58622 research outputs found
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Multi-Objective Optimisation of a Hydrogen Combustion Mechanism with Direct Kinetic Modelling:Application to Combustion Engines
Full text linkHydrogen combustion can decarbonise difficult-to-abate sectors. However, practical deployment depends on reliable prediction of combustion behaviour under transient conditions, which contrasts with the steady-state experiments typically used for combustion mechanism development. This study presents a fully optimised H2-NOx mechanism, calibrated against 118 fundamental combustion datasets containing 1695 datapoints, which shows significant improvements in the prediction of ignition onset in an internal combustion engine with nitric oxide injection into the intake system.In contrast to prior single-objective approaches, this study introduces a fundamentally new approach to chemical kinetic mechanism optimisation, which leverages a Multi-Objective Particle Swarm Optimisation framework on a High-Performance Computing platform. The framework simultaneously balances accuracy and consistency across datasets, explicitly incorporates experimental uncertainty, and evaluates all candidate mechanisms with full chemical simulations. Prediction accuracy is quantified using the normalised root mean square error (nRMSE) to experimental measurements and the proportion of predictions within experimental uncertainty limits. Relative to the best existing mechanism, the optimised model achieves a 35 % reduction in nRMSE and a 19 % increase in the number of predictions within uncertainty bounds, demonstrating improved predictive performance for fundamental combustion targets.When the optimised mechanism was applied to autoignition timing in a Homogeneous Charge Compression Ignition engine, significant improvements were found for data with nitric oxide. Nevertheless, the overall accuracy in autoignition prediction is insufficient for practical applications, indicating that transient engine conditions are not adequately represented by steady-state datasets. These findings underscore that even fully optimised mechanisms based solely on fundamental experiments will not deliver high-accuracy predictions under real-world, transient conditions and integration of transient combustion data into future development of chemical mechanisms is recommended.<br/
The Quality of Government and Educational Performance Across Countries
Full text linkUsing a new indicator of government quality, two different indicators of educational performance and two different datasets covering up to 120 countries, this study finds robust evidence that a higher quality of government improves educational performance. This is probably because a competent bureaucracy, a good legal system, and an able government that is responsive to its people all combine to support and impel education providers to achieve high standards. By contrast, poor governance, as exemplified by widespread corruption, military involvement in politics and a weak, incompetent and unpopular government, hampers the working of the educational system, thus reducing learning outcomes.</p
The Influence of Axial Throughflow Swirl on Buoyancy-Induced Flow in a Compressor Cavity
Full text linkNext-generation aero-engine compressors will operate with overall pressure ratios exceeding 70:1. This will require shorter compressor blades, presenting a challenge to the designer when predicting tip clearance and efficiency. Buoyancy-induced flow within co-rotating compressor discs drives the heat transfer that determines rotor expansion and the resulting blade-tip clearance. This inherently unstable flow is influenced by the radial temperature distribution of the discs, rotational speed, as well as enthalpy and momentum exchange with an axial throughflow of cooled air at low radius. Due to the rotation of the engine compressor, this throughflow may become swirled, altering the temperature, mass exchange, and swirl within the rotating cavity. The University of Bath Compressor Cavity Rig has been adapted to introduce preswirl into the axial throughflow by passing it through rotating holes. The effects of inlet swirl have been characterized in terms of Rossby and Reynolds numbers. Measurements of disc temperature, shroud heat flux, and unsteady pressure in the rotating frame of reference are used to quantify the effects of ingestion (entrainment) of fluid into the cavity. The unsteady dynamics and rotation of the core relative to the disc have been measured in both the stationary and rotating frames of reference with consistent results. A single correlation between shroud Nusselt and Grashof numbers has been established, effectively capturing the impact of swirl, Rossby number, and free convection
Hybrid Simulation-Based Algorithm Tuning for Production Speed Management System as a Stand-Alone Online Digital Twin
