An investigation into water and sanitation in the Eastern Cape Province and potential for implementation of biotechnology platforms
- Authors: Gumunyu, Wilbert
- Date: 2022-10-14
- Subjects: Sewage South Africa Eastern Cape , Sanitation South Africa Eastern Cape , Algae Biotechnology , Biotechnology , Sewage Purification Biological treatment , Algal biofuels
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362830 , vital:65366
- Description: In contemporary South Africa, a country in transition, destruction rather than reconstruction seems commonplace. Electricity supply is at an all-time low and ‘load shedding’ is an almost daily occurrence. Similarly, more fragility of water delivery and sanitation service is being reported with the likelihood of ‘water shedding’ a soon-to-be reality. In view of the ever-increasing reported mismanagement of South Africa’s water and sanitation infrastructure, which is likely nearing the point of collapse if not already collapsed, this thesis set out to interrogate at a provincial and municipal level the status of water and sanitation in Chris Hani District Municipality (CHDM), Eastern Cape Province. One major driver behind this study was to evaluate provincial and municipal water/wastewater infrastructure as a platform to support implementation of locally developed bioprocess technologies. First, publicly available historical data was used to derive a baseline or benchmark from which to determine gains/losses in compliance, water quality and efficiency. The period 2009-2013/4 during which Blue and Green Drop reporting was routine, was used as an appropriate start point. Data thus derived indicated that, at provincial and district municipality (DM) level, potable water supply was by bulk water schemes and, sanitation was typically by waste stabilization pond (WSP) treatment of municipal sewage. The derived benchmark for the period 2009-2013/14 indicated that most plants were not compliant (~75% of the Eastern Cape Province water treatment plants (WTP) operating between average performance to critical state), operated either at- or above design capacity (Eastern Cape Province, 16%; CHDM, 19%). A large number of plants for the province (62.4%) and district (81.25%) had hydraulic design capacity or average daily flows that were unknown (information not provided in available literature or plant reports) and final effluent did not always meet the general standard (70.3% of the CHDM wastewater treatment works (WWTW)). To determine the contemporary state (2020 - 2022) of water and sanitation within CHDM, a scoping exercise of WTP and WWTW in selected local municipalities was carried out. This was done along a west-east transect by appraising WTP and WWTW in the towns of Cradock, Tarkastad, Komani, Tsomo, Cacadu, and Ngcobo. Furthermore, targeted assessment of the Queenstown WTP and the Cradock WWTW was used to derive real-time data on the status of water and sanitation infrastructure. Results showed that water and sanitation services within CHDM had, in the years between 2009-2013/14 to date, deteriorated. Freshwater demand significantly exceeded capability of water supply schemes, where demand was as much as three times greater than reported available supply. For most WWTW, operation was in excess of capacity and between 1.52 and 12 times installed hydraulic loading. The targeted scoping exercise revealed that Queenstown WTP is a moderate risk plant (Cumulative risk rating, CRR = 11 and maximum risk rating, MRR = 47.8%), whereas Cradock WWTW was in working condition but with challenges and some infrastructural dysfunction. Assessment of water/effluent quality revealed that turbidity and TOC were above SANS 241 general limit. Non-compliance in terms of nitrate/nitrite-N, ammonium-N, phosphate-P, TSS, total coliforms, E. Coli, and free chlorine was evident at Cradock WWTW. Unstructured interviews with plant operators corroborated these findings. The overwhelming support for bulk schemes for potable water provision and WSP for sanitation indicated a partially water secure municipal district but derelict in terms of its sanitation services. The later, it was concluded, in particular provides an ideal opportunity for implementation of platform technologies to support bioprocesses for entrepreneurship, employment, economic benefit and to secure a closed circular economy for regional water and sanitation through valorisation of co-product streams. Among the co-product streams considered in this thesis are biomass, biogas, biofertilizers, biofuels and several high value chemical products. , Thesis (MSc) -- Faculty of Science, Institute for Environmental Biotechnology, 2022
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An investigation of the English language demands of mathematical texts on data handling used in intermediate phase mathematics
- Authors: Jones, Angela Peta
- Date: 2022-10-14
