Students with disabilities in higher education

This study reviews and critically analyses literature from 2000 onwards to obtain a perspective of the latest research trends and interests as well as the theoretical development in the study of  students with special education needs in higher education. The diversity of research themes indicates that higher education faces multiple challenges. The research further finds that this field of study is still in an exploratory phase. Qualitative studies in smaller settings are the most popular, and progress towards generalisable theories is still relatively young. It is encouraging to note that research is increasingly addressing the empirical issues experienced in higher education institutions. Suggestions for future research are given

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

Remote monitoring and diagnosis for control of EDM parameters

M.Ing.This thesis presents the concept of remote (Internet) data acquisition and processing for control of EDM parameters. It incorporates aspects of data analysis while performing diagnosis of process behavior. A working neuro-macro model of the EDM process is utilized for process correlation and diagnosis recommendations. The approach allows selective ways to vary the EDM process performance. The focus in this work is on the process efficiency. The process efficiency is related to the input parameters through the neuro-macro model of the EDM process. A comprehensive description of on-line monitoring and processing of data is included. Experimental results based on the suggested analysis and diagnosis for possible process adaptation particularly with respect to the EDM process efficiency is presented

Cost savings on mine dewatering pumps by reducing preparation– and comeback loads

MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014Using chilled water within South African gold mines is paramount to the purpose of extracting gold ore efficiently. Using water for cooling, drilling and sweeping and the release of underground fissure water causes the accumulation of vast amounts of water in underground dams. Deep mines use cascading pump systems for dewatering, which is an electrical energy intensive dewatering method. Due to the recent equalisation of demand to generation capacity of electrical energy in South Africa, various methods towards demand side reduction have been implemented. With the introduction of a time-of-use (TOU) tariff structure by Eskom, the implementation of projects that shift load from peak TOU times to times of the day when electrical energy is less expensive has increased. To enable load shifting on mine dewatering pumps, preparation before and recovery after peak TOU is needed for effective results. This induces a preparation- and comeback load in the standard TOU. With an annual increase in TOU tariffs and the rate of increase of standard TOU being greater than that of the peak TOU, a reduction in electrical energy consumption before and after peak TOU is needed. To enable this, a step-by-step control technique was developed to promote the shifting of load from standard- to off-peak TOU, while still realising a full load shift from peak TOU. This technique entails dynamic control ranges of underground dam levels as opposed to the conventional constant control range method. Two case studies were used to test the developed technique. Results indicated significant additional financial savings when compared to conventional control methods. Additional savings of R1,096,056.65 and R579,394.27 per annum were respectively achieved for both case studies.Master

Benchmarking electricity use of deep-level mines

PhD (Mechanical Engineering), North-West University, Potchefstroom Campus, 2016Electricity consumption, and the cost thereof, has become a large contributor to operating costs in deep-level mining in South Africa. Up to 60% of electricity used on deep-level mines can be attributed to five high power demand systems that continuously operate for maximum production output. Compressed air, cooling, dewatering, ventilation and hoisting systems form part of these high demand systems. The need to reduce electricity consumption of high power demand systems is identified as a means to increase mining profit. Various initiatives that aim to increase energy efficiency of high power demand systems have been implemented. However, these initiatives are often driven by external parties with no stake in mining profitability. It is important to create awareness of system performance in terms of comparative energy consumption to start focusing on identifying possible energy efficiency initiatives for mines. Numerous energy benchmarking studies have been conducted on systems ranging from commercial to industrial. The focus of these studies was on increasing energy consumption awareness and, in doing so, identifying the need to reduce energy consumption. The objective of this study is to benchmark the electricity use of deep-level mines in a new way that considers relevant external factors and variables. New models were created using actual data obtained from South African deep-level mines. Models for both average and best practice benchmarking were developed. A novel technique for determining the priorities of energy efficiency initiatives on high demand systems was also developed. This study creates additional real-time awareness by developing a new method to determine operational energy budgets. 2015 Benchmarking electricity use on deep-level mines. The developed models and techniques were verified by using external methods. The models were then validated by applying them to the high power demand systems of nine case study mines. The results showed that the benchmarking, prioritisation and dynamic energy budgeting models accurately distinguished between efficient and inefficient mine systems. With the knowledge obtained, awareness of system-specific and overall energy consumption was achieved and mitigating initiatives could be implemented.Doctora

