Cape Peninsula University of Technology
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Organ failure: a computational model and perspective
No full textOrgan failure in biological systems is perceived as a physiological failure which is addressable via organ transplantation. Transplantation is challenging when donor organs are not easily available. Therefore, the development of a perspective capable of yielding potential therapies is required. The presented research addresses this problem and considers the biological system’s poly-computing capability. The proposed solution considers that the organs are biological computing nodes. It considers that organ failure arises when biological computing nodes don’t perform their expected function. The proposed approaches are the micro-brain and macro-brain consciousness paradigm (MMCP) and evolutionary consciousness paradigm (ECP). MMCP and ECP describe aspects concerning the relations, synaptic evolution, communication, and adaptation to handle multi-sensory inputs. The research describes how MMCP and ECP influence technology and application development. Furthermore, performance evaluation is done to investigate the operational duration of the concerned biological entities. Analysis shows that using the proposed approach enhances the operational duration by an average of (25.2–54.1)%
Damage assessment of low-velocity impacted sandwich composite structures using X-RayMicro-computed tomography
No full textSandwich composite structures offer significant versatility in structural system design but are susceptible to low-velocity impact damage, impacting their structural robustness. This study focused on nondestructive testing, particularly using X-ray micro-computed tomography, to assess damage on these structures, comprised of thin glass fibre reinforced polymer face sheets and a polyvinyl chloride foam core, under low-velocity impacts. Impacts were induced by a constant mass of 5.61 kg, dropped from various heights, generating impact energies between 2 and 22 J. This resulted in varied damage levels, from indentations to full perforations. The X-ray micro-computed tomography technique was chosen for its ability to detect internal damage. However, the system’s efficacy in accurately assessing damage depends on numerous factors like focus-to-detector distance, focus-to-object distance, and spatial resolution of the detector, among others. The system yielded an approximated resolution range of 10–25 μm for a focal spot size of 4 μm and the resolution range of 11–26 μm for a spot size of 7 μm. To this end, the system was able to reveal damage inflicted across the specimen through captured and reconstructed images. The quality of the reconstructed images was validated using ImageJ2 software by comparing with the processed images. The median filter was found to deliver images that closely resembled the original ones, albeit with a slight reduction in quality. Damage types varied based on impact energies. Low-level impacts caused matrix cracking and delamination at the foam interface. Medium-level impacts led to intralaminar and interlaminar damage, fibre fractures, and significant damage to the foam core through shearing and crushing. High-level impacts resulted in near or full perforations, with more pronounced delamination at the bottom interface, and fibre fractures in the impact zone, displaying a distinctive diamond-like damage pattern. These findings can be instrumental in developing a predictive impact damage model
A predictive control algorithm in ab and ABC frames for a three-phase voltage source inverter
No full textPredictive control algorithms are a promising piece of technology and feature accurate current tracking capabilities and good dynamic responses for power converters. In this paper, the authors focus on the application of predictive control algorithms to voltage source inverters (VSI), which aims to optimize the threephase, two-level VSI such that the load current can be controlled to obtain a good quality output current in the ab and ABC reference frames. In this paper, the authors present an analysis of a finite set model predictive current control (FSMPCC) with three unique scenarios that develops an FS-MPCC approach with a single step prediction time that controls a three-phase two-level VSI. The analysis considers both the ab and ABC reference frames for the reference current and the load model with respect to the output current quality and decoupling capabilities of the control loop in three unique scenarios. Each algorithm tested in this paper are presented and compared to create a unified objective criterion. The proposed algorithm involved in ab frame with ab load model performed excellent tracking behaviour and showed no interaction between the components of the load current when compared to the other cases in this paper. It is recommended to design the control algorithm and load model in two-phase complex coordinates whereas the power inverter remains in three-phase coordinates when hardware execution is developed. The simulation results are presented for both algorithms within the different reference frames and scenarios using the Simulink and MATLAB software packages
Functional fitness of adults with Down syndrome: a longitudinal study
No full textBackground:
Individuals with Down syndrome (DS) are born with and develop many health-related complications. The purpose of this study was to determine the longitudinal functional fitness profile of adults with DS.
