Cape Peninsula University of Technology
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The production of hydrogen from the water gas shift reaction through the use of a palladium-silver membrane reactor
No full textThesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2016.The Water Gas Shift (WGS) reaction describes the reaction between carbon monoxide and water vapour to produce carbon monoxide and hydrogen. This work describes the application of a Palladium-Silver (Pd-Ag)-based membrane film reactor, wherein the Pd-Ag film was supported by porous stainless steel (PSS), for the potential replacement of the current multi-stage WGS reaction. The objective of this work was to develop a better understanding of impediments which are relevant to the application of Pd-Ag membrane reactor for the WGSR. The long term behaviour (hydrogen permeability and selectivity) of Pd-Ag membrane under hydrogen exposure was studied, and the use of the Pd-Ag membrane reactor to produce hydrogen through the WGSR was also performed.
A detailed literature review was conducted, based on the information gathered from literature. A Permeability and WGS reaction testing stations was designed and built. A thin (20μm) 77%wtPd-23%wtAg film was purchased from Takanaka Company in Japan. The membrane film was enclosed between two stainless steel plates to form a membrane reactor. The membrane reactor was fitted at the two different testing stations
Froth flotation of a Merensky platinum bearing ore with various THIOL collectors and their mixtures
No full textThesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2016.The Bushveld igneous complex in northern South Africa has the largest deposit of platinum
group elements (PGE) in the world. In trace amounts, these are closely associated with base
metal sulphides (BMS). Froth flotation is used to beneficiate these PGE ores. The process
constitutes a bulk sulphide recovery. Improvement of recovery of the BMS is required to
maximise the recovery of PGEs. The performance of the froth flotation process is largely
dependent on the chemical additives used and these chemicals have been extensively studied.
Mixtures of collectors are widely used in the flotation of sulphide and platinum group mineral
(PGM) ores. A range of performance benefits for the use of mixtures over pure collectors have
been observed on many systems. These include improved valuable metal grades and
recoveries, lower reagent dosage requirements, improved rates of flotation and enhanced
recovery of coarse particles. Improvements observed with mixtures of chemical reagent have
been attributed to synergism; defined as the interaction of two or more agents to produce a
combined effect greater than the sum of their individual effects. Synergism is highly desired in
froth flotation. For this study, mixtures of thiol collectors were used in batch froth flotation tests in an attempt
to identify synergism between the different collectors on flotation performance of a typical
platinum ore from the Merensky reef. Flotation performance was evaluated in terms of grades
and recoveries of copper and nickel, and the rate of metal flotation. Single thiol collectors of
xanthate (SIBX), a dithiocarbamate (DTC) and a dithiophosphate (DTP) were evaluated to
determine the effect of functional group on flotation performance. SIBX was then used in
mixtures with both DTC and DTP at various molar ratios to establish whether synergism occurs
between these collectors on this particular platinum ore. Molar ratios of 90:10, 80:20, 70:30
60:40 and 50:50 were considered with SIBX being the major component. Further tests were
conducted with the addition of a carboxymethyl cellulose depressant to the collector mixtures
Mathematics teachers’ experiences of the influence of the changing curriculum on their professional practice in grades 10 - 12 in the Cape Winelands district
No full textThesis (MEd (Education))--Cape Peninsula University of Technology, 2016.Education in South Africa is a concern to many stakeholders, including government, teachers, teacher unions and non-governmental organisations, owing to the poor academic performances of learners. Mathematics teachers, the focus of this study, are confronted with a constantly changing curriculum. Teachers are often targeted by the education authorities and general public as the primary cause of the poor outcomes of education in South Africa. This study considers the experiences of Grades 10–12 mathematics teachers in the Cape Winelands regarding curriculum change and its influence on their professional practice. The basic assumptions of social constructivism served as overarching theory. The researcher judged that a conceptual framework would make for a clearer and more systematic way of dealing with the constructs that underpin this study. The conceptual analysis framework, which was developed by combining the work of Rogan and Grayson, as well as that of Remillard, which is a perfect fit to this study, guided the interpretation and analysis of the data. A deductive approach in data analysis was applied in accordance with the conceptual framework used in this study. Being explorative in nature, this study is a qualitative design and therefore an interpretive methodological approach was followed. A purposive and convenience sampling method was used whereby teachers from six schools were pre-selected: two from ex-Model C schools, two from previously disadvantaged black schools and two from previously disadvantaged coloured schools. Semi-structured interviews were conducted. The findings of this study pointed to teachers’ acceptance of education reform and changes in the curriculum, provided they were not too radical. Teachers requested involvement on a broad spectrum throughout the planning and implementation process, and proper training and support prior to implementation. Factors that militated against implementation were, among others, poor facilities, resources and instructional aides; poorly trained change facilitators; poor leadership and management at schools; and the many constraints that the learners brought to the school and the classroom
Optimising the performance of domestic wall mounted space comfort heater