Jeugmisdaad en die blanke sekondere skool in die Kaapse Skiereiland : 'n opvoedkundig-sielkundige studie

Proefskrif (M. Ed.) -- Universiteit van Stellenbosch, 1982.Full text to be digitised and attached to bibliographic record

n Opvoedkundig-sielkundige hulpverleningsprogam vir die hantering van jeugwangedrag in sekondere skole onder provinsiale onderwysdepartemente in die Republiek van Suid-Afrika

Proefskrif (D. Ed.) -- Universiteit van Stellenbosch, 1989.Full text to be digitised and attached to bibliographic record

A deep framework for predictive maintenance

Computer ScienceENGLISH ABSTRACT: Predictive maintenance (PdM) is a well-known maintenance approach that comprises of two problems, machine prognostic modelling and maintenance scheduling. The objective of prognostic modelling is to predict faults in machine components such as aircraft engines, lithium-ion batteries or bearings. The objective of maintenance scheduling is to reduce the cost of performing maintenance once the future degradation behaviour of a component has been established. Sensors are used to monitor the degradation behaviour of components as they change over time. Supervised learning is a suitable solution for prognostic modelling problems, especially with the increase in sensor readings being collected with Internet of Things (IoT) devices. Prognostic modelling can be formulated as remaining useful life (RUL)- or machine state estimation. The former is a regression- and the later is a classification problem. Long short-term memory (LSTM) recurrent neural networks (RNNs) are an extension of traditional RNNs that are effective at interpreting trends in the sensor readings and making longer term estimations. An LSTM uses a window of sequential sensor readings when making prognostic estimates which causes it to be less sensitive to local sensor variations, which results in improved prognostic model performance. In this study we create a framework to implement PdM approaches. The work consists of a codebase which can be used to create testable, comparable and repeatable prognostic modelling results and maintenance scheduling simulations. The codebase is designed to be extensible, to allow future researchers to standardise prognostic modelling results. The codebase is used to compare the prognostic modelling performance of an LSTM with tradition supervised prognostic modelling approaches such as Random Forests (RF)s, Gradient boosted (GB) trees and Support Vector Machines (SVM)s. The prognostic models are tested on three well-known prognostic datasets, the Commercial Modular Aero-Propulsion System Simulation (C-MAPSS) engine aircraft-, Center for Advanced Life Cycle Engineering (CALCE) battery- and Intelligent Maintenance Systems (IMS) bearing datasets. During the study we highlight factors that influence prognostic model performance, such as the effect of de-noising sensor readings and the size of the sample window used by the LSTM when making estimations. The results of the prognostic models are compared with previous studies and the LSTM shows improved performance on considered cases. The developed prognostic models are used to perform preventative maintenance scheduling with assumed costs in two simulations. The objective is first to compare the efficacy of traditional maintenance approaches, such as a mean time between failure (MTBF) strategy, with a PdM strategy, and second to investigate the effect of using a better performing prognostic model (such as the LSTM) in a PdM strategy. The