34028 research outputs found
Sort by
High-Temperature Tribological Behaviour and Wear Mechanisms of SAMs-Modified Zr-Cu-Al-Ni Bulk Metallic Glass
No full textMicro moulds are widely used in the fabrication of micro/nano structures, where wear resistance is critical. This study presents a mixed phosphonic acid self-assembled monolayers (SAMs)-modified Zr-Cu-Al-Ni bulk metallic glass (BMG), which not only retains hydrophobic properties but also demonstrates exceptional high-temperature tribological performance. The wear behavior and mechanisms were systematically studied in the range from room temperature (RT) to 250°C. Tribological tests were conducted using a multifunctional friction and wear tester in a ball-on-disk configuration, with polyetheretherketone (PEEK) balls as the counterface material against both bare and SAMs-modified Zr-based BMG specimens. The evolution of wear mechanisms in the PEEK-SAMs-modified BMG tribosystem at different temperatures was analyzed, particularly focusing on the coupled effects of the PEEK glass transition temperature and the melting and decomposition temperatures of SAMs on the tribosystem. Results demonstrate that the wear rate of Zr-Cu-Al-Ni BMG exhibits a progressive decrease within the RT to 140 °C range, declining from 53.26×10⁻⁶ mm³·N⁻¹·m⁻¹ to 0.156×10⁻⁶ mm³·N⁻¹·m⁻¹.At RT, abrasive and minor oxidative wear dominate. Between 90°C and 140°C, molten SAMs films provide stable lubrication, with the friction coefficient dropping to 0.004 at 110°C, indicating full lubrication, while maintaining hydrophobicity. At 150°C, exceeding the glass transition temperature of the ball material (PEEK), the ball softens and increases the wear rate to 0.324×10⁻⁶ mm³·N⁻¹·m⁻¹. The wear mechanism in this stage is still dominated by oxidative wear due to high temperature. Interestingly, at 200-250°C, the friction coefficient follows a different trend, initially increasing, then decreasing, and stabilising after 800-1000 s. At stabilization, the friction coefficient matches that of unmodified BMG, while the wear rate rises to 17.205×10⁻⁶ mm³·N⁻¹·m⁻¹, attributed to the thermal decomposition of SAMs and lubrication film failure. sam softening promotes adhesive wear and becomes the dominant mechanism. Meanwhile, interfacial property analysis systematically reveals the temperature-dependent effects on the chemical bonding, molecular ordering, and adsorption density of SAMs, elucidating their collective impact on wear evolution. This study demonstrates the exceptional wear resistance of SAMs-modified Zr-Cu-Al-Ni BMG, particularly at 110 °C, and further reveals that molecular interface engineering provides a novel design strategy for high-temperature wear-resistant metallic systems beyond conventional bulk strengthening approaches.</p
Factors influencing the invitation for national squad selection in youth basketball The role of relative age maturity and birthplace
No full textThis study examined within-group factors associated with youth basketball players invited to national squad selection camps within Basketball England's talent identification and development system. Data from 253 players (140 males, 113 females) were analysed for relative age, biological maturity, anthropometric characteristics, playing position, and region of birth. A significant Relative Age Effect was evident in both sexes, with an overrepresentation of players born in the first two quarters of the selection year (males: χ2 (3) = 27.07, p < .001; females: χ2 (3) = 9.47, p = .024). However, there were no significant differences in maturity timing or anthropometric characteristics by birth quarter, suggesting prior filtering of later-maturing players before national camp selection. Regional differences in height and mass were significant in males (height: F(8,125) = 2.34, p = .022; mass: F(8,125) = 2.31, p = .024). Guards were the most frequently selected playing position in both sexes (males: χ2 (3) = 23.37, p < .001; females: χ2 (3) = 33.31, p < .001). These findings highlight the multifactorial nature of selection influences within TID systems and suggest that regional context and population concentration may influence access to national pathways.</p
(Re-thinking) values and virtues: A network approach to mapping athletes’ personal values and the spirit of sport
No full textPromoting the values of sport in anti-doping education requires understanding the relations among athletes' personal values and societal sport values. However, the interplay between these value systems and their impact on doping prevention remains unclear. This study mapped these relations via network analysis among 833 (53% male, 59% competitive) European athletes, assessing Schwartz’s personal values and WADA’s Spirit of Sport Values (SSV) using Likert scales and Best-Worst Scaling. Hedonism and universalism as general values, and fun, joy, and respect as sport values were the most important for athletes. Tradition and power among general values, and courage and excellence in performance among sport values were ranked as least important. Network analysis revealed interconnectedness without distinct clusters, highlighting paradoxical centrality: SSV principles like excellence and fair play — though less endorsed individually — emerged as critical or “central” hubs (high strength, closeness, betweenness), bridging personal values (risk-taking, leadership) and SSV priorities. Only two cross-system links existed: personal achievement ↔ SSV dedication and personal enjoyment ↔ SSV fun. Despite moderate correlation (r = 0.58) between aggregated values, SSV principles showed limited resonance as internalized personal values. This apparent disconnect presents a significant challenge for values-based anti-doping education, as the Spirit of Sport principles may not resonate with athletes’ personal value priorities. Further research into the cultural and contextual dynamics between personal and societal value adoption is warranted to enhance value-aligned intervention and the promotion of sport values as a doping prevention strategy.</p
