https://commons.ru.ac.za/vital/access/manager/Index ${session.getAttribute("locale")} 5 Agribusiness challenges to effectiveness of contract farming in commercialisation of small-scale vegetable farmers https://commons.ru.ac.za/vital/access/manager/Repository/vital:27363 Wed 13 Mar 2024 09:16:24 SAST ]]> A strategic HRM framework for improving corporate governance in a municipal environment https://commons.ru.ac.za/vital/access/manager/Repository/vital:35349 Wed 12 May 2021 23:57:15 SAST ]]> A chemo-enzymatic process for the production of beta-thymidine, a key intermediate in antiretrovirol manufacture https://commons.ru.ac.za/vital/access/manager/Repository/vital:10423 Wed 12 May 2021 22:17:41 SAST ]]> Product development as part of a positioning strategy for the hunting industry in the Eastern Cape https://commons.ru.ac.za/vital/access/manager/Repository/vital:10894 Wed 12 May 2021 21:06:54 SAST ]]> Development of a reciprocating aerofoil wind energy harvester https://commons.ru.ac.za/vital/access/manager/Repository/vital:9622 Wed 12 May 2021 20:56:09 SAST ]]> Causal determinants of the public's attitudes towards hunting as a basis for strategies to improve the social legitimacy of hunting https://commons.ru.ac.za/vital/access/manager/Repository/vital:10759 Wed 12 May 2021 20:37:37 SAST ]]> Tailoring a lean product development framework for the South African automotive industry https://commons.ru.ac.za/vital/access/manager/Repository/vital:8792 Wed 12 May 2021 19:01:50 SAST ]]> A critical analysis of organisational strategies for employee engagement https://commons.ru.ac.za/vital/access/manager/Repository/vital:9378 Wed 12 May 2021 18:38:14 SAST ]]> Analysis processes as antecedents for decision-making related to growth strategies of South African Game Ranchers https://commons.ru.ac.za/vital/access/manager/Repository/vital:9356 Wed 12 May 2021 17:45:32 SAST ]]> Continuous flow synthesis of silicon compounds as feedstock for solar-grade silicon production https://commons.ru.ac.za/vital/access/manager/Repository/vital:20613 500 oC) resulted in a lower rate of reaction and selectivity than when slightly lower temperatures are used (<350 oC) in both reactors, although much difference was noticed in the packed bed flow tubular reactor. Synthesis in the batch reactor needed longer silicon-catalyst activation time, higher pre-heating temperature and higher catalyst amounts as compare to the packed bed flow tubular reactor. Reaction temperature and alcohol flow rate influenced the reaction in both methods. The optimum reaction temperature range and alcohol flow rate was comparable in both reactors (230 to 240 oC) and 0.1mL/min respectively. The effect of alcohol R-group (C1 to C4) on the reaction revealed that conversion and selectivity generally decrease with an increase in carbon chain length in both methods. Ethanol showed highest selectivity (>95% in batch and >97% in flow) and conversion (about 88% in batch and about 64% in flow) as compared to all other alcohols studied showing that it could be the most efficient alkoxylation alcohol for this reaction. Overally, the packed bed flow tubular reactor resulted in higher selectivity to trialkoxysilanes than the batch system. Performing the reaction under pressure resulted in increased conversion but selectivity to the desire trialkoxysilane diminished. Synthesis in a continuous flow falling film tubular reactor was not successful as it resulted in very poor conversion and selectivity. Monosilane was successfully synthesized from the disproportionation of triethoxysilane using homogeneous and heterogeneous catalysts in batch mode. The results obtained from homogeneous catalysis showed that the reaction can be conducted at room temperature. The heterogeneous catalysis method resulted in slow conversion at room temperature but mild heating up to 55 oC greatly improved the reaction. Conducting the reaction under neat conditions produced comparable results to reactions which were carried out using solvents. The disproportionation reaction was best described by the first order kinetic model. The results obtained in this research indicate that the packed bed flow tubular reactor can be utilized with future modifications for continuous flow synthesis of alkoxysilanes as feedstock for the solar-grade silicon production.]]