Heriot-Watt University

In recent years, quantum information technology, as a subversive and strategic technology that has attracted much attention, acquires, transmits, and processes information by means of unique physical phenomena such as quantum entanglement, nonlocality, and non-cloning. Quantum imaging technology achieves non-local imaging of targets by extracting entangled light quantum information with temporal and spatial correlation characteristics. By using the anti-interference and anti-turbulence characteristics of quantum entangled states, quantum imaging technology can break through the physical limits of traditional imaging fields, thereby improving imaging resolution and sensitivity. The latest technological development in quantum imaging has prompted researchers to study high-resolution and fast quantum imaging based on the spatial correlation characteristics of entangled photon pairs. In this circumstance, we propose a novel quantum imaging method based on two-step adaptive sampling optimization and carry out experimental verification. In concrete terms, in order to solve the problem that the efficiency of entangled light quantum imaging is limited by Digital Micromirror Device (DMD) sampling, we select the two-step adaptive sampling optimization algorithm to reduce the influence of DMD scanning on imaging efficiency. At the same time, for the sake of solving the problem that the quality of entangled photon quantum imaging is limited by the accuracy of coincidence counting, we add delay difference calculation in the imaging process and correct the signal photon arrival time pulse sequence to ensure the accuracy of coincidence counting. Finally, we conduct a large number of experiments to evaluate the performance of the two-step adaptive sampling optimization algorithm and verify the superiority of the proposed entangled quantum imaging method practically.

Digital technologies can help support the health of migrants and refugees and facilitate research on their health issues. However, ethical concerns include security and confidentiality of information; informed consent; how to engage migrants in designing, implementing and researching digital tools; inequitable access to mobile devices and the internet; and access to health services for early intervention and follow-up. Digital technical solutions do not necessarily overcome problems that are political, social, or economic. There are major deficits with regard to (1) reliable data on the health needs of migrants and mobile populations and on how they can use digital tools to support their health; (2) evidence on effectiveness of solutions; and (3) a broad framework to guide future work. This article provides a wide socio-technical perspective, as a framework for analysis and developing coherent agendas across global-to-local spaces, with particular attention to the European region.

Over the past two decades, numerous hand exoskeletons have been developed for rehabilitation scenarios, yet very few have the capability to assess spasticity. This paper introduces a quantitative assessment approach for hand spasticity developed on a cable-driven hand exoskeleton that was specifically designed with spastic hand in mind. The exoskeleton features an adaptive cable-linkage transmission mechanism equipped with bi-directional force transducers, enabling constant-velocity extension and flexion of individual finger joints while simultaneously recording joint torque and angle. Based on the exoskeleton, a multi-layered quantitative assessment approach is proposed to evaluate spasticity on individual finger joints. The basis of the approach is collecting joint resistance information automatically following Modified Tardieu Scale, serving for the computation of six middle-level parameters related to the properties of a spastic joint. The parameters include the range of motion, average resistance torque, joint stiffness, joint viscosity, catch angle, and reflex-induced resistance torque. The first four mechanical parameters are finally combined into a biomechanical metric, whereas the rest two reflex-related parameters result in a neurological metric, to neatly describe spasticity level. The performance of the exoskeleton to measure the parameters was tested on six healthy subjects. The assessment approach applied with the developed exoskeleton shows good reliability, repeatability, and validity to capture the features of spastic hands, providing strong evidence for further validation on real patients.

Resonant dispersive wave (RDW) generation in hollow capillary fibers (HCFs) is a powerful technique for producing ultrashort light pulses in the deep ultraviolet range, which are important for ultrafast spectroscopy and material processing. However, the complex nonlinear dynamics governing this process and the large associated parameter space make it challenging to achieve optimal RDW pulses with the highest peak power. In this study, Bayesian optimization (BO) is coupled with the open source Luna.jl simulation framework to optimize the HCF and pump pulse paramters for less than 5 femtosecond (fs) RDW generation at a target wavelength of 200 nm. Temporally non-structured RDW were consistently identified with peak powers of up to 14 GW, exceeding experimentally published values by up to 70 %. Furthermore, a subset of the RDW optima exhibited an energy stability that is better than that of the pump pulse. Given that this approach can be generalized to other RDW wavelengths, our findings suggest that BO is a valuable tool in developing HCF systems that support RDW generation tailored to a particular experimental need.

