EPSRC Grant Research Articles

UK meteotsunamis: a revision and update on events and their frequency

<scp>UK</scp> meteotsunamis: a revision and update on events and their frequency

Failure analysis with a focus on thermal aspect towards developing safer Na-ion batteries**Project supported by the National Key Technologies R&D Program, China (Grant No. 2016YFB0901500), the National Natural Science Foundation (NSFC) of China (Grant Nos. 51725206 and 51421002), NSFCUKRI EPSRC (Grant No. 51861165201), the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA21070500), Beijing Municipal Science

Safety requirements stimulate Na-based batteries to evolve from high-temperature Na–S batteries to room-temperature Na-ion batteries (NIBs). Even so, NIBs may still cause thermal runaway due to the external unexpected accidents and internal high activity of electrodes or electrolytes, which has not been comprehensively summarized yet. In this review, we summarize the significant advances about the failure mechanisms and related strategies to build safer NIBs from the selection of electrodes, electrolytes and the construction of electrode/electrolyte interfaces. Considering the safety risk, the thermal behaviors are emphasized which will deepen the understanding of thermal stability of different NIBs and accelerate the exploitation of safe NIBs.

Gap anisotropy in multiband superconductors based on multiple scattering theory

We implement the Bogoliubov-de Gennes (BdG) equation in a screened Korringa-Kohn-Rostoker (KKR) method for solving, self-consistently, the superconducting state for 3d crystals. This method combines the full complexity of the underlying electronic structure and Fermi surface geometry with a simple phenomenological parametrisation for the superconductivity. We apply this theoretical framework to the known s-wave superconductors Nb, Pb, and MgB$_2$. In these materials multiple distinct peaks at the gap in the density of states were observed, showing significant gap anisotropy which is in good agreement with experiment. Qualitatively, the results can be explained in terms of the k-dependent Fermi velocities on the Fermi surface sheets exploiting concepts from BCS theory.

Neutralization of SARS-CoV-2 by Destruction of the Prefusion Spike

There are as yet no licenced therapeutics for the COVID-19 pandemic. The causal coronavirus (SARS-CoV-2) binds host cells via a trimeric Spike whose receptor binding domain (RBD) recognizes angiotensin-converting enzyme 2 (ACE2), initiating conformational changes that drive membrane fusion. We find that monoclonal antibody CR3022 binds the RBD tightly, neutralising SARS-CoV-2 and report the crystal structure at 2.4 A of the Fab/RBD complex. Some crystals are suitable for screening for entry-blocking inhibitors. The highly conserved, structure-stabilising, CR3022 epitope is inaccessible in the prefusion Spike, suggesting that CR3022 binding would facilitate conversion to the fusion-incompetent post-fusion state. Cryo-EM analysis confirms that incubation of Spike with CR3022 Fab leads to destruction of the prefusion trimer. Presentation of this cryptic epitope in an RBD-based vaccine might advantageously focus immune responses. Binders at this epitope may be useful therapeutically, possibly in synergy with an antibody blocking receptor attachment.Funding: This work was supported by a grant from the CAMS-Oxford Institute to D.I.S. E.E.F and J.Ren are supported by the Wellcome Trust (101122/Z/13/Z), Y.Z. by Cancer Research UK (C375/A17721) and D.I.S. and E.E.F. by the UK Medical Research Council (MR/N00065X/1). J.H. is supported by a grant from the EPA Cephalosporin Fund. PPUK is funded by the Rosalind Franklin Institute EPSRC Grant no. EP/S025243/1. The National Institute for Health Research Biomedical Research Centre Funding Scheme supports G.R.S. together with the Chinese Academy of Medical Sciences (CAMS) Innovation Fund for Medical Science (CIFMS), China (grant number: 2018-I2M-2-002), which also supports D.I.S. G.R.S. is also supported as a Wellcome Trust Senior Investigator (grant 095541/A/11/Z). T.M. is supported by Cancer Research UK grants C20724/A14414 and C20724/A26752 to Christian Siebold. This is a contribution from the UK Instruct-ERIC Centre. The Wellcome Centre for Human Genetics is supported by the Wellcome Trust (grant 090532/Z/09/Z). Virus used for the neutralisation assays was a gift from Julian Druce, Doherty Centre, Melbourne, Australia. Conflict of Interest: The authors declare no competing interests.