- Subjects: Mathematics Study and teaching (Elementary) South Africa , Middle school education South Africa , Information storage and retrieval systems Mathematics , Language complexity , Textbooks Readability , Language arts Correlation with content subjects South Africa , Content area reading South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405259 , vital:70155
- Description: In the Intermediate Phase the majority of South African learners are transitioning from learning in their mother tongue to learning in English as well as from learning to read to reading to learn, and this is a major challenge. Textbooks are a key mediating artefact in the learning of mathematics and they present a challenge to the learner in terms of the language comprehension demands The data handling sections of mathematics textbooks are particularly dense in text. This is an important part of the mathematics curriculum as it is the beginning of statistical literacy learning. We need to be able to question, evaluate claims based on data, create arguments we can defend and use data meaningfully, it is thus crucial that learners acquire statistical literacy. This research sets out to examine the text in the data handling sections of four Intermediate Phase Mathematics book series in order to answer the following research question: What are the language comprehension demands of English mathematical texts on data handling that are used in South African Intermediate Phase Mathematics? The theories framing the study are Vygotsky’s sociocultural theory and Cummins’ second language acquisition theory. It is an interpretivist mixed method case study that takes the form of a document analysis.. The findings indicate that many units in the books analysed have a higher readability level than the grade level and will thus present a challenge to learners in terms of their ability to access the mathematical content. An analysis of the linguistic complexity revealed that the features contributing most to the complexity of the texts included words with seven or more letters, prepositional phrases, infinitives, complex verbs and complex/compound sentences. An examination of the non-textual elements revealed that most of them are accurate, connected, concise, contextual and these add to the comprehensibility although there were a few which could be possibly be distractors. It is hoped that the empirical findings of this study, will sensitise educators and publishers involved with the design of textbooks and workbooks to the type of language currently found and that they might give attention to the needs of English language learners when developing these texts. , Thesis (MEd) -- Faculty of Education, Education, 2022
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Design, synthesis, manufacture, characterization and evaluation of lipid nanocapsules in chitosan-iota-carrageenan based hydrogel scaffold as a potential anti-Covid-19 drug delivery system
- Authors: Mukubwa, Grady Kathondo
- Date: 2022-10-14
- Subjects: Nanocapsules Design , Hydrogel , COVID-19 (Disease) , Characterization , Drug delivery systems
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/364955 , vital:65665
- Description: Covid-19 is a deadly viral disease that has been rampant around the world since 2019. Although the successful introduction of the vaccine has reduced the spread of covid-19, new cases and deaths are still being recorded. To date, no specific curative antiviral treatment has been approved for covid-19. However, many existing antiviral drugs have been and are still being studied against covid-19 and some of them, such as Remdesivir, have shown promise and could be repurposed to treat this infection. Unfortunately, antiviral drugs are prone to resistance as most of them have poor biopharmaceutical properties, including low solubility, permeability and bioavailability, which could hinder any clinical success. Recent advances in nanotechnology-based delivery systems have made it possible to improve the biopharmaceutical properties of many drugs, especially those of poorly water-soluble drugs, by formulating them as lipid nanoparticles (LNP). Thus, in order to contribute to the fight against covid-19, this work aimed to develop Lipid Nanocapsules (LNC), based on some natural raw materials, which could improve the biopharmaceutical properties of antiviral drugs. In addition, since covid-19 infection is mainly respiratory, this work also aimed to fabricate a targeted delivery system based on a hydrogel capable of entrapping LNC and ensuring their efficient deposition and release in the lungs. The LNC consisted of a mixture of medium-chain triglycerides oil (MCT oil), crude soy lecithin, tween 80, NaCl and water, while the hydrogel consisted of a chitosan-grafted-iota carrageenan-grafted-poly (acrylamide-co-acrylic acid) system (CS-iCar-p (AAm-Co-AA)). Efavirenz (EFV), a drug with very low water solubility that has recently been demonstrated to have the potential to influence sars-cov-2 life cycle through different targets (3CLP, RdRp, Hellicase, 