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Advances in Optimizing Mechanical Performance of 3D-Printed Polymer Composites: A Microstructural and Processing Enhancements Review
Get PDFArticle, Faculty of Natural and Agricultural Sciences (Material Science Innovation and Modelling (MaSIM)--Northwest University, Mahikeng CampusThis review investigates the recent advancements aimed at optimizing the mechanical performance of three-dimensional (3D)-printed polymer matrix composites (PMCs), motivated by the need to overcome the inherent limitations of additive manufacturing (AM) in achieving desired mechanical properties. The study focuses on two primary areas: (1) microstructural refinements through strategic control of parameters such as reinforcement type, size, orientation, and interfacial properties and (2) processing enhancements involving the modification of build parameters, material formulations, and posttreatments. The review systematically analyzes the interdependencies between microstructure property relationships and processing-performance characteristics. Key findings include an improvement of up to 50% in strength and toughness through optimized microstructure and printing techniques, which are compared with results from other studies that reported a maximum of 30%–40% improvement under similar conditions. The review also highlights the successful application of these approaches in various case studies, demonstrating their potential to substantially enhance the dimensional control and functional properties of 3D-printed PMCs, making them suitable for diverse applications ranging from aerospace components to flexible sensors. Despite these advancements, challenges such as performance consistency, part quality, and scalability remain, emphasizing the need for continued research to fully exploit the potential of 3D-printed PMCs
Promoting youths’ skills acquisition through experiential learning theory in vocational education and training in South Africa
Get PDFJournal Article. Faculty of Education, Education and Human Rights in Diversity, North-West University, MafikengPurpose: There is a global concern about the effectiveness of vocational education and training (VET) programmes in developing job-related skills and competencies for real-world environments for disadvantaged and unemployed youths. Experiential learning (EL) is a major component of VET programmes. This article aims to examine the effects of facilitating VET through EL theory to promote youths' skills acquisition. The study looks at the effects of material resources on the use of experiential learning theory (ELT), the types of EL and the contribution of ELT to VET programmes.
Design/methodology/approach: The research design mainly entails a qualitative research design and research method to allow the researcher to view the reality as is experienced from the inside out by the trainees and training centre managers on important data for a thorough understanding. The study participants were 512 young trainees who completed different training courses from the VET programmes and 24 centre managers in the KwaZulu-Natal province of South Africa.
Findings: The findings reveal that the use of ELT in VET programmes helped the trainees to gain real-world skills, hence contributing to their empowerment in terms of work experience and competence for their future employment. Based on the findings, the study concludes that ELT is an effective instrument to promote VET programmes for disadvantaged and unemployed youths.
Practical implications: The practical and social implications of the findings are that, while disadvantaged youths cannot access and afford higher education, public and private sectors can remedy their situation by providing non-school-based technical and vocational training to help such youths enter the labour market. The findings will motivate the providers of skills development for unemployed youths to use ELT in designing course curricula, planning resources and directing teaching-learning approaches to help trainees to acquire skills and competencies to perform tasks close to real-work situations.
Social implications: The socio-economic implication of the article is that skills development plays an important role in poverty reduction. Investing in the skills development of citizens is vital to raise the incomes of poor groups and to reduce poverty (ILO, 2018). Although the causes of unemployment have also to do with economic factors in a country, skills development is an essential ingredient in developing capacities for labour market entry and increased income generation of a vulnerable group of people.
