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Chapman SC, Dudok de Wit T. A solar cycle clock for extreme space weather. Sci Rep 2024; 14:8249. [PMID: 38589701 PMCID: PMC11001994 DOI: 10.1038/s41598-024-58960-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 04/04/2024] [Indexed: 04/10/2024] Open
Abstract
The variable solar cycle of activity is a long-standing problem in physics. It modulates the overall level of space weather activity at earth, which in turn can have significant societal impact. The Hilbert transform of the sunspot number is used to map the variable length, approximately 11 year Schwabe cycle onto a uniform clock. The clock is used to correlate extreme space weather seen in the aa index, the longest continuous geomagnetic record at earth, with the record of solar active region areas and latitudes since 1874. This shows that a clear switch-off of the most extreme space weather events occurs when > 90 % of solar active region areas have moved to within about 15° of the solar equator, from regions of high gradient in solar differential rotation which can power coronal mass ejections, to a region where solar differential rotation is almost constant with latitude. More moderate space weather events which coincide with 27 day solar rotation recurrences in the aa index, consistent with stable, persistent source regions of high speed streams, commence when the centroid of solar active region areas moves to within 15° of the solar equator. This offers a physical explanation for the longstanding identification of a two component cycle of activity in the aa index.
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Affiliation(s)
- S C Chapman
- Physics Department, Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry, UK.
- International Space Science Institute, Bern, Switzerland.
- Department of Physics and Statistics, University of Tromso, Tromsö, Norway.
| | - T Dudok de Wit
- International Space Science Institute, Bern, Switzerland
- LPC2E, CNRS, CNES, University of Orléans, Orléans, France
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Fairlamb IJS, Lynam JM. Unveiling Mechanistic Complexity in Manganese-Catalyzed C-H Bond Functionalization Using IR Spectroscopy Over 16 Orders of Magnitude in Time. Acc Chem Res 2024; 57:919-932. [PMID: 38412502 PMCID: PMC10956383 DOI: 10.1021/acs.accounts.3c00774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 01/25/2024] [Accepted: 01/30/2024] [Indexed: 02/29/2024]
Abstract
ConspectusAn understanding of the mechanistic processes that underpin reactions catalyzed by 3d transition metals is vital for their development as potential replacements for scarce platinum group metals. However, this is a significant challenge because of the tendency of 3d metals to undergo mechanistically diverse pathways when compared with their heavier congeners, often as a consequence of one-electron transfer reactions and/or intrinsically weaker metal-ligand bonds. We have developed and implemented a new methodology to illuminate the pathways that underpin C-H bond functionalization pathways in reactions catalyzed by Mn-carbonyl compounds. By integrating measurements performed on catalytic reactions with in situ reaction monitoring and state-of-the-art ultrafast spectroscopic methods, unique insight into the mode of action and fate of the catalyst have been obtained.Using a combination of time-resolved spectroscopy and in situ low-temperature NMR studies, we have shown that photolysis of manganese-carbonyl precatalysts results in rapid (<5 ps) CO dissociation─the same process that occurs under thermal catalytic conditions. This enabled the detection of the key states relevant to catalysis, including solvent and alkyne complexes and their resulting transformation into manganacycles, which results from a migratory insertion reaction into the Mn-C bond. By systematic variation of the substrates (many of which are real-world structurally diverse substrates and not simple benchmark systems) and quantification of the resulting rate constants for the insertion step, a universal model for this migratory insertion process has been developed. The time-resolved spectroscopic method gave insight into fundamental mechanistic pathways underpinning other aspects of modern synthetic chemistry. The most notable was the first direct experimental observation of the concerted metalation deprotonation (CMD) mechanism through which carboxylate groups are able to mediate C-H bond activation at a metal center. This step underpins a host of important synthetic applications. This study demonstrated how the time-resolved multiple probe spectroscopy (TRMPS) method enables the observation of mechanistic process occurring on time scales from several picoseconds through to μs in a single experiment, thereby allowing the sequential observation of solvation, ligand substitution, migratory insertion, and ultimate protonation of a Mn-C bond.These studies have been complemented by an investigation of the "in reaction flask" catalyst behavior, which has provided additional insight into new pathways for precatalyst activation, including evidence that alkyne C-H bond activation may occur before heterocycle activation. Crucial insight into the fate of the catalyst species showed that excess water played a key role in deactivation to give higher-order hydroxyl-bridged manganese carbonyl clusters, which were independently found to be inactive. Traditional in situ IR and NMR spectroscopic analysis on the second time scale bridges the gap to the analysis of real catalytic reaction systems. As a whole, this work has provided unprecedented insight into the processes underpinning manganese-catalyzed reactions spanning 16 orders of magnitude in time.
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Affiliation(s)
- Ian J. S. Fairlamb
- Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Jason M. Lynam
- Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
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3
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Ayres NJ, Ban G, Bison G, Bodek K, Bondar V, Bouillaud T, Bowles D, Chanel E, Chen W, Chiu PJ, Crawford C, Naviliat-Cuncic O, Doorenbos CB, Emmenegger S, Fertl M, Fratangelo A, Griffith WC, Grujic ZD, Harris PG, Kirch K, Kletzl V, Krempel J, Lauss B, Lefort T, Lejuez A, Li R, Mullan P, Pacura S, Pais D, Piegsa FM, Rienäcker I, Ries D, Pignol G, Rebreyend D, Roccia S, Rozpedzik D, Saenz-Arevalo W, Schmidt-Wellenburg P, Schnabel A, Segarra EP, Severijns N, Svirina K, Tavakoli Dinani R, Thorne J, Vankeirsbilck J, Voigt J, Yazdandoost N, Zejma J, Ziehl N, Zsigmond G, nEDM collaboration at PSI T. Achieving ultra-low and -uniform residual magnetic fields in a very large magnetically shielded room for fundamental physics experiments. Eur Phys J C Part Fields 2024; 84:18. [PMID: 38205101 PMCID: PMC10774228 DOI: 10.1140/epjc/s10052-023-12351-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 12/08/2023] [Indexed: 01/12/2024]
Abstract
High-precision searches for an electric dipole moment of the neutron (nEDM) require stable and uniform magnetic field environments. We present the recent achievements of degaussing and equilibrating the magnetically shielded room (MSR) for the n2EDM experiment at the Paul Scherrer Institute. We present the final degaussing configuration that will be used for n2EDM after numerous studies. The optimized procedure results in a residual magnetic field that has been reduced by a factor of two. The ultra-low field is achieved with the full magnetic-field-coil system, and a large vacuum vessel installed, both in the MSR. In the inner volume of ∼ 1.4 m 3 , the field is now more uniform and below 300 pT. In addition, the procedure is faster and dissipates less heat into the magnetic environment, which in turn, reduces its thermal relaxation time from 12 h down to 1.5 h .
