Characterisation of single event effects and total ionising dose effects of an intel atom microprocessor
- Authors: Malinda, Muema
- Date: 2019
- Subjects: Microprocessors , Mechatronics
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/41875 , vital:36605
- Description: The rapid advancements of COTS microprocessors compared to radiation hardened microprocessors has attracted the interest of system designers within the aerospace sector. COTS microprocessors offer higher performance with lower energy requirements, both of which are desired characteristics for microprocessors used in spacecraft. COTS microprocessors, however, are much more susceptible to radiation damage therefore their SEE and TID responses needs to be evaluated before they can be incorporated into spacecraft. This thesis presents the process followed to evaluate said characteristics of a COTS Intel Atom E3815 microprocessor mounted on a DE3815TYBE single board PC. Evaluation of the SEE response was carried out at NRF iThemba Labs in Cape Town, South Africa where the device was irradiated by a proton beam at 55.58 MeV and with varying beam currents. The device showed a higher sensitivity to functional interrupts when running with the onboard cache on compared to when running with the cache off, as would be expected. The cross-sections, respectively, are: 4.5𝑥 10−10 𝑐𝑚2 and 2.8 𝑥 10−10 𝑐𝑚2. TID testing on the other hand was carried out at the irradiation chamber of FruitFly Africa in Stellenbosch, South Africa. The test device was irradiated by gamma radiation from a Cobalt-60 source at a dose rate of 9.7kRad/h and to a total dose of 67.25kRad. Noticeable TID degradation, in the form of leakage currents, was observed once a total dose of about 20kRad was absorbed. The device then completely failed once a total dose of approximately 32kRad was absorbed. These results suggest that the E3815 microprocessor would not be suitable for long term missions that require higher TID survivability. The processor could however be considered for short term missions launched into polar or high incline orbits where the dose rate is relatively low, and the mission is capable of tolerating functional interrupts.
- Full Text:
- Date Issued: 2019
- Authors: Malinda, Muema
- Date: 2019
- Subjects: Microprocessors , Mechatronics
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/41875 , vital:36605
- Description: The rapid advancements of COTS microprocessors compared to radiation hardened microprocessors has attracted the interest of system designers within the aerospace sector. COTS microprocessors offer higher performance with lower energy requirements, both of which are desired characteristics for microprocessors used in spacecraft. COTS microprocessors, however, are much more susceptible to radiation damage therefore their SEE and TID responses needs to be evaluated before they can be incorporated into spacecraft. This thesis presents the process followed to evaluate said characteristics of a COTS Intel Atom E3815 microprocessor mounted on a DE3815TYBE single board PC. Evaluation of the SEE response was carried out at NRF iThemba Labs in Cape Town, South Africa where the device was irradiated by a proton beam at 55.58 MeV and with varying beam currents. The device showed a higher sensitivity to functional interrupts when running with the onboard cache on compared to when running with the cache off, as would be expected. The cross-sections, respectively, are: 4.5𝑥 10−10 𝑐𝑚2 and 2.8 𝑥 10−10 𝑐𝑚2. TID testing on the other hand was carried out at the irradiation chamber of FruitFly Africa in Stellenbosch, South Africa. The test device was irradiated by gamma radiation from a Cobalt-60 source at a dose rate of 9.7kRad/h and to a total dose of 67.25kRad. Noticeable TID degradation, in the form of leakage currents, was observed once a total dose of about 20kRad was absorbed. The device then completely failed once a total dose of approximately 32kRad was absorbed. These results suggest that the E3815 microprocessor would not be suitable for long term missions that require higher TID survivability. The processor could however be considered for short term missions launched into polar or high incline orbits where the dose rate is relatively low, and the mission is capable of tolerating functional interrupts.
- Full Text:
- Date Issued: 2019
The morale and motivation of government employees in a science environment
- Authors: Alberts, Lauren Erna
- Date: 2017
- Subjects: Employee morale -- South Africa -- Cape Town Employee motivation -- South Africa -- Cape Town , Civil service -- Personnel management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/46262 , vital:39541
- Description: This study investigated the problem of low morale and motivation of government employees in a scientific environment. There is not a significant amount of research about morale and motivation of government or public sector employees, specifically in the scientific environment. The emphasis of this study was to establish those factors contributing to the causes of low morale in government employees through identifying motivational factors that impact their morale. This quantitative study of a sample of 74 respondents develops a framework to foster morale and motivation in government employees working at the Forensic Science Laboratory in Cape Town, South Africa. Extrinsic motivational factors (working environment, salary and job security) and intrinsic motivational factors (recognition, responsibility and training) were measured against morale. In identifying the key areas relating to those of the motivation factors and morale in government employees, the issue can be addressed and measures implemented to meet the needs of these employees. The findings demonstrated evidence of the presence of a significant relationship between morale and the extrinsic motivational factor, job security, as well as the intrinsic motivation factors of recognition, responsibility and training.
