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
Design of a dedicated IFT microcontroller
- Authors: Himunzowa, Grayson
- Date: 2018
- Subjects: Feedback control systems , Automatic control , Engineering design -- Data processing
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30017 , vital:30809
- Description: The design of a Dedicated IFT Microcontroller originated from the successful implementation of the Iterative Feedback Tuning (IFT) technique into the Digital Signal Processor microcontroller (DSP56F807C) at the University of Cape Town in 2006. However, implementation of the IFT technique on a general-purpose microcontroller is neither optimal, nor a cost-effective exercise, as most of the microcontroller peripherals remain unused, and drain energy for doing nothing. In addition, microcontrollers and DSPs are software-driven devices whose nature is sequential in executing algorithms, and hence have a significant effect on the bandwidth of the closed-loop control. To mitigate the said problem, the design of a Dedicated IFT Microcontroller is proposed in this thesis. To accomplish this goal, the preliminary task was to explore the IFT theory and its applications, followed by a review of the literature on FPGA design methodology for industrial control systems, Microcontroller design principles, and FPGA theory and trends. Furthermore, a survey of electronic design automation (EDA) tools and other application software was also conducted. After the literature review, the IFT was investigated exhaustively by applying it to three types of plants, namely: a DC motor, an oscillatory plant, and an unstable plant. Each of these plants were tested using three types of initial controllers, namely heavilydamped, critically damped and under-damped initial controllers. The plants were also tested by varying the amplitude of the reference signal, followed by using a single-step signal of constant amplitude of one volt. The intention of exploring all of these possibilities was meant to firmly expose the IFT boundaries of applicability, so that the final product would not be vulnerable to unnecessary post-production discoveries. The design methodology adopted in this research was a popular hierarchical and modular top-down procedure, which is an array of abstraction levels that are detailed as: system level, behavioural level, Register-Transfer Level (RTL) and Gate level. At system level, the Dedicated IFT Microcontroller was defined. Thereafter, at behavioural level, the design was simulated using VHDL, created by porting the LabView IFT code to the Xilinx EDA tool. At the RTL, the synthesisable VHDL code utilising fixed-point number representation was written. The compiled bit file was downloaded onto National Instruments (NI) Digital Electronics FPGA Board featuring iii the Spartan 3 series FPGA. This was tested, using a method known as simulation in the hardware. The key contribution of this thesis is the experimental validation of the IFT technique on FPGA hardware as it has never been published before, the work described in chapter four and five. The other contribution is the analysis of 1DOF IFT technique in terms of limitations of applicability for correct implementation, which is the main work of chapter three. This work could be used to explore other computational methods, like the use of floating-point number representation for high resolution and accuracy in numerical computations. Another avenue that could be exploited is Xilinx's recent Vivado methodology, which has the capacity for traditional programming languages like C or C++, as these have in-built floating-point number capability. Finally, out of this work, two papers have already been published by Springer and IEEE Xplore Publishers, and a journal paper has also been written for publication in the Control Systems Technology journal.
- Full Text:
- Date Issued: 2018
- Authors: Himunzowa, Grayson
- Date: 2018
- Subjects: Feedback control systems , Automatic control , Engineering design -- Data processing
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30017 , vital:30809
- Description: The design of a Dedicated IFT Microcontroller originated from the successful implementation of the Iterative Feedback Tuning (IFT) technique into the Digital Signal Processor microcontroller (DSP56F807C) at the University of Cape Town in 2006. However, implementation of the IFT technique on a general-purpose microcontroller is neither optimal, nor a cost-effective exercise, as most of the microcontroller peripherals remain unused, and drain energy for doing nothing. In addition, microcontrollers and DSPs are software-driven devices whose nature is sequential in executing algorithms, and hence have a significant effect on the bandwidth of the closed-loop control. To mitigate the said problem, the design of a Dedicated IFT Microcontroller is proposed in this thesis. To accomplish this goal, the preliminary task was to explore the IFT theory and its applications, followed by a review of the literature on FPGA design methodology for industrial control systems, Microcontroller design principles, and FPGA theory and trends. Furthermore, a survey of electronic design automation (EDA) tools and other application software was also conducted. After the literature review, the IFT was investigated exhaustively by applying it to three types of plants, namely: a DC motor, an oscillatory plant, and an unstable plant. Each of these plants were tested using three types of initial controllers, namely heavilydamped, critically damped and under-damped initial controllers. The plants were also tested by varying the amplitude of the reference signal, followed by using a single-step signal of constant amplitude of one volt. The intention of exploring all of these possibilities was meant to firmly expose the IFT boundaries of applicability, so that the final product would not be vulnerable to unnecessary post-production discoveries. The design methodology adopted in this research was a popular hierarchical and modular top-down procedure, which is an array of abstraction levels that are detailed as: system level, behavioural level, Register-Transfer Level (RTL) and Gate level. At system level, the Dedicated IFT Microcontroller was defined. Thereafter, at behavioural level, the design was simulated using VHDL, created by porting the LabView IFT code to the Xilinx EDA tool. At the RTL, the synthesisable VHDL code utilising fixed-point number representation was written. The compiled bit file was downloaded onto National Instruments (NI) Digital Electronics FPGA Board featuring iii the Spartan 3 series FPGA. This was tested, using a method known as simulation in the hardware. The key contribution of this thesis is the experimental validation of the IFT technique on FPGA hardware as it has never been published before, the work described in chapter four and five. The other contribution is the analysis of 1DOF IFT technique in terms of limitations of applicability for correct implementation, which is the main work of chapter three. This work could be used to explore other computational methods, like the use of floating-point number representation for high resolution and accuracy in numerical computations. Another avenue that could be exploited is Xilinx's recent Vivado methodology, which has the capacity for traditional programming languages like C or C++, as these have in-built floating-point number capability. Finally, out of this work, two papers have already been published by Springer and IEEE Xplore Publishers, and a journal paper has also been written for publication in the Control Systems Technology journal.
- Full Text:
- Date Issued: 2018
Facilities management awareness amongst high school learners and teachers in the Soutpansberg west circuit in the Limpopo province
- Authors: Nephawe, Tshilidzi
- Date: 2018
- Subjects: Facility management -- South Africa -- Limpopo , Facility management -- Research Construction industry -- Forecasting -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/32894 , vital:32395
- Description: The Facilities Management (FM) profession in South Africa needs to start recognising and acknowledging the importance of formal education amongst the population. The question of FM being a career normally receives shallow responses; and it sometimes leads to a contradiction. The FM profession seems to be taking an ‘as it is’ approach, when it comes to the establishment of an education agenda; since there is no clear evidence regarding alignment and transition from high school to tertiary level, and then to the workplace. The level of awareness plays a significant role in all elements of FM practice. Even at the present moment, FM is still not a career of choice, meaning that anyone can be a facilities manager. There are parts of South Africa where the population is unaware of FM. Some had never heard about it at all. It was important to establish the level of awareness: with the intention of developing a critical awareness of FM as a career path amongst high school learners and teachers in the Soutpansberg West Circuit, in order to inform them of a possible career choice in FM. In this study, a mixed-model research methodology was used, which combines both qualitative and quantitative research approaches. A population was identified from which a sample of 14 high schools, 87 high school teachers and 2 299 high school learners was drawn. A ‘fit for purpose’ questionnaire was distributed to the participants. The data were collected by means of a survey. It focused on a survey; and it used a questionnaire that was composed of multiple closed-ended or quantitative-type items, as well as several open-ended or qualitative-type items. Thematic analysis was used for the open-ended questions. This study has successfully managed to determine the awareness levels of high school learners and teachers relating to FM, the need for FM awareness in high schools; and whether there were high school learners who wished to become facilities managers in the future. FM companies, tertiary institutions, and high schools must collaborate in the development of the FM career-guidance programme, in order to increase awareness amongst the teachers and learners. There were students who indicated that they were interested in FM as their career of choice.
- Full Text:
- Date Issued: 2018
- Authors: Nephawe, Tshilidzi
- Date: 2018
- Subjects: Facility management -- South Africa -- Limpopo , Facility management -- Research Construction industry -- Forecasting -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/32894 , vital:32395
- Description: The Facilities Management (FM) profession in South Africa needs to start recognising and acknowledging the importance of formal education amongst the population. The question of FM being a career normally receives shallow responses; and it sometimes leads to a contradiction. The FM profession seems to be taking an ‘as it is’ approach, when it comes to the establishment of an education agenda; since there is no clear evidence regarding alignment and transition from high school to tertiary level, and then to the workplace. The level of awareness plays a significant role in all elements of FM practice. Even at the present moment, FM is still not a career of choice, meaning that anyone can be a facilities manager. There are parts of South Africa where the population is unaware of FM. Some had never heard about it at all. It was important to establish the level of awareness: with the intention of developing a critical awareness of FM as a career path amongst high school learners and teachers in the Soutpansberg West Circuit, in order to inform them of a possible career choice in FM. In this study, a mixed-model research methodology was used, which combines both qualitative and quantitative research approaches. A population was identified from which a sample of 14 high schools, 87 high school teachers and 2 299 high school learners was drawn. A ‘fit for purpose’ questionnaire was distributed to the participants. The data were collected by means of a survey. It focused on a survey; and it used a questionnaire that was composed of multiple closed-ended or quantitative-type items, as well as several open-ended or qualitative-type items. Thematic analysis was used for the open-ended questions. This study has successfully managed to determine the awareness levels of high school learners and teachers relating to FM, the need for FM awareness in high schools; and whether there were high school learners who wished to become facilities managers in the future. FM companies, tertiary institutions, and high schools must collaborate in the development of the FM career-guidance programme, in order to increase awareness amongst the teachers and learners. There were students who indicated that they were interested in FM as their career of choice.
