Cape Peninsula University of Technology
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Artificial intelligence-based forecasting models for integrated energy system management planning: an exploration of the prospects for South Africa
No full textThe regional energy demand for Southern Africa has been predicted to increase by ten to fourteen times between the years 2010 and 2070. Thus, to address the proliferation of energy demand, South Africa’s integrated resource plan, which includes using renewable energy sources to increase the electricity supply and reduce the country’s carbon footprint, has been formulated. However, integrating renewable power into the power grid brings different dynamics for the system operators, as renewable power sources are variable and uncertain. Thus, accurate demand and generation forecasting become critical to the safe operation and ensuring continuity of supply, as consumers require. Due to the complexity of the earth’s atmosphere, weather forecasting uncertainty, and region-specific criteria, traditional forecasting models are limited. Thus, Machine Learning, Deep Learning, and other artificial intelligence techniques are attractive possibilities for improving classical forecasting models. This study comprehensively reviewed relevant works on AI-based models for generation potential and load demand forecasting toward intelligent energy resource management and planning. The approach involved searching research databases and other sources for studies, reports, and publications on location-specific energy resource management using criteria such as demography, policy, and sociotechnical information. Consequently, the review study has highlighted how AI predictive analytics can enhance long-term energy resource potential and load forecasting toward improving electricity sector performance and promoting integrated energy system management implementation in South Africa
Enhancing and comparing shrinkage prediction models for High-Strength Concrete with and without admixtures
No full textThis study aimed to improve and compare the parameterization of three prominent shrinkage prediction models—RILEM B4, MC 2010, and WITS—tailored specifically for High-Strength Concrete (HSC), both with and without the inclusion of admixtures. The dataset used for refining model parameters consisted of 220 experiments related to drying shrinkage and 342 experiments concerning autogenous shrinkage. Model performance evaluation involved various statistical metrics applied to the entire HSC dataset, subdatasets, and distinct time periods of shrinkage (0–99 days, 100–199 days, 200–499 days, and ≥500 days). The statistical indicators included Root Mean Square Error (RMSE), R-squared adjusted (R2adj), Akaike’s Information Criterion (AIC), and the overall coefficient of variation (C.o.Vall). Modified models exhibited significantly improved predictions compared to the original models, with most predictions falling within ±20% of the measured shrinkages. For HSC drying shrinkage, the original model accuracy ranked as WITS, RILEM B4, and MC 2010. However, after parameter adjustments, WITS, MC 2010, and RILEM B4 were the best-performing models. Conversely, for HSC autogenous shrinkage predictions, the RILEM B4 model surpassed the MC 2010 model, demonstrating superior accuracy and reliability in forecasting this specific type of shrinkage behaviour within High-Strength Concrete
Phenolic compounds occurrence and human health risk assessment in potable and treated waters in Western Cape, South Africa
No full textPhenolic pollutants from industrial and agricultural activities pose a major threat to the world’s potable water supply. The persistent micro-pollutants often find their way into drinking water sources with possible adverse human health implications. In this study, bottled water, tap water, and wastewater treatment plant (WWTP) effluent samples from the Boland region of the Western Cape, South Africa were assessed to determine 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) levels using HPLC/DAD instrumentation. The selected area is known for its vast agricultural ventures and wineries. Evaluation of the human health risk (cancer risk) for the pollutants was conducted using the hazard quotient (HQ). The Ames mutagenicity test was also conducted using the Salmonella typhimurium T98 and T100 strains and the S9 activation enzyme. Trace levels of the phenolics were detected in the samples with a range of 9.32 × 10−7—1.15 × 10−4 mg/L obtained for 4-CP, and 8.80 × 10−7—1.72 × 10−4 mg/L recorded for 2,4-DCP. Both compounds had levels below the limit of 0.01 mg/L prescribed by South African legislation. The assessed HQ for the phenolic concentrations indicates a low level of potential ecological risk and none of the samples had a cancer risk value that exceeded the regulatory limit. The possibility of the analyzed samples causing cancer is unlikely, but non-carcinogenic adverse effects were found. Strong mutagenicity was observed for the T98 strains with a potential ability to cause mutation toward the insertion or deletion of a nucleotide. The T100 bacterial strain showed very slight mutagenicity potential, however, it is unlikely to cause any mutation. The levels of phenolics in the potable water samples may pose a significant threat to human health. Hence, screening persistent organic chemicals in potable water sources and evaluating their potential human health effects is pertinent to prevent associated health challenges
