2,183 research outputs found
Kultuurorganisasies binne bepaalde beroepsgroepe
Daar bestaan in Suid-Afrika ’n aantal kultuurverenigings wat hulle lede uitsluitlik of hoofsaaklik uit die personeel van ’n bepaalde beroepsgroep trek, naamlik die Afrikaanse Taalen Kultuurvereniging (Suid-Afrikaanse Spoorweë en Hawens), afgekort tot A.T.K.V. (S.A.S. en H.), die Afrikaanse Taal- en Kultuurbond (Pos- en Telegraafwese), (A.T.K.B. (P. en T.)), die Afrikaanse Kultuurvereniging van die Suid-Afrikaanse Polisie (Akpol) en die Afrikaanse Kultuurvereniging van die Weermag (A.K.V.V.)
Destratification induced by bubble plumes as a means to reduce evaporation from open impoundments
The use of thermal mixing by means of compressed air appears to have important potential for evaporation suppression on deep reservoirs. Current methods used to reduce evaporation from open-water impoundments such as floating covers, modular covers, monolayers and shade structures have many disadvantages and negative impacts on the environment. These methods impact the natural/modified aquatic ecosystem established in the dam; alter aesthetic qualities; increase the risk of dam failure in times of flood; could potentially lead to an oxygen reduction in the water; and may compromise the natural water treatment functions and operations such as the reduction of harmful bacteria, exposure to sunlight (form of disinfection) and natural and mechanical aeration thereby increasing treatment costs.The methodology proposed in this paper to help reduce evaporation losses from open-water impoundments, which indirectly addresses problems of water shortage and the associated economic impacts, involves the destratification of the water body using a bubble plume operated with minimal energy input to reduce surface water temperatures, with, a subsequent reduction in evaporation. The literature, although limited, indicates that this proposed method has merit and requires further research to identify specific reservoirs (size, depth, usage) that could benefit from such a destratification system. Evaporation suppression of as high as 30 % was achieved in some case studies
Student-informed directives for clinical communication skills training in undergraduate healthcare programmes: Perspectives from a South African university
Background. Clinical communication skills (CCS) are fundamental to good-quality healthcare and health outcomes, but remain problematic for healthcare students – in particular in the multilingual, multicultural South African context. As CCS can be taught, the importance of CCS training in healthcare programmes, as the basis of clinical practice, is well known.Objectives. To suggest practical, student-informed directives for CCS training, we explored current challenges of undergraduate healthcare students and their CCS training.Methods. The research was conducted in two phases. A mixed-methods approach was followed in phase 1, including a questionnaire survey (n=38) and semi-structured interviews (n=19), among third-year physiotherapy students. A quantitative questionnaire survey was conducted in phase 2 among final-year allied healthcare students (n=105).Results. Results from phase 1 indicated that students found it difficult to communicate with other members of the healthcare team (64%) and with patients’ families (82%). Students indicated that language barriers influenced their treatment of patients negatively. In phase 2 of the research, only 43% of students indicated previous exposure to CCS training, and they supported the inclusion of specific CCS training methods throughout their undergraduate education.Conclusions. CCS training directives, which are specifically focused on patient, family, interdisciplinary and written communication and enhancement of the student voice in the training, are suggested for inclusion in undergraduate healthcare programmes
Optimising water distribution systems using a weighted penalty in a genetic algorithm
Genetic algorithms (GAs) have become the preferred water system design optimisation technique for many researchers and practitioners. The main reason for using GAs is their ability to deal with nonlinear complex optimisation problems. The optimal decision in terms of designing, expansion/extending, addition or rehabilitation of water supply systems has to review possible options and select a cost-effective and efficient solution. This paper presents a new approach in determining a penalty value depending on the degree of failure, of the set pressure criteria, and the importance of the link supplying a specific node. Further modifications are also made in the cross-over and mutation procedures to ensure an increase in algorithm convergence. EPANET, a widely used water distribution network simulation model, is used in conjunction with the proposed newly developed GA for the optimisation of water distribution systems. The developed GA procedure has been incorporated in a software package called GANEO, which can be used to design new networks, analyse existing networks and prioritise improvements on existing networks. The developed GA has been tested on several international benchmark problems and has proved to be very efficient and robust. The EPANET hydraulic modelling software as well as the developed GANEO software, which performs the optimisation of the water distribution network, is freeware. The software provides a tool for consulting engineers to optimise the design or rehabilitation of a water distribution network.Keywords: optimising, water distribution system, genetic algorith
Дотик до вічності. Про розроблення нового історико/архітектурного плану м. Керчі
У 2009 р. автору статті було доручено очолити історико-містобудівні дослідження одного з найцікавіших стародавніх міст нашої країни Керчі. Метою досліджень було складання нового історико/архітектурного опорного плану з визначенням історичного ареалу і зони охорони найбільш цінних територій в межах сучасного міста
Performance analysis of production lines with continuous material flows and finite buffers
This paper deals with the approximative analysis of production lines with continuous material flow consisting of a number of machines or servers in series and finite buffers in between. Each server suffers from operational dependent breakdowns, characterized by exponentially distributed up- and down-times. We construct an iterative method to efficiently and accurately estimate performance characteristics such as throughput and mean total buffer content. The method is based on decomposition of the production line into single-buffer subsystems. Novel features of the method are (i) modeling of the aggregate servers in each subsystem, (ii) equations to iteratively determine the processing behavior of these servers, and (iii) use of modern matrix-analytic techniques to analyze each subsystem. The proposed method performs very well on a large test set, including long and imbalanced production lines. For production lines with imbalance in mean down-times, we show that a more refined modeling of the servers in each subsystem performs significantly better. Lastly, we apply the iterative method to predict the throughput of a bottle line at brewery Heineken Den Bosch yielding errors of less than two percent
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