Theses / Dissertations

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Open Access
20th-century serial thought and its development from performed to electronic music.
(1966) Mears, Guy Edgar Frank
Unable to copy abstract from PDF document
Open Access
30 day outcomes of 1000 consecutive laparoscopic cholecystectomies across four Cape Metropole hospitals in Cape Town
(2024) Kariem, Maahir; Kloppers, Jacobus
Background: Laparoscopic Cholecystectomy (LC) is the standard of care for symptomatic gallstone disease. It has a steep learning curve and can associated with significant post operative morbidity and mortality. LC carries a morbidity of 1.6 – 5.3%, mortality of 0.05 – 0.14% and readmission rates of 3.3% (0-11.7%). We aimed to evaluate the 30 day outcomes of LC across four metropole hospitals in the Western Cape (WC) including mortality, length of stay, readmissions and complications according to the Clavien-Dindo Classification system. Methods: A retrospective review of a prospective database was performed. The data collection was collected between September 2019 and July 2022. Relative clinical, operative findings and post operative outcomes were analysed. Results: There were 1000 consecutive LC included in this study. The mean post operative length of stay was 1.92 days. Fifty-one patients developed surgical complications of which the most common surgical complication was a bile leak (n = 14) and intra-abdominal collections (n=11). Seven patients with bile leaks required reintervention. Four (0.4%) bile duct injuries (BDI) were reported in our series. Twenty-five percent of post operative complications were graded Clavien-Dindo IIIa and 28% were graded Clavien-Dindo IIIb. The 30 day readmission rate was 3.8% (n=38). Thirty-five surgical complications were noted of which 22 (62.8%) required reintervention. There were three reported mortalities (0.3%). Conclusion: Laparoscopic Cholecystectomy is considered the standard of treatment for gallstone disease and has potential serious complications. Our outcomes reported in this series is similar to that of other studies.
Open Access
3D intrawall imaging using backprojection for synthetic aperture radar (SAR)
(2024) Dass, Reevelen; Paine, Stephen
The Council of Scientific and Industrial Research (CSIR) has evolving synthetic aperture radar (SAR) capabilities in the C-band and the L-band. Currently, these capabilities are used to generate aerial landscape images; however, to explore the feasibility of using this technology in different environments, an experimental SAR system has been developed. This is referred to as the wall scanner. The purpose of the wall scanner is to image the interior of a wall, revealing details of the substructures inside the wall such as conduits and piping. This is done by moving the antenna system across the wall surface to create SAR images using backprojection. The radar used two different types of antennas, a log periodic dipole array (LPDA) antenna and horn antenna. The horn antenna performed well in the experiments, producing images with minimal artefacts. On the contrary, the LPDA antenna did not perform as well in the experiments and as such the characteristics of the antenna were investigated. The investigation revealed that the antenna did not function throughout the frequency range specified by its manufacturer. This produced artefacts in the image; however, some of the effects of these artefacts were minimised by a series of preprocessing techniques. A variety of preprocessing techniques were used to improve image quality. In addition to compensating for the properties of the LPDA antenna, windowing and different methods of background subtraction were used. It was difficult to compensate for the antenna issues in preprocessing; however, windowing and background subtraction had a significant effect on the images that were produced. Two postprocessing techniques were used, gradient descent optimisation based on image contrast and polarimetry. The developed gradient descent optimiser was able to automatically adjust for the system group delay based on the contrast of the image. Polarimetry post-processing revealed that the horizontally transmitted horizontally received polarisation (HH) and vertically transmitted vertically received polarisation (VV) were effective in creating images in this environment; however, cross-polarisation in the form of horizontally transmitted vertically received polarisation (HV) was not effective. The wall scanning environment that was measured consisted of scanning both drywall and brick wall. This was split into three experiments. The experiments used different materials that were placed in front of a wall, behind the wall at a distance, and directly behind the wall. The wall scanner was able to successfully create images of the three different experiments for the drywall; however, the desired results for the brick wall were not achieved. For drywall, the substructures placed directly behind the wall were more difficult to see because they were masked by the wall and its sidelobes. The materials scanned were a copper pipe, a PVC pipe, a wooden beam, and a highly reflective calibration target. The calibration target and the copper target performed well in the three experiments. The wooden beam did not perform as well; especially when placed directly behind the wall; however, it was still visible in all experiments. The PVC performed the worst and was only faintly visible in the experiments and was not visible when placed directly behind the wall.
