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The effect of uncertainty in predictions of nutrient concentrations from soil spectra on variable-rate fertilizer applications
No full textThe concentrations of available phosphorus (P) and potassium (K) in soil can be estimated by soil spectroscopy, and with sufficient sampling can be mapped to guide farmers to apply fertilizer at variable rates. Mapping errors arise from both spatial variation and calibration of the spectra against chemically determined concentrations. We aimed to develop a loss-function framework to explore how sizes of sample sets and calibration sets affect the likely profitability of variable-rate applications of P and K fertilizers. We demonstrate the approach through simulation. Based on our previous observations of variation in P and K from four fields in Cambridgeshire, England, we generated 100 realizations of P and K in each field using geostatistical simulation. We did so with various combinations of sizes of total sample and calibration set. For each such sample we assigned various proportions for calibration on which notionally both soil spectroscopy and chemical concentrations were determined. Knowing the costs for labour in the field for sampling, the preparation of soil in the laboratory, the spectroscopy, chemical analysis and amortization of equipment, we estimated the costs of acquiring data. Set against these were the costs of error, i.e. of uncertainty, in the final predictions by kriging arising from calibration error and spatial variation. For each combination we computed the fertilizer required to minimize the expected loss associated with predictions, where the expected loss is the difference in profit between applying fertilizer for the estimated concentrations of P and K and their true concentrations. The size of the calibration set outweighed the effect of total sample size on the uncertainty associated with predictions. Equally, for the same size of calibration set, there were large differences in the kriging variances between total sample sizes. When the costs of acquiring data were disregarded, the expected loss for available P was strongly affected by the total sample size. For available K, the effect of the size of the calibration sample dominated the expected loss. The expected loss showed diminishing returns with increasing sample size. None of the sample sizes considered would result in a financial gain: spectroscopy needs to become cheaper for it to be cost-effective for variable-rate applications of P and K fertilizer.Funding was provided by Biotechnology and Biological Sciences Research Council (Grant Nos. BBS/E/C/000I0320, BBS/E/C/000I0330, BBS/E/C/000I0100).Geoderm
Guidance and control system for an unmanned combat aerial vehicle as a wingman
No full textThe software and data used for this paper are available from the second author, J.F.W, on request.This study focuses on designing and testing a formation guidance system for a UCAV as a wingman to an F-16 fighter jet. A critical assessment of the UCAV autopilot revealed areas for improvement, which were addressed to refine the stable foundation of the autopilot for implementing the guidance system. This system uses PID controllers to minimise the along-track, cross-track, and vertical-track errors during standard manoeuvres. The system performed exceptionally well in the vertical (z) direction but showed robustness challenges in the along-track (x) and cross-track (y) directions under wind disturbances. A notable outcome was the identification of a novel mathematical relationship between the along-track offset command and its gains, offering a pathway for advanced formation systems. These findings pave the way for future enhancements in diverse formation operations.Drones and Autonomous Vehicle
From accidental project manager to intentional project leader: a reset whose time has come
No full textThis essay revisits the enduring figure of the “accidental project manager” and questions its continued relevance in today’s increasingly complex and politicized project environments. While the concept remains a useful metaphor in some sectors, the profession must now reckon with deeper shifts in power, conflict, and contested notions of performance. Drawing on past work on power and politics in projects, as well as emerging evaluations of megaproject governance, the piece critiques the field’s overcorrection towards harmony and collaboration, arguing that conflict is not only inevitable but essential to effective project delivery. It further challenges prevailing assumptions about project performance, proposing that success is a negotiated and political construct rather than an objective outcome. The essay ultimately calls for a reimagining of the project professional — from accidental manager to political actor and leader — equipped to navigate the realities of today’s turbulent and multi-stakeholder environments.International Journal of Project Managemen
Plain weave glass-fibre composite joints With Co2 Laser ablation architected treatments
No full textGlass Fibre Reinforced Polymers (GFRP) are particularly notable for their cost-effectiveness and versatility, finding widespread applications across aerospace, automotive, marine, medical, and sport industries. While the use of adhesive joints in GFRPs is widespread, laser ablation as a surface treatment prior to joining remains relatively unexplored. This study investigates the effects of laser ablation parameters, specifically scanning speed and power, on the surface characteristics of plain weave GFRP. Single-lap shear tests compare untreated and laser-treated joints with different architected groove spacings. Higher scanning speeds, particularly with 0.5 mm spacing, reduce fibre damage, whereas higher laser power levels increase it. Laser treatment improves shear strength by 19%, due to improved mechanical interlocking between the adhesive and the treated surface. When fibres exposure is carefully controlled, the strength of the joints improves by up to 60%. However, excessive resin degradation lowers performance; this indicates that balancing surface roughness and preserving surface integrity is critical to optimise laser ablation treatments.This work was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Fundação de Amparo à Pesquisa do Estado de Minas Gerais, (grant number UG grant, 305553/2023-2, 405506/2023-6, APQ-01007-25, APQ-04336-23).Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Application
