Mineral asset valuation of Kimberley Mine for divestment purposes

A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Masters of Science in Engineering. Johannesburg 2015Divestment is always an option for each and every mining operation. It only becomes a viable option if in the hands of the current owner when a point is reached where the life of mine is limited and continued depletion of the remaining mineral resources cannot be achieved due to economic considerations. Kimberley Mine, a diamond mine, is finding itself in this situation. The research study was focused on determining a divestment range where divestment can be considered by the current owner, to handover the going concern to a new owner. The new owner will be able to extend the life of mine through the adoption of a different operating model to enable economic extraction of the current marginal and sub economic mineral resources. The long term analysis of supply and demand of diamonds indicates an opportunity associated with the predicted long-term gap between declining supply and demand growth. This gap will enable diamond producers to take advantage of future pricing increases. It is envisaged that this in turn will impact on the viability of existing marginal and sub economical diamond mineral resources and operations, such as Kimberley Mine, whether it be in the hands of De Beers Consolidated Mines Proprietary Limited (DBCM) or an envisaged new owner. The study also determined that the Kimberley Mine operational entity is a current going concern with a good business case in the hands of a potential new owner prepared to make material operational cost adjustments. It is logistically well located, with very good supporting infrastructure both at municipal and provincial level. The Tailings Mineral Resource (TMR) operational complexity is comparatively low in relation to underground operations and is well equipped with industry aligned best practice equipment, machinery, and human capital. Based on the literature review of the main valuation methods and research conducted on historical comparable transactions, there is value for a new investor in Kimberley Mine. The asset package as envisaged offers a very attractive revenue stream between 2017 and 2018. The economic viability of TMR 29 has been demonstrated through the adoption of a “small miner” fit for purpose operating cost model and could extend the life of mine to 2030. This will enable the economic extraction of an estimated 4.5 million carats from the remaining TMR’s. Based on the comparable transaction methodology for TMR operations the divestment value that could result in a suitable positive outcome for both the current owner and the potential future owner resides in the range ZAR 287 million to ZAR 527 million. The discounted cash flow analysis proved that the new owner models can deliver a positive net present value with asset acquisition prices ranging between ZAR 324 million and ZAR 527 million. Lastly, the Monte Carlo simulation results reflect a medium to high probability of success for the “small miner” new owner scenario and return on investment. The study concluded that the current owner must target a divestment price commencing at ZAR 527 million for negotiation purposes

Fuzzy set covering as a new paradigm for the induction of fuzzy classification rules

In 1965 Lofti A. Zadeh proposed fuzzy sets as a generalization of crisp (or classic) sets to address the incapability of crisp sets to model uncertainty and vagueness inherent in the real world. Initially, fuzzy sets did not receive a very warm welcome as many academics stood skeptical towards a theory of imprecise'' mathematics. In the middle to late 1980's the success of fuzzy controllers brought fuzzy sets into the limelight, and many applications using fuzzy sets started appearing. In the early 1970's the first machine learning algorithms started appearing. The AQ family of algorithms pioneered by Ryszard S. Michalski is a good example of the family of set covering algorithms. This class of learning algorithm induces concept descriptions by a greedy construction of rules that describe (or cover) positive training examples but not negative training examples. The learning process is iterative, and in each iteration one rule is induced and the positive examples covered by the rule removed from the set of positive training examples. Because positive instances are separated from negative instances, the term separate-and-conquer has been used to contrast the learning strategy against decision tree induction that use a divide-and-conquer learning strategy. This dissertation proposes fuzzy set covering as a powerful rule induction strategy. We survey existing fuzzy learning algorithms, and conclude that very few fuzzy learning algorithms follow a greedy rule construction strategy and no publications to date made the link between fuzzy sets and set covering explicit. We first develop the theoretical aspects of fuzzy set covering, and then apply these in proposing the first fuzzy learning algorithm that apply set covering and make explicit use of a partial order for fuzzy classification rule induction. We also investigate several strategies to improve upon the basic algorithm, such as better search heuristics and different rule evaluation metrics. We then continue by proposing a general unifying framework for fuzzy set covering algorithms. We demonstrate the benefits of the framework and propose several further fuzzy set covering algorithms that fit within the framework. We compare fuzzy and crisp rule induction, and provide arguments in favour of fuzzy set covering as a rule induction strategy. We also show that our learning algorithms outperform other fuzzy rule learners on real world data. We further explore the idea of simultaneous concept learning in the fuzzy case, and continue to propose the first fuzzy decision list induction algorithm. Finally, we propose a first strategy for encoding the rule sets generated by our fuzzy set covering algorithms inside an equivalent neural network