Open Access
6-deoxy-6-amino chitosan: A plant defence priming biopolymer that enhances resistance against Botrytis cinerea in tomato and Fusarium verticillioides in maize
(2024) Moola, Naadirah; Rafudeen, Mohamed; Jardine Mogamat
Aminochitosan, derived from chitosan, features enhanced water solubility, and improved antifungal efficacy attributed to an additional amine group at the C-6 position, hinting at its superior antifungal potential compared to native chitosan. This PhD thesis aimed to explore the optimal concentration of aminochitosan and its molecular weight fractions for enhanced antifungal and priming properties in the tomato/Botrytis cinerea and maize/ Fusarium verticillioides pathosystems. In the B. cinerea pathosystem, various concentrations of aminochitosan were assessed for their antifungal effectiveness against B. cinerea growth and sporulation. Additionally, in planta studies were conducted to phenotype and quantify temporal stress responses using both qualitative and quantitative chlorophyll fluorescence imaging as well as DAB assays combined with microscopy. Despite batch-to-batch variations, aminochitosan consistently inhibited fungal growth and sporulation in a dose-dependent manner. In planta, aminochitosan pre-treatment induced robust defence responses in tomato leaves, resulting in a resistant phenotype that was mediated through a combination of enhanced photosynthetic efficiency as evidenced by enhanced Fv/Fm and chlorophyll content. The DAB assays suggested that these resistant phenotypes were also ROS-independent (H2O2 specifically) due to the strong positive impact of direct inhibition. The resistant phenotype and optimal efficacy of the aminochitosan MW fractions was observed at 3.5-15 kDa for antifungal efficacy and 15-20 kDa for in planta efficacy. Consequently, leaf senescence, hypersensitive responses and therefore necrosis were mitigated suggesting that aminochitosan primed defence responses in both mock and B. cinerea inoculated leaves. A temporal, label-free quantitative proteomic analysis revealed the differential priming of key molecular mechanisms underpinning aminochitosan primed states both with and without B. cinerea infection at 6 and 9 hpi in the tomato/B. cinerea pathosystem. Aminochitosan treatment (1 mg/mL) differentially regulated proteins as early as 6 hpi with some of the induced responses being sustained up to 9 hpi. Additionally, several proteins were oppositely regulated between aminochitosan pre-treatment and B. cinerea infection, indicating differential regulation patterns between the “primed state” and the “triggered state”. The proteomic data therefore partially validated the ‘priming' capacity of aminochitosan in 5- week-old tomato leaves, specifically diamino 3 when used as a foliar spray at a concentration of 1 mg/mL. The bimodal effects of aminochitosan in a maize/Fusarium verticillioides pathosystem were investigated by assessing the direct antifungal efficacy and elicitation of plant defence properties in planta. Aminochitosan displayed significant antifungal activity on both radial growth and sporulation at a minimum concentration of 1 mg/mL. Aminochitosan was also assessed in planta as preventative or curative treatments in maize seedlings infected with F. verticillioides at two time points. In the preventative treatment, salicylic acid accumulated during the early stages of infection (biotrophic phase) whereas in the curative treatment, jasmonic acid accumulated during the necrotrophic phase. In summary, we demonstrated that water-soluble aminochitosan possesses key properties that enable plant priming in addition to its superior direct antifungal activity compared to native chitosan. We also identified the optimal molecular weights and concentrations necessary for achieving maximum and 50% inhibition activity
Open Access
A 'Foodshed' Moment for Planning: Investigating the Role of Food-Sensitive Planning in supporting Cape Town?s Resilience Strategy to strengthen Food Security, using the Philippi Horticultural Area as a case study
(2023) Zaloumis, Georgina; Katzschner, Tania
In recognition of the complexities and urgency brought about by increasing present and expected future intersectional crises, the CoCT developed and adopted its own Resilience Strategy. This strategy realises the fragility of urban food systems and the importance of achieving resilience to better support food security within Cape Town. Small-scale farms which make up the Philippi Horticultural Area (PHA) have been effective in retaining the production and accessibility of food which is resilient in the face of numerous shocks and stresses. It currently produces 50-70% of Cape Town's nutritionally dense and fresh food making it a vital component of Cape Town's foodshed. Additionally, it is also essential because it achieves multiple benefits across the Resilience Strategy due to its ecological, agricultural as well as socio-economic value to Cape Town. However, a proactive planning approach is needed as the PHA is under threat due to land-use pressures from mismanagement of land regulations, planning uncertainty and a lack adequate governance. Thus, there is a need to examine the role of food-sensitive planning in strengthening Cape Town's Resilience Strategy with achieving food security, using the PHA as a case study. This site provides an opportunity for planners to rethink how food-sensitive planning can be better integrated into the MSDF. The aim of the study is to investigate how the MSDF can better aligned with Cape Town's Resilience Strategy to mitigate threats to the PHA and enhance the resilience of local food production in Cape Town using food-sensitive planning. This aim will be achieved through desktop research, semistructured interviews, and field observations in the PHA. The results of this study indicate that foodsensitive planning is an innovative method to better harness and harmonise with the MSDF and Resilient Strategy to enable a more resilient food system in Cape Town. This is through the integration of bottom-up knowledge and top-down action to implement targeted interventions that value and protect food security assets such as the PHA. Nevertheless, going forward this research can contribute to studies around strengthening planning and governance of peri-urban agriculture areas in the global South to better support urban resilience and food security as well as broaden literature around food-sensitive planning.
