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The electrocatalytic response of metallophthalocyanines when clicked to electrodes and to nanomaterials

  • Authors: Mpeta, Lekhetho Simon
  • Date: 2021
  • Subjects: Phthalocyanines , Nanostructured materials , Electrocatalysis , Nanoparticles , Environmental chemistry , Electrodes , Organic wastes -- Purification
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/172191 , vital:42174 , 10.21504/10962/172191
  • Description: Conjugates of nanomaterials and metallophthalocyanines (MPcs) have been prepared and their electrocatalytic activity studied. The prepared nanomaterials are zinc oxide and silver nanoparticles, reduced graphene oxide nanosheets and semiconductor quantum dots. The MPcs used in this work are cobalt (II) (1a), manganese(III) (1b) and iron (II) (1c) 2,9(10),16(17),23(24)- tetrakis 4-((4-ethynylbenzyl) oxy) phthalocyaninato, 2,9(10),16(17),23(24)- tetrakis(5-pentyn-oxy) cobalt (II) phthalocyaninato (2), 9(10),16(17),23(24)- tris-[4-tert-butylphenoxy)-2- (4-ethylbezyl-oxy) cobalt (II) phthalocyaninato (3), 9(10),16(17),23(24)- tris-[4-tertbutylphenoxy)-2-(pent-4yn-yloxy)] cobalt (II) phthalocyaninato (4), cobalt (II) (5a) and manganese (III) (5b) 2,9(10),16(17),23(24)- tetrakis [4-(4-(5-chloro-1H-benzo [d]imidazol-2-yl)phenoxy] phthalocyaninato and 9(10),16(17),23(24)- tris tert butyl phenoxy- 2- [4-(4-(5-chloro-1H-benzo[d]imidazole-2-yl)phenoxy] cobalt (II) phthalocyaninato (6). Some of these MPcs (1a, 3 and 4) were directly clicked on azide grafted electrode, while some (1b, 1c, 2, 5a and 5b) were clicked to azide functionalised nanomaterials and then drop-dried on the electrodes. One phthalocyanine (5b) was drop-dried on the electrode then silver nanoparticles were electrodeposited on it taking advantage of metal-N bond. Scanning electrochemical microscopy, voltammetry, chronoamperometry, electrochemical impedance spectroscopy are among electrochemical methods used to characterise modified electrodes. Transmission electron microscopy, X-ray photoelectron spectroscopy, Xray diffractometry, Raman spectroscopy and infrared spectroscopy were employed to study surface functionalities, morphology and topography of the nanomaterials and complexes. Electrocatalytic activity of the developed materials were studied towards oxidation of 2-mercaptoethanol, hydrazine and hydrogen peroxide while the reduction study was based on oxygen and hydrogen peroxide. In general, the conjugates displayed superior catalytic activity when compared to individual materials. Complex 2 alone and when conjugated to zinc oxide nanoparticles were studied for their nonlinear optical behaviour. And the same materials were explored for their hydrazine detection capability. The aim of this study was to develop sensitive, selective and affordable sensors for selected organic waste pollutants. Conjugates were found to achieve the aim of the study compared to when individual materials were employed.
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The impact of labour legislation on selected small firms in Mbombela (Nelspruit)

  • Authors: Dlamini, Sikhulile Blessing
  • Date: 2021
  • Subjects: Labor laws and legislation -- South Africa , Small business -- Law and legislation-- South Afric , Small business -- South Africa -- Mbombela -- Case studies
  • Language: English
  • Type: text , Thesis , Masters , MSocSci
  • Identifier: http://hdl.handle.net/10962/170781 , vital:41959
  • Description: This study uses the theoretical framework of industrial relations pluralism, to study and analyse the impacts of labour legislation on six small firms (employing less than 50 workers) based in Mbombela (formerly Nelspruit), Mpumalanga province, South Africa. The analysis is based on the viewpoints of six managers and how they see the impacts of labour legislation on their respective firms. The analysis is aided by utilising theory and literature to make sense of the manager perspectives on the topic. Also, utilising a qualitative research design to collect and analyse the data, the study presents diverse findings in terms of how the participants perceived and experienced certain types of legislation. Some managers believed that the benefits of labour legislation outweighed the costs. While others believed the exact opposite. At an overall level, the study revealed that most of the participants were not as severely affected by labour legislation as might be expected; given the scarcity of resources in most small firms. This was partly because of various coping strategies and practices (mostly involving the use of informal procedures) that were adopted by the firms. Also, some small firms who aimed at expanding their businesses strategised to adopt some formal procedures and practices in order to easily absorb labour legislation and subsequently mordenise their businesses in the process. While a few firms persisted with more informal customs as they appeared cost-effective and necessary in their particular market positioning.
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The invasion ecology of Pontederia cordata L. (Pontederiaceae) in South Africa

  • Authors: Wansell, Sage Nora-Lee
  • Date: 2021
  • Subjects: Plant invsions -- South AFrica , Invasive plants -- Ecology -- South Africa , Pontederiaceae -- South AFrica
  • Language: English
  • Type: text , Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/172433 , vital:42200
  • Description: Pontederia cordata L. (Pontederiaceae) is a tristylous invasive macrophyte – originating from North and South America – that has caused detrimental environmental, agricultural and socio-economic impacts in South Africa (SA). This novel study investigates the invasive ecology of P. cordata in SA by determining population genetics, pollination ecology and floral traits. Preliminary field surveys suggest that only one of three tristylous forms of P. cordata is invading SA and no seeds have been observed in any invasive populations. This study therefore determined the population genetics, mode of spread of P. cordata in SA and possible reasons for the lack of seed production, as well as providing suggestions for future control and management strategies. Inter Simple Sequence Repeats of leaf samples from invasive populations in SA and the native range of the United States of America (USA) were performed to determine the population genetics of P. cordata. The clarification of population structure of an alien invasive plant can provide insight into founder effects, introduction events and modes of spread and is important for the development of management plans such as biological control. Results from the genetic analyses indicated that P. cordata populations have low genetic diversity within and amongst invasive populations in comparison to native populations. This suggests that high gene flow and sexual reproduction is not present in invasive populations, and that only a single or very few introductory events have occurred in SA. Furthermore, invasive P. cordata populations shared the highest genetic similarity with native samples from Belle Haven, Virginia, USA, and thus further sampling and future genetic surveys should be conducted in this area to identify source populations to survey for potential biological control agents. Following these findings, I investigated whether sexual reproduction and seed production is absent from invasive P. cordata populations in SA as speculated. Floral traits from populations throughout all the invaded provinces were measured and, along with pollen grain measurements, it was determined that only short-morphed plants are present in SA. It was speculated that the absence of native pollinators in the invasive range may be responsible for the absence of sexual reproduction. However, a pollination study confirmed the presence of generalist insect pollinators. Thereafter, artificial pollination experiments on 8 865 flowers were conducted to determine whether an incompatibility system was present which prevented seed production. No seeds were produced and it was concluded that illegitimate pollination of the short-morphed plants prevented seed production and rhizomes are responsible for the invasion of P. cordata throughout SA. The implications of these findings and possible management strategies such as biological control is discussed in Chapter 4. These findings suggest that control programmes should target the plants rhizomes to prevent and reduce spread. Preventing the introduction of medium- and long-morphed plants into SA is crucial to prevent P. cordata from producing seeds and intensifying invasion further through both asexual and sexual spread.
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The potential conflict of interest associated with the management of Rosa rubiginos L. (Rosehip) in South Africa

