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Are diamonds really for everyone? Investigating the impact of lab-created gems (LCG) on cultural changes, market differentiation strategies and audience’s preferences
No full textThe explosive growth of lab-grown diamonds (LGD) or lab-created gems (LCG) is causing a significant shift in the gem market and audience preferences in some countries. Today, the rise of LGD reflects a broader movement toward man-made stones in jewellery. Companies like Pandora have embraced lab-created gems, marketing them as ethical and sustainable alternatives. Jewellery artists are investigating new design applications of synthetic gems, expanding artistic possibilities. This chapter examines LCG’ market impact, and shifting consumer’s attitudes analysed through the lens of social constructions and symbolic meanings associated with fine jewellery, as well as the socio-cultural and emotional relationships individuals have with luxury objects.The research is grounded in social constructionism, material culture, jewellery studies and the approach to analysis is interpretative. It employs data triangulation by considering findings extrapolated from the author’s survey with findings from a governmental commerce study. This chapter is timely, proposing a relevant discourse in a moment where LCG are disrupting jewellery market and lowering price barriers. It extends our knowledge of how this has an impact on constructed symbolic and socio-cultural meanings, especially for diamond jewellery like engagement rings, where status symbol perceptions are challenged. Ethical and sustainable implications around mined stones are increasingly questioned, shifting audiences’ choices to favour LCG. While this chapter is primarily concerned with audiences’ attitudes toward LCG versus natural gems, the historical and cultural framework is crucial. It examines the long-standing significance of jewellery in our society and emotional space, by highlighting how deeply embedded the meanings of gems are engrained in societal systems and rituals helping us to grasp the magnitude of the shift. A selection of case studies investigates how jewellery artists, such as the recent project at the University of Bristol, address LCG challenges. This analysis is further enriched by the results of an online survey, conducted by the author with the ethical Loughborough University approval, aimed at understanding individuals’ attitude and awareness of LCG. The findings emerging from this analysis offer valuable suggestions for understanding the role of ethical and sustainable considerations in purchasing decisions, the individual’s awareness and perceptions around synthetic gemstones and the potential impact of wearing and purchasing LCG on our emotional attachment to jewellery.</p
A generalizable decentralised sequential assignment learning spiking neural network for a perimeter defense problem
No full textIn this paper, a generalizable Decentralized sequential multitask Assignment Learning Spiking neural network (DeALS) approach is presented for solving a Perimeter Defense Problem (PDP). In PDP, a team of defenders is considered to operate on the perimeter of the territory to be protected from incoming intruders. The territory is divided into multiple angular segments. A multitask assignment Spiking Neural Network (SNN) is presented that allocates to defenders, appropriate perimeter segments corresponding to the intruder entry points, in a decentralized manner. The SNN is trained in a supervised manner based on a ground truth developed from a centralized solution for PDP. Due to the decentralized formulation, the SNN trained for one defender can be used to obtain the assignments for other defenders without the need for re-training. A consensus algorithm is also used to resolve any conflicts present in the defenders’ assigned trajectories. Detailed performance evaluation studies show that the proposed DeALS approach produces an approximate 11% higher success rate in defending the perimeter when compared with other existing state-of-the-art decentralized sequential assignment strategies. Detailed Ablation studies indicate that DeALS is easily generalizable with good performance when there are large variations in the intruder velocities, shape of the territory, size of the defender team, and the area to be protected.</p
Design, manufacture and validation of biocompatible Bulk Metallic Glasses (BMGs) for bioengineering applications
No full textBiomedical alloys are central in both research and clinical translation for the development of solutions and devices to be deployed to improve health and quality of life. Bulk metallic glasses (BMGs) offer a compelling combination of high specific strength, relatively low elastic modulus, good corrosion resistance and near-net-shape processability, making them particularly attractive for orthopaedic applications. However, a critical challenge remains in fine-tuning their multifunctional properties, including mechanical response, electrochemical stability, and cytocompatibility of alloys. This thesis investigates two types of BMGs: (1) bioresorbable (Ca-Mg-Zn) and (2) non-bioresorbable (Ti-Zr-Cu-Pd) alloys, using a comprehensive strategy integrating thermodynamic modelling, microstructural characterisation, and experimental validation approaches. The role of amorphicity-to-crystallinity ratio was also investigated. For Ca-Mg-Zn BMGs, compositions from Ca-rich and Zn-rich domains were selected using the deep-eutectic concept. Ca-rich BMGs displayed superior glass-forming ability (GFA) and bone-like stiffness in the amorphous state, while Zn-rich alloys were more