Modelling and numerical optimisation of refractive surface patterns for transmissive solar sails

Transmissive solar sail designs have been proposed with performance and utility benefits over traditional solar sails, particularly in low Earth orbit. The functional element of these new sails is their refractive or diffractive surface pattern. This paper explores the design of refractive sail patterns using numerical optimisation, and explores the validity of using model-free reinforcement learning algorithms for this purpose. In particular, the performances of triangular prism and semi-cylindrical lightfoil patterns from prior literature are iteratively improved. To do this, a ray tracing optical simulation was developed that models the solar radiation pressure and torque per unit area of illuminated, refractive patterns in a vacuum. Meanwhile, a numerical optimiser was developed to iteratively improve upon simulated patterns according to user-defined fitness functions. Depending on their purpose, patterns were optimised for either tangential-to-sail solar radiation pressure or self-stabilising corrective torque at a Sun-pointing attitude, or range of attitudes. The optimiser was shown to be capable of substantially improving the performance of optical elements, particularly through the harnessing of total internal reflection. In one case, the numerical optimiser was shown to improve the maximum tangential radiation pressure of an analytically optimised polystyrene prism pattern by 58%. In another case, the optimiser improved the peak corrective torque of a pattern of polyethylene terephthalate lightfoils by 74%

"People in my life just play different roles": A retrospective qualitative study of friendships among young adults who self-harmed during adolescence

Self-harm is a global public health concern presenting increasing rates in recent years, especially among young people. This population seldom access formal help, and typically rely on informal sources of support, mainly friends. The role, importance and meaning of friendships in the context of self-harm remains poorly understood, highlighting the need to explore young people's lived experiences. In the present study we conducted semi-structured retrospective qualitative interviews, prompted by the Card-sort Task for Self-Harm About Friends (CaTS-AF), to explore the experiences of 11 young adults (M=19.09; SD=0.70; M=2, F=9) who self-harmed during adolescence. Data were analysed using Reflexive Thematic Analysis (RTA). Three themes were developed which consider 1) the role of friendships in self-harm progression; 2) the role of self-harm in friendship evolution; and 3) the meaning of friendships in the context of adolescents' self-harm. The first two themes highlight the interdependent nature of friendships and self-harm, where these two experiences influence one another. Furthermore, not only are friendships shaped by self-harm, but they acquire specific meanings, dynamics and expectations within the context of the behaviour. Overall, friends are a key part of adolescents' self-harm, as sources of both risk and protection. It is essential to further integrate friendships, a developmentally significant aspect of adolescents' social experiences, into self-harm research and clinical practice

Measuring the elastic properties of the Gibeon meteorite using laser ultrasound

Meteorites provide access to information on the formation and evolution of planetary bodies which is otherwise difficult to study. The unique nature of these samples and their relative scarcity means that non-destructive analysis techniques are needed to study their properties. This paper uses the laser ultrasound technique spatially resolved acoustic spectroscopy to non-destructively determine both the crystal orientation and the single crystal elastic constants (Cij) of a sample of the Gibeon meteorite. There are no published values to directly compare the results of this study, as non-destructive measurements of the single crystal elasticity on granular material have not been possible. Therefore, comparisons with theoretical values for man-made iron-nickel alloys are given showing the Cij values are in the expected range. There are studies providing bulk elastic properties of meteorites, and so calculated bulk properties derived from the single crystal elasticity measurements are compared and also agree well

Molecular beam epitaxy of boron arsenide layers

Thermal management is the main technological challenge for next generation electronic devices. Recently, several groups successfully demonstrated boron arsenide (BAs) microcrystals with an ultrahigh thermal conductivity approaching that of diamond. The development of scalable epitaxial BAs growth techniques is urgently required to enable a transition of BAs material to real applications. We have grown boron arsenide layers on 3C-SiC/Si and sapphire substrates over a wide temperature range using molecular beam epitaxy (MBE). We have confirmed the incorporation of arsenic by a wide range of characterization techniques. The best quality of the boron arsenide layers was achieved at high growth temperatures of around 750 °C. We have demonstrated that high temperatures nucleation of the boron arsenide layer started with deposition of boron-rich monolayers on the substrate surface. For the epitaxy on sapphire during the initial growth phase, the cubic boron arsenide layers align with the hexagonal structure of the sapphire substrate and grow in the (111) direction for a few crystalline monolayers; however, currently, we are not able to sustain that, and the boron arsenide layer becomes amorphous. For boron arsenide layers grown at high temperatures, we have observed an increase in the thermal conductivity and cathodoluminescence optical response with a reproducible peak centered at ∼1.67 eV. The experimental results are explained by increased chemical interaction between arsenic and boron at growth temperatures above ∼600 °C. Our experimental data show that MBE growth conditions need to be further optimized first to improve stoichiometry and after that to decrease point-defect densities in boron arsenide layers to achieve an increase in the thermal conductivity

