This thesis studies the different ways in which the localized plasmon heating effect of gold nanostructures -activated by plasmon excitation via visible and/or NIR irradiation- can be used to obtain different outcomes following the nanofabrication of applicable devices. Both spatial and temporal control were obtained for each one of the systems developed upon the incorporation of plasmonic gold nanostructures. Spatial control was enabled in hybrid mesoporous drug delivery systems fabricated in this thesis through the localized surface plasmon heating effect that allowed the modification of the dynamics of diffusion of the cargo being delivered, thus giving rise to different rates of release that can be controlled by plasmon excitation. At the same time, the plasmon heating effect proved to be capable of controlling the start of the release by dismantling thermo-responsive gates previously incorporated, thus enabling also a wavelength-controlled feature that enhances the versatility of these systems. Spatial control was also conferred to the photo-patterning applications presented in this dissertation by influencing the degree of motility of gold nanorods (AuNRs) embedded in polymer matrices allowing them to self-assemble when the longitudinal plasmon of the incorporated nanostructures was excited; the patterns generated were quite robust and persisted for extended periods of time. Finally, the feature of spatial heating control was also conferred to catalysis. The Friedel-Crafts alkylation of anisole by benzyl chloride using spherical gold nanoparticles (AuNPs) supported on Nb2O5-based catalysts was performed at bulk temperatures below those necessary for the reaction to occur when using bare or modified Nb2O5; this was the result of the combination of bulk and localized plasmon heating produced -both- via plasmon excitation. This also demonstrates the possibility of using plasmon excitation as an alternative heat source in this type of reactions. By combining the plasmonic properties of metallic nanostructures with those granted by mesoporous materials, polymer matrices and Nb2O5-based materials it was possible to obtain light-activated systems endowed also with temporal control and wavelength control while preserving the original properties of each systems' components. Overall, the content of this thesis describes in detail the practical aspects of combining gold nanostructures with different materials and the rationale behind the development of systems with customized and controllable properties.

New towns is the form of settlement replacing camps and company towns in the resource areas of Canada. Resource companies, still requiring Skilled workers living near the site of its development, are planning and building towns which are incorporated soon after completion. This feature distinguishing new towns from company towns and camps is intended to alleviate the resource company of direct responsibility to the town and its residents. The economic mainstay of the town, though, is still the resource company's operation. Very broadiy, this thesis seeks to discover who is responsible for the development of new towns in resource areas and what programmes they are undertaking. It is important that the large social and financial investments in these new towns not be left to the vagaries of the single resource market, the economic base of the town. Specifically, this thesis examines Gold River, a forest-based new town in British Columbia. Rather than generalizing the findings of this study, this thesis is indicating a method by which such communities can be studied and compared in order to make general statements concerning the growth and development of new towns. By examining the role and relative impact of organizations on the development of the town and by examining the values of the residents through their objectives for their town, it is possible to relate societal values to the direction of development. The British Columbia government has two objectives in the development of its forest resource. One ensures the perpetual yield of the resource through strictly enforced management policies. And the second seeks the perpetuation of prosperous communities for which no policies have been made to ensure its fulfillment. Even though the town is incorporated, the Council tends to be inexperienced. Therefore, with no counterbalancing force, it is hypothesized that, the policy of the resource company will continue to actively determine the future development of the town. To test the hypothesis, the author gleaned the policies of the resource company by examining its activity in the town. Finding little to substantiate the hypothesis the author examined the role and impact of other organizations. The residents are adamant that the responsibility for the future development of the town rest on themselves. The Council, and to a lesser extent, the Chamber of Commerce, are active in promoting new activity in their town. The residents see the development of their town into a more viable and varied community, in terms of the development and growth of the region. Even though there exists a social fabric receptive to further development, the power and the control over the use of the region rests principally with the forest company and the initiative for further development of the region rests with the Provincial Government. If a general statement could be made from this study it would be that, the further development and growth of single enterprise resource-based new towns is an integral part of regional planning and resource development. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate

