors: Oladipo, Joshua Femi
- Date: 2018
- Subjects: Ants -- Behavior -- Mathematical models , Distributed algorithms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/34733 , vital:33432
- Description: Optical Burst Switching (OBS) over transparent exi-grid optical networks, is considered a potential solution to the increasing pressure on backbone networks due to the increase in internet use and widespread adoption of various high bandwidth applications. Both technologies allow for more e cient usage of a networks resources. However, transmissions over exi-grid networks are more susceptible to optical impairments than transmissions made over xed-grid networks, and OBS suers from high burst loss due to contention. These issues need to be solved in order to reap the full benets of both technologies. An open issue for OBS whose solution would mitigate both issues is the Routing and Wavelength Assignment (RWA) algorithm. Ant Colony Optimisation (ACO) is a method of interest for solving the RWA problem on OBS networks. This study aims to improve on current dynamic ACO-based solutions to the Routing and Wavelength Assignment problem on transparent exi-grid Optical Burst Switched networks.
- Full Text:
- Date Issued: 2018
- Authors: Oladipo, Joshua Femi
- Date: 2018
- Subjects: Ants -- Behavior -- Mathematical models , Distributed algorithms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/34733 , vital:33432
- Description: Optical Burst Switching (OBS) over transparent exi-grid optical networks, is considered a potential solution to the increasing pressure on backbone networks due to the increase in internet use and widespread adoption of various high bandwidth applications. Both technologies allow for more e cient usage of a networks resources. However, transmissions over exi-grid networks are more susceptible to optical impairments than transmissions made over xed-grid networks, and OBS suers from high burst loss due to contention. These issues need to be solved in order to reap the full benets of both technologies. An open issue for OBS whose solution would mitigate both issues is the Routing and Wavelength Assignment (RWA) algorithm. Ant Colony Optimisation (ACO) is a method of interest for solving the RWA problem on OBS networks. This study aims to improve on current dynamic ACO-based solutions to the Routing and Wavelength Assignment problem on transparent exi-grid Optical Burst Switched networks.
- Full Text:
- Date Issued: 2018
A crowdsensing method for water resource monitoring in smart communities
- Authors: Banda, Clara Mloza
- Date: 2019
- Subjects: Data collection platforms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/42449 , vital:36658
- Description: Crowdsensing aims to empower a large group of individuals to collect large amounts of data using their mobile devices, with the goal of sharing the collected data. Existing crowdsensing studies do not consider all the activities and methods of the crowdsensing process and the key success factors related to the process. Nor do they investigate the profile and behaviour of potential participants. The aim of this study was to design a crowdsensing method for water resource monitoring in smart communities. This study opted for an exploratory study using the Engaged Scholarship approach, which allows the study of complex real-world problems based on the different perspectives of key stakeholders. The proposed Crowdsensing Method considers the social, technical and programme design components. The study proposes a programme design for the Crowdsensing Methodwhich is crowdsensing ReferenceFrameworkthat includes Crowdsensing Processwith key success factors and guidelines that should be considered in each phase of the process. The method also uses the Theory of Planned Behaviour (TPB) to investigate citizens’intention to participate in crowdsensing for water resource monitoring and explores their attitudes, norms and perceived behavioural control on these intentions. Understanding the profiles of potential participants can assist with designing crowdsensing systems with appropriate incentive mechanisms to achieve adequate user participation and good service quality. A survey was conducted to validate the theoretical TB model in a real-world context. Regression and correlation analyses demonstrated that the attitudes, norms and perceived behavioural control can be used to predict participants’ intention to participate in crowdsensing for water resource monitoring. The survey results assisted with the development of an Incentive Mechanism as part of the Crowdsensing Method. This mechanism incorporates recruitment and incentive policies, as well as guidelines derived from the literature review and extant system analysis. The policies, called the OverSensepolicies, provide guidance for recruitment and rewarding of participants using the popular Stackelberg technique. The policies were evaluated using simulation experiments with a data set provided by the case study, the Nelson Mandela Bay Municipality. The results of the simulation experiments illustrated that the OverSenserecruitmentpolicycan reduce the computing resources required for the recruitment of participants and that the recruitment policy performs better than random or naïve recruitment policies. The proposed Crowdsensing Method was evaluated using an ecosystem of success factors for mobile-based interventions identified in the literature and the Crowdsensing Method adhered to a majority (90%) of the success factors. This study also contributes information systems design theory by proposing several sets of guidelines for crowdsensing projects and the development of crowdsensing systems. This study fulfils an identified need to study the applicability of crowdsensing for water resource monitoring and explores how a crowdsensing method can create a smart community.
- Full Text:
- Date Issued: 2019
- Authors: Banda, Clara Mloza
- Date: 2019
- Subjects: Data collection platforms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/42449 , vital:36658
- Description: Crowdsensing aims to empower a large group of individuals to collect large amounts of data using their mobile devices, with the goal of sharing the collected data. Existing crowdsensing studies do not consider all the activities and methods of the crowdsensing process and the key success factors related to the process. Nor do they investigate the profile and behaviour of potential participants. The aim of this study was to design a crowdsensing method for water resource monitoring in smart communities. This study opted for an exploratory study using the Engaged Scholarship approach, which allows the study of complex real-world problems based on the different perspectives of key stakeholders. The proposed Crowdsensing Method considers the social, technical and programme design components. The study proposes a programme design for the Crowdsensing Methodwhich is crowdsensing ReferenceFrameworkthat includes Crowdsensing Processwith key success factors and guidelines that should be considered in each phase of the process. The method also uses the Theory of Planned Behaviour (TPB) to investigate citizens’intention to participate in crowdsensing for water resource monitoring and explores their attitudes, norms and perceived behavioural control on these intentions. Understanding the profiles of potential participants can assist with designing crowdsensing systems with appropriate incentive mechanisms to achieve adequate user participation and good service quality. A survey was conducted to validate the theoretical TB model in a real-world context. Regression and correlation analyses demonstrated that the attitudes, norms and perceived behavioural control can be used to predict participants’ intention to participate in crowdsensing for water resource monitoring. The survey results assisted with the development of an Incentive Mechanism as part of the Crowdsensing Method. This mechanism incorporates recruitment and incentive policies, as well as guidelines derived from the literature review and extant system analysis. The policies, called the OverSensepolicies, provide guidance for recruitment and rewarding of participants using the popular Stackelberg technique. The policies were evaluated using simulation experiments with a data set provided by the case study, the Nelson Mandela Bay Municipality. The results of the simulation experiments illustrated that the OverSenserecruitmentpolicycan reduce the computing resources required for the recruitment of participants and that the recruitment policy performs better than random or naïve recruitment policies. The proposed Crowdsensing Method was evaluated using an ecosystem of success factors for mobile-based interventions identified in the literature and the Crowdsensing Method adhered to a majority (90%) of the success factors. This study also contributes information systems design theory by proposing several sets of guidelines for crowdsensing projects and the development of crowdsensing systems. This study fulfils an identified need to study the applicability of crowdsensing for water resource monitoring and explores how a crowdsensing method can create a smart community.
- Full Text:
- Date Issued: 2019
A deep learning approach to classifying tyres using sidewall images
- Authors: Gifford, Dean
- Date: 2019
- Subjects: Image processing -- Digital techniques , Image processing Computer science
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39720 , vital:35351
- Description: End of Life Tyres (ELT's) pose a potential health and environmental risk when dumped in illegal stockpiles. For recycling to be considered feasible, a profitable business opportunity needs to be created. One method of making the recycling process of tyres more profitable is by understanding the compounds found within each tyre. This study aims at classifying these tyres in order to achieve this knowledge. A literature review was done to investigate neural networks, convolutional neural networks as well as existing deep learning architectures for image classification. A deep learning approach was applied in order to classify the logos of tyres as these approaches have proved their success in both image classification and more specifically logo classification. Although tyre classification has been implemented in the past, a deep learning approach has not been applied and the logo has not been the classifying element in any other studies. The main difference of this study compared to previous research surrounding deep learning and logo classification is the properties of the tyre logo. Logos on tyres are very similar in colour as they are purely formed in rubber and very seldom have any colour to them. Additionally, the embossed logos can contain variation among same branded tyres due to small inconsistencies in the moulds. The implementation of this deep learning solution saw multiple convolutional neural networks implemented. Some of these architectures were also implemented using transferred learning. The metrics obtained as outputs from training and testing the architectures were the accuracy, precision, recall, and F1-score. These metrics were compared in conjunction with the confusion matrix produced from testing. To ensure that variance was accounted for in the experiments, the k-fold cross-validation technique was adopted. The results of this study identified that one convolutional neural network model, MobileNet, was particularly well suited for the context of classifying logos on tyre sidewalls. The MobileNet architecture had the highest performance metrics for both training from scratch (96.7% accuracy) and transferred learning (98.8% accuracy). Three other models performed particularly well when trained from scratch, these were a modification of the LeNet architecture, ResNet50 and InceptionV3. The transferred learning results were also impressive with four out of the 5 models achieving an accuracy above 94%. Interestingly, the ResNet50 architecture failed to train when transferred learning was applied. Contrasting to this, the two models VGG16 and VGG19 failed to train when trained from scratch but performed equally as well as the other models when transferred learning was implemented. This indicates that although transferred learning can improve the performance of models, it is highly dependent on the task as well as the model. Overall the results obtained proved that a deep learning approach could be applied in order to classify tyres accurately.
