Thesis (MCom)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The construction industry is a large, diverse and complex industry. In recent times, this industry has experienced a long-lasting period of inactivity. One sector that forms part of the construction industry is the civil engineering sector. This sector is the largest contributor to the income of the industry as a whole. Recent reports indicate that the construction companies within this industry are experiencing many challenges in both the internal and external environments. A preliminary discussion with a number of engineers indicated that these individuals felt as if they were required to do more than what was expected of them in terms of their job requirements. These expectations not only include being expected to voluntarily work overtime and to be tolerant of non-ideal site conditions, but also to informally develop the interpersonal skills necessary to minimise conflict and to motivate and support each other. The majority of the participating companies admitted to having a lack of such voluntary behaviour, namely organisational citizenship behaviour (OCB), amongst their engineers on site. It is for this reason that the core objective of the study was to develop and empirically study a structural model that explains the antecedents that contribute the most to the variance in OCB amongst civil engineers on various sites within South African engineering companies. During the preliminary discussion and subsequent literature review, the main antecedent found was personality. A quantitative research method with an ex post facto correlation design was utilised, where primary data was collected from a sample of 119 site employees of a number of South African construction companies. The self-administered questionnaire consisted of four sections, three of which were an amalgamation of the three valid and reliable measuring instruments that reflect the central focus of the structural model, i.e. personality, job satisfaction and organisational citizenship behaviour. The collected data was then analysed by means of Partial Least Squares Structural Equation Modelling. The results of the study indicate that certain personality characteristics do contribute to the occurrence of organisational citizenship behaviour amongst site employees. Within the areas of personality and job satisfaction theories, this research adds to the existing literature on OCB. In order to assist South African industrial psychologists within this industry, managerial implications and suggested interventions pertaining to the research findings are provided. / AFRIKAANSE OPSOMMING: Die konstruksiebedryf is 'n groot, diverse en komplekse bedryf. Gedurende die afgelope tydperk, het hierdie bedryf 'n voortdurende tydperk van onaktiwiteit ervaar. Een sektor wat deel vorm van die konstruksiebedryf is die siviele ingenieurswese sektor. Hierdie sektor is die grootste bydraer tot die inkomste van die bedryf as 'n geheel. Onlangse verslae dui daarop dat konstruksie maatskappye in die bedryf baie uitdagings in beide die interne en eksterne omgewings ervaar. 'n Voorlopige bespreking met 'n aantal ingenieurs het daarop gedui dat hierdie individue voel asof dit van hulle verwag word om vrywillig oortyd te werk asook verdraagsaam te wees van die nie-ideale werksterreine en omstandighede. Hulle voel dat die informele ontwikkeling van die interpersonlike vaardighede wat nodig is om konflik te verminder, asook mekaar te motiveer en ondersteun, ook vrywillig verwag word. Die meerderheid van die deelnemende maatskappye het bevestig dat daar ‘n gebrek is aan vrywillige gedrag, naamlik organiesatoriese burgerskap, onder die ingeniers op die werksterrein. Dit is vir hierdie spesifieke rede dat die kern doel van hierdie studie was om ‘n struktrele model te ontwikkel en empiries te bestudeier wat die geskiedenis uiteensit wat die tot die wisseling in OCB onder siviele ingenieurs op verskillende werksterreine in die Suid-Afrikaanse ingenieurs maatskappye. Tydens die voorlopige besprekings en die daaropvolgende literatuuroorsig was persoonlikheid die kern voorafgaande kenmerk. 'n Kwantitatiewe navorsingsmetode met 'n ex post facto korrelasie-ontwerp is gebruik, waar primêre data vanuit 'n steekproof van 119 werknemers van 'n aantal Suid-Afrikaanse konstruksie maatskappye versamel is. Die selftoegepaste vraelys het bestaan uit vier afdelings, waarvan drie 'n samesmelting was van die drie geldige en betroubare meetinstrumente wat die sentrale fokus van die strukturele model, naamlik persoonlikheid, werksbevrediging en organisatoriese burgerskaps-gedrag weerspieël. Die ingesamelde data is deur middel van Parsiële Kleinste Kwadrate Struktuurvergelykingmodellering ontleed. Die resultate van die studie het getoon dat sekere persoonlikheidseienskappe bydra tot die voorkoms van organisatoriese burgerskaps gedrag onder terreinwerknemers. Binne die gebiede van die persoonlikheid- en werkstevredenheid-teorieë, dra hierdie navorsing by tot die bestaande literatuur oor OCB. Ten einde Suid-Afrikaanse bedryfsielkundiges binne hierdie bedryf te help, is bestuurs-implikasies en voorgestelde ingrypings met betrekking tot die navorsing voorskaf.

