This study provides a thorough approach for fault detection and classification in a 200 kW gridconnected photovoltaic (PV) system using Long Short-Term Memory (LSTM) neural networks. As PV systems and other renewable energy sources are being included into modern power networks, stability and reliability must be maintained. One of the biggest problems is recognizing and classifying short-circuit failures, which can result in serious damage and downtime if ignored. Conventional fault detection techniques frequently fall short in addressing their limitations in practical settings due to their inability to adjust to a variety of fault types and system dynamics. Traditional methods struggle with detection accuracy because system dynamics and fault types vary greatly. LSTM networks, which are great at managing timeseries data and detecting temporal relationships in electrical signals, are used in the proposed method. By analysing voltage and current waveforms, the LSTM model effectively detects and classifies a wide variety of short-circuit fault types, including single-line-to-ground, line-to-line, and three-phase faults. The grid-connected PV system is simulated using Python, and synthetic fault data is generated for the training and validation of the LSTM network. By creating a solid dataset with a variety of fault scenarios, this study also fills an empirical gap and allows for a more thorough assessment of the model's performance. The model is trained on a large dataset that includes both usual operating conditions and different fault scenarios. Data augmentation approaches, like the Synthetic Minority Over-Sampling Technique (SMOTE), are also utilized to address the imbalance in the fault data so that the model can accurately categorize less prevalent problem types. The effectiveness of the LSTM-based fault detection and classification system is evaluated using confusion matrix measurements and receiver over the curve (ROC). The simulation's results demonstrate that the LSTM model outperforms conventional techniques in terms of accuracy, defect detection rates, and response times. In contrast to MATLAB, which offered configured blocks that were typically set to predict the best performance and did not permit investigation because poor results scenarios could not be evaluated and upgraded as the study that was conducted, Python allowed for a great understanding of the development of a deep learning model.

Sauvignon blanc (Vitis vinifera), one of the most extensively cultivated white wine grape varieties globally, is renowned for producing wines with characteristic “grassy” and “tropical” varietal aromas. These aromas result from aroma compounds, such as methoxypyrazines and varietal thiols, present in the grape skin and pulp, the latter being released by yeast during the alcoholic fermentation process. Similarly, Chenin blanc, another popular white wine cultivar that shares a genetic origin with Sauvignon blanc (both originating from Savagnin blanc or Traminer), was also shown to possess varietal thiols. Several anthropogenic factors have been investigated to increase varietal aroma compounds, specifically the varietal thiols; however, the reported results varied. Alternative technologies, such as low-temperatures and cryogenic pre-treatment, have been researched and shown promise. Additionally, the impact of harvesting technique (hand versus machine-harvested) has been researched, reporting that grape juice and wines from mechanically harvested grapes had higher levels of varietal thiol precursors and varietal thiols in the final wines. Therefore, this research aimed to investigate the effect of pre-fermentative cryogenic freezing (-20 ºC and -4 ºC) at four production stages (whole grapes [WG], macerated grapes [MG], turbid must [TM] and clear juice [CJ]), immediately (T0) and for a four-month (T4) storage period on the standard physicochemical properties, varietal aroma compounds (volatile thiols and methoxypyrazines) and the sensory profiles of two popular South African (SA) white wine varieties (Sauvignon blanc and Chenin blanc). Following complete defrosting, a standard white winemaking protocol was followed. The control wines were not subjected to any cryogenic treatments. Subsequently, all grape musts were analysed for physicochemical properties, and wines were analysed for physicochemical properties, varietal aroma compounds, and sensory properties. Physicochemical parameters in the grape must were generally unaffected by the cryogenic pre-treatments (total sugar, glucose/fructose ratio, and total soluble solids), except for the pH (higher in cryogenically pre-treated grape must) and total acidity (TA) (lower in cryogenically pre-treated grape must) when compared to the unfrozen control. Furthermore, the yeast assimilable nitrogen (YAN) was higher in the unfrozen control and cryogenically pre-treated grape must for all Producers in 2020 compared to 2021, suggesting that the differences were vintage-related. The physicochemical parameters of the final wines were generally within the legal limits for SA white wines, except for pH, which was slightly higher (> 3.4) in the wines made from the cryogenic pre-treatments. The concentrations of the varietal thiol, 3-sulfanylhexyl acetate (3-SHA), detected in the Sauvignon blanc wines exceeded the aroma perception threshold (4 ng L -1 ) and the reported range for SA Sauvignon blanc wines (23-151 ng L -1 ), whilst the concentrations of 3-sulfanylhexan-1-ol (3-SH) were generally within the aroma perception threshold (60 ng L-1 ) and reported range (178-904 ng L-1 ). Moreover, the concentrations of 4-methyl-4-sulfanylpentan-2-one (4-MSP) were found to be below the aroma perception threshold (0.8 ng L -1 ) and the typically reported range (0-21.9 ng L -1 ). For the Chenin blanc wines, the concentrations of 3-SHA were found to be higher than the typical reported range for SA Chenin blanc (5-253 ng L-1 ) and above the aroma perception threshold (4 ng L -1 ), whilst the concentration of 3-SH were generally below its reported range (99-1124 ng L -1 ) and aroma perception threshold (60 ng L -1 ). Furthermore, the concentrations of 4-MSP were detected above the reported range, not detected (n.d.), but below the aroma perception threshold (0.8 ng L -1 ). Methoxypyrazines were detected at concentrations above the reported aroma perception threshold (2-16 ng L-1 ) and range for 3-isobutyl-2-methoxypyrazine (ibMP) (2-30 ng L -1 ) and 2-methoxy-3-sec-butylpyrazine (sbMP) (< 10 g L -1 ) in Sauvignon blanc wines, for most cryogenic treatments compared to the control wines. Differences were also observed between producers from different regions and between vintages (2020 and 2021), with overall methoxypyrazine levels higher in 2021. Moreover, from a sensory perspective, the wines made from WG and MG subjected to cryogenic pre-treatment technologies yielded wines with higher tropical, thiol-type, pineapple and banana aromas as well as higher body, general quality and overall intensity when compared to most wines made from the control grapes as well as the remaining cryogenic treatments. This study highlighted that the production stage at which the cryogenic treatment was applied had the most prominent effect, whilst the effects of the cryogenic temperatures and storage times were negligible. Furthermore, vintage and regional differences also influenced the final wine sensory profiles. Differences in varietal thiol concentrations for Sauvignon blanc wines resulted mainly from wine region and vintage for the T4 wines made from cryogenically pre-treated WG and MG (-4 ºC). Although no definite trends were observed in terms of which cryogenic temperature, stage of production, or storage time yielded the most favourable levels in final wines, indications are that the region from which the grapes originated, the harvesting method, and the vintage contributed the most. Therefore, the industry recommendation would be to apply cryogenic pre-fermentative treatments to WG or MG at -4 ºC (energy efficient) for T0 (more economical), considering the region and vintage to achieve the desired outcome.

