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A model for measuring and predicting stress for software developers using vital signs and activities
Get PDFOccupational stress is a well-recognised issue that affects individuals in various professions and industries. Reducing occupational stress has multiple benefits, such as improving employee's health and performance. This study proposes a model to measure and predict occupational stress using data collected in a real IT office environment. Different data sources, such as questionnaires, application software (RescueTime) and Fitbit smartwatches were used for collecting heart rate (HR), facial emotions, computer interactions, and application usage. The results of the Demand Control Support and Effort and Reward questionnaires indicated that the participants experienced high social support and an average level of workload. Participants also reported their daily perceived stress and workload level using a 5- point score. The perceived stress of the participants was overall neutral. There was no correlation found between HR, interactions, fear, and meetings. K-means and Bernoulli algorithms were applied to the dataset and two well-separated clusters were formed. The centroids indicated that higher heart rates were grouped either with meetings or had a higher difference in the center point values for interactions. Silhouette scores and 5-fold-validation were used to measure the accuracy of the clusters. However, these clusters were unable to predict the daily reported stress levels. Calculations were done on the computer usage data to measure interaction speeds and time spent working, in meetings, or away from the computer. These calculations were used as input into a decision tree with the reported daily stress levels. The results of the tree helped to identify which patterns lead to stressful days. The results indicated that days with high time pressure led to more reported stress. A new, more general tree was developed, which was able to predict 82 per cent of the daily stress reported. The main discovery of the research was that stress does not have a straightforward connection with computer interactions, facial emotions, or meetings. High interactions sometimes lead to stress and other times do not. So, predicting stress involves finding patterns and how data from different data sources interact with each other. Future work will revolve around validating the model in more office environments around South Africa.Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 202
Investigation of the host potential of compounds derived from tartaric acid, succinic acid and 1,4-cyclohexanedioic acid
Get PDFThe present investigation considered the host behaviour of three compounds, namely (+)-(2R,3R)-1,1,4,4-tetraphenylbutane-1,2,3,4-tetraol (H1), 1,1,4,4-tetraphenyl-1,4-butanediol (H2) and cyclohexane-1,4-diylbis(diphenylmethanol) (H3) in various guest mixtures. These host compounds were readily synthesized by means of Grignard addition reactions on the diesters of tartaric acid, succinic acid and 1,4-cyclohexanedioic acid. The guest mixtures included cyclopentanone, cyclohexanone, cycloheptanone and cyclooctanone, γ-butyrolactone, 2-pyrrolidone, N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone, and pyridine, 2-methylpyridine, 3-methylpyridine and 4-methylpyridine. Crystals of (+)-(2R,3R)-1,1,4,4-tetraphenylbutane-1,2,3,4-tetraol (H1) were grown from cyclopentanone (5-ONE), cyclohexanone (6-ONE), cycloheptanone (7-ONE) and cyclooctanone (8-ONE,) producing 1:1 host:guest complexes in each instance. Thermal analysis showed the thermal stabilities of these complexes to be in the order 6-ONE > 7-ONE > 8-ONE > 5-ONE which correlated exactly with results from binary guest/guest competition experiments, where 6-ONE was always preferred by H1, while 5-ONE was consistently disfavoured. Single crystal X-ray diffraction (SCXRD) analyses demonstrated that each guest compound was retained in the crystals by means of a hydrogen bond with an alcohol moiety of the host compound. Furthermore, preferred guests 6- and 7-ONE produced crystals with greater densities than guests less favoured (5- and 8-ONE). A conformational analysis of the guest geometries in the four complexes with H1 revealed that the low energy guest conformers were present. The host selectivity for 6- and 7-ONE was proposed to be due to the improved molecular packing in the crystals of the complexes containing these two guest compounds, observed from their higher crystal densities. Hirshfeld surface analyses were not useful in explaining the preference of H1 for 6-ONE relative to 7-ONE (these types of analyses were not possible for the 5-ONE and 8-ONE-containing inclusion compounds due to the nature and degree of disorder present in the guest molecules). H1 was also crystallized from γ-butyrolactone (GBL), 2-pyrrolidone (NP), N-methyl-2-pyrrolidone (NMP) and N-ethyl-2-pyrrolidone (NEP), and 1H-NMR spectroscopy revealed that all but GBL were included. The host compound was also presented