- Full Text:
- Date Issued: 2019
- Authors: Gifford, Dean
- Date: 2019
- Subjects: Image processing -- Digital techniques , Image processing Computer science
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39720 , vital:35351
- Description: End of Life Tyres (ELT's) pose a potential health and environmental risk when dumped in illegal stockpiles. For recycling to be considered feasible, a profitable business opportunity needs to be created. One method of making the recycling process of tyres more profitable is by understanding the compounds found within each tyre. This study aims at classifying these tyres in order to achieve this knowledge. A literature review was done to investigate neural networks, convolutional neural networks as well as existing deep learning architectures for image classification. A deep learning approach was applied in order to classify the logos of tyres as these approaches have proved their success in both image classification and more specifically logo classification. Although tyre classification has been implemented in the past, a deep learning approach has not been applied and the logo has not been the classifying element in any other studies. The main difference of this study compared to previous research surrounding deep learning and logo classification is the properties of the tyre logo. Logos on tyres are very similar in colour as they are purely formed in rubber and very seldom have any colour to them. Additionally, the embossed logos can contain variation among same branded tyres due to small inconsistencies in the moulds. The implementation of this deep learning solution saw multiple convolutional neural networks implemented. Some of these architectures were also implemented using transferred learning. The metrics obtained as outputs from training and testing the architectures were the accuracy, precision, recall, and F1-score. These metrics were compared in conjunction with the confusion matrix produced from testing. To ensure that variance was accounted for in the experiments, the k-fold cross-validation technique was adopted. The results of this study identified that one convolutional neural network model, MobileNet, was particularly well suited for the context of classifying logos on tyre sidewalls. The MobileNet architecture had the highest performance metrics for both training from scratch (96.7% accuracy) and transferred learning (98.8% accuracy). Three other models performed particularly well when trained from scratch, these were a modification of the LeNet architecture, ResNet50 and InceptionV3. The transferred learning results were also impressive with four out of the 5 models achieving an accuracy above 94%. Interestingly, the ResNet50 architecture failed to train when transferred learning was applied. Contrasting to this, the two models VGG16 and VGG19 failed to train when trained from scratch but performed equally as well as the other models when transferred learning was implemented. This indicates that although transferred learning can improve the performance of models, it is highly dependent on the task as well as the model. Overall the results obtained proved that a deep learning approach could be applied in order to classify tyres accurately.
- Full Text:
- Date Issued: 2019
A gatherer's paradise? Early humans and plant foraging on the cape south coast, South Africa
- Authors: Gummow, William Thomas
- Date: 2019
- Subjects: Soil amendments , Plants -- Nutrition Plant physiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39687 , vital:35348
- Description: South Africa is a semi-arid country that is experiencing population growth and the associated pressure of producing sufficient crops to sustain the population. Furthermore, poor land management has also led to increased degradation of valuable arable land. To improve poor soil quality and possibly avoid or reverse degradation and ultimately desertification, it was suggested that soil amendments are a potential solution to some of these problems. Although soil amendment is a relatively well-known practice to improve soil quality, the use of rubber crumb as a soil amendment is not well studied. Rubber crumb is produced from end-of-life tyres that have been ground up to fine particles and as such can be used as a secondary resource to replace the use of virgin materials. Rubber crumb has been used in an array of industries, however, the present study investigated the possibility that rubber crumb might be used as a soil amendment to alleviate various forms of soil degradation, specifically soil compaction and crusting, and potentially improve crop establishment and growth.To determine this, a soil that is prone to crusting and compaction was amended with rubber crumb at rates of 5%, 15% and 25%. Various soil physical characteristics, such as bulk density, particle density, porosity, field capacity and penetration resistance were investigated and it was determined that as the percentage rubber crumb increases in the soil, so do the beneficial characteristics of the soil. Furthermore, the rubber crumb was also treated in various ways in order to determine how the treatments might affect the chemical properties of the soil, as well as the amount of zinc that is leached from the rubber crumb. It was found that washing the rubber with a weak acid or even water prior to adding it to the soil resulted in more desirable chemical condition compared to untreated rubber crumb. Lastly, maize (Zea mays L.) was used to determine whether amending soil with pre-treated rubber crumb in different percentages had an influence on the germination success and growth rate of maize. In terms of germination success, amending soil with rubber crumb does not seem to have a significant influence, however, growth rate decreased as the percentage rubber crumb increased, while treating the rubber with a weak acid or water prior to adding it to soil had the most positive effect on plant growth. It can therefore be concluded that rubber crumb amendment rates between 5% and 15% resulted in the most desirable soil physical properties and plant growth amongst the amendments. However the best plant growth was still seen in the control soil, to which no rubber crumb had been added.
- Full Text:
- Date Issued: 2019
- Authors: Gummow, William Thomas
- Date: 2019
- Subjects: Soil amendments , Plants -- Nutrition Plant physiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39687 , vital:35348
- Description: South Africa is a semi-arid country that is experiencing population growth and the associated pressure of producing sufficient crops to sustain the population. Furthermore, poor land management has also led to increased degradation of valuable arable land. To improve poor soil quality and possibly avoid or reverse degradation and ultimately desertification, it was suggested that soil amendments are a potential solution to some of these problems. Although soil amendment is a relatively well-known practice to improve soil quality, the use of rubber crumb as a soil amendment is not well studied. Rubber crumb is produced from end-of-life tyres that have been ground up to fine particles and as such can be used as a secondary resource to replace the use of virgin materials. Rubber crumb has been used in an array of industries, however, the present study investigated the possibility that rubber crumb might be used as a soil amendment to alleviate various forms of soil degradation, specifically soil compaction and crusting, and potentially improve crop establishment and growth.To determine this, a soil that is prone to crusting and compaction was amended with rubber crumb at rates of 5%, 15% and 25%. Various soil physical characteristics, such as bulk density, particle density, porosity, field capacity and penetration resistance were investigated and it was determined that as the percentage rubber crumb increases in the soil, so do the beneficial characteristics of the soil. Furthermore, the rubber crumb was also treated in various ways in order to determine how the treatments might affect the chemical properties of the soil, as well as the amount of zinc that is leached from the rubber crumb. It was found that washing the rubber with a weak acid or even water prior to adding it to the soil resulted in more desirable chemical condition compared to untreated rubber crumb. Lastly, maize (Zea mays L.) was used to determine whether amending soil with pre-treated rubber crumb in different percentages had an influence on the germination success and growth rate of maize. In terms of germination success, amending soil with rubber crumb does not seem to have a significant influence, however, growth rate decreased as the percentage rubber crumb increased, while treating the rubber with a weak acid or water prior to adding it to soil had the most positive effect on plant growth. It can therefore be concluded that rubber crumb amendment rates between 5% and 15% resulted in the most desirable soil physical properties and plant growth amongst the amendments. However the best plant growth was still seen in the control soil, to which no rubber crumb had been added.
- Full Text:
- Date Issued: 2019
A Geochemical Comparison of Southern African Stromatolites and Stromatolite Pools
- Authors: Dodd, Carla
- Date: 2020
- Subjects: Stromatolites
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48235 , vital:40527
- Description: Microbialite accretion takes place via either mineral precipitation, the trapping and binding of mineral and sediment grains, or a combination of the two. Recently, the geochemistry of carbonate deposits, including microbialites, has been used to reconstruct palaeoenvironments and infer biogenicity. Numerous modern stromatolite (layered microbialites) systems are located on the southern African coastline and are formed predominantly by mineral precipitation with minor detrital input. In order to better understand the environmental and biological processes influencing the formation of microbialites, the geochemistry of southern African coastalstromatolites is examined. This is done by a spatial comparison of the hydrochemistry as well as the major and trace element geochemistry of various coastal stromatolite systems. The influence of the underlying geology on the composition of the stromatolites forms a particular focus of the study. In addition, the effect of metazoans on the micro-fabrics and sediment incorporation into the stromatolite matrix is assessed. Finally, the trace element geochemistry of active, inactive, and ancient stromatolites is compared with a speleothem sample in order to test the validity of using trace elements as a means to determine biogenicity of deposition. Results show that the bulk geochemistry of the South African stromatolites is not a simple function of the associated bedrock lithologies, although certain parallels do exist. It was found that metazoans indirectly influence sediment incorporation by increasing porosity and thereby accommodation space for detrital input. Furthermore, trace element signatures could not be directly attributed to microbial influence in the deposition of the carbonates. Ultimately, this study provides valuable insights into the formation processes of the active South African stromatolites and the use of trace elements as a geochemical tool to investigate the evolution of life and determine past environmental conditions.
- Full Text:
- Date Issued: 2020
- Authors: Dodd, Carla
- Date: 2020
- Subjects: Stromatolites
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48235 , vital:40527
- Description: Microbialite accretion takes place via either mineral precipitation, the trapping and binding of mineral and sediment grains, or a combination of the two. Recently, the geochemistry of carbonate deposits, including microbialites, has been used to reconstruct palaeoenvironments and infer biogenicity. Numerous modern stromatolite (layered microbialites) systems are located on the southern African coastline and are formed predominantly by mineral precipitation with minor detrital input. In order to better understand the environmental and biological processes influencing the formation of microbialites, the geochemistry of southern African coastalstromatolites is examined. This is done by a spatial comparison of the hydrochemistry as well as the major and trace element geochemistry of various coastal stromatolite systems. The influence of the underlying geology on the composition of the stromatolites forms a particular focus of the study. In addition, the effect of metazoans on the micro-fabrics and sediment incorporation into the stromatolite matrix is assessed. Finally, the trace element geochemistry of active, inactive, and ancient stromatolites is compared with a speleothem sample in order to test the validity of using trace elements as a means to determine biogenicity of deposition. Results show that the bulk geochemistry of the South African stromatolites is not a simple function of the associated bedrock lithologies, although certain parallels do exist. It was found that metazoans indirectly influence sediment incorporation by increasing porosity and thereby accommodation space for detrital input. Furthermore, trace element signatures could not be directly attributed to microbial influence in the deposition of the carbonates. Ultimately, this study provides valuable insights into the formation processes of the active South African stromatolites and the use of trace elements as a geochemical tool to investigate the evolution of life and determine past environmental conditions.
