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An Investigation of the variability of oceanic turbulence in the Agulhas Current: focus on the Durban Eddies and Natal Pulses
Get PDFCoastal-ocean waters inshore of the Agulhas Current (AC) are largely affected by oceanic (sub-)mesoscale turbulence. These events are generally in the form of meanders, such as AC cyclonic meanders (Natal Pulses and Durban Eddies), and have been observed to play a role in shelf upwelling. Using several high-resolution sea surface temperature (SST) satellite products, the turbulent inshore region of the AC was investigated by means of an automated algorithm designed to identify thermal gradients along cross-shore transects. These features are associated with strong SST gradients which are better represented in higher-resolution products. Results yielded high amounts of variability in the regions south of 33.7°S and north of 32.2°S. Four types of inshore boundary features were identified from the variability, which are Natal Pulses, Durban Eddies, upwelling and the fourth was identified as a frontal change. In the Level 4 (L4) SST dataset, the algorithm resulted in 0.46 occurrences of Natal Pulses per year Manual detection resulted in 1.4 events per year. The DE occurred more regularly and was observed spawning at 30°S every one to three weeks in the Level 2 (L2) datasets. Both the L2 and L4 datasets revealed similar characteristics of Natal Pulses and Durban Eddies based on three case studies. Lastly, the RESILIENCE cruise case study compared SST thermosalinograph data to the L2 and L4 SST products and found that the L2 product had better agreement with the in situ data compared to the L4 product.Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 202
Implementation of technological innovations within the South African construction industry
Get PDFIn South Africa the construction industry has grown by more than 15% per annum over the past five-years and the construction industry is facing several pressures to decrease costs, improve productivity and to develop a competitive edge in terms of quality of service and customer satisfaction. Faced with a growing demand for service delivery the industry must seek new and improved ways to stay competitive in this market space. By effectively analysing the construction market all role players within the AEC industry can adopt new trends and techniques being implemented by either their foreign counterparts or direct competitors. One of these trends within the industry is technological innovations; each designed to play a beneficial role in construction industry advancements. It is clear that our industry is moving forward at an alarming rate, yet our foreign counterparts seem to be one step ahead. Based on the 2010 Soccer World Cup it was clear that the South African AEC Industry had the ability to conform and deliver on world class infrastructure, yet we still seem to have a slow adoption rate surrounding technological innovations. Investigating the depth of knowledge based around the most popular technological innovations currently being implemented can provide a clear view as to what S.A industry role players see as potentially profitable within our marketplace and the steps that could be taken to provide further research pertaining to those technological innovations which are being overlooked. Establishing the most prominent barriers preventing technological adoption within the South African AEC Industry can effectively be compared with those faced by foreign counterparts to mirror their solutions to similar problems. Finally, by establishing whether resistance to a changing environment plays a vital role in the hindrance to technological adoption one can access the extent to which the AEC Industry may effectively change based on a projected industry time frame.Thesis (MSc) -- Faculty of Faculty of Engineering, the Built Environment and Technology, 202
Effect of livestock management and services to ecosystems on rangeland health and resilience in the NamaKaroo
Get PDFRangelands offer great opportunities for mutualisms between nature conservation and economic productivity if positive feedback loops can be identified and described. The effects of different livestock management practices are controversial. This research examined the effect of different grazing intensities on soil health using springtails (Collembola) and ants (Formicidae) as bioindicators, combined with soil and vegetation variables. The relationship between rangeland managers and rangeland ecosystems, particularly with regard to feedback loops between land care and economic production, was also investigated. Bioindicator samples were collected at different treatments of livestock grazing intensity and a questionnaire was submitted to 65 rangeland managers in the semi-arid Nama-Karoo biome of South Africa. In most cases we found no significant relationship between grazing intensity and Collembola and ant community composition, vegetation variables, and soil variables. The few significant relationships we found were contradictory in their