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Item Characterising the spatio-temporal patterns of water quality parameters in the cradle of humankind world heritage site using Sentinel-2 and random forest regressor(2025-07) Ngamile, S; Kganyago, M; Madonsela, Sabelo; Mvandaba, VuyelwaIntroduction: Water quality assessment is essential for monitoring and managing freshwater resources, particularly in ecologically and culturally significant areas like the Cradle of Humankind World Heritage Site (COHWHS). This study aimed to predict and map the spatio-temporal patterns of both optically and non-optically active water quality parameters within small inland water bodies located in the COHWHS. Methods: High-resolution Sentinel-2 Multispectral Instrument (MSI) satellite data and two random forest models (Model 1 [consisting of sensitive spectral bands] and Model 2 [consisting of spectral bands + indices]) were used alongside In-situ measurements of chlorophyll-a, suspended solids, dissolved oxygen (DO), pH, Temperature, and electrical conductivity (EC) were integrated to establish empirical relationships and assess spatial variability across high-flow and low-flow conditions. Results: The results indicated that DO could be predicted with the highest accuracy under low-flow conditions, followed by EC. Specifically, Model 2 achieved an R2 of 0.88 and an RMSE of 1.37 for DO, while Model 1 achieved an R2 of 0.63 and an RMSE of 291.48 for EC. For optically active parameters, suspended solids showed the highest prediction accuracy under high-flow conditions using Model 2 (R2p = 0.55; RMSE = 118.19). Due to the over-pixelation of other smaller water bodies within the COHWHS in Sentinel-2 imagery, Cradlemoon Lake was selected to show distinct seasonal (high- and low-flow) and spatial variations in optically and non-optically active water quality parameters. Discussion: Variations in the results were influenced by runoff dynamics and upstream pollution: lower Temperatures and suspended solids under low-flow conditions increased DO concentrations, whereas higher suspended solid concentrations under high-flow conditions likely reduced light penetration, resulting in lower spectral reflectance and chlorophyll-a levels. These findings highlight the potential of Sentinel-2 MSI data and machine learning models for monitoring dynamic water quality variations in freshwater ecosystems.Item The effect of fiber parameters and surface treatment in caster fiber- reinforced polyester composites(2025-03) Nijandhan, K; Muralikannan, R; Thimiri Govindaraj, Deepak B; Pradeesh, ELThis investigation focused on identifying the effect of fiber parameters (fiber length, fiber weight) on the mechanical properties of pretreated caster fiber-reinforced polyester composites. The composite plates were fabricated using the hand layup technique by varying the fiber length and fiber content in polyester matrix composites. The tensile, flexural, and impact tests were conducted as per ASTM standards. Fracture mechanism was analyzed using scanning electron microscopy (SEM) images. It is found that the highest tensile (20.8 MPa), flexural (46.4 MPa), and impact (38.2 kJ/m2) strengths of composites with 30 mm fiber length and 40% fiber wt. content. The regression equation was formulated and optimum fiber parameters for better mechanical properties were identified using response surface methodology and pattern search optimization algorithm. This study confirms that caster fiber-reinforced polyester composites were used to lightweight engineering applications.Item Agile local manufacturing of active pharmaceutical ingredients in Africa could improve health security and economic growth(2025-08) Sagandira, Cloudius RAfter decades of dependence on imported Active Pharmaceutical Ingredients (APIs) and multilateral aid, Africa faces a critical turning point, seeking to assert control over its health and economic future. Here we discuss how agile local API manufacturing offers a strategic solution to enhance health and economic security, transforming Africa’s pharmaceutical landscape for sustainable medicine access.Item Librarians to the Rescue! An LIS-Associated Workflow Model for the Rescue of Research Data at Risk(2025) Patterton, Louise H; Bothma, Theo JD; Van Deventer, Martie JThis study presents a data rescue workflow model and explores the potential roles and responsibilities of the library and information services (LIS) sector in rescuing at-risk data. The methodology was multifaceted, consisting of three distinct phases of data collection and analysis. First, content analysis was conducted on 15 purposively selected data rescue publications to identify key activities that are integral to the data rescue process. This phase resulted in the creation of an initial data rescue workflow model. Second, feedback