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Performance improvement of a limaçon gas expander using an inlet control valve : two case studies
Get PDFRenewable energy-based compact energy-generation systems based on the organic Rankine cycle (ORC) can be employed to meet the ever-growing thirst for affordable and clean energy. The overall performance and effectiveness of ORC systems are constrained by the low efficiency of the gas expander, specifically the positive displacement expander, which is responsible for energy conversion from the working fluid. This low-efficiency scenario can be significantly improved by employing a control valve to regulate and restrict the flow of the working fluid into the expander. A control valve can effectively curve the loss of costly compressed and energized working fluids by allowing them to expand in the expander chamber before discharging through the outlet port. They can thus be used to regulate the amount of energy yield and output power. In this work, two direct drive rotary valves (DDRVs) operated by a stepper motor (SM-DDRV) and rotary solenoid (RS-DDRV) are suggested, and the behavior of the valves is examined. The effect of friction and temperature on the valve response is also studied. Additionally, the effect of inlet control valves on the overall system performance of the limaçon expander is assessed. Thermodynamic properties such as the isentropic efficiency and filling factor are also computed. The effect of leakage due to valve response delay is analyzed at different inlet pressures. The performance indices are compared to the expander performance without any inlet valve. The SM-DDRV setup results in a 14.86% increase in isentropic efficiency and a 220% increase in the filling factor, whereas the RS-DDRV performs moderately with a 2.58% increase in isentropic efficiency and an 80% increase in the filling factor compared to a ported expander. The SM-DDRV provides better performance indices compared to the RS-DDRV and without valve setups. However, the performance of the limaçon expander with the SM-DDRV is sensitive to the inlet pressure and degrades at higher pressure. Overall, the valves proposed in this work present key insights into improving the performance characteristics of gas expanders of ORC systems. © 2024 by the authors
Intellectual freedom and teaching performance assessment in Australia
Get PDFThe requirement for Australian initial teacher education (ITE) providers to administer a Teaching Performance Assessment (TPA) highlights a tension between policymaking directives and academic independence. It has raised fears of entrenching simplistic notions of measurement and evidence into a professional field distinguished by its complex relationship with intellectual and academic labour. Drawing on focus group data and reflections of academics co-designing an Australian TPA, this study considers how intellectual labour intertwines with its operational field, wherein co-construction of knowledge, critical thinking, and reflection define both academic and teachers’ work. Our analysis explains how education academics, as principle-designers of an assessment instrument, might also negotiate the intellectual premise of a TPA within their own ITE programs. We find that Australia’s initial TPA policy framework has been mediated with ITE academics. This offers opportunities for building knowledge to understand more precisely the TPA in its contexts, including admissible evidence to measure classroom-readiness. © The Author(s) 2023
Nonchemical aquatic weed control methods: exploring the efficacy of UV-C radiation as a novel weed control tool
Get PDFAquatic weeds, including invasive species, are a worldwide problem. The presence of aquatic weeds poses several critical issues, such as hindering the continuous flow of water in irrigation channels and preventing the proper distribution of adequate water quantities. Therefore, effective control measures are vital for agriculture and numerous downstream industries. Numerous methods for controlling aquatic weeds have emerged over time, with herbicide application being a widely used established method of weed management, although it imposes significant environmental risks. Therefore, it is important to explore nonchemical alternative methods to control existing and emerging aquatic weeds, potentially posing fewer environmental hazards compared with conventional chemical methods. In this review, we focus on nonchemical methods, encompassing mechanical, physical, biological, and other alternative approaches. We primarily evaluated the different nonchemical control methods discussed in this review based on two main criteria: (1) efficiency in alleviating aquatic weed problems in location-specified scenarios and (2) impacts on the environment, as well as potential health and safety risks. We compared the nonchemical treatments with the UV-C-radiation-mediated aquatic weed control method, which is considered a potential novel technique. Since there is limited published literature available on the application of UV-C radiation used exclusively for aquatic weed control, our review is based on previous reports of UV-C radiation used to successfully control terrestrial weeds and algal populations. In order to compare the mechanisms involved with nonchemical weed control methods, we reviewed respective pathways leading to plant cell death, plant growth inhibition, and diminishing reemergence to justify the potential use of UV-C treatment in aquatic habitats as a viable novel source for aquatic weed control. © 2024 by the authors
A snapshot of sport management courses in australia
No full textTo prepare sport management students, curricula should align with industry. Given recent changes in sport management, the first step in aligning curricula with industry is to review current curricula. This study reviewed Australian sport management curricula using content analysis of the Common Professional Components based on the Commission on Sport Management Accreditation. From 39 universities, 11 (28%) undergraduate sport management programs were identified. The most common required sport management course was management concepts, followed by sport marketing and finance, budgeting, accounting, and economics. Public relations and ethical aspects were the least common required courses. Technology and sport sales were not offered. Results indicate that the current curricula may not be keeping pace with the sport management industry. © 2024 North American Society for Sport Management
Applying landscape-level principles to koala management in Australia : a comparative analysis
No full textWe provide a comparative analysis of two koala management plans for populations in two Australian municipalities, based on principles of landscape management: Ballarat (Victoria) and Bellingen (New South Wales). A landscape-based approach is required to protect the species, but evaluation of landscape management is limited. We present an assessment framework for evaluating local koala management plans. The plans are evaluated against a common set of principles and criteria, despite very different approaches stemming from context-specific factors. Interestingly, despite a variation in the number of indicators in the plans, the overall results of the evaluation demonstrate a similar level of performance against the criteria, and common strengths and weaknesses. In the absence of consistent standards for the protection of the koala across Australia, the species will continue to decline, and management practices will fail to protect the koala from extinction, as is currently predicted. © 2022 Newcastle University
