The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Davide Donadio - One of the best experts on this subject based on the ideXlab platform.
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structure and dynamics of the quasi Liquid Layer at the surface of ice from molecular simulations
Journal of Physical Chemistry C, 2018Co-Authors: Tanja Kling, Felix Kling, Davide DonadioAbstract:We characterized the structural and dynamical properties of the quasi-Liquid Layer (QLL) at the surface of ice by molecular dynamics simulations with a thermodynamically consistent water model. Our simulations show that for three low-index ice surfaces, only the outermost molecular Layer presents short-range and midrange disorder and is diffusive. The onset temperature for normal diffusion is much higher than the glass temperature of supercooled water, although the diffusivity of the QLL is higher than that of bulk water at the corresponding temperature. The underlying subsurface Layers impose an ordered template, which produces a regular patterning of the ice/water interface at any temperature and is responsible for the major differences between QLL and bulk water, especially for what concerns the dynamics and the midrange structure of the hydrogen-bonded network. Our work highlights the need for a holistic approach to the characterization of QLL, as a single experimental technique may probe only one spe...
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structure and dynamics of the quasi Liquid Layer at the surface of ice from molecular simulations
The Journal of Physical Chemistry, 2018Co-Authors: Tanja Kling, Felix Kling, Davide DonadioAbstract:We characterized the structural and dynamical properties of the quasi-Liquid Layer (QLL) at the surface of ice by molecular dynamics simulations with a thermodynamically consistent water model. Our simulations show that for three low-index ice surfaces, only the outermost molecular Layer presents short-range and midrange disorder and is diffusive. The onset temperature for normal diffusion is much higher than the glass temperature of supercooled water, although the diffusivity of the QLL is higher than that of bulk water at the corresponding temperature. The underlying subsurface Layers impose an ordered template, which produces a regular patterning of the ice/water interface at any temperature and is responsible for the major differences between QLL and bulk water, especially for what concerns the dynamics and the midrange structure of the hydrogen-bonded network. Our work highlights the need for a holistic approach to the characterization of QLL, as a single experimental technique may probe only one specific feature, missing part of the complexity of this fascinating system.
Valeria Molinero - One of the best experts on this subject based on the ideXlab platform.
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The Quasi-Liquid Layer of Ice under Conditions of Methane Clathrate Formation
The Journal of Physical Chemistry C, 2012Co-Authors: Tricia D. Shepherd, Matthew A. Koc, Valeria MolineroAbstract:A premelted Layer of water wets the surface of ice at temperatures below the melting temperature. Experiments suggest that this quasi-Liquid Layer may play an important role in the nucleation of clathrate hydrates from ice. Nevertheless, the structure of the quasi-Liquid Layer of ice in the presence of methane or other clathrate-forming gases has not yet been elucidated. In this work, we perform large-scale molecular dynamic simulations with a coarse-grained molecular model to investigate the properties of the quasi-Liquid Layer of ice in the presence of methane gas under pressure. We characterize the structure and thickness of the ice/methane and ice/vacuum interfaces, and the solubility of methane in the premelted Layer as a function of temperature. We find that the width of the quasi-Liquid Layer fluctuates between 5 and 45 A in the presence of a methane-like solute at temperatures within 1 K of the melting point. The width of the quasi-Liquid Layer of ice at temperatures lower than 270 K is less than ...
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the quasi Liquid Layer of ice under conditions of methane clathrate formation
Journal of Physical Chemistry C, 2012Co-Authors: Tricia D. Shepherd, Matthew A. Koc, Valeria MolineroAbstract:A premelted Layer of water wets the surface of ice at temperatures below the melting temperature. Experiments suggest that this quasi-Liquid Layer may play an important role in the nucleation of cl...
A. M. Bagno - One of the best experts on this subject based on the ideXlab platform.
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Effect of Prestresses on the Dispersion of Lamb Waves in a System Consisting of a Viscous Liquid Layer and a Compressible Elastic Layer
International Applied Mechanics, 2018Co-Authors: A. N. Guz, A. M. BagnoAbstract:The propagation of acoustic waves in a pre-deformed compressible elastic Layer that interacts with a Layer of compressible viscous fluid is studied. The results are obtained using the three-dimensional linearized equations of the theory of elasticity of finite strains for the elastic Layer and the three-dimensional linearized Navier–Stokes equations for the viscous compressible fluid. A problem formulation and approach based on the general solutions of the linearized equations for elastic and Liquid Layers are applied. A dispersion equation describing the propagation of harmonic waves in the hydroelastic system over a wide frequency range for a thick Liquid Layer is derived. The effect of the initial stresses and the thicknesses of the elastic and Liquid Layers on the phase velocities and damping factors of Lamb modes is analyzed. It is shown that the viscosity of the fluid helps to reduce the depth of penetration of the lowest quasi-Lamb mode into the fluid Layer. The approach developed and the results obtained make it possible to establish the limits of applicability of the models, based on different versions of the theory of small initial deformations, the classical theory of elasticity, and the model of an ideal fluid. The numerical results presented in the form of plots are analyzed.
