Thu 14 Mar 11:30: New understanding of liquid thermodynamics, viscosity and its lower bounds
Theories of gases and solids are well developed and date back 100-150 years ago. In contrast, understanding most basic thermodynamic properties (eg energy and heat capacity) of the third state of matter – the liquid state – turned out to be a long-standing problem in physics [1]. Landau&Lifshitz textbook states that no general formulas can be derived for liquid thermodynamic functions because the interactions are both strong and system-specific. Phrased aptly by Pitaevskii, liquids have no small parameter.
Recent theoretical results open a new way to understand liquid thermodynamics on the basis of collective excitations (phonons) as is done in the solid state theory. Differently from solids, the number of phonons is variable in liquids and decreases with temperature [1,2]. This effect is quantified in a phonon theory of liquid thermodynamics and explains the universal decrease of liquid constant-volume specific heat with temperature. One implication of this theory is that liquids can now be consistently understood on par with solids and are no longer “Cinderella of Physics” as believed until recently. I will also explain how this picture extends above the critical point where the Frenkel line separates two physically distinct states on the supercritical phase diagram [3].
I will subsequently describe how this picture leads to the theory of minimal quantum viscosity in terms of fundamental physical constants including the Planck constant [4]. This answers the long-standing question discussed by Purcell and Weisskopf of why viscosity never drops below a certain value [5]. This also means that water and life and well attuned to the degree of quantumness of the physical world [5]. This, in turn, implies, that we can better understand fundamental physical constants from biological and life processes [6].
1. K Trachenko, Theory of liquids: from excitation to thermodynamics (Cambridge University Press, 2023); K Trachenko and V Brazhkin, Reports on Progress in Physics 2016 2. M Baggioli, M Vasin, V Brazhkin and K Trachenko, Physics Reports 2020 3. C Cockrell, V Brazhkin and K Trachenko, Physics Reports 2021 4. K Trachenko and V Brazhkin, Minimal quantum viscosity from fundamental physical constants, Science Advances 2020; K Trachenko, Properties of condensed matter from fundamental physical constants, Advances in Physics (2023) 5. K Trachenko and V Brazhkin, Physics Today 74, 12, 66 (2021) 6. K Trachenko, Constraints on fundamental constants from bio-friendly viscosity and diffusion, Science Advances 2023
- Speaker: Kostya Trachenko ( Queen Mary, University of London)
- Thursday 14 March 2024, 11:30-12:30
- Venue: Open Plan Area, Institute for Energy and Environmental Flows, Madingley Rise CB3 0EZ.
- Series: Institute for Energy and Environmental Flows (IEEF); organiser: Catherine Pearson.
Wed 06 Mar 17:30: 50,000 years of turnover and extinction in high-latitude megafauna communities Building doors are card operated, so latecomers may not be able to access the venue.
Abstract not available
Building doors are card operated, so latecomers may not be able to access the venue.
- Speaker: Alistair Monteath, British Antarctic Survey
- Wednesday 06 March 2024, 17:30-19:00
- Venue: Small Lecture Theatre, Department of Geography, Downing Site.
- Series: Quaternary Discussion Group (QDG); organiser: Jinheum Park.
Wed 21 Feb 17:30: Microplastics from geologists' perspective Building doors are card operated, so latecomers may not be able to access the venue.
Abstract not available
Building doors are card operated, so latecomers may not be able to access the venue.
- Speaker: Saija Saarni, University of Turku
- Wednesday 21 February 2024, 17:30-19:00
- Venue: Small Lecture Theatre, Department of Geography, Downing Site.
- Series: Quaternary Discussion Group (QDG); organiser: Jinheum Park.
Thu 14 Mar 11:30: New understanding of liquid thermodynamics, viscosity and its lower bounds
Theories of gases and solids are well developed and date back 100-150 years ago. In contrast, understanding most basic thermodynamic properties (eg energy and heat capacity) of the third state of matter – the liquid state – turned out to be a long-standing problem in physics [1]. Landau&Lifshitz textbook states that no general formulas can be derived for liquid thermodynamic functions because the interactions are both strong and system-specific. Phrased aptly by Pitaevskii, liquids have no small parameter.