Tales to Change the World
No full textThis second edition of Tales to Change the World, is an English only edition. Translated by Jack Zipes, the six stories are beautifully illustrated by Robert Mason.In Italy, Gianni Rodari would need no introduction. A household name among educators and parents, not to mention children, he is already considered by many literary historians to be Italy’s most important writer of children’s literature in the twentieth century.</p
Appraising the UK Labour Government’s Early Approach to Reforming Parental Leave: The Limits of Incrementalism for Gender Equality and Social Inclusion
No full textThis article critically appraises the UK Labour government’s early approach to parental leave reform following the 2024 election, comparing pre-election promises with post-election policy directions. Drawing on Daly’s conceptualisation of care as a policy good (Daly, 2002), we analyse Labour’s reforms across three overlapping dimensions central to their pre-election pledges: access and pay levels, leave design and entitlements, and inclusion of diverse families. We argue that Labour’s current approach adheres to liberal welfare principles, with market-oriented reforms prioritising economic productivity over care provision, perpetuating implicit maternalism while systematically excluding working-class, minority ethnic, and self and precariously employed families. In contrast, care-centred approaches pioneered elsewhere in Europe demonstrate that gender equality, social inclusion, and economic productivity are mutually reinforcing rather than competing objectives. Echoing calls from the Women and Equalities Committee for transformative change, we argue that Labour’s incremental approach cannot achieve reforms that work for parents or the economy without embracing care-centred policies.</p
<p dir="ltr">Who Leads the Story? Comparing Autonomous vs. Adult-Supported Child-Robot Interactions </p>
No full textThis study investigates the potential of large language model (LLM)-enabled robots to support inclusive child-robot storytelling activities in elementary education. 65 children (ages 6–11) engaged in story co-construction with an LLM-enabled Pepper robot across two experimental conditions. In the child-robot dyad, the robot autonomously guided the interaction through questioning and cartoon displays. In the child-adult-robot triad, Pepper displayed story visuals while an adult co-facilitated dialogue. Evidence-based, neuro-affirming strategies were embedded throughout.Parents completed the Autism Spectrum Quotient (AQ-10), while children provided post-session self-reports on engagement and affect. Interaction transcripts were analysed for structural linguistic features. Results showed that both conditions effectively supported story recall and engagement. Affect toward the robot was consistently high, though a negative correlation with age in the dyad condition suggested increased awareness of technical limitations. Linguistic analyses revealed no differences in grammatical complexity between conditions, yet triadic sessions fostered broader vocabulary use and greater recall for older children. Outcomes correlation with AQ-10 scores indicate that both the autonomous robot and the human-robot team were equally effective and engaging across the neurodiverse spectrum.Findings demonstrate that LLM-enabled robots can be both standalone educational partners and tools for hybrid human-robot facilitation. We discuss implications for inclusive pedagogy, highlight technical challenges, and propose future directions for research.</p
Selective Lithium extraction from clay minerals using a Superacidic urea–Methanesulfonic acid deep eutectic solvent
No full textThis article reports, for the first time, the use of urea–methanesulfonic acid (MSA) deep eutectic solvents as a green and superacidic system for the selective extraction of lithium from clay-bearing ores. The solvent system was systematically designed and characterised using advanced spectroscopic techniques (FTIR, Raman, NMR, UV–Vis) combined with density functional theory (DFT) to understand its molecular structure and tunable acidity.The study demonstrates that increasing the MSA content transforms the solvent from a hydrogen-bonded network into an ionic, highly acidic medium capable of breaking strong mineral bonds while maintaining selectivity. An optimised urea–MSA formulation achieved 100% lithium recovery with minimal co-leaching of aluminium and potassium, significantly outperforming conventional mineral and organic acids.These findings introduce a recyclable, low-temperature, and highly selective solvent platform for lithium extraction and provide a promising pathway for the sustainable processing of complex clay resources, supporting future low-impact lithium supply for the energy transition.</p
Policy Art Brief (2): Youth Researchers as Generational “Translators” in Educational Policy
No full textNational education policies and curricula play a profound role in shaping the experiences and future of the youth and the communities they belong to. A large part of youth’s lives is spent in formal education, but they have little influence over it. The process of formal curricula development often overlooks the voice and perspective of the young people they are designed to serve. This creates a gap between the educational systems and the needs and communication styles of young learners.</p
Microplastic contamination of donated blood and red cell concentrates
No full textMicroplastics in blood.</p