Full text linkOne of the primary in-built components of smart, continuous manufacturing lines is the production speed management system (PSMS). In addition to being overly cautious, the decisions made in these systems may center on making local adjustments to the manufacturing process, indicating a major drawback of such systems that prevents them from acting as proper digital twins. This study delves into hybridizing the continuous and discrete event simulation, DOE, and V-graph methods to redefine PSMS's internal decision algorithms and procedures, giving it an aerial perspective of the line and turning it into a stand-alone online digital twin with decisions at a system level. The proposed approach is applied to a practical case from the food and beverage industry to validate its effectiveness. Numerical results demonstrated an intelligent, dynamic balancing of the production line, a substantial increment in productivity, and up to 37.7 % better resiliency against new failure and repair patterns
AI governance under the second Trump administration:implications for labour
Full text linkThis commentary examines the emerging body of rules, policies and practices governing the development, adoption and use of artificial intelligence (AI) technologies in the United States, and its implications for work and workers. At the federal level, the United States has so far pursued a strategy based on export controls and a relatively permissive regulatory environment with a patchwork of measures to promote responsible AI innovation and use. As the second Trump administration now begins to implement plans to entirely overhaul frameworks adopted under President Biden, however, the situation is more volatile. Major initiatives designed to hold employers accountable and prevent harms to workers, including Biden’s flagship Executive Order, are no longer in place. While some progress can be observed at the state level, many proposals for legislation to strengthen workers’ rights in relation to AI have stalled. A conservative majority in the Supreme Court meanwhile lays the ground for further rulings that could undermine the power of organised labour. Despite these enormous challenges, workers are increasingly regarding AI adoption and use as a site of collective struggle. Alongside jurisdiction case reports on China, Canada, Brazil, India and the EU, the following discussion of the US’s AI regulation, development and governance approaches today is part of the Artificial Intelligence Policy Observatory for the World of Work (AIPOWW) symposium
The case against duty free tobacco sales:An analysis from Aotearoa (New Zealand)
Full text linkIntroduction: Duty-free sales of tobacco reduce the impact of excise tax increases, a measure many governments have introduced to reduce tobacco consumption and smoking prevalence. We investigated the excise tax revenue foregone in Aotearoa (New Zealand), a country once regarded as having progressive tobacco control policies.Methods: Using data tobacco companies are required to supply to the NZ Ministry of Health, we estimated the revenue from excise tax and the Goods and Services sales tax (GST) forgone by sales of duty-free tobacco since 2014, when duty-free allowances were reduced.Results: The number of cigarettes and volume of roll-your-own (RYO) tobacco released for sale decreased following changes to the duty-free allowance and declined sharply in 2020 and 2021, when the international border was closed as a Covid-19 pandemic measure. Since 2022, forgone excise revenue has risen steadily and, in 2024, had nearly reached pre-pandemic levels. In total, foregone revenue amounted to between NZ96 million between 2015 and 2024.Conclusion: Duty-free sales of tobacco products represent a government-sanctioned price discount that undermines Aotearoa’s Smokefree 2025 goal and its obligations as a Party to the Framework Convention on Tobacco Control
Performance-based reliability assessment of quay walls
Full text linkFunctional demands on quay walls are steadily rising with increases in both ship size and the frequency of port calls, requiring robust safety and performance assessment frameworks. Most existing studies on quay walls remain constrained by simplified analytical or numerical models, limited consideration of failure modes, insufficient model validation, and the absence of site-specific soil correlation, making it difficult to assess real structures under realistic loading conditions. This study presents a novel Cone Penetration Tests (CPT)-driven, performance-based reliability framework that samples directly from measured CPT distributions to preserve field consistent parameter relationships without requiring site-specific covariance matrices. The framework is demonstrated on a recently constructed, full-scale instrumented quay wall in the Port of Rotterdam. A two-dimensional finite element model with the Hardening Soil