Recent theoretical results open a new way to understand liquid thermodynamics on the basis of collective excitations (phonons) as is done in the solid state theory. Differently from solids, the number of phonons is variable in liquids and decreases with temperature [1,2]. This effect is quantified in a phonon theory of liquid thermodynamics and explains the universal decrease of liquid constant-volume specific heat with temperature. One implication of this theory is that liquids can now be consistently understood on par with solids and are no longer “Cinderella of Physics” as believed until recently. I will also explain how this picture extends above the critical point where the Frenkel line separates two physically distinct states on the supercritical phase diagram [3].
I will subsequently describe how this picture leads to the theory of minimal quantum viscosity in terms of fundamental physical constants including the Planck constant [4]. This answers the long-standing question discussed by Purcell and Weisskopf of why viscosity never drops below a certain value [5]. This also means that water and life and well attuned to the degree of quantumness of the physical world [5]. This, in turn, implies, that we can better understand fundamental physical constants from biological and life processes [6].
1. K Trachenko, Theory of liquids: from excitation to thermodynamics (Cambridge University Press, 2023); K Trachenko and V Brazhkin, Reports on Progress in Physics 2016 2. M Baggioli, M Vasin, V Brazhkin and K Trachenko, Physics Reports 2020 3. C Cockrell, V Brazhkin and K Trachenko, Physics Reports 2021 4. K Trachenko and V Brazhkin, Minimal quantum viscosity from fundamental physical constants, Science Advances 2020; K Trachenko, Properties of condensed matter from fundamental physical constants, Advances in Physics (2023) 5. K Trachenko and V Brazhkin, Physics Today 74, 12, 66 (2021) 6. K Trachenko, Constraints on fundamental constants from bio-friendly viscosity and diffusion, Science Advances 2023
- Speaker: Kostya Trachenko ( Queen Mary, University of London)
- Thursday 14 March 2024, 11:30-12:30
- Venue: Open Plan Area, Institute for Energy and Environmental Flows, Madingley Rise CB3 0EZ.
- Series: Institute for Energy and Environmental Flows (IEEF); organiser: Catherine Pearson.
Mon 12 Feb 18:00: Understanding the circumstances surrounding Late Pleistocene Megafaunal Extinctions in Australia
The timing, drivers, and ecological consequences of Late Pleistocene megafaunal extinctions remain subjects of global debate, constrained by limited data spanning this period. This study employs a novel combination of proxy-based palaeoecological and a functional palaeoecological approach to identify the most precise timing of megafaunal extinction in Australia to date, as well as the likely occurrences surrounding extinction and the floristic response to extinction. This talk will explore the topic and results within the context of the global debate.
- Speaker: Matthew Adeleye - Department of Geography
- Monday 12 February 2024, 18:00-19:00
- Venue: Harker 1, Department of Earth Sciences, Downing Street.
- Series: Sedgwick Club talks; organiser: Lucas Measures.
Wed 07 Feb 17:30: The West Antarctic Ice Sheet and sea level in the last interglacial Building doors are card operated, so latecomers may not be able to access the venue.
There is intense interest in the future stability of the West Antarctic Ice Sheet (WAIS). Models range widely in their predictions and in the physics they include. We can constrain possible outcomes by observing what happened to ice sheets at previous times when the polar regions were warmer than present. The last interglacial (LIG) is a particularly important time because both Greenland and Antarctic temperature were higher than present and so was sea level.
Within the WACSWAIN (WArm Climate Stability of the West Antarctic ice sheet in the last INterglacial) project, in 2019 we retrieved a 651 metre ice core to the bed of Skytrain Ice Rise. This ice rise is adjacent to the Ronne Ice Shelf and the WAIS , and therefore sensitive to their extent. The ice core has been processed and analysed continuously for a range of analytes, and we can show that ice from the LIG is present.