with these guest solvents in various mixtures, and it was observed that NMP was an extremely favoured guest solvent, followed by NEP and NP, with GBL being consistently disfavoured in every experiment. It was therefore shown that in certain instances, H1 may serve as an alternative tool for separating some of these mixtures through host-guest chemistry strategies. The hydrogen bonding motifs present in each of the successfully formed complexes were extensively investigated through SCXRD analysis, as was the thermal behaviour of these complexes. In the latter instance, the peak temperature of the endotherm (from the DSC trace) representing the guest release was greater for the inclusion compound with favoured NMP (145.5 °C) relative to the complexes with NP (139.8 °C) and NEP (120.5 °C). Host compounds H2 and H3 were revealed to have the ability to include each of pyridine (PYR), 2-methylpyridine (2MP), 3-methylpyridine (3MP) and 4-methylpyridine (4MP). H2 displayed selective behaviour for 3MP and 4MP when presented with mixtures of these guest compounds, whilst H3 preferred PYR. In the latter case, this PYR-containing inclusion compound was also the more stable one (the guest release onset temperature was highest, Ton 66.0 °C). It was demonstrated that H2 has the ability to separate very many binary mixtures of these pyridines on a practical platform, since K (the selectivity coefficient) values were 10 or greater in many instances. However, unfortunately, the more difficult-to-separate mixtures containing 3MP and 4MP cannot be purified or separated by employing H2 and supramolecular chemistry strategies. H3 was also shown to be a likely candidate for binary guest separations in very many of the guest solutions considered here, where K was also 10 or greater, and even infinity in many cases. SCXRD demonstrated that 2MP, 3MP and 4MP were retained in the crystals of their complexes by means of classical hydrogen bonds with the host compound. Satisfyingly, this hydrogen bond between 2MP and H2 (3.0213(18) Å) was significantly longer than that between this host compound and both disorder components of 3MP (2.875(2) and 2.825(9) Å) and that between H2 and 4MP (2.8458(13) Å). This observation explains the affinity of H2 for both 3MP and 4MP, and why 2MP was disfavoured. The results of thermal experiments did not wholly concur with observations from the guest/guest competition experiments. Hirshfeld surface analyses were also conducted but were not entirely conclusive with respect to explaining the host selectivity behaviour. In the case of H3, SCXRD analyses revealed that favoured PYR experienced a classical hydrogen bond with the host compound that was statistically significantly shorter (2.795(2) Å, 165°) than those between the other guest compounds and H3. Additionally, this guest compound was the only one to be involved in a (host)C−H···π(guest) interaction (2.91 Å, 139°) and also a non-classical hydrogen bond with the host compound ((host)C−H···N−C(guest), 2.77 Å (144°)). Finally, Hirshfeld surface analyses showed also that preferred PYR experienced a greater percentage of C···H/H···C (33.1%) and H···N/N···H (11.1%) interactions compared with the complexes with 2MP, 3MP and 4MP. However, it is not clear whether these Hirshfeld observations explain the affinity of H3 for PYR.Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 202
Implementation of the world health organization surgical safety checklist in the operating room in a private hospital in the Nelson Mandela Bay Municipality
Get PDFThe World Health Organisation Surgical Safety Checklist (WHO SSC) was developed to improve teamwork among healthcare professionals and ensure consistent use of safety processes in the operating room (Abbott et al., 2018: 147). The WHO SSC has successfully reduced common and avoidable surgical errors relating to nerve cutting, among others (Jain et al., 2018:7). However, the implementation of the WHO SSC has not been widely acknowledged in South Africa due to specific barriers (Koopman, 2018: 20; Sauls, 2019: 15). To this end, the aim of this study was two-fold: (i) to determine the factors that contribute to the implementation of the WHO SSC among operating room healthcare professionals and (ii) to develop a contextually appropriate process implementation guide that may be used to facilitate utilisation of the WHO SSC in a private operating room healthcare facility. A non-experimental descriptive quantitative approach underpinned by positivism and a descriptive exploratory survey was used to study the factors contributing to implementing the WHO SSC. A self-reported questionnaire was used as the method for data collection. Purposive sampling was adopted by selecting all the 130 operating room staff directly involved in completing the WHO SSC. All 130 respondents completed and returned the questionnaire. Data were analysed using the Statistical Package Software for the Social Sciences (SPSS) Version 28.0 for Windows (IBM Corp, 2021). The study described four factors (i.e. awareness, relative advantage, complexity, and