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Ultra-highly electrically sensitive UHPC for defect detection: Electrical signal response and imaging
No full textImage visualization mainly focuses on structural surface damage monitoring, whereas detecting internal defects necessitate additional parameters. Therefore, this study proposes a detection method that combines electrode arrays and reconstruction algorithm for probabilistic inspection of damage (RAPID) to detect image defects in ultra-highly electrically sensitive UHPC (UHES-UHPC). UHES-UHPC, as a self-sensing concrete sensors intrinsically integrate sensing and data acquisition capabilities. The resistivity distribution curves and sensing pathways of UHES-UHPC were further analyzed with different defect locations and sizes. The RAPID algorithm and elliptical model were implemented for defect visualization, which improves the positioning accuracy and enhances the testing efficiency by fewer sensors than conventional ERT method. The full-summation imaging method was applied to eliminate the phenomenon of uneven probability distribution of the array (UPDA), enhancing the quality of imaging outcomes. Receiver operating characteristic (ROC) curves and probability value curves were used to objectively evaluate the performance of this method. The results showed the defects at different locations can be detected based on the intersection of the maximum resistivity sensing pathways, whilst the maximum detected deviation was 1.13 cm. For defects of different diameters, the minimum detection threshold was 0.6 cm, further defining the detection range. In addition, the imaging noise area was reduced by 34.4 % by the full-sum imaging method. The probability value curve showed that the localization accuracy of the imaged region reached 96 %, and the area under the ROC curve reached 0.96, which was close to the ideal value of 1. This NDT method can detect accurate defection and visualize the internal defects, which provides a theoretical basis for building structure health monitoring
Fatal drug overdoses in healthcare workers: A thematic framework analysis of coroner reports
Get PDFBackground and aims: Healthcare workers face specific vulnerabilities for drug overdose due to their unique access to medications, clinical knowledge and work‐related stress. This study aimed to understand the characteristics of fatal overdoses in healthcare workers with a view to providing guidance for preventative strategies. Design, setting and cases: We retrospectively identified cases in England, Wales and Northern Ireland reported to the National Programme on Substance Use Mortality between 2000 and 2022 where decedents were working or studying within a healthcare setting at the time of their death or had previously worked in healthcare. Measurements: Quantitative analyses were conducted to report summary demographics of decedents, the circumstances of deaths and the drugs involved. A qualitative thematic framework analysis was performed to identify and explore factors that may contribute to fatal drug overdose in healthcare professionals. Findings: In the identified cases, doctors were the most represented profession (48% of cases, n = 28/58) with opioids the drug class most often implicated in causing death (43% of cases, n = 25/58). Whilst there was scant evidence of recreational drug use in the identified cases (n = 3), hospital‐only medications prominently featured [propofol in 29% (n = 17/58); midazolam in 10% (n = 6/58); neuromuscular blocking agents in 9% (n = 5/58)]. Qualitative analysis identified seven themes including accessing drugs from the workplace, use of skills and/or equipment for intravenous drug administration, obtainment of private prescriptions, diagnosed mental health conditions, recent events likely to have negatively impacted mental health, chronic pain and self‐medicating and history of substance use disorder and/or overdose. Conclusions: The characteristics of fatal drug overdoses among healthcare workers in England, Wales and Northern Ireland appear to differ from those observed in the overall population of people who use drugs in the UK. To prevent such deaths, it is important that healthcare workers can access bespoke care and support tailored to the specific challenges that they face
Democracy and Natural Resources: Their Institutional Impact on Tax Haven Use by Emerging Market Multinational Enterprises
Get PDFThis paper examines how the institutional environment influences multinational enterprise (MNE) strategies regarding tax haven use. We develop a theoretical framework linking democracy and natural resource endowments to the strategic use of tax havens in emerging markets. Using data from 4630 emerging market MNEs (EMNEs) between 2008 and 2018, we find that higher levels of democracy in an EMNE’s country of origin are associated with reduced tax haven use. However, the use of tax havens by EMNEs increases with higher natural resource rents in their home economies. Additionally, we find that natural resource rents moderate the impact of democracy on tax haven use, such that the natural resource curse weakens the positive effect of democracy on firm behavior. Our results offer important managerial and policy implications
