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Energy efficiency of solar heat concentrators using glass coated Al doped ZnO transparent conducting oxide as selective absorber
No full textThesis (Master of Engineering in Mechanical Engineering)--Cape Peninsula University of Technology, 2017.Transparent conductive oxides (TCOs), which are widely used in transparent electronics, possess a spectral selectivity that is suitable for a solar material absorber. TCO materials have a plasma wavelength in the infrared region. Consequently electromagnetic waves shorter than a plasma wavelength are transmitted through the material, while longer electromagnetic waves are reflected on the surface. In contrast to the opaque solar selective absorbers, the plasma wavelength in TCO materials can be easily tuned by controlling the heavy doping process to match the peak shift of thermal radiation at higher temperatures. Furthermore, the use of TCO in conjunction with a solar absorber relaxes the spectral selectivity of the latter and thus widens the selection of the solar absorber; subsequently the only requirement is a thermally stable black body. Aluminum doped Zinc Oxide (AZO) is a class of TCO materials which is cost effective to manufacture due to abundance ZnO, and Aluminum raw materials. This thesis is based on the synthesis of Al doped ZnO thin films nanostructure using radio frequency RF magnetron sputtering process. The influence of the deposition parameters, including argon working pressure and substrate temperature, on the structural and optical properties of the AZO thin films is investigated by means of X-ray diffraction (XRD) and optical spectroscopy (UV-VIS-NIR). The optical constants of AZO films are extracted from transmittance and reflectance spectra using a combination of Drude and Lorentz dielectric function model. A computer simulation is developed to calculate the radiative properties of Al doped ZnO thin films nanostructure. The thermal emittance and solar absorptance is predicted indirectly from optical reflectance and transmittance of AZO films by invoking Kirchhoff’s law. A Special attention has been paid to the parameters that influence the spectral properties of the AZO films including carrier’s mobility, Al doping concentration and film thickness. Carrier’s mobility turned out to have the most significant influence on the spectrally selective performance of AZO films
Effects of compost tea extract on growth, nutritional value, soil quality of Hypoxis hemerocallidea and Siphonochilus aethiopicus
No full textThesis (MTech (Horticulture))--Cape Peninsula University of Technology, 2017.The exact responses to the concentration of compost tea extract and methods of irrigation application were not previously measured on Hypoxis hemerocallidea and Siphonochilus aethiopicus. Commercial exploitation, habitat loss and degradation, overharvesting, and enhancement of their medicinal properties, have led to this investigation and the need to replenish both these valuable plant species. This is crucial for plant survival, especially in the wild and for use of the traditional medicinal plants. Hypoxis hemerocallidea and Siphonochilus aethiopicus, known as star flower and wild ginger respectively continue to decline, due to overharvesting from their natural habitat. Both these species have tremendous traditional medicinal value among localized African people. To enhance their commercial cultivation, compost tea extracts, in the following ratios (no catalyst added (control1); T 1000:1, T750:1, T500:1, and T250:1L) were applied in equal dosages to determine an optimal compost tea extract ratio. The experiment was conducted in a temperature controlled greenhouse. Mushroom compost (500 g, per brew) was used for all extracts. Brewing was done with no catalyst added (Control 1), and 24 hours later
another brew was done with catalyst added, weekly for 20 weeks. The Control treatment received water only. Both species were slow growing and comparatively, the Hypoxis plants responded faster than the Siphonochilus plants. In this investigation, plant growth parameters such as plant height, number of leaves, leaf width, leaf length and leaf colour, were measured and evaluated. Despite the plants positive response to the mushroom compost tea extracts, across all the above plant growth parameters, no significant differences were noted between the treatments during the twenty-week application period.
