A model for information security management and regulatory compliance in the South African health sector
- Authors: Tuyikeze, Tite
- Date: 2005
- Subjects: Computer networks -- Security measures , Public health -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9740 , http://hdl.handle.net/10948/425 , Computer networks -- Security measures , Public health -- South Africa
- Description: Information Security is becoming a part of the core business processes in every organization. Companies are faced with contradictory requirements to ensure open systems and accessible information while maintaining high protection standards. In addition, the contemporary management of Information Security requires a variety of approaches in different areas, ranging from technological to organizational issues and legislation. These approaches are often isolated while Security Management requires an integrated approach. Information Technology promises many benefits to healthcare organizations. It helps to make accurate information more readily available to healthcare providers and workers, researchers and patients and advanced computing and communication technology can improve the quality and lower the costs of healthcare. However, the prospect of storing health information in an electronic form raises concerns about patient privacy and security. Healthcare organizations are required to establish formal Information Security program, for example through the adoption of the ISO 17799 standard, to ensure an appropriate and consistent level of information security for computer-based patient records, both within individual healthcare organizations and throughout the entire healthcare delivery system. However, proper Information Security Management practices, alone, do not necessarily ensure regulatory compliance. South African healthcare organizations must comply with the South African National Health Act (SANHA) and the Electronic Communication Transaction Act (ECTA). It is necessary to consider compliance with the Health Insurance Portability and Accountability Act (HIPAA) to meet healthcare international industry standards. The main purpose of this project is to propose a compliance strategy, which ensures full compliance with regulatory requirements and at the same time assures customers that international industry standards are being used. This is preceded by a comparative analysis of the requirements posed by the ISO 17799 standard and the HIPAA, SANHA and ECTA regulations.
- Full Text:
- Date Issued: 2005
- Authors: Tuyikeze, Tite
- Date: 2005
- Subjects: Computer networks -- Security measures , Public health -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9740 , http://hdl.handle.net/10948/425 , Computer networks -- Security measures , Public health -- South Africa
- Description: Information Security is becoming a part of the core business processes in every organization. Companies are faced with contradictory requirements to ensure open systems and accessible information while maintaining high protection standards. In addition, the contemporary management of Information Security requires a variety of approaches in different areas, ranging from technological to organizational issues and legislation. These approaches are often isolated while Security Management requires an integrated approach. Information Technology promises many benefits to healthcare organizations. It helps to make accurate information more readily available to healthcare providers and workers, researchers and patients and advanced computing and communication technology can improve the quality and lower the costs of healthcare. However, the prospect of storing health information in an electronic form raises concerns about patient privacy and security. Healthcare organizations are required to establish formal Information Security program, for example through the adoption of the ISO 17799 standard, to ensure an appropriate and consistent level of information security for computer-based patient records, both within individual healthcare organizations and throughout the entire healthcare delivery system. However, proper Information Security Management practices, alone, do not necessarily ensure regulatory compliance. South African healthcare organizations must comply with the South African National Health Act (SANHA) and the Electronic Communication Transaction Act (ECTA). It is necessary to consider compliance with the Health Insurance Portability and Accountability Act (HIPAA) to meet healthcare international industry standards. The main purpose of this project is to propose a compliance strategy, which ensures full compliance with regulatory requirements and at the same time assures customers that international industry standards are being used. This is preceded by a comparative analysis of the requirements posed by the ISO 17799 standard and the HIPAA, SANHA and ECTA regulations.
- Full Text:
- Date Issued: 2005
A SOAP-based Model for secure messaging in a global context
- Authors: Van Eeden, Johannes Jurie
- Date: 2005
- Subjects: Telecommunication systems -- Security measures
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9777 , http://hdl.handle.net/10948/817 , Telecommunication systems -- Security measures
- Description: For integration between application-systems in a global context, interoperability needs to be established on a global level; global interoperability, in turn, is based on a global common application-interface. This is achieved through resolving differences in, inter alia, protocol profiles, among participants in the global network. ebXML is used as the point of departure. A messaging framework, which is based on existing Web technology and standards, is proposed. Certain security and Web service standards are examined to determine specific parameters for an interoperable secure messaging environment. A security based framework comprising a predefined message format and architecture is investigated for a secure interoperable global electronic marketspace.
- Full Text:
- Date Issued: 2005
- Authors: Van Eeden, Johannes Jurie
- Date: 2005
- Subjects: Telecommunication systems -- Security measures
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9777 , http://hdl.handle.net/10948/817 , Telecommunication systems -- Security measures
- Description: For integration between application-systems in a global context, interoperability needs to be established on a global level; global interoperability, in turn, is based on a global common application-interface. This is achieved through resolving differences in, inter alia, protocol profiles, among participants in the global network. ebXML is used as the point of departure. A messaging framework, which is based on existing Web technology and standards, is proposed. Certain security and Web service standards are examined to determine specific parameters for an interoperable secure messaging environment. A security based framework comprising a predefined message format and architecture is investigated for a secure interoperable global electronic marketspace.
- Full Text:
- Date Issued: 2005
Applying a framework for IT governance in South African higher education institutions
- Authors: Viljoen, Stephen
- Date: 2005
- Subjects: Computer security , Universities and colleges -- Computer networks -- Security measures -- South Africa , Data protection
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9739 , http://hdl.handle.net/10948/416 , Computer security , Universities and colleges -- Computer networks -- Security measures -- South Africa , Data protection
- Description: Background: Higher Education (HE), through HE Institutions, plays a very important role in society. There is thus a need for this sector to be well managed, especially with regards to planning, organising, and controlling. Corporate Governance has received a lot of attention in recent times, especially to engender trust on the part of the stakeholders. There are many similarities, but also significant differences in the governance of HE institutions and public companies. Information Technology (IT) plays an extremely important role in the modern organisation, creating huge opportunities, but also increasing the risk to the organisation. Therefore, effective governance of IT in HE Institutions is of great importance.
- Full Text:
- Date Issued: 2005
- Authors: Viljoen, Stephen
- Date: 2005
- Subjects: Computer security , Universities and colleges -- Computer networks -- Security measures -- South Africa , Data protection
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9739 , http://hdl.handle.net/10948/416 , Computer security , Universities and colleges -- Computer networks -- Security measures -- South Africa , Data protection
- Description: Background: Higher Education (HE), through HE Institutions, plays a very important role in society. There is thus a need for this sector to be well managed, especially with regards to planning, organising, and controlling. Corporate Governance has received a lot of attention in recent times, especially to engender trust on the part of the stakeholders. There are many similarities, but also significant differences in the governance of HE institutions and public companies. Information Technology (IT) plays an extremely important role in the modern organisation, creating huge opportunities, but also increasing the risk to the organisation. Therefore, effective governance of IT in HE Institutions is of great importance.