Open Access
A 23-year retrospective review of heart transplant donor and recipient referrals to Groote Schuur hospital between 1997 and 2019
(2025) Kanyongo, Rusununguko; Pennel, Timothy
Background. Heart transplantation in South Africa faces numerous challenges related to organ scarcity and unequal access to advanced heart therapy. There is an urgent need to analyse the current transplant referral pathway to optimise equitable access to transplantation. Objectives. To provide an audit of heart transplant referrals to Groote Schuur Hospital, Cape Town, over a 23-year period, focusing on patient demographics, indications for referral, waiting-list dynamics, and transplant referral outcomes. Methods. The study utilised a retrospective patient folder review for the period 1 January 1997 - 31 December 2019 and audited the trends in heart transplant referrals and associated outcomes of the referral at a tertiary academic hospital. Results. A total of 625 recipients were referred for heart transplantation, with the majority being male (n=412; 65.9%), while gender was undocumented for 69 cases (11.0%). The mean age was 38.1 (14.6) years, and 153 (24.5%) were listed for transplant, while 215 (34.4%) were deemed ineligible for listing. Contraindications for listing included social (n=106; 49.3%), medical (n=83; 38.6%) and psychological (n=26; 12.0%) factors, while 134 patients (21.4%) were considered too well. Poor social circumstances (n=38; 39.6%), poor insight (n=28; 29.2%) and poor compliance (n=21; 21.9%) were the most common non-medical reasons for not listing recipients, while obesity (n=30; 31.3%) and smoking (n=23; 24.0%) were notable medical contraindications. Forty-nine patients (7.8%) died during work-up, while 130 (85.0%) of the listed patients received a heart transplant. Of the 429 donor referrals, 139 (32.4%) were accepted for organ procurement. Reasons for declining donors included unsuitability for transplantation (30.3%), lack of capacity (1.8%), and recipient-donor mismatch (66.9%). Conclusion. Three-quarters of the referred patients were deemed unsuitable for heart transplantation for medical and/or social reasons. The ratio of referral to listing has decreased over time. However, once listed, the likelihood of receiving a transplant was high.
Open Access
A biomass-fueled combined steam and sCO2 heat and power cycle for Southern African conditions
(2025) Haffejee, Rashid Ahmed; Collier-Reed, Brandon
Biomass is a renewable, cost-efficient, carbon-neutral fuel obtained from agricultural waste streams or energy crops that can be combusted in a furnace to co-generate electricity and heat. Integrating a supplementary high efficiency cycle, such as the supercritical-CO2 (sCO2) Brayton cycle, with an existing industrial Rankine cycle and a biomass fired boiler may be an economical option to increase overall thermal efficiency and net generation. However, the integration of sCO2 heaters within the biomass boiler presents challenges related to operating philosophies and component specifications. The focus of this research was to investigate the integration of a sCO2 Brayton cycle with a combined heat and power steam cycle with a modular biomass boiler firing typical Southern African bagasse fuel. A quasi-steady state 1D thermofluid network-based process model of the sCO2, steam and flue gas cycles was developed for nominal and partial load analysis. It accounts for the detailed component characteristics for the Rankine and Brayton cycles, as well as the biomass boiler, together with the complex interactions between all of the components in the different cycles. To facilitate the analysis of these intricate systems, a sophisticated simulation code was developed to allow for necessary customization and enforcement of required boundary conditions and control parameters. The network model solves the mass, energy, momentum, and species balance equations for the various fluid streams, accounting for radiative and convective heat transfer phenomena in the boiler. Due to the novelty of the proposed integrated cycle, high-fidelity 3D CFD modelling was then also used to validate the heat uptakes for the sCO2 heaters in the biomass boiler. Two configurations with the sCO2 heater/s situated within the flue gas flow path were investigated, namely a single convective-dominant heater, and a dual heater configuration with a radiative and a convective heater. At nominal load, the network model results show the required rate of overfiring for the sCO2 configurations, with a 15.3% increase in fuel flow rate resulting in an additional 21.2% in net power output. The impact of the sCO2 heaters situated in the gas flow path was quantified, with reduced heat uptakes for downstream steam heat exchangers offset by increased furnace waterwall heat transfer. At partial loads, between 100%-60%, inventory control proves to be the better performing control strategy for load following, maintaining high thermal efficiency across partial loads. Notably, at 60% load, the sCO2 compressor inlet conditions are near the pseudo-critical point, which requires careful management of inventory control. The boiler CFD modelling highlighted lower heat uptakes for sCO2 heaters compared to the 1D model, exacerbated at lower loads, particularly for the dual heater configuration. The 1D model was consequently calibrated based on these results. The single sCO2 heater configuration is recommended as the preferred configuration to minimise adverse impacts on the Rankine cycle superheaters. Further iterations between the 1D process model and CFD model are recommended.
