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Dual-Chamber microbial fuel cell for Azo-Dye degradation and electricity generation in Textile wastewater treatment
Get PDFTextile wastewater, particularly azo dyes, poses significant environmental challenges due to its poor biodegradability and toxicity. This study explores a dual-chamber microbial fuel cell (MFC) for simultaneous wastewater treatment and electricity generation. The MFC consists of an anaerobic anode chamber and an aerobic cathode chamber, separated by a proton exchange membrane (PEM). Electroactive microorganisms in the anode chamber metabolize organic substrates, including azo dye contaminants, breaking them down into simpler by-products. Electrons released during this process flow through an external circuit to generate current, while protons migrate across the PEM to the cathode chamber for oxygen reduction. Electrochemically active microbes were isolated from azo-dye-contaminated soil, and their degradation abilities validated through assays. Optimized carbon-based electrodes and a Nafion 117 PEM were used to enhance conductivity and microbial activity. UV–Vis spectroscopy tracked dye degradation, with the absorbance peak of reactive yellow dye at 410 nm decreasing from 2.9 to 0.4, indicating effective azo-bond cleavage. The MFC achieved peak voltage and current outputs of 0.20 mV and 0.16 mA, respectively, demonstrating its dual functionality. Adding NaCl as a supporting electrolyte further improved ionic conductivity and performance. This study demonstrates MFC technology as a sustainable solution for industrial wastewater challenges, integrating microbial degradation with bioelectricity generation. Future work should address scalability, operational stability, and advanced electrode designs to enhance its practical applications.Waste Management Bulleti
Integrated power and thermal management system in a parallel hybrid-electric aircraft: an exploration of passive and active cooling and temperature control
Get PDFHybrid-electric aircraft (HEAs) represent a promising solution for reducing fuel consumption and emissions. However, the additional heat loads generated by the electrical propulsion systems in HEAs can diminish these benefits. To address this, an integrated power and thermal management system (IPTMS) is essential to mitigate these challenges by optimizing the interaction between thermal management and power management. This paper presents a preliminary IPTMS design for a parallel HEA operating under International Standard Atmosphere (ISA) conditions. The design includes an evaluation of active cooling, passive cooling, and active temperature control strategies. The IPTMS accounts for heat loads from the engine system, including the generators, shaft bearings, and power gearboxes, as well as from the electrical propulsion system, such as motors, batteries, converters, and the electric bus. This study investigates the impact of battery power (BP) contribution to cooling power on required coolant pump power and induced ram air drag. A comparison of IPTMS performance under 0% and 100% BP conditions revealed that the magnitude of battery power contribution to cooling power does not significantly impact the thermal management system (TMS) performance due to the large disparity between the total battery power (maximum 950 kW) and the required cooling power (maximum 443 W). Additionally, it was determined that the motor-inverter loop accounts for 95% of the pump power and 97% of the ram air drag. These findings suggest that IPTMS optimization should prioritize the thermal domain, particularly the motor-inverter loop. This study provides new insights into IPTMS design for HEAs, paving the way for further exploration of IPTMS performance under various operating conditions and refinement of cooling strategies.14th EASN International ConferenceEngineering Proceeding
In-situ monitoring the structural pathway of a Ti-based alloy from metallic liquid to metallic glass
Get PDFA metallic glass is formed when a molten metallic alloy is cooled rapidly enough that crystallisation is avoided. However, the way the atomic structure of the liquid converts to that of the glass is generally unknown. The main challenge is the sufficiently fast experimental acquisition of structural data in the undercooled liquid regime necessitated by the high cooling rates needed to avoid crystallisation. In the present study, using aerodynamic levitation, the Ni-free Ti-based alloy Ti40Zr10Cu34Pd14Sn2 was vitrified in-situ in a high-energy synchrotron X-ray beam while diffraction data were acquired during cooling from above the liquidus temperature Tliq to well below the glass-transition temperature Tg. The structure in