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Flower margins support natural enemies adjacent to apple orchards but evidence of spill-over is mixed
Get PDFData available from the University of Reading Research Data ArchivePerennial flower margins next to apple orchards can reduce the spread of aphid pests on apple trees and reduce the percentage of trees with fruit damage. To explore the mechanism behind this, we compared the vegetation community in three orchard habitats (flower margins, headlands, and alleyways) to determine whether the presence of a flower margin changed the diversity, abundance, and community of natural enemies of rosy apple aphid (Dysaphis plantaginea) in orchard ground vegetation and apple trees. Despite no evident spill-over of plant species into orchards, there was an increased Shannon diversity of natural enemies in the ground vegetation of flower margin orchards compared with controls. This suggests spill-over of natural enemies from the flower margins can reach up to 50 m from the orchard edge. However, we did not find evidence of broad differences between natural enemy taxa abundance, diversity, or community structure on the apple trees themselves. The mechanism behind improved pest control by flower margins is unclear but could be linked to the mobility of certain natural enemy groups or mutualistic relationships with ants. A better understanding of this mechanism would help to optimise the use of flower margins for sustainable pest suppression.Biotechnology and Biological Sciences Research CouncilThis work was financially supported by Syngenta and Biotechnology and Biological Sciences Research Council (BBSRC), part of UK Research and Innovation (UKRI) with the FoodBioSystems Doctoral Training Partnership (FBSDTP) (BB/T008776/1).Agriculture, Ecosystems and Environmen
An interdisciplinary literature review of floating solar power plants
Get PDFFloating photovoltaic is predicted to be the most ubiquitous energy technology in the future, with global installations projected to reach 10 GW by 2030, potentially generating 13.5 TWh of clean electricity annually. The extrapolation of solar power plants from land-based to water-based requires interdisciplinary expertise from fields such as energy systems, hydrodynamics, structures, environments, and electrical engineering. To bridge the disciplines, the present review analyses existing floating solar related publications comprehensively. Initially, a comprehensive literature scan of over 900 publications is presented, selectively leading to approximately 400 papers included. Subsequently, three review sectors are presented: design, modelling, and environmental effects. These cover various structural components, system-air-water interactions, their modelling approaches, power output prediction, and potential impacts on the surrounding environment including vegetation and animals. Key findings suggest the potential for enhancing energy efficiency through water-based cooling techniques, innovative modularised designs to support upscaling, positive environmental impacts including artificial habitats, and the utilisation of advanced marine structure designs such as a breakwater to protect the solar systems from ocean wave loads. In addition, the levelised cost of electricity of various floating solar studies are presented, including both theoretical and practical projects. The levelised cost of electricity has been decreasing, to a level of 0.05–0.07 USD/kWh, making FPV increasingly competitive as a clean and affordable energy choice. Overall, this review aims to facillitate interdisciplinary research and projects on the booming floating photovoltaic industry.L.H. acknowledges grants received from Innovate UK, United Kingdom (No. 10048 187, 10079774, 10081314) and the Royal Society, United Kingdom (IEC∖NSFC∖223253, RG∖R2∖232462) and UK Department for Transport (TRIG2023 - No. 30066).Renewable and Sustainable Energy Review
Coupled fan-intake dynamic distortion characterization at crosswind conditions
Get PDFThis project has received funding from the Clean Sky 2 Joint Undertaking (JU) under Grant Agreement No. 864911. The JU receives support from the European Union’s Horizon 2020 research and innovation program and the Clean Sky 2 JU members other than the Union.AIAA Journa
Modelling the operations of a circular economy fashion start-up
Get PDFPresented at: 56th CIRP International Conference on Manufacturing Systems 2023, 24-26 October 2023, Cape Town, South AfricaThis paper presents a case study of Pantala, a fashion start-up, intending to operationalise a circular supply of luxury womenswear through a monthly subscription-fee model. To optimize the company's cashflow and ensure success, the operational flows were modelled and analysed through discrete-event simulation techniques, with a focus on inventory management and minimizing operational costs. Simulation results demonstrated a high level of accuracy in predicting system performance, with an average relative error of less than 5% for most performance indicators. Insights are provided into the benefits of using simulation modelling for operational planning and optimization of complex systems, especially in the case of start-ups.Procedia CIR