improvements are measured by the reduction in costs. Key words: Predictive maintenance; remaining useful life; machine state estimation; preventative maintenance scheduling.AFRIKAANSE OPSOMMING: Voorspellende instandhouding (PdM) is ’n bekende instandhoudingsbenadering wat bestaan uit twee probleme, naamlik masjienprognostiese modellering en instandhoudingskedulering. Die doel van prognostiese modellering is om foute in masjienkomponente soos vliegtuigenjins, litiumioonbatterye of laers te voorspel. Die doel van instandhoudingskedulering is om die koste van die uitvoering van instandhouding te verminder sodra die toekomstige degradasiegedrag van ’n komponent vasgestel is. Sensors word monitor die degradasiegedrag van komponente soos hulle verander oor tyd. Toesigleer is ’n geskikte oplossing vir prognostiese modelleringsprobleme, veral met die toename in sensorlesings wat met Internet of Things (IoT) toestelle ingesamel word. Prognostiese modellering kan geformuleer word as oorblywende nuttige lewensduur (RUL)- of masjientoestandberaming. Eersgenoemde is ’n regressie- en die latere is ’n klassifikasieprobleem. Langtermyngeheue (LSTM) herhalende neurale netwerke (RNN) is ’n uitbreiding van ’n tradisionele RNN wat effektief is om tendense in die sensorlesings te interpreteer en langertermynskattings te maak. ’n LSTM gebruik ’n venster van opeenvolgende sensorlesings wanneer prognostiese skattings gemaak word, wat veroorsaak dat dit minder sensitief is vir plaaslike sensorvariasies, wat lei tot verbeterde prognostiese modelwerkverrigting. In hierdie studie skep ons ’n raamwerk om PdM-benaderings te implementeer. Die werk bestaan uit ’n kodebasis wat gebruik kan word om toetsbare, vergelykbare en herhaalbare prognostiese modelleringsresultate en onderhoudskeduleringssimulasies te skep. Die kodebasis is ontwerp om uitbreidbaar te wees, sodat toekomstige navorsers prognostiese modelleringsresultate kan standaardiseer. Die kodebasis word gebruik om die prognostiese modelleringsprestasie van ’n LSTM te vergelyk met tradisionele prognostiese modelleringsbenaderings soos Random Forests (RF)’e, Gradient boosted (GB) trees en Support Vector Machines (SVM)’s. Die prognostiese modelle word getoets op drie bekende prognostiese datastelle, die Commercial Modular Aero-Propulsion System Simulation (C-MAPSS) enjinvliegtuie, Sentrum vir Gevorderde Lewensiklusingenieurswese (CALCE) battery en Intelligente Onderhoudstelsels (IMS) dradatastelle. Tydens die studie beklemtoon ons faktore wat prognostiese modelprestasie beïnvloed, soos die effek van die ruisonderdrukking van sensorlesings en die grootte van die monstervenster wat deur die LSTM gebruik word wanneer ramings gemaak word. Die resultate van die prognostiese modelle word vergelyk met vorige studies en die LSTM toon verbeterde prestasie op die oorwoë gevalle. Die ontwikkelde prognostiese modelle word gebruik om voorkomende instandhoudingskedulering uit te voer met veronderstelde koste in twee simulasies. Die doelwit is eerstens om die doeltreffendheid van tradisionele-instandhoudingsbenaderings, vb. ’n gemiddelde tyd tussen mislukking (MTBF)-strategie, met ’n PdM-strategie te vergelyk en tweedens om die effek van die gebruik van ’n beter presterende prognostiese model (soos die LSTM) in ’n PdM strategie te ondersoek. PdM strategie. Die verbeterings word gemeet aan die vermindering in koste. Sleutelwoorde: Voorspellende instandhouding; oorblywende nuttige lewensduur; masjien toestand skatting; voorkomende onderhoudskedulering