- Full Text:
- Date Issued: 2020
A nutrition education tool for practical application of the food based dietary guidelines for primary school teachers in Nelson Mandela Bay
- Authors: Joubert, Tayla Kate
- Date: 2019
- Subjects: Nutrition -- Education
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/44616 , vital:38152
- Description: Background: The South Africa Food-Based Dietary Guidelines (SAFBDG) was developed to promote better food choices for a healthy lifestyle and are included in the school syllabus. Schools remain viable platforms for nutrition education with teachers playing significant roles, but research has shown that teachers do not necessarily know about the SAFBDG and how to incorporate these into the teaching programme. Aim: The aim of this study was to develop a tool in the form of a nutrition education guide for primary school teachers, aimed at the practical application of the SAFBDG, in order to enhance the nutrition knowledge, attitudes and dietary practices of the teachers. Research design and methodology: A quasi-experimental, one group, quantitative design was employed. Forty-six teachers were conveniently chosen from schools in previously disadvantaged areas of Nelson Mandela Bay. The study design consisted of four phases. Phase one consisted of a pre-test where the teachers’ nutrition knowledge, nutrition attitudes, dietary practices, staff wellness and physical activity were determined by means of a standardised questionnaire. A nutritional assessment was also conducted in phase one. In phase two, the nutrition guide, which was Curriculum Assessment Policy Statement compliant for grades four to seven, was developed. In phase three, the guide was used in a workshop to train the teachers that attended phase one of the study, on how to use the nutrition education guide. In phase four, a post-test was conducted after the training to evaluate the effectiveness of the training and to determine whether there has been an increase in the teachers’ nutrition knowledge. Data from the questionnaires were analysed on Microsoft Excel 2016 MSO (16.0.4639.1000). Ethical approval for this study was obtained from the Faculty Postgraduate Studies Committee (FPGSC) of the Faculty of Health Sciences, Nelson Mandela University (Ethics clearance reference number: H18-HEA-DIET-005) and all ethical principles were upheld according to the Belmont report and the Declaration of Helsinki. Results: Of the 46 teachers who participated 36 (78 %) were obese. The mean waist circumference and waist-to-hip ratio was 109.99 and 0.887 respectively (± 17.32 and ± 0.089). The teachers obtained a relatively high mean overall score in the pre-test of 69 % (± 10.78). Only 42 % of the teachers had heard of the SAFBDG before the study. There was an overall statistical significant increase in knowledge of 6 % (p = 0.03) from the pre-test to the post-test. The dietary practice was obtained through a food frequency questionnaire (FFQ), which showed under-reporting. The most neglected food groups were legumes, dairy and vegetables/ fruit. Hypertension was the highest self-reported condition, with just under a quarter of the teachers having hypertension (high blood pressure). There was no statistical significance between the teachers’ BMI and their nutrition knowledge as well as no statistical significance between their BMI and their physical activity level. Conclusion and recommendations: Even though the teachers obtained a relatively high mean overall score in their pre-test, there were still gaps in their nutrition knowledge. These gaps in the teachers’ knowledge results in insufficient nutrition knowledge being provided to the learners, leading to poor dietary practices and misconceptions regarding different foods among the learners as well as the teachers. By providing training for the teachers, it will not only improve their nutrition knowledge but potentially also help to improve their lifestyle. With enhanced nutrition knowledge, the teachers can communicate sufficient information to their learners. The DoBE need to advocate for a healthier school environment in which the SAFBDG are implemented more extensively in the curriculum as well as part of school food policies.
- Full Text:
- Date Issued: 2019
- Authors: Joubert, Tayla Kate
- Date: 2019
- Subjects: Nutrition -- Education
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/44616 , vital:38152
- Description: Background: The South Africa Food-Based Dietary Guidelines (SAFBDG) was developed to promote better food choices for a healthy lifestyle and are included in the school syllabus. Schools remain viable platforms for nutrition education with teachers playing significant roles, but research has shown that teachers do not necessarily know about the SAFBDG and how to incorporate these into the teaching programme. Aim: The aim of this study was to develop a tool in the form of a nutrition education guide for primary school teachers, aimed at the practical application of the SAFBDG, in order to enhance the nutrition knowledge, attitudes and dietary practices of the teachers. Research design and methodology: A quasi-experimental, one group, quantitative design was employed. Forty-six teachers were conveniently chosen from schools in previously disadvantaged areas of Nelson Mandela Bay. The study design consisted of four phases. Phase one consisted of a pre-test where the teachers’ nutrition knowledge, nutrition attitudes, dietary practices, staff wellness and physical activity were determined by means of a standardised questionnaire. A nutritional assessment was also conducted in phase one. In phase two, the nutrition guide, which was Curriculum Assessment Policy Statement compliant for grades four to seven, was developed. In phase three, the guide was used in a workshop to train the teachers that attended phase one of the study, on how to use the nutrition education guide. In phase four, a post-test was conducted after the training to evaluate the effectiveness of the training and to determine whether there has been an increase in the teachers’ nutrition knowledge. Data from the questionnaires were analysed on Microsoft Excel 2016 MSO (16.0.4639.1000). Ethical approval for this study was obtained from the Faculty Postgraduate Studies Committee (FPGSC) of the Faculty of Health Sciences, Nelson Mandela University (Ethics clearance reference number: H18-HEA-DIET-005) and all ethical principles were upheld according to the Belmont report and the Declaration of Helsinki. Results: Of the 46 teachers who participated 36 (78 %) were obese. The mean waist circumference and waist-to-hip ratio was 109.99 and 0.887 respectively (± 17.32 and ± 0.089). The teachers obtained a relatively high mean overall score in the pre-test of 69 % (± 10.78). Only 42 % of the teachers had heard of the SAFBDG before the study. There was an overall statistical significant increase in knowledge of 6 % (p = 0.03) from the pre-test to the post-test. The dietary practice was obtained through a food frequency questionnaire (FFQ), which showed under-reporting. The most neglected food groups were legumes, dairy and vegetables/ fruit. Hypertension was the highest self-reported condition, with just under a quarter of the teachers having hypertension (high blood pressure). There was no statistical significance between the teachers’ BMI and their nutrition knowledge as well as no statistical significance between their BMI and their physical activity level. Conclusion and recommendations: Even though the teachers obtained a relatively high mean overall score in their pre-test, there were still gaps in their nutrition knowledge. These gaps in the teachers’ knowledge results in insufficient nutrition knowledge being provided to the learners, leading to poor dietary practices and misconceptions regarding different foods among the learners as well as the teachers. By providing training for the teachers, it will not only improve their nutrition knowledge but potentially also help to improve their lifestyle. With enhanced nutrition knowledge, the teachers can communicate sufficient information to their learners. The DoBE need to advocate for a healthier school environment in which the SAFBDG are implemented more extensively in the curriculum as well as part of school food policies.
- Full Text:
- Date Issued: 2019
A nutrition education tool for practical application of the food based dietary guidelines for primary school teachers in Nelson Mandela Bay
- Authors: Joubert, Tayla Kate
- Date: 2019
- Subjects: Malnutrition -- South Africa -- Port Elizabeth , Nutrition—Evaluation Nutrition -- Evaluation Nutrition -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/45019 , vital:38226
- Description: The South Africa Food-Based Dietary Guidelines (SAFBDG) was developed to promote better food choices for a healthy lifestyle and are included in the school syllabus. Schools remain viable platforms for nutrition education with teachers playing significant roles, but research has shown that teachers do not necessarily know about the SAFBDG and how to incorporate these into the teaching programme. The aim of this study was to develop a tool in the form of a nutrition education guide for primary school teachers, aimed at the practical application of the SAFBDG, in order to enhance the nutrition knowledge, attitudes and dietary practices of the teachers. A quasi-experimental, one group, quantitative design was employed. Forty-six teachers were conveniently chosen from schools in previously disadvantaged areas of Nelson Mandela Bay. The study design consisted of four phases. Phase one consisted of a pre-test where the teachers’ nutrition knowledge, nutrition attitudes, dietary practices, staff wellness and physical activity were determined by means of a standardised questionnaire. A nutritional assessment was also conducted in phase one. In phase two, the nutrition guide, which was Curriculum Assessment Policy Statement compliant for grades four to seven, was developed. In phase three, the guide was used in a workshop to train the teachers that attended phase one of the study, on how to use the nutrition education guide. In phase four, a post-test was conducted after the training to evaluate the effectiveness of the training and to determine whether there has been an increase in the teachers’ nutrition knowledge. Data from the questionnaires were analysed on Microsoft Excel 2016 MSO (16.0.4639.1000). Ethical approval for this study was obtained from the Faculty Postgraduate Studies Committee (FPGSC) of the Faculty of Health Sciences, Nelson Mandela University (Ethics clearance reference number: H18-HEA-DIET-005) and all ethical principles were upheld according to the Belmont report and the Declaration of Helsinki. Results of the research 46 teachers who participated 36 (78 %) were obese. The mean waist circumference and waist-to-hip ratio was 109.99 and 0.887 respectively (± 17.32 and ± 0.089). The teachers obtained a relatively high mean overall score in the pre-test of 69 % (± 10.78). Only 42 % of the teachers had heard of the SAFBDG before the study. There was an overall statistical significant increase in knowledge of 6 % (p = 0.03) from the pre-test to the post-test. The dietary practice was obtained through a food frequency questionnaire (FFQ), which showed under-reporting. The most neglected food groups were legumes, dairy and vegetables/ fruit. Hypertension was the highest self-reported condition, with just under a quarter of the teachers having hypertension (high blood pressure). There was no statistical significance between the teachers’ BMI and their nutrition knowledge as well as no statistical significance between their BMI and their physical activity level. Even though the teachers obtained a relatively high mean overall score in their pre-test, there were still gaps in their nutrition knowledge. These gaps in the teachers’ knowledge results in insufficient nutrition knowledge being provided to the learners, leading to poor dietary practices and misconceptions regarding different foods among the learners as well as the teachers. By providing training for the teachers, it will not only improve their nutrition knowledge but potentially also help to improve their lifestyle. With enhanced nutrition knowledge, the teachers can communicate sufficient information to their learners. The DoBE need to advocate for a healthier school environment in which the SAFBDG are implemented more extensively in the curriculum as well as part of school food policies.
