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Diagnostic features emerging in near-infrared reflectance spectroscopy for low petroleum hydrocarbon pollution after spectral subtraction
Get PDFDiagnostic features in near-infrared reflectance spectroscopy (NIRS) are the foundation of knowledge-based approach of petroleum hydrocarbon determination. However, a significant challenge arises when analyzing samples with low levels of petroleum hydrocarbon pollution, as they often lack distinctive diagnostic features in their sample NIRS spectra, limiting the effectiveness of this approach. To address this issue, we have developed a technical workflow for diagnostic spectrum construction and parameterization based on spectral subtraction. This method was applied on a set of NIRS spectra from soil samples that were contaminated with petroleum hydrocarbons (ranged between 178 and 1716 mg/kg of total petroleum hydrocarbon). Then two diagnostic features for low-level petroleum hydrocarbon pollution were found: (1) An overall downward concave emerged on diagnostic spectrum within both 2290–2370 nm and 1700–1780 nm for all low pollution levels even below 200 mg/kg; (2) An indicative pattern of asymmetric “W-shaped” double absorption valley occurred for those exceeding 1000 mg/kg, and its valleys located near 2310 nm, 2348 nm or 1727 nm, 1762 nm stably. These two features on diagnostic spectrum could be parameterized to detect, and the detection limit was at least about 10–50 times lower than that based on sample spectrum. These findings update our understanding on the detectability of spectral response from low petroleum hydrocarbon pollution, and widely extend the application of knowledge-based NIRS approach in either field detection or remote sensing identification for environmental management.Science of The Total Environmen
From brew to table: unleashing the potential of spent grains protein
Get PDFUnited Nations and Upcycled Food Association have suggested the possible use of food processing residues and waste materials to improve food quality as well as overcome hunger and malnutrition. Brewer's spent grains (BSG) account 85% of brewery waste having high nutritive value. Spent grains are initially exploited for animal feed only and restricted to the local area due to high moisture content that leads to spoilage. Spent grains are rich in fibre and proteins and were explored for the preparation of cookies, bread, pasta, and noodles which showed higher nutritive value and health benefits in comparison to conventional materials. The bioactive compounds in spent grains also provide additional advantages and can be used in drug formulation for commercial products. However, it needs in-depth research and technical support that aid in contributing to the circular economy.Journal of Cereal Scienc
Effects of cornering conditions on the aerodynamic characteristics of a high-performance vehicle and its rear wing
Get PDFThis study investigates the aerodynamic behavior of a high-performance vehicle and the interaction with its rear wing in straight-line and steady-state cornering conditions. Analyses are performed with Reynolds-averaged Navier–Stokes based computational fluid dynamics simulations using a moving reference frame and overset mesh technique, validated against moving ground wind tunnel experiments. The results indicate a significant 20% decrease in downforce and 35% increase in drag compared to straight-line conditions at the smallest considered corner radius of 2.9 car-lengths. Downforce losses primarily stem from performance deficits on the underbody and rear wing, alongside elevated upper body lift. Drag penalties mainly result from additional pressure drag induced by a recirculation wake vortex generated behind the vehicle's inboard side. The vehicle's lateral pressure distribution is also affected, introducing a centripetal force that increases with smaller corner radii. Additionally, analyses of the rear wing reveal alternations of its aerodynamic characteristics in cornering, particularly impacting vortical flow and suction on the lower surface. Throughout the operating conditions, the rear wing's individual downforce contribution falls off beyond its stall angle. At higher angles of attack, the rear wing primarily generates downforce by pressurizing the vehicle's upper surfaces, but its interaction with the near-wake leads to a substantially increased pressure drag. Overall, these findings provide crucial insights into the intricate aerodynamic interactions of high-performance vehicles in diverse operating conditions as well as form an essential foundation for future research on static and active aerodynamic designs in the pursuit to optimize vehicle performance in dynamic driving conditions.Physics of Fluid
A study on co-simulation digital twin with MATLAB and AirSim for future advanced air mobility
Get PDFThe exponential growth in Unmanned Aerial Vehicle (UAV) operations highlights the need for reliable and efficient airspace management. Ensuring the integrity and reliability of UAV Traffic Management (UTM) systems requires extensive testing, verification and validation. Overcoming these challenges is essential to guarantee that UAVs can be successfully integrated into operational airspace while maintaining the highest standards of safety and effectiveness. The development and improvement of virtual environment testing capabilities are critical to the advancement and rapid deployment of UTM services; however, building a high-fidelity digital environment that enables the development, verification and validation of UTM solutions in a compliant, scalable and sustainable manner remains demanding. By integrating MATLAB, Simulink, AirSim, Unreal Engine and Cesium, this study aims to extend the performance and functionality of a