> Wed 12 May 2021 17:32:11 SAST ]]> Material characterisation of laser formed dual phase steel components https://commons.ru.ac.za/vital/access/manager/Repository/vital:9609 Wed 12 May 2021 17:31:11 SAST ]]> The development of a framework to reduce water and energy consumption through the use of water and energy value stream mapping for the South African manufacturing industry https://commons.ru.ac.za/vital/access/manager/Repository/vital:20564 Wed 12 May 2021 16:37:37 SAST ]]> The development of motivational strategies for public sector workers in Kenya https://commons.ru.ac.za/vital/access/manager/Repository/vital:9380 Wed 12 May 2021 16:23:56 SAST ]]> Selective para-funtionalization of phenol https://commons.ru.ac.za/vital/access/manager/Repository/vital:10402 Wed 12 May 2021 16:16:45 SAST ]]> The development of best practice guidelines for the contingency management of health-related absenteeism in the motor manufacturing industry https://commons.ru.ac.za/vital/access/manager/Repository/vital:9379 Thu 13 May 2021 10:32:55 SAST ]]> A model for evaluating training and development initiatives in the Botswana public service https://commons.ru.ac.za/vital/access/manager/Repository/vital:9384 Thu 13 May 2021 10:23:25 SAST ]]> Monitoring and intelligent control for complex curvature friction stir welding https://commons.ru.ac.za/vital/access/manager/Repository/vital:9612 Thu 13 May 2021 09:31:30 SAST ]]> The selective dechlorination of poly-chlorophenols https://commons.ru.ac.za/vital/access/manager/Repository/vital:10391 Thu 13 May 2021 07:30:13 SAST ]]> A strategy for the development of team leaders in the East Cape motor industry cluster : a competency based approach https://commons.ru.ac.za/vital/access/manager/Repository/vital:8568 Thu 13 May 2021 07:23:47 SAST ]]> The development of a commercial production process for p-menthane-3,8-diol https://commons.ru.ac.za/vital/access/manager/Repository/vital:10427 Thu 13 May 2021 07:20:06 SAST ]]> Practical and scalable synthesis of N-Alkyl-N,N'Diacylhydrazines https://commons.ru.ac.za/vital/access/manager/Repository/vital:10406 Thu 13 May 2021 07:03:18 SAST ]]> Restoring trust by verifying information integrity through continuous auditing https://commons.ru.ac.za/vital/access/manager/Repository/vital:9796 Thu 13 May 2021 06:56:34 SAST ]]> Customer satisfaction with the guesthouse experience in Ghana https://commons.ru.ac.za/vital/access/manager/Repository/vital:21036 Thu 13 May 2021 06:54:53 SAST ]]> A model to improve the effectiveness of the Occupational Health and Safety Inspectorate function relative to South African construction https://commons.ru.ac.za/vital/access/manager/Repository/vital:9695 Thu 13 May 2021 06:50:02 SAST ]]> Characterisation of dissimilar friction stir welds between 5754 Aluminium alloy and C11000 copper https://commons.ru.ac.za/vital/access/manager/Repository/vital:9629 75 percent joint efficiency). High Vickers microhardness values were measured at the joint interfaces, which corresponded with the intermetallic compounds. The Energy Dispersive Spectroscopy analysis revealed the presence of thin layers of intermetallics in nanoscale at the interfacial regions. The diffractograms of the X-Ray Diffraction analysis showed small peaks for intermetallics in some of the welds. Low electrical resistivities were measured at the joint interfaces. The statistical analysis showed that the downward vertical force, (Fz) can significantly influence the resulting weld qualities. An overall summary of the analysis of the weld qualities - with respect to the shoulder diameter tools employed showed that the 18 mm shoulder diameter tool is most appropriate among the three shoulder diameters considered, and a process window of medium spindle speed of 950 rpm and low-to-medium feed rate between 50 and 150 mm/min is established for FSW of Aluminium and Copper. Welds produced at 1200 rpm and 300 mm/min with low heat input did not have intermetallics formed at the joint interface.]]