• A Monte Carlo Algorithm for Immiscible Two-Phase Flow in Porous Media 

      Savani, Isha; Sinha, Santanu; Hansen, Alex; Bedeaux, Dick; Kjelstrup, Signe; Vassvik, Morten (Journal article; Peer reviewed, 2017)
      We present a Markov Chain Monte Carlo algorithm based on the Metropolis algorithm for simulation of the flow of two immiscible fluids in a porous medium under macroscopic steady-state conditions using a dynamical pore ...
    • A procedure to find thermodynamic equilibrium constants for CO2 and CH4 adsorption on activated carbon 

      Trinh, Thuat; van Erp, Titus Sebastiaan; Bedeaux, Dick; Kjelstrup, Signe; Grande, Carlos Adolfo (Journal article; Peer reviewed, 2015)
      Thermodynamic equilibrium for adsorption means that the chemical potential of gas and adsorbed phase are equal. A precise knowledge of the chemical potential is, however, often lacking, because the activity coefficient of ...
    • Adsorption of an Ideal Gas on a Small Spherical Adsorbent 

      Strøm, Bjørn André; Bedeaux, Dick; Schnell, Sondre Kvalvåg (Peer reviewed; Journal article, 2021)
      The ideal gas model is an important and useful model in classical thermodynamics. This remains so for small systems. Molecules in a gas can be adsorbed on the surface of a sphere. Both the free gas molecules and the adsorbed ...
    • Bridging scales with thermodynamics: From nano to macro 

      Kjelstrup, Signe; Schnell, Sondre K.; Vlugt, Thijs J.H.; Simon, Jean-Marc; Bardow, André; Bedeaux, Dick; Trinh, Thuat (Journal article; Peer reviewed, 2014)
      We have recently developed a method to calculate thermodynamic properties of macroscopic systems by extrapolating properties of systems of molecular dimensions. Appropriate scaling laws for small systems were derived using ...
    • Defining the pressures of a fluid in a nanoporous, heterogeneous medium 

      Galteland, Olav; Rauter, Michael Tobias; Varughese, Kevin K.; Bedeaux, Dick; Kjelstrup, Signe Helene (Journal article, 2022)
      We describe the thermodynamic state of a single-phase fluid confined to a porous medium with Hill's thermodynamics of small systems, also known as nanothermodynamics. This way of defining small system thermodynamics, with ...
    • Ensemble distribution for immiscible two-phase flow in porous media 

      Savani, Isha; Bedeaux, Dick; Kjelstrup, Signe; Vassvik, Morten; Sinha, Santanu; Hansen, Alex (Journal article, 2017)
      We construct an ensemble distribution to describe steady immiscible two-phase flow of two incompressible fluids in a porous medium. The system is found to be ergodic. The distribution is used to compute macroscopic flow ...
    • Entropy facilitated active transport 

      Rubi, Miguel; Lervik, Anders; Bedeaux, Dick; Kjelstrup, Signe (Journal article; Peer reviewed, 2017)
      We show how active transport of ions can be interpreted as an entropy facilitated process. In this interpretation, a particular change in the pore geometry through which substrates are transported gives rise to a driving ...
    • Entropy production beyond the thermodynamic limit from single-molecule stretching simulations 

      Bering, Eivind; Kjelstrup, Signe; Bedeaux, Dick; Rubi, Miguel; de Wijn, Astrid S. (Peer reviewed; Journal article, 2020)
      Single-molecular systems are a test bed to analyze to what extent thermodynamics applies when the size of the system is drastically reduced. Isometric and isotensional single-molecule stretching experiments and their ...
    • Equilibrium properties of the reaction H2=2H by classical molecular dynamics simulations 

      Skorpa, Ragnhild; Simon, Jean-Marc; Bedeaux, Dick; Kjelstrup, Signe (Journal article; Peer reviewed, 2014)
      We have developed a classical molecular dynamics model for the hydrogen dissociation reaction, containing two- and three-particle potentials derived by Kohen, Tully and Stillinger. Two fluid densities were investigated for ...
    • Finite-size effects of Kirkwood–Buff integrals from molecular simulations 

      Dawass, Noura; Kruger, Pieter; Schnell, Sondre Kvalvåg; Bedeaux, Dick; Kjelstrup, Signe; Simon, Jean Marc; Vlugt, Thijs (Journal article; Peer reviewed, 2017)
      The modelling of thermodynamic properties of liquids from local density fluctuations is relevant to many chemical and biological processes. The Kirkwood–Buff (KB) theory connects the microscopic structure of isotropic ...
    • Fluctuation-Dissipation Theorems for Multiphase Flow in Porous Media 

