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Modelling heat transfer of timber sections subjected to non-standard fire action
Get PDFUsing timber as a structural material in buildings is promising in reducing the carbon footprint of construction, although fire safety has been a long-standing challenge prohibiting its wider use. The current design practice usually complies with Eurocode 5, but it is largely prescribed only for standard fire scenario. While investigating the fire behavior in real compartments containing timber members, the fire action imposed on the surface of timber members can be hardly represented by the standard fire curve. Therefore, modelling the heat transfer of timber sections in these real fire scenarios requires adequate numerical models. In this paper, the heat transfer model equipped with temperature-variant thermal properties of timber as well as a heat generation model addressing timber combustion effect, has been developed and implemented in the open-source simulation platform OpenSees for fire. Advancing from the existing heat transfer models, the present model has been validated against test results of timber sections subjected to the prescribed non-standard fire actions supported by the e-controlled radiant panel system. The modelling results have shown good performance in predicting the temperature evolution at various depths of the timber sections subjected to non-standard heating conditions
Reducing the exceptional affordability of hand-rolling tobacco using tax escalators: a health and economic impact modelling study for England
Get PDFBackground
Hand-rolling tobacco (HRT) remains more affordable than factory-made (FM) cigarettes in the UK, which could undermine the health benefits of tobacco tax increases. This study modelled health and economic impacts of raising HRT duty annually to reduce this affordability gap.
Methods
We used the Sheffield Tobacco and Alcohol Policy Model V.2.5.0, an individual-level microsimulation, to project tobacco consumption, spending and health outcomes for adults in England aged 18–89 from 2024 to 2030. Four duty policies were compared against a business-as-usual scenario of duty rising 2% above the Retail Price Index (RPI) annually: Policy A increased duty by RPI+12% in 2024 only (the UK Government’s October 2023 policy); Policy B applied RPI+10% annually to align with FM duty by 2030; Policy C applied RPI+12% annually; and Policy D applied RPI+18% annually to equalise average HRT and FM prices by 2030.
Results Policy
A was estimated to prevent 1770 deaths, add 36 947 life years and save the National Health Service £12 million, with greater gains in deprived areas. Policies B–D achieved larger health benefits and reduced inequalities, but increased spending by people who smoke. Policy D generated £3.19 billion additional tax revenue and reduced tobacco industry revenue by £400 million by 2030. Revenue effects depended on assumptions about how higher HRT prices affected FM consumption.
Conclusions
Sustained duty increases on the least expensive tobacco products could deliver substantial public health gains and reduce health inequalities. Such measures should coincide with strong enforcement against illicit tobacco and comprehensive smoking cessation support
Experiences of young people, parents and delivery staff of the social prescribing intervention ‘Safety Nets’: A qualitative investigation
No full textHigh numbers of young people in the United Kingdom (UK) experience mental health difficulties. Referrals to Child and Adolescent Mental Health Services (CAMHS) have increased and young people often face lengthy waits before accessing treatment, during which time young people's mental health can deteriorate further. Safety Nets was developed to support young people on CAMHS waiting lists. It is a social prescribing intervention that runs for 2 h a week for 8 weeks at local professional sports clubs. Sessions include 1 h of psychoeducation and 1 h of physical activity co-delivered by a CAMHS clinician and sports club coach. The aim of this qualitative work was to explore the experiences of young people who attended and staff who delivered Safety Nets, to inform future delivery and research. Qualitative semi-structured interviews were conducted with 25 participants, including young people who attended Safety Nets (n = 6), their parents/carers (n = 6) and delivery staff (n = 14). Interviews explored the acceptability and suitability of the intervention and recommendations for future delivery. A thematic analysis identified four themes and one sub-theme from the data: (1) Motivations to attend or deliver Safety Nets, (2) Positive experiences of Safety Nets, (3) Perceived positive impact of Safety Nets (sub-theme ‘Staff development opportunity’) and (4) Application of skills learned. Overall, qualitative data indicated the Safety Nets programme was well received and highlighted important aspects of delivery for implementation. Future research, such as large-scale evaluation of the efficacy and cost-effectiveness of Safety Nets, is warranted
