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Critical interlayers and interfaces in ceramic armour systems
No full textPoster contribution to the Defence and Security Doctoral Symposium 2023RBS
Towards fully autonomous drone tracking by a reinforcement learning agent controlling a pan–tilt–zoom camera
Get PDFPan–tilt–zoom cameras are commonly used for surveillance applications. Their automation could reduce the workload of human operators and increase the safety of airports by tracking anomalous objects such as drones. Reinforcement learning is an artificial intelligence method that outperforms humans on certain specific tasks. However, there exists a lack of data and benchmarks for pan–tilt–zoom control mechanisms in tracking airborne objects. Here, we show a simulated environment that contains a pan–tilt–zoom camera being used to train and evaluate a reinforcement learning agent. We found that the agent can learn to track the drone in our basic tracking scenario, outperforming a solved scenario benchmark value. The agent is also tested on more complex scenarios, where the drone is occluded behind obstacles. While the agent does not quantitatively outperform the optimal human model, it shows qualitative signs of learning to solve the complex, occluded non-linear trajectory scenario. Given further training, investigation, and different algorithms, we believe a reinforcement learning agent could be used to solve such scenarios consistently. Our results demonstrate how complex drone surveillance tracking scenarios may be solved and fully autonomized by reinforcement learning agents. We hope our environment becomes a starting point for more sophisticated autonomy in control of pan–tilt–zoom cameras tracking of drones and surveilling airspace for anomalous objects. For example, distributed, multi-agent systems of pan–tilt–zoom cameras combined with other sensors could lead towards fully autonomous surveillance, challenging experienced human operators.This project was funded through the UK Government’s Industrial PhD Partnership (IPPs) Scheme by the Future Aviation Security Solutions Programme (FASS)—a joint Department for Transport and Home Office venture, in collaboration with Aveillant Ltd. and Autonomous Devices Ltd.Drone
Fabrication of animal shell and sugarcane bagasse particulate hybrid reinforced epoxy composites for structural applications
Get PDFThis study investigated the effects of using egg and snail shells, along with sugarcane bagasse, on various properties of hybrid reinforced epoxy composites for structural applications. The particulate shells and sugarcane bagasse serve as reinforcements while the matrix consists of epoxy resin and hardener. The composites were produced using the hand lay-up technique, and the mechanical, wear and physical properties of the prepared samples were evaluated. The fractured surfaces of the samples were examined using a scanning electron microscope. The results revealed that the source of the shell had an impact on the properties of the composites as eggshell-sugarcane bagasse particulate reinforced epoxy composites exhibited improved strengths, while snail shell-sugarcane bagasse particulate reinforced epoxy composites showed improved moduli. Optimal values were obtained for flexural and tensile strengths at 15 and 18 wt%, respectively, while flexural and tensile moduli were optimal at 12 and 15 wt%, respectively. Eggshell-sugarcane bagasse particulate reinforced epoxy composites demonstrated an optimal impact strength value of 21.81 J/m2, while snail shell-sugarcane bagasse particulate reinforced epoxy composites showed optimal results in all other properties mostly at 20 wt%. Conclusively, the use of snail shell-sugarcane bagasse particles was found to be more effective than eggshell-sugarcane bagasse particles for enhancing the properties of epoxy-based composites for structural applications while particulate reinforcement content within the range of 12–20 wt% are responsible for optimum performances.Polymers and Polymer Composite
Mitigating phase changes in the gas-phase that disrupt CO2 capture in membrane contactors: CO2-NH3-H2O as a model ternary system
Get PDFSolid and liquid products can form in the gas phase of membrane contactors applied to reactive ternary systems for CO2 absorption, which poses a critical barrier for carbon capture applications. The mechanism initiating these unwanted phase changes in the gas phase is unclear. This study therefore systematically characterises CO2 absorption in distinct regions of the vapour-liquid equilibrium (VLE) within an illustrative ternary system (CO2-NH3-H2O), to provide an explanation for the formation and mitigation of these solid and liquid products in the gas-phase. Unstable CO2 absorption and increased pressure drop indicated product formation within the gas-phase, which occurred at high CO2 capture ratios. Temporal analysis of gas-phase composition enabled gas-phase products to be related to the relative ternary composition. This was subsequently correlated to distinct regions of the VLE. Consequently, mitigation strategies can be developed with recognition for where products are least likely to form. Pressurisation was proposed to modify the relative gas-phase ammonia composition to reposition conditions within the VLE. The commensurate increase of CO2 into the solvent shifts the ammonia-ammonium equilibrium towards ammonium to indirectly reduce vapour pressure. This synergistic strategy allows sustained operation of membrane contactors for CO2 separation within reactive ternary systems which are critical to delivering carbon capture economically at scale.We are grateful for the financial and technical support offered by Anglian Water, Northumbrian Water and Severn Trent Water. We also acknowledge the funding and training resources provided to Benjamin Luqmani from the Engineering and Physical Sciences Research Council through the STREAM Industrial Doctorate Centre (EP/L015412/1).Journal of Membrane Science Letter
