EHPRG

Welcome to the official website of the European High Pressure Research Group (EHPRG).

EHPRG is non-profitable academic association established in 1963 which is devoted to science and technology of matter under high pressure. It organizes an annual meeting which brings together hundreds of scientists of various fields, mainly physics, chemistry, Earth and planetary sciences, bio- and food science and technology.

The reasonable size of the group, low conference fees, and a friendly relationship between the attendants have made EHPRG meetings a major event in the European high-pressure community for more than half a century.

Selection of high-pressure related titles from top scientific journals.

Hidden fluid mechanics: Learning velocity and pressure fields from flow visualizations
by Raissi, M., Yazdani, A., Karniadakis, G. E.


For centuries, flow visualization has been the art of making fluid motion visible in physical and biological systems. Although such flow patterns can be, in principle, described by the Navier-Stokes equations, extracting the velocity and pressure fields directly from the images is challenging. We address this problem by developing hidden fluid mechanics (HFM), a physics-informed deep learning framework capable of encoding the Navier-Stokes equations into the neural networks, while being agnostic to the geometry or the initial and boundary conditions. We demonstrate HFM for several physical and biomedical problems by extracting quantitative information for which direct measurements may not be possible. Important for potential applications, HFM is robust to low resolution and significant noise in the observation data.


30 Jan 2020 at 7:46pm
Formation of stable aggregates by fluid-assembled solid bridges [Applied Physical Sciences]
by Ali Seiphoori, Xiao-guang Ma, Paulo E. Arratia, Douglas J. Jerolmack
When a colloidal suspension is dried, capillary pressure may overwhelm repulsive electrostatic forces, assembling aggregates that are out of thermal equilibrium. This poorly understood process confers cohesive strength to many geological and industrial materials. Here we observe evaporation-driven aggregation of natural and synthesized particulates, probe their stability under rewetting, and...
18 Feb 2020 at 7:01pm
Hydration free energies and solvation structures with molecular density functional theory in the hypernetted chain approximation
by Sohvi Luukkonen
The Journal of Chemical Physics, Volume 152, Issue 6, February 2020.
The capability of molecular density functional theory in its lowest, second-order approximation, equivalent to the hypernetted chain approximation in integral equations, to predict accurately the hydration free-energies and microscopic structure of molecular solutes is explored for a variety of systems: spherical hydrophobic solutes, ions, water as a solute, and the Mobley’s dataset of organic molecules. The successes and the caveats of the approach are carefully pinpointed. Compared to molecular simulations with the same force field and the same fixed solute geometries, the theory describes accurately the solvation of cations, less so that of anions or generally H-bond acceptors. Overall, the electrostatic contribution to solvation free-energies of neutral molecules is correctly reproduced. On the other hand, the cavity contribution is poorly described but can be corrected using scaled-particle theory ideas. Addition of a physically motivated, one-parameter cavity correction accounting for both pressure and surface effects in the nonpolar solvation contribution yields a precision of 0.8 kcal/mol for the overall hydration free energies of the whole Mobley’s dataset. Inclusion of another one-parameter cavity correction for the electrostatics brings it to 0.6 kcal/mol, that is, kBT. This is accomplished with a three-orders of magnitude numerical speed-up with respect to molecular simulations.
12 Feb 2020 at 2:46am
Hydration properties of a protein at low and high pressures: Physics of pressure denaturation
by Masao Inoue
The Journal of Chemical Physics, Volume 152, Issue 6, February 2020.
Using experimentally determined structures of ubiquitin at 1 and 3000 bar, we generate sufficiently large ensembles of model structures in the native and pressure-induced (denatured) states by means of molecular dynamics simulations with explicit water. We calculate the values of a free-energy function (FEF), which comprises the hydration free energy (HFE) and the intramolecular (conformational) energy and entropy, for the two states at 1 and 3000 bar. The HFE and the conformational entropy, respectively, are calculated using our statistical-mechanical method, which has recently been shown to be accurate, and the Boltzmann-quasi-harmonic method. The HFE is decomposed into a variety of physically insightful components. We show that the FEF of the native state is lower than that of the denatured state at 1 bar, whereas the opposite is true at 3000 bar, thus being successful in reproducing the pressure denaturation. We argue that the following two quantities of hydration play essential roles in the denaturation: the WASA-dependent term in the water-entropy loss upon cavity creation for accommodating the protein (WASA is the water-accessible surface area of the cavity) and the protein–water Lennard-Jones interaction energy. At a high pressure, the mitigation of the serious water crowding in the system is the most important, and the WASA needs to be sufficiently enlarged with the increase in the excluded-volume being kept as small as possible. The denatured structure thus induced is characterized by the water penetration into the protein interior. The pressure denaturation is accompanied by a significantly large gain of water entropy.
11 Feb 2020 at 3:13am
Rounded Layering Transitions on the Surface of Ice
by Pablo Llombart, Eva G. Noya, David N. Sibley, Andrew J. Archer, and Luis G. MacDowell
Author(s): Pablo Llombart, Eva G. Noya, David N. Sibley, Andrew J. Archer, and Luis G. MacDowell


