Fracture behavior of boehmite-filled polypropylene block copolymer nanocomposites as assessed by the essential work of fracture concept

The essential work of fracture (EWF) method was adapted to determine the fracture toughness of poly(propylene-block-ethylene) (EPBC) based nanocomposites with different amounts (from 0 up to 5 wt.%) of synthetic boehmite alumina (BA). The dispersion of BA in the matrix was studied by transmission and scanning electron microscopies. Agglomerated micronscale along with well dispersed nanoscale BA particles were present in the EPBC matrix. By contrast to the neat EPBC, all nanocomposites failed by unstable necking. Therefore the energy partitioning concept of the EWF was adapted and attention paid to the yielding-related term. Both specific yielding-related essential and non-essential work of fracture parameters increased linearly with the product of the yield stress and elongation at yield derived from static tensile tests

Images of Futures : Education Systems and Multiculturalism for Third World Development : Case: eSwatini, UWC and National Education curricula

This study is exploratory in nature, combining Futures Studies with Ethnographic interview and analysis, while using methods as an Action Research exercise with interviewees. The research question: What are some future images of third world development driven by multicultural education? Firstly, focused on national development of developing countries, from the pragmatic view that education is the main driver for development. I look closely at the United World College (UWC) Waterford Kamhlaba and the eSwatini education systems. Drawing a link between education and multi-culturalism constitutes the answer to a development themed sub-question: Does the national school system of eSwatini benefit from the influence of globalization on both education and business? The overarching issue being addressed in this study is that there are the yet unexplored avenues of development and innovation in education that include issues of equality, competitiveness, quality and delivery of education in a more globally connected learning and working environment. A total of eight interviews were carried out with interviewees in two general groups, Educators and Alumni. They are linked to Waterford Kamhlaba UWC, eSwatini or the discipline of education as experts. Each interview was about half an hour exploring the Futures Studies method of Causal Layered Analysis (CLA) as a form of Action Learning while discussing the ideas of the research questions. Analysis of interview material is a rigorous computer-aided textual analysis that extracts and distils ideas using the CLA method as a framework for image creation. Four imaginative yet logical im- ages of the future in eSwatini’s education systems and the Waterford Kamhlaba UWC are included in the results. These images are combined to assert the existence of a Desired Future which borrows elements of all the four images. The background research and images produced show that there are some key areas to consider changing education in eSwatini from an increase in infrastructure and investment to changes in the outlook of what it means to be a contemporary economy, including ecology and other cycles. Research findings also include suggestions of new directions within UWC as well as eSwatini education systems

What is the impact of World Heritage status and related positioning for a tourist audience on Robben Island's meanings and public narratives?

The advent of democracy brought about changes in the cultural heritage landscape. Cultural heritage used to be a preserve of the rich and experts. Heritage of places is not found lying around for it to be discovered, but it is continually reproduced to suit the needs of that particular society. Reproduction of heritage is due to it being amenable to be used and reused to suit the needs of that grouping. Cultural heritage in South Africa offers is used as an economic tool as it offers easy access for participants to the cultural tourism industry. The capital outlay is usually minimal. Politicians also use cultural heritage to create new identities. In South Africa, during the early stages of democracy, heritage was used to promote national reconciliation and nation-building. Robben Island was used as a flagship institution to open up the cultural heritage space and give voice to those previously denied access or whose heritage was distorted or misrepresented. Robben Island, a place of atrocity stemming from the colonial period, was seen as a beacon of hope and promoted as a symbol of the triumph of the human spirit over adversity. The site's positioning as an economic tool and fostering notions of national unity invariably leads to selecting a layer that will resonate with the nationalist ideals. The exploratory study uses interviews with tour guides and heritage experts to examine the message told to visitors. The results obtained are contrasted with the national legislation, the site's conservation management plans, and UNESCO's requirements for listed sites. At an international level, UNESCO is concerned with preserving the outstanding universal value of sites. The preservation of the heritage at a local level is done through national legislation