Treatment of pharmaceutical industry wastewater for water reuse in Jordan using hybrid constructed wetlands
Get PDFDeveloping cost-efficient wastewater treatment technologies for safe reuse is essential, especially in developing countries simultaneously facing water scarcity. This study developed and evaluated a hybrid constructed wetlands (CWs) approach, incorporating tidal flow (TF) operation and utilising local Jordanian zeolite as a wetland substrate for real pharmaceutical industry wastewater treatment. Over 273 days of continuous monitoring, the results revealed that the first-stage TFCWs filled with either raw or modified zeolite performed significantly higher reductions in Chemical Oxygen Demand (COD, 58 %–60 %), Total Nitrogen (TN, 32 %–37 %), and Phosphate (PO4, 46 %–64 %) compared to TFCWs filled with normal sand. Water quality further improved after the second stage of horizontal subsurface flow CWs treatment, achieving log removals of 1.09–2.47 for total coliform and 1.89–2.09 for E. coli. With influent pharmaceutical concentrations ranging from 275 to 2000 μg/L, the zeolite-filled hybrid CWs achieved complete removal (>98 %) for ciprofloxacin, ofloxacin, erythromycin, and enrofloxacin, moderate removal (43 %–81 %) for flumequine and lincomycin, and limited removal (<8 %) for carbamazepine and diclofenac. The overall accumulation of pharmaceuticals in plant tissue and substrate adsorption accounted for only 2.3 % and 4.3 %, respectively, of the total mass removal. Biodegradation of these pharmaceuticals (up to 61 %) through microbial-mediated processes or within plant tissues was identified as the key removal pathway. For both conventional pollutants and pharmaceuticals, modified zeolite wetland media could only slightly enhance treatment without a significant difference between the two treatment groups. The final effluent from all hybrid CWs complied with Jordanian treated industry wastewater reuse standards (category III), and systems filled with raw or modified zeolite achieved over 95 % of samples meeting the highest water reuse category I. This study provides evidence of using hybrid CWs technology as a nature-based solution to address water safety and scarcity challenges.This work was supported by two consecutive Transforming Systems through Partnership (TSP) projects sponsored by the UK Royal Academy of Engineering (TSP2021\100376 and TSP-2324-6\136).Science of The Total Environmen
Structural pathways for ultrafast melting of optically excited thin polycrystalline Palladium films
Get PDFDue to its extremely short timescale, the non-equilibrium melting of metals is exceptionally difficult to probe experimentally. The knowledge of melting mechanisms is thus based mainly on the results of theoretical predictions. This work reports on the investigation of ultrafast melting of thin polycrystalline Pd films studied by optical laser pump – X-ray free-electron laser probe experiments and molecular-dynamics simulations. By acquiring X-ray diffraction snapshots with sub-picosecond resolution, we capture the sample's atomic structure during its transition from the crystalline to the liquid state. Bridging the timescales of experiments and simulations allows us to formulate a realistic microscopic picture of the crystal-liquid transition. According to the experimental data, the melting process gradually accelerates with the increasing density of deposited energy. The molecular dynamics simulations reveal that the transition mechanism progressively varies from heterogeneous, initiated inside the material at structurally disordered grain boundaries, to homogenous, proceeding catastrophically in the crystal volume on a picosecond timescale comparable to that of electron-phonon coupling. We demonstrate that the existing models of strongly non-equilibrium melting, developed for systems with relatively weak electron-phonon coupling, remain valid even for ultrafast heating rates achieved in femtosecond laser-excited Pd. Furthermore, we highlight the role of pre-existing and transiently generated crystal defects in the transition to the liquid state.We acknowledge European XFEL in Schenefeld, Germany, for provision of X-ray free-electron laser beamtime at the Scientific Instrument FXE (Femtosecond X-Ray Experiments) and would like to thank the staff for their assistance. The authors thank Professor Jerry Hastings for valuable discussion and advice on design of the X-ray diffraction experiment.