implications for the effect of high intensity grazing on soil health. The results suggested that differences in livestock management are relatively unimportant for soil health, at least in semi-arid systems under conditions immediately following a drought. The questionnaire yielded results on outline of management practices, basis of management decisions, consequences of monitoring veld to inform management decisions, and indicators of successful management. Respondents characterized by higher ecological fluency focused on livestock production when making management decisions, stocked at higher densities, and monitored the rangeland ecosystem to inform their decisions. For monitoring the ecosystem, they used bioindicators such as diversity of biota, successional stage, and ecologically important functional groups. We concluded that the development of ecological knowledge in rangeland managers enables the establishment of feedback loops between ecosystem services and services to ecosystems, which are desirable for economic productivity and nature conservation. Development of relevant ecological knowledge and management techniques should be based on forums and dialogue among rangeland managers, developing distributed cognition and resilience in the community of rangeland managers.Thesis (MSc) -- Faculty of Science, School Natural Resource Science and Management, 202
Perceptions of mental illness among the residents of the Eastern Cape Province in South Africa: The influence of culture and religion on their coping strategies.: subtitle if needed. If no subtitle follow instructions in manual
No full textMental illness has become a global concern, with consequences that may result in a mental health pandemic. Studies conducted on mental illness suggest that religious and cultural beliefs not only affect the expression of mental illness, but also the diagnosis and treatment of mental conditions. South Africa is a country imbued with cultural and religious diversity, which creates different groupings of people, holding diverse beliefs regarding mental illness. In many contexts, supernatural beliefs, traditional healing and indigenous medicines and treatments are considered in the treatment of the symptoms associated with mental illnesses, especially on contexts where there is a reliance on religio-cultural beliefs. Even though there has been a significant increase in the contribution to research focusing on mental health in diverse contexts, much of this research has focused on subjective experiences. Little to no information is available on population-based studies in South Africa regarding mental illness in diverse contexts, thus limiting the generalisation of findings related to cultural and religious influences on mental illness. This dearth of information further limits the development of psychological interventions. The study aimed to explore how mental illness is perceived by the participants and thereafter explored the influence of culture and religion in coping with mental illness by the residents of the Eastern Cape. The study was quantitative in nature and adopted an exploratory-descriptive design. The researcher made use of a questionnaire as a research tool and QuestionPro was utilized as a platform. A convenience sampling technique was utilised. In ensuring rigour of the study, the researcher ensured maximal validity (accurate representation of the data) and reliability (ability to repeat the research procedure). Ethical principles have been adhered to as per the principles on the Belmont Report, to ensure safety of the participants and this includes anonymity, confidentiality and the right to withdraw from participation in the study. Data has been analysed using descriptive and inferential statistics. A sample size of 101 participants from the general population of residents of the Eastern Cape completed the online survey. The results of the study revealed that the residents of the Eastern Cape have substantial knowledge pertaining the cause of mental illness and indicated both positive and negative attitudes towards the mentally ill and possess coping strategies to deal with a mental illness. In addition, the results show that there is a relation between religion/culture and coping with a mental illness by the participants of the study. The findings of this study emphasize the necessity of public education efforts that understand and respect people's cultural diversity, as well as teamwork among traditional and medical professionals. Future studies should focus on the use of discourse analysis to better investigate indigenous groups' conceptions of mental illness and their views about its aetiology and treatment.Thesis (MA) -- Faculty of Health Sciences, School of Behavioural Science, 202
Workplace Discrimination Based on Pregnancy