3’to5’exonuclease, 2’-O-ribose methyltransferase and EndoRNAse), was chosen as the model drug to evaluate the developed delivery system. The combination of LNP and hydrogel results in a delivery system known as the LNP-hydrogel composite, an emerging area of research in the field of drug delivery. To date, no research has reported the design and fabrication of an LNC-CS-iCar-p (AAm-Co-AA) hydrogel composite that could effectively deliver an antiviral drug to the lungs in addition to its advantages in terms of biological activities. Prior to the design of experiment, EFV solubility was assessed in water, labrafac lipophile 1349 and MCT oil. After that, the Design Expert Software version 13 was used to design the different experiments performed in this work. The I-optimal mixture design of experiments was performed for both LNC preparation and CS-iCar-p (AAm-Co-AA) hydrogel synthesis to study the impact of raw materials on the characteristics of these delivery systems. LNC were prepared using the phase inversion method while the free radical precipitation graft copolymerization method was used to synthesize hydrogel. In order to build polynomial models that could predict the amount of drug both LNC and CS-iCar-p (AAm-Co-AA) hydrogel can entrap, a D-optimal (custom) randomized design was performed. Moreover, various characterization techniques were used to investigate the physicochemical properties of the developed delivery systems. Thereafter, drug release studies were performed using a 1% sodium lauryl sulfate solution adjusted to either pH 4 or 7. Solubility studies revealed that EFV was more soluble in labrafac lipophile 1349 and in MCT oil than in water; therefore, given its affordability, MCT oil was used for the LNC formulation. The design of experiment carried out allowed the construction of polynomial models that could predict, on the one hand, the droplet size, the polydispersity index and the Zeta potential of LNC, which were respectively around 50nm, below 0.2 and below -33. On the other hand, the model could predict the swelling capacity of the synthesized hydrogel, which was optimised to about 30,000% (300 g of water to 1 g of hydrogel). This turned out to be influenced by the proportion of polymers, the ratio of monomers as well as the concentration of the cross-linking agent. In addition, the characterization techniques further supported the improvement of EFV solubility by highlighting its conversion into its amorphous state after encapsulation in LNC. They also confirmed successful synthesis of CS-iCar-p (AAm-co-AA) hydrogel. LNC were able to encapsulate about 87% of EFV while the synthesized CS-iCar-p (AAm-co-AA) hydrogel entrapped around 53% of EFV encapsulated in LNC. While LNC were able to release 42% and 27% of EFV after 74 hours in a 1% sodium lauryl sulfate solution (SLS) at pH 7 and pH 4 respectively, the LNC-CS-iCar-p (AAm-co-AA) hydrogel composite released about 50% and 40% of the drug after 9 days in the same release medium. Interestingly, the chemical integrity of the drug was preserved throughout the manufacturing process up to after its release, suggesting that the developed LNC-CS-iCar-p (AAm-co-AA) hydrogel composite could be used as a novel potential anticovid-19 drugs delivery system. , Thesis (MSc) -- Faculty of Science, Chemistry, 2022
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Electrocatalytic activity of symmetric and asymmetric Co(II) and Mn(III) porphyrins in the presence of graphene quantum dots towards the oxidation of hydrazine
- Authors: Jokazi, Mbulelo
- Date: 2022-10-14
- Subjects: Electrocatalysis , Hydrazine , Quantum dots , Graphene , Porphyrins
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362894 , vital:65372
- Description: The influence of metal porphyrins in electro-oxidation of hydrazine is explored. A series of symmetric and asymmetric porphyrins alone and in the presence of graphene quantum dots (GQDs) are employed in this work. Tetra 4-aminophenyl porphyrin, manganese tetra 4-aminophenyl porphyrin, manganese tetra 4-aminophenyl porphyrin--GQDs, and manganese tetra 4-aminophenyl porphyrin@GQDs are the symmetric porphyrins. The asymmetric porphyrin and composites are 5, 10, 15-tris(aminophenyl)-20-(4-carboxyphenyl) porphyrins, manganese 5, 10, 15-tris(aminophenyl)-20-(4-carboxyphenyl) porphyrins, cobalt 5, 10, 15-tris(aminophenyl)-20-(4-carboxyphenyl) porphyrins, manganese 5, 10, 15-tris(aminophenyl)-20-(4-carboxyphenyl) porphyrins--GQDs, and cobalt 5, 10, 15-tris(aminophenyl)-20-(4-carboxyphenyl) porphyrins--GQDs. These complexes were synthesized and characterized accordingly and applied for electrocatalysis. The electrocatalytic experiments were carried out using glassy carbon electrode and the modification was through drop-dry method. The porphyrin and GQDs synthesized were characterized using UV-Vis spectroscopy, Mass spectrometry, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and energy dispersive x-ray spectroscopy. The modified electrodes were characterized using cyclic voltammetry and electrochemical Impedance spectroscopy. The introduction of metal ion in the center of the porphyrin improved electrocatalysis. The presence of push-pull substituents in the porphyrin lowered the oxidation potential and improved the catalysis. The presence of GQDs improved catalysis in both symmetric and asymmetric porphyrin compared to individual components. Cobalt porphyrins showed better activity than manganese porphyrin. , Thesis (MSc) -- Faculty of Science, Chemistry, 2022