  • Authors: Westwood, Timothy
  • Date: 2021
  • Subjects: Invasive plants -- South Africa , Biological invasions -- Economic aspects , Rose hips -- Economic aspects -- South Africa , Roses -- South Africa , Rose culture -- Economic aspects -- South Africa
  • Language: English
  • Type: text , Thesis , Masters , MCom
  • Identifier: http://hdl.handle.net/10962/172458 , vital:42204
  • Description: Rosa rubiginosa L. is a category 1b invasive plant species in South Africa and must be controlled according to NEM:BA. However, R. rubiginosa has the potential to provide economic benefit in South Africa due to the expanding market for the shrubs fruit, rosehips. The shrub is not permitted to be cultivated in South Africa due to legislation, limiting the economic potential as the rosehips are only able to be collected from wild R. rubiginosa shrubs. In order to expand the rosehip market in South Africa a downgrade or removal of R. rubiginosa from the invasive species list would be required, as wild harvest is limited. This study aims to assess the benefits and cost associated with R. rubiginosa in order to determine whether the legislation should be altered allowing for the cultivation of the shrub in South Africa. Due to the limited literature surrounding R. rubiginosa three different questionnaires and a case study were used in order to assess the benefits and negatives associated with the shrub. Experts in the field of invasion biology were surveyed to bridge the gap in the R. rubiginosa literature. Landowners, where the shrub is abundant, were surveyed to determine the negative impacts of R. rubiginosa. Rosehip companies were surveyed in order to determine the current size and potential of the R. rubiginosa (rosehip) market. The case study looked at how a rosehip company would benefit if R. rubiginosa was allowed to be cultivated in South Africa. The study found R. rubiginosa to have great economic potential and market growth, with very little negative economic impact. The case study showed that one rosehip company would grow from 1500 tons of raw rosehip to 20 000 tons if cultivation was allowed, resulting in a growth in turnover from R57 million to R760 million ($1=R14.8). The findings in the study show that R. rubiginosa does not significantly affect landowners where it is abundant. Therefore, it is suggested that a change to the legislation should be considered allowing for the cultivation of R. rubiginosa should be implemented.
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The relationship between organisational leadership and job satisfaction of three generational age groups in a school context

  • Authors: Haasbroek, Juan Gert Diedericks
  • Date: 2021
  • Subjects: Educational leadership -- South Africa , High Schools -- Administration -- South Africa -- Western Cape , Management , High school teachers -- South Africa -- Western Cape -- Case studies , High school teachers -- South Africa -- Western Cape -- Job satisfaction , High school teachers -- South Africa -- Western Cape -- Attitudes
  • Language: English
  • Type: Thesis , Masters , MBA
  • Identifier: http://hdl.handle.net/10962/170802 , vital:41961
  • Description: With multiple generations in education, there are different leadership styles preferred by schoolteachers that affect their job satisfaction (Cufaude and Riemersma, 1999:1-3). Schools should ensure that leadership works toward satisfied teachers to reach sustainable organisational performance. The resource-based view argues that organisations should look within the organisation, particularly human resources, to find sources that lead to improved organisational performance (Jurevicius, 2013:1). Therefore, organisations should equip themselves with the required leadership style(s) to meet employee expectations. Furthermore, it is imperative to look at different generations within the school’s context, as it will strengthen or weaken the relationship between organisational leadership and job satisfaction. The study adopted a quantitative approach, using the Multiple Leadership Questionnaire and the Minnesota Satisfaction Questionnaire as instruments for collecting primary data. The population consists of high school teachers in the Eden District, Western Cape that work at affluent schools, which are declared as quantile 4 and 5 model schools. There is a total of 13 high schools that fall within this specification with a total population of 220 teachers. In total, 111 questionnaires were distributed, of which 73 were returned. Sixty-eight were considered usable. Both sample parameters specified by the research instruments were met. The primary purpose of the study was to investigate the relationship between leadership within the organisation (referring to transformational, transactional, and passive-avoidant organisational leadership styles) and employee job satisfaction of high school teachers in the Eden District. Different generations, from the age group perspective, is composed as a moderating variable in the relationship between organisational leadership and job satisfaction. The empirical study established that the independent variables, the leadership styles employed by the organisation, are directly related to employee job satisfaction. Of the three independent variables, transformational leadership and, to a lesser extent, transactional leadership proved to have a positive association with job satisfaction. In contrast, passive-avoidant leadership has a negative relationship with job satisfaction. It is also established that the relationship is stronger or weaker based on generations, positioning generations from the age group perspective as satisfactory moderator. It was found that Millennials prefer the transactional leadership style as this will strengthen the relationship between organisational leadership and job satisfaction. Baby Boomers prefer transformational leadership for the greatest positivity. To a lesser extent, transactional leadership will also contribute to the relationship’s strength between organisational leadership and job satisfaction. Generation X is indifferent to transactional or transformational leadership.
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Towards the development of a pro-environmental strategy for improving catch-and-release behaviour in recreational fisheries – a case study on a competitive South African angling body