Open Access
A brief excursus through the concept of the trust, dealing with its origins and history and generally traversing taxation of a trust and its implications for the taxpayer
(1995) De Mink, Jason; Emslie, T S
A 'trust' is defined in the Income Tax Act [1] at section one as 'any trust fund consisting of cash or other assets which are administered and controlled by a person acting in a fiduciary capacity, where such person is appointed under a deed of trust or by agreement or under the will of a deceased person'. This is a recent introduction to the Act, coming into affect in respect of years of assessment ending on or after 1 January 1993 and sums up reasonably regarding satisfactorily what the various authorities have said to date trusts. In Estate Kemp v McDonald's Trustee [2] judge Solomons referred to the fact that in a trust the 'legal dominium of property is vested in the trustee' but that they have 'no beneficial interest in it but are bound to hold and apply it for the purpose of some persons or for the accomplishment of same purpose' [3] In Thome & Molenaar NNO v Receiver of Revenue, Cape Town [4] a trust was described as being 'created by contract, very often by contract of donation . . . or by way of a will. It is created in respect of defined administer property transferred to a trustee, who is burdened with the obligation to the property for the benefit of a third person’ [5]. In the case of Goodricke and Son (Pty) Ltd v Registrar of Deeds. Natal [6] the court held that the concept of a valid trust revolved around the removal of dominium (ownership) from the beneficiaries and placing it in the hands of the trustees [7]. ' ... [A] trust exists when property is to be held or administered by one person on behalf of another, or for some purpose other than his own benefit' [8]. The court went on to say that the essential elements which made up a trust were 'segregation of the trust assets by the founder' and the 'creation of an obligation to administer otherwise than purely for oneself' [9].
Open Access
A bundle adjustment solution for a personal computer environment
(1990) Rommelaere, C L M
Photogrammetry is the science and art of using and measuring photographs for various purposes. The word photogrammetry literally means the measuring of something "written" with light. Various photogrammetric techniques have been developed to solve a wide variety of problems in many fields of endeavour. The bundle solution is one technique which has proven very useful and versatile.
Open Access
A Cambridge structural database search for entangled MOFS and the synthesis and analysis of the non-entangled counterparts of a set of entangled MOFs
(2024) Bambiso, Lungelo Tervin; Oliver, Clive L; Mogodi, Wilson M
Metal-organic frameworks (MOFs) have become a fast-growing field of research in the areas of synthetic chemistry, crystal engineering, materials science and supramolecular chemistry in recent years. The synthesis and characterization of novel MOFs have been of particular interest to researchers around the world due to their potential in several applications, such as gas sorption and separation, drug delivery and catalysis. The focus and pursuit in the early stages of MOF research was to design materials with as large pore volumes as possible, which lead to the phenomenon called entanglement. Entanglement in MOFs, of which interpenetration is a subtype, refers to when networks within the same crystal structure cannot be hypothetically separated from one another without breaking chemical bonds. This has a significant impact on the porous nature, structure, and functional applications of MOFs. Thus, initially entanglement was viewed as undesirable, however, it has since been recognized that entanglement could be advantageous, since these MOFs may be more stable. The primary objective of this work was (i) to data mine the Cambridge Structural Database (CSD) for entangled MOFs and (ii) to investigate the structural, thermal and sorption properties of a set of non-entangled MOFs with their previously published isoreticular and entangled counterparts. The first section of this thesis, the computer-based section, presents the MOFs (not discriminating between entangled and non-entangled MOFs) belonging to seven different families extracted (using the CSD version 5.37 - May 2016 update) according to the search criteria used by Moghadam and Fairen-Jimenez et al. In this thesis, these seven families were updated using the CSD version 5.43 - April 2021. These families formed the basis sets from which entangled MOF structures were searched using search criteria based on intermolecular, non-bonded contacts such as hydrogen bonding, π–π and C–H⋯π interactions. The average of the two success rate indicators, showed that the percentage of retrieved entangled MOF structures from the four MOF families that had entangled structures, ranged from 13.6 – 38.6%, 11.8 – 38% and 4.4 – 34%, respectively, for the three search criteria. The second section of this thesis, the experimental section, describes two novel non-entangled two-dimensional (2D), 2-periodic isoreticular fluorinated MOFs of formulae [Cu2(hfipbb)2(DMF)2]n·n(DMF)4 (1), [Cu(hfipbb)(DEF)]n·n(DEF)2 (2), where hfipbb = 4,4′-(hexafluoroisopropylidene)bis(benzoate), DMF = N,N′-dimethylformamide and, DEF = N,N′-diethylformamide. These structures are compared to their entangled, isoreticular counterparts published by Chatterjee et al. in terms of their syntheses, structures, thermal and sorption properties. The entangled structures had decomposition temperatures of 310 °C and 400 °C for the MOFs obtained from DMF and for DEF, respectively whilst the non-entangled MOFs had decomposition temperatures of 350 °C and 370°C for 1 and 2, respectively. The non-entangled MOFs had contact surface potential void space of 39% and 40.4% for 1 and 2, respectively, significantly higher than those of entangled MOFs with contact surface potential void spaces of 8.2% and 12.5% for the entangled MOFs obtained from DMF and DEF, respectively. Despite the lack of entanglement in 1 and 2, as compared to their entangled counterparts, their 195 K CO2 sorption isotherms also display inflection points and significantly increased sorption, as well as large extents of hysteresis, of 35% and 39% obtained for 1 and 2, respectively, whilst both entangled MOFs displayed extents of hysteresis of 44%. Interestingly, the activated phase of a third MOF, [Cu2(hfipbb)2(H2O)2]n (3), synthesized through DMF ligand exchange with water in 7 days, does not display an inflection point in its 195 K CO2 isotherm and subsequent increased sorption, despite also being non-entangled. This confirms that subtle differences in the desolvated phases can lead to marked differences in the sorption behaviour of isoreticular MOFs.
