121 results on '"Interface Analysis Centre"'
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2. Thermal conductivity and Seebeck coefficients of icosahedral boron arsenide films on silicon carbide
- Author
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Heard, P [Interface Analysis Centre, University of Bristol, Bristol BS2 8BS (United Kingdom)]
- Published
- 2010
- Full Text
- View/download PDF
3. New waste based clinkers: Belite and lime formulations
- Author
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Allen, Geoffrey [University of Bristol, Interface Analysis Centre, Oldbury House, 121 St Michael's Hill, Bristol, BS2 8BS (United Kingdom)]
- Published
- 2008
- Full Text
- View/download PDF
4. In-situ, time resolved monitoring of uranium in BFS:OPC grout. Part 2: Corrosion in water
- Author
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C. A. Stitt, C. Paraskevoulakos, A. Banos, N. J. Harker, K. R. Hallam, H. Pullin, A. Davenport, S. Street, T. B. Scott, Interface Analysis Centre, University of Bristol [Bristol], European Synchrotron Radiation Facility (ESRF), School of Metallurgy and Materials, and University of Birmingham [Birmingham]
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Multidisciplinary ,[SDV]Life Sciences [q-bio] ,lcsh:R ,lcsh:Medicine ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,OXYGEN ,Article ,0104 chemical sciences ,MECHANISMS ,IMMOBILIZATION ,CEMENT ,TEMPERATURES ,VAPOR ,lcsh:Q ,0210 nano-technology ,lcsh:Science ,(null) - Abstract
To reflect potential conditions in a geological disposal facility, uranium was encapsulated in grout and submersed in de-ionised water for time periods between 2–47 weeks. Synchrotron X-ray Powder Diffraction and X-ray Tomography were used to identify the dominant corrosion products and measure their dimensions. Uranium dioxide was observed as the dominant corrosion product and time dependent thickness measurements were used to calculate oxidation rates. The effectiveness of physical and chemical grout properties to uranium corrosion and mobilisation is discussed and Inductively Coupled Plasma Mass Spectrometry was used to measure 238U(aq) content in the residual water of several samples.
- Published
- 2018
5. Exploring the distribution of copper-Schiff base complex covalently anchored onto the surface of mesoporous MCM 41 silica
- Author
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Allen, Geoffrey [Interface Analysis Centre, University of Bristol, Bristol BS2 8BS (United Kingdom)]
- Published
- 2005
- Full Text
- View/download PDF
6. In-situ, time resolved monitoring of uranium in BFS:OPC grout. Part 1: Corrosion in water vapour
- Author
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A. Banos, Steven R. Street, Huw Pullin, Keith R Hallam, N. J. Harker, C.A. Stitt, Alison J. Davenport, C. Paraskevoulakos, Thomas Bligh Scott, Interface Analysis Centre, University of Bristol [Bristol], European Synchrotron Radiation Facility (ESRF), School of Metallurgy and Materials, and University of Birmingham [Birmingham]
- Subjects
Materials science ,Science ,Uranium dioxide ,0211 other engineering and technologies ,Oxide ,Analytical chemistry ,chemistry.chemical_element ,Mineralogy ,02 engineering and technology ,engineering.material ,OXIDATION ,Oxygen ,Article ,OXYGEN ,Corrosion ,MECHANISMS ,Reaction rate ,chemistry.chemical_compound ,PHASES ,TEMPERATURES ,CEMENT ,021105 building & construction ,KINETICS ,[PHYS]Physics [physics] ,Multidisciplinary ,Science & Technology ,Grout ,MIXTURES ,Uranium ,021001 nanoscience & nanotechnology ,Multidisciplinary Sciences ,chemistry ,RAY PHOTOELECTRON-SPECTROSCOPY ,engineering ,Medicine ,Science & Technology - Other Topics ,0210 nano-technology ,Water vapor ,DIOXIDE - Abstract
Uranium encapsulated in grout was exposed to water vapour for extended periods of time. Through synchrotron x-ray powder diffraction and tomography measurements, uranium dioxide was determined the dominant corrosion product over a 50-week time period. The oxide growth rate initiated rapidly, with rates comparable to the U + H2O reaction. Over time, the reaction rate decreased and eventually plateaued to a rate similar to the U + H2O + O2 reaction. This behaviour was not attributed to oxygen ingress, but instead the decreasing permeability of the grout, limiting oxidising species access to the metal surface.
- Published
- 2017
7. Nanoscale Metallic Iron for Environmental Remediation: Prospects and Limitations
- Author
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Sabine Caré, Chicgoua Noubactep, Richard A. Crane, Department of Applied Geology [Göttingen], Georg-August-University [Göttingen], Kultur und Nachhaltige Entwicklung CDD e.V, Kultur und Nachhaltige Entwicklung CDD e.V ONG de droit allemand, Rhéophysique, Laboratoire Navier (navier umr 8205), École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), Interface Analysis Centre, and University of Bristol [Bristol]
- Subjects
Environmental remediation ,Material reactivity ,Nanoscale iron ,Roll-front ,Zerovalent iron ,Environmental Engineering ,Groundwater remediation ,0211 other engineering and technologies ,FOS: Physical sciences ,Physics - Classical Physics ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Article ,[SPI.MAT]Engineering Sciences [physics]/Materials ,[PHYS.MECA.MEMA]Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph] ,Environment ,Atmospheric Protection/Air Quality Control/Air Pollution ,Climate Change ,Environment, general ,Soil Science & Conservation ,Hydrogeology ,Waste Water Technology / Water Pollution Control / Water Management / Aquatic Pollution ,[SPI.MECA.MEMA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph] ,Environmental Chemistry ,0105 earth and related environmental sciences ,Water Science and Technology ,021110 strategic, defence & security studies ,Ecological Modeling ,Classical Physics (physics.class-ph) ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Pollution ,6. Clean water ,Ecological Modelling ,13. Climate action ,Environmental remediation . Material reactivity . Nanoscale iron . Roll-front . Zerovalent iron ,Environmental science ,Biochemical engineering - Abstract
International audience; The amendment of the subsurface with nanoscale metallic iron particles (nano-Fe0) has been discussed in the literature as an efficient in situ technology for groundwater remediation. However, the introduction of this technology was controversial and its efficiency has never been univocally established. This unsatisfying situation has motivated this communication whose objective was a comprehensive discussion of the intrinsic reactivity of nano-Fe0 based on the contemporary knowledge on the mechanism of contaminant removal by Fe0 and a mathematical model. It is showed that due to limitations of the mass transfer of nano-Fe0 to contaminants, available concepts cannot explain the success of nano-Fe0 injection for in situ groundwater remediation. It is recommended to test the possibility of introducing nano-Fe0 to initiate the formation of roll-fronts which propagation would induce the reductive transformation of both dissolved and adsorbed contaminants. Within a roll-front, FeII from nano-Fe0 is the reducing agent for contaminants. FeII is recycled by biotic or abiotic FeIII reduction. While the roll-front concept could explain the success of already implemented reaction zones, more research is needed for a science-based recommendation of nano- Fe0 for subsurface treatment by roll-fronts
- Published
- 2011
8. An Investigation on the Persistence of Uranium Hydride during Storage of Simulant Nuclear Waste Packages
- Author
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Stitt, CA, Harker, NJ, Hallam, KR, Paraskevoulakos, C, Banos, A, Rennie, S, Jowsey, J, Scott, TB, Interface Analysis Centre [Bristol ], H. H. Wills Physics Laboratory [Bristol], University of Bristol [Bristol]-University of Bristol [Bristol], European Synchrotron Radiation Facility (ESRF), Sellafield Ltd, Seascale, Cumbria, England, and Janssen, PJ
- Subjects
General Science & Technology ,[SDV]Life Sciences [q-bio] ,MD Multidisciplinary ,lcsh:R ,lcsh:Medicine ,lcsh:Q ,lcsh:Science - Abstract
International audience; Synchrotron X-rays have been used to study the oxidation of uranium and uranium hydride when encapsulated in grout and stored in de-ionised water for 10 months. Periodic synchrotron X-ray tomography and X-ray powder diffraction have allowed measurement and identification of the arising corrosion products and the rates of corrosion. The oxidation rates of the uranium metal and uranium hydride were slower than empirically derived rates previously reported for each reactant in an anoxic water system, but without encapsulation in grout. This was attributed to the grout acting as a physical barrier limiting the access of oxidising species to the uranium surface. Uranium hydride was observed to persist throughout the 10 month storage period and industrial consequences of this observed persistence are discussed
- Published
- 2015
9. Modeling the permeability loss of metallic Iron water filtration Systems
- Author
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Richard A. Crane, Chicgoua Noubactep, Antoine Ghauch, Sabine Caré, Emile Temgoua, Paolo S. Calabrò, Matériaux et Structures Architecturés (msa), Laboratoire Navier (navier umr 8205), École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), Interface Analysis Centre, University of Bristol [Bristol], Mechanics and Materials department MECMAT, Reggio Calabria, Universita Mediterranea of Reggio Calabria [Reggio Calabria], Department of Chemistry, American University of Beirut, Faculty of Engineering, Beirut, Lebanon, Department of Applied Geology [Göttingen], Georg-August-University [Göttingen], Kultur und Nachhaltige Entwicklung CDD e.V, and Kultur und Nachhaltige Entwicklung CDD e.V ONG de droit allemand
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Materials science ,Hydraulic conductivity ,Groundwater remediation ,0207 environmental engineering ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Corrosion ,[SPI.MAT]Engineering Sciences [physics]/Materials ,Environmental Chemistry ,020701 environmental engineering ,0105 earth and related environmental sciences ,Water Science and Technology ,Zerovalent iron ,Aqueous solution ,Deep-bed filtration ,Modelling, Permeability loss ,Environmental engineering ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Pollution ,6. Clean water ,Permeability (earth sciences) ,Chemical engineering ,Permeable reactive barrier ,Porous medium - Abstract
International audience; Over the past 30 years the literature has burgeoned with in situ approaches for groundwater remediation. Of the methods currently available, the use of metallic iron (Fe0) in permeable reactive barrier (PRB) systems is one of the most commonly applied. Despite such interest, an increasing amount of experimental and field observations have reported inconsistent Fe0 barrier operation compared to contemporary theory. In the current work, a critical review of the physical chemistry of aqueous Fe0 corrosion in porous media is presented. Subsequent implications for the design of Fe0 filtration systems are modeled. The results suggest that: (i) for the pH range of natural waters (>4.5), the high volumetric expansion of Fe0 during oxidation and precipitation dictates that Fe0 should be mixed with a non-expansive material; (ii) naturally occurring solute precipitates have a negligible impact on permeability loss compared to Fe0 expansive corrosion; and (iii) the proliferation of H2 metabolizing bacteria may contribute to alleviate permeability loss. As a consequence, it is suggested that more emphasis must be placed on future work with regard to considering the Fe0 PRB system as a physical (size-exclusion) water filter device.