I will start by describing the project, fieldwork and analyses. Eventually, I will show what happened to the ice around Skytrain Ice Rise in the LIG , and discuss how this fits with other evidence about LIG sea level.
Building doors are card operated, so latecomers may not be able to access the venue.
- Speaker: Eric Wolff, Department of Earth Sciences, and the WACSWAIN team
- Wednesday 07 February 2024, 17:30-19:00
- Venue: Harker 2, Department of Earth Sciences, Downing Street.
- Series: Quaternary Discussion Group (QDG); organiser: Jinheum Park.
Thu 07 Mar 11:30: Novel processing and 3D correlative imaging of electrodes for batteries
Rechargeable batteries can contribute to powering electric transportation and storing electrical energy generated from intermittent renewable sources. There are increasing demands for improving the rate capability and energy density of current Li ion batteries (LIBs) and solid-state Li metal batteries (SSLMBs), along with other types of batteries. Two novel processing technologies have been developed to optimise the battery electrode microstructure and improve ion diffusion kinetics: (i) directional ice templating (DIT) for fabricating thick (900 µm) cathodes with vertical pore arrays and porosity gradient for LIBs [1]; and (ii) directional freezing and polymerisation (DFP) for fabricating cathodes with vertical arrays of solid polymer electrolyte (SPE) directly incorporated in the cathode microstructure during processing for SSLM Bs [2]. Both techniques reduced tortuosity τ of ion diffusion pathways through electrode thickness to 1.5 from ~3.3 for commercial electrodes.
We then show a new correlative imaging technique of combining X-ray Compton scattering imaging (XCS-I) and computed tomography (XCT) that allows 3D pixel-by-pixel mapping of Li chemical stoichiometry variations in a LiNi0.8Mn0.1Co0.1O2 electrode within a coin cell battery (Fig. 1) [3,4]. Using this technique, we show how the anisotropic electrode microstructure improved Li+ ion diffusivity, homogenised Li+ ion concentration, and improved energy storage performance.
Abstract attached
- Speaker: Dr Chun Ann Huang, Imperial College London
- Thursday 07 March 2024, 11:30-12:30
- Venue: Open Plan Area, Institute for Energy and Environmental Flows, Madingley Rise CB3 0EZ.
- Series: Institute for Energy and Environmental Flows (IEEF); organiser: Catherine Pearson.
Wed 07 Feb 16:00: Repeated rupture of persistent fault zone asperities: structure and variability of large earthquakes at the Kermadec subduction zone
Repeated slip on the same section of fault with earthquakes of similar size and mechanism, are so-called ‘characteristic earthquakes’. Such fault patches may be created by the existence of persistent asperities (isolated high strength regions) on the fault interface. However, many aspects of this apparent repeating behaviour are unclear – including i) how variable large events on the same fault segment are, ii) whether the same asperities are truly re-rupturing each time and iii) what factors limit slip to a particular region.
Rare occurrences of a complete earthquake cycle within the time of modern instrumentation are at rapidly slipping faults, particularly old oceanic subduction zones, such as Tonga-Kermadec. Here, the same portion of the plate interface has ruptured in M8+ earthquakes in 1917, 1976 and 2021. In this talk, I’ll present detailed observations of these earthquakes and show that although the same asperities likely re-ruptured in 1976 and 2021, the detailed slip distribution is different. Additionally, all earthquakes occur in an isolated area of the megathrust, which is bounded by changes in the lithospheric structure of the overriding plate. This high-seismicity region is coincident with an isolated forearc sedimentary basin, possibly formed by basal erosion related to seismogenesis, suggesting that seismic slip has persisted in this isolated area for several million years. I conclude that stress heterogeneity within this bounded seismogenic zone is long-lived and has produced a rich spectrum of earthquake ruptures.
