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Novel prognostic methodology of bootstrap forest and hyperbolic tangent boosted neural network for aircraft system
Get PDFComplex aviation systems’ integrity deteriorates over time due to operational factors; hence, the ability to forecast component remaining useful life (RUL) is vital to their optimal operation. Data-driven prognostic models are essential for system RUL prediction. These models benefit run-to-failure datasets the most. Thus, significant factors that could affect systematic integrity must be examined to quantify the operational component of RUL. To expand predictive approaches, the authors of this research developed a novel method for calculating the RUL of a group of aircraft engines using the N-CMAPSS dataset, which provides simulated degradation trajectories under real flight conditions. They offered bootstrap trees and hyperbolic tangent NtanH(3)Boost(20) neural networks as prognostic alternatives. The hyperbolic tangent boosted neural network uses damage propagation modelling based on earlier research and adds two accuracy levels. The suggested neural network architecture activates with the hyperbolic tangent function. This extension links the deterioration process to its operating history, improving degradation modelling. During validation, models accurately predicted observed flight cycles with 95–97% accuracy. We can use this work to combine prognostic approaches to extend the lifespan of critical aircraft systems and assist maintenance approaches in reducing operational and environmental hazards, all while maintaining normal operation. The proposed methodology yields promising results, making it suitable for adoption due to its relevance to prognostic difficulties.This research has received funding from the European Commission under the Marie
Skłodowska Curie program through the H2020 ETN MOIRA project (GA 955681).Applied Science
Grain structure control of titanium alloys during wire + arc additive manufacturing
No full textDing, Jialuo - Associate SupervisorPrior-β grain structure control of titanium alloys during Wire + Arc Additive
Manufacturing (WAAM) is reliant on post-processing following deposition. Multiple
methods are typically employed including cold working, melt pool agitation, inoculation
and constitutional additions, all of which have distinct limitations. This research has
demonstrated prior-β grain structure control in the as-deposited condition whilst utilising
a stable deposition process. Prior-β grain structure control of Ti-6Al-4V was achieved
through the reduction of the specific energy density of deposited material (SED). As SED
decreased, the thermal gradient and potential for constitutional supercooling increased. A
linear thermal gradient approximation was calculated via pyrometry to record the melt
pool temperature. The SED was controlled via the wire feed speed and fixed energy input.
It was determined that SED did not affect the peak melt pool temperature. Instead, arc
shading was responsible for the cooling of the melt pool. Electron back-scattered
diffraction (EBSD) analysis demonstrated a refinement of the prior-β grain morphology
and weakening of texture. Analysis of the prior-β grain boundary misorientations
demonstrated that as SED reduced, the misorientations had a propensity to the Mackenzie
distribution. However, distinct peaks of 51° β and 60° β misorientations were
observed and the tilting of grains to the deposition direction. The SED hypothesis was
tested using various process parameters and additional titanium alloys, Ti-6Al-2Sn-4Zr 2Mo and Ti-5Al-5Mo-5V-3Cr, which had an increased potential for constitutional
supercooling. It was determined that SED was not the primary mechanism behind prior β grain refinement. Instead, dendrite twinning in the {332}β β and {112}β β
during solidification characterised by 51° β and 60° β misorientations
respectively, as melt pool curvature, measured by the length/depth ratio proxy, increased.
