Combined spectral and stimulated luminescence study of charge trapping and recombination processes in α-Al2O3:C
- Authors: Nyirenda, Angel Newton
- Date: 2018
- Subjects: Luminescence , Thermoluminescence , Luminescence spectroscopy , Carbon-doped aluminium oxide , Radioluminescence , Time-resolved X-ray excited optical luminescence
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62683 , vital:28235
- Description: The main objective of this project was to gain a deeper and better understanding of the luminescence processes in a-Al₂O₃:C, a highly-sensitive dosimetric material, using a combined spectral and stimulated luminescence study. The spectral studies concentrated on the emission spectra obtained using X-ray induced radioluminescence (XERL), thermoluminescence (XETL) and time-resolved X-ray excited optical luminescence (TR-XEOL) techniques. The stimulated luminescence studies were based on thermoluminescence (TL), optically stimulated luminescence (OSL) and phototransferred TL (PTTL) methods that were used in the study of the radiation-induced defects at high beta-doses and the deep traps, that is, traps with thermal depths beyond 500°C. The spectral and stimulated luminescence measurements were carried out using a high sensitivity luminescence spectrometer and a Ris0 TL/OSL Model DA-20 Reader, respectively. The XERL emission spectrum measured at room temperature shows seven gaussian peaks associated with F-centres (420 nm), F+-centres (334 nm), F2+-centres (559 nm), Stoke’s vibronic band of Cr3+ (671 nm), Cr3+ R-line emission (694 nm), anti-Stokes vibronic band of Cr3+ (710 nm) and an unidentified emission band (260-300 nm) which we associate with hole recombinations at a luminescence centre. The 694-nm R-line emission from Cr3+ impurity ions is most likely due to recombination of holes at Cr2+ during stimulated luminescence and as a result of an intracentre excitation of Cr3+ in photoluminescence (PL) due to photon absorption. The Cr3+ emission decreases in intensity, whereas the intensity of F-centre emission band is almost constant with repeated XERL measurements. Depending on the amount of X-ray irradiation dose, both holes and/or electrons may take place in the emission processes of peaks I (30-80°C), II (90-250°C) and III (250-320°C) during a TL readout, albeit, electron recombination is dominant regardless of dose. At higher doses, the XETL emission spectra indicate that the dominant band associated with TL peak III (250-320°C) in the material, shifts from F-centre to Cr3+. Using the deep-traps OSL, it has been confirmed that the main TL trap is also the main OSL trap whereas the TL traps lying in the temperature range of 400-550°C constitute the secondary OSL traps. There is evidence of strong retrapping at the main trap during optical stimulation of charges from the secondary OSL traps and the deep traps and that the retrapping occurs via the delocalized bands. At high-irradiation beta-doses, aggregate defect centres which significantly alter the TL and OSL properties, are induced in the material. The induced aggregate centres get completely obliterated by heating a sample to 700°C. The radiation-induced defects cause the main TL peak to shift towards higher temperatures, increase its FWHM, reduce its maximum intensity and cause an underestimation of both the activation energy and order of kinetics of the peak. On the other hand, the OSL response of the material is enhanced following a high-irradiation dose. During sample storage in the dark at ambient temperature, charges do migrate from the deep traps (donors) to the main and intermediate traps (acceptors) and that the major donor traps during this charge transfer phenomenon lie between 500-600°C.
- Full Text:
- Date Issued: 2018
- Authors: Nyirenda, Angel Newton
- Date: 2018
- Subjects: Luminescence , Thermoluminescence , Luminescence spectroscopy , Carbon-doped aluminium oxide , Radioluminescence , Time-resolved X-ray excited optical luminescence
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62683 , vital:28235
- Description: The main objective of this project was to gain a deeper and better understanding of the luminescence processes in a-Al₂O₃:C, a highly-sensitive dosimetric material, using a combined spectral and stimulated luminescence study. The spectral studies concentrated on the emission spectra obtained using X-ray induced radioluminescence (XERL), thermoluminescence (XETL) and time-resolved X-ray excited optical luminescence (TR-XEOL) techniques. The stimulated luminescence studies were based on thermoluminescence (TL), optically stimulated luminescence (OSL) and phototransferred TL (PTTL) methods that were used in the study of the radiation-induced defects at high beta-doses and the deep traps, that is, traps with thermal depths beyond 500°C. The spectral and stimulated luminescence measurements were carried out using a high sensitivity luminescence spectrometer and a Ris0 TL/OSL Model DA-20 Reader, respectively. The XERL emission spectrum measured at room temperature shows seven gaussian peaks associated with F-centres (420 nm), F+-centres (334 nm), F2+-centres (559 nm), Stoke’s vibronic band of Cr3+ (671 nm), Cr3+ R-line emission (694 nm), anti-Stokes vibronic band of Cr3+ (710 nm) and an unidentified emission band (260-300 nm) which we associate with hole recombinations at a luminescence centre. The 694-nm R-line emission from Cr3+ impurity ions is most likely due to recombination of holes at Cr2+ during stimulated luminescence and as a result of an intracentre excitation of Cr3+ in photoluminescence (PL) due to photon absorption. The Cr3+ emission decreases in intensity, whereas the intensity of F-centre emission band is almost constant with repeated XERL measurements. Depending on the amount of X-ray irradiation dose, both holes and/or electrons may take place in the emission processes of peaks I (30-80°C), II (90-250°C) and III (250-320°C) during a TL readout, albeit, electron recombination is dominant regardless of dose. At higher doses, the XETL emission spectra indicate that the dominant band associated with TL peak III (250-320°C) in the material, shifts from F-centre to Cr3+. Using the deep-traps OSL, it has been confirmed that the main TL trap is also the main OSL trap whereas the TL traps lying in the temperature range of 400-550°C constitute the secondary OSL traps. There is evidence of strong retrapping at the main trap during optical stimulation of charges from the secondary OSL traps and the deep traps and that the retrapping occurs via the delocalized bands. At high-irradiation beta-doses, aggregate defect centres which significantly alter the TL and OSL properties, are induced in the material. The induced aggregate centres get completely obliterated by heating a sample to 700°C. The radiation-induced defects cause the main TL peak to shift towards higher temperatures, increase its FWHM, reduce its maximum intensity and cause an underestimation of both the activation energy and order of kinetics of the peak. On the other hand, the OSL response of the material is enhanced following a high-irradiation dose. During sample storage in the dark at ambient temperature, charges do migrate from the deep traps (donors) to the main and intermediate traps (acceptors) and that the major donor traps during this charge transfer phenomenon lie between 500-600°C.
- Full Text:
- Date Issued: 2018
Community education and training colleges as agents of community development in Olievenhoutbosch, Tshwane Municipality
- Authors: Mfenyane, Nozuko Primrose
- Date: 2018
- Subjects: Community education -- South Africa , Community development -- South Africa Vocational education -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/32762 , vital:32355
- Description: The study investigated how the current Community Education and Training (CET) colleges model, as conceptualized by the Department of Higher Education and Training (DHET), hence the ability of Community Education and Training Colleges to contribute to community development in Olievenbosch community. The findings support the DHET's conceptual model of CET colleges, as a new form of institution that will meet the needs of citizens that may not be able to make it to universities and TVET colleges in South Africa.
- Full Text: false
- Date Issued: 2018
- Authors: Mfenyane, Nozuko Primrose
- Date: 2018
- Subjects: Community education -- South Africa , Community development -- South Africa Vocational education -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/32762 , vital:32355
- Description: The study investigated how the current Community Education and Training (CET) colleges model, as conceptualized by the Department of Higher Education and Training (DHET), hence the ability of Community Education and Training Colleges to contribute to community development in Olievenbosch community. The findings support the DHET's conceptual model of CET colleges, as a new form of institution that will meet the needs of citizens that may not be able to make it to universities and TVET colleges in South Africa.
- Full Text: false
- Date Issued: 2018
Community participation in urban revitalization in Buffalo City
- Authors: Magwala, Tandiswa
- Date: 2018
- Subjects: Urban renewal -- South Africa -- Buffalo City Municipality , Community development -- South Africa -- Buffalo City Municipality Neighborhoods -- South Africa -- Buffalo City Municipality Sustainable development -- South Africa -- Eastern Cape -- Citizen participation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/31521 , vital:31501
- Description: Community participation relates to the process by which community members are involved in the projects that determine pertains to their development needs. It is a means of empowering people by developing their skills and abilities to enable them to negotiate and make appropriate decisions for their development. However, community participation faces many challenges in South Africa and some other countries. For instance, in most, if not all, development projects commenced by local municipalities, community participation is often neglected or becomes an afterthought. In most cases, the communities are consulted after decisions have already been made by government agencies in relation to the kind of development projects that need to be executed. As a result, community participation is a prerequisite in development projects which are meant to improve the livelihoods and standard of living of the majority of communities in South Africa. The Buffalo City Municipality Metro (BCMM) is not an exception to this. The BCMM is located in the Eastern Cape Province, which is one of the poorest provinces in South Africa. In one of the towns in the municipal area, namely Dimbaza in the former Ciskei ‘homeland’, where there are high levels of unemployment and poverty, a prominent feature in the landscape is the many abandoned factory buildings. In recent years, the BCMM has recognized the need to revitalize the nodal areas such as Mdantsane, Dimbaza and Bisho, but due to the fragmented patterns of Bantustan policies the program was negatively affected (BCMM 2014/15/141). As a consequence, the BCMM has supported the implement an urban revitalization project within its area. The aim of this study was to investigate and interrogate whether local communities are involved in urban revitalization in the BCMM. That is, to evaluate community participation in urban revitalization projects in the BCMM, and focusing on Dimbaza community in the Eastern Cape province of South Africa as a case study. The study asks the following questions: Do the BCMM’s urban redevelopment initiatives have community participation component? How can the community be more involved in neighbourhood revitalization? v To what extent do these perceptions and priorities of the people living in neighbourhood of the disused factories match those of the policy makers? What are the perceptions of the people living in the neighbourhood of the disused factories in Dimbaza with regard to redevelopment? What recommendations can emanate from the study to address the current challenges regarding community participation in urban revitalization in BCMM? The study revealed that the majority of the respondents did not participate in the initiation and planning stages of the urban revitalization projects. The study further showed that a considerable proportion of the surveyed Dimbaza residents did not know about the urban revitalization programme, but learnt about it only in the local newspaper. It is therefore recommended that, the BCMM should support the community at all levels of planning to ensure a strong commitment to participation in their urban revitalization or development projects. It is hoped that this study will sensitize the community members of Dimbaza and the roles players involved in the Dimbaza urban revitalization projects including, among others, the Buffalo City Municipality Metropolitan, the Eastern Cape Development Cooperation and the Department of Economic Development, Environmental Affairs and Tourism of the Eastern Cape, to realise the significance and advantages of community participation, and that they will work through the challenges therein in order to increase community participation in development projects.
