scholarly journals A Study of the Liquid–Vapor Phase Change of Mercury Based on Irreversible Thermodynamics

1972 ◽  
Vol 94 (3) ◽  
pp. 257-261 ◽  
Author(s):  
R. R. Adt ◽  
G. N. Hatsopoulos ◽  
W. J. Bornhorst
Keyword(s):  
Phase Change ◽  
Kinetic Analysis ◽  
Rate Equation ◽  
Transport Coefficient ◽  
Transport Coefficients ◽  
Irreversible Thermodynamic ◽  
Irreversible Thermodynamics ◽  
Rate Equations ◽  
Mass Rate ◽  
Evaporation Coefficient

The object of this work is to determine the transport coefficients which appear in linear irreversible-thermodynamic rate equations of a phase change. An experiment which involves the steady-state evaporation of mercury was performed to measure the principal transport coefficient appearing in the mass-rate equation and the coupling transport coefficient appearing in both the mass-rate equation and the energy-rate equation. The principal transport coefficient σ, usually termed the “condensation” or “evaporation” coefficient, is found to be approximately 0.9, which is higher than that measured previously in condensation-of-mercury experiments. The experimental value of the coupling coefficient K does not agree with the value predicted from Schrage’s kinetic analysis of the phase change. A modified kinetic analysis in which the Onsager reciprocal law and the conservation laws are invoked is presented which removes this discrepancy but which shows that the use of Schrage’s equation for predicting mass rates of phase change is a good approximation.

Analysis of a Liquid Vapor Phase Change by the Methods of Irreversible Thermodynamics

1967 ◽  
Vol 34 (4) ◽  
pp. 840-846 ◽  
Author(s):  
W. J. Bornhorst ◽  
G. N. Hatsopoulos
Keyword(s):  
General Theory ◽  
Kinetic Theory ◽  
Phase Change ◽  
Vapor Phase ◽  
Transport Coefficients ◽  
Phase Interface ◽  
Irreversible Thermodynamics ◽  
Rate Equations ◽  
Phenomenological Equations ◽  
Rate Processes

The object of this theoretical investigation is to obtain a set of equations which will predict the behavior of a fluid as it changes phase. Irreversible thermodynamics is employed to obtain general rate equations which relate the fluxes and forces across the nonequilibrium region existing at a phase interface. Both plane and spherical interfaces are considered. Experimental means for determining the three transport coefficients which appear in the resulting equations are discussed. Approximate values for the transport coefficients are obtained from kinetic theory arguments. The present analysis is limited to phase-change problems which may be described by linear phenomenological equations; this is so when the change in the driving potentials is small as compared to their value on either side of the phase interface. This restriction is necessary since presently no general theory exists for nonlinear rate processes.

A New Adsorption Rate Equation in Batch Systems

2018 ◽  
Author(s):  
yongson hong ◽  
Kye-Ryong Sin ◽  
Jong-Su Pak ◽  
Chol-Min Pak
Keyword(s):  
Experimental Data ◽  
Kinetic Analysis ◽  
Adsorption Kinetics ◽  
Rate Equation ◽  
Kinetic Models ◽  
Adsorption Kinetic ◽  
Adsorption Rate ◽  
Batch Systems ◽  
New View

<p><b>In this paper, the deficiencies and cause of previous adsorption kinetic models were revealed, new adsorption rate equation has been proposed and its validities were verified by kinetic analysis of various experimental data.</b> <b>This work is a new view on the adsorption kinetics rather than a comment on the previous adsorption papers.</b></p>

Self-Diffusion Coefficient and Viscosity in Fluids

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Lawrence Novak
Keyword(s):  
Experimental Data ◽  
Diffusion Coefficient ◽  
Transport Coefficient ◽  
Transport Coefficients ◽  
Dynamics Simulation ◽  
Residual Entropy ◽  
Transport Reaction ◽  
Self Diffusion ◽  
Coefficient Corrélation ◽  
Self Diffusion Coefficient

