We investigate the value of the correlation function of an inhomogeneous hard-sphere fluid at contact. This quantity plays a critical role in statistical associating fluid theory, which is the basis of a number of recently developed classical density functionals. We define two averaged values for th…

[Phys. Rev. E 86, 061201] Published Fri Dec 28, 2012

In this paper, we study the influence of platinum (100) surface morphology on the tangential-momentum accommodation coefficient with argon using a molecular dynamics method. The coefficient is computed directly by beaming Ar atoms onto the surfaces and measuring the relative momentum changes. The wa…

[Phys. Rev. E 86, 051201] Published Mon Nov 26, 2012

In this paper, molecular dynamics simulations of a simple Lennard-Jones fluid confined in narrow slit pores and undergoing shear have been performed. The aim is to investigate the effects of density inhomogeneities at the fluid-solid interfaces on the shear viscosity profiles. It has been found that…

[Phys. Rev. E 86, 021202] Published Mon Aug 20, 2012

Based on the results of computer simulation of transport coefficients in a Lennard-Jones fluid, it has been shown that in ($p$,$T)$ coordinates, lines of constant values of coefficients of self-diffusion $D$ and excess shear viscosity $\Delta \eta$ extended into the region of superheated liquid and supersaturated va…

[Phys. Rev. E 86, 021201] Published Fri Aug 17, 2012

Negative thermophoresis is a phenomenon of particle transport induced by a temperature gradient, by which small particles migrate from low to high temperatures. In gas media, it depends strongly on the gas-particle interaction and temperature. In this paper, we show that negative thermophoresis is p…

[Phys. Rev. E 86, 011201] Published Fri Jul 20, 2012

In a recent paper, Valdès-Parada and Alvarez-Ramirez [Phys. Rev. E 84, 031201 (2011)] used the technique of volume averaging to derive a “frequency-dependent” dispersion tensor, ${\mathsf{\text{D}}}_{\gamma }^{*}$, the goal of which is to describe solute transport in porous media undergoing periodic processes. We describe two issu…

[Phys. Rev. E 86, 013201] Published Tue Jul 10, 2012

In a recent paper [Valdés-Parada and Alvarez-Ramirez, Phys. Rev. E 84, 031201 (2011)], we studied the passive transport of a solute in a rigid and homogeneous porous medium in the domain of frequency and obtained good agreement between upscaled and pore-scale results for several values of the freque…

[Phys. Rev. E 86, 013202] Published Tue Jul 10, 2012

We derive an analytical pair potential of mean force for Brownian molecules in the liquid state. Our approach accounts for many-particle correlations of crowding particles of the liquid and for diffusive transport across the spatially modulated local density of crowders in the dense environment. Foc…

[Phys. Rev. E 85, 061202] Published Fri Jun 15, 2012

Irreversible thermodynamics provides interface conditions that yield temperature and chemical potential jumps at phase boundaries. The interfacial jumps allow unexpected transport phenomena, such as the inverted temperature profile [Pao, Phys. Fluids 14, 306 (1971)] and mass transfer from a cold to …

[Phys. Rev. E 85, 061201] Published Mon Jun 04, 2012

A molecular dynamics (MD) methodology based on Eyring theory of reaction rates is proposed for investigating solid-liquid interfacial properties crucial to the development of many nanotechnology applications. The method involves the calculation of activation energy required for the flow process dire…

[Phys. Rev. E 85, 051205] Published Tue May 29, 2012

A hallmark of the changes in dynamics towards the glass transition is the stretched exponential structural relaxation. Quasielastic neutron scattering results on liquid rubidium demonstrate such a nonexponential relaxation process in a simple liquid metal above the melting point. The nonexponential …

[Phys. Rev. E 85, 051204] Published Fri May 18, 2012

A density functional perturbation theory, which is based both on the modified fundamental-measure theory and on the first-order mean-spherical approximation for long-range attractive and repulsive interactions, has been developed for studying the structure and phase behaviors of a competing system r…

[Phys. Rev. E 85, 051203] Published Mon May 14, 2012

In this study, we use two nonequilibrium molecular dynamics algorithms, boundary-driven shear and homogeneous shear, to explore the rheology and flow properties of a simple fluid undergoing steady simple shear. The two distinct algorithms are designed to elucidate the influences of nanoscale confine…

