The objective of this project is to design an antenna for use in the electronic monitoring of persons convicted of non-violent crimes. If implemented, electronic monitoring will lighten the load on the South African prison system. Electronic monitoring makes use of an electronic tether connected to the person being monitored. This led to specific performance requirements and size constraints being placed on the antenna. The antenna should be physically small while still being able to perform as specified. It is also necessary to test the design with various frequencies, to determine the best possible frequency to use. It was decided to use a Transformer Coupled Loop (TCL) antenna, after various designs were considered. The TCL antenna can be used in various configurations, with some of these configurations being simulated to determine the best antenna structure to use. After various antenna structures were discarded, a specific antenna structure emerged as a possible solution, which was then optimised to deliver the best possible performance. The optimised antenna model was constructed to test the antenna performance. The receiving antenna was a directional Log-Periodic Dipole Antenna (LPDA), connected to a spectrum analyser. Tests were conducted in an open-field environment to minimise the effect of reflections. The azimuth- and elevation radiation patterns for the antenna could be compared to the simulated results. The same tests were performed with the antenna attached to a saline solution bag, simulating the effects of the human body on the antenna performance. The radiation patterns obtained from the measured results proved to be similar to the simulated results for both frequencies tested. When making use of the human analogue, the radiation pattern tended to be more omnidirectional in both the azimuthand elevation planes. These results are ideal, since omnidirectional communication by the tethering device is required by a security application. The primary objective was achieved, together with the secondary objectives of comparing different frequencies. / Thesis (M.Ing. (Computer and Electronic Engineering))--North-West University, Potchefstroom Campus, 2012

The objective of this project is to design an antenna for use in the electronic monitoring of persons convicted of non-violent crimes. If implemented, electronic monitoring will lighten the load on the South African prison system. Electronic monitoring makes use of an electronic tether connected to the person being monitored. This led to specific performance requirements and size constraints being placed on the antenna. The antenna should be physically small while still being able to perform as specified. It is also necessary to test the design with various frequencies, to determine the best possible frequency to use. It was decided to use a Transformer Coupled Loop (TCL) antenna, after various designs were considered. The TCL antenna can be used in various configurations, with some of these configurations being simulated to determine the best antenna structure to use. After various antenna structures were discarded, a specific antenna structure emerged as a possible solution, which was then optimised to deliver the best possible performance. The optimised antenna model was constructed to test the antenna performance. The receiving antenna was a directional Log-Periodic Dipole Antenna (LPDA), connected to a spectrum analyser. Tests were conducted in an open-field environment to minimise the effect of reflections. The azimuth- and elevation radiation patterns for the antenna could be compared to the simulated results. The same tests were performed with the antenna attached to a saline solution bag, simulating the effects of the human body on the antenna performance. The radiation patterns obtained from the measured results proved to be similar to the simulated results for both frequencies tested. When making use of the human analogue, the radiation pattern tended to be more omnidirectional in both the azimuthand elevation planes. These results are ideal, since omnidirectional communication by the tethering device is required by a security application. The primary objective was achieved, together with the secondary objectives of comparing different frequencies. / Thesis (M.Ing. (Computer and Electronic Engineering))--North-West University, Potchefstroom Campus, 2012

Please read the abstract in the dissertation. / Dissertation (MSc)--University of Pretoria, 1978. / gm2014 / Electrical, Electronic and Computer Engineering / Unrestricted