Leaf chlorophyll content peaked in week 11 of the hypoxis plants and was the highest in week 14 of the Siphonochilus plants with no significant interaction between weeks vs. treatment over the twenty-week experiment. The chlorophyll readings indicate that both species increased their chlorophyll production over time. Although the total wet leaf length, root length, corm diameter, leaf weight, corm weight and
root weight of Hypoxis were non-significant between treatments, T500:1 total wet weight was
significantly higher when compared to the rest of the treatments. The total dry weight analysis of hypoxis was non-significant. Control Calcium level was significantly lower between the control and the treatments of the Hypoxis total dry leaf nutrient analysis. The Hypoxis dried roots nutrient analysis was non-significant across treatments
Thermal electric solar power conversion panel development
No full textThesis (DTech (Engineering))--Cape Peninsula University of Technology, 2017.The world has been experiencing energy-related problems following pressuring energy demands which go along with the global economy growth. These problems can be phrased in three paradoxical statements: Firstly, in spite of a massive and costless solar energy, global unprecedented energy crisis has prevailed, resulting in skyrocketing costs. Secondly, though the sun releases a clean energy, yet conventional plants are mainly being run on unclean energy sources despite their part in the climate changes and global warming. Thirdly, while a negligible percentage of the solar energy is used for power generation purposes, it is not optimally exploited since more than its half is wasted in the form of heat which contributes to lowering efficiency of solar cells and causes their premature degradation and anticipated ageing. The research is geared at addressing the issue related to unsatisfactory efficiencies and anticipated ageing of solar modules.
The methodology adopted to achieve the research aim consisted of a literature survey which in turn inspired the devising of a high-efficiency novel thermal electric solar power panel. Through an in-depth overview, the literature survey outlined the rationale of the research interest, factors affecting the performance of PVs as well as existing strategies towards addressing spotted shortcomings.
While photovoltaic (PV) panels could be identified as the most reliable platform for sunlight-to-electricity conversion, they exhibit a shortcoming in terms of following the sun so as to maximize exposure to sunlight which negatively affects PVs’ efficiencies in one hand. On the other hand, the inability of solar cells to reflect the unusable heat energy present in the sunlight poses as a lifespan threat. Strategies and techniques in place to track the sun and keep PVs in nominal operational temperatures were therefore reviewed
The adaptive reuse of the former Thesen Island power station : a case study
No full textThesis (MTech (Architectural Technology))--Cape Peninsula University of Technology, 2017.In the developed Western world, the need to preserve buildings, including industrial buildings, is well established, and the many charters that exist for guidance for preservation of the built environment point to the necessity of preservation.
It can be posited that many of South Africa buildings with industrial architectural heritage are being lost either through neglect, obsolescence, demolition or vandalisation. At an international conference, David Worth, the sole South African representative for the International Committee for the Conservation of the Industrial Heritage (TICCIH), stated that South Africa‟s industrial heritage has been neglected by the public, by professionals and academics, and by commercial and political interests. Läuferts and Mavunganidze make the point that South Africa continues to lag behind other countries in the preservation of and declaration of its industrial heritage.
The purpose of this research was to investigate if adaptive reuse is a successful strategy to preserve industrial architectural heritage in South Africa. A further aim was to investigate whether adaptive reuse can be considered sustainable or „green‟ (in terms of the UN‟s sustainable development goals
Modulatory effects of Moringa oleifera extracts on Streptozotocin-induced diabetes in male Wistar rats
No full textThesis (DTech (Biomedical Technology))--Cape Peninsula University of Technology, 2017.Diabetes mellitus (DM) is characterized by deficiency in insulin resulting in hyperglycaemia with metabolic alterations in carbohydrate, lipid and protein. DM has been associated with increased formation of reactive oxygen species (ROS) and inflammatory mediators. Many drugs have been designed for its treatment and management; however, limitations persist in the use of anti-hyperglycemic medications due to numerous side effects, high cost, limited action and secondary failure rates. Moringa oleifera (MO) tree is distributed in the tropics and subtropics and has been found to be very nutritious with a variety of applications. This plant has been reported to possess antidiabetic, antioxidant and other medicinal properties which may be helpful in managing diabetes and its associated complications.
This study investigated the antioxidant status, antidiabetic, antilipidemic, anti-inflammatory, anti-apoptotic properties and phytochemical constituents of the leaf extract of MO (250 mg/kg). Diabetes was induced in Wistar rats by a single intraperitoneal injection of streptozotocin (STZ) in buffered citrate (0.1, pH 4.5). Forty-eight Wistar rats were randomly divided into four (4) groups and treated for six weeks: group one- non-diabetic control (Control), group two- non-diabetic Moringa treated (Moringa), group three- diabetic control (Diabetic) and group four- diabetic Moringa treated (Diabetic + Moringa).