- Full Text:
- Date Issued: 2018
Factors that impact on the user experience of a mobile school health application
- Authors: Chetty, Avineshin
- Date: 2018
- Subjects: Wireless communication systems in medical care , Medical informatics Application software Technology -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/21801 , vital:29780
- Description: In South Africa, the National Department of Health through its Integrated School Health Policy, use school nurses, to visit schools and perform health screening of learners which focus mainly on nutrition, eyesight and hearing. To date, this was done manually, but with the advance of technology, there is a need to investigate the use of for example, mobile applications to assist with health screening tasks. As part of the TECH4RED project in the Chris Hani district, a mobile school health assessment application was implemented and used over a period three years. As this is a new way of conducting the health screening, there is a need to understand the user experiences of the end users who interact with both the technology and the application. The objective of this study was to investigate the perceived factors that impact on the UX of the school health assessment application. The research aimed to understand the uses, advantages and disadvantages of mobile health applications. It also aimed at determining whether there are unique characteristics of the targeted end users and if so, whether such characteristics would affect the overall UX when using the application. Determining the levels of satisfaction and investigating the apparent challenges the users faced while interacting with the application provided some insights into underlying factors. A theoretical framework was constructed using existing literature. Using a case study approach, data was collected by means of end user satisfaction and user experience questionnaires. Additional data collection was done by means of an expert review to obtain feedback on the content and workflow of the school health assessment application. The resulting findings from the research included, a descriptive list of factors that impact the school health assessment application, as well as a subsequent list of recommendations for improvements. These key-findings could lead to possible guidelines, while additionally, providing valuable insight into mobile school health applications on the whole.
- Full Text:
- Date Issued: 2018
- Authors: Chetty, Avineshin
- Date: 2018
- Subjects: Wireless communication systems in medical care , Medical informatics Application software Technology -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/21801 , vital:29780
- Description: In South Africa, the National Department of Health through its Integrated School Health Policy, use school nurses, to visit schools and perform health screening of learners which focus mainly on nutrition, eyesight and hearing. To date, this was done manually, but with the advance of technology, there is a need to investigate the use of for example, mobile applications to assist with health screening tasks. As part of the TECH4RED project in the Chris Hani district, a mobile school health assessment application was implemented and used over a period three years. As this is a new way of conducting the health screening, there is a need to understand the user experiences of the end users who interact with both the technology and the application. The objective of this study was to investigate the perceived factors that impact on the UX of the school health assessment application. The research aimed to understand the uses, advantages and disadvantages of mobile health applications. It also aimed at determining whether there are unique characteristics of the targeted end users and if so, whether such characteristics would affect the overall UX when using the application. Determining the levels of satisfaction and investigating the apparent challenges the users faced while interacting with the application provided some insights into underlying factors. A theoretical framework was constructed using existing literature. Using a case study approach, data was collected by means of end user satisfaction and user experience questionnaires. Additional data collection was done by means of an expert review to obtain feedback on the content and workflow of the school health assessment application. The resulting findings from the research included, a descriptive list of factors that impact the school health assessment application, as well as a subsequent list of recommendations for improvements. These key-findings could lead to possible guidelines, while additionally, providing valuable insight into mobile school health applications on the whole.
- Full Text:
- Date Issued: 2018
Impact of intergrating teebus hydro power on the unbalanced distribution MV network
- Authors: Mthethwa, Lindani
- Date: 2018
- Subjects: Electric power systems , Renewable energy sources Hydroelectric power plants
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/33054 , vital:32512
- Description: Small hydro power sources have been identified as one of the renewable energy technologies that the South African government is focusing on in order to generate more electricity from renewable/independent resources. Due to the low carbon output of most renewable energy technologies and the carbon intensive power generation technologies that are currently being used in South Africa e.g. Hydro, coal, gas, and etc. further pressure is increasing to incorporate cleaner forms of generation. In 2002 a study focusing on the hydropower potential was compiled providing an assessment according to conventional and unconventional possibilities for all the provinces. Nowadays, the power electricity demand is growing fast and one of the main tasks for power engineers is to generate electricity from renewable energy sources to overcome this increase in the energy consumption and at the same time reduce environmental impact of power generation. Eskom Distribution Eastern Cape Operating Unit (ECOU) was requested to investigate the feasibility of connecting a small hydro power scheme located in the Teebus area in the Eastern Cape. The Eastern Cape in particular, was identified as potentially the most productive area for small hydroelectric development in South Africa for both the grid connected and off grid applications. These network conditions are in contrast to the South African electricity network where long radial feeders with low X/R ratios and high resistance, spanning large geographic areas, give rise to low voltages on the network. Practical simulation networks have been used to test the conditions set out in the South African Grid Code/NERSA standard and to test the impact of connecting small hydro generation onto the unbalanced distribution network. These networks are representative of various real case scenarios of the South African distribution network. Most of the findings from the simulations were consistent with what was expected when comparing with other literatures. From the simulation results it was seen that the performance of the variable speed generators were superior to that of the fixed speed generators during transient conditions. It was also seen that the weakness of the network had a negative effect on the stability of the system. It is also noted that the stability studies are a necessity when connecting the generators to a network and that each case should be reviewed individually. The fundamental cause of voltage instability is identified as incapability of combined distribution and generation system to meet excessive load demand in either real power or reactive power form.
- Full Text:
- Date Issued: 2018
- Authors: Mthethwa, Lindani
- Date: 2018
- Subjects: Electric power systems , Renewable energy sources Hydroelectric power plants
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/33054 , vital:32512
- Description: Small hydro power sources have been identified as one of the renewable energy technologies that the South African government is focusing on in order to generate more electricity from renewable/independent resources. Due to the low carbon output of most renewable energy technologies and the carbon intensive power generation technologies that are currently being used in South Africa e.g. Hydro, coal, gas, and etc. further pressure is increasing to incorporate cleaner forms of generation. In 2002 a study focusing on the hydropower potential was compiled providing an assessment according to conventional and unconventional possibilities for all the provinces. Nowadays, the power electricity demand is growing fast and one of the main tasks for power engineers is to generate electricity from renewable energy sources to overcome this increase in the energy consumption and at the same time reduce environmental impact of power generation. Eskom Distribution Eastern Cape Operating Unit (ECOU) was requested to investigate the feasibility of connecting a small hydro power scheme located in the Teebus area in the Eastern Cape. The Eastern Cape in particular, was identified as potentially the most productive area for small hydroelectric development in South Africa for both the grid connected and off grid applications. These network conditions are in contrast to the South African electricity network where long radial feeders with low X/R ratios and high resistance, spanning large geographic areas, give rise to low voltages on the network. Practical simulation networks have been used to test the conditions set out in the South African Grid Code/NERSA standard and to test the impact of connecting small hydro generation onto the unbalanced distribution network. These networks are representative of various real case scenarios of the South African distribution network. Most of the findings from the simulations were consistent with what was expected when comparing with other literatures. From the simulation results it was seen that the performance of the variable speed generators were superior to that of the fixed speed generators during transient conditions. It was also seen that the weakness of the network had a negative effect on the stability of the system. It is also noted that the stability studies are a necessity when connecting the generators to a network and that each case should be reviewed individually. The fundamental cause of voltage instability is identified as incapability of combined distribution and generation system to meet excessive load demand in either real power or reactive power form.
- Full Text:
- Date Issued: 2018
Ineffective quality management on civil engineering projects
- Authors: Kruger, Casper Stephanus
- Date: 2018
- Subjects: Total quality management , Quality management -- South Africa Civil engineering -- South Africa Construction industry -- South Africa -- Management Project management -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/30984 , vital:31243
- Description: Quality is a fundamental expectancy in the construction industry. Together with cost and time, it is one of the basic and most important performance indicators in construction projects. The non-achievement of such a crucial aspect of construction can result in construction failures and client dissatisfaction (Zunguzane et al., 2012: 20). The increased pressure on project stakeholders to produce projects that achieve these aspects can become unrealistic, which in turn can contribute to the development of disputes within the construction sector (Love et al., 2010a: 405). Civil engineering project stakeholders employ Quality Management Systems as a tool to increase industry quality performance. The effective implementation of these systems contribute to the mitigation and elimination of rework/non-conformances while enhancing client satisfaction and increasing the project performance concerning cost, quality and time (Bello et al., 2010: 9). The main objectives of this study were to determine whether quality management is implemented effectively on civil engineering projects in order prevent claims against consulting engineers and to further investigate the barriers that impact quality management on civil engineering projects. In addition, the research aimed to determine what impact, if any, the aspects of public sector procurement policy, implementation and management have on the ability of civil engineering stakeholders to manage quality during the design, procurement and construction phases of a project. The study therefore focussed on quality management in the civil engineering industry and investigated the barriers that contribute to ineffective quality management on civil engineering projects under design, procurement and construction related barriers. This study was done in two parts. Firstly, the research adopted a quantitative research approach with a descriptive research strategy. The second part entailed an in-depth study of the current existing theory by means of a literature review. Data was collected via a questionnaire survey and analysed to test the three hypotheses and answer questions relating to the current status of the subject of inquiry. iv The findings of the research confirmed the challenges and frustrations experienced during the procurement implementation activities of public sector clients. The results confirmed that the appointment of incompetent and unqualified civil engineering contractors has a direct impact on the quality of civil engineering projects and the effective implementation of quality management systems.