The national electricity utility in South Africa, Eskom, is currently under pressure to supply the increasing demand for electricity on a national level. To address this problem in the short term, Eskom partially funds load management and energy efficiency projects. In the meantime, Eskom is also increasing their generation capacity through the erection of new power stations. To finance these capital projects, sharp tariff increases, higher than inflation, are levied, resulting in higher operating expenditures for the consumers. These increased tariffs are especially affecting industrial institutions. Large industries are therefore willing participants in the partially Eskom funded electricity savings programme that hold benefits for both parties. One of these large industries is the Mining Sector. This sector is an energy intensive group and consumes up to 15% of Eskom’s total output. The refrigeration and pumping systems used in the sectors are two of the major electricity consumers. As part of Eskom’s Demand Side Management (DSM) initiative, an electrical energy savings project was implemented in the deep mines’ chilled water systems. The cooling system is optimally controlled to ensure less underground water usage. This ensures that less water is pumped out by the dewatering system, reducing electrical energy usage. A variety of components, such as refrigeration and energy recovery depend on chilled water to function properly. Every relevant component was simulated and the verification of results was done through correlations with process data obtained from the mine. The simulation results showed acceptable error margins that would not influence accuracy. Two sites where a water supply optimisations project was implemented were selected as case studies. In both case studies, thermal results of the refrigeration and cooling system showed a reduction in cooling effectiveness. In case study A, the energy recovery components showed negative results. All of the results were converted to electrical energy costs to enable comparison. Constraints were evident during deep mine water supply optimisation. These were determined and the thermal effects were simulated. This study enabled basic quantifications of environmental impact and also determining project cost savings. The studies showed that positive and negative effects can be brought on in the mining systems with the reduction in chilled water use. In some cases the cooling system components showed a decrease in cooling effectiveness, but exhibited electrical energy savings. This impact was during periods where no personnel were underground in the working area. In conclusion the study also showed that cost savings resulting from the reduced chilled water are substantially higher than negative financial losses seen on the other components. / MIng (Electrical and Electronic Engineering), North-West University, Potchefstroom Campus, 2014

The national electricity utility in South Africa, Eskom, is currently under pressure to supply the increasing demand for electricity on a national level. To address this problem in the short term, Eskom partially funds load management and energy efficiency projects. In the meantime, Eskom is also increasing their generation capacity through the erection of new power stations. To finance these capital projects, sharp tariff increases, higher than inflation, are levied, resulting in higher operating expenditures for the consumers. These increased tariffs are especially affecting industrial institutions. Large industries are therefore willing participants in the partially Eskom funded electricity savings programme that hold benefits for both parties. One of these large industries is the Mining Sector. This sector is an energy intensive group and consumes up to 15% of Eskom’s total output. The refrigeration and pumping systems used in the sectors are two of the major electricity consumers. As part of Eskom’s Demand Side Management (DSM) initiative, an electrical energy savings project was implemented in the deep mines’ chilled water systems. The cooling system is optimally controlled to ensure less underground water usage. This ensures that less water is pumped out by the dewatering system, reducing electrical energy usage. A variety of components, such as refrigeration and energy recovery depend on chilled water to function properly. Every relevant component was simulated and the verification of results was done through correlations with process data obtained from the mine. The simulation results showed acceptable error margins that would not influence accuracy. Two sites where a water supply optimisations project was implemented were selected as case studies. In both case studies, thermal results of the refrigeration and cooling system showed a reduction in cooling effectiveness. In case study A, the energy recovery components showed negative results. All of the results were converted to electrical energy costs to enable comparison. Constraints were evident during deep mine water supply optimisation. These were determined and the thermal effects were simulated. This study enabled basic quantifications of environmental impact and also determining project cost savings. The studies showed that positive and negative effects can be brought on in the mining systems with the reduction in chilled water use. In some cases the cooling system components showed a decrease in cooling effectiveness, but exhibited electrical energy savings. This impact was during periods where no personnel were underground in the working area. In conclusion the study also showed that cost savings resulting from the reduced chilled water are substantially higher than negative financial losses seen on the other components. / MIng (Electrical and Electronic Engineering), North-West University, Potchefstroom Campus, 2014