Originality/value: The article is significant because the study provides new insights into the use of ELT in VET programmes to improve their effectiveness in developing job-related skills and competencies for real-world environments for disadvantaged and unemployed youths. The study contributes to the body of knowledge by establishing a solid base for the evidence-informed practice of the effects of facilitating the VET programme through ELT to promote skills acquisition for the employment of unemployed and disadvantaged youths
Exploring Personality Traits, Coping Strategies, and 5-Year Change in Blood Pressure in Young Adults: The African-PREDICT Study
Get PDFJournal Article, Faculty of Natural and Agricultural Sciences, Pure and Applied Analytics-- Potchefstroom CampusThis sub-study of the African Prospective Study on the Early Detection and Identification of Cardiovascular Disease and Hypertension (African-PREDICT) explored possible early psychological predictors of change in blood pressure. In a sample of normotensive at baseline black and white South Africans (n = 105; mean age at baseline 24.93), this study investigated the relationship between personality traits, coping strategies, and 24-hour ambulatory blood pressure measured at baseline and 5-year follow-up. Another aim was to investigate a possible mediating effect of coping strategies on the relationship between personality traits and change in blood pressure. Extraversion, agreeableness, openness, and problem-solving skills were identified as possible protective factors against cardiovascular risk, confirming previous research in this regard. However, the effect of these was different for gender and ethnic subgroups. Preconditions for a possible mediation role for coping in the relationship between personality and change in blood pressure were not met. Future research should further explore gender and ethnic differences in the relationship between personality, coping, and cardiovascular health.Funding
The authors disclosed receipt of the following financial support for the research, authorship, and publication of this article: The authors are grateful toward all individuals participating voluntarily in the study. The dedication of the support and research staff as well as students at the Hypertension Research and Training Clinic at the North-West University are also duly acknowledged. The research funded in this manuscript is part of an ongoing research project financially supported by the South African Medical Research Council (SAMRC) with funds from National Treasury under its Economic Competitiveness and Support Package; the South African Research Chairs Initiative (SARChI) of the Department of Science and Technology and National Research Foundation (NRF) of South Africa (GUN 86895); SAMRC with funds received from the South African National Department of Health, GlaxoSmithKline R&D (Africa Non-Communicable Disease Open Lab grant), the UK Medical Research Council and with funds from the UK Government’s Newton Fund; as well as corporate social investment grants from Pfizer (South Africa), Boehringer-Ingelheim (South Africa), Novartis (South Africa), the Medi Clinic Hospital Group (South Africa) and in kind contributions of Roche Diagnostics (South Africa).
Any opinion, findings, and conclusions or recommendations expressed in this material are those of the authors, and therefore, the NRF does not accept any liability in this regar
Historic water quality patterns in endemic schistosomiasis regions of southern Africa: Implications for disease vector distribution
Get PDFArticle, Faculty of Natural and Agricultural Sciences (Unit for Environmental Sciences and Management)--Northwest University, Potchefstroom CampusAlterations in atmospheric temperature and rainfall have a major influence on the distribution patterns of vector-borne diseases, including schistosomiasis, by changing the optimum habitat of the intermediate hosts (vectors) that transmit these diseases. Water quality degradation and the creation of artificial freshwater habitats may widen or restrict the distribution of disease vectors. Understanding the influence of water quality on ecosystems is essential in determining the environments that vectors thrive in and where potential outbreaks of the disease they carry will occur. This study aims to analyse the changes in various water quality variables between 1977 and 2009 in the Mbombela river systems and how this may have altered the presence of schistosomiasis snail vectors in these areas. Historical water quality data for the Sabie, Kaap, Komati and Crocodile rivers were obtained from the Department of Water and Sanitation monitoring stations and separated into three decades (1977–1987; 1988–1998 and 1999–2009). The Physicochemical Driver Assessment Index (PAI) was used to determine the ecological category of the rivers in each decade. A Principal Component Analysis was also created for the different river systems to identify possible changes in water quality over the 3 decades. According to the PAI, the Sabie River remained in a relatively good state while the Crocodile, Komati and Kaap rivers had a low water quality to begin with and became further degraded over the three decades. The PCAs indicated the Sabie and Crocodile rivers had increased levels of salts, nutrients and pH between 1988-1998 and 1999–2009 while the Kaap River had high salt content and pH between 1977 and 1998 and high nutrients during the decade of 1999–2009. These results indicate that there has been a change in the water quality of Mbombela river systems with notable increases in salt, pH and nutrient levels. As a result, the aquatic biota have likely been negatively affected and this poses severe impacts on the presence and abundance of schistosomiasis vectors as the snails are sensitive to changes in salinity, nutrients and pH
