Monatomic plasma-thermal radiation interaction: a weakly-ionized kinetic model

1975 ◽  
Vol 13 (3) ◽  
pp. 523-537 ◽  
Author(s):  
Warren F. Phillips ◽  
Vedat S. Arpaci
Keyword(s):  
Kinetic Model ◽  
Thermal Radiation ◽  
Local Equilibrium ◽  
Degree Of Ionization ◽  
Kinetic Formulation ◽  
Equilibrium Degree ◽  
Proposed Model ◽  
Weakly Ionized ◽  
Conservation Principles ◽  
Monatomic Gas

A model for the kinetic formulation of a weakly-ionized monatomic gas, which interacts with thermal radiation, is proposed. The collision terms for particle-initiated ionization, developed in terms of a non-equilibrium degree of ionization, and the collision terms for photon-initiated ionization, developed by assuming particles remain in local equilibrium during photon relaxation, all satisfy the usual conservation principles. It is also shown that the proposed model leads to an H theorem.

scholarly journals Model for the Interaction of Thermal Radiation with a Monatomic Plasma

1976 ◽  
Vol 31 (9) ◽  
pp. 1038-1041 ◽  
Author(s):  
J. R. Saraf
Keyword(s):  
Kinetic Model ◽  
Thermal Radiation ◽  
Coordinate System ◽  
Inertial Coordinate System ◽  
Proposed Model ◽  
Weakly Ionized ◽  
H Theorem ◽  
Weakly Ionized Plasma ◽  
Energy And Momentum

Abstract A kinetic model for a weakly-ionized plasma interacting with radiation is proposed based on the energy-momentum method, in which both energy and momentum of the system are conserved. The radiation-initiated ionization is obtained in a non-inertial coordinate system, and the proposed model satisfies the H-theorem.

Time-temperature and time-stress correspondence in nonlinear creep. Experimental behaviour of amorphous polymers and quantitative modelling approaches

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
José R. S. André ◽  
José J. C. Cruz Pinto
Keyword(s):  
Nonlinear Creep ◽  
Predictive Capability ◽  
Kinetic Formulation ◽  
Time Stress ◽  
Relative Contribution ◽  
Proposed Model ◽  
Fully Coupled ◽  
Experimental Behaviour ◽  
Modelling Approach

Abstract Non-linear creep is described by a non-simulative, analytical, dynamic molecular modelling approach. Elementary, molecular-scale, process-relevant frequencies are derived by adequate kinetic formulation. They follow almost exactly an Arrhenius-like behaviour with a range of activation enthalpies. Their relative contribution to the overall macroscopic behaviour of the materials is quantified to account for the materials’ retardation time spectra and final non-Arrhenius behaviour. A new creep compliance equation is derived, yielding a fully coupled timetemperature- stress formulation, with long-term predictive capability. Experimental data for poly(methyl methacrylate) are analysed to identify the extent to which timetemperature and time-stress correspondence relationships may be valid, and it is shown that they are approximations (especially the latter), limited to narrow ranges of experimental variables, in contrast to the proposed model, which more reasonably fits the experimental behaviour.

scholarly journals A kinetically defined Na+/H+ antiporter within a mathematical model of the rat proximal tubule.

1995 ◽  
Vol 105 (5) ◽  
pp. 617-641 ◽  
Author(s):  
A M Weinstein
Keyword(s):  
Kinetic Model ◽  
Proximal Tubule ◽  
Membrane Vesicles ◽  
Model Calculations ◽  
Kinetic Formulation ◽  
Luminal Membrane ◽  
Least Squares Fit ◽  
Velocity Effect ◽  
Rat Proximal Tubule

The luminal membrane antiporter of the proximal tubule has been represented using the kinetic formulation of E. Heinz (1978. Mechanics and Engergetics of Biological Transport. Springer-Verlag, Berlin) with the assumption of equilibrium binding and 1:1 stoichiometry. Competitive binding and transport of NH+4 is included within this model. Ion affinities and permeation velocities were selected in a least-squares fit to the kinetic parameters determined experimentally in renal membrane vesicles (Aronson, P.S., M.A. Suhm, and J. Nee. 1983. Journal of Biological Chemistry. 258:6767-6771). The modifier role of internal H+ to enhance transport beyond the expected kinetics (Aronson, P.S., J. Nee, and M. A. Suhm. 1982. Nature. 299:161-163) is represented as a velocity effect of H+ binding to a single site. This kinetic formulation of the Na+/H+ antiporter was incorporated within a model of the rat proximal tubule (Weinstein, A. M. 1994. American Journal of Physiology. 267:F237-F248) as a replacement for the representation by linear nonequilibrium thermodynamics (NET). The membrane density of the antiporter was selected to yield agreement with the rate of tubular Na+ reabsorption. Simulation of 0.5 cm of tubule predicts that the activity of the Na+/H+ antiporter is the most important force for active secretion of ammonia. Model calculations of metabolic acid-base disturbances are performed and comparison is made among antiporter representations (kinetic model, kinetic model without internal modifier, and NET formulation). It is found that the ability to sharply turn off Na+/H+ exchange in cellular alkalosis substantially eliminates the cell volume increase associated with high HCO3- conditions. In the tubule model, diminished Na+/H+ exchange in alkalosis blunts the axial decrease in luminal HCO3- and thus diminishes paracellular reabsorption of Cl-. In this way, the kinetics of the Na+/H+ antiporter could act to enhance distal delivery of Na+, Cl-, and HCO3- in acute metabolic alkalosis.