- Full Text:
- Date Issued: 2019
- Authors: Joubert, Tayla Kate
- Date: 2019
- Subjects: Malnutrition -- South Africa -- Port Elizabeth , Nutrition—Evaluation Nutrition -- Evaluation Nutrition -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/45019 , vital:38226
- Description: The South Africa Food-Based Dietary Guidelines (SAFBDG) was developed to promote better food choices for a healthy lifestyle and are included in the school syllabus. Schools remain viable platforms for nutrition education with teachers playing significant roles, but research has shown that teachers do not necessarily know about the SAFBDG and how to incorporate these into the teaching programme. The aim of this study was to develop a tool in the form of a nutrition education guide for primary school teachers, aimed at the practical application of the SAFBDG, in order to enhance the nutrition knowledge, attitudes and dietary practices of the teachers. A quasi-experimental, one group, quantitative design was employed. Forty-six teachers were conveniently chosen from schools in previously disadvantaged areas of Nelson Mandela Bay. The study design consisted of four phases. Phase one consisted of a pre-test where the teachers’ nutrition knowledge, nutrition attitudes, dietary practices, staff wellness and physical activity were determined by means of a standardised questionnaire. A nutritional assessment was also conducted in phase one. In phase two, the nutrition guide, which was Curriculum Assessment Policy Statement compliant for grades four to seven, was developed. In phase three, the guide was used in a workshop to train the teachers that attended phase one of the study, on how to use the nutrition education guide. In phase four, a post-test was conducted after the training to evaluate the effectiveness of the training and to determine whether there has been an increase in the teachers’ nutrition knowledge. Data from the questionnaires were analysed on Microsoft Excel 2016 MSO (16.0.4639.1000). Ethical approval for this study was obtained from the Faculty Postgraduate Studies Committee (FPGSC) of the Faculty of Health Sciences, Nelson Mandela University (Ethics clearance reference number: H18-HEA-DIET-005) and all ethical principles were upheld according to the Belmont report and the Declaration of Helsinki. Results of the research 46 teachers who participated 36 (78 %) were obese. The mean waist circumference and waist-to-hip ratio was 109.99 and 0.887 respectively (± 17.32 and ± 0.089). The teachers obtained a relatively high mean overall score in the pre-test of 69 % (± 10.78). Only 42 % of the teachers had heard of the SAFBDG before the study. There was an overall statistical significant increase in knowledge of 6 % (p = 0.03) from the pre-test to the post-test. The dietary practice was obtained through a food frequency questionnaire (FFQ), which showed under-reporting. The most neglected food groups were legumes, dairy and vegetables/ fruit. Hypertension was the highest self-reported condition, with just under a quarter of the teachers having hypertension (high blood pressure). There was no statistical significance between the teachers’ BMI and their nutrition knowledge as well as no statistical significance between their BMI and their physical activity level. Even though the teachers obtained a relatively high mean overall score in their pre-test, there were still gaps in their nutrition knowledge. These gaps in the teachers’ knowledge results in insufficient nutrition knowledge being provided to the learners, leading to poor dietary practices and misconceptions regarding different foods among the learners as well as the teachers. By providing training for the teachers, it will not only improve their nutrition knowledge but potentially also help to improve their lifestyle. With enhanced nutrition knowledge, the teachers can communicate sufficient information to their learners. The DoBE need to advocate for a healthier school environment in which the SAFBDG are implemented more extensively in the curriculum as well as part of school food policies.
- Full Text:
- Date Issued: 2019
A seismic characterization of the crustal structure underlying the offshore Natal valley within the south-west Indian Ocean
- Authors: Moorcroft, David
- Date: 2018
- Subjects: Seismology , Seismology -- Kwa Zulu Natal -- Research Coasts -- Kwa Zulu Natal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/22387 , vital:29965
- Description: The Natal Valley is a ~1000 km long, elongated depression in the seafloor, located within the south-west Indian Ocean, between the coastline of south-east Africa and the offshore aseismic Mozambique Ridge. Knowledge of its present-day crustal structure is important to reconstruct the Gondwana supercontinent break-up history and the concurrent opening of the Indian Ocean, which started during the Jurassic, some ~180 – 150 million years ago. Major geological events relating to this supercontinent break-up including continental rifting, magmatism, the emplacement of extensive oceanic flood basalt as submarine plateaus, vertical processes associated with tectonic uplift, flexural subsidence of the margin and relative global sea-level change are recorded within the crust underlying the south-west Indian Ocean. Although these events have been well modelled, fundamental questions remain regarding the nature and tectonic structure of the crust. Today, the Natal Valley region represents a frontier for geophysical exploration. Early attempts at imaging the crust beneath the seafloor within the south-west Indian Ocean made use of now primitive seismic reflection data acquisition and processing techniques available to them at the time (1960’s - 1970’s). Considering the advancements made in marine seismic reflection imaging, these vintage datasets lacked the horizontal and vertical resolution necessary to most accurately account for and describe features of the upper crust underlying the northern Natal Valley. This study is based on the acquisition, processing and preliminary interpretation of a newly acquired, regional seismic reflection profile, Profile Mz5-007, acquired across the northernmost region of the Natal Valley during the PAMELA-Moz5 cruise in 2016. The methods of marine seismic reflection data acquisition, processing and interpretation are described. The seismic reflection data presented in this dissertation provides a regional-scaled appraisal of the upper crust underlying the northern Natal Valley for the first time. The imagery allows a comprehensive description of crustal structures and features from the very northern Natal Valley, close to the Mozambique coastline, southwards into the southern Natal Valley offshore of Durban. The findings presented here support the notion that the crust underlying the northern Natal Valley experienced roughly N-S orientated trans-tensional stresses in relation to the breakup of West Gondwana. At least two major phases of volcanism are imaged within the seismic stratigraphy. The lower-most event underlies the Limpopo Fan in the northernmost regions of the Natal Valley at a depth of 2 seconds TWT and is interpreted as a seismic expression of the upper surface of the Lower – Middle Jurassic Karoo LIP. The progressive disappearance of this horizon towards the south coincides with the emergence of a second, overlying, as yet unreported volcanic horizon, which extends southwards throughout the Natal Valley. On the basis of its regional distribution, spatial relationship with the underlying event boundary and its deformation history, this volcanic horizon is interpreted to represent a series of basaltic lava outpourings during the Lower Cretaceous, initiated in response to trans-tensional crustal deformation associated with the breakup of West Gondwana. In addition to these two major phases of flood basalt outpouring, a number of localized volcanic flows are imaged throughout the stratigraphy, most notably over the Central Terrace. In addition, at least four major unconformities are identified, all of which are well developed within the Limpopo Fan. One of these is interpreted to represent the well-developed Mid-Cretaceous hiatus in sedimentation, providing a relative seismo-stratigraphic constraint to overlying and underlying seismic units. A review of the structural elements of the crust reveals how the northern Natal Valley is partitioned into two sub-basins separated by a prominent basement high, the Central Terrace, imaged across the central portions of Profile Mz5-007. To the north of the Central Terrace, structural deformation appears largely extensional, characterized by a large (~37 km wide) asymmetrical depression directly to the north of the Central Terrace and only minor structural faulting. To the south of the Central Terrace, trans-tensional stresses associated with withdrawal of the Falkland Malvinas Plateau have deformed the upper crust into a series of apparently southwards tilted crustal blocks, producing a series of deep (3.5 s TWT) half graben-like structures, within which syn-rift fill has an apparent dip towards the south. There is evidence to suggest ongoing reactivation of these fault structures. This zone of deformation is shown to bear resemblances to the faulting mapped onshore of the Kwa-Zulu Natal coastline, providing reason to consider the two regions as a continuous zone of deformation associated with the withdrawal of the Falkland-Malvinas Plateau during the breakup of West Gondwana. Furthermore, a number of post-sedimentary intrusive features are imaged, the largest of which is the Naude Ridge; a large pinnacle-like feature which has penetrated the upper crust towards the southern limit of the profile. This feature corresponds to an abrupt change in seafloor depth and upper crustal structure, suggesting that this feature may mark the transition between subsided continental crust interpreted to underlie the northern Natal Valley to the north and oceanic crust known to underlie the southern Natal Valley to the south.