Fuzzy set covering as a new paradigm for the induction of fuzzy classification rules

In 1965 Lofti A. Zadeh proposed fuzzy sets as a generalization of crisp (or classic) sets to address the incapability of crisp sets to model uncertainty and vagueness inherent in the real world. Initially, fuzzy sets did not receive a very warm welcome as many academics stood skeptical towards a theory of imprecise'' mathematics. In the middle to late 1980's the success of fuzzy controllers brought fuzzy sets into the limelight, and many applications using fuzzy sets started appearing. In the early 1970's the first machine learning algorithms started appearing. The AQ family of algorithms pioneered by Ryszard S. Michalski is a good example of the family of set covering algorithms. This class of learning algorithm induces concept descriptions by a greedy construction of rules that describe (or cover) positive training examples but not negative training examples. The learning process is iterative, and in each iteration one rule is induced and the positive examples covered by the rule removed from the set of positive training examples. Because positive instances are separated from negative instances, the term separate-and-conquer has been used to contrast the learning strategy against decision tree induction that use a divide-and-conquer learning strategy. This dissertation proposes fuzzy set covering as a powerful rule induction strategy. We survey existing fuzzy learning algorithms, and conclude that very few fuzzy learning algorithms follow a greedy rule construction strategy and no publications to date made the link between fuzzy sets and set covering explicit. We first develop the theoretical aspects of fuzzy set covering, and then apply these in proposing the first fuzzy learning algorithm that apply set covering and make explicit use of a partial order for fuzzy classification rule induction. We also investigate several strategies to improve upon the basic algorithm, such as better search heuristics and different rule evaluation metrics. We then continue by proposing a general unifying framework for fuzzy set covering algorithms. We demonstrate the benefits of the framework and propose several further fuzzy set covering algorithms that fit within the framework. We compare fuzzy and crisp rule induction, and provide arguments in favour of fuzzy set covering as a rule induction strategy. We also show that our learning algorithms outperform other fuzzy rule learners on real world data. We further explore the idea of simultaneous concept learning in the fuzzy case, and continue to propose the first fuzzy decision list induction algorithm. Finally, we propose a first strategy for encoding the rule sets generated by our fuzzy set covering algorithms inside an equivalent neural network

Process development and commissioning of a bioreactor for mass culturing of USAB granules by process induction and microbial stimulation

