38139 research outputs found
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Hygrothermal Durability and Damage Evolution of Bio-Epoxy-Based Composites Reinforced with Different Fibre Types
No full textbasalt, and flax fibres. Fibre yarns and bio-composites were exposed for 3000 h at 60 °C and 98% relative humidity. The tensile strength reduction in the fibres and the interfacial shear strength (IFSS) reduction in the composites were assessed after ageing. Chemical deterioration was evaluated using energy-dispersive X-ray spectroscopy (EDS); morphological changes in fibres and composites fracture surfaces were examined using a scanning electron microscope (SEM). Results indicated that the durability was significantly influenced by fibre types. Tensile strength reduction was higher in carbon, glass and basalt compared to flax yarns because of chemical degradation of the sizing layer in synthetic fibres, while only physical damage was observed in flax. The IFSS reduction was highest in flax composites (10%), and lowest in carbon (4%). EDS indicated the hydrolysis and erosion of fibre sizing, with reduced silica content in glass and basalt fibres. SEM revealed matrix-dominated failure in carbon/bio-epoxy, interfacial debonding in glass and basalt composites, fibre slip and pull-out in flax/bio-epoxy. Overall, the results highlighted damage propagation pathways and demonstrated that bio-epoxy composites exhibited reasonable performance under hygrothermal ageing, supporting their potential as a sustainable alternative in durability-critical applications
Enhancing flame retardancy and ultraviolet aging resistance of intumescent flame retardant polypropylene by incorporating cerium oxide
No full textThe flame-retardant modification of polypropylene (PP) often deteriorates its resistance to ultraviolet (UV) radiation, leading to severe degradation in both flame retardancy and mechanical properties during long-term service. To address this issue, cerium oxide (CeO₂) was incorporated into an intumescent flame retardant (IFR) system to achieve synergistic flame retardancy and enhance anti-UV performance. The resultant PP/IFR/CeO2 achieved a UL-94 V-0 rating with a limiting oxygen index (LOI) of 32.7 % at a total loading of only 20 wt% IFR and CeO2. After UV irradiation for 120 h, the surface of PP/IFR/CeO2 remained smooth, with only shallow cracks, and its water contact angle was maintained at 64.5°. The carbonyl index increased merely to 1.45, indicating a markedly low degree of photo-oxidative aging. In addition, the tensile strength and elongation at break decreased by 9.4 % and 28.5%, respectively, which were significantly smaller reductions than those of PP/IFR. The results indicate that CeO2 can effectively improve the anti-UV performance and flame retardancy of PP/IFR, providing a valuable foundation for developing durable, flame-retardant PP composites with improved anti-UV performance
Mental health at risk: Predicting psychological distress in Australian youth through machine learning models
No full textBackground: Psychological distress among youth is a growing global health concern and a leading non-communicable disease burden. Early and accurate prediction is vital for effective intervention. This study applied machine learning (ML) techniques to predict psychological distress risk in young Australians.
Methods: This study used data from the most recent two waves, 9C1 and 9C2, of the Longitudinal Study of Australian Children (LSAC). From an initial set of 31 features, relevant predictors were selected based on individual classification accuracy (threshold ≥0.60). Five ML algorithms (Decision Tree, Naive Bayes, Random Forest, Support Vector Machines, eXtreme Gradient Boosting) were developed and rigorously evaluated using 10-fold cross-validation repeated 25 times. Logistic regression was applied for interpretive insights into the top predictors.
Results: Random Forest (RF) model consistently demonstrated superior predictive performance across both waves, achieving higher accuracy (0.8168 and 0.8011), F1-scores (0.8276 and 0.8430), AUC values (0.8919 and 0.8833), and Matthews correlation coefficients (0.6321 and 0.5735), along with the lowest Brier scores (0.1348 and 0.1366). Key predictors included loneliness, bullying victimisation, social media addiction, total social support, stressful life events, and coping level.