This work was supported by the Materials Technologies project granted by Warsaw University of Technology under the program Excellence Initiative: Research University (ID-UB), the National Science Centre, Poland, grant agreement No 2017/27/B/ST3/02860, the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), Project No. 278162697-SFB 1242.
The access to the European XFEL was supported by a grant of the Polish Ministry of Science and Higher Education - decision no. 2022/WK/13.
We also acknowledge the usage of the computer cluster DWARF at Warsaw University of Technology supported by the Polish National Science Center (NCN) under Contracts No. UMO-2017/26/E/ST3/00428.
I.M. gratefully acknowledges financial support from Dutch Research Council (NWO) (Project ‘PROMT’, Grant Rubicon Science 2021–1 S, file number 019.211EN.026), and the Industrial Partnership Program ‘X-tools’, project number 741.018.301.
C.B. and K.K. acknowledge support by the Deutsche Forschungsgemeinschaft (DFG) via the Cluster of Excellence ‘Advanced Imaging of Matter’, EXC 2056, Project ID 390715994. KK gratefully acknowledges funding by the DFG within the program “Sachbeihilfe” project ID 497431350 (KU 4184/1-1).Acta Materiali
Communication network architecture with 6G capabilities for urban air mobility
Get PDFAs the demand for urban air mobility (UAM) increases, a robust communication, navigation, and surveillance (CNS) network architecture is needed to support the integration of sustainable UAM vehicles and technologies. Specifically, a new digital communication infrastructure is imperative to support increased levels of digitisation and autonomy within the aviation industry. This infrastructure must remain compatible with existing technologies, while enabling the integration of future 6G systems. This paper thereby discusses the communication challenges and opportunities associated with UAM integration. Potential communication technologies and standards needed to support UAM operations are presented and consolidated into a unified communication architecture with ground-, air-, and satellite-based infrastructure. The functional requirements of this architecture are also discussed, to enable seamless communication between UAM vehicles, air traffic control, and other ground- or air-based systems. Notably, 6G is highlighted as a key enabler of dense and sustainable UAM operations with high data traffic demands. A simple link budget analysis for a 6G air-to-ground data link in a green urban environment is thereby performed, em-phasising the infrastructural development necessary to support 6G roll-out. These findings pave the way for a more sustainable and accessible UAM transportation system, backed by a secure and reliable communication infrastructure.This work was partially supported by the grant received from Department for Transport (DfT), UK Government, FASS program.2024 IEEE International Conference on Consumer Electronics (ICCE
Vehicle-to-vehicle energy trading framework: a systematic literature review
Get PDFAs transportation evolves with greater adoption of electric vehicles (EVs), vehicle-to-vehicle (V2V) energy trading stands out as an important innovation for managing energy resources more effectively as it reduces dependency on traditional energy infrastructures and, hence, alleviates the pressure on the power grid during peak demand times. Thus, this paper conducts a systematic review of the V2V energy trading frameworks. Through the included article analysis (n = 61), this paper discusses the state-of-the-art energy trading frameworks’ structure, employed methodologies, encountered challenges, and potential directions for future research. To the best of the authors’ knowledge, this is the first review explicitly focused on V2V energy trading. We detail four critical challenges to face while establishing the framework in current research, providing an overview of various methodologies, including auctions, blockchain, game theory, optimisation, and demand forecasting, that are used to address these challenges and explore their integration within the research landscape. Additionally, this paper forecasts the evolution of V2V energy trading, highlighting the potential incorporation of advanced and established technologies like artificial intelligence (AI), digital twins, and smart contracts. This review aims to encapsulate the existing state of V2V energy trading research and stimulate future advancements and technological integration within the field.Nazmiye Balta-Ozkan and Ali Alderete Peralta’s time were partially funded by Engineering and Physical Sciences Research Council, part of the UK Research and Innovation (UKRI), under the grant number EP/V039164/1.Sustainabilit
Supporting Dataset for "Calibration and testing strategies to correct atmospheric effects on star tracking algorithms"
No full textThis dataset contains an archive with experimental pictures for testing star tracker algorithms. Camera calibration parameters are also included. The dataset is used for obtaining the results presented in: Louis Jannin, Leonard Felicetti, "Calibration and testing strategies to correct atmospheric effects on star tracking algorithms", Astronomy and Computing, 202
Data Supporting "A comprehensive CFD investigation of tip vortex trajectory in shrouded wind turbines using compressible RANS solver"
No full textThis dataset support the publication "A comprehensive CFD investigation of tip vortex trajectory in shrouded wind turbines using compressible RANS solver" it contains mesh, isosurface and additional dataThe UK Turbulence Consortiu