This work presents a comparative study on the influence of low-concentration (1 wt
The decarbonisation of urban mobility is accelerating the development of alternative propulsion technologies for light vehicles, including hydrogen fuel cell systems. In powered two-wheelers, hybrid battery-hydrogen architectures can extend operational range while preserving the advantages of battery-electric mobility. However, such multi-source energy systems introduce additional complexity that must be effectively communicated through the vehicle's human-machine interface (HMI). This study investigates rider perception, trust, and visual attention when interacting with an HMI designed for a hydrogen fuel cell range-extended motorcycle. The evaluation was conducted using a high-fidelity motorcycle riding simulator combined with eye-tracking measurements and user experience questionnaires. Results show that riders predominantly prioritize battery-derived range information, while hydrogen indicators attract attention mainly during propulsion transitions. Participants reported high trust in the displayed information and positive usability ratings. The study provides experimental eye-tracking evidence on how riders interpret multi-source energy information and highlights the importance of clear visual hierarchy and transition signalling in HMI design for hybrid electric-hydrogen motorcycles.
This paper presents an analysis of student engagement patterns from 714 students across four offerings of a first-year online course to inform the design of metacognitive nudges. We proposed an analytics-to-intervention mapping framework that specifies learning analytics indicators for three metacognitive categories: planning, monitoring, and evaluating. Statistical analysis confirmed significant differences in weekly engagement patterns among grade groups. Engagement followed a consistent temporal trajectory. Low start in Week 1, peak during Weeks 2–4, then decline through Weeks 5–10, identifying Weeks 4–5 as the critical intervention threshold. Planning nudge indicators include irregular access frequency, declining session duration, late-night or rushed access patterns, lack of course outline review, and reactive resource access. Monitoring indicators encompass unusually short or long time-on-task, surface-level content interaction, low help-seeking behavior, and incomplete material coverage. Evaluation indicators include non-access of assignment feedback, lack of revision after feedback, and declining reflection participation. Faculty survey validation (N = 89) showed strong alignment, with 62
This paper presents the results of the Power To Melt and Maneuverability (P2M) Simulation Exercise on past fuel melting irradiation experiments, organized within the Organisation for Economic Co-operation and Development/Nuclear Energy Agency Framework for IrraDiation ExperimentS (FIDES) framework by the Core Group (CEA, EDF, and SCK.CEN) and open to all FIDES members. The exercise consisted in simulating two past power ramps where fuel melting was detected: (1) the xM3 staircase power transient [ramp terminal level (RTL) 70 kW.m(-1), average burnup 27 GWd.tU(-1)], carried out in 2005 in the R2 reactor at Studsvik (Sweden), where the rodlet maintained its integrity, and (2) the HBC4 fast power transient (RTL 66 kW.m(-1), average burnup 48 GWd.tU(-1)), carried out in 1987 in the BR2 reactor at SCK.CEN (Belgium), where the cladding failed during the experiment. The exercise was joined by 13 organizations from 9 countries using 11 different fuel performance codes. In this paper, the main results of the Simulation Exercise are presented and compared to available postirradiation examinations (PIE) or on-line measurements during the power ramps (fuel and clad diameters, rod elongation, pellet-clad gap, and fission gas release). Since the focus of the Simulation Exercise is on fuel melting assessment, determination of the boundary between melted/nonmelted fuel and the consequent definition of a melting radius from PIE are first discussed. During the HBC4 ramp, fuel melting was predicted by most of the codes despite differences in the melting models. Higher discrepancies were observed for the xM3 rod that can be attributed partly to power uncertainty and partly to the limited capability of the models to describe partial melting of the fuel during this ramp. Finally, possible code developments to improve simulation results are presented.
