Demand Side Management (DSM) is one of the most viable and sustainable short term methods to address the shortfall in electricity generation in South Africa. This is because DSM projects can be implemented relatively quickly and inexpensively when compared with alternative generation options. This specifically applies to the mining industry. South African mines presently consume 15% of Eskom-generated electricity. Mine compressed air systems are some of the biggest users, consuming approximately 21% of mine electricity consumption. Electricity savings on compressed air systems are therefore important. With this study, various Energy Efficiency methods on compressed air systems were investigated. These methods include variable speed drives on compressor motors, temperature control of compressor discharge, minimising pressure drops in the air distribution systems, eliminating compressed air leaks, and optimising compressor selection and control. The most efficient strategies were identified, taking into account factors such as financial viability, sustainability, and ease of implementation. The best strategies were found to be the optimised control and selection of compressors, minimising compressed air leaks, and the optimal control of system pressure. These strategies were implemented and tested on large compressed air systems in gold and platinum mines. Savings of between 10% and 35% on the maximum demand of the systems were achieved. In present monetary terms this translates to as much as R108 million savings for the mines per year at the end of 2009 tariffs. If total mine compressed air electricity consumption can reduce by 30%, it will result in nearly a 1% reduction in total Eskom demand. This shows that mine compressed air savings can make a significant contribution to the drive for Energy Efficiency in South Africa. / Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2010.

Unreliable and unsustainable electricity supply has been experienced in South Africa since 2007. Eskom implemented Demand Side Management (DSM) as a short-term solution to alleviate this problem. Several compressed-air DSM projects were implemented to help reduce the strain on the electrical network. Compressed air is an integral part of production in deep-level mining, and is extensively utilised. Problems are encountered with the effective management and repairing of leaks, since the majority of mines have little to no procedures in place for leak management. Awareness of the condition of the compressed-air system and leaks needed to be created at management level in order to achieve the best results. The purpose of this study is to investigate the effect of proper leak management on compressed-air systems in the mining industry. Peak-clipping DSM projects implemented in the mining industry were used for evaluation of results. Contribution to the sustainability of compressed-air DSM projects savings through successful leak documentation was the prime focus of this study. This was achieved through the development of a Compressed Air Leakage Documentation System (CALDS). This entailed the electronic field-data capture and record keeping of field data, using rugged PDA devices suitable for the extreme environmental conditions encountered in deep-level mining. Report generation on the status of detected leaks created awareness of compressedair- system performance and leak-repair tracking at management level. Audible detection was sufficient for this study, since the focus was on the larger more-severe leaks. Leaks were expressed in monetary terms to indicate the severity. It was found that successful management of leaks could contribute to an increase of as much as 85% in project savings. The results also showed that creating awareness through documentation of leaks, and the effect this has on the system, resulted in regular repairing of these leaks. Sustainability of projects was maintained during an evaluation period of ten months, with projects achieving on average 125% of target savings. The study showed that effective reporting on compressed-air leaks resulted in increased system efficiency and sustainable DSM project savings. It was also seen that leak detection by outsourced companies did not necessarily result in financial savings. When the mine took responsibility for its own leak detection and repairs, significant savings were realised. / Thesis (M.Ing. (Electrical and Electronic Engineering))--North-West University, Potchefstroom Campus, 2011.

Demand Side Management (DSM) is one of the most viable and sustainable short term methods to address the shortfall in electricity generation in South Africa. This is because DSM projects can be implemented relatively quickly and inexpensively when compared with alternative generation options. This specifically applies to the mining industry. South African mines presently consume 15% of Eskom-generated electricity. Mine compressed air systems are some of the biggest users, consuming approximately 21% of mine electricity consumption. Electricity savings on compressed air systems are therefore important. With this study, various Energy Efficiency methods on compressed air systems were investigated. These methods include variable speed drives on compressor motors, temperature control of compressor discharge, minimising pressure drops in the air distribution systems, eliminating compressed air leaks, and optimising compressor selection and control. The most efficient strategies were identified, taking into account factors such as financial viability, sustainability, and ease of implementation. The best strategies were found to be the optimised control and selection of compressors, minimising compressed air leaks, and the optimal control of system pressure. These strategies were implemented and tested on large compressed air systems in gold and platinum mines. Savings of between 10% and 35% on the maximum demand of the systems were achieved. In present monetary terms this translates to as much as R108 million savings for the mines per year at the end of 2009 tariffs. If total mine compressed air electricity consumption can reduce by 30%, it will result in nearly a 1% reduction in total Eskom demand. This shows that mine compressed air savings can make a significant contribution to the drive for Energy Efficiency in South Africa. / Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2010.