- Full Text:
- Date Issued: 2018
- Authors: Magwala, Tandiswa
- Date: 2018
- Subjects: Urban renewal -- South Africa -- Buffalo City Municipality , Community development -- South Africa -- Buffalo City Municipality Neighborhoods -- South Africa -- Buffalo City Municipality Sustainable development -- South Africa -- Eastern Cape -- Citizen participation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/31521 , vital:31501
- Description: Community participation relates to the process by which community members are involved in the projects that determine pertains to their development needs. It is a means of empowering people by developing their skills and abilities to enable them to negotiate and make appropriate decisions for their development. However, community participation faces many challenges in South Africa and some other countries. For instance, in most, if not all, development projects commenced by local municipalities, community participation is often neglected or becomes an afterthought. In most cases, the communities are consulted after decisions have already been made by government agencies in relation to the kind of development projects that need to be executed. As a result, community participation is a prerequisite in development projects which are meant to improve the livelihoods and standard of living of the majority of communities in South Africa. The Buffalo City Municipality Metro (BCMM) is not an exception to this. The BCMM is located in the Eastern Cape Province, which is one of the poorest provinces in South Africa. In one of the towns in the municipal area, namely Dimbaza in the former Ciskei ‘homeland’, where there are high levels of unemployment and poverty, a prominent feature in the landscape is the many abandoned factory buildings. In recent years, the BCMM has recognized the need to revitalize the nodal areas such as Mdantsane, Dimbaza and Bisho, but due to the fragmented patterns of Bantustan policies the program was negatively affected (BCMM 2014/15/141). As a consequence, the BCMM has supported the implement an urban revitalization project within its area. The aim of this study was to investigate and interrogate whether local communities are involved in urban revitalization in the BCMM. That is, to evaluate community participation in urban revitalization projects in the BCMM, and focusing on Dimbaza community in the Eastern Cape province of South Africa as a case study. The study asks the following questions: Do the BCMM’s urban redevelopment initiatives have community participation component? How can the community be more involved in neighbourhood revitalization? v To what extent do these perceptions and priorities of the people living in neighbourhood of the disused factories match those of the policy makers? What are the perceptions of the people living in the neighbourhood of the disused factories in Dimbaza with regard to redevelopment? What recommendations can emanate from the study to address the current challenges regarding community participation in urban revitalization in BCMM? The study revealed that the majority of the respondents did not participate in the initiation and planning stages of the urban revitalization projects. The study further showed that a considerable proportion of the surveyed Dimbaza residents did not know about the urban revitalization programme, but learnt about it only in the local newspaper. It is therefore recommended that, the BCMM should support the community at all levels of planning to ensure a strong commitment to participation in their urban revitalization or development projects. It is hoped that this study will sensitize the community members of Dimbaza and the roles players involved in the Dimbaza urban revitalization projects including, among others, the Buffalo City Municipality Metropolitan, the Eastern Cape Development Cooperation and the Department of Economic Development, Environmental Affairs and Tourism of the Eastern Cape, to realise the significance and advantages of community participation, and that they will work through the challenges therein in order to increase community participation in development projects.
- Full Text:
- Date Issued: 2018
Comparison of contraceptive discontinuation in users of a copper intrauterine device against depot medroxyprogesterone acetate injectable
- Authors: Dekile-Yonto, Nolusindiso
- Date: 2018
- Subjects: Contraceptives Birth control Women's health services
- Language: English
- Type: Thesis , Masters , Magister of Curationis
- Identifier: http://hdl.handle.net/10353/15520 , vital:40422
- Description: The dynamics of continued contraceptive use, switches to alternatives, or the outright failure of contraception is strong indicators of the effectiveness of health care programmes for women or couples (Ali, Cleland & Shah, 2012:6). Furthermore, unplanned pregnancies often lead to undesirable health, economic, social, and psychological consequences for women (Sedgh, Singh & Hussain., 2014). There is a need to better understand the reasons for discontinuation of contraception to enable health care workers to address the gaps in the provision of family planning services. For this reason, the researcher embarked on a follow-up study of a randomised, controlled trial, which compared the effects on depression and sexual functioning of women after childbirth of a Copper Intrauterine Contraceptive Device (Cu-IUD) with Depot Medroxyprogesterone Acetate (DMPA), (Singata-Madliki, 2014:5). The objectives of the follow-up study was to do a once-off follow-up of the original participants, three years after randomisation.
- Full Text:
- Date Issued: 2018
- Authors: Dekile-Yonto, Nolusindiso
- Date: 2018
- Subjects: Contraceptives Birth control Women's health services
- Language: English
- Type: Thesis , Masters , Magister of Curationis
- Identifier: http://hdl.handle.net/10353/15520 , vital:40422
- Description: The dynamics of continued contraceptive use, switches to alternatives, or the outright failure of contraception is strong indicators of the effectiveness of health care programmes for women or couples (Ali, Cleland & Shah, 2012:6). Furthermore, unplanned pregnancies often lead to undesirable health, economic, social, and psychological consequences for women (Sedgh, Singh & Hussain., 2014). There is a need to better understand the reasons for discontinuation of contraception to enable health care workers to address the gaps in the provision of family planning services. For this reason, the researcher embarked on a follow-up study of a randomised, controlled trial, which compared the effects on depression and sexual functioning of women after childbirth of a Copper Intrauterine Contraceptive Device (Cu-IUD) with Depot Medroxyprogesterone Acetate (DMPA), (Singata-Madliki, 2014:5). The objectives of the follow-up study was to do a once-off follow-up of the original participants, three years after randomisation.
- Full Text:
- Date Issued: 2018
Compensation for distribution of timing and reference signals over optical fibre networks for telescope arrays
- Authors: Wassin, Shukree
- Date: 2018
- Subjects: Fiber optics , Optical communications Very large array telescopes Optical fiber detectors
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/36425 , vital:33941
- Description: Significant advancements and developments have been made in optical frequency standards, in recent years. In order to verify the accuracy and preciseness of the disseminated RF signal, it is essential to compare its stability with the standards provided in literature as well as by metrology institutes. However, conventional frequency comparison techniques via satellites have extremely inferior stability qualities. As a result, the need for an alternative ultra-high precision RF transfer method presented itself. Highly accurate and precise frequency dissemination across optical fiber has proved a leading contender and a possible solution. When compared to conventional data transfer media, optical fiber has proven to be more superior and yields lower transmission errors and is immune to radio frequency interference. A further quality of optical fibre is that its transmission distance can be extended to greater degree than the traditional coaxial cable due to its low loss property. This thesis deals with the compensation of phase noise in single mode optical fibre. Phase noise degrades the performance and stability of the RF signal as well as the optical carrier frequency across long-haul optical networks. This work begins by experimentally demonstrating a unique and novel way for measuring the round-trip optical fibre latency times. The technique is based on all optical wavelength conversion using a stable PPS injection signal. The result highlighted the importance for active phase error compensation along a fibre link. Various computer simulations were used to study the influence of temperature fluctuation on the optical fibre. The first ever error signals generated at NMU was experimentally demonstrated. Results illustrated that, by minimizing the error voltage the phase difference between the transmitted and reference signals were reduced to zero. Performance analysis testing of the VCSEL phase correction actuator showed that majority of the dither iterations that induced the phase compensation took approximately 0.15 s. Residual frequency instabilities of 3.39791 x 10-12 at 1 s and 8.14848 x 10-12 at 103 s was measured when the 26 km G.655 fibre link was running freely. Experimental results further showed that the relative frequency stabilities measured at 1 s and 103 s were 4.43902 x 10-12 and 1.62055 x 10-13 during active compensation, respectively. The novel work presented in this thesis is exciting since the VCSEL is used as the optical source as well as the phase correction actuator. The benefits of such a device is that is reduces system costs and complexities.
- Full Text:
- Date Issued: 2018
- Authors: Wassin, Shukree
- Date: 2018
- Subjects: Fiber optics , Optical communications Very large array telescopes Optical fiber detectors
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/36425 , vital:33941
- Description: Significant advancements and developments have been made in optical frequency standards, in recent years. In order to verify the accuracy and preciseness of the disseminated RF signal, it is essential to compare its stability with the standards provided in literature as well as by metrology institutes. However, conventional frequency comparison techniques via satellites have extremely inferior stability qualities. As a result, the need for an alternative ultra-high precision RF transfer method presented itself. Highly accurate and precise frequency dissemination across optical fiber has proved a leading contender and a possible solution. When compared to conventional data transfer media, optical fiber has proven to be more superior and yields lower transmission errors and is immune to radio frequency interference. A further quality of optical fibre is that its transmission distance can be extended to greater degree than the traditional coaxial cable due to its low loss property. This thesis deals with the compensation of phase noise in single mode optical fibre. Phase noise degrades the performance and stability of the RF signal as well as the optical carrier frequency across long-haul optical networks. This work begins by experimentally demonstrating a unique and novel way for measuring the round-trip optical fibre latency times. The technique is based on all optical wavelength conversion using a stable PPS injection signal. The result highlighted the importance for active phase error compensation along a fibre link. Various computer simulations were used to study the influence of temperature fluctuation on the optical fibre. The first ever error signals generated at NMU was experimentally demonstrated. Results illustrated that, by minimizing the error voltage the phase difference between the transmitted and reference signals were reduced to zero. Performance analysis testing of the VCSEL phase correction actuator showed that majority of the dither iterations that induced the phase compensation took approximately 0.15 s. Residual frequency instabilities of 3.39791 x 10-12 at 1 s and 8.14848 x 10-12 at 103 s was measured when the 26 km G.655 fibre link was running freely. Experimental results further showed that the relative frequency stabilities measured at 1 s and 103 s were 4.43902 x 10-12 and 1.62055 x 10-13 during active compensation, respectively. The novel work presented in this thesis is exciting since the VCSEL is used as the optical source as well as the phase correction actuator. The benefits of such a device is that is reduces system costs and complexities.
- Full Text:
- Date Issued: 2018
Computational analysis and cavity optimisation to achieve directional solidification in a cast aluminium alloy [Al7SiMg] component
- Authors: Nohanyaza, Melikhaya
- Date: 2018
- Subjects: Metal castings , Automobiles -- Materials , Alloys , Light metal alloys
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/22913 , vital:30141
- Description: The study at hand focussed on A356.0 industrial and high production die casting alloy. Since the birth of metal casting, numerous researchers have addressed the multiple phenomena that influence the casting quality and mechanical properties of castable alloys. This study harnessed research findings on A356.0 alloy and the aluminium family as a whole, to improve the casting soundness of the component already in the production process. The local foundry showed interest in understanding solidification and quality of A356.0 alloy fluxed with NaCl+KCl melt cleaning flux plus 4 of TiB2 5:1 master alloy grain refining rods and A356.0 alloy processed with KCl+Ti (presumably KCl+TiB2) grain refining flux plus 4 of TiB2 5:1 master alloy rods. Numerical analysis was used to define the progressive nature and directional solidification of the alloy using MAGMA5. MAGMA5.3 virtual optimisation capabilities were used for development of future component casting methods and procedures to solve macro- and microporosity evident on the casting. To find a direct link between the virtual and foundry environment, a preliminary study was conducted on a simple foundry stage of cone billet casting for both alloys with and without mould/casting interface coating. The findings indicated that A356.0 maintained its shrinkage volume percentage at mould temperatures above 300 °C, but progressively increased at temperatures below. Furthermore, thermal insulation coat (also used on Right Hand Side [RHS] mould of the foundry component) influenced the shrinkage distribution on the casting while localised at the centre on non-coated mould/casting interfaces for both KCl+Ti and NaCl+KCl melt fluxed A356.0 at similar percentage shrinkage for mould temperatures greater or equal to 300 °C. Near thin foundry castings for both flux treatments indicated similar mechanical properties at similar casting stages. The mechanical properties of both conditions seemed to degrade as a function of die casting period. Secondary dendrite arm spacing microstructure parameter for NaCl+KCl and KCl+Ti fluxed alloy averaged 40 μm and 35 μm respectively across all test zones. However, individual SDAS definitions per test zone indicated possible micro segregation on NaCl+KCl fluxed alloy and instantaneous solidification as a result of constitutional supercooling on alloys fluxed with KCl+Ti alloy. The growth rate solidification parameter was symmetrical about the centre of the component, where the centre of the component experienced an exponential drop from the top (away from the filling gate) to the bottom (near the filling gate) of the component. A virtual approach to tooling geometrical design indicated a weak influence on both micro- and macroporosity. However, the introduction of low thermal capacity, high heat transfer at Left Hand Side [LHS] tooling and a new cooling system arrangement indicated a higher influence in achieving sound casting. Knowledge gained in this study will improve local foundry competitiveness and introduce cost effective virtual approach foundry developments. The study will also introduce new methods for industrial research and position Nelson Mandela University as a leader in this field.