- Full Text:
- Date Issued: 2018
- Authors: Moorcroft, David
- Date: 2018
- Subjects: Seismology , Seismology -- Kwa Zulu Natal -- Research Coasts -- Kwa Zulu Natal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/22387 , vital:29965
- Description: The Natal Valley is a ~1000 km long, elongated depression in the seafloor, located within the south-west Indian Ocean, between the coastline of south-east Africa and the offshore aseismic Mozambique Ridge. Knowledge of its present-day crustal structure is important to reconstruct the Gondwana supercontinent break-up history and the concurrent opening of the Indian Ocean, which started during the Jurassic, some ~180 – 150 million years ago. Major geological events relating to this supercontinent break-up including continental rifting, magmatism, the emplacement of extensive oceanic flood basalt as submarine plateaus, vertical processes associated with tectonic uplift, flexural subsidence of the margin and relative global sea-level change are recorded within the crust underlying the south-west Indian Ocean. Although these events have been well modelled, fundamental questions remain regarding the nature and tectonic structure of the crust. Today, the Natal Valley region represents a frontier for geophysical exploration. Early attempts at imaging the crust beneath the seafloor within the south-west Indian Ocean made use of now primitive seismic reflection data acquisition and processing techniques available to them at the time (1960’s - 1970’s). Considering the advancements made in marine seismic reflection imaging, these vintage datasets lacked the horizontal and vertical resolution necessary to most accurately account for and describe features of the upper crust underlying the northern Natal Valley. This study is based on the acquisition, processing and preliminary interpretation of a newly acquired, regional seismic reflection profile, Profile Mz5-007, acquired across the northernmost region of the Natal Valley during the PAMELA-Moz5 cruise in 2016. The methods of marine seismic reflection data acquisition, processing and interpretation are described. The seismic reflection data presented in this dissertation provides a regional-scaled appraisal of the upper crust underlying the northern Natal Valley for the first time. The imagery allows a comprehensive description of crustal structures and features from the very northern Natal Valley, close to the Mozambique coastline, southwards into the southern Natal Valley offshore of Durban. The findings presented here support the notion that the crust underlying the northern Natal Valley experienced roughly N-S orientated trans-tensional stresses in relation to the breakup of West Gondwana. At least two major phases of volcanism are imaged within the seismic stratigraphy. The lower-most event underlies the Limpopo Fan in the northernmost regions of the Natal Valley at a depth of 2 seconds TWT and is interpreted as a seismic expression of the upper surface of the Lower – Middle Jurassic Karoo LIP. The progressive disappearance of this horizon towards the south coincides with the emergence of a second, overlying, as yet unreported volcanic horizon, which extends southwards throughout the Natal Valley. On the basis of its regional distribution, spatial relationship with the underlying event boundary and its deformation history, this volcanic horizon is interpreted to represent a series of basaltic lava outpourings during the Lower Cretaceous, initiated in response to trans-tensional crustal deformation associated with the breakup of West Gondwana. In addition to these two major phases of flood basalt outpouring, a number of localized volcanic flows are imaged throughout the stratigraphy, most notably over the Central Terrace. In addition, at least four major unconformities are identified, all of which are well developed within the Limpopo Fan. One of these is interpreted to represent the well-developed Mid-Cretaceous hiatus in sedimentation, providing a relative seismo-stratigraphic constraint to overlying and underlying seismic units. A review of the structural elements of the crust reveals how the northern Natal Valley is partitioned into two sub-basins separated by a prominent basement high, the Central Terrace, imaged across the central portions of Profile Mz5-007. To the north of the Central Terrace, structural deformation appears largely extensional, characterized by a large (~37 km wide) asymmetrical depression directly to the north of the Central Terrace and only minor structural faulting. To the south of the Central Terrace, trans-tensional stresses associated with withdrawal of the Falkland Malvinas Plateau have deformed the upper crust into a series of apparently southwards tilted crustal blocks, producing a series of deep (3.5 s TWT) half graben-like structures, within which syn-rift fill has an apparent dip towards the south. There is evidence to suggest ongoing reactivation of these fault structures. This zone of deformation is shown to bear resemblances to the faulting mapped onshore of the Kwa-Zulu Natal coastline, providing reason to consider the two regions as a continuous zone of deformation associated with the withdrawal of the Falkland-Malvinas Plateau during the breakup of West Gondwana. Furthermore, a number of post-sedimentary intrusive features are imaged, the largest of which is the Naude Ridge; a large pinnacle-like feature which has penetrated the upper crust towards the southern limit of the profile. This feature corresponds to an abrupt change in seafloor depth and upper crustal structure, suggesting that this feature may mark the transition between subsided continental crust interpreted to underlie the northern Natal Valley to the north and oceanic crust known to underlie the southern Natal Valley to the south.
- Full Text:
- Date Issued: 2018
A smart home environment simulation tool to support the recognition of activities of daily living
- Authors: Ho, Brandon
- Date: 2020
- Subjects: Artificial intelligence , Internet of things Home automation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/49334 , vital:41622
- Description: The prevalence of internet of things technologies and internet-connected devices enables the potential of introducing intelligence to a wide range of applications and fields. Smart homes are popular application of internet of things. Smart homes refer to domestic environments that can monitor their own state and the state of their inhabitants. Smart homes are identified as a promising solution for assisting inhabitants in completing daily activities and improving quality of life for inhabitants. This dissertation discusses the design and implementation of smart home simulation tool prototype, called smart environment stimulation (SESim). SESim is designed to conduct smart home simulation and generate synthetic sensor datasets which describe activity performances. This dissertation also discusses the evaluation of SESim, which focused on validating the utility of conducting smart home simulations and generating sensor datasets.
- Full Text: false
- Date Issued: 2020
- Authors: Ho, Brandon
- Date: 2020
- Subjects: Artificial intelligence , Internet of things Home automation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/49334 , vital:41622
- Description: The prevalence of internet of things technologies and internet-connected devices enables the potential of introducing intelligence to a wide range of applications and fields. Smart homes are popular application of internet of things. Smart homes refer to domestic environments that can monitor their own state and the state of their inhabitants. Smart homes are identified as a promising solution for assisting inhabitants in completing daily activities and improving quality of life for inhabitants. This dissertation discusses the design and implementation of smart home simulation tool prototype, called smart environment stimulation (SESim). SESim is designed to conduct smart home simulation and generate synthetic sensor datasets which describe activity performances. This dissertation also discusses the evaluation of SESim, which focused on validating the utility of conducting smart home simulations and generating sensor datasets.
- Full Text: false
- Date Issued: 2020
A Statistical assessment of available solar resource across multiple sites in South Africa
- Authors: Eastwood, Kirstie
- Date: 2019
- Subjects: Mathematical statistics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39907 , vital:35505
- Description: Around the globe, fossil fuels remain the primary source of energy at around 78% of the world’s total energy consumption. However, the associated carbon emissions, environmental impact, the depletion of fossil fuels and price and cost volatility are factors influencing the growing popularity of research into renewable energy. Solar power is acknowledged as the fastest-growing renewable energy, but the uncertainty surrounding the long-term projections of solar irradiance available for energy conversion is a hindrance when discussing the financial risk with potential investors. This study investigates the quality of freely available solar resource data in South Africa as well as proposes techniques for potential solar farm site comparisons. Tolerance intervals derived within a Bayesian framework provide information on the future available solar resource across multiple sites. These techniques capture the inherent variability in the available solar resource which equips investors with statistical methods that lead to the better understanding of the solar resource and thus aids in better decision-making.
- Full Text:
- Date Issued: 2019
- Authors: Eastwood, Kirstie
- Date: 2019
- Subjects: Mathematical statistics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39907 , vital:35505
- Description: Around the globe, fossil fuels remain the primary source of energy at around 78% of the world’s total energy consumption. However, the associated carbon emissions, environmental impact, the depletion of fossil fuels and price and cost volatility are factors influencing the growing popularity of research into renewable energy. Solar power is acknowledged as the fastest-growing renewable energy, but the uncertainty surrounding the long-term projections of solar irradiance available for energy conversion is a hindrance when discussing the financial risk with potential investors. This study investigates the quality of freely available solar resource data in South Africa as well as proposes techniques for potential solar farm site comparisons. Tolerance intervals derived within a Bayesian framework provide information on the future available solar resource across multiple sites. These techniques capture the inherent variability in the available solar resource which equips investors with statistical methods that lead to the better understanding of the solar resource and thus aids in better decision-making.
- Full Text:
- Date Issued: 2019
A study of contaminants in fish in South Africa : linking science, management and society
- Authors: Ramparsad, Kerina
- Date: 2020
- Subjects: Estuarine fishes -- Contamination -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48609 , vital:40895
- Description: Contaminants in fish is a concern globally and locally. Fish have the propensity to accumulate contaminants to levels that may pose a threat to human health and disrupt ecosystem function. The purpose for investigating contaminants in this study for fish provides the public with information on the potential human health risks from the contaminated fish we consume. This study also investigated contaminants in estuarine fish and sediment, and is important to monitor as these components of ecosystems can indicate contamination in estuaries. Effective methods to determine contaminants in fish and sediment included the Direct Mercury Analyser 80 for mercury, Gas Chromatography for fatty acids and polychlorinated biphenyls and Inductively Coupled Plasma for aluminium, arsenic, cadmium, chromium, cobalt, copper, iron, lead, manganese, mercury, nickel, vanadium and zinc. Basic statistical tools, geochemical techniques, a bioaccumulation model and human health risk assessment tools provided by the United States Environmental Protection Agency were used to interpret the data. Ultimately consumption advice was developed from the risk assessment results and showed predatory fish such as swordfish and bluenose species are recommended to be avoided while yellow tail, red roman, mackerel, fish fingers and canned tuna are some of the fish that can be eaten 10-14 times per month that would not cause potential health risks. It was found that estuarine ambassid fish investigated in this study were not suitable for contaminant monitoring. There were no clear spatial and seasonal trends observed in the estuaries suggesting that ambassid fish efficiently assimilate contaminants. There was little evidence that contaminants were transferred from sediment to ambassid fish in the eThekwini estuaries. Therefore, their use is limited as a cost-effective estuarine contaminant monitoring tool. Each estuary investigated is unique and requires its own management plan.
