Analysis of reactive ion transport in weakly ionized gas mixtures

1991 ◽  
Vol 69 (7) ◽  
pp. 1090-1099 ◽  
Author(s):  
Koichi Iinuma
Keyword(s):  
Ion Transport ◽  
Transport Theory ◽  
Dynamic Equilibrium ◽  
Transport Coefficients ◽  
Three Dimensional ◽  
Reaction Rates ◽  
Gas Mixtures ◽  
Reaction Scheme ◽  
Inelastic Process ◽  
Neutral Gas

A new formulation for the analysis of low density multiple-ion swarms drifting, diffusing, and inter-reacting in a neutral gas is proposed on a transport theory basis. A set of coupled three-dimensional transport equations for an arbitrary number of ion species, which governs the number densities of the ion swarms as functions of time and position coordinates, is exactly solved using a Fourier transform in a matrix representation. A picture of dynamic equilibrium state for hypothetical four ion swarms in a neutral gas is numerically obtained. Also, experimental data of transport coefficients and reaction rates for (Li+, Li+•N2, Li+•2N2)flN2 system are examined in a complete reversible cyclic reaction scheme and compared with a Green's function method. The initial and boundary conditions, the analysis in gas mixtures, and the inelastic process associated with the present formulation are briefly discussed. Key words: ion swarm, cluster ion, transport equation, ion–molecule reaction.

scholarly journals Nonlinear Diffusion of Ions in a Gas

1975 ◽  
Vol 28 (5) ◽  
pp. 523 ◽  
Author(s):  
RE Robson
Keyword(s):  
Kinetic Equation ◽  
Ion Transport ◽  
Nonlinear Diffusion ◽  
Drift Tube ◽  
Diffusion Processes ◽  
Transport Coefficients ◽  
Model Kinetic Equation ◽  
Neutral Gas

The evolution in time of an initially closely bunched group of ions in a neutral gas is examined by solving a model kinetic equation, and limits to the validity of the linear law of diffusion (Pick's law) are established. The implications of nonlinear diffusion processes for determination of ion transport coefficients in drift tube experiments are discussed.

Composition dependence of ion-transport coefficients in gas mixtures

1974 ◽  
Vol 9 (2) ◽  
pp. 1017-1020 ◽  
Author(s):  
J. H. Whealton ◽  
E. A. Mason ◽  
R. E. Robson
Keyword(s):  
Ion Transport ◽  
Composition Dependence ◽  
Transport Coefficients ◽  
Gas Mixtures

Three Dimensional Tests on Dynamic Equilibrium and Artificial Nourishment

1977 ◽  
Author(s):  
J. W. Kamphuis ◽  
R.M. Myers
Keyword(s):  
Dynamic Equilibrium ◽  
Three Dimensional ◽  
Artificial Nourishment

Experimental and simulation study of impurity transport response to RMPs in RF-heated H-mode plasmas at EAST

2021 ◽  
Vol 87 (2) ◽  
Author(s):  
Germán Vogel ◽  
Hongming Zhang ◽  
Yongcai Shen ◽  
Shuyu Dai ◽  
Youwen Sun ◽  
...  
Keyword(s):  
Inner Core ◽  
Extreme Ultraviolet ◽  
Transport Coefficients ◽  
Three Dimensional ◽  
Line Emission ◽  
Core Region ◽  
Emission Mitigation ◽  
One Dimensional ◽  
Impurity Transport ◽  
Transport Code

Spatial profiles of impurity emission measurements in the extreme ultraviolet (EUV) spectroscopic range in radiofrequency (RF)-heated discharges are combined with one-dimensional and three-dimensional transport simulations to study the effects of resonant magnetic perturbations (RMPs) on core impurity accumulation at EAST. The amount of impurity line emission mitigation by RMPs appears to be correlated with the ion Z for lithium, carbon, iron and tungsten monitored, i.e. stronger suppression of accumulation for heavier ions. The targeted effect on the most detrimental high-Z impurities suggests a possible advantage using RMPs for impurity control. Profiles of transport coefficients are calculated with the STRAHL one-dimensional impurity transport code, keeping $\nu /D$ fixed and using the measured spatial profiles of $\textrm{F}{\textrm{e}^{20 + }}$ , $\textrm{F}{\textrm{e}^{21 + }}$ and $\textrm{F}{\textrm{e}^{22 + }}$ to disentangle the transport coefficients. The iron diffusion coefficient ${D_{\textrm{Fe}}}$ increases from $1.0- 2.0\;{\textrm{m}^2}\;{\textrm{s}^{ - 1}}$ to $1.5- 3.0\;{\textrm{m}^2}\;{\textrm{s}^{ - 1}}$ from the core region to the edge region $(\rho \gt 0.5)$ after the onset of RMPs. Meanwhile, an inward pinch of iron convective velocity ${\nu _{\textrm{Fe}}}$ decreases in magnitude in the inner core region and increases significantly in the outer confined region, simultaneously contributing to preserving centrally peaked $\textrm{Fe}$ profiles and exhausting the impurities. The ${D_{\textrm{Fe}}}$ and ${\nu _{\textrm{Fe}}}$ variations lead to reduced impurity contents in the plasma. The three-dimensional edge impurity transport code EMC3-EIRENE was also applied for a case of RMP-mitigated high-Z accumulation at EAST and compared to that of low-Z carbon. The exhaust of ${\textrm{C}^{6 + }}$ toward the scrape-off layer accompanying an overall suppression of heavier ${\textrm{W}^{30 + }}$ is observed when using RMPs.