- Full Text:
- Date Issued: 2018
- Authors: Nohanyaza, Melikhaya
- Date: 2018
- Subjects: Metal castings , Automobiles -- Materials , Alloys , Light metal alloys
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/22913 , vital:30141
- Description: The study at hand focussed on A356.0 industrial and high production die casting alloy. Since the birth of metal casting, numerous researchers have addressed the multiple phenomena that influence the casting quality and mechanical properties of castable alloys. This study harnessed research findings on A356.0 alloy and the aluminium family as a whole, to improve the casting soundness of the component already in the production process. The local foundry showed interest in understanding solidification and quality of A356.0 alloy fluxed with NaCl+KCl melt cleaning flux plus 4 of TiB2 5:1 master alloy grain refining rods and A356.0 alloy processed with KCl+Ti (presumably KCl+TiB2) grain refining flux plus 4 of TiB2 5:1 master alloy rods. Numerical analysis was used to define the progressive nature and directional solidification of the alloy using MAGMA5. MAGMA5.3 virtual optimisation capabilities were used for development of future component casting methods and procedures to solve macro- and microporosity evident on the casting. To find a direct link between the virtual and foundry environment, a preliminary study was conducted on a simple foundry stage of cone billet casting for both alloys with and without mould/casting interface coating. The findings indicated that A356.0 maintained its shrinkage volume percentage at mould temperatures above 300 °C, but progressively increased at temperatures below. Furthermore, thermal insulation coat (also used on Right Hand Side [RHS] mould of the foundry component) influenced the shrinkage distribution on the casting while localised at the centre on non-coated mould/casting interfaces for both KCl+Ti and NaCl+KCl melt fluxed A356.0 at similar percentage shrinkage for mould temperatures greater or equal to 300 °C. Near thin foundry castings for both flux treatments indicated similar mechanical properties at similar casting stages. The mechanical properties of both conditions seemed to degrade as a function of die casting period. Secondary dendrite arm spacing microstructure parameter for NaCl+KCl and KCl+Ti fluxed alloy averaged 40 μm and 35 μm respectively across all test zones. However, individual SDAS definitions per test zone indicated possible micro segregation on NaCl+KCl fluxed alloy and instantaneous solidification as a result of constitutional supercooling on alloys fluxed with KCl+Ti alloy. The growth rate solidification parameter was symmetrical about the centre of the component, where the centre of the component experienced an exponential drop from the top (away from the filling gate) to the bottom (near the filling gate) of the component. A virtual approach to tooling geometrical design indicated a weak influence on both micro- and macroporosity. However, the introduction of low thermal capacity, high heat transfer at Left Hand Side [LHS] tooling and a new cooling system arrangement indicated a higher influence in achieving sound casting. Knowledge gained in this study will improve local foundry competitiveness and introduce cost effective virtual approach foundry developments. The study will also introduce new methods for industrial research and position Nelson Mandela University as a leader in this field.
- Full Text:
- Date Issued: 2018
Conflict analysis with a focus on community polarisation: a case study of a wind energy project in Switzerland
- Authors: Bachmann, Melanie
- Date: 2018
- Subjects: Conflict management
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/42428 , vital:36654
- Description: Switzerland, like many other countries, wants to expand the production and usage of renewable energies, including wind energy. However, wind energy causes much conflict due to the emissions and possible impacts on the people, nature and landscape. In the canton of Glarus a wind energy project called LinthWind is currently projected. This has resulted in a public dispute involving several parties and members of the community. In opposition to the project, the association LinthGegenWind was formed with the aim of keeping the area free from wind turbines. The project developer, as well as LinthGegenWind, are organising information events and provide information through other platforms. The aim of this research is to provide the community with a thorough understanding of the conflict, including its dynamics and possible destructive processes. Through the conduction of conflict analysis, it investigates the conflict evolving around the project LinthWind. With the help of an online questionnaire, the opinions of the participants regarding the project and also the factors influencing the opinion-formation were enquired. This allowed for an examination of the polarization of the community and the factors contributing to it. The conflict analysis presents detailed information regarding the conflict history and background, the parties involved, issues under contention, sources and causes of the conflict, driving factors and the dynamics. Many factors indicate that the dispute is in an escalating phase. It was further shown that the affected community is clearly polarised regarding the project LinthWind. The polarisation is most likely enhanced by certain measures applied by the parties and the voting process. Independently gathered information by the people themselves seem to be the strongest influencing factors for the opinion formation. The success of the tactics applied by the project developer and the association opposing the project vary regarding their influence on the opinion formation. Missing communication between the parties and a polarised community exacerbates effective conflict management. In the case of LinthWind, a forum is therefore suggested where communication and information – the basics for constructive conflict management – are enabled.
- Full Text:
- Date Issued: 2018
- Authors: Bachmann, Melanie
- Date: 2018
- Subjects: Conflict management
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/42428 , vital:36654
- Description: Switzerland, like many other countries, wants to expand the production and usage of renewable energies, including wind energy. However, wind energy causes much conflict due to the emissions and possible impacts on the people, nature and landscape. In the canton of Glarus a wind energy project called LinthWind is currently projected. This has resulted in a public dispute involving several parties and members of the community. In opposition to the project, the association LinthGegenWind was formed with the aim of keeping the area free from wind turbines. The project developer, as well as LinthGegenWind, are organising information events and provide information through other platforms. The aim of this research is to provide the community with a thorough understanding of the conflict, including its dynamics and possible destructive processes. Through the conduction of conflict analysis, it investigates the conflict evolving around the project LinthWind. With the help of an online questionnaire, the opinions of the participants regarding the project and also the factors influencing the opinion-formation were enquired. This allowed for an examination of the polarization of the community and the factors contributing to it. The conflict analysis presents detailed information regarding the conflict history and background, the parties involved, issues under contention, sources and causes of the conflict, driving factors and the dynamics. Many factors indicate that the dispute is in an escalating phase. It was further shown that the affected community is clearly polarised regarding the project LinthWind. The polarisation is most likely enhanced by certain measures applied by the parties and the voting process. Independently gathered information by the people themselves seem to be the strongest influencing factors for the opinion formation. The success of the tactics applied by the project developer and the association opposing the project vary regarding their influence on the opinion formation. Missing communication between the parties and a polarised community exacerbates effective conflict management. In the case of LinthWind, a forum is therefore suggested where communication and information – the basics for constructive conflict management – are enabled.
- Full Text:
- Date Issued: 2018
Conflict narratives of young males in the Blue Crane Route Municipality who experienced domestic violence during childhood
- Authors: Martin, Jonathan Malvin
- Date: 2018
- Subjects: Family violence , Abusive men -- Psychology , Abusive men -- Rehabilitation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/31863 , vital:31855
- Description: Domestic Violence is a growing concern globally and currently one of the most dominant negative social forces in South Africa. Many children are experiencing or witnessing Domestic Violence in their households or community, with potentially devastating consequences (Dawes, Long, Alexander & Ward, 2007; Burton, 2007). This study investigates the personal conflict narratives of eleven young adult males who experienced Domestic Violence as children. The young men completed a self-administered questionnaire which included a request for a personal conflict narrative or story. The study then engaged these young men in a two-day workshop of an international conflict management programme, known as the Alternatives to Violence Project (AVP), which teaches attitudes and strategies to manage conflict (such as self-awareness, empathy and community-building). After the workshop, the participants were asked to re-write their conflict narratives and any changes in their attitudes and strategies to conflict were discussed in group interviews. The study was qualitative; that is, exploratory, descriptive and contextual in nature. Non-probability purposive sampling was employed to identify suitable young adult males between 18-35 years of age from the Blue Crane Route Municipality (Somerset East and Pearston), who experienced Domestic Violence during their childhood. Workers at Victim Support Centres in the Blue Crane Route Municipality assisted with the recruitment of potential participants and requested permission to provide the researcher with their personal information. In analysing the data obtained, the study used a narrative analysis approach to the participants’ pre- and post-AVP workshop conflict narratives. The trustworthiness of the research process and findings was enhanced by employing a variety of data verification strategies.
- Full Text:
- Date Issued: 2018
- Authors: Martin, Jonathan Malvin
- Date: 2018
- Subjects: Family violence , Abusive men -- Psychology , Abusive men -- Rehabilitation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/31863 , vital:31855
- Description: Domestic Violence is a growing concern globally and currently one of the most dominant negative social forces in South Africa. Many children are experiencing or witnessing Domestic Violence in their households or community, with potentially devastating consequences (Dawes, Long, Alexander & Ward, 2007; Burton, 2007). This study investigates the personal conflict narratives of eleven young adult males who experienced Domestic Violence as children. The young men completed a self-administered questionnaire which included a request for a personal conflict narrative or story. The study then engaged these young men in a two-day workshop of an international conflict management programme, known as the Alternatives to Violence Project (AVP), which teaches attitudes and strategies to manage conflict (such as self-awareness, empathy and community-building). After the workshop, the participants were asked to re-write their conflict narratives and any changes in their attitudes and strategies to conflict were discussed in group interviews. The study was qualitative; that is, exploratory, descriptive and contextual in nature. Non-probability purposive sampling was employed to identify suitable young adult males between 18-35 years of age from the Blue Crane Route Municipality (Somerset East and Pearston), who experienced Domestic Violence during their childhood. Workers at Victim Support Centres in the Blue Crane Route Municipality assisted with the recruitment of potential participants and requested permission to provide the researcher with their personal information. In analysing the data obtained, the study used a narrative analysis approach to the participants’ pre- and post-AVP workshop conflict narratives. The trustworthiness of the research process and findings was enhanced by employing a variety of data verification strategies.