was obtained from six experienced researchers at a South African research institute, chosen from a sample of criterion-based researchers, after they reviewed the initial model. This feedback was used to revise the model. Third, additional feedback on both the initial and revised models was gathered during a mini focus group session with three purposively selected LIS experts at the same research institute. This feedback was used to refine the model and develop a final recommended data rescue workflow model, which is presented in this study. The recommended model outlines the crucial stages, activities, and outputs of data rescue in a chronological sequence. The study’s outcomes provide new insights into data rescue and the involvement of LIS professionals, highlighting how various LIS experts can contribute to data rescue projects.Item Identifying the optimal dose of cannabidiol by intrabuccal administration in Kramnik (C3HeB/FeJ) mice(2025-06) Omotayo, OP; Bhengu, S; Venter, K; Lemmer, Yolandy , OP Bhengu; Mason, SBackground: Cannabidiol (CBD) has numerous therapeutic properties, and is used to treat neurological conditions, such as neuroinflammation. However, the optimal dose of CBD to penetrate the brain requires further investigation. The primary aim of this study was to use a mouse model and the intrabuccal route for CBD administration to determine the optimal dose at which CBD can penetrate the brain. The secondary aim was to determine whether sex is a confounding factor. Methods: Thirty adult Kramnik mice, divided equally into three groups, were administered CBD oil intrabuccally at three doses-10, 20, and 30 mg/kg, euthanized 6 h later, and whole brain, urine, and blood samples were collected. Liquid chromatography with tandem mass spectrometry was used to analyze the collected samples. Results: CBD and its three metabolites-7-carboxy cannabidiol (7-COOH-CBD), 7-hydroxy cannabidiol (7-OH-CBD) and 6-hydroxy cannabidiol (6-OH-CBD), were identified and quantified in all samples. The 10 and 20 mg/kg doses of CBD produced similar results in the brain, but the group given the 10 mg/kg dose had the least variation. The 30 mg/kg dose yielded the highest abundance of CBD and its metabolites in all samples, but also the greatest variation. Sex only became a confounding factor at 30 mg/kg. Conclusions: This study shows that the intrabuccal route of CBD administration is reliable and the 10 mg/kg dose of CBD is recommended in mice because there were good CBD metabolite concentrations in all samples, with the least variation among the doses, and sex was not a confounder at 10 mg/kg.Item The efficacy of alkaline hydrolysis on selective degradation and recovery of high-purity terephthalic acid and cotton cellulose from postconsumer polyester/cotton waste(2025-05) Baloyi, Rivalani B; Sithole, BS , Rivalani B Sithole; Moyo, MTextile waste is one of the biggest global waste problems requiring innovative and sustainable solutions. This study focused on developing a potential sustainable solution to textile waste by recycling of blended polyester/cotton fabric waste. The blends were pretreated prior to selective alkaline degradation and then vacuum filtered into constituent materials. Terephthalic acid (TPA), ethylene glycol (EG), and cotton were the constituent materials. The effects of the processing conditions and determination of optimum conditions were ascertained by analysis of the constituent materials’ properties. Electron microscopy (SEM), Ultraviolet spectroscopy (UV–VIS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analyses (TGA-DSC) and viscometer were utilized in characterizing the recovered materials. The optimum processing conditions were found to be 15 % (w/v) NaOH in the presence of 1 mol BTBAC: 1 mol per repeating unit of polyester phase transfer catalyst and processing temperature and time of 80 °C and 270 mins, respectively. These conditions resulted in complete hydrolysis of the polyester in polyester/cotton blended fabrics waste achieving a TPA recovery rate of 80 % and recovery rate of 97 % for cotton fibres. The recovered cellulose had viscosities between 340 and 520 ml/g which is within the range of pulp utilized in the production of regenerated fibres. The successful separation of TPA and cotton fibres implies that the recycling of blended textiles can be accomplished contributing to sustainable textile waste management and circular economy. The research indicates significant potential for scalable textile waste solution to confront the increasing crisis of textile waste globally.Item Valorisation of insect infested sweet sorghum reeds towards production of a fermented beverage(2025-05) Makopa, TP; Semumu, T; Gaaipone, MT; Masemola, Thato; Ramchuran, Santosh; Vrhovsek, U; Zhou, NSweet sorghum variety (Sorghum bicolour (L)) commonly known as sweet reeds, Ntšhe, in Setswana, is a valuable cash crop mostly for small scale farmers in Botswana and other southern African countries. These reeds are widely consumed as a delicacy and contribute significantly to food security, employment, and rural incomes. However, infestations by the larval stages of Chilo partellus (stem borer moths) lead to substantial economic losses, as consumers reject worm-infested reeds. To mitigate these losses, valorisation of condemned sweet reeds is attractive. Here, we took advantage of our understanding of yeast-insect interactions to isolate yeasts associated with larval stages of the stem borer moths and investigated their potential for use in the production of an alcoholic sweet sorghum beverage. We report the isolation of thirty-two yeast strains from the larvae and assessed their ability to ferment the simplest sugar, glucose, a constituent of the sweet sorghum juice. Out of the selected yeasts, a subset of fourteen strains belonging to Hanseniaspora and Candida genera were further characterised based on their capacity to ferment more sugars found in sweet sorghum juice. We further assessed the isolates for the ability to tolerate brewing/fermentation-associated stresses and production of complex aroma profiles towards the use of sweet sorghum juice as a sole feedstock to produce a commercial beverage. Our findings suggest that yeastinsect interactions offer a promising approach for converting rejected sweet sorghum stalks into a novel alcoholic beverage, adding economic value to an otherwise discarded resource.Item Discovering HPC Resources in Africa: Empowering Collaborative Research Opportunities(2025-07) Johnston, Bryan J; Johnston, K; Maslamoney, SAfrica faces significant challenges in accessing advanced cyberinfrastructure due to resource constraints. Consequently, the African scientific community must explore innovative approaches, such as fostering collaboration and leveraging shared resources, to overcome financial barriers to cyberinfrastructure adoption. We outline the methodology and results of a preliminary discovery survey aimed at mapping High-Performance Computing (HPC) resources across Africa to support scientific computing research. The initiative stemmed from the recognition of the critical importance of an African HPC resource catalogue in fostering research and scientific collaboration. The survey is a result of the collective efforts of diverse stakeholders to promote scientific advancement throughout the continent by generating a preliminary overview of available computational resources in Africa. The survey gathered a total of 51 completed submissions from 23 African countries, establishing a solid foundation for further exploration of existing HPC resources across Africa.Item Ethylene detection performance of Co3O4 sheet-like hierarchical structures: Experimental and DFT calculations(2025-04) Letsoalo, MR; Dima, Ratshilumela S; Maluta, NE; Shingange, KThis study investigates the gas detection of ethylene (C2H4) using cobalt oxide (Co3O4) structures synthesized via hydrothermal method for 6, 12, and 24 hrs. X-ray diffraction (XRD) confirmed the strong crystallinity. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed a sheet-like morphology forming hierarchical structures, with the surface area obtained through the Brunauer-Emmett-Teller (BET) method decreasing as the reaction duration increased. Selectivity studies conducted at 100 ◦C using 100 ppm of several gases (CH4, CO, C3H6O, C2H5OH, and C6H6) revealed distinct responses among the different Co3O4-based sensors. The Co3O4_6hrs-based sensor exhibited high selectivity for C2H4, whereas the Co3O4_12hrs-based sensor showed a strong response to C2H5OH. Additionally, the Co3O4_24hrs sensor demonstrated a high response to C6H6. Notably, the Co3O4_6hrs sensor recorded the highest overall response of 49.6 and exhibited rapid response and recovery times of 27 seconds and 42 seconds, respectively. BET and Photoluminescence (PL) analyses indicated that the superior performance of the Co3O4_6 hrs sensor was due to its high surface area and defects. Density functional theory (DFT) calculations were used to provide insights into the gas-sensing mechanisms. The calculations were performed using the Perdew–Burke–Ernzerhof (PBE) exchange–correlation functional within the generalized gradient approximation (GGA) for optimization. DFT calculations showed that the gas performance of Co3O4 towards ethylene is influenced by the physisorption gas adsorption mechanism and electron transfer process. In the future, optimizing defect engineering could further enhance the sensor performance.Item Design and applications of multi-frequency programmable metamaterials for adaptive stealth(2025-08) Orasugh, JT; Mohanty, A; Malakar, A; Bose, S; Ray, Suprakas