usability) contributing to the implementation of the WHO SSC. The analysis revealed a significant inter-relationship between two factors (i.e. relative advantage and awareness) and characteristics of the operating room healthcare professionals (regarding highest qualification, current age and work experience). The study’s main contribution to the existing body of knowledge is the proposed process-oriented implementation guide, including a readiness assessment template for effective implementation of the WHO SSC. It is recommended that good knowledge of the WHO SSC should be created by making operating room healthcare professionals aware of the arrangements and interventions by the private hospital to implement the WHO SSC.Thesis (MCur) -- Faculty of Health Sciences, School of Clinical care & medicinal sciences , 202
Translanguaging as pedagogical practice in high-school examination question papers: a South African case study
Get PDFThis study explores sociolinguistic practices such as translanguaging, in which “diglossia is presumably allowed without isolation and bilinguals’ linguistic resources are viewed as an integrated system.” While bilinguals select and deploy particular features from their linguistic repertoires for meaning-making, translanguaging is widely used by teachers and students in multilingual classroom settings, as guided by the Personnel Administrative Measures (PAM). Translanguaging also provides a path for students to bring in and use their linguistic repertoires to produce the required learning outcomes, perform their identities and facilitate language development. Thus, this study is based on the view, subscribed to in contemporary sociolinguistics, that monoglossic language ideology is embedded in modes of oppression steeped in neoliberal, colonial and linguistic purist forms”. The purpose of the study was to make a case for the implementation of translanguaging in the written assessment of isiXhosa/English bilingual high-school learners in the Eastern Cape. The study employed a qualitative approach in the form of document analysis, whereby the researcher used selected Grade 12 question papers to find out how often translanguaging occurred. This was done by illustrating how examiners are moving past forms of linguistic purism when setting papers.Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 202
Toughened wood plastic composites for low technology and advanced manufacturing applications
Get PDFThe utilization of wood plastic composites (WPCs) has increasingly emerged as an appealing alternative for products where traditional wood and conventional composites would typically be used. This is primarily due to their cost-effectiveness, mouldability, recyclability, renewability, and potential biodegradability. However, the incorporation of wood flour (WF) in thermoplastics to produce WPCs presents several challenges, two of which are addressed in the current study: the WF-thermoplastic matrix adhesion, and the resulting brittleness of the WPC. The hydrophilic nature of WF filler and the hydrophobic polypropylene matrix, which typically lead to poor mixing due to their differing surface energies. Consequently, the current research focuses on enhancing WF-matrix (i.e. polypropylene, PP) adhesion and dispersion through compatibilization using maleic anhydride grafted polypropylene (MAPP). Additionally, the brittleness of WPC, exacerbated by the WF content, is addressed through the incorporation of crumb rubber (CR), a process commonly referred to as "toughening" the WPC. Prior to the use of CR in WPCs, optimization of the CR amount and compatibility within the PP-matrix were conducted to establish a toughening system that would achieve the highest impact strength without significantly affecting the tensile strength. The CR was compatibilized by employing dynamic vulcanization of varying amounts of ethylene propylene diene monomer rubber (EPDM) in the CR/PP blends using both sulphur and dicumyl peroxide cure systems. The results indicated that the sulphur dynamic cure system exhibited higher crosslinking efficiency, as reflected by the highest impact strength. Furthermore, to enhance WPC processability and adhesion, WF alkalization was conducted following a central composite design to optimize treatment temperature, time, and alkali concentration. This optimization resulted in improved WPC processability and mechanical properties at mild alkalization conditions. Subsequently, the optimum CR/EPDM dynamic cure system was employed to toughen both untreated and alkalized WPCs, resulting in toughened WPCs with improved thermal stability, impact strength, and elongation at break, while the tensile strength was only slightly compromised.Thesis (PhD) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 202
Formulation of Fish Feed for Aquaculture using Olive Pomace Extract as an Antioxidant