Conclusions: This study's innovative ML approach uncovers critical social and emotional risk factors for psychological distress in Australian youth. The findings highlight ML's significant role in enhancing early prediction, guiding targeted public health actions, and supporting clinical decisions to improve mental health outcomes for young people. Additionally, they reveal strong real-world potential for integration into school, community, and digital health initiatives, facilitating early detection and personalised mental health assistance
Indigenizing Research via Talanoa: Vā in Higher Education
No full textIn the tradition of approaches that call for decolonizing research, this study demonstrates how talanoa, an Indigenous research methodology, exceeds the scope of Collaborative Auto-Ethnography (CAE) by embedding cultural authenticity, relationality, and reciprocity within the research process. By framing talanoa, the authors examined the sociocultural phenomenon and practice of “nurturing vā”, as a core concept of Pacific Indigenous research. Hence, this study can help to inform academic research and advance scholarly knowledge beyond CAE's framework
Biological skin-inspired damage warning and self-healing thermoelectric aerogel fiber via coaxial wet spinning for wearable temperature sensing
Full text linkBiopolymer-based temperature-sensing fibers are increasingly employed to realize the eco-friendly concept of wearable electronics. However, keeping their long-term development remains challenging due to limited mechanical robustness and poor environmental tolerance. Herein, a bionic autonomous self-healing thermoelectric (TE) aerogel fiber with visual damage warning function (STDF) inspired by biological skin was prepared via a coaxial wet spinning strategy, which yielded a core-shell heterogeneous structure with a protective sheath with an intrinsic self-healing ability and a temperature-sensing core layer. The core layer of STDF, composed of flexible thermoplastic polyurethane embedded with rigid Ti3C2Tx MXene, effectively minimizes disruptions in continuous conductive pathways during repeated extreme bending. Featuring a synergistic network of reversible hydrogen bonds and dynamic Schiff-base linkages constructed among oxidized alginate, sericin, and tannic acid, the fractured STDF aerogel fiber exhibits exceptional water-responsive self-healing efficiency (97.51 % stress recovery). Moreover, the visual damage location in STDF fiber is enabled through a coloration reaction at the damaged interface between the Fe2+ ions and 1,10-phenanthroline incorporated into the core and sheath layers, respectively. Furthermore, the resultant STDF demonstrates a wide-range temperature-sensing performance at 100–500 °C and an ultrasensitive alarm response time (within 2 s) when encountering fires. This work sheds new light on the design of bionic temperature sensing fibers with environment-adaptive self-healing and damage warning abilities for improved reliability and durability in real-world wearable application scenarios
Education, green technology, and clean energy as indicators of sustainability and resilience in BRICS economies
No full textThis study investigates how education, green technology, and clean energy function as explicit indicators of sustainability and ecological resilience in BRICS economies over the period 1995–2021. Moving beyond income-centered Environmental Kuznets Curve (EKC) analyses, the study employs advanced econometric techniques, including cross-sectional dependence tests, panel unit root analysis, and panel cointegration to examine long-run indicator–environment linkages between socioeconomic drivers and CO2 emissions. A panel quantile regression framework reveals that higher educational investment and increased clean energy utilization consistently reduce CO2 emissions across emission quantiles, reinforcing their role as robust sustainability and resilience indicators aligned with SDG objectives. In contrast, economic growth, population expansion, and green technology adoption are associated with higher emissions, reflecting short-term transition costs and structural constraints in emerging economies. Robustness checks using Driscoll–Kraay standard errors, generalized least squares, and the generalized method of moments confirm the stability and consistency of the estimated effects. Furthermore, Dumitrescu–Hurlin causality analysis demonstrates bidirectional causal relationships between GDP and CO2 emissions, as well as between clean energy and emissions, underscoring the dynamic feedback mechanisms linking growth, energy transition, and environmental outcomes. By integrating education, technology, and energy variables into an indicator-based sustainability framework, this study contributes to sustainability science by clarifying transmission pathways through which human capital formation and energy transformation enhance ecological resilience. The findings offer actionable policy insights for strengthening sustainability strategies and guiding BRICS economies toward balanced growth and long-term environmental resilience
Reliability of Ultrasonography to Assess Spinal Compression During Heavy Load Carriage
No full textBackground
Back pain and spinal injury are leading contributors to premature retirement, particularly in physically demanding occupations. Direct and practical methods of spinal assessment are needed to evaluate interventions aimed at reducing spinal loading and injury risk. Ultrasonography has been reliably used to estimate spinal compression via intervertebral disc height, but its reliability for measuring inter-transverse process distances under load has not been established.