Species which play particularly important roles in ecosystem patterns and processes are recognised as keystone species or ecosystem engineers. The conservation of these species is critical for the maintenance of the ecological role they play in ecosystem function. The aardvark, Orycteropus afer, is known to play a role in biopedturbation through digging for refuges and for prey, and as a consequence of these digging activities is expected to serve the role of an ecosystem engineer and keystone species. This study aimed to describe and quantify the ecological patterns and processes driven by the aardvark through their digging activities, within the eastern Karoo, and thereby evaluate the significance of aardvarks as ecosystem engineers and keystone species in a semi-arid environment. The landscape pattern (dig abundance and distribution) and soil displacement of aardvark forage and refuge digs in a semi-arid Karoo landscape, as well as the ecological processes (generating fertile, seed retention hotspots) driven by aardvark forage digs was measured. Refuge digs occurred in the highest densities in areas characterised by a specific suite of soil, vegetation and elevation features, while forage digs occurred in high abundance in most habitats measured, and were likely driven by prey availability. Forage digs served as litter and seed retention hotspots, with accelerated decomposition rates of litter as a function of increased soil moisture in digs. The functional processes (i.e. resource capture, shelter for plants and animals, germination sites, soil aeration, organic turnover, mineralization rates, fertile soil displacement and transport) driven by aardvark digs are not restricted to refuge digs. Forage digs occurred in most habitats measured and their functional role is unique and perhaps greater across the landscape in comparison to refuge digs. The aardvark has a disproportionate effect in ecosystems, in terms of its refuge and forage digs relative to its abundance and therefore its role as a keystone species and ecosystem engineer is confirmed. Conservation and protection of this species is therefore essential to maintain its important role in ecosystem function.

Submitted in fulfillment of the requirements of the degree of Master of Applied Science in Biotechnology, Durban University of Technology, 2015. / In light of the world’s declining fossil fuel reserves, the use of microalgal biodiesel has come to the forefront as a potentially viable alternative liquid fuel. The depleting freshwater reserves make the feasibility of this concept questionable. The use of wastewater reduces the requirement for depleting freshwater supplies. This project aimed to determine the viability of municipal domestic wastewater effluent as a substrate for microalgal growth, in order to generate an economical and environmentally friendly source of biofuel. Wastewater effluents from three domestic wastewater treatment plants were characterized in terms of known microalgal nutrients viz., ammonia, phosphate and nitrates. Phosphate concentrations varied throughout the year and were found to be low (< 3 mgL-1) whilst ammonia and nitrate concentrations ranged from 0 to 10 mgL-1 throughout the experimental period. These wastewaters were found to be suitable for cultivating microalgae. The study explored the cultivation of Chlorella sorokiniana on pre- and post-chlorinated domestic wastewater effluent to assess their potential as a medium for high microalgal culture density and lipid production. Post-chlorinated wastewater effluent was found to be superior to pre-chlorinated wastewater effluent, as evident by the higher biomass concentration. This wastewater stream did not contain high concentrations of bacteria when compared to pre-chlorinated wastewater effluent. Nitrogen is an essential nutrient required for regulating the growth and lipid accumulation in microalgae. Cultures growing in post-chlorinated effluent had a lifespan of 18 d. Residual nitrogen in wastewater effluent supported microalgal growth for limited periods. Supplementation using cheap, readily available nitrogen sources was required for optimal biomass and lipid production. Urea, potassium nitrate, sodium nitrate and ammonium nitrate were evaluated in terms of biomass and lipid production of C. sorokiniana. Urea showed the highest biomass yield of 0.216 gL-1 and was selected for further experimentation. Urea concentrations (0–10 gL-1) were assessed for their effect on growth and microalgal physiology using pulse amplitude modulated fluorometry. A concentration of 1.5 gL-1 urea produced 0.218 gL-1 biomass and 61.52 % lipid by relative fluorescence. Physiological stress was evident by the decrease in relative Electron Transport Rate from 10.45 to 6.77 and quantum efficiency of photosystem II charge separation from 0.665 to 0.131. Gas chromatography analysis revealed that C16:0, C18:0, C18:1, C18:2 and C18:3 were the major fatty acids produced by C. sorokiniana. Wastewater effluent has been considered an important resource for economical and sustainable microalgal biomass/lipid production. The study showed that C. sorokiniana was sufficiently robust to be cultivated on wastewater effluent supplemented with urea. The results indicate that supplemented wastewater effluent was an acceptable alternative to conventional media. Using a relatively cheap nitrogen source like urea can certainly improve the techno-economics of large scale biodiesel production.