Methanol, aqueous and petroleum ether extract of MO leaves were evaluated for its antioxidant and phytochemical contents. Assays for total antioxidant capacity such as trolox equivalence antioxidant capacity (TEAC), oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP), flavonoids, flavonols and total polyphenols content were analysed. Other parameters analysed include glucose level; glycated haemoglobin level; hepatic biomarkers; endogenous antioxidants (SOD, CAT, GSH, GPx) in the liver; kidney and erythrocytes; inflammatory biomarkers in the serum, liver and kidney; high-density lipoprotein (HDL), low-density lipoprotein (LDL) and total cholesterol (TC) in serum. Assessment of apoptotic cell death biomarkers (caspase 3, caspase 9, BCL-2, NFKβ, p53) in the liver and kidney were performed. Histopathological analysis was conducted on the liver, kidney and pancreatic sections.
In vitro results showed that aqueous and methanol extract of MO demonstrated a high antioxidant capacity, phenolic contents and revealed more chemical constituents than the petroleum ether extract. HPLC analysis of the leaf extract indicated the presence of flavonoids: quercetin, rutin and myricetin and phenolic acids. High levels of polyphenols, flavonols and alkaloids were reported in MO extracts.
Treatment with MO in normal and diabetic rats daily for six weeks resulted in significant (p<0.05) decrease in glucose and glycated haemoglobin levels. Liver and kidney size which increased in diabetic rats, decreased significantly (p<0.05) after treatment with MO. Pancreas size showed significant (p<0.05) decrease in diabetic rats and increased significantly (p<0.05) after MO administration. Similarly, serum albumin level increased in non-diabetic and diabetic groups after MO treatment. Also, a significantly increased level of T-bilirubin in diabetic groups relative to normal control rats which reduced greatly after MO administration was observed.
Serum lipid profile: LDL and TC levels were increased in rats exposed to STZ. HDL level decreased in diabetic rats when compared to normal control. The activities of MO extracts was shown to lower TC and LDL levels. HDL level also increased after MO administration. Similarly, lipid peroxidation (MDA) level significantly (p<0.05) decreased in the diabetic group following MO treatment. An observable improvement was seen in the antioxidant enzyme system. Activities of antioxidant enzymes such as superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and concentration of glutathione (GSH) were restored or increased in the homogenate of the liver, kidney, and erythrocytes, indicative of the protective effect of MO in diabetic and non-diabetic rats.
The expression of cell death markers (caspase 3, caspase 9, BCL-2, NFKβ, p53) showed remarkable improvement after treatment with MO relative to the non-diabetic control. A significant (p<0.05) reduction in inflammatory cytokines (IL-1α, IL-6, IL-12, IL-18, TNF-α) and (chemokine MCP-1 concentrations) were observed in the serum, liver, and kidney of non-diabetic and diabetic treated groups. Histopathological sections of the liver, kidney and pancreas of diabetic rats revealed severe damage which showed significant improvements after MO treatment. Liver, kidney and pancreatic histological sections revealed the protective effect of MO in both non-diabetic and diabetic rats.
MO exerted modulatory effects in STZ-induced diabetes by its antidiabetic, hypoglycemic, antioxidant, anti-inflammatory, anti-apoptotic and anti-lipidemic activities and offered protective effects against diabetic-induced nephrotoxicity and hepatotoxicity, but equally improved antioxidant status. The study concluded that MO could play a significant role in the early treatment and management of diabetes that pharmaceutical industry should consider it in the future as a possible therapeutic agent
The identification and exploitation of entrepreneurial opportunities by African immigrants in a selected township in Cape Town
No full textThesis (MTech (Business Administration (Entrepreneurship)))--Cape Peninsula University of Technology, 2017.Many people from African countries immigrate to South Africa because they perceive South Africa as a country which offers many opportunities and an advanced standard of living. Although immigrants often resort to entrepreneurial activities as a means of survival when few other options are available to them, increasing numbers of African immigrants are coming to South Africa with the express intention of starting businesses in the country. An unfortunate consequence of their entrepreneurial success in the SMME sector in South Africa has been manifested in outbreaks of xenophobic violence which have targeted entrepreneurs in the townships of South Africa.