- Full Text:
- Date Issued: 2005
Development and analysis of a friction stir spot welding process for aluminium
- Authors: Stephen, Michael George
- Date: 2005
- Subjects: Friction welding , Electric welding , Aluminum alloys -- Welding
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9631 , http://hdl.handle.net/10948/1351 , Friction welding , Electric welding , Aluminum alloys -- Welding
- Description: Friction Stir Spot Welding (FSSW) has been developed from the conventional Friction Stir Welding (FSW) process, developed at The Welding Institute (TWI). FSSWs have been done without the keyhole being eliminated. Elimination of the keyhole would result in the process being more commercially viable. This dissertation focuses on an attempt of eliminating the keyhole using a retractable pin tool as well as a comparison of the weld integrity of a FSSW to that of a conventional Resistance Spot Weld (RSW). Welds were conducted on aluminium alloy 6063 T4. Comparisons between different weld procedures were done. Further analysis of the weld integrity between FSSW and RSW were conducted, comparing tensile strengths, microstructure and hardness. For the above welding procedure to take place, the current retractable pin tool, patented by PE Technikon, was redesigned. Problems associated during the welding process and the results obtained are documented. Reasons for the keyhole not being eliminated as well as recommendations for future work in the attempt to remove the keyhole are discussed.
- Full Text:
- Date Issued: 2005
- Authors: Stephen, Michael George
- Date: 2005
- Subjects: Friction welding , Electric welding , Aluminum alloys -- Welding
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9631 , http://hdl.handle.net/10948/1351 , Friction welding , Electric welding , Aluminum alloys -- Welding
- Description: Friction Stir Spot Welding (FSSW) has been developed from the conventional Friction Stir Welding (FSW) process, developed at The Welding Institute (TWI). FSSWs have been done without the keyhole being eliminated. Elimination of the keyhole would result in the process being more commercially viable. This dissertation focuses on an attempt of eliminating the keyhole using a retractable pin tool as well as a comparison of the weld integrity of a FSSW to that of a conventional Resistance Spot Weld (RSW). Welds were conducted on aluminium alloy 6063 T4. Comparisons between different weld procedures were done. Further analysis of the weld integrity between FSSW and RSW were conducted, comparing tensile strengths, microstructure and hardness. For the above welding procedure to take place, the current retractable pin tool, patented by PE Technikon, was redesigned. Problems associated during the welding process and the results obtained are documented. Reasons for the keyhole not being eliminated as well as recommendations for future work in the attempt to remove the keyhole are discussed.
- Full Text:
- Date Issued: 2005
Establishing an information security culture in organizations : an outcomes based education approach
- Van Niekerk, Johannes Frederick
- Authors: Van Niekerk, Johannes Frederick
- Date: 2005
- Subjects: Computer security , Management information systems -- Security measures , Competency-based education
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9742 , http://hdl.handle.net/10948/164 , Computer security , Management information systems -- Security measures , Competency-based education
- Description: Information security is crucial to the continuous well-being of modern orga- nizations. Humans play a signfiicant role in the processes needed to secure an organization's information resources. Without an adequate level of user co-operation and knowledge, many security techniques are liable to be misused or misinterpreted by users. This may result in an adequate security measure becoming inadequate. It is therefor necessary to educate the orga- nization's employees regarding information security and also to establish a corporate sub-culture of information security in the organization, which will ensure that the employees have the correct attitude towards their security responsibilities. Current information security education programs fails to pay su±cient attention to the behavioral sciences. There also exist a lack of knowledge regarding the principles, and processes, that would be needed for the establishment of an corporate sub-culture, specific to information security. Without both the necessary knowledge, and the desired attitude amongst the employee, it will be impossible to guarantee that the organi- zation's information resources are secure. It would therefor make sense to address both these dimensions to the human factor in information security, using a single integrated, holistic approach. This dissertation presents such an approach, which is based on an integration of sound behavioral theories.
- Full Text:
- Date Issued: 2005
Establishing an information security culture in organizations : an outcomes based education approach
- Authors: Van Niekerk, Johannes Frederick
- Date: 2005
- Subjects: Computer security , Management information systems -- Security measures , Competency-based education
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9742 , http://hdl.handle.net/10948/164 , Computer security , Management information systems -- Security measures , Competency-based education
- Description: Information security is crucial to the continuous well-being of modern orga- nizations. Humans play a signfiicant role in the processes needed to secure an organization's information resources. Without an adequate level of user co-operation and knowledge, many security techniques are liable to be misused or misinterpreted by users. This may result in an adequate security measure becoming inadequate. It is therefor necessary to educate the orga- nization's employees regarding information security and also to establish a corporate sub-culture of information security in the organization, which will ensure that the employees have the correct attitude towards their security responsibilities. Current information security education programs fails to pay su±cient attention to the behavioral sciences. There also exist a lack of knowledge regarding the principles, and processes, that would be needed for the establishment of an corporate sub-culture, specific to information security. Without both the necessary knowledge, and the desired attitude amongst the employee, it will be impossible to guarantee that the organi- zation's information resources are secure. It would therefor make sense to address both these dimensions to the human factor in information security, using a single integrated, holistic approach. This dissertation presents such an approach, which is based on an integration of sound behavioral theories.
- Full Text:
- Date Issued: 2005
Introducing hippocratic log files for personal privacy control
- Authors: Rutherford, Andrew
- Date: 2005
- Subjects: Computer security , Internet -- Security measures
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9743 , http://hdl.handle.net/10948/171 , Computer security , Internet -- Security measures
- Description: The rapid growth of the Internet has served to intensify existing privacy concerns of the individual, to the point that privacy is the number one concern amongst Internet users today. Tools exist that can provide users with a choice of anonymity or pseudonymity. However, many Web transactions require the release of personally identifying information, thus rendering such tools infeasible in many instances. Since it is then a given that users are often required to release personal information, which could be recorded, it follows that they require a greater degree of control over the information they release. Hippocratic databases, designed by Agrawal, Kiernan, Srikant, and Xu (2002), aim to give users greater control over information stored in a data- base. Their design was inspired by the medical Hippocratic oath, and makes data privacy protection a fundamental responsibility of the database itself. To achieve the privacy of data, Hippocratic databases are governed by 10 key privacy principles. This dissertation argues, that asides from a few challenges, the 10 prin- ciples of Hippocratic databases can be applied to log ¯les. This argument is supported by presenting a high-level functional view of a Hippocratic log file architecture. This architecture focuses on issues that highlight the con- trol users gain over their personal information that is collected in log files. By presenting a layered view of the aforementioned architecture, it was, fur- thermore, possible to provide greater insight into the major processes that would be at work in a Hippocratic log file implementation. An exploratory prototype served to understand and demonstrate certain of the architectural components of Hippocratic log files. This dissertation, thus, makes a contribution to the ideal of providing users with greater control over their personal information, by proposing the use of Hippocratic logfiles.