Study on Engineering Mechanical Properties of Mayanpo Slope at Xiangjiaba Hydropower Station

2012 ◽  
Vol 548 ◽  
pp. 511-515
Author(s):  
Jian Hui Sun ◽  
Long Jiang ◽  
Wan Shun Wang ◽  
Chen Lin Xiong ◽  
Zhao Hui Zhu
Keyword(s):  
Mechanical Properties ◽  
Field Test ◽  
Dynamic Equilibrium ◽  
Three Dimensional ◽  
Strength Reduction ◽  
Hydropower Station ◽  
Weak Interlayer ◽  
Internal Deformation ◽  
Three Stages ◽  
Changing Rate

Through the field test of Mayanpo slope at Xiangjiaba Hydropower Station, external deformation, deep deformation, groundwater level and stability of the slope with weak interlayer are analyzed in this paper. The results show that: ① displacement deformation increases with time and decreases with increasing depth. Changes of displacement can be divided into three stages: deformation rapidly increases in the early, and slowly increases in the medium, and becomes gradually stable in the later. Changing rate of displacement decreases with time, and the rate can also be divided into three stages, basically consistent with the displacement changing stage; ② a certain thickness of weak interlayer and evident dislocation exists in slope strata. Dislocation rate first increases and then decreases until basically stable, and local fluctuation is mainly affected by rainfall and dynamic equilibrium adjustment of the slope internal deformation; ③based on the penalty function contact of pile soil and the surface of rock mass, the three-dimensional numerical model of coupling of seepage and strain has been established, and through analyzing and comparing with field test data, it is verified that the model is feasible in the study on slope deformation; ④ through stability analysis of Mayanpo slope by strength reduction FEM, stability coefficient is 1.72.

Experimental evidence for the need of thermodynamic considerations in modelling of anaerobic environmental bioprocesses

1997 ◽  
Vol 36 (10) ◽  
pp. 109-115 ◽  
Author(s):  
Choon-Yee Hoh ◽  
Ralf Cord-Ruwisch
Keyword(s):  
Free Energy ◽  
Experimental Evidence ◽  
Positive Reaction ◽  
Rate Equation ◽  
Dynamic Equilibrium ◽  
Reaction Rates ◽  
Product Inhibition ◽  
Experimental Results ◽  
Biological Processes ◽  
Laws Of Thermodynamics

For modeling of biological processes that operate close to the dynamic equilibrium (eg. anaerobic processes), it is critical to prevent the prediction of positive reaction rates when the reaction has already reached dynamic equilibrium. Traditional Michaelis-Menten based models were found to violate the laws of thermodynamics as they predicted positive reaction rates for reactions that were endergonic due to high endproduct concentrations. The inclusion of empirical “product inhibition factors” as suggested by previous work could not prevent this problem. This paper compares the predictions of the Michaelis-Menten Model (with and without product inhibition factors) and the Equilibrium Based Model (which has a thermodynamic term introduced into its rate equation) with experimental results of reactions in anaerobic bacterial environments. In contrast to the Michaelis-Menten based models that used traditional inhibition factors, the Equilibrium Based Model correctly predicted the nature and the degree of inhibition due to endproduct accumulation. Moreover, this model also correctly predicted when reaction rates must be zero due to the free energy change of the conversion reaction being zero. With these added advantages, the Equilibrium Based Model thus seemed to provide a scientifically correct and more realistic basis for a variety of models that describe anaerobic biosystems.

Nanofluidic carbon-dioxide sensor using nanoscale hydronium-dominated ion transport theory

2011 ◽  
Author(s):  
A.M. Crumrine ◽  
D. Shah ◽  
M.B. Andersen ◽  
H. Bruus ◽  
S. Pennathur
Keyword(s):  
Carbon Dioxide ◽  
Ion Transport ◽  
Transport Theory ◽  
Carbon Dioxide Sensor

Highly Conjugated Three-Dimensional Covalent Organic Frame- works with Enhanced Li-ion Conductivity as Solid-State Electrolytes for High-Performance Lithium Metal Batteries

2022 ◽  
Author(s):  
Shi Wang ◽  
Xiang-Chun Li ◽  
Tao Cheng ◽  
Yuan-Yuan Liu ◽  
Qiange Li ◽  
...  
Keyword(s):  
Solid State ◽  
Ion Transport ◽  
High Performance ◽  
Three Dimensional ◽  
Ion Conductivity ◽  
Covalent Organic Frameworks ◽  
Lithium Metal ◽  
Lithium Metal Batteries ◽  
Li Ion ◽  
Solid State Electrolytes

Covalent organic frameworks (COFs) with well-tailored channels have the potential to efficiently transport ions yet remain to be explored. The ion transport capability is generally limited due to the lack...

Sign in / Sign up

Export Citation Format

Share Document