Traditional Balinese architecture is commonly related to culture and traditional reasoning. When subjected to several modem problems such as energy demand, pollution, and impact of urbanisation and tourism, traditional architecture becomes less attractive since the definitions behind traditional reasoning are not clear and can be interpreted in different ways. To understand this feature, the study of traditional Balinese architecture starts by using several key parameters such as wind engineering and heat transfer, as presented and used in several countries. The flow patterns around a cubic building have been studied by many researchers. The velocity profile at the model position and the local surface roughness are specific to each building model and cannot be estimated from general tests of a standard building shape, therefore specific velocity profiles and conditions are used in this particular study. The air flow around a cluster of traditional Balinese buildings is extremely complicated and difficult to determine by modelling an isolated building (via symmetric conditions) since the buildings are linked to each other. Full scale models of traditional buildings have been investigated by using CFD to predict the above aspects. Simulations using this method can be done more quickly and less expensively than with wind tunnel experiments, and are capable of delivering more detailed and comprehensive information about the flow structure. Two-dimensional models of traditional Balinese building arrangements are simulated by using a commercial code Fidap based on the finite element method to assess the effects of type of roof, fence and surface roughness. Three-dimensional models are simulated by using a commercial code CFX based on the finite volume method to verify some traditional definitions. A standard к-ε model is adopted because it needs less computational power and has achieved notable successes in calculating a wide variety of thin shear layer and recirculating flows without the need of adjustment of the model constants, but with the imposition of boundary conditions to reduce the over-prediction near windward edges. Adopting lower values of к and ε combined with multi-blocks is shown to reduce this over-estimation. For a cubic building, the results can be compared with several other turbulence models. It appears that traditional Balinese architecture has a strong and significant correlation with several engineering fields, therefore traditional communities can develop by considering the Tri Hita Karana concept in order to improve thermal comfort and reduce cooling loads, with corresponding energy savings.

The introduction of building management systems in large buildings have improved the control of building services and provided energy savings. However, current building management systems are limited by the physical level of integration of the building's services and the lack of intelligence provided in the control algorithms. This thesis proposes a new approach to the design and operation of building management systems using rule-based artificial intelligence techniques. The main aim of is to manage the services in the building in a more co-ordinated and intelligent manner than is possible by conventional techniques. This approach also aims to reduce the operational cost of the building by automatically tuning the energy consumption in accordance with occupancy profile of the building. A rule-based design methodology is proposed for building management systems. The design adopts the integrated structure made possible by the introduction of a common communications network for building services. The 'intelligence' is coded in the form of rules in such a way that it is both independent of any specific building description and easy to facilitate subsequent modification and addition. This is achieved using an object-oriented approach and classifying the range of data available into defined classes. The rules are divided into two knowledge-bases which are concerned with the building's control and its facilities management respectively. A wide range of rule-based features are proposed to operate on this data structure and are classified in terms of the data classes on which they operate. The concepts presented in this thesis were evaluated using software simulations, mathematical analysis and some hardware implementation. The conclusions of this work are that a rule-based building management system could provide significant enhancements over existing systems in terms of energy savings and improvements for both the building's management staff and its occupants.

Within the design community, a growing number of researchers have shown interest in extending the value context to include design, such that designers focus on maximizing the 'value' of the product or service, rather than simply satisfying a set of requirements. Thus, by applying a value-driven approach to design, the design community hopes to show that the magnitude of cost and schedule overruns may be reduced, or even eliminated. However, a common criticism of value-driven approaches is that they are difficult to implement, and not sufficiently pragmatic to be used for large scale engineering problems. Further, some argue that less rigorous methods appear to provide reasonable results in practice, and so rigor is not necessary. To reconcile these disparate viewpoints, it must be shown that value-driven approaches contribute to the design process, and can be implemented in practice at a reasonable cost. In response, I propose that the cause for the lack of practicality in value-driven approaches is attributable to the lack of well established and verified methods and tools. This dissertation presents research that attempts to address this deficiency by first developing a better understanding of effectiveness for methods that seek to enable value-driven design. This investigation leads to a concise set of desired characteristics for methods for guiding the development of value-models which then motivate the creation of a Systematic Method for Developing Value Models (SMDVM). To evaluate the SMDVM, it is applied to the design and retrofit of buildings for energy efficiency. A simulation workbench is developed as a tool to automate the development and analysis of value models for building design and retrofit contexts. The workbench enables architects, engineers, and other practitioners to easily incorporate uncertainty into analyses of building energy consumption, as part of a value-driven approach to design and retrofit.