Preface - Biotechnology is generally accepted to be the next economical wave of the future. In order to attain the many benefits associated with this growing industry simulation modelling techniques have to be implemented successfully. One of the simulations that ne' ed to be performed is that of the human energy system. Pharmaceutical companies are currently pouring vast amounts of capital into research regarding simulation of bodily processes. Their aim is to develop cures, treatments, medication, etc. for major diseases. These diseases include epidemics like diabetes, cancer, cardiovascular diseases, obesity, stress, hypertension, etc. One of the most important driving forces behind these diseases is poor blood sugar control. The blood glucose system is one of the major subsystems of the complete human energy system. In this study a simulation model and procedure for simulating blood glucose response due to various external influences on the human body is presented. The study is presented in two parts. The first is the development of a novel concept for quantifying glucose energy flow into, within and out of the human energy system. The new quantification unit is called ets (equivalent teaspoons sugar). The second part of the study is the implementation of the ets concept in order to develop the simulation model. Development of the ets concept - In the first part of the study the ets concept, used for predicting glycaemic response, is developed and presented. The two current methods for predicting glycaemic response due to ingestion of food are discussed, namely carbohydrate counting and the glycaemic index. Furthermore, it is shown that it is currently incorrectly assumed that 100% of the chemical energy contained in food is available to the human energy system after consumption. The ets concept is derived to provide a better measure of available energy from food. In order to verify the ets concept, two links with ets are investigated. These are the links with insulin response prediction as well as with endurance energy expenditure. It is shown that with both these links linear relationships provide a good approximation of empirical data. It is also shown that individualised characterisation of different people is only dependent on a single measurable variable for each link. Lastly, two novel applications of the ets concept are considered. The first is a new method to use the ets values associated with food and energy expenditure in order to calculate both short-acting and long-acting insulin dosages for Type 1 diabetics. The second application entails a new quantification method for describing the effects of stress and illness in terms of ets. Development of the blood glucose simulation model - The second part of the study presents a literature study regarding human physiology, the development for the blood glucose simulation model as well as a verification study of the simulation model. Firstly, a brief overview is given for the need and motivation behind simulation is given. A discussion on the implementation of the techniques for construction of the model is also shown. The procedure for solving the model is then outlined. During the literature study regarding human physiology two detailed schematic layouts are presented and discussed. The first layout involves the complex flow pathways of energy through the human energy system. The second layout presents a detailed discussion on the control system involved with the glucose energy pathway. Following the literature review the model for predicting glycaemic response is proposed. The design of the component models used for the simulations of the internal processes are developed in detail as well as the control strategies implemented for the control system of the simulation model. Lastly, the simulation model is applied for glycaemic response prediction of actual test subjects and the quality of the predictions are evaluated. The verification of the model and the procedure is performed by comparing simulated results to measured data. Two evaluations were considered, namely long-term and short-term trials. The quality of both are determined according to certain evaluation criteria and it is found that the model is more than 70% accurate for long-term simulations and more than 80% accurate for short-term simulations. Conclusion - In conclusion, it is shown that simplified simulation of the human energy system is not only possible but also relatively accurate. However, in order to accomplish the simulations a simple quantification method is required and this is provided by the ets concept developed in the first part of this study. Some recommendations are also made for future research regarding both the ets concept and the simulation model. Finally, as an initial endeavour the simulation model and the ets concept proposed in this study may provide the necessary edge for groundbreaking biotechnological discoveries. / PhD (Mechanical Engineering) North-West University, Potchefstroom Campus, 2003