Understanding the wetting properties of premelting films requires knowledge of the film’s equation of state, which is not usually available. Here we calculate the disjoining pressure curve of premelting films and perform a detailed thermodynamic characterization of premelting behavior on ice. Analys...


[Phys. Rev. Lett. 124, 065702] Published Tue Feb 11, 2020
11 Feb 2020 at 11:00am
Decompression-Induced Diamond Formation from Graphite Sheared under Pressure
by Jiajun Dong, Zhen Yao, Mingguang Yao, Rui Li, Kuo Hu, Luyao Zhu, Yan Wang, Huanhuan Sun, Bertil Sundqvist, Ke Yang, and Bingbing Liu
Author(s): Jiajun Dong, Zhen Yao, Mingguang Yao, Rui Li, Kuo Hu, Luyao Zhu, Yan Wang, Huanhuan Sun, Bertil Sundqvist, Ke Yang, and Bingbing Liu


Graphite is known to transform into diamond under dynamic compression or under combined high pressure and high temperature, either by a concerted mechanism or by a nucleation mechanism. However, these mechanisms fail to explain the recently reported discovery of diamond formation during ambient temp...


[Phys. Rev. Lett. 124, 065701] Published Mon Feb 10, 2020
10 Feb 2020 at 11:00am
Real-Time Observation of Stacking Faults in Gold Shock Compressed to 150 GPa
by Surinder M. Sharma, Stefan J. Turneaure, J. M. Winey, P. A. Rigg, N. Sinclair, Xiaoming Wang, Y. Toyoda, and Y. M. Gupta
Author(s): Surinder M. Sharma, Stefan J. Turneaure, J. M. Winey, P. A. Rigg, N. Sinclair, Xiaoming Wang, Y. Toyoda, and Y. M. Gupta


A new experimental approach reveals, for the first time, the formation of microstructural defects in gold when shock compressed to high pressure, a critical insight to understanding shocked states of materials.


[Phys. Rev. X 10, 011010] Published Wed Jan 15, 2020
15 Jan 2020 at 11:00am
Critical Phenomena in the Temperature-Pressure-Crowding Phase Diagram of a Protein
by Andrei G. Gasic, Mayank M. Boob, Maxim B. Prigozhin, Dirar Homouz, Caleb M. Daugherty, Martin Gruebele, and Margaret S. Cheung
Author(s): Andrei G. Gasic, Mayank M. Boob, Maxim B. Prigozhin, Dirar Homouz, Caleb M. Daugherty, Martin Gruebele, and Margaret S. Cheung


Proteins balance contradictory demands of folding tightly yet remaining flexible by tuning where they operate in a temperature-pressure-crowding phase diagram.


[Phys. Rev. X 9, 041035] Published Mon Nov 18, 2019
18 Nov 2019 at 11:00am
Solids, liquids, and gases under high pressure
by Ho-Kwang Mao, Xiao-Jia Chen, Yang Ding, Bing Li, and Lin Wang
Author(s): Ho-Kwang Mao, Xiao-Jia Chen, Yang Ding, Bing Li, and Lin Wang


The effect of adding high pressure as a control parameter in solids, liquids, and gases expands opportunities to observe unexpected novel phenomena and understand matter in extreme environments. This review on high pressure science highlights subjects ranging from quantum criticality to Earth science. State-of-the-art experimental methods at megabar pressures are also discussed. The proliferation of pressure-induced phases illustrate promising new directions for this field of research.