[Phys. Rev. E 85, 051202] Published Wed May 09, 2012

We have performed extensive molecular dynamics simulations to study noise-power spectra of density and potential energy fluctuations of a Lennard-Jones model of a fluid in the supercritical region. Emanating from the liquid-vapor critical point, there is a locus of isobaric specific heat maxima, cal…

[Phys. Rev. E 85, 051201] Published Wed May 02, 2012

There are some hydrodynamic equations that, while their parent kinetic equation satisfies fundamental mechanical properties, appear themselves to violate mechanical or thermodynamic properties. This paper aims to shed some light on the source of this problem. Starting with diffusive volume hydrodyna…

[Phys. Rev. E 85, 041202] Published Tue Apr 17, 2012

We report a molecular-dynamics study of flow of Lennard-Jones fluid through a nanochannel where size effects predominate. The momentum and energy accommodation coefficients, which determine the amount of slip and temperature jumps, are calculated for a three-dimensional Poiseuille flow through a nan…

[Phys. Rev. E 85, 041201] Published Mon Apr 16, 2012

It is generally agreed that the supercritical region of a liquid consists of one single state (supercritical fluid). On the other hand, we show here that liquids in this region exist in two qualitatively different states: “rigid” and “nonrigid” liquids. Rigid to nonrigid transition corresponds to th…

[Phys. Rev. E 85, 031203] Published Fri Mar 30, 2012

We use molecular dynamics (MD) to simulate diffusion in molten aluminum-copper (AlCu) alloys. The self-diffusivities and Maxwell-Stefan diffusivities are calculated for AlCu mixtures using the Green-Kubo formulas at temperatures from 1000 to 4000 K and pressures from 0 to 25 GPa, along with addition…

[Phys. Rev. E 85, 031202] Published Tue Mar 27, 2012

The behavior of thermodynamic response functions and the thermodynamic scalar curvature in the supercritical region have been studied for a Lennard-Jones fluid based on a revised modified Benedict-Webb-Rubin equation of state. Response function extrema are sometimes used to estimate the Widom line, …

[Phys. Rev. E 85, 031201] Published Mon Mar 05, 2012

By application of the field-cycling technique, we measure the dispersion of the ${}^1$H nuclear magnetic resonance (NMR) spin-lattice relaxation time $T_1$(ω) for a series of molecular liquids. We demonstrate that such NMR relaxometry studies can be used for determining diffusion coefficients. A broad frequ…

[Phys. Rev. E 85, 020201(R)] Published Thu Feb 23, 2012

In this Brief Report we investigate the multiscale hydrodynamical response of a liquid as a function of mixture composition. This is done via a series of molecular dynamics simulations in which the wave-vector-dependent viscosity kernel is computed for three mixtures, each with 7–15 different compos…

[Phys. Rev. E 85, 022201] Published Tue Feb 21, 2012

A rolling-sphere technique has been used to measure shear viscosities of (supercritical) fluid methane in a diamond-anvil cell between temperatures of 294 and 673 K, up to a pressure of 6 GPa. A correlation between a reduced viscosity and reduced residual entropy is shown to give a good account of m…

[Phys. Rev. E 84, 062201] Published Fri Dec 30, 2011

We perform molecular dynamics simulations to investigate dynamical properties of a supercritical Lennard-Jones fluid. We find that in the supercritical region there is a short-ranged deviation in dynamic character. We further find that this anomalous change is associated with the presence of the Wid…

[Phys. Rev. E 84, 051204] Published Tue Nov 15, 2011

We give a variational formulation of classical statistical mechanics where the one-body density and the local entropy distribution constitute the trial fields. Using Levy's constrained search method, it is shown that the grand potential is a functional of both distributions, that it is minimal in eq…

[Phys. Rev. E 84, 051203] Published Fri Nov 11, 2011

We report experiments with very compressible fluids near the liquid-gas critical point. These experiments are performed (i) under microgravity in low Earth orbit by using SF${}_6$ at liquidlike density and (ii) under Earth's gravity with CO${}_2$ at gaslike density. The sample fluid is filled in an interferom…