Micron and nano iron particles: experimental investigation of size dependent combustion in ethanol slurries and bimetallic thermite
Get PDFThe combustion dynamics and characteristics of dense iron–ethanol slurry droplets containing 30 wt% Fe (in both micron- and nano-sized forms) and Fe-doped Al/Fe2O3 thermites containing 5 wt% Fe (in both micron- and nano-sized forms) are investigated as a function of iron particle size. Single droplet experiments with high-speed imaging and in-situ thermocouple measurements are combined with TGA–DSC and SEM/EDS to link burning behavior to aggregate morphology. In ethanol, micron Fe (10 µm) settles toward the droplet periphery (terminal velocity ∼0.06 mm/s), forming a porous shell that improves O₂ access, raises the peak internal temperature to ∼326°C, and increases the d²-law burning rate to 0.76 mm² s⁻¹ (+10%) while shortening the total burn time. Nano Fe (40 nm) remains more uniformly dispersed (terminal velocity ∼0.04 mm/s) and forms smoother, less-porous aggregates; despite a higher peak temperature (∼266.5°C) and frequent small disruptive events, the burning rate decreases to 0.63 mm² s⁻¹ (–9%) and the total burn time contracts through secondary atomization. These outcomes show that aggregate architecture and settling, not surface area alone, govern heat/mass transfer and apparent burning rate in highly loaded metal fuel droplets. Translating these insights to thermites, adding 5 wt% nano-Fe triggers earlier ignition and rapid energy release, whereas 5 wt% micron-Fe yields more completely reduced, Fe-rich, semi-spherical residues, indicating locally more complete conversion. The work establishes a transport-to-morphology-to-combustion framework for designing metalized fuels and tailoring ignition and energy release in aluminothermic composites
Application of continuous glucose monitoring and automated insulin delivery technologies for pregnant women with type 1, type 2, or gestational diabetes: an international consensus statement
No full textInsulin resistance increases after the first trimester of pregnancy, leading to glycaemic challenges for women with pregestational type 1 diabetes or type 2 diabetes. Additionally, insulin resistance can promote hyperglycaemia in pregnant women without type 1 diabetes or type 2 diabetes, who develop gestational diabetes. Although most (>95%) women with diabetes deliver healthy babies, maternal dysglycaemia can have consequences for the mother and child, including prenatal, perinatal, immediate, and long-term postnatal complications. Diabetes technologies, such as continuous glucose monitoring (CGM) and automated insulin delivery (AID) systems can aid in optimising glycaemia outside of pregnancy. These novel technologies have not been extensively tested in large randomised controlled trials before and during pregnancy. However, compelling data report the benefits of CGM in type 1 diabetes, and increasing data report on AID systems in pregnancies complicated by type 1 diabetes. Appropriate CGM glucose thresholds for the diagnosis of gestational diabetes and the recommended time in range treatment targets for the routine management of gestational diabetes and type 2 diabetes still need to be determined. The recommendations in this Consensus Statement emphasise the value of CGM during preconception and pregnancy for women with pregestational type 1 diabetes in reducing pregnancy complications. Recommendations also include the use of AID systems in women with pregestational type 1 diabetes to improve glycaemic management during preconception, during pregnancy and delivery, and in the postpartum period. This Consensus Statement has been endorsed by 24 societies and groups
Corrigendum to “Catalytic dissociation of a water molecule on the (1 1 1) surfaces of Pt0₀.₅Ni₀.₅ bimetal: Density functional theory (DFT) study”. [Appl. Surf. Sci. 602 (2022) 154238]
No full textEffect of hyperdiffusion on rotating Rayleigh-Bénard convection
Get PDFWe analyse the effect of a scale-dependent hyperdiffusivity in rotating Rayleigh-Benard convection. The hyperdiffusion (HD) is parameterised by a cutoff wavenumber k0 and a growth rate q to limit its effects to the smaller scales, enabling simulations to be conducted at more rapid rotation rates and buoyancy forcing (as measured by the Ekman number Ek and Rayleigh number Ra respectively) than in conventional direct numerical simulations (DNS). We have performed 107 simulations spanning the ranges E = 10-4 - 10-7 and Ra = 106 - 7 and directly compared HD and DNS heat transfer (measured by the Nusselt number N u), flow speeds P e, force balances and boundary layer thicknesses. We identify two different effects of HD that are particularly clear when k0 is below the dominant scale of the flow, k: at low supercriticality fRa, N u and P e are increased compared to DNS due to a weakening of the rotational constraint; at high Ra, Nu and Pe are decreased compared to DNS owing to suppression of energy at scales greater than k. The thermal boundary layer thickness changes in proportion to N u, while the mechanical boundary layer thickness is marginally affected because it is determined by a vertical balance, whereas HD is applied horizontally. Heat transfer diagnostics are more strongly affected by HD than flow diagnostics, while changing k0 has a greater impact on solution behaviour than changing q over the range of values studied. For all HD simulations with k0 3k, all diagnostics remain within the standard deviation of the DNS