  • Authors: Mannheim, Samantha L
  • Date: 2021
  • Subjects: Fishing -- Environmental aspects -- South Africa , Fishing -- South Africa , Fishers -- Attitudes -- South Africa , Fishers -- Attitudes -- South Africa -- Cast studies , Fishes -- Conservation -- South Africa , Rock and Surf Super Pro League , Southern African Fisheries Ecology Research Lab
  • Language: English
  • Type: text , Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/171862 , vital:42133
  • Description: Catch-and-release (C&R) is becoming increasingly popular in recreational fisheries with the potential to contribute towards conserving the oceans limited fish stocks. Several studies have highlighted high rates of mortality and many sub-lethal effects which ultimately have a negative impact on fish population viability. With poorly developed handling practices, the fish that are released suffer the consequences of physical and physiological stress and do not always survive, thus making the ethics of C&R fishing questionable. Many studies have contributed to our understanding of the factors that influence the fate of fish released by anglers. Despite this, few interventions have been able to improve angler C&R behaviour. Pro-environmental behavioural strategies however hold some potential for improving angler C&R behaviour. To test their potential, we partnered with the South African Rock and Surf Super Pro League (RASSPL Africa), the biggest exclusively C&R competitive shore-based angling league in South Africa. The first two years (2013 and 2014) of the partnership were purely focused on building trust and relationships and making observations on angler behaviour. In 2015, we collected baseline data on angler behaviour and fish health during the RASSPL national fishing competition. This was followed by comparable data collection at the following two national competitions in 2016 and 2017 after the introduction of a combination of pro- environmental behaviour interventions, including rule changes, improving angler knowledge, behavioural modelling, rewards, penalties and feedback to improve C&R behaviour. There were significant improvements in angler behaviour, including a decline in total air exposure from 101.93s ± 64.34 in 2015 to 77.37s ± 60.52 in 2017 (F(2,618) = 9.27, P < 0.01), and the time taken for an angler to place their fish into a bucket declined from 105.86s ± 69.47 in 2015 to 23.05s ± 24.13 in 2017 (F(2,556) = 158.71, P < 0.01). There were also improvements in the health of the fish, with a decline in the blood lactate concentration and mean reflex action mortality predictor (RAMP’s) scores for the dominant species, Diplodus capensis (lactate – 9.46 ± 3.80 mmol.l-1 in 2015 and 6.69 ± 2.99 mmol.l-1 in 2017, RAMP – 0.28 ± 0.22 in 2015 and 0.19 ± 0.17 in 2017), and Haploblapharus fuscus (lactate – 4.25 ± 1.89 mmol.l-1 in 2015 and 1.76 ± 0.78 mmol.l-1in 2017, RAMP – 0.15 ± 0.18 in 2015 and 0 ± 0 in 2017). In 2018, surveys were conducted to gain insight into angler demographics and external (social, economic, cultural and institutional) and internal factors (knowledge and awareness, motivations, attitudes and perceptions) associated with the RASSPL anglers. Surveys were also designed to assist in identifying what components were key drivers behind the angler’s behavioural changes. The demographic characteristics of RASSPL anglers were not dissimilar from the general recreational angling public in South Africa, suggesting that this kind of intervention may have potential at a broader scale. In terms of the drivers of behavioural change, the surveys revealed that 68% of respondents strongly agreed that the structural rule changes contributed to their improved behaviour. This was followed by the educational presentations (66% of the respondents) and modelling / demonstrative videos (59% of the respondents). The conservation prizes were considered less effective, with only 27% of anglers strongly agreeing that this intervention improved their C&R behaviour. Overall this study has demonstrated that it is possible to improve the C&R behaviour of anglers in a competitive setting, with the most effective component of the intervention being the use of rule changes (structural approach). These findings suggest that proenvironmental strategies hold potential for improving the C&R behaviour of anglers and the health of released fishes. It is suggested that interventions to improve C&R behaviour should aim to develop long-term relationships, and implement a broad range of well communicated strategies based on reliable data and sound rationality. Key words: marine shore-based fisheries; community engagement; pro- environmental behaviour; behavioural intervention.
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“Munhu wese ihama yako (everyone is your relative)”: Ubuntu and the social inclusion of students with disabilities at South African universities

  • Authors: Chiwandire, Desire
  • Date: 2021
  • Subjects: College students with disabilities -- Education -- South Africa , Inclusive education -- South Africa
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/170578 , vital:41938 , 10.21504/10962/170578
  • Description: Background: During apartheid, South African students with disabilities (SWDs) were educated in special schools and taught an inferior curriculum. Black learners with disabilities were discriminated against on grounds of both race and disability. Following South Africa’s first democratic election in 1994, the African National Congress (ANC) government put in place arrange of new laws to address the educational and other needs of those disadvantaged under apartheid, including persons with disabilities (PWDs). The South African government is a signatory of the 2006 United Nations Convention on the Rights of Persons with Disabilities (UNCRPD) which has resulted in the country assuming obligations to promote inclusive education for ASWDs. However, research (see, for instance, Chiwandire & Vincent 2019; Chiwandire 2019; Mutanga 2019; Majoko & Phasha 2018; Mutanga et al. 2018; Mutanga 2017a; Chiwandire 2017; Israel 2017) has shown that SWDs continue to fare differently in comparison to their non-disabled peers in terms of participation in education with the likelihood of success. Higher education institutions (HEIs) have thus been urged to create conducive environments for the academic inclusion of SWDs with particular attention being paid to lecturers employing inclusive instructional strategies as well as flexible curricula, if they are to ensure the equal opportunity for academic success of SWDs in the regular classroom setting. The focus, to date, on academic inclusion, while important, has meant that issues relating to the social inclusion of SWDs have received minimal attention. Purpose: To date, there is a dearth of South African studies which have investigated the social inclusion needs of SWDs on South African campuses. Although a number of studies have given voice to the perspectives of SWDs and lecturers, with respect to their experiences in relation to matters of academic inclusion in South African higher education (HE), few have focused on Disability Unit Staff Members(DUSMs) who are pivotal to ensuring fair and equitable policies and practices for SWDs in HEIs. Disability Studies (DS) as a field has been criticised for being dominated by voices from the Global North, which fail to consider or effectively theorise Global South disability experiences in a contextually relevant way. The thesis argues that the failure to recognise the value of diversity and to treat SWDs as valued and welcomed participants in South African HEIs partly stems from policy, practice and relationships being informed by the Western individualist paradigm that prizes individual achievement and success rather than cooperation and mutuality. The African philosophy of Ubuntu, which stresses values of communalism, hospitality and respect for human dignity is offered here as an alternative starting point for achieving genuinely inclusive campuses. Methods: In-depth face-to-face qualitative interviews were conducted with 40 participants, most of whom were, at the time of being interviewed, Heads of Disability Units and DUSMs based at 10 different universities in four of South Africa’s nine provinces. Data were coded and analysed using Braun & Clarke’s (2006) method of inductive and deductive thematic analysis. Results: The findings of this study indicate that South African campuses are ableist spaces in which the social needs of SWDs are not prioritised. The thesis argues that in order for campuses to become genuinely inclusive, South African campuses ought to seek to inculcate in their members the values of the African worldview Ubuntu, in contrast to the dominant Western individualist orthodoxy. SWDs are being excluded and denied a sense of belonging and equal participation despite universities giving lip service to embracing such inclusive education-oriented values as co-operative learning. Non-disabled students steeped in Western individualism, which affirms the solitary pursuit of individual success rather than the value of interdependence and diversity, end up marginalising SWDs who are seen as less capable. DUSMs addressing the needs of SWDs through an ableist/Western individualist lens are not challenging unfair practices which are impairing the dignity of SWDs, particularly students with physical disabilities who are being forced to “fit into” oppressive inaccessible built environments on campuses. These DUSMs may unwittingly re-inscribe ableist assumptions that normalise discrimination against SWDs. Conclusions and Recommendations: Ubuntu values offer a starting point for building mutual respect and interdependence between SWDs and their non-disabled peers. The thesis finds however that as was the case in traditional African communities, which embraced the values of Ubuntu, acts of leadership are required if Ubuntu’s values of human dignity, mutual respect and acceptance are to be fostered on campuses. In a range of important ways, the dignity of SWDs is not respected at HEIs in South Africa. This includes, for example, such practical matters as the inaccessibility of toilets to wheelchair users and the lack of appropriate signage for blind students. Disrespectful attitudes and assumptions about SWDs on the part of non-disabled university members also result in SWDs’ human dignity being impaired. Ubuntu’s value of hospitality stresses the importance of promoting relations of group solidarity and interdependence between SWDs and their non-disabled peers. Both academic inclusion-oriented programmes and the promotion of a wide range of social activities, involving both SWDs and non-disabled students, can play an important role in cultivating the formation of long-term fruitful and respectful friendships between SWDs and non-disabled students. An enabling classroom environment alone is not enough to holistically address the social inclusion needs of SWDs. South African HEIs that embrace the Ubuntu values of communalism, human dignity and hospitality will be in a position to respect the needs of SWDs as “whole persons”. Amongst other things, this requires DUSMs to be fully empowered to make important decisions regarding vital matters such as disability inclusion, and it necessitates university management to relinquish their power, so that they may work collaboratively with DUSMs and SWDs, all on equal footing, to ensure that HE funding allocation, policy and planning also prioritises the social needs of SWDs.
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A drug utilisation review of lithium at a public sector psychiatric hospital