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Affiliation(s)
- N. J. Ayres
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zurich, Switzerland
| | - G. Ban
- Normandie Université, ENSICAEN, UNICAEN, CNRS/IN2P3, LPC Caen, 14000 Caen, France
| | - G. Bison
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - K. Bodek
- Marian Smoluchowski Institute of Physics, Jagiellonian University, 30-348 Kraków, Poland
| | - V. Bondar
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zurich, Switzerland
| | - T. Bouillaud
- Université Grenoble Alpes, CNRS, Grenoble INP, LPSC-IN2P3, 38026 Grenoble, France
| | - D. Bowles
- Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 USA
| | - E. Chanel
- Laboratory for High Energy Physics and Albert Einstein Center for Fundamental Physics, University of Bern, 3012 Bern, Switzerland
| | - W. Chen
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zurich, Switzerland
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - P.-J. Chiu
- University of Zürich, 8057 Zurich, Switzerland
| | - C. B. Crawford
- Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 USA
| | - O. Naviliat-Cuncic
- Normandie Université, ENSICAEN, UNICAEN, CNRS/IN2P3, LPC Caen, 14000 Caen, France
| | - C. B. Doorenbos
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zurich, Switzerland
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - S. Emmenegger
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zurich, Switzerland
| | - M. Fertl
- Institute of Physics, Johannes Gutenberg University, 55128 Mainz, Germany
| | - A. Fratangelo
- Laboratory for High Energy Physics and Albert Einstein Center for Fundamental Physics, University of Bern, 3012 Bern, Switzerland
| | - W. C. Griffith
- Department of Physics and Astronomy, University of Sussex, Falmer, Brighton, BN1 9QH UK
| | - Z. D. Grujic
- Institute of Physics, Photonics Center, University of Belgrade, Belgrade, 11080 Serbia
| | - P. G. Harris
- Department of Physics and Astronomy, University of Sussex, Falmer, Brighton, BN1 9QH UK
| | - K. Kirch
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zurich, Switzerland
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - V. Kletzl
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zurich, Switzerland
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - J. Krempel
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zurich, Switzerland
| | - B. Lauss
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - T. Lefort
- Normandie Université, ENSICAEN, UNICAEN, CNRS/IN2P3, LPC Caen, 14000 Caen, France
| | - A. Lejuez
- Normandie Université, ENSICAEN, UNICAEN, CNRS/IN2P3, LPC Caen, 14000 Caen, France
| | - R. Li
- Instituut voor Kern-en Stralingsfysica, University of Leuven, 3001 Leuven, Belgium
| | - P. Mullan
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zurich, Switzerland
| | - S. Pacura
- Marian Smoluchowski Institute of Physics, Jagiellonian University, 30-348 Kraków, Poland
| | - D. Pais
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zurich, Switzerland
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - F. M. Piegsa
- Laboratory for High Energy Physics and Albert Einstein Center for Fundamental Physics, University of Bern, 3012 Bern, Switzerland
| | - I. Rienäcker
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - D. Ries
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - G. Pignol
- Université Grenoble Alpes, CNRS, Grenoble INP, LPSC-IN2P3, 38026 Grenoble, France
| | - D. Rebreyend
- Université Grenoble Alpes, CNRS, Grenoble INP, LPSC-IN2P3, 38026 Grenoble, France
| | - S. Roccia
- Université Grenoble Alpes, CNRS, Grenoble INP, LPSC-IN2P3, 38026 Grenoble, France
| | - D. Rozpedzik
- Marian Smoluchowski Institute of Physics, Jagiellonian University, 30-348 Kraków, Poland
| | - W. Saenz-Arevalo
- Normandie Université, ENSICAEN, UNICAEN, CNRS/IN2P3, LPC Caen, 14000 Caen, France
| | | | - A. Schnabel
- Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin, Germany
| | - E. P. Segarra
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - N. Severijns
- Instituut voor Kern-en Stralingsfysica, University of Leuven, 3001 Leuven, Belgium
| | - K. Svirina
- Université Grenoble Alpes, CNRS, Grenoble INP, LPSC-IN2P3, 38026 Grenoble, France
| | - R. Tavakoli Dinani
- Instituut voor Kern-en Stralingsfysica, University of Leuven, 3001 Leuven, Belgium
| | - J. Thorne
- Laboratory for High Energy Physics and Albert Einstein Center for Fundamental Physics, University of Bern, 3012 Bern, Switzerland
| | - J. Vankeirsbilck
- Instituut voor Kern-en Stralingsfysica, University of Leuven, 3001 Leuven, Belgium
| | - J. Voigt
- Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin, Germany
| | - N. Yazdandoost
- Department of Chemistry-TRIGA Site, Johannes Gutenberg University Mainz, 55128 Mainz, Germany
| | - J. Zejma
- Marian Smoluchowski Institute of Physics, Jagiellonian University, 30-348 Kraków, Poland
| | - N. Ziehl
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zurich, Switzerland
| | - G. Zsigmond
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - The nEDM collaboration at PSI
- Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zurich, Switzerland
- Normandie Université, ENSICAEN, UNICAEN, CNRS/IN2P3, LPC Caen, 14000 Caen, France
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
- Marian Smoluchowski Institute of Physics, Jagiellonian University, 30-348 Kraków, Poland
- Université Grenoble Alpes, CNRS, Grenoble INP, LPSC-IN2P3, 38026 Grenoble, France
- Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 USA
- Laboratory for High Energy Physics and Albert Einstein Center for Fundamental Physics, University of Bern, 3012 Bern, Switzerland
- University of Zürich, 8057 Zurich, Switzerland
- Institute of Physics, Johannes Gutenberg University, 55128 Mainz, Germany
- Department of Physics and Astronomy, University of Sussex, Falmer, Brighton, BN1 9QH UK
- Institute of Physics, Photonics Center, University of Belgrade, Belgrade, 11080 Serbia
- Instituut voor Kern-en Stralingsfysica, University of Leuven, 3001 Leuven, Belgium
- Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin, Germany
- Department of Chemistry-TRIGA Site, Johannes Gutenberg University Mainz, 55128 Mainz, Germany
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4