- Full Text:
- Date Issued: 2018
- Authors: Kruger, Casper Stephanus
- Date: 2018
- Subjects: Total quality management , Quality management -- South Africa Civil engineering -- South Africa Construction industry -- South Africa -- Management Project management -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/30984 , vital:31243
- Description: Quality is a fundamental expectancy in the construction industry. Together with cost and time, it is one of the basic and most important performance indicators in construction projects. The non-achievement of such a crucial aspect of construction can result in construction failures and client dissatisfaction (Zunguzane et al., 2012: 20). The increased pressure on project stakeholders to produce projects that achieve these aspects can become unrealistic, which in turn can contribute to the development of disputes within the construction sector (Love et al., 2010a: 405). Civil engineering project stakeholders employ Quality Management Systems as a tool to increase industry quality performance. The effective implementation of these systems contribute to the mitigation and elimination of rework/non-conformances while enhancing client satisfaction and increasing the project performance concerning cost, quality and time (Bello et al., 2010: 9). The main objectives of this study were to determine whether quality management is implemented effectively on civil engineering projects in order prevent claims against consulting engineers and to further investigate the barriers that impact quality management on civil engineering projects. In addition, the research aimed to determine what impact, if any, the aspects of public sector procurement policy, implementation and management have on the ability of civil engineering stakeholders to manage quality during the design, procurement and construction phases of a project. The study therefore focussed on quality management in the civil engineering industry and investigated the barriers that contribute to ineffective quality management on civil engineering projects under design, procurement and construction related barriers. This study was done in two parts. Firstly, the research adopted a quantitative research approach with a descriptive research strategy. The second part entailed an in-depth study of the current existing theory by means of a literature review. Data was collected via a questionnaire survey and analysed to test the three hypotheses and answer questions relating to the current status of the subject of inquiry. iv The findings of the research confirmed the challenges and frustrations experienced during the procurement implementation activities of public sector clients. The results confirmed that the appointment of incompetent and unqualified civil engineering contractors has a direct impact on the quality of civil engineering projects and the effective implementation of quality management systems.
- Full Text:
- Date Issued: 2018
Integrating sustainability principles in construction health and safety management practices in Zimbabwe
- Authors: Chigara, Benviolent
- Date: 2018
- Subjects: Sustainable construction -- Zimbabwe , Construction industry -- Safety measures Industrial safety -- Zimbabwe -- Management
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/23459 , vital:30565
- Description: The construction industry is an important industry to national development through the provision of infrastructure and creation of employment, and hence contributing to sustainable development. Nevertheless, the construction industry has a poor health and safety (H&S) and environmental record. Globally, the construction industry is a leading contributor to workplace fatalities, injuries, and disease. In Zimbabwe, the Millennium Towers accident, which resulted in 15 construction workers losing their lives, compromised the integrity of construction H&S management, and highlighted the need to improve H&S management in the sector. This study examined H&S management in Zimbabwe and developed a framework for integrating sustainability into H&S management practices. The study employed a mixed method research design involving the use of interviews and questionnaires to collect primary data from contractors, consultants, government, clients, and workers in Harare and Bulawayo. A total of 101 questionnaires were successfully completed and analysed, representing a response rate of 55.6%. The data from questionnaires were analysed with the help of the SPSS software v.23 to produce descriptive and inferential statistics. The results of the study suggest that H&S practices are inadequate as demonstrated by the extent to which workers are exposed to hazards and the occurrence of injuries, disease, and fatalities. The factors contributing to workers’ exposure to hazards and the occurrence of injuries, disease, and fatalities include, inter alia, inadequate planning for H&S, inadequate hazard identification and risk assessments (HIRAs), inadequate management of hazards, inadequate occupational health (OH) surveillance, appointment of stakeholders who do not systematically manage H&S, inadequate design HIRAs, and unsafe work practices. The problem is amplified by inadequate integration of H&S within procurement systems, which limit the extent to which contractors make financial provision for H&S. Regrettably, workplace fatalities, injuries, and disease diminish the quality of life for the injured workers, increase project cost and delays project completion. Against this background, the study investigated the integration of sustainability principles in construction H&S as a strategy to improve H&S practices in Zimbabwe. The outcome of that investigation was a strategy and interventions, and a framework for improved practices in the form of a Sustainability Framework for Construction H&S (SFCHS). The validation of the SFCHS by construction practitioners confirms the importance of the recommended practices to reducing workplace fatalities, injuries, and disease in Zimbabwe and beyond. The development of a SFCHS, as a strategy to improve H&S practices in Zimbabwe, and the validation thereof, resulted in a significant contribution to the related body of knowledge. Nevertheless, the transition to sustainable H&S practices require contractors, consultants, government, clients and workers to take a proactive role relative to the recommended practices in the SFCHS. Further studies can explore the responsiveness of sustainability factors relative to the occurrence of injuries, disease and fatalities based on selected case studies.
- Full Text:
- Date Issued: 2018
- Authors: Chigara, Benviolent
- Date: 2018
- Subjects: Sustainable construction -- Zimbabwe , Construction industry -- Safety measures Industrial safety -- Zimbabwe -- Management
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/23459 , vital:30565
- Description: The construction industry is an important industry to national development through the provision of infrastructure and creation of employment, and hence contributing to sustainable development. Nevertheless, the construction industry has a poor health and safety (H&S) and environmental record. Globally, the construction industry is a leading contributor to workplace fatalities, injuries, and disease. In Zimbabwe, the Millennium Towers accident, which resulted in 15 construction workers losing their lives, compromised the integrity of construction H&S management, and highlighted the need to improve H&S management in the sector. This study examined H&S management in Zimbabwe and developed a framework for integrating sustainability into H&S management practices. The study employed a mixed method research design involving the use of interviews and questionnaires to collect primary data from contractors, consultants, government, clients, and workers in Harare and Bulawayo. A total of 101 questionnaires were successfully completed and analysed, representing a response rate of 55.6%. The data from questionnaires were analysed with the help of the SPSS software v.23 to produce descriptive and inferential statistics. The results of the study suggest that H&S practices are inadequate as demonstrated by the extent to which workers are exposed to hazards and the occurrence of injuries, disease, and fatalities. The factors contributing to workers’ exposure to hazards and the occurrence of injuries, disease, and fatalities include, inter alia, inadequate planning for H&S, inadequate hazard identification and risk assessments (HIRAs), inadequate management of hazards, inadequate occupational health (OH) surveillance, appointment of stakeholders who do not systematically manage H&S, inadequate design HIRAs, and unsafe work practices. The problem is amplified by inadequate integration of H&S within procurement systems, which limit the extent to which contractors make financial provision for H&S. Regrettably, workplace fatalities, injuries, and disease diminish the quality of life for the injured workers, increase project cost and delays project completion. Against this background, the study investigated the integration of sustainability principles in construction H&S as a strategy to improve H&S practices in Zimbabwe. The outcome of that investigation was a strategy and interventions, and a framework for improved practices in the form of a Sustainability Framework for Construction H&S (SFCHS). The validation of the SFCHS by construction practitioners confirms the importance of the recommended practices to reducing workplace fatalities, injuries, and disease in Zimbabwe and beyond. The development of a SFCHS, as a strategy to improve H&S practices in Zimbabwe, and the validation thereof, resulted in a significant contribution to the related body of knowledge. Nevertheless, the transition to sustainable H&S practices require contractors, consultants, government, clients and workers to take a proactive role relative to the recommended practices in the SFCHS. Further studies can explore the responsiveness of sustainability factors relative to the occurrence of injuries, disease and fatalities based on selected case studies.
- Full Text:
- Date Issued: 2018
Mitigation of single event upsets in a XILINX ARTIX-7 field programmable gate array
- Authors: Omolo, Joshua
- Date: 2018
- Subjects: Field programmable gate arrays -- Design and construction Prototypes, Engineering
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/22310 , vital:29942
- Description: Field programmable gate arrays are increasingly being used in harsh environments like space where high energy particles from radiation affect the integrity of the data. Before deployment of satellites in space, characterisation and consequently mitigation of radiation effects is necessary to avoid failure. By irradiating a digital microelectronic device, using accelerated energetic particles, it is possible to predict the likelihood of an event effect happening. Such irradiation tests can only be done at a particle accelerator facility such as iThemba LABS in Cape Town. It is the one of the few particle accelerators in the southern hemisphere and offers the capacity to perform these event effect characterisation tests. Triple Modular Redundancy (TMR) is a commonly used mitigation technique in microelectronics. Although effective, it has the downside of increased resource area. A DMR-Filter combination mitigation technique was developed at the Nelson Mandela University. It uses fewer resources than TMR and it is envisaged to significantly reduce event upsets in a FPGA. This research project seeks to investigate the effectiveness of the DMR-Filter combination mitigation technique in reducing the likelihood of event upsets occurring in Xilinx’s Artix-7 FPGA when exposed to highly accelerated particles, similar to those in space.
- Full Text:
- Date Issued: 2018
- Authors: Omolo, Joshua
- Date: 2018
- Subjects: Field programmable gate arrays -- Design and construction Prototypes, Engineering
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/22310 , vital:29942
- Description: Field programmable gate arrays are increasingly being used in harsh environments like space where high energy particles from radiation affect the integrity of the data. Before deployment of satellites in space, characterisation and consequently mitigation of radiation effects is necessary to avoid failure. By irradiating a digital microelectronic device, using accelerated energetic particles, it is possible to predict the likelihood of an event effect happening. Such irradiation tests can only be done at a particle accelerator facility such as iThemba LABS in Cape Town. It is the one of the few particle accelerators in the southern hemisphere and offers the capacity to perform these event effect characterisation tests. Triple Modular Redundancy (TMR) is a commonly used mitigation technique in microelectronics. Although effective, it has the downside of increased resource area. A DMR-Filter combination mitigation technique was developed at the Nelson Mandela University. It uses fewer resources than TMR and it is envisaged to significantly reduce event upsets in a FPGA. This research project seeks to investigate the effectiveness of the DMR-Filter combination mitigation technique in reducing the likelihood of event upsets occurring in Xilinx’s Artix-7 FPGA when exposed to highly accelerated particles, similar to those in space.