[Rev. Mod. Phys. 90, 015007] Published Tue Mar 20, 2018
20 Mar 2018 at 11:00am
Colloquium: High pressure and road to room temperature superconductivity
by Lev P. Gor’kov and Vladimir Z. Kresin
Author(s): Lev P. Gor’kov and Vladimir Z. Kresin


Even after three decades of development, high-temperature superconductivity remains one of the most challenging theoretical and experimental areas in condensed matter physics. In this Colloquium some new discoveries in this area are reviewed and possible routes toward much higher transition temperatures are analyzed.


[Rev. Mod. Phys. 90, 011001] Published Tue Jan 09, 2018
9 Jan 2018 at 11:00am
Large barocaloric effects in thermoelectric superionic materials
by Jie Min, Arun K. Sagotra, and Claudio Cazorla
Author(s): Jie Min, Arun K. Sagotra, and Claudio Cazorla


We predict the existence of large barocaloric effects above room temperature in the thermoelectric fast-ion conductor ${\mathrm{Cu}}_{2}\mathrm{Se}$ by using classical molecular dynamics simulations and first-principles computational methods. A hydrostatic pressure of 1 GPa induces large isothermal ...


[Phys. Rev. Materials 4, 015403] Published Wed Jan 29, 2020
29 Jan 2020 at 11:00am
Structural study of the pressure-induced metal-insulator transition in $\mathrm{Li}{\mathrm{V}}_{2}{\mathrm{O}}_{4}$
by Alexander J. Browne, Edward J. Pace, Gaston Garbarino, and J. Paul Attfield
Author(s): Alexander J. Browne, Edward J. Pace, Gaston Garbarino, and J. Paul Attfield


At ambient pressure the spinel $\mathrm{Li}{\mathrm{V}}_{2}{\mathrm{O}}_{4}$ is a metal with a heavy fermion ground state. However, under applied pressure a transition to an insulating, nonmagnetic state occurs. Powder x-ray diffraction has been used to study structural changes associated with this ...


[Phys. Rev. Materials 4, 015002] Published Tue Jan 21, 2020
21 Jan 2020 at 11:00am
Crystal structure and magnetism of MnO under pressure
by S. Klotz, K. Komatsu, A. Polian, S. Machida, A. Sano-Furukawa, J.-P. Itié, and T. Hattori
Author(s): S. Klotz, K. Komatsu, A. Polian, S. Machida, A. Sano-Furukawa, J.-P. Itié, and T. Hattori


Manganese oxide is a prototype of an antiferromagnetic Mott insulator. Here, we investigate the interplay of magnetic ordering and lattice distortion across the Néel temperature ${T}_{N}$ under pressure using neutron and x-ray diffraction. We find an increase in ${T}_{N}$ with a rate of $d{T}_{N}/dP...


[Phys. Rev. B 101, 064105] Published Tue Feb 18, 2020
18 Feb 2020 at 11:00am
Anisotropic lattice compression and pressure-induced electronic phase transitions in ${\mathrm{Sr}}_{2}\mathrm{IrO}{}_{4}$
by K. Samanta, R. Tartaglia, U. F. Kaneko, N. M. Souza-Neto, and E. Granado
Author(s): K. Samanta, R. Tartaglia, U. F. Kaneko, N. M. Souza-Neto, and E. Granado


The crystal lattice of ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$ is investigated with synchrotron x-ray powder diffraction under hydrostatic pressures up to $P=43$ GPa and temperatures down to 20 K. The tetragonal unit cell is maintained over the whole investigated pressure range, within our resolution ...


[Phys. Rev. B 101, 075121] Published Tue Feb 18, 2020
18 Feb 2020 at 11:00am
Valence instability across the magnetostructural transition in ${\mathrm{USb}}_{2}$
by Z. E. Brubaker, Y. Xiao, P. Chow, C. Kenney-Benson, J. S. Smith, H. Cynn, C. Reynolds, N. P. Butch, R. J. Zieve, and J. R. Jeffries
Author(s): Z. E. Brubaker, Y. Xiao, P. Chow, C. Kenney-Benson, J. S. Smith, H. Cynn, C. Reynolds, N. P. Butch, R. J. Zieve, and J. R. Jeffries


We have performed pressure-dependent x-ray diffraction and resonant x-ray emission spectroscopy experiments on ${\mathrm{USb}}_{2}$ to further characterize the antiferromagnetic-ferromagnetic transition occurring near 8 GPa. We have found the magnetic transition coincides with a tetragonal to orthor...