Title: Salvage of red blood cell units containing haemolysis by a cell wash process in George Blood Bank Background: Premature haemolysis in red blood cell (RBC) units received at the George blood bank became problematic. A saline wash method was successfully utilized in other countries to restore red blood cell (RBC) units containing haemolysis, to remove waste products of haemolysis. This saline wash method has not been used in South Africa. Methods The content of the quad bags, used for blood donation, was investigated to determine the cause of premature haemolysis. The volume of the saline, adenine, glucose and mannitol (SAGM) preservatives as well as the citrate, phosphate and dextrose (CPD) anticoagulants were verified to investigate the compliance with the package insert. The haematological autoanalyzer was used to develop a colour chart to be used with the HemoCue at George blood bank to select premature haemolysed RBC units received at the George blood bank.. The RBC units were divided into five groups: a control group which were not haemolysed nor washed (NHNW), non-haemolysed units which were washed and reconstituted in saline (NHWSI), non-haemolysed units washed in saline and reconstituted in SAGM (NHWSGM), haemolysed units washed and reconstituted in saline (HWSI) and haemolysed units washed in saline and reconstituted in SAGM (HWSGM). These units were stored in accordance with WCBS storage guidelines for a period of two weeks. All five groups were initially subjected to a full blood count (FBC) and their haemoglobin, RBC count, haematocrit, mean corpuscular volume, mean molecular haemoglobin, mean corpuscular haemoglobin concentration, white blood cell count, platelet count, RBC distribution width-standard deviation and RBC distribution width - coefficient of variation (RDW-CV) were determined as well as one and two weeks subsequently. Results: The quad bags had inconsistent CPD volumes and were not compliant to the package inserts, whereas the SAGM volumes were compliant. The FBC results at the initial stage as well as after one and two weeks showed that the waste products of haemolysis could be removed and that the RBC remained undamaged, and retained their shape and size. The research question was answered, more cells were lost in the cell wash process for units with premature haemolysis present. About 24% of red blood cells were lost, were in red blood cell units with no haemolysis present the cells in literature is estimated at 20%. The SAGM preserved the cells better than the 0.9% Saline, we only had one outlier that stated differently. Conclusion: Inconsistent anticoagulant levels in the quad bags impacted on the premature haemolysis in the red blood cell units received at the George blood bank. Premature haemolysis is an ongoing challenge, and the colour chart could be useful for visual inspection of haemolysis of the RBC units. This study showed that the washing of premature haemolysis in red blood cell units is viably even when stored for up to 14 days.