  • Authors: Mapfumo, Charlotte
  • Date: 2020-04
  • Subjects: Lithium -- Therapeutic use , Psychiatric hospitals -- South Africa -- Grahamstown , Drug utilization , Psychiatric hospital care , Manic-depressive illness , Lithium -- Toxicology , Drug monitoring
  • Language: English
  • Type: text , Thesis , Masters , M.Pharm
  • Identifier: http://hdl.handle.net/10962/150541 , vital:38983
  • Description: Bipolar disorder (BD) is a common mental condition that affects about 60 million people globally. Lithium is among the drugs of choice used to treat BD and other affective disorders such as schizoaffective disorder (SD). Lithium is a mood stabiliser with antimanic, antidepressant and anti-suicidal properties. Lithium has complex mechanisms of action and a narrow therapeutic index (NTI). Therapeutic drug monitoring (TDM) is a vital component of lithium therapy due to its NTI. Lithium toxicity can occur at therapeutic levels and is characterised by symptoms such as blurred vision and convulsions. Lithium interacts with a number of drugs resulting in lithium toxicity or diminished effects of lithium. Symptoms of lithium toxicity range from abdominal pain, convulsions and death. Lithium use is associated with serious adverse effects on renal and thyroid function. Other adverse effects include tremor and weight gain. Monitoring of lithium serum levels, renal and thyroid function are therefore recommended for patients on lithium therapy. Monitoring of these parameters assists in the early detection of any problems associated with lithium use. The metabolic monitoring of lithium is vital due to the adverse effect profile of lithium and the current South African Standard Treatment Guidelines Hospital level: Adults, do not have any recommendations for the monitoring of metabolic parameters. The National Institute for Health and Care Excellence (NICE) may be used and adapted for the South African setting. Aim and Objectives: The general aim of the study was to conduct a drug utilisation review (DUR) on lithium through investigating its prescribing and monitoring patterns in both inpatients and outpatients at Fort England Hospital. Methodology: The study was in the form of a retrospective DUR. Data was collected from 40 files (n=40) of patients who were on treatment with lithium between 1 January 2017-31 December 2017 at Fort England Hospital. The data was collected retrospectively for both in- and outpatients. Compliance of the monitoring requirements with both South African and international guidelines was analysed. Results and Discussion: In 87.50% (n=37) of the cases, patients had been on lithium therapy before 2017 with most patients (n=13; 37.50%) being maintained on 500 mg of lithium. Non-compliance with the South African and NICE guidelines for renal baseline monitoring was 65.00% (n=26) in both guidelines. Non-compliance for baseline thyroid monitoring was 70.00% (n=28) for both guidelines. There was non-compliance in 45.00% (n=18) of the cases for lithium serum level monitoring for both guidelines. Non-compliance with follow-up renal monitoring was 47.50% (n=19) for both guidelines. Compliance with the NICE guidelines for follow-up metabolic monitoring was 67.50% (n=27). Conclusion: There was non-compliance in most cases leaving room for clinical improvement in the monitoring of lithium. Healthcare professionals should be educated on the recommended monitoring guidelines to promote the rational use of lithium in South Africa. Pharmacists should be more involved in the TDM of lithium to promote its safe and effective use.
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Application of quality by design to the manufacture of a multiparticulate prednisone dosage form

  • Authors: Manda, Arthur
  • Date: 2020-04
  • Subjects: Drugs -- Quality control , Drugs -- Design -- Quality control , Drugs -- Dosage forms , Drug development -- Quality control , Pharmaceutical industry -- Quality control , Prednisone , High throughput screening (Drug development)
  • Language: English
  • Type: text , Thesis , Masters , MSc (Pharmacy)
  • Identifier: http://hdl.handle.net/10962/117986 , vital:34583
  • Description: For many years, quality by testing was the only approach to guarantee quality of drug products before the Food and Drug Administration launched the concept of current Good Manufacturing Practice. In order to gain more knowledge of the manufacturing process, a new system known as Quality by Design was introduced into the pharmaceutical industry. Quality by Design is based on thorough understanding of how materials, process parameters and interaction thereof impact final product quality. Quality by Design is a systematic approach to product development which ensures that quality is built into a product during product development and not just tested into it. The aim of Quality by Design is to achieve optimum product quality with consistent dosage form performance and minimal risk of failure in patients. The objective of these studies was to implement a Quality by Design approach to establish a design space for the development and manufacture of a safe, effective and stable multi-partite solid oral dosage form for prednisone as an alternative to currently marketed prednisone formulations. Multi-particulate dosage forms offer significant advantages over conventional technologies. In addition to lowering the incidence of gastrointestinal irritation they exhibit a reduced risk of dose dumping and a large surface area which favours dissolution. Furthermore, their free flowing nature facilitates reproducible capsule filling and consequently uniformity of dosing. Different multi-particulate dosage forms exist however a multiple-unit pellet system was investigated during these studies. Quality by Design principles were used to develop and establish a reversed-phase high performance liquid chromatographic method for quantifying prednisone from solid oral dosage forms. A Central Composite Design was used to generate multivariate experiments and to investigate the impact of input variables on the quality and performance of the analytical method. The optimized method was validated according to International Council for Harmonization guidelines and was found to be linear, precise, accurate and specific for the quantitation of prednisone. Pre-formulation studies were conducted and included the assessment of particle size, particle shape, powder flow properties and compatibility studies. Carr’s index, Hausner ratio and the Angle of Repose were used to evaluate powder flow properties and results generated from all studies suggest the need for adding a glidant and lubricant to improve pellet flow. The images generated from Scanning Electron Microscopy were used to analyze particle shape and size. Differential Scanning Calorimetry and Fourier Transform Infrared Spectroscopy were used to evaluate API-excipient compatibility. All excipients investigated were found to be compatible with prednisone and suitable for formulation development studies. Extrusion-spheronization was used to manufacture prednisone pellets. Extrusion-spheronization is a multi-step process involving many factors. Quality risk management tools particularly an Ishikawa Fishbone (cause and effect) diagram and failure mode and effects analysis were used to narrow down potentially significant factors to a reasonable number that could be investigated experimentally. Risk priority numbers were used to quantify risk and factors above a set threshold value were considered to be of high risk. A total of eleven risk factors were identified as high. A Plackett-Burman study was conducted to narrow down the eleven high risk factors to identify the most impactful factors viz., microcrystalline cellulose content, sodium starch glycolate content, extrusion speed and spheronization time. Evaluation of four factors was carried over to optimization studies using a Box-Behnken Design and following identifaction of the optimum process settings and excipient content a design space for the manufacture of a multi-partite dosage form containing prednisone was established.
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Evaluating the prescribing and management practices of clozapine at a public sector psychiatric hospital

