Ideale vir die uitbouing van tegniese en beroepsonderwys in Suid-Afrika

Problems emanating from the colonial structure, and which tend to reduce man to being a “human machine”, are discussed, and it is indicated that these tend to impinge on the status oj technical and professional education and lower it. From the demands the modern human-machine system makes one’s full capacity for being human, the author draws the conclusion that in technical and professional training human development has to be given primary consideration. A discussion of the problems surrounding cultural change and modernization in post-colonial set-ups indicates the fact that technical and professional education has a unique education task and opportunity in South Africa too

Reducing the electricity cost of a Three-Pipe Water Pumping System – a case study using software

Efficient control is often the most cost-effective option to improve on the running cost of a ThreePipe Water Pumping System. However, the effect of changing the control strategy (i.e. on energy consumption) is usually difficult to predict. A new simulation tool, QUICKcontrol, was used to investigate the energy cost savings potential in a Three-Pipe Water Pumping System. The influence of pump scheduling, dam level set points, control parameters and different combinations thereof were investigated. The simulation models were firstly verified with measurements obtained from the existing system to confirm their accuracy for realistic control retrofit simulations. With the aid of the integrated simulation tool, it was possible to predict savings of R195 000 per year with an average 3.8 MW of load shifted out of peak times. These control strategies can be implemented in the pumping system with a direct payback period of less than 6 months

Reducing the electricity cost of a Three-Pipe Water Pumping System – a case study using software

Efficient control is often the most cost-effective option to improve on the running cost of a ThreePipe Water Pumping System. However, the effect of changing the control strategy (i.e. on energy consumption) is usually difficult to predict. A new simulation tool, QUICKcontrol, was used to investigate the energy cost savings potential in a Three-Pipe Water Pumping System. The influence of pump scheduling, dam level set points, control parameters and different combinations thereof were investigated. The simulation models were firstly verified with measurements obtained from the existing system to confirm their accuracy for realistic control retrofit simulations. With the aid of the integrated simulation tool, it was possible to predict savings of R195 000 per year with an average 3.8 MW of load shifted out of peak times. These control strategies can be implemented in the pumping system with a direct payback period of less than 6 months

Monitoring the oceanic flow between Africa and Antarctica: Report of the first GoodHope cruise

The southern ocean plays a major role in the global oceanic circulation role in the global oceanic circulation, as a component of the Meridional Overturning Circulation, and it is postulated that it has a great influence on present-day climate. However, our understanding of its complex three-dimensional dynamics and of the impact of its variability on the climate system is rudimentary. The newly constituted, international GoodHope research venture aims to address this knowledge gap by establishing a programme of regular observations across the Southern Ocean between the African and Antarctic continents. The objectives of this programme are fivefold: (1) to improve understanding of Indo-Atlantic inter-ocean exchanges and their impact on the global thermohaline circulation and thus on global climate change; (2) to understand in more detail the influence these exchanges have on the climate variability of the southern African subcontinent; (3) to monitor the variability of the main Southern Ocean frontal systems associated with the Antarctic Circumpolar Current; (4) to study air–sea exchanges and their role on the global heat budget, with particular emphasis on the intense exchanges occurring within the Agulhas Retroflection region south of South Africa, and (5) to examine the role of major frontal systems as areas of elevated biological activity and as biogeographical barriers to the distribution of plankton. We present here preliminary results on the physical and biological structure of the frontal systems using the first GoodHope transect that was completed during February–March 2004

South African Paediatric Surgical Outcomes Study : a 14-day prospective, observational cohort study of paediatric surgical patients

BACKGROUND : Children comprise a large proportion of the population in sub-Saharan Africa. The burden of paediatric surgical disease exceeds available resources in Africa, potentially increasing morbidity and mortality. There are few prospective paediatric perioperative outcomes studies, especially in low- and middle-income countries (LMICs). METHODS : We conducted a 14-day multicentre, prospective, observational cohort study of paediatric patients (aged <16 yrs) undergoing surgery in 43 government-funded hospitals in South Africa. The primary outcome was the incidence of in-hospital postoperative complications. RESULTS : We recruited 2024 patients at 43 hospitals. The overall incidence of postoperative complications was 9.7% [95% confidence interval (CI): 8.4–11.0]. The most common postoperative complications were infective (7.3%; 95% CI: 6.2–8.4%). In-hospital mortality rate was 1.1% (95% CI: 0.6–1.5), of which nine of the deaths (41%) were in ASA physical status 1 and 2 patients. The preoperative risk factors independently associated with postoperative complications were ASA physcial status, urgency of surgery, severity of surgery, and an infective indication for surgery. CONCLUSIONS : The risk factors, frequency, and type of complications after paediatric surgery differ between LMICs and high-income countries. The in-hospital mortality is 10 times greater than in high-income countries. These findings should be used to develop strategies to improve paediatric surgical outcomes in LMICs, and support the need for larger prospective, observational paediatric surgical outcomes research in LMICs. CLINICAL TRIAL REGISTRATION : NCT03367832.Jan Pretorius Research Fund; Discipline of Anaesthesiology and Critical Care, Nelson R Mandela School of Medicine, University of KwaZulu-Natal; Department of Anaesthesia and Perioperative Medicine, Groote Schuur Hospital and University of Cape Town; Department of Anaesthesia, University of the Witwatersrand; and the Paediatric Anaesthesia Community of South Africa (PACSA).https://bjanaesthesia.org2020-02-01gl2019Anaesthesiolog

Effect of inoculum size on the rates of whole ore colonisation of mesophilic, moderate thermophilic;thermophilic acidophiles

Bioheap leaching of low grade copper sulphides has been applied successfully at the commercial scale for the extraction of copper from secondary sulphide minerals. It is important to optimise the inoculation of heaps in order to minimise the residence time required for the heap and to maximise extraction. Thermophilic bioleaching of the primary sulphide chalcopyrite poses an additional challenge of rising temperatures inside the heap demanding microbial succession. After heap start up, rising heap core temperatures make conditions less favourable for mesophilic microbial species, and the moderately thermophilic community succeeds them in the consortium. In turn, thermophilic microorganisms succeed the moderately thermophilic microbes as the higher temperatures are reached. A detailed understanding of the microbial colonisation of whole ore is necessary to optimise microbial succession during thermophilic bioleaching, as is that of microbial growth kinetics on whole ore. Most published research is focused on microbial growth rates of bioleaching organisms in liquid cultures; little work is reported on microbial colonisation of whole ore and subsequent microbial activity. To extend the information available on the microbial diversity and succession in a bioleaching habitat, a study of bioleaching microbes colonising the ore body is required. The aim of this work was to explore aspects of colonisation of low grade chalcopyrite ore at 23 °C, 50 °C and 65 °C by acidophilic micro-organisms. Laboratory column packed bed reactors were designed to simulate heap leach environments and to provide a systematic way of studying microbial dynamics on whole ore. The effect of inoculum size and inoculation strategies on microbial activity established and the subsequent leaching performance were investigated under conditions that support mesophilic, moderately thermophilic and thermophilic microorganisms. A relationship was shown between the inoculum size and the culture time required to achieve Eh values greater than 700 mV, especially at 23 °C and 65 °C. However, the culture time required to establish an active iron- (and sulphur-) oxidising culture was also influenced by ore type, irrigation rate and inoculum adaptation. The effect on effluent Eh, pH and dissolved iron levels is also discussed