- Published
- 2013
10. The Distribution of Boron within the Microstructure of a Ferritic Steel determined using Secondary Ion Mass Spectroscopy
- Author
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Peter J Heard, R.K. Wild, Peter E J Flewitt, Interface Analysis Ctr, Retired-Bristol University, Interface Analysis Centre, and University of Bristol [Bristol]
- Subjects
inorganic chemicals ,Materials science ,020502 materials ,fungi ,Metallurgy ,Analytical chemistry ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,Secondary ion mass spectrometry ,0205 materials engineering ,chemistry ,Bulk samples ,Physical Sciences ,High spatial resolution ,0210 nano-technology ,Boron ,Volume concentration - Abstract
International audience; Boron in ferritic steels at low concentrations can potentially have a significant effect on the mechanical properties. High spatial resolution microanalyses have been undertaken on a normalised C-Mn ferritic steel containing less than 1 wt. ppm boron. Secondary ion mass spectroscopy on bulk samples has been used to map the distribution of boron with the overall microstructure. Image analysis has been used to determine the location and concentration of boron within the overall microstructure of the steel. The results are discussed in terms of the microstructure, distribution, detection capability and overall audit of boron.
- Published
- 2006
11. The measurement of water transport in porous materials using impedance spectroscopy
- Author
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GC Allen, Richard J Ball, Interface Analysis Centre, and University of Bristol [Bristol]
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Absorption of water ,Acoustics and Ultrasonics ,0211 other engineering and technologies ,Mineralogy ,02 engineering and technology ,engineering.material ,law.invention ,impedance spectroscopy ______________________________________________________________________ ,law ,021105 building & construction ,Composite material ,Lime ,Brick ,Water transport ,Chemistry ,Hydraulic lime ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Dewatering ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Portland cement ,mortar ,engineering ,Mortar ,0210 nano-technology ,dewatering - Abstract
International audience; Short title: Measurement of water transport in porous materials using impedance spectroscopy Classification numbers: Abstract This paper describes the application of electrical measurements to monitor the extraction (movement of water from the mortar) of water from calcium lime, natural hydraulic lime and Portland cement mortars placed on an adsorbent brick substrate. Impedance measurements were used to identify the changes in bulk resistance of the mortar. A model has been developed combining sharp front theory and Boltzmann's distribution law of statistical thermodynamics to identify the point at which no further absorption of water in to the brick occurs. A linear relationship was found between the exponential of bulk resistance and square root of time during dewatering. A change in gradient was attributed to the end of dewatering.
- Published
- 2010
12. Grief and coping among relatives of patients who died of COVID-19 in intensive care during the height of the COVID-19 pandemic.
- Author
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Rodriguez-Villar S, Okegbola EO, Arevalo-Serrano J, Duval Y, Mathew A, Rodriguez-Villar C, Smith KV, Kennedy RC, and Prigerson HG
- Abstract
Background: The grief of relatives of patients who died of COVID-19 in an intensive care unit (ICU) has exacted an enormous toll worldwide., Aims: To determine the prevalence of probable prolonged grief disorder (PGD) at 12 months post-loss and beyond. We also sought to examine circumstances of the death during the COVID-19 pandemic that might pose a heightened risk of PGD, and the associations between probable PGD diagnosis, quality of life and social disconnection., Method: We conducted an observational, cross-sectional multicentre study of the next of kin of those who died of COVID-19 between March 2020 and December 2021. Participants were recruited from ICUs in South-East London. The Prolonged Grief Disorder Scale (PG-13-R), Quality-of-Life Scale (QOLS) and Oxford Grief-Social Disconnection Scale (OG-SD) were used., Results: A total of 73 relatives were recruited and assessed, all of them over a year after their loss. Twenty-five (34.2%; 95% CI 23.1-45.4%) relatives of patients who died in the ICU met the criteria for PGD. Those who met the criteria had significantly worse quality of life (QOLS score mean difference 26; 95% CI 17-34; P < 0.001) and endorsed greater social disconnection (OG-SD score means difference 41; 95% CI 27-54; P < 0.001)., Conclusions: The findings suggest that rates of PGD are elevated among relatives of patients who died of COVID-19 in the ICU. This, coupled with worse quality of life and greater social disconnection experienced by those meeting the criteria, suggests the need to attend to the social deprivations and social dysfunctions of this population group.
- Published
- 2024
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13. In Vivo Raman Spectroscopy of Muscle Is Highly Sensitive for Detection of Healthy Muscle and Highly Specific for Detection of Disease.
- Author
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Alix JJP, Plesia M, Stockholm D, Shaw PJ, Mead RJ, and Day JCC
- Subjects
- Animals, Mice, Muscular Diseases diagnosis, Mice, Inbred C57BL, Biomarkers analysis, Spectrum Analysis, Raman methods, Muscle, Skeletal chemistry, Muscle, Skeletal pathology
- Abstract
Raman spectroscopy of muscle provides a molecular fingerprint to identify the disease. Previous work has demonstrated effectiveness in differentiating between two groups of equal sizes (e.g., healthy vs disease) but imbalanced multiclass scenarios are more common in medicine. We performed in vivo Raman spectroscopy in a total of 151 mice across four different histopathologies (healthy, acute myopathy, chronic myopathy, neurogenic), with variable numbers in each (class "imbalance"). Using hierarchical modeling and synthetic data generation, we demonstrate high sensitivity (94%) for detection of healthy muscle and high specificity (≥97%) for disease. Further, we demonstrate the potential for unique biomarker development by demonstrating variations in the protein structure across different pathologies. The findings demonstrate the potential of Raman spectroscopy to provide accurate disease identification and unique molecular insights.
- Published
- 2024
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14. Long-Range Imaging of Alpha Emitters Using Radioluminescence in Open Environments: Daytime and Night-Time Applications.
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Kong L, Scott TB, Day JCC, and Megson-Smith DA
- Abstract
Alpha emitters like plutonium pose severe health risks when ingested, damaging DNA and potentially causing cancer. Traditional detection methods require proximity within millimeters of the contamination source, presenting safety risks and operational inefficiencies. Long-range detection through alpha radioluminescence (RL) offers a promising alternative. However, most of the previous experiments have been carried out under controlled conditions that preclude the overwhelming effect of ambient light. This study demonstrates the successful detection of a 3 MBq alpha emitter in an open environment using a compact alpha camera. This camera incorporates a deep-cooled CCD and a low f-number lens system designed to minimize the blue shift effects of filters. Night-time imaging was achieved with a dual-filter system using a sandwich filter assembly centered at 337 nm and 343 nm for capturing alpha RL and subtracting background light, respectively. At night, the alpha source was detected from 1 m away within one minute, and the lowest detection limit can be calculated as 75 kBq. The system was also evaluated under simulated urban lighting conditions. For daytime imaging, a stack of tilted 276 nm short pass filters minimized sunlight interference, enabling the detection of the alpha source at 70 cm within 10 min under indirect sunlight. This research highlights the viability of long-range optical detection of alpha emitters for environmental monitoring in real-world settings.