the undercooled liquid regime shows an accelerated evolution. Both the local order in the short (SRO) and medium range (MRO) increases rapidly as the undercooled liquid approaches Tg, below which the amorphous structure “freezes”. Nevertheless, distinct differences between the evolution of SRO and MRO were observed. The structural rearrangements in the undercooled liquid are found to be correlated with a rapid increase in viscosity of the metallic liquid upon cooling. The new findings shed light on the evolution of the atomic structure of metallic liquids during vitrification and the structural origins of the sluggish kinetics that suppress nucleation and growth of crystalline phases.Financial support by the ‘‘BioTiNet’’ EU Initial Training Network (ITN) (Grant agreement ID: 264635), the JSPS KAKENHI (Grant Number: 15K18201) as well as the EPSRC-DTP studentship “Bulk Metallic Glasses: Revealing the Structural Pathway of Liquid Metals to Vitrification” (project reference 2043971) within the framework of the EPSRC Doctoral Training Partnership with Cranfield University (EP/N509450/1) is gratefully acknowledged. MES thankfully acknowledges the support by a Cranfield University 75th Anniversary Research Fellowship.Journal of Alloys and Compound
Cluster-based tracking method for the identification and characterisation of vortices
Get PDFAn unsupervised, flow-agnostic and automatic cluster-based tracking algorithm for the segmentation of vortex-dominated flows has been successfully developed. It combines the Rortex method and density-based clustering algorithms. The Rortex method differs shear from rotation and overcomes the sensitivity to user-defined thresholds that characterises current practice of vortex identification methods. The algorithm is demonstrated with experimental Stereoscopic Particle Image Velocimetry data from two cases; a high-Reynolds (≈ 106) vortex generated by a half-delta wing, and distorted flow in a scaled-model of a civil aero-engine intake under cross-wind conditions. The approach is a successful method for the segmentation of complex vortical flows under a wide range of conditions.The work presented in this paper was conducted under a Doctoral Training Partnership, sponsored by the Engineering and Physical Sciences Research Council (EPSRC) and LaVision UK under Grant Agreement No. P2224759th 3AF International Conference on Applied Aerodynamics, 202
Enhancing performance and interpretability of multivariate time-series model through sparse saliency
Get PDFExplainable time-series modelling is an essential task for modern intelligent transportation systems (ITS). How-ever, balancing accuracy and interpretability in multivariate time series forecasting presents significant challenges. These challenges arise from the necessity to understand the significance of features and their temporal variations. Factors such as autocorrelation in time series and data processing techniques like sliding windows expand feature sets, thereby complicating pattern recognition using traditional post-hoc explanation methods and making the issue even more complex. To overcome these challenges, in this study, we propose a flexible post-process approach which generates sparse and normalized saliency values based on existing saliency generation methods such as GradientSHAP. Additionally, an optional window aggregation and alignment strategy is introduced to align with the original time series dataset, enhancing the intuitive understanding of feature importance. Furthermore, the potential use of sparse saliency for data augmentation to improve the model is explored. Lastly, we utilize naturalistic data from San Francisco airport to demonstrate our approach for ITS time-series prediction and explanation. The evaluation results indicate that integrating sparse saliency from high-performing models not only boosts the performance of XGBoost models by 10.92% but also simplifies model complexity, facilitating easier interpretation.Engineering and Physical Sciences Research Council (EPSRC)This project is supported by the Engineering and Physical Sciences Research Council (EPSRC) training grant entitled “DTP 2020-2021 Cranfield University” bearing reference EP/T518104/1.2024 IEEE 27th International Conference on Intelligent Transportation Systems (ITSC
Microstructure engineering during wire-arc additive manufacturing of high-strength martensitic steels