- Full Text:
- Date Issued: 2005
- Authors: Rutherford, Andrew
- Date: 2005
- Subjects: Computer security , Internet -- Security measures
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9743 , http://hdl.handle.net/10948/171 , Computer security , Internet -- Security measures
- Description: The rapid growth of the Internet has served to intensify existing privacy concerns of the individual, to the point that privacy is the number one concern amongst Internet users today. Tools exist that can provide users with a choice of anonymity or pseudonymity. However, many Web transactions require the release of personally identifying information, thus rendering such tools infeasible in many instances. Since it is then a given that users are often required to release personal information, which could be recorded, it follows that they require a greater degree of control over the information they release. Hippocratic databases, designed by Agrawal, Kiernan, Srikant, and Xu (2002), aim to give users greater control over information stored in a data- base. Their design was inspired by the medical Hippocratic oath, and makes data privacy protection a fundamental responsibility of the database itself. To achieve the privacy of data, Hippocratic databases are governed by 10 key privacy principles. This dissertation argues, that asides from a few challenges, the 10 prin- ciples of Hippocratic databases can be applied to log ¯les. This argument is supported by presenting a high-level functional view of a Hippocratic log file architecture. This architecture focuses on issues that highlight the con- trol users gain over their personal information that is collected in log files. By presenting a layered view of the aforementioned architecture, it was, fur- thermore, possible to provide greater insight into the major processes that would be at work in a Hippocratic log file implementation. An exploratory prototype served to understand and demonstrate certain of the architectural components of Hippocratic log files. This dissertation, thus, makes a contribution to the ideal of providing users with greater control over their personal information, by proposing the use of Hippocratic logfiles.
- Full Text:
- Date Issued: 2005
Investigation of the effect of selected polypropylene fibres and ultra-fine aggregate on plastic shrinkage cracks on South African roads
- Authors: Kluyts, Grant
- Date: 2005
- Subjects: Concrete roads -- South Africa -- Design and construction , Fiber-reinforced concrete , Reinforced concrete -- Cracking , Concrete -- Expansion and contraction , Polypropylene fibers
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9592 , http://hdl.handle.net/10948/174 , Concrete roads -- South Africa -- Design and construction , Fiber-reinforced concrete , Reinforced concrete -- Cracking , Concrete -- Expansion and contraction , Polypropylene fibers
- Description: Plastic shrinkage cracks, although not inherently structurally debilitating, expose the reinforcement in low-volume reinforced concrete roads to deleterious substances, which may reduce its effectiveness leading ultimately to structural failure. In un-reinforced low-volume concrete road these cracks appear unsightly and cause the road user an unpleasant riding experience. Many researchers believe that plastic shrinkage crack development remains a concern to the concrete industry, occurring in particularly large–area pours such as low-volume concrete roads, and therefore requires further research to understand their formation and minimization. This study reports findings on the effectiveness of oxyfluorinated polypropylene fibres to control plastic shrinkage cracks, and the effect the addition of ultra-fine material has on the formation and/or propagation of these cracks. Findings indicate that low volume dosages (2 kg/m³), of oxyfluorinated polypropylene fibre significantly reduced the formation of plastic shrinkage cracks under test conditions. Furthermore, that the addition of ultra-fine material in excess of 63 kg/m³ increased the formation and/or development of plastic shrinkage cracks.
- Full Text:
- Date Issued: 2005
- Authors: Kluyts, Grant
- Date: 2005
- Subjects: Concrete roads -- South Africa -- Design and construction , Fiber-reinforced concrete , Reinforced concrete -- Cracking , Concrete -- Expansion and contraction , Polypropylene fibers
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9592 , http://hdl.handle.net/10948/174 , Concrete roads -- South Africa -- Design and construction , Fiber-reinforced concrete , Reinforced concrete -- Cracking , Concrete -- Expansion and contraction , Polypropylene fibers
- Description: Plastic shrinkage cracks, although not inherently structurally debilitating, expose the reinforcement in low-volume reinforced concrete roads to deleterious substances, which may reduce its effectiveness leading ultimately to structural failure. In un-reinforced low-volume concrete road these cracks appear unsightly and cause the road user an unpleasant riding experience. Many researchers believe that plastic shrinkage crack development remains a concern to the concrete industry, occurring in particularly large–area pours such as low-volume concrete roads, and therefore requires further research to understand their formation and minimization. This study reports findings on the effectiveness of oxyfluorinated polypropylene fibres to control plastic shrinkage cracks, and the effect the addition of ultra-fine material has on the formation and/or propagation of these cracks. Findings indicate that low volume dosages (2 kg/m³), of oxyfluorinated polypropylene fibre significantly reduced the formation of plastic shrinkage cracks under test conditions. Furthermore, that the addition of ultra-fine material in excess of 63 kg/m³ increased the formation and/or development of plastic shrinkage cracks.
- Full Text:
- Date Issued: 2005
A flexible vehicle measurement system for modern automobile production
- Authors: Lichtenberg, Thilo
- Subjects: Automobile industry and trade -- Quality control -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9632 , http://hdl.handle.net/10948/546 , Automobile industry and trade -- Quality control -- South Africa
- Description: To stay competitive and to be able to sell high-class products in the modern automobile production it is absolutely necessary to check the quality standard of a manufactured vehicle. The normal measurement strategy to check the quality standard of a completely assembled car is through a complex measurement strategy whilst the vehicle is in the actual series production. This is an immensely time and money consuming process. Furthermore, measurement systems are fixed within a certain position and the flexible measurement of a produced vehicle is very difficult to realize. This project presents a measurement system compliant to all quality guidelines, with which it is possible to measure any mounted component from a completely assembled vehicle wherever and whenever required. For the first time it is possible to measure the vehicle quality and dimensional standard from the first body in white prototype assembled in production up to the completely assembled vehicle delivered to the customer. The result of this project is a measurement system that consists of a hardware tool and a specially programmed software add-on. The complete system could easily be carried to the vehicle that must be analysed. This gives a lot of advantages. Furthermore it is possible to use this developed technology for the whole Volkswagen Company including the other brands like Audi, Skoda and Seat.
- Full Text:
- Authors: Lichtenberg, Thilo
- Subjects: Automobile industry and trade -- Quality control -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9632 , http://hdl.handle.net/10948/546 , Automobile industry and trade -- Quality control -- South Africa
- Description: To stay competitive and to be able to sell high-class products in the modern automobile production it is absolutely necessary to check the quality standard of a manufactured vehicle. The normal measurement strategy to check the quality standard of a completely assembled car is through a complex measurement strategy whilst the vehicle is in the actual series production. This is an immensely time and money consuming process. Furthermore, measurement systems are fixed within a certain position and the flexible measurement of a produced vehicle is very difficult to realize. This project presents a measurement system compliant to all quality guidelines, with which it is possible to measure any mounted component from a completely assembled vehicle wherever and whenever required. For the first time it is possible to measure the vehicle quality and dimensional standard from the first body in white prototype assembled in production up to the completely assembled vehicle delivered to the customer. The result of this project is a measurement system that consists of a hardware tool and a specially programmed software add-on. The complete system could easily be carried to the vehicle that must be analysed. This gives a lot of advantages. Furthermore it is possible to use this developed technology for the whole Volkswagen Company including the other brands like Audi, Skoda and Seat.