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Kugel R, Schaye J, Schaller M, Helly JC, Braspenning J, Elbers W, Frenk CS, McCarthy IG, Kwan J, Salcido J, van Daalen MP, Vandenbroucke B, Bahé YM, Borrow J, Chaikin E, Huško F, Jenkins A, Lacey CG, Nobels FSJ, Vernon I. FLAMINGO: calibrating large cosmological hydrodynamical simulations with machine learning. Mon Not R Astron Soc 2023; 526:6103-6127. [PMID: 37900898 PMCID: PMC10602225 DOI: 10.1093/mnras/stad2540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 08/08/2023] [Accepted: 08/12/2023] [Indexed: 10/31/2023]
Abstract
To fully take advantage of the data provided by large-scale structure surveys, we need to quantify the potential impact of baryonic effects, such as feedback from active galactic nuclei (AGN) and star formation, on cosmological observables. In simulations, feedback processes originate on scales that remain unresolved. Therefore, they need to be sourced via subgrid models that contain free parameters. We use machine learning to calibrate the AGN and stellar feedback models for the FLAMINGO (Fullhydro Large-scale structure simulations with All-sky Mapping for the Interpretation of Next Generation Observations) cosmological hydrodynamical simulations. Using Gaussian process emulators trained on Latin hypercubes of 32 smaller volume simulations, we model how the galaxy stellar mass function (SMF) and cluster gas fractions change as a function of the subgrid parameters. The emulators are then fit to observational data, allowing for the inclusion of potential observational biases. We apply our method to the three different FLAMINGO resolutions, spanning a factor of 64 in particle mass, recovering the observed relations within the respective resolved mass ranges. We also use the emulators, which link changes in subgrid parameters to changes in observables, to find models that skirt or exceed the observationally allowed range for cluster gas fractions and the SMF. Our method enables us to define model variations in terms of the data that they are calibrated to rather than the values of specific subgrid parameters. This approach is useful, because subgrid parameters are typically not directly linked to particular observables, and predictions for a specific observable are influenced by multiple subgrid parameters.
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Affiliation(s)
- Roi Kugel
- Leiden Observatory, Leiden University, PO Box 9513, NL-2300 RA Leiden, the Netherlands
| | - Joop Schaye
- Leiden Observatory, Leiden University, PO Box 9513, NL-2300 RA Leiden, the Netherlands
| | - Matthieu Schaller
- Leiden Observatory, Leiden University, PO Box 9513, NL-2300 RA Leiden, the Netherlands
- Lorentz Institute for Theoretical Physics, Leiden University, PO box 9506, NL-2300 RA Leiden, the Netherlands
| | - John C Helly
- Institute for Computational Cosmology, Department of Physics, University of Durham, South Road, Durham DH1 3LE, UK
| | - Joey Braspenning
- Leiden Observatory, Leiden University, PO Box 9513, NL-2300 RA Leiden, the Netherlands
| | - Willem Elbers
- Institute for Computational Cosmology, Department of Physics, University of Durham, South Road, Durham DH1 3LE, UK
| | - Carlos S Frenk
- Institute for Computational Cosmology, Department of Physics, University of Durham, South Road, Durham DH1 3LE, UK
| | - Ian G McCarthy
- Astrophysics Research Institute, Liverpool John Moores University, Liverpool L3 5RF, UK
| | - Juliana Kwan
- Astrophysics Research Institute, Liverpool John Moores University, Liverpool L3 5RF, UK
| | - Jaime Salcido
- Astrophysics Research Institute, Liverpool John Moores University, Liverpool L3 5RF, UK
| | - Marcel P van Daalen
- Leiden Observatory, Leiden University, PO Box 9513, NL-2300 RA Leiden, the Netherlands
| | - Bert Vandenbroucke
- Leiden Observatory, Leiden University, PO Box 9513, NL-2300 RA Leiden, the Netherlands
| | - Yannick M Bahé
- Leiden Observatory, Leiden University, PO Box 9513, NL-2300 RA Leiden, the Netherlands
- Institute of Physics, Laboratory of Astrophysics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Observatoire de Sauverny, CH-1290 Versoix, Switzerland
| | - Josh Borrow
- Institute for Computational Cosmology, Department of Physics, University of Durham, South Road, Durham DH1 3LE, UK
- Department of Physics, Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Evgenii Chaikin
- Leiden Observatory, Leiden University, PO Box 9513, NL-2300 RA Leiden, the Netherlands
| | - Filip Huško
- Institute for Computational Cosmology, Department of Physics, University of Durham, South Road, Durham DH1 3LE, UK
| | - Adrian Jenkins
- Institute for Computational Cosmology, Department of Physics, University of Durham, South Road, Durham DH1 3LE, UK
| | - Cedric G Lacey
- Institute for Computational Cosmology, Department of Physics, University of Durham, South Road, Durham DH1 3LE, UK
| | - Folkert S J Nobels
- Leiden Observatory, Leiden University, PO Box 9513, NL-2300 RA Leiden, the Netherlands
| | - Ian Vernon
- Department of Mathematical Sciences, Durham University, Stockton Road, DH1 3LE Durham, UK
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Mukherjee S, Voneshen DJ, Duff A, Goddard P, Powell AV, Vaqueiro P. Beyond Rattling: Tetrahedrites as Incipient Ionic Conductors. Adv Mater 2023; 35:e2306088. [PMID: 37581205 DOI: 10.1002/adma.202306088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/04/2023] [Indexed: 08/16/2023]
Abstract
Materials with ultralow thermal conductivity are crucial to many technological applications, including thermoelectric energy harvesting, thermal barrier coatings, and optoelectronics. Liquid-like mobile ions are effective at disrupting phonon propagation, hence suppressing thermal conduction. However, high ionic mobility leads to the degradation of liquid-like thermoelectric materials under operating conditions due to ion migration and metal deposition at the cathode, hindering their practical application. Here, a new type of behavior, incipient ionic conduction, which leads to ultralow thermal conductivity, while overcoming the issues of degradation inherent in liquid-like materials, is identified. Using neutron spectroscopy and molecular dynamics (MD) simulations, it is demonstrated that in tetrahedrite, an established thermoelectric material with a remarkably low thermal conductivity, copper ions, although mobile above 200 K, are predominantly confined to cages within the crystal structure. Hence the undesirable migration of cations to the cathode can be avoided. These findings unveil a new approach for the design of materials with ultralow thermal conductivity, by exploring systems in which incipient ionic conduction may be present.