Thesis (MScEng (Process Engineering))--University of Stellenbosch, 2005.The Up-flow Anaerobic Sludge Blanket Reactor (UASB) provides a state-of–the-art solution to effluent treatment by anaerobic digestion: sludge production is dramatically lower than in other digestion processes, and energy is gained from the system if the produced biogas is converted to electricity and/or heat. The UASB is a modified fluidised bed reactor, with the solid state ‘catalyst’ being granulated anaerobic sludge, and the liquid phase the effluent that needs to be treated. A gas cap is installed to serve as a carbon dioxide and methane collector. This biogas (carbon dioxide and methane) is produced by the stepwise decomposition of complex carbohydrates and proteins via a consortium of micro-organisms living in a symbiotic environment known as a granule. A typical UASB reactor has an organic removal rate of 89-93% Chemical Oxygen Demand (COD) and operates optimally at loadings of 9.8-11 kg COD/ m3 reactor volume/day. Unfortunately, one major problem hampers the efficiency of this reactor to such an extent that the unit is only economically viable in exceptional cases; if the reactor is inoculated with un-granulated anaerobic sludge, start-up times of up to 12 months can be expected. The lengthy start-up times motivated the search for an artificial way to cultivate USAB granules. Early research (done on lab-scale, 400ml vessel volumes) proved that, under a specified set of environmental conditions, granule growth can occur in an artificial environment. Yet these laboratory-scale vessels did not facilitate scale-up or the study thereof. This led to the main problem statement of this research project: namely to design, commission, and optimise benchscale bioreactors that will generate granulated anaerobic sludge in an incubation period of 20 days. These units should also facilitate in the determining of parameters that will assist in the design of a scale-up to a UASB granule producing reactor of economically viable size. Two bench-scale reactors were initially designed specifically to “mimic” the motion found in the laboratory-scale vessels. The results from these initial reactors proved that granulation cannot only be enhanced, but granules can actually be cultivated from dispersed anaerobic sludge in a larger artificial environment over an incubation period of only 20 days. The results were still far from satisfactory, as the granules produced were irregular in shape and the yield of usable granules (2.2 kg/m3 reactor volume) insufficient. A third test reactor was designed to “mimic” roller table movement and baffles were included. These results were much better and the yield was 4.4 kg/m3 reactor volume at a baffle tipspeed of 0.0055 m/s. The optimisation was extended further to include the inoculation sludge and the feed medium. A C:N:P ratio of 10:1:4 proved to yield the best results. Monovalent anions, hydrogen concentration and a pH-level outside the 6.5 to 7.2 range evidently had an inhibitory effect on the granulation rate. After the optimisation study the third test unit produced a usable granule yield of 15.2 kg/m3 reactor volume over the 20-day incubation period. The incubation period can be separated into 3 distinct phases, namely the acidification, stabilisation and growth phases. From the mass balance it was found that most of the COD and nutrients were used for ECP production in the acidification phase. During the stabilisation phase, the COD and nutrients were mostly used for nucleus formation, and finally in the growth phase the COD was used for granule growth. To study the effect the internal surface area of the reactor has on the granulation process, 3 scale-down versions of the third test unit were constructed. Within the studied range, a yield of usable granules of 40 kg/m2 reactor internal surface area was obtained

Barriers to enhancing project performance through experiential learning

Experiential learning has been empirically confirmed to enhance performance of project organisations. This research investigates the literature and included field surveys to get insights into the barriers (and by default any enablers) relating to project related knowledge transfer in project orientated organisations. It seeks to explore the reality and perceptions related to experiential learning within an international group of organisations to confirm expected obstacles to learning.The research follows a quantitative approach in the form of a field survey and includes qualitative insights gained from a secondary data review. It seeks to test the validity of propositions articulating suspected barriers to learning as it is experienced or perceived to exist within the selected sample of organisations.This study is unique as, although it build on previous research, it introduces a new dimension in that experiential learning aspects as experienced by international organisations are measured simultaneously with conditions within related local organisations. The results confirmed a similar outcome between the two groups in terms of the research propositions and must be used by project orientated organisations to create management awareness in terms of the reality of specific barriers so as to guide implementation of suitable corrective measures.Dissertation (MBA)--University of Pretoria, 2012.Gordon Institute of Business Science (GIBS)unrestricte

Challenges of transition from school to senior level athletics in South Africa

At present, very few South African athletes who compete at a junior level and perform well make a successful transition to senior athletics. Far too many discontinue their participation when transitioning to senior track and field athletics to the detriment of our country’s athletics. This study provides insights into the transitional challenges that South African track and field athletes face and highlights the effects of various factors on transition. The available literature suggests that there are multiple factors, which cause an unsuccessful transition. Furthermore, the effectiveness of support systems that are meant to assist athletes in overcoming these challenges is questionable. A qualitative research design, which employed narrative interviews with 12 South African athletes who had competed internationally as junior athletes, was used in the study. The results revealed that support systems, coaches, training plans, injuries and qualification standards are the main challenges that South African athletes face during their transition to senior level athletics. Vast improvements in communication and decisive commitments need to be made in the existing support structures to help young athletes. Furthermore, there is disparity between the challenges for which structures provide support and the actual challenges athletes in South Africa encounter.Dissertation (MEd)--University of Pretoria, 2018.Humanities EducationMEdUnrestricte

The predictive modelling of the performance of a crude oil fractionator in terms of gas chromotographic characterization.