A kinetic model for fluid—wall interaction

2008 ◽  
Vol 222 (5) ◽  
pp. 787-795 ◽  
Author(s):  
A Frezzotti ◽  
L Gibelli
Keyword(s):  
Kinetic Model ◽  
Kinetic Equations ◽  
Particle Methods ◽  
Simple Extension ◽  
Enskog Theory ◽  
Dense Fluids ◽  
Proposed Model ◽  
Different Temperatures ◽  
Wall Interaction ◽  
Dynamics Simulations

A kinetic model of fluid—wall interaction is proposed, on the basis of a simple extension of Enskog theory of dense fluids. The model leads to a linear integro-differential equation which can be solved by the same statistical particle methods used to solve kinetic equations for dilute or dense fluids. The proposed model is applied to study the heat transport through a low density gas confined between two parallel walls kept at different temperatures. The results are compared with molecular dynamics simulations.

Kinetic Model with Effect of Water Content for Enzyme-Catalyzed Citronellyl Laurate Esterification Process

2013 ◽  
Vol 284-287 ◽  
pp. 423-428 ◽  
Author(s):  
Siti Asyura Zulkeflee ◽  
Suhairi Abd Sata ◽  
Norashid Aziz
Keyword(s):  
Experimental Data ◽  
Kinetic Model ◽  
Water Content ◽  
Model Development ◽  
Initial Water Content ◽  
Initial Water ◽  
Effect Of Water ◽  
Proposed Model ◽  
Optimal Value ◽  
Influence Of Water

A kinetic model with effect of water content for enzyme-catalyzed citronellyl laurate was developed. These models incorporate the combined influences of established kinetics model with the function model on the effect of initial water content with kinetic parameters. The model development was carried out by performing a linear and nonlinear regression based on the behavior of the kinetic parameter profiles and validated with experimental data. Using the developed models, the influence of water content towards the enzyme-catalyzed initial rate of reaction was theoretically explained. It has been shown that the proposed model have good agreement between experimental data and intends to capture the effect of water content towards the conversion of ester. With this model, the optimal value of initial water content for this process could be estimated.

Diatomic gas—thermal radiation interaction A model equation for the internal fluid

1972 ◽  
Vol 7 (2) ◽  
pp. 235-246 ◽  
Author(s):  
Warren F. Phillips ◽  
Vedat S. Arpaci
Keyword(s):  
Kinetic Equation ◽  
Thermal Radiation ◽  
Model Equation ◽  
Diatomic Molecules ◽  
Collision Term ◽  
Model Kinetic Equation ◽  
Photon Interaction ◽  
Internal Fluid ◽  
Proposed Model ◽  
Alternative Approach

A model kinetic equation for the internal fluid of diatomic molecules which interacts with thermal radiation is proposed. The cross-collision term developed for the molecule-photon interaction has the property that molecules and the sum of internal and photon energies are conserved. An alternative approach to this term based on the product of two BGKW collision operators yields the same result. It is also shown that the proposed model leads to an H-theorem.

scholarly journals Solution Polymerization of Acrylic Acid Initiated by Redox Couple Na-PS/Na-MBS: Kinetic Model and Transition to Continuous Process

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 850
Author(s):  
Federico Florit ◽  
Paola Rodrigues Bassam ◽  
Alberto Cesana ◽  
Giuseppe Storti
Keyword(s):  
Kinetic Model ◽  
Acrylic Acid ◽  
Continuous Process ◽  
Scale Up ◽  
Tubular Reactor ◽  
Kinetic Scheme ◽  
Redox Couple ◽  
Polymerization Process ◽  
Proposed Model ◽  
Population Balances

This work aims at modeling in detail the polymerization of non-ionized acrylic acid in aqueous solution. The population balances required to evaluate the main average properties of molecular weight were solved by the method of moments. The polymerization process considered is initiated by a persulfate/metabisulfate redox couple and, in particular, the kinetic scheme considers the possible formation of mid-chain radicals and transfer reactions. The proposed model is validated using experimental data collected in a laboratory-scale discontinuous reactor. The developed kinetic model is then used to intensify the discontinuous process by shifting it to a continuous one based on a tubular reactor with intermediate feeds. One of the experimental runs is selected to show how the proposed model can be used to assess the transition from batch to continuous process and allow faster scale-up to industrial scale using a literature approach.

scholarly journals Zur Lumineszenzschädigung von ZnS/Cu

1969 ◽  
Vol 24 (6) ◽  
pp. 937-942 ◽  
Author(s):  
R. Grasser ◽  
A. Scharmann
Keyword(s):  
Kinetic Model ◽  
Radiation Damage ◽  
Green Emission ◽  
Experimental Results ◽  
Mass Energy ◽  
Proposed Model ◽  
Luminescent Centers

The resistance to radiation damage of the blue and green emission bands of ZnS/Cu is found to vary with mass, energy and dose of incident ions. The experimental results are discussed with Schön’s kinetic model and our proposed model for luminescent centers in ZnS.

scholarly journals Three species one-dimensional kinetic model for weakly ionized plasmas

2016 ◽  
Vol 23 (6) ◽  
pp. 062311 ◽  
Author(s):  
J. Gonzalez ◽  
J. M. Donoso ◽  
S. P. Tierno
Keyword(s):  
Kinetic Model ◽  
One Dimensional ◽  
Ionized Plasmas ◽  
Weakly Ionized
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