Preface - Biotechnology is generally accepted to be the next economical wave of the future. In order to attain the many benefits associated with this growing industry simulation modelling techniques have to be implemented successfully. One of the simulations that ne' ed to be performed is that of the human energy system. Pharmaceutical companies are currently pouring vast amounts of capital into research regarding simulation of bodily processes. Their aim is to develop cures, treatments, medication, etc. for major diseases. These diseases include epidemics like diabetes, cancer, cardiovascular diseases, obesity, stress, hypertension, etc. One of the most important driving forces behind these diseases is poor blood sugar control. The blood glucose system is one of the major subsystems of the complete human energy system. In this study a simulation model and procedure for simulating blood glucose response due to various external influences on the human body is presented. The study is presented in two parts. The first is the development of a novel concept for quantifying glucose energy flow into, within and out of the human energy system. The new quantification unit is called ets (equivalent teaspoons sugar). The second part of the study is the implementation of the ets concept in order to develop the simulation model. Development of the ets concept - In the first part of the study the ets concept, used for predicting glycaemic response, is developed and presented. The two current methods for predicting glycaemic response due to ingestion of food are discussed, namely carbohydrate counting and the glycaemic index. Furthermore, it is shown that it is currently incorrectly assumed that 100% of the chemical energy contained in food is available to the human energy system after consumption. The ets concept is derived to provide a better measure of available energy from food. In order to verify the ets concept, two links with ets are investigated. These are the links with insulin response prediction as well as with endurance energy expenditure. It is shown that with both these links linear relationships provide a good approximation of empirical data. It is also shown that individualised characterisation of different people is only dependent on a single measurable variable for each link. Lastly, two novel applications of the ets concept are considered. The first is a new method to use the ets values associated with food and energy expenditure in order to calculate both short-acting and long-acting insulin dosages for Type 1 diabetics. The second application entails a new quantification method for describing the effects of stress and illness in terms of ets. Development of the blood glucose simulation model - The second part of the study presents a literature study regarding human physiology, the development for the blood glucose simulation model as well as a verification study of the simulation model. Firstly, a brief overview is given for the need and motivation behind simulation is given. A discussion on the implementation of the techniques for construction of the model is also shown. The procedure for solving the model is then outlined. During the literature study regarding human physiology two detailed schematic layouts are presented and discussed. The first layout involves the complex flow pathways of energy through the human energy system. The second layout presents a detailed discussion on the control system involved with the glucose energy pathway. Following the literature review the model for predicting glycaemic response is proposed. The design of the component models used for the simulations of the internal processes are developed in detail as well as the control strategies implemented for the control system of the simulation model. Lastly, the simulation model is applied for glycaemic response prediction of actual test subjects and the quality of the predictions are evaluated. The verification of the model and the procedure is performed by comparing simulated results to measured data. Two evaluations were considered, namely long-term and short-term trials. The quality of both are determined according to certain evaluation criteria and it is found that the model is more than 70% accurate for long-term simulations and more than 80% accurate for short-term simulations. Conclusion - In conclusion, it is shown that simplified simulation of the human energy system is not only possible but also relatively accurate. However, in order to accomplish the simulations a simple quantification method is required and this is provided by the ets concept developed in the first part of this study. Some recommendations are also made for future research regarding both the ets concept and the simulation model. Finally, as an initial endeavour the simulation model and the ets concept proposed in this study may provide the necessary edge for groundbreaking biotechnological discoveries. / PhD (Mechanical Engineering) North-West University, Potchefstroom Campus, 2003

The School for Mechanical Engineering at the North-West University is home to one of South Africa's most established Measurement & Verification (M&V) teams. The team is involved with South Africa's electricity utility, Eskom, and their efforts to reduce the energy demand of the nation through Demand Side Management (DSM). One of the DSM initiatives in the residential energy sector is a National Solar Water Heating Program which encourages homeowners to purchase and install an Eskom accredited solar water heating system by means of a financial incentive. Massive financial investments have been incurred and it is only natural for stakeholders to question their return on investment. The need consequently exists to determine the impact of the National Solar Water Heating Program and establish whether it is being sustained. Before developing a methodology to measure and verify the impact of a solar water heating program an in-depth study had to be done on M&V as well as the concepts around solar water heating itself. After considering financial, time and accuracy constraints it was decided that an M&V Solar Water Heating Application along with the M&V methodology be developed. The primary aim of the application was to simulate the electrical hot water demand caused by the electrical-backup elements of the solar water heating systems and thereby avoiding the logistically and financially impossible process of measuring the electrical demand. A high-level simulation application, based on energy balances, was developed with solar water heating system types, geographical locations, weather conditions, hot water demand profiles and installation positions as inputs. The outputs of the application were the uncontrolled, simulated electrical hot water demand and were compared to the actual measured electrical hot water demand of a solar water heating system located in Cape Town. The outputs from two scenarios were compared to the measured data; one calculated with weather data from the global weather database Meteonorm, and the second calculated with the measured weather parameters acquired during the measurement period. The first scenario indicated relative accuracy with a mean bias error (MBE) and coefficient of variation of the root mean squared errors (CV (RMSE)) of 13.5% and 16.00/o respectively. The second scenario revealed improved accuracy with an MBE and CV (RMSE) of -1.1% and 5.5% respectively. The M&V Solar Water Heating Application and methodology has set the process in motion to measure and verify the impact of the National Solar Water Heating Program and will be refined as more data and information become available. / Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2010.