  • Authors: Mukoko, Vimbisai Millicent
  • Date: 2020-04
  • Subjects: Clozapine , Schizophrenia -- Chemotherapy , Schizophrenia -- South Africa -- Treatment
  • Language: English
  • Type: text , Thesis , Masters , M.Pharm
  • Identifier: http://hdl.handle.net/10962/123266 , vital:35422
  • Description: Approximately one percent (1%) of the South African population suffers from schizophrenia. Clozapine has proven to be more effective than conventional antipsychotics in the treatment of schizophrenia, particularly in alleviating positive symptoms. Clozapine is primarily indicated for treatment-resistant schizophrenia due to its severe adverse effect profile. The prescribing guidelines recommend a trial of at least two different antipsychotic drugs before the initiation of clozapine. At least one should be a non-clozapine second generation antipsychotic. Compared to other atypical antipsychotics, clozapine poses the greatest risk of causing a haematological event, such as neutropenia and agranulocytosis. Agranulocytosis (estimated prevalence of 1.3%) is a life-threatening adverse effect. Common adverse effects include weight gain and metabolic syndrome, hypersalivation and constipation. These can also predispose the patient to co-morbid diseases which further complicate their current diagnosis. Haematological and metabolic monitoring is paramount throughout the duration of clozapine therapy. International (NICE guidelines, Clozapine REMS, and Maudsley prescribing guidelines) and national (South African STGs, SASOP treatment guidelines and the SAMF) guidelines recommend these monitoring patterns to assist with the prevention and management of the adverse effects of clozapine.
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Evaluating the prescribing and management practices of venlafaxine at a public sector psychiatric hospital

  • Authors: Naidu, Bavika
  • Date: 2020-04
  • Subjects: Venlafaxine , Anxiety disorcers -- Treatment , Depression, Mental -- Treatment
  • Language: English
  • Type: text , Thesis , Masters , M.Pharm
  • Identifier: http://hdl.handle.net/10962/123200 , vital:35414
  • Description: Neuropsychiatric conditions have been ranked third in South Africa according to some of the most recent reviews of disease burden, following human immunodeficiency virus/acquired immune deficiency syndrome and other infectious diseases (Bateman, 2012:70; South African Depression and Anxiety Group, 2018). For depressive disorders, the conventional selective serotonin reuptake inhibitors (e.g. fluoxetine), are common first-step treatments due to their relatively low toxicity and high tolerability (Rush et al., 2006:1231). The class of selective noradrenaline reuptake inhibitors (e.g. venlafaxine) is relatively new on the market. The first SNRI to be marketed in the United States was venlafaxine immediate-release (IR). It was approved by the United States FDA in 1993 (Sansone and Sansone, 2014:37) and was soon followed by the introduction of a micro-encapsulated extended-release (XR) formulation in 1997. Currently there is no published or readily available information concerning the prescribing and management patterns of venlafaxine as well as the incidence and types of adverse effects experienced by patients in the public health sector of South Africa besides the established increased in blood pressure.
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Preparation, characterization and optimization of carbamazepine based pellets prepared by extrusion-spheronization technique

300 grams

  • Authors: Ainslie, Michelle
  • Date: 2020
  • Subjects: South African fiction (English) -- 21st century
  • Language: English
  • Type: text , Thesis , Masters , MA
  • Identifier: http://hdl.handle.net/10962/140597 , vital:37903
  • Description: This document consists of two (2) parts:Part A: Thesis (Creative Work)Part B: Portfolio.
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A 150 MHz all sky survey with the Precision Array to Probe the Epoch of Reionization

  • Authors: Chege, James Kariuki
  • Date: 2020
  • Subjects: Epoch of reionization -- Research , Astronomy -- Observations , Radio interferometers
  • Language: English
  • Type: text , Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/117733 , vital:34556
  • Description: The Precision Array to Probe the Epoch of Reionization (PAPER) was built to measure the redshifted 21 cm line of hydrogen from cosmic reionization. Such low frequency observations promise to be the best means of understanding the cosmic dawn; when the first galaxies in the universe formed, and also the Epoch of Reionization; when the intergalactic medium changed from neutral to ionized. The major challenges to these observations is the presence of astrophysical foregrounds that are much brighter than the cosmological signal. Here, I present an all-sky survey at 150 MHz obtained from the analysis of 300 hours of PAPER observations. Particular focus is given to the calibration and imaging techniques that need to deal with the wide field of view of a non-tracking instrument. The survey covers ~ 7000 square degrees of the southern sky. From a sky area of 4400 square degrees out of the total survey area, I extract a catalogue of sources brighter than 4 Jy whose accuracy was tested against the published GLEAM catalogue, leading to a fractional difference rms better than 20%. The catalogue provides an all-sky accurate model of the extragalactic foreground to be used for the calibration of future Epoch of Reionization observations and to be subtracted from the PAPER observations themselves in order to mitigate the foreground contamination.
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A Bayesian approach to tilted-ring modelling of galaxies

  • Authors: Maina, Eric Kamau
  • Date: 2020
  • Subjects: Bayesian statistical decision theory , Galaxies , Radio astronomy , TiRiFiC (Tilted Ring Fitting Code) , Neutral hydrogen , Spectroscopic data cubes , Galaxy parametrisation
  • Language: English
  • Type: text , Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/145783 , vital:38466
  • Description: The orbits of neutral hydrogen (H I) gas found in most disk galaxies are circular and also exhibit long-lived warps at large radii where the restoring gravitational forces of the inner disk become weak (Spekkens and Giovanelli 2006). These warps make the tilted-ring model an ideal choice for galaxy parametrisation. Analysis software utilizing the tilted-ring-model can be grouped into two and three-dimensional based software. Józsa et al. (2007b) demonstrated that three dimensional based software is better suited for galaxy parametrisation because it is affected by the effect of beam smearing only by increasing the uncertainty of parameters but not with the notorious systematic effects observed for two-dimensional fitting techniques. TiRiFiC, The Tilted Ring Fitting Code (Józsa et al. 2007b), is a software to construct parameterised models of high-resolution data cubes of rotating galaxies. It uses the tilted-ring model, and with that, a combination of some parameters such as surface brightness, position angle, rotation velocity and inclination, to describe galaxies. TiRiFiC works by directly fitting tilted-ring models to spectroscopic data cubes and hence is not affected by beam smearing or line-of-site-effects, e.g. strong warps. Because of that, the method is unavoidable as an analytic method in future Hi surveys. In the current implementation, though, there are several drawbacks. The implemented optimisers search for local solutions in parameter space only, do not quantify correlations between parameters and cannot find errors of single parameters. In theory, these drawbacks can be overcome by using Bayesian statistics, implemented in Multinest (Feroz et al. 2008), as it allows for sampling a posterior distribution irrespective of its multimodal nature resulting in parameter samples that correspond to the maximum in the posterior distribution. These parameter samples can be used as well to quantify correlations and find errors of single parameters. Since this method employs Bayesian statistics, it also allows the user to leverage any prior information they may have on parameter values.
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A business process model for blockchain-based South African real estate transactions