The aim of the current paper is to demonstrate the use of a novel prototype horizontal rotation stage, within a scanning electron microscope (SEM). Here we utilise sedimentary rock chips and grains, with images collected every 10 ° of rotation, to produce a continuous overlapping field of view 360° montage. The same procedure can also be used to collect elemental X‐ray maps. The collected images and maps can be simply combined into an image stack and saved as a movie format of the rotating specimen through 360°. More significantly, individual images and elemental maps can be reconstructed using photogrammetry imaging software, producing three‐dimensional (3D) models with mesh worked surfaces and rendered texture (colour or greyscale) based on SEM image and X‐ray data. This produces photorealistic smoothly transitioning movies with 360° fields of view around each object and can also be saved for stereo‐viewing using a virtual reality (VR) headset. This new technique generates highly detailed information on the 3D structural and compositional relationships between components at the submicron to millimetre scale. The technique has widespread applications, including imaging other geological materials, biological mineralised tests and material science specimens such as metals, ceramics and building materials.

Cavitation erosion caused by the energy released from collapsing bubbles is a major failure mode of engineering components in hydraulic and marine environments. Thermal spray coatings provide a cost-effective and environmentally friendly solution to improve the cavitation erosion resistance of components. Functionally graded WC-NiCrBSi coatings were deposited by the high-velocity oxy-fuel (HVOF) process and post-retreated using hot isostatic pressing (HIPing) to improve the interlamellar bonding at two different temperatures of 850 °C and 1200 °C. ASTM G32 cavitation erosion tests were conducted in seawater for a total test time of 24 hours. Microstructural and post-cavitation test investigations were conducted on the coating surface and cross sections using scanning electron microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS). Microstructural phases were investigated using x-ray diffraction (XRD). Changes in microstructure, hardness, fracture toughness, and porosity due to HIPing post-treatment are discussed. The results of this investigation show that the cavitation erosion resistance of coatings improves after HIPing post-treatment. This improvement was five times the cavitation wear resistance of as-sprayed coating at the HIPing temperature of 1200 °C, surpassing the cavitation erosion resistance of the AISI 440 C steel substrate. Microstructural changes leading to the strengthening of interlamellar and carbide-matrix boundaries, which reduce intergranular and transgranular crack propagation, are attributed to this improvement. A combination of the improvement in hardness, elastic modulus, porosity, and fracture toughness due to microstructural changes resulted in the superior cavitation erosion resistance of HIPed coatings.

This study explores whether live transcription generated with the technology of automatic-speech-recognition (ASR) can be used to facilitate simultaneous interpreting. This article reports an analysis of trainee interpreters’ perceptions based on post-task structured interviews after an eye-tracked interpreting task without live transcription in the first half and with live transcription in the second half, which was done by a group of trainee interpreters from a postgraduate professional interpreting programme. The interviews were analysed in triangulation with the eye-tracking data about their interpreting behaviours. The results show that most participants perceived live transcription beneficial, with data indicating improved performance and lowered error rates in terms of terminologies, numbers, and proper names. It is also found that while some interpreters reported that they can adeptly manage multimodal inputs, others reported challenges in optimizing their focus of attention when live transcription was provided. The overall interference score in interpreting with live transcription spikes from 9 to 13.2, suggesting fluctuating cognitive demand. Eye-tracking data further corroborate these attentional dynamics, echoing participants’ self-reported behaviours. The study points to the need for training programmes to equip interpreters with capabilities to utilize technological tools such as live transcription, ensuring optimal attention management and overall performance.

