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Friction stir processing (FSP), a solid-state post-processing technique that can provide localized modification and control of microstructures in near-surface layers of metallic components is developed based on the principles of friction stir welding (FSW). In this study, FSP was carried out in two phases. In Phase I, FSP was applied to one inch thick, sand casting A206 aluminum and 0.25 inch A367 bending fatigue sample. Optical microscope, SEM and EDS measurements have been performed to reveal a homogenous microstructure in the stirred zone, in which the porosities were quantitatively reduced, the second phase particles have been broken up and distributed in the Al matrix and there were some new components generated. Thermocouples have been applied to acquire the temperature gradient and thermo history during FSP. A range of material properties, including hardness and tensile measurement in A206, and bending fatigue test in A367 were examined. FSP resulted in an increase in hardness of the nugget compared to the hardness profile of the T4 condition. A significant improvement of the ductility of A206 was found after FSP compared to the ductility of T4 A206, but the FSP process slightly reduced the strength of A206. In Phase II, FSP was used for composite fabrication in the top layer of A206 substrate. The discontinuously reinforced aluminum (DRA) which contained 15% weight percent SiC was introduced into one inch thick sand cast A206 substrate. The surface composite layer is well bonded to the aluminum alloy substrate. Defects were not visible validating that FSP is an effective way for composite fabrication in Al cast alloys.

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Aluminum dross is a by-product of Aluminum production. At present, dross is processed in rotary kilns to recover the Al, and the resultant salt cake is sent to landfills; although it is sealed to prevent from leaching, the potential for leaching exists and could harm the environment as the salt cake contains fluorides and other salts. Furthermore, much energy is consumed to recover the Al from the dross; this is energy that can be saved if the dross could be diverted and utilized as an engineering material. The objective of this work is to eliminate waste and instead utilize the waste in a natural cycle (closed loop) by using it as an engineered material. Three avenues were investigated to utilize the dross: (i) refractory materials; (ii) aluminum composites; (iii) high temperature additive for de-sulphurizing steel. We have found that the use of dross waste to manufacture refractory material has much merit. Mechanical property evaluations revealed the possibility for dross waste to be utilized as filler in concrete, resulting in a 40% higher flexural strength and a 15% higher compressive strength compared to pure cement. These results will be presented and discussed.

South Africa has faced many changes in the last 20 years. There are some glaringly obvious ones such as democracy while others, such as the considerable increase of the legislative and regulatory requirements in the financial-services industry, are more subtle. Both however, have far-reaching consequences for both individuals and businesses. In Schaeffer's keynote address at the 2011 Financial Planning Convention, the global trends currently influencing the financial-planning profession were pointed out. These included the move towards a more relationship-based approach between financial planners and their clients, with holistic service offerings and regulatory change. Currently close to 100 000 Financial Services Board (FSB)-registered brokers/ advisors/ planners/ consultants claim to offer financial advice. Of these representatives only 4 600 (approximately) are Certified Financial Planner® professionals. The Financial Planning Institute of Southern Africa (FPI) maintains that the regulatory environment governing the financial industry is dynamic. Coupled with a tumultuous economic environment, this enforces the importance of an expert to assist individuals and businesses in planning for the future. The primary purpose of the Financial Advisory and Intermediaries Services Act (FAIS Act) is to: 1. protect the client against indecorous conduct by the financial service provider (FSP) and its representatives when providing financial advice and/or rendering intermediary services to clients; 2. ensure economic efficiency of the industry; 3. ensure that clients of FSPs are provided with sufficient information regarding their financial products, the representatives selling the products, the represented FSP and the product provider offering the products. The effect of the FAIS Act is that key individuals and representatives are now being held responsible for their actions, which may include providing incorrect information or not having sufficient qualifications or experience. According to the FSB the FAIS Fit and Proper requirements determine a set of requirements that all FSPs, key individuals and representatives need to comply with. The Determination of Fit and Proper Requirements of 2008 outlines the categories of fit and proper requirements for FSPs, their key individuals and representatives. The categories of the FAIS Fit and Proper requirements are: - honesty and integrity requirements for FSPs, key individuals and representatives; - competency requirements of FSPs, key individuals and representatives; - experience requirements of FSPs, key individuals and representatives; - qualifications requirements of key individuals and representatives; - regulatory examinations requirements of key individuals and representatives; - continuous professional development requirements of FSPs, key individuals and representatives; - operational ability of FSPs, key individuals and representatives; and - solvency of FSPs. The empirical study of the research was conducted nationally, within South Africa. The focus of the study was to investigate the perception of financial planners with regard to the regulatory and legislative prescriptions of the financial-services industry. The general objective of the study is to provide a quantitative measure of the perception of financial planners of the effect that the legislative and regulatory requirements in South Africa have on the ethicality of the financial-planning industry. To achieve this objective, the empirical study focussed on the responsibilities of financial-services providers and the FAIS fit and proper requirements as set out by the FAIS Act. The population identified for the empirical study consisted of financial planners that provide advisory and/or intermediary services in South Africa. The population of the study consisted of the full advisory complement, 826, which form part of the advisory division of a major South African financial-services provider. These financial planners are located across South Africa, in all nine provinces and in rural and metropolitan areas. Based on the result of the adjusted sample size equation, the required sample size for the study is reduced from 266 to 201. A total of 260 responses were received for the study which ensures a high level of accuracy is achieved from the findings of the research. The results of the empirical study provide ample proof that financial planners support the necessity and specificity of the FAIS fit and proper requirements as defined by the FAIS Act. Additionally, the financial planners agree that the determinants of the FAIS Act are not only beneficial to the sustainability and ethicality of the industry, but also support the success of the planner and ultimately ensure that clients receive the best possible financial advisory and/or intermediary services. / MBA, North-West University, Potchefstroom Campus, 2015