- Speaker: Karen Lythgoe, University of Edinburgh
- Wednesday 07 February 2024, 16:00-17:00
- Venue: Wolfson Lecture Theatre.
- Series: Bullard Laboratories Wednesday Seminars; organiser: Janneke de Laat.
Thu 08 Feb 11:30: Catalysing Net Zero and Energy Transition Strategies through Thermodynamic Principles
Efficient repurposing of existing oil and gas infrastructure for Carbon Capture, Utilisation, and Storage (CCUS) and hydrogen applications necessitates careful consideration of challenges, including potential inaccuracies in flow measurement and heightened risks of corrosion and rock dissolution leading to gas leakage. These challenges are largely rooted in the inherent thermodynamic properties of CCUS and hydrogen systems. Hence, a foundational requirement is a comprehensive understanding of the theoretical and thermodynamic principles governing the entire CCUS process and hydrogen economy. Addressing these challenges requires the development of a robust model capable of accurately predicting properties in H2 and CO2 -rich streams. Precise determination of critical parameters, including density, speed of sound, and phase boundaries, is essential for accurate flow measurement. This approach seeks to establish safer CO2 and hydrogen transportation and storage processes by proactively avoiding conditions contributing to corrosion and reservoir rock dissolution challenges. An informed and thorough grasp of thermodynamic aspects, coupled with the creation of an appropriate prediction model, will play a critical role in ensuring the success and sustainability of CCUS and hydrogen implementations.
- Speaker: Edris Joonaki, TÜV SÜD UK National Engineering Laboratory
- Thursday 08 February 2024, 11:30-12:30
- Venue: Open Plan Area, Institute for Energy and Environmental Flows, Madingley Rise CB3 0EZ.
- Series: Institute for Energy and Environmental Flows (IEEF); organiser: Catherine Pearson.
Wed 15 May 17:30: Title to be confirmed
Abstract not available
- Speaker: Maarten Blaauw, Queen's University Belfast
- Wednesday 15 May 2024, 17:30-19:00
- Venue: Venue to be confirmed.
- Series: Quaternary Discussion Group (QDG); organiser: Jinheum Park.
Fri 09 Feb 16:00: Seismicity distribution and fault plane solutions from the 2021 Fagradalsfjall dyke intrusion, Reykjanes Peninsula
Abstract not available
- Speaker: Esme Glastonbury-Southern
- Friday 09 February 2024, 16:00-17:00
- Venue: Tea Room, Old House.
- Series: Bullard Laboratories Tea Time Talks; organiser: David Al-Attar.
Wed 24 Apr 17:30: Title to be confirmed
Abstract not available
- Speaker: Georgnia Falster, Australian National University
- Wednesday 24 April 2024, 17:30-19:00
- Venue: Venue to be confirmed.
- Series: Quaternary Discussion Group (QDG); organiser: Jinheum Park.
Wed 12 Jun 17:30: Title to be confirmed
Abstract not available
- Speaker: Simon Haberle, Australian National University
- Wednesday 12 June 2024, 17:30-19:00
- Venue: Venue to be confirmed.
- Series: Quaternary Discussion Group (QDG); organiser: Jinheum Park.
Thu 07 Mar 11:30: TBC
Abstract not available
- Speaker: Dr Chun Ann Huang, Imperial College London
- Thursday 07 March 2024, 11:30-12:30
- Venue: Open Plan Area, Institute for Energy and Environmental Flows, Madingley Rise CB3 0EZ.
- Series: Institute for Energy and Environmental Flows (IEEF); organiser: Catherine Pearson.
Mon 05 Feb 18:00: Exploring the seafloor: the rock record of hydrothermal fluid circulation
Samples of seafloor rocks provide insights on processes at ridges and transform faults. I will present constraints on hydrothermal fluid circulation recorded in ultramafic rock samples from the Gakkel and Southwest Indian ridges. Petrographic and geochemical datasets for these samples indicate that fluid circulation occurred to temperatures >900C, which suggests that seawater is able to circulate to depths >20 km. Hydration to these depths implies that the oceanic lithosphere can be a significant reservoir of water from the time that it is created.