M.Com. (Business Management) / South-Africa's market share in gold produced dropped from 80 percent in 1980 to about 34 percent currently. This is due to entrance of cheaper producers of gold on the world market. The USA is our main competitor with a market share of about 17 percent. The difference is that South-Africa's remaining reserves is deep below surface and the USA are using open pit techniques to mine cheaply. In order for South-Africa to stay competitive and win back the lost market share it will be necessary to utilise the current available ore resources to it's full potential. This will also create new jobs in a South-Africa that needs it desperately. The calculation of the pay limit is investigated and found to be adequate. The different types of pay limits and their usage was explained. It was found that the current method, of using the pay limit directly as a cutoff limit, was incorrect. The use of a proposed pay limit was suggested. The definition of the proposed pay limit is slightly different than the current pay limit changed in order to clarify the correct use of the pay limit. The inadequacies of the pay limit was recognised and explained. A new term in gold mining was formulated namely the optimal limit. The purpose of this cutoff limit is to determine the cutoff value at which the resultant grade will be such that the mine's profit will be maximised over the long term. The combined usage of the proposed pay limit and the optimal limit in order to manage the ore resource, was described. This method of ore resource management is easily understandable, easy to use and addresses the inadequacies of the current pay limit successfully.

While as South Africans, we support the dream of an African Renaissance our developing country and economy has experienced a critical shortage of skills, which is clearly reflected in our matured gold mining industry. Against this background, I undertook a modernist qualitative study to (i) capture, describe, understand skills development on a marginal South African gold mine, and (ii) create a development framework for human development. Using symbolic interactionism as broad theoretical framework I designed a single case study, gathered material first hand through 22 unstructured in-depth interviews and other data sources, analysed the material by applying a blended strategy of grounded theory and analytical induction created with a black male skills development facilitator storyteller his life history. Exploring the fifteen sets of legislated transformational requirements, over forty practical opportunities emerged, including an indigenous mindset and cultural theme, UBUNTU. In addition to the range of recommendations, an UBUNTU driven skills development framework is suggested as catalyst for optimizing human resources development on our marginal gold mines. This broad framework could facilitate a learning culture where people could experience service delivery of legislation, implementation of existing policy, and effective skills development. The two-year study was generally written as a realist tale, which as I left the research scene represented a co-constructed story bordering an autoethnographical tale. / Prof. Willem Schurink

M.Sc. / This study focuses on the mineralogical variability of the A1, A5 and UE1A Elsburg reefs, obtained at Rand Uranium’s underground mining areas. A total of 133 reef samples, consisting of the Elsburg UE1A, A1 and A5-reefs have been obtained from Cooke 2 and 3 (two of the three Rand Uranium Mines) using the conventional chip sampling method. One of the challenges faced by Rand Uranium Gold Mines in the Cooke section area is the difficulty in differentiating between the various reef types by means of their macroscopic characteristics (colour, pebble types/sizes/shapes, sorting, matrix type, visible sulphide mineralization etc.). This difficulty led to this study which is aimed at utilizing mineral liberation analyzer (MLA)-based automated mineralogy to distinguish between the various reefs and to assess the mineralogical variation within the A1, A5 and UE1A-reefs. The mineralization in this area is hosted by the upper Central Rand Group of the Witwatersrand Supergroup. The main orebodies that are exploited at the mines occur within the Gemsbokfontein Member of the Elsburg Formation. These orebodies have been deformed into an east-west trending anticline at Cooke 3. The present study also attempts to prove or disprove the equivalence of the UE1A-reef on the western limb of the anticline to the A1 or A5-reefs on the eastern limb of the anticline on the basis of mineralogy. Representative splits of the samples were subjected to mineralogical abundance quantification as possible through quantitative MLA-based modal abundance protocols such as XMOD. A standard file on the various mineralogical phases encountered, was created on the 600F MLA and complemented by quantitative XRD (X-ray diffraction) data. Mineral abundances were quantified by MLA, based on integrated backscatter electron (BSE) images and energy dispersive spectrometry (EDS) analyses. Thirty one minerals have been detected using the MLA and they include phases such as quartz, pyrophyllite, chlorite, brannerite, gold, monazite and pyrite as well as minor unknown minerals. Only a few of the minerals are relatively more abundant within the reefs while the majority occurs in very low abundance. Albite, chlorite, muscovite, pyrite, pyrophyllite, quartz, uraninite and zircon are relatively more abundant than the rest of the minerals.