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Affiliation(s)
- Shriparna Mukherjee
- Department of Chemistry, University of Reading, Whiteknights, Reading, RG6 6DX, UK
| | - David J Voneshen
- ISIS Pulsed Neutron and Muon Source, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, UK
- Department of Physics, Royal Holloway University of London, Egham, TW20 0EX, UK
| | - Andrew Duff
- Scientific Computing Department, STFC Daresbury Laboratory, Warrington, WA4 4AD, UK
| | - Pooja Goddard
- Department of Chemistry, Loughborough University, Loughborough, LE11 3TU, UK
| | - Anthony V Powell
- Department of Chemistry, University of Reading, Whiteknights, Reading, RG6 6DX, UK
| | - Paz Vaqueiro
- Department of Chemistry, University of Reading, Whiteknights, Reading, RG6 6DX, UK
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6
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Zagaria F, Rosotti GP, Alexander RD, Clarke CJ. Dust dynamics in planet-forming discs in binary systems. Eur Phys J Plus 2023; 138:25. [PMID: 36686498 PMCID: PMC9842575 DOI: 10.1140/epjp/s13360-022-03616-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
In multiple stellar systems, interactions among the companion stars and their discs affect planet formation. In the circumstellar case, tidal truncation makes protoplanetary discs smaller, fainter and less long-lived than those evolving in isolation, thereby reducing the amount of material (gas and dust) available to assemble planetary embryos. On the contrary, in the circumbinary case the reduced accretion can increase the disc lifetime, with beneficial effects on planet formation. In this chapter we review the main observational results on discs in multiple stellar systems and discuss their possible explanations, focusing on recent numerical simulations, mainly dealing with dust dynamics and disc evolution. Finally, some open issues and future research directions are examined.
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Affiliation(s)
- F. Zagaria
- Institute of Astronomy, University of Cambridge, Madingley Rd, Cambridge, CB3 0HA UK
| | - G. P. Rosotti
- Leiden Observatory, Leiden University, Niels Bohrweg 2, PO Box 9513, 2300 RA Leiden, The Netherlands
- School of Physics and Astronomy, University of Leicester, University Rd, Leicester, LE1 7RH UK
- Dipartimento di Fisica, Università degli Studi di Milano, Via Giovanni Celoria 16, 20133 Milano, Italy
| | - R. D. Alexander
- School of Physics and Astronomy, University of Leicester, University Rd, Leicester, LE1 7RH UK
| | - C. J. Clarke
- Institute of Astronomy, University of Cambridge, Madingley Rd, Cambridge, CB3 0HA UK
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7
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Achúcarro A, Avgoustidis A, López-Eiguren A, Martins CJAP, Urrestilla J. Cosmological evolution of semilocal string networks. Philos Trans A Math Phys Eng Sci 2019; 377:20190004. [PMID: 31707960 PMCID: PMC6863475 DOI: 10.1098/rsta.2019.0004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/02/2019] [Indexed: 06/10/2023]
Abstract
Semilocal strings-a particular limit of electroweak strings-are an interesting example of a stable non-topological defect whose properties resemble those of their topological cousins, the Abrikosov-Nielsen-Olesen vortices. There is, however, one important difference: a network of semilocal strings will contain segments. These are 'dumbbells' whose ends behave almost like global monopoles that are strongly attracted to one another. While closed loops of string will eventually shrink and disappear, the segments can either shrink or grow, and a cosmological network of semilocal strings will reach a scaling regime. We discuss attempts to find a 'thermodynamic' description of the cosmological evolution and scaling of a network of semilocal strings, by analogy with well-known descriptions for cosmic strings and for monopoles. We propose a model for the time evolution of an overall length scale and typical velocity for the network as well as for its segments, and some supporting (preliminary) numerical evidence. This article is part of a discussion meeting issue 'Topological avatars of new physics'.
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Affiliation(s)
- A. Achúcarro
- Institute Lorentz of Theoretical Physics, University of Leiden, 2333CA Leiden, The Netherlands
- Department of Theoretical Physics, University of the Basque Country UPV-EHU, 48040 Bilbao, Spain
| | - A. Avgoustidis
- School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - A. López-Eiguren
- Department of Physics and Helsinki Institute of Physics, University of Helsinki, PL 64, Finland, 00014, Finland
| | - C. J. A. P. Martins
- Centro de Astrofísica da Universidade do Porto, CAUP, Rua das Estrelas, Porto, 4150-762, Portugal
- Instituto de Astrofísica e Ciências do Espaço, CAUP, Rua das Estrelas, Porto, 4150-762, Portugal
| | - J. Urrestilla
- Department of Theoretical Physics, University of the Basque Country UPV-EHU, 48040 Bilbao, Spain
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Abstract
The topological structure of field theory often makes inevitable the existence of stable and unstable localized solutions of the field equations. These are minima and saddle points of the energy. Saddle point solutions occurring this way are known as sphalerons, and the most interesting one is in the electroweak theory of coupled W, Z and Higgs bosons. The topological ideas underpinning sphalerons are reviewed here. This article is part of a discussion meeting issue 'Topological avatars of new physics'.
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Affiliation(s)
- N. S. Manton
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, UK
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9
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Melin H, Fletcher LN, Stallard TS, Miller S, Trafton LM, Moore L, O'Donoghue J, Vervack RJ, Dello Russo N, Lamy L, Tao C, Chowdhury MN. The H 3+ ionosphere of Uranus: decades-long cooling and local-time morphology. Philos Trans A Math Phys Eng Sci 2019; 377:20180408. [PMID: 31378181 PMCID: PMC6710888 DOI: 10.1098/rsta.2018.0408] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/07/2019] [Indexed: 05/04/2023]
Abstract
The upper atmosphere of Uranus has been observed to be slowly cooling between 1993 and 2011. New analysis of near-infrared observations of emission from H3+ obtained between 2012 and 2018 reveals that this cooling trend has continued, showing that the upper atmosphere has cooled for 27 years, longer than the length of a nominal season of 21 years. The new observations have offered greater spatial resolution and higher sensitivity than previous ones, enabling the characterization of the H3+ intensity as a function of local time. These profiles peak between 13 and 15 h local time, later than models suggest. The NASA Infrared Telescope Facility iSHELL instrument also provides the detection of a bright H3+ signal on 16 October 2016, rotating into view from the dawn sector. This feature is consistent with an auroral signal, but is the only of its kind present in this comprehensive dataset. This article is part of a discussion meeting issue 'Advances in hydrogen molecular ions: H3+, H5+ and beyond'.