  • Authors: Tilbury, Jack Laurie
  • Date: 2020
  • Subjects: Blockchains (Databases) , Conveyancing -- Technological innovations , Real estate business -- Data processing , Real estate business -- South Africa -- Technological innovations
  • Language: English
  • Type: text , Thesis , Masters , MCom
  • Identifier: http://hdl.handle.net/10962/148380 , vital:38734
  • Description: The real estate transaction process has been described as inefficient and technologically outdated due to numerous stakeholders and predominantly paper-based operations. Despite the apparent bottlenecks in the current process, the implementation of new technology into the real estate sector has lagged. Several attempts have been made to modernise and digitise the business process but committed integration of assisting technology has lacked attention. This study examined the applicability and potential integration of blockchain technology into the business process of South African real estate transactions. Blockchain’s novelty means that research in this space, especially within South Africa, is limited. Of the research that has been conducted, no models of the business processes for South African or blockchain-based real estate transactions have been constructed. This study provides two business process models, illustrating the two different processes. The main contribution of this paper was an integrated business process model, illustrating how the various processes and stakeholder interactions for South African blockchain-based real estate transactions are conducted on one transaction platform, common to all participating stakeholders. This platform was named the South African Blockchain Land Exchange System (SABLES), which manages and facilitates these transactions in their entirety from start to finish. This model depicts an enhanced business process that provides increased security, transparency, and speed. These benefits will be realised by those who register, adopt, and transact on the platform. Through in-depth interviews, the integrated business process model was assessed. The findings produced a final and combined thematic map, representing the main themes of the analysed interview data, namely blockchain implementation strategies, business process applicability, information technology assimilation, current transaction context, and PropTech 3.0 success factors. The discussion revealed that the current transaction process lacks technological innovation, which increases pressure on the conveyancing role. It was also revealed that there is not only a need within the industry, but a desire, for newer technologies to assist the transaction process. In order to streamline and improve efficiency, business processes should leverage digital records and data, and strive for a solution beyond digitisation, achieving digitalisation. Digitalisation recognises digital documents as official and legal documents as opposed to simply being digital back-ups. This, coupled with the business process models, represent theoretical contributions.
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A case study of how a leader shaped the culture of an organisation during a post-merger integration

  • Authors: Zozi, Vuyokazi
  • Date: 2020
  • Subjects: Corporate culture -- South Africa -- East London , Leadership -- South Africa -- East London , Organizational behavior -- South Africa -- East London , Strategic planning -- South Africa -- East London , Mission statements -- South Africa -- East London , Government accountability -- South Africa -- East London , Government corporations -- South Africa -- East London , Consolidation and merger of corporations -- South Africa -- East London , Consolidation and merger of corporations -- Management , Crisis management -- South Africa -- East London , Core competencies -- South Africa -- East London , Resource allocation -- South Africa -- East London , Personnel management -- South Africa -- East London , Communication in management -- South Africa -- East London , Qualitative research
  • Language: English
  • Type: Thesis , Masters , MBA
  • Identifier: http://hdl.handle.net/10962/146643 , vital:38544
  • Description: This research took the form of a case study of the post-merger integration of a government organisation. The study had four objectives, namely to: (1) describe the cultural value of accountability; (2) analyse how strategic leadership and relational leadership roles were exercised to address post-merger integration challenges; (3) analyse how a leader applied selected primary mechanisms to shape organisational culture; (4) analyse how strategic and relational leadership complemented each other in addressing the challenges of post-merger integration and thereby shaping a culture of accountability; and (5) describe how some of the secondary articulation and reinforcing mechanisms supported the culture that was created through primary mechanisms. The literature reviewed, identified some of the critical challenges that are experienced in a post-merger integration, and highlighted the role of leadership in culture formation. The critical challenges that were identified are as follows: What is the vision and organisational purpose? How does the leader structure the organisation? What kind of culture does the leader need to create? How does the leader maintain trust and keep communication with employees? How does a leader build new core competences and develop human capital? Two leadership approaches were adopted, namely strategic and relational leadership. These two leadership approaches were selected because, based on a review of the literature, they appeared to address these post-integration challenges. The roles associated with strategic leadership that were investigated, were creating a vision and purpose for the organisation, developing core competences and developing human capital. From the perspective of relational leadership, this study was concerned with how a leader communicated through regular formal and informal dialogues to keep employees abreast of things, and how the leader built trust. In reviewing the literature linking leadership and culture, the work of Schein (2010) featured prominently. Schein (2010) referred to primary embedding mechanisms that create culture and secondary articulation and reinforcing mechanisms that reinforce or support the culture being created through the primary mechanisms. This study looked at how that happens, and hence six propositions were crafted from the literature. These propositions are as follows: (1) Formal dialogues between the leader and employees demonstrate what the leader pays attention to, measures and controls, which then clarifies what the employees are accountable for. (2) What the leader pays attention to, measures and controls during regular informal interactions between the leader and employees, contributes to strong mutual relationships between them, which promotes ownership and accountability amongst employees for their actions. (3) A leader who behaves consistently when handling critical incidents and organisational crises, is trusted by employees, who then act responsibly and take full responsibility for their actions, and even their mistakes. (4) A leader creates a vision and sense of purpose for the organisation through what he pays attention to, measures and controls, thereby clarifying for employees what they are required to do. (5) A leader who pays attention to developing the organisational core competence and allocates resources to it, instils confidence in his employees with regards to carrying out their own responsibilities. (6) A leader who develops human capital through the allocation of additional resources, thereby instilling confidence in employees who are willing and able to realise or take up their responsibilities. This research adopted a qualitative approach. Data was collected through conducting interviews and the analysis of relevant documents. A deductive thematic analysis of the data was used for the purpose of identifying, analysing and reporting patterns, or themes within the data collected. The research confirmed these propositions as being relevant to the case study. It also confirmed that strategic and relational leadership as reflected in the propositions have complemented one another in the successful implementation of the post-merger integration, thereby shaping a particular culture. It was concluded that the challenges associated with a post-merger integration could not have been addressed through only one of the leadership approaches. The findings of the study also recognised that an architectural role was also required. That is, in a merger, the structure has to be carefully designed and not taken for granted. It was therefore recognised as a critical leadership role. The study considers the implications of the findings and makes recommendations for managers of this organisation, as well as for other organisations that are engaging in a post-merger integration. It further outlines the limitations, delimitations as well as the contribution that the study has made to the body of knowledge. Some of the recommendations made for further research were to analyse how other primary mechanisms that were not part of the propositions may shape the organisational culture; and to research how architectural leadership roles combine with strategic and relational leadership to address post-merger integration challenges. Lastly, this study has explained how leadership, through various mechanisms, shaped a culture of accountability. Other studies can be done using a similar design with different theories of leadership and other mechanisms that apply to shaping other kinds of cultural values.
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A classification of large wetlands in Africa’s elevated drylands based on their formation, structure, and hydrological functioning using Earth Observation (EO) data and Geographic Information System (GIS)