SMetamaterials (MMs) are precisely designed composites with electromagnetic properties not found in natural materials, emerging as a groundbreaking technology for advanced stealth applications. This review offers a thorough synthesis of recent advancements in MM design, highlighting their exceptional capability to manipulate electromagnetic waves across microwave, infrared, and visible spectral ranges. The core principles behind MM-enabled stealth, such as negative refractive index, cloaking, and wavefront shaping are explored, showcasing their effectiveness in significantly lowering radar cross-section and thermal signatures, thus improving concealment. A detailed evaluation of nanoscale synthesis techniques, using both inorganic and organic materials, underscores the crucial importance of precise structural control to achieve these sophisticated functionalities. This work provides a comprehensive analysis of MM applications within military and aerospace stealth contexts, while also addressing contemporary challenges related to scalability, cost-effectiveness, and environmental stability. Additionally, it presents a balanced evaluation of the technology's current maturity and its prospects for near-future deployment. Beyond strategic defense uses, the transformative potential of MMs in civilian fields like transportation and communication is examined, highlighting their extensive influence on the progress of next-generation technologies. This review outlines a clear path for future research, highlighting the crucial role of MMs in advancing electromagnetic control and stealth.Item Facial expression recognition using visible and IR by early fusion of deep learning with attention mechanism(2025-03) Naseem, MT; Lee, CS; Shahzad, T; Khan, MA; Abu-Mahfouz, Adnan MI; Ouahada, KFacial expression recognition (FER) has garnered significant attention due to advances in artificial intelligence, particularly in applications like driver monitoring, healthcare, and human-computer interaction, which benefit from deep learning techniques. The motivation of this research is to address the challenges of accurately recognizing emotions despite variations in expressions across emotions and similarities between different expressions. In this work, we propose an early fusion approach that combines features from visible and infrared modalities using publicly accessible VIRI and NVIE databases. Initially, we developed single-modality models for visible and infrared datasets by incorporating an attention mechanism into the ResNet-18 architecture. We then extended this to a multi-modal early fusion approach using the same modified ResNet-18 with attention, achieving superior accuracy through the combination of convolutional neural network (CNN) and transfer learning (TL). Our multi-modal approach attained 84.44% accuracy on the VIRI database and 85.20% on the natural visible and infrared facial expression (NVIE) database, outperforming previous methods. These results demonstrate that our single-modal and multi-modal approaches achieve state-of-the-art performance in FER.Item Applying the Deconstruction and Reuse Evaluation (DERUE) Tool to Evaluate the End-Of-Life Circularity Potential of Building(2025-04) Gibberd, Jeremy TConstruction and demolition generate large amounts of waste that is directed to landfills. This means the valuable resources and productive land are lost. As a result, there is an increasing interest in recovering materials and components from buildings that have reached the end of their useful life and reusing these in other buildings. There is, however, limited research and guidance in this area. This study aims to contribute to addressing this gap by developing and testing a methodology for the deconstruction of buildings and the reuse of components and materials. The study shows how a tool, referred to as the Deconstruction and Reuse (DERUE), is developed. The DERUE is presented and tested by applying this to a case study building. Results from the application of the DERUE are used to critically evaluate the tool and its value as means for supporting deconstruction and reuse. The results indicate that the DERUE is a useful tool for deconstruction planning, by providing reports that categorise and quantify materials and components in a building by type, condition, extractability, and reusability. DERUE reports enable the value of deconstruction to be more readily understood and can be used to encourage building owners, contractors, and municipalities to deconstruct buildings and reuse components instead of demolishing buildings and directing materials to landfills. The study recommends that the tool is developed and refined by applying it to a wide range of buildings.Item Evaluation of a photonic crystal-based biosensing platform for HIV