African immigrants are widely perceived to pose threats to the livelihoods of South Africans, either by invading local labour markets or putting South African entrepreneurs in the SMME sector out of business because of the competitive edge which their businesses often enjoy over those of their South African counterparts. Relatively little emphasis has been given to the socio-economic contribution which African immigrant entrepreneurs make, by providing employment to South Africans in the face of alarmingly high rates of unemployment in South Africa and by contributing directly to the South African economy through the payment of taxes.
The researcher formulated this research study to determine how African immigrants identify and exploit business opportunities in South Africa by studying a group of African immigrant entrepreneurs in the township of Nomzamo in Strand, which lies some 50 kilometres to the southeast of Cape Town. The significance of this study lies in the fact that, to date, there has been relatively little research concerning this research topic and also in the contention that obtaining a comprehensive understanding of the successful business practices of African immigrant entrepreneurs could play a very meaningful role in improving the performance of South African entrepreneurs in the SMME sector and in normalising relationships between immigrant communities and South African population groups in the townships of South Africa
The implementation of shared writing when teaching the writing process in the Intermediate Phase Afrikaans home language
No full textThesis (MEd (Education))--Cape Peninsula University of Technology, 2017.Since 2012, the poor literacy levels of intermediate phase (IP) learners have been a concern
for officials in the Western Cape Education Department (WCED). Responding to the literacy
crisis, the WCED has implemented the South African Curriculum and Assessment Policy
Statement (CAPS), along with various other literacy interventions, but in the West Coast
District, IP learners’ writing skills remain poor. Focusing on the West Coast District, this
thesis sheds light on the implementation of the writing-instruction practices prescribed by
CAPS: specifically, the implementation of “shared writing” as a scaffolding method for
teaching writing to learners. The thesis maps the theoretical and conceptual framework of the
writing process, with an emphasis on shared writing. In particular, it discusses Vygotsky’s
and Piaget’s ideas on social-cognitive development and scaffolding. The gradual release of
responsibility (GRR) and balanced language approach (BLA) instruction models propose that
a competent adult should interactively model the writing process to learners before group
writing (practice) and independent writing (assessment) are attempted. While these stages of
instruction are included in CAPS, this study investigated the extent of their implementation.
Current literature in the field of writing instruction foregrounds the concepts of “thinking
aloud” and “shared pen”, according to which the teacher and the learner co-compose a text,
allowing learners to become competent writers. In this study, quantitative and qualitative
research methods were used to describe and understand West Coast District IP Afrikaans
Home Language (HL) teachers’ perceptions of their use of shared writing to teach the writing
process. Data collection consisted of quantitative and qualitative questionnaires, as well as
interviews, with results converted into percentages. Subsequent data analysis disclosed the
patterns, strengths, and weaknesses experienced by IP Afrikaans HL teachers in the West
Coast District. Current IP writing-instruction practices can provide the South African
Department of Basic Education (DBE) with valuable insights into the implementation of
shared writing, and of CAPS as a whole
A phenomenological investigation into the lived experiences of grade 12 Physical Sciences learners from selected schools in the Western Cape Province
No full textThesis (MEd (Education))--Cape Peninsula University of Technology, 2017.This study aims to narrate the lived experiences of Grade 12 Physical Sciences learners. According to UMALUSI reports on National Senior Certificate (NSC) of 2011 and 2013, there seems to be a steady decrease in the number of learners writing Physical Sciences from 2008 to 2013. One of the aims of this study is to investigate why there is a steady decline in the number of learners choosing the subject and what their classroom experiences are. A related aim is to describe how these learners’ perceptions of their Physical Sciences educators affect their mental experiences in the subject. The study used phenomenology both as a research methodology as well as the underpinning theoretical framework. Twelve Grade 12 learners from 3 different schools in the Metro North Education District in Cape Town were chosen to participate in this research. The data were collected using two rounds of in-depth semi-structured interviews. The interviews were transcribed and explicated using Giorgi’s phenomenological method. The findings show that although Physical Sciences educators are trying to support their learners, they are failing to meet the expectations of the learners. These findings provide new insights into understanding the world of the learner better and that the recommendations could have transformative implications for curriculum planners, curriculum advisors and pedagogical strategies in how the subject is presented to learners
Communication methods and internal systems for the transfer of knowledge in a financial service provider in the Western Cape, South Africa
No full textThesis (MTech (Business Information Systems))--Cape Peninsula University of Technology, 2017.Knowledge Management (KM) is a role player in assisting organisations to accomplish their
desired goals and objectives by managing the knowledge embedded within individuals and
available in systems. Furthermore, knowledge management considers the use of advanced
technology to enhance existing knowledge, create new knowledge, and transfer knowledge.