Short-Term Risk of Cardiovascular Events in People Newly Diagnosed With Gout

ObjectiveTo investigate the temporal association between first diagnosis of gout and cardiovascular events in the short-term.MethodsWe performed a self-controlled case series analysis and a cohort study using data from linked primary care, hospitalisation, and mortality records from the UK's Clinical Practice Research Database (GOLD). We included individuals with a new diagnosis of gout either in the primary care or secondary care between 01/01/1997 and 31/12/2020.The first consultation at which gout was diagnosed was the exposure of interest. The main outcome consisted of cardiovascular events (i.e., a composite of fatal and non-fatal myocardial infarction, ischaemic or haemorrhagic stroke, and transient ischaemic attack).Results4,398 patients (66.9% male, mean age 74.6 years) had a cardiovascular event within ±2 years of their first recorded diagnosis of gout. The incidence of cardiovascular events was significantly higher in the 30 days after the first diagnosis of gout compared to baseline (adjusted incidence rate ratio: 1.55 ((95% confidence interval) 95%CI: 1.33-1.83)).Among 76,440 patients (72.9% male, mean age 63.2 years) included in the cohort study, the incidence of cardiovascular events in the 30 days after the first gout diagnosis (31.2 events/1,000 person-years, 95%CI: 27.1-35.9) was significantly higher than in days 31-730 after gout diagnosis (21.6 events/1,000 person-years, 95%CI:20.8-22.4) with a rate difference of -9.6 events/1,000 person-years, 95%CI: -14.0 to -5.1).ConclusionIndividuals had a short-term increased risk of cardiovascular events in the 30 days following the first consultation at which gout was diagnosed

Responsible Generative AI for SMEs in UK and Africa Case Study Cocreation Workshop Report

The University of Nottingham hosted a co-creational workshop from 29th to 31st January at the Jubilee Hotel & Conference facilities, bringing together participants from the RAISE project’s case studies across the UK and Africa. The workshop focused on small and medium-sized enterprises (SMEs) utilising generative AI for their products and services that form part of the RAISE case studies. The aim was to explore the challenges of integrating responsible research and innovation (RRI) practices into AI applications and to get feedback on current Responsible Artificial Intelligence (RAI) guidelines including the first draft of the RAISE guidelines.The workshop also evaluated tools for assessing AI’s responsible use, including the UK Government’s AI Management Essentials, ALTAI, and Microsoft’s Responsible AI Impact Assessment Tool. While these tools were considered useful, participants highlighted issues with their formatting and suggested improvements, such as the ability to save progress and revisit answers. Feedback on the RAISE guidelines emphasised the need for adaptable, SME-focused frameworks and a maturity scoring system to prioritise RRI elements at various stages of development. The workshop highlighted the challenges SMEs face in adopting responsible AI practices and will inform updates to the RAISE guidelines to better support SMEs in integrating responsible AI strategie

T₁-Dark Rim as a Marker of New and Chronic Active Multiple Sclerosis Lesions: A Serial Study With Frequent 7T MRI