The increasing resistance to conventional antibiotics and urgent need for alternative immunomodulatory therapies have driven growing interest in plant derived bioactive compounds. Medicinal plants have historically been a rich source of bioactive compounds with diverse pharmacological properties, yet a large number of species remain unexplored for their therapeutic potential. Among these, Cotyledon orbiculata has shown promising traditional uses, suggesting the presence of biologically active constituents. However, scientific validation of their antimicrobial and immunomodulatory properties remains limited. This study aimed to investigate the antimicrobial activity and immunomodulatory effects of solvent-derived fractions from Cotyledon orbiculata plant leaves. Water and methanol extracts were prepared and then fractionated. After fractionation, all fractions were spotted on TLC plates to either pool together as a combined sample or kept individually. Separation was based on observed visual TLC profiles. The water extract yielded 32 fractions whereas the methanol extract yielded 46 fractions which were collected in glass vials. The resulting fractions were evaluated for antimicrobial efficacy against a panel of microorganisms namely, Staphylococcus aureus, Staphylococcus epidermidis, Methicillin Resistant Staphylococcus aureus, and Pseudomonas aeruginosa using standardized microbiological assays. The selected fractions showed notable antimicrobial activity, and the immunomodulatory effects were assessed through cytokine profiling.

The thesis explores the role that the learning area, EMS, plays in preparing learners for Accounting in grade 10. EMS in grade 9 includes accounting related assessment standards upon which the grade 10 Accounting curriculum builds. The grade 10 Accounting curriculum is based on the assumption that learners have mastered the related content in grade 9. The effective implementation of EMS in grade 9 is therefore important for the teaching and learning of Accounting in grade 10. The main objective of the study was to determine to what extent the accounting related assessment standards were taught and to engage with the key factors that impact on the effective delivery of the accounting focus in EMS. A sample of five schools within a specific geographical area in the Western Cape was identified. The study used multiple data collection methods in order to increase the validity of the results, namely, a learner assessment, interviews and document analysis. The planning and assessment documents of EMS teachers as well as the assessment tasks of the EMS learners were analysed to ascertain how teachers planned to teach and assess the learning area, particularly the accounting focus within EMS. The conclusions were drawn against the policy-practice theoretical framework. The study revealed a gap between EMS policy and EMS practice. There was very limited exposure to the accounting related assessment standards in EMS. This could be attributed to a number of factors including teacher qualifications and training, lack of support, policy shortcomings, absent guidelines, etc. There was a disjuncture between what teachers believed and what they were translating into practice. Even though all the teachers enjoyed teaching Accounting and most of them believed in the importance of this discipline in preparing learners for the Further Education and Training Band and their personal lives, they were not teaching it effectively. Recommendations have been made in terms of the learning area policy, professional development and support for teachers and learners. Even though the study was limited to five schools in a particular geographical area, its findings may be applicable to many South African schools where EMS teachers face the same policy, teacher and learner challenges or shortcomings.

This research explores design-build projects in architectural education. The design-build studio is an alternative to the conventional theory-oriented studio. In design-build projects students both design and build real buildings. Internationally, design-build projects have increased rapidly in architectural programmes over the past decade. Literature suggests that design-build projects are relevant for architectural education, but that there is a definite need for more theoretical and critical exploration. Design-build projects in the context of this study are defined as socially responsive, inhabitable, full-scale investigations. The value of this pedagogical construct for educators, students, architectural practice and society in general was an underpinning theme guiding this exploration. Design-build projects are located on the boundary between theory and practice. This research provides a view into my journey across this boundary, immersing myself in both the theoretical and practical. Principles of the designbuild process and design research mapped the research path. The research process commenced with the initiation of and active participation in a number of design-build constructions. Through critical reflection on the construction experiences and the literature, specific pedagogical and practice implications were explored. Cultural historical activity theory provided me with a sense of theoretical direction in this journey. Collaboration as a pedagogical tool and the possibility of exposing students to alternative practice possibilities were foregrounded as being uniquely situated within the design-build project. The value of this research is the contribution it makes to the current international call for a clearer understanding of the pedagogical and practice merit of design-build projects.