- Full Text:
Applications of thermal spray technology for surface protection
- Authors: Gorlach, I A
- Subjects: Metal spraying , Surfaces (Technology)
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/21866 , vital:29795
- Description: With the rapid development of modern industry, the quality of surfaces of structures, products and components is important in terms of many aspects such as efficiency, reliability, appearance, maintenance costs and economy. A local failure on the surface usually causes the entire component to be rejected or it may lead to a failure of a machine or structure. It is estimated that in developed countries, the loss caused by corrosion is up to 2-4% of gross national product [1]. Thus, many countries have made great efforts to improve the surface performance of parts in order to enhance the reliability of mechanical equipment and prolong their service life.
- Full Text: false
- Authors: Gorlach, I A
- Subjects: Metal spraying , Surfaces (Technology)
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/21866 , vital:29795
- Description: With the rapid development of modern industry, the quality of surfaces of structures, products and components is important in terms of many aspects such as efficiency, reliability, appearance, maintenance costs and economy. A local failure on the surface usually causes the entire component to be rejected or it may lead to a failure of a machine or structure. It is estimated that in developed countries, the loss caused by corrosion is up to 2-4% of gross national product [1]. Thus, many countries have made great efforts to improve the surface performance of parts in order to enhance the reliability of mechanical equipment and prolong their service life.
- Full Text: false
Characterization of friction hydro pillar process weld properties as applied to 10CrMo910 creep resistant steel for application in the power generation Industry
- Authors: Bulbring, Daniel Louis Hans
- Subjects: Materials -- Creep , Friction welding
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9636 , http://hdl.handle.net/10948/d1020586
- Description: Creep degradation of steam carrying vessels in the power generation industry is a concern that needs to be constantly monitored. The Weldcore® process has been earmarked as a potential method of creep sampling which will allow for thick-walled sections to be analysed. A component of the process involves plugging the resultant hole after removing a creep sample using a novel welding technique called friction hydro pillar processing. At the commencement of this study, insufficient data was available to warrant safe industrial application of the process. This research was conducted to evaluate the performance of 10CrMo910 friction hydro pillar process welds. The effects of downward force, stud taper angle, hole taper angle and hole base diameter on process response, defect population, static properties and dynamic performance were evaluated. The variation of downward force showed that higher forces produce significantly smaller defects and higher fatigue life. The occurrence of defects was linked to process parameters and geometry thereby identifying the correct parameters for safe use in the power generation industry. Flash formation was identified as an early indicator of weld defects and can assist with quality control in industrial applications. Methods of standardising the plunge depth and forge force were developed to identify the correct magnitudes for different geometries, without the need for testing. Defects were shown to populate specific regions of the weld and produce variations in fatigue life. Crack initiation sites were detected which will aid in identifying areas of focus in further research and development. Temperature measurements were linked to the occurrence of defects and crack initiation sites and have been identified as a method of identifying defective welds. The effects of process parameters and stud and hole taper angles on energy inputs and near interface temperatures were statistically evaluated. Downward force was shown to have the largest effect on energy input rates, total energy input and temperatures at the 11.5mm and 20.5mm positions. Smaller hole and stud taper angles produced lower energy inputs and were identified as more energy efficient than the larger taper angles. A regression model was also developed to predict the fatigue life of welds and can assist with critical process related decision making. A range of hole base diameters were identified which produced welds with low defect populations and fatigue performance similar to that of the parent plate. Larger hole base diameters were shown to produce significant defects along the hole bottom fillet, in the weld nugget and along the bond line. Temperature measurements of the larger diameter welds showed a delay in response and are attributed to a delayed contact of plasticised stud material with the sidewall. Welds with hole base diameters larger than 11mm produced unrepeatable and defective welds, and also required higher energy inputs making smaller diameters more desirable. Analysis of all welds in this study revealed that clearance and interfacial pressures characterise the quality of friction hydro pillar process welds, therefore models were developed to aid in critical decision making with respect to downward force and geometry. This study has successfully evaluated the effects of process parameters and geometry on the properties of friction hydro pillar process welds and thereby has increased understanding of the process.
- Full Text:
- Authors: Bulbring, Daniel Louis Hans
- Subjects: Materials -- Creep , Friction welding
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9636 , http://hdl.handle.net/10948/d1020586
- Description: Creep degradation of steam carrying vessels in the power generation industry is a concern that needs to be constantly monitored. The Weldcore® process has been earmarked as a potential method of creep sampling which will allow for thick-walled sections to be analysed. A component of the process involves plugging the resultant hole after removing a creep sample using a novel welding technique called friction hydro pillar processing. At the commencement of this study, insufficient data was available to warrant safe industrial application of the process. This research was conducted to evaluate the performance of 10CrMo910 friction hydro pillar process welds. The effects of downward force, stud taper angle, hole taper angle and hole base diameter on process response, defect population, static properties and dynamic performance were evaluated. The variation of downward force showed that higher forces produce significantly smaller defects and higher fatigue life. The occurrence of defects was linked to process parameters and geometry thereby identifying the correct parameters for safe use in the power generation industry. Flash formation was identified as an early indicator of weld defects and can assist with quality control in industrial applications. Methods of standardising the plunge depth and forge force were developed to identify the correct magnitudes for different geometries, without the need for testing. Defects were shown to populate specific regions of the weld and produce variations in fatigue life. Crack initiation sites were detected which will aid in identifying areas of focus in further research and development. Temperature measurements were linked to the occurrence of defects and crack initiation sites and have been identified as a method of identifying defective welds. The effects of process parameters and stud and hole taper angles on energy inputs and near interface temperatures were statistically evaluated. Downward force was shown to have the largest effect on energy input rates, total energy input and temperatures at the 11.5mm and 20.5mm positions. Smaller hole and stud taper angles produced lower energy inputs and were identified as more energy efficient than the larger taper angles. A regression model was also developed to predict the fatigue life of welds and can assist with critical process related decision making. A range of hole base diameters were identified which produced welds with low defect populations and fatigue performance similar to that of the parent plate. Larger hole base diameters were shown to produce significant defects along the hole bottom fillet, in the weld nugget and along the bond line. Temperature measurements of the larger diameter welds showed a delay in response and are attributed to a delayed contact of plasticised stud material with the sidewall. Welds with hole base diameters larger than 11mm produced unrepeatable and defective welds, and also required higher energy inputs making smaller diameters more desirable. Analysis of all welds in this study revealed that clearance and interfacial pressures characterise the quality of friction hydro pillar process welds, therefore models were developed to aid in critical decision making with respect to downward force and geometry. This study has successfully evaluated the effects of process parameters and geometry on the properties of friction hydro pillar process welds and thereby has increased understanding of the process.