Analysis and systematic literature review on energy harvesting from roads
No full textAs the global warming crisis escalates, the demand for greener energy production methods becomes increasingly urgent and important. Energy harvesting has emerged as a key area of interest for researchers seeking innovative solutions. The goal is to eventually replace fossil fuels with renewable energy sources, which are non-renewable and the primary contributors to global warming. In this study, an analysis and systematic literature review are conducted on studies that presented ways of efficiently harvesting energy from roads. This study will focus on three energy harvesting techniques (Thermoelectric, Piezoelectric, and Electromagnetic) and propose future research directions in energy harvesting from roads, including exploring new materials and technologies. The study will also suggest novel solutions to issues relating to energy harvesting from roads, such as improving the construction and installation of energy-harvesting systems and creating innovative materials and cost-cutting methods
Structuralisation of the practice of enterprise architecture in organizations
No full textDespite the immense growing popularity of enterprise architecture (EA), the practice remains excruciatingly challenging. This study explores the challenges from an impelling standpoint, which is to gain a deeper understanding of the factors that influence decision-making in enabling the practice of EA in organizations. This helps to comprehend why EA practice is increasingly difficult in many organizations, as it affects the realization of its benefits. The document analysis technique was employed in gathering existing literature. The structuration theory (ST) was applied as a lens, to view the materials, from which three fundamental factors, Institutional articulation, Rigidity, and Instantiation were revealed. The originality of the factors makes them useful, reduces constraints and guides the formulation of policies and governance for EA practice in an organization
Cultivating critical thinking, social justice awareness and empathy among pre-service teachers through online discussions on global citizenship education
No full textThere is a paucity of research on the efficacy of online asynchronous discussion forums in fostering critical thinking, social justice awareness and empathy in pre-service teachers. This study adopted a case study design rooted in the social constructivist/interpretive paradigm. South African university pre-service teachers comprised the study’s sample. To examine how online discussions about Global Citizenship Education (GCE) affected the critical thinking and social justice awareness of a group of pre-service teachers (n = 31), a questionnaire based on Andreotti’s (2006) Soft vs Critical GCE framework was used. To further understand how their involvement in online discussions on global issues influenced their sense of social justice awareness, empathy and critical thinking, certain pre-service teachers’ (n = 9) reflective essays were used. The findings revealed that pre-service teachers’ responses were more consistent with the soft GCE approach. The Soft vs Critical GCE framework was useful for identifying which aspects of online interactions require a more critical understanding of GCE. The findings showed that pre-service teachers who participated in the online GCE conversations had increased social justice awareness, critical thinking skills and empathy
The effect of a walking, dancing, and strength training program on the functional fitness of adults with intellectual disability: a randomised controlled trial
No full textBackground:
Many adults with intellectual disabilities live a sedentary lifestyle, have low levels of functional fitness and are overweight. The purpose of this study was to determine whether an exercise intervention with activities which are simple, fun, accessible and adapted for socialising in a group would elicit significant improvements in various parameters associated with functional fitness for adults with intellectual disabilities.
Methods:
Forty-two adults with intellectual disability (44.5 ± 11.5 years) were randomly located to an exercise group (n = 19) and a control group (n = 23). The program consisted of walking, dancing, and resistance training exercises and was implemented, three times a week for 6 weeks.
Results:
Significant ameliorations (p < 0.05) were reported for body mass, hip circumference, aerobic capacity, functional ability, muscular strength, balance, and flexibility with varying degrees of effect sizes.