Open Access
A case for the extension of the 'comply or explain' philosophy to a national code of corporate governance in Zimbabwe: a comparative analysis
(2009) Simbo, Chiedza; Mongalo, Tshepo
After the wave of corporate collapses in the United Kingdom (UK) in the late 1980s and early 1990s, a need for corporate governance reform was realised in that country. There was an introduction of self-regulation as a method of corporate governance. The private sector initiated efforts to improve corporate governance leading to recommendations by the Cadbury, the Greenbury, the Hampel, the Turnbul, the Smith and the Higgs Committees.
Open Access
A case study exploration of the therapeutic phenomena of projective identification, transference and countertransference: a brief therapy with a patient with psychotic anxiety
(1996) Abrahams, Deborah L; Miller, Sheila; Swartz, Sally
This dissertation reviews the concepts of projective identification, transference and countertransference from an Object Relations theoretical perspective. The developmental mother-infant relationship is explored as a model for understanding the therapist-patient interaction in both its normal and pathological forms. Projective identification is used to illuminate the workings of transference and countertransference. W.R. Bion's conception of the mother-therapist as 'Container' and infant-patient as 'Contained' is presented as pivotal to understanding that interaction. Failures in projective identification - and therefore in symbolic functioning - are explored, with particular focus given to psychotic and psychosomatic manifestations in patients. The relevance of transference and countertransference phenomena to brief psychotherapy is also considered. These concepts are then applied to a specific therapeutic case. The patient was seen as an in-and outpatient over a 5 month period 1-3 times per week. The patient's history and a brief formulation are presented, followed by a discussion of how the above-mentioned theoretical issues manifested in the therapy. The patient operated on the border between psychosis and neurosis and communicated in primitive pre-verbal and powerful symbolic ways. Case illustrations focus on the interplay between her psyche and soma, the impact of the hospital setting as well as particular transference and countertransference difficulties incurred.
Open Access
A case study of aspects of the political life of Advocate Benjamin Magson Kies (1917 - 1979) and of "The Torch" newspaper with which he was closely connected, showing how the criminal justice system in South Africa was employed in an attempt to silence political and ideological opposition to the apartheid regime
(1993) Cavernelis, Dennis Burt; Rose-Innes, Laurie
Charles van Onselen( 1) writes that in his biography of Nongoloza Mathebula "we , can ,see ..... the story of one man's search for justice within the context of the most important labour repressive institutions that developed during the South African industrial revolution. He states that he has provided a local illustration of the assertion by C Wright Mills that: "the biographies of men and women, the kinds of individuals they variously become, cannot be understood without reference to the historical structures in which the miliEH,IX of their everyday life are organised." (2) . This paper is in some respects both biographical and historical. B M Kies was a leading figure in the Anti-CAD (Coloured Affairs Department) Movement, The Teachers' League of South Africa and the Non-European Unity Movement, sectors of the liberatory movement in South Africa. His involvement in the liberatory struggle began in his student days in the late 193Os and continued up to the time of his death at the end of the 1970s. This paper is not a political biography of BM Kies, but the story of his life (which has yet to be written) may also accurately be described as "the story of one man's search for justice". The focus of this study will be on the contact which B M Kies had with the criminal justice foe system and the broader legal system in South Africa from 1948, when the Nationalist government with its platform of apartheid policies came to power, to 1963 when that government's repressive measures to enforce its apartheid policies reached new heights. A number of reported Supreme Court decisions will be considered. These decisions, all relate to cases in which B M Kies was either directly or indirectly involved as a result of his political activities .