Online corrections to neural policy guidance for pinpoint powered descent
Get PDFThis study presents incremental correction methods for refining neural network parameters or control functions entering into a continuous-time dynamic system to achieve improved solution accuracy in satisfying the interim point constraints placed on the performance output variables. The proposed approach is to linearize the dynamics around the baseline values of its arguments and then to solve for the corrective input required to transfer the perturbed trajectory to precisely known or desired values at specific time points, in other words, the interim points. Depending on the type of decision variables to adjust, parameter correction and control function correction methods are developed. These incremental correction methods can be used as a means to compensate for the prediction errors of pretrained neural networks in real-time applications where high accuracy of the prediction of dynamical systems at prescribed time points is imperative. In this regard, the online update approach can be useful for enhancing overall targeting accuracy of finite-horizon control subject to point constraints using a neural policy. A numerical example demonstrates the effectiveness of the proposed approach in an application to a powered descent problem on Mars.Journal of Guidance, Control, and Dynamic
Temperature monitoring of through-thickness temperature gradients in thermal barrier coatings using ultrasonic guided waves
Get PDFUltrasonic guided waves offer a promising method of monitoring the online temperature of plate-like structures in extreme environments, such as aero-engine nozzle guide vanes (NGVs), and can provide the resolution, response rate, and robust operation that is required in aerospace. Previous investigations have shown the potential of such a system but the effect of the complex physical environment on wave propagation is yet to be considered. This article uses a numerical approach to investigate how thermal barrier coatings (TBCs) applied to the surface of many components designed for extreme thermal conditions will affect ultrasonic guided wave propagation, and how a system can be employed to monitor through-thickness temperature changes. The top coat/bond coat boundary in NGVs has been shown to be a temperature critical point that is difficult to monitor with traditional temperature sensors, which highlights the potential of ultrasonic guided waves. Differences in application method and layer thickness are considered, and analysis of through-thickness displacement profiles and dispersion curves are used to predict signal response and determine the most suitable mode of operation. Heat transfer simulations (COMSOL) have been used to predict temperature gradients within a TBC, and dispersion curves have been produced from the temperature dependant material properties. Time dependant simulations of wave propagation are in good agreement with dispersion curve predictions of wave velocity for the two lowest order modes in three thicknesses of TBC top coat (100, 250, and 500 μ). When wave velocity measurements from the simulations are compared to dispersion curves generated at isotropic temperatures, the corresponding temperature represents the average temperature of a gradient system well. Such a measurement system could, in principle, be used in conjunction with surface temperature measurement systems to monitor through-thickness temperature changes
Editorial: Environmental data, governance and the sustainable city
Get PDFThe availability of new types of environmental data has the potential to change the ways in which cities are governed to improve their sustainability, resilience, and livability. Distributed sensors delivering real-time data can improve the monitoring and management of urban systems, as well as enabling robust assessments of policy and planning interventions. Real-time high-resolution sensor data provides a wealth of new opportunities for understanding systems and the interaction of physical, technical and anthropogenic activity. These benefits include long (multi-year) data baselines of high-resolution data enabling new statistical and artificial intelligence approaches; real-time analytics and visualizations supporting decision support systems; vulnerability or incipient failure detection to enable (proactive) maintenance rather than (subsequent, reactive) repair; parameterization of urban digital twins of physical and natural systems for simulation and prediction and what-if scenario testing; post-event analysis and post-intervention analysis across multiple phenomena at different timescales; and digital playback of systems when singularities, oversights, mistakes or other unforeseen events occur.Frontiers in Sustainable Citie
Autonomous navigation with taxiway crossings identification using camera vision and airport map