[Phys. Rev. E 84, 051201] Published Thu Nov 10, 2011

The most familiar approaches used to describe the dynamical structure factor from adiabatic density fluctuations in liquids are based on generalized hydrodynamics and on the memory function, respectively. We show that, contrary to the common belief, the two approaches are not fully equivalent. In pa…

[Phys. Rev. E 84, 051202] Published Thu Nov 10, 2011

Supporting-electrolyte solutions comprise chemically inert cations and anions, produced by salt dissolution, together with a reactive ionic species that may be consumed and generated on bounding ion-selective surfaces (e.g., electrodes or membranes). Upon application of an external voltage, a Farada…

[Phys. Rev. E 84, 041204] Published Fri Oct 28, 2011

Structural and thermodynamic properties of multicomponent hard-sphere fluids at odd dimensions have recently been derived in the framework of the rational function approximation (RFA) [Rohrmann and Santos, Phys. Rev. E 83, 011201 (2011)]. It is demonstrated here that the RFA technique yields the exa…

[Phys. Rev. E 84, 041203] Published Mon Oct 24, 2011

We study the thermalization of energetic electrons dilutely dispersed in inert gas atomic moderators, with and without the presence of an external electric field. We investigate the shape relaxation of the electron distribution function relative to the steady-state distribution by means of the Kullb…

[Phys. Rev. E 84, 041202] Published Wed Oct 19, 2011

We construct a nonperturbative fully analytical approximation for the thermodynamics and the structure of nonadditive hard-sphere fluid mixtures. The method essentially lies in a heuristic extension of the Percus-Yevick solution for additive hard spheres. Extensive comparison with Monte Carlo simula…

[Phys. Rev. E 84, 041201] Published Wed Oct 12, 2011

Several studies have shown that the performance of different chemical processes can be improved by means of periodic operation. An accurate modeling and simulation of these processes requires accounting for the dependence of the system parameters with the operating frequency. This work uses the meth…

[Phys. Rev. E 84, 031201] Published Tue Sep 13, 2011

Despite their importance for solar thermal power applications, phase-diagrams of molten salt mixture heat transfer fluids (HTFs) are not readily accessible from first principles. We present a molecular dynamics scheme general enough to identify eutectics of any HTF candidate mixture. The eutectic mi…

[Phys. Rev. E 84, 030201(R)] Published Thu Sep 01, 2011

Near the liquid-vapor critical point in pure fluids, material and thermal properties vary considerably with temperature. In a series of microgravity experiments, sulfur hexafluoride (SF${}_6$) was heated ∼1 K above its critical temperature, then quenched below the critical temperature in order to form ga…

[Phys. Rev. E 84, 021202] Published Mon Aug 22, 2011

We theoretically investigate the thermophoretic force on spherical particles in binary monatomic gas mixtures in the free molecular regime. Based on gas kinetic theory and by considering the gas-particle interactions, we derive the analytical formulas of the thermophoretic force for two limiting gas…

[Phys. Rev. E 84, 021201] Published Wed Aug 03, 2011

The temperature field inside an evaporating two-dimensional droplet resting on curved or flat isothermal substrates is studied under various evaporation conditions. An analytical solution for the temperature is derived, which can be directly used in the cases of pinned and depinned contact lines as …

[Phys. Rev. E 84, 011201] Published Mon Jul 25, 2011

The mixture of isobutyric acid and water has a consolute point at a temperature of 25.75 °C and mole fraction 0.1148 isobutyric acid. When charcoal is added to this mixture, the concentration of isobutyric acid is reduced by adsorption. We have measured the action of charcoal on solutions of isobuty…

[Phys. Rev. E 83, 061201] Published Thu Jun 16, 2011

The second self-diffusion and viscosity virial coefficients of the Lennard-Jones (LJ) fluid were calculated by a detailed evaluation of the velocity and shear-stress autocorrelation functions using equilibrium molecular dynamics simulations at low and moderate densities. Accurate calculation of thes…

[Phys. Rev. E 83, 061202] Published Thu Jun 16, 2011

We develop a microscopic theoretical framework for the time-dependent pair distribution function starting from the Liouville equation. An exact Zwanzig-Mori equation of motion for the time-dependent pair distribution function is derived based on the projection-operator formalism. It is demonstrated …