A project report submitted to the Faculty of Engineering. University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering. Johannesburg, 1997. / The previously disadvantaged communities of Greater Johannesburg generally rely on publlc transport to get from place to place. Disabled people, who can be considered to be part of the previously disadvantaged community, often do not have any form of transport available to them at all. People from these communities wishing to attend an event at the Ellis Park Precinct would either have to use the existing public transport or make their own transport arrangements. Traffic and transportation management plans have been implemented at the Ellis Park Precinct with the intention of ensuring the Precinct's transportation accessibility for all the people of Greater Johannesburg, but the needs of the previously disadvantaged communities, who are captive to public transport, were not formally provided for. This project report provides details of the truffle and transportation management plans that have been implemented and then recummends/suggests various transportation options that could improve the transportation accessibility of the Precinct for these previously disadvantaged communities.

This study describes the social practices involved in the situated activity of report writing in an engineering automotive discourse community in South Africa. In particular, the study focuses on the subjectivity of predominantly English Second Language (ESL) engineers writing reports by determining what literacy means to them and what meanings they give to dominant literacy practices in report writing, especially feedback in text production. In the South African engineering workplace, because of the diversity and complexity of language and identity issues, the appropriation of the required literacy skills tends to be multifaceted. This context is made more complex as English is the business language upon which engineering is based with engineering competence often related to English proficiency. Therefore, the study is located within the understanding that literacy is always situated within specific discoursal practices whose ideologies, beliefs, power relations, values and identities are manifested rhetorically. The basis for this critical theory of literacy is the assertion that literacy is a social practice which involves not only observable units of behaviour but values, attitudes, feelings and social relationships. As the institution’s socio-cultural context in the form of embedded historical and institutional forces impact on writer identity and writing practices or ways of doing report writing, notions of writing as a transparent and autonomous system are also challenged. As critical ethnography is concerned with multiple perspectives, it was selected as the preferred methodology and critical realism to derive definitions of truth and validity. Critical ethnography explores cultural orientations of local practice contexts and incorporates multiple understandings providing a holistic understanding of the complexity of writing practices. As human experience can only be known under particular descriptions, usually in terms of available discourses such as language, writing and rhetoric, the dominant practices emerging in response to the report acceptance event are explored, especially that of supervisor feedback practices as they causally impact on report-writing practices during the practice of report acceptance. Although critical realism does not necessarily demonstrate successful causal explanations, it does look for substantial relations within wider contexts to illuminate part-whole relationships. Therefore, an attempt is made to find representativeness or fit with situated engineering literacy practices and wider and changing literacy contexts, especially the impact of Higher Education and world Englishes as well as the expanding influence of technological and digital systems on report-writing practices.

Submitted in fulfillment of the requirements of Doctor of Engineering, Durban University of Technology, Durban, South Africa, 2017. / The need to quantify and model transformations that have taken place in the cities of South Africa is one of the grand challenges linked to country’s transition to Democracy. Given the complexities associated with different stages of city transformation, it is imperative that models used to unpack processes of city transformation are novel. In this study it emerged that statistical methods alone are not adequate to fully present, in a comprehensible way, all facets of drivers of city transformation. As a result, statistical methods have been combined with mathematical and system dynamics models. Results revealed that city transformations derive from a number of triggers. Underlining these are income, migration and houses. The empirical data collected through questionnaire survey that was later incorporated into mathematical models demonstrated that income is a primary driver that fuels city migration. System Dynamic Models demonstrated that the availability of houses or accommodation serve as constraints that keep the city population within the limits of the carrying capacity of a city. In addition it was further confirmed, through mathematical models that income has varying effects on the attractiveness of cities. This was found to be linked to the shape of the distribution of income in the city. A normally distributed income with a peak in the middle results in a city being more attractive than an evenly distributed income that peaks either at very low or high income levels. This observation brought forth a need to test heterogeneity when analyzing city transformation using income as an index. Mathematical Models that incorporated heterogeneity demonstrated the usefulness of systems analysis in unpacking the mechanism of city transformation, a component of city management that requires serious consideration for planning, budgeting and provision of limited resources like houses in the cities. Success of methods used in this study led to a conclusion that these can be enhanced through other techniques like agent based models. With this call, improvements on this study that can be attained through these techniques are recommended. This will enrich the understanding of the transformation and dynamics of cities under different conditions than those that exist in South Africa. / D