Non-Aqueous Electrodeposition of 2-D Layered MoS2 from a Tailored Single Source Precursor

2-D layered transition metal dichalcogenide (TMDC) materials have been intensively investigated in the past few years because of their remarkable properties such as semiconductivity, strong spin splitting, tunable band gaps etc.1, that make them ideal candidates for optoelectronic and electronics applications2-3. The flagship of TMDCs is MoS2 due to its unique electronic, optical and other features, including size-dependent band gap4. A number of techniques have been recently established for obtaining ultra-thin MoS2 films, however, improved processing methods for scalable production of the films are highly desirable. At present, the TMDCs are typically deposited by vapour deposition methods such as magnetron sputtering5 and chemical vapour deposition (CVD)6. However, these techniques are expensive and mostly involve constraining deposition conditions such as high temperature and high vacuum. On the other hand, electrodeposition, being a low cost alternative technique, has a number of key advantages that make it an interesting materials deposition process. First, electrodeposition is a ‘bottom-up’ growth technique where conformal deposition occurs via atom by atom growth over the exposed electrode surface. Secondly, electrodeposition is, in general, a low temperature technique that is mostly performed in ambient conditions and it is very efficient in use of materials. The deposition only occurs in areas defined by the electrical contact and is under direct electrical control during the growth. Thanks to these advantages, electrodeposition finds use in key high tech areas such as deposition of magnetic read-write heads and the copper interconnects in microprocessor chips7. Water is the most commonly employed solvent in electrodeposition, however, its narrow potential window induces limitations in depositing metals/compounds requiring large negative overpotentials, and also the water reduction and H2 evolution reactions introduce additional complexity to the experiments. Here, we employ an electrolyte system based on tetrabutylammonium tetrathiomolybdate as a single source precursor for MoS2, with compatible tetrabutylammonium halide supporting electrolyte and trimethylammonium chloride as proton source in a weakly coordinating, non-aqueous solvent, which provides the ability to deposit 2-D TMDC films with desired structures and properties. In the present study, we report on the electrodeposition of 2-D MoS2 films from dichloromethane. The electrodeposited MoS2 films were characterized by variety of methods including Scanning Electron Microscopy (SEM), Raman spectroscopy and X-ray diffraction. A detailed investigation on the electrochemical growth mechanism of MoS2 has been conducted using Electrochemical Quartz Crystal Microbalance (EQCM). The influence of various growth parameters on the structure and composition of the thin films will also be discussed. This work was funded by EPSRC grant reference EP/P025137/1. [1] Nature Chemistry, 2013. 5: 263. [2] Chemical Society Reviews, 2015. 44(21): 7715-7736. [3] Chemical Society Reviews, 2015. 44(9): 2664-2680. [4] Chemical Society Reviews, 2018. 47(16): 6101-6127. [5] Nanoscale, 2015. 7(6): 2497-2503. [6] Chemical Society Reviews, 2015. 44(9): 2744-2756. [7] IBM Journal of Research and Development, 1998. 42(5): 567-574.

Moving to or from a carbon dependent countryside

This work was supported by the Economic and Social Research Council [grant number RES-240-25-00250] and Engineering and Physical Sciences Research Council and Department of Science and Technology India (EPSRC grant number EP/J000361/1).

The size‐Ramsey number of powers of paths

Most of the work for this paper was done during my PhD, which was half funded by EPSRC grant reference 1360036, and half by Merton College Oxford. The third author was partially supported by FAPESP (Proc.~2013/03447-6) and by CNPq (Proc.~459335/2014-6, 310974/2013-5). The fifth author was supported by FAPESP (Proc.~2013/11431-2, Proc.~2013/03447-6 and Proc.~2018/04876-1) and partially by CNPq (Proc.~459335/2014-6). This research was supported in part by CAPES (Finance Code 001). The collaboration of part of the authors was supported by a CAPES/DAAD PROBRAL grant (Proc.~430/15).