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Affiliation(s)
- Henrik Melin
- Department of Physics & Astronomy, University of Leicester, Leicester, UK
| | - L. N. Fletcher
- Department of Physics & Astronomy, University of Leicester, Leicester, UK
| | - T. S. Stallard
- Department of Physics & Astronomy, University of Leicester, Leicester, UK
| | - S. Miller
- Department of Physics & Astronomy, University College London, London, UK
| | - L. M. Trafton
- Department of Astronomy, University of Texas, Austin, TX, USA
| | - L. Moore
- Center for Space Physics, Boston University, Boston, MA, USA
| | | | - R. J. Vervack
- Johns Hopkins Applied Physics Laboratory, Laurel, MD, USA
| | - N. Dello Russo
- Johns Hopkins Applied Physics Laboratory, Laurel, MD, USA
| | - L. Lamy
- LESIA, Observatoire de Paris, PSL, CNRS, Sorbonne Université, Meudon, France
| | - C. Tao
- National Institute of Information and Communications Technology, Tokyo, Japan
| | - M. N. Chowdhury
- Department of Physics & Astronomy, University of Leicester, Leicester, UK
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10
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Moore L, Melin H, O'Donoghue J, Stallard TS, Moses JI, Galand M, Miller S, Schmidt CA. Modelling H 3+ in planetary atmospheres: effects of vertical gradients on observed quantities. Philos Trans A Math Phys Eng Sci 2019; 377:20190067. [PMID: 31378180 PMCID: PMC6710898 DOI: 10.1098/rsta.2019.0067] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/07/2019] [Indexed: 05/20/2023]
Abstract
Since its detection in the aurorae of Jupiter approximately 30 years ago, the H3+ ion has served as an invaluable probe of giant planet upper atmospheres. However, the vast majority of monitoring of planetary H3+ radiation has followed from observations that rely on deriving parameters from column-integrated paths through the emitting layer. Here, we investigate the effects of density and temperature gradients along such paths on the measured H3+ spectrum and its resulting interpretation. In a non-isothermal atmosphere, H3+ column densities retrieved from such observations are found to represent a lower limit, reduced by 20% or more from the true atmospheric value. Global simulations of Uranus' ionosphere reveal that measured H3+ temperature variations are often attributable to well-understood solar zenith angle effects rather than indications of real atmospheric variability. Finally, based on these insights, a preliminary method of deriving vertical temperature structure is demonstrated at Jupiter using model reproductions of electron density and H3+ measurements. The sheer diversity and uncertainty of conditions in planetary atmospheres prohibits this work from providing blanket quantitative correction factors; nonetheless, we illustrate a few simple ways in which the already formidable utility of H3+ observations in understanding planetary atmospheres can be enhanced. This article is part of a discussion meeting issue 'Advances in hydrogen molecular ions: H3+, H5+ and beyond'.
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Affiliation(s)
- L. Moore
- Boston University, Boston, MA, USA
| | - H. Melin
- University of Leicester, Leicester, UK
| | - J. O'Donoghue
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | | | | | - M. Galand
- Department of Physics, Imperial College London, London, UK
| | - S. Miller
- University College London, London, UK
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11
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Archontis V, Syntelis P. The emergence of magnetic flux and its role on the onset of solar dynamic events. Philos Trans A Math Phys Eng Sci 2019; 377:20180387. [PMID: 31079584 PMCID: PMC6527958 DOI: 10.1098/rsta.2018.0387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/14/2019] [Indexed: 05/08/2023]
Abstract
A plethora of solar dynamic events, such as the formation of active regions, the emission of jets and the occurrence of eruptions is often associated with the emergence of magnetic flux from the interior of the Sun to the surface and above. Here, we present a short review on the onset, driving and/or triggering of such events by magnetic flux emergence. We briefly describe some key observational examples, theoretical aspects and numerical simulations, towards revealing the mechanisms that govern solar dynamics and activity related to flux emergence. We show that the combination of important physical processes like shearing and reconnection of magnetic fieldlines in emerging flux regions or at their vicinity can power some of the most dynamic phenomena in the Sun on various temporal and spatial scales. Based on previous and recent observational and numerical studies, we highlight that, in most cases, none of these processes alone can drive and also trigger explosive phenomena releasing considerable amount of energy towards the outer solar atmosphere and space, such as flares, jets and large-scale eruptions (e.g. coronal mass ejections). In addition, one has to take into account the physical properties of the emerging field (e.g. strength, amount of flux, relative orientation to neighbouring and pre-existing magnetic fields, etc.) in order to better understand the exact role of magnetic flux emergence on the onset of solar dynamic events. This article is part of the theme issue 'Solar eruptions and their space weather impact'.
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Affiliation(s)
- V. Archontis
- Mathematics Institute, St Andrews University, St Andrews KY16 9SS, UK
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12
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Perico C, Sparkes I. Plant organelle dynamics: cytoskeletal control and membrane contact sites. New Phytol 2018; 220:381-394. [PMID: 30078196 DOI: 10.1111/nph.15365] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 06/10/2018] [Indexed: 05/22/2023]
Abstract
Contents Summary 381 I. Introduction 381 II. Basic movement characteristics 382 III. Actin and associated motors, myosins, play a primary role in plant organelle movement and positioning 382 IV. Mechanisms of myosin recruitment: a tightly regulated system? 384 V. Microtubules, associated motors and interplay with actin 386 VI. Role of organelle interactions: tales of tethers 387 VII. Summary model to describe organelle movement in higher plants 390 VIII. Why is organelle movement important? 390 IX. Conclusions and future perspectives 391 Acknowledgements 391 References 391 SUMMARY: Organelle movement and positioning are correlated with plant growth and development. Movement characteristics are seemingly erratic yet respond to external stimuli including pathogens and light. Given these clear correlations, we still do not understand the specific roles that movement plays in these processes. There are few exceptions including organelle inheritance during cell division and photorelocation of chloroplasts to prevent photodamage. The molecular and biophysical components that drive movement can be broken down into cytoskeletal components, motor proteins and tethers, which allow organelles to physically interact with one another. Our understanding of these components and concepts has exploded over the past decade, with recent technological advances allowing an even more in-depth profiling. Here, we provide an overview of the cytoskeletal and tethering components and discuss the mechanisms behind organelle movement in higher plants.