viral load quantification(2025-08) Ombinda-Lemboumba, Saturnin; Manoto, SB; Maphanga, Charles P; Lugongolo, Masixolo Y; Tjale, Mabotse A; Mngwengwe, Luleka; Kasem, MA; Elfaham, MM; El-Hussein, A; Mthunzi-Kufa, PatienceAccurate quantification of HIV viral load (VL) is critical for monitoring antiretroviral therapy (ART) efficacy. Traditional VL testing methods are often expensive and require centralized laboratory infrastructure, limiting their accessibility in resource-constrained settings. In the current study, we present a photonic crystal (PhC)- based optical biosensor functionalized with anti-HIV-gp120 antibodies for the sensitive detection of HIV-1 pseudovirus. Characterization techniques, including dynamic light scattering, zeta potential analysis, UV–visible spectroscopy, and scanning electron microscopy, confirmed effective antibody-analyte interactions. Transmission spectroscopy revealed significant resonance wavelength shifts corresponding to varying viral titers. The proposed biosensor demonstrated reliable detection and quantification down to a concentration of 0.99 × 10 TCID 50 /ml (D3), with measurable resonance wavelength shifts clearly distinguishable from background signals. The detection limit was as low as 0.99 × 10 3 TCID 50 /ml. Validation with real-time quantitative PCR (rt- qPCR) demonstrated the biosensor’s sensitivity. These findings underscore the potential of the PhC-based biosensor as a rapid, accurate, and accessible platform for HIV VL monitoring, particularly in low-resource environments.Item Using a data observatory approach to support 4IR-enabled sustainable decarbonisation in South Africa(2025) Ford, Merryl; Kanjare, Julian SAs global industries pivot towards sustainability and decarbonisation, South Africa’s manufacturing sector faces significant challenges due to its reliance on fossil fuels and energy-intensive processes. Many small and medium-sized enterprises (SMEs) struggle to adopt emissions monitoring technologies, limiting compliance with international regulations like the EU’s Carbon Border Adjustment Mechanism (CBAM) and restricting access to export markets. This paper introduces a novel solution: a Greenhouse Gas (GHG) Data Observatory that leverages Fourth Industrial Revolution (4IR) technologies, including IoT sensors, artificial intelligence, and blockchain, to verifiably collect, store, and analyse GHG emissions data. A pilot project at a local foundry demonstrates the observatory’s potential to provide real-time, trusted data to ensure affordable compliance with international standards and national reporting requirements. By addressing sector-wide and national decarbonisation challenges, the observatory supports inclusive, sustainable industrial development while offering actionable recommendations for scaling its implementation across South Africa.Item Biobased Biodegradable Polybutylene Succinate Polymers and Composites: Synthesis, Structure Properties and Applications—A Review(2025) Makgwane, Peter R; Muniyasamy, Sudhakar; Hlekelele, Lerato; Swanepoel, Andri; Sypu, Venkata S; Mdlalose, Lindani M; Naidoo, Saloshee; Cele, Zamani; Maity, Arjun; Balogun, Mohammed O; Botlhoko, OJThe materialization of polybutylene succinate (PBS) belongs to the family of polyesters which are degradable and biodegradable, their biodegradability properties have attracted enormous interest for product development towards different polymer-based applications. Besides its biodegradability, PBS can be derived from petroleum and biobased monomers. At the same time, the latter is the driving factor for its growing interest in bioplastics for fully green and sustainable biobased-derived polymer products. The processes and techniques presented herein, are based on the production of biobased succinic acid monomer to PBS. However, the counterpart biobased monomer 1,4-butanediol (1,4-BDO) production has not been commercially demonstrated. This review discusses the progress in state-of-the-art developments in the synthesis strategies of PBS, its copolymers, and composites with the view to improve molecular weight, thermal, and mechanical properties. It further analyzes the different strategies to synthesize modified PBS polymer composites from organic and inorganic nanofillers to enhance their chemical, thermal, stability and mechanical structural properties. Importantly, the review highlights the progress in the applications of PBS copolymers and composites with tailored structure-designed properties for specific sectors such as packaging films, biomedical and drug release, fire retardants, and agricultural products. The structure-functional performance characteristics of these developments in the PBS, copolymers, and composites are highlighted to provide baseline insights for future developments in engineering the specific applications, and