- Full Text:
- Date Issued: 2018
Constitutional and human-rights aspects of marine spatial planning
- Authors: Chasakara, Rachael Sharon
- Date: 2018
- Subjects: Human rights , Marine resources development -- Law and legislation Law of the sea
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/23470 , vital:30566
- Description: The importance of oceans cannot be overstated as they are vital for the environmental and economic well-being of South Africa. The state of South Africa’s ocean is on the decline due to increased human activities within its waters, which have caused devastation among marine resources that are limited in space, time and amount. These activities have caused elevated competition among ocean users resulting in undesirable effects such as loss of biodiversity. The challenge is not that these human activities are unregulated or unplanned, rather that there are planned and regulated on a sectoral basis by different sectors each with its own specific approach to the allocation and use of the ocean space. There is, therefore, a need for a holistic approach to ocean governance that views the ocean as a whole and not merely on a sectoral basis. The relatively new notion of Marine Spatial Planning (MSP) which establishes its authority in MSP instruments,1 has emerged as a comprehensive way to achieve this. This dissertation grapples with the questions surrounding whether the MSP instruments are consistent with the Constitution of the Republic of South Africa, 1996 (the Constitution). The dissertation departs by providing a background into the spatial jurisdiction of coastal states in the ocean space to clarify how far at sea South Africa can exercise its authority. This study concluded that even though the area of application claimed by the MSP Bill is consistent with the internationally prescribed territory of coastal states at sea, the MSP Bill should expressly state the different sovereign rights vested in coastal states by the United Nations Convention on the Law of the Sea, 1982 (‘the LOSC’) subject to the rights of other states in these waters. From here, the dissertation ventures into an analysis of which organs of state will be responsible for the development and implementation of MSP since it is an exercise of public power by the state. This part of the discussion involves inter alia an in-depth analysis of the separation of powers doctrine as far as planning matters are concerned. An essential premise is that MSP regulation requires all spheres of government to cooperate with each other. It is proposed that the MSP Bill should 1 The MSP Bill, GN 347 in GG 39847 of 2016-03-24 and the National MSP Framework for South Africa, GN 936 in GG 40219 of 2016-08-19. provide how these spheres of government should work together for the successful implementation of MSP. This dissertation then proceeds to discuss the right to equality, the environmental right, and the right to freedom of trade, occupation and profession which could potentially be impacted by the implementation of MSP. It is submitted that in the implementation of MSP, the goal must be to achieve an appropriate balance amongst these competing rights. Finally, considering the above analysis and discussions this dissertation moves to propose recommendations on how the MSP instruments can be amended to give effect to the requirements of these rights. Generally, the findings of this research reflect the consistency of the MSP instruments with the Constitution. However, for MSP to be implemented constitutionally, the proposed recommendations must be adhered to.
- Full Text:
- Date Issued: 2018
- Authors: Chasakara, Rachael Sharon
- Date: 2018
- Subjects: Human rights , Marine resources development -- Law and legislation Law of the sea
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/23470 , vital:30566
- Description: The importance of oceans cannot be overstated as they are vital for the environmental and economic well-being of South Africa. The state of South Africa’s ocean is on the decline due to increased human activities within its waters, which have caused devastation among marine resources that are limited in space, time and amount. These activities have caused elevated competition among ocean users resulting in undesirable effects such as loss of biodiversity. The challenge is not that these human activities are unregulated or unplanned, rather that there are planned and regulated on a sectoral basis by different sectors each with its own specific approach to the allocation and use of the ocean space. There is, therefore, a need for a holistic approach to ocean governance that views the ocean as a whole and not merely on a sectoral basis. The relatively new notion of Marine Spatial Planning (MSP) which establishes its authority in MSP instruments,1 has emerged as a comprehensive way to achieve this. This dissertation grapples with the questions surrounding whether the MSP instruments are consistent with the Constitution of the Republic of South Africa, 1996 (the Constitution). The dissertation departs by providing a background into the spatial jurisdiction of coastal states in the ocean space to clarify how far at sea South Africa can exercise its authority. This study concluded that even though the area of application claimed by the MSP Bill is consistent with the internationally prescribed territory of coastal states at sea, the MSP Bill should expressly state the different sovereign rights vested in coastal states by the United Nations Convention on the Law of the Sea, 1982 (‘the LOSC’) subject to the rights of other states in these waters. From here, the dissertation ventures into an analysis of which organs of state will be responsible for the development and implementation of MSP since it is an exercise of public power by the state. This part of the discussion involves inter alia an in-depth analysis of the separation of powers doctrine as far as planning matters are concerned. An essential premise is that MSP regulation requires all spheres of government to cooperate with each other. It is proposed that the MSP Bill should 1 The MSP Bill, GN 347 in GG 39847 of 2016-03-24 and the National MSP Framework for South Africa, GN 936 in GG 40219 of 2016-08-19. provide how these spheres of government should work together for the successful implementation of MSP. This dissertation then proceeds to discuss the right to equality, the environmental right, and the right to freedom of trade, occupation and profession which could potentially be impacted by the implementation of MSP. It is submitted that in the implementation of MSP, the goal must be to achieve an appropriate balance amongst these competing rights. Finally, considering the above analysis and discussions this dissertation moves to propose recommendations on how the MSP instruments can be amended to give effect to the requirements of these rights. Generally, the findings of this research reflect the consistency of the MSP instruments with the Constitution. However, for MSP to be implemented constitutionally, the proposed recommendations must be adhered to.
- Full Text:
- Date Issued: 2018
Constructing an EMF radiation Hygeia framework and model to demonstrate a public interest override
- Authors: Lech, James Chrystopher
- Date: 2018
- Subjects: Electromagnetic fields , Electromagnetic fields -- Health aspects , Electromagnetic fields -- Measurement , Public interest , Radiation -- Measurement , HYGEIA , Promotion of Access to Information Act (PAIA)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/58695 , vital:27364
- Description: Scientific views on EMF radiation dosimetry and models increasingly suggest that even a tiny increase in the incidence of diseases resulting from exposure to EMF radiation could have broad¹ implications for public health, social accounting and the economy. In South Africa (SA) there is no national EMF radiation exposure protection standard, statutory monitoring or regulations. Multinational High Court deliberations indicate the need for public interest EMF radiation exposure protection standards in South Africa. Domestic citizens, academics, as well as regulatory and legislative practitioners, are unable to effectively monitor and investigate EMF radiation exposure emissions from infrastructure sources, because industries refuse to provide the required data. Industries have, since 2003, continually obstructed access to the data and the establishment of a national EMF radiation standard, citing that it would be in conflict with their strategic economic interests. The demonstration of a public interest override (PIO) function is legislatively required to gain access to the required data. This study constructed (1) a framework and (2) a model to perform test simulations against the (3) PIO criteria to demonstrate a PIO function and tested one PIO simulation scenario. Testing the PIO scenario firstly required the construction of a public interest framework, drawing input from multiple disciplines. The framework literature review used systematic case law and scientific-technical analysis whilst the framework science sought to understand the connections, feedbacks, and trajectories that occur as a result of natural and human system processes and exchanges. The EMF radiation exposure system functions to support human wellbeing needs and to explore the benefits and losses associated with alternative futures with the goal to uncover the current and future limits thereof. In the second instance a HYGEIA² model was selected as a base investigation and forecast simulation tool. The study had to uncover the key attributes and parameters necessary to construct and to run successful EMF radiation exposure simulations. Thereafter the HYGEIA model was modified to specifically identify and evaluate EMF radiation exposure hazard conditions. Through subsequent simulation runs, the constructed framework was then tested. Requested anthroposphere information was synthesized within a systems model to forecast ecosystem services and human-use dynamics under alternative scenarios. The simulation used the model, the model references and the framework for guidelines, thus allowing multiple simulation / demonstration runs for different contexts or scenarios. The third step was the construction of a PIO checklist which guides criteria testing and provides a means of gaining pertinent information for further studies, based on this dissertation. Framework EMF radiation policy inputs into the model were intersected with identified vulnerable area facilities which were selected based on international criteria. The research output revealed potential EMF radiation violations which served as system feedback inputs in support of a demonstrated PIO function. The research recommends that the identified EMF radiation exposure violations of public health undergo a Promotion of Access to Information Act (PAIA) judicial review process to confirm the research findings. The judicial qualification of a PAIA PIO function of ‘substances released into the environment’ and ‘public safety or environmental risk’ would enable access to EMF radiation emissions data essential to future studies.
- Full Text:
- Date Issued: 2018
- Authors: Lech, James Chrystopher
- Date: 2018
- Subjects: Electromagnetic fields , Electromagnetic fields -- Health aspects , Electromagnetic fields -- Measurement , Public interest , Radiation -- Measurement , HYGEIA , Promotion of Access to Information Act (PAIA)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/58695 , vital:27364
- Description: Scientific views on EMF radiation dosimetry and models increasingly suggest that even a tiny increase in the incidence of diseases resulting from exposure to EMF radiation could have broad¹ implications for public health, social accounting and the economy. In South Africa (SA) there is no national EMF radiation exposure protection standard, statutory monitoring or regulations. Multinational High Court deliberations indicate the need for public interest EMF radiation exposure protection standards in South Africa. Domestic citizens, academics, as well as regulatory and legislative practitioners, are unable to effectively monitor and investigate EMF radiation exposure emissions from infrastructure sources, because industries refuse to provide the required data. Industries have, since 2003, continually obstructed access to the data and the establishment of a national EMF radiation standard, citing that it would be in conflict with their strategic economic interests. The demonstration of a public interest override (PIO) function is legislatively required to gain access to the required data. This study constructed (1) a framework and (2) a model to perform test simulations against the (3) PIO criteria to demonstrate a PIO function and tested one PIO simulation scenario. Testing the PIO scenario firstly required the construction of a public interest framework, drawing input from multiple disciplines. The framework literature review used systematic case law and scientific-technical analysis whilst the framework science sought to understand the connections, feedbacks, and trajectories that occur as a result of natural and human system processes and exchanges. The EMF radiation exposure system functions to support human wellbeing needs and to explore the benefits and losses associated with alternative futures with the goal to uncover the current and future limits thereof. In the second instance a HYGEIA² model was selected as a base investigation and forecast simulation tool. The study had to uncover the key attributes and parameters necessary to construct and to run successful EMF radiation exposure simulations. Thereafter the HYGEIA model was modified to specifically identify and evaluate EMF radiation exposure hazard conditions. Through subsequent simulation runs, the constructed framework was then tested. Requested anthroposphere information was synthesized within a systems model to forecast ecosystem services and human-use dynamics under alternative scenarios. The simulation used the model, the model references and the framework for guidelines, thus allowing multiple simulation / demonstration runs for different contexts or scenarios. The third step was the construction of a PIO checklist which guides criteria testing and provides a means of gaining pertinent information for further studies, based on this dissertation. Framework EMF radiation policy inputs into the model were intersected with identified vulnerable area facilities which were selected based on international criteria. The research output revealed potential EMF radiation violations which served as system feedback inputs in support of a demonstrated PIO function. The research recommends that the identified EMF radiation exposure violations of public health undergo a Promotion of Access to Information Act (PAIA) judicial review process to confirm the research findings. The judicial qualification of a PAIA PIO function of ‘substances released into the environment’ and ‘public safety or environmental risk’ would enable access to EMF radiation emissions data essential to future studies.
