Public Request to Take Stronger Measures of Social Distancing Across the UK with Immediate Effect 14Th March 2020 (Last Update: 14Th March 2020, 23:00)
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Supplemental Material for Molecular Simulations of Heterogeneous Ice
Supplemental Material for Molecular simulations of heterogeneous ice nucleation I: Controlling ice nucleation through surface hydrophilicity Stephen J. Cox,1, 2 Shawn M. Kathmann,3 Ben Slater,1 and Angelos Michaelides1, 2, a) 1)Thomas Young Centre and Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, U.K. 2)London Centre for Nanotechnology, 17{19 Gordon Street, London WC1H 0AH, U.K. 3)Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States (Dated: 22 April 2015) This Supplemental Material contains further details of the simulation methods and the data fitting procedure used. A movie and still images of a nucleation event at the NP with Eads=∆Hvap ≈ 0:9 are also provided. a)Electronic mail: [email protected] 1 I. FURTHER SIMULATIONS DETAILS To construct the NP, the ASE package1 was used: 6 atomic layers were used in the f1,0,0g family of directions; 9 layers in the f1,1,0g family; and 5 layers in the f1,1,1g family, except along the (1¯; 1¯; 1)¯ direction where no layers were used. As the equations of motion for the atoms in the NP were not integrated (i.e. they were fixed) no interaction potential was defined between them, and the adsorption energy Eads of a water monomer to the NP was therefore simply defined as the total energy after geometry optimization of a single water molecule at the center of the (111) face. The velocity Verlet algorithm was used to propagate the equations of motion of the water molecules, using a 10 fs time step. -
Generalised Noncommutative Geometry on Finite Groups and Hopf
J. Noncommut. Geom. 13 (2019), 1055–1116 Journal of Noncommutative Geometry DOI 10.4171/JNCG/345 © European Mathematical Society Generalised noncommutative geometry on finite groups and Hopf quivers Shahn Majid and Wen-Qing Tao Abstract. We explore the differential geometry of finite sets where the differential structure is given by a quiver rather than as more usual by a graph. In the finite group case we show that the data for such a differential calculus is described by certain Hopf quiver data as familiar in the context of path algebras. We explore a duality between geometry on the function algebra vs geometry on the group algebra, i.e. on the dual Hopf algebra, illustrated by the noncommutative Riemannian geometry of the group algebra of S3. We show how quiver geometries arise naturally in the context of quantum principal bundles. We provide a formulation of bimodule Riemannian geometry for quantum metrics on a quiver, with a fully worked example on 2 points; in the quiver case, metric data assigns matrices not real numbers to the edges of a graph. The paper builds on the general theory in our previous work [19]. Mathematics Subject Classification (2010). 81R50, 58B32, 16G20. Keywords. Hopf algebra, nonsurjective calculus, quiver, duality, finite group, bimodule connection. 1. Introduction Noncommutative differential geometry is an extension of geometry to the case where the coordinate algebra A may be noncommutative or “quantum.” The starting point is a “differential structure” on A defined as a pair .1; d/ where the space of “1-forms” 1 is an A-A-bimodule (so one can multiply by the algebra from the left or the right) and d A 1 obeys the Leibniz rule. -
What Makes a Good Descriptor for Heterogeneous Ice Nucleation on OH-Patterned Surfaces
What Makes a Good Descriptor for Heterogeneous Ice Nucleation on OH-Patterned Surfaces Philipp Pedevilla Thomas Young Centre and London Centre for Nanotechnology, 17-19 Gordon Street, London, WC1H 0AH, United Kingdom and Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, United Kingdom Martin Fitzner and Angelos Michaelides∗ Thomas Young Centre and London Centre for Nanotechnology, 17-19 Gordon Street, London, WC1H 0AH, United Kingdom and Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, United Kingdom (Dated: October 5, 2018) Freezing of water is arguably one of the most common phase transitions on Earth and almost always happens heterogeneously. Despite its importance, we lack a fundamental understanding of what makes substrates efficient ice nucleators. Here