Ore characterization studies are of great importance to the mining industry, especially when dealing with precious metals by-products. It is a way towards increasing mining efficiency. The Swedish Boliden’s Zn–Pb–Ag–(Cu–Au) Lappberget Deposit is the main ore body at the Garpenberg Mine producing concentrates of zinc, lead, copper, and a gravity concentrate of silver and gold, which accounts for a significant revenue for the mine. Garpenberg Mine is an ancient and traditional mining site in Sweden, nonetheless the Lappberget deposit is a relatively recent discovery and there are still on-going studies on this ore body. More recently detailed ore investigations have been carried out on the sulfides and silver mineralization in different geological domains within the Lappberget deposit. In this context, the present work is focused on investigating the gold mineralization of the deposit, aiming to study the occurrence and distribution of gold minerals, characterize the gold in the ore and how its characteristics affect gold recoveries during its processing. To achieve these goals, different investigative methods were applied on drill core samples of the footwall disseminated to semi-massive mineralization (FWD), and on samples from the gravity concentrator at Boliden’s processing plant. The techniques applied were optical microscopy, scanning electron microscopy, energy dispersive x-ray spectrometry, electron probe microanalysis, laser ablation inductively couple plasma mass spectrometry, and bulk chemical analysis. The main findings pointed electrum as the main gold mineral, occurring with a strong sulfide association, in a variety of textures and grain sizes. The study also identified the occurrence of Au-Bi alloy, not previously described in literature of the Garpenberg region. The potential of invisible gold in the sulfide carriers was also a subject of investigation, as well as the evaluation of the characteristics of the samples from the gravity concentrator.

The Björkdal gold deposit is situated in the Skellefte mining district, northern Sweden. The ore is mined from a complex system of quartz veins ranging from a few cm to a meter in width. The mineral processing steps at Björkdal comprises a flotation circuit, which performance is dependent on the pH of the ore feed. A total of ten samples from five different ore zones from the underground development was investigated with the purpose of improving the understanding of factors that causes the pH value of rock samples to vary which is deleterious to the metal recovery. The samples were investigated with optical microscopy together with scanning electron microscopy (SEM) and automated mineralogy (QEMSCAN) to carry out the modal mineralogy. The analyses identified a total of 37 different minerals in the samples. Chlorite was identified with significantly higher values in parts of the investigated ore zones and especially in the sample with the highest pH value, suggesting chlorite-hosting shear zones that crosscut the sampled ore zones to be a contributing factor that could be affecting the elevated pH values, resulting in a decreased recovery of gold.

The diploma thesis deals with fundamental share analyss in order to propose a variant of investing in shares of selected gold mining companies. The subject is macroeconomic analysis of the environment in which selected gold mining companies operate, gold industry analysis and company analysis comprising evaluation of the development of corporate indicators and their issued shares. On the basis of these analyzes ind inter-company comparison, the most profitable options will be proposed to the management of the hedge fund.

Department of Mining and Environmental Geology / MESMEG

During the past few years, gold nanoparticles (AuNPs) have received considerable attention in many fields due to their optical properties, photothermal effect and biocompatibility. AuNPs, particularly AuNCs and AuNRs, exhibit great potential in diagnostics and imaging. In the present study, AuNCs were used to selectively image and quantify intracellular antioxidants. It was reported by Chen et al. that the strong fluorescence of AuNCs is quenched by highly reactive oxygen species (hROS). Most of applications depend on fluorescence quenching, however, for our project we designed turn-on fluorescent sensors using AuNCs that sense antioxidants. In the presence of antioxidants, AuNCs fluorescence switch on, while in the absence of antioxidants their fluorescence immediately turn off due to hROS effect. AuNRs were also used for cellular imaging in which AuNRs were conjugated to Cy3-labelled molecular beacon (MB) DNA. Next, the previous complex was loaded in two different strains of magnetotactic bacteria (MTB). MTB were used as a targeted delivery vehicle in which magnetosomes direct the movement of bacteria. The DNA sequence was specific to a certain sequence in mitochondria. The exposure of MTB to an alternating magnetic field (AMF) leads to the increase of temperature inside the bacteria, which destruct the cell wall, and hence, bacterial payload is released. When MD-DNA hybrid with the target sequence, AuNR and Cy3 separate from each other, the fluorescence of the Cy3 is restored.