[Phys. Rev. E 83, 041201] Published Tue Apr 26, 2011

We studied the ionic conductance through Al${}_2$O${}_3$ nanopore transistors to probe the surface charge density and its dependence on the applied gate field. The observed conductance modulations are entirely attributable to the electrostatic field effect, and their dependence on pH, ionic strength, and gate…

[Phys. Rev. E 83, 031203] Published Fri Mar 18, 2011

We propose a method by which the generalized transport properties and coefficients at all wavelengths and frequencies can be obtained by inversion of an exact kinetic equation. The necessary data are the density-density, energy-energy, and density-energy time correlation functions, which can be obta…

[Phys. Rev. E 83, 031201] Published Fri Mar 11, 2011

In the present paper, we extend the method described in paper I [D. Bertolini and A. Tani, preceding paper, Phys. Rev. E 83, 031201 (2011)] to molecular liquids, which allows us to solve the exact kinetic equation proposed by de Schepper et al. [Phys. Rev. A 38, 271 (1988)] without approximations. …

[Phys. Rev. E 83, 031202] Published Fri Mar 11, 2011

A new method is devised to derive a thermodynamic perturbation theory that is suitable for short-ranged potentials. We have calculated structure and thermodynamic of short-ranged square-well potential with good agreement with computer simulation data even at low temperatures. We have also compared t…

[Phys. Rev. E 83, 021203] Published Tue Feb 22, 2011

For radiative heat transfer applications, in particular in homogenized phases of porous media, an exhaustive and accurate validity criterion of the radiative Fourier law, depending only on the logarithmic derivative of the temperature field and an effective absorption coefficient, accounting for pos…

[Phys. Rev. E 83, 021202] Published Fri Feb 18, 2011

We represent the free energy functional by a diagrammatic series with tensorial coefficients indexed by powers of the length scale. For hard cores, we obtain Percus’s exact functional in one dimension and the Kierlik-Rosinberg form of fundamental measures theory in three dimensions. In five dimensio…

[Phys. Rev. E 83, 021201] Published Thu Feb 10, 2011

Mixtures of hard hyperspheres in odd-space dimensionalities are studied with an analytical approximation method. This technique is based on the so-called rational function approximation and provides a procedure for evaluating equations of state, structure factors, radial distribution functions, and …

[Phys. Rev. E 83, 011201] Published Fri Jan 21, 2011

Molecular dynamics simulations are carried out to investigate the diffusion behavior of penetrable-sphere model fluids characterized by a finite energy barrier $ϵ$. The self-diffusion coefficient is evaluated from the time-dependent velocity autocorrelation function and mean-square displacement. Detai…

[Phys. Rev. E 82, 051202] Published Wed Nov 17, 2010

The phase rule states that a fluid element is determined locally by $c+1$ independent intensive variables when there are $c$ components. In solving the Boltzmann equation for gas transport coefficients, the standard procedures involve only $c$ independent gradients of intensive variables for the local pro…

[Phys. Rev. E 82, 051201] Published Tue Nov 09, 2010

The problem of relaxation of a nonequilibrium state to the state of molecular hydrodynamics is considered for a classical system of interacting particles using the Zubarev nonequilibrium statistical operator method. The wave-vector and frequency dependencies of the dynamical structure factor and mom…

[Phys. Rev. E 82, 041202] Published Thu Oct 07, 2010

We use molecular simulation to study the ability of excess entropy scaling relationships to describe the kinetic properties of a confined molecular system. We examine a model for a confined fluid consisting of dumbbell-shaped molecules that interact with atomistically detailed pore walls via a Lenna…

[Phys. Rev. E 82, 041201] Published Mon Oct 04, 2010

We study the dynamics of charged macroscopic particles (millimetric steel balls) confined in a linear channel of finite length, sufficiently narrow to avoid particles crossing. We show that their individual response to thermal fluctuations strongly depends either on their position in the channel or …

[Phys. Rev. E 82, 031201] Published Mon Sep 20, 2010

We study the interplay between the fluid-crystal transition and the glass transition of elastic sphere system with polydispersity using nonequilibrium molecular dynamics simulations. It is found that the end point of the crystal-fluid transition line, which corresponds to the critical polydispersity…