we address this by computing the ice nucleation (IN) ability of numerous model hydroxylated substrates with diverse surface hydroxyl (OH) group arrangements. Overall, for the substrates considered, we find that neither the symmetry of the OH patterns nor the similarity between a substrate and ice correlate well with the IN ability. Instead, we find that the OH density and the substrate-water interaction strength are useful descriptors of a material's IN ability. This insight allows the rationalization of ice nucleation ability across a wide range of materials, and can aid the search and design of novel potent ice nucleators in the future. I. INTRODUCTION ing and ice formation on well-defined atomically flat sur- faces [10, 11], but these experiments are currently not ap- Nucleation is a process that plays a pivotal role in nu- plicable under atmospherically relevant conditions. -
Public Request to Take Stronger Measures of Social Distancing Across the UK with Immediate Effect 14Th March 2020
Public request to take stronger measures of social distancing across the UK with immediate effect 14th March 2020 (last update: 15th March 2020, 18:25) As scientists living and working in the UK, we would like to express our concern about the course of action announced by the Government on 12th March 2020 regarding the Coronavirus outbreak. In particular, we are deeply preoccupied by the timeline of the proposed plan, which aims at delaying social distancing measures even further. The current data about the number of infections in the UK is in line with the growth curves already observed in other countries, including Italy, Spain, France, and Germany [1]. The same data suggests that the number of infected will be in the order of dozens of thousands within a few days. Under unconstrained growth, this outbreak will affect millions of people in the next few weeks. This will most probably put the NHS at serious risk of not being able to cope with the flow of patients needing intensive care, as the number of ICU beds in the UK is not larger than that available in other neighbouring countries with a similar population [2]. Going for \herd immunity" at this point does not seem a viable option, as this will put NHS at an even stronger level of stress, risking many more lives than necessary. By putting in place social distancing measures now, the growth can be slowed down dramatically, and thousands of lives can be spared. We consider the social distancing measures taken as of today as insufficient, and we believe that addi- tional and more restrictive measures should be taken immediately, as it is already happening in other countries across the world. -
4Th International Conference on New Frontiers in Physics, ICNFP2015, from 23 to 30 August 2015, Kolymbari, Crete, Greece
4th International Conference on New Frontiers in Physics, ICNFP2015, from 23 to 30 August 2015, Kolymbari, Crete, Greece From 23 to 24 August, Lectures From 24 to 30 August, Main Conference http://indico.cern.ch/e/icnfp2015 Yiota Foka on behalf of the ICNFP2015 Organizing Committee: Larissa Bravina, University of Oslo (Norway) (co-chair) Yiota Foka, GSI (Germany) (co-chair) Sonia Kabana, University of Nantes and Subatech (France) (co-chair) Evgeny Andronov, SPbSU (Russia) Panagiotis Charitos, CERN (Switzerland) Laszlo Csernai, University of Bergen (Norway) Nikos Kallithrakas, Technical University of Chania (Greece) Alisa Katanaeva, SPbSU (Russia) Elias Kiritsis, APC and University of Crete (Greece) Adam Kisiel, WUT (Poland) Vladimir Kovalenko, SPbSU (Russia) Emanuela Larentzakis, OAC, Kolymbari (Greece) Patricia Mage-Granados, CERN (Switzerland) Anton Makarov, SPbSU (Russia) Dmitrii Neverov, SPbSU (Russia) Ahmed Rebai, Completude Ac. Nantes (France) Andrey Seryakov, SPbSU (Russia) Daria Shukhobodskaia, SPbSU (Russia) Inna Shustina, (Ukraine) Abstract We apply for financial aid to support the participation of graduate students and postdoctoral research associates at the 4th International Conference on New Frontiers in Physics, to be held in Kolymbari, Crete, Greece, from 23 to 30 Au- gust 2015. The conference series \New Frontiers in Physics" aims to promote interdisciplinarity and cross-fertilization of ideas between different disciplines addressing fundamental physics. 1 Introduction While different fields each face a distinct set of field-specific challenges in the coming decade, a significant set of commonalities has emerged in the technical nature of some of these challenges, or are underlying the fundamental concepts involved. A Grand Unified Theory should in principle reveal this underlying relationship. -