- Full Text:
- Date Issued: 2018
Motivation of construction workers in the nelson Mandela Bay Metropole, South Africa
- Jesumoroti, Christtestimony Oluwafemi
- Authors: Jesumoroti, Christtestimony Oluwafemi
- Date: 2018
- Subjects: Employee motivation -- South Africa -- Nelson Mandela Bay Municipality , Performance standards -- South Africa -- Nelson Mandela Bay Municipality Construction workers -- South Africa -- Nelson Mandela Bay Municipality Construction industry -- Employees -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/30573 , vital:30962
- Description: The issue of construction workers’ motivation has become a subject of debate among construction project management professionals. Construction workers mostly work long hours in relatively disagreeable environments and, far from their families. Most of the activities are done under difficult conditions including harsh weather conditions, however, employees are required to be motivated towards ensuring the attractiveness of the industry to them. Moreover, there are diverse perceptions that the motivation of construction workers positively impacts construction workers performance or rather adversely affects the general performance of construction workers. Although, workers motivation has been proven to improve construction productivity globally, motivation of construction workers seems not to be effectively implemented in South African Construction Industry. As a result, it is difficult for management to identify motivational factors that affect workers productivity in a work environment. A quantitative research approach was employed to analyse the result obtained from a structured questionnaire survey. The research respondents included: bricklayers, plumbers, concrete workers, electricians, carpenters, and professionals. This study used data from primary source which focus on tradesman, labourer and professional context. A survey was conducted with tradesmen, labourers and professionals regarding motivation on construction workers which was conducted in the Nelson Mandela Bay Metropole, Eastern Cape. It was found that motivation is important to construction workers’ performance. Awarding bonuses to workers is important to improving workers’ efficiency and there is a need for construction workers recognition by management. Construction industry stakeholder should shift their attention and prioritise the motivation of its workers since the industry has a way of cubing poverty and uplifting the county’s economy. The findings revealed that motivational communication, rather than functional communication, would enhance worker productivity. It was found that both intrinsic and extrinsic rewards are needed to improve worker productivity. It was also found that positive reinforcement techniques, should be used to enhance worker productivity. The findings from this research study revealed that the motivational theories apply to construction workers, and management needs to apply these theories wisely to achieve improved productivity. The study therefore concludes that motivational techniques are necessary to improve construction workers productivity on a vii construction site. It is recommended that supervisors use motivational communication, extrinsic rewards, intrinsic rewards and positive reinforcement to motivate their workers to achieve higher levels of productivity.
- Full Text:
- Date Issued: 2018
- Authors: Jesumoroti, Christtestimony Oluwafemi
- Date: 2018
- Subjects: Employee motivation -- South Africa -- Nelson Mandela Bay Municipality , Performance standards -- South Africa -- Nelson Mandela Bay Municipality Construction workers -- South Africa -- Nelson Mandela Bay Municipality Construction industry -- Employees -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/30573 , vital:30962
- Description: The issue of construction workers’ motivation has become a subject of debate among construction project management professionals. Construction workers mostly work long hours in relatively disagreeable environments and, far from their families. Most of the activities are done under difficult conditions including harsh weather conditions, however, employees are required to be motivated towards ensuring the attractiveness of the industry to them. Moreover, there are diverse perceptions that the motivation of construction workers positively impacts construction workers performance or rather adversely affects the general performance of construction workers. Although, workers motivation has been proven to improve construction productivity globally, motivation of construction workers seems not to be effectively implemented in South African Construction Industry. As a result, it is difficult for management to identify motivational factors that affect workers productivity in a work environment. A quantitative research approach was employed to analyse the result obtained from a structured questionnaire survey. The research respondents included: bricklayers, plumbers, concrete workers, electricians, carpenters, and professionals. This study used data from primary source which focus on tradesman, labourer and professional context. A survey was conducted with tradesmen, labourers and professionals regarding motivation on construction workers which was conducted in the Nelson Mandela Bay Metropole, Eastern Cape. It was found that motivation is important to construction workers’ performance. Awarding bonuses to workers is important to improving workers’ efficiency and there is a need for construction workers recognition by management. Construction industry stakeholder should shift their attention and prioritise the motivation of its workers since the industry has a way of cubing poverty and uplifting the county’s economy. The findings revealed that motivational communication, rather than functional communication, would enhance worker productivity. It was found that both intrinsic and extrinsic rewards are needed to improve worker productivity. It was also found that positive reinforcement techniques, should be used to enhance worker productivity. The findings from this research study revealed that the motivational theories apply to construction workers, and management needs to apply these theories wisely to achieve improved productivity. The study therefore concludes that motivational techniques are necessary to improve construction workers productivity on a vii construction site. It is recommended that supervisors use motivational communication, extrinsic rewards, intrinsic rewards and positive reinforcement to motivate their workers to achieve higher levels of productivity.
- Full Text:
- Date Issued: 2018
Potable water production from atmospheric vapour using an ejector evacuated solar powered refrigeration system
- Authors: Cawood, John Henry
- Date: 2018
- Subjects: Solar energy , Solar radiation
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/23481 , vital:30567
- Description: This research project explores the possibility of using solar radiation energy to produce safe liquid water through the condensation of atmospheric water vapour for human consumption, livestock watering and also for small scale high value crop irrigation. The research activities are comprised of a literature study, comparison of similar devices in use, a design and prototyping exercise, a measure of development work to enhance the performance of the prototype and testing in Al-Batinah province in the Sultanate of Oman, where the author is currently on a work assignment. This dissertation describes the research activities performed to answer the following question: ‘Is it possible to economically produce sufficient quantities of liquid water from atmospheric vapour using only heat energy from the sun?’ This question poses a further two questions which need to be answered in the literature study. These are: ‘What is an economical price for clean drinking water?’ and ‘What is a sufficient quantity of water?’ The purpose of producing liquid water from atmospheric water vapour is an attempt to develop the technology to harvest an alternative and almost inexhaustible water source. The reason for requiring a new source of water is due to the fact that the available fresh water resources of the world are diminishing due to pollution, extensive utilisation and salination. Several references indicate that the problem is compounding itself due the increasing demand on a diminishing resource, with deepening negative effects on agriculture1, health2, economy3, industry and lifestyle4. Many future scenarios depict clean water as a scarce and expensive commodity, unaffordable to many. The condensation of atmospheric vapour is not a new concept. The literature study explores historical attempts to achieve this, as well as detailing the shortcomings of contemporary vapour condensation units as the modern state of the art. This survey covers the spectrum from large versions deployed by military and remote area construction operations to produce water for all purposes, to small desktop electrical water producing machines. The focus of the research is on a more environmentally conscious process, attempting to use a simple ejector driven device with sunshine as the energy source and water as the refrigerant. A further environmental enhancement of the concept is that of designing the machine to last for an extremely long working life, thereby diluting the carbon footprint of manufacture over a great number of years. A portion of the research is devoted to the development of a basic model which takes into account the climatic and meteorological variables to accurately predict a water harvest. The development of the model is then used to optimise the process, narrow the variability of assumptions and assist with the design. The model also serves to predict the performance of the unit in other locations under different prevailing climatic conditions. A design specification and a prototype are produced and tested. Finally the design is scrutinised using value engineering principles to reduce cost, effort and environmental impact and also to reduce the overall cost to provide a more economically viable appliance. The prototype device used in this study will use a collector area of 1 square meter, roughly equivalent to 1000 Watts of solar power under ideal conditions.
- Full Text:
- Date Issued: 2018
- Authors: Cawood, John Henry
- Date: 2018
- Subjects: Solar energy , Solar radiation
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/23481 , vital:30567
- Description: This research project explores the possibility of using solar radiation energy to produce safe liquid water through the condensation of atmospheric water vapour for human consumption, livestock watering and also for small scale high value crop irrigation. The research activities are comprised of a literature study, comparison of similar devices in use, a design and prototyping exercise, a measure of development work to enhance the performance of the prototype and testing in Al-Batinah province in the Sultanate of Oman, where the author is currently on a work assignment. This dissertation describes the research activities performed to answer the following question: ‘Is it possible to economically produce sufficient quantities of liquid water from atmospheric vapour using only heat energy from the sun?’ This question poses a further two questions which need to be answered in the literature study. These are: ‘What is an economical price for clean drinking water?’ and ‘What is a sufficient quantity of water?’ The purpose of producing liquid water from atmospheric water vapour is an attempt to develop the technology to harvest an alternative and almost inexhaustible water source. The reason for requiring a new source of water is due to the fact that the available fresh water resources of the world are diminishing due to pollution, extensive utilisation and salination. Several references indicate that the problem is compounding itself due the increasing demand on a diminishing resource, with deepening negative effects on agriculture1, health2, economy3, industry and lifestyle4. Many future scenarios depict clean water as a scarce and expensive commodity, unaffordable to many. The condensation of atmospheric vapour is not a new concept. The literature study explores historical attempts to achieve this, as well as detailing the shortcomings of contemporary vapour condensation units as the modern state of the art. This survey covers the spectrum from large versions deployed by military and remote area construction operations to produce water for all purposes, to small desktop electrical water producing machines. The focus of the research is on a more environmentally conscious process, attempting to use a simple ejector driven device with sunshine as the energy source and water as the refrigerant. A further environmental enhancement of the concept is that of designing the machine to last for an extremely long working life, thereby diluting the carbon footprint of manufacture over a great number of years. A portion of the research is devoted to the development of a basic model which takes into account the climatic and meteorological variables to accurately predict a water harvest. The development of the model is then used to optimise the process, narrow the variability of assumptions and assist with the design. The model also serves to predict the performance of the unit in other locations under different prevailing climatic conditions. A design specification and a prototype are produced and tested. Finally the design is scrutinised using value engineering principles to reduce cost, effort and environmental impact and also to reduce the overall cost to provide a more economically viable appliance. The prototype device used in this study will use a collector area of 1 square meter, roughly equivalent to 1000 Watts of solar power under ideal conditions.