Phytochemical Profiles, Micromorphology, and Elemental Composition of Gomphocarpus fruticosus (L.)W.T. Aiton and Leonotis leonurus (L.) R.Br., Plants Used for Managing Antidepressant-like Conditions in Folk Medicine
Get PDFJournal Article, Faculty of Health Sciences, Preclinical Drug Development Platform (PCDDP)-- Potchefstroom CampusMedicinal plants have been used to treat mental health-related conditions among different ethic groups. Among the commonly used plants in South Africa are Gomphocarpus fruticosus (L.) W.T.Aiton and Leonotis leonurus (L.) R.Br. This study aimed at generating the phytochemical profiles, micromorphology, and elemental composition of the leaves of G. fruticosus and L. leonurus as possible means of explaining the basis for their utilisation for mental health-related conditions in folk medicine and consideration for further development. The plant parts were subjected to successive solvent extractions using an ultrasonic method with dichloromethane (DCM) and were chemically characterised using ultra-performance liquid chromatography coupled to mass spectrometry (UPLC-MS). Scanning electron microscopy (SEM) was used to examine the micromorphology of the fresh leaves and energy-dispersive X-ray Spectrometry (EDX) was utilised to perform mineral elemental analyses of G. fruticosus and L. leonurus using their leaf powder. We identified phytochemicals including rutin and marrubiin, which are known to alleviate depression-like symptoms. Glandular and non-glandular trichomes were present in the plants. A weight (%) of 1.32 and 0.82 for calcium, 1.16 and 1.99 for potassium, and 0.38 and 0.38 magnesium were present in G. fruticosus and L. leonurus, respectively. These minerals have been linked to mental health stability, with imbalances associated with various disorders. We established the chemical composition that could suggest potential therapeutic effects of these two medicinal plants, offering insights into their uses in folk medicine and potential modern applications in treating mental health issues.Acknowledgments
We thank Alison Young (horticulturist, University of KwaZulu-Natal Botanical Garden) and McMaster Vambe (Mangosuthu University of Technology) for assisting with plant collection. We are grateful to Christina Potgieter (Bews Herbarium, NU) and Prin Naidu (A.P. Goossens Herbarium, North-West University) for assisting with the identification of the plants. We acknowledge the technical support of Anine Jordaan (Laboratory for Electron Microscopy, Chemical Resource Beneficiation (CRB), North-West University). We also thank Weiyang Chen (Department of Pharmaceutical Sciences, Tshwane University of Technology) for assistance with the phytochemical quantification of plant extracts.
Funding
This study was supported by the National Research Foundation (NRF, UID 129 870) and partially support from the International Brain Research Organisation (IBRO) and the Welcome Trust Neuroscience Capacity Accelerator for Mental Health programme
Assessing the Place of Christo-Peace in Transforming the Life of Nigerian Christians
Get PDFJournal Article.School of Public Management, Governance and Public Policy, North West University. VanderbijlparkThe quest for peace by men has remained a major existential need of man. People go to different places including the church in the search for peace. This
study focuses on Christo-peace. Christo-peace is a form of peace that emanates from the communion of man with Christ as well as a strong belief in the
teachings of Christ as well as the church. The study is a qualitative research that was developed from the random selection of scriptural quotations from biblical
texts. It revealed that Christo-peace is gotten through prayers and ecclesia teachings of the church. It also found that this form of peace has a strong sociopsychological and spiritual impact on the lives of men. The study concluded that Christo-peace as found in the scripture has direct implications on the physical and mental peace of the Nigerian Christians. It recommends the advancement of peace-based preaching, increased prayers for the advancement of prophetic gifts that are needed for Christian understanding of time and the management of the culture of corruption in the Nigerian Christian churches as paths toChristo-peace by Christians, bearing in mind that there are multiple crises undermining the reality of peace on eart
Embodied grace: The implications of the incarnation to public practical theology in Sub-Saharan Africa
Get PDFJournal Article, Unit for Reformed Theology and Development in South Africa, Faculty of Theology, North-West University, Potchefstroom,Christian incarnation, illustrated through the example of Jesus Christ, involves the embodiment of God, the guardian of all creation and the manifestation of Christian beliefs. This divine incarnation operates through boundless love and concern, as demonstrated in God’s choice to intimately connect with humanity, as noted in John 3:16. Although global challenges abound, it is evident that sub-Saharan Africa faces unique difficulties, hindering its inhabitants from experiencing the fullness of life intended by God. There is a need to find solutions to the challenges faced by the African continent. In the context of sub-Saharan Africa, the question is: How can practical public theology, informed by the incarnation, be practised in tackling the challenges people face in Africa? The study addresses this inquiry, presenting the implications of the incarnation doctrine as a means to tackle African challenges. It posits incarnation as a foundation for comprehending God’s love for Africans and proposes practical ways for resiliently confronting their adversities. The article draws upon existing literature in the field of public practical theology to underpin the core argument of its thesis.