Scientific Report 2011 / 2012 Max-Planck-Institut Für Eisenforschung Gmbh Max-Planck-Institut Für Eisenforschung Gmbh
Scientific Report 2011 / 2012 Max-Planck-Institut für Eisenforschung GmbH Max-Planck-Institut für Eisenforschung GmbH Scientific Report 2011/2012 November 2012 Max-Planck-Institut für Eisenforschung GmbH Max-Planck-Str. 1 · 40237 Düsseldorf Germany Front cover Oxygen is one of the critical components that give rise to the excellent mechanical properties of Ti-Nb based gum metal (Ti−23Nb−0.7Ta− 2Zr−1.2O at%) and its complex deformation mechanism. Yet, its role is not fully clear, for which reason an extensive project is being carried out at MPIE (see highlight article on page 113). As a part of this project, deformation structures in gum metal (Ti−22.6Nb−0.47Ta−1.85Zr−1.34O at%) are compared to those in a reference alloy that has the same chemical composition, but no oxygen (Ti−22.8Nb−0.5Ta−1.8Zr at%). The cover page shows a light microscope image of a sample of the reference alloy deformed in uniaxial tension, revealing mechanically-induced crystallographic twin steps on a priorly-polished surface (1 cm corresponds to approx. 125 µm). Imprint Published by Max-Planck-Institut für Eisenforschung GmbH Max-Planck-Str. 1, 40237 Düsseldorf, Germany Phone: +49-211-6792-0 Fax: +49-211-6792-440 Homepage: http://www.mpie.de Editorship, Layout and Typesetting Yasmin Ahmed-Salem Gabi Geelen Brigitte Kohlhaas Frank Stein Printed by Bonifatius GmbH Druck-Buch-Verlag Paderborn, Germany © November 2012 by Max-Planck-Institut für Eisenforschung GmbH, Düsseldorf All rights reserved. PREFACE This report is part of a series documenting the scientific activities and achievements of the Max-Planck- Institut für Eisenforschung GmbH (MPIE) in 2011 and 2012. -
Department of Physics Review
The Blackett Laboratory Department of Physics Review Faculty of Natural Sciences 2008/09 Contents Preface from the Head of Department 2 Undergraduate Teaching 54 Academic Staff group photograph 9 Postgraduate Studies 59 General Departmental Information 10 PhD degrees awarded (by research group) 61 Research Groups 11 Research Grants Grants obtained by research group 64 Astrophysics 12 Technical Development, Intellectual Property 69 and Commercial Interactions (by research group) Condensed Matter Theory 17 Academic Staff 72 Experimental Solid State 20 Administrative and Support Staff 76 High Energy Physics 25 Optics - Laser Consortium 30 Optics - Photonics 33 Optics - Quantum Optics and Laser Science 41 Plasma Physics 38 Space and Atmospheric Physics 45 Theoretical Physics 49 Front cover: Laser probing images of jet propagating in ambient plasma and a density map from a 3D simulation of a nested, stainless steel, wire array experiment - see Plamsa Physics group page 38. 1 Preface from the Heads of Department During 2008 much of the headline were invited by, Ian Pearson MP, the within the IOP Juno code of practice grabbing news focused on ‘big science’ Minister of State for Science and (available to download at with serious financial problems at the Innovation, to initiate a broad ranging www.ioppublishing.com/activity/diver Science and Technology Facilities review of physics research under sity/Gender/Juno_code_of_practice/ Council (STFC) (we note that some the chairmanship of Professor Bill page_31619.html). As noted in the 40% of the Department’s research Wakeham (Vice-Chancellor of IOP document, “The code … sets expenditure is STFC derived) and Southampton University). The stated out practical ideas for actions that the start-up of the Large Hadron purpose of the review was to examine departments can take to address the Collider at CERN. -
About Imperial College London