- Published
- 2024
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15. Advancements in Remote Alpha Radiation Detection: Alpha-Induced Radio-Luminescence Imaging with Enhanced Ambient Light Suppression.
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Kong L, Scott TB, Day JCC, and Megson-Smith DA
- Abstract
Heavy nuclides like uranium and their decay products are commonly found in nuclear industries and can pose a significant health risk to humans due to their alpha-emitting properties. Traditional alpha detectors require close contact with the contaminated surface, which can be time-consuming, labour-intensive, and put personnel at risk. Remote detection is urgently needed but very challenging. To this end, a candidate detection mechanism is alpha-induced radio-luminescence. This approach uses the emission of photons from radio-ionised excited nitrogen molecules to imply the presence of alpha emitters from a distance. Herein, the use of this phenomenon to remotely image various alpha emitters with unparalleled levels of sensitivity and spatial accuracy is demonstrated. Notably, the system detected a 29 kBq Am-241 source at a distance of 3 m within 10 min. Furthermore, it demonstrated the capability to discern a 29 kBq source positioned 7 cm away from a 3 MBq source at a 2 m distance. Additionally, a 'sandwich' filter structure is described that incorporates an absorptive filter between two interference filters to enhance the ambient light rejection. The testing of the system is described in different lighting environments, including room light and inside a glovebox. This method promises safer and more efficient alpha monitoring, with applications in nuclear forensics, waste management and decommissioning.
- Published
- 2024
- Full Text
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16. Conformational fingerprinting with Raman spectroscopy reveals protein structure as a translational biomarker of muscle pathology.
- Author
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Alix JJP, Plesia M, Dudgeon AP, Kendall CA, Hewamadduma C, Hadjivassiliou M, Gorman GS, Taylor RW, McDermott CJ, Shaw PJ, Mead RJ, and Day JC
- Subjects
- Humans, Animals, Muscle, Skeletal chemistry, Muscle, Skeletal pathology, Mice, Amyotrophic Lateral Sclerosis diagnosis, Amyotrophic Lateral Sclerosis pathology, Male, Spectrum Analysis, Raman methods, Biomarkers analysis, Muscular Dystrophy, Duchenne pathology, Muscular Dystrophy, Duchenne diagnosis
- Abstract
Neuromuscular disorders are a group of conditions that can result in weakness of skeletal muscles. Examples include fatal diseases such as amyotrophic lateral sclerosis and conditions associated with high morbidity such as myopathies (muscle diseases). Many of these disorders are known to have abnormal protein folding and protein aggregates. Thus, easy to apply methods for the detection of such changes may prove useful diagnostic biomarkers. Raman spectroscopy has shown early promise in the detection of muscle pathology in neuromuscular disorders and is well suited to characterising the conformational profiles relating to protein secondary structure. In this work, we assess if Raman spectroscopy can detect differences in protein structure in muscle in the setting of neuromuscular disease. We utilise in vivo Raman spectroscopy measurements from preclinical models of amyotrophic lateral sclerosis and the myopathy Duchenne muscular dystrophy, together with ex vivo measurements of human muscle samples from individuals with and without myopathy. Using quantitative conformation profiling and matrix factorisation we demonstrate that quantitative 'conformational fingerprinting' can be used to identify changes in protein folding in muscle. Notably, myopathic conditions in both preclinical models and human samples manifested a significant reduction in α-helix structures, with concomitant increases in β-sheet and, to a lesser extent, nonregular configurations. Spectral patterns derived through non-negative matrix factorisation were able to identify myopathy with a high accuracy (79% in mouse, 78% in human tissue). This work demonstrates the potential of conformational fingerprinting as an interpretable biomarker for neuromuscular disorders.
- Published
- 2024
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17. Examining the residual radiological footprint of a former colliery: An industrial nuclear archaeology investigation.
- Author
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Parker E, Ryan Tucker M, Okeme I, Holland E, Connor DT, Mohamed O, Martin PG, and Scott TB
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- Archaeology, Radioisotopes analysis, Coal Ash analysis, Coal analysis, Radiation Monitoring methods, Uranium analysis, Coal Mining
- Abstract
Nuclear industrial archaeology utilises radiation mapping and characterisation technologies to gain an insight into the radiological footprint of industrial heritage sites. Increased concentrations of naturally occurring radioactive materials at legacy mine sites are the result of elemental enrichment during coal mining and subsequent combustion. Public safety is of concern around these sites, and therefore, an increased understanding of their associated hazard is essential. Using coincident laser scanning and gamma detection technologies, this study sought to assess the radiological legacy of a coal mine located in Bristol, UK. From this, we can increase our understanding of the residual footprints associated with the local coal mining industry. Samples taken from inside the site were characterised using high resolution gamma spectrometry, wherein the radionuclide content and activities of samples were then quantified. An area of elevated low-level radioactivity was observed at and around buildings believed to belong to the colliery, while Th, U, and K are confirmed at the site from photopeak's of daughter radionuclides. Activities of the radionuclides K-40, U-238, and Th-232 were further quantified during subsequent laboratory analysis. Results highlight an enrichment of naturally occurring radionuclides when compared with global averages for unburned coal. Employing these techniques at further legacy sites would enable an increased understanding of the lasting traces of the coal mining industry, with a focus on NORM enrichment in residual fly ash., Competing Interests: Declaration of competing interest The authors declare no conflict of interest, financial or otherwise. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2023
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18. Combining electromyography and Raman spectroscopy: optical EMG.
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Alix JJP, Plesia M, Shaw PJ, Mead RJ, and Day JCC
- Subjects
- Mice, Animals, Electromyography, Superoxide Dismutase-1 genetics, Muscle, Skeletal, Mice, Transgenic, Disease Models, Animal, Superoxide Dismutase, Spectrum Analysis, Raman, Amyotrophic Lateral Sclerosis diagnosis, Amyotrophic Lateral Sclerosis genetics
- Abstract
Introduction/aims: Electromyography (EMG) remains a key component of the diagnostic work-up for suspected neuromuscular disease, but it does not provide insight into the molecular composition of muscle which can provide diagnostic information. Raman spectroscopy is an emerging neuromuscular biomarker capable of generating highly specific, molecular fingerprints of tissue. Here, we present "optical EMG," a combination of EMG and Raman spectroscopy, achieved using a single needle., Methods: An optical EMG needle was created to collect electrophysiological and Raman spectroscopic data during a single insertion. We tested functionality with in vivo recordings in the SOD1
G93A mouse model of amyotrophic lateral sclerosis (ALS), using both transgenic (n = 10) and non-transgenic (NTg, n = 7) mice. Under anesthesia, compound muscle action potentials (CMAPs), spontaneous EMG activity and Raman spectra were recorded from both gastrocnemius muscles with the optical EMG needle. Standard concentric EMG needle recordings were also undertaken. Electrophysiological data were analyzed with standard univariate statistics, Raman data with both univariate and multivariate analyses., Results: A significant difference in CMAP amplitude was observed between SOD1G93A and NTg mice with optical EMG and standard concentric needles (p = .015 and p = .011, respectively). Spontaneous EMG activity (positive sharp waves) was detected in transgenic SOD1G93A mice only. Raman spectra demonstrated peaks associated with key muscle components. Significant differences in molecular composition between SOD1G93A and NTg muscle were identified through the Raman spectra., Discussion: Optical EMG can provide standard electrophysiological data and molecular Raman data during a single needle insertion and represents a potential biomarker for neuromuscular disease., (© 2023 The Authors. Muscle & Nerve published by Wiley Periodicals LLC.)- Published
- 2023
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19. Production of Magnetic Arsenic-Phosphorus Alloy Nanoribbons with Small Band Gaps and High Hole Conductivities.
- Author
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Zhang FF, Aw E, Eaton AG, Shutt RRC, Lim J, Kim JH, Macdonald TJ, Reyes CIDL, Ashoka A, Pandya R, Payton OD, Picco L, Knapp CE, Corà F, Rao A, Howard CA, and Clancy AJ
- Abstract
Quasi-1D nanoribbons provide a unique route to diversifying the properties of their parent 2D nanomaterial, introducing lateral quantum confinement and an abundance of edge sites. Here, a new family of nanomaterials is opened with the creation of arsenic-phosphorus alloy nanoribbons (AsPNRs). By ionically etching the layered crystal black arsenic-phosphorus using lithium electride followed by dissolution in amidic solvents, solutions of AsPNRs are formed. The ribbons are typically few-layered, several micrometers long with widths tens of nanometers across, and both highly flexible and crystalline. The AsPNRs are highly electrically conducting above 130 K due to their small band gap (ca. 0.035 eV), paramagnetic in nature, and have high hole mobilities, as measured with the first generation of AsP devices, directly highlighting their properties and utility in electronic devices such as near-infrared detectors, quantum computing, and charge carrier layers in solar cells.