However, the process of managing knowledge cannot be successful without proper
communication. When this knowledge and the associated expertise are not transferred,
organisations are faced with a loss of intellectual capital as employees enter and leave with
knowledge and expertise. It is therefore critical to understand who knows what, who needs to
know what, and how to transfer the knowledge throughout the organisations.
Hence, this research explores the dynamics of knowledge transfer in relation to
communication strategies, tools, methods or systems that the selected company can
implement in order to transfer knowledge between interest groups and throughout the
organisation. The research philosophy adopted is subjectivism with an interpretivist stance. A
qualitative research approach was applied. The data were collected using semi-structured
questionnaires and analysed using descriptive data analysis techniques.
The results point to poor levels of understanding the concept of knowledge management and
knowledge transfer in the organisation, resulting in departments following silo processes in
an effort to transfer knowledge within their specific areas. However, these processes are not
sufficiently effective and cause crucial man risk within departments. The results of this study
should help the organisation improve its knowledge management processes and organise
internal communication in a way that will improve knowledge transfer
Effect of building materials cost on housing delivery towards sustainability
No full textThesis (MTech (Construction Management))--Cape Peninsula University of Technology, 2017.The study investigates the predominant factors responsible for increase in the cost of building materials and the effect of this cost increase on housing delivery in Western Cape, South Africa.
Sustainable housing is buildings produced to meet the present housing needs of people without conceding the ability of the future generation to meet their future needs. However, a significant increase in the cost of building materials has been a major constraint to the delivery of sustainable housings, as made evident in the literature, leading to project cost and time overruns or even project abandonment. However, building materials consume up to 65% of the total cost of construction. This factor on cost has, over the years, threatened the ability of the construction industry to deliver projects within budgeted cost, at stipulated time, and at satisfactory quality. This prompted the need to proffer solutions to these factors identified which are causing increases in the cost of building materials towards sustainable housing delivery in Western Cape. Based on this research study, housing is termed to be sustainable when it is available and affordable for the masses timely and at quality expected.
The research study adopted a mixed methodological approach, involving the use of semi-structured qualitative interviews and closed-ended quantitative questionnaires administered to construction stakeholders (architects, quantity surveyors, engineers, construction managers, project managers, site supervisors and material suppliers) in the Western Cape Province of South Africa. SPSS version 24 software was used for analysing the quantitative data collected and ‘content analysis’ method was used to analyse the information collected through the qualitative interviews. The findings revealed that the major factors responsible for increasing the cost of building materials are inflation, wastages of building materials by labourers, cost of transportation and distribution of labour, design changes, client contribution to design change and change in government policies and regulation. Moreover, the research showed that fluctuation in the cost of construction and high maintenance costs due to poor workmanship also impact the cost increase of building materials for housing delivery. In addition, research findings affirmed that for optimum materials usage for the enhancement of sustainable construction, the following criteria should be considered in the selection of building materials: maintenance cost, energy consumption and maintainability.
The adoption of these findings by construction stakeholders in the South African construction industry would enhance the delivery of affordable housing at reduced cost, at the required time and at the expected quality. Therefore, an adequate implementation of the framework presented in this study will enhance sustainable housing delivery