[Phys. Rev. E 82, 021201] Published Tue Aug 10, 2010

Nonequilibrium molecular-dynamics simulations are presented for the shear rheology of suspensions of extended “jack”-shaped nanoparticles in an explicit solvent. The shear viscosity is measured for two jack-shaped nanoparticle suspensions for volume fractions from 0.01 to 0.15 and compared to spheri…

[Phys. Rev. E 82, 010201(R)] Published Tue Jul 13, 2010

The pressure and energy behavior of the Gaussian core model (GCM) fluid as a function of strain-rate are obtained from nonequilibrium molecular dynamics simulations for a wide range of thermodynamic state points. An analytical dependence of pressure on strain-rate is observed which is in agreement w…

[Phys. Rev. E 82, 011201] Published Tue Jul 06, 2010

In this work, we test the ability of the Ornstein-Zernike equation in the Percus-Yevick approximation (OZPY) to generate interaction potentials from pair correlation functions (PCFs) of monatomic and diatomic Lennard-Jones fluids. The PCFs are generated by solving OZPY equation (monatomic fluid) and…

[Phys. Rev. E 81, 061204] Published Mon Jun 28, 2010

Molecular dynamics computer simulations are used to study the aging dynamics of ${\text{SiO}}_2$ (modeled by the BKS model). Starting from fully equilibrated configurations at high temperatures $T_{\text{i}}∊\left\{5000\text{K},3760\text{K}\right\}$, the system is quenched to lower temperatures $T_{\text{f}}∊\left\{2500\text{K},2750\text{K},3000\text{K},3250\text{K}\right\}$ and observed after a…

[Phys. Rev. E 81, 061203] Published Fri Jun 25, 2010

We linearize the Uehling-Uhlenbeck equation for bosonic gases close to thermal equilibrium under the assumption of a contact interaction characterized by a scattering length $a$. We show that the spectrum of relaxation rates is similar to that of a classical hard-sphere gas. However, the relaxation ra…

[Phys. Rev. E 81, 061202] Published Wed Jun 16, 2010

This paper presents a simulation study of the applicability of the Rosenfeld entropy scaling to the systems which cannot be approximated by the effective hard spheres. Three systems are studied: the Herzian spheres, the Gauss core model, and a soft repulsive shoulder potential. These systems demonst…

[Phys. Rev. E 81, 061201] Published Wed Jun 02, 2010

In this paper, we study a macroscopic system of electrically interacting metallic beads organized as a sequence along an annulus. A random mechanical shaking mimics the thermal excitation. We exhibit non-Fickian diffusion (single-file diffusion) at large time. We measure the mobility of the particle…

[Phys. Rev. E 81, 051201] Published Wed May 26, 2010

In applying vibration-transit (V-T) theory of liquid dynamics to the thermodynamic properties of monatomic liquids, the point has been reached where an improved model is needed for the small $\left(\sim 10\mathrm{\%}\right)$ transit contribution. Toward this goal, an analysis of the available high-temperature experimental ent…

[Phys. Rev. E 81, 041201] Published Wed Apr 21, 2010

We introduce a family of bounded repulsive potentials, which we call the cut ramp potential, obtained by cutting a linear ramp potential at different heights. We find that for the uncut ramp potential the system shows a region of anomalous re-entrant melting (a negative slope of the melting line in …

[Phys. Rev. E 81, 031201] Published Mon Mar 22, 2010

We present a study of hydrogen at pressures higher than molecular dissociation using the coupled electron-ion Monte Carlo method. These calculations use the accurate reptation quantum Monte Carlo method to estimate the electronic energy and pressure while doing a Monte Carlo simulation of the proton…

[Phys. Rev. E 81, 021202] Published Wed Feb 24, 2010

Liquid water, at ambient conditions, has short-range density correlations which are well known in literature. Surprisingly, large scale molecular-dynamics simulations reveal an unusually long-distance correlation in “longitudinal” part of dipole-dipole orientational correlations. It is nonvanishing …

[Phys. Rev. E 81, 021201] Published Tue Feb 09, 2010

The physics of the heat conduction and viscous dissipation in rarefied gases is analyzed and discussed. A heat transfer model valid for arbitrary Knudsen numbers, defined as the ratio of the molecular mean free path to the characteristic length of channels, is derived by treating the heat transfer b…