South Africa has faced many changes in the last 20 years. There are some glaringly obvious ones such as democracy while others, such as the considerable increase of the legislative and regulatory requirements in the financial-services industry, are more subtle. Both however, have far-reaching consequences for both individuals and businesses. In Schaeffer's keynote address at the 2011 Financial Planning Convention, the global trends currently influencing the financial-planning profession were pointed out. These included the move towards a more relationship-based approach between financial planners and their clients, with holistic service offerings and regulatory change. Currently close to 100 000 Financial Services Board (FSB)-registered brokers/ advisors/ planners/ consultants claim to offer financial advice. Of these representatives only 4 600 (approximately) are Certified Financial Planner® professionals. The Financial Planning Institute of Southern Africa (FPI) maintains that the regulatory environment governing the financial industry is dynamic. Coupled with a tumultuous economic environment, this enforces the importance of an expert to assist individuals and businesses in planning for the future. The primary purpose of the Financial Advisory and Intermediaries Services Act (FAIS Act) is to: 1. protect the client against indecorous conduct by the financial service provider (FSP) and its representatives when providing financial advice and/or rendering intermediary services to clients; 2. ensure economic efficiency of the industry; 3. ensure that clients of FSPs are provided with sufficient information regarding their financial products, the representatives selling the products, the represented FSP and the product provider offering the products. The effect of the FAIS Act is that key individuals and representatives are now being held responsible for their actions, which may include providing incorrect information or not having sufficient qualifications or experience. According to the FSB the FAIS Fit and Proper requirements determine a set of requirements that all FSPs, key individuals and representatives need to comply with. The Determination of Fit and Proper Requirements of 2008 outlines the categories of fit and proper requirements for FSPs, their key individuals and representatives. The categories of the FAIS Fit and Proper requirements are: - honesty and integrity requirements for FSPs, key individuals and representatives; - competency requirements of FSPs, key individuals and representatives; - experience requirements of FSPs, key individuals and representatives; - qualifications requirements of key individuals and representatives; - regulatory examinations requirements of key individuals and representatives; - continuous professional development requirements of FSPs, key individuals and representatives; - operational ability of FSPs, key individuals and representatives; and - solvency of FSPs. The empirical study of the research was conducted nationally, within South Africa. The focus of the study was to investigate the perception of financial planners with regard to the regulatory and legislative prescriptions of the financial-services industry. The general objective of the study is to provide a quantitative measure of the perception of financial planners of the effect that the legislative and regulatory requirements in South Africa have on the ethicality of the financial-planning industry. To achieve this objective, the empirical study focussed on the responsibilities of financial-services providers and the FAIS fit and proper requirements as set out by the FAIS Act. The population identified for the empirical study consisted of financial planners that provide advisory and/or intermediary services in South Africa. The population of the study consisted of the full advisory complement, 826, which form part of the advisory division of a major South African financial-services provider. These financial planners are located across South Africa, in all nine provinces and in rural and metropolitan areas. Based on the result of the adjusted sample size equation, the required sample size for the study is reduced from 266 to 201. A total of 260 responses were received for the study which ensures a high level of accuracy is achieved from the findings of the research. The results of the empirical study provide ample proof that financial planners support the necessity and specificity of the FAIS fit and proper requirements as defined by the FAIS Act. Additionally, the financial planners agree that the determinants of the FAIS Act are not only beneficial to the sustainability and ethicality of the industry, but also support the success of the planner and ultimately ensure that clients receive the best possible financial advisory and/or intermediary services. / MBA, North-West University, Potchefstroom Campus, 2015

