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Label-free analysis of protein biomarkers using pattern-optimized graphene-nanopyramid SERS for rapid diagnosis of Alzheimer’s disease
Get PDFThe quantitative and highly sensitive detection of biomarkers such as Tau proteins and Aβ polypeptides is considered one of the most effective methods for the early diagnosis of Alzheimer’s disease (AD). Surface-enhanced Raman spectroscopy (SERS) detection is a promising method that faces, however, challenges like insufficient sensitivity due to the non-optimized nanostructures for specialized analyte sizes and insufficient control of the location of SERS hot spots. Thus, the SERS detection of AD biomarkers is restricted. We reported here an in-depth study of the analytical Raman enhancement factor (EF) of the wafer-scale graphene-Au nanopyramid hybrid SERS substrates using a combination of both theoretical calculation and experimental measurements. Experimental results show that larger nanopyramids and smaller gap spacing lead to a larger SERS EF, with an optimized analytical EF up to 1.1 × 1010. The hybrid SERS substrate exhibited detection limits of 10–15 M for Tau and phospho-Tau (P-Tau) proteins and 10–14 M for Aβ polypeptides, respectively. Principal component analysis correctly categorized the SERS spectra of different biomarkers at ultralow concentrations (10–13 M) using the optimized substrate. Amide III bands at 1200–1300 cm–1 reflect different structural conformations of proteins or polypeptides. Tau and P-Tau proteins are inherently disordered with a few α-helix residuals. The structure of Aβ42 polypeptides transitioned from the α-helix to the β-sheet as the concentration increased. These results demonstrate that the hybrid SERS method could be a simple and effective way for the label-free detection of protein biomarkers to enable the rapid early diagnosis of AD and other diseases.ACS Applied Nano Material
Modelling the impacts of climate change on the sustainability of rainfed and irrigated maize in Pakistan
Get PDFMaize is a globally significant food crop but its future sustainability under rainfed conditions is at risk due to climate change and increased climate uncertainty. In Pakistan most maize is rainfed but there is increasing interest in the role of supplemental irrigation to reduce the vulnerability of crop yields to future drought and climate risks. Using a crop model (DSSAT CERES-Maize) with downscaled data from a weather generator (LARS-WG) and for five selected GCMs, two RCPs (4.5 and 8.5) and two time slices (2050s and 2080s), this study assessed the impacts of climate change and climate variability on rainfed maize grown in the Pothwar region of Pakistan, and the extent to which irrigation could offset future yield reductions. Model simulations were calibrated and validated using experimental data from 2021 and 2022. The outputs showed that on average the yield of maize could be increased by 55% with a single irrigation of 60 mm during the reproductive stage. For the baseline (1991–2020) the average rainfed yield was 3370 kg/ha. The climate change scenarios for the 2050s indicated a −13.5% and −5.8% decline in rainfed yield under RCP4.5 and RCP8.5, respectively. Irrigation applications (between 162 mm and 180 mm) increased grain yields by 5615 kg/ha and 5732 kg/ha, respectively. For the 2080s scenarios there was a projected decrease in yield by -9.3% and -39.7% under RCP4.5 and RCP8.5, respectively. Modelling also confirmed significant reductions in maize biomass production which would negatively impact on feedstocks for both livestock and renewable energy generation.Commonwealth Scholarship Commission in the UKAgricultural Water Managemen
Fracture toughness investigation of AL6082-T651 alloy under corrosive environmental conditions
Get PDFThe crack initiation and propagation in an aluminium alloy in a corrosive environment are complex because of the loading parameters and material properties, which may result in a sudden failure in real-time applications. This paper investigates the fracture toughness of aluminium alloy under varying environmental and corrosion conditions. The main objective of the work is to link the interdependencies of humidity and temperature for an AL6082-T651 alloy in a corrosive environment. This study investigates AL6082-T651alloy's fracture behaviour and mechanism through microstructure and fractographic studies. The results show that a non-corroded sample, at room conditions, provided more load-carrying capacity than a corroded sample. Additionally, an increase in temperature improves fracture toughness, while an increase in humidity results in a decrease in fracture toughness.Engineering Innovation
Sense and avoid considerations for safe sUAS operations in urban environments
Get PDFOperations involving small Unmanned Aerial Systems (sUAS) in urban environments are occurring ever more frequently as recognized applications gain acceptance, and new use cases emerge, such as urban air mobility, medical deliveries, and support of emergency services. The presence of Detect and Avoid (DAA) capability of sUAS is one of the major requirements for its safe operation in urban environments. The platform or its operator proves a full awareness of all potential obstacles within the mission, maintains a safe distance from other airspace users, and, ultimately, performs Collision Avoidance (CA) maneuvers to avoid imminent impacts. Communication and navigation defined scenarios are designed and performed within the simulation model in Systems Tool Kit (STK) software environment, covering several practical cases. The acquired data supports the assessment of feasibility and requirements for real-time processing. Utilizing Unreal Engine and MATLAB analysis of the findings and simulation results leads to a holistic approach to implementation of sUAS operations in urban environments, focusing on extracting critical DAA capability for safe mission completion. The proposed approach forms a valuable asset for safe operations validation, enabling better evaluation of risk mitigation for sUAS urban operations and safety-focused design of the sensor payload and algorithms.Innovate UK funding, under the Grant number 75259.