- Published
- 2023
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20. Airborne gamma-ray mapping using fixed-wing vertical take-off and landing (VTOL) uncrewed aerial vehicles.
- Author
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Woodbridge E, Connor DT, Verbelen Y, Hine D, Richardson T, and Scott TB
- Abstract
Low-cost uncrewed aerial vehicles (UAVs) are replacing manned aircraft for airborne radiation mapping applications such as nuclear accident response scenarios or surveying ore deposits and mine sites because of their cost-effectiveness and ability to conduct surveys at lower altitude compared to manned counterparts. Both multi-rotor UAVs and fixed-wing UAVs are well established technologies for aerial radiation mapping applications, however, both also have drawbacks: multi-rotor UAVs are very limited in flight time and range, and fixed-wing UAVs usually require facilities for take-off and landing. A compromise solution is introduced in this work, using a fixed-wing vertical take-off and landing (VTOL) UAV that combines the flexibility of a multi-rotor UAV with the range and flight time of a fixed-wing UAV. The first implementation of a VTOL with radiation mapping capabilities is presented, based on a commercial WingtraOne UAV augmented with CsI scintillator and CZT semiconductor gamma spectrometers. The radiation mapping capabilities of the prototype are demonstrated in a case study, mapping the distribution of radionuclides around the South Terras legacy uranium mine in the south of England, United Kingdom, and the results are compared with previous studies using multi-rotor and manned aircraft to survey the same area., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Woodbridge, Connor, Verbelen, Hine, Richardson and Scott.)
- Published
- 2023
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21. Modelling 'Type B' ejecta formation reveals reactor Unit 1 conditions during the Fukushima Daiichi Nuclear Disaster.
- Author
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Carno LAS, Turner JJ, and Martin PG
- Abstract
For the first time, a model was developed to simulate the cooling of the Fukushima Daiichi Nuclear Power Plant reactor Unit 1-derived, 'Type B' radiocaesium bearing microparticles, distributed into the environment during the 2011 nuclear meltdown. By establishing an analogy between 'Type B' CsMP and volcanic pyroclasts, the presented model simulates the rapid cooling of an effervescent silicate melt fragment upon atmospheric release. The model successfully reproduced the bi-modal distribution of internal void diameters observed in 'Type B' CsMP, however, discrepancies resulted primarily due to the neglection of surface tension and internal void coalescence. The model was subsequently utilised to estimate the temperature within reactor Unit 1 in the instant preceding the hydrogen explosion-between 1900 and 1980 K. Such a model demonstrates the accuracy of the volcanic pyroclast-'Type B' CsMP analogue, and confirms radial variations in cooling rate as the cause of the vesicular texture of Unit 1 ejecta. The presented findings provide scope to further explore the comparison between volcanic pyroclasts and 'Type B' CsMP via experimentation, which will provide a deeper understanding of the specific conditions within reactor Unit 1 during the catastrophic meltdown at the Japanese coastal plant., (© 2023. The Author(s).)
- Published
- 2023
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22. Non-negative matrix factorisation of Raman spectra finds common patterns relating to neuromuscular disease across differing equipment configurations, preclinical models and human tissue.
- Author
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Alix JJP, Plesia M, Schooling CN, Dudgeon AP, Kendall CA, Kadirkamanathan V, McDermott CJ, Gorman GS, Taylor RW, Mead RJ, Shaw PJ, and Day JC
- Abstract
Raman spectroscopy shows promise as a biomarker for complex nerve and muscle (neuromuscular) diseases. To maximise its potential, several challenges remain. These include the sensitivity to different instrument configurations, translation across preclinical/human tissues and the development of multivariate analytics that can derive interpretable spectral outputs for disease identification. Nonnegative matrix factorisation (NMF) can extract features from high-dimensional data sets and the nonnegative constraint results in physically realistic outputs. In this study, we have undertaken NMF on Raman spectra of muscle obtained from different clinical and preclinical settings. First, we obtained and combined Raman spectra from human patients with mitochondrial disease and healthy volunteers, using both a commercial microscope and in-house fibre optic probe. NMF was applied across all data, and spectral patterns common to both equipment configurations were identified. Linear discriminant models utilising these patterns were able to accurately classify disease states (accuracy 70.2-84.5%). Next, we applied NMF to spectra obtained from the mdx mouse model of a Duchenne muscular dystrophy and patients with dystrophic muscle conditions. Spectral fingerprints common to mouse/human were obtained and able to accurately identify disease (accuracy 79.5-98.8%). We conclude that NMF can be used to analyse Raman data across different equipment configurations and the preclinical/clinical divide. Thus, the application of NMF decomposition methods could enhance the potential of Raman spectroscopy for the study of fatal neuromuscular diseases., (© 2022 The Authors. Journal of Raman Spectroscopy published by John Wiley & Sons Ltd.)
- Published
- 2023
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23. A highly scalable and autonomous spectroscopic radiation mapping system with resilient IoT detector units for dosimetry, safety and security.
- Author
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Russell-Pavier FS, Kaluvan S, Megson-Smith D, Connor DT, Fearn SJ, Connolly EL, Scott TB, and Martin PG
- Subjects
- Humans, Radiation, Ionizing, Radiometry, Radiation Monitoring methods
- Abstract
Technologies utilizing radiological materials across power generation, defence, industry, research and medicine have increased the global inventory of highly active and hazardous materials. Consequently, an amplified threat exists of illicitly obtained materials being used as part of hostile acts. The potential for intentional releases occurs alongside risks from natural disasters or facility accidents. In any such event, it is crucial to rapidly assess the release composition and extent of response and remediation activities. Therefore, the deployment of an effective, resilient and autonomous radiation monitoring network is pivotal both during and after an incident. Underpinning this assessment is a detailed understanding of the pre-event or background, radiation levels, the knowledge of which is also essential in assessing a population's dosimetric exposure to, and impact from anthropogenic and naturally occurring/varying sources of ionizing radiation. Presented here is a fully operational cloud-based spectroscopic radiation mapping platform comprising IoT modules compatible with cellular networks, without modification, in over 180 countries. Combined with locally roaming vehicles, a continuous multi-pass radiological characterization of an urban environment was performed. Such IoT devices are deployable as either individual sensors for specific localized temporal events or integrated over a greater time period (and area) to represent a larger static sensor. Over several months of continued operation, more than 1000 000 individual location-referenced gamma-ray spectra were collected and securely uploaded, in real-time, to an online cloud database and automatically characterized via a custom multi-step workflow. Fine-scale local variations in the radiological fingerprint of a 1 km × 1 km urban area were subsequently rendered in near-real-time to an interactive secure online graphical dashboard for temporal, spatial and spectral interrogation by the user. Considerations for the automated 'elastic' handling of ever-expanding volumes of input data have been carried out, facilitating propagation and expansion of the system's database without human input., (Creative Commons Attribution license.)
- Published
- 2023
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24. Modelling acute antibody-mediated rejection of human kidney transplants using ex-vivo warm machine perfusion.
- Author
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Chandak P, Phillips BL, Bennett D, Uwechue R, Kessaris N, Shaw O, Maggs T, Woodford L, Veniard D, Perera R, Parmar K, Hunt BJ, Callaghan C, Dorling A, and Mamode N
- Subjects
- Humans, HLA Antigens, ABO Blood-Group System, Graft Rejection, Antibodies, Kidney pathology, Perfusion, Kidney Transplantation adverse effects
- Abstract
Background: Transplant rejection is a major cause of graft loss and morbidity. Currently, no human models of antibody-mediated rejection (AMR) exist, limiting mechanistic investigation and organ-specific targeted therapy. Here, using 12 human kidneys and ex-vivo normothermic machine perfusion, we demonstrate phenotypes of AMR after addition of antibodies against either human HLA class I or blood group antigens (A, B), thus modelling clinical AMR that can follow HLA incompatible (HLAi) or blood group incompatible (ABOi) transplantation., Methods: Discarded human kidneys with wide ranging demographics and cold ischaemia times (11-54 h) were perfused with red blood cells and fresh frozen plasma (FFP) as a source of complement/coagulation factors. For the HLAi model, 600 μg of W6/32 anti-class 1 HLA antibody was added to the circuit (time '0'). For the ABOi model, high titre FFP of the relevant blood group antibody was added. Renal blood flow index (RBFi, mL/min/100 g), C3 desArg, prothrombin fragments 1 + 2 and histology were determined. Our endpoints included haemodynamic changes, thrombosis, and biopsy proven complement deposition., Findings: Compared to control kidneys perfused without anti-donor antibodies, both models demonstrated haemodynamic collapse after antibody perfusion with only the HLAi model showing glomerular C4d deposition., Interpretation: We show that a clinically relevant human kidney model of AMR is feasible, and anticipate that these models, with refinements, could provide a basis to test different strategies to prevent AMR., Funding: The Rosetrees and Stonygate Trust, The Royal College of Surgeons of England Fellowship Grant, NIHR Biomedical Research Centre/KCL Early Career Grant, Kidney Research U.K., Competing Interests: Declaration of interests The authors declare that they have no conflict of interest., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2022
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25. Label-free fibre optic Raman spectroscopy with bounded simplex-structured matrix factorization for the serial study of serum in amyotrophic lateral sclerosis.