In existing economic literature on finance and economy, it is argued and generally accepted that financial intermediation contributes to economic growth though the contending argument is that financial development is simply a result of economic growth. However, studies on the contribution of financial intermediation of nonbanks (as opposed to banks) to economic growth are relatively scant and too general to clarify the mechanism through which nonbank financial intermediation might help economy to expand and develop. The focus of this study is on whether nonbank financial intermediation contributed to economic growth in the case of Korea where the share of nonbank financial intermediation increased from around 20% in 1970 to more than 60% in the early 1990's. This study is particularly interesting in light of the fact that rapid economic growth in Korea was accompanied by a concomitant increase in the share of nonbank financial intermediation. As a precursor to the empirical analysis, this study shows theoretically that financial intermediation of nonbanks subject to lesser liquidity control is complementary to, rather substitutional for, that of banks. Further, it is shown by optimizing a two-period dynamic model that under certain conditions nonbank intermediation increases an economy's savings mobilization and contributes to the economic growth. For empirical analysis, we used the annual data from 1972 to 1994 which can be considered as a financially repressed period. The empirical results are all consistent with the theoretically expected: nonbanks are complementary to banks in financial intermediation, increased the savings mobilization, and in the end contributed to the economic growth of the Korean economy during the sample period. Further, the estimated allocative efficiencies of nonbanks are almost in phase with business cycles, which may well be interpreted as consistent with the proposition that nonbanks financial intermediation made a significant contribution to Korea's economic growth.

<p>In South Africa, as in many developing countries, most households are poor and do not save, as a result of which they do not acquire any positive net worth and which also constrains access to formal means of finance. South Africa is a consuming nation, with increasing ratios of household consumption resulting in dissaving and often unsustainable levels of household debt, which is also stimulated by the current lower level of interest rates. This situation is worse amongst poorhouseholds who also often experience financial shocks, for instance because of the death of family membersas a result of HIV/AIDS. This report provided an overview of household saving in South Africa for the period 1983 to 2003. It identified the main factors responsible for the lack of a commitment to saving which are particularly relevant in the case of poor households.</p>

Coronary heart disease (CHD) is the single largest cause of death in Australia. Lack of physical activity is a primary risk factor for CHD. The thesis aimed to quantify the efficacy of walking in reducing CHD risk. Meta-analyses were performed for the quantification with the application of random-effect meta-regression models. The thesis also aimed to quantify reductions in CHD-related direct healthcare costs, productivity loss and disease burden resulting from walking interventions in Australia, using the population attributable fraction model, the work and leisure models, and the consumer surplus model. Economic evaluations were also conducted to estimate CHD-related productivity loss using the human capital and the friction methods. The results indicated that 30 minutes of normal walking a day for 5-7 days a week compared to physical inactivity reduced CHD risk by 24%. There existed a dose-response relationship between walking and CHD risk reduction. An increment of approximately 30 minutes of normal walking a day for 5 days a week reduced CHD risk by 19%. The annual productivity loss resulting from CHD was estimated at AU$1.79 billion based on the human capital method and AU$25.05 million under the friction method. 30 minutes of normal walking a day for 5-7 days a week by the country???s ???sufficient??? walking population was shown to generate an estimated $126.73 million in net direct healthcare savings annually. The net economic savings could increase to AU$419.9 million if the whole inactive population engaged in ???sufficient??? walking. The study also found that 30 minutes of normal walking a day for 5-7 days a week reduced the burden of CHD by an estimated 25,065 DALYs and the productivity loss by AU$162.65 million annually under the leisure model. If the whole inactive population engaged in such walking, the total disease burden and productivity loss could be reduced by approximately one third. The findings present epidemiological and economic evidence in support of the national physical activity guidelines, which encourage the general public to engage in moderate physical activity including walking for a minimum of 30 minutes a day for 5-7 days a week.

Thesis (Ph.D.) - Carleton University, 2006. / Includes bibliographical references. Also available in electronic format on the Internet.