Synthesis and biological activity of ajoenes with increased aqueous solubility

The synthesis of four new ajoene analogues is presented in this thesis. The key to the synthesis was gaining access to a phenol derivative containing the ajoene core structure (sulfoxide / vinyl disulfide) that could be functionalised with various substituents. Evaluation of biological activity returned excellent in vitro activity against a WHCO1 oesophageal cell-line, in which a derivative with a methoxycarbonylmethylene substituent (PMB-ester) was shown to be the most active analogue that was fifteen times more active than Z-ajoene with an IC50 of 1.7 M. An aqueous solubility assay reveals that aqueous solubility increased with subsituition and the analogues with amido or acetate substituents were the most soluble ones. The analogues were also shown to enhance the apoptotic effects of two chemotherapeutic drugs Doxorubicin and Vincristine via chemosensitization. This effect was attributed to the presence of at least one p-methoxybenzyl substituent in the structure

Chief with a Double Agenda: Unravelling the Puzzle to Buthelezi’s Animosity towards Mzala Nxumalo

The demise of King Goodwill Zwelithini kaBhekuzulu in 2021, the longest-reigning Zulu monarch on record (3 December 1971-12 March 2021), and that of the queen regent Mantfombi Dlamini Zulu, brought Prince Mangosuthu Buthelezi into the limelight. As the traditional prime minister of the Zulu kingdom and an elder statesman, Buthelezi strategically seized upon this solemn occasion to reinforce his preferred historical narrative. Seeking sympathy and aiming to portray himself as a peacemaker on the right side of history, he singled out Mzala Nxumalo as a “propagandist” intent on tarnishing his reputation. This article contends that Mzala’s book, “Gatsha Buthelezi: Chief with a Double Agenda”, lies at the core of this animosity, spanning over three decades. Therefore, it traces Mzala’s central arguments presented in the book and examines Buthelezi’s responses to them. Additionally, the article provides an overview of Mzala’s background and his relationship with Buthelezi, summarising the primary thesis articulated in his book regarding Buthelezi’s role in the South African political landscape. While acknowledging weaknesses in Mzala’s methodology and academic approach, particularly in terms of rigour, the article asserts the enduring significance of his book in shaping scholarly discourse. It argues for the “unbanning” of the book, emphasising its importance in fostering academic dialogue and upholding principles of academic freedom. The article underscores the necessity of diverse perspectives, including critical ones, in achieving a comprehensive understanding of historical events

Analysis of operational risk in the South African banking sector using the standardised measurement approach