- Full Text:
Characterizing the influence of process variables in laser cladding Al-20WT%Si onto an Aluminium Substrate
- Authors: Von Wielligh, Louis George
- Subjects: Lasers -- Industrial applications , Metal cladding
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9625 , http://hdl.handle.net/10948/721 , Lasers -- Industrial applications , Metal cladding
- Description: The research investigated the application of continuous coaxial laser cladding by powder injection as a surface treatment or coating process. The investigation aimed to establish the relationship between a change in the main laser cladding process variables and the geometry and characteristics of an Al-20wt-Si single pass clad layer formed on an Al 1370-F substrate using a Nd:YAG laser. The main process variables considered were: laser power, laser scanning velocity and the powder feed rate. The relationship between a change in the main laser cladding process variables and the geometry and characteristics of the clad layer was established by statistically analysing the variation in the process response with a change in the main laser cladding process variables. The process variables were varied based on a full-factorial, experimentally optimized test matrix. The clad geometry which is mainly defined by: the clad height, width, clad aspect ratio, depth of alloy penetration, and the clad root angle/wetting angle was investigated. In addition to the clad geometry several clad characteristics were investigated such as the dilution of the clad layer in the substrate material, the Vickers microhardness and microstructure of the clad crosssection, the powder efficiency of the process and the amount of visible defects. The study successfully established the relationship between the main laser cladding process variables and the clad geometry and characteristics. The secondary objective of establishing a suitable processing window by considering the relationship mentioned above was only partially met since it is believed that further refinement of the experimental cladding test setup and therefore also the experimental variable test levels is required.
- Full Text:
- Authors: Von Wielligh, Louis George
- Subjects: Lasers -- Industrial applications , Metal cladding
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9625 , http://hdl.handle.net/10948/721 , Lasers -- Industrial applications , Metal cladding
- Description: The research investigated the application of continuous coaxial laser cladding by powder injection as a surface treatment or coating process. The investigation aimed to establish the relationship between a change in the main laser cladding process variables and the geometry and characteristics of an Al-20wt-Si single pass clad layer formed on an Al 1370-F substrate using a Nd:YAG laser. The main process variables considered were: laser power, laser scanning velocity and the powder feed rate. The relationship between a change in the main laser cladding process variables and the geometry and characteristics of the clad layer was established by statistically analysing the variation in the process response with a change in the main laser cladding process variables. The process variables were varied based on a full-factorial, experimentally optimized test matrix. The clad geometry which is mainly defined by: the clad height, width, clad aspect ratio, depth of alloy penetration, and the clad root angle/wetting angle was investigated. In addition to the clad geometry several clad characteristics were investigated such as the dilution of the clad layer in the substrate material, the Vickers microhardness and microstructure of the clad crosssection, the powder efficiency of the process and the amount of visible defects. The study successfully established the relationship between the main laser cladding process variables and the clad geometry and characteristics. The secondary objective of establishing a suitable processing window by considering the relationship mentioned above was only partially met since it is believed that further refinement of the experimental cladding test setup and therefore also the experimental variable test levels is required.
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Consumer health informatics in the information age and beyond
- Authors: Pottas, Dalenca
- Subjects: Medical informatics , Information technology , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/20757 , vital:29386
- Description: This paper reviews current and future trends and challenges in the field of consumer health informatics. Emergent innovations driving consumer health informatics in the information age include devices, tools and applications supporting personalised healthcare, electronic personal health record (PHR) systems and a plethora of tools in the health social media domain. Within this domain, a new kind of social media citizen, the consumer specialist or patient opinion leader, is taking the lead in online communities of patients. A new generation of personal health records combining PHRs and social media is emerging, even though pervasive adoption and use of PHRs remains elusive. The accuracy of information, security and privacy of personal health information, legislative matters and the digital divide remain recurring challenges of consumer health informatics. In future, PHR vendors will have to address the lack of espousal of PHRs in innovative ways to provide a compelling case for adoption. The continued uptake of health social media necessitates efforts to understand, through longitudinal studies, precisely who the users are, what they use it for and how it contributes to the achievement of both personal and public health outcomes. Health information consumers, of varying levels of techno-literacy, needs and preferences, must be assisted to move from simply accessing information to distilling relevant and credible information and making informed decisions. Further research is required to understand the changing relationships between patients and healthcare providers and how consumer health information technologies can best support these. There is a need to evaluate the effectiveness of consumer health information technologies to inform both public policy and the next generation of tools, technologies and artefacts that could better facilitate improved health outcomes. Lastly, more effort is required to erode digital inequalities. As we move into a future emphasising both the global and the individual, accelerated connectedness and speed of change, consumer health informatics must respond such that it remains germane and amplifies the value that can be gained by all stakeholders.
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- Authors: Pottas, Dalenca
- Subjects: Medical informatics , Information technology , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/20757 , vital:29386
- Description: This paper reviews current and future trends and challenges in the field of consumer health informatics. Emergent innovations driving consumer health informatics in the information age include devices, tools and applications supporting personalised healthcare, electronic personal health record (PHR) systems and a plethora of tools in the health social media domain. Within this domain, a new kind of social media citizen, the consumer specialist or patient opinion leader, is taking the lead in online communities of patients. A new generation of personal health records combining PHRs and social media is emerging, even though pervasive adoption and use of PHRs remains elusive. The accuracy of information, security and privacy of personal health information, legislative matters and the digital divide remain recurring challenges of consumer health informatics. In future, PHR vendors will have to address the lack of espousal of PHRs in innovative ways to provide a compelling case for adoption. The continued uptake of health social media necessitates efforts to understand, through longitudinal studies, precisely who the users are, what they use it for and how it contributes to the achievement of both personal and public health outcomes. Health information consumers, of varying levels of techno-literacy, needs and preferences, must be assisted to move from simply accessing information to distilling relevant and credible information and making informed decisions. Further research is required to understand the changing relationships between patients and healthcare providers and how consumer health information technologies can best support these. There is a need to evaluate the effectiveness of consumer health information technologies to inform both public policy and the next generation of tools, technologies and artefacts that could better facilitate improved health outcomes. Lastly, more effort is required to erode digital inequalities. As we move into a future emphasising both the global and the individual, accelerated connectedness and speed of change, consumer health informatics must respond such that it remains germane and amplifies the value that can be gained by all stakeholders.