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Alix JJP, Verber NS, Schooling CN, Kadirkamanathan V, Turner MR, Malaspina A, Day JCC, and Shaw PJ
- Subjects
- Humans, Spectrum Analysis, Raman, Biomarkers, C-Reactive Protein, Amyotrophic Lateral Sclerosis diagnosis, Amyotrophic Lateral Sclerosis metabolism, Neurodegenerative Diseases
- Abstract
Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease in urgent need of disease biomarkers for the assessment of promising therapeutic candidates in clinical trials. Raman spectroscopy is an attractive technique for identifying disease related molecular changes due to its simplicity. Here, we describe a fibre optic fluid cell for undertaking spontaneous Raman spectroscopy studies of human biofluids that is suitable for use away from a standard laboratory setting. Using this system, we examined serum obtained from patients with ALS at their first presentation to our centre ( n = 66) and 4 months later ( n = 27). We analysed Raman spectra using bounded simplex-structured matrix factorization (BSSMF), a generalisation of non-negative matrix factorisation which uses the distribution of the original data to limit the factorisation modes (spectral patterns). Biomarkers associated with ALS disease such as measures of symptom severity, respiratory function and inflammatory/immune pathways (C3/C-reactive protein) correlated with baseline Raman modes. Between visit spectral changes were highly significant ( p = 0.0002) and were related to protein structure. Comparison of Raman data with established ALS biomarkers as a trial outcome measure demonstrated a reduction in required sample size with BSSMF Raman. Our portable, simple to use fibre optic system allied to BSSMF shows promise in the quantification of disease-related changes in ALS over short timescales.
- Published
- 2022
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26. First record of biofluorescence in lumpfish (Cyclopterus lumpus), a commercially farmed cleaner fish.
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Juhasz-Dora T, Teague J, Doyle TK, and Maguire J
- Subjects
- Animals, Fishes, Fish Diseases, Perciformes
- Abstract
This study is the first known observation of biofluorescence in the lumpfish (Cyclopterus lumpus). Individual lumpfish were illuminated with blue excitation lighting for photography with both hyperspectral and filtered multispectral cameras. All photographed juvenile lumpfish (n = 11) exhibited green biofluorescence. Light emissions were characterised with two peaks observed at 545 and 613 nm, with the greatest intensity along the tubercles of the high crest and the three longitudinal ridges. Further research on the dynamics of biofluorescence through the lifecycle of this species is required., (© 2022 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles.)
- Published
- 2022
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27. Fiber optic Raman spectroscopy for the evaluation of disease state in Duchenne muscular dystrophy: An assessment using the mdx model and human muscle.
- Author
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Alix JJP, Plesia M, Hool SA, Coldicott I, Kendall CA, Shaw Dbe PJ, Mead RJ, and Day JC
- Subjects
- Animals, Disease Models, Animal, Humans, Mice, Mice, Inbred C57BL, Mice, Inbred mdx, Muscle, Skeletal pathology, Spectrum Analysis, Raman, Muscular Dystrophy, Duchenne diagnosis, Muscular Dystrophy, Duchenne pathology
- Abstract
Introduction/aims: Raman spectroscopy is an emerging technique for the evaluation of muscle disease. In this study we evaluate the ability of in vivo intramuscular Raman spectroscopy to detect the effects of voluntary running in the mdx model of Duchenne muscular dystrophy (DMD). We also compare mdx data with muscle spectra from human DMD patients., Methods: Thirty 90-day-old mdx mice were randomly allocated to an exercised group (48-hour access to a running wheel) and an unexercised group (n = 15 per group). In vivo Raman spectra were collected from both gastrocnemius muscles and histopathological assessment subsequently performed. Raman data were analyzed using principal component analysis-fed linear discriminant analysis (PCA-LDA). Exercised and unexercised mdx muscle spectra were compared with human DMD samples using cosine similarity., Results: Exercised mice ran an average of 6.5 km over 48 hours, which induced a significant increase in muscle necrosis (P = .03). PCA-LDA scores were significantly different between the exercised and unexercised groups (P < .0001) and correlated significantly with distance run (P = .01). Raman spectra from exercised mice more closely resembled human spectra than those from unexercised mice., Discussion: Raman spectroscopy provides a readout of the biochemical alterations in muscle in both the mdx mouse and human DMD muscle., (© 2022 The Authors. Muscle & Nerve published by Wiley Periodicals LLC.)
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- 2022
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28. Rapid identification of human muscle disease with fibre optic Raman spectroscopy.
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Alix JJP, Plesia M, Lloyd GR, Dudgeon AP, Kendall CA, Hewamadduma C, Hadjivassiliou M, McDermott CJ, Gorman GS, Taylor RW, Shaw PJ, and Day JCC
- Subjects
- Fiber Optic Technology methods, Humans, Muscles, Muscular Diseases diagnosis, Spectrum Analysis, Raman methods
- Abstract
The diagnosis of muscle disorders ("myopathies") can be challenging and new biomarkers of disease are required to enhance clinical practice and research. Despite advances in areas such as imaging and genomic medicine, muscle biopsy remains an important but time-consuming investigation. Raman spectroscopy is a vibrational spectroscopy application that could provide a rapid analysis of muscle tissue, as it requires no sample preparation and is simple to perform. Here, we investigated the feasibility of using a miniaturised, portable fibre optic Raman system for the rapid identification of muscle disease. Samples were assessed from 27 patients with a final clinico-pathological diagnosis of a myopathy and 17 patients in whom investigations and clinical follow-up excluded myopathy. Multivariate classification techniques achieved accuracies ranging between 71-77%. To explore the potential of Raman spectroscopy to identify different myopathies, patients were subdivided into mitochondrial and non-mitochondrial myopathy groups. Classification accuracies were between 74-89%. Observed spectral changes were related to changes in protein structure. These data indicate fibre optic Raman spectroscopy is a promising technique for the rapid identification of muscle disease that could provide real time diagnostic information. The application of fibre optic Raman technology raises the prospect of in vivo bedside testing for muscle diseases which would significantly streamline the diagnostic pathway of these disorders.
- Published
- 2022
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29. A study of the application of graphite MALDI to the analysis of lanthanides and deconvolution of the isobaric species observed.
- Author
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Conway U, Warren AD, and Gates PJ
- Abstract
Matrix-assisted laser desorption/ionisation mass spectrometry has always suffered from matrix interference at low-masses making it an unsuitable method for the analysis of low molecular weight analytes. In recent years, there has been considerable interest in the use of graphite as a matrix. In this study, we demonstrate the application of colloidal graphite for the analysis of lanthanides in the positive ion mode. Positive ion mode is of academic interest as spectra are dominated by lanthanide cations, oxides, hydroxides and carbides with the metal having been reduced to oxidation state I, II or III. The ratios of the different ions are considered in terms of redox potentials of the lanthanides and rates of reaction with oxygen. Positive ion mode is shown to be useful as a rapid technique for confirming which metal(s) are present in a sample which can have an application in environmental monitoring, for example. Demonstration of a least squares approach to deconvolution is applied for the complete separation and relative quantification of the different isobaric species observed due to the complex isotope distributions of some lanthanides.
- Published
- 2021
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30. X-ray nanotomography and electron backscatter diffraction demonstrate the crystalline, heterogeneous and impermeable nature of conodont white matter.
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Atakul-Özdemir A, Warren X, Martin PG, Guizar-Sicairos M, Holler M, Marone F, Martínez-Pérez C, and Donoghue PCJ
- Abstract
Conodont elements, microfossil remains of extinct primitive vertebrates, are commonly exploited as mineral archives of ocean chemistry, yielding fundamental insights into the palaeotemperature and chemical composition of past oceans. Geochemical assays have been traditionally focused on the so-called lamellar and white matter crown tissues; however, the porosity and crystallographic nature of the white matter and its inferred permeability are disputed, raising concerns over its suitability as a geochemical archive. Here, we constrain the characteristics of this tissue and address conflicting interpretations using ptychographic X-ray-computed tomography (PXCT), pore network analysis, synchrotron radiation X-ray tomographic microscopy (srXTM) and electron back-scatter diffraction (EBSD). PXCT and pore network analyses based on these data reveal that while white matter is extremely porous, the pores are unconnected, rendering this tissue closed to postmortem fluid percolation. EBSD analyses demonstrate that white matter is crystalline and comprised of a single crystal typically tens of micrometres in dimensions. Combined with evidence that conodont elements grow episodically, these data suggest that white matter, which comprises the denticles of conodont elements, grows syntactically, indicating that individual crystals are time heterogeneous. Together these data provide support for the interpretation of conodont white matter as a closed geochemical system and, therefore, its utility of the conodont fossil record as a historical archive of Palaeozoic and Early Mesozoic ocean chemistry., (© 2021 The Authors.)