Post-fire effects of invasive exotic plants on seed banks, regeneration, soil chemistry and selected soil microbial populations in the Silvermine Nature Reserve, Cape Peninsula, South Africa

Thesis (MSc) -- University of Stellenbosch, 2002.ENGLISH ABSTRACT: The fires, which occurred during January 2000 on the Southern Cape Peninsula, Cape Province, South Africa, focused attention on the importance of sound, informed management of exotic plant invaders in fynbos, especially at the urban interface. The fires also highlighted the relative lack of knowledge about the combined impacts of fire, exotic plants and the exotic-clearing programme on soil seed banks and regeneration. This study examines soil borne seed banks, regeneration, soil chemistry and micro biota in different postfire environments, focusing on three components of exotic plant management: The post-fire effects of standing invasive exotic plants; stacks of slashed exotic plant material which were deliberately burnt and stacks reduced to heat scars by a wildfire. The primary hypothesis addressed is that post-fire vegetation regeneration patterns, seed bank diversity and seed bank abundance are linked to pre-fire vegetation characteristics and, in particular, to the treatment of exotic plant species. It is also hypothesised that soil microbe population sizes are linked to pre-fire vegetation and soil chemical composition. Differences in soil seed banks, soil micro biota and vegetation regeneration patterns occur in different post-fire environments. High volumes of (live or dead) woody exotic biomass negatively impact upon postfire indigenous species diversity and abundance, both above and below-ground. Soil seed banks and above-ground regeneration decline with increasing fire intensity, wildfire burnt stack treatments showing the largest declines followed by wildfire burnt standing exotics, control burnt stacks, wildfire burnt cleared areas and wildfire burnt Mountain Fynbos treatments. Persistent indigenous seed banks are found under some exotic dominated stands. Heat damage, associated with high woody exotic biomass, affects seeds of all species into deep soil layers. Depth of burial is a more important determinant of seed survival during fires than seed size. Soil microbial populations are variably affected by exotic plants, their management and increases in fire intensity. The most drastic microbial population changes are in post-fire treatments of high exotic plant biomass. Soil chemistry affects microbial population sizes as does seasonal climatic changes. In this thesis vegetation, seed bank and microbial responses to various exotic plant management practices are shown and management recommendations are made. Keywords: exotic plants, fire, Fynbos Siome, microbes, post-fire succession, soil seed banks.AFRIKAANSE OPSOMMING: Die Januarie 2000 vure op die Suid Kaapse Skiereiland het fokus gerig op die belangrikheid van goeie, ingeligte bestuur van uitheemse indringerplante in fynbos, veral naby stedelike gebiede. Die vure het ook 'n relatiewe .gebrek aan kennis aangaande die gekombineerde impakte van vuur, uitheemse plantegroei en indringer plant beheer programme op grond saadbanke en die hergroei van plante na 'n vuur aan die lig gebring. Hierdie projek bestudeer die invloed van vuur op grond saadbanke, hergroei van plante, grond chemie en mikro-organismes. Die klem lê op drie komponente van uitheemse plant bestuur: waar staande uitheemse plante voorkom; waar skoongekapte uitheemse plante in hope gestapel is en gekontraleerd gebrand is en waar soortgelyke hope in 'n onbeplande weghol vuur gebrand is. Die primêre hipotese is dat plant herstelpatrone, saadbank diversiteit en grootte gekoppel is aan veldtoestande voordat daar gebrand is, en veral aan die bestuur van uitheemse plantspesies. Nog 'n sentrale hipotese is dat die grootte van grond mikrobiale populasies gekoppel is aan veld toestande voor die brand en aan grond chemiese samestelling. Hierdie studie dui verskille aan in grond saadbanke, mikro-organismes en plant hergroeipatrone onder verskeie toestande na vuur. Die brand van hoë volumes (lewende of dooie) houtagtige uitheemse plant biomassa benadeel inheemse plant spesie diversiteit en getalle (bo en onder die grond oppervlak). Grond saadbanke neem af met vehogings in vuur intensiteit. Die grootste afnames is in wegholvuur gebrande gestapelde uitheemse plantmateriaal gevolg deur wegholvuur gebrande staande uitheemse plante, opsetlik gebrande hope uitheemse plante, gebrande skoongekapte areas en wegholvuur gebrande Berg Fynbos. Ou inheemse saadbanke is gevind onder sommige areas wat voor die vuur oorheers was deur uitheemse plantegroei. Hitteskade, geassosieer met hoë volumes houtagtige uitheemse biomassa, affekteer sade van alle spesies tot diep in die grond. Saad oorlewing tydens brande is meer geaffekteer deur diepte van begrawing in die grond as deur saad grootte. Grond mikro-organisme populasies is geaffekteer deur uitheemse indringer plante, die bestuur van uitheemse plante en vuur intensiteit. Die grootste veranderinge is waar die biomassa van uitheemse plantegroei baie hoog is. Grond chemiese samestelling en seisoenale veranderinge in weerspatrone affekteer die grootte van mikrobiale bevolkings. In hierdie tesis word verskille in plantegroei, saad store en grond mikrobes, soos geaffekteer deur uitheemse plant beheer programme uitgewys en voorstelle vir toekomstige bestuur gemaak. Sleutelwoorde: Fynbos Bioom, grond saad stoor, mikrobes, plant hergroei, uitheemse plante, vuur

Vigs in die werkplek : 'n regsperspektief

M.Phil. (Labour Relations)The aim of this study was to investigate the impact of Aids in the workplace from a legal point of view and to isolate some of the most important areas where legal regulation could become problematical. In general it was found that the best way to deal with Aids is to try and prevent it by eliminating ignorance as far as .possible and to bring the disease into the open by means of the early distribution of facts through proper education and counselling and especially the formulation and implementation of a sympathetic Aids policy. This should prevent litigation on the basis of the unfair labour practice concept in the industrial court to a large extent. The legal position regarding problem areas such as confidentiality, testing, the value and regulation of screening, the freedom to employ, dismissal, termination and safety was analysed both in terms of existing South African law and also by comparison with developments internationally. It was found that a high premium is placed on security of employment and that Aids victims should not be discriminated against, but treated objectively like other cases of serious illness