- Full Text:
- Date Issued: 2018
Procurement challenges faced by Eskom contractors during the tender stage
- Authors: Hlalutye, Thandiwe
- Date: 2018
- Subjects: Management -- Procurement -- South Africa -- Northern Cape , Project management -- South Africa -- Northern Cape Contractors' operation -- South Africa -- Northern Cape -- Finance
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/30260 , vital:30913
- Description: The procurement process within South Africa has become an increasing focus in open market access for local economic development. The government introduced Preferential Procurement Policy Frame Act 5 of 2000 (PPPFA) which must be followed by all government owned organisations, including parastatals. Eskom, therefore, has to abide to this regulation and, since it started utilising the Act in its tendering process, there has been a challenge to getting contractors who are commercially and technically approved to be able to execute work or projects. The aim of this study is to examine challenges faced by Eskom Northern Cape Operating Unit contractors during the tender stage in terms of tender requirements, whereby they fail to submit all required tender returnables and fail to meet a set threshold in order to be successful and being awarded with the contract. This study undertook an empirical study using a case study of Eskom after a literature review. A questionnaire was used to collect data from all the active contractors on the Eskom Northern Cape Operating Unit data base. The key findings included that; contractors agreed that they still lack understanding of a quality management system. However they disagreed that they are not complying with safety health and environment and that they lack knowledge of technical requirements which leads them to not submitting objective evidence. The study concluded that contracting firms still do not comply with procurement requirements during the tender stage.
- Full Text:
- Date Issued: 2018
- Authors: Hlalutye, Thandiwe
- Date: 2018
- Subjects: Management -- Procurement -- South Africa -- Northern Cape , Project management -- South Africa -- Northern Cape Contractors' operation -- South Africa -- Northern Cape -- Finance
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/30260 , vital:30913
- Description: The procurement process within South Africa has become an increasing focus in open market access for local economic development. The government introduced Preferential Procurement Policy Frame Act 5 of 2000 (PPPFA) which must be followed by all government owned organisations, including parastatals. Eskom, therefore, has to abide to this regulation and, since it started utilising the Act in its tendering process, there has been a challenge to getting contractors who are commercially and technically approved to be able to execute work or projects. The aim of this study is to examine challenges faced by Eskom Northern Cape Operating Unit contractors during the tender stage in terms of tender requirements, whereby they fail to submit all required tender returnables and fail to meet a set threshold in order to be successful and being awarded with the contract. This study undertook an empirical study using a case study of Eskom after a literature review. A questionnaire was used to collect data from all the active contractors on the Eskom Northern Cape Operating Unit data base. The key findings included that; contractors agreed that they still lack understanding of a quality management system. However they disagreed that they are not complying with safety health and environment and that they lack knowledge of technical requirements which leads them to not submitting objective evidence. The study concluded that contracting firms still do not comply with procurement requirements during the tender stage.
- Full Text:
- Date Issued: 2018
Solar thermal performance of a conical helix receiver tube mounted on a parabolic dish
- Nandjembo, Frans Nelongo Pandeni
- Authors: Nandjembo, Frans Nelongo Pandeni
- Date: 2018
- Subjects: Solar energy , Power resources Energy conversion
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/32860 , vital:32379
- Description: This report presents the investigation of a conical helix receiver tube with a zero shading factor to achieve optimal performance of a small concentrating solar thermal collector. In order to understand the working performance of the conical helix receiver tube, it was compared to that of a flat spiral receiver tube. This was done by measuring temperatures at various points as well as the volume airflow rate. Optical studies were achieved using SolTrace to quantify spillage losses and optical efficiency of the dish used in the study from the parabolic dish using a simulation in SolTrace. Comparative tests were conducted between the conical receiver tube and equivalent flat receiver tube at volume air flow rates between 30 m3.h−1 and 45 m3.h−1. The conical helix receiver tube showed a linear temperature distribution, from the outer surface tube towards the inner surface tube in an ascending order, while the flat spiral receiver tube showed a non-linear temperature distribution, its temperature increased in the middle section and decreased towards the inner surface tube. The research showed that an optimally configured helical receiver tube with linear temperature change along its length outperformed the flat receiver tube.
- Full Text:
- Date Issued: 2018
- Authors: Nandjembo, Frans Nelongo Pandeni
- Date: 2018
- Subjects: Solar energy , Power resources Energy conversion
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/32860 , vital:32379
- Description: This report presents the investigation of a conical helix receiver tube with a zero shading factor to achieve optimal performance of a small concentrating solar thermal collector. In order to understand the working performance of the conical helix receiver tube, it was compared to that of a flat spiral receiver tube. This was done by measuring temperatures at various points as well as the volume airflow rate. Optical studies were achieved using SolTrace to quantify spillage losses and optical efficiency of the dish used in the study from the parabolic dish using a simulation in SolTrace. Comparative tests were conducted between the conical receiver tube and equivalent flat receiver tube at volume air flow rates between 30 m3.h−1 and 45 m3.h−1. The conical helix receiver tube showed a linear temperature distribution, from the outer surface tube towards the inner surface tube in an ascending order, while the flat spiral receiver tube showed a non-linear temperature distribution, its temperature increased in the middle section and decreased towards the inner surface tube. The research showed that an optimally configured helical receiver tube with linear temperature change along its length outperformed the flat receiver tube.
- Full Text:
- Date Issued: 2018
The impact of project performance on the image of the construction industry in Botswana
- Authors: Ndadi, Thabo Enert
- Date: 2018
- Subjects: Project management -- Botswana , Construction industry -- Botswana Construction industry -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/32826 , vital:32367
- Description: The construction industry is one of the largest sectors in the economy of Botswana, and contributes significantly to the socio-economic development of the country, averaging 6.7 per cent of the country’s gross domestic product (GDP). Botswana operates a free enterprise system where anyone is free to participate, which is supported by the existence of multi-national construction firms operating in the country. The construction industry in Botswana consists of various role players. As a developing country, Botswana’s construction industry is facing challenges of poor project implementation. The performance of the construction industry has not escaped the public‘s scrutiny of commercial construction and social development projects, resulting in negative perceptions with respect to the sector. This study focuses on the impact of project performance on the image of the construction industry in Botswana, and was conducted on projects underway. When public opinion is formed, a certain image of the business results, therefore the investigation endeavoured to establish the sources of negative perceptions towards the construction industry. To realise the aforementioned study objectives, an exploratory design sequence method was adopted henceforth applying established and tested quantitative and qualitative systems. A questionnaire was formulated and established to obtain the empirical data on randomly selected projects that were on-going or completed in the past ten years .These included public sector projects, private sector and those undertaken by parastatal organisation. The sample stratum deemed representative picture of the population, included various construction industry stakeholders. To facilitate for an effective data to inform the study, the questionnaire was categorised in three key areas of, biographic data, demographic and the industry best practice perceptions. The study determined that the capability of firms is influenced by construction management skills, and established regulatory systems. These can determine the extent to which the construction industry delivers the project within the business environment that is guided by the micro, macro and market parameters. As evidenced in the findings, the Botswana construction industry faces a skills’ gap and therefore is reliant on imported labour, and many international firms operating in the country affirm this observation. The study also addressed the existing regulatory systems, and the effectiveness of institutions. The study concludes that the existing performance regulatory systems are not adequate or they are ineffectively controlled; industry role players’ behaviour is irresponsible; there is limited skills’ capacity, and political interference accompanies project implementation. While the deterioration in the construction industry can be attributed to imported culture, it is noted that multi-national corporations (MNCs) and other foreign firms can be conduits for technology and knowledge (T&K) transfer to host countries in the developing world. Botswana with its free enterprise market and limited skill capacity and informed by the behaviour of construction industry role players, there is need for a structured integrity restoration process from both regulator and the operators. There is further need for a specific sector regulatory instrument (Act) to regulate the safety, health, and environmental operations in the construction industry. The construction industry also need to support research and development of the industry to be competitive both local and international.
- Full Text:
- Date Issued: 2018
- Authors: Ndadi, Thabo Enert
- Date: 2018
- Subjects: Project management -- Botswana , Construction industry -- Botswana Construction industry -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/32826 , vital:32367
- Description: The construction industry is one of the largest sectors in the economy of Botswana, and contributes significantly to the socio-economic development of the country, averaging 6.7 per cent of the country’s gross domestic product (GDP). Botswana operates a free enterprise system where anyone is free to participate, which is supported by the existence of multi-national construction firms operating in the country. The construction industry in Botswana consists of various role players. As a developing country, Botswana’s construction industry is facing challenges of poor project implementation. The performance of the construction industry has not escaped the public‘s scrutiny of commercial construction and social development projects, resulting in negative perceptions with respect to the sector. This study focuses on the impact of project performance on the image of the construction industry in Botswana, and was conducted on projects underway. When public opinion is formed, a certain image of the business results, therefore the investigation endeavoured to establish the sources of negative perceptions towards the construction industry. To realise the aforementioned study objectives, an exploratory design sequence method was adopted henceforth applying established and tested quantitative and qualitative systems. A questionnaire was formulated and established to obtain the empirical data on randomly selected projects that were on-going or completed in the past ten years .These included public sector projects, private sector and those undertaken by parastatal organisation. The sample stratum deemed representative picture of the population, included various construction industry stakeholders. To facilitate for an effective data to inform the study, the questionnaire was categorised in three key areas of, biographic data, demographic and the industry best practice perceptions. The study determined that the capability of firms is influenced by construction management skills, and established regulatory systems. These can determine the extent to which the construction industry delivers the project within the business environment that is guided by the micro, macro and market parameters. As evidenced in the findings, the Botswana construction industry faces a skills’ gap and therefore is reliant on imported labour, and many international firms operating in the country affirm this observation. The study also addressed the existing regulatory systems, and the effectiveness of institutions. The study concludes that the existing performance regulatory systems are not adequate or they are ineffectively controlled; industry role players’ behaviour is irresponsible; there is limited skills’ capacity, and political interference accompanies project implementation. While the deterioration in the construction industry can be attributed to imported culture, it is noted that multi-national corporations (MNCs) and other foreign firms can be conduits for technology and knowledge (T&K) transfer to host countries in the developing world. Botswana with its free enterprise market and limited skill capacity and informed by the behaviour of construction industry role players, there is need for a structured integrity restoration process from both regulator and the operators. There is further need for a specific sector regulatory instrument (Act) to regulate the safety, health, and environmental operations in the construction industry. The construction industry also need to support research and development of the industry to be competitive both local and international.