Methods:
The functional fitness of adults with DS was tested twice, 12 years apart. Sixty-six adults with DS were tested for body mass, stature and 10 functional fitness tests. Data were categorised according to gender and age-specific categories.
Results:
Static balance, shoulder flexibility, trunk strength and aerobic capacity deteriorated significantly with medium to large effect sizes for both DS men and women (most age categories). For women, dynamic balance deteriorated significantly, and for men, leg- and upper body-strength deteriorated significantly.
Conclusions:
Practitioners working in the field of adapted physical activity should take cognisance of the functional fitness ageing profile of adults with DS and timeously develop habitual physical activity interventions to reduce the effect of accelerated ageing experienced by this population
Leadership dynamics: managing and leading continuous professional teacher development in schools to enhance learner performance
No full textPrincipals and school management teams are expected to provide unwavering leadership and professional and sustainable support to create opportunities for teachers and themselves to develop professionally. Currently, the lack of teacher content knowledge, low rates of motivation and accountability are key challenges resulting in the low-quality education systems in South Africa. Management teams perceive their roles to be managerial and administrative and detracts from leading teaching and learning and curriculum coverage. Furthermore, there are few systems to hold principals and teachers accountable for the academic performance of learners. This makes school leadership’s role inimitable with regard to creating a learning environment for teachers where they realise the value professional development has for the effective management of schools as well as improved learner performance. Fullan’s (2002) theory: “leadership in a culture of change” purports that school leadership has the responsibility to transform schools through collaborative efforts, working towards creating change as education evolves preparing for 21st century teaching and learning. This interpretive, qualitative study explores how principals and school management teams lead professional development in public schools in order to improve learner performance. Two principals and their management teams were purposively sampled. Data was collected through semi-structured and focus group interviews and was inductively analysed. The results show evidence of the importance of school leadership understanding the value of managing and leading development in order to attain organisational goals. Continuously capacitating teachers improved teaching and learning and ultimately improved learner performance
Regaining consciousness
No full textThis paper draws on the central ideas of John Dewey’s ‘pragmatic technology’ – as explored by Larry Hickman in his book of that name published in 1992, and, secondly, on the understanding that reality can be understood to be ‘natural but not naturalizable’ (Margolis, 2002). It thus takes issue with the ‘naturalizing’ assumptions (specifically the ‘causal closure of physics’) which deny any initiating role for the mind, currently prevalent within biologist understandings of cognitive science, Rortyan neo-pragmatism, and interpretations of the future role of Artificial Intelligence. I argue both that any attempt to resolve the ‘mind-body problem’ in naturalizing terms is logically untenable in terms of Dewey’s pragmatic ‘tools of enquiry’, and further that the ongoing attempts to resolve/ discuss the problem while ignoring this impasse, have resulted in some significant negative consequences within the real world. The paper acknowledges more recent work on consciousness within the pragmatist tradition, but argues that this is either compatible with Dewey’s understanding of body-mind, and thus widens the argument without changing it, or else it differs in ways which may be incompatible with the arguments of the paper, which seek to engage with dominant thought systems outside of pragmatism. I argue that a relativist stance will disallow this wider engagement. The paper concludes with a discussion of current arguments concerning alternative ‘natural’, immaterial (and thus not physical) approaches to understanding consciousness
Radiation therapist education and the changing landscape in Africa
No full textIn the changing global landscape, education programs for radiation therapists (RTTs), also known as therapeutic radiographers or radiation therapy technologists, at higher education institutions (HEIs) are non-existent in many African countries. In countries with local RTT education programs, there is evidence of a wide variety of qualification types, including in-house training, diploma and degree offerings. However, what is consistent is the integrated curriculum approach to classroom theory and clinical work-based learning that across the continent follows the general structure of a work-integrated learning (WIL) approach, to enhance clinical competence and meet the needs of the health sector. This study used a qualitative approach with thematic analysis of publicly available documents and reflective writings followed by further analysis through application of the Cultural Historical Activity Theory (CHAT) to explore the changing landscape of oncology in Africa and the impact of this on the education of RTTs. The study was guided by the reflective research question: How can the systemic understanding of RTT training in a changing landscape enable competent and caring practice? The study extends prior research on RTT education in Africa and contributes to debates on the changing role of RTTs in a rapidly changing environment