Shapley effects are enjoying increasing popularity as importance measures. These indices allocate the variance of the quantity of interest among every risk factor, and a risk factor explaining more variance than another one is more important. Recently, Vallarino et al. (ASTIN Bull J IAA, 2023. https://doi.org/10.1017/asb.2023.34 ) propose a computational strategy for Shapley effects using the idea of cohorts of similar observations. However, this strategy becomes extremely computationally demanding if the dataset contains many observations. In this work we propose a computational shortcut based on design of experiments and clustering techniques to speed up the computational time. Using the well-known French claim frequency dataset, we demonstrate the huge reduction in computational time, without a significant loss of accuracy in the estimation of the Shapley effects.

Single-photon time-of-flight light detection and ranging (LiDAR) is a versatile technique for the measurement of absolute distances and for depth profiling. It has a wide variety of applications (e.g., land surveying, autonomous car navigation, underwater imaging) with the potential to achieve high-resolution three-dimensional images over long ranges when the key components of the measurement system are of a suitably high specification. In this work, a novel, high-efficiency, and low timing jitter superconducting nanowire single-photon detector, in conjunction with a custom single-pixel scanning transceiver system, and the time-correlated single-photon counting technique, enable the acquisition of millimeter-scale resolution depth images of scenes at standoff distances of hundreds of meters. A 1550 nm wavelength fiber laser was coupled to the monostatic transceiver to provide the illumination. The system was eye-safe with the maximum average optical output power being $\le \;{3.5}\;{\rm mW}$ for measurements of a scene at a standoff distance of 1 km. The overall system instrumental response was approximately 13 ps full width half maximum. This enabled 1 mm depth features on a reference board and a human head to be clearly resolved when measured by the system in broad daylight at standoff distances of 45 and 325 m using per-pixel acquisition times of between 0.25 and 1 ms. These high-resolution results demonstrate the enormous potential of such a system to acquire detailed depth and intensity images of scenes from long distances in daylight or darkness conditions. This could lead to step change improvements in applications such as facial and human activity recognition and the imaging of scenes through clutter and atmospheric obscurants.

As quantum key distribution progresses into commercial products and services, there is growing interest in technological solutions that improve performance and/or reduce costs. We present an experimental demonstration of the polarization-based three-level decoy-state BB84 quantum key distribution (QKD) protocol, at a clock frequency of 50 MHz, that relies on fewer resources at the receiver and increases robustness to side-channel attacks for both the transmitter and receiver. A single-laser source and cascade of electro-optic modulators provide the four polarization states, while a photonic recombiner with time-multiplexed inputs enables detection with a single detector.

Enhanced weathering (EW) with agriculture uses crushed silicate rocks to drive carbon dioxide removal (CDR)1,2. If widely adopted on farmlands, it could help achieve net-zero emissions by 20502, 3–4. Here we show, with a detailed US state-specific carbon cycle analysis constrained by resource provision, that EW deployed on agricultural land could sequester 0.16–0.30 GtCO2 yr⁻¹ by 2050, rising to 0.25–0.49 GtCO2 yr⁻¹ by 2070. Geochemical assessment of rivers and oceans suggests effective transport of dissolved products from EW from soils, offering CDR on intergenerational timescales. Our analysis further indicates that EW may temporarily help lower ground-level ozone and concentrations of secondary aerosols in agricultural regions. Geospatially mapped CDR costs show heterogeneity across the USA, reflecting a combination of cropland distance from basalt source regions, timing of EW deployment and evolving CDR rates. CDR costs are highest in the first two decades before declining to about US$100–150 tCO2⁻¹ by 2050, including for states that contribute most to total national CDR. Although EW cannot be a substitute for emission reductions, our assessment strengthens the case for EW as an overlooked practical innovation for helping the USA meet net-zero 2050 goals5,6. Public awareness of EW and equity impacts of EW deployment across the USA require further exploration7,8 and we note that mobilizing an EW industry at the necessary scale could take decades.