corrosion-resistant. Controlled heat treatment enabled partial and full crystallisation, revealing that devitrification consistently accelerated degradation and mechanical performance of BMGs was strongly dependent on their microstructures. In the Ti-Zr-Cu-Pd system, annealing produced a nanocrystalline BMG composite (BMGC) with enhanced compressive strength and osteoblastogenesis, attributed to a thinner, ZrO2-rich oxide layer with higher surface energy and reduced CuxO content. Moreover, thermodynamic modelling using the PHSS parameter effectively predicted GFA of this quaternary system, providing a cost-effective tool for flexible exploration of new compositions. A new cost-effective Ti42Zr8Cu42Pd8 BMG was subsequently proposed, lowering raw-material costs by ~28.5% while preserving high compressive strength (~2 GPa) and biocompatibility. Overall, this thesis provides a framework for tailoring BMGs performance through controlled crystallinity and compositional design. This strategy connects thermodynamic screening with manufacturable solutions, paving the way for patient-specific, performance-optimised biomedical implants.</p
Influence of inter-filament voids on the failure mechanism and compressive strength of 3D printed concrete
No full textMaterial that has been manufactured using extrusion-based 3D Concrete Printing (3DCP) exhibits anisotropy and larger variability in its mechanical properties. These effects are influenced by the agglomeration of extruded filaments, which presents greater opportunity for air entrapment within the printed volume, as well as creating a network of inter-filament material with different properties. Manufacturing ‘defect free’ is challenging and hence understanding the impact of these defects on mechanical performance is critical, however, there is no published work to date. This reports on an empirical investigation of 155 samples with and without inter-filament void defects. It is demonstrated the presence of the inter-filament voids does influence the failure characteristics: defect free samples exhibit shear failure in all three anisotropic loading directions, whereas the samples containing inter-filament voids predominantly exhibited shear failure in the u-direction (parallel to the filament direction), with a greater occurrence of mixed shear–splitting failures in the v (perpendicular to the filament direction in horizontal plane) and w-directions (layer build-up direction), especially in the w-direction. Inter-filament void size had little effect on the compressive strength in the u and w-direction, while a clear reduction trend in the compressive strength was observed in the v-direction. Therefore, these findings reveal that inter-filament voids introduce direction-dependent failure modes and strength penalties that cannot be captured by design values calibrated for cast concrete. By quantifying the mechanical tolerance envelope of void populations, the study demonstrates the need for recalibrating partial safety factors and acceptance criteria in emerging 3D printed concrete design codes.</p
Understanding the role of supplementary cementitious materials in 3D printed concrete
No full textThree-dimensional (3D) concrete printing has emerged as a transformative construction technology; however, its sustainable deployment hinges critically on supplementary cementitious materials (SCMs), whose comprehensive effects on printability, buildability, mechanical performance and durability have not been systematically assessed. Although a growing body of research has been conducted to examine individual SCM substitutions, such as fly ash, ground granulated blast-furnace slag, silica fume, rice husk ash and limestone, these studies often treat material performance in isolation and lack a cohesive analysis linking SCM physicochemical characteristics to fresh-state rheology and hardened properties. To bridge this gap, a structured review has been conducted, highlighting key challenges and mitigation strategies. Durability outcomes are analysed to determine the influence of SCM type and dosage on long-term performance. This synthesis reveals critical interdependencies between SCM properties and extrusion, setting time, strength and durability. Finally, pressing research needs are identified to guide future investigations aimed at advancing sustainable 3D printed concrete.</p
An optimised metasurface-based vertical axis wind energy harvester for power-autonomous monitoring in piping and ducting systems
No full textA novel vertical airflow energy harvester with an optimised, metasurface-based elliptical Savonius blade design to harness broadband is presented in this paper. The elliptical turbine harnesses wind energy when positive torque is produced on the rotor; if the static pressure difference across the advancing blade is greater than that of the returning blade, the driving torque from the concave advancing blade overcomes the resistive torque from the returning blade, causing the rotor to rotate. The turbine is fixed to an array of alternating magnets, arranged near a stator containing an array of series-connected coils axially aligned, inspired by an axial flux brushless motor configuration. When the rotor is in motion, electrical energy is extracted through the coils and stored in a capacitor for powering a sensing unit. The blade design is optimised by investigating three metasurface configurations to improve power generation efficiency and minimise the cut-in speed. The novel designs were tested experimentally in a subsonic wind tunnel and the optimised design outputs a maximum power of 53.66 mW at 18 m/s.</p
Are psychopathic traits a shield against burnout in policing?