Open Access
A case study of factors influencing primary healthcare Continuity of Care for persons with disabilities
(2024) Padayachee, Thesandree; Kathard, H
Background: “Continuity of Care” refers to how a patient experiences care over time and is considered to be a central pillar in the delivery of high-quality person-centred healthcare. In South Africa (SA), persons with disabilities experience a range of structural barriers to health services and even when access to health services is realised, poorly integrated health systems and services, limited human resources and poor awareness of the needs of persons with disabilities result in unmet healthcare needs. Given the rapidly transforming healthcare context of SA and the adoption of policies towards the realisation of universal health coverage, an understanding of how the health system is responding to the “Continuity of Care” needs of persons with disabilities through policy and practice is valuable step towards realising the goal of integrated people-centred health systems; particularly in the delivery of primary healthcare (PHC). Objectives: The study aimed to explore factors influencing “Continuity of Care” for persons with disabilities within the PHC context. Experiences and expectations of persons with disabilities were explored, relevant policies governing PHC and “Continuity of Care” were analysed and health systems responsiveness was explored to understand what influences “Continuity of Care” for persons with disabilities. Method: This exploratory case study used a critical social theory and a health policy and systems approach to better understand how primary healthcare “Continuity of Care” for persons with disabilities can be strengthened. The Conceptual Framework for Health Systems Responsiveness (Mirzoev & Kane, 2017) informed the case study design by exploring how persons with disabilities experienced “Continuity of Care” and supported a deeper understanding of health systems gaps through perspectives of service providers in responding to the “Continuity of Care” needs of persons with disabilities. The study was conducted within the context of the SA primary healthcare policy and implementation in an urban suburb in the city of Durban, KwaZulu Natal in South Africa. The study included multiple data collection methods including interviews, focus group discussions, document reviews and analysis of relevant policies using an adapted EquiFrame (Amin, 2011). Qualitative data was analysed thematically using inductive and deductive analysis. Results: Participants with disabilities were found to experience primary healthcare discontinuity resulting from known factors such as lack of reliable and accessible transport, negative attitudes of health facility staff and sub-optimal management of clinic and outreach services. New insights that were found to negatively affect “Continuity of Care” for persons with disabilities included the combined influences of institutional distrust; the medical model as a legacy of apartheid; incoherence in policies supporting “Continuity of care” and poor user-centred design practices in the delivery of new innovations that were unresponsive to the needs of persons with disabilities. Positive influences on “Continuity of Care” included emergent community leadership, family resilience to navigate through treatment uncertainty and supportive servant leadership styles of healthcare providers. Conclusion: The study points to the need for an expanded understanding of “Continuity of Care” for persons with disabilities within an African paradigm where care continuity extends beyond the health facility and with a stronger emphasis on community driven models of care that respect the role and influence of traditional health practitioners and cultural practices. More research is needed to better understand institutional distrust and how traditional western models of healthcare can be reshaped to deliver services.
Open Access
A case study of how a centre-based preschool programme for children who are blind/visually impaired supports early multilingual communication development
(2023) Kamedien, Layla; Kathard, H
Communication development is an essential part of a child's development – socially, academically, and vocationally. For children with visual impairment/blindness (VI/B), the literature indicates that opportunities supporting early communication development can benefit a child with VI/B. Speech-language therapists' (SLTs) core focus on communication is instrumental in supporting children to develop their communication. However, little is known about the practices which support the communication development of children with VI/B. The study therefore aimed to explore and describe how the centre-based preschool programme at the League of the Friends of the Blind (LOFOB) in Cape Town supported early multilingual communication development. A qualitative case study design was used to explore and describe the programme's knowledge, values, principles, skills, and practices. Semi-structured interviews were conducted with key stakeholders, along with classroom observations and document reviews of key government policies, principles and standards. Thematic analysis was used to analyse and interpret findings. During this process a key informant with VI was used to assist with the interpretation of the data. The findings are presented as a narrative and accompanying individual vignettes. The narrative explores the activities and opportunities available for multilingual communication support. While the individual vignettes describe the knowledge, values, principles and skills that inform the practices of the programme. Key themes that emerged from thematic analysis of the data include an inclusive approach to encourage multilingual engagements and support, a structured programme that focussed on capabilities, and a committed team offering support. The study argued that there is an opportunity for the SLT profession to rethink how communication is typically supported and shifting from a focus on pathology to communication supports that explore capabilities and inclusion.
Open Access
A case study of public transport preference in Cape Town using the best-worst scaling method
(2025) Thanjekwayo, Maxine Nokuthula; Zuidgeest, Marcus; Behrens, Roger
Commuter preference and service satisfaction influences transport mode choice and even when there is no choice (captive travellers) there is dignity in providing minimal quality. It has been proven that a shift from private transport towards public transport is rare. It is therefore easier to improve satisfaction or perceptions of captive public transport users than to move car users to public transport. Except in Greece where well-timed transport improvement during an economic downturn resulted in an increase in public transport use. The national fiscus has competing priorities it supports infrastructure, health, education, public transport and many other government services. Justification for funding public transport in lieu of other government priorities is linked to commuter demand. Commuter demand is measured by the number of passengers per mode or trip. The goal for public transport modes is full occupancy of vehicles. Higher occupancy rates justify the trip and by implication the fiscal investment on the trip and or mode. Commuters choose transport modes based on a number of attributes such as: cost, travel time, access time, frequency of service, comfort, safety etc. Therefore, improving public transport users preference capture may lead to better informed public transport improvement investments decisions. Case 2 best worst scaling is a survey method that compares varying attributes to one another by soliciting a ranking of one best and one worst. The method allows for at least three attributes per domain of investigation. Each attribute's attribute level is compared, in a choice set, to other attributes' attribute level. Commuters seek a transport service from origin to destination that is safe, economical and comfortable. Commuter studies show that needs and levels of satisfaction vary from person to person and mode choices are usually restricted by affordability. However, as soon as there is affordability for better options, commuters always choose the most responsive mode. In urban areas this choice is evidenced by higher percentage of low-occupancy private car commute. The aim of this research was to determine the applicability of case 2 best worst scaling; and commuter preferred service attribute levels for travel, safety and comfort for Bus, Minibus Taxi, MyCiTi and Train commuters in Cape Town. The study used attributes and dissatisfaction data from the National Household Travel Survey to identify key attributes and attribute levels for investigation. Case 2 best worst scaling surveys were designed as follows: three domains – travel, safety and comfort; three to four attributes per domain; and each attribute tiered into attribute three levels. The field work was intercept surveys to Cape Town commuters. Data were analysed using R and yielded the following key findings: Case 2 best worst scaling is applicable for preference studies in South Africa and beyond; paying more, experiencing sudden braking and overcrowding were least preferred (disutility); there were nuanced variations for other attribute levels based on mode and demographic groups.