[Phys. Rev. E 81, 011204] Published Tue Jan 26, 2010

For understanding the behavior of a gas close to a channel wall it is important to model the gas-wall interactions as detailed as possible. When using molecular dynamics simulations these interactions can be modeled explicitly, but the computations are time consuming. Replacing the explicit wall wit…

[Phys. Rev. E 81, 011203] Published Fri Jan 22, 2010

The generalized Langevin theory for a solution has been derived as the infinite dilution limit of the theory for a two component mixture. Following a similar formalism, the mode coupling approximations of the memory kernel have been also obtained. We have applied this method for one component bulk l…

[Phys. Rev. E 81, 011202] Published Thu Jan 14, 2010

The dynamic flow behavior of a hard-disk fluid under external force field in two-dimensional microchannels is investigated using an event-driven molecular dynamics simulation method. Simulations have been carried out under laminar and subsonic conditions in both slip regime and transition regime, an…

[Phys. Rev. E 81, 011201] Published Tue Jan 05, 2010

We discuss some interesting physical features stemming from our previous analytical study of a simple model of a fluid with dipolarlike interactions of very short range in addition to the usual isotropic Baxter potential for adhesive spheres. While the isotropic part is found to rule the global stru…

[Phys. Rev. E 80, 061207] Published Thu Dec 31, 2009

Thermally induced variation in wetting ability in a confined nanoenvironment, indicated by the change in infiltration pressure as water molecules enter a model single-walled carbon nanotube submerged in aqueous environment, is investigated using molecular dynamics simulations. The temperature-depend…

[Phys. Rev. E 80, 061206] Published Tue Dec 15, 2009

Rosenfeld [Phys. Rev. A 15, 2545 (1977)] originally noticed that casting the transport coefficients of simple monatomic equilibrium fluids in a specific dimensionless form makes them approximately single-valued functions of excess entropy. This observation has predictive value because, while the tra…

[Phys. Rev. E 80, 061205] Published Mon Dec 14, 2009

Nonequilibrium molecular dynamics simulations have been performed to estimate, analyze, and correlate the thermal conductivity of a fluid composed of short Lennard-Jones chains (up to 16 segments) over a large range of thermodynamic conditions. It is shown that the dilute gas contribution to the the…

[Phys. Rev. E 80, 061202] Published Thu Dec 10, 2009

We analyze the models that account the ionic contribution to the complex dielectric constant of a nematic liquid crystal. We compare the predictions of the model of [Sawada et al., Mol. Cryst. Liq. Cryst. Sci. Technol., Sect. A 318, 225 (1998)] based on the assumption that the electric field in the…

[Phys. Rev. E 80, 061203] Published Thu Dec 10, 2009

The validity of the Stokes-Einstein (SE) relation for particle diffusion in the nano- and molecular scales has attracted much interest, but the results in the literature are controversial. In this work, it is shown that there exists a critical particle size where the SE relation breaks down by compa…

[Phys. Rev. E 80, 061204] Published Thu Dec 10, 2009

Thermodiffusion in associating mixtures is a complex phenomenon, owing to the strong dependence of the molecular structure of such mixtures on concentration. In this paper, we attempt to elucidate this phenomenon and propose a qualitative mechanism for the separation of species in binary associating…

[Phys. Rev. E 80, 061201] Published Thu Dec 03, 2009

Kirkwood-Buff (KB) solution theory is a means to obtain certain thermodynamic derivatives from knowledge of molecular distributions. In actual practice the required integrals over radial distribution functions suffer inaccuracies due to finite-distance truncation effects and their use in closed syst…

[Phys. Rev. E 80, 051203] Published Mon Nov 23, 2009

We apply the method of invariant manifolds to derive equations of generalized hydrodynamics from the linearized Boltzmann equation and determine exact transport coefficients, obeying Green-Kubo formulas. Numerical calculations are performed in the special case of Maxwell molecules. We investigate, t…

[Phys. Rev. E 80, 051202] Published Tue Nov 10, 2009

We consider the one-dimensional transport of ions into a perm-selective solid. Direct attempts to evaluate the current-voltage characteristics for currents exceeding the diffusion limit are frustrated by the appearance of nonconverging integrals. We describe how to overcome this obstacle using a reg…