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Exploring primary school mathematics teachers use of gamification in formative assessment: a case study
- Authors: Simelane, Thando
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405412 , vital:70169
- Description: Technology integration has gained much influence with the emergence of technological tools in educational areas. The vast resources and opportunities that technologies and the Internet have brought new approaches, strategies, and tools to assess learners' performance in many subject areas. Teachers have many computer/mobile device applications and learning management systems. Most teachers are trying new ways of integrating technology into the mathematics classroom to increase the quality of teaching and learning. Thus, this study explored how primary school mathematics teachers use Kahoot as a formative assessment tool. The study adopted an exploratory case study underpinned by the interpretive paradigm. It was conducted in a primary school in the Shiselweni Region in Swaziland. The participants were ten mathematics teachers teaching different grades at the school. Data was generated using observations, workshops, structured questionnaires, journal reflections and focus group interviews. The theoretical and analytical framework that underpinned this study was a combination of Davis' (1989) Technology Acceptance Model (TAM) and Mishra & Koehler's (2006) Technological Pedagogical Content Knowledge (TPACK) framework. The study results showed that the perceptions and attitudes of primary school mathematics teachers towards using Kahoot generally appear to be positive. The study also revealed that all the participants found Kahoot helpful and perceived it as easy to use. The study found that the provision of technical support for teachers; and financial support for schools to implement technology use in the classroom were enabling factors for using Kahoot as a formative assessment technology. Constraining factors were lack of high-speed internet connectivity; and lack of basic technological knowledge for using Kahoot in formative assessment. The study concluded that Kahoot increases learner motivation, engagement, attention, enjoyment, and knowledge retention. This study recommended the integration of Kahoot gamification into the mathematics curriculum.The study recommends that there is a need for schools to initiate the presence of technologies in mathematics classrooms and encourage teachers to integrate technologies assessment and teaching. The study suggest future research to explore use of Kahoot as a formative assessment technology in resource-constrained schooling contexts using multiple cases. , Thesis (MEd) -- Faculty of Education, Education, 2022
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The regeneration of palmiet (prionium serratum) following hydrogeomorphic disturbance: a case study of the Kromme River wetland
- Authors: Van Eck, Caydon Daniël
- Date: 2022-10-14
- Subjects: Biogeomorphology South Africa Kromme Estuary (Eastern Cape) , Wetland ecology , Prionium serratum Regeneration , Fluvial geomorphology , River channels
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/365555 , vital:65759
- Description: The Kromme River wetland in the Eastern Cape of South Africa occupies a broad valley (up to 350 m wide) with a gentle longitudinal slope of less than 2 % that has been formed by cut-and-fill cycles that are initiated by trunk-tributary interactions. These hydrogeomorphic disturbance events trigger gully erosion and generate sediments, the coarse fraction of which is deposited less than 2 km downstream, leading to depositional floodout features that fill gullies headwards. This process has been occurring at intervals for at least 10 000 years, and as such pre-dates the introduction of European farming practices in the area. Plants that regenerate by colonising these features are thought to have evolved adaptions necessary to colonise intermittently produced bare sandy sediments. This study aimed to examine the regeneration ecology of palmiet (Prionium serratum), the dominant vegetation community within these cut-and-fill wetlands, by relating its regeneration characteristics to environmental factors in a reach of the Kromme River wetland that has experienced a recent hydrogeomorphic disturbance event (approximately 10 years before the commencement of this study). Palmiet