[Phys. Rev. B 101, 085123] Published Fri Feb 14, 2020
14 Feb 2020 at 11:00am
Lattice distortion-induced sluggish phase transition in CoCrFeNixAl1-x (x = 0.5, 0.75) high-entropy alloys at high pressures
by Lei Liu
Volume 39, Issue 4, December 2019, Page 533-546
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16 Aug 2019 at 12:07pm
High-temperature electrical resistivity measurements of hcp iron to Mbar pressure in an internally resistive heated diamond anvil cell
by Sho Suehiro
Volume 39, Issue 4, December 2019, Page 579-587
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18 Nov 2019 at 10:28am
TiSi2-SiC agglomerates toughened TiC composites prepared by in-situ reaction under high pressure
by Qingyun Chen
Volume 39, Issue 4, December 2019, Page 598-607
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19 Nov 2019 at 7:45am
Hydrostaticity of pressure-transmitting media for high pressure infrared spectroscopy
by A. Celeste
Volume 39, Issue 4, December 2019, Page 608-618
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20 Sep 2019 at 11:59am
The application of manganin wire pressure gauges in a large volume press under high-temperature conditions
by Ren Dongsheng
Volume 39, Issue 4, December 2019, Page 619-627
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8 Oct 2019 at 10:58am
Parallel background subtraction in diamond anvil cells for high pressure X-ray data analysis
by Weizhao Cai
Volume 39, Issue 4, December 2019, Page 628-639
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6 Dec 2019 at 3:40am
High pressure influence on the Diels–Alder reaction volume in the solid phase at pressure up to 7000 bar and in solution
by Dmitry A. Kornilov
Volume 39, Issue 4, December 2019, Page 640-654
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8 Oct 2019 at 10:58am
Enhancing the pressure limitation in large-volume Bridgman-anvil cell used for in situ neutron diffraction
by Qiwei Hu
Volume 39, Issue 4, December 2019, Page 655-665
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19 Sep 2019 at 1:28pm
High hydrostatic pressure processing of beetroot juice: effects on nutritional, sensory and microbiological quality
by Marta Ubeira-Iglesias
Volume 39, Issue 4, December 2019, Page 691-706
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19 Sep 2019 at 1:24pm
Pressure stability of the first hydration shell of yttrium in aqueous YCl3 solution
by M. Elbers
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12 Feb 2020 at 6:14am
Recent progress in high pressure X-ray absorption spectroscopy studies at the ODE beamline
by Lucie Nataf
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14 Jan 2020 at 5:33am
Opposed type double stage cell for Mbar pressure experiment with large sample volume
by Yoshio Kono
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9 Jan 2020 at 7:33am
Changes of microflora in high pressure treated Indian white prawn (Fenneropenaeus indicus)
by J. Ginson
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7 Jan 2020 at 7:50am
Review: high pressure generation techniques beyond the limit of conventional diamond anvils
by Takehiko Yagi
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26 Dec 2019 at 11:21am
Synthesis of nano-polycrystalline diamond from glassy carbon at pressures up to 25 GPa
by Tetsuo Irifune
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23 Dec 2019 at 9:02am
Pressure effect on the electromotive force of the type R thermocouple
by Yu Nishihara
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23 Dec 2019 at 12:29pm
Exploiting optical properties of nanopolycrystalline diamond in high pressure experiments
by J. Antonio Barreda-Argüeso
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18 Dec 2019 at 7:57am
An application of NPD to double-stage diamond anvil cells: XAS spectra of rhenium metal under high pressures above 300 GPa
by K. Kuramochi
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18 Dec 2019 at 6:03am
Data-driven exploration for pressure-induced superconductors using diamond anvil cell with boron-doped diamond electrodes and undoped diamond insulating layer
by Ryo Matsumoto
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3 Dec 2019 at 2:04am
High pressure atomic structure of Zr–Cu metallic glass via EXAFS spectroscopy and molecular dynamics simulations
by P. Dziegielewski
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27 Nov 2019 at 11:46am
High pressure generation in the Kawai-type multianvil apparatus equipped with sintered diamond anvils
by D. Yamazaki
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15 Nov 2019 at 5:19am
The messy, secretive reality behind OpenAI’s bid to save the world
The AI moonshot was founded in the spirit of transparency. This is the inside story of how competitive pressure eroded that idealism.
17 Feb 2020 at 10:32pm