- Full Text:
- Date Issued: 2018
Construction company joint ventures in South Africa
- Authors: Sisilana, Owethu
- Date: 2018
- Subjects: Construction industry -- South Africa , Joint ventures Strategic alliances (Business) Project management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/35554 , vital:33756
- Description: In the construction industry, construction joint ventures (CJVs) have become one of the major organisational forms utilised in large-scale projects. However, because of the complexity of CJVs, the management of CJVs is much more difficult than that of usual projects undertaken by a single construction firm. In South Africa the existence of a clear and effective strategy for the successful transformation of organisational culture in a CJV is not clear. Similarly, poorly organised administrative structures in a CJV can also be a barrier to organisational performance. In South Africa there seems to be no evidence of a common understanding on the CJV formation process. According to CIDB (2004) there is no standard CJV agreement document. Therefore, a need arises to establish guidelines on the formation of a CJV agreement. Secondly, there is a need to establish strategies for the successful transformation of organisational culture in CJV. The research obtains an inside view with contractors who have participated in CJV’s, therefore, utilising the qualitative research method. The choice of data collection method was semi-structured one-on-one face to face interviews. In deriving the findings of the research, the ATLAS.ti software was used throughout the research process to manage both the secondary and primary data. The main factors which cause major problems in CJV's is the preliminary agreement, the partner selection and cultural differences. There is no evidence of a collective understanding among CJV partners regarding the successful formation processes of a CJV. The concept that the industry needs a standardised CJV agreement has been welcomed by the participants, the existence of a common CJV agreement would certainly resolve many problems in the way things are done currently including the implementation of joint venture projects. There is consensus between all participants that there is no standard CJV agreement in use in the South African construction industry and exploring a common approach is an idea that is viewed reasonable and to be one of the practical solutions to the problems in the industry. There are several limitations in this study. First, the sample included emerging and established contractors who are currently registered with the CIDB under Contractor Development Program only. While the sample size is relatively small, the researcher was cautious when interpreting the results. Secondly the targeted population for this research was selected using a sample of convenience method as opposed to a random sample, then the results of the study cannot be generally applied to a larger population. Thirdly, an obvious weakness of the research is the methodological difficulties related to qualitative research which relies on the inferences that are made by the researcher based on their own understanding of the data collected. It is therefore crucial that the data gathered is credible and that the findings represent the truth and actual sentiments as they appear from the data collection process. The research is of importance to managers and supervisors of construction companies of all sizes. The findings of this study will assist in ensuring that CJV are efficiently managed irrespective of the cultural differences.
- Full Text:
- Date Issued: 2018
- Authors: Sisilana, Owethu
- Date: 2018
- Subjects: Construction industry -- South Africa , Joint ventures Strategic alliances (Business) Project management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/35554 , vital:33756
- Description: In the construction industry, construction joint ventures (CJVs) have become one of the major organisational forms utilised in large-scale projects. However, because of the complexity of CJVs, the management of CJVs is much more difficult than that of usual projects undertaken by a single construction firm. In South Africa the existence of a clear and effective strategy for the successful transformation of organisational culture in a CJV is not clear. Similarly, poorly organised administrative structures in a CJV can also be a barrier to organisational performance. In South Africa there seems to be no evidence of a common understanding on the CJV formation process. According to CIDB (2004) there is no standard CJV agreement document. Therefore, a need arises to establish guidelines on the formation of a CJV agreement. Secondly, there is a need to establish strategies for the successful transformation of organisational culture in CJV. The research obtains an inside view with contractors who have participated in CJV’s, therefore, utilising the qualitative research method. The choice of data collection method was semi-structured one-on-one face to face interviews. In deriving the findings of the research, the ATLAS.ti software was used throughout the research process to manage both the secondary and primary data. The main factors which cause major problems in CJV's is the preliminary agreement, the partner selection and cultural differences. There is no evidence of a collective understanding among CJV partners regarding the successful formation processes of a CJV. The concept that the industry needs a standardised CJV agreement has been welcomed by the participants, the existence of a common CJV agreement would certainly resolve many problems in the way things are done currently including the implementation of joint venture projects. There is consensus between all participants that there is no standard CJV agreement in use in the South African construction industry and exploring a common approach is an idea that is viewed reasonable and to be one of the practical solutions to the problems in the industry. There are several limitations in this study. First, the sample included emerging and established contractors who are currently registered with the CIDB under Contractor Development Program only. While the sample size is relatively small, the researcher was cautious when interpreting the results. Secondly the targeted population for this research was selected using a sample of convenience method as opposed to a random sample, then the results of the study cannot be generally applied to a larger population. Thirdly, an obvious weakness of the research is the methodological difficulties related to qualitative research which relies on the inferences that are made by the researcher based on their own understanding of the data collected. It is therefore crucial that the data gathered is credible and that the findings represent the truth and actual sentiments as they appear from the data collection process. The research is of importance to managers and supervisors of construction companies of all sizes. The findings of this study will assist in ensuring that CJV are efficiently managed irrespective of the cultural differences.
- Full Text:
- Date Issued: 2018
Construction management’s perceptions of health and safety
- Authors: Sigama, Takalani
- Date: 2018
- Subjects: Construction industry -- Management , Building -- Safety measures Construction industry -- Health aspects Construction industry -- Safety regulations
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/35713 , vital:33784
- Description: Projects in the construction sector are reputed for poor health and safety (H&S) performance, compared to other industries. This can be attributed to, inter alia, a relatively uncontrolled working environment, inherent operational risks, workers' behaviour in relation to H&S commitment, cultural and religious beliefs, and uncertainties inherent in projects. Hazards and risk arising from poor H&S practices result in injuries, and in some cases, fatalities. The aim of this study is to explore the perceptions of construction management regarding H&S on construction sites. This study investigates the relationship between behaviours, attitudes, perceptions, and behaviours towards H&S, and compares cultural divergences among levels of construction personnel, namely construction management, construction supervision, construction H&S personnel, and H&S representatives. The construction industry has for many years developed and maintained a very bad reputation for coping with project cost, H&S, quality, and schedule. The industry often delivers projects late, and contributes to a disproportionate rate of work-related injuries, and fatalities. Project H&S management is acknowledged as one of the techniques that could be improved on construction projects to enhance performance of construction contractors in South Africa. To answer the research question: ‘Why construction management perceive H&S as a hindrance to production?” the mixed-method research approach was used. An indepth literature review with respect to project H&S was carried out, followed by qualitative and quantitative empirical research. The study established the need for H&S training and awareness of Construction Managers, Construction Supervisors, Construction Health and Safety Managers (CHSMs), Officers (CHSOs), and H&S Representatives. The study recommends that an H&S training needs analysis is critical for all employees, since it raises H&S awareness among all stakeholders in the construction industry, and enables the development of training plans, thereby supporting the reduction of accidents and related incident.
- Full Text:
- Date Issued: 2018
- Authors: Sigama, Takalani
- Date: 2018
- Subjects: Construction industry -- Management , Building -- Safety measures Construction industry -- Health aspects Construction industry -- Safety regulations
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/35713 , vital:33784
- Description: Projects in the construction sector are reputed for poor health and safety (H&S) performance, compared to other industries. This can be attributed to, inter alia, a relatively uncontrolled working environment, inherent operational risks, workers' behaviour in relation to H&S commitment, cultural and religious beliefs, and uncertainties inherent in projects. Hazards and risk arising from poor H&S practices result in injuries, and in some cases, fatalities. The aim of this study is to explore the perceptions of construction management regarding H&S on construction sites. This study investigates the relationship between behaviours, attitudes, perceptions, and behaviours towards H&S, and compares cultural divergences among levels of construction personnel, namely construction management, construction supervision, construction H&S personnel, and H&S representatives. The construction industry has for many years developed and maintained a very bad reputation for coping with project cost, H&S, quality, and schedule. The industry often delivers projects late, and contributes to a disproportionate rate of work-related injuries, and fatalities. Project H&S management is acknowledged as one of the techniques that could be improved on construction projects to enhance performance of construction contractors in South Africa. To answer the research question: ‘Why construction management perceive H&S as a hindrance to production?” the mixed-method research approach was used. An indepth literature review with respect to project H&S was carried out, followed by qualitative and quantitative empirical research. The study established the need for H&S training and awareness of Construction Managers, Construction Supervisors, Construction Health and Safety Managers (CHSMs), Officers (CHSOs), and H&S Representatives. The study recommends that an H&S training needs analysis is critical for all employees, since it raises H&S awareness among all stakeholders in the construction industry, and enables the development of training plans, thereby supporting the reduction of accidents and related incident.
- Full Text:
- Date Issued: 2018
Contesting Boko Haram: A postcolonial critique of media representation of the ethnoreligious, socio-economic and political conflict in Nigeria
- Authors: Mjekula, Somila
- Date: 2018
- Subjects: Mass media -- Nigeria , Television broadcasting -- Social aspects -- Nigeria Nigeria -- In mass media
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/22780 , vital:30085
- Description: Representative and narrative discourses from international media and academia present an essentialist and misleading idea of African issues, and this misrepresentation has leaked, by association, into a flawed portrayal of the Boko Haram insurgency in Nigeria. That is, just as reductionism, ahistorical attributions, and contradictions tend to occur in writing on African conflicts, this has become the tendency with insufficient attempts to define the identity and explain the actions of Boko Haram. Using a postcolonial critique, this dissertation reveals how news media and scholarly reports often undermine and negate the historical, ethno-religious and ideological nuances of Boko Haram’s identity, as well as the socio-economic and political issues that motivate the actions of the sect. Additionally, the examination of Boko Haram’s origins, influences and ever-evolving identity confronts the contradictions and flaws within the group’s own representation, through its ideology and pragmatism. This multi-fold analysis is done through an initial exploration of Nigeria’s history under British colonial rule and the lasting legacy thereafter, which has been responsible for the contemporary violent conflicts that journalist and scholars tend to reduced to Islamic fundamentalism and terrorism. This is followed by a critical acknowledgement of the complicity of Nigeria’s political leadership in the socio-economic injustices prevalent between the two predominant religious populations of Nigeria’s rich and educated Christian South, and the poor and disadvantaged Muslim North. Critical Discourse Analysis is used as a method to analyse the representation of Boko Haram from three academic journal reports by African scholars and three international print media news reports. This study seeks to contribute to reports/writings on postcolonial interpretations of violence and conflict in African media studies, and to account for the historical and contemporary complexities within African countries and their inhabitants who are often negated by influential libertarian media and trusted analytical-scholarly articles.
- Full Text:
- Date Issued: 2018
- Authors: Mjekula, Somila
- Date: 2018
- Subjects: Mass media -- Nigeria , Television broadcasting -- Social aspects -- Nigeria Nigeria -- In mass media
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/22780 , vital:30085
- Description: Representative and narrative discourses from international media and academia present an essentialist and misleading idea of African issues, and this misrepresentation has leaked, by association, into a flawed portrayal of the Boko Haram insurgency in Nigeria. That is, just as reductionism, ahistorical attributions, and contradictions tend to occur in writing on African conflicts, this has become the tendency with insufficient attempts to define the identity and explain the actions of Boko Haram. Using a postcolonial critique, this dissertation reveals how news media and scholarly reports often undermine and negate the historical, ethno-religious and ideological nuances of Boko Haram’s identity, as well as the socio-economic and political issues that motivate the actions of the sect. Additionally, the examination of Boko Haram’s origins, influences and ever-evolving identity confronts the contradictions and flaws within the group’s own representation, through its ideology and pragmatism. This multi-fold analysis is done through an initial exploration of Nigeria’s history under British colonial rule and the lasting legacy thereafter, which has been responsible for the contemporary violent conflicts that journalist and scholars tend to reduced to Islamic fundamentalism and terrorism. This is followed by a critical acknowledgement of the complicity of Nigeria’s political leadership in the socio-economic injustices prevalent between the two predominant religious populations of Nigeria’s rich and educated Christian South, and the poor and disadvantaged Muslim North. Critical Discourse Analysis is used as a method to analyse the representation of Boko Haram from three academic journal reports by African scholars and three international print media news reports. This study seeks to contribute to reports/writings on postcolonial interpretations of violence and conflict in African media studies, and to account for the historical and contemporary complexities within African countries and their inhabitants who are often negated by influential libertarian media and trusted analytical-scholarly articles.