Stable and reliable source of electrical energy is a requirement for efficient operation of satellites. Several sources of electrical power for satellites exist such as fuel cells, nuclear or battery stored Direct Current energy but of late concentration has been on solar cells as the advantages compared to the other sources are many. Solar cells are p-n semiconductor devices which convert light energy into electrical energy by photovoltaic effect. The biggest drawback of solar cell energy system is the low light to electricity conversion efficiency. Apart from powering satellites, solar cells and panels have found other numerous applications such as in water pumping systems, rural electrification, street lightning. Photovoltaic principle of solar cells started way back in 1839 when Alexandre Edmund Becquerel observed that electrical currents arose from certain light induced chemical reactions. A comprehensive understanding of this phenomenon became clear when the science of quantum theory was unveiled in the early parts of the 20th century. Most solar cells and panels available today in the market are silicon based made of single junction technology. The disadvantage with single junction technology is that the p-n junction is made of a single type of solar cell material which absorbs a fraction of light wavelengths from the spectrum of light. The disability of the single p-n junction to convert all the light energy to electricity accounts for the low efficiency for the solar cells. One way to go around the problem of efficiency is to use multi-junction solar cells. Multijunction solar cells are designed to absorb a large fraction of the light spectrum and convert them to electrical energy. They are made of multiple p-n junctions made of different solar cell materials which absorb different parts of light spectrum and convert them to electrical energy. In this thesis, a design of a multi-junction solar cell for developing space solar panel is presented. The multi-junction cell has been designed from simulation results of different solar cell materials simulated with space conditions. Ideas and recommendations for future work are also presented.

Current insights into the South African education crisis suggest that emphasis needs to be placed on developing teachers’ mathematical knowledge for teaching (MKfT) through ongoing professional development. Aiming to provide insight into teacher professional development, this research describes an initiative undertaken by a group of Mathematics teachers who formed a Community of Practice at their school. Through the implementation of Habits of Mind that promotes Relational Understanding, these teachers attempt to improve the teaching and learning of Mathematics at their school, and further their professional development. A qualitative phenomenological design of inquiry was conducted to describe the teachers’ experiences when implementing Habits of Mind in their teaching. Group interviews, individual interviews and documentary sources were used to gain a rich description of the lived experiences of these teachers during the research period. To analyse the data a combination of Giorgi’s phenomenological model and the interconnected model of professional growth was used. Results indicate three insights into teacher professional development: (1) Communities of Practice promote the sharing and development of MKfT though the mechanism of collaboration; (2) Teachers are challenged when implementing intervention strategies as firstly their learners are challenged in their literacy ability which limits their articulation in Mathematics lessons, and secondly they are faced with time constraints imposed by workload demands; (3) The attempt to implement intervention strategies within a Community of Practice, despite being challenging, encourages reflective practice which informs individuals’ professional practice and supports ongoing professional development.

Met hierdie studie word daar gepoog om omgewingsgesondheid, soos dit op plaaslike owerheidsvlak in Suid-Afrika manifesteer, te fundeer. In hierdie poging tot fundering van omgewingsgesondheid word daar spesifiek na omgewingsgesondheidsbeamptes se betrokkenheid by omgewingsgesondheidsdienslewering verwys. ampte1ik as Gesondword die benaming deur die benaming omgewingsgesondheidsbeamptes staan tans heidsinspekteurs bekend, daarenteen I Gesondheidsinspekteur , progressief 'Omgewingsgesondheidsbeampte' vervang. Die funksionele werksveld van omgewingsgesondheidsbeamptes bestaan uit omgewingsaangeleenthede (nie-persoonlike gesondheid) en behels aangeleenthede soos drinkwatersuiwering, waterbesoedelingsbeheer, die suiwering van afloopwater, sanitasie, afvalbeheer (vaste, vloeibare en toksiese afval), voedselhigiene, vleishigiene, omgewingsaspekte ten opsigte van aansteeklike siektes, boukunde, behuising, die daarstel van 'n sosiale omgewing, berdryfshigiene, bedryfsveiligheid, stralingsbeheer, omgewingsgeraasbeheer, termiese besoedelingsbeheer en lugbesoedelingsbeheer. Buiten oorerflikheidsfaktore, kan mens like siektes deur middel van 'n effektiewe omgewingsgerigte diens voorkom word. nit is wenslik om te voorkom dat iemand siek word eerder as om 'n siek persoon te genees. nit is verder irrasioneel om 'n persoon wat genees is, weer in dieselfde omgewing terug te plaas wat homjhaar aanvanklik siek gemaak het.