- Full Text:
- Date Issued: 2020
- Authors: Ramparsad, Kerina
- Date: 2020
- Subjects: Estuarine fishes -- Contamination -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48609 , vital:40895
- Description: Contaminants in fish is a concern globally and locally. Fish have the propensity to accumulate contaminants to levels that may pose a threat to human health and disrupt ecosystem function. The purpose for investigating contaminants in this study for fish provides the public with information on the potential human health risks from the contaminated fish we consume. This study also investigated contaminants in estuarine fish and sediment, and is important to monitor as these components of ecosystems can indicate contamination in estuaries. Effective methods to determine contaminants in fish and sediment included the Direct Mercury Analyser 80 for mercury, Gas Chromatography for fatty acids and polychlorinated biphenyls and Inductively Coupled Plasma for aluminium, arsenic, cadmium, chromium, cobalt, copper, iron, lead, manganese, mercury, nickel, vanadium and zinc. Basic statistical tools, geochemical techniques, a bioaccumulation model and human health risk assessment tools provided by the United States Environmental Protection Agency were used to interpret the data. Ultimately consumption advice was developed from the risk assessment results and showed predatory fish such as swordfish and bluenose species are recommended to be avoided while yellow tail, red roman, mackerel, fish fingers and canned tuna are some of the fish that can be eaten 10-14 times per month that would not cause potential health risks. It was found that estuarine ambassid fish investigated in this study were not suitable for contaminant monitoring. There were no clear spatial and seasonal trends observed in the estuaries suggesting that ambassid fish efficiently assimilate contaminants. There was little evidence that contaminants were transferred from sediment to ambassid fish in the eThekwini estuaries. Therefore, their use is limited as a cost-effective estuarine contaminant monitoring tool. Each estuary investigated is unique and requires its own management plan.
- Full Text:
- Date Issued: 2020
A stunting profile of children under the age of five visiting Bhisho hospital clinic, part of the umbrella project: a profile of stunting in children under the age of five in food insecure villages in Mqanduli, Ngqushwa and Bhisho hospital, Eastern Cape, South Africa
- Authors: Beyleveld, Janine
- Date: 2020
- Subjects: Children -- growth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/50201 , vital:42066
- Description: Introduction and Background: Stunting is the most prevalent form of childhood malnutrition where about 149 million children under the age of five can be classified as stunted globally. South Africa has one of the highest stunting rates in the world at 27%, causing devastating effects on economic productivity as well as on an individual’s nutritional status. The presence of stunted growth in children is a strong indicator of chronic undernutrition and highlights injustices experienced within communities. Aims and Objectives: The aim of this study is to develop a stunning profile of children under the age of five, visiting BhishoHospital’s gateway clinic in the Eastern Cape, South Africa. The objectives were to determine the prevalence of stunting of the children visiting Bhisho Hospital’s clinic and to identify the drivers of stunting in the area. Methodology: A quantitative study with a descriptive, cross-sectional design was used. The study population included all children under the age of five visiting Bhisho Hospital’s clinic. Data was collected by means of an interview-administered questionnaire. Results: The prevalence of stunting in the area was 47.5%. A significant association was found between the participants' main form of sanitation and stunting category in the group of infants younger than six months (p = 0.007) and the group older than six months(p = 0.040). Discussion: The prevalence of stunting in the area was far higher than the national average of 27%, although the majority of the sample had a normal weight. The use of non-flush toilets was found to be a risk factor for childhood stunting. Recommendation: Financial and political investment in child health needs to be placed as a top priority in South Africa to reduce stunting rates.
- Full Text:
- Date Issued: 2020
- Authors: Beyleveld, Janine
- Date: 2020
- Subjects: Children -- growth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/50201 , vital:42066
- Description: Introduction and Background: Stunting is the most prevalent form of childhood malnutrition where about 149 million children under the age of five can be classified as stunted globally. South Africa has one of the highest stunting rates in the world at 27%, causing devastating effects on economic productivity as well as on an individual’s nutritional status. The presence of stunted growth in children is a strong indicator of chronic undernutrition and highlights injustices experienced within communities. Aims and Objectives: The aim of this study is to develop a stunning profile of children under the age of five, visiting BhishoHospital’s gateway clinic in the Eastern Cape, South Africa. The objectives were to determine the prevalence of stunting of the children visiting Bhisho Hospital’s clinic and to identify the drivers of stunting in the area. Methodology: A quantitative study with a descriptive, cross-sectional design was used. The study population included all children under the age of five visiting Bhisho Hospital’s clinic. Data was collected by means of an interview-administered questionnaire. Results: The prevalence of stunting in the area was 47.5%. A significant association was found between the participants' main form of sanitation and stunting category in the group of infants younger than six months (p = 0.007) and the group older than six months(p = 0.040). Discussion: The prevalence of stunting in the area was far higher than the national average of 27%, although the majority of the sample had a normal weight. The use of non-flush toilets was found to be a risk factor for childhood stunting. Recommendation: Financial and political investment in child health needs to be placed as a top priority in South Africa to reduce stunting rates.
- Full Text:
- Date Issued: 2020
A suitability study for the implementation of a corporate geographic information system at the King Sabata Dalindyebo Municipality
- Authors: Triegaardt, Inge
- Date: 2019
- Subjects: Geographic information systems , Information storage and retrieval systems -- Geography Information technology Sustainable development
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/${Handle} , vital:37044
- Description: A tender in the Government Gazette in 2013 for the implementation of a Corporate Geographic Information System (CGIS) at the King Sabata Dalindeybo (KSD) Local Municipality, created an opportunity for a study to be conducted for the implementation of a Corporate Geographic Information System (CGIS). A CGIS is a suitable management system for implementation at a municipality, given that the municipality is ready. Internationally the implementation of CGIS at municipalities has been done successfully. In South Africa, however, the implementation of said software has been slow and at times unsuccessful. The purpose of this research study was to evaluate the current GIS knowledge and infrastructure of the KSD Local Municipality for the municipality to be a suitable candidate for the implementation of a CGIS. The evaluation was done by the collection of data through three questionnaires, two interviews and observations. The findings of this research study are discussed according to the qualitative data collected from the KSD Local Municipality and recommendations based on the results of the data collection have been made for the municipality to be implementation ready. The qualitative instruments such as pre-training, post-training/pre-implementation and postimplementation questionnaires, observations and interviews with the IT Technician and the CGIS Specialist were processed by the researcher to obtain insight to the perceptions of the employees and the current state of GIS in the KSD Local Municipality. The results from this research study were in-line with the benefits and barriers of implementation of a CGIS in municipalities in international literature.
- Full Text:
- Date Issued: 2019
- Authors: Triegaardt, Inge
- Date: 2019
- Subjects: Geographic information systems , Information storage and retrieval systems -- Geography Information technology Sustainable development
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/${Handle} , vital:37044
- Description: A tender in the Government Gazette in 2013 for the implementation of a Corporate Geographic Information System (CGIS) at the King Sabata Dalindeybo (KSD) Local Municipality, created an opportunity for a study to be conducted for the implementation of a Corporate Geographic Information System (CGIS). A CGIS is a suitable management system for implementation at a municipality, given that the municipality is ready. Internationally the implementation of CGIS at municipalities has been done successfully. In South Africa, however, the implementation of said software has been slow and at times unsuccessful. The purpose of this research study was to evaluate the current GIS knowledge and infrastructure of the KSD Local Municipality for the municipality to be a suitable candidate for the implementation of a CGIS. The evaluation was done by the collection of data through three questionnaires, two interviews and observations. The findings of this research study are discussed according to the qualitative data collected from the KSD Local Municipality and recommendations based on the results of the data collection have been made for the municipality to be implementation ready. The qualitative instruments such as pre-training, post-training/pre-implementation and postimplementation questionnaires, observations and interviews with the IT Technician and the CGIS Specialist were processed by the researcher to obtain insight to the perceptions of the employees and the current state of GIS in the KSD Local Municipality. The results from this research study were in-line with the benefits and barriers of implementation of a CGIS in municipalities in international literature.
- Full Text:
- Date Issued: 2019
A technical survey of the South African harvesting machine population
- Authors: Mathelele, Ouma Florah
- Date: 2019
- Subjects: Harvesting -- South Africa , Energy harvesting -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/40999 , vital:36281
- Description: South Africa adopted the practice of conducting technical surveys from Austria three decades ago. The Austrian technical survey was used to model the South African technical survey. The survey was conducted with the aim of providing the forestry industry with a detailed analysis of the state of timber harvesting operations. The first technical survey in South Africa was conducted in 1987, and the second one in 1998. The most recent study was carried out in 2007. Since 2007, there has been no other technical survey of a similar nature conducted on harvesting and transport operations. There is no recent information quantifying the volumes harvested, identifying harvesting systems and methods used, and determining volumes harvested using these systems and methods. Furthermore, no updated information exists on the type and quantities of timber trucks transporting the volume. A fourth technical survey that quantifies and analyses these aspects in harvesting operations, therefore, was due. The fourth technical survey aimed at quantifying the number of harvesting machines and timber trucks. The survey further investigated the drivers behind the mechanisation and system preference. The four technical surveys were compared to identify trends in harvesting machines and methods. The data were collected from grower companies, harvesting and transport contractors and small-scale timber growers. Questionnaires were sent to all potential respondents from the three target groups, and interviews were later conducted with selected respondents. The harvesting machines were quantified per function i.e. felling, extraction, processing and loading. The results showed that some machines were more common compared to other machines performing the same function. Mechanised felling machines sampled had more units in the fourth survey than the previous surveys had. Of the 10.6 million m3 volume surveyed in 2017, chainsaws had 1 048 units, and their number had decreased from the 5 000 sampled in the first technical survey in 1987 that sampled about 12.8 million m3. Harvesters and feller bunchers also increased from zero in the first technical survey to 94 and 13, respectively in the fourth survey. The drivers towards the increased use of mechanised equipment were identified as safety and health, ergonomics, productivity, labour issues, operational costs, terrain, and company policies. Despite the introduction of mechanisation, however, the use of manual labour was evident in hardwood processing and loading operations. Manual debarking was more common than mechanised debarking in the fourth technical survey. When comparing all four technical surveys, the cut to length (CTL) harvesting method was dominant in hardwood; harvesting 79% of the volume sampled in the 2017 survey. The full tree method was barely applied in the first three technical surveys and in the 2007 survey, it was absent. It was only in the fourth technical survey that the method was applied, felling 27% and 9% of the sampled volumes in softwood and hardwood, respectively. The technical survey provides information to the different stakeholders in the forest industry. Such include harvesting managers and contractors, grower companies, machine distributors and researchers. The information will bring awareness to harvesting managers and contractors about the different machine options available to assist in decision making when selecting systems. Machine distributors will know the number of machines, where machines are operating and their target market. A gap in knowledge will be bridged between the different provinces regarding the different types of harvesting machines out there.