Conclusions:
The combined exercise training program showed a significant positive impact on various parameters associated with functional fitness for adults with intellectual disability
Evaluating the relationship between accounting variables, value-based management variables, and shareholder returns: an empirical approach
No full textThis study assessed the accounting-based variables and value-based management (VBM) variables that jointly affect firm value and performance. The study applied the causality test and variance decomposition to determine the variability of the variables, and further empirically employed fully modified ordinary least squares (FMOLS) and dynamic ordinary least squares (DOLS) techniques to justify the results. Data covering 356 industries were purposively sampled to arrive at 61 companies spanning 2011–2020. Overall, the causality test found no relationship between economic value added and market value added but only found unidirectional causality from shareholder returns to MVA, EVA to shareholder returns, ROA to MVA, ROE to MVA, EVA to MVA, MVA to EVA, ROE to ROA, EVA to ROA, and EVA to ROE. A very strong bidirectional causality relationship was found between return on asset and shareholder return as a measure of company performance. Further results from the forecast error of the variance decomposition showed that shareholder returns are explained only by its own shock, contributing 45.38 percent in the long run, while the remaining variables, namely market value added, return on asset, return on equity, and economic value added, contribute about 35.96%, 14.06%, 4.08%, and 0.51%, respectively, to predicting the future values of shareholder return. This confirms the relationships between the variables from the short run to the long run. Additionally, results from the FMOL and DOL revealed that all accounting variables and VBM are good approaches for evaluating company performance as the empirical result from ROA, ROE, and EVA revealed positive and significant relationships. This confirms that a combination of both variables would produce a better evaluation as the accounting variables and VBM variables jointly relate to shareholder returns. This study serves as a guide to companies’ management and boards of directors in having better ways to evaluate company performance. Consequently, it is recommended that managers select combinations of accounting and VBM variables that suit their operations and jointly apply them in the performance evaluation of the company. This will be useful in providing both the relative and incremental performance information needed for diverse decision-making
Evaluation of selected operating process variables for a bioflocculant supported column flotation system
No full textThe poultry industry generates significant volumes of slaughterhouse wastewater, laden with numerous pollutants, thus requiring pretreatment prior to discharge. However, new technologies must be used to re-engineer the existing wastewater treatment equipment and incorporate new designs to improve the treatment processes or system performance. In this study, three variables, i.e., diffuser design, bioflocculant form, and flow rate, were evaluated to determine their effect on the performance of a bioflocculant-supported column flotation (BioCF) system. It was found that bioflocculants influenced diffuser performance with limited impact when the feed flow rate was varied, i.e., 3D-printed air diffusers and cell-free flocculants imparted high BioCF performance when compared to moulded diffusers and cell-bound flocculants. Notably, the combination of 3D-printed air diffusers and cell-free flocculants resulted in relatively high pollutant removal (81.23% COD, 94.44% TSS, 97.77% protein, and 90.38% turbidity reduction). The study lays a foundation for exploring 3D-printed air diffusers, a relatively new technology in conjunction with microbial flocculants usage that are regarded as eco-friendly for application in industry to enhance the performance of column flotation systems
Assessing the Spatio-temporal variation of water quality over time at Malelane area in the lower catchment of the Crocodile River, Mpumalanga, South Africa
No full textFreshwater is a limited resource experiencing accelerated contamination in several nations due to various reasons, including both natural and human-induced influences such as climate, topography, mining, industry, and agriculture. South Africa is characterized by water scarcity, a condition exacerbated by its status as a developing nation. Consequently, the country has the dual task of safeguarding water quality while simultaneously striving to enhance water supply and sanitation infrastructure. This study aims to assess the impact of agricultural activities on the water quality of the Crocodile River by using physiochemical tests and a water quality index tool. The grab sampling methodology was utilized on-site to collect water quality parameters which were analysed at a SANAS (South African National Accreditation System) laboratory. Statistical analysis was performed using the Seaborn software due to the extensive dataset contained in the present study. Highest concentrations of NO2+NO3 were recorded in the Autumn season between 2020 and 2022 with levels ranging between 1,2 to 0.7 mg/l. While spring and summer of 2018 and 2019 recorded the lowest concentration of NO2+NO3 at <0.4 mg/L, the low concentrations could be due to the dilution of the summer rainfalls as compared to the high concentrations that were recorded in the drier season of the year leading into winter. This could also explain significant concentration of PO4 (0.35 mg/L) that were recorded during the winter of 2016. The findings indicate that throughout the autumn of 2017 and spring of 2019, the reported ammonia nitrate concentration exceeded 0.225mg/L. The WQI results revealed that the water quality at Malelane is regular at a value of 62.18, which suggests that the quality of the water is average to below standard