Get PDFOlive pomace is a significant by-product of the olive oil extraction process and is an environmental issue in olive-producing countries. This project aimed to add extracts from olive pomace as an antioxidant to a fish feed formulation without compromising growth performance and meat quality, thereby contributing to the aquaculture industry. To produce the olive pomace extracts, Coratina cultivar olives were collected from a farm near Oudtshoorn, and the fresh pomace was immediately frozen at -22oC for preservation. The extracts were obtained using a large-scale extraction method using a solvent blend of n-heptane, ethanol, and water. A pressure filtration and centrifuge method were then applied to separate any residue from the extracts. An HPLC method was developed to characterise the extracts' content, identifying various bioactive compounds such as squalene, α-tocopherol, and water-soluble polyphenols like oleuropein, hydroxytyrosol, and tyrosol. In a fish feeding trial it was concluded that the fish fed with the feed without olive pomace gained more weight than those fed the feed with the added pomace extract. Overall, the results indicate that fish sustained on the feed without the olive pomace extract ate more food, consuming more energy to support weight gain but that this did not necessarily translate to an improved feed conversion ratio. The morphometric variables suggest that fish used in the trial remained healthy, implying that there may be a taste or palatability difference between feeds that could explain why less of the feed with olive pomace extract was eaten. Overall, the observed feed conversion ratio values were somewhat lower than the expected values for tilapia (FCR: 1.5-2.0). The peroxide value of fish feed with an addition of 0.3% olive pomace extract was lower than that of the feed without olive pomace extract after 12 weeks of stability testing at room temperature. The results showed a value of 1.48 MeqO2/kg for the feed containing olive pomace extract compared to the peroxide value for the fish feed without olive pomace extract, which was 2.75 MeqO2/kg. This indicates that the nutritional content of the feed was preserved.Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 202
Portfolio effect and bet-hedging adaptations in sea turtles
Get PDFA great proportion of marine species are at risk of going extinct as a result of profound changes in the world’s oceans, primarily driven by human activities. Sea turtles are not exempt from this fate. Despite sea turtles being exposed to a range of environmental conditions and threats that vary in frequency and intensity, these ancient marine reptiles have persisted for millennia. In the past, sea turtles have been able to adapt to natural perturbations while other animal groups have not. The ability of sea turtles to adapt to contemporary changes in conditions, produced by human activities, has become limited. The persistence of sea turtles may be explained by the application of a concept termed “portfolio effect”. An aggregate system is more stable and less prone to fluctuations over time (i.e. portfolio effect) if a diversity of finer components comprises the entire system and displays asynchronous fluctuations over time. Biological entities (e.g. species measured by the abundance trend) may achieve long-term stability even though the individual components (e.g. populations measured in abundance trend) display weak or negative correlations with each other in space and time. Different sea turtle populations may display independent trends in abundances over time, resulting in a portfolio effect at species levels. Trends in sea turtle abundances may be affected by individual behaviour. The adoption of bet-hedging adaptations may enable populations to thrive despite environmental changes or stochasticity, by lowering short-term fitness in exchange for maximising long-term fitness. Individual sea turtles may exhibit bet-hedging adaptations through changes in their temporal nesting behaviour, including the remigration interval. Since remigration interval length regulates the number of nesting females per nesting season, changes in remigration interval will affect abundance trends. The ability of individuals to change their remigration interval allows them to “skip” the breeding migration when environmental conditions seem unfavourable. The overall aim of this thesis was to investigate potential reasons for observed sea turtle abundance trends at species, population, and rookery levels. I tested whether the portfolio effect applies to sea turtles by analysing and interpreting spatiotemporal trends in loggerhead (Caretta caretta) and leatherback (Dermochelys coriacea) abundances at the population and species levels using global datasets. The application of bet-hedging strategies was tested at a local level using data from the long-term monitoring program for South African nesting sea turtles. The majority of loggerhead rookeries displayed an increase in abundance over time, while most leatherback rookeries declined (Chapter 2). Population growth rates also differed among rookeries within Regional Management Units (RMUs) (Chapter 2). This diversity in abundance trends among rookeries suggested