Background and Purpose: Chronic active multiple sclerosis (MS) lesions represent a particularly destructive subset of lesions on pathology. However, their imaging correlates, including paramagnetic rim lesions (PRLs) detected on susceptibility-weighted imaging, lack sensitivity and are difficult to implement in clinical practice. This exploratory, longitudinal study investigates the prevalence and temporal dynamics of a novel imaging marker, T 1-dark rims, and their relationship with PRLs observed on quantitative susceptibility mapping (QSM). Methods: Four untreated people with MS underwent 7-Tesla MRI scanning six times over a period of 36 weeks. New and pre-existing lesions were analyzed for the presence and temporal evolution of T 1-dark and QSM rims. Quantitative T 1 values were derived using B 1 maps, and the relationship between rim status and lesion size was evaluated. Results:Of the 159 baseline lesions, 22 (14%) had T 1-dark rims, 11 (7%) had QSM rims, and five lesions had both. T 1-dark and QSM rims showed temporal changes, with T 1-dark rims preceding new QSM rim appearance in three out of four (75%) lesions. Eleven out of 20 (55%) newly formed lesions had T 1-dark rims, with a T 1-dark rim present in all new lesions over 100 mm 3. Small new lesions lacked discernible rims, but their overall T 1 values aligned with those of larger lesion T 1-dark rims implying shared pathological processes. Conclusions: T 1-dark rims were more common than QSM rims, with greater prevalence in newly formed lesions. We propose they represent edema and inflammation associated with early stages of chronic active lesion formation visible despite, not because of, iron accumulation

Application of life cycle assessment for enhancing sustainability of district heating: A multi-level approach

District heating (DH) is a proven heat generation and distribution technology that enhances energy efficiency and reduces carbon emissions at scale, making it a key component of sustainable energy strategies. Compared to traditional heat generation methods such as using onsite fossil-fuelled combustion boilers or electrically driven heating systems, DH offers superior environmental advantages, particularly when renewable energy and waste heat are deployed as primary fuel energy mix. To comprehensively evaluate the sustainability of DH, life cycle assessment (LCA) is widely adopted to determine environmental impacts across all life cycle stages, from material extraction to disposal. This systematic review identifies the absence of a unified, adaptable framework for LCA application in DH systems. To address this, the study proposes a structured multi-level framework, interpreting methodological diversity across component, facility, and network levels. Component-level studies offer insights into specific technologies and materials; facility-level assessments focus on operational performance and energy sources; network-level evaluations provide holistic system impacts. Aligning studies within these analytical levels enables fairer comparisons, supports cross-regional learning, and promotes methodological integration. Recurring challenges include inconsistent methodologies, varying system boundaries, and limited local data. Emerging technologies such as hybrid systems, smart grids, and energy storage remain underrepresented in LCA studies. Tools like SimaPro, GaBi, and OpenLCA are widely used, yet the rapid evolution of DH systems calls for more tailored applications. This review supports the development of standardised, yet flexible LCA practices and proposes a refined multi-level framework to guide comprehensive, context-specific evaluations. It emphasises the importance of validating approaches across diverse contexts and strengthening LCA's contribution to the design of sustainable, low-carbon DH solutions for urban energy systems

Additive manufacturing of functionalised atomic vapour cells for next-generation quantum technologies

Atomic vapour cells are an indispensable tool for quantum technologies (QT), but potential improvements are limited by the capacities of conventional manufacturing techniques. Using an additive manufacturing (AM) technique—vat polymerisation by digital light processing—we demonstrate, for the first time, a 3D-printed glass vapour cell. The exploitation of AM capacities allows intricate internal architectures, overprinting of 2D optoelectronical materials to create integrated sensors and surface functionalisation, while also showing the ability to tailor the optical properties of the AM glass by in-situ growth of gold nanoparticles. The produced cells achieve ultra-high vacuum of 2 × 10−9 mbar and enable Doppler-free spectroscopy; we demonstrate laser frequency stabilisation as a QT application. These results highlight the transformative role that AM can play for QT in enabling compact, optimised and integrated multi-material components and devices

Investigation of support structure configurations for selective laser melting of In718

The Selective Laser Melting (SLM), as a widely used metallic Additive manufacturing (AM) process, relies heavily on support structures. This study investigated the impact of different support structure configurations on the quality of In718 samples fabricated through SLM. On the basis of a comprehensive review of existing support structures configurations from the literature, three typical configurations: block, cone, and lattice, were designed to support cantilever parts for performance comparison. A coupled thermo-structural finite element simulation using ANSYS was performed to evaluate the temperature, deformation, and thermal stress evolution during the printing process of the three supported cantilever structures. The residual stress and deformation of the printed In718 cantilevers with different support structures were measured for validation. The results showed that block support exhibits the best strength and heat dissipation capability, making it the most effective support configuration for the SLM of In718 material. This research provides a fundamental procedure for evaluating the supporting performances among various support structures for the SLM process