No full textThesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2016.The performance of a wall Mounted space comfort heater has been studied with respect to the geometry of its mounting condition. Tests were conducted in a laboratory with the heater positioned at various heights from the floor and the channel that is created by the various gaps with the wall on which the heater was mounted. Tests were also performed with the heater mounted on the wall whose emissivity was adjusted to low, medium and high values as well as placing insulation material on the wall directly behind the heater. The outcome of the experiments revealed an acceptable geometry of the heater’s mounting at least 200 mm above the floor, and 50 mm off-set from the wall. The results of the heater mounted against the wall revealed a drop in performance as compared to the heater’s “benchmark” performance when it was freely standing on the floor of the laboratory; with an efficiency of about 41% (almost evenly shared by each face). This efficiency, which is based on the convective heat transfer generated by the heater’s warm/hot surfaces, is relative to the electrical energy input and it dropped when the heater was mounted against a grey wall to around 35%, of which only 26% was produced inside the channel. The heat transfer by radiation from the heater’s surface is treated as net loss to the walls of the room/enclosure.The performance of the heater when mounted against the wall improved almost to the benchmark value when the wall behind the heater was made refelective (low emissivity). It is recommended that further research should be undertaken to thoroughly investigate the “mode” of heat transfer, by the induced flow through the channel, in a more formal or scientific modelling approach
Corporate communication strategy : aligning theory and practice amongst selected public relations practitioners in South Africa
No full textThesis (MTech (Public Relations Management))--Cape Peninsula University of Technology, 2016.This research reports on the findings from a study that explores how the principles of corporate communication strategies outlined in public relations theory align to public relations practice. Using the theoretical framework of strategic public relations within corporate communication strategies, this qualitative research seeks to understand what theoretical principles inform corporate communication strategies and how public relations practitioners develop and implement these strategies. The findings suggest that public relations practitioners have a more practical approach than a theoretical approach to public relations practice. This study identifies the importance of increasing the credibility of the discipline as public relations practitioners are able to constantly improve and adjust their strategies according to what works and what does not. Measurement and evaluation in application of corporate communication strategies increases research in public relations practice which will in due course influence public relations theory. Further study is recommended in increasing the knowledge of public relations practitioners regarding the theory of communication strategies which will assist in improving the status of public relations and the perceived value of the profession
Managing electronic resources at selected tertiary institutions in the Western Cape, South Africa
No full textThesis (MTech (Business Information Systems))--Cape Peninsula University of Technology, 2016.The aim of this research study is to explore the management of electronic resources used in libraries. Three tertiary institutions were used as case studies. The unit of analysis was the three libraries, with library employees (14) working and managing electronic resources being the unit of observation. Non-random, purposive sampling techniques were used. The finding of this study suggests that the participants do not use the Aleph integrated library system (ILS) optimally to manage electronic resources. Library employees do not keep up with current and new emerging technology trends in the library and academic environment. There is a lack of training, as well as understanding, of business processes and workflows. This is emphasised by a lack of knowledge of library system environments and, finally, the high cost of implementing the library systems. Electronic resource management (ERM) systems emerged in the early 2000s, and it became clear that traditional integrated library systems did not have sufficient capacity to provide efficient processing for meeting the changing needs and challenges of libraries at tertiary institutions. Libraries find it challenging to manage the wide range of licensed electronic resources, collaborating, cooperating and sharing resources with different libraries. The increasing number of electronic resource demands from users for remote or off campus access makes it difficult for libraries to manage electronic resources. As a result of this inability to manage the electronic resources, libraries are not effectively and efficiently using appropriate electronic resource systems to meet their business requirements
Enhanced biosurfactant production by Bacillus licheniformis stk 01 for hydrocarbons targeted for bioremediation
No full textThesis (MTech (Environmental Health))--Cape Peninsula University of Technology, 2016.Environmental remediation of organic and inorganic contaminants such as hydrocarbons has been a research focus area of interest. Chemical surfactants have been extensively used for the remediation of contaminated sites for immobilisation of hydrocarbons from environmental matrices. The focus has been on the impact of chemical surfactants on the environment. These petroleum-based chemical surfactants have raised serious environmental concerns as: 1) they are toxic, 2) they deteriorate the environment owing to their non-biodegradability, 3) they are costly, and 4) most are not intended for environmental applications. As such, alternatives had to be found to mitigate concerns associated with the application of such synthetic surfactants in bioremediation. Biosurfactants produced by microorganisms are a potential alternative to these synthetic surfactants. They have minimal environmental impact, are biodegradable and can withstand extreme conditions. However, biosurfactants are associated with high production costs and low production yield. Currently, large-scale production of biosurfactants cannot be achieved. Most research focuses on improving production yield which will contribute to the reduction in production costs. A lichenysin lipopeptide biosurfactant producing Bacillus sp., which grew exclusively on Beta vulgaris agrowaste, was identified. The microorganism was found to be an effective emulsifier for high molecular weight hydrocarbons such as, lubricant oil and diesel.