Unveiling the mass transport dynamics in PEDOT:PSS films: insights from a probe beam deflection analysis
No full textThe redox conversion of PEDOT:PSS synthesised potentiostatically and galvanostatically at 0 °C was monitored by in-situ Probe Beam Deflection (PBD) in NaClO4/CH3CN. The analysis of the redox current and laser beam deflection, as a function of time, is carried out by applying a mathematical treatment based on individual temporal convolutions with specific transfer functions for each species moving between the electrode surface and the solution. A quantitative determination of the extent of the ion transfer involvement in the redox conversion process has been carried out, allowing to dynamically estimate the relative proportion of each species during the oxidation and reduction process of the polymer film through the respective transport numbers. It was confirmed that the conversion process is dominated by the cation, which validates unequivocally the pseudocationic doping of films synthesised galvanostatically at 0 °C (approximately 77% Na+ compared to approximately 23% ClO4⁻). By complementing the information obtained through PBD with the electromicrogravimetric technique, the quantitative contribution of each species involved in the conversion process was determined for the first time, confirming the significant participation of solvent accompanying the charge-transfer-dependent ions.This work was funded by the Portuguese Fundação para a Ciência e a Tecnologia (FCT) I.P./MCTES through projects UIDB/00100/2020 and UIDP/00100/2020Electrochimica Act
Cure kinetics, glass transition and chemoviscosity models for an aerospace-grade disulphide-based benzoxazine vitrimer
No full textThis study reports the matrix material models for the manufacturing of reinforced fibre composites using a disulphide-enabled aerospace-grade benzoxazine vitrimer. Cure kinetics and chemoviscosity models, crucial for fibrous composite manufacturing optimisation, were developed using calorimetric and rheometric data, respectively. An autocatalytic model with a logistic term accounting for diffusion represents accurately the resin cure kinetics, with 4 % average relative error in degree of cure prediction. The glass transition (Tg) evolution follows the DiBenedetto equation, with a curvature parameter (λ) of 1.84. A chemorheological model based on the kinetics of viscosity at a reference temperature and an inverse temperature exponential dependence—appropriate for low degrees of cure prevailing during the filling/consolidation step of fibrous composite manufacturing—simulates rheological behaviour with an average error of 8.3 %. The initial viscosity ranges from 144.7 mPa·s at 130°C to 1119 mPa·s at 100°C, with fast evolution which limits impregnation, meaning that composites processing using a resin film infusion or pre-impregnation route is applicable to this vitrimeric matrix.Tertiary Education Trust Fund [grant number TETF/ES/POLY/IMO STATE/TSAS/2019/VOL.I]European Union's Horizon Europe programme under grant agreement no. 101192721 (PLEIADES project)Polyme
Inter-pass peening for residual stress control in additive manufacturing: validation using ultrasonic, X-ray and contour method
No full textIn this study, round-robin experiments were carried out to evaluate the effectiveness of inter-pass peening as an in-process residual stress (RS) mitigation technique for Wire Arc Additive Manufacturing (WAAM) of Ti-6Al-4V components. A newly developed method, Phased Array Ultrasonics for Residual Stress Measurement (PAURS), was evaluated for its capability to accurately characterise residual stress distributions. To validate PAURS, two established techniques, X-ray Diffraction (XRD), a non-destructive method, and the Contour Method (CM), a destructive technique, were employed. PAURS, particularly when implemented with Full Matrix Capture (FMC), demonstrated enhanced accuracy through improved data redundancy and outlier rejection. Results from PAURS and XRD showed good qualitative agreement with finite element (FE) models derived from CM data, despite some quantitative differences. Inter-pass peening was found to significantly reduce tensile RS in the heat-affected zone, with performance comparable to post-process peening. These findings support the use of inter-pass peening as an effective in-process RS mitigation strategy and highlight the potential of PAURS as a reliable, non-destructive RS measurement method for WAAM Ti-6Al-4V components.The authors would like to acknowledge the support of NEWAM (EPSRC grant EP/R027218/1) for the production of the samples.Materials & Desig
The effects of prenatal GenX (HFPO-DA) exposure on gut microbiota and metabolic function in pregnant rats and their offspring