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Effect of Liquid Viscosity on Dispersion of Quasi-Lamb Waves in an Elastic-Layer-Viscous-Liquid-Layer System
International Applied Mechanics, 2017Co-Authors: A. N. Guz, A. M. BagnoAbstract:The dispersion curves are constructed and propagation of quasi-Lamb waves are studied for wide range of frequencies based on the Navier–Stokes three-dimensional linearized equations for a viscous Liquid and linear equations of the classical theory of elasticity for an elastic Layer. For a thick Liquid Layer, the effect of the viscosity of the Liquid and the thickness of elastic and Liquid Layers on the phase velocities and attenuation coefficients of quasi-Lamb modes is analyzed. It is shown that in the case of a thick Liquid Layer for all modes, there are elastic Layers of certain thickness with minimal effect of Liquid viscosity on the phase velocities and attenuation coefficients of modes. It is also discovered that for some modes, there are both certain thicknesses and certain ranges of thickness where the effect of Liquid viscosity on the phase velocities and attenuation coefficients of these modes is considerable. We ascertain that Liquid viscosity promotes decrease of the penetration depth of the lowest quasi-Lamb mode into the Liquid. The developed approach and the obtained results make it possible to ascertain for wave processes the limits of applicability of the model of ideal compressible fluid. Numerical results in the form of graphs are adduced and analyzed.
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Effect of Liquid Viscosity on Dispersion of Quasi-Lamb Waves in an Elastic-Layer–Viscous-Liquid-Layer System
International Applied Mechanics, 2017Co-Authors: A. M. BagnoAbstract:The dispersion curves are constructed and propagation of quasi-Lamb waves are studied for wide range of frequencies based on the Navier – Stokes three-dimensional linearized equations for a viscous Liquid and linear equations of the classical theory of elasticity for an elastic Layer. For a thick Liquid Layer, the effect of the viscosity of the Liquid and the thickness of elastic and Liquid Layers on the phase velocities and attenuation coefficients of quasi-Lamb modes is analyzed. It is shown that in the case of a thick Liquid Layer for all modes, there are elastic Layers of certain thickness with minimal effect of Liquid viscosity on the phase velocities and attenuation coefficients of modes. It is also discovered that for some modes, there are both certain thicknesses and certain ranges of thickness where the effect of Liquid viscosity on the phase velocities and attenuation coefficients of these modes is considerable. We ascertain that Liquid viscosity promotes decrease of the penetration depth of the lowest quasi-Lamb mode into the Liquid. The developed approach and the obtained results make it possible to ascertain for wave processes the limits of applicability of the model of ideal compressible fluid. Numerical results in the form of graphs are adduced and analyzed.
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Effect of Prestresses on the Dispersion of Waves in a System Consisting of a Viscous Liquid Layer and a Compressible Elastic Layer
International Applied Mechanics, 2016Co-Authors: A. M. BagnoAbstract:The propagation of acoustic waves in a prestrained compressible elastic Layer that interacts with a compressible viscous Liquid Layer is considered. Use is made of the three-dimensional equations of the linearized theory of finite deformations for the elastic Layer and the three-dimensional linearized Navier–Stokes equations for the Liquid Layer. The problem statement and problem-solving method used are based on the general solutions of the linearized equations for the elastic and Liquid Layers. A dispersion equation describing the propagation of harmonic waves in the hydroelastic system over a wide frequency range is derived for both thin and thick elastic Layers. The effect of the prestresses and the thickness of the Layers on the phase velocities and damping factors of modes is analyzed for thin and thick elastic Layers. It is established that for all the modes beginning from the second one, there are certain values of fluid thicknesses and frequency at which the pretension in the elastic Layer do not affect their phase velocities and damping factors. If the elastic Layer is thick, each mode generated by the fluid is shown to have three such frequencies. The approach developed and the results obtained allow us to identify the limits of applicability of models based on various theories of small initial deformations and the ideal-fluid model
Tanja Kling - One of the best experts on this subject based on the ideXlab platform.