structural interface PBS composites with enhanced structure-functional performance properties.Item Fracture toughness of laser-based powder bed fusion produced Ti-6Al-4V(2025) Louw, Daniel F; Neaves, M; McDuling, Christoffel P; Becker, THThe rapid solidification and cooling rates, directional cooling, and the line-by-line, layer-by-layer consolidation inherent in laser-based powder bed fusion (LPBF) create unique microstructures, often leading to high strength but limited ductility and toughness. In load-bearing applications, where strength and toughness are critical, fracture toughness is a fundamental property and is pivotal in structural design. This study examines the relationship between these unique microstructural features, the LPBF process, post-processing heat treatments, and the fracture toughness of Ti-6Al-4V. First, elongated prior-β grains induce anisotropy in fracture toughness, which can be altered by heat treatment above the β-transus temperature. Second, a below β-transus temperature heat treatment that coarsens α laths improves fracture toughness due to a combination of lower yield strength and increased ductility. This increased ductility is attributed to a reduced strength difference between larger primary and smaller secondary and tertiary laths. Third, anisotropy in the rising J-R curve behaviour is linked to a dominant ∼45° lath orientation relative to the dominant ⟨001⟩ prior-β grain texture aligned with the build direction (Z-axis). Notably, a fracture toughness of 90 MPa, yield strength of 964 MPa, ultimate tensile strength of 1010 MPa, and 18 % elongation after the break is achieved, which compare favourably with the properties of the wrought counterpart.Item Global biodiversity framework for freshwater wetlands of South Africa: Preliminary calculation of progress towards achieving the restoration target of goal 2(2025-03) Van Deventer, Heidi; Durand, F; Grundling, PLThe National Biodiversity Assessment of 2018 listed wetlands (estuaries and freshwater ecosystems) as the most threatened ecosystem of South Africa. By 2030, South Africa must report to the United Nations’ Global Biodiversity Framework (GBF) to which degree we have reached Target 2 that aims to have 30% of the extent of degraded ecosystems under restoration. This study aimed to calculate the preliminary extent as a percentage of wetlands that have been under ecological restoration interventions, relative to the total extent of degraded freshwater wetlands of South Africa. We also assessed the percentage of extent relative to ownership of the degraded wetlands and those that are under ecological restoration. Data released by the Working for Wetlands and Working for Water programmes were combined with the National Wetland Map version 6 as well as information on land ownership and protection level status of the country. The majority of the freshwater wetlands (51%) were modelled as degraded, with > 2 million ha of the 4 million ha of wetlands showed impacts resulting from various pressures, including changes to the hydrological cycle, water quality, fragmentation and degradation of habitats, climate change, or a combination of these pressures. The 30% GBF Target 2 requires that almost 613 136 ha of freshwater wetlands should be under restoration by 2030. The government’s two restoration programmes have reached only 203 283 ha (10%) of the desired target. The majority (82,8%) of freshwater wetlands is located on private land, of which the majority is degraded. Many of the impacts and none of the restoration interventions undertaken by the private sector or individuals are refl ected. Monitoring and quantifi cation of all freshwater habitats are therefore needed to attain the 30% extent target of the GBF.Item The first-in-Africa ex vivo drug sensitivity testing platform identifies novel drug combinations for South African leukaemia patient cohort(2025-03) Kenmogne, VL; Takundwa, Mutsa M; Nweke, EE; Monchusi, Bernice A; Dube, Phumzile; Maher, H; Du Toit, J; Philip-Cherian, V; Fru, PN; Thimiri Govinda Raj, Deepak BIn South Africa, leukemia remains a major health concern, posing significant challenges in treatment due to its varied subtypes. There is an unmet need for a testing pipeline that can identify drug effects on patient samples in an ex-vivo setting. Using the pilot study with South African patient samples, this paper reports the development of a drug-sensitivity testing pipeline for studying the drug effects in leukemia patient-derived cells. Forty-one (41) patients with Acute myeloid leukemia (AML) (n = 7), Chronic myelogenous leukemia (CML) (n = 30), and Chronic lymphocytic leukemia (CLL) (n = 4) were recruited for this study. Thirty (30) FDA-approved drugs were utilized for single drug sensitivity screening (DSS) on leukemia patient-derived cells with