No full textWith increasing demands of unmanned aerial vehicle (UAV) operations envisioned for the future of aviation, the number of pilots will be much lower than the number of drones, necessitating an increased level of autonomy in drones to alleviate workload. Autonomous UAV taxiing enables autonomy to move on the ground, specifically from the gate to the runway and vice versa without human intervention. This study presents a lightweight vision-based autonomous taxiway navigation system, exploring the fusion of camera vision feed under the nose and airport map data to offer guidance and navigation. A sliding window mechanism is applied in centreline identification to detect line divergence. Centreline representations including divergence, direction and heading are cross-referenced with the airport database for localisation and generating navigation solutions. A simple proportional integral derivative (PID) controller is developed over aircraft dynamic models aligned with Eagle Dynamic’s Digital Combat Simulator to demonstrate the centreline following function. The overall system performance is assessed through simulations, encompassing individual functionality performance tests including centreline extraction test, line matching test, line-to-follow test, generalisation capability test, and computational complexity test. The performance evaluations indicate the promising potential of camera visions in enabling autonomous UAV taxiing with a 71% successful rate of detecting correct lines to follow and the remaining 29% as background. The proposed system also suggests a high generalization capability of more than a 67% success rate when testing over other paths. The source code of this proposition is open-sourced at https://github.com/DelQuentin/TaxiEye.AIAA SCITECH 2024 Foru
Microbial water quality investigation through flow cytometry fingerprinting: from source to tap
Get PDFEnsuring the quality of treated drinking water is crucial for preventing potential health impacts, regulatory fines, and reputation damage. Traditional culture-based microbiological methods often fail to capture the heterogeneity of the bacterial communities in drinking water. This study employed daily interstage monitoring and flow cytometry (FCM) analysis over a period of one year to investigate the dynamics of water treatment processes and service reservoirs. The objective of this study was to test the utility of FCM fingerprints for aiding in microbial event detection. We found that the chlorine concentration contact time was pivotal for microbial log reduction across the treatment works. FCM fingerprints exhibited significant deviations during operational events, such as process interruptions, but did not correlate with the presence of bacterial indicator organisms in the distributed and tap water. Furthermore, the diversity of bacterial fingerprints, quantified by the Bray–Curtis dissimilarity index, served as an indicator for identifying potentially poor microbial water quality. In chlorinated waters with low cell counts, the background signal shows potential as a metric to differentiate between different water sources, thereby offering the possibility to characterize breakthrough events in these circumstances that challenge most other microbial analytical methods. Interestingly, groundwater from simpler treatment works showed a higher occurrence of bacterial indicators, whereas surface water works had a lower incidence. These findings underpin the importance of appropriate disinfection even for “low-risk” source waters and the added value that the statistical interpretation of FCM data can offer objective decision making.Sustainable Microbiolog
What kinds of insights do Safety-I and Safety-II approaches provide? a critical reflection on the use of SHERPA and FRAM in healthcare
Get PDFOver the past decade, the field of healthcare has seen a significant shift in its approach to patient safety. Traditionally, safety efforts focused on understanding past harm and preventing errors, primarily through the use of standardisation and the introduction of barriers and safeguards, such as standardised communication protocols (e.g., SBAR (Haig et al., 2006)), checklists (e.g., WHO surgical safety checklist (Haynes et al., 2009)) and technology with safety features (e.g., smart infusion pumps (Taxis and Franklin, 2011)). This type of thinking about patient safety in terms of past harm and errors is also referred to as Safety-I (Hollnagel, 2014), even though this terminology has been criticised as it does not reflect adequately the diversity in safety science thinking (Leveson, 2020). However, the evidence for whether interventions based on this (Safety-I) thinking lead to improvements in patient safety is mixed at best (Kellogg et al., 2017, Wears and Sutcliffe, 2019), and critics have argued that the additional “safety clutter” produced as a result of such interventions might be counterproductive (Rae et al., 2018, Halligan et al., 2023).This work was funded by the National Institute for Health Research (NIHR) [Programme Grant for Applied Research NIHR200868]Safety Scienc