Abstract : Over the last decade, financial markets across the world have been devastated by operational risk-related incidents. These incidents were caused by a number of aspects, such as, inter alia, fraud, improper business practices, natural disasters, and technology failures. As new losses are incurred, they become part of each financial institution’s internal loss database. The inclusion of these losses has caused notable upward spikes in the operational risk Pillar I regulatory capital charge for financial institutions across the board. The inherent imperfections in people, processes, and systems–be it by intention or oversight–are exposures that cannot be entirely eliminated from bank operations. Thus, the South African Reserve Bank mandates South African financial institutions to reserve capital to cover their idiosyncratic operational risk exposures. Investors fund capital reserves that are held by financial institutions, and these stakeholders demand a viable return on their investment. Consequently, the risk exposure and capital held relationship should be fully understood, managed, and optimised. This thesis extends Sundmacher (2007)’s work through the use of one instance of the Standardised Measurement Approach data against that of the Advanced Measurement Approach, the Standardised Approach, and the Basic Indicator Approach to estimate the potential financial benefit that financial institutions in South Africa could attain or lose, should they move from a Basic Indicator Approach to a Standardised Approach, or from a Standardised Approach to an Advanced Measurement Approach, or from an Advanced Measurement Approach to a Standardised Measurement Approach. The Advanced Measurement Approach, a Loss Distribution Approach coupled with a Monte Carlo simulation was used. Parametric models were imposed to generate the annual loss distribution through the convolution of the annual loss severity and frequency distribution. To fit the internal loss data for each class, the mean annual number of losses was calculated and was assumed to follow a Poisson distribution. The Maximum Likelihood Estimator was used to fit four severity distributions: Lognormal;Weibull; Generalized Pareto; and Burr distributions. To determine the goodness of fit, the Kolmogorov-Smirnov Test at a 5% level of significance was used. To select the best fitting distribution, the Akaike Information Criterion was used. Robustness and stability tests where then performed, using bootstrapping and stress-testing respectively. Overall, we find that the Basel Committee on Banking Supervision’s primary consideration that postulates that there is value in a financial institution moving from the Basic Indicator Approach to the Standardised Approach, or from the Standardised Approach to the Advanced Measurement Approach is indeed valid, but fails in the movement from an Advanced Measurement Approach to a Standardised Measurement Approach. The best Pillar I Capital reprieve is offered by the Diversified Advanced Measurement Approach, whilst the second best is the Standardised Measurement Approach based on an average total loss threshold of €100k (0.87% higher than the Diversified Advanced Measurement Approach), closely followed by the default Standardised Measurement Approach based on average total loss threshold of €20k (5.63% higher than the Diversified Advanced Measurement Approach). To the best of our abilities, we could not find any work that is comprehensive enough to include all four available operational risk quantification approaches (Basic Indicator Approach, Standardised Approach, Advanced Measurement Approach, and Standardised Measurement Approach), for the South African market in particular. This work foresees South African financial institutions pushing back on the implementation of SMA, and potentially lobbying the regulator to remain in AMA – as the alternative might mean increased capital requirements leading to reduced Economic Value Added to shareholders (as more capital is required at the same level of profitability or business activity). The financial institutions are anticipated to sight advanced modelling techniques as helping management have a deeper understanding of their exposures – whilst the Scenario Analysis process allows them a method of identifying their key risks and quantifying them (adding to management’s tools set). However, if South African financial institutions want to compete at a global stage and wanted to be accepted among ‘internationally active’ institutions – their adoption of SMA may not be a choice but an obligation and an entry ticket to the game (global trade).M.Com. (Financial Economics

Use of Biotechnology in Improving Crop Yields and Sustainability in South Africa

Purpose: The aim of the study was to investigate the use of biotechnology in improving crop yields and sustainability in south Africa. Methodology: The study adopted a desktop methodology. Desk research refers to secondary data or that which can be collected without fieldwork. Desk research is basically involved in collecting data from existing resources hence it is often considered a low cost technique as compared to field research, as the main cost is involved in executive\u27s time, telephone charges and directories. Thus, the study relied on already published studies, reports and statistics. This secondary data was easily accessed through the online journals and library Findings: The use of biotechnology in South Africa to improve crop yields and sustainability has yielded significant positive outcomes. Biotech crops, including drought-tolerant varieties and genetically modified maize, have been widely adopted by smallholder farmers, particularly in drought-prone areas. These crops have contributed to enhanced food security and increased resilience in the face of climate variability. Furthermore, studies have demonstrated that the adoption of biotech crops is associated with higher yields and reduced production costs, making farming more profitable. Overall, biotechnology plays a pivotal role in South Africa\u27s agriculture, fostering both increased productivity and sustainability. Unique Contribution to Theory, Practice and Policy: Theory of Green Revolution, Theory of Technological Determinism, Theory of Innovation Diffusion may be used to anchor future studies on use of biotechnology in improving crop yields and sustainability in south Africa. Findings can prioritize the development of drought-resistant crop varieties using biotechnology. Public-private partnerships can accelerate technology adoption and promote sustainable agriculture practices

Performance of geopolymer concrete subjected to mineral acid corrosion and related to microbially-induced corrosion (MIC) of concrete in sewers