> Thu 13 May 2021 06:36:12 SAST ]]> The oxidative coupling of phenols using stoichiometric metal oxidants https://commons.ru.ac.za/vital/access/manager/Repository/vital:10977 Thu 13 May 2021 06:35:34 SAST ]]> Factors influencing survivor qualities after downsizing https://commons.ru.ac.za/vital/access/manager/Repository/vital:9381 Thu 13 May 2021 06:15:46 SAST ]]> MISSTEV : model for information security shared tacit espoused values https://commons.ru.ac.za/vital/access/manager/Repository/vital:9787 Thu 13 May 2021 05:21:31 SAST ]]> An evaluation of leadership characteristics required to meet the demands of a strategic change process in the automative cluster in the Eastern Cape region https://commons.ru.ac.za/vital/access/manager/Repository/vital:9341 Thu 13 May 2021 04:41:25 SAST ]]> The development and evaluation of a new manufacturing process for β-sitosterol-D glucoside https://commons.ru.ac.za/vital/access/manager/Repository/vital:39320 0oC, and partly due to the thermodynamic equilibrium between two stereoisomers. An economically alternative process was developed, evaluated and scaled-up in a 2l reactor. The project was initiated with a specific limitation in terms of the starting material that comprised a mixture of plant sterols, which necessitated a study of the isolation and purification of the desired product from a rather complex reaction mixture. The use of silver as halide acceptor for the Koenigs-Knorr synthesis did not give statistically significant different results from the same approach but using cadmium as halide acceptor instead. However, using the direct O-glucosylation approach not only gave statistically significant higher results, but also resulted in a much more convenient procedure. Under optimum conditions, a yield of approximately 83% (isolated) of 2,3,4,6- tetra-О-acetyl-β-sitosterol-D-glucoside could be achieved, which was substantially higher than that achieved with the traditional Koenigs-Knorr methodology and above reported yields in the literature (60-80%) for direct glycosylation. Separation of 2,3,4,6-tetra-О-acetyl-β-sitosterol-D-glucoside (BSSGT) from a reaction mixture that contains 2,3,4,6-tetra-О-acetyl-campesterol-D-glucoside (CSGT), 2,3,4,6-tetra-О-acetyl campestanol-glucoside (CSSGT), and 2,3,4,6-tetra-О-acetyl-sitostanol-Dglucoside (SSGT) was investigated using column chromatography. When using silica gel particles, very good separation efficiency and product recovery could be achieved using hexane/ethyl hexane as eluent. The isolated 2,3,4,6-tetra-О-acetyl-β-sitosterol-Dglucoside was easily hydrolysed to β-sitosterol-D-glucoside in high yields (79%) using methanolic KOH. The process for the production of β-sitosterol-D-glucoside was scaled-up from the laboratory bench scale (250 cm3) to a laboratory scale of 2 l using the direct Oglycosylation method. The overall yields of the scaled reaction for β-sitosterol-D-glucoside was slightly above the literature reported values (59%, 8/92) for the KnoenigsKnorr synthesis and compares well above (62%, 0/100) the current production process (less than 20% yields). When using catalogue prices, the material costs (without recycling) for the direct Oglucosylation route is approximately 57% less for the synthesis of 1kg of β-sitosterol-Dglucoside compared to the Koenigs-Knorr route. Given further savings for recycling, the direct O-glucosylation route provides an attractive alternative route for the synthesis ofthe target compound.]]> Thu 13 May 2021 03:47:07 SAST ]]> Impact of ambient air pollution on human health health in the Nelson Mandela Bay Municipality https://commons.ru.ac.za/vital/access/manager/Repository/vital:29134 Thu 13 May 2021 02:42:08 SAST ]]> The development of a self-disintegrating core-body for use in an art bronze-casting foundry which employs the ceramic-shell investment technique https://commons.ru.ac.za/vital/access/manager/Repository/vital:8499 Thu 13 May 2021 02:31:23 SAST ]]> The development of an integrated value chain cost reduction methodology https://commons.ru.ac.za/vital/access/manager/Repository/vital:8775 Thu 13 May 2021 01:59:48 SAST ]]> Histopathological changes in male wistar rats maintained on a water-based sutherlandia frutescens extract https://commons.ru.ac.za/vital/access/manager/Repository/vital:20670 Thu 13 May 2021 01:58:33 SAST ]]> Development of a process for the preparation of linalool from CIS-2-pinanol https://commons.ru.ac.za/vital/access/manager/Repository/vital:10425 Thu 13 May 2021 00:38:35 SAST ]]> Trust building strategies to enhance collective bargaining processes in organisations https://commons.ru.ac.za/vital/access/manager/Repository/vital:9398 Thu 13 May 2021 00:06:14 SAST ]]> An investigation of the long term chemical stability and physical performance of PMD-citronellal acetal compared with dibutyl phthalate and BIS(2-ethylhexyl) terephthalate as plasticisers in selected cosmetic formulations https://commons.ru.ac.za/vital/access/manager/Repository/vital:36669 Fri 15 Mar 2024 13:06:48 SAST ]]>