爱丁堡大学

Urban parks are important biodiversity hotspots as well as recreational spaces in cities. It is desirable for urban residents to derive pleasure from parks that also embody biodiversity values due to their ecological and health benefits. Despite the evidence that urban residents are happier and healthier when they have access to green spaces of good quality, it remains unclear how residents prioritise biodiversity when considering the joint effects of other green space attributes, and how these priorities differ from those of landscape/ecology professionals. We used Adaptive Choice-Based Conjoint (ACBC) analysis to examine how biodiversity was prioritised in trade-offs with other important park attributes among residents and professionals. The ACBC study was conducted in Hangzhou (N = 187) and Shanghai (N = 194), two cities in eastern China. Utility values and average importances were estimated using Hierarchical Bayes (HB). While both residents and professionals preferred higher biodiversity levels, biodiversity improvements from poor to moderate yielded greater utility gains than from moderate to rich. Residents prioritised facilities over biodiversity when making trade-offs, whereas professionals prioritised biodiversity as the most important park attribute and valued it significantly more than residents. In both groups, preferences for higher biodiversity were associated with preferences for fewer facilities, denser tree cover, and low-maintenance, wild-looking landscapes. Urban park planning may prioritise biodiversity enhancement in biodiversity-poor sites over further enhancement in biodiversity-moderate sites to optimise resource allocation. Professionals should account for differences between their own preferences and those of residents, while recognising the importance of managing biodiversity-amenity trade-offs and supporting the coexistence of both objectives.

The building sector faces increasing pressure to reduce embodied carbon as operational emissions decline and life-cycle impacts of construction materials gain greater attention. Structural components such as roof purlins are widely used in industrial and commercial buildings and therefore represent an important opportunity for reducing material-related environmental burdens. This study presents a life-cycle environmental and economic assessment of alternative roof purlin systems manufactured from conventional and circular materials within a performance-based structural design framework.A life-cycle assessment and life-cycle cost analysis was conducted in accordance with EN 15804 + A2, covering Modules A1–A3 and C1–C4, with Module D benefits reported separately, using Australian life-cycle inventory datasets. Five purlin systems were evaluated, including recycled waste composite (RWP), cold-formed steel (CFS), timber (TP), fibre-reinforced polymer (FRP), and aluminium alloy (AAP). All systems were structurally optimised to achieve equivalent load-bearing capacity and serviceability over a 50-year service life, using 1 m2 of supported roof area as the functional unit. Results indicate that TP exhibits the lowest global warming potential (1.21 kg CO2-eq/m2), while RWP provides competitive environmental performance (6.96 kg CO2-eq/m2) and the lowest life-cycle cost (4.93 A$/m2). FRP and AAP exhibit the highest impacts under the primary Modules A–C comparison, although metallic systems show improved apparent performance when Module D benefits are reported separately. Integrated environmental–economic evaluation indicates that TP and RWP consistently outperform alternatives across multiple decision scenarios.The findings demonstrate that combining structural optimisation with appropriate material selection enables significant reductions in embodied carbon and cost and provides a decision-support framework for sustainable material selection under varying environmental and economic priorities.

The accurate measurement of the motion of rigid solid fuel particles is important for the study of many applications in energy science. These dynamics influence the particle-turbulence interaction as well as the heat and mass transfer processes governing reactor performance and chemical conversion. While many methods for the tracking of the translational velocity of such particles are available, methods for the robust measurement of angular velocity are scarce, especially for nearly circular particles and particles with complex shapes. To address the issue, this study presents a novel methodology for computing the angular velocity of dispersed particles in two-phase flows using a wavelet-based optical flow velocimetry (wOFV) algorithm. First, the applicability of wOFV for particle velocimetry was validated against a synthetic ground-truth dataset of walnut shell fragments as a representative biomass and the influence of the regularization parameter λ was investigated. It was found that for 0.01≤λ≤5, particle rotation can be accurately determined using the presented wOFV method. Additionally, findings reveal that particle shape significantly influences the performance of both wOFV and a commonly used ellipse fit tracking method, which is used as a benchmark. While the accuracy of ellipse fit tracking correlates strongly with the particle aspect ratio, the accuracy of wOFV is more strongly determined by the ellipticity of fuel particles. The implementation of a hybrid approach that integrates wOFV and ellipse fit tracking has been demonstrated to leverage the strengths of both algorithms. This is achieved through a shape-dependent selection of the most suitable algorithm for each specific particle based on a support vector machine classification. Overall, this hybrid approach yields a reduction in the median relative error of angular velocity predictions from 4.2 % (benchmark method ellipse fit tracking) to 3.7 % (hybrid method) for the employed test set. The proposed framework demonstrates considerable potential for enhancing the precision of rotational measurements in the field of particle dynamics.

The study of pyrolyzing fuels is essential in both combustion and fire safety research; however there exist few reliable experimental methods by which the pyrolyzing area of a fuel surface can be identified. Quantifying the location of the pyrolysis region is critical in the study of phenomena such as flame spread over solid fuels. Identifying the pyrolysis region can be achieved through temperature measurements or through visual observations; however both of these techniques can be heavily influenced by the presence of a flame (e.g., upward flame spread). A recent study has identified that the pyrolysis region of burning polymethyl methacrylate (PMMA) can be defined using laser-induced fluorescence. This study expands on these recent findings and presents the pyrolysis fluorescence characteristics of other common solid fuels. Experiments were conducted using PMMA, high density polyethylene (PE), polyoxymethylene (POM), poly-vinyl chlorate (PVC), polycarbonate (PC), nylon (PA6), polyisocyanurate foam (PIR), phenolic foam (PF), and untreated timber (pine). Each material was first pyrolyzed in a standard Cone Calorimeter exposed to 35 kW/m2. Both pyrolyzed and virgin materials were exposed to 266 nm light from an Nd:YAG laser. The fluorescence response was recorded using a Thorlabs CCS100 spectrometer. The results presented in this work allow experimentalists to identify the material specific fluorescence signature of polymer fuels, providing an explicitly defined pyrolysis region for a wide range of fuel types.

Connecting mathematical logic and computation, it ensures that some aspects of programming are absolute.