drug concentrations (1–1000 nM). The single DSS showed a distinct sensitivity pattern with different profiles among patients of the same subtype, confirming the need for precision therapy. This study observed irinotecan, used in solid tumour treatment, demonstrated efficacy in PBMCs in many patient samples compared to conventional leukemia drugs such as nilotinib. For drug combination studies, ten clinically relevant drugs were selected and tested based on the results of single drug sensitivity tests. This pilot study marks a crucial stride towards revolutionizing leukemia treatment in South Africa through an innovative ex vivo drug sensitivity testing platform. This pioneering initiative forms the basis for tailored and effective treatment options holding promise for more personalized treatment. Further exploration and validation of these findings could significantly contribute to cancer precision medicine efforts in South Africa.Item Selection of a suitable wear-resistant metal matrix composite for remanufacturing continuous miner cutter (CMC) sleeves via a two-step laser-based technique(2025-09) Lindsay, EE; Akintunde, IB; Olakanmi, EO; Prasad, RVS; Botes, A; Pityana, Sisa L; Skhosane, Besabakhe SThe premature failure of continuous miner cutter (CMC) sleeves in underground coal mining necessitates remanufacturing to enable a closed-loop system and enhanced sustainable mining operations. However, a techno-economic analysis conducted revealed that exclusively using laser cladding (LC) to remanufacture failed sleeves is not economically viable. Thus, this research aims to explore a two-step laser-based remanufacturing technique that incorporates gas metal arc welding (GMAW) and LC, as well as identify suitable wear-resistant metal matrix composites (MMCs) for restoring damaged sleeves. Consequently, an LC process was used to deposit three MMC materials onto optimised GMAW overlays. A comparative analysis of the manufactured MMC coatings revealed that WC/TiC/AISI4340 coating exhibited a well-consolidated, crack- and pore-free microstructure and a superior microhardness of 931 HV0.5 compared to WC- and TiC-reinforced composites, which had average hardness values of 670 HV0.5 and 744 HV0.5, respectively. Additionally, the WC/TiC/AISI4340 coating demonstrated an excellent low wear rate (0.0007 g/s) comparable to TiC-reinforced coating, and a propensity to extend the sleeve’s lifespan by a factor of four. These enhancements are attributed to the formation of an umbrella-like network of TiC, predominantly distributed in the coating top region and solid solution strengthening [(Ti, W)C] caused by the partial dissolution of WC/TiC carbides and their precipitation into the eutectic carbide network within the interdendritic grain regions. Hence, combining GMAW and LC processes with WC/TiC/AISI4340 presents a promising remanufacturing strategy for restoring mining equipment, offering improved performance, longer lifespan, and economically viable and sustainable mining operations.Item Blue Carbon at the southern tip of Africa: Current knowledge and future perspectives for dynamic estuarine environments(2025-09) Adams, JB; Buttner, D; Hawkes, S; Human, LRD; Machite, A; Mfikili, AN; Ndhlovu, A; Smit, L-A; Van Deventer, Heidi; Van Niekerk, LaraBlue Carbon Ecosystems (BCEs), specifically salt marsh, seagrass, mangroves, occur in South Africa's relatively small, sheltered estuaries that are often disconnected from the ocean. These are dynamic environments where shifts between BCEs and other habitats along ecotones occur in response to mouth changes, floods and droughts, as well as anthropogenic pressures. Although Blue Carbon is becoming well established in South Africa, critical knowledge gaps remain; these are summarised under seven themes and future research and management actions identified. A holistic approach is recommended for Blue Carbon studies in estuaries to measure across elevation gradients (rather than focusing on individual vegetation types) and to include reeds, sedges and forested wetlands. Additionally, quantifying data deficient carbon stocks and processes, modelling future climate change impacts, instilling a sustainable long-term monitoring program, incorporating relevant emerging blue carbon stocks, realizing nationally inclusive restoration and protection co-management plans, and aligning local approaches with global frameworks of reporting are advocated as future recommendations with respect to South African BCEs. South Africa has high biodiversity and unique pressures influencing BCEs and is well positioned to inform the global research agenda. While the limited spatial extent of BCEs restricts the feasibility of carbon credit opportunities, high biodiversity values of these ecosystems hold potential under emerging ‘nature credit’ frameworks.