Thesis (Ph.D.)-University of Natal, 1973.No abstract available

The amounts of fluorides (alkali-soluble as well as insoluble) gained on and in enamel of third molars from a high fluoride area

Magister Chirurgiae Dentium (MChD)A total of 25 third molar teeth (erupted [9], as well as unerupted [16]), from subjects who had lived continuously since birth in an area where the water fluoride concentration was more than 1,8 ppm, were studied. (The range was 1,8 ppm - 2,64 ppm of F-). The subjects had no systemic fluoride supplementation. Tooth brushing with a fluoride containing dentifrice and, perhaps, occasional fluoride mouth rinsing was the only additional exposure to fluoride. The acid-etch biopsy technique was used to determine the fluoride and calcium concentrations at various depths on the enamel surface. The fluoride concentration of the buffered etch solution was determined with an adapted fluoride ion-selective electrode technique, and the amount of calcium by flame atomic absorption spectrophotometry. Six consecutive etchings were done on the mesio-buccal and mesio-lingual cusps of each tooth; the teeth were then washed in an alkali and the same procedure repeated on the disto-buccal and disto-lingual cusps. The depth of etch of each biopsy was calculated assuming that human enamel contains 37% Ca and has a density of 2,95g/ml. It was previously reported, (Grobler & Joubert, 1988), that the enamel fluoride levels of the mesio-buccal and mesio-Iingual sides did not differ from that of the disto-buccal and disto-Iingual sides. The average etch depth and fluoride concentration value as calculated from the values for the two cusps per tooth were used for statistical analysis. The mean etch depths (pm) and mean enamel fluoride concentrations of alkali-washed and unwashed enamel of both erupted and unerupted teeth were tabled, together with the standard deviations and range for each etch. Contrary to the results obtained from a low F- area, no significant difference (p>O.05) could be found in the etch depth between erupted and unerupted enamel in this study. Graphs were plotted by a line fitted to the mean enamel fluoride concentration and mean etch depths values of unwashed erupted, unwashed unerupted, alkali-washed erupted and alkali-washed unerupted third molar teeth. These graphs were compared to the graphs obtained in a comparable study done by Grobler and Kotze (1990), on erupted and unerupted third molar teeth from a low fluoride area (F- 1,8 ppm), is higher than that of teeth from a low fluoride area « 0,10 ppm ). In contrast to the teeth from a low fluoride area, where there was a significant increase (p0,05). There was, in addition, no significant (p>0.05) difference between the enamel fluoride content of alkali-washed and unwashed, erupted and unerupted teeth, which showed that very little CaF 2-like material was gained by the enamel after eruption. In both studies the subjects had brushed with a fluoride dentifrice for a period of 1 - 16 years. It was expected that this topical exposure would increase the surface enamel concentration in the high fluoride area similar to the increase found in the low fluoride area. However, this was not the case, and as all the teeth from the high fluoride area exhibited some degree of fluorosis, it was concluded that posteruptive fluoride uptake by fluorotic human enamel without severe enamel loss is limited. This is in agreement with work done by Richards, Fejerskov, Baelum and Likimani (1989)

The message of the church in view of dialectical theology (A sip of theology from the old wine-skins)

This article attempts to ascertain the essence of the message preached by churches whose dogma is influenced by dialectical theology, especially that of Karl Barth. The basic point of departure is that although the theology to which churches subscribe is not actually preached, the content and quality of sermons cannot escape its influence. As dialectical theology is generally regarded and understood as an extension of Reformation theology, it is imperative to integrate both the basic truths of Reformation theology and the innovative trends of dialectic thinking as far as the preaching of the gospel is concerned. In view of the enormous scope of Barthian theology, the author was compelled to limit his article to the essence of the church's message, namely the gospel of reconciliation, according to many scholars the heart of Barth 's theology.Spine cut of Journal binding and pages scanned on flatbed EPSON Expression 10000 XL; 400dpi; text/lineart - black and white - stored to Tiff Derivation: Abbyy Fine Reader v.9 work with PNG-format (black and white); Photoshop CS3; Adobe Acrobat v.9 Web display format PDFhttp://explore.up.ac.za/record=b100134