- Published
- 2021
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31. Raptor wing morphing with flight speed.
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Cheney JA, Stevenson JPJ, Durston NE, Maeda M, Song J, Megson-Smith DA, Windsor SP, Usherwood JR, and Bomphrey RJ
- Subjects
- Animals, Biomechanical Phenomena, Flight, Animal, Wings, Animal, Eagles, Raptors
- Abstract
In gliding flight, birds morph their wings and tails to control their flight trajectory and speed. Using high-resolution videogrammetry, we reconstructed accurate and detailed three-dimensional geometries of gliding flights for three raptors (barn owl, Tyto alba ; tawny owl, Strix aluco , and goshawk, Accipiter gentilis ). Wing shapes were highly repeatable and shoulder actuation was a key component of reconfiguring the overall planform and controlling angle of attack. The three birds shared common spanwise patterns of wing twist, an inverse relationship between twist and peak camber, and held their wings depressed below their shoulder in an anhedral configuration. With increased speed, all three birds tended to reduce camber throughout the wing, and their wings bent in a saddle-shape pattern. A number of morphing features suggest that the coordinated movements of the wing and tail support efficient flight, and that the tail may act to modulate wing camber through indirect aeroelastic control.
- Published
- 2021
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32. An assessment of contamination pickup on ground robotic vehicles for nuclear surveying application.
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Banos A, Hayman J, Wallace-Smith T, Bird B, Lennox B, and Scott TB
- Subjects
- Computer Simulation, Monte Carlo Method, Robotic Surgical Procedures, Robotics
- Abstract
Ground robotic vehicles are often deployed to inspect areas where radioactive floor contamination is a prominent risk. However, the accuracy of detection could be adversely affected by enhanced radiation signal through self-contamination of the robot occurring over the course of the inspection. In this work, it was hypothesised that a six-legged robot could offer advantages over the more conventional ground robotic devices such as wheeled and tracked rovers. To investigate this, experimental contamination testing and computational Monte Carlo simulation techniques (GEANT4) were employed to understand how radioactive contamination pick-up on three different robotic vehicles would affect their detection accuracy. Two robotic vehicles were selected for comparison with the hexapod robot based on their type of locomotion; a wheeled rover and a tracked rover. With the aid of a non-toxic fluorescent tracer dust, the contamination received by the all three vehicles when traversing a contaminated area was initially compared through physical inspection using high definition cameras. The parametric results from these tests where used in the computational study carried out in GEANT4. A cadmium zinc telluride detector was simulated at heights ranging from 10 to 50 cm above each contaminated vehicle, as if it were mounted on a plinth. Assuming a uniform activity of 60 Bq cm
-2 on all contaminated surfaces, the results suggested that due to the hexapod's small ground-contacting surface area and geometry, radiation detection rates using an uncollimated detector are likely to be overestimated by between only 0.07%-0.12%, compared with 3.95%-8.43% and 1.75%-14.53% for the wheeled and tracked robot alternatives, respectively., (Creative Commons Attribution license.)- Published
- 2021
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33. In Vivo Fiber Optic Raman Spectroscopy of Muscle in Preclinical Models of Amyotrophic Lateral Sclerosis and Duchenne Muscular Dystrophy.
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Plesia M, Stevens OA, Lloyd GR, Kendall CA, Coldicott I, Kennerley AJ, Miller G, Shaw PJ, Mead RJ, Day JCC, and Alix JJP
- Subjects
- Animals, Disease Models, Animal, Humans, Mice, Mice, Inbred mdx, Muscle, Skeletal, Muscles, Spectrum Analysis, Raman, Amyotrophic Lateral Sclerosis, Muscular Dystrophy, Duchenne
- Abstract
Neuromuscular diseases result in muscle weakness, disability, and, in many instances, death. Preclinical models form the bedrock of research into these disorders, and the development of in vivo and potentially translational biomarkers for the accurate identification of disease is crucial. Spontaneous Raman spectroscopy can provide a rapid, label-free, and highly specific molecular fingerprint of tissue, making it an attractive potential biomarker. In this study, we have developed and tested an in vivo intramuscular fiber optic Raman technique in two mouse models of devastating human neuromuscular diseases, amyotrophic lateral sclerosis, and Duchenne muscular dystrophy (SOD1
G93A and mdx , respectively). The method identified diseased and healthy muscle with high classification accuracies (area under the receiver operating characteristic curves (AUROC): 0.76-0.92). In addition, changes in diseased muscle over time were also identified (AUROCs 0.89-0.97). Key spectral changes related to proteins and the loss of α-helix protein structure. Importantly, in vivo recording did not cause functional motor impairment and only a limited, resolving tissue injury was seen on high-resolution magnetic resonance imaging. Lastly, we demonstrate that ex vivo muscle from human patients with these conditions produced similar spectra to those observed in mice. We conclude that spontaneous Raman spectroscopy of muscle shows promise as a translational research tool.- Published
- 2021
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34. Miniaturised Low-Cost Gamma Scanning Platform for Contamination Identification, Localisation and Characterisation: A New Instrument in the Decommissioning Toolkit.
- Author
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Verbelen Y, Martin PG, Ahmad K, Kaluvan S, and Scott TB
- Abstract
Formerly clandestine, abandoned and legacy nuclear facilities, whether associated with civil or military applications, represent a significant decommissioning challenge owing to the lack of knowledge surrounding the existence, location and types of radioactive material(s) that may be present. Consequently, mobile and highly deployable systems that are able to identify, spatially locate and compositionally assay contamination ahead of remedial actions are of vital importance. Deployment imposes constraints to dimensions resulting from small diameter access ports or pipes. Herein, we describe a prototype low-cost, miniaturised and rapidly deployable 'cell characterisation' gamma-ray scanning system to allow for the examination of enclosed (internal) or outdoor (external) spaces for radioactive 'hot-spots'. The readout from the miniaturised and lead-collimated gamma-ray spectrometer, that is progressively rastered through a stepped snake motion, is combined with distance measurements derived from a single-point laser range-finder to obtain an array of measurements in order to yield a 3-dimensional point-cloud, based on a polar coordinate system-scaled for radiation intensity. Existing as a smaller and more cost-effective platform than presently available, we are able to produce a millimetre-accurate 3D volumetric rendering of a space-whether internal or external, onto which fully spectroscopic radiation intensity data can be overlain to pinpoint the exact positions at which (even low abundance) gamma-emitting materials exist.
- Published
- 2021
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35. A Non-Destructive, Tuneable Method to Isolate Live Cells for High-Speed AFM Analysis.
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Evans CT, Baldock SJ, Hardy JG, Payton O, Picco L, and Allen MJ
- Abstract
Suitable immobilisation of microorganisms and single cells is key for high-resolution topographical imaging and study of mechanical properties with atomic force microscopy (AFM) under physiologically relevant conditions. Sample preparation techniques must be able to withstand the forces exerted by the Z range-limited cantilever tip, and not negatively affect the sample surface for data acquisition. Here, we describe an inherently flexible methodology, utilising the high-resolution three-dimensional based printing technique of multiphoton polymerisation to rapidly generate bespoke arrays for cellular AFM analysis. As an example, we present data collected from live Emiliania huxleyi cells, unicellular microalgae, imaged by contact mode High-Speed Atomic Force Microscopy (HS-AFM), including one cell that was imaged continuously for over 90 min.
- Published
- 2021
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36. Sample preparation methods for optimal HS-AFM analysis: Duplex stainless steel.
- Author
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Moore S, Warren AD, Burrows R, Payton OD, Picco L, Russell-Pavier FS, Martin PG, and Martin TL
- Abstract
The contact mode high-speed atomic force microscope (AFM) operates orders of magnitude faster than conventional AFMs. It is capable of capturing multiple frames per second with nanometre-scale lateral resolution and subatomic height resolution. This advancement in imaging rate allows for microscale analysis across macroscale surfaces, making it suitable for applications across materials science. However, the quality of the surface analysis obtained by high-speed AFM is highly dependent upon the standard of sample preparation and the resultant final surface finish. In this study, different surface preparation techniques that are commonly implemented within metallurgical studies are compared for samples of SAF 2205 duplex stainless steel. It was found that, while acid etching and electrolytic etching were optimal for the low resolution of optical microscopy, these methods were less suited for analysis by high resolution high-speed AFM. Mechanical and colloidal silica polishing was found to be the optimal method explored, as it provided a gentle etch of the surface allowing for high quality topographic maps of the sample surface., (Copyright © 2021. Published by Elsevier B.V.)
- Published
- 2021
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37. Resonant inelastic x-ray spectroscopy on UO 2 as a test case for actinide materials.
