Time-Dependent Diffusion−Migration at Cylindrical and Spherical Microelectrodes:  Steady- and Quasi-Steady-State Analytical Solution Can Be Used under Transient Conditions

2007 ◽  
Vol 79 (16) ◽  
pp. 6341-6347 ◽  
Author(s):  
Oleksiy V. Klymenko ◽  
Christian Amatore ◽  
Irina Svir
Keyword(s):  
Steady State ◽  
Analytical Solution ◽  
Time Dependent ◽  
Quasi Steady State ◽  
Transient Conditions ◽  
Diffusion Migration

Development of Local Heat Transfer Models for Safety Assessment of Pebble Bed High Temperature Gas-Cooled Reactor Cores

2008 ◽  
Author(s):  
Richard Stainsby ◽  
Matthew Worsley ◽  
Andrew Grief ◽  
Ana Dennier ◽  
Frances Dawson ◽  
...  
Keyword(s):  
Steady State ◽  
Analytical Solution ◽  
Local Heat Transfer ◽  
Research Programme ◽  
Local Heat ◽  
Normal Operation ◽  
Fuel Particle ◽  
Transient Conditions ◽  
Multi Scale ◽  
The Individual

This paper presents a model developed for determining fuel particle and fuel pebble temperatures in normal operation and transient conditions based on multi-scale modelling techniques. This model is qualified by comparison with an analytical solution in a one-dimensional linear steady state test problem. Comparison is made with finite element simulations of an idealised “two-dimensional” pebble in transient conditions and with a steady state analytical solution in a spherical pebble geometry. A method is presented for determining the fuel temperatures in the individual batches of a multi-batch recycle refuelling regime. Implementation of the multi-scale and multibatch fuel models in a whole-core CFD model is discussed together with the future intentions of the research programme.

Kinetics of Biocatalytical Synergistic Reactions

2005 ◽  
Vol 10 (3) ◽  
pp. 223-233 ◽  
Author(s):  
J. Kulys
Keyword(s):  
Steady State ◽  
Analytical Solution ◽  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Stationary State ◽  
Initial Rate ◽  
Kinetic Constants ◽  
Quasi Steady State ◽  
The Novel ◽  
Kinetics Of

Kinetics of biocatalytical synergistic reactions has been analyzed at non-stationary state (NSS) and at quasi steady state (QSS) conditions. The application to the model kinetic constants taken from the first type of the experiments shows that QSS can be established for the enzyme and the mediator at time less than 1 s. Therefore, the analytical solution of the initial rate (IR) may be produced at relevant to an experiment time, and the dependence of the IR on substrates concentration may be analyzed rather easy. The use of kinetic constants from the second type of reactions shows that QSS is formed for the enzyme but not for the mediator. For this reason the modeling of the synergistic process was performed by solving the ordinary differential equations (ODE). For this purpose the novel program KinFitSim (c) was used.

Magnetic Field Assisted Finishing of Ceramics—Part II: On the Thermal Aspects of Magnetic Float Polishing (MFP) of Ceramic Balls

1998 ◽  
Vol 120 (4) ◽  
pp. 652-659 ◽  
Author(s):  
Zhen-Bing Hou ◽  
R. Komanduri
Keyword(s):  
Steady State ◽  
Thermal Model ◽  
Small Area ◽  
A Priori ◽  
Mechanical Action ◽  
Quasi Steady State ◽  
Flash Duration ◽  
Transient Conditions ◽  
Low Load ◽  
Magnetic Float

The thermal model developed in Part I of this three-part series is applied in this paper to magnetic float polishing (MFP) of ceramic (Si3N4) balls. Using this method, the flash temperatures, flash times, and temperature distribution at the interface between the balls and the shaft of the MFP apparatus are calculated. Examination of the polished surfaces (scratch lengths) of the balls showed that the length of most scratches during the final stage of polishing is <20 μm and most are formed under transient conditions. But because of the small area of contact and low load encountered in MFP, the results of the calculations under these conditions were found to be very close to the quasi-steady-state conditions. However, it is not possible to know a priori if the conditions are transient or quasi-steady state unless solutions are available for each case. The use of the general solution developed in Part I enables this determination. The minimum flash temperatures and minimum flash times that occur during polishing ensure the determination if adequate temperatures are generated for chemo-mechanical polishing to take place. Of course, the lengths of the scratches would be much longer and the corresponding flash duration longer during the semifinishing operation than during flnishing. The combined temperature and flash duration would determine the extent of chemo-mechanical action under these conditions. The flash temperatures and flash times required for chemo-mechanical action can be used as a basis for the optimization of polishing conditions in MFP.

scholarly journals MATHEMATICAL MODEL OF ELECTRODIFFUSION, DISSOCIATION AND RECOMBINATION IN THE DIFFUSIVE LAYER

2014 ◽  
Vol 19 (4) ◽  
pp. 443-449
Author(s):  
Andrey V. Shobukhov ◽  
Nadejda P. Savenkova ◽  
Runar N. Kuzmin ◽  
Dmitry S. Maximov
Keyword(s):  
Mathematical Model ◽  
Steady State ◽  
Negative Ions ◽  
Time Dependent ◽  
Stable Steady State ◽  
Electrochemical System ◽  
Various Boundary Conditions ◽  
Electrochemical Processes ◽  
Diffusion Migration ◽  
Diffusive Layer

We study a mathematical model of electrochemical processes in the thin diffusive layer of polymer electrolyte between the electrode and the bulk. We consider diffusion, migration, dissociation and recombination of positive and negative ions in the electric field that take place in this region under various boundary conditions. We demonstrate that the unique stable steady state of the electrochemical system is determined by the ratio of dissociation to recombination. This state attracts time-dependent solutions of the model, but their convergence strongly depends on the electroneutrality of the bulk.

Network reconstruction based on steady-state data

2008 ◽  
Vol 45 ◽  
pp. 161-176 ◽  
Author(s):  
Eduardo D. Sontag
Keyword(s):  
Steady State ◽  
Reverse Engineering ◽  
Theoretical Method ◽  
Network Reconstruction ◽  
Quasi Steady State ◽  
State Data

This paper discusses a theoretical method for the “reverse engineering” of networks based solely on steady-state (and quasi-steady-state) data.

Quasi-steady-state performance of a heat pipe subjected to transient acceleration loadings

10.2514/3.895 ◽  
1997 ◽  
Vol 11 ◽  
pp. 306-309 ◽  
Author(s):  
Edwin H. Olmstead ◽  
Edward S. Taylor ◽  
Meng Wang ◽  
Parviz Moin ◽  
Scott K. Thomas ◽  
...  
Keyword(s):  
Steady State ◽  
Heat Pipe ◽  
Quasi Steady State ◽  
Steady State Performance
Sign in / Sign up

Export Citation Format

Share Document