Digital Twin (DT) system. This integration leverages the sophisticated modelling capabilities of MATLAB and the advanced 3-dimensional (3D) simulation capabilities of AirSim. It also aligns with emerging trends in the aerospace sector, including autonomous flight and advanced sensing technologies. Firstly, co-simulation is explored as a potential technique to overcome the limitations of individual simulation software available on the market. The general principles are then applied to define and model a communication interface between the software selected to build the DT ecosystem. This interface is then evaluated by proposing practical and achievable test cases. Only after validating the proposed co-simulation framework, further experiments are introduced aiming at improving the vehicle and sensor model performance to obtain more accurate synthetic data. A series of experiments of increasing difficulty is proposed, starting from co-simulating a single sensor (GNSS, INS, LIDAR and camera) up to co-simulating the entire aircraft system for the development of intelligent algorithms such as waypoint following and collision avoidance. Ultimately, this research contributes to the practical application of co-simulation, providing insight into its capabilities and potential influence on the advancement of autonomous aircraft and DT systems.This research is funded by the UKRI Future Flight Challenge Phase 3 project HADO (High-intensity Autonomous Drone Operations), grant number 10024815.2024 IEEE Aerospace Conferenc
Alternative bootstrap confidence regions for multiple correspondence analysis
Get PDFA new approach for constructing elliptical bootstrap confidence regions for Multiple Correspondence Analysis is proposed, where the difference in method follows directly from the adoption of a different objective criterion to previous approaches. This includes a new correction for the well-known problems caused by the diagonal of the Burt matrix. Simulation experiments show that the method performs reasonably well in many cases, with exceptions being noted. Simulated data sets with known structure are also used to illustrate cases where the proposed method produces results in line with what would be expected, but some alternatives do not.Communications in Statistics-Simulation and Computatio
Achieving a columnar-to-equiaxed transition through dendrite twinning in high deposition rate additively manufactured titanium alloys
Get PDFThe coarse β-grain structures typically found in titanium alloys like Ti–6Al–4V (wt pct, Ti64) and Ti–6Al–2Sn–4Zr–2Mo–0.1Si (Ti6242), produced by high deposition rate additive manufacturing (AM) processes, are detrimental to mechanical performance. Certain modified processing conditions have been shown to lead to a more refined grain structure, which has generally been attributed to a change in the solidification conditions with respect to the experimental Hunt diagram proposed by Semiatin and Kobryn. It is shown that with Wire Arc AM (WAAM) increasing the wire feed speed (WFS) is effective in promoting a columnar-equiaxed transition (CET). Conversely, estimates of the dendrite-tip undercooling using the KGT model suggest that this will be too small for free nucleation without the addition of artificial nucleants, due to the very low solute partitioning in Ti alloys. It is also shown that it is difficult to promote a CET with plasma transferred arc WAAM as computational fluid dynamics (CFD) melt-pool simulations indicate that the solidification parameters remain within the columnar region on the Semiatin-Kobryn Hunt map, within the constraints of a stable process. However, a high fraction of twin boundaries was observed in the refined β-grain structures seen at high WFS. This has been attributed to departure of {001}β alignment from the direction of maximum thermal gradient, caused by the curvature of the fusion boundary, stimulating dendrite twinning during solidification. In addition, it is shown that increasing the WFS leads to a change in melt-pool geometry and a reduction of remelt depth, which promoted dendrite twinning and grain refinement.The authors are appreciative of the EPSRC program grants NEWAM (EP/R027218/1) and LightForm (EP/R001715/1), for supporting aspects of this research. The authors acknowledge the use of equipment associated with the Advanced Metals Processing and Characterization 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. P.B. Prangnell is grateful to the Royal Academy of Engineering, UK, and Airbus for supporting his research through the Airbus-University of Manchester Centre for Metallurgical Excellence.Metallurgical and Materials Transactions
HRM, institutional complementarities, and performance: the case of the healthcare sector in Jordan
Get PDFBuilding on the comparative capitalism literature, we aim to understand the impact of HRM practice on hospitals performance within the healthcare sector in Jordan, and the role of HRM in mitigating and overcoming systemic shortfalls. Two different surveys were distributed for both hospital and HR managers across all hospitals. Our findings indicate that certain HR practices are positively associated with performance, despite contextual challenges such as informal networks and cultural limitations that could undermine efficiency. We further tested the potential impact of HR complementarities on performance; nevertheless, the results did not significantly surpass the explanatory power of the individual HR practices. It might have been anticipated that mutually supportive bundles of practices might compensate for systemic weaknesses. However, it may be the case that players have devised solutions in other areas of managerial practice that may be more effective than HRM in compensating for systemic limitations. Our study also highlights that in oligopolistically structured markets, common in private healthcare systems, the effectiveness of HR practices may be less crucial for profitability, though this does not diminish their broader relevance for societal and community outcomes which are beyond the scope of this work.European Management Journa