About Imperial College London Overview Imperial College London is one of the world’s greatest universities, renowned for its ground- breaking research, talented community of staff, students and alumni and its international reach. With a mission to achieve enduring excellence in research and education in science, engineering, medicine and business for the benefit of society, the College was founded in 1907 in South Kensington, bringing together nineteenth century institutions including the Royal College of Science, Royal School of Mines and City and Guilds College. Today Imperial collaborates extensively with neighbouring institutions, including the Royal College of Art and the Royal College of Music. From its location in this great cultural quarter, Imperial provides one of the world’s best educations in STEM subjects for more than 18,400 students, over half of whom come from overseas, reflecting its status as the UK’s most international university. Imperial has three academic faculties – Engineering, Medicine, and Natural Sciences – and the Imperial College Business School, as well as a significant number of interdisciplinary research centres focusing on challenging world problems. The College’s mission is supported by over 8,000 diverse staff, who collaborate in the UK and internationally, often across disciplines. In 2017-2018 the College had a total turnover of over £1 billion, of which £364.2 million directly supported research through grants and contracts. The College’s 2015-2020 Strategy is built on the foundations that make Imperial a strong academic institution and the talented and inspirational people who make up its community. The College’s success is recognised all over the world, as is evidenced by daily coverage of Imperial discoveries and innovations in the international media and claims many distinguished members, including 14 Nobel laureates, three Fields Medallists, and members of the Royal Further Particulars: Lecturer / Senior Lecturer in Statistics 1 Society and National Academies. -
Matched Pairs of Lie Groups Associated to Solutions of the Yang-Baxter Equations
Pacific Journal of Mathematics MATCHED PAIRS OF LIE GROUPS ASSOCIATED TO SOLUTIONS OF THE YANG-BAXTER EQUATIONS SHAHN MAJID Vol. 141, No. 2 December 1990 PACIFIC JOURNAL OF MATHEMATICS Vol. 141, No. 2, 1990 MATCHED PAIRS OF LIE GROUPS ASSOCIATED TO SOLUTIONS OF THE YANG-BAXTER EQUATIONS SHAHN MAJID Two groups G, H are said to be a matched pair if they act on each other and these actions, (a, /?), obey a certain compatibility condition. In such a situation one may form a bicrossproduct group, denoted Gβ cχiQ H. Also in this situation one may form a bicrossproduct Hopf, Hopf-von Neumann or Kac algebra obtained by simultaneous cross product and cross coproduct. We show that every compact semi-simple simply-connected Lie group G is a member of a matched pair, denoted (G, G*)9 in a natural way. As an example we construct the matched pair in detail in the case (SU(2), SU(2)*) where SU(2)* = is the simply-connected group of a Lie algebra su(2)*. Here su(2)* is defined with respect to a standard canonical solution of the CYBE on the complexification of su(2). 1. Introduction and preliminaries. The notion of a matched pair of groups was studied in [18] and more recently in [12]. Two groups G, H are a matched pair if they act on each other and these actions α, β obey the condition (*) \/x,y e G, &,* e Hy ax-χ{e) = e, β<?-ι(e) = e, where e denotes the relevant group identity. We have chosen here conventions in which the natural objects are right actions αri, β&-ι. -
Quantum Riemannian Geometry of Phase Space and Nonassociativity
Demonstr. Math. 2017; 50: 83–93 Demonstratio Mathematica Open Access Research Article Edwin J. Beggs and Shahn Majid* Quantum Riemannian geometry of phase space and nonassociativity DOI 10.1515/dema-2017-0009 Received August 3, 2016; accepted September 5, 2016. Abstract: Noncommutative or ‘quantum’ differential geometry has emerged in recent years as a process for quantizing not only a classical space into a noncommutative algebra (as familiar in quantum mechanics) but also differential forms, bundles and Riemannian structures at this level. The data for the algebra quantisation is a classical Poisson bracket while the data for quantum differential forms is a Poisson-compatible connection. We give an introduction to our recent result whereby further classical data such as classical bundles, metrics etc. all become quantised in a canonical ‘functorial’ way at least to 1st order in deformation theory. The theory imposes compatibility conditions between the classical Riemannian and Poisson structures as well as new physics such as n typical nonassociativity of the differential structure at 2nd order. We develop in detail the case of CP where the i j commutation relations have the canonical form [w , w¯ ] = iλδij similar to the proposal of Penrose for quantum twistor space. Our work provides a canonical but ultimately nonassociative differential calculus on this algebra and quantises the metric and Levi-Civita connection at lowest order in λ. Keywords: Noncommutative geometry, Quantum gravity, Poisson geometry, Riemannian geometry, Quantum mechanics MSC: 81R50, 58B32, 83C57 In honour of Michał Heller on his 80th birthday. 