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Inverse analysis for dynamic characteristics of a historic Masonry Pagoda using segmental low-amplitude earthquake vibrations
Get PDFHistorical structures are inherently prone to degradation, necessitating structural health monitoring for their preservation. This study proposes an inverse analysis methodology to determine structural dynamic properties, offering insights into fundamental behavior. The algorithm integrates Newmark’s time-stepping method with the Gauss-Newton scheme for improved accuracy. Its effectiveness is demonstrated using four seismic datasets from distant earthquakes. A Historic Masonry Pagoda in Chiang Mai, Thailand, was monitored via segmental low-amplitude earthquake data. Two 3-directional vibration sensors at the top and base recorded responses during seismic events. Given the low amplitude, each 120-s event was divided into twelve segments for enhanced analysis. The results show that segmenting seismic waves increases output data, reducing uncertainties through probabilistic techniques. As the pagoda’s structural properties remain partially unknown, the derived dynamic properties establish a baseline for future assessments of deterioration
Computational analysis of an ammonia-fuelled hybrid solid oxide fuel cell–gas turbine propulsion system for commercial aviation
Get PDFThis study investigates the performance of a hybrid solid oxide fuel cell–gas turbine (SOFC-GT) propulsion system for commercial aviation, using ammonia–hydrogen blends as fuel. A computational model was developed by combining NASA’s T-MATS toolbox with Cantera-based chemical equilibrium calculations to simulate thermodynamic, aerodynamic, and electrochemical interactions. The analysis examined key design and operational parameters, including fan pressure ratio (FPR), bypass ratio (BPR), equivalence ratio, altitude, and Mach number. Results showed that pure ammonia produced the highest thrust (14.5 MW total power and 2.2 kg/s fuel flow) but at the cost of lower thermal efficiency and higher specific fuel consumption (SFC). Increasing the hydrogen content in the fuel reduced fuel flow by up to 86%, improved thermal efficiency by 4.5%, and eliminated CO emissions, though NO emissions increased by 20%. Variations in equivalence ratio demonstrated a trade-off between thrust and efficiency, with net thrust increasing by 68% and thermal efficiency decreasing by 34% as equivalence ratio rose from 0.24 to 0.8. Optimal FPR and BPR combinations improved net thrust by up to 35% and reduced SFC by 26%. Although the hybrid system’s power-to-weight ratio was 30%–37% lower than that of a conventional turbofan, advancements in lightweight SOFC materials and designs could enhance feasibility. These findings demonstrate the potential of SOFC-GT systems to enable zero-carbon aviation while maintaining competitive performance metrics
Perceptual Calibration and Passive Adaptation in Under-Pillow Audio Systems for Sleep and Care Environments
Get PDFThis technical report outlines a perceptually grounded calibration model for under-pillow and near-field audio systems. The approach enables real-time tuning based on how sound is actually perceived through materials like foam and fabric. It supports sleep clarity, dementia care, and low-volume accessibility by using comparative signal analysis, passive interaction modelling, and non-diagnostic EQ shaping. All processing occurs locally, preserving privacy while adapting to listener context. Though focused on sleep environments, the same principles apply to wearable, embedded, or surface-coupled audio systems
Opportunities and challenges for monitoring terrestrial biodiversity in the robotics age
No full textWith biodiversity loss escalating globally, a step change is needed in our capacity to accurately monitor species populations across ecosystems. Robotic and autonomous systems (RAS) offer technological solutions that may substantially advance terrestrial biodiversity monitoring, but this potential is yet to be considered systematically. We used a modified Delphi technique to synthesize knowledge from 98 biodiversity experts and 31 RAS experts, who identified the major methodological barriers that currently hinder monitoring, and explored the opportunities and challenges that RAS offer in overcoming these barriers. Biodiversity experts identified four barrier categories: site access, species and individual identification, data handling and storage, and power and network availability. Robotics experts highlighted technologies that could overcome these barriers and identified the developments needed to facilitate RAS-based autonomous biodiversity monitoring. Some existing RAS could be optimized relatively easily to survey species but would require development to be suitable for monitoring of more ‘difficult’ taxa and robust enough to work under uncontrolled conditions within ecosystems. Other nascent technologies (for instance, new sensors and biodegradable robots) need accelerated research. Overall, it was felt that RAS could lead to major progress in monitoring of terrestrial biodiversity by supplementing rather than supplanting existing methods. Transdisciplinarity needs to be fostered between biodiversity and RAS experts so that future ideas and technologies can be codeveloped effectively