The present study adopted a “field-laboratory-field” approach in the assessment of the efficacy of ergonomics interventions specific to two selected tasks evaluated in a South African automotive industry. Initial field testing was conducted in an Eastern Cape (South Africa) automotive plant where high risk areas were identified during walkthrough ergonomics surveys in conjunction with interaction with operators. Temporal factors and working postures of 12 industrial workers were recorded and observed, while physiological and perceptual responses were assessed. Two priority areas were focused upon for analysis, namely the Paintshop and Bodyshop with the former identified as being the more taxing of the two tasks. Responses of 30 students participating in rigourously controlled laboratory simulations were subsequently collected while completing the two tasks, namely the Paintshop Trolley Transfer (PTT) and Car Door Carriage (CDC) for participants. Working postures, kinematic, physiological and perceptual responses were assessed pre- and post-intervention. Following the laboratory experimentation a basic re-evaluation was conducted at the plant to assess whether the proposed changes had a positive effect on working postures, physiological and perceptual responses. The results of the preliminary field investigation revealed a prevalence of awkward working postures and excessive manual work in both areas. Laboratory experimentation revealed a notable reduction in task demands pre- versus post-intervention. The PTT mean lean angle for two-handed pre-intervention pulling observations of 23.7° (±3.51) was reduced to 13.9° (±2.21) post-intervention. Low back disorder (LBD) risk was reduced during the two-handed pull intervention (from 36.8% ±8.03 to 21.7% ±5.31). A significant decrement in heart rate responses from 103 bt.min-1 (±11.62) to 93 bt.min[superscript -1] (±11.77) was recorded during the two-handed symmetrical pushing intervention. The electromyography (EMG) responses for one-handed pushing and pulling pre-intervention showed the highest levels of muscular activity in the right medial deltoid due to an awkward and asymmetrical posture. CDC responses demonstrated that minor changes in the storage height of the door resulted in a significant reduction in sagittal flexion from 28.0° (±4.78) to 20.7° (±5.65). Predictions of average probability of LBD risk were significantly reduced from 50.3% (±5.91) to 39.8% (±5.10) for post-intervention car door lifting. In addition, the greatest reduction in EMG activity as a %MVC was achieved during sub-task ii (reduced from 35.1 to 13.7% and 30.5 to 13.9% for left and right erector spinae respectively) which was associated with the introduction of the transfer trolley for the door transfer phase of the CDC. Re-evaluation in the automotive plant revealed that the most notable change has been the implementation of automated ride on trolleys in the Paintshop. The Bodyshop area has also been modified to allow more effective job rotation and the step into the storage bin has been reduced via a “low-cost” stepping platform. Mean heart rate recordings were reduced from 94 (±9.77) bt.min[superscript -1] to 81 (±3.72) bt.min[superscript -1] in the Paintshop. Overall the results demonstrate the effect of “low-cost” interventions in reducing the physical stresses placed on workers in the automotive industry where much of the work is still done manually.

South Africa provides a fascinating interface between the developed and the developing world and poses a multitude of opportunities for enhancing the sustainable development of local cities. The concept of City Logistics is concerned with the mobility of cities, and entails the process of optimizing urban logistics activities by considering the social, environmental, economic, financial, and energy impacts of urban freight movement. Vehicle routing and scheduling has the potential to address a number of these key focus areas. Applying optimization to vehicle routing and scheduling results in a reduced number of trips, better fleet utilization, and lower maintenance costs; thereby improving the financial situation of the fleet owner. Improved fleet utilization could have a positive environmental impact, while also improving the mobility of the city as a whole. Energy utilization is improved while customer satisfaction could also increase through on-time deliveries and reliability. The Vehicle Routing Problem (VRP) is a well-researched problem in Operations Research literature. The main objective of this type of problem is to minimize an objective function, typically distribution cost for individual carriers. The area of application is wide, and specific variants of the VRP transform the basic problem to conform to application specific requirements. It is the view of this dissertation that the various VRP variants have been researched in isolation, with little effort to integrate various problem variants into an instance that is more appropriate to the South African particularity with regards to logistics and vehicle routing. Finding a feasible, and integrated initial solution to a hard problem is the first step in addressing the scheduling issue. This dissertation attempts to integrate three specific variants: multiple time windows, a heterogeneous fleet, and double scheduling. As the problem is burdened with the added constraints, the computational effort required to find a solution increases. The dissertation therefore also contributes to reducing the computational burden by proposing a concept referred to as time window compatibility to intelligently evaluate the insertion of customers on positions within routes. The initial solution algorithm presented proved feasible for the integration of the variants, while the time window compatibility decreased the computational burden by 25%, and as much as 80% for specific customer configurations, when using benchmark data sets from literature. The dissertation also improved the quality of the initial solution, for example total distance traveled, by 13%. Finding an initial solution is the first step in solving vehicle routing problems. The second step is to improve the initial solution iteratively through an improvement heuristic in an attempt to find a global optimum. Although the improvement heuristic falls outside the scope of this dissertation, improvement of the initial solution has a significant impact on the quality of improvement heuristics, and is therefore a valuable contribution. / Dissertation (MEng)--University of Pretoria, 2007. / Industrial and Systems Engineering / MEng / Unrestricted