      Bedeaux, Dick; Kjelstrup, Signe (Peer reviewed; Journal article, 2022)
      A thermodynamic description of porous media must handle the size- and shape-dependence of media properties, in particular on the nano-scale. Such dependencies are typically due to the presence of immiscible phases, contact ...
    • Fluid-Fluid Interfaces of Multi-Component Mixtures in Local Equilibrium 

      Bedeaux, Dick; Kjelstrup, Signe (Journal article; Peer reviewed, 2018)
      We derive in a new way that the intensive properties of a fluid-fluid Gibbs interface are independent of the location of the dividing surface. When the system is out of global equilibrium, this finding is not trivial: In ...
    • Gibbs ensemble Monte Carlo simulation of fluids in confinement: Relation between the differential and integral pressures 

      Erdős, Máté; Galteland, Olav; Bedeaux, Dick; Kjelstrup, Signe; Moultos, Othonas A.; Vlugt, Thijs J.H. (Peer reviewed; Journal article, 2020)
      The accurate description of the behavior of fluids in nanoporous materials is of great importance for numerous industrial applications. Recently, a new approach was reported to calculate the pressure of nanoconfined fluids. ...
    • Heat transport through a solid-solid junction: the interface as an autonomous thermodynamic system 

      Rurali, R.; Colombo, L.; Cartoixà, X.; Wilhelmsen, Øivind; Trinh, Thuat; Bedeaux, Dick; Kjelstrup, Signe (Journal article; Peer reviewed, 2016-04)
      We perform computational experiments using nonequilibrium molecular dynamics simulations, showing that the interface between two solid materials can be described as an autonomous thermodynamic system. We verify the local ...
    • Hill's nano-thermodynamics is equivalent with Gibbs' thermodynamics for surfaces of constant curvatures 

      Bedeaux, Dick; Kjelstrup, Signe (Journal article; Peer reviewed, 2018)
      We review first how properties of curved surfaces can be studied using Hill’s thermodynamics, also called nano-thermodynamics. We proceed to show for the first time that Hill’s analysis is equivalent to Gibbs analysis for ...
    • Kirkwood–Buff integrals: From fluctuations in finite volumes to the thermodynamic limit 

      Simon, Jean-Marc; Krüger, Peter; Schnell, Sondre Kvalvåg; Vlugt, Thijs J.H.; Kjelstrup, Signe; Bedeaux, Dick (Peer reviewed; Journal article, 2022)
      The Kirkwood–Buff theory is a cornerstone of the statistical mechanics of liquids and solutions. It relates volume integrals over the radial distribution function, so-called Kirkwood–Buff integrals (KBIs), to particle ...
    • Legendre-Fenchel transforms capture layering transitions in porous media 

      Galteland, Olav; Bering, Eivind; Kristiansen, Kim; Bedeaux, Dick; Kjelstrup, Signe (Peer reviewed; Journal article, 2022)
      We have investigated the state of a nanoconfined fluid in a slit pore in the canonical and isobaric ensembles. The systems were simulated with molecular dynamics simulations. The fluid has a transition to a close-packed ...
    • A Legendre–Fenchel Transform for Molecular Stretching Energies 

      Bering, Eivind; Bedeaux, Dick; Kjelstrup, Signe; de Wijn, Astrid S.; Latella, Ivan; Rubi, Miguel (Peer reviewed; Journal article, 2020)
      Single-molecular polymers can be used to analyze to what extent thermodynamics applies when the size of the system is drastically reduced. We have recently verified using molecular-dynamics simulations that isometric and ...
    • Local equilibrium in liquid phase shock waves 

      Maltby, Tage Winther; Hafskjold, Bjørn; Bedeaux, Dick; Kjelstrup, Signe; Wilhelmsen, Øivind (Peer reviewed; Journal article, 2023)
    • Local thermodynamic description of isothermal single-phase flow in porous media 

      Galteland, Olav; Rauter, Michael Tobias; Bratvold, Mina S.; Trinh, Thuat; Bedeaux, Dick; Kjelstrup, Signe (Journal article; Peer reviewed, 2022)
      Darcy's law for porous media transport is given a new local thermodynamic basis in terms of the grand potential of confined fluids. The local effective pressure gradient is determined using non-equilibrium molecular dynamics, ...