[Phys. Rev. E 80, 051201] Published Fri Nov 06, 2009

Molecular-dynamics calculations of the translational dynamic structure factor in liquid ${\text{CO}}_2$ and ${\text{CD}}_4$ are analyzed by means of the generalized Langevin equation for the intermediate scattering function in the second-order memory function approximation. We give a rigorous general relation among the dec…

[Phys. Rev. E 80, 040201(R)] Published Mon Oct 12, 2009

Recently we proposed a method to solve the perturbed Boltzmann equation modeled by the Bhatnagar-Gross-Krook operator [Phys. Rev. E 74, 041204 (2006)]. In this work we use this method to derive linear transport equations in the whole collisionality range. A comparison of the closure relations derive…

[Phys. Rev. E 80, 041201] Published Fri Oct 02, 2009

Correlation functions and transport coefficients of self-diffusion and shear viscosity of a binary Lennard-Jones mixture with components differing only in their particle mass are studied up to high values of the mass ratio $\mu$, including the limiting case $\mu =\infty$, for different mole fractions $x$. Within a …

[Phys. Rev. E 80, 021202] Published Mon Aug 31, 2009

Shear viscosities of supercritical carbon dioxide have been measured to 673 K and 8 GPa (80 kbar). Measurements were made in a diamond-anvil cell with a rolling-ball technique. Individual isotherms are well fit by a modified free-volume equation. The data demonstrate a close relation between viscosi…

[Phys. Rev. E 80, 021201] Published Wed Aug 19, 2009

Following the nonequilibrium thermodynamics approach, we develop a dynamic model to emulate thermo-diffusion process and propose expressions for estimating the thermal diffusion factor in binary nonassociating liquid mixtures. Here, we correlate the net heat of transport in thermodiffusion with para…

[Phys. Rev. E 80, 011201] Published Mon Jul 20, 2009

In the original formulation of vibration-transit (V-T) theory for monatomic liquid dynamics, the transit contribution to entropy was taken to be a universal constant, calibrated to the constant-volume entropy of melting. This model suffers two deficiencies: (a) it does not account for experimental e…

[Phys. Rev. E 79, 051201] Published Wed May 20, 2009

We report a computer-simulation study of the equilibrium phase diagram of a three-dimensional system of particles with a repulsive-shoulder potential. The phase diagram was obtained using free-energy calculations. At low temperatures, we observe a number of distinct crystal phases. We show that at c…

[Phys. Rev. E 79, 051202] Published Wed May 20, 2009

Using nonequilibrium molecular-dynamics simulation, we study the shear-rate dependence of pressure and potential energy in a liquid metal subjected to shear. We show that both thermodynamic properties vary according to a power law ${\dot{\gamma }}^{\beta }$ of the shear rate $\dot{\gamma }$, in which the exponent $\beta$ is a simple linear …

[Phys. Rev. E 79, 052201] Published Thu May 14, 2009

We perform molecular dynamics simulations to investigate hydrogen-bond dynamics of the TIP5P (transferable intermolecular potential with five points) model of water confined in a quasi-two-dimensional hydrophobic nanopore slit. We find that even if the average number and the lifetime of hydrogen bon…

[Phys. Rev. E 79, 041202] Published Tue Apr 14, 2009

We study the dynamic susceptibility ${\chi }_T\left(Q,t\right)$ of deeply supercooled water by means of quasielastic neutron scattering and molecular dynamics simulations. Both techniques show an increase in the peak height of ${\chi }_T\left(Q,t\right)$ as the temperature is lowered toward the dynamic crossover temperature $T_L$. Below $T_L$, …

[Phys. Rev. E 79, 040201(R)] Published Tue Apr 07, 2009

The radiometric force on several configurations of heated plates placed in a stagnant gas is examined experimentally, with a high-resolution thrust stand, and numerically using the direct simulation Monte Carlo method and a discrete ordinate solution of a model kinetic equation. A wide range of pres…

[Phys. Rev. E 79, 041201] Published Mon Apr 06, 2009

A theoretical approach to the description of the Soret effect in binary nonpolar liquids is proposed. The temperature gradient of the partial pressure is determined as the driving force of thermal diffusion. The hard-sphere fluid is chosen as a reference system and an explicit relation for the Soret…