How inclusive and representative is research on foster caring in the UK? Findings from a scoping review
Get PDFThe importance of inclusivity and representation is increasingly recognised in fostering services and within research to ensure that services are meeting the needs of all the diverse communities they aim to support. However, the extent to which research with foster carers is inclusive in its participant recruitment is not clear. A scoping review was conducted to explore the characteristics of foster carers who take part in research, how these characteristics are reported and the methods used by researchers to promote inclusivity and diversity in their recruitment. Across the 82 journal articles included, the review found substantial variation in how studies report the characteristics of participants, and some characteristics such as disability and religion are absent across the literature. Notwithstanding the inconsistencies in reporting, the review found that some communities of carers are underrepresented within research compared with national levels, including kinship foster carers and non-White carers. There is also a lack of discussion about inclusivity and participant representation within research papers, indicating that although there is broader recognition of the need for inclusive and representative research in health and social care, there is substantial room for improvement within research with foster carers
The three-dimensional flow of force in a damaged, skewed masonry arch railway bridge – Insights from fibre Bragg rosettes, videogrammetry, and modelling
Get PDFMasonry arch bridges are common, especially in the UK and Europe, but interpretation of their structural behaviour can be challenging and is often complicated by histories of damage over their long working lives. Assessing the performance of repair works at these bridges is vital, to provide confidence in their continued use. This paper presents novel applications of fibre-optic sensing and videogrammetry to measure and visualise the three-dimensional, dynamic structural response of a skewed masonry arch railway bridge in unprecedented detail. In particular, fibre-optic strain rosettes are used to map the distributions of principal strains, and hence force flow, throughout the arch, while videogrammetry reveals a secondary load path in the form of transverse arch bending. Monitoring results are then combined with simplified analytical models of this transverse bending, to study the effectiveness of intervention works aimed at restoring structural connectivity between the arch and its spandrel walls
Oxysterols, age-related-diseases and nutritherapy: Focus on 7-ketocholesterol and 7β-hydroxycholesterol
Get PDFAge-related diseases are often associated with a disruption of RedOx balance that can lead to lipid peroxidation with the formation of oxysterols, especially those oxidized on carbon-7: 7-ketocholesterol (also known as 7-oxo-cholesterol) and 7β-hydroxycholesterol. Like cholesterol, these oxysterols have 27 carbons, they are composed of a sterane nucleus and have a hydroxyl function in position 3. The oxysterols 7-ketocholesterol and 7β-hydroxycholesterol are mainly formed by cholesterol autoxidation and are biomarkers of oxidative stress. These two oxysterols are frequently found at increased levels in the biological fluids (plasma, cerebrospinal fluid), tissues and/or organs (arterial wall, retina, brain) of patients with age-related diseases, especially cardiovascular diseases, neurodegenerative diseases (mainly Alzheimer's disease), ocular diseases (cataract, age-related macular degeneration), and sarcopenia. Depending on the cell type considered, 7-ketocholesterol and 7β-hydroxycholesterol induce either caspase- dependent or -independent types of cell death associated with mitochondrial and peroxisomal dysfunctions, autophagy and oxidative stress. The caspase dependent type of cell death associated with oxidative stress and autophagy is defined as oxiapoptophagy. These two oxysterols are also inducers of inflammation. These biological features associated with the toxicity of 7-ketocholesterol, and 7β-hydroxycholesterol are often observed in patients with age-related diseases, suggesting an involvement of these oxysterols in the pathophysiology of these disorders. The cytotoxic effects of 7-ketocholesterol and 7β-hydroxycholesterol are counteracted on different cell models by representative nutrients of the Mediterranean diet: ω3 and ω9 fatty acids, polyphenols, and tocopherols. There are also evidences, mainly in cardiovascular diseases, of the benefits of α-tocopherol and phenolic compounds. These in vitro and in vivo observations on 7-ketocholesterol and 7β-hydroxycholesterol, which are frequently increased in age-related diseases, reinforce the interest of nutritherapeutic treatments to prevent and/or cure age-related diseases currently without effective therapies
CFD-ANN-based model for parametric analysis of segmented plate-fin heat sinks: Exploring heat transfer and pressure drop trade-offs