spatiotemporal variation in environmental conditions, threats and/or level of protection accompanying sea turtles. The species-level growth rate for both species displayed an overall increase in abundance over time. However, larger (more turtles) leatherback rookeries/RMUs experienced more rapid declines in abundance compared to smaller rookeries/RMUs, resulting in a recent species-level decline. Uncorrelated trends in abundances at the RMU-level could have stabilised species-level trends. Differences in the remigration intervals as a possible bet-hedging adaptation could potentially explain differences in population recovery rates between South Africa’s loggerhead and leatherback sea turtles (Chapter 3), but found no evidence that individuals from either species exhibit bet-hedging adaptations. Loggerheads, however, have increased their remigration intervals over time, while leatherbacks have not. These increases were accompanied by declines in adult body size (previously established) which could be an effect of diminishing foraging area quality. The increased remigration interval shown by loggerheads may be a response rather than an adaptation to the prevailing environmental conditions that impact their food supply in their foraging areas. The population growth rate of leatherback sea turtles may surpass that of the loggerheads in the near future, although there is a global decline in abundance (Chapter 2). This dissertation provides information on possible reasons for observed trends in sea turtle abundances at various levels of biological organisation. While a variety of factors have the potential to influence trends in sea turtle abundance, the possible occurrence of portfolio effects and investigating nesting behaviour may resolve any uncertainties regarding the reasons for observed trends in abundance.Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 202
Vocational Education and the relentless struggles of TVET graduates in the Eastern Cape, South Africa: A Freirean approach
Get PDFThis study employs Paulo Freire’s framework to contribute to debates surrounding social justice and transformation in vocational education and training (TVET). By offering a critical perspective on dominant discourse and practices, it challenges prevailing trajectories of powerful knowledge and inherent assumptions and biases in TVET. Drawing on a Freirean framework, the research provides insights to develop more equitable and transformative practices by addressing power, privilege, and social inequality in TVET. Through dialogue and collaboration with students, it promotes critical consciousness and relevant skills and knowledge. Highlighting the significance of context, it underscores the need to understand the social and cultural context of learning. Demonstrating the potential of a Freirean framework to challenge the status quo, it promotes more equitable and empowering practices in TVET. The chosen methodology for this study is Participatory Action Research (PAR), integrating theory, action, and participation to address social issues. Recruiting 15 NC(V) graduates from Algoa TVET College, forming a Learning Cycle Group (LCG), the study aimed to comprehend graduates’ experiences, challenges, and opportunities. Life narrative interviews and LCG meetings generated data, ensuring every participant had a voice and strengthening group cohesion. Data were grounded in ethical values such as respect, equality, inclusion, democratic participation, active learning, making a difference, collective action, and personal integrity. Employing Paulo Freire’s theoretical framework, this study offers a novel perspective on TVET in South Africa, fostering dialogue with TVET students to challenge conventional discourses. It aimed to develop an alternative conceptualisation of TVET by incorporating student experiences and perspectives, promoting positive change through dialogue and addressing power dynamics and social justice issues. The study explores Powell’s (2014) question regarding TVET colleges’ role in expanding opportunities for students and asks: “How do TVET graduates experience life after graduation? Are they empowered and satisfied with their social status?” Sub-questions inquire about students’ expectations upon enrolling, opportunities after completing NC(V) programs, and the extent to which TVET colleges address unemployment and socio-economic injustices, aiming to inspire the development of praxis and frameworks that better serve the needs of TVET graduates and address social concerns.The study’s findings, analysed through Freire’s ideology in “We Make the Road by Walking” (1990) and “Pedagogy of Hope” (1994), reveal that the NC(V) program predominantly attracts underprivileged students and is rarely their first choice. This research highlights that the NC(V) program does not fully empower or transform students’ circumstances, instead perpetuating cycles of poverty, unemployment, and social inequality—contrary to Freire’s vision of education as a tool for liberation and societal change. The program fails to provide meaningful employment opportunities, leaving graduates often unemployed or in low-paying jobs, unable to escape poverty. This underscores the program’s inadequacies. Furthermore, insufficient support structures and practical application opportunities further diminish graduates’ employability. The study’s findings emphasise the need for systemic reforms in the NC(V) program. Embracing Freire’s principles and moving beyond traditional banking education models to more inclusive, participatory approaches is essential. This transformation is crucial for the TVET system to genuinely empower students and foster significant personal and societal change.Thesis (PhD) -- Faculty of Education, School of Secondary School Education, 202