The primary objective of the current study was to conduct a survey on the job satisfaction of line managers in the City of Windhoek (CoW) Municipality. The identifying of such variables could empower the CoW Municipality to develop programmes and policies that are designed to improve their job satisfaction levels. The literature review confirmed the impact of motivation on the job satisfaction of employees, and, in turn, its impact on employee productivity, and, ultimately, on organisational performance. The level of job satisfaction experienced by an individual describes how content he or she is with his or her job. The purpose of this study was to measure the job satisfaction facets (supervision, relationship with co-workers, present pay notch, nature of work, and opportunities for promotion) among line managers in the CoW, and how such facets affected their overall job satisfaction. The non-probability sampling technique was adopted to collect data from 102 respondents from nine different departments by means of a structured questionnaire, resulting in a response rate of (N = 76), 75%. The study was, however, limited to the line managers in the CoW Municipality. Following on which the Cronbach’s alpha coefficient was used to determine the internal consistency or average correlation of items in the survey instrument. The Spearman’s rank correlation coefficient (Spearman’s rho) analysis was used to analyse the data with the aid of the Statistical Package for the Social Sciences (SPSS), version 16. In addition, the independent-samples t-test and the analysis of variance (ANOVA) were employed to empirically test the relationships between the employees’ job satisfaction and their gender and age. The findings showed a significant linear relationship between the existing levels of job satisfaction and job performance. Furthermore, the findings suggested that the employees were significantly satisfied with certain aspects of their jobs (the nature of the work, and their salary, supervision and co-workers), but not with the one aspect of their job (opportunity for promotion). They were, however, significantly satisfied with their jobs in general, with there being no significant difference between the male and female employees’ levels of job satisfaction. The analysis showed that promotion has a modest and positive effect on job satisfaction. The study concluded that the line managers were, in general, satisfied with their jobs. Thus, the results cannot be generalised to other departments and Local Authorities. The study needs to be replicated in other departments and Local Authorities, using the same method.

This study is aimed at determining whether the potential exists for further developing cultural and heritage tourism activities in the redeveloping District Six. A rich and diverse cultural heritage provides the basis from which the study examines whether the implementation of a cultural heritage tourism plan in the redeveloping area, is appropriate, will help address issues of restitution and ultimately contribute to the country’s cultural heritage tourism assets. Currently no formal tourism plan for District Six exists. A historical study provides an assessment of the areas’ cultural heritage assets, manifested in politics, music and dance, art, literature, and architecture. A search of existing cultural and heritage tourism literature was conducted in order to gain insight into the descriptive, theoretical and conceptual research questions identified. Relevant development policies and frameworks impacting and supporting potential tourism development in the area were examined. These include the DFD6 (2011) and the National Heritage Tourism Strategy (2012). Creative tourism was further examined as a tool to augment the tourism product and positively contribute to cultural regeneration. Business and functional linkages to assist the integration of District Six tourism into the broader economy were then identified. A comparative analysis of the introduction of a cultural heritage tourism plan in Genadendal is made. This area experienced similar socio- political and historical conditions as District Six. Thus, parallels of the potential challenges were drawn and opportunities identified. A theoretical model for cultural heritage tourism in District Six is then presented by identifying and explaining elements of model theory, discussing models applicable to the research area and adapting a normative framework for cultural heritage tourism on the Cape Flats. The model recommends solutions to problems such as a lack of capacity and skills, funding and investment, public participation and stakeholder engagement. Furthermore, an empirical survey in the form of in-depth interviews was administered to seventeen relevant academics, heritage and tourism practitioners, resident representatives and development consultants. The methodology included extracting qualitative data through transcribing interviews and thematically presenting and analysing the data. Finally, a list of recommendations is provided.

Poverty and a lack of parental involvement have a dual negative effect on the academic performance of learners with learning disabilities, and are prevalent in rural areas. While parental involvement in schools in impoverished rural communities is very low, research also indicates parental involvement is key in addressing barriers to learning and associated learning disabilities. This study sought to explore the nature and extent of parental involvement of learners with learning disabilities at schools in impoverished rural communities. The study targeted a specific impoverished rural community in the Western Cape where the combination of learning disability and a lack of parental involvement negatively affects the literacy and numeracy skills, resulting in learning outputs that are below standard. The study drew on Epstein’s theory of parental involvement. Thematic data analysis was used in employing a constant comparative method. By applying Epstein’s model, this study not only contributes to understanding the nature and dynamics of parental involvement in impoverished rural schools as well as factors contributing towards the improvement of parental involvement; it also contributes towards an understanding of Epstein by applying her model to a rural setting.