No full textMartensitic steel components produced using wire-arc additive manufacturing (WAAM) can contain coarse, highly textured columnar prior austenite grain (PAG) structures in the as-built state, which may exacerbate cracking issues during building and are difficult to remove with conventional post-build heat treatments. Here, we demonstrate that fine PAG structures can be achieved in WAAM’d martensitic steel by using a sufficiently low interpass temperature and ensuring a large enough heat-affected zone (HAZ) depth relative to the deposited layer height. It was found that controlling these two conditions during the building of 300M steel ensured that each layer of steel deposited was repeatedly cycled between austenite and martensite, refining the PAGs since they were in the HAZs of subsequent layers. The interpass temperature and HAZ depth required for 300M were found using dilatometry followed by electron backscatter diffraction (EBSD) mapping and validated through the microstructural characterization of three 300M WAAM walls built with different interpass temperatures and HAZ overlaps. EBSD characterization revealed that, when austenitised, 300M exhibited a memory effect that was followed by recrystallisation without applied external deformation. Importantly, since the grain refinement was achieved through austenite-martensite cycling, it is highly likely that the principles exploited here could be applied to achieve similar grain refinement in other martensitic steels.This work was undertaken within the ATI I-Break project led by Airbus.The authors gratefully acknowledge financial support from Innovate UK (project reference 10003486). The authors acknowledge the use of equipment associated with the Advanced Metals Processing and Characterisation themes of the Henry Royce Institute for Advanced Materials, funded through EPSRC grants EP/R00661X/1, EP/S019367/1, EP/P025021/1 and EP/P025498/1.Metallurgical and Materials Transactions
Safe reinforcement learning-based energy management for fuel cell hybrid electric aircraft with longevity considerations
No full textFuel Cell Hybrid Electric Aircraft (FCHEA) represent a promising solution for decarbonizing short- to medium-range aviation. However, the hybrid-electric architecture introduces increased control complexity and poses challenges in ensuring component longevity and operational safety. Although reinforcement learning (RL)-based energy management strategies (EMS) have been explored in ground vehicle application, they often prioritize fuel efficiency while neglecting component degradation and safety-critical constraints, both of which are vital for the reliability of electric aviation. This study presents a Longevity-Conscious Safe Energy Management Strategy (LC-SEMS) to minimize operational and degradation-related costs over long-term use, while ensuring the satisfaction of multi-type constraint. The strategy is implemented within a multidisciplinary simulation framework that integrates propulsion, aerodynamics, hybrid powertrain, and flight dynamics models for mission-level evaluation. The EMS problem is formulated as a Constrained Markov Decision Process (CMDP) incorporating physical, cumulative, and instantaneous constraints. Instantaneous safety is enforced via an adaptive shielding mechanism that leverages a pretrained transition model to detect potential constraint violations and applies minimal corrective actions without interfering with policy learning. The proposed strategy is validated on a simulated FCHEA retrofitted from the NASA X-57 Maxwell, achieving fast convergence and strict constraint adherence across turbulent and multi-mission scenarios. It achieves a 26.96% reduction in depreciation cost compared to baseline RL-based EMS, with a minimal 4.21% performance gap relative to the globally optimal Dynamic Programming (DP) benchmark, demonstrating its adaptability and robustness under uncertain and unseen mission scenarios.Energ
Evaluating propionate production in Clostridium ljungdahlii inoculated bioelectrochemical system
No full textBioproduction of chemical building block such as propionic acid (propionate) is of great interest in current time as it is a sustainable alternative to petrochemical synthesis. Clostridium ljungdahlii as an electroactive homoacetogen is able to ferment sugars or utilize CO2 to produce organic acids under bioelectrochemical system (BES). However, few reports evaluated the ability of bioelectrochemically assisted propionate production via C. ljungdahlii. In this study, BES equipped with three-dimensional nanostructure electrode and inoculated with C. ljungdahlii in cathode chamber was developed to evaluate propionate production. It found that applied negative potential on cathode was necessary to stimulate propionate production from fructose. Bioelectrochemical characterizations of bacteria attached electrode revealed that C. ljungdahlii was able to assimilate extracellular electron. Notably, optimization of negative potential on electrode remarkably increased NAD(P)H/NAD(P)+ ratio, ATP