- Full Text:
- Date Issued: 2018
Contribution of the wool clip project to beneficiaries in King Sabata Dalindyebo Local Municipality
- Madiba, Nangamso Vuyo Hillary
- Authors: Madiba, Nangamso Vuyo Hillary
- Date: 2018
- Subjects: Economic development -- South Africa -- Eastern Cape , Wool industry -- South Africa -- Eastern Cape Sheep industry -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/30800 , vital:31136
- Description: The focus of the study was on the contribution of the Wool Clip Project to beneficiaries in King Sabata Dalindyebo Local Municipality (KSD LM). KSD LM is predominantly rural and constitutes an integral part of OR Tambo District Municipality which is part of the Eastern Cape Province. The poverty head count in KSD LM was at 14,7% in 2016. The Eastern Cape had the highest percentage of households owning sheep in the country. Approximately 775, 300 sheep were in KSD LM in 2012. This study was located within the local economic development framework. A gap was identified in the yields in terms of national sales of wool which are not commensurate with the portion accounted for in the national flock. The National, Provincial and Local spheres of government intervened resulting in the introduction of the Wool Clip Project as a vehicle to mitigate the challenges encountered with regard to wool production. Through the intervention, it was expected that there should be an improvement in the national sales of wool. The aim of the research was to determine whether the Wool Clip Project has made a contribution to the beneficiaries. This was done through the following objectives: - Determination of whether the project has made a contribution to its intended beneficiaries in terms of its objectives, which are outlined in the Business Plan for the Wool Clip Project (2014). - Determination of whether there has been adequate public participation as dictated by Chapter 4, sections 17 to 22 of the Municipal Systems Act No. 32 of 2000. - Investigation of whether the project has made a meaningful contribution to the relevant communities through the creation of sustainable employment opportunities. v A literature review was done using relevant sources of information and knowledge such as books, journals, policies, research outputs. The aim was to provide a well thought out theoretical framework. The research methodology applied to this study was qualitative, taking into account the nature of the study. Data was collected by conducting semi-structured interviews with ten respondents, who were selected through purposive sampling. The data was then analysed and interpreted using themes and sub-themes. Based on the findings, it was concluding that the project has had a positive effect on the lives of the beneficiaries, even though there is room for improvement. Secondly, it has been established that public participation took place during the introduction of the project as legislated. Thirdly, the project has not contributed to sustainable job creation but there are, however, some benefits that the community has gained from it. Recommendations were made towards improved implementation of the project.
- Full Text:
- Date Issued: 2018
- Authors: Madiba, Nangamso Vuyo Hillary
- Date: 2018
- Subjects: Economic development -- South Africa -- Eastern Cape , Wool industry -- South Africa -- Eastern Cape Sheep industry -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/30800 , vital:31136
- Description: The focus of the study was on the contribution of the Wool Clip Project to beneficiaries in King Sabata Dalindyebo Local Municipality (KSD LM). KSD LM is predominantly rural and constitutes an integral part of OR Tambo District Municipality which is part of the Eastern Cape Province. The poverty head count in KSD LM was at 14,7% in 2016. The Eastern Cape had the highest percentage of households owning sheep in the country. Approximately 775, 300 sheep were in KSD LM in 2012. This study was located within the local economic development framework. A gap was identified in the yields in terms of national sales of wool which are not commensurate with the portion accounted for in the national flock. The National, Provincial and Local spheres of government intervened resulting in the introduction of the Wool Clip Project as a vehicle to mitigate the challenges encountered with regard to wool production. Through the intervention, it was expected that there should be an improvement in the national sales of wool. The aim of the research was to determine whether the Wool Clip Project has made a contribution to the beneficiaries. This was done through the following objectives: - Determination of whether the project has made a contribution to its intended beneficiaries in terms of its objectives, which are outlined in the Business Plan for the Wool Clip Project (2014). - Determination of whether there has been adequate public participation as dictated by Chapter 4, sections 17 to 22 of the Municipal Systems Act No. 32 of 2000. - Investigation of whether the project has made a meaningful contribution to the relevant communities through the creation of sustainable employment opportunities. v A literature review was done using relevant sources of information and knowledge such as books, journals, policies, research outputs. The aim was to provide a well thought out theoretical framework. The research methodology applied to this study was qualitative, taking into account the nature of the study. Data was collected by conducting semi-structured interviews with ten respondents, who were selected through purposive sampling. The data was then analysed and interpreted using themes and sub-themes. Based on the findings, it was concluding that the project has had a positive effect on the lives of the beneficiaries, even though there is room for improvement. Secondly, it has been established that public participation took place during the introduction of the project as legislated. Thirdly, the project has not contributed to sustainable job creation but there are, however, some benefits that the community has gained from it. Recommendations were made towards improved implementation of the project.
- Full Text:
- Date Issued: 2018
Cooperatives in Mhlontlo Local Municipality, Eastern Cape Province : an examination of the ablers and disablers of grassroots development
- Authors: Mahlasela, Chwayitile
- Date: 2018
- Subjects: Cooperative societies--South Africa--Eastern Cape Rural development--South Africa--Eastern Cape Rural development
- Language: English
- Type: Thesis , Masters , Rural Development
- Identifier: http://hdl.handle.net/10353/16264 , vital:40705
- Description: Scholars and policy makers often see cooperatives as agents of rural economic development. However, experiences have showed that cooperatives in some rural communities have not brought sustainable rural development as levels of poverty and unemployment are still staggeringly high. It is against this background that this study examines the enablers and disablers of cooperatives in Mhlontlo Local Municipality in the Eastern Cape. In order to achieve this aim, the study adopted qualitative research design. Oral interviews and Focus Group Discussions were used to collect qualitative data from the purposively selected participants. Also, official documents on the roles of cooperatives to rural development were used to complement primary sources of data collection. Thematic analytical technique was used to analyse data obtained. The result of the analysis revealed that lack of basic infrastructures, inadequate value addition and inefficient monitoring and evaluation of the programmes have disabled the cooperative societies in Mhlontlo Local Municipality from achieving the goals of rural development. Based on the analysis of data, the study concluded that cooperatives in Mhlontlo Local Municipality are faced with immense challenges, which are hampering their contributions to achieving sustainable rural development in the municipality. Based on this conclusion, the study recommended that in order to improve the efficiency of cooperative societies in terms of achieving rural development, government needs to engage relevant stakeholders such as the local government officials, private sector, community members and the NGOs in the formulation and implementation of strategies to be adopted by the cooperative societies in bringing about sustainable rural development.
- Full Text:
- Date Issued: 2018
- Authors: Mahlasela, Chwayitile
- Date: 2018
- Subjects: Cooperative societies--South Africa--Eastern Cape Rural development--South Africa--Eastern Cape Rural development
- Language: English
- Type: Thesis , Masters , Rural Development
- Identifier: http://hdl.handle.net/10353/16264 , vital:40705
- Description: Scholars and policy makers often see cooperatives as agents of rural economic development. However, experiences have showed that cooperatives in some rural communities have not brought sustainable rural development as levels of poverty and unemployment are still staggeringly high. It is against this background that this study examines the enablers and disablers of cooperatives in Mhlontlo Local Municipality in the Eastern Cape. In order to achieve this aim, the study adopted qualitative research design. Oral interviews and Focus Group Discussions were used to collect qualitative data from the purposively selected participants. Also, official documents on the roles of cooperatives to rural development were used to complement primary sources of data collection. Thematic analytical technique was used to analyse data obtained. The result of the analysis revealed that lack of basic infrastructures, inadequate value addition and inefficient monitoring and evaluation of the programmes have disabled the cooperative societies in Mhlontlo Local Municipality from achieving the goals of rural development. Based on the analysis of data, the study concluded that cooperatives in Mhlontlo Local Municipality are faced with immense challenges, which are hampering their contributions to achieving sustainable rural development in the municipality. Based on this conclusion, the study recommended that in order to improve the efficiency of cooperative societies in terms of achieving rural development, government needs to engage relevant stakeholders such as the local government officials, private sector, community members and the NGOs in the formulation and implementation of strategies to be adopted by the cooperative societies in bringing about sustainable rural development.
- Full Text:
- Date Issued: 2018
Correlation of photovoltaics plant performance metrics
- Authors: Vumbugwa, Monphias
- Date: 2018
- Subjects: Photovoltaic cells , Perfomance -- Evaluation , Thin films
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/45657 , vital:38924
- Description: The generation of electrical energy using Photovoltaic (PV) technology has increased globally with the decrease in the cost of PV systems and the rise in electrical power demand. In South Africa, the support by the government in implementing the Renewable Energy Independent Power Producer Procurement Programme (REIPPPP) has seen a growth in PV system deployment and investment in roof and ground mounted, stand alone and grid connected PV plants. This rapid growth shows that the PV industry is becoming highly competitive as there is a shift to low carbon emissions and it is anticipated to be the most affordable source of electricity. Hence, there is need to develop maintenance and fault diagnosis expertise and capabilities in the PV industry, which can in turn improve the dependability, productiveness and lifespan of PV systems. Solar PV modules directly receive and convert solar irradiance into electricity and may not generate the expected optimum energy due to abnormalities which arise when they are exposed to harsh unfavorable environmental conditions in the field. Thermal Infrared (TIR) imaging is widely used as a fault diagnosis tool in operating PV modules and mostly in large PV power plants. Therefore, there is need to research the interpretation of the observed thermal signatures and the impact that the anomalies have on electrical output of the system so as to improve the PV maintenance systems. This research focuses on identifying performance limiting defects using an Infra-Red (I-R) camera, mounted on an Unmanned Aerial Vehicle (UAV), to understand the effect of thermal signatures on current-voltage (I-V) characteristics of PV module strings. Aerial TIR imaging using a UAV can rapidly identify abnormalities in operational PV modules strings as hotspots. Any deviation of the string I-V curve, from the expected, indicates a problem with one or more PV modules in the string. However, locating the faulty module involves measuring I-V parameters of the individual modules in a string, which is not feasible in large PV power plants. Therefore, there is a need to estimate the power loss associated with the thermal signatures in PV module strings. Visual inspection may help in identifying the exact cause of some hotspots, while other hotspots need special characterization techniques, such as Electroluminescence (EL) and UV Fluorescence (UV-F), which can indicate if a solar cell is cracked or has weak busbars or contact finger connections.