The analysis of an scheme often assumes that the process standard deviation is accurately assessed and remains constant. However, in practice, this is rarely true. Noting that the group runs (GR) scheme performs better than the synthetic scheme, in this research, we proposed the GR exponentially weighted moving average (GR EWMA) and t schemes and determined their true optimal parameters using the optimisation programmes. Our findings indicate that similar to the synthetic EWMA scheme, the proposed GR EWMA scheme is not resilient to errors in the estimation of the standard deviation of the process or when the standard deviation changes. Therefore, we also proposed the GR EWMA t scheme for surveilling the mean of a process. We demonstrate that this t scheme possesses the required robust characteristic. We showcase our developed schemes’ superiority over existing schemes in a detailed performance comparison. An illustrative example related to the hard‐baking process is utilised to demonstrate the applicability of the suggested schemes.

Owing to their good efficiency and use as heat exchangers, heat sinks support electronic devices in effective heating dissipation. However, heat dissipation remains a huge challenge to optimum thermal performance of heat sinks. The paper divides into two main broad categories. The first part deals with thermal design and thermal modeling of some various aspects of heat sinks: effects of natural convection heat dissipation mechanisms; geometrical configurations of heat sinks; and intake and outflow positions. The study broadens to the core materials, flat fins (particularly FPFHS and PFHS fins), and porous fins. Multi-wicks and multi-medium heat sinks are investigated, and a comprehensive analysis of the attributes affecting heat transfer and the efficacy of heat dissipation in these mechanisms is also provided. The latter portion examines interior heating by examining several indoor geometries, including cylindrical, circular, rectangular, and hexagonal forms, and evaluating their influence on heat transport. Additionally, empirical investigations examining enclosures with diverse fin designs are evaluated, along with the impact of interior layouts on different fin arrangements for both natural and mixed convection. The project encompasses multiple research initiatives aimed at developing a framework for the continued investigation of heat sinks within cavities. This work offers insightful recommendations for scientists and researchers, providing fundamental understanding of heat sinks and cavitation Procedures. The use of cavitation-based technologies in operations enhances the heat transfer efficiency of heat sinks, specifically heat exchangers employed for cooling electrical equipment, hence accelerating the research process. Their principal attributes, including cost efficiency, good heat dissipation, and ease of production, account for the advantages.

Purpose This study aims to investigate the association between daily fruit and vegetable consumption and healthcare utilization among older European adults. Our findings inform policies aimed at optimizing healthcare resource allocation and promoting healthy ageing in Europe's growing elderly population. Methods Leveraging data from the 8th wave of the Survey of Health, Ageing and Retirement in Europe (SHARE) conducted in 2019–2020, this cross-sectional analysis examines associations between daily fruit and vegetable intake and hospitalization rates, hospital length of stay, visits to general practitioners, and specialist consultations. Results Our results reveal no significant difference in hospitalization probability between individuals consuming fruits/vegetables daily versus less frequently. However, among hospitalized individuals, daily consumption is associated with fewer hospitalizations and shorter hospital stays. Moreover, daily fruit and vegetable intake is positively associated with increased likelihood of consulting general practitioners and specialists. This association may be indicative of a broader health consciousness and proactive approach to well-being management among individuals who prioritize dietary choices. Conclusion These findings suggest that while fruit and vegetable consumption alone may not prevent hospitalizations in this segment of the population, it is linked to reduced re-hospitalization risk and shorter inpatient durations when hospitalized. Additionally, a diet rich in fruits and vegetables appears to promote greater engagement with preventive primary and speciality care among older European adults. Overall, the study highlights dietary behaviour as a potential factor influencing healthcare utilization and expenditures for ageing populations.