  • Authors: Lidzhegu, Zwidofhelangani
  • Date: 2020
  • Subjects: Wetlands -- Africa -- Classification , Wetlands -- Africa -- Research , Wetlands -- Africa -- Monitoring , Topographical surveying -- Africa , Hydrological surveys == Africa
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/142668 , vital:38100
  • Description: Due to wetland inaccessibility and limited wetland geomorphological studies, there is limited information on the geomorphological origin and hydrological functioning of different types of wetlands in Africa’s elevated drylands. As a result, there is limited information for the development of a comprehensive wetland classification system that classifies wetlands based on long-term geomorphic processes that determine their formation and shape, their structure and hydrological functioning. Therefore, the current study was designed to classify large wetlands in Africa’s elevated drylands based on processes that determine their formation, and shape their structure and hydrological functioning using remote sensing and Geographic Information System (GIS) techniques. Although wetlands perform a number of hydrological functions including groundwater recharge and water purification, the current study focuses mainly on their flood attenuation function. Detailed analysis of topographic information was undertaken using Shuttle Radar Topographic Mission (SRTM) elevations measured at the scale of 30 m x 30 m. LandsatLook and Google Earth images, tectonic as well as geological data were used as supplementary data for developing an understanding of the origin, structure and hydrological characteristics of wetlands. The Principal Component Analysis (PCA) of wetland environmental variables was used to identify and explain wetland heterogeneity. The results of the study showed that fluvial processes, tectonic history and the evolution of Africa’s landscape played a fundamental role in the formation and evolution of wetlands. This study demonstrates a wide range of processes that contribute to wetland formation, structure and functioning. At one extreme it is clear that tectonic processes may be primarily responsible for the creation of basins that host wetlands. At another extreme, wetlands may be structured primarily by fluvial processes. At a third extreme are wetlands that superficially appear to be structured by fluvial processes, but which have their structures modified by gradual rising of the base level at their distal ends, either through marginal uplift adjacent to rift valleys, or through aggradation of a floodplain that blocks a tributary valley. Overall, the classification of wetlands considered in this study can be summarised into four distinct groupings, with two of these divided further into two groupings each: (1) Tectonic basins with little or no indication of fluvial development (Bahi and Wembere wetlands), (2) Tectonic basins evolving towards a wetland with a structure increasingly shaped by fluvial characteristics (Usangu wetland), (3) Fluvially modified valleys with a local base level at the toe of the wetland such as a resistant lithology or a tectonic control that limits the rate of incision of easily weathered and eroded lithologies, leading to valley widening and longitudinal slope reduction, which are of two distinct types: (a) With a catchment on Kalahari Group sediment that is transported fluvially as bedload, and therefore with no prominent alluvial ridge or backwater depressions (Upper Zambezi and Barotse wetlands), (b) With a catchment that produces abundant fine sediment that is deposited as overbank sediments, leading to channel migration via meandering and to the construction of an elevated alluvial ridge (Lufira wetland), (4) Fluvially modified basins with evidence of gradual elevation of the base level at the toe of the wetland, which are of two types: (a) Tectonic marginal rift valley uplift such that they behave more as depression wetlands rather than as wetlands shaped by fluvial processes (Kafue and Luapula wetlands), (b) Tributary valley wetlands blocked by aggradation of the trunk valley (Lukanga wetland). In conclusion, although few geomorphological studies have been conducted on southern African wetlands because of their inaccessibility, Africa’s surface topography and its historical evolution, as well as aridity, provide an opportunity for illustrating the important role that the long-term tectonic, geological and geomorphological processes play in determining wetland origin, structure and dynamics. GIS methodology and Earth Observation (EO) data on the other hand, provide a practical means for acquiring information on inaccessible and hard to traverse wetland systems. A novel cut-and-fill approach for delineating wetlands from a Digital Elevation Model (DEM) was presented as another way in which GIS methodology and Earth Observation (EO) data can provide practical means for assessing inaccessible and hard to traverse wetland systems.
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A cloud adoption framework for South African SMEs

  • Authors: Mudzamba, Ronald Ratidzo
  • Date: 2020
  • Subjects: Cloud computing , Cloud computing -- Security measures , Small business -- Technological innovations -- South Africa -- Eastern Cape , Small business -- Information technology -- South Africa -- Eastern Cape , Information technology -- South Africa -- Eastern Cape , Technology-Organisation-Environment (TOE) framework , Small to Medium Enterprises (SMEs)
  • Language: English
  • Type: text , Thesis , Masters , MCom
  • Identifier: http://hdl.handle.net/10962/148574 , vital:38751
  • Description: Small to Medium Enterprises (SMEs) have been touted as key enablers to the economic development of most countries. Despite growing evidence that most SMEs fail within their initial years, ICTs have been found to add substantial value in facilitating their success. However, in most developing countries, ICT adoption by SMEs has been plagued with a plethora of challenges ranging from poor electricity supply, high ICT costs, lack of ICT expertise to lack of government support. While this might seem problematic for SMEs, the adoption and the use of cloud services mitigates some of these challenges. The problem, however, is that a limited amount of literature has provided guidance with regard to how the cloud adoption process should be carried out by SMEs. The objective of this research, was therefore, to address this by developing a framework that can be used by SMEs to guide them through the cloud adoption process. To this end, thirteen (13) semi-structured interviews were conducted across nine (9) SMEs in the Eastern Cape. The resultant interview transcripts were analysed using an established thematic approach; the result of which allowed for the development of a rich interpretive narrative about SME cloud adoption. Combined with theory from extant literature, this culminated in the development of a framework for cloud services adoption for SMEs in the Eastern Cape.
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A combined modelling approach for simulating channel–wetland exchanges in large African river basins