The single energy source deposition was limited by the reliance of melt pool shape on the
SED. Therefore, the applicability of a scanning laser and arc multi energy source (MES)
system was investigated for the deposition of Ti-6Al-4V. It was demonstrated via optical
microscopy that the bead width, height and melt pool length could be independently
controlled from the SED. Using the MES system various melt pool length/depth ratios
were deposited whilst maintaining an equivalent SED. This confirmed the melt pool shape
as controlling factor of the prior-β grain structure morphology via EBSD analysis.Engineering and Physical Sciences Research Council (EPSRC)PhD in Manufacturin
Characterisation of blackwater from human transportation systems equipped with vacuum toilets and controlled emissions tanks and its impact on solid/liquid separation technologies
Get PDFThe first ever detailed characterisation of blackwater from human transportation systems equipped with vacuum toilets and Controlled Emissions Tanks (CET) revealed a stream that is very concentrated in salts and nutrients when compared to other blackwater sources. Escherichia Coli (E. coli) levels in the blackwater characterised were comparatively lower than the range reported for septic tanks, for example. Suspended solids were significantly lower than the levels found in pit latrines, but closely comparable to those reported for gravity toilets. The average COD of 3566 ± 2049 mg/L was typically lower than in pit latrines and gravity flush toilets. These findings then show that the characteristics of the blackwater from human transportation systems are directly impacted by a combination of the low flush vacuum toilets, storage in the CET, and different behaviour for passengers with increased usage for urination over defecation when compared to common uses of toilets. Such factors collectively dictate the nature of the blackwater and require that a solid/liquid separation technology for further processing is fundamentally robust in operation. The greater solids pulverisation, largely resulting from vacuum flushing combined with the storage environment, reduces the suitability of centrifugal and settling technologies whilst making filtration the most suitable option.The authors acknowledge GBR-Rail Ltd. for providing the funding for this projectJournal of Water Process Engineerin
A review of simulation modelling approaches in aviation spare parts inventory optimisation
Get PDFAviation spare parts are expensive and are being kept as a buffer for unscheduled and scheduled maintenance activities. Apart from cash flow being locked in the inventory, spare parts for aircraft or helicopters are also critical in the continuous operations of air assets. In addition, the holding cost is roughly 20 per cent of the total inventory value. Holding costs are costs such as insurance, utilities and manpower. Minimising the total inventory value could be done by adopting a lower inventory count through various methods, such as the provision of spare parts, which can be done either by forecasting the failure of components or by using new maintenance methodologies, such as predictive maintenance. The methods have been used widely in the aviation industry for a long time. The upward trend of papers published from 1963 to 2023 shows that aviation spare parts optimisation is still being discussed. This paper reviews the simulation modelling approaches to optimise aviation spare inventory. 221 papers were reviewed from Scopus and Web of Science (WoS) literature databases, and 17 papers from 1982 to 2023 were chosen based on the simulation modelling approach, such as System Dynamics and Discrete-Event Simulation. The papers were classified according to simulation modelling techniques, spare parts and operations classification, and challenges and opportunities.12th International Conference on Through-life Engineering Services – TESConf202
Viral metagenome reveals microbial hosts and the associated antibiotic resistome on microplastics
No full textMicroplastics provide a unique niche for viruses, promoting viral interactions with hosts and accelerating the rapid ‘horizontal’ spread of antibiotic resistance genes (ARGs). Currently, however, there is a lack of knowledge concerning the main drivers for viral distribution on microplastics and on the resulting patterns of viral biogeographic distributions and the spread of the associated ARGs. Here we performed metagenomic and virus enrichment-based viromic sequencings on both polyethylene and polypropylene microplastics along a river. Experimental results show that Proteobacteria, Firmicutes, Actinobacteria and Cyanobacteria were the potential hosts of viruses on microplastics, but only approximately 4.1% of viral variations were associated with a bacterial community. Notably, two shared ARGs and six metal resistance genes were identified in both viral and their host bacterial genomes, indicating the occurrence of horizontal gene transfer between viruses and bacteria. Furthermore, microplastics introduce more distinctive elements to viral ecology, fostering viral diversification and virus–host linkage while refraining from an escalated level of horizontal gene transfer of ARGs in contrast to natural matrixes. Our study provides comprehensive profiles of viral communities, virus-related ARGs and their driving factors on microplastics, highlighting how these anthropogenic niches provide unique interfaces that comprise highly defined viral ecological features in the environment.Nature Wate
Causal AI-powered Digital Product Passports for enabling a circular and sustainable manufacturing ecosystem