Rate-based models suitable for equipment or transport-reaction modeling require a capability for predicting transport coefficients over a sufficient range of temperature and pressure. This paper demonstrates a relatively simple novel approach to correlate and estimate transport coefficients for pure components over the entire fluid region.The use of Chapman-Enskog transport coefficients for reducing self-diffusion coefficient and viscosity to dimensionless form results in relatively simple mathematical relationships between component dimensionless transport coefficients and residual entropy over the entire fluid region. Dimensionless self-diffusion coefficients and viscosities were calculated from extensive molecular dynamics simulation data and experimental data on argon, methane, ethylene, ethane, propane, and n-decane. These dimensionless transport coefficients were plotted against dimensionless residual entropy calculated from highly accurate reference equations of state.Based on experimental data, the new scaling model introduced here shows promise as: (1) an equation of state-based transport coefficient correlation over the entire fluid region (liquid, gas, and critical fluid), (2) a component transport coefficient correlation for testing transport data consistency, and (3) a component transport coefficient correlation for interpolation and extrapolation of self-diffusion coefficient and viscosity.

Determination of transport constants of isolated Nitella cell walls

1968 ◽  
Vol 46 (4) ◽  
pp. 317-327 ◽  
Author(s):  
M. T. Tyree
Keyword(s):  
Activation Energy ◽  
Cell Wall ◽  
Diffusion Coefficient ◽  
Cell Walls ◽  
Transport Coefficients ◽  
Irreversible Thermodynamics ◽  
Kcal Mole ◽  
Limiting Value ◽  
Nitella Flexilis

Transport coefficients LPP, LPE, LEP, and LEE for electrokinetic equations according to irreversible thermodynamics, the Onsager coefficients, were measured for isolated Nitella flexilis cell walls in KCl solutions ranging from 10−4 to 100 normal. LPP and LPE (= LEP) were found to be independent of KCl concentration and equal to 1.4 × 10−6 cm3 sec−1 cm−2 (joule cm−3)−1 cm and 6 × 10−5 cm3 sec−1 cm−2 volt−1 cm respectively. LEE was a function of the salt concentration, reaching a limiting value of about 1.2 × 10−3 mho cm−1 in 10−4 N KCl. The activation energy for movement of KCl in cell walls was found to be 4.33 Kcal mole−1; the diffusion coefficient for KCl in cell walls was calculated by two methods to be 8 × 10−6 cm2 sec−1; and the concentration of the fixed ions in Nitella cell walls from the above data was estimated at greater than 0.04 equivalent per liter of cell wall. Electroosmosis in Nitella membranes is re-examined in the light of the measured transport coefficients and it is concluded that under proper conditions the cell wall of Nitella can contribute significantly (~20% or more) to the observed electroosmosis of living Nitella cells.

Modeling of Gas Turbine Combustors—A Convenient Reaction Rate Equation

1972 ◽  
Vol 94 (3) ◽  
pp. 173-180 ◽  
Author(s):  
D. Kretschmer ◽  
J. Odgers
Keyword(s):  
Rate Equation ◽  
Reaction Rate ◽  
Reaction Order ◽  
Bimolecular Reaction ◽  
Rate Equations ◽  
Combustion System ◽  
Wide Range ◽  
Simple Mass ◽  
Rich Mixtures ◽  
Reaction Rate Equation

In order to model a practical combustion system successfully, it is necessary to develop one or more reaction rate equations which will describe performance over a wide range of conditions. The equations should be kept as simple as possible and commensurate with the accuracy needed. In this paper a bimolecular reaction is assumed, based upon a simple mass balance. Temperatures derived from the latter are related to measured practical ones such that, if required, an evaluation of the partly burned product composition can be made. A convenient reaction rate equation is given which describes a wide range of blow-out data for spherical reactors at weak mixture conditions. NVP2φ={1.29×1010(m+1)[5(1−yε)]φ[φ−yε]φe−C/(Ti+εΔT)}/{0.082062φyε[5(m+1)+φ+yε]2φ[Ti+εΔT]2φ−0.5} Analysis of the components used in the above equation (especially the variation of activation energy) clearly shows its empirical nature but does not detract from its engineering value. Rich mixtures are considered also, but lack of data precludes a reliable analysis. One of the major results obtained is the variation of the reaction order (n) with equivalence ratio (φ): weak mixtures, n = 2φ; rich mixtures, n = 2/φ. Some support for this variation has been noticed in published literature of other workers.

scholarly journals Externally driven molecular ratchets on a periodic potential surface: a rate equations approach

2019 ◽  
Vol 21 (42) ◽  
pp. 23310-23319
Author(s):  
Hongqian Sang ◽  
David Abbasi-Pérez ◽  
José Manuel Recio ◽  
Lev Kantorovich
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Rate Equation ◽  
Periodic Potential ◽  
Energy Surface ◽  
Potential Surface ◽  
Rate Equations ◽  
Time Dynamics ◽  
Long Time ◽  
Long Time Dynamics

The long time dynamics of molecular ratchets on a 1D periodic potential energy surface (PES) subjected to an external stimulus is studied using the rate equation method.

