Mixed Surface Reaction and Diffusion-Controlled Kinetic Model for Adsorption at the Solid/Solution Interface

2013 ◽  
Vol 117 (16) ◽  
pp. 8310-8317 ◽  
Author(s):  
Monireh Haerifar ◽  
Saeid Azizian
Keyword(s):  
Solid Solution ◽  
Kinetic Model ◽  
Surface Reaction ◽  
Solution Interface ◽  
Diffusion Controlled ◽  
And Diffusion ◽  
Reaction And Diffusion

Reliability of cable insulation under reaction- and diffusion-controlled thermal degradation

2018 ◽  
Vol 233 (4) ◽  
pp. 639-647
Author(s):  
Yuan-Shang Chang ◽  
Ali Mosleh
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Safety Issue ◽  
Metal Core ◽  
Cable Insulation ◽  
Elongation At Break ◽  
Degree Of Reaction ◽  
Diffusion Controlled ◽  
And Diffusion ◽  
Reaction And Diffusion

Cables transmit signals and power in nuclear power plants. The primary material for the cable insulation is cross-linked polyethylene, which inevitably degrades due to thermal stress. The degradation can become a safety issue, since the brittleness of degraded cross-linked polyethylene may render the exposure of the metal core in a cable. Elongation at break is a widely accepted measurement, evaluating the degree of the brittleness of the insulation. Reaction- and diffusion-controlled kinetics are proposed in this article to quantitatively predict the decrease of the elongation at break as a function of time and temperature. The proposed approaches are based on dichotomy model and Fick’s Law to respectively define the degree of reaction- and diffusion-controlled degradation. Probabilistic techniques are developed by Bayesian parameter estimation to determine the reliability of the cable insulation. These approaches are validated by experimental data.

Combined reaction and diffusion controlled kinetics of silicidation

1994 ◽  
Vol 250 (1-2) ◽  
pp. 53-55 ◽  
Author(s):  
V.E. Borisenko ◽  
L.I. Ivanenko ◽  
E.A. Krushevski
Keyword(s):  
Diffusion Controlled ◽  
Kinetics Of ◽  
And Diffusion ◽  
Reaction And Diffusion

A New Crack Healing Kinetic Model and Application of Crack Healing Diagram

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Y. Kan ◽  
H. Liu ◽  
S. H. Zhang ◽  
L. W. Zhang ◽  
M. Cheng
Keyword(s):  
Kinetic Model ◽  
Grain Growth ◽  
Healing Time ◽  
Creep Mechanism ◽  
Internal Crack ◽  
Crack Healing ◽  
New Model ◽  
Diffusion Controlled ◽  
Power Law Creep ◽  
And Diffusion

An internal crack is a common defect which can lead to failure of the material. There are few published studies which can quantitatively predict healed fractions under given conditions such as temperature, pressure and healing time. In the current study, a new crack healing kinetic model is developed to predict the healed crack fraction under any given temperature, pressure and healing time. In contrast to previous models, this new model describes the crack surface topography as a series of semi spherical pores, and proposes a new diffusion healing mechanism involving grain growth. Plastic deformation, power law creep and diffusion controlled creep mechanism are considered in this model. A crack healing diagram for 34MnV steel is constructed with axes of healed fraction and temperature or pressure. The predictions from the new model compare well with experimental results. The results of the model indicate that the diffusion controlled creep mechanism contributes little at high temperatures because of grain growth. The critical healing time and pressure can be determined by using the crack healing diagram.

Determination of Diffusion Parameters of Solved Molecules by Measuring the Relaxation Kinetics on the Picosecond Time Scale

1981 ◽  
Vol 36 (12) ◽  
pp. 1323-1326 ◽  
Author(s):  
E. Heumann
Keyword(s):  
Kinetic Model ◽  
Probe Beam ◽  
Time Scale ◽  
Solvent Viscosity ◽  
Diffusion Parameters ◽  
Diffusion Controlled ◽  
Picosecond Time Scale ◽  
Excimer Formation ◽  
And Diffusion

AbstractPicosecond probe beam spectroscopy is used to measure the nonstationary contribution to diffusion controlled excimer formation in dependence on concentration and solvent viscosity. Utilizing a kinetic model, the effective encounter radius and diffusion parameters of pyrene molecules in different solvents have been determined.

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