- Author
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Lander GH, Sundermann M, Springell R, Walters AC, Nag A, Garcia-Fernandez M, Zhou KJ, van der Laan G, and Caciuffo R
- Abstract
Resonant inelastic x-ray spectroscopy at the uranium N
4 absorption edge at 778 eV has been used to reveal the excitations in UO2 up to 1 eV. The earlier (1989) studies by neutron inelastic scattering of the crystal-field states within the3 H4 multiplet are confirmed. In addition, the first excited state of the3 F2 multiplet at ∼520 meV has been established, and there is a weak signal corresponding to the next excited state at ∼920 meV. This represents a successful application of soft x-ray spectroscopy to an actinide sample, and resolves an open question in UO2 that has been discussed for 50 years. The technique is described and important caveats are drawn about possible future applications.- Published
- 2021
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38. Structural and compositional characteristics of Fukushima release particulate material from Units 1 and 3 elucidates release mechanisms, accident chronology and future decommissioning strategy.
- Author
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Martin PG, Jones CP, Bartlett S, Ignatyev K, Megson-Smith D, Satou Y, Cipiccia S, Batey DJ, Rau C, Sueki K, Ishii T, Igarashi J, Ninomiya K, Shinohara A, Rust A, and Scott TB
- Abstract
The structural form and elemental distribution of material originating from different Fukushima Daiichi Nuclear Power Plant reactors (Units 1 and 3) is hereby examined to elucidate their contrasting release dynamics and the current in-reactor conditions to influence future decommissioning challenges. Complimentary computed X-ray absorption tomography and X-ray fluorescence data show that the two suites of Si-based material sourced from the different reactor Units have contrasting internal structure and compositional distribution. The known event and condition chronology correlate with the observed internal and external structures of the particulates examined, which suggest that Unit 1 ejecta material sustained a greater degree of melting than that likely derived from reactor Unit 3. In particular, we attribute the near-spherical shape of Unit 1 ejecta and their internal voids to there being sufficient time for surface tension to round these objects before the hot (and so relatively low viscosity) silicate melt cooled to form glass. In contrast, a more complex internal form associated with the sub-mm particulates invoked to originate from Unit 3 suggest a lower peak temperature, over a longer duration. Using volcanic analogues, we consider the structural form of this material and how it relates to its environmental particulate stability and the bulk removal of residual materials from the damaged reactors. We conclude that the brittle and angular Unit 3 particulate are more susceptible to further fragmentation and particulate generation hazard than the round, higher-strength, more homogenous Unit 1 material.
- Published
- 2020
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39. Radiation Mapping and Laser Profiling Using a Robotic Manipulator.
- Author
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White SR, Megson-Smith DA, Zhang K, Connor DT, Martin PG, Hutson C, Herrmann G, Dilworth J, and Scott TB
- Abstract
The use of a robotic arm manipulator as a platform for coincident radiation mapping and laser profiling of radioactive sources on a flat surface is investigated in this work. A combined scanning head, integrating a micro-gamma spectrometer and Time of Flight (ToF) sensor were moved in a raster scan pattern across the surface, autonomously undertaken by the robot arm over a 600 × 260 mm survey area. A series of radioactive sources of different emission intensities were scanned in different configurations to test the accuracy and sensitivity of the system. We demonstrate that in each test configuration the system was able to generate a centimeter accurate 3D model complete with an overlaid radiation map detailing the emitted radiation intensity and the corrected surface dose rate., Competing Interests: JD was employed by the company KUKA Systems UK Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2020 White, Megson-Smith, Zhang, Connor, Martin, Hutson, Herrmann, Dilworth and Scott.)
- Published
- 2020
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40. A review of the reaction rates of uranium corrosion in water.
- Author
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Banos A and Scott TB
- Abstract
This work conducts a review on the kinetics of the uranium and water reaction system by gathering all available kinetic data and across a wide range of reaction conditions. Temperature and pressure dependent kinetic equations that describe the reaction are derived for the uraniumwater vapour and uranium-liquid water systems. Detailed tables which provide information about the reaction conditions and other parameters for each rate point are constructed. From evaluation of the tables, the effects of underlying parameters on the reaction kinetics are discussed. It is suggested that these parameters contribute to the reported discrepancies between reaction rate values under similar conditions. Better prediction of the corrosion rate and rate behaviour can be achieved by combining the kinetic rate equations with the effect of these underlying parameters., (Copyright © 2020. Published by Elsevier B.V.)
- Published
- 2020
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41. Flavone as a novel matrix for the matrix-assisted laser desorption/ionisation analysis of lanthanide and transition metal salts.
- Author
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Warren AD and Gates PJ
- Abstract
The mass spectral analysis of metal salts, especially lanthanide and transition metal salts, can be challenging. Although getting information on the metal present is usually straightforward, obtaining information on the correct oxidation state and anion composition is challenging. Many ionisation techniques have some redox component to the ionisation process, which commonly results in changing the oxidation state of the metal and the associated loss of ligand and anion information. We present here a simple method for negative ion matrix-assisted laser desorption/ionisation mass spectrometry using the non-acidic flavonoid flavone as a novel matrix. This results in reliable information on the oxidation state of the metal as spectra are dominated by anion adduct ions with very little (typically no) redox processes occurring., (© 2020 John Wiley & Sons, Ltd.)
- Published
- 2020
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42. Development of a facile fluorophosphonate-functionalised titanium surface for potential orthopaedic applications.
- Author
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Shiel AI, Ayre WN, Blom AW, Hallam KR, Heard PJ, Payton O, Picco L, and Mansell JP
- Abstract
Background: Aseptic loosening of total joint replacements (TJRs) continues to be the main cause of implant failures. The socioeconomic impact of surgical revisions is hugely significant; in the United Kingdom alone, it is estimated that £137 m is spent annually on revision arthroplasties. Enhancing the longevity of titanium implants will help reduce the incidence and overall cost of failed devices., Methods: In realising the development of a superior titanium technology, we exploited the natural affinity of titanium for phosphonic acids and developed a facile means of coating the metal with (3S)1-fluoro-3-hydroxy-4-(oleoyloxy)butyl-1-phosphonate (FHBP), a phosphatase-resistant analogue of lysophosphatidic acid (LPA). Importantly LPA and selected LPA analogues like FHBP synergistically cooperate with calcitriol to promote human osteoblast formation and maturation., Results: Herein, we provide evidence that simply immersing titanium in aqueous solutions of FHBP afforded a surface that was superior to unmodified metal at enhancing osteoblast maturation. Importantly, FHBP-functionalised titanium remained stable to 2 years of ambient storage, resisted ∼35 kGy of gamma irradiation and survived implantation into a bone substitute (Sawbone™) and irrigation., Conclusion: The facile step we have taken to modify titanium and the robustness of the final surface finish are appealing properties that are likely to attract the attention of implant manufacturers in the future., The Translational Potential of This Article: We have generated a functionalised titanium (Ti) surface by simply immersing Ti in aqueous solutions of a bioactive lipid. As a facile procedure it will have greater appeal to implant manufacturers compared to onerous and costly developmental processes., Competing Interests: The authors have no conflicts of interest to disclose in relation to this article., (© 2020 The Author(s).)
- Published
- 2020
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43. The kinetics and mechanism of the uranium hydride - water vapour system under ambient conditions.
- Author
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Banos A and Scott TB
- Abstract
This work investigated the reaction of uranium hydride powder with saturated water vapour at 25 °C. Two corrosion experiments were conducted one with deionised water (H
2 O) and one with deuterated water (D2 O). The kinetics of the reaction were measured through gas generation method while concurrent residual gas analysis (RGA) allowed better understanding of the oxidation mechanism governing the system. From the analysis, it was found that the kinetics of the reaction are robust initially, followed by quasi-linear decelerating regime indicative of a 'shrinking core' type oxidation behaviour. The extent of the reaction (conversion to UO2 ) was lower in comparison to other works. The reaction remained incomplete bolstering the case of UH3 persistence in legacy wastes. Through interpretation of the gas analysis data, a mechanism for the uranium hydride water reaction was suggested.- Published
- 2020
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44. Project Gatekeeper: An Entrance Control System Embedded Radiation Detection Capability for Security Applications.
- Author
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Martin PG, Verbelen Y, Sciama Bandel E, Andrews M, and Scott TB
- Abstract
Threat assessments continue to conclude that terrorist groups and individuals as well as those wanting to cause harm to society have the ambition and increasing means to acquire unconventional weapons such as improvised nuclear explosive devices and radiological disposal devices. Such assessments are given credence by public statements of intent by such groups/persons, by reports of attempts to acquire radioactive material and by law enforcement actions which have interdicted, apprehended or prevented attempts to acquire such material. As a mechanism through which to identify radioactive materials being transported on an individual's person, this work sought to develop a detection system that is of lower-cost, reduced form-factor and more covert than existing infrastructure, while maintaining adequate sensitivity and being retrofittable into an industry standard and widely utilised Gunnebo Speed Gate system. The system developed comprised an array of six off-set Geiger-Muller detectors positioned around the gate, alongside a single scintillator detector for spectroscopy, triggered by the systems inbuilt existing IR proximity sensor. This configuration served to not only reduce the cost for such a system but also allowed for source localisation and identification to be performed. Utilising the current setup, it was possible to detect a 1 µSv/h source carried into the Speed Gate in all test scenarios, alongside locating and spectrally analysing the material in a significant number.