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Affiliation(s)
- Chiara Perico
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - Imogen Sparkes
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK
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13
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van Veggel AMA. Quasi-monolithic mirror suspensions in ground-based gravitational-wave detectors: an overview and look to the future. Philos Trans A Math Phys Eng Sci 2018; 376:rsta.2017.0281. [PMID: 29661973 PMCID: PMC5915646 DOI: 10.1098/rsta.2017.0281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/08/2018] [Indexed: 05/14/2023]
Abstract
At the commencement of a new era in astrophysics, with added information from direct detections of gravitational-wave (GW) signals, this paper is a testament to the quasi-monolithic suspensions of the test masses of the GW detectors that have enabled the opening of a new window on the universe. The quasi-monolithic suspensions are the final stages in the seismic isolation of the test masses in GW detectors, and are specifically designed to introduce as little thermal noise as possible. The history of the development of the fused-silica quasi-monolithic suspensions, which have been so essential for the first detections of GWs, is outlined and a glimpse into the status of research towards quasi-monolithic suspensions made of sapphire and silicon is given.This article is part of a discussion meeting issue 'The promises of gravitational-wave astronomy'.
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14
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Ho WCG. Gravitational waves from neutron stars and asteroseismology. Philos Trans A Math Phys Eng Sci 2018; 376:rsta.2017.0285. [PMID: 29661975 PMCID: PMC5915648 DOI: 10.1098/rsta.2017.0285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/08/2018] [Indexed: 06/08/2023]
Abstract
Neutron stars are born in the supernova explosion of massive stars. Neutron stars rotate as stably as atomic clocks and possess densities exceeding that of atomic nuclei and magnetic fields millions to billions of times stronger than those created in laboratories on the Earth. The physical properties of neutron stars are determined by many areas of fundamental physics, and detection of gravitational waves can provide invaluable insights into our understanding of these areas. Here, we describe some of the physics and astrophysics of neutron stars and how traditional electromagnetic wave observations provide clues to the sorts of gravitational waves we expect from these stars. We pay particular attention to neutron star fluid oscillations, examining their impact on electromagnetic and gravitational wave observations when these stars are in a wide binary or isolated system, then during binary inspiral right before merger, and finally at times soon after merger.This article is part of a discussion meeting issue 'The promises of gravitational-wave astronomy'.
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Affiliation(s)
- Wynn C G Ho
- Mathematical Sciences, Physics and Astronomy, and STAG Research Centre, University of Southampton, Southampton SO17 1BJ, UK
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15
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Robertson SN, Campsie P, Childs PG, Madsen F, Donnelly H, Henriquez FL, Mackay WG, Salmerón-Sánchez M, Tsimbouri MP, Williams C, Dalby MJ, Reid S. Control of cell behaviour through nanovibrational stimulation: nanokicking. Philos Trans A Math Phys Eng Sci 2018; 376:20170290. [PMID: 29661978 PMCID: PMC5915650 DOI: 10.1098/rsta.2017.0290] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/07/2018] [Indexed: 05/05/2023]
Abstract
Mechanical signals are ubiquitous in our everyday life and the process of converting these mechanical signals into a biological signalling response is known as mechanotransduction. Our understanding of mechanotransduction, and its contribution to vital cellular responses, is a rapidly expanding field of research involving complex processes that are still not clearly understood. The use of mechanical vibration as a stimulus of mechanotransduction, including variation of frequency and amplitude, allows an alternative method to control specific cell behaviour without chemical stimulation (e.g. growth factors). Chemical-independent control of cell behaviour could be highly advantageous for fields including drug discovery and clinical tissue engineering. In this review, a novel technique is described based on nanoscale sinusoidal vibration. Using finite-element analysis in conjunction with laser interferometry, techniques that are used within the field of gravitational wave detection, optimization of apparatus design and calibration of vibration application have been performed. We further discuss the application of nanovibrational stimulation, or 'nanokicking', to eukaryotic and prokaryotic cells including the differentiation of mesenchymal stem cells towards an osteoblast cell lineage. Mechanotransductive mechanisms are discussed including mediation through the Rho-A kinase signalling pathway. Optimization of this technique was first performed in two-dimensional culture using a simple vibration platform with an optimal frequency and amplitude of 1 kHz and 22 nm. A novel bioreactor was developed to scale up cell production, with recent research demonstrating that mesenchymal stem cell differentiation can be efficiently triggered in soft gel constructs. This important step provides first evidence that clinically relevant (three-dimensional) volumes of osteoblasts can be produced for the purpose of bone grafting, without complex scaffolds and/or chemical induction. Initial findings have shown that nanovibrational stimulation can also reduce biofilm formation in a number of clinically relevant bacteria. This demonstrates additional utility of the bioreactor to investigate mechanotransduction in other fields of research.This article is part of a discussion meeting issue 'The promises of gravitational-wave astronomy'.