[Phys. Rev. E 79, 031204] Published Mon Mar 30, 2009

Diffusivity, ionic conductivity, and viscosity of network-forming ionic melts are examined using molecular dynamics simulations of $\mathrm{Be}{\mathrm{F}}_2$ and $\mathrm{Si}{\mathrm{O}}_2$ melts. These tetrahedral, network-forming ionic melts are shown to possess a conductivity anomaly, in addition to waterlike viscosity and diffusivity anoma…

[Phys. Rev. E 79, 030202(R)] Published Wed Mar 25, 2009

It is known that there are thermodynamic states for which the Gaussian-core fluid displays anomalous properties such as expansion upon isobaric cooling (density anomaly) and increased single-particle mobility upon isothermal compression (self-diffusivity anomaly). Here, we investigate how temperatur…

[Phys. Rev. E 79, 031203] Published Wed Mar 18, 2009

We simulate numerically the time evolution of 1000 interacting hard spheres in a finite box with periodic boundary conditions, and repeat the simulations many times for a selected random distribution of initial conditions. We use the resulting data to compute, directly, the smallest nonzero eigenval…

[Phys. Rev. E 79, 031202] Published Mon Mar 16, 2009

We study the shear-induced diffusion effect and the transition to irreversibility in suspensions under oscillatory shear flow by performing an analysis of the entropy production associated with the motion of the particles. We show that the Onsager coupling between different contributions to the entr…

[Phys. Rev. E 79, 031201] Published Fri Mar 06, 2009

The smallest maximum-kissing-number Voronoi polyhedron of three-dimensional (3D) Euclidean spheres is the icosahedron, and the tetrahedron is the smallest volume that can show up in Delaunay tessellation. No periodic lattice is consistent with either, and hence these dense packings are geometrically…

[Phys. Rev. E 79, 030201(R)] Published Tue Mar 03, 2009

We develop a nonequilibrium mode-coupling theory for uniformly sheared systems starting from microscopic, thermostatted Sllod equations of motion. Our theory aims at describing stationary-state properties including rheological ones of sheared systems, and this is accomplished via two steps. First, a…

[Phys. Rev. E 79, 021203] Published Fri Feb 20, 2009

The Kelvin equation relates the equilibrium vapor pressure of a fluid to the curvature of the fluid-vapor interface and predicts that vapor condensation will occur in pores or irregularities that are sufficiently small. Past analyses of capillary condensation in porous systems with fractal structure…

[Phys. Rev. E 79, 021202] Published Tue Feb 10, 2009

Extensive nonequilibrium molecular dynamics (NEMD) simulations have been carried out in order to estimate the Newtonian shear viscosity of a fluid composed of short chains (up to 16 segments) of jointed spheres [Lennard-Jones chain (LJC)] over a large range of thermodynamic conditions. Using the NEM…

[Phys. Rev. E 79, 021201] Published Wed Feb 04, 2009

The temperature increase of a thin water layer is investigated, both experimentally and numerically, when the layer is heated by an infrared laser. The laser is focused to a waist of $5.3\mu \mathrm{m}$ inside a $28\mu \mathrm{m}$ gap that contains fluorescent aqueous solutions between two glass slides. Temperature fields are …

[Phys. Rev. E 79, 011201] Published Wed Jan 07, 2009

We investigate the microscopic structure of strongly coupled ions in warm dense matter using ab initio simulations and hypernetted chain (HNC) equations. We demonstrate that an approximate treatment of quantum effects by weak pseudopotentials fails to describe the highly degenerate electrons in warm…

[Phys. Rev. E 79, 010201(R)] Published Tue Jan 06, 2009

We demonstrate that, in general, only for fluid flows in which the gradient of the strain rate is constant or zero can the classical Navier-Stokes equations with constant transport coefficients be considered exact. This is typical of two of the most common types of flow: Couette and Poiseuille. For …

[Phys. Rev. E 78, 051202] Published Fri Nov 21, 2008

Using the five-site transferable intermolecular potential (TIP5P) we perform molecular dynamics simulations to investigate the relationship between the excess entropy and anomalies of water. We find that the two-body excess entropy is an ideal quantity to predict the regions of structural, dynamic, …

[Phys. Rev. E 78, 051201] Published Wed Nov 19, 2008