Spatial and temporal water quality monitoring in the Crocodile River of Mpumalanga, South Africa
No full textWater quality problems are a major challenge that humans encounter in the 21st Century. Water security presents a pressing concern in South Africa due to persistent difficulties in ensuring water availability, accessibility, and quality. Given the numerous activities that are taking place adjacent to riverbanks, there has been a decline in water quality. This study determined the state of the Crocodile River’s intermediate water quality and assessed the effects of various human-induced activities. Water samples were collected during 2016–2023 in different sites within the Crocodile River, and physicochemical parameters were analysed in an accredited laboratory. The Python package Seaborn was used for statistical analysis of the data to provide visualizations and data variations. Overall, the results show that elevated concentrations of electrical conductivity (EC) and sulphate (SO42−) were recorded in the Crocodile River. The presence of elevated EC levels in R571 Bridge exceeded 133.90 µs/cm between 2020 and 2021, whilst the highest concentration levels (114 mg/L) for SO42− were recorded in Malelane in the year 2020. The elevated concentrations of concern were recorded during the dry season (winter) and the wet season (spring). Overall, the comparisons of the spatiotemporal concentration indicate that the water quality parameters fluctuate over time. Moreover, the monitoring practice of detecting the water quality change over time is also fundamental for providing valuable information necessary for the management of integrated water resources
A model for supporting information technology solutions selection and evaluation in a Nigerian bank
No full textThe relevance and reliance on information technology (IT) solutions continue to increase, yet challenges experienced by some banking institutions are not reducing. In some discourse, the challenges are argued to emanate from the interaction and relationship between actors, which affect and influence the support and management of IT solutions. The problem is twofold: firstly, the influencing factors are unknown. Secondly, how the factors of influence manifest to enable or constrain processes and activities are unclear. A Nigerian bank was used in the study, following the interpretive paradigm. A sociotechnical theory, the actor-network theory was selected to underpin the study. From the analysis, six factors were found to be of fundamental influence. Based on the factors, a model was developed, which can be used to gain a better understanding and, therefore, guide support of IT solutions in an organisation
Improving grid-connected tidal power systems through PWM inverters based on voltage-oriented control
No full textPulse width modulation (PWM) rectifiers play a critical role in AC to DC power conversion for renewable energy applications. Existing systems predominantly employ basic voltage-oriented control (VOC) strategies and conventional 2-level converters, which often face challenges such as suboptimal steady-state performance, slower transient response, and elevated harmonic distortions. Moreover, these systems typically lack sophisticated control mechanisms for managing active and reactive power, thereby potentially compromising overall efficiency and stability. This proposed voltage-oriented control strategy aims to overcome these limitations by enhancing both steady-state performance and transient response through an inherent current control loop. Specifically, in the context of grid-connected tidal energy systems, the generator side utilizes field-oriented control (FOC), while the grid side employs a 3-level H-bridge voltage source converter integrated with VOC and a phase-locked loop (PLL). These advanced control strategies are designed to optimize power extraction and more effectively manage active and reactive powers. MATLAB/Simulink simulations have been conducted to validate the efficacy of the proposed controller, demonstrating its ability to ensure system stability, reduce harmonic distortions, and manage reactive power effectively. The system, featuring a 1.5 MW/C, 1.2 MW three-level inverter, and LCL filter, achieves harmonic distortion below 5%, showcasing the filter's efficiency. The comprehensive simulation results support the feasibility and effectiveness of the proposed voltageoriented control strategy, addressing total harmonic distortion (THD), dynamic performance, and parameter sensitivity