  • Authors: Makungu, Eunice J
  • Date: 2020
  • Subjects: Watersheds -- Africa , Watershed management -- Africa , Water resources development -- Africa -- International cooperation , Floodplain management -- Africa , Wetland ecology -- Simulation methods -- Africa , Wetland management -- Africa
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/123288 , vital:35424
  • Description: In Africa, many large and extensive wetlands are hydrologically connected to rivers, and their environmental integrity, as well as their influence on downstream flow regimes, depends on the prevailing channel–wetland exchange processes. These processes are inherently complex and vary spatially and temporally. Understanding channel–wetland exchanges is therefore, indispensable for the effective management of wetlands and the associated river basins. However, this information is limited in most of the river basins containing large wetlands in Africa. Furthermore, it is important to understand the links between upstream and downstream flow regimes and the wetland dynamics themselves, specifically where there are water resource developments that may affect these links (upstream developments), or be affected by them (downstream developments). Hydrological modelling of the entire basin using basin-scale models that include wetland components in their structures can be used to provide the information required to manage water resources in such basins. However, the level of detail of wetland processes included in many basin-scale models is typically very low and the lack of understanding of the wetland dynamics makes it difficult to quantify the relevant parameters. Detailed hydraulic models represent the channel-wetland exchanges in a much more explicit manner, but require relatively more data and time resources to establish than coarser scale hydrological models. The main objective of this study was, therefore, to investigate the use of a detailed hydraulic wetland model to provide a better understanding of channel–wetland exchanges and wetland dynamics, and to use the results to improve the parameterisation of a basin-scale model. The study focused on improving the water resource assessments modelling of three data-scarce African river basins that contain large wetlands: the floodplains of the Luangwa and Upper Zambezi River basins and the Usangu wetland in the Upper Great Ruaha River basin. The overall objective was achieved through a combined modelling approach that uses a detailed high-resolution LISFLOOD-FP hydraulic model to inform the structure and parameters of the GW Pitman monthly hydrological model. The results from the LISFLOOD-FP were used to improve the understanding of the channel–wetland exchange dynamics and to establish the wetland parameters required in the GW Pitman model. While some wetland parameters were directly quantified from the LISFLOOD-FP model results, others, which are highly empirical, were estimated by manually calibrating the GW Pitman wetland sub-model implemented in excel spreadsheets containing the LISFLOOD-FP model results. Finally, the GW Pitman model with the inclusion of the estimated wetland parameters was applied for each basin and the results compared to the available downstream observed flow data. The two models have been successfully applied in southern Africa, with the GW Pitman model being one of the most widely applied hydrological models in this region. To address the issue of data scarcity, during setup of these models, the study mainly relied on the global datasets which clearly adds to the overall uncertainty of the modelling approach. However, this is a typical situation for most of the data scarce regions of the continent. A number of challenges were, however, faced during the setup of the LISFLOOD-FP, mainly due to the limitations of the data inputs. Some of the LISFLOOD-FP data inputs include boundary conditions (upstream and downstream), channel cross-sections and wetland topography. In the absence of observed daily flows to quantify the wetland upstream boundary conditions, monthly flow volumes simulated using the GW Pitman monthly model (without including the wetland sub-model) were disaggregated into daily flows using a disaggregation sub-model. The simulated wetland inflows were evaluated using the observed flow data for downstream gauging stations that include the wetland effects. The results highlighted that it is important to understand the possible impacts of each wetland on the downstream flow regime during the evaluations of the model simulation results. Although the disaggregation approach cannot be validated due to a lack of observed data, it at least enables the simulated monthly flows to be used in the daily time step hydraulic model. One of the recommendations is that improvements are required in gauging station networks to provide more observed information for the main river and the larger tributary inflows into these large and important wetland systems. Even a limited amount of newly observed data would be helpful to reduce some of the uncertainties in the combined modelling approach. The SRTM 90 m DEM (used to represent wetland topography) was filtered to reduce local variations and noise effects (mainly vegetation bias), but there were some pixels that falsely affect the inundation results, and the recently released vegetation-corrected DEMs are suggested to improve the simulation results. Channel cross-section values derived from global datasets should be examined because some widths estimated from the Andreadis et al. (2013) dataset were found to be over-generalised and did not reflect widths measured using high-resolution Google Earth in many places. There is an indication that channel cross-sections digitised from Google Earth images can be successfully used in the model setup except in densely vegetated swamps where the values are difficult to estimate, and in such situations, field measured cross-section data are required. Small channels such as those found in the Usangu wetland could play major role in the exchange dynamics, but digitising them all was not straightforward and only key ones were included in the model setup. Clearly, this inevitably introduced uncertainties in the simulated results, and future studies should consider applying methods that simplify extractions of most of these channels from high-resolution images to improve the simulated results. The study demonstrated that the wetland and channel physical characteristics, as well as the seasonal flow magnitude, largely influence the channel–wetland exchanges and wetland dynamics. The inundation results indicated that the area–storage and storage–inflow relationships form hysteretic curves, but the shape of these curves vary with flood magnitude and wetland type. Anticlockwise hysteresis curves were observed in both relationships for the floodplains (Luangwa and Barotse), whereas there appears to be no dominant curve type for the Usangu wetlands. The lack of well-defined hysteretic relationships in the Usangu could be related to some of the difficulties (and resulting uncertainties) that were experienced in setting up the model for this wetland. The storage–inflow relationships in all wetlands have quite complex rising limbs due to multiple flow peaks during the main wet season. The largest inundation area and storage volume for the Barotse and Usangu wetlands occurred after the peak discharge of the wet season, a result that is clearly related to the degree of connectivity between the main channel and those areas of the wetlands that are furthest away from the channel. Hysteresis effects were found to increase with an increase in flood magnitudes and temporal variations in the wetland inflows. Overall, hysteresis behaviour is common in large wetlands and it is recommended that hysteresis curves should be reflected in basin-scale modelling of large river basins with substantial wetland areas. At a daily time scale, inflow–outflow relationships showed a significant peak reduction and a delayed time to peak of several weeks in the Barotse and Usangu wetlands, whereas the attenuation effects of the Luangwa floodplain are minimal. To a large extent, the LISFLOOD-FP results provided useful information to establish wetland parameters and assess the structure of Pitman wetland sub-model. The simple spreadsheet used to estimate wetland parameters did not account for the wetland water transfers from the upstream to the next section downstream (the condition that is included in the LISFLOOD-FP model) for the case when the wetlands were distributed across more than one sub-basin. It is recommended that a method that allows for the upstream wetland inflows and the channel inflows should be included in the spreadsheet. The same is true to the Pitman model structure, and a downstream transfer of water can be modelled through return flows to the channel. The structure of the wetland sub-model was modified to allow an option for the return flows to occur at any time during the simulation period to provide for types of wetlands (e.g. the Luangwa) where spills from the channel and drainage back to the channel occur simultaneously. The setup of the GW Pitman model with the inclusion of wetland parameters improved the simulation results. However, the results for the Usangu wetlands were not very satisfactory and the collection of additional field data related to exchange dynamics is recommended to achieve improvements. The impacts of the Luangwa floodplain on the flow regime of the Luangwa River are very small at the monthly time scale, whereas the Barotse floodplain system and the Usangu wetlands extensively regulate flows of the Zambezi River and the Great Ruaha River, respectively. The results highlighted the possibilities of regionalising some wetland parameters using an understanding of wetland physical characteristics and their water exchange dynamics. However, some parameters remain difficult to quantify in the absence of site-specific information about the water exchange dynamics. The overall conclusion is that the approach implemented in this study presents an important step towards the improvements of water resource assessments modelling for research and practical purposes in data-scarce river basins. This approach is not restricted to the two used models, as it can be applied using different model combinations to achieve similar study purpose.
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