worse than degradation at the crown of the sewer pipe. Furthermore, results from this study show that high resistance under the static acid corrosion exposure condition cannot be extended to mean high resistance under the erosion-corrosion exposure condition for some concrete mixes. In this study, the static HCl test and the dynamic HCl test were used to measure the resistance of concrete mixes under the static corrosion exposure condition and erosion-corrosion exposure condition respectively. However, concretes that exhibited high resistance to the erosion-corrosion exposure condition were consistent in exhibiting high resistance to the static corrosion exposure condition. This finding is consistent with the sequence of corrosion processes in MIC, wherein dissolution of the concrete components occurs before the precipitation of corrosion products. Therefore, it expected that high resistance in the dynamic acid test (i.e. resistance to dissolution) implies high resistance in the static test, which measures the combined resistance of dissolution and resistance emanating from corrosion products. Both static and dynamic acid corrosion tests revealed that the geopolymer concretes tested in this study outperformed PC and CAC concretes. Results from the static HCl test showed that GP-ferro-quartz concrete, the most durable concrete specimen, provided a 69-fold improvement in resistance when compared to PC-dolomite mixes (control #1) and a 4.72-fold improvement in resistance when compared to CAC-dolomite mixes (control #2). Results from the dynamic HCl test show that the GP-ferro-quartz mix provided a 180-fold increase in resistance when compared to the PC-dolomite mix and a 275-fold increase when compared to CAC-dolomite mix. The CACdolomite mix was found to have the lowest resistance to the erosive-corrosive exposure conditions of the dynamic HCl test. Thus, in terms of the concrete MIC resistance properties identified in this study, it is suggested that the CAC-dolomite mix had poor kinetic resistance to dissolution. However, under the static acid test (static corrosion exposure condition), the CAC-dolomite mix performed better than the PC-dolomite mix and GP-dolomite mix. CAC-dolomite concrete performed inferiorly only to the set of GP-siliceous-aggregate mixes in the static HCl test. The difference in the performance of CAC-dolomite concrete performance between the static and dynamic test is largely attributed to the formation of alumina gel, an acid corrosion product of CAC hardened paste, which envelopes the concrete specimen and reduces the rate of surface corrosion in the static HCl test. However, under v the dynamic HCl test, the gel layer is brushed off the surface of the concrete specimen rendering it ineffective in protecting the concrete specimen from corrosion. Previous research on the acid attack of concrete posits that the chemical make-up of concrete materials has a strong bearing on corrosion behaviour. To this end, various measures have been suggested such as the ratio of calcium to silicon (Ca/Si) in concrete. The approach utilised in this study was to calculate the “basicity value” which provides the ratio of major basic to acidic oxides found in the concrete. XRF analysis of the hardened cement pastes and the 5 aggregate types used in the experiments enabled the calculation of basicity values. The combined basicity value for concrete specimens was determined by proportionally summing (according to mass) the basicity values of the aggregate and hardened cement paste parts. A strongly correlated linear relationship between the basicity value of concrete and the corrosion rate from the dynamic HCl test was established. This empirical relationship warrants further investigation and verification, as it would, in principle provide a means to estimate the dissolution rate of concrete by calculating its basicity instead of undertaking laboratory acid tests. Basicity was also found to be useful in determining the corrosion compatibility of binder type and aggregate types. It was found that the difference between the basicity value of hardened cement paste and the basicity value of the aggregate was useful in determining the type and extent of preferential corrosion of a concrete specimen tested under the dynamic HCl test. For ease of reading, this difference was called the “basicity differential”. By visually assessing corroded concrete specimens from the dynamic HCl test, it is was possible to determine whether the hardened cement paste or aggregate component was preferentially corroded, and to gauge the extent of preferential corrosion visually. GP-ferro-quartz and GP-granite concretes had the lowest levels of preferential corrosion which corresponded to their low basicity differential values. In contrast, CAC-dolomite concrete had the highest basicity discrepancy which corresponded visually to a high preferential corrosion of the hardened cement paste. Mineralogical analysis via XRD, found that the hardened cement pastes of the three binder types consisted mainly of amorphous phases (>70%). The crystalline phase of the geopolymer hardened cement paste was mostly constituted by insoluble minerals such as mullite. This partially explains the higher corrosion resistance of geopolymer concretes. However, a more comprehensive explanation needs to include analysis of the amorphous phases, which fell outside the scope of this study. SEM analysis of HCl corroded geopolymer hardened cement paste found that fly ash spheres embedded within the geopolymer matrix were preferentially corroded. This indicates that fly ash content negatively affected the rate of corrosion of the geopolymer hardened cement paste. Furthermore, SEM analysis showed that the geopolymer matrix surrounding the fly ash spheres was relatively intact