Get PDFIn the past, South Africa was marked by widespread discriminatory practices, many of which still exist to date. This study investigates the persistent discrimination against pregnant women. The study revealed that in South Africa, pregnant women continue to face discrimination in employment and are often denied the right to go on maternity leave, nursing or breastfeeding and childcare facilities. Presently, pregnancy is listed as a prohibited ground for discrimination in the South African Constitution as well as many ILO Conventions. Similarly, the South African labour law framework which gives effect to the Constitution provides for the protection of women and pregnant workers. This protection comes in the form of measures that proscribe dismissal and discrimination based on. Despite these legislation, this study finds that the less favorable treatment of women and pregnant workers in South African workplaces has become increasingly common, and this has turned into a contentious subject. This study focused on labour legislation that has been developed to safeguard pregnant women in the workplace in light of applicable constitutional protections. Notwithstanding these legislative protections for pregnant women in the workplace, the analysis shows that many pregnant women continue to be treated unfairly due to their pregnancies or for reasons linked to their pregnancies. Consequently, there has been a regression in the actual execution of laws and regulations protecting pregnant workers. The study highlights the need to establish mechanisms to ensure that legislation protecting pregnant workers in the workplace achieves its intended purpose and is implemented properly. Consequently, this study presents pertinent suggestions about the implementation of labour legislation so that the employment rights of women and pregnant workers are adequately safeguarded.Thesis (LLB) -- Faculty of Law, School of Mercantile Law, 202
Assessing diatom community composition and structure in palaeosediments of a southern Cape coastal wetland
Get PDFPalaeoenvironmental studies are important as they aid in reconstructing histories of past landscapes and provide key long-term information for the conservation and management of ecosystems. The southern Cape coast is a focus area for palaeoenvironmental research due to its high botanical and climatic importance. A three-metre sediment core was retrieved from Whale Rock wetland (Plettenberg Bay, southern Cape Coast) and spanned ~8000 years – a large proportion of the Holocene epoch. Diatom data preserved in palaeosediments of the Whale Rock wetland are presented within this study. A total of 48 diatom species was identified. Based on the multivariate statistical analysis, the diatom assemblages were divided into three zones: Zone WR-1-A (~7200 – 6450 cal yr BP); Zone WR-1- B (~6450 – 6250 cal yr BP) and Zone WR-1-C (~250 cal yr BP – to present). Two diatom preservation hiatus periods were observed at ~8000 – 7200 cal yr BP and ~6400 – 230 cal yr BP. The results indicated that benthic diatom species were significantly dominant throughout the Whale Rock record. The diatom evidence revealed that the Whale Rock wetland system freshened over time as diatom species identified in Zone WR-1-A and Zone WR-1- B indicated marine influences whereas Zone WR-1-C displayed a dominance of species that thrive in freshwater conditions. A transitional phase occurred at ~6400 cal yr BP where abrupt changes began prior to the significant ~6400 – 230 cal yr BP diatom preservation hiatus period. Principal Component Analysis showed that salinity was the main environmental driver of change impacting the species abundance and diversity of diatom communities within the wetland system throughout the Holocene. When compared with regional palaeoenvironmental and palaeolimnological data, it is evident that several other wetland systems moved from a marine/brackish favoured system to a freshwater system with the transitional phase occurring at different periods within the Holocene. This study indicated that diatoms are powerful biological proxies of environmental change. It is recommended that the site be revisited to investigate further the hiatus phases to further explore the lack of diatom preservation for these periods and to also contribute more palaeoenvironmental proxy evidence as well as modern hydrological information.Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 202
Isolation, characterization and functionalization of cellulose fibres derived from the waste pineapple leaf fibres by hydrolysis to produce cellulose acetate
Get PDFThis thesis forms part of the Nelson Mandela University biomass and nanotechnology project, which aims at using agricultural waste for many applications, including biomedical applications, water treatment, and agricultural films. Pineapple leaf fiber (PALF) is one of the natural fibers with the highest cellulose content (about 80%), and they produce about 2.5–3.3% of the weight of green leaves. However, the other parts of the pineapple fruit, such as the leaves and crown, are still treated as waste due to a lack of understanding of the benefits and risks of these parts of the pineapple fruit. The transformation of PALF as a renewable and abundantly available natural residue into cellulose fibers (CFs) will reduce the waste accumulated in the atmosphere, and it will add value to the cultivation