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Affiliation(s)
- Shaun N Robertson
- SUPA, Department of Biomedical Engineering, University of Strathclyde, Graham Hills, 50 George Street, Glasgow G1 1QE, UK
| | - Paul Campsie
- SUPA, Department of Biomedical Engineering, University of Strathclyde, Graham Hills, 50 George Street, Glasgow G1 1QE, UK
| | - Peter G Childs
- Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow G12 8QQ, UK
| | - Fiona Madsen
- Institute of Healthcare, Policy and Practice, School of Health, Nursing and Midwifery, University of the West of Scotland, Paisley PA1 2BE, UK
| | - Hannah Donnelly
- Centre for Cell Engineering, Institute for Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Fiona L Henriquez
- Institute of Biomedical and Environmental Health Research, School of Science and Sport, University of the West of Scotland, Paisley PA1 2BE, UK
| | - William G Mackay
- Institute of Healthcare, Policy and Practice, School of Health, Nursing and Midwifery, University of the West of Scotland, Paisley PA1 2BE, UK
| | - Manuel Salmerón-Sánchez
- Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow G12 8QQ, UK
| | - Monica P Tsimbouri
- Centre for Cell Engineering, Institute for Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Craig Williams
- Institute of Healthcare, Policy and Practice, School of Health, Nursing and Midwifery, University of the West of Scotland, Paisley PA1 2BE, UK
| | - Matthew J Dalby
- Centre for Cell Engineering, Institute for Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Stuart Reid
- SUPA, Department of Biomedical Engineering, University of Strathclyde, Graham Hills, 50 George Street, Glasgow G1 1QE, UK
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16
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Middlemiss RP, Bramsiepe SG, Douglas R, Hild S, Hough J, Paul DJ, Samarelli A, Rowan S, Hammond GD. Microelectromechanical system gravimeters as a new tool for gravity imaging. Philos Trans A Math Phys Eng Sci 2018; 376:rsta.2017.0291. [PMID: 29661979 PMCID: PMC5915651 DOI: 10.1098/rsta.2017.0291] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/22/2017] [Indexed: 06/08/2023]
Abstract
A microelectromechanical system (MEMS) gravimeter has been manufactured with a sensitivity of 40 ppb in an integration time of 1 s. This sensor has been used to measure the Earth tides: the elastic deformation of the globe due to tidal forces. No such measurement has been demonstrated before now with a MEMS gravimeter. Since this measurement, the gravimeter has been miniaturized and tested in the field. Measurements of the free-air and Bouguer effects have been demonstrated by monitoring the change in gravitational acceleration measured while going up and down a lift shaft of 20.7 m, and up and down a local hill of 275 m. These tests demonstrate that the device has the potential to be a useful field-portable instrument. The development of an even smaller device is underway, with a total package size similar to that of a smartphone.This article is part of a discussion meeting issue 'The promises of gravitational-wave astronomy'.
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Affiliation(s)
- Richard P Middlemiss
- SUPA School of Physics and Astronomy, University of Glasgow, Kelvin Building, University Avenue, Glasgow G12 8SU, UK
| | - Steven G Bramsiepe
- SUPA School of Physics and Astronomy, University of Glasgow, Kelvin Building, University Avenue, Glasgow G12 8SU, UK
| | - Rebecca Douglas
- SUPA School of Physics and Astronomy, University of Glasgow, Kelvin Building, University Avenue, Glasgow G12 8SU, UK
| | - Stefan Hild
- SUPA School of Physics and Astronomy, University of Glasgow, Kelvin Building, University Avenue, Glasgow G12 8SU, UK
| | - James Hough
- SUPA School of Physics and Astronomy, University of Glasgow, Kelvin Building, University Avenue, Glasgow G12 8SU, UK
| | - Douglas J Paul
- School of Engineering, University of Glasgow, Rankine Building, Oakfield Avenue, Glasgow G12 8LT, UK
| | - Antonio Samarelli
- SUPA School of Physics and Astronomy, University of Glasgow, Kelvin Building, University Avenue, Glasgow G12 8SU, UK
| | - Sheila Rowan
- SUPA School of Physics and Astronomy, University of Glasgow, Kelvin Building, University Avenue, Glasgow G12 8SU, UK
| | - Giles D Hammond
- SUPA School of Physics and Astronomy, University of Glasgow, Kelvin Building, University Avenue, Glasgow G12 8SU, UK
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17
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Abstract
Gravitational waves are detected by measuring length changes between mirrors in the arms of kilometre-long Michelson interferometers. Brownian thermal noise arising from thermal vibrations of the mirrors can limit the sensitivity to distance changes between the mirrors, and, therefore, the ability to measure gravitational-wave signals. Thermal noise arising from the highly reflective mirror coatings will limit the sensitivity both of current detectors (when they reach design performance) and of planned future detectors. Therefore, the development of coatings with low thermal noise, which at the same time meet strict optical requirements, is of great importance. This article gives an overview of the current status of coatings and of the different approaches for coating improvement.This article is part of a discussion meeting issue 'The promises of gravitational-wave astronomy'.
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Affiliation(s)
- J Steinlechner
- Institut für Laserphysik and Zentrum für Optische Quantentechnologien, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK
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18
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Abstract
The discovery of the Higgs boson in 2012 and other results from the Large Hadron Collider have confirmed the standard model of particle physics as the correct theory of elementary particles and their interactions up to energies of several TeV. Remarkably, the theory may even remain valid all the way to the Planck scale of quantum gravity, and therefore it provides a solid theoretical basis for describing the early Universe. Furthermore, the Higgs field itself has unique properties that may have allowed it to play a central role in the evolution of the Universe, from inflation to cosmological phase transitions and the origin of both baryonic and dark matter, and possibly to determine its ultimate fate through the electroweak vacuum instability. These connections between particle physics and cosmology have given rise to a new and growing field of Higgs cosmology, which promises to shed new light on some of the most puzzling questions about the Universe as new data from particle physics experiments and cosmological observations become available.This article is part of the Theo Murphy meeting issue 'Higgs cosmology'.
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Affiliation(s)
- Arttu Rajantie
- Department of Physics, Imperial College London, London SW7 2AZ, UK
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19
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Russell SS, Ballentine CJ, Grady MM. The origin, history and role of water in the evolution of the inner Solar System. Philos Trans A Math Phys Eng Sci 2017; 375:rsta.2017.0108. [PMID: 28416731 PMCID: PMC5394259 DOI: 10.1098/rsta.2017.0108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/21/2017] [Indexed: 05/06/2023]
Affiliation(s)
- Sara S Russell
- Department of Earth Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK
- Open University, Walton Hall, Milton Keynes MK7 6AA, UK
| | | | - Monica M Grady
- Department of Earth Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK
- Open University, Walton Hall, Milton Keynes MK7 6AA, UK
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20
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Bagnaschi E, Borsato M, Sakurai K, Buchmueller O, Cavanaugh R, Chobanova V, Citron M, Costa JC, De Roeck A, Dolan MJ, Ellis JR, Flächer H, Heinemeyer S, Isidori G, Lucio M, Luo F, Santos DM, Olive KA, Richards A, Weiglein G. Likelihood analysis of the minimal AMSB model. Eur Phys J C Part Fields 2017; 77:268. [PMID: 28515671 PMCID: PMC5409153 DOI: 10.1140/epjc/s10052-017-4810-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 04/05/2017] [Indexed: 06/07/2023]
Abstract
We perform a likelihood analysis of the minimal anomaly-mediated supersymmetry-breaking (mAMSB) model using constraints from cosmology and accelerator experiments. We find that either a wino-like or a Higgsino-like neutralino LSP, [Formula: see text], may provide the cold dark matter (DM), both with similar likelihoods. The upper limit on the DM density from Planck and other experiments enforces [Formula: see text] after the inclusion of Sommerfeld enhancement in its annihilations. If most of the cold DM density is provided by the [Formula: see text], the measured value of the Higgs mass favours a limited range of [Formula: see text] (and also for [Formula: see text] if [Formula: see text]) but the scalar mass [Formula: see text] is poorly constrained. In the wino-LSP case, [Formula: see text] is constrained to about [Formula: see text] and [Formula: see text] to [Formula: see text], whereas in the Higgsino-LSP case [Formula: see text] has just a lower limit [Formula: see text] ([Formula: see text]) and [Formula: see text] is constrained to [Formula: see text] in the [Formula: see text] ([Formula: see text]) scenario. In neither case can the anomalous magnetic moment of the muon, [Formula: see text], be improved significantly relative to its Standard Model (SM) value, nor do flavour measurements constrain the model significantly, and there are poor prospects for discovering supersymmetric particles at the LHC, though there are some prospects for direct DM detection. On the other hand, if the [Formula: see text] contributes only a fraction of the cold DM density, future LHC [Formula: see text]-based searches for gluinos, squarks and heavier chargino and neutralino states as well as disappearing track searches in the wino-like LSP region will be relevant, and interference effects enable [Formula: see text] to agree with the data better than in the SM in the case of wino-like DM with [Formula: see text].