- Full Text:
- Date Issued: 2018
The impact of the construction regulations 2014 on a water utility’s projects’ health and safety performance in South Africa
- Authors: Malindi, Rajandree Mandy
- Date: 2018
- Subjects: Construction industry -- Safety regulations -- South Africa , Construction industry -- Standards -- South Africa Construction industry -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/31655 , vital:31645
- Description: The construction industry plays a major role in South Africa’s economic development. Since promulgation of the Construction Regulations, the expectation is that project stakeholders are placing more emphasis on H&S to contribute to project success. The study aimed to assess the impact of the involvement of clients and other project stakeholders on the overall project H&S performance on projects undertaken by a large water utility. The scope was limited to the organisation’s engineering and operations division and its internal project stakeholders, namely the designers, quantity surveyors, project managers, and construction H&S professionals. Local literature pointed out that poor construction H&S performance is attributable to a lack of management commitment, inadequate supervision, inadequate or lack of H&S training, lack of worker involvement, personal risk appreciation and work pressures (cidb, 2009: 37). International literature indicated that the total CoA exceeds the cost of H&S (cidb, 2009: 9). Quantitative methods were utilised in two phases to gather and analyse data. In Phase 1, a questionnaire was developed and distributed to a target population, and in Phase 2, data was obtained from existing records of historic and completed project files for projects undertaken by the water utility. A total of 67 responses were used to analyse data. All stakeholders somehow contributed to H&S however, most respondents regarded CHS professionals, contractors and PMs as the primary stakeholders. The study found that stakeholders perceived H&S to be influenced during the later rather than the initial stages of projects and that H&S actions were significantly undertaken during stage 5. The frequency of H&S actions varied with each stakeholder dependent on the stage in which they were involved in. Recommendations were for H&S to be integrated in the initial stages of projects and for a follow up research to be conducted to investigate if there are improvements during the six project stages after full implementation of the Construction Regulations 2014. This requirement will force industry to comply and most importantly to drive joint efforts by the various stakeholders.
- Full Text:
- Date Issued: 2018
- Authors: Malindi, Rajandree Mandy
- Date: 2018
- Subjects: Construction industry -- Safety regulations -- South Africa , Construction industry -- Standards -- South Africa Construction industry -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/31655 , vital:31645
- Description: The construction industry plays a major role in South Africa’s economic development. Since promulgation of the Construction Regulations, the expectation is that project stakeholders are placing more emphasis on H&S to contribute to project success. The study aimed to assess the impact of the involvement of clients and other project stakeholders on the overall project H&S performance on projects undertaken by a large water utility. The scope was limited to the organisation’s engineering and operations division and its internal project stakeholders, namely the designers, quantity surveyors, project managers, and construction H&S professionals. Local literature pointed out that poor construction H&S performance is attributable to a lack of management commitment, inadequate supervision, inadequate or lack of H&S training, lack of worker involvement, personal risk appreciation and work pressures (cidb, 2009: 37). International literature indicated that the total CoA exceeds the cost of H&S (cidb, 2009: 9). Quantitative methods were utilised in two phases to gather and analyse data. In Phase 1, a questionnaire was developed and distributed to a target population, and in Phase 2, data was obtained from existing records of historic and completed project files for projects undertaken by the water utility. A total of 67 responses were used to analyse data. All stakeholders somehow contributed to H&S however, most respondents regarded CHS professionals, contractors and PMs as the primary stakeholders. The study found that stakeholders perceived H&S to be influenced during the later rather than the initial stages of projects and that H&S actions were significantly undertaken during stage 5. The frequency of H&S actions varied with each stakeholder dependent on the stage in which they were involved in. Recommendations were for H&S to be integrated in the initial stages of projects and for a follow up research to be conducted to investigate if there are improvements during the six project stages after full implementation of the Construction Regulations 2014. This requirement will force industry to comply and most importantly to drive joint efforts by the various stakeholders.
- Full Text:
- Date Issued: 2018
The implications of utilising small, medium and micro sized enterprises on construction projects
- Authors: Kampman, Juan
- Date: 2018
- Subjects: Small business -- South Africa , Construction industry -- Management Construction industry -- Economic aspects Construction industry -- Cost effectiveness
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/30698 , vital:31031
- Description: The National Development Plan envisages that eleven million jobs will be created in South Africa by small and medium enterprises (SME) by 2030. This vehicle aims to generate employment opportunities, redistribute income and contribute to poverty alleviation. This research highlights the main hurdles associated with the appointment of small, medium and micro-enterprise (SMME) contractors while providing recommendations geared towards the development of a sustainable industry. This study focuses on the cost, quality, programme, and health and safety implications of utilising SMMEs on construction projects. The study is seen from the perspective of the client’s representatives on construction projects and it focuses on South African National Roads Agency Limited (SANRAL) projects in the Eastern Cape. The respondents answered a structured web-based questionnaire which included open and closed questions. The research determined that in order to provide the best quality work, at the best price, on time, and in a safe manner, SMMEs who are employed on construction projects should be experienced or should be trained and mentored, or both. To ensure that SMMEs function at the required level with regard to the cost of their service, the quality of work, construction duration, and health and safety, it is fundamental to train and mentor the SMMEs. In order to assist SMMEs, they should be supported by providing construction material, the required tools, and personal protective equipment at the start of a project. It was proposed that SMME guidelines be drafted in order to standardise implementation methodologies which can be applied throughout the construction industry.
- Full Text:
- Date Issued: 2018
- Authors: Kampman, Juan
- Date: 2018
- Subjects: Small business -- South Africa , Construction industry -- Management Construction industry -- Economic aspects Construction industry -- Cost effectiveness
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/30698 , vital:31031
- Description: The National Development Plan envisages that eleven million jobs will be created in South Africa by small and medium enterprises (SME) by 2030. This vehicle aims to generate employment opportunities, redistribute income and contribute to poverty alleviation. This research highlights the main hurdles associated with the appointment of small, medium and micro-enterprise (SMME) contractors while providing recommendations geared towards the development of a sustainable industry. This study focuses on the cost, quality, programme, and health and safety implications of utilising SMMEs on construction projects. The study is seen from the perspective of the client’s representatives on construction projects and it focuses on South African National Roads Agency Limited (SANRAL) projects in the Eastern Cape. The respondents answered a structured web-based questionnaire which included open and closed questions. The research determined that in order to provide the best quality work, at the best price, on time, and in a safe manner, SMMEs who are employed on construction projects should be experienced or should be trained and mentored, or both. To ensure that SMMEs function at the required level with regard to the cost of their service, the quality of work, construction duration, and health and safety, it is fundamental to train and mentor the SMMEs. In order to assist SMMEs, they should be supported by providing construction material, the required tools, and personal protective equipment at the start of a project. It was proposed that SMME guidelines be drafted in order to standardise implementation methodologies which can be applied throughout the construction industry.
- Full Text:
- Date Issued: 2018
The machinability of rapidly solidified aluminium alloy for optical mould inserts
- Authors: Otieno, Timothy
- Date: 2018
- Subjects: Aluminum alloys , Automobiles -- Materials Materials -- Mechanical properties
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23097 , vital:30415
- Description: Ultra-high precision machining is a material removing process under the nanotechnology regime whereby the highest dimensional accuracies are attained. Critical components for optical devices and optical measuring systems are mainly produced through ultra-high precision machining. Their mass production is usually implemented by utilising optical moulds. Aluminium alloys have proven to be advantageous and very commonly used in the photonics industry for moulds. This ever-increasing use and demand within optics have led to the development of newly modified grades of aluminium alloys produced by rapid solidification in the foundry process. The newer grades are characterised by finer microstructures and improved mechanical and physical properties. The main inconvenience in their usage currently lies in their very limited machining database. This research investigates the machinability of rapidly solidified aluminium, RSA 905, under varying cutting conditions in single point diamond turning. The machining parameters varied were cutting speed, feed rate and depth of cut. The resulting surface roughness of the workpiece and wear of the diamond tool were measured at various intervals. Acoustic emissions and cutting force were also monitored during machining. The results were statistically analysed and accurate predictive models were developed. Generally, very low tool wear, within 3 to 5 μm, and very low surface roughness, within 3 to 8 nm, was obtained. Acoustic emissions recorded were in the range of 0.06 to 0.13 V and cutting forces were in the range of 0.08 to 0.94 N. The trends of the monitored acoustic emissions and cutting force showed to have a linked representation of the tool wear and surface roughness results. Contour maps were generated to identify zones where the cutting parameters produced the best results. In addition, a range of machining parameters were presented for optimum quality where surface roughness and tool wear can be minimised. As the machining is of a nanometric scale, a molecular dynamics approach was applied to investigate the underlying mechanisms at atom level. The nanomachining simulations were found to have a correlation to the actual machining results and microstructural nature of the alloy. This research proves that rapidly solidified aluminium is a superior alternative to traditional aluminium alloys and provides a good reference with room for flexibility that machinists can apply when using rapidly solidified aluminium alloys. Efficiency could be improved by reducing the required machining interruption through effective monitoring and performance could be improved by maintaining quality and extending tool life through parameter selection.