Particulate matter (PM) air pollution has been identified as one cause of human health impact with the estimated global 8.8 million attributable deaths. Thailand experiences haze episode every year, which can lead to high ambient concentrations of particulate matter in ambient air. This study aims to investigate the relationship of indoor and outdoor air quality in both haze and non-haze period in two cities in Thailand: namely Bangkok and Chiang Mai. We conducted the air quality sampling in various styles of house, with 17 houses in both urban and rural areas, between April to October 2019. The results indicated that the concentration of PM2.5 in indoor air in Bangkok were 19.85 and 11.40 μg/m³ for haze and non-haze period, respectively, whereas the PM10 concentrations were 32.124 and 17.49 μg/m³ for haze and non-haze period, respectively. The corresponding average of outdoor air concentrations were 26.26 and 16.68 μg/m³ for haze and non-haze, respectively. While the PM10 concentrations were 46.36 and 23.86 μg/m³ for haze and non-haze period, respectively. In Chiang Mai, it was observed that the mean concentration of PM2.5 in indoor was 106.80 μg/m³ and 5.52 μg/m³ for haze and non-haze periods, respectively. Regarding PM10, it was observed that the mean concentration in indoor was 118.54 μg/m³ and 9.74 μg/m³ for haze and non-haze periods, respectively. Indoor/Outdoor (I/O) ratios of PM2.5 varied in Bangkok average was 0.76 for haze and 0.68 for non-haze period. The I/O ratio in Chiang Mai was 0.91 and 1.16 for haze and non-haze episode, respectively. Indoor/Outdoor (I/O) ratios of PM10 varied in Bangkok average was 0.70 for haze and 0.73 for non-haze period. The I/O ratio in Chiang Mai was 0.92 and 0.96 for haze and non-haze episode, respectively Our findings indicated the influences of outdoor air quality on indoor air quality during both haze and non-haze episode. The intrusion of outdoor air in Chiang Mai to the houses caused a higher I/O ratio than Bangkok due to the characteristics of house and culture. The indoor air quality in terms of particulate matter were dominated by outdoor air quality. Thus, people should close doors/windows during the haze as well as non-haze episode to avoiding the pollutant accumulation.

This review provides an insightful and comprehensive exploration of the emerging 2D material borophene, both pristine and modified, emphasizing its unique attributes and potential for sustainable applications. Borophene's distinctive properties include its anisotropic crystal structures that contribute to its exceptional mechanical and electronic properties. The material exhibits superior electrical and thermal conductivity, surpassing many other 2D materials. Borophene's unique atomic spin arrangements further diversify its potential application for magnetism. Surface and interface engineering, through doping, functionalization, and synthesis of hybridized and nanocomposite borophene‐based systems, is crucial for tailoring borophene's properties to specific applications. This review aims to address this knowledge gap through a comprehensive and critical analysis of different synthetic and functionalisation methods, to enhance surface reactivity by increasing active sites through doping and surface modifications. These approaches optimize diffusion pathways improving accessibility for catalytic reactions, and tailor the electronic density to tune the optical and electronic behavior. Key applications explored include energy systems (batteries, supercapacitors, and hydrogen storage), catalysis for hydrogen and oxygen evolution reactions, sensors, and optoelectronics for advanced photonic devices. The key to all these applications relies on strategies to introduce heteroatoms for tuning electronic and catalytic properties, employ chemical modifications to enhance stability and leverage borophene's conductivity and reactivity for advanced photonics. Finally, the review addresses challenges and proposes solutions such as encapsulation, functionalization, and integration with composites to mitigate oxidation sensitivity and overcome scalability barriers, enabling sustainable, commercial‐scale applications.

We undertake a detailed study of the gaugings of two-dimensional Yang–Mills theory by its intrinsic charge conjugation 0-form and centre 1-form global symmetries, elucidating their higher algebraic and geometric structures, as well as the meaning of dual lower form symmetries. Our derivations of orbifold gauge theories make use of a combination of standard continuum path integral methods, networks of topological defects, and techniques from higher gauge theory. We provide a unified description of higher and lower form gauge fields for a p-form symmetry in the geometric setting of p-gerbes, and derive reverse orbifolds by the dual $(-1)$-form symmetries. We identify those orbifolds in which charge conjugation symmetry is spontaneously broken, and relate the breaking to mixed anomalies involving $(-1)$-form symmetries. We extend these considerations to gaugings by the non-invertible 1-form symmetries of two-dimensional Yang–Mills theory by introducing a notion of generalized $\theta$-angle.