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Affiliation(s)
| | - M. Borsato
- Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Spain
| | - K. Sakurai
- Science Laboratories, Department of Physics, Institute for Particle Physics Phenomenology, University of Durham, South Road, Durham, DH1 3LE UK
- Faculty of Physics, Institute of Theoretical Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - O. Buchmueller
- High Energy Physics Group, Blackett Laboratory, Imperial College, Prince Consort Road, London, SW7 2AZ UK
| | - R. Cavanaugh
- Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 USA
- Physics Department, University of Illinois at Chicago, Chicago, IL 60607-7059 USA
| | - V. Chobanova
- Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Spain
| | - M. Citron
- High Energy Physics Group, Blackett Laboratory, Imperial College, Prince Consort Road, London, SW7 2AZ UK
| | - J. C. Costa
- High Energy Physics Group, Blackett Laboratory, Imperial College, Prince Consort Road, London, SW7 2AZ UK
| | - A. De Roeck
- Experimental Physics Department, CERN, 1211 Geneva 23, Switzerland
- Antwerp University, 2610 Wilrijk, Belgium
| | - M. J. Dolan
- ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, University of Melbourne, Melbourne, 3010 Australia
| | - J. R. Ellis
- Theoretical Particle Physics and Cosmology Group, Department of Physics, King’s College London, London, WC2R 2LS UK
- Theoretical Physics Department, CERN, 1211 Geneva 23, Switzerland
| | - H. Flächer
- H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL UK
| | - S. Heinemeyer
- Campus of International Excellence UAM+CSIC, Cantoblanco, 28049 Madrid, Spain
- Instituto de Física Teórica UAM-CSIC, C/ Nicolas Cabrera 13-15, 28049 Madrid, Spain
- Instituto de Física de Cantabria (CSIC-UC), Avda. de Los Castros s/n, 39005 Cantabria, Spain
| | - G. Isidori
- Physik-Institut, Universität Zürich, 8057 Zurich, Switzerland
| | - M. Lucio
- Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Spain
| | - F. Luo
- Kavli IPMU (WPI), UTIAS, The University of Tokyo, Kashiwa, Chiba 277-8583 Japan
| | - D. Martínez Santos
- Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Spain
| | - K. A. Olive
- William I. Fine Theoretical Physics Institute, School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 USA
| | - A. Richards
- High Energy Physics Group, Blackett Laboratory, Imperial College, Prince Consort Road, London, SW7 2AZ UK
| | - G. Weiglein
- DESY, Notkestraße 85, 22607 Hamburg, Germany
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21
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Scott CJ, Bradford J, Bell SA, Wilkinson J, Barnard L, Smith D, Tudor S. Using the ionospheric response to the solar eclipse on 20 March 2015 to detect spatial structure in the solar corona. Philos Trans A Math Phys Eng Sci 2016; 374:rsta.2015.0216. [PMID: 27550766 PMCID: PMC5004048 DOI: 10.1098/rsta.2015.0216] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/12/2016] [Indexed: 06/01/2023]
Abstract
The total solar eclipse that occurred over the Arctic region on 20 March 2015 was seen as a partial eclipse over much of Europe. Observations of this eclipse were used to investigate the high time resolution (1 min) decay and recovery of the Earth's ionospheric E-region above the ionospheric monitoring station in Chilton, UK. At the altitude of this region (100 km), the maximum phase of the eclipse was 88.88% obscuration of the photosphere occurring at 9:29:41.5 UT. In comparison, the ionospheric response revealed a maximum obscuration of 66% (leaving a fraction, Φ, of uneclipsed radiation of 34±4%) occurring at 9:29 UT. The eclipse was re-created using data from the Solar Dynamics Observatory to estimate the fraction of radiation incident on the Earth's atmosphere throughout the eclipse from nine different emission wavelengths in the extreme ultraviolet (EUV) and X-ray spectrum. These emissions, having varying spatial distributions, were each obscured differently during the eclipse. Those wavelengths associated with coronal emissions (94, 211 and 335 Å) most closely reproduced the time varying fraction of unobscured radiation observed in the ionosphere. These results could enable historic ionospheric eclipse measurements to be interpreted in terms of the distribution of EUV and X-ray emissions on the solar disc.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'.
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Affiliation(s)
- C J Scott
- Department of Meteorology, University of Reading, Earley Gate, PO Box 243, Reading RG6 6BB, UK
| | - J Bradford
- RAL Space, Rutherford Appleton Laboratory, Chilton, Oxfordshire OX11 0QX, UK
| | - S A Bell
- H.M. Nautical Almanac Office, UK Hydrographic Office, Admiralty Way, Taunton TA1 2DN, UK
| | - J Wilkinson
- Zooniverse, c/o Astrophysics Department, University of Oxford, Oxford OX1 3RH, UK
| | - L Barnard
- Department of Meteorology, University of Reading, Earley Gate, PO Box 243, Reading RG6 6BB, UK
| | - D Smith
- North Wales Astronomy Society, Colwyn Bay, UK
| | - S Tudor
- North Wales Astronomy Society, Colwyn Bay, UK
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