The ledge mechanism of pearlite growth: Some thoughts on the solution to the kinetic problem

1994 ◽  
Vol 30 (8) ◽  
pp. 1031-1036 ◽  
Author(s):  
M.J. Whiting ◽  
P. Tsakiropoulos
Keyword(s):  
Kinetic Problem ◽  
Ledge Mechanism

Features of Difference Scheme for the Diffusion-Kinetic Problem of Ion Implantation with Intermetallic Phases Formation

2016 ◽  
Vol 685 ◽  
pp. 195-199
Author(s):  
Khan Asfandyar ◽  
Anna G. Knyazeva
Keyword(s):  
Ion Implantation ◽  
Difference Scheme ◽  
Intermetallic Phase ◽  
Relaxation Times ◽  
Phase Evolution ◽  
Linear Difference Equations ◽  
Sweep Method ◽  
Diffusion Kinetic ◽  
Kinetic Problem ◽  
Mass Fluxes

The implicit difference scheme has been suggested for the solution of diffusion-kinetic problem describing the ion implantation by intermetallic phase formation. The model corresponds to irreversible conditions and includes finite relaxation times for mass fluxes. The linear difference equations are solved by double-sweep method. The result illustrates the convergence of difference scheme at variation of its parameters. Qualitative picture of phase evolution in the surface layer is obtained different for problem with finite relaxation times and for zero relaxation times.

1. On Some Capillary Phenomena

1866 ◽  
Vol 5 ◽  
pp. 593-594
Author(s):  
Tait
Keyword(s):  
Rapid Change ◽  
Closed Shell ◽  
Soap Bubble ◽  
Coal Gas ◽  
Kinetic Problem ◽  
Capillary Phenomena ◽  
Two Bubbles

This communication was intended to illustrate by experiments with the solution of glycerine and oleate of soda, devised by Plateau, the mode in which a soap-bubble is detached as a closed shell from the mouth of a funnel; the mode in which two bubbles unite; and the process of cutting one into two or more.A statical investigation of the form of an unclosed film, blown with coal gas, was given (the kinetic problem presenting very grave difficulties), and the results were shown to be in accordance with observation, so far as the eye can follow the rapid change which takes place in the neck of the film just before the closed bubble is detached.

The atomic structure of growth interfaces in Y–Ba–Cu–O thin films

1991 ◽  
Vol 6 (11) ◽  
pp. 2264-2271 ◽  
Author(s):  
R. Ramesh ◽  
A. Inam ◽  
D.M. Hwang ◽  
T.S. Ravi ◽  
T. Sands ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Structure ◽  
Film Growth ◽  
Substrate Surface ◽  
Oriented Growth ◽  
Surface Steps ◽  
Nucleation Sites ◽  
Oriented Films ◽  
Second Phases ◽  
Ledge Mechanism

We have examined the atomic structure of growth interfaces in thin films of Y–Ba–Cu–O grown on [001] perovskite or cubic substrates. At substrate heater temperatures in the range of 780–820 °C c-axis oriented growth is observed on these substrates. On SrTiO3, the first layer appears to be either a BaO or a CuO2 plane while on LaAlO3 the first layer appears to be a CuO chain layer. The mismatch on the a-b plane is accommodated by the formation of interface dislocations. Defects on the substrate surface propagate as defects in the film. These defects are primarily translational boundaries and in some cases second phases. At lower substrate heater temperatures, i.e., 650–700 °C, a, b-axis growth dominates. Defects and steps on the substrate surface are more detrimental in the growth of a, b-axis oriented films, since they tend to favor the nucleation of c-axis oriented domains. This is ascribed to the ledge mechanism of c-axis film growth, for which the surface steps are good nucleation sites.

Effect of Ta on the Structure and Dynamics of γ/α2 Interfaces in Tial

1990 ◽  
Vol 213 ◽  
Author(s):  
S. R. Singh ◽  
J. M. Howe
Keyword(s):  
Partial Dislocation ◽  
Growth Mechanisms ◽  
Tial Alloys ◽  
Shockley Partial ◽  
Structure And Dynamics ◽  
Partial Dislocations ◽  
Α2 Phase ◽  
Atomically Flat ◽  
Ledge Mechanism ◽  
Image Simulations

ABSTRACTThe structure of γ/α interfaces in binary and Ta-containing TiAl alloys were analyzed by HRTEM and image simulations. Growth of α2 was found to be due to a ledge mechanism, consisting of Shockley partial dislocations on alternate (111)γ planes. The interface is atomically flat between the ledges and addition of Ta was found to transform arrays of growth ledges in the binary alloy into islands on the plate faces in the Ta-containing alloy. These islands of α2 on the γ/α2 interfaces were 4–7nm wide and increased in size with decreasing ageing temperature. The height of the ledges and islands were always a multiple of the c-parameter (0.46nm) of the α2 phase. The islands were bounded by 90°(edge) and 30° screw) Shockley partial dislocations. The 30° partial dislocation cores were localized whereas the 90° partial dislocation cores appeared to be highly delocalized due to presence of a high density of kinks, which in one case was found to be about 0.65nm−1.These results are interpreted in terms of the growth mechanisms and morphology of the α2 phase.

The Growth Kinetics and Shape Evolution of Precipitates Growing by the Ledge Mechanism

1991 ◽  
Vol 237 ◽  
Author(s):  
Masato Enomoto ◽  
George Spanos ◽  
Robert A. Masumura
Keyword(s):  
Growth Kinetics ◽  
Diffusion Field ◽  
Shape Evolution ◽  
Field Interaction ◽  
Relative Growth ◽  
Nucleation Sites ◽  
Simulation Results ◽  
Kinetics Of ◽  
Ledge Mechanism ◽  
Evolution Of Precipitates

ABSTRACTThe characteristics of ledge growth of precipitates are investigated by a previously developed finite-difference computer model. The plate lengthening simulation results which incorporate measured ledge heights and spacings are in reasonable agreement with the observed lengthening behavior of plates in Fe-C alloys. The simulation which takes into account the diffusion field interaction among multiple precipitates shows that a variety of precipitate morphologies actually observed can possibly be formed solely by the change in the extent of diffusion field overlap among ledges and/or neighboring precipitates. This overlap is in turn caused by changes in the solute supersaturation, distribution of ledge nucleation sites and ledge nucleation rates. A brief discussion is made of the relative growth kinetics of ledged and disordered interfaces.

Investigating the Effect of Gripping on Upper Limbs Muscles by Modeling and Electromyography Test

2012 ◽  
Vol 232 ◽  
pp. 147-151
Author(s):  
Ghazaleh Azizpour ◽  
Mohsen Sadeghimehr ◽  
Mesbahoreza Sharifi
Keyword(s):  
The Other ◽  
Cost Functions ◽  
Upper Limbs ◽  
Power Grip ◽  
Inverse Kinetic Problem ◽  
Kinetic Problem ◽  
Other Hand

These days most of the workers use hand controller tools. Because of this it is useful to know the relations between hand and these kinds of tools. One of these relations is cylindrical power grip. For this reason first of all a device is prepared for measuring the torque value. After that by creating a model in ANYBODY software for gripping motion for forces and muscular activities have been calculated. In this case for solving the inverse kinetic problem several cost functions are defined and the results are compared. On the other hand, by using Electromyography tests in gripping motion the activity of 3 surface muscles are investigated and finally the modeling and Electromyography’s results are compared.

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