- Published
- 2020
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45. Nanometre to micrometre length-scale techniques for characterising environmentally-assisted cracking: An appraisal.
- Author
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Clark RN, Burrows R, Patel R, Moore S, Hallam KR, and Flewitt PEJ
- Abstract
The appraisal is strongly focussed on challenges associated with the nuclear sector, however these are representative of what is generally encountered by a range of engineering applications. Ensuring structural integrity of key nuclear plant components is essential for both safe and economic operation. Structural integrity assessments require knowledge of the mechanical and physical properties of materials, together with an understanding of mechanisms that can limit the overall operating life. With improved mechanistic understanding comes the ability to develop predictive models of the service life of components. Such models often require parameters which can be provided only by characterisation of processes occurring in situ over a range of scales, with the sub-micrometre-scale being particularly important, but also challenging. This appraisal reviews the techniques currently available to characterise microstructural features at the nanometre to micrometre length-scale that can be used to elucidate mechanisms that lead to the early stages of environmentally-assisted crack formation and subsequent growth. Following an appraisal of the techniques and their application, there is a short discussion and consideration for future opportunities., (© 2020 The Author(s).)
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- 2020
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46. Corrigendum: Radiological Mapping of Post-Disaster Nuclear Environments Using Fixed-Wing Unmanned Aerial Systems: A Study From Chornobyl.
- Author
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Connor DT, Wood K, Martin PG, Goren S, Megson-Smith D, Verbelen Y, Chyzhevskyi I, Kirieiev S, Smith NT, Richardson T, and Scott TB
- Abstract
[This corrects the article DOI: 10.3389/frobt.2019.00149.]., (Copyright © 2020 Connor, Wood, Martin, Goren, Megson-Smith, Verbelen, Chyzhevskyi, Kirieiev, Smith, Richardson and Scott.)
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- 2020
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47. Compositional and structural analysis of Fukushima-derived particulates using high-resolution x-ray imaging and synchrotron characterisation techniques.
- Author
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Martin PG, Jones CP, Cipiccia S, Batey DJ, Hallam KR, Satou Y, Griffiths I, Rau C, Richards DA, Sueki K, Ishii T, and Scott TB
- Subjects
- Dust analysis, Fukushima Nuclear Accident, Japan, Nuclear Power Plants, Radiation Monitoring methods, Radiography methods, Soil Pollutants, Radioactive, Synchrotrons, Water Pollutants, Radioactive analysis, X-Rays, Cesium Radioisotopes chemistry, Radioactive Fallout analysis
- Abstract
Both the three-dimensional internal structure and elemental distribution of near-field radioactive fallout particulate material released during the March 2011 accident at the Fukushima Daiichi Nuclear Power Plant is analysed using combined high-resolution laboratory and synchrotron radiation x-ray techniques. Results from this study allow for the proposition of the likely formation mechanism of the particles, as well as the potential risks associated with their existence in the environment, and the likely implications for future planned reactor decommissioning. A suite of particles is analyzed from a locality 2 km from the north-western perimeter of the site - north of the primary contaminant plume in an area formerly attributed to being contaminated by fallout from reactor Unit 1. The particles are shown to exhibit significant structural similarities; being amorphous with a textured exterior, and containing inclusions of contrasting compositions, as well as an extensive internal void volume - bimodal in its size distribution. A heterogeneous distribution of the various elemental constituents is observed inside a representative particle, which also exhibited a Fukushima-derived radiocesium (134Cs, 135Cs and 137Cs) signature with negligible natural Cs. We consider the structure and composition of the particle to suggest it formed from materials associated with the reactor Unit 1 building explosion, with debris fragments embedded into the particles surface. Such a high void ratio, comparable to geological pumice, suggests such material formed during a rapid depressurisation and is potentially susceptible to fragmentation through attrition.
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- 2020
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48. Radiological Mapping of Post-Disaster Nuclear Environments Using Fixed-Wing Unmanned Aerial Systems: A Study From Chornobyl.
- Author
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Connor DT, Wood K, Martin PG, Goren S, Megson-Smith D, Verbelen Y, Chyzhevskyi I, Kirieiev S, Smith NT, Richardson T, and Scott TB
- Abstract
In the immediate aftermath following a large-scale release of radioactive material into the environment, it is necessary to determine the spatial distribution of radioactivity quickly. At present, this is conducted by utilizing manned aircraft equipped with large-volume radiation detection systems. Whilst these are capable of mapping large areas quickly, they suffer from a low spatial resolution due to the operating altitude of the aircraft. They are also expensive to deploy and their manned nature means that the operators are still at risk of exposure to potentially harmful ionizing radiation. Previous studies have identified the feasibility of utilizing unmanned aerial systems (UASs) in monitoring radiation in post-disaster environments. However, the majority of these systems suffer from a limited range or are too heavy to be easily integrated into regulatory restrictions that exist on the deployment of UASs worldwide. This study presents a new radiation mapping UAS based on a lightweight (8 kg) fixed-wing unmanned aircraft and tests its suitability to mapping post-disaster radiation in the Chornobyl Exclusion Zone (CEZ). The system is capable of continuous flight for more than 1 h and can resolve small scale changes in dose-rate in high resolution (sub-20 m). It is envisaged that with some minor development, these systems could be utilized to map large areas of hazardous land without exposing a single operator to a harmful dose of ionizing radiation., (Copyright © 2020 Connor, Wood, Martin, Goren, Megson-Smith, Verbelen, Chyzhevskyi, Kirieiev, Smith, Richardson and Scott.)
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- 2020
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49. A comparison of two high spatial resolution imaging techniques for determining carbide precipitate type and size in ferritic 9Cr-1Mo steel.
- Author
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Liu C, Heard PJ, Payton OD, Picco L, and Flewitt PEJ
- Abstract
Two high spatial resolution imaging techniques, focused gallium ion beam imaging in conjunction with XeF
2 gas (FIB/XeF2 ) and high-speed atomic force microscopy (HS-AFM), were used to analyse 9Cr-1Mo ferritic steel samples, which had been exposed for extended periods to hot CO2 gas containing traces of CO, H2 , H2 O and CH4 . The carbide precipitates embedded in the metal matrix were observed and their morphology, size and spatial distribution were quantified using these two techniques. The lower resolution of the FIB/XeF2 imaging technique suggested that small carbide precipitates (<50 nm) may be missed, while the existence of a limited flow layer introduced by sample preparation may influence the HS-AFM results. The gallium ion beam was used to remove a thin oxide layer of approximately 50 nm from sample surfaces prior to FIB/XeF2 imaging, avoiding the influence of surface contamination. HS-AFM provided higher resolution (∼5 nm) than FIB/XeF2 imaging. A quantitative comparison of the experimental data confirmed the value of both FIB/XeF2 and HS-AFM for imaging carbide precipitates, while clarifying their strengths and limitations., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2019
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50. In-situ growth of NiWO 4 saw-blade-like nanostructures and their application in photo-electrochemical (PEC) immunosensor system designed for the detection of neuron-specific enolase.
- Author
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Soomro RA, Kalwar NH, Avci A, Pehlivan E, Hallam KR, and Willander M
- Subjects
- Electrochemical Techniques methods, Electrodes, Humans, Immunoassay methods, Light, Nanostructures ultrastructure, Nanotechnology methods, Phosphopyruvate Hydratase analysis, Tin Compounds chemistry, Biosensing Techniques methods, Nanostructures chemistry, Nickel chemistry, Oxides chemistry, Phosphopyruvate Hydratase blood, Tungsten chemistry
- Abstract
This study describes the construction of highly-sensitive photo-electrochemical (PEC) immunosensor for the detection of neuron-specific enolase (NSE). The biosensing platform is comprised of photo-active NiWO
4 nanostructures, in-situ-grown over a conductive substrate (indium tin oxide) using a low-temperature template-based co-precipitation approach. The discussed approach enables the formation of discrete, yet morphologically-analogous, nanostructures with complete coverage (pinhole-free) of the electrode surface. The in-situ-grown nanostructure possess dense population with sharp saw-blade like morphological features that can support substantial immobilisation of anti-NSE agent. The constructed platform demonstrated excellent photo-catalytic activity towards uric acid (UA) which served as the base for the Electrochemical -mechanism (EC) based PEC inhibition sensing. The detection of NSE, relied on its obstruction in analytical signal observed for the photo-oxidation of UA after binding to the electrode surface via protein-antibody interaction. The constructed PEC immunosensor exhibits signal sensitivity up to 0.12 ng mL-1 of NSE with excellent signal reproducibility and electrode replicability. Moreover, the constructed platform was successfully used for NSE determination in human serum samples., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
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