Thales iCase and EPSRCIEEE Aerospace and Electronic Systems Magazin
A co-simulation digital twin with SUMO and AirSim for testing lane-based UTM system concept
Get PDFThe UAS (Unmanned Aircraft System) Traffic Management (UTM) System Concept of Operations (ConOps) is the first formal design reference document of the UTM system, ConOps aims to bring Class G Airspace into government regulation. However, it should be noted that there are still some shortcomings in ConOps that require further discussion. For example, there are concerns about operational rights, privacy rights, and the potential interference caused by high-rise buildings in urban core areas. The Lane-based UTM systems could potentially help in solving the above issues. The flight paths of Unmanned Aerial Vehicles (UAVs) in urban areas or other areas will interact with the road network, which can facilitate airspace traffic development. Ground traffic flow simulation is generally conducted on three levels: macroscopic, mesoscopic, and microscopic. Some of the commonly used car traffic flow simulation tools include Vissim, SUMO, and MATSim. However, UAV traffic simulation is mostly at a single level, and all of the current mainstream simulation software for UAV, such as Gazebo, AirSim, and Flight Gear, are microscopic-level analyses of UAV operations, lacking uniform management of drone traffic flow and operations. In addition, these UAV traffic simulation studies do not consider the city traffic and road network. In this context, a lane-based cosimulation UAV traffic simulation method is proposed in this study. The co-simulation architecture will be based on the highfidelity three-dimensional (3D) environment developed in the Unreal Engine, UAV simulation with AirSim, and twodimensional (2D) road network simulation with SUMO. A standardized and universal co-simulation architecture and communication interface to ensure interoperability, compatibility, and synchronization will be developed in this study. The lane-based co-simulation method will effectively leverage the road network simulation capacities to turn complex 3D space planning into simple 2D planning, it could reduce computational load and improve system efficiency. The 3D environment will also enhance the simulation capacities with its unique and high-fidelity simulation capacities. Overall, the proposed co-simulation method will support the Digital Twin development by interfacing several simulation tools, incorporating different communications, and adding realistic visualization, which could create unprecedented opportunities for software tool combinations.This research is funded by the UKRI Future Flight Challenge Phase 3 project HADO (High-intensity Autonomous Drone Operations), grant number 10024815
A numerical study of the performance of point absorber wave energy converters
Get PDFFree-floating and submerged wave energy converters (SWECs) are regarded as promising technologies for renewable energy production. These converters rely on a heave-motion buoy to capture the kinetic energy of ocean waves and convert it into electrical energy through power conversion systems. To better understand the impact of various factors on power generation and efficiency, the effects of different buoy shapes (rectangular, circular cylinder, and trapezoidal fin), submergence depths (0, 0.1, and 0.2 m), wave heights (0.04, 0.06, and 0.1 m), and spring stiffness (50 and 100 N/m) were investigated. A 2D numerical wave tank with a buoy was simulated, and the results were validated against experimental data. Information on vorticity, vertical displacement, power absorption, and efficiency are provided. The findings indicate that the buoy shape and wave height significantly affect power absorption and efficiency. Additionally, this study reveals that increasing submergence leads to higher power absorption and lower conversion efficiency.UK Commonwealth Split-Site CommissionApplied Science
Necessary and sufficient conditions for deploying hydrogen homes: a consumer-oriented perspective
Get PDFAs part of its efforts to secure a ‘net-zero society’, the UK government will take a strategic decision on the role of hydrogen in decarbonising homes within the next years. While scholars have recently advanced the social science research agenda on hydrogen technology acceptance, studies are yet to engage with the prospective dynamics of adopting ‘hydrogen homes’. In response, this study examines the perceived adoption potential of hydrogen heating and cooking technologies, as evaluated through the eyes of consumer. Engaging with behavioural and market acceptance, this research draws on data from a broadly nationally representative online survey to examine the influence of safety, technological, economic, environmental, and emotional factors on the domestic hydrogen transition in the UK context. The analysis follows a multi-stage empirical approach, integrating findings from partial least squares structural equation and necessary condition analysis to crystallise insights on this emergent subject. At this juncture, perceived adoption potential may hinge primarily on emotional, environmental, safety, and to a lesser extent, technological perspectives. However, consumers have an expressed preference for hydrogen heating over hydrogen cooking, with perceived boiler performance emerging as a necessary condition for enabling adoption potential. At the formative phase of the transition, risks associated with energy insecurity and fuel poverty exceed concerns over purchasing and running costs. Nevertheless, economic factors remain less critical during the pre-deployment phase of the innovation-decision process. Across the full sample, simple slope analysis highlights the moderating effects of gender, age, and housing tenure. Moreover, statistically significant differences from both a sufficiency- and necessity-based perspective are detected between male property owners aged 55+ and female mortgage owners 18–34 years old. By bridging the knowledge gap between social acceptance and adoption intention, this contribution reinforces the need for consumer engagement in the hydrogen economy, advocating for more fine-grained, mixed-methods analyses of technology acceptance dynamics to support decarbonisation strategies.Financial support was provided by the UK Research and Innovation Engineering and Physical Sciences Research Council. and Cadent Gas Ltd.International Journal of Hydrogen Energ