1 Introduction There are today lots of reasons to think that spacetime itself is better modelled as ‘quantum’ due to Planck-scale corrections. -
Quantum Geometry, Logic and Probability
Quantum geometry, logic and probability Shahn Majid School of Mathematics, Queen Mary University of London Abstract Quantum geometry on a discrete set means a directed graph with a weight associated to each arrow defining the quantum metric. How- ever, these ‘lattice spacing’ weights do not have to be independent of the direction of the arrow. We use this greater freedom to give a quantum geometric interpretation of discrete Markov processes with transition probabilities as arrow weights, namely taking the diffusion form @ f = ( ∆θ + q p)f for the graph Laplacian ∆θ, potential + − − functions q; p built from the probabilities, and finite difference @+ in the time direction. Motivated by this new point of view, we intro- duce a ‘discrete Schrödinger process’ as @ = {( ∆ + V ) for the + − Laplacian associated to a bimodule connection such that the discrete evolution is unitary. We solve this explicitly for the 2-state graph, finding a 1-parameter family of such connections and an induced ‘gen- eralised Markov process’ for f = 2 in which there is an additional j j source current built from . We also mention our recent work on the CC-BY-NC-ND 4.0 quantum geometry of logic in ‘digital’ form over the field F2 = 0; 1 , • f g including de Morgan duality and its possible generalisations. Keywords logic, noncommutative geometry, digital geometry, quantum gravity, duality, power set, Heyting algebra. Philosophical Problems in Science (Zagadnienia FilozoficzneNo w Nauce) 69 (2020), pp. 191–236 192 Shahn Majid 1. Introduction hese are notes growing out of a conference in Kraków with Tthe wonderful question “Is logic physics?”. -
LMS Elections 2018 Candidate Biographies
LMS ELECTIONS TO COUNCIL AND NOMINATING COMMITTEE 2019: CANDIDATE BIOGRAPHIES Candidate for election as President (1 vacancy) Jon Keating Candidates for election as Vice-President (2 vacancies) Iain Gordon Catherine Hobbs Candidate for election as Treasurer (1 vacancy) Robert Curtis Candidate for election as General Secretary (1 vacancy) Stephen Huggett Candidate for election as Publications Secretary (1 vacancy) John Hunton Candidate for election as Programme Secretary (1 vacancy) Chris Parker Candidates for election as Education Secretary (1 vacancy) Kevin Houston Candidate for election as Librarian (Member-at-Large) (1 vacancy) Mark McCartney Candidates for election as Member-at-Large of Council (5 x 2-year terms and 1 x 1-year term vacant) Elaine Crooks Andrew Dancer Tony Gardiner Anotida Madzvamuse Brita Nucinkis Richard Pinch Marika Taylor Alina Vdovina Candidates for election to Nominating Committee (2 x 3-year terms vacant) Shahn Majid Beatrice Pelloni Mary Rees Colin Sparrow 1 CANDIDATE FOR ELECTION AS PRESIDENT (1 VACANCY) Jonathan Peter Keating FRS, Henry Overton Wills Professor of Mathematics, University of Bristol (until 31 August 2019); Sedleian Professor of Natural Philosophy, University of Oxford (from 1 September 2019) Chair of the Heilbronn Institute for Mathematical Research Email address: [email protected] Homepage: http://www.bristol.ac.uk/maths/people/jon-p-keating/index.html PhD: University of Bristol, 1989 Previous appointments: Royal Society Research Assistant, University of Bristol 1989–1991; Lecturer in Applied Mathematics, University of Manchester 1991-1995; Reader in Applied Mathematics, University of Bristol 1995-1997; BRIMS Research Fellow, Hewlett-Packard Laboratories, Bristol 1995-2001; Professor of Mathematical Physics 1997- 2012; Head of Department 2001-2004; EPSRC Senior Research Fellow 2004-2009; Dean of Science, University of Bristol 2009-2013.