- Full Text:
- Date Issued: 2018
- Authors: Otieno, Timothy
- Date: 2018
- Subjects: Aluminum alloys , Automobiles -- Materials Materials -- Mechanical properties
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23097 , vital:30415
- Description: Ultra-high precision machining is a material removing process under the nanotechnology regime whereby the highest dimensional accuracies are attained. Critical components for optical devices and optical measuring systems are mainly produced through ultra-high precision machining. Their mass production is usually implemented by utilising optical moulds. Aluminium alloys have proven to be advantageous and very commonly used in the photonics industry for moulds. This ever-increasing use and demand within optics have led to the development of newly modified grades of aluminium alloys produced by rapid solidification in the foundry process. The newer grades are characterised by finer microstructures and improved mechanical and physical properties. The main inconvenience in their usage currently lies in their very limited machining database. This research investigates the machinability of rapidly solidified aluminium, RSA 905, under varying cutting conditions in single point diamond turning. The machining parameters varied were cutting speed, feed rate and depth of cut. The resulting surface roughness of the workpiece and wear of the diamond tool were measured at various intervals. Acoustic emissions and cutting force were also monitored during machining. The results were statistically analysed and accurate predictive models were developed. Generally, very low tool wear, within 3 to 5 μm, and very low surface roughness, within 3 to 8 nm, was obtained. Acoustic emissions recorded were in the range of 0.06 to 0.13 V and cutting forces were in the range of 0.08 to 0.94 N. The trends of the monitored acoustic emissions and cutting force showed to have a linked representation of the tool wear and surface roughness results. Contour maps were generated to identify zones where the cutting parameters produced the best results. In addition, a range of machining parameters were presented for optimum quality where surface roughness and tool wear can be minimised. As the machining is of a nanometric scale, a molecular dynamics approach was applied to investigate the underlying mechanisms at atom level. The nanomachining simulations were found to have a correlation to the actual machining results and microstructural nature of the alloy. This research proves that rapidly solidified aluminium is a superior alternative to traditional aluminium alloys and provides a good reference with room for flexibility that machinists can apply when using rapidly solidified aluminium alloys. Efficiency could be improved by reducing the required machining interruption through effective monitoring and performance could be improved by maintaining quality and extending tool life through parameter selection.
- Full Text:
- Date Issued: 2018
The role of psychosocial recuperative therapy in enhancing construction performance on projects
- Authors: Obiozo, Rita Ngozi
- Date: 2018
- Subjects: Building -- Psychological aspects , Construction industry -- Accidents Building -- Economic aspects Feng shui
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23080 , vital:30414
- Description: Research findings indicate that recent improvements in construction management initiatives have not substantially reduced the incidence of fatal occurrences and accidents in construction due to negligence and error. Some of the traumatic and causative factors include the dissipation of vital energy, health, safety, and wellbeing in the construction workforce due to the lack of contact with nature on construction sites, combined with the exhaustive nature of the work, and multiple stress factors in construction. The resultant effect is visible in the form of increased rework, disputes, and socio-psycho-traumatic factors that result in a reduction in profit margins due to the daily repetition of health and safety (H&S) hazards and quality errors. To address these issues there is a need for the exploration of the inherent potential to achieve exceptional environmental credentials on construction worksites attributable to the biophilic design concept of the intelligent construction workplace. This would involve the introduction of a biophilic construction site model (BCSM) that has the potential of establishing the continuous flow of natural energy that would replenish the vital life force and impact on the improvement of the performance of the construction workforce and management throughout the life cycle of the construction process. The objective of the initiative involves the introduction of dynamic harmonious energy in consonance with the theory of biophilia and feng shui principles of wellness interventions, which would introduce and enhance the flow of natural energy relative to the greening of construction sites in aid of H&S, wellbeing and human factors for ergonomics in construction. The methodology adopted, involved a survey of the related literature, and the triangulation and longitudinal assessment of multiple case studies of viable construction sites in progress. The applied technique included a greening construction site survey, interviews, observations, photo elicitation, questionnaire surveys, and a focus group study conducted with the construction workforce during the construction process. Findings indicate a potential increase in the level of sustainable behaviour in construction that impacts on the enhanced concentration and level of focus of the workforce, as well as a reduction in H&S and quality errors that militate against consistent improvement of the construction process. These efforts add value and novelty to the construction management body of knowledge (CMBOK) with regards to the green building construction and sustainable sites initiative. Research findings established the ‘greening of the construction site / biophilic construction site model (BCSM)’ as a cost-effective strategy towards the healing of the ‘sick construction site syndrome’ and the psychosocial recuperative and rejunative therapy for the workforce in construction for productive performance. It is significant and notable that the empirical findings relative to the BCSM strategy were found to substantiate effectively as the missing link in the establishment and reconstitution of Maslow’s hierarchy of needs, which according to research findings, is currently conceptual. The recommendations include the suggestions for the ‘informal dynamic rock garden design’ as suitable for the BCSM with the inclusion of ‘plants as a primary indicator’ in construction site premises, site offices, material sheds, welfare facilities including ‘lunch break retreats and outdoor shelters’. The recommendation of the BCSM strategy for the construction site is aimed towards the onset of construction as opposed to the conclusion of works / external works at the end of the project as is currently practiced. For effective application, the empirical findings relative to the study recommend that the procurement of the BCSM as a ‘silent and indispensable team mate’ should commence from the conceptual design, pre-bid / tender stages, to the fiscal planning and setting out of worksites, as well as its inclusion in the ‘curriculum of studies’ for the instruction of emerging construction management practitioners. In furtherance of the CMBOK and the enhancement of the BCSM strategy and the ‘humanistic value of the intelligent construction worksite’, the study recommends that the concept of ‘frozen music’ be addressed in future research relative to the ‘biophilic design concept’ to determine its role in enhancing cost effective performance, H&S, ergonomics, and the health and wellbeing of workers in construction.
- Full Text:
- Date Issued: 2018
- Authors: Obiozo, Rita Ngozi
- Date: 2018
- Subjects: Building -- Psychological aspects , Construction industry -- Accidents Building -- Economic aspects Feng shui
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23080 , vital:30414
- Description: Research findings indicate that recent improvements in construction management initiatives have not substantially reduced the incidence of fatal occurrences and accidents in construction due to negligence and error. Some of the traumatic and causative factors include the dissipation of vital energy, health, safety, and wellbeing in the construction workforce due to the lack of contact with nature on construction sites, combined with the exhaustive nature of the work, and multiple stress factors in construction. The resultant effect is visible in the form of increased rework, disputes, and socio-psycho-traumatic factors that result in a reduction in profit margins due to the daily repetition of health and safety (H&S) hazards and quality errors. To address these issues there is a need for the exploration of the inherent potential to achieve exceptional environmental credentials on construction worksites attributable to the biophilic design concept of the intelligent construction workplace. This would involve the introduction of a biophilic construction site model (BCSM) that has the potential of establishing the continuous flow of natural energy that would replenish the vital life force and impact on the improvement of the performance of the construction workforce and management throughout the life cycle of the construction process. The objective of the initiative involves the introduction of dynamic harmonious energy in consonance with the theory of biophilia and feng shui principles of wellness interventions, which would introduce and enhance the flow of natural energy relative to the greening of construction sites in aid of H&S, wellbeing and human factors for ergonomics in construction. The methodology adopted, involved a survey of the related literature, and the triangulation and longitudinal assessment of multiple case studies of viable construction sites in progress. The applied technique included a greening construction site survey, interviews, observations, photo elicitation, questionnaire surveys, and a focus group study conducted with the construction workforce during the construction process. Findings indicate a potential increase in the level of sustainable behaviour in construction that impacts on the enhanced concentration and level of focus of the workforce, as well as a reduction in H&S and quality errors that militate against consistent improvement of the construction process. These efforts add value and novelty to the construction management body of knowledge (CMBOK) with regards to the green building construction and sustainable sites initiative. Research findings established the ‘greening of the construction site / biophilic construction site model (BCSM)’ as a cost-effective strategy towards the healing of the ‘sick construction site syndrome’ and the psychosocial recuperative and rejunative therapy for the workforce in construction for productive performance. It is significant and notable that the empirical findings relative to the BCSM strategy were found to substantiate effectively as the missing link in the establishment and reconstitution of Maslow’s hierarchy of needs, which according to research findings, is currently conceptual. The recommendations include the suggestions for the ‘informal dynamic rock garden design’ as suitable for the BCSM with the inclusion of ‘plants as a primary indicator’ in construction site premises, site offices, material sheds, welfare facilities including ‘lunch break retreats and outdoor shelters’. The recommendation of the BCSM strategy for the construction site is aimed towards the onset of construction as opposed to the conclusion of works / external works at the end of the project as is currently practiced. For effective application, the empirical findings relative to the study recommend that the procurement of the BCSM as a ‘silent and indispensable team mate’ should commence from the conceptual design, pre-bid / tender stages, to the fiscal planning and setting out of worksites, as well as its inclusion in the ‘curriculum of studies’ for the instruction of emerging construction management practitioners. In furtherance of the CMBOK and the enhancement of the BCSM strategy and the ‘humanistic value of the intelligent construction worksite’, the study recommends that the concept of ‘frozen music’ be addressed in future research relative to the ‘biophilic design concept’ to determine its role in enhancing cost effective performance, H&S, ergonomics, and the health and wellbeing of workers in construction.