A note on non-unique enhancements

The first author was a Postdoctoral Research Fellow at the University of Edinburgh. She was supported by EPSRC grant EP/N021649/1. The second author was a senior researcher at the Research Foundation - Flanders (FWO). He was supported by the FWO-grant G0D8616N Hochschild cohomology and deformation theory of triangulated categories.

Direct numerical simulation of a compressible boundary-layer flow past an isolated three-dimensional hump in a high-speed subsonic regime

This work was supported by the Laminar Flow Control Centre funded by Airbus/EADS and EPSRC under Grant No. EP/I037946 and computational resources were also provided through the UK Turbulence resource under EPSRC Grant No. EP/L000261/1. The authors would like to acknowledge the use of Imperial College High Performance Computing facility. S.J.S. would also like to acknowledge support under the RAEng Fellowship through Grant No. 10145/86.

A characterization of linearly repetitive cut and project sets**Research supported by EPSRC grants EP/L001462, EP/J00149X, EP/M023540. HK also gratefully acknowledges the support of the Osk. Huttunen foundation.

For the development of a mathematical theory which can be used to rigorously investigate physical properties of quasicrystals, it is necessary to understand regularity of patterns in special classes of aperiodic point sets in Euclidean space. In one dimension, prototypical mathematical models for quasicrystals are provided by Sturmian sequences and by point sets generated by substitution rules. Regularity properties of such sets are well understood, thanks mostly to well known results by Morse and Hedlund, and physicists have used this understanding to study one dimensional random Schrödinger operators and lattice gas models. A key fact which plays an important role in these problems is the existence of a subadditive ergodic theorem, which is guaranteed when the corresponding point set is linearly repetitive.In this paper we extend the one-dimensional model to cut and project sets, which generalize Sturmian sequences in higher dimensions, and which are frequently used in mathematical and physical literature as models for higher dimensional quasicrystals. By using a combination of algebraic, geometric, and dynamical techniques, together with input from higher dimensional Diophantine approximation, we give a complete characterization of all linearly repetitive cut and project sets with cubical windows. We also prove that these are precisely the collection of such sets which satisfy subadditive ergodic theorems. The results are explicit enough to allow us to apply them to known classical models, and to construct linearly repetitive cut and project sets in all pairs of dimensions and codimensions in which they exist.

Interpreting physical flows in networks as a communication system

ACKNOWLEDGEMENTS NR acknowledges the support of PEDECIBA, Uruguay. CG and MSB thank the Scottish University Physics Alliance (SUPA) support. MSB also acknowledges the support of EPSRC grant Ref. EP/I032606/1.

Random Hermitian matrices and Gaussian multiplicative chaos

N. Berestycki’s work is supported by EPSRC Grants EP/L018896/1 and EP/I03372X/1. M. D. Wong is a PhD student at the Cambridge Centre for Analysis, supported by EPSRC Grant EP/L016516/1. Some of this work was carried out while the first and third authors visited the University of Helsinki, funded in part by EPSRC Grant EP/L018896/1. They also wish to thank the University of Helsinki for its hospitality during this visit. C.Webb wishes to thank the Isaac Newton Institute for Mathematical Sciences for its hospitality during the Random Geometry program, during which this project was initiated. C.Webb was supported by the Eemil Aaltonen Foundation grant Stochastic dynamics on large random graphs and Academy of Finland Grants 288318 and 308123.

On the $L^q$-dimensions of measures on Hueter-Lalley type self-affine sets

The authors were financially supported by an LMS Scheme 4 Research in Pairs grant. The second author also acknowledges financial support from the EPSRC grant EP/K029061/1, and the first author acknowledges financial support from a Leverhulme Trust Research Fellowship (RF-2016-500).