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Develoment of a navigation system for an autonomous guided vehicle using android technology
- Authors: Snyman, Christo Johannes
- Subjects: Automated guided vehicle systems , Global Positioning System
- Language: English
- Type: Thesis , Masters , MEngineering (Mechatronics)
- Identifier: vital:9660 , http://hdl.handle.net/10948/d1020917
- Description: Modern cell phone hardware, due to its integrated peripherals, provides a low cost intelligent controller for use in the navigation of an Automated Guided Vehicle (AGV). Most commercial AGV’s use proprietary hardware which is expensive to replace and also difficult to maintain. Using industrial hardware components combined with Android mobile platforms could provide a low-cost alternative. This would be easier to maintain, using existing in-house factory maintenance knowledge. A prototype AGV was designed and developed based on an integrated system between an industrial Programmable Logic Controller (PLC) and an Android operating system mobile platform. This system utilises the mobile platforms integrated Global Position System (GPS) or video camera as tools for navigation. Experimental tests were performed to determine whether the prototype can navigate a predefined course by making use of GPS and camera line following algorithms. The accuracy of the line following algorithm was influenced by the speed at which the research AGV moved. Mounting the Android camera higher above the ground improved the vision and therefore accuracy of the algorithm. The GPS algorithm successfully navigated to various waypoints. The accuracy of the implemented GPS unit on the Android device is its limitation. The research unit was only capable of reaching a waypoint consistently within a three-metre radius.
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- Authors: Snyman, Christo Johannes
- Subjects: Automated guided vehicle systems , Global Positioning System
- Language: English
- Type: Thesis , Masters , MEngineering (Mechatronics)
- Identifier: vital:9660 , http://hdl.handle.net/10948/d1020917
- Description: Modern cell phone hardware, due to its integrated peripherals, provides a low cost intelligent controller for use in the navigation of an Automated Guided Vehicle (AGV). Most commercial AGV’s use proprietary hardware which is expensive to replace and also difficult to maintain. Using industrial hardware components combined with Android mobile platforms could provide a low-cost alternative. This would be easier to maintain, using existing in-house factory maintenance knowledge. A prototype AGV was designed and developed based on an integrated system between an industrial Programmable Logic Controller (PLC) and an Android operating system mobile platform. This system utilises the mobile platforms integrated Global Position System (GPS) or video camera as tools for navigation. Experimental tests were performed to determine whether the prototype can navigate a predefined course by making use of GPS and camera line following algorithms. The accuracy of the line following algorithm was influenced by the speed at which the research AGV moved. Mounting the Android camera higher above the ground improved the vision and therefore accuracy of the algorithm. The GPS algorithm successfully navigated to various waypoints. The accuracy of the implemented GPS unit on the Android device is its limitation. The research unit was only capable of reaching a waypoint consistently within a three-metre radius.
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Factors impacting the introduction of information technology usage in netball coaching
- Authors: Daniell, Janine
- Subjects: Information technology , Netball -- Coaching
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9828 , http://hdl.handle.net/10948/d1020878
- Description: With the growth in the use of technology in sports, there has been an improvement in sporting performances. Some may argue that the two go hand in hand, while others will write it off as coincidence. Nevertheless the use of technology in sport is seen on a daily basis. Cricket uses Hotspot, tennis uses Hawk-Eye and rugby uses slow motion video replays. In these sports codes, technology is already an aid to umpires. Little is known, however, about the technologies used to assist coaches in sports codes such as netball. This study investigated the factors impacting the introduction of information technology in the coaching of netball. The study commenced with using the term technology in the broader sense of the word to gain an understanding from netball coaches as to how technology could be incorporated into the sport. It was later narrowed down more specifically to computer technologies. The investigation was done at the Spar National Netball Championships in 2012, where coaches were surveyed about the preparation for the tournament of the provincial teams. The surveys included questions to coaches regarding the technologies used in preparation for a national tournament. The results obtained from the coaches were used to identify the current technologies used. Interviews were conducted after the analysis of the initial results to probe into the potential use of social media as a tool to assist coaches. Based on the results of the study, a number of factors that impact on the introduction of technology in the coaching of netball were identified. The factors and basic guidelines were validated through expert focus groups. Based on the findings from the experts, the factors and guidelines were refined. It is envisaged that the findings from this research can be used to assist netball coaches in deciding how to introduce the use of information technology into the sport.
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- Authors: Daniell, Janine
- Subjects: Information technology , Netball -- Coaching
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9828 , http://hdl.handle.net/10948/d1020878
- Description: With the growth in the use of technology in sports, there has been an improvement in sporting performances. Some may argue that the two go hand in hand, while others will write it off as coincidence. Nevertheless the use of technology in sport is seen on a daily basis. Cricket uses Hotspot, tennis uses Hawk-Eye and rugby uses slow motion video replays. In these sports codes, technology is already an aid to umpires. Little is known, however, about the technologies used to assist coaches in sports codes such as netball. This study investigated the factors impacting the introduction of information technology in the coaching of netball. The study commenced with using the term technology in the broader sense of the word to gain an understanding from netball coaches as to how technology could be incorporated into the sport. It was later narrowed down more specifically to computer technologies. The investigation was done at the Spar National Netball Championships in 2012, where coaches were surveyed about the preparation for the tournament of the provincial teams. The surveys included questions to coaches regarding the technologies used in preparation for a national tournament. The results obtained from the coaches were used to identify the current technologies used. Interviews were conducted after the analysis of the initial results to probe into the potential use of social media as a tool to assist coaches. Based on the results of the study, a number of factors that impact on the introduction of technology in the coaching of netball were identified. The factors and basic guidelines were validated through expert focus groups. Based on the findings from the experts, the factors and guidelines were refined. It is envisaged that the findings from this research can be used to assist netball coaches in deciding how to introduce the use of information technology into the sport.
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ICT as an enabler of Socio Economic Development
- Authors: Van Greunen, Darrelle
- Subjects: Information technology , Digital divide , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/20725 , vital:29383
- Description: Today’s is a world of many divides, one of the most typical being the Digital Divide, which in itself has given birth to or is worsening other economic and social divides. In this world, more suffer and less are able to benefit from technology. This paper aims to promote the importance of and need for inter-disciplinary cooperation for the use and promotion of Information and Communication Technologies (ICT) as a bridge for the Digital Divide within disciplines. Information and communication technologies (ICTs) include any communication device—radio, television, cellular phones, computer and network hardware and software, satellite systems, the services and applications associated with them, such as the Internet, geographic positioning systems (GPS), banking, e-health, e-learning and electronic government services. The paper will touch on tangible examples of inter-disciplinary cooperation and the use of ICT in different community interventions.
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- Authors: Van Greunen, Darrelle
- Subjects: Information technology , Digital divide , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/20725 , vital:29383
- Description: Today’s is a world of many divides, one of the most typical being the Digital Divide, which in itself has given birth to or is worsening other economic and social divides. In this world, more suffer and less are able to benefit from technology. This paper aims to promote the importance of and need for inter-disciplinary cooperation for the use and promotion of Information and Communication Technologies (ICT) as a bridge for the Digital Divide within disciplines. Information and communication technologies (ICTs) include any communication device—radio, television, cellular phones, computer and network hardware and software, satellite systems, the services and applications associated with them, such as the Internet, geographic positioning systems (GPS), banking, e-health, e-learning and electronic government services. The paper will touch on tangible examples of inter-disciplinary cooperation and the use of ICT in different community interventions.