This study is part of an NRF sponsored research project entitled “Neotectonics and its applications for the exploration of groundwater in the fractured Karoo aquifers in the Eastern Cape” under the NRF Niche area of Water Resources Management and Sustainable Development in the Eastern Cape Province. The identification of relatively highly productive wells in the Karoo fractured aquifers is extremely difficult. This study aims to identify neotectonic zones and lower stress fields, and apply the results to groundwater exploration in the Eastern Cape Province. The methodologies adopted in this study include: a comprehensive literature review, extensive field mapping and investigation such as road cuts, sampling for laboratory studies, examination of seismic data, study of hot and ordinary springs, and interpretation of aerial photography and satellite images. Three main neotectonic belts were identified in the Eastern Cape (southern neotectonic belt, northern neotectonic belt and eastern neotectonic belt) based on literature review and field interpretations. The southern neotectonic belt (from the Cape Fold Belt to the lower Beaufort Group boundary) is characterized by the reactivation of the Coega-Bavianskloof and Sauer faults, the presence of a hot spring near Fort Beaufort, the slickenlines and discrete slickenlines and specifically the seismic events that were recorded in the Eastern Cape from 1850 to 2007. In this southern neotectonic belt the remote sensing has also revealed the presence of the Fort Beaufort fracture, the quartz veins seen in some dolerites and the different vegetation types along it may indicate that this fracture is possibly a fault; moreover the Quaternary sediments and weathered dolerites indicate that the Fort iii Beaufort fracture is characterized by groundwater circulation and accordingly is a good target for groundwater exploration, this fracture is a post-Karoo structure and possibly a neotectonic feature. In addition, the kaolin deposit, chiefly developed in the Dwyka tillite near Grahamstown is clearly controlled by neotectonic fracture zones. The northern neotectonic belt near the country of Lesotho is marked by the presence of the Senqu seismotectonic regime and hot springs. The Quaternary Amatole-Swaziland (formerly Ciskei-Swaziland) axis of uplift makes the eastern part of the province the third neotectonic zone, the asymmetric meanders of the Mbashe river in the vicinity of Qunu near Mthatha derived possibly from this Quaternary uplift; this asymmetric feature of meanders implies that the river has tried to maintain stability of its valley where tilting occurred. Within these neotectonic belts the central part of the Eastern Cape may be considered a static and inactive belt. A northwesterly trend for the maximum principal compresssional stress predominates in the Eastern Cape and is correlated with the present major structural control of the province. The current stress regime determination was derived from faults, joints and quartz veins only on kaolin deposits. Systematic joints reflect regional tectonic stress trajectories at the time of fracturing. Discharge rates of groundwater from boreholes as provided by the Department of Water and Forestry were used to confirm and predict water exploration targets. The region of Tabankulu (near Kwazulu Natal) in the northern neotectonic belt has remarkable discharge rates of groundwater (11.1 l/s, 4.65 l/s, 6.49 l/s, 42 l/s). The region of Mthatha, nearly surrounding the Amatole-Swaziland axis (former Ciskei-Swaziland iv axis) of uplift which might have generated some new faults, has a number of springs. These two regions should serve as case studies for future research. Apart from these two regions, two others regions can be considered as case studies for future groundwater exploration targets: the Bath Farm hot spring near the Fort Beaufort neotectonic fault and the vicinity of what is known as the Fort Beaufort fracture near Teba and Cimezile villages 20km north west of Fort Beaufort. It is concluded that the study of neotectonics and stress fields may be a useful tool for groundwater exploration in the Karoo fractured aquifers in the Eastern Cape, and in similar regions elsewhere in South Africa and in Africa.

MEnv.Sc / Department of Geography and Geo-Information Sciences