Changes in the optical scattering and absorption spectra of ex vivo chicken breast tissue following exposure to high-intensity focused ultrasound

Real-time acousto-optic (AO) sensing has been shown to non-invasively detect changes in ex vivo tissue optical properties during high-intensity focused ultrasound (HIFU) exposures. Baseline changes in optical properties have been previously measured as a function of thermal dose for chicken breast exposed to a temperature-controlled water bath (doi:10.1088/0031-9155/59/13/3249). In this work, the wavelength-dependent optical scattering and absorption coefficients of ex vivo chicken breast tissue exposed to HIFU were measured using an integrating sphere spectrophotometric technique employed previously. A focused HIFU transducer coupled to an acoustic lens was used to produce a large focal heating area in a thin (approximately 2 mm) section of tissue. Spatiotemporal surface temperature elevations were measured using an infrared camera and used to calculate the spatially dependent thermal dose delivered to a localized region of tissue as the exposure intensity and time were varied. Results will show how wavelength-dependent optical property changes can be used to improve the AO sensing of lesion formation during HIFU therapy as an alternative to thermometry and dosimetery. [Work supported by the F. V. Hunt Postdoctoral Fellowship, the University of Oxford, and EPSRC grant number EP/K02020X/1.]

Privacy, Governance and Public Acceptability in Population Data Linkage for Research

ABSTRACT&#x0D; IntroductionFor several years, Population Data Linkage initiatives around the world have been successfully linking population‐based administrative and other datasets and making extracts available for research under strong confidentiality protections1. This paper provides an overview of current approaches in a range of scenarios, then outlines current relevant trends and potential implications for population data linkage initiatives.MethodsApproaches to protecting the confidentiality of data in research can also reduce the statistical usefulness, and the trade‐off between confidentiality protection and statistical usefulness is often represented as a Risk‐Utility map [2, 3, 5, 7]. Positioning the range of current approaches on such a Risk‐Utility map can indicate the relative nature of the trade‐off in each case.Such a Risk‐Utility map is only part of the story, however. Each approach needs to be implemented with appropriate levels of governance, information technology security, and ethical oversight. In addition, there are several changes in the external environment that have potential implications for population data linkage initiatives.Results and DiscussionCurrent approaches to protecting the confidentiality of data in research fall into one of two classes. The first class comprises approaches that anonymise the data before analysis, namely:&#x0D; &#x0D; Removal of identifying information such as names and addresses&#x0D; Secure data centres on‐site at the custodian premises&#x0D; Public use files made widely available&#x0D; Synthetic data files made widely available&#x0D; Open data files published on the internet&#x0D; &#x0D; The second class comprises approaches that anonymise the analysis outputs, namely:&#x0D; &#x0D; Virtual data centres that are on‐line versions of secure data centres [8]&#x0D; Remote analysis centres where users can request analyses but cannot see data.&#x0D; &#x0D; Many such initiatives implicitly or explicitly use criteria that have been recently captured in the Five Safes model [3]. However, changes in the external environment may add potential implications to address [6].First, there is a rapid increase in scenarios for data use, many of which involve multiple datasets from multiple sources with multiple custodians. This raises the question of whether there should be centralised data integration versus a proliferation of ad‐hoc decentralised but inter‐related initiatives. In any case, harmonised and shared governance will be essential. Next, the public are becoming increasingly informed and are increasingly exercising their privacy preferences in selecting between competing service providers. It is likely that the public will demand that initiatives move beyond education gain acceptance to a model of full partnership.ConclusionsWhile Population Data Linkage initiatives have been successful to date, changes in the external environment have potential implications such as a need for harmonised and shared governance, as well as full partnership with the public. Meeting the future challenges will require sophistication in the selection, design and operation of approaches to protecting the confidentiality of data in research. Useful frameworks in this context include [1, 4]. Importantly, it is necessary to have a range of approaches in order to adequately meet the needs of a range of different scenarios.AcknowledgementsThis work was partially supported by a grant from the Simons Foundation. The author thanks the Isaac Newton Institute for Mathematical Sciences, University of Cambridge, for support and hospitality during the programme Data Linkage and Anonymisation, which was supported by EPSRC grant no EP/K032208/1.&#x0D; 1For a list of administrative data linkage centres around the world, see www.ipdln.org/data‐linkage‐centres&#x0D; Key References[1] Desai T, Felix Ritchie F, Welpton R. Five safes: designing data access for research. Preprint 2016.[2] Duncan G, Elliot M, Salazar‐Gonzàlez JJ. Statistical Confidentiality. Springer: New York, 2011.[3] El Emam K. A Guide to the De‐identification of Health Information. CRC Press: New York, NY, 2013.[4] Elliot M, Mackey E, O’Hara K, Tudor C. The Anonymisation Decision‐Making Framework. http://ukanon.net/wp‐content/uploads/2015/05/The‐Anonymisation‐Decision‐making‐Framework.pdf[5] Hundepool A, Domingo‐Ferrer J, Franconi L, Giessing S, Nordholt E, Spicer K, deWolf PP. Statistical Disclosure Control, Wiley Series in Survey Methodology. John Wiley &amp; Sons: United Kingdom, 2012.[6] O’Keefe CM, Gould P, Chipperfield JO. A Five Safes perspective on administrative data integration initiatives, submitted.[7] O'Keefe CM and Rubin DB. Individual Privacy versus Public Good: Protecting Confidentiality in Health Research, Statistics in Medicine 34 (2015), 3081‐3103. DOI: 10.1002/sim.6543[8] O’Keefe CM, Westcott M, O’Sullivan M, Ickowicz A, Churches T. Anonymization for outputs of population health and health services research conducted via an online data centre, JAMIA in press.&#x0D;