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Optimisation of cold rolling process parameters to improve surface quality of the AA 3003-H22 treadbright coils
- Authors: Makhanya, Lehlohonolo
- Subjects: Aluminum alloys
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9611 , http://hdl.handle.net/10948/554 , Aluminum alloys
- Description: The main objective of this dissertation was to investigate how cold rolling process parameters could be optimised to improve surface quality of the AA 3003 H22 treadbright coils. This treadbright product is one of Hulett Aluminium’s main products and is exported mainly to the North American market. One of its critical requirements is a defect-free bright surface. The literature review was conducted with particular focus on the effects of selected parameters or settings with respect to surface quality and a chapter outlining these aspects has been included. It was clear from the literature review that selected parameters do affect the surface quality and if adjusted accordingly can improve surface quality on treadbright coils. Subsequent chapters after the literature review outline how the tests were conducted, procedures followed and equipments used from the cold rolling machine to laboratories. Surface appearance results after each parameter was adjusted, showed that the surface quality did improve and even got better when other parameters like the colouring roll angle and percentage reduction were adjusted. Correct working limits within which each parameter would yield acceptable surface quality were also established. All experiments conducted had no influence on the microstructure of the metal as it remained the same throughout each experiment. The same has been found with the mechanical properties as percentage reductions experiments led to no change in tensile strength, proof strength and percentage elongation. In conclusion, this research has proved that cold rolling process parameters selected did affect the product surface quality. If controlled they can be used to optimise the surface quality on the treadbright product as required by Hulett Aluminium and its customers.
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- Authors: Makhanya, Lehlohonolo
- Subjects: Aluminum alloys
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9611 , http://hdl.handle.net/10948/554 , Aluminum alloys
- Description: The main objective of this dissertation was to investigate how cold rolling process parameters could be optimised to improve surface quality of the AA 3003 H22 treadbright coils. This treadbright product is one of Hulett Aluminium’s main products and is exported mainly to the North American market. One of its critical requirements is a defect-free bright surface. The literature review was conducted with particular focus on the effects of selected parameters or settings with respect to surface quality and a chapter outlining these aspects has been included. It was clear from the literature review that selected parameters do affect the surface quality and if adjusted accordingly can improve surface quality on treadbright coils. Subsequent chapters after the literature review outline how the tests were conducted, procedures followed and equipments used from the cold rolling machine to laboratories. Surface appearance results after each parameter was adjusted, showed that the surface quality did improve and even got better when other parameters like the colouring roll angle and percentage reduction were adjusted. Correct working limits within which each parameter would yield acceptable surface quality were also established. All experiments conducted had no influence on the microstructure of the metal as it remained the same throughout each experiment. The same has been found with the mechanical properties as percentage reductions experiments led to no change in tensile strength, proof strength and percentage elongation. In conclusion, this research has proved that cold rolling process parameters selected did affect the product surface quality. If controlled they can be used to optimise the surface quality on the treadbright product as required by Hulett Aluminium and its customers.
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Sustainable construction (development) in the city of Cape Town
- Authors: Mgudlwa, Nosiyabonga Portia
- Subjects: Construction industry -- South Africa -- Cape Town , Biodiversity -- South Africa -- Cape Town , Sustainable development -- South Africa -- Cape Town
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9700 , http://hdl.handle.net/10948/d1015042
- Description: Considering the challenges faced by the City of Cape Town such as loss of biodiversity, limited supply of energy and unsustainable land use, it is argued that it is imperative for the construction industry to promote sustainable development. The objective of the research was to understand the contributions of the construction industry to over exploitation of resources such as biodiversity, energy and land. Secondly, the study considers initiatives to be undertaken by the construction industry to enhance the environment so as to promote sustainable development. The research mixed methods was used as the form of collecting required data. The collection of data comprised of the design and administration of open-ended and closed-ended questionnaires among a non-random selected population of building contractor, public works officials and practising Architectural firms within the City of Cape Town. The data obtained from open-ended questionnaire on building contractors and public works officials was analysed qualitatively and data from the closed-ended questionnaires through practising Architectural firms was analysed quantitatively. Research results showed that biodiversity in the City of Cape Town is under threat. Passive design has a significant role in protecting the biodiversity and should be encouraged by the construction industry and the City of Cape Town. The City of Cape Town should strongly enforce polices that support the conservation of biodiversity. This will have a positive impact through encouraging the construction industry to adhere to these polices. The City of Cape Town is faced with energy shortage. The construction industry needs to reduce its energy usage as a dominant energy user. This will be achieved through energy efficient designs and retrofitting the existing buildings. The City of Cape Town has a responsibility to promote sustainable land use. Land prices are highly priced in the City of Cape Town as a result the poor cannot enter the market without external assistance. The construction industry has a role to encourage sustainable land use in the city.
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- Authors: Mgudlwa, Nosiyabonga Portia
- Subjects: Construction industry -- South Africa -- Cape Town , Biodiversity -- South Africa -- Cape Town , Sustainable development -- South Africa -- Cape Town
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9700 , http://hdl.handle.net/10948/d1015042
- Description: Considering the challenges faced by the City of Cape Town such as loss of biodiversity, limited supply of energy and unsustainable land use, it is argued that it is imperative for the construction industry to promote sustainable development. The objective of the research was to understand the contributions of the construction industry to over exploitation of resources such as biodiversity, energy and land. Secondly, the study considers initiatives to be undertaken by the construction industry to enhance the environment so as to promote sustainable development. The research mixed methods was used as the form of collecting required data. The collection of data comprised of the design and administration of open-ended and closed-ended questionnaires among a non-random selected population of building contractor, public works officials and practising Architectural firms within the City of Cape Town. The data obtained from open-ended questionnaire on building contractors and public works officials was analysed qualitatively and data from the closed-ended questionnaires through practising Architectural firms was analysed quantitatively. Research results showed that biodiversity in the City of Cape Town is under threat. Passive design has a significant role in protecting the biodiversity and should be encouraged by the construction industry and the City of Cape Town. The City of Cape Town should strongly enforce polices that support the conservation of biodiversity. This will have a positive impact through encouraging the construction industry to adhere to these polices. The City of Cape Town is faced with energy shortage. The construction industry needs to reduce its energy usage as a dominant energy user. This will be achieved through energy efficient designs and retrofitting the existing buildings. The City of Cape Town has a responsibility to promote sustainable land use. Land prices are highly priced in the City of Cape Town as a result the poor cannot enter the market without external assistance. The construction industry has a role to encourage sustainable land use in the city.