Get PDFDigital product passport (DPP) has been recently introduced by policymakers (e.g., the European Commission) to advance sustainable business practices towards a circular economy (CE). As a newly introduced concept, DPP is still relatively high-level and vague. Therefore, its definition, information flow architecture, what relevant information needs to be stored, and how to use such information in the context of a circular and sustainable manufacturing ecosystem, etc., are still open research questions. This paper addresses these research questions by proposing a novel conceptual framework for DPP, facilitating seamless information exchanges among CE stakeholders, and providing a transparent and trustworthy basis for decision-making. Causal AI utilisation is proposed to extract causal relationships among sustainability/circularity KPIs comprehensively, encompassing raw material supply chain, circularity-compliant product design, manufacturing optimisation on the shop floor, and after-sale product usage optimisation. Seamless information exchange will be achieved through semantic interoperability and a comprehensive model of the whole supply chain by employing an ontology model. The causal AI approach is proposed to identify causalities among KPIs and other factors to predict environmental impacts. This way, a causal model integrating domain expert knowledge and causality discovered from measured data will increase the transparency/explainability of prediction/decision made by machine learning algorithms.DMG-MORI12th International Conference on Through-life Engineering Services – TESConf202
Assessing the impact of voluntary certification schemes on future sustainable coffee production
Get PDFCoffee production faces major sustainability issues and consumers increasingly look to choose certified coffee as awareness grows. While consumers’ understanding of sustainability issues is limited, independent voluntary certification schemes such as Fairtrade, Rainforest Alliance, and certified organic—three high-profile schemes—can play a role in future-proofing coffee production through standard-setting. These schemes can also inform consumers about sustainability issues from economic, environmental, and social perspectives, thus driving up demand for sustainably grown coffee, and supporting an enabling environment for farmers and coffee-producing countries to improve the status quo. Sustainably grown coffee ensures that farmers sustain production while protecting the environment and the income that farmers rely on to maintain their livelihood. Based on a thematic analysis and synthesis of previous studies, this paper examines the social, economic, and environmental effects of voluntary certification schemes for coffee production. It evaluates the current state of coffee production and explores how certification schemes can be effective in encouraging more sustainable practices among producers. Three major voluntary certification schemes are evaluated to identify the impacts on producers, including key barriers and enablers to comply with sustainability standards and to determine how fit-for-purpose certification schemes are in assuring future sustainable coffee production.Sustainabilit
The roles of directors from related industries on enterprise innovation
Get PDFTo remain agile in response to market dynamics, foster innovation, and effectively manage potential risks, companies draw upon information from both their upstream and downstream sup-ply chain collaborators to enhance their core competitiveness. This research, conducted on A-share listed companies in Shanghai and Shenzhen from 2010 to 2021, empirically investigates the influence of directors from upstream or downstream supply chain collaborators, referred to as Directors from Related Industries (DRIs), on corporate innovation activities. This study reveals that DRIs significantly boost the innovation activities of enterprises, irrespective of their position within the operational structure. When there is considerable information asymmetry in the related industries of the industry chain, the impact of DRIs on enterprise innovation is evident in both input and output aspects. Conversely, when management has serious concerns about their career, the impact is primarily on the input side. This underscores the role of DRIs in providing relevant information about upstream and downstream industries and alleviating management’s career anxieties, enhancing their effectiveness in consulting and supervising innovation. By examining the economic consequence, corporate innovation emerges as a potential mechanism through which industry chain directors can enhance corporate value. This research delves into the effects of DRIs on enterprise innovation, offering valuable theoretical and practical insights for advancing innovation within the context of value chain integration.This research was funded by the Zhejiang Philosophy and Social Science Planning Project (No. 24NDJC218YBM), the Hangzhou Philosophy and Social Science Planning Project (No. Z22JC094), And the National Social Science Foundation of China (No. 21BGL184).Sustainabilit
Report of the working group to identify future challenges faced by the implementation of resource management in remote and distributed teams
Get PDFCrew Resource Management (CRM) was introduced on the commercial aircraft flight deck to promote pilots acting in a well-coordinated manner. This was a result of several accidents where aircraft with no, or minor technical faults, crashed from a failure to utilize effectively the human resources available on the flight deck. CRM draws upon the disciplines of management science, organizational and social psychology. It originated in civil aviation, but its practices have now been adopted in other high-risk, high-performance industries where staff work in coordinated teams, e.g. Air Traffic Control, surgery, nuclear power operations and shipping. CRM is now facing new challenges to promote effective, coordinated teamwork. Teams are often now distributed across many locations but are still required to coordinate their activities in real time. CRM now must evolve to support the actions of remote and distributed teams. At the 2023 HCI International Conference in Copenhagen, a working group formed from subject matter experts to identify application areas and describe the key challenges faced in promoting CRM for remoted and distributed teams both during normal and non-normal operations. This paper describes the workings and initial findings of this working group. The results show that process areas, such as such as promoting Team Situation Awareness, workload management, coordination, and monitoring of the cognitive and affective states of others are more important for developing remote and distributed team CRM than are addressing the limitations imposed by the underpinning technology.21st International Conference, EPCE 2024, Held as Part of the 26th HCI International Conference, HCII 202