Sex differences in the association between nutritional status and in‐hospital mortality in HFpEF patients
Get PDFAims: The study aimed to assess whether the effect of nutritional risk score (NRS‐2002) on the odds of in‐hospital mortality would be modulated by sex and body mass index (BMI) in patients with heart failure with preserved ejection fraction (HFpEF). Methods and results: A retrospective analysis was conducted on 234 patients admitted with acute heart failure, in whom HFpEF was identified as the underlying diagnosis, during the period 08.2018–08.2020. Nutritional status was assessed using BMI and NRS2002. NRS‐2002 is a validated screening tool recommended by ESPEN that evaluates nutritional risk based on recent weight loss, reduced dietary intake, severity of illness and age. Logistic regression models were used to evaluate the associations between these nutritional indices and in‐hospital mortality. The models were adjusted for sex, age and comorbidities. Interactions between NRS2002, BMI and sex were also explored to assess whether the effect of nutritional status on mortality was modulated by these factors. The analysis revealed that male patients with elevated NRS2002 scores had significantly higher odds of in‐hospital mortality (odds = 47.512 at NRS2002 = 4 compared to odds = 0.031 at NRS2002 = 1; BMI = 28 in both cases). BMI negatively modulated the odds of death (OR = 0.843, P = 0.012) in the population sample. This effect was consistent across the sample regardless of NRS2002 score, as NRS2002 did not significantly influence the BMI–mortality relationship (P = 0.289). Importantly, this relationship was observed only in male patients, as no such association between NRS2002 and mortality was found in women. Conclusions: In male patients with HFpEF, elevated NRS2002 scores showed significantly higher odds of in‐hospital mortality. Higher BMI was generally associated with lower odds of mortality, with this protective effect remaining consistent in the population sample, regardless of the NRS2002 score
Perceptually Adaptive Alarm Systems Using Doppler-Based Pitch Modulation
Get PDFThis technical note presents a novel alarm system design that uses Doppler-based pitch and amplitude modulation to help people better understand emergency situations through sound alone. By embedding intuitive rising and falling pitch cues into familiar alarm tones, the system conveys urgency, direction, and safety—even through walls, smoke, or in unfamiliar environments. It is designed to support everyone, including those with hearing or visual impairments, and works alongside existing fire, hospital, or building alarms without requiring new hardware.The system adapts to real-time sensor data (e.g., heat, smoke, gas), allowing alarms to reflect the severity and location of danger. It also includes digital watermarking so each alarm tone carries a unique identity that can be decoded remotely, such as through a phone microphone. This document shares the design openly to establish prior art, prevent enclosure, and support inclusive safety innovation in public and private spaces
From Design to Deployment: A Comprehensive Review of Theoretical and Experimental Studies of Multi-Energy Systems for Residential Applications
Get PDFMulti-energy systems (MESs) use more than one energy vector to fulfil users' electrical, thermal, and cooling demands. This paper examines the recent developments in the design, optimisation, and implementation of MESs, focusing on residential applications. Firstly, recent advances in the design and optimisation of MESs are explained and analysed. The field is characterised by the proliferation of bespoke optimisation methods suitable for this kind of problem. Secondly, practical implementation in the laboratory of MESs and microgrids supplying electrical and thermal loads is discussed. The hardware requirements, in terms of controllers and converters, are critically analysed. This is contrasted with the real-world implementation of MESs or multi-output microgrids in the real world. A description of the communication infrastructure required for real-world implementation is discussed. Finally, a critical review of the entire process, the areas of challenge, and potential research opportunities are presented