Small-strain (HSS) formulation is calibrated against construction-stage monitoring (wall deformations and anchor forces) and coupled to a probabilistic engine to evaluate multiple ultimate and serviceability limit states through an explicit failure tree. Results indicate that the structural failure of the wall governs the overall reliability of the quay wall, while wall deformation is the most variable response requiring close monitoring. Sensitivity analyses reveal that deeper dredging and higher surcharge loads markedly reduce reliability with wall structural failure governing and serviceability limit states showing the highest sensitivity to these hypothetical changes. The proposed approach provides a generalisable CPT-based methodology for reliability assessment of geotechnical structures based on site investigation data and monitoring data, supporting more informed, data-driven decision-making in design, and life-cycle management.</p
A scoping review of followership literature in compulsory schooling contexts
Full text linkThis scoping review examines 61 peer-reviewed studies (1984–2024) on followership in compulsory schooling to map existing research and highlight future research areas. Findings show a predominance of quantitative studies, with limited attention to relational and co-constructive frameworks. Middle leadership and cross-cultural contexts are underrepresented. The review highlights a lack of focus on building followership capacity and its impact on school culture. While followership is acknowledged as critical to organizational success, its reciprocal role with leadership remains underexplored. The review calls for diverse methodologies and greater attention to sociocultural factors to inform more collaborative and sustainable leadership practices in schools.</p
Research methods and generative artificial intelligence in applied linguistics
Full text linkSince the release of ChatGPT, there has been an explosion of interest in Generative Artificial Intelligence (GenAI) and a desire to understand how these tools can be utilised in almost every domain of human activity. Never before in human history have we had a tool that could simulate so many human capabilities. Yet, just as with humans, these tools have been found to have substantial limitations. These limitations have led us to question the roles they can play in high-stakes tasks, such as research. At the same time, they have challenged our current conventions and norms of authorship, transparency, and accountability, thus forcing us to consider:•What tasks should be left to humans exclusively?•What tasks can AI do alone?•What tasks can/should AI and humans do together?For some scholars, clear red lines have been drawn. For example, 416 experienced qualitative researchers from 38 countries wrote a commentary rejecting the use of GenAI for reflexive qualitative research (Jowsey, Braun, Clark et al., 2025). They provided three legitimate reasons for their rejection: (1) GenAI as simulated intelligence is incapable of meaning-making; (2) Qualitative research should remain a distinctly human practice; (3) the established harms of GenAI, especially to the environment and workers in the Global South. Nguyen and Welch (2025) have similar concerns and arguments against the use of GenAI in qualitative research. For other scholars, GenAI offers significant potential to reshape “the academic research lifecycle—from ideation and literature discovery to hypothesis formation, methodological planning, and data acquisition” (Haber et al., 2025, p. 27). Meanwhile, other scholars, including us, take a pragmatic stance, trying to balance the potential of these tools with the explicit threats they pose to our epistemologies, methodological rigor, integrity, and ethics (Roe, 2025; Moorhouse, Nejadghanbar & Yeo, 2025; Moorhouse, Consoli & Curle, 2025)
Irreverent Pessimism (A Planetary Life Without Appeal)
Full text linkPerhaps the most disorienting feature of the long socioecological disaster that makes ever sprawling environmental disasters amplify the effects of ongoing and uneven conditions of poverty, violence, and dispossession, is not its urgency, but its permanence: that there is no foreseeable future in which redemption would prevail. What might it take to refuse the cruel hope for a redemptive future without seeking consolation in the despair that such forlorn hope precipitates? At a time when everyone is extorted to save the world or be damned, this article explores the irreverent pessimism of what, after Camus, one might call a planetary “life without appeal.” Refusing to be content with what is now deemed proper to damned of the earth, irreverent pessimism affirms the insubordinate disposition of a life lived in the most radical immanence of a freedom born not of hope but of the ongoing improvisation of a revolt without future
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