The aim of this study was to improve biosurfactant production yield from this Bacillus sp., including emulsification efficacy by optimising fermentation conditions by supplementing the broth with biocompatible nanoparticles synthesised using a green chemistry approach with B. vulgaris (B. vulgaris) extracts. This study also aimed at reducing production costs by using B. vulgaris agrowaste exclusively as the production medium, both for the biosurfactant and the nanoparticles
Application of innovative beverage fermentation technology to plums and selected berries
No full textThesis (MTech (Food Technology))--Cape Peninsula University of Technology, 2016.This study focused on alcoholic fermented fruit beverages that were produced from various types of fruit, value addition and thus potentially increasing the diversity of commercially available fruit wines. Non-grape alcoholic fermented fruit beverages is a complex mixture of water, alcohol, and other components, that are either initially present in the fruit, or are formed during the fermentation process. The evaluation of wine and similar fermented products quality is important for manufacturers and consumers. The routine analysis of alcoholic fermented fruit beverages acts as an important tool that is useful for wine classification, quality control and sensory evaluation. Therefore, the aims of this study were (1) to measure methanol, ethanol, titratable acidity, objective colour, total soluble solids and sensory profile as a function of yeast strain and percentage pulp in order to adapt existing technologies toward producing new fermented fruit beverage products using plums, an under-utilized agricultural produce; and (2) to measure methanol, ethanol, titratable acidity, objective colour, total soluble solids and sensory profile as a function of yeast strain, pulp percentage and sugar levels in order to adapt existing technologies toward producing new fermented fruit beverages based on red and white wine styles, while applying the technology developed in the first part of the study using red-fleshed plums, blueberries and blackberries. The independent variables (ID) were yeast strains (1) Saccharomyces cerevisiae VIN13, (2) Saccharomyces cerevisiae NT116, and (3) Saccharomyces bayanus N96, with formulations containing percentage pulp concentrations at (40%, 50% and 60%). The dependent variables (DV) constituted key quality parameters for white and red wine style, namely methanol, ethanol, titratable acidity, objective colour, total soluble solids, pH and sensory profile were measured. The optimal combination of independent variables was ascertained and in terms of the overall consumer response, for the red-fleshed plum beverage sample treatment N 96, 60% pulp showed the highest preference amongst consumers. In terms of the other dependent variables, namely methanol, ethanol, titratable acidity, objective colour, total soluble solids, pH and sensory profiles of alcoholic fermented fruit beverages based on white and red wine styles. The processing conditions developed and applied in this study towards the development of alcoholic fermented beverages utilizing plums and selected berries demonstrated ways of improving the utilization of fruit commodities by developing niche products. Hence, the development of alcoholic fermented beverages utilizing (plums and selected berries) showed potential for micro agro-industries, as well as the impact on its potential role in employment creation and income generation
Functional and nutritional characteristics of Bambara groundnut milk powder as an ingredient in yoghurt
No full textThesis (MTech (Food Technology))--Cape Peninsula University of Technology, 2016.The aim of this study was to evaluate Bambara groundnut (BGN) milk subjected to spray drying with a view to establish functional, nutritional and physical properties as an ingredient in BGN yoghurt production. BGN milk powder (BGNMP) was successfully produced employing the spray drying technology. Maltodextrin was used as the drying carrier to elevate total solids of BGNM prior to spray drying. There were three levels of maltodextrin (5, 10 and 15%) employed and 10% was ideal. The optimum spray drying parameters were estimated to be the following; inlet temperature (150oC), outlet temperature (74oC), air pressure (3 bars), flow rate (10% or 16mL/min), and air flow (42.9 m3/h). The functional properties evaluated revealed high water solubility capabilities, making BGNMP readily soluble in water, which is one of the most crucial aspects of milk powders. The water solubility index of BGNMP at all maltodextrin levels ranged from 85.15 to 90.25%. There was a significant (p 0.05)
Nitrification and aerobic denitrification in cyanide-containing wastewater
No full textThesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2016.Anthropogenic activities that utilise cyanide in various chemical forms have resulted in the disposal of cyanide-contaminated effluents into drainage systems that ultimately reach wastewater treatment plants (WWTP), without prior treatment. Cyanides (CN) and soluble salts could potentially inhibit biological processes in WWTP, which are responsible for the removal of contaminants from incoming wastewaters. The removal of nitrogenous compounds from such waters in processes such as nitrification and denitrification is among the core biological processes used to treat wastewaters in WWTP. Electroplating and mining industries are among the perpetrators of cyanide contamination of WWTP. The presence of these hazardous contaminants results in the alteration of metabolic functions of the microbial populations that are utilised in WWTP, thus rendering the wastewater treatment process ineffective. In this study, bacterial isolates that were able to carry out nitrification and aerobic denitrification under high salinity cyanogenic conditions were isolated from poultry slaughterhouse effluent. These strains were referred to as I, H and G. The isolated bacterial species were found to be able to oxidise ammonium nitrogen (NH4-N) in the presence of free cyanide (CN-) under halophilic conditions. Isolates I, H and G were identified using the 16S rDNA gene and were identified to be Enterobacter sp., Yersinia sp. and Serratia sp., respectively. Furthermore, Response Surface Methodology was used to optimise the physicochemical conditions suitable for the proliferation of the isolates for free-cyanide degradation, nitrification and aerobic denitrification