Methods
Eleven healthy adults underwent ultrasonographic measurement of inter-transverse process distances at each lumbar level (L1–L5), and the total lumbar distance under four loading conditions: (1) immediately on standing while unloaded, (2) after 15 min of unloaded standing, (3) after 15 min of standing loaded with a 25 kg weighted vest, and (4) after 30 min of loaded standing. These procedures were repeated after 1–7 days. Inter-rater, within-visit, and between-visit reliability were assessed using intraclass correlation coefficients (ICCs) and coefficients of variation (CV). Bland–Altman plots were used to assess agreement. A one-way analysis of variance was used to determine the effects of each loading condition on inter-transverse process distances.
Results
Inter-rater, within-visit, and between-visit reliability was good to excellent with ICCs between 0.81 and 0.99 and CVs between 5.24% and 13.0% for all measurements. Inter-transverse process distances were reduced at L2/3 (p = 0.007), L3/4 (p = 0.006), and across the total lumbar distance (p = 0.02) following 15 and 30 min of loaded standing.
Conclusion
Ultrasonography is a reliable, low-cost method for quantifying changes in lumbar spine geometry during loaded standing. This technique may have value in occupational and clinical settings for assessing spinal compression in response to mechanical load
Relationships between cognitive appraisals of threat and challenge, psychophysiological responses, and clinical performance during high-stress simulated OSCES
No full textIntroduction: In healthcare education, Objective Structured Clinical Examinations (OSCEs) are often utilised as a practical assessment tool and can cause marked elevations in psychophysiological stress levels for students. Cognitive Appraisal Theory asserts that individuals engage in evaluative processes to determine whether their available coping resources are sufficient to meet the demands of a given situation. This study examined the relationship between cognitive appraisals and psychophysiological responses, as well as clinical performance, in final-year paramedicine students during simulated high-stress OSCEs. Specifically, it investigated whether threat appraisals are associated with distinct physiological stress markers and poorer clinical outcomes compared to challenge appraisals.
Methods: A total of twenty-six undergraduate paramedicine students participated in the study, evaluated through cardiovascular indicators, functional near-infrared spectroscopy (fNIRS) neuroimaging, clinical performance evaluations, and stress and decision-making assessments.
Results: The results revealed that students who approached the simulated OSCE with a challenge-oriented mindset demonstrated more regulated cardiovascular and cerebral stress responses and achieved significantly higher scores on clinical performance measures. In contrast, those exhibiting threat appraisals showed heightened physiological arousal, demonstrated by significant increases in cortisol levels, whilst achieving lower clinical competence.
Conclusion: These findings suggest that the way students cognitively appraise high-pressure clinical scenarios can meaningfully influence both their biological stress responses and their ability to perform effectively. This study highlights the importance of fostering challenge appraisals which may enhance students' resilience under pressure and ultimately improve patient care outcomes in real-world emergency settings
Virtual Simulations to Educate Social Work Students about Domestic and Family Violence: A Scoping Review
No full textThis scoping review systematically assesses and documents the landscape of immersive virtual simulation pedagogies used within social work education to teach students about domestic and family violence (DFV). The intent of this article is to map the existing methodologies, technologies, and pedagogical strategies employed in virtual simulations to educate social work students about DFV. In doing so, this article demonstrates the different types of virtual simulations that are used to educate social work students about DFV, the types of knowledge and skills that they seek to address, and identifies how this has been evaluated. The key findings highlight that virtual simulations are useful in building student confidence, reducing anxiety, and providing tailored exposure to complex practice scenarios. Developing insights about what has been done, the strategies used to implement them, along with gaps and limitations of virtual simulation use are instrumental in shaping future design strategies. Each contribute to building a continuation of innovative approaches to enhance social workers’ education about DFV
Cybernetic Imaginations
No full textCybernetics, the science of control systems, was first popularised as an idea in 1948, following Norbert Wiener’s seminal publication on the topic. Almost immediately, cybernetics gripped the imagination of science fiction writers and film and television producers. This collection explores decades of the intersection between cybernetics and speculative fiction, from the Cybermen of Doctor Who to the Borg of Star Trek, sci-fi luminaries from Isaac Asimov to George Lucas, and classic works like The Terminator to current outputs like The Mandalorian. It is intended as both an introduction to and a showcase for new and cutting-edge scholarship on the topic, highlighting the urgency of cybernetics research with the rise of artificial intelligence (AI), anxieties over the potential dehumanisation of society, and new futures envisioned for human-machine integration. As we become accustomed to speaking to nonhuman answering services, using AI technology in our writing, and even seeing films with nonhuman actors, this collection gives us access to rich fictional speculations about cybernetics that may help us to understand our rapidly changing world