- Full Text:
- Date Issued: 2019
- Authors: Mathelele, Ouma Florah
- Date: 2019
- Subjects: Harvesting -- South Africa , Energy harvesting -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/40999 , vital:36281
- Description: South Africa adopted the practice of conducting technical surveys from Austria three decades ago. The Austrian technical survey was used to model the South African technical survey. The survey was conducted with the aim of providing the forestry industry with a detailed analysis of the state of timber harvesting operations. The first technical survey in South Africa was conducted in 1987, and the second one in 1998. The most recent study was carried out in 2007. Since 2007, there has been no other technical survey of a similar nature conducted on harvesting and transport operations. There is no recent information quantifying the volumes harvested, identifying harvesting systems and methods used, and determining volumes harvested using these systems and methods. Furthermore, no updated information exists on the type and quantities of timber trucks transporting the volume. A fourth technical survey that quantifies and analyses these aspects in harvesting operations, therefore, was due. The fourth technical survey aimed at quantifying the number of harvesting machines and timber trucks. The survey further investigated the drivers behind the mechanisation and system preference. The four technical surveys were compared to identify trends in harvesting machines and methods. The data were collected from grower companies, harvesting and transport contractors and small-scale timber growers. Questionnaires were sent to all potential respondents from the three target groups, and interviews were later conducted with selected respondents. The harvesting machines were quantified per function i.e. felling, extraction, processing and loading. The results showed that some machines were more common compared to other machines performing the same function. Mechanised felling machines sampled had more units in the fourth survey than the previous surveys had. Of the 10.6 million m3 volume surveyed in 2017, chainsaws had 1 048 units, and their number had decreased from the 5 000 sampled in the first technical survey in 1987 that sampled about 12.8 million m3. Harvesters and feller bunchers also increased from zero in the first technical survey to 94 and 13, respectively in the fourth survey. The drivers towards the increased use of mechanised equipment were identified as safety and health, ergonomics, productivity, labour issues, operational costs, terrain, and company policies. Despite the introduction of mechanisation, however, the use of manual labour was evident in hardwood processing and loading operations. Manual debarking was more common than mechanised debarking in the fourth technical survey. When comparing all four technical surveys, the cut to length (CTL) harvesting method was dominant in hardwood; harvesting 79% of the volume sampled in the 2017 survey. The full tree method was barely applied in the first three technical surveys and in the 2007 survey, it was absent. It was only in the fourth technical survey that the method was applied, felling 27% and 9% of the sampled volumes in softwood and hardwood, respectively. The technical survey provides information to the different stakeholders in the forest industry. Such include harvesting managers and contractors, grower companies, machine distributors and researchers. The information will bring awareness to harvesting managers and contractors about the different machine options available to assist in decision making when selecting systems. Machine distributors will know the number of machines, where machines are operating and their target market. A gap in knowledge will be bridged between the different provinces regarding the different types of harvesting machines out there.
- Full Text:
- Date Issued: 2019
Adolescent mothers’ breastfeeding experiences in Nelson Mandela Bay health district
- Authors: Fordjour Afriyie, Vera
- Date: 2017
- Subjects: Breastfeeding -- South Africa -- Eastern Cape , Children -- Nutrition -- South Africa -- Port Elizabeth , Teenage mothers -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/13879 , vital:27316
- Description: Rationale: There is limited research available in South Africa that explores the breastfeeding experience among adolescent mothers; most of the studies were conducted in developed countries. One such study relating to the above mentioned developed countries stated that social and commitment factors influence the decision to breastfeed by adolescents. Furthermore, while adolescent mothers appreciate the benefits of breastfeeding, pain, public exposure and perceived complexities related to breastfeeding create barriers for them. The researcher was unable to ascertain if similar ambiguities exist among adolescent mothers in South Africa, and in the Eastern Cape (EC) in particular with its high rates of adolescent pregnancy. In order to attempt to develop age appropriate recommendations to assist adolescent mothers with their breastfeeding journey, the researcher undertook this research study to answer the following question: What are the breastfeeding experiences of adolescent mothers in the Nelson Mandela Bay Heath District (NMBHD)? Aim: The research aim was to determine the experiences of adolescent mothers regarding breastfeeding in NMBHD. Methods: The study implemented a qualitative research approach. To enhance the design, the researcher utilised an explorative, descriptive and contextual research design. The ethical principles that guided this study were autonomy, nonmaleficence, beneficence and justice. Fourteen adolescent mothers, attending PHC facilities in the NMBHD participated in the study. Participants were chosen from a purposive sampling technique and data were collected from semi-structured interviews, compromising of individual interviews. The researcher analysed the data using the using the eight steps of the Tesch analysis technique. Data was also analysed by an independent coder. Results obtained from the Tesch approach were compared to that of the independent coder results. Thereafter, the major themes and sub-themes that related to the study objectives were identified. Results: Three themes and 10 sub-themes were identified. Lack of knowledge and poor adherence to EBF, perceived breastmilk insufficiency, as well as incorrect infant feeding advice given by maternal mothers and grandmothers were associated with early introduction of complementary feeding. Most participants were motivated to breastfeed due to its economic and bonding benefits, as well as seeing their infant‟s progress in growth. Challenges of breastfeeding mentioned by the participants include: lack of support from the fathers of their infants and from health care providers, breast milk leakage, and the foul smell associated with the leaking of breast milk. The participants of the study also had suggestions to help improve the support given to adolescent mothers by health care providers in PHC facilities. Conclusions and recommendations: In conclusion, this study‟s findings revealed that adolescent mothers may need extra age appropriate education and support to assist them in breastfeeding successfully at PHC facilities, the community and schools. Maternal mothers and grandmothers were found to be the primary source of a support network for most adolescent mothers as opposed to health care providers who were categorised as being the secondary source of support. Thus, breastfeeding promotion tailored at maternal mothers and grandmothers would be beneficial in improving their knowledge about the recommended infant feeding practices and consequently aid in providing appropriate support and advice to adolescent mothers. Additionally, training and attitude modification of health care providers is needed to provide adolescent mothers with age-appropriate, effective and sensitive care and counselling.
- Full Text:
- Date Issued: 2017
- Authors: Fordjour Afriyie, Vera
- Date: 2017
- Subjects: Breastfeeding -- South Africa -- Eastern Cape , Children -- Nutrition -- South Africa -- Port Elizabeth , Teenage mothers -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/13879 , vital:27316
- Description: Rationale: There is limited research available in South Africa that explores the breastfeeding experience among adolescent mothers; most of the studies were conducted in developed countries. One such study relating to the above mentioned developed countries stated that social and commitment factors influence the decision to breastfeed by adolescents. Furthermore, while adolescent mothers appreciate the benefits of breastfeeding, pain, public exposure and perceived complexities related to breastfeeding create barriers for them. The researcher was unable to ascertain if similar ambiguities exist among adolescent mothers in South Africa, and in the Eastern Cape (EC) in particular with its high rates of adolescent pregnancy. In order to attempt to develop age appropriate recommendations to assist adolescent mothers with their breastfeeding journey, the researcher undertook this research study to answer the following question: What are the breastfeeding experiences of adolescent mothers in the Nelson Mandela Bay Heath District (NMBHD)? Aim: The research aim was to determine the experiences of adolescent mothers regarding breastfeeding in NMBHD. Methods: The study implemented a qualitative research approach. To enhance the design, the researcher utilised an explorative, descriptive and contextual research design. The ethical principles that guided this study were autonomy, nonmaleficence, beneficence and justice. Fourteen adolescent mothers, attending PHC facilities in the NMBHD participated in the study. Participants were chosen from a purposive sampling technique and data were collected from semi-structured interviews, compromising of individual interviews. The researcher analysed the data using the using the eight steps of the Tesch analysis technique. Data was also analysed by an independent coder. Results obtained from the Tesch approach were compared to that of the independent coder results. Thereafter, the major themes and sub-themes that related to the study objectives were identified. Results: Three themes and 10 sub-themes were identified. Lack of knowledge and poor adherence to EBF, perceived breastmilk insufficiency, as well as incorrect infant feeding advice given by maternal mothers and grandmothers were associated with early introduction of complementary feeding. Most participants were motivated to breastfeed due to its economic and bonding benefits, as well as seeing their infant‟s progress in growth. Challenges of breastfeeding mentioned by the participants include: lack of support from the fathers of their infants and from health care providers, breast milk leakage, and the foul smell associated with the leaking of breast milk. The participants of the study also had suggestions to help improve the support given to adolescent mothers by health care providers in PHC facilities. Conclusions and recommendations: In conclusion, this study‟s findings revealed that adolescent mothers may need extra age appropriate education and support to assist them in breastfeeding successfully at PHC facilities, the community and schools. Maternal mothers and grandmothers were found to be the primary source of a support network for most adolescent mothers as opposed to health care providers who were categorised as being the secondary source of support. Thus, breastfeeding promotion tailored at maternal mothers and grandmothers would be beneficial in improving their knowledge about the recommended infant feeding practices and consequently aid in providing appropriate support and advice to adolescent mothers. Additionally, training and attitude modification of health care providers is needed to provide adolescent mothers with age-appropriate, effective and sensitive care and counselling.