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Tool wear monitoring in end milling of mould steel using acoustic emission
- Authors: Olufayo, Oluwole Ayodeji
- Subjects: Acoustic emission testing , Tool-steel
- Language: English
- Type: Thesis , Masters , MEngineering
- Identifier: vital:9651 , http://hdl.handle.net/10948/d1014688
- Description: Today’s production industry is faced with the challenge of maximising its resources and productivity. Tool condition monitoring (TCM) is an important diagnostic tool and if integrated in manufacturing, machining efficiency will increase as a result of reducing downtime resulting from tool failures by intensive wear. The research work presented in the study highlights the principles in tool condition monitoring and identifies acoustic emission (AE) as a reliable sensing technique for the detection of wear conditions. It reviews the importance of acoustic emission as an efficient technique and proposes a TCM model for the prediction of tool wear. The study presents a TCM framework to monitor an end-milling operation of H13 tool steel at different cutting speeds and feed rates. For this, three industrial acoustic sensors were positioned on the workpiece. The framework identifies a feature selection, extraction and conditioning process and classifies AE signals using an artificial neural network algorithm to create an autonomous system. It concludes by recognizing the mean and rms features as viable features in the identification of tool state and observes that chip coloration provides direct correlation to the temperature of machining as well as tool condition. This proposed model is aimed at creating a timing schedule for tool change in industries. This model ultimately links the rate of wear formation to characteristic AE features.
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- Authors: Olufayo, Oluwole Ayodeji
- Subjects: Acoustic emission testing , Tool-steel
- Language: English
- Type: Thesis , Masters , MEngineering
- Identifier: vital:9651 , http://hdl.handle.net/10948/d1014688
- Description: Today’s production industry is faced with the challenge of maximising its resources and productivity. Tool condition monitoring (TCM) is an important diagnostic tool and if integrated in manufacturing, machining efficiency will increase as a result of reducing downtime resulting from tool failures by intensive wear. The research work presented in the study highlights the principles in tool condition monitoring and identifies acoustic emission (AE) as a reliable sensing technique for the detection of wear conditions. It reviews the importance of acoustic emission as an efficient technique and proposes a TCM model for the prediction of tool wear. The study presents a TCM framework to monitor an end-milling operation of H13 tool steel at different cutting speeds and feed rates. For this, three industrial acoustic sensors were positioned on the workpiece. The framework identifies a feature selection, extraction and conditioning process and classifies AE signals using an artificial neural network algorithm to create an autonomous system. It concludes by recognizing the mean and rms features as viable features in the identification of tool state and observes that chip coloration provides direct correlation to the temperature of machining as well as tool condition. This proposed model is aimed at creating a timing schedule for tool change in industries. This model ultimately links the rate of wear formation to characteristic AE features.
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Tribological characteristics of polymers under high force small oscillating angular contact
- Authors: Bradfield, Jarad Wade
- Subjects: Tribology , Polymers.
- Language: English
- Type: Thesis , Masters , MTech (Mechanical Engineering)
- Identifier: vital:9637 , http://hdl.handle.net/10948/d1020598
- Description: This study was intended to establish which polymer material is best suited as the material for bushes used in high force small oscillating angular contact applications as typically found in a large sugar mill coupling. A Tribometer as well as a designed and manufactured Bearing Testing Machine, which simulates and accelerates the wear caused in the intended application, was used to determine the wear rates and coefficients of friction for seven polymer materials. Materials were selected for their superior mechanical and thermal properties. The Tribometer was fitted with a linear reciprocating rig, so as to simulate the small oscillating movement prevalent in the intended application. Each Tribometer test ran for a duration of two hours with a frequency of 33.1 Herts and a normal loading of 40N. Bearing Testing Machine tests were done under similar constraints but with 30kN loading present on the surface of a bushes inner race. These tests had a longer duration of 24 or 48 hours or until intense wearing occurred. Initially both testing methods will be analysed independently of each other in order to try and identify a relationship between the wear rate and coefficient of friction for the different polymers. The different testing methods’ results will be compared to each other in order to establish if a correlation between the materials tested could be found.
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- Authors: Bradfield, Jarad Wade
- Subjects: Tribology , Polymers.
- Language: English
- Type: Thesis , Masters , MTech (Mechanical Engineering)
- Identifier: vital:9637 , http://hdl.handle.net/10948/d1020598
- Description: This study was intended to establish which polymer material is best suited as the material for bushes used in high force small oscillating angular contact applications as typically found in a large sugar mill coupling. A Tribometer as well as a designed and manufactured Bearing Testing Machine, which simulates and accelerates the wear caused in the intended application, was used to determine the wear rates and coefficients of friction for seven polymer materials. Materials were selected for their superior mechanical and thermal properties. The Tribometer was fitted with a linear reciprocating rig, so as to simulate the small oscillating movement prevalent in the intended application. Each Tribometer test ran for a duration of two hours with a frequency of 33.1 Herts and a normal loading of 40N. Bearing Testing Machine tests were done under similar constraints but with 30kN loading present on the surface of a bushes inner race. These tests had a longer duration of 24 or 48 hours or until intense wearing occurred. Initially both testing methods will be analysed independently of each other in order to try and identify a relationship between the wear rate and coefficient of friction for the different polymers. The different testing methods’ results will be compared to each other in order to establish if a correlation between the materials tested could be found.
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Ultra-high precision manufacturing
- Authors: Abou-El-Hossein, Khaled
- Subjects: Machining , Diamond turning , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/20878 , vital:29410
- Description: One of the engineering areas focusing on the research and development of highvalue components and manufacturing technologies is precision engineering. Precision engineering represents a variety of engineering and science disciplines ranging from areas such as mechanical, electronics and industrial engineering to chemistry, physics, optics and materials science. This paper aims at familiarising the reader with the recent advances in ultra-high precision manufacturing technologies and their applications for the production of various critical components employed in different sectors of the industry. In this paper, the principles of ultra-high precision manufacturing will be discussed followed by examples of its use in various industrial applications. The status of ultra-high precision manufacturing in terms of current research issues and future trends will be discussed. In addition, research activities and projects in the area of precision manufacturing that are currently conducted at the NMMU will be also highlighted. Finally, the author looks forward to presenting herewith comprehensive information that could be useful to the reader and easy to understand by the bigger NMMU’s community.
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- Authors: Abou-El-Hossein, Khaled
- Subjects: Machining , Diamond turning , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/20878 , vital:29410
- Description: One of the engineering areas focusing on the research and development of highvalue components and manufacturing technologies is precision engineering. Precision engineering represents a variety of engineering and science disciplines ranging from areas such as mechanical, electronics and industrial engineering to chemistry, physics, optics and materials science. This paper aims at familiarising the reader with the recent advances in ultra-high precision manufacturing technologies and their applications for the production of various critical components employed in different sectors of the industry. In this paper, the principles of ultra-high precision manufacturing will be discussed followed by examples of its use in various industrial applications. The status of ultra-high precision manufacturing in terms of current research issues and future trends will be discussed. In addition, research activities and projects in the area of precision manufacturing that are currently conducted at the NMMU will be also highlighted. Finally, the author looks forward to presenting herewith comprehensive information that could be useful to the reader and easy to understand by the bigger NMMU’s community.
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