amounts, and propionate production. Furthermore, BES optimization results showed that propionate achieved 16.29 ± 0.16 mM maximum titer (43 % ratio of total organic acids) and 0.2 g/g mass yield (0.24 mol/mol carbon atom yield) from fructose. A theoretical value (1.6 mmol) of fixed CO2 was calculated from mass/electron balance analysis. This work not only evaluated the performance of bioelectrochemical technology but also provided a new choice for sustainable and efficient propionate production.Ministry of Science and Technology of the People's Republic of China, National Natural Science Foundation of ChinaThis work was supported by the National Key Research and Development Program of China (2021YFA0910400), National Natural Science Foundation of China (21908083), and Young Talents Cultivation Program of Jiangsu University.Process Biochemistr
Decarbonising agriculture with green hydrogen: a stakeholder-guided feasibility study
No full textGreen hydrogen offers a promising yet underexplored pathway for agricultural decarbonisation, requiring technological readiness and coordinated action from policymakers, industry, and farmers. This paper integrates techno-economic modelling with stakeholder engagement (semi-structured interviews and an expert workshop) to assess its potential. Analyses were conducted for farms of 123 hectares and clusters of 10 farms, complemented by seven interviews and a workshop with nine sector experts. Findings show both opportunities and barriers. While on-farm hydrogen production is technically feasible, it remains economically uncompetitive due to high levelised costs, shaped by seasonal demand variability and low utilisation of electrolysers and storage. Pooling demand across multiple users is essential to improve cost-effectiveness. Stakeholders identified three potential business models: fertiliser production via ammonia synthesis, cooperative-based models, and local refuelling stations. Of these, cooperative hydrogen hubs emerged as the most promising, enabling clusters of farms to jointly invest in renewable-powered electrolysers, storage, and refuelling facilities, thereby reducing costs, extending participation to smaller farms, and mitigating risks through collective investment. By linking techno-economic feasibility with stakeholder perspectives and business model considerations, the results contribute to socio-technical transition theory by showing how technological, institutional, and social factors interact in shaping hydrogen adoption in agriculture. With appropriate policy support, cooperative hubs could lower costs, ease concerns over affordability and complexity, and position hydrogen as a practical driver of agricultural decarbonisation and rural resilience.Engineering and Physical Sciences Research Council (EPSRC) Impact Acceleration Award block grant allocation to Cranfield University|EP/X525534/1, UKRI-EPSRC|EP/Y026098/1This research was undertaken as part of the project Prototype Planning Tool for Green Hydrogen Generation and Use in UK Agriculture, supported by the EPSRC Impact Acceleration Award block grant allocation to Cranfield University (EP/X525534/1). Huo and Balta-Ozkan wish to acknowledge the support of UKRI-EPSRC under grant reference EP/Y026098/1, under the Building a Green Future theme and the International Science Partnerships Fund as part of the Global Hydrogen Production Technologies (HyPT) Center.Sustainabilit
The impact of financial currency warfare in civil war duration and severity: the case of the Nigerian-Biafran War
No full textCurrency warfare is an accounting concept used as part of a military campaign strategy, which can manifest in the form of counterfeiting, currency manipulation and other strategic accounting techniques. As a strategy, it can be used to cut off the enemy's war financing capability. Despite its strategic importance in military campaigns, there is a notable lack of research on currency warfare in internal or civil conflicts, with most existing studies focusing on international disputes. The current research examines the Nigerian Civil War to determine how currency changes by both the government and the rebel group (Biafran) influenced the duration and severity of the conflict. This study develops a currency warfare theory and establishes bankruptcy, arms shortage, loss of territory, limited access to foreign currency, hunger and famine, and static conflict zones as the underlying themes that influence the effectiveness of currency warfare on the duration and severity of wars. Our findings indicate that the currency change by Nigeria helped shorten the length of the war (duration) and caused more casualties (severity) on the side of the Biafran separatists.Accounting Histor