- Full Text:
- Date Issued: 2017
- Authors: Alberts, Lauren Erna
- Date: 2017
- Subjects: Employee morale -- South Africa -- Cape Town Employee motivation -- South Africa -- Cape Town , Civil service -- Personnel management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/46262 , vital:39541
- Description: This study investigated the problem of low morale and motivation of government employees in a scientific environment. There is not a significant amount of research about morale and motivation of government or public sector employees, specifically in the scientific environment. The emphasis of this study was to establish those factors contributing to the causes of low morale in government employees through identifying motivational factors that impact their morale. This quantitative study of a sample of 74 respondents develops a framework to foster morale and motivation in government employees working at the Forensic Science Laboratory in Cape Town, South Africa. Extrinsic motivational factors (working environment, salary and job security) and intrinsic motivational factors (recognition, responsibility and training) were measured against morale. In identifying the key areas relating to those of the motivation factors and morale in government employees, the issue can be addressed and measures implemented to meet the needs of these employees. The findings demonstrated evidence of the presence of a significant relationship between morale and the extrinsic motivational factor, job security, as well as the intrinsic motivation factors of recognition, responsibility and training.
- Full Text:
- Date Issued: 2017
Sustainability of agricultural cooperatives in Emalahleni Local Municipality
- Authors: Tsholoba, Nokulunga
- Date: 2015
- Subjects: Agriculture, Cooperative -- South Africa -- Mpumalanga , Sustainable development -- South Africa -- Mpumalanga
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/4133 , vital:20555
- Description: Long term growth and sustainability of cooperatives has become the focus of many countries worldwide. Cooperatives have been seen as the platform for uplifting disadvantaged communities while improving standards of the poor in countries such as Canada, Kenya, Ghana and Nigeria (Department of Trade and Industry, 2012). In South Africa, cooperatives are seen as playing a role in poverty eradication, equal distribution of wealth, employment creation, food security and as a contributor to the economic activity. The South African government have implemented policies aimed at improving the performance and sustainability of agriculture cooperatives in South Africa. Despite all the efforts cooperatives still face sustainability challenges. Therefore the purpose of this research was to investigate the sustainability challenges that prevent the permanent establishment of cooperatives and to understand the dynamics and nature of failure associated with agricultural cooperatives .A case study methodology was used to examine a single case in-depth and to understand the factors affecting agricultural cooperatives. The main challenges identified in the study include; poor communication, limited access to markets, access to finance, a lack of good governance and a lack of managerial skills. The study recommended capacity building as the first point of reference in order to deal with challenges such as communication, access to markets and a lack of managerial skills. A lack of good governance is regarded as an attitude problem which requires setting ethical standards and rules accompanied by a penalty to the member if they are found to be breaking the rules. Access to finances is regarded as a skills and competence phenomenon which requires people to develop planning and financial literacy skills, which will enable them to formulate business plans and use them as a control tool for managing the cooperative. The business plan is also regarded as an asset or security document which acts as a proof that the cooperative is well planned, organised and sustainable. The research concludes with suggesting areas for future study to investigate the impact of informal education practices on skills development in the success of cooperatives.
- Full Text:
- Date Issued: 2015
- Authors: Tsholoba, Nokulunga
- Date: 2015
- Subjects: Agriculture, Cooperative -- South Africa -- Mpumalanga , Sustainable development -- South Africa -- Mpumalanga
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/4133 , vital:20555
- Description: Long term growth and sustainability of cooperatives has become the focus of many countries worldwide. Cooperatives have been seen as the platform for uplifting disadvantaged communities while improving standards of the poor in countries such as Canada, Kenya, Ghana and Nigeria (Department of Trade and Industry, 2012). In South Africa, cooperatives are seen as playing a role in poverty eradication, equal distribution of wealth, employment creation, food security and as a contributor to the economic activity. The South African government have implemented policies aimed at improving the performance and sustainability of agriculture cooperatives in South Africa. Despite all the efforts cooperatives still face sustainability challenges. Therefore the purpose of this research was to investigate the sustainability challenges that prevent the permanent establishment of cooperatives and to understand the dynamics and nature of failure associated with agricultural cooperatives .A case study methodology was used to examine a single case in-depth and to understand the factors affecting agricultural cooperatives. The main challenges identified in the study include; poor communication, limited access to markets, access to finance, a lack of good governance and a lack of managerial skills. The study recommended capacity building as the first point of reference in order to deal with challenges such as communication, access to markets and a lack of managerial skills. A lack of good governance is regarded as an attitude problem which requires setting ethical standards and rules accompanied by a penalty to the member if they are found to be breaking the rules. Access to finances is regarded as a skills and competence phenomenon which requires people to develop planning and financial literacy skills, which will enable them to formulate business plans and use them as a control tool for managing the cooperative. The business plan is also regarded as an asset or security document which acts as a proof that the cooperative is well planned, organised and sustainable. The research concludes with suggesting areas for future study to investigate the impact of informal education practices on skills development in the success of cooperatives.
- Full Text:
- Date Issued: 2015
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