Open Access
A case study: the regulation of public power in the local sphere of government in the Republic of South Africa
(2009) Fabing, Jill Gloria; Corder, Hugh
This paper seeks to explore the progress which has been made in controlling the exercise of public power by South African Municipalities. The tension between the concepts of administrative and operational efficiency and adequate checks and balances in respect of the exercise of delegated power are examined. It highlights the internal administrative appeal system that exists at local government level. The conclusion is reached that in respect of local government in South Africa. Many of the objectives of the Breakwater Declaration of 1993 have been realized. The courts however have not played a very constructive role in this respect with the result that urgent legislative intervention may be required. Only this will ensure that public power at the local government level is adequately regulated in the interest of transparency, accountability and democracy.
Open Access
A CFD Model for a Fixed Bed Reactor for Fischer Tropsch Reaction using Ansys
(2023) Chitranshi, Vidushi; Moller, Klaus
Fischer-Tropsch (FT) is a process which can convert synthesis gas derived from natural gas, coal or even biomass to a variety of products including saturated and unsaturated hydrocarbon chains, while keeping the emission of greenhouse gases minimum. Among various types of reactors used for commercial FT, fixed bed tubular reactors are among the most common type of reactor. However, there is a big challenge faced by these tubular reactors. FT is a highly exothermic process and therefore, heat removal in these reactors is needed to be highly efficient to avoid a thermal runaway. To improve the heat transfer in any reactor, it is necessary to estimate the heat production correctly. Therefore, the kinetics in the FT system needs to correctly represent the heat transfer behaviour in the system. This requires an effective description of the reaction kinetics. FT is a polymerisation reaction, so the rate expressions must be able to retain the chain reaction behaviour. This is not possible with a lumped approach model which is used by most researchers in literature. Therefore, a partial equilibrium approach was employed, where thermodynamic and kinetic models were coupled, and the reaction rates depended on the concentration of reactants as well as products. The kinetic model employed in the current project was taken directly from the work of Davies and Moller. The abovementioned partial equilibrium kinetics was used to develop a CFD model for the FT reaction system. This model was reproduced using COCO simulator for a plug flow reactor for same operating conditions as Ansys to compare the results from both the softwares. The results showed a close agreement and hence, assured that the CFD model could be used for further testing. The other challenge with the FT in FBRs is the heat dissipation. To avoid the thermal runaway, some innovations in reactor design have been studied in literature. In terms of heat transfer capabilities, when shell and tube heat exchangers are compared with the plate and frame heat exchangers, various sources in literature claim that the latter is found to be more effective. However, plate type reactors have not yet been explored in detail for their heat transfer capabilities. Taking an idea from this, the CFD model developed for the tubular reactors was adapted for plate type reactors. The heat transfer capabilities of the plate type reactors were compared relative to the tubular reactors. The tube reactor and plate type reactor were compared on the basis of two criteria. One criterion was based on physical similarity between the reactors. It included having equal Reynolds Number and equal surface area available per unit volume for both type of reactors. For a plate with plate spacing t and a tube with diameter D, the latter condition resulted in the expression, D = 2t. The factors that Reynolds number for a packed bed depends on were all same for both the geometries, so by default, the Reynolds Number was identical for both cases. The other criterion was based on catalyst packing. It included having equal tube-to-particle diameter ratio for both geometries. For tube reactors, diameter is an important parameter that determines the heat dissipation behaviour, so a parametric study was carried out to study the effect of a diameter and plate spacing on heat transfer behaviour for the same set of operating conditions. It was found that the plate type reactor had a hotspot temperature which was less than the hotspot temperature of corresponding tube reactor at all plate spacings. This indicated that the heat dissipation in a plate type reactor is better than in the corresponding tube reactor. Since the tube reactors observed higher temperatures than corresponding plate reactors, the CO conversion observed in the tube reactors was higher. When the product distributions for the two geometries were compared at isothermal conditions, the results almost overlapped for the two geometries. But when they were compared for non- isothermal conditions, significant differences were observed. This showed that heat dissipation mechanisms in the system had a huge role in bringing out different performances for the two geometries. Effect of temperature and conversion on the product distribution were also studied. On the basis of tube to particle diameter ratio criterion, tube reactor was found to outperform the plate reactors in terms of temperature control when compared using the tube-to-particle diameter ratio. Therefore, the superiority of one reactor over the other was dependent on the criterion they are being compared for. The plate type reactor was then represented in PFR model by tuning the heat transfer coefficient of the tubular model in COCO. The difference between the CO conversions achieved between the plate type reactor in Ansys and the representative model in COCO was found to be very little. Hence, the plate type reactor representation could be successfully achieved in COCO. There can be a lot of further research that can be done using the current model. The areas of reaction kinetics and reactor design were highlighted in this regard. The current model can be extended to a larger number of species, for a better representation of the FT product spectrum. Formation of liquids was completely neglected in the current project. It can be taken into account as presence of liquid can affect the FT reactor system by imposing internal and external mass transfer limitations to the reactions. The current model can also be used to study the HTFT process and also to study the isomeric products in the LTFT which were assumed to be not present in the current project. In the areas of reactor design, the geometry of catalyst particles can be included in the reactor geometry. This model can also be used for plates of other shapes and sizes to study the effect of shape and size on heat transfer capabilities. Different types of corrugated plates are used in the Plate and Frame Heat exchangers nowadays. The corrugations increase the surface area available and also increase mixing. Using the current model, such modifications can be studied for their effect on the reactions in a reactive system.