Should there be a legal duty to rewild to remedy ecocides of the past: the case of the lost bears, wolves and lynxes of the United Kingdom
Get PDFIn light of the ongoing environmental crisis, amending Article 5 of the Rome Statute of the International Criminal Court to include the crime of ecocide has been under consideration for a number of years. With this objective in mind, an Independent Expert Panel provided a legal definition of ecocide in 2021. The initiative was well received among legal scholars although some amount of criticism was levelled at the definition. It will be respectfully submitted that any legal recognition of ecocide regardless of the wording of the definition – albeit a significant progress – would still fall short of expectations. Prosecution of ecocide can only be prospective pursuant to the principle of legality and cannot cover past ecocides the effects of which can still be felt today. While legal efforts focus on the prevention of ecocide, issues of past ecocides in the form of extinction of species and possible remedies remain scarcely addressed. Polly Higgins in her seminal works on ecocide mentioned restoration as a possible remedy to ecocide. Should there be a legal obligation on states to restore nature through rewilding when native species have gone extinct through ecocide? The article will use the United Kingdom (UK) as a case study. Bears, wolves and lynx went extinct as a result of human persecution in the UK. Should there be an additional legal duty on the UK, on the ground of ecocide, to reintroduce extinct native species aside from other international legal commitments? Ultimately, this raises the question of whether ecocide in the form of extinction of species should not be covered under a dedicated legal instrument especially given the fact that animals are sentient beings
Privacy–preserving dementia classification from EEG via hybrid–fusion EEGNetv4 and federated learning
Get PDFAs global life expectancy rises, a growing proportion of the population is affected by dementia, particularly Alzheimer's disease (AD) and Frontotemporal dementia (FTD). Electroencephalography (EEG) based diagnosis presents a non-invasive, cost effective alternative for early detection, yet existing methods are challenged by data scarcity, inter-subject variability, and privacy concerns. This study proposes lightweight and privacy-preserving EEG classification framework combining deep learning and Federated Learning (FL). Five convolutional neural networks (EEGNetv1, EEGNetv4, EEGITNet, EEGInception, EEGInceptionERP) have been evaluated on resting-state EEG dataset comprising 88 subjects. EEG signals are preprocessed using band-pass (1–45 Hz) and notch filtering, followed by exponential standardization and 4-second windowing. EEGNetv4 outperformed among other EEG tailored models, and upon utilizing the hybrid fusion techniques it achieves 97.1% accuracy using only 1,609 parameters and less than 1 MB of memory, demonstrating high efficiency. Moreover, FL using FedAvg is implemented across five stratified clients, achieving 96.9% accuracy on the hybrid fused EEGNetV4 model while preserving data privacy. This work establishes a scalable, resource-efficient, and privacy-compliant framework for EEG-based dementia diagnosis, suitable for deployment in real-world clinical and edge-device settings
A computational mechanistic analysis of transport–chemistry interactions controlling the complex pressure dependence of laminar premixed hydrogen flames
Get PDFThe mechanisms governing the complex pressure (p) dependence of premixed laminar hydrogen/air flame speed () are investigated computationally. Using 1D unstretched flame simulations, we explain why decreases monotonically with pressure when lean but exhibits a non-monotonic turnover near stoichiometry and a plateau when rich. We demonstrate that this response is fundamentally controlled by transport–chemistry coupling, as diffusion-neutral (Le=1) models fail to reproduce the trends. Our analysis reveals that increasing pressure induces critical structural penalties: the flame’s explosive kernel progressively de-aligns from the zone of maximum mixing, and local reactant diffusive asymmetry weakens. This structural-transport competition, which overrides pure chemical acceleration, is captured by a kernel-level Damköhler number that consistently decreases with pressure. Computational Singular Perturbation analysis confirms this mechanistic picture, showing pressure shifts kinetic control from prompt branching to a contested HO subsystem and activates key recombination sinks
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