Exploring children’s understandings of gender using critical literacy in a reading club
Get PDFSchool literacy practices have always favoured traditional, gender stereotypical portrayals of characters in books. These portrayals are not troublesome as it helps children build a sense of identity. However, these portrayals often fail to represent people in more diverse ways and thus does not reflect how societies have progressed. These narrow portrayals are also often limiting and do not take into consideration people’s personal interests which can lead to them being ostracised and marginalised. The People’s Republic of China is the context for this study where traditional, conservative views are upheld about ways of being and doing for males and females. This is a qualitative study within the interpretivist paradigm which recognised the individual perceptions of participants within their specific sociocultural context. By establishing a reading club as a Third Space for literacy engagement, this study sought to explore how grade 2 learners at a school in Beijing, China responded to traditional and diverse portrayals of characters in books. This study regarded the establishment of a reading club as an empowering practice as it allowed a safe space for the participants to freely share their deliberations about ways of being in the world. Coupled with critical literacy as a practice, participants took a critical stance in instances of gender bias and injustices and in doing so, allowed them to accentuate their morality. Findings of this study suggest that the Chinese participants had very flexible ideas about ways of being and doing in the world as long as these did not conflict with their understandings of the law. Participants also upheld that gender performances and gendered behaviour are open to all with impunity. The findings of this study also highlight the importance of providing diverse literature to children as this helps them to deal with, and examine, issues they might not ordinarily encounter in a safe way and in doing so, expand their worldviews and cultivate empathy.Thesis (PhD) -- Faculty of Education, School of Primary Schooling, 202
The effect of illicit financial flows on Zimbabwe's economic growth and development
Get PDFThis study examines the effect of Illicit Financial Flows (IFFs) and capital flight on Zimbabwe’s economic growth and development. The study data covered the period 1980-2020 applying the Autoregressive Distributed Lag (ARDL) regression model to assess the relationship between IFFs and capital flight and Zimbabwe’s economic growth and development. Most empirical studies on developing countries show that in both the short and long run, IFFs and capital flight not only reduce the revenue base of the economy but its multiplier effects result in a negative significant relationship between economic growth and development. This supports the continued call for policymakers and government to develop effective policies and continue to have intergovernmental and bilateral engagements to share knowledge and information to deter and control these activities. Unless these activities are controlled, most developing countries will have revenue shortfalls that will have to be funded from Other Donor Assistance (ODA), AID and loans. The study used two ARDL models to assess the impact of GDP and Manufacturing output to assess the impact. GDP and Manufacturing output have been chosen as the proxies of economic growth. Data showed that capital flight had a positive coefficient relationship with GDP in the long run. It was statistically significant and capital flight also had a negative and insignificant effect on manufacturing output during the period 1980-2020. Thus, Zimbabwe should effectively engage in policies and measures that identify and deter IFFs and capital flight activities because the multiplier effects of the activities have a negative impact on economic growth and development. The continued depletion of state resources discredits the objectives of the government to achieve the 2030 Millennium Development Goals. Government expenditure in nonproductive sectors must be avoided, instead, priority must be given to sectors that attract investors and stimulate economic growth and development.Thesis (MA) -- Faculty of business and economic sciences, 202