Contribution: This article contributes to the discussion on how theology should be used to address people’s concrete challenges in sub-Saharan Africa. The doctrine of incarnation is a unique example whose implications can help the enhancement of addressing people’s challenges in Africa
Passive autocatalytic recombination of hydrogen on a Pt/Al2O3-coated metal foam: Experimental evaluation and CFD modelling
No full textJournal Article,Faculty of Engineering, North--West University-PotchefstroomPt/Al2O3-coated Al foams were tested for the passive autocatalytic recombination of H2. The characterisation of the washcoat surface confirmed the uniform distribution of Pt and Al2O3 over the entire washcoat surface. Transmission electron microscopy results revealed a slight increase in particle size from 3.8 to 6.2 nm after prolonged reaction. High H2 conversions of 57–89% are achieved and the catalyst activity is maintained for >480 h on stream. The performance of the foam-based catalyst bed is similar to that of plates but surpasses that of catalyst pellets. Temperatures recorded at the hottest spots on the foam surface reach a maximum of only 393 ◦C at the highest H2 inflow. Computational fluid dynamics simulations were performed on the actual foam geometry obtained using computed tomography. The simulations demonstrate the importance of thermal radiation in the model. There is good agreement between results of experimental H2 conversions and maximum combustion temperatures
Future managerial competencies required for the manufacturing sector in South Africa
Get PDFJournal Article, North-West UniversityThe impact of the Fourth Industrial Revolution (4IR) and resulting technological advancements on the manufacturing environment requires new competencies from managers. The purpose of this study was to explore the perceptions of managers concerning essential managerial competencies for future success in the manufacturing sector in South Africa. Studies on future managerial competencies are currently under-represented and served as motivation for this study. An exploratory qualitative research approach was followed and an interpretivist paradigm was employed. A qualitative descriptive empirical research design was used. The research sample comprised 20 managers from a variety of manufacturing organisations. Purposive sampling was used, and online semi-structured interviews were conducted to collect the data. Conventional qualitative content analysis was employed to analyse the data. The participants indicated that cognitive, general managerial, intrapersonal, macroeconomic, mesi-economic, organisational-focused and social skills will be critical managerial competencies for future success in the manufacturing sector. Limitations of the current study were reported and recommendations for future research were made. The findings of this study can inform talent acquisition, development and retention in the manufacturing sector of South Africa. In this study, we highlight the importance of social skills for managers such as people management, employee empowerment and interpersonal skills. Our study adds to the body of literature by highlighting the essential managerial competency of adaptability in the manufacturing sector. Managers should have the ability to adapt to change if they wish to be successful in the South African manufacturing sector. Another significant contribution was to qualitatively explore critical managerial competencies for the 4IR in this sector, from the perspective of those managers who already function in these roles
Plant-Microbes’ Interactions and their Roles in Bioremediation: A Case Study of Phragmites australis in Acid Mine Condition
Get PDFJournal Article, Human Metabolomics, North-West University, PotchefstroomThe interactions between plants and microbial communities are vital in shaping the dynamism of a particular ecosystem toward ecological sustainability. In an acid mine drainage (AMD) system characterized by the abundance of heavy metals and physicochemical parameters, the survival of plants could be limited. Hence, plants surviving in such environmental conditions tend to develop a particular microsystem that promotes their growth. Plant-microbes interaction is among the systems that most plants develop to enhance their ability to withstand the toxicity of heavy metals and possibly grow. The common reed (CR), Phragmites australis, an invasive weed, has been found to withstand the toxicity of heavy metals and survive in AMD environments. In addition, the association between CR and the microbial communities at the rhizosphere level plays a crucial role in the growth of CR by reducing the toxicity of the heavy metals. These interactions culminate in the release of diverse metabolites by the plant and microbial communities controlled by specific genes. This review collated information on the different microbial communities associated with CR and the metabolites released to promote the growth of CR and enhance their remediation potential. Although the interactions were under the influence of secreted metabolites, a gap still existed in elucidating the specific metabolites secreted either by the microbes or the CR. Further study is recommended that could cut across interdisciplinary approaches, including molecular docking,
to enhance the elucidation of diverse metabolites from the microbes and CR