- Full Text:
- Date Issued: 2018
- Authors: Vumbugwa, Monphias
- Date: 2018
- Subjects: Photovoltaic cells , Perfomance -- Evaluation , Thin films
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/45657 , vital:38924
- Description: The generation of electrical energy using Photovoltaic (PV) technology has increased globally with the decrease in the cost of PV systems and the rise in electrical power demand. In South Africa, the support by the government in implementing the Renewable Energy Independent Power Producer Procurement Programme (REIPPPP) has seen a growth in PV system deployment and investment in roof and ground mounted, stand alone and grid connected PV plants. This rapid growth shows that the PV industry is becoming highly competitive as there is a shift to low carbon emissions and it is anticipated to be the most affordable source of electricity. Hence, there is need to develop maintenance and fault diagnosis expertise and capabilities in the PV industry, which can in turn improve the dependability, productiveness and lifespan of PV systems. Solar PV modules directly receive and convert solar irradiance into electricity and may not generate the expected optimum energy due to abnormalities which arise when they are exposed to harsh unfavorable environmental conditions in the field. Thermal Infrared (TIR) imaging is widely used as a fault diagnosis tool in operating PV modules and mostly in large PV power plants. Therefore, there is need to research the interpretation of the observed thermal signatures and the impact that the anomalies have on electrical output of the system so as to improve the PV maintenance systems. This research focuses on identifying performance limiting defects using an Infra-Red (I-R) camera, mounted on an Unmanned Aerial Vehicle (UAV), to understand the effect of thermal signatures on current-voltage (I-V) characteristics of PV module strings. Aerial TIR imaging using a UAV can rapidly identify abnormalities in operational PV modules strings as hotspots. Any deviation of the string I-V curve, from the expected, indicates a problem with one or more PV modules in the string. However, locating the faulty module involves measuring I-V parameters of the individual modules in a string, which is not feasible in large PV power plants. Therefore, there is a need to estimate the power loss associated with the thermal signatures in PV module strings. Visual inspection may help in identifying the exact cause of some hotspots, while other hotspots need special characterization techniques, such as Electroluminescence (EL) and UV Fluorescence (UV-F), which can indicate if a solar cell is cracked or has weak busbars or contact finger connections.
- Full Text:
- Date Issued: 2018
Correlations between the occurence of virulent helicobacter pylori strains and chronic disease conditions in dyspeptic patients hospitalized in Chris Hani Baragwanath Hospital, Gauteng Province, South Africa
- Authors: Mzukwa, Asisipho
- Date: 2018
- Subjects: Helicobacter pylori infections Helicobacter pylori Bacterial diseases
- Language: English
- Type: Thesis , Masters , Microbiology
- Identifier: http://hdl.handle.net/10353/10885 , vital:35905
- Description: Introduction: Individuals predisposed to different chronic disease conditions such as type 2 diabetes mellitus (T2DM), hypertension (HPT) and human immunodeficiency virus (HIV) might be susceptible to persistent H. pylori colonization, which overtime encourages infection with virulent strains. The presence of different types of H. pylori virulence factors especially cagA, dupA and various combinations of vacA subtypes (s1/m1, s2/m1 and s2m2) confer a higher risk of gastric disease development. Aim: This study seeks to recover H. pylori from gastric biopsy specimen from patients with different chronic disease conditions referred to the GIT unit at Chris Hani Baragwanath Academic Hospital, Soweto, and confirm them and further determine the presence of virulent H. pylori strains in patients with T2DM, HPT and HIV. Methods: Gastric biopsies were obtained from 101 patients with different chronic disease conditions after obtaining consent between August 2017 and February 2018. H. pylori was isolated on selective Colombia blood agar. Presumptive isolates were identified following standard microbiology and biochemical technique. These isolates were confirmed by polymerase chain reaction (PCR) targeting the glmM gene. The H. pylori positive samples were further screened for cagA, dupA and vacA genotypes. Results: H. pylori was recovered from 26 patients, of which 8 were patients with T2DM, 10 with HPT and 8 with HIV. There was no correlation between H. pylori infection and the chronic conditions, but the majority of H. pylori positive participant carried virulent H. pylori strains. The cagA and the dupA genes were more prevalent in T2DM and HPT patients, however the association between these genes and the 2 chronic conditions was not significant. The vacA subtypes common in hypertensive patients compared to the other conditions were the s1m1, s1m2, and s2m2 and the association between these vacA forms and hypertension was significant. Majority of HIV infected patients were found to carry non-virulent H. pylori strains. Conclusion: The prevalence of H. pylori among the general population of patients with T2DM, HPT and HIV was low. Although infected patients are found to be carrying virulent strains of H. pylori, there is no significant association established between the virulent strains and the chronic conditions. Furthermore, HIV-infected patients were found to be carrying non-virulent strains of H. pylori.
- Full Text:
- Date Issued: 2018
- Authors: Mzukwa, Asisipho
- Date: 2018
- Subjects: Helicobacter pylori infections Helicobacter pylori Bacterial diseases
- Language: English
- Type: Thesis , Masters , Microbiology
- Identifier: http://hdl.handle.net/10353/10885 , vital:35905
- Description: Introduction: Individuals predisposed to different chronic disease conditions such as type 2 diabetes mellitus (T2DM), hypertension (HPT) and human immunodeficiency virus (HIV) might be susceptible to persistent H. pylori colonization, which overtime encourages infection with virulent strains. The presence of different types of H. pylori virulence factors especially cagA, dupA and various combinations of vacA subtypes (s1/m1, s2/m1 and s2m2) confer a higher risk of gastric disease development. Aim: This study seeks to recover H. pylori from gastric biopsy specimen from patients with different chronic disease conditions referred to the GIT unit at Chris Hani Baragwanath Academic Hospital, Soweto, and confirm them and further determine the presence of virulent H. pylori strains in patients with T2DM, HPT and HIV. Methods: Gastric biopsies were obtained from 101 patients with different chronic disease conditions after obtaining consent between August 2017 and February 2018. H. pylori was isolated on selective Colombia blood agar. Presumptive isolates were identified following standard microbiology and biochemical technique. These isolates were confirmed by polymerase chain reaction (PCR) targeting the glmM gene. The H. pylori positive samples were further screened for cagA, dupA and vacA genotypes. Results: H. pylori was recovered from 26 patients, of which 8 were patients with T2DM, 10 with HPT and 8 with HIV. There was no correlation between H. pylori infection and the chronic conditions, but the majority of H. pylori positive participant carried virulent H. pylori strains. The cagA and the dupA genes were more prevalent in T2DM and HPT patients, however the association between these genes and the 2 chronic conditions was not significant. The vacA subtypes common in hypertensive patients compared to the other conditions were the s1m1, s1m2, and s2m2 and the association between these vacA forms and hypertension was significant. Majority of HIV infected patients were found to carry non-virulent H. pylori strains. Conclusion: The prevalence of H. pylori among the general population of patients with T2DM, HPT and HIV was low. Although infected patients are found to be carrying virulent strains of H. pylori, there is no significant association established between the virulent strains and the chronic conditions. Furthermore, HIV-infected patients were found to be carrying non-virulent strains of H. pylori.
- Full Text:
- Date Issued: 2018
Corrosion resistance of nanocrystalline titanium zirconium nitride layers deposited on ZIRLO
- Nyembe, Hlanganani Siphelele
- Authors: Nyembe, Hlanganani Siphelele
- Date: 2018
- Subjects: Zirconium alloys , Titanium alloys Nanocrystals Nanotechnology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/34744 , vital:33435
- Description: Zirconium (Zr) alloys are used as nuclear fuel cladding in water-cooled nuclear reactors. Being in contact with steam, the Zr-alloy is oxidised and it absorbs hydrogen. The hydrogen pickup in Zr-alloys induces embrittlement of the tubes due to hydride formation. In this study, effectiveness of corrosion resistant nanocrystalline titanium zirconium nitride (nc-TiZrN) coatings on the surface of a Zr-alloy for the reduction of corrosion and hydrogen pickup is investigated. The nc-TiZrN layers were deposited onto the surface of ZIRLO® using the cathodic arc vapour deposition (CAVD) technique. The influence of nc-TiZrN coatings on the corrosion performance of ZIRLO® was investigated under the following conditions: (a) In an oxygen atmosphere at various temperatures from 400 to 900 ℃ for 30 minutes, (b) for various exposure times from 6 – 24 hours with the temperature kept constant at 500 ℃ in a tube furnace, and (c) in pure steam for 30 days at 360 ℃ and 18.7 MPa in an autoclave. The corrosion properties of the nc-TiZrN coated ZIRLO were compared to uncoated ZIRLO for all experiments. Following corrosion testing, the TiZrN coatings and oxide layers were investigated by scanning and transmission electron microscopy and energy dispersive X-ray spectroscopy. The TiZrN coating had a thickness of ~3.8 μm with a small number of Ti-rich and Nb-rich inclusions. The coating exhibited a single phase solid solution of Ti0.42Zr0.58N with a NaCl-type crystal structure and columnar nanocrystals. These columnar nanocrystals showed a strong {111} preferred orientation and the {111} planes of the TiZrN crystals are oriented parallel to the (001) planes of α-ZIRLO grains with <001> direction perpendicular to the coating/ZIRLO interface. The corrosion testing at various temperatures from 400 to 900 ℃ for 30 minutes showed that the TiZrN coating oxidises slowly and retained its microstructure, composition and crystallinity up to 600 ℃. At higher temperatures above 600 ℃, the TiZrN layer completely oxidised to a non-protective TiZr-oxide layer and resulted in rapid corrosion of the underlying ZIRLO substrate. The rapid corrosion was not observed in the uncoated ZIRLO sample for all temperatures. The results of samples subjected to annealing treatment at 500 ℃ in an oxygen atmosphere at various times up to 24 hours revealed that the TiZrN layer oxidises faster than ZIRLO. This was confirmed by sub-cubic and sub-parabolic oxide growth kinetics observed in the uncoated ZIRLO which are slower than the parabolic kinetics of TiZrN coated samples. In all coated samples, the spallation was observed near the edges of the samples. The spallation was caused by rapid corrosion of the underlying ZIRLO substrate which resulted from the penetration of oxygen ions between the TiZrN coating and ZIRLO substrate along the edges of the samples. In pure steam for 30 days at 360 ℃, a complete loss of the TiZrN layer occurred but the results show that the coating might have delayed the corrosion of ZIRLO. In summary, corrosion resistance of nc-TiZrN coated ZIRLO was lower than that of uncoated ZIRLO. The study shows that the failure of TiZrN coatings leads to rapid corrosion of the underlying ZIRLO substrate which was not observed on the uncoated ZIRLO. It is not yet understood why the presence TiZrN coatings reduced the oxidation resistance of ZIRLO.