of pineapple. In the biomedical industry, CF is very promising in terms of drug delivery. Cellulose acetate is a remarkable biomaterial extensively used in biomedical applications due to its properties such as being non-toxic, non-irritant, biodegradable, heat resistant, and less hygroscopic. In this research, the isolation, functionalization, and characterization of cellulose from PALFs were conducted. The PALFs were dried and ground into small particles before being alkali treated with sodium hydroxide to remove the non-cellulosic components. Moreover, the remaining lignin in the residue was removed using sodium chlorite and acetic acid; this process is known as the bleaching process. The bleaching process resulted in white CFs, which was an indication of the successful removal of the non-cellulosic material. The obtained CFs were further functionalized using acetic acid, acetic anhydride, and sulfuric acid, and this reaction is known as the acetylation reaction. Subsequently, both treated, untreated, and functionalized CFs were characterised using the following instruments: FTIR, SEM, SPM, TGA, XRD, and XPS. In the FTIR data of raw PALFs, the following functional groups were more pronounced: C-O, C=C-O, and C=O, whereas peak C-O-C disappeared and peak CH2, C-O, were less pronounced. These FTIR results confirmed the successful removal of non-cellulosic components. The SEM and SPM images visually suggested the partial removal of hemicellulose and lignin from the raw PALFs after the chemical treatment, which are the cementing materials around the fiber bundles. The TGA studies revealed good thermal stability for the isolated CFs from PALFs. The XRD diffractograms of the PALFs showed a cellulose I crystal pattern where the peaks were located at angular positions (2θ) of around 18°, 26°, and 41°. Lastly, after the functionalization of CFs, the cellulose structure remained intact (not damaged); instead, the newly ix introduced functional groups (the acetyl group) were attached at the ends of the cellulose structure. These results are therefore confirmation of the successful removal of non-cellulose material from the PALFs after the chemical treatment.Thesis (MSc) -- Faculty of Science, School of Natural Resource Science and Management, 202
Top-down control by grapsoid crabs in South African estuarine salt marshes
No full textSalt marshes are one of the most productive ecosystems globally. These ‘blue carbon’ habitats are in many respects resilient to climate change effects, able to track sea level rise and act as carbon sinks. Since salt marshes are economically and ecologically essential habitats (for example providing foraging grounds for invertebrates, fish, birds and humans), understanding the processes that control their structure is crucial to best maintain ecosystem services provided by these habitats. For decades the importance of top-down forces, such as grazing, has not been recognised as being important in controlling salt marsh plant productivity. Rather, bottom-up forces, such as the availability of oxygen, was thought to be the main constraint to primary production. Therefore, a better understanding of salt marsh ecosystem dynamics and whether grazer control exists is needed. Although grazer top-down control has been demonstrated in salt marshes in locations such as the United States, this has not been investigated in South Africa. This is a crucial knowledge gap locally considering the importance of salt marsh ecosystems. The aim of this study was therefore to determine what role consumers play in structuring South Africa’s estuarine salt marsh vegetation, thereby also contextualising this process internationally. In order to achieve this, the abundance of grapsoid crabs was estimated and related to key salt marsh features, such as Spartina maritima stem height and stem density, which was quantified from observational surveys. Sampling took place at the beginning and end of the early-spring and late-summer growth period (September 2021 and April 2022) in the Knysna, Kromme and Swartkops estuaries. If a correlation was observed between crab density and salt marsh features, it was important to determine whether they consume the salt marsh vegetation or if the effect was due to their burrowing activities. Hence, the diet of grapsoid crabs was investigated using stable isotope and gut content analysis. To examine the importance of crab grazing in controlling the growth of salt marsh vegetation, crab abundance was manipulated in situ by means of exclusion cages. This experiment ran for five months in the Kromme Estuary, from November 2021 to March 2022 over the salt marsh growing season. An ex situ feeding experiment was also conducted on 30 crab specimens collected from the Kromme Estuary, during May 2022. These crabs were starved for 48 hours and thereafter fed different components of Spartina (growing and dead blades, and roots and rhizomes). The food consumed was quantified as the change in plant length and dry weight after 48 hours, which gave a maximum grazing rate for the different food sources. It was found that crabs