Patch-based corner detection for cervical vertebrae in X-ray images

Corners hold vital information about size, shape and morphology of a vertebra in an x-ray image, and recent literature (Al-Arif et al., 2015) [1,2] has shown promising performance for detecting vertebral corners using a Hough forest-based architecture. To provide spatial context, this method generates a set of 12 patches around a vertebra and uses a machine learning approach to predict corners of a vertebral body through a voting process. In this paper, we extend this framework in terms of patch generation and prediction methods. During patch generation, the square region of interest has been replaced with data-driven rectangular and trapezoidal region of interest which better aligns the patches to the vertebral body geometry, resulting in more discriminative feature vectors. The corner estimation or the prediction stage has been improved by utilising more efficient voting process using a single kernel density estimation. In addition, advanced and more complex feature vectors are introduced. We also present a thorough evaluation of the framework with different patch generation methods, forest training mechanisms and prediction methods. In order to compare the performance of this framework with a more general method, a novel multi-scale Harris corner detector-based approach is introduced that incorporates a spatial prior through a naive Bayes method. All these methods have been tested on a dataset of 90 X-ray images and achieved an average corner localization error of 2.01 mm, representing a 33% improvement in localization accuracy compared to the previous state-of-the-art method (Al-Arif et al., 2015) [2].11This work was supported by the EPSRC grant number EP/K037641/1.

Majorana spectroscopy of Kitaev spin-liquids

The collaboration was supported by the Helmholtz Virtual Institute “New States of Matter and their Excitations” and the German Science Foundation under SFB 1143. The work of J.K. is supported by a Fellowship within the Postdoc-Program of the German Academic Exchange Service (DAAD). A.S. would like to acknowledge the EPSRC for studentship funding under Grant No. EP/M508007/1. J.T.C. is supported by EPSRC Grant No. EP/I032487/1, D.K. is supported by EPSRC Grant No. EP/M007928/1.

Tautological rings for high-dimensional manifolds

S.G. was partially supported by NSF grants DMS-1105058 and DMS-1405001, the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 682922), as well as the Danish National Research Foundation through the Centre for Symmetry and Deformation (DNRF92) and ERC-682992. O.R.W. was partially supported by EPSRC grant EP/M027783/1.

Preface to the Themed Issue on ‘Statistical Network Science and Its Applications’

Veronica Vinciotti and Ernst Wit thank the Isaac Newton Institute for Mathematical Sciences, Cambridge, for its hospitality during the programme Theoretical Foundations of Statistical Network Analysis, which was supported by the EPSRC grant EP/K032208/1.

A Liouville hyperbolic souvlaki

Supported by an EPSRC grant EP/L505110/1, and by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 639046).