- Full Text:
- Date Issued: 2018
- Authors: Nyembe, Hlanganani Siphelele
- Date: 2018
- Subjects: Zirconium alloys , Titanium alloys Nanocrystals Nanotechnology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/34744 , vital:33435
- Description: Zirconium (Zr) alloys are used as nuclear fuel cladding in water-cooled nuclear reactors. Being in contact with steam, the Zr-alloy is oxidised and it absorbs hydrogen. The hydrogen pickup in Zr-alloys induces embrittlement of the tubes due to hydride formation. In this study, effectiveness of corrosion resistant nanocrystalline titanium zirconium nitride (nc-TiZrN) coatings on the surface of a Zr-alloy for the reduction of corrosion and hydrogen pickup is investigated. The nc-TiZrN layers were deposited onto the surface of ZIRLO® using the cathodic arc vapour deposition (CAVD) technique. The influence of nc-TiZrN coatings on the corrosion performance of ZIRLO® was investigated under the following conditions: (a) In an oxygen atmosphere at various temperatures from 400 to 900 ℃ for 30 minutes, (b) for various exposure times from 6 – 24 hours with the temperature kept constant at 500 ℃ in a tube furnace, and (c) in pure steam for 30 days at 360 ℃ and 18.7 MPa in an autoclave. The corrosion properties of the nc-TiZrN coated ZIRLO were compared to uncoated ZIRLO for all experiments. Following corrosion testing, the TiZrN coatings and oxide layers were investigated by scanning and transmission electron microscopy and energy dispersive X-ray spectroscopy. The TiZrN coating had a thickness of ~3.8 μm with a small number of Ti-rich and Nb-rich inclusions. The coating exhibited a single phase solid solution of Ti0.42Zr0.58N with a NaCl-type crystal structure and columnar nanocrystals. These columnar nanocrystals showed a strong {111} preferred orientation and the {111} planes of the TiZrN crystals are oriented parallel to the (001) planes of α-ZIRLO grains with <001> direction perpendicular to the coating/ZIRLO interface. The corrosion testing at various temperatures from 400 to 900 ℃ for 30 minutes showed that the TiZrN coating oxidises slowly and retained its microstructure, composition and crystallinity up to 600 ℃. At higher temperatures above 600 ℃, the TiZrN layer completely oxidised to a non-protective TiZr-oxide layer and resulted in rapid corrosion of the underlying ZIRLO substrate. The rapid corrosion was not observed in the uncoated ZIRLO sample for all temperatures. The results of samples subjected to annealing treatment at 500 ℃ in an oxygen atmosphere at various times up to 24 hours revealed that the TiZrN layer oxidises faster than ZIRLO. This was confirmed by sub-cubic and sub-parabolic oxide growth kinetics observed in the uncoated ZIRLO which are slower than the parabolic kinetics of TiZrN coated samples. In all coated samples, the spallation was observed near the edges of the samples. The spallation was caused by rapid corrosion of the underlying ZIRLO substrate which resulted from the penetration of oxygen ions between the TiZrN coating and ZIRLO substrate along the edges of the samples. In pure steam for 30 days at 360 ℃, a complete loss of the TiZrN layer occurred but the results show that the coating might have delayed the corrosion of ZIRLO. In summary, corrosion resistance of nc-TiZrN coated ZIRLO was lower than that of uncoated ZIRLO. The study shows that the failure of TiZrN coatings leads to rapid corrosion of the underlying ZIRLO substrate which was not observed on the uncoated ZIRLO. It is not yet understood why the presence TiZrN coatings reduced the oxidation resistance of ZIRLO.
- Full Text:
- Date Issued: 2018
Cost and time overruns on Mpumalanga Province infrastructure projects
- Authors: Phalanndwa, Shonisani Aaron
- Date: 2018
- Subjects: Project management -- South Africa -- Mpumalanga , Infrastructure (Economics) industrial management -- South Africa -- Mpumalanga Business enterprises -- South Africa -- Mpumalanga -- Finance
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/34169 , vital:33248
- Description: Cost and time overruns in construction projects are a common issue affecting project performance, and Mpumalanga is no exception. Completion of any project within the estimated cost of a project is a basic criterion for success of any project. The success of any project highly depends on adequate availability and efficient management of various resources. Construction projects often face a lot of uncertainties, which places building construction projects at the risk of cost, time overruns as well as poor quality delivery. This study assesses the causes, effects and measures of minimising construction project cost and time overrun in the Mpumalanga Province. The data used in this study were derived from both primary and secondary sources. The primary data was collected through case study interviews with construction professionals, project owners, contractors and consultants involved in Mpumalanga construction projects. Findings from the case study revealed that clients inability to meet payment obligations on time, additional work requested by the client, proper feasibility study not done, ensuring transparency in awarding of contracts, contractors financial difficulties, late delivery of materials, contractors lack of experience, bribery and corruption involving the contractor or contractor’s team, and poor site management and consultants insufficient geotechnical investigations, insufficient/unknown information regarding site conditions during design phase, mistakes and discrepancies in design documents are the major causes of cost and time overruns that are incidental to project implementation in Mpumalanga. Furthermore the study also reveals that the major effect of cost and time overrun are: poor quality workmanship, total abandonment, and disputes, discouragement of investors, community unrest and service delivery is negatively affected. It was revealed that all stakeholders of construction parties are deeply involved in contributing to the causes of the problems, clients should bear the greatest responsibility and play the most important role in lessening the impact of cost and time overrun. Thus, interventions that could be adopted by the Mpumalanga province to achieve project delivery that is within estimated cost and time are: Government must adopt ‘financial assignment’ to deal with suppliers in order to supply materials to the contractor and have available funds for projects on time, soil investigation and testing should be conducted by clients prior to the commencement of a project; encourage whistleblowing and punish fraudsters more severely. Contractors must have enough cash before commencing of projects, v monitor financial spending of the projects and payments; consultants must review and approve design documents, shop drawings, and payments of contractor. It is recommended that training courses, seminars and workshops on project management should be made available to help improve the abilities of construction teams responsible for management and supervision of sites and client organisations should encourage whistleblowing, punish fraudsters more efficiently and pay commensurate reward to whistle-blowers in order to minimise cost and time overruns.
- Full Text:
- Date Issued: 2018
- Authors: Phalanndwa, Shonisani Aaron
- Date: 2018
- Subjects: Project management -- South Africa -- Mpumalanga , Infrastructure (Economics) industrial management -- South Africa -- Mpumalanga Business enterprises -- South Africa -- Mpumalanga -- Finance
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/34169 , vital:33248
- Description: Cost and time overruns in construction projects are a common issue affecting project performance, and Mpumalanga is no exception. Completion of any project within the estimated cost of a project is a basic criterion for success of any project. The success of any project highly depends on adequate availability and efficient management of various resources. Construction projects often face a lot of uncertainties, which places building construction projects at the risk of cost, time overruns as well as poor quality delivery. This study assesses the causes, effects and measures of minimising construction project cost and time overrun in the Mpumalanga Province. The data used in this study were derived from both primary and secondary sources. The primary data was collected through case study interviews with construction professionals, project owners, contractors and consultants involved in Mpumalanga construction projects. Findings from the case study revealed that clients inability to meet payment obligations on time, additional work requested by the client, proper feasibility study not done, ensuring transparency in awarding of contracts, contractors financial difficulties, late delivery of materials, contractors lack of experience, bribery and corruption involving the contractor or contractor’s team, and poor site management and consultants insufficient geotechnical investigations, insufficient/unknown information regarding site conditions during design phase, mistakes and discrepancies in design documents are the major causes of cost and time overruns that are incidental to project implementation in Mpumalanga. Furthermore the study also reveals that the major effect of cost and time overrun are: poor quality workmanship, total abandonment, and disputes, discouragement of investors, community unrest and service delivery is negatively affected. It was revealed that all stakeholders of construction parties are deeply involved in contributing to the causes of the problems, clients should bear the greatest responsibility and play the most important role in lessening the impact of cost and time overrun. Thus, interventions that could be adopted by the Mpumalanga province to achieve project delivery that is within estimated cost and time are: Government must adopt ‘financial assignment’ to deal with suppliers in order to supply materials to the contractor and have available funds for projects on time, soil investigation and testing should be conducted by clients prior to the commencement of a project; encourage whistleblowing and punish fraudsters more severely. Contractors must have enough cash before commencing of projects, v monitor financial spending of the projects and payments; consultants must review and approve design documents, shop drawings, and payments of contractor. It is recommended that training courses, seminars and workshops on project management should be made available to help improve the abilities of construction teams responsible for management and supervision of sites and client organisations should encourage whistleblowing, punish fraudsters more efficiently and pay commensurate reward to whistle-blowers in order to minimise cost and time overruns.
- Full Text:
- Date Issued: 2018
Couples’ perceptions of the effectiveness of imago enrichment workshops on relationship satisfaction
- Authors: O’Keeffe, Shanna-Lee
- Date: 2018
- Subjects: Interpersonal relations -- Psychological aspects , Couples therapy -- Research Marital psychotherapy
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/34454 , vital:33381
- Description: Romance is a prevalent component of the human relationship. The magnitude of research and literature on what constitutes relationship satisfaction, demonstrates the importance placed on understanding relationship satisfaction, and consequently a means to understanding its effect on the family unit. Relationship enrichment workshops are designed to strengthen the relationship satisfaction of romantic committed couples, thereby improving the couples’ overall well-being. However, limited research has been conducted on Imago workshops in the South African context, particularly in understanding couples’ unique experiences of these workshops. The primary aim of the research study was to explore and describe couples’ perceptions and experiences of the Imago Getting the Love You Want (GTLYW) relationship enrichment workshop on their relationship satisfaction. More specifically, the study explored how couples experienced relationship satisfaction in relation to having attended the Imago GTLYW workshop. This exploratory-descriptive study was conducted using qualitative methods, adopting the four guidelines of phenomenological analysis. Participants were obtained through purposive sampling methods and the data was gathered via semi-structured interviews, whereby it was analysed according to Braun and Clarkes six phases of thematic analysis. The three main themes identified were; Couples’ expectations of the workshop, Couples’ experience and understanding of the workshop and Couples’ shared vision of their relationship ahead. The couples reported improved experiences of relationship satisfaction post-workshop and reflected on their perceptions of significant aspects of the workshop that assisted them in achieving improved satisfaction within the relationship.
- Full Text:
- Date Issued: 2018
Couples’ perceptions of the effectiveness of imago enrichment workshops on relationship satisfaction
- Authors: O’Keeffe, Shanna-Lee
- Date: 2018
- Subjects: Interpersonal relations -- Psychological aspects , Couples therapy -- Research Marital psychotherapy
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/34454 , vital:33381
- Description: Romance is a prevalent component of the human relationship. The magnitude of research and literature on what constitutes relationship satisfaction, demonstrates the importance placed on understanding relationship satisfaction, and consequently a means to understanding its effect on the family unit. Relationship enrichment workshops are designed to strengthen the relationship satisfaction of romantic committed couples, thereby improving the couples’ overall well-being. However, limited research has been conducted on Imago workshops in the South African context, particularly in understanding couples’ unique experiences of these workshops. The primary aim of the research study was to explore and describe couples’ perceptions and experiences of the Imago Getting the Love You Want (GTLYW) relationship enrichment workshop on their relationship satisfaction. More specifically, the study explored how couples experienced relationship satisfaction in relation to having attended the Imago GTLYW workshop. This exploratory-descriptive study was conducted using qualitative methods, adopting the four guidelines of phenomenological analysis. Participants were obtained through purposive sampling methods and the data was gathered via semi-structured interviews, whereby it was analysed according to Braun and Clarkes six phases of thematic analysis. The three main themes identified were; Couples’ expectations of the workshop, Couples’ experience and understanding of the workshop and Couples’ shared vision of their relationship ahead. The couples reported improved experiences of relationship satisfaction post-workshop and reflected on their perceptions of significant aspects of the workshop that assisted them in achieving improved satisfaction within the relationship.
- Full Text:
- Date Issued: 2018