Evaluating LCA product families in an approach to determine baseline emissions within aerospace manufacturing
Get PDF31st CIRP Conference on Life Cycle Engineering (LCE 2024), 19-21 June 2024, Turin, ItalyThis paper investigates a Life Cycle Assessment (LCA) based methodology to determine baseline emissions for an aerospace manufacturer. Aerospace manufacturing entails high complexity and low throughput of a vast array of components. Rather than establishing the environmental footprint through waste, electric, and gas data alone; an LCA cradle-to-gate approach extends to a product's raw material acquisition and shipment to provide a comprehensive set of environmental performance indicators. The approach combines several products that follow a similar manufacturing process and can be denoted as a product family. This paper discusses the ability that LCA product families must develop baseline emissions for products validated with a case study of an aerospace component. The methodology can be extended to other product families manufactured within the facility which when combined will accumulate to a site-wide environmental footprint. The paper further evaluates how this methodology can identify environmental hotspots at a process and product level. The aerospace component case study incorporates several manual and automated stages. This work aims to demonstrate the ease of determining baseline emissions using an LCA product family and enable aerospace manufacturing companies to adopt a similar approach to establishing environmental hotspots. This can drive strategic internal change for sustainable manufacturing aligning with company environmental, social, and financial frameworks.We thank all involved in the LCA data collection. This work was supported as part of the Metallic Aerospace Structures Technologies for Eco-social Returns (MASTER) project (funded through UKRI ATI program grant agreement 103040).31st CIRP Conference on Life Cycle Engineering (LCE 2024)Procedia CIR
Hydrogen Homes Dataset for H2 Acceptance Matrix analysis
No full textThis dataset records qualitative answers (written statements) given by respondents at the end of an online survey (programmed in Qualtrics) on domestic hydrogen in the United Kingdom (N= 1845). The open-ended question was specified as follows: lease use this text box to explain more about your attitudes towards hydrogen or any other reflections on this topic. Around two-thirds (N = 1213) provided written responses, which were subsequently coded according to one-dimensional (hydrogen pessimist, hydrogen sceptic, hydrogen cautious, hydrogen neutral, hydrogen curious, hydrogen hopeful, or hydrogen optimist) and multi-dimensional responses (e.g. hydrogen hopeful yet cautious, or hydrogen cautious but otherwise neutral etc.) 81.8% of respondents expressed a one-dimensional perspective (N = 992). The data collection period ran between 06/10/2023–23/12/2023. The survey duration was approximately 15–20 minutes. In published materials, we use the term Hydrogen Homes (H2H) dataset to denote outputs from this project.DTP 2020-2021 Cranfield Universit
Heterogeneous preferences for living in a hydrogen home: an advanced multigroup analysis
No full textThe UK Hydrogen Strategy (August 2021) and subsequent Heat and Buildings Strategy (October 2021) affirm that a strategic decision is set to be taken by 2026 on the prospect of residential decarbonisation via ‘hydrogen homes’. As this decision date draws nearer, quantitative insights on consumer perceptions of hydrogen-fuelled heating and cooking appliances remain limited. The existing knowledge deficit presents a substantial barrier to implementing a socially acceptable deployment pathway for residential decarbonisation. Despite recent efforts to advance the social science research agenda on hydrogen acceptance, few studies have advanced theoretical knowledge or pursued comprehensive statistical analyses. This study responds to the extant research gap by analysing the perceived adoption potential for hydrogen homes via partial least squares-necessary condition-multigroup analysis. Drawing on data from a nationally representative online survey (N = 1845) conducted in the UK, the adoption dynamics for domestic hydrogen are compared across four sub-groups of the population. The findings suggest that non-economic constructs such as safety perceptions and production perceptions are potentially more influential at this stage of the domestic hydrogen transition. Differences between consumer sub-groups are explained by safety, technology, and production perceptions, whereas financial perceptions are relatively homogeneous across the segments. These patterns underline the opportunity to strengthen residential decarbonisation efforts through segment-specific polices and strategic engagement with different parts of the housing stock. Policy makers and key stakeholders should factor consumer heterogeneity into net-zero decision-making processes by firstly acknowledging the amplifying effect of technology and environmental engagement in supporting adoption prospects for hydrogen homes. Socially acceptable strategies for decarbonising the residential sector can be supported by actively responding to heterogeneous household preferences for living in a hydrogen home.This research was supported by the UK Research and Innovation Engineering and Physical Sciences Research Council (UKRI-EPSRC) Grant EP/T518104/1, and sponsored by Cadent Gas Ltd.Sustainable Energy & Fuel