- Full Text:
- Date Issued: 2018
The use of building information modelling as a tool to improve informed design communication between student and lecturer during critique sessions
- Authors: Basson, Jean-Pierre
- Date: 2018
- Subjects: Building information modeling , Building -- Data processing Construction industry -- South Africa Construction projects -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/23680 , vital:30598
- Description: Within the design studio at the Department of Architecture, Nelson Mandela University, the timeous submission of design projects is a problem. After close inspection, it is noted that students spend weeks on conceptual design ideas with no progressions towards completion. The purpose of the study is thus to determine whether building information modelling (BIM), as opposed to the traditional method of design, can be used to improve informed design communication during conceptual design for the first-year master of architecture students and contribute to timeous design project submission. A cohort comparison rubric will be used as the method for looking at the qualitative attributes of design intention, function, aesthetics, and sustainability. The 2016 cohort made use of the traditional design method, whereas for the 2017 cohort the BIM course was introduced in the computer module with implementation in the design studio. The work of nine students from both cohorts was analysed and findings include the following: improved drawing type availability, accuracy, and quality; reduced time spent on redundant work; inclusive discussions compared to isolated critique sessions; reduced printing costs - and the establishment of “what if” scenarios early in the project. Based upon the research findings it can be concluded that BIM as a teaching strategy and process has the capability of improving the communication between student and lecturer in the conceptual stage, thereby leading to a more timeous submission. It is recommended that BIM education must be incorporated in the undergraduate programme thereby providing students with an appropriate platform for expressing conceptual ideas more effectively within the design course.
- Full Text:
- Date Issued: 2018
- Authors: Basson, Jean-Pierre
- Date: 2018
- Subjects: Building information modeling , Building -- Data processing Construction industry -- South Africa Construction projects -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/23680 , vital:30598
- Description: Within the design studio at the Department of Architecture, Nelson Mandela University, the timeous submission of design projects is a problem. After close inspection, it is noted that students spend weeks on conceptual design ideas with no progressions towards completion. The purpose of the study is thus to determine whether building information modelling (BIM), as opposed to the traditional method of design, can be used to improve informed design communication during conceptual design for the first-year master of architecture students and contribute to timeous design project submission. A cohort comparison rubric will be used as the method for looking at the qualitative attributes of design intention, function, aesthetics, and sustainability. The 2016 cohort made use of the traditional design method, whereas for the 2017 cohort the BIM course was introduced in the computer module with implementation in the design studio. The work of nine students from both cohorts was analysed and findings include the following: improved drawing type availability, accuracy, and quality; reduced time spent on redundant work; inclusive discussions compared to isolated critique sessions; reduced printing costs - and the establishment of “what if” scenarios early in the project. Based upon the research findings it can be concluded that BIM as a teaching strategy and process has the capability of improving the communication between student and lecturer in the conceptual stage, thereby leading to a more timeous submission. It is recommended that BIM education must be incorporated in the undergraduate programme thereby providing students with an appropriate platform for expressing conceptual ideas more effectively within the design course.
- Full Text:
- Date Issued: 2018
Understanding factors that influence the acceptance of electronic medical records by nurses in hospitals: a framework
- Authors: Makalima, Melissa
- Date: 2018
- Subjects: Electronic records -- Management , Information storage and retrieval systems -- Management Medical records -- South Africa Medical records -- Data processing
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/31488 , vital:31495
- Description: Globally, unlike in the past, it is rare for a patient to consult the same healthcare provider throughout his or her lifetime. However, this makes it difficult to maintain informational continuity of care. Researchers have confirmed that paper-based methods of record keeping do not meet the needs of informational continuity of care. As a result, the popularity of electronic means of recordkeeping, specifically, electronic medical records (EMRs), is growing. However, the implementation of EMRs in hospitals is not without challenges with these challenges playing a significant role in the failure of EMRs. One such challenge is a lack of user acceptance. Research reveals that nurses comprise the largest user group of EMRs in the hospital setting. However, there is inadequate literature that focuses on the factors contributing to EMR acceptance with nurses as the user group. Hence, the main problem addressed in this research study relates to the inadequate understanding of the factors that influence the acceptance of EMRs by nurses. In order to address this problem, a literature review and a case study were conducted to ascertain and investigate the factors that influence the acceptance of EMRs by nurses. A total of 39 factors were formulated. Subsequent to the formulation of these factors, knowledge on the impact of each factor on EMR acceptance was collected. Socio-technical Systems Theory (STS) was used as a theoretical lens through which to view the resulting factors. The STS dimension from which each factor originates as well as the STS dimension influenced by the factor were identified. The analysis of the different stages of acceptance as well as the STS analysis resulted in a framework that could play an important role in providing a better understanding of EMR acceptance by nurses in hospitals. It was anticipated that this study would contribute to a better understanding of the factors that hospitals should address in order to create a conducive environment for EMR acceptance by nurses within the hospitals.
- Full Text:
- Date Issued: 2018
- Authors: Makalima, Melissa
- Date: 2018
- Subjects: Electronic records -- Management , Information storage and retrieval systems -- Management Medical records -- South Africa Medical records -- Data processing
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/31488 , vital:31495
- Description: Globally, unlike in the past, it is rare for a patient to consult the same healthcare provider throughout his or her lifetime. However, this makes it difficult to maintain informational continuity of care. Researchers have confirmed that paper-based methods of record keeping do not meet the needs of informational continuity of care. As a result, the popularity of electronic means of recordkeeping, specifically, electronic medical records (EMRs), is growing. However, the implementation of EMRs in hospitals is not without challenges with these challenges playing a significant role in the failure of EMRs. One such challenge is a lack of user acceptance. Research reveals that nurses comprise the largest user group of EMRs in the hospital setting. However, there is inadequate literature that focuses on the factors contributing to EMR acceptance with nurses as the user group. Hence, the main problem addressed in this research study relates to the inadequate understanding of the factors that influence the acceptance of EMRs by nurses. In order to address this problem, a literature review and a case study were conducted to ascertain and investigate the factors that influence the acceptance of EMRs by nurses. A total of 39 factors were formulated. Subsequent to the formulation of these factors, knowledge on the impact of each factor on EMR acceptance was collected. Socio-technical Systems Theory (STS) was used as a theoretical lens through which to view the resulting factors. The STS dimension from which each factor originates as well as the STS dimension influenced by the factor were identified. The analysis of the different stages of acceptance as well as the STS analysis resulted in a framework that could play an important role in providing a better understanding of EMR acceptance by nurses in hospitals. It was anticipated that this study would contribute to a better understanding of the factors that hospitals should address in order to create a conducive environment for EMR acceptance by nurses within the hospitals.
- Full Text:
- Date Issued: 2018
Use of recycled rubber tyres as an alternative ingredient in cementitious building materials
- Authors: Yuill, Robert Mark
- Date: 2018
- Subjects: Building materials , Building materials -- Environmental aspects Sustainable construction Recycled products
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/29783 , vital:30777
- Description: The need to incorporate recycled materials in building products is becoming more important than ever before. There is an abundance of waste rubber tyres which in turn results in a waste management issue. The use of waste rubber tyres in cementitious building material provides a possible solution to the problem (Kathomi, 2009:10). Previous research has shown the introduction of recycled rubber tyre crumb can improve the durability, thermal and acoustic performance in residential and commercial buildings. This could result in lives of dwellers in concrete block buildings in South Africa improving due to these characteristics whilst potentially creating a cost-effective, sustainable building material. A grading analysis, loose and compacted bulk densities and relative densities were determined to provide a mix design. Three tests were conducted for this study namely compressive strength, fire and thermal performance and acoustic performance. The testing was conducted on 100mmx100mm cubes at varying rubber replacement percentages. The replacement values were 10%, 20% and 30% tested against a control of ordinary concrete. The waste rubber crumb was a replacement for sand. The research of this study showed 20 % decrease of compression strength at 10 % rubber replacement compared to the control, 55 % decrease at 20 % rubber replacement and 75% decrease at 30 % rubber replacement. The thermal performance test showed a 24 % lower temperature for 10 % rubber replacement compared to the control, 39 % lower temperature at 20 % rubber replacement and 52 % lower temperature at 30 % rubber replacement. All rubber replacement % samples and the control performed adequately in the flame resistance test. The smoke density test showed that all rubber replacement % samples did not release a quantity of smoke which would be deemed dangerous. The acoustic performance test showed the values at 10% rubber replacement was 6 % lower; at 20% rubber replacement; 4% lower and at 30% rubber replacement 14 % lower. Based on these results, the acoustic performance regarding transmission increases with a rubber replacement % higher than 20 %.
- Full Text:
- Date Issued: 2018
- Authors: Yuill, Robert Mark
- Date: 2018
- Subjects: Building materials , Building materials -- Environmental aspects Sustainable construction Recycled products
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/29783 , vital:30777
- Description: The need to incorporate recycled materials in building products is becoming more important than ever before. There is an abundance of waste rubber tyres which in turn results in a waste management issue. The use of waste rubber tyres in cementitious building material provides a possible solution to the problem (Kathomi, 2009:10). Previous research has shown the introduction of recycled rubber tyre crumb can improve the durability, thermal and acoustic performance in residential and commercial buildings. This could result in lives of dwellers in concrete block buildings in South Africa improving due to these characteristics whilst potentially creating a cost-effective, sustainable building material. A grading analysis, loose and compacted bulk densities and relative densities were determined to provide a mix design. Three tests were conducted for this study namely compressive strength, fire and thermal performance and acoustic performance. The testing was conducted on 100mmx100mm cubes at varying rubber replacement percentages. The replacement values were 10%, 20% and 30% tested against a control of ordinary concrete. The waste rubber crumb was a replacement for sand. The research of this study showed 20 % decrease of compression strength at 10 % rubber replacement compared to the control, 55 % decrease at 20 % rubber replacement and 75% decrease at 30 % rubber replacement. The thermal performance test showed a 24 % lower temperature for 10 % rubber replacement compared to the control, 39 % lower temperature at 20 % rubber replacement and 52 % lower temperature at 30 % rubber replacement. All rubber replacement % samples and the control performed adequately in the flame resistance test. The smoke density test showed that all rubber replacement % samples did not release a quantity of smoke which would be deemed dangerous. The acoustic performance test showed the values at 10% rubber replacement was 6 % lower; at 20% rubber replacement; 4% lower and at 30% rubber replacement 14 % lower. Based on these results, the acoustic performance regarding transmission increases with a rubber replacement % higher than 20 %.
- Full Text:
- Date Issued: 2018