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structure and dynamics of the quasi Liquid Layer at the surface of ice from molecular simulations
Journal of Physical Chemistry C, 2018Co-Authors: Tanja Kling, Felix Kling, Davide DonadioAbstract:We characterized the structural and dynamical properties of the quasi-Liquid Layer (QLL) at the surface of ice by molecular dynamics simulations with a thermodynamically consistent water model. Our simulations show that for three low-index ice surfaces, only the outermost molecular Layer presents short-range and midrange disorder and is diffusive. The onset temperature for normal diffusion is much higher than the glass temperature of supercooled water, although the diffusivity of the QLL is higher than that of bulk water at the corresponding temperature. The underlying subsurface Layers impose an ordered template, which produces a regular patterning of the ice/water interface at any temperature and is responsible for the major differences between QLL and bulk water, especially for what concerns the dynamics and the midrange structure of the hydrogen-bonded network. Our work highlights the need for a holistic approach to the characterization of QLL, as a single experimental technique may probe only one spe...
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structure and dynamics of the quasi Liquid Layer at the surface of ice from molecular simulations
The Journal of Physical Chemistry, 2018Co-Authors: Tanja Kling, Felix Kling, Davide DonadioAbstract:We characterized the structural and dynamical properties of the quasi-Liquid Layer (QLL) at the surface of ice by molecular dynamics simulations with a thermodynamically consistent water model. Our simulations show that for three low-index ice surfaces, only the outermost molecular Layer presents short-range and midrange disorder and is diffusive. The onset temperature for normal diffusion is much higher than the glass temperature of supercooled water, although the diffusivity of the QLL is higher than that of bulk water at the corresponding temperature. The underlying subsurface Layers impose an ordered template, which produces a regular patterning of the ice/water interface at any temperature and is responsible for the major differences between QLL and bulk water, especially for what concerns the dynamics and the midrange structure of the hydrogen-bonded network. Our work highlights the need for a holistic approach to the characterization of QLL, as a single experimental technique may probe only one specific feature, missing part of the complexity of this fascinating system.
Pierre Colinet - One of the best experts on this subject based on the ideXlab platform.
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benard instabilities in a binary Liquid Layer evaporating into an inert gas
Journal of Colloid and Interface Science, 2010Co-Authors: Hatim Machrafi, Pierre Colinet, Alexei Rednikov, Pierre DaubyAbstract:A linear stability analysis is performed for a horizontal Layer of a binary Liquid of which solely the solute evaporates into an inert gas, the latter being assumed to be insoluble in the Liquid. In particular, a water-ethanol system in contact with air is considered, with the evaporation of water being neglected (which can be justified for a certain humidity of the air). External constraints on the system are introduced by imposing fixed "ambient" mass fraction and temperature values at a certain effective distance above the free Liquid-gas interface. The temperature is the same as at the bottom of the Liquid Layer, where, besides, a fixed mass fraction of the solute is presumed to be maintained. Proceeding from a (quasi-)stationary reference solution, neutral (monotonic) stability curves are calculated in terms of solutal/thermal Marangoni/Rayleigh numbers as functions of the wavenumber for different values of the ratio of the gas and Liquid Layer thicknesses. The results are also presented in terms of the critical values of the Liquid Layer thickness as a function of the thickness of the gas Layer. The solutal and thermal Rayleigh and Marangoni effects are compared to one another. For a water-ethanol mixture of 10wt.% ethanol, it appears that the solutal Marangoni effect is by far the most important instability mechanism. Furthermore, its global action can be described within a Pearson-like model, with an appropriately defined Biot number depending on the wavenumber. On the other hand, it is also shown that, if taken into account, water evaporation has only minor quantitative consequences upon the results for this predominant, solutal Marangoni mechanism.
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surface tension driven instabilities of a pure Liquid Layer evaporating into an inert gas
Journal of Colloid and Interface Science, 2005Co-Authors: Benoit Haut, Pierre ColinetAbstract:A theoretical model of the evaporation of a pure Liquid Layer is developed. We focus on the influence of an inert gaseous component, in addition to vapor, on surface-tension-driven Benard instabilities. It is assumed that the gas phase is perfectly mixed at some distance from the Liquid–gas interface (given composition, pressure, and temperature). If this distance is not much larger than the Liquid Layer thickness, it is shown that a reduction of the full two-Layer problem to a one-Layer problem is possible, provided the evaporation rate is not too large. An analytical expression is given for the corresponding dimensionless heat transfer coefficient (a generalized, wavenumber-dependent Biot number) at the evaporating interface. The approach is validated through a comparison with a direct numerical resolution of the full two-Layer problem.