are having a minimal impact on the salt marsh vegetation structure. Spartina maritima does form an important component of the diet of grapsoid crabs, however, this is not their only source of food, and possibly not their preferred source of food. They are however contributing to sediment properties through their burrowing activities. The iii ex situ feeding experiment showed that grapsoid crabs can consume all vegetative components of Spartina, with a significantly greater amount of roots and rhizomes consumed. There was no consistent effect in terms of the exclusion of grazers, indicating that other mitigating factors could be reducing the impacts of grapsoid exclusion in situ. Together, these findings contribute knowledge that can be used to inform conservation by quantifying what the salt marsh risks losing in the absence or overabundance of crabs, as has occurred elsewhere globally. These results influence how salt marshes are managed, and highlight how not recognising the importance of consumers, such as crabs, could misalign management objectives.Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 202
Implementation of technological innovations within the South African construction industry
Get PDFIn South Africa the construction industry has grown by more than 15% per annum over the past five-years and the construction industry is facing several pressures to decrease costs, improve productivity and to develop a competitive edge in terms of quality of service and customer satisfaction. Faced with a growing demand for service delivery the industry must seek new and improved ways to stay competitive in this market space. By effectively analysing the construction market all role players within the AEC industry can adopt new trends and techniques being implemented by either their foreign counterparts or direct competitors. One of these trends within the industry is technological innovations; each designed to play a beneficial role in construction industry advancements. It is clear that our industry is moving forward at an alarming rate, yet our foreign counterparts seem to be one step ahead. Based on the 2010 Soccer World Cup it was clear that the South African AEC Industry had the ability to conform and deliver on world class infrastructure, yet we still seem to have a slow adoption rate surrounding technological innovations. Investigating the depth of knowledge based around the most popular technological innovations currently being implemented can provide a clear view as to what S.A industry role players see as potentially profitable within our marketplace and the steps that could be taken to provide further research pertaining to those technological innovations which are being overlooked. Establishing the most prominent barriers preventing technological adoption within the South African AEC Industry can effectively be compared with those faced by foreign counterparts to mirror their solutions to similar problems. Finally, by establishing whether resistance to a changing environment plays a vital role in the hindrance to technological adoption one can access the extent to which the AEC Industry may effectively change based on a projected industry time frame.Thesis (MSc) -- Faculty of Engineering, the Built Environment and Technology, School of the Built Environment, 202
Parental perceptions of their child’s social and emotional wellness amid a diagnosis of attention deficit/hyperactivity disorder
Get PDFAttention Deficit/Hyperactivity Disorder (ADHD) is well described from a biomedical perspective, which is consistent with the typical pharmacological treatment approach. Measures of improvement are for the most part based on the scholastic performance. However, a child’s wellness is not only limited to academic performance, but also involves their functioning outside of the learning environment. It is therefore important to explore alternative measures of social and emotional wellness to support the biomedical treatment of a child. This study explored parental perceptions related to the social and emotional wellness of a diagnosed child, using principles of wellness put forward by Roscoe (2009). It took an instrumental case study approach using a semi-structured interview to gather data with a single participant. The participant is the parent of a child diagnosed with ADHD and was selected through non-probability purposive sampling. Data collection and analysis followed Miles, Huberman, and Saldana’s (2020) data analysis method. Lincoln and Guba’s (1985) model of trustworthiness was used to ensure the integrity of the study. Findings confirmed the prioritisation of academic wellness above that of social and emotional wellness. Parental emotional intelligence is vital to the child’s social and emotional wellness. Parental investment into the child’s exploration of self may further contribute to a positive, realistic and development sense of self which fosters resilience. Based on these findings, a multimodal intervention approach to ADHD is suggested.Thesis (MA) -- Faculty of Health Science, Department of Behavioral Sciences, 202