The School for Mechanical Engineering at the North-West University is home to one of South Africa's most established Measurement & Verification (M&V) teams. The team is involved with South Africa's electricity utility, Eskom, and their efforts to reduce the energy demand of the nation through Demand Side Management (DSM). One of the DSM initiatives in the residential energy sector is a National Solar Water Heating Program which encourages homeowners to purchase and install an Eskom accredited solar water heating system by means of a financial incentive. Massive financial investments have been incurred and it is only natural for stakeholders to question their return on investment. The need consequently exists to determine the impact of the National Solar Water Heating Program and establish whether it is being sustained. Before developing a methodology to measure and verify the impact of a solar water heating program an in-depth study had to be done on M&V as well as the concepts around solar water heating itself. After considering financial, time and accuracy constraints it was decided that an M&V Solar Water Heating Application along with the M&V methodology be developed. The primary aim of the application was to simulate the electrical hot water demand caused by the electrical-backup elements of the solar water heating systems and thereby avoiding the logistically and financially impossible process of measuring the electrical demand. A high-level simulation application, based on energy balances, was developed with solar water heating system types, geographical locations, weather conditions, hot water demand profiles and installation positions as inputs. The outputs of the application were the uncontrolled, simulated electrical hot water demand and were compared to the actual measured electrical hot water demand of a solar water heating system located in Cape Town. The outputs from two scenarios were compared to the measured data; one calculated with weather data from the global weather database Meteonorm, and the second calculated with the measured weather parameters acquired during the measurement period. The first scenario indicated relative accuracy with a mean bias error (MBE) and coefficient of variation of the root mean squared errors (CV (RMSE)) of 13.5% and 16.00/o respectively. The second scenario revealed improved accuracy with an MBE and CV (RMSE) of -1.1% and 5.5% respectively. The M&V Solar Water Heating Application and methodology has set the process in motion to measure and verify the impact of the National Solar Water Heating Program and will be refined as more data and information become available. / Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2010.

Preface - Biotechnology is generally considered to be the wave of the future. To facilitate accurate and rapid development of medication and treatments, it is critical that we are able to simulate the human body. One section of this complex model would be the human energy system. Pharmaceutical companies are currently pouring vast amounts of capital into research regarding general simulation of cellular structures, protein structures and bodily processes. Their aim is to develop treatments and medication for major diseases. Some of these diseases are epidemics like cancer, cardiovascular diseases, stress, obesity, etc. One of the most important causes of these diseases is poor blood glucose control. Current management methods for insulin dependent diabetes are limited to trial and error systems: clearly ineffective and prone to errors. It is critical that better management systems be developed, to ease the diabetic epidemic. The blood glucose control system is one of the major systems in the body, as we are in constant need of energy to facilitate the optimum functioning of the human body. This study makes use of a developed simulation model for the human energy system to ease the management of Diabetes mellitus, which is a malfunction of the human energy system. This dissertation is presented in two parts: The first part discusses the human energy simulation model, and the verification thereof, while the second presents possible applications of this model to ease the management of Diabetes. The human energy system simulation model - This section discusses the development and verification of the model. It also touches on the causes, and current methods, of managing diabetes, as well as the functioning of the human energy system. The human energy model is approached with the conservation of energy in mind. A top down model is developed, using data from independent studies to verify the model. Application of human energy simulation model - The human energy simulation model is of little use if the intended audience cannot use it: people suffering from malfunctioning energy systems. These include people having trouble with obesity, diabetes, cardiovascular disease, etc. To facilitate this, we need to provide a variety of products useable by this group of people. We propose a variety of ways in which the model can be used: Cellular phone applications, Personal digital assistants (PDAs) applications, as well as computer software. By making use of current technology, we generate a basic proof-of-concept application to demonstrate the intended functionality. / MIng (Mechanical Engineering) North-West University, Potchefstroom Campus, 2004