No full textHexafluoropropylene oxide dimer acid [(HFPO-DA), GenX] is listed as Substances of Very High Concern (SVHC) by the Commission of Member States (MSC) in 2019. The threat of GenX to human health, especially to sensitive populations such as pregnant women, infants and children cannot be ignored. We aimed to investigate the effects of GenX on the intestinal barrier function and gut microbiota of both pregnant rats and their offspring. We subsequently performed a metabolomic analysis of the maternal gut to investigate the metabolic disruptions associated with GenX exposure. Pregnant Sprague-Dawley rats (n = 12/group) received GenX once daily by gavage at 0, 1, 10, or 100 mg/kg body weight from gestational day (GD) 0.5 through GD 19.5. We observed intestinal tissue damage and changes in the gut microbiota in both pregnant rats and their offspring. Additionally, we performed untargeted LC/MS metabolomic analysis on the intestinal tissues of the pregnant rats. The intestinal barrier function of the pregnant rats was impaired. The results of 16S rRNA gene sequencing indicate that GenX alters the gut microbiota diversity and composition in both pregnant rats and their offspring. The metabolites of pregnant rats were also found to be significantly altered, and these metabolites are mainly associated with amino acid metabolism, carbohydrate metabolism, and lipid metabolism. Collectively, Exposure to GenX disrupts the intestinal barrier function of pregnant rats, exacerbates microbiome toxicity, and disturbs the gut microbiome-metabolome homeostasis.This work was supported by the National Natural Science Foundation of China (Grant No. 81903271), the Shandong Province Medical and Health Science and Technology Project (Grant No. 202306031042), Shandong Provincial Natural Science Foundation (Grant No. ZR2023QH301), Shandong Province Natural Science Foundation (No. ZR202111120048), 2022 Shinan District Science and Technology Plan Project (2023-2-015-YY), 2024 Qingdao Science and Technology Plan Park Cultivation Plan Project (24-1-5-yqpy-23-qy) and Qingdao Outstanding Health Professional Development Fund.Environmental Pollutio
Assessing the skills gap for industrial operators in industry 5.0
No full textThe following paper presents a study that investigates the existence of a skill gap for operators of Industry 5.0. This study is part of the CONVERGING project, a project that aims to develop and deploy smart-production systems for different industrial use cases. In each use case, a manually performed task is being redesigned as a smart-production system that leverages collaboration between human operators and smart machines such as collaborative robots. The current study’s aim is twofold – firstly, to identify the current skill set of the operators and the skills expected from them to perform the future roles in the smart-production systems. This was achieved through a literature review, hierarchical task analysis and task decomposition. The second aim is to assess whether there is a gap between operators’ current skills and the skills expected from them for performing roles in the future systems. To meet the second aim, an online survey was developed using the list of skills already identified for the first aim, and the survey was administered to use case supervisors and managers. The following paper details the methodology for skill identification and survey development and the results from the survey are discussed.The work has been conducted on the CONVERGING project (101058521 HORIZON-CL4–2021-TWIN-TRANSITION-01–01 – Innovation action)10th International Conference on Robot Ethics and Standards: ICRES 2025Lecture Notes in Networks and System
Cultural Identity Value Intersectionality Calculous (CIVIC) An inductive study of British Army cultural sensemaking
Get PDFInductive PhD study, sponsored by the British Army and researched by a serving officer, to develop understandings of cultural value intersections within British Army organisations, from the internal, grounded perspectives of people that live that experience. The project application of an interpretivist social constructionist philosophy enabled the combination of Pike’s (1982) emic theory, that the people inhabiting a culture are best placed to understand it, with Crenshaw’s (1994) idea of interlocking power systems, and rejection of the analytical treatment of cultural axis in isolation, to develop Cultural Identity Value Intersectionality Calculous (CIVIC) as a sensemaking framework. Using the inductive reasoning of grounded
theory, the project’s participatory research design enabled the audience-centric development of CIVIC as an intuitively usable framework for the emic sensemaking of audiences’ own Identity Value ‘Theories of Action’ and say/do gaps (Argyris & Schon, 1978). This addresses a gap in contemporary British Army capabilities, enabling volunteer participants to articulate their lived-experiences of organisational cultural dynamics (Schein & Schein, 2017) in terms of risks (Gigerenzer, 2002) and behaviour motivations (Atkins, West & Michie, 2014), within anthro-complexity (Snowden, 2020), to inform leadership initiatives and develop the force. This work highlights the importance of cultural intersectionality within the British Army, from the perspectives of the soldiers with that organisational lived-experience. It consequently delivers: (1.) Approach. An audience-centric risk-based approach to the sensemaking of cultural intersectionality; (2.) Method. A straight-forward, risk calculous method of systemic reasoning, using CIVIC to score participants’ cultural risks and build their agency for positive change; (3.) Knowledge-base. A thematic knowledge-base of qualitative evidence from the workforce grounded perspectives. This will enable the British Army leadership of tomorrow to leverage the best from a better informed, proactive, and contextually integrated future force,
tackling cultural misconceptions and enabling competitive advantage within anthro complexity, through empowered organisational agency.HQ Army, EP(A)Defence and Security Doctoral Symposia 2024 (DSDS24