Building evidence regarding nature-based solutions indicators and their implications for policy – the case of air quality
Get PDFAir pollution is one of world's largest planetary health risk factors. Nature-based solutions (NBS) have been key in integrating air quality indicators into the urban green planning and public health discourse. Despite important contributions, approaches that include multidimensional indicators into research, planning and policies are still limited. National standards for some types of air pollutants are missing, with little evidence for a threshold for health effects. To respond to these gaps, we provide an overview and guidance for air pollution indicators, using three case studies in Europe and Latin America. We discuss the importance of context, specific pollutants and vulnerable groups and suggest new approaches at finer scales. Our findings also point out that knowledge of pollutants uptake in edible plants can give a hint to potential exposure risks for humans. Our lessons learned target specific policies and are organized into three main ideas: (a) multidimensional indicators and their implications for NBS and policy; (b) plants as biological indicators and as schools’ subjects and (c) the integration of the co-benefits to manage air quality
‘It Smelt Real’:Jorvik Viking Centre and the Experience of Museum Smellscapes
No full textDespite the emergence of sensory history and the increasing use of smell at museums and heritage sites, little attention has been paid to how smell experiences and public perceptions of the past mutually shape each other. Using newspapers, user-generated reviews, participant observation, and surveys, this article provides an analysis of smell’s use and reception at Jorvik Viking Centre, one of the first UK museums to use artificial ambient scents, from its opening in 1984 to the present. Both distributions of the sensible and longer histories of smell media have shaped the way academics, museums professionals, and visitors have responded to Jorvik’s smells. In contrast to existing work that has dismissed the use of smell in museums and heritage spaces as a curatorial trick that contrasts a foul-smelling past with contemporary odorlessness, this article argues that Jorvik’s scents offer an example of a ‘key smell’ that allows for the exploration of multiple overlapping experiences of the past and which draw on an audience equation of realism and authenticity with the strength, emotional intensification, and distillatory quality of reconstructed smellscapes
Strategic design of parcel locker networks for urban delivery
Get PDFThis paper focuses on the strategic design of a Parcel Locker (PL) network in the context of last-mile delivery. While PLs are emerging as a promising alternative to home delivery, their implementation poses practical challenges, including high deployment costs, inefficient capacity utilization, replenishment scheduling, and coordination with end users. To address this, we consider a network consisting of a depot, candidate locations for PLs, and service regions, each representing a group of customers with known aggregate daily demand distributed across multiple periods. Each period corresponds to a time window preferred by some customers for parcel pickup. The problem extends the classical location-routing problem by incorporating a multi-period horizon, a two-echelon network structure, and flexible replenishment planning. The objective is to minimize upfront strategic costs and anticipated operational costs over the network’s economic life. Strategic decisions concern selecting locations and capacities for PLs, and the size of a fleet to replenish PLs from the depot. Operational decisions, which can be revisited after the network is deployed, involve planning replenishment and routes over a single-day, multi-period horizon. The problem is formulated as a mixed-integer linear program and solved using a variable neighborhood search embedded in a branch-and-cut framework, leveraging tailored valid inequalities and local search moves. Computational experiments, along with a case study in Chicago using real data from Amazon, demonstrate that incorporating expected operational costs into network design process leads to more cost-efficient PL networks. Moreover, flexibility in replenishment planning affects both operational cost and network configuration, leading to further improvements in overall system efficiency
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