No full textEffective air cooling remained critical for high-power electronics as heat fluxes increased. This study integrated experimental measurements, three-dimensional Computational Fluid Dynamics simulations (CFD), and an Artificial Neural Network (ANN) surrogate model to assess air-cooled plate-fin heat sinks under forced convection. Five different modified designs with segmented and staggered fins achieved up to 46.8% reduction in junction-to-ambient thermal resistance relative to the baseline, but the most aggressive layout (HS6) raised the pressure drop to approximately 1000 Pa, about 20x higher. The trained neural network model reproduced CFD temperatures and pressure drops with R2 > 0.99, enabling rapid exploration of the design space. From these data, two closed-form correlations for maximum junction temperature and pressure drop were derived, offering instant estimates during preliminary design without further CFD runs. Overall, staggered-segmented fins delivered substantial thermal gains, yet the associated rise in pumping power must be weighed during early design
Yeast as C1 cell factory: Transforming methanol and Formate into high-value compounds
Get PDFMicrobial transformation of greenhouse gases, such as carbon dioxide and methane, into valuable biochemicals appears as a key strategy to sustainably decarbonize manufacturing industries. Numerous unresolved technological constraints still hamper the industrial adoption of these single‑carbon (C1) gas-based bioprocesses. Conversion of these gases into liquid C1 compounds like methanol and formate helps to reduce emissions and close the carbon loop. Certain industrial yeasts possess intrinsic capabilities to tolerate and assimilate methanol and formate, which opens an attractive route to eco-efficiently valorise these compounds. To increase the C1-based biomanufacturing potential of yeasts, synthetic methylotrophy has been developed in versatile non-methylotrophic chassis. Strategic non-rational genome engineering and strain evolutions combined with rational designs brings to light hidden C1-pathways and mechanisms of substrate tolerance. Developments in methanol-based bioproduction include simple organic acids with clear promise for industrial scale-up as well as proof-of-concept investigations of complex polyketides with intricate pathways. Recent advances in bioproduction have demonstrated encouraging results from techniques such as modular co-culture engineering and peroxisomal coupling of biosynthetic pathways with C1 metabolism. Formate-based growth and biosynthesis in yeasts is in its early stages but holds the potential to be transformative in the coming decade. This review discusses the advances, challenges, and future perspectives in methanol-based biomanufacturing and innovative initiatives in formatotrophy in yeasts. Although it is a long way off, developments in synthetic biology assisted evolutionary engineering and artificial pathways will fill up the gaps in the scalability of C1-based bioprocesses, transforming yeasts into a reliable, climate-neutral, and resource-efficient platform for the green bioeconomy of the future
Sustainable aviation fuel-range intermediates from self-aldol condensation of cyclohexanone using low-cost niobium phosphate catalyst
Get PDFBiomass-derived chemical feedstocks are sustainable precursors for producing the range of compounds found in conventional hydrocarbon fuels. For instance, pyrolysis of lignin can produce high yields of phenolic compounds, which in turn can be quantitatively converted into cyclic ketones such as cyclohexanone, a model precursor for energy-dense aviation fuel hydrocarbons. Producing aviation fuel range hydrocarbons from short-chain oxygenated compounds such as cyclohexanone, requires both carbon chain elongation and oxygen removal via deoxygenation chemistries. In this study, a range of high-density fuel precursor molecules with fuel relevant carbon numbers (C12 – C18), have been produced via solvent-free carbon-carbon coupling of cyclohexanone as a model lignin-derived ketone. In the experiments, niobium phosphate (NbOPO4) was synthesised and used as a solid acid heterogeneous catalyst. Batch reactions were carried out at 160 °C with 1h–3 h reaction times, under nitrogen or hydrogen atmospheres. Cyclohexanone conversions of between 68.4 % and 95.4 % were achieved depending on reaction atmosphere. High selectivity towards dimeric ketones, the primary products of aldol condensation of cyclohexanone, was obtained under hydrogen gas. Initial hydrogen pressure of 5 bar gave the highest selectivity (nearly 90 %) mainly towards the dimeric 2-cyclohexylidenecyclohexanone and 2-(1-cyclohexen-l-yl) cyclohexanone. In contrast, mostly alkyl aromatic hydrocarbons with >C12 carbon atoms (e.g., cyclohexylbenzene) were formed under nitrogen, indicating that the inert atmosphere promoted the dehydration and dehydrogenation of primary aldol products. Correspondingly, the Brønsted acid and Lewis acid sites of the NbOPO4 were enhanced under nitrogen, with 3.7 wt% coke formation compared to 0.9 wt% under hydrogen. This work highlights the effectiveness of a low-cost catalyst to produce high yields of compounds that can be converted, via further deoxygenation and hydrogenation, to potentially energy-dense liquid hydrocarbons within the sustainable aviation fuel range
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