No full textThis study investigated how psychopathic traits relate to job satisfaction and burnout in police officers. 101 Polish officers completed self-report measures for psychopathic traits, burnout, and job satisfaction. Findings indicate strong negative correlations between all psychopathy subscales and emotional exhaustion. Depersonalization also showed weak negative correlations with affective and cognitive responsiveness, and interpersonal manipulation. Conversely, personal accomplishment had moderate positive correlations with affective responsiveness and interpersonal manipulation. All psychopathy subscales strongly and positively correlated with overall job satisfaction. Results suggest that subclinical psychopathic traits may act as a protective factor against burnout and positively influence job satisfaction in police work.</p
The quantity of thermodynamic depth produced per worker-second of average labor under advancing conditions of production
No full textThis article develops a two-sector model of surplus thermodynamic depth using the Sraffian approach. The effect on the model from ongoing advances in production technology is considered. The conclusion is that, absent countervailing tendencies, the per-worker-second production of thermodynamic depth under capitalism will tend to increase exponentially. The implications of this conclusion for political economists who conceive of “value” as the quantity of labor that may be treated as embodied in commodities by reference to average labor under given conditions of production are considered.</p
A case study on hybrid machine learning and quantum-informed modelling for solubility prediction of drug compounds in organic solvents
No full textMachine learning pipeline integrates COSMO-RS and multiple molecular descriptors to predict and interpret solubility across diverse solute–solvent systems.Solubility is a physicochemical property that plays a critical role in pharmaceutical formulation and processing. While COSMO-RS offers physics-based solubility estimates, its computational cost limits large-scale application. Building on earlier attempts to incorporate COSMO-RS-derived solubilities into Machine Learning (ML) models, we present a substantially expanded and systematic hybrid QSAR framework that advances the field in several novel ways. The direct comparison between COSMOtherm and openCOSMO revealed consistent hybrid augmentation across COSMO engines and enhanced reproducibility. Three widely used ML algorithms, eXtreme Gradient Boosting, Random Forest, and Support Vector Machine, were benchmarked under both 10-fold and leave-one-solute-out cross-validation. The comparison between four major descriptor sets, including MOE, Mordred, RDKit descriptors, and Morgan Fingerprints, offering the first descriptor-level assessment of how COSMO-RS calculated solubility augmentation interacts with diverse chemical feature space. The statistical Y-scrambling was conducted to confirm that the hybrid improvements are genuine and not artefacts of dimensionality. SHAP-based feature analysis further revealed substructural patterns linked to solubility, providing interpretability and mechanistic insight. This study demonstrates that combining physics-informed features with robust, interpretable ML algorithms enables scalable and generalisable solubility prediction, supporting data-driven pharmaceutical design.</p
Modelling hydrological response to nature-based solutions in a mixed land-use catchment
No full textMixed land-use river catchments are a common feature of cities around the world. The paradigm shift towards Nature-Based Solutions (NbS) and integrated catchment management over the last decade offers the potential for flood risk management interventions in these catchments which also bring a wide range of co-benefits. Whilst the efficacies of natural flood management interventions in rural landscapes (NFM) and sustainable drainage interventions in urban landscapes (SuDS) have received significant scientific attention, there is a relative lack of research that investigates interactions at scale between the two, which is especially relevant to peri-urban river catchments. This article presents the results of a hydrodynamic modelling study of a peri-urban stream in the UK which has experienced flooding in recent years. The research was designed to evaluate the spatial extent of benefits arising from NbS interventions in a mixed land-use catchment and to explore hydrological interactions between NbS located in rural and urban sub-catchments. Results indicate that whilst NbS interventions can reduce peak flows at both local and catchment scale, it is important to assess the spatial extent of these benefits, which diminish with increasing distance from the intervention. In addition, the concurrent installation of NbS in both the rural and urban sub-catchments may, in certain locations, offer significant benefits when compared to a focus on any one type of intervention. The research findings also support a view that integrated funding streams which address land-use across the catchment may lead to more cost-effective solutions than those which support specific intervention types.</p