A New Adsorption Rate Equation in Batch Systems

2018 ◽  
Author(s):  
yongson hong ◽  
Kye-Ryong Sin ◽  
Jong-Su Pak ◽  
Chol-Min Pak
Keyword(s):  
Experimental Data ◽  
Kinetic Analysis ◽  
Adsorption Kinetics ◽  
Rate Equation ◽  
Kinetic Models ◽  
Adsorption Kinetic ◽  
Adsorption Rate ◽  
Batch Systems ◽  
New View

<p><b>In this paper, the deficiencies and cause of previous adsorption kinetic models were revealed, new adsorption rate equation has been proposed and its validities were verified by kinetic analysis of various experimental data.</b> <b>This work is a new view on the adsorption kinetics rather than a comment on the previous adsorption papers.</b></p>

“Fast” and “Slow” Metastable Defects in a-Si:H

1993 ◽  
Vol 297 ◽  
Author(s):  
Liyou Yang ◽  
Liang-Fan Chen
Keyword(s):  
Rate Equation ◽  
Defect Density ◽  
Convincing Evidence ◽  
Experimental Results ◽  
Component Model ◽  
Rate Equations ◽  
Defect States ◽  
Defect Generation ◽  
Two Component ◽  
Different Characteristics

A two-step light soaking experiment at high and low intensities provided convincing evidence that defect generation and annealing in a-Si:H are controlled by defect states of different characteristics. We point out that the total defect density by itself cannot uniquely determine the state of material or be described by a single rate equation, even though it might be the only quantity that is experimentally measurable. A system of rate equations for all defect components, therefore, must be established in order to accurately describe the defect kinetics. A simple two-component model in which defects are categorized as “fast” or “slow” is shown to be adequate to explain a variety of experimental results in a consistent fashion.

Irreversible Thermodynamic Discussions about Ferroelectric Phase Transitions

2013 ◽  
Vol 756-759 ◽  
pp. 4419-4422
Author(s):  
Jin Song Wang
Keyword(s):  
Phase Transitions ◽  
Ferroelectric Phase ◽  
Thermal Hysteresis ◽  
Intrinsic Property ◽  
Irreversible Thermodynamic ◽  
Irreversible Thermodynamics ◽  
Minimum Entropy ◽  
First Order ◽  
Minimum Entropy Production ◽  
Ferroelectric Phase Transitions

The irreversibility of ferroelectric phase transitions has been studied by using the irreversible thermodynamics. The thermal hysteresis of first-order ferroelectric phase transitions and the polydomain structure of ferroelectrics can be explained on the basis of the principle of minimum entropy production. A conclusion has been derived that the thermal hysteresis is not an intrinsic property of a system in which a first-order ferroelectric phase transition occurs. The finiteness of the systems surface is connected with the thermal hysteresis.

Irreversible Thermodynamic Description of Domain Occurrences in Ferroics

2012 ◽  
Vol 560-561 ◽  
pp. 140-144
Author(s):  
Yuan Zhen Cai
Keyword(s):  
Phase Transitions ◽  
Entropy Production ◽  
Stationary State ◽  
Thermodynamic Description ◽  
Irreversible Thermodynamic ◽  
Irreversible Thermodynamics ◽  
Minimum Entropy ◽  
Spatial Symmetry ◽  
Domain Structures ◽  
Minimum Entropy Production

Based on the irreversible thermodynamics, a irreversible thermodynamic description of domain occurrences in ferroics such as ferroelectrics, ferromagnetics and ferroelastics was given. The ferroic domain structures occur at the ferroic phase transitions from the prototype phases to the ferroic phases. The processes of transition are stationary state processes so that the principle of minimum entropy production is satisfied. The domain occurrences are a consequence of this principle. The time-spatial symmetry related to the domains and their occurrences was also expounded.

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