was found to be regenerating on sedimentary deposits on beds of gullies and on depositional bars on the margins of gully beds. The large depositional floodout downstream of a large gully also favoured palmiet regeneration, where it was found to be regenerating along not only the active channel, but also along old abandoned flow paths and sometimes areas well elevated above the channel. The geomorphic features that favoured palmiet regeneration were characterised by coarse-grained sediments (mean particle size approximately 310 μm) with low organic matter content (0.61 %), a low depth to the water table and low elevation above the thalweg (mean depth to water table is approximately 0.6 m), and a relatively close distance to the thalweg (< 10 m). This understanding of palmiet’s regeneration characteristics was viewed in relation to existing literature on undisturbed palmiet wetland plant communities and its reported contribution to conditions that favour wetland formation through gully filling, which allowed for the creation of a conceptual model of palmiet regeneration, colonisation and long-term persistence. This model was based on the Fluvial Biogeomorphic Succession concept. It suggests that palmiet’s interaction with the hydrogeomorphic environment throughout the different stages of its life cycle results in self-organising biogeomorphic landforms. Over hundreds of years, the reciprocal interactions between palmiet, sediments and water, fills gullies and restores valley bottoms, ultimately leading to the formation of a wetland landform. It is further proposed that through continued accretion, the geomorphic wetland landscape becomes more and more disconnected from the hydrogeomorphic dynamics of the fluvial system, such that the prevailing conditions begin to favour fynbos establishment, which may outcompete palmiet. , Thesis (MSc) -- Faculty of Science, Geography, 2022
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Towards an improved understanding of episodic benthic turbidity events (Benthic Nepheloid Layer) on the Eastern Agulhas Bank, South Africa
- Authors: Johnstone, Brett Mordaunt
- Date: 2022-10-14
- Subjects: Nepheloid layer , Turbidity , Loligo reynaudii , Fisheries South Africa , Oceanography , Remote sensing , Altimetry , Climatic changes
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362883 , vital:65371
- Description: The harvest of Loligo reynaudii, or "chokka," represents a critical source of revenue and job creation in the historically impoverished Eastern Cape Province of South Africa. Due to the importance of visual stimuli in the reproductive processes, it has been hypothesized that a primary driver of successful reproduction is the clarity of the water column. The presence of increased particulate matter concentrations within the water column generates turbid conditions near the seafloor (visibility < 1m), that are proposed to restrict spawning activity. This benthic nepheloid layer (BNL) contains both organic and inorganic components, with the BNL intensity a function of bottom turbulence, substratum type, and detritus level. However, the spatial and temporal resolution of BNL intensity on the Eastern Agulhas Bank (EAB) and the environmental drivers thereof remain unknown. Here we show that benthic turbidity events are a common but highly variable occurrence on the EAB. Results from a 17-month time-series of in-situ and remote sensing data between 2002 – 2004 in Algoa Bay, supplemented by experiments in other bays important for spawning, show that turbid conditions existed for ∼ 30 % of the sample period. Exploration of environmental drivers, including the influence of wind, altimeter-derived significant wave height (Hs), sea surface temperature (SST), and chlorophyll-a (Chl-a) concentrations indicate that BNL intensity does not conform to a "one-size-fits-all" approach. Rather, complex local hydrological and physiochemical parameters control the BNL characteristics on the EAB. Global warming is likely to increase the frequency and intensity of extreme westerly-wind and storm events, promoting BNL events on the Eastern Agulhas Bank and possibly causing a shift in the reproductive strategy of chokka squid to the cooler mid shelf region. This is likely to have consequences for both the species in terms of reproductive success and the fishery, which is concentrated on inshore spawning aggregations. Future research needs to quantify and characterize the constituents, source particles and spatial-temporal variability of BNL events in order to build a predictive capacity. Through incorporating the qualitative analysis of the dynamics of nepheloid layers on the EAB into Regional Oceanographic Models (ROMS), General Linear Models (GLM) and particle distribution models such as DELFT-3D, it is possible to move toward predicting the timing and intensity of these events. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
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