Open Access
A climate change vulnerability assessment of 58 Richtersveld plant species
(2025) Pather, Keyura; Foden, Wendy; Cunningham, Susan; Raimondo, Domitilla
The Richtersveld is the northernmost region of the Succulent Karoo and is located in the north-western region of South Africa's Northern Cape Province. This region has an incredible arid plant diversity, with both the highest succulent plant diversity and highest rate of endemism in an arid area, globally. It forms part of both a global biodiversity hotspot and a UNESCO world heritage site. However, it is already experiencing significant climate change exposure which is predicted to worsen. Changes in the area's climate are also interacting synergistically with other anthropogenic pressures including mining, poaching and agriculture. The threats to this area, including climate change, are documented but knowledge gaps still remain – especially with regards to plants and climate change vulnerability. In this study I aimed to find which Richtersveld species are the most vulnerable to climate change while trialling a relatively novel approach in this context. I used a trait-based assessment with correlative species distribution model outputs to assess the sensitivity, adaptive capacity and exposure of 58 plant species occurring within the Richtersveld National Park. This included assessing biological, ecological, environmental and spatial traits of species that contribute to climate change vulnerability. Traits were scored based on literature, expert opinion and correlative modelling outputs. Trait scores were then combined using both additive and ordinal methods, creating a best-case scenario where unknowns were assumed to have ‘low' scores, and a worst-case scenario when these were assumed to be ‘high'. These scenarios were applied to both the ordinal and additive scoring methods. For the additive scoring method, there was an additional consideration – trait weighting. It would be inaccurate to assume all traits hold the same importance in determining a species' vulnerability to climate change. Each trait was assigned a weighting based on literature and expert opinion and applied in an additional weighted scoring approach. Therefore, each species had a total of six climate change vulnerability scores: a best-case ordinal, a worst-case ordinal, a best-case unweighted additive, a worst-case unweighted additive, a best-case weighted additive and a worst-case weighted additive score. Under the worst-case ordinal scoring method, 34 species (59 %), were scored as highly vulnerable to climate change. The most vulnerable species were those that consistently scored high vulnerability scores, across all six scoring methods. This included Cheilanthes namaquensis (Not endemic to the region nor the park and Least Concern), Trachyandra ardimontana (almost endemic to park and Endangered), Albuca etesiogaripensis (almost endemic to park and Data Deficient), Ruschia glauca (almost endemic to park and Endangered) and Schwantesia herrei (Richtersveld endemic and Least Concern). I also found a mismatch between species' Red List status and their scores in my climate change vulnerability assessment. This suggests that highly climate change vulnerable species identified in this study currently have a low Red List threat status assigned to them by the responsible conservation organisation. This finding could mean that their status does not accurately reflect their level of conservation risk – especially if climate change is not accounted for. This can cause them to be overlooked in terms of conservation resource provision and decision- making. The IUCN Red List Version 16 Section 12 provides guidelines for assessing climate change vulnerability and its application in determining a species' threat status to climate change. However, its development is relatively recent, and its use is limited, possibly due to the data and technical expertise required. My study provides a possible example of how, even in highly biodiverse region with low data availability, climate change vulnerability assessments may be carried out, and of the value for preventing extinctions. The highest concentration of climate change vulnerable species were found to be in the central western and northern areas of Richtersveld National Park. The spatial representation of these data may aid where within the Park conservation and management can be prioritized. In conclusion, I trialled an approach that has not previously been applied for Richtersveld plants. The approach produced predictions of climate change vulnerability that could be used for conservation. The approach used in this study helped identify species and areas to which climate change conservation measures could be applied. This approach can be applied to other arid areas and aid in climate- related conservation, including in section 12 of the Red Listing Guidelines (Version 16).
Open Access
A collection of diverse theoretical, philosophical and sociological writings on various aspects of the sonata principle
(1974) Christopher Ballentine
The diverse works presented in these two volumes bear a sit;nificant relationship· to ca.ch other and to a common underlying theme, whi.ch may be said to be an attempt to enlarge our aYmreness of the nature and the possibilities of the Sonata Principle. All were expressly written for publication; one has already been published.

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