Fast emitting nanocomposites for high-resolution ToF-PET imaging based on multicomponent scintillators
Get PDFTime-of-Flight Positron Emission Tomography (ToF-PET) is a medical imaging technique, based on the detection of two back-to-back γ-photons generated from radiotracers injected into the body. Its limit is the ability of employed scintillation detectors to discriminate in time the arrival of γ-pairs, that is, the coincidence time resolution (CTR). A CTR < 50 ps will enable fast imaging with ultralow radiotracer dose. Monolithic materials do not have simultaneously the required high light output and fast emission characteristics, thus the concept of scintillating heterostructure is proposed, where the device is made of a dense scintillator coupled to a fast-emitting light material. Here a composite polymeric scintillator loaded with hafnium oxide nanoparticles is presented. This enhanced by +300% its scintillation yield, by surpassing commercial plastic scintillators. The nanocomposite is coupled to bismuth germanate oxide (BGO) realizing a multilayer metascintillator. The energy sharing between its components is observed, which activates the nanocomposite's fast emission enabling a net CTR improvement of 25% with respect to monolithic BGO. These results demonstrate that a controlled loading with dense nanomaterials is an excellent strategy to enhance the performance of polymeric scintillators for their use in advanced radiation detection and imaging technologies.We acknowledge support from the European Community through the grant no. 899293, HORIZON 2020 - SPARTE FET OPEN. Financial support from the Italian Ministry of University (MUR) through grant no. PRIN 2020—SHERPA no. H45F2100343000. CERN knowledge transfer for medical applications budget. Cranfield University, acknowledges that part of this research was funded by the UK Engineering and Physical Sciences Research Council (EPSRC) grant EP/S013652/1.Advanced Materials Technologie
Brecciation at the grain scale within the lithologies of the Winchcombe Mighei-like carbonaceous chondrite
Get PDFSpecial Issue: The science of the Winchcombe meteoriteThe Mighei-like carbonaceous (CM) chondrites have been altered to various extents by water–rock reactions on their parent asteroid(s). This aqueous processing has destroyed much of the primary mineralogy of these meteorites, and the degree of alteration is highly heterogeneous at both the macroscale and nanoscale. Many CM meteorites are also heavily brecciated juxtaposing clasts with different alteration histories. Here we present results from the fine-grained team consortium study of the Winchcombe meteorite, a recent CM chondrite fall that is a breccia and contains eight discrete lithologies that span a range of petrologic subtypes (CM2.0–2.6) that are suspended in a cataclastic matrix. Coordinated multitechnique, multiscale analyses of this breccia reveal substantial heterogeneity in the extent of alteration, even in highly aqueously processed lithologies. Some lithologies exhibit the full range and can comprise nearly unaltered coarse-grained primary components that are found directly alongside other coarse-grained components that have experienced complete pseudomorphic replacement by secondary minerals. The preservation of the complete alteration sequence and pseudomorph textures showing tochilinite–cronstedtite intergrowths are replacing carbonates suggest that CMs may be initially more carbonate rich than previously thought. This heterogeneity in aqueous alteration extent is likely due to a combination of microscale variability in permeability and water/rock ratio generating local microenvironments as has been established previously. Nevertheless, some of the disequilibrium mineral assemblages observed, such as hydrous minerals juxtaposed with surviving phases that are typically more fluid susceptible, can only be reconciled by multiple generations of alteration, disruption, and reaccretion of the CM parent body at the grain scale.Meteoritics & Planetary Scienc
Indirect tuning of a complementary orientation filter using velocity data and a genetic algorithm
Get PDFIn this paper, the accuracy of inertial sensor orientation relative to the level frame is improved through optimal tuning of a complementary filter by a genetic algorithm. While constant filter gains have been used elsewhere, these may introduce errors under dynamic motions when gyroscopes should be trusted more than accelerometers. Optimal gains are prescribed by a Mamdani fuzzy rule base whose membership functions are found using a genetic algorithm and experimental data. Furthermore, model fitness is not based directly on orientation but the error between estimated and ground truth velocities. This paper has three interrelated novel elements. The main novelty is the indirect tuning method, which is simple, low-cost and requires a single camera and inertial sensor. The method is shown to increase tracking accuracy compared with popular baseline filters. Secondary novel elements are the bespoke genetic algorithm and the time agnostic velocity error metric. The contributions from this work can help improve the localization accuracy of assets and human personnel. This research has a direct impact in command and control by improving situational awareness and the ability to direct assets to safe locations using safer routes. This results in increasing safety in applications such as firefighting and battlespace.This research is funded by the Engineering and Physical Sciences Research Council (EPSRC) iCASE Grant reference EP/S513623/1 and BAE Systems.Systems Science & Control Engineerin