- Speaker: Jessica Warren - University of Delaware
- Monday 05 February 2024, 18:00-19:00
- Venue: Harker 1, Department of Earth Sciences, Downing Street.
- Series: Sedgwick Club talks; organiser: Lucas Measures.
Fri 01 Mar 16:00: High Performance Computing (HPC): what is it? how can I use it?
Computation is an important aspect of most scientific research these days. I will describe what is generally meant by “high performance” computing, and highlight different “workloads”, such as simulation, data processing and machine learning. I will also talk about locally available systems, national and international infrastructure. Finally, I will mention how to use the machines, whether that is with your own code, or using a well-known package, such as ASPECT or SPECFEM3D . I am also keen to hear what people are interested in doing, and happy to help them get started.
- Speaker: Chris Richardson
- Friday 01 March 2024, 16:00-17:00
- Venue: Tea Room, Old House.
- Series: Bullard Laboratories Tea Time Talks; organiser: David Al-Attar.
Tue 27 Feb 12:00: The TTG window and the formation of Earth’s earliest continental crust.
A large number of papers have been written on the processes responsible for the formation of the Earth’s earliest continental crust. These range from plume-based processes, through modern style plate tectonics all the way through to formation from bombardment as the solar system passed through galactic regions with high impact potential. Simultaneously, numerous papers have Attempted to identify the melting sources for the magnetic suites that define early continental crust, The Trondjhemite- Tonalite-Granodiorite suite. Despite the progress in these studies there remains considerable disagreement on sources and processes for TTG generation – in part because of a tendency to try and identify a single process and a single source for all the earliest fragments of continental crust. In this talk I will discuss a number of these issues and, in particular, whether or not a single source and single process is a geologically sensible approach, arguing instead that a number of different processes may operate and may independently form crust that is sufficiently thick and buoyant as to be preservable in the geological record.
- Speaker: Richard White, School of Earth and Environmental Sciences, University of St Andrews
- Tuesday 27 February 2024, 12:00-13:00
- Venue: Department of Earth Sciences, Tilley Lecture Theatre.
- Series: Department of Earth Sciences Seminars (downtown); organiser: Dr Rachael Rhodes.
Thu 01 Feb 11:30: Transport and Settling of Buoyant Microplastics in Turbidity Currents
Although tens of millions of tons of plastic waste are released into the ocean each year, less than 300 kilotons remain on or near the ocean surface. This is particularly puzzling because more than half of plastics that are produced are buoyant in sea water. One mechanism that can result in buoyant plastic settling is the process of biofouling in which microbes and other organic material can accumulate on the plastics rendering them more dense. Less studied is the accumulation of inorganic material on the plastics. For example, clay has recently been shown to attach to plastics, particularly in the presence of surfactants. Here we report on laboratory experiments showing that plastic particles which are less dense than fresh water can settle due to the accumulation of glass spheres (“sand”) on their surface. This process is shown to occur dynamically as sand and plastic particles mix turbulently during the impulsive release of a turbidity current, which can carry some of the plastic particles to depth along with the settling sand. [This work reports on experiments performed by Woods Hole Oceanographic Institute (WHOI) Geophysical Fluid Dynamics (GFD) Fellow Quentin Kriaa during the WHOI GFD Summer Program 2023, co-supervised by Claudia Cenedese and Jim McElwaine.]
- Speaker: Professor Bruce Sutherland, Uni of Alberta
- Thursday 01 February 2024, 11:30-12:30
- Venue: Open Plan Area, Institute for Energy and Environmental Flows, Madingley Rise CB3 0EZ.
- Series: Institute for Energy and Environmental Flows (IEEF); organiser: Catherine Pearson.