Connectivity-preserving distributed informative path planning for mobile robot networks
No full textThis letter addresses the distributed informative path planning (IPP) problem for a mobile robot network to optimally explore a spatial field. Each robot is able to gather noisy environmental measurements while navigating the environment and build its own model of a spatial phenomenon using the Gaussian process and local data. The IPP optimization problem is formulated in an informative way through a multi-step prediction scheme constrained by connectivity preservation and collision avoidance. The shared hyperparameters of the local Gaussian process models are also arranged to be optimally computed in the path planning optimization problem. By the use of the proximal alternating direction method of multiplier, the optimization problem can be effectively solved in a distributed manner. It theoretically proves that the connectivity in the network is maintained over time whilst the solution of the optimization problem converges to a stationary point. The effectiveness of the proposed approach is verified in synthetic experiments by utilizing a real-world dataset. © 2016 IEEE
Investigating pedagogical, technological and school factors underpinning effective ‘critical thinking curricula’ in K-6 education
Get PDFObjective: This study investigated factors underpinning a successful technology-supported classroom curriculum, specifically designed to promote K-6 students’ critical thinking. Methods: Video and audio data illustrating 41 students’ application of critical thinking were collected using a unique display recording app installed on iPads. These were timeline analysed using a literature-generated framework comprising Indicators of critical thinking. Interview data were thematically analysed to build knowledge of teacher pedagogical and school factors supporting the curriculum. Results: Data indicated students mostly applied critical thinking for defining and clarifying concepts, presenting reasoned arguments and conclusions, questioning and challenging others’ perspectives, seeking evidence for claims made, and identifying and critiquing assumptions. Results highlight the important contribution of teacher theoretical knowledge, school-wide commitment to a ‘critical thinking’ curriculum, and common understanding of the broader purpose schooling, as foundational to the curriculum's success. Conclusion: Teaching for critical thinking was facilitated by close alignment between pedagogical, technological, and school environment factors. It was underpinned by a school-wide learning virtues and values framework emphasising students’ future competencies developed from extensive reading of research and learning theory, and was deliberately planned for. It reflected in theory-informed task design, technology selection, and pedagogy. Practice: Critical thinking has been identified in school curricula as an important capability. However, while imperatives and general principles promoting critical thinking in schools are detailed in official documents, few examples exist illustrating how critical thinking can be fostered in K-6 education. Implications: Explicit teaching for critical thinking should be considered a priority by teachers at all school levels. Given rapid technological advances such as AI, and implications these hold for students’ critical information literacy, this study provides timely guidance on how explicit teaching for critical thinking might be approached in K-6 education. © 2023 The Author(s
Enhanced learner interactions and academic integrity with bespoke interactive online tutorials in a hybrid learning model
No full textConventional teaching methods have morphed into blended and hybrid learning models with the evolution of online platforms. These have gained importance and popularity during and post-COVID-19. While the previous studies reported great success in this transition, they are mainly oriented around flexibility and learner interactions with online materials, instead of interactions with instructors. This paper discusses the development and implementation of interactive online tutorials to enhance hybrid learning in a first-year engineering subject over six years. These tutorials were designed not only to replicate the benefits of face-to-face tutorial classes, but also to enhance student interactions and engagement with teaching staff, and to detect potential academic misconduct. This study found that the interactive online tutorials (i) provided a motivational and positive learning experience to all students, (ii) narrowed the gap in satisfaction levels between on-campus and online students, and (iii) benefited the higher academic achievers within the online student cohorts. © 2024 IEEE
Attachment styles, continuing bonds, and grief following companion animal death
Get PDFThe death of a companion animal can cause severe grief, yet previous research investigating factors predicting grief has been hampered by limitations. We explored how attachment styles, continuing bonds, and time since loss interacted to predict grief severity in a large sample of individuals grieving the loss of a variety of companion animals. Participants (n = 496) aged between18 and 79 years (Mage = 41.60, SD = 13.62) who had lost a companion animal in the previous three years completed a continuing bonds questionnaire, and animal-oriented assessments of grief and attachment styles online. After controlling for time since loss, higher attachment anxiety predicted more severe grief, a relationship partially moderated by continuing bonds, whereas attachment avoidance predicted less severe grief irrespective of continuing bonds. We recommend reconsideration of the non-human animal exclusion in prolonged grief disorder, and suggest that bereavement supports embrace targeted approaches that consider attachment styles. © 2023 The Author(s). Published with license by Taylor & Francis Group, LLC
The experience of witnessing resuscitation among patients’ families : a phenomenological study
Get PDFBackground: Understanding the experiences of patients’ family members witnessing resuscitation helps develop care plans. Accordingly, this study aimed to explore the experiences of witnessing resuscitation among the patients’ family members. Methods: A total of 15 patients’ family members were interviewed over a 4-month period (from April to July 2019). The participants were recruited through purposive sampling, and they were enlisted from three educational hospitals in Tabriz. Data were analyzed using Smith’s interpretative phenomenological analysis (IPA) via the MAXQDA12 software. Results: Data analysis led to the identification of four main themes and nine subthemes. The main themes included “the insistence on being present”, “achieving calmness”, “partnership and collaboration” and “hindrance”. Conclusion: Although family members reported feelings of agitation towards the health professionals, there was also strong evidence of the benefits of witnessing resuscitation such as open communication, psychological support, and facilitating acceptance of the patient’s prognosis. The study highlighted the importance of developing formal policies based on a family-centered care (FCC) approach to observe family presence during resuscitation while maintaining the patient’s and family’s rights. © 2024 The Author(s);