Friction stir processing (FSP) was applied to produce aluminum based in situ composites from powder mixtures of Al-Fe, Al-Mo, and Al-Fe2O3. Billet of powder mixtures was prepared by the use of conventional pressing and sintering route. The sintered billet was then subjected to multiple passages of FSP. During FSP, the material has experienced both high temperature and very large plastic strain. The basic idea for fabricating the composites is to combine the hot working nature of friction stir processing (FSP) and the exothermic reaction between aluminum and transition metals (Al-Fe, Al-Mo) or metal oxides (Al-Fe2O3). In the Al-Fe alloy, in situ Al¡VFe reaction can be induced during FSP and form Al-Al13Fe4 composite. The size of reinforcing particles formed by the in-situ reaction is ~100 nm. In Al-Mo alloys, fine Al-Mo intermetallic particles with an average size of ~200 nm were formed and uniformly dispersed in the aluminum matrix by FSP. The Al-Mo intermetallic particles were identified mainly as Al12Mo with minor amount of Al5Mo. The exothermic reaction could result in local melting of Al at the Al/TM interface, and the liquid Al may accelerate the reaction. In addition, it is suggested that the critical mechanism responsible for the rapid reaction and the formation of nanometer sized particles in FSP is the effective removal of the Al-TM intermetallic phase from the Al-TM interface, maintaining an intimate contact between TM and Al. In the Al-Fe2O3 system, the reactions taking place during FSP includes the thermite reaction (2Al +Fe2O3 ¡÷ Al2O3 + 2Fe), and the reaction between the reduced Fe and Al to form Al13Fe4. In the FSPed Al-Fe2O3 specimens, there are two types of second phase particles, Al13Fe4 and Al2O3. The Al2O3 particles (about 10 nm in size) usually appear as a cluster of 100-200 nm in diameter. There are two types of Al2O3 phases existed in the Al matrix after FSP passes, depending on the content of Fe2O3. One is £^-Al2O3 in Al-2Fe2O3 specimens, and the other is £\-Al2O3 in Al-4Fe2O3 specimens. It is suggested that the formation of different type of Al2O3 particles in the Al-Fe2O3 composites may be attributed to different heat release in each system. The lower heat release in Al-2Fe2O3 sample favors the formation of the while the higher heat release in Al-4Fe2O3 sample results in the £\-Al2O3. The Al-Al13Fe4/Al2O3 composite produced by FSP exhibits both high strength and good tensile ductility. The higher strength in Al-Fe2O3 specimen may be due to the presence of fine Al2O3 particles. The flow stress of the Al-4Fe2O3 composite can maintain at 100 MPa even at 773 K. The good thermal stability and high temperature strength of Al-Al13Fe4/Al2O3 composites could be attributed to the fine dispersion of second phase particles in the aluminum matrix, especially the nanometric Al2O3 particles. These Al2O3 particles are very stable at elevated temperatures, even after long time exposure at 873 K. The temperature excursion in FSP is determined by both the FSP parameters and the exothermic reaction involved. The peak temperature in Al-Fe or Al-Fe2O3 system during FSP was calculated as a function of the fraction of Fe or Fe2O3 reacted. Based on calculated results, it is noted that with the in situ reaction, the value of can easily reach the melting point of Al, especially for the Al-Fe2O3 system. The reaction mechanism and microstructure evolution during FSP are discussed.

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Friction stir processing (FSP) is one of the new and promising thermomechanical processing techniques that alters the microstructural and mechanical properties of the material in single pass to achieve maximum performance with low production cost in less time using a simple and inexpensive tool. Preliminary studies of different FS processed alloys report the processed zone to contain fine grained, homogeneous and equiaxed microstructure. Several studies have been conducted to optimize the process and relate various process parameters like rotational and translational speeds to resulting microstructure. But there is only a little data reported on the effect of the process parameters on the forces generated during processing, and the resulting microstructure of aluminum alloys especially AA5052 which is a potential superplastic alloy. In the present work, sheets of aluminum alloys were friction stir processed under various combinations of rotational and translational speeds. The processing forces were measured during the process and the resulting microstructure was analyzed using TEM. The results indicate that the processing forces and the microstructure evolved during FSP are sensitive to the rotational and translational speed. It is observed that the forces generated increase with the increasing rotational speed. The grain refinement was observed to vary directly with rotational speed and inversely with the translational speed. Also these forces generated were proportional to the grain refinement i.e., greater refinement of grains occurred at lower forces. Thus the choice of process parameters especially the rotational speed has a significant effect on the control and optimization of the process.

A traffic conditioner is an element of the Differentiated Services architecture. This architecture is used to regulate quality of service in computer networks. Five traffic conditioners were selected for the study. These include the token bucket marker and four conditioners described in RFCs. The contribution of this dissertation is two-fold. Firstly, it presents process algebra models of the five identified traffic conditioners. These models provide succinct descriptions of the conditioners thereby highlighting essential features. The models are, however, not intended for model checking purposes, but rather serve as a convenient pedagogical device. The second and main contribution of the dissertation is a simulation study to investigate the relative performance of the five traffic conditioners across a range of simulated scenarios in which traffic patterns and subscription levels are varied in a fixed network topology. Two performance measures—TargetRatio and GreenRatio—are defined, justified, and used to compare the traffic conditioners. The GreenRatio measure was found to be more discriminating than the TargetRatio measure. A variant of the GreenRatio measure was used to further illuminate the differences between conditioners. The simulation results suggest that the performance of the conditioners are sensitive to parameter values such as token bucket size and that bursty traffic patterns are particularly sensitive to these parameters. Under such bursty conditions, these parameters should be chosen with care. / Dissertation (MSc (Computer Science))--University of Pretoria, 2007. / Computer Science / unrestricted