- Full Text:
- Date Issued: 2017
Affordability of housing in the gap market: a case of Walmer link in Port Elizabeth, South Africa
- Makeleni, Nokukhanya Precious
- Authors: Makeleni, Nokukhanya Precious
- Date: 2019
- Subjects: Home ownership -- South Africa -- Port Elizabeth , Housing -- South Africa -- Port Elizabeth Public housing -- South Africa -- Port Elizabeth Rental housing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/42562 , vital:36668
- Description: The new dispensation, after 1994, in South Africa has been criticised a lot for not being able to satisfactorily achieve its election promise of redistribution and poverty alleviation. While success has been noted in the provision of low cost housing and subsequently home ownership for lower income earners, housing demand continues to be a challenge in the delivery capacity of housing for most South Africans. The people most excluded from homeownership include the public sector employees and laborers who face common, but different constraints. These people are classified as middle-income earners, they are either earn too much to qualify for a housing subsidy (RDP house), or too less to afford a house in the prime market. These people are referred to as the “gap market” because they fall with the gap of high and lowincome earners. Adopting a qualitative research method, survey questionnaire were sent to selective respondents involved in the development of affordable housing in the gap market in Walmer Link, Port Elizabeth, Nelson Mandela Bay Metropolitan area. This research sought to assess the affordability of housing in gap market, by understanding the challenges faced by the housing market in addressing the needs of the gap market in Walmer Link. Obstacles that hinders closure in the gap housing delivery, such as affordability, over indebtedness, poor credit ratings and inadequate supply for affordable housing in the gap market were identified during the research. While these obstacles show little indication of abating, this research’s findings and recommendations suggest new pathways for formulating new housing policies that address the housing backlog in the gap market. This also suggests that government policies are critical in developing a healthy and inclusive housing market.
- Full Text:
- Date Issued: 2019
- Authors: Makeleni, Nokukhanya Precious
- Date: 2019
- Subjects: Home ownership -- South Africa -- Port Elizabeth , Housing -- South Africa -- Port Elizabeth Public housing -- South Africa -- Port Elizabeth Rental housing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/42562 , vital:36668
- Description: The new dispensation, after 1994, in South Africa has been criticised a lot for not being able to satisfactorily achieve its election promise of redistribution and poverty alleviation. While success has been noted in the provision of low cost housing and subsequently home ownership for lower income earners, housing demand continues to be a challenge in the delivery capacity of housing for most South Africans. The people most excluded from homeownership include the public sector employees and laborers who face common, but different constraints. These people are classified as middle-income earners, they are either earn too much to qualify for a housing subsidy (RDP house), or too less to afford a house in the prime market. These people are referred to as the “gap market” because they fall with the gap of high and lowincome earners. Adopting a qualitative research method, survey questionnaire were sent to selective respondents involved in the development of affordable housing in the gap market in Walmer Link, Port Elizabeth, Nelson Mandela Bay Metropolitan area. This research sought to assess the affordability of housing in gap market, by understanding the challenges faced by the housing market in addressing the needs of the gap market in Walmer Link. Obstacles that hinders closure in the gap housing delivery, such as affordability, over indebtedness, poor credit ratings and inadequate supply for affordable housing in the gap market were identified during the research. While these obstacles show little indication of abating, this research’s findings and recommendations suggest new pathways for formulating new housing policies that address the housing backlog in the gap market. This also suggests that government policies are critical in developing a healthy and inclusive housing market.
- Full Text:
- Date Issued: 2019
Alternative pine species/hybrids for the Cape timber growing regions of South Africa
- Authors: Van der Hoef, André
- Date: 2020
- Subjects: Species -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/47613 , vital:40258
- Description: Pinus radiata has been the preferred commercial sawtimber species for the Cape forestry region for many years. Since the introduction of Fusarium circinatum, and the susceptibility of P. radiata to this disease, the sustainable production of this pine species for the Cape has been negatively impacted due to poor survival in the nursery and in field plantings. For this reason, a number of additional pine species and hybrids have been established in the Cape region of South Africa since 2006 to identify taxa that would perform as well as or better than P. radiata. Three research trials were implemented on contrasting sites that contained eight common species/hybrids treatments that included P. elliottii, P. elliottii x P. caribaea, P. radiata, P. patula x P. greggii var. australis, P. patula x P. oocarpa, P. patula x P. tecunumanii (HE), P. patula x P. tecunumanii (LE) and P. tecunumanii (HE) x P. oocarpa were established at Witelsbos, Kruisfontein and Garcia across diverse soil types, drainage and climate conditions in the Cape. Survival, growth data and tree morphology (forking, foxtails, broken tops and stem form) were assessed at five years of age and individual tree volume was calculated. Five year results indicate that on the waterlogged site at Witelsbos P. elliottii and its hybrid with P. caribaea was best in terms of productivity, at the dry site of Garcia, P. taeda and P. elliottii demonstrated promise, and at Kruisfontein, the most fertile site, P. elliottii x P. caribaea, P. patula x P. tecunumanii (LE) and P. maximinoi were found to be promising alternatives to P. radiata. Wood properties were assessed at Kruisfontein at six-years of age. Basic density and Modulus of Elasticity (MOE) were found to be significantly different for the various species/hybrids. Pinus patula x P. tecunumanii (LE), P. patula x P. greggii (S), P. maximinoi and P. patula x P. tecunumanii (HE) were all significantly better than P. radiata, which would suggest that these taxa would have similar or superior wood strength over P. radiata, the preferred sawtimber species for the Cape region. Only P. tecunumanii (HE) x P. oocarpa had a higher basic density than P. radiata, but not significantly different. Species that had similar basic density were P. patula x P. greggii (S), P. taeda and P. tecunumanii (LE) x P. caribaea. Although P. elliottii x P. caribaea had the highest volume at Witelsbos and Kruisfontein, the timber qualities were the worst, suggesting that some breeding is needed to improve this hybrid to be an acceptable sawtimber species. From this study, several potential alternative species/hybrids have been identified that are tolerant to the F. circinatum pathogen and have acceptable growth and wood properties, compared to P. radiata.
- Full Text:
- Date Issued: 2020
- Authors: Van der Hoef, André
- Date: 2020
- Subjects: Species -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/47613 , vital:40258
- Description: Pinus radiata has been the preferred commercial sawtimber species for the Cape forestry region for many years. Since the introduction of Fusarium circinatum, and the susceptibility of P. radiata to this disease, the sustainable production of this pine species for the Cape has been negatively impacted due to poor survival in the nursery and in field plantings. For this reason, a number of additional pine species and hybrids have been established in the Cape region of South Africa since 2006 to identify taxa that would perform as well as or better than P. radiata. Three research trials were implemented on contrasting sites that contained eight common species/hybrids treatments that included P. elliottii, P. elliottii x P. caribaea, P. radiata, P. patula x P. greggii var. australis, P. patula x P. oocarpa, P. patula x P. tecunumanii (HE), P. patula x P. tecunumanii (LE) and P. tecunumanii (HE) x P. oocarpa were established at Witelsbos, Kruisfontein and Garcia across diverse soil types, drainage and climate conditions in the Cape. Survival, growth data and tree morphology (forking, foxtails, broken tops and stem form) were assessed at five years of age and individual tree volume was calculated. Five year results indicate that on the waterlogged site at Witelsbos P. elliottii and its hybrid with P. caribaea was best in terms of productivity, at the dry site of Garcia, P. taeda and P. elliottii demonstrated promise, and at Kruisfontein, the most fertile site, P. elliottii x P. caribaea, P. patula x P. tecunumanii (LE) and P. maximinoi were found to be promising alternatives to P. radiata. Wood properties were assessed at Kruisfontein at six-years of age. Basic density and Modulus of Elasticity (MOE) were found to be significantly different for the various species/hybrids. Pinus patula x P. tecunumanii (LE), P. patula x P. greggii (S), P. maximinoi and P. patula x P. tecunumanii (HE) were all significantly better than P. radiata, which would suggest that these taxa would have similar or superior wood strength over P. radiata, the preferred sawtimber species for the Cape region. Only P. tecunumanii (HE) x P. oocarpa had a higher basic density than P. radiata, but not significantly different. Species that had similar basic density were P. patula x P. greggii (S), P. taeda and P. tecunumanii (LE) x P. caribaea. Although P. elliottii x P. caribaea had the highest volume at Witelsbos and Kruisfontein, the timber qualities were the worst, suggesting that some breeding is needed to improve this hybrid to be an acceptable sawtimber species. From this study, several potential alternative species/hybrids have been identified that are tolerant to the F. circinatum pathogen and have acceptable growth and wood properties, compared to P. radiata.
- Full Text:
- Date Issued: 2020