The possible existence within the framework of the ?atomic block? reinforcement theory of certain extrema in the ?property-impurity concentration? curves

1967 ◽  
Vol 10 (6) ◽  
pp. 88-90
Author(s):  
E. G. Okonnikov
Keyword(s):  
Impurity Concentration ◽  
Reinforcement Theory ◽  
Atomic Block ◽  
Concentration Curves

The nucleation of cavities at grain boundaries

1987 ◽  
Vol 45 ◽  
pp. 288-291
Author(s):  
P. J. Goodhew
Keyword(s):  
Surface Tension ◽  
Surface Energy ◽  
Grain Boundaries ◽  
Radiation Damage ◽  
Impurity Concentration ◽  
Driving Force ◽  
Nucleation And Growth ◽  
Phase Boundaries ◽  
Cavity Nucleation ◽  
Spherical Bubble

Cavity nucleation and growth at grain and phase boundaries is of concern because it can lead to failure during creep and can lead to embrittlement as a result of radiation damage. Two major types of cavity are usually distinguished: The term bubble is applied to a cavity which contains gas at a pressure which is at least sufficient to support the surface tension (2g/r for a spherical bubble of radius r and surface energy g). The term void is generally applied to any cavity which contains less gas than this, but is not necessarily empty of gas. A void would therefore tend to shrink in the absence of any imposed driving force for growth, whereas a bubble would be stable or would tend to grow. It is widely considered that cavity nucleation always requires the presence of one or more gas atoms. However since it is extremely difficult to prepare experimental materials with a gas impurity concentration lower than their eventual cavity concentration there is little to be gained by debating this point.

INTERSECTING TAX CONCENTRATION CURVES AND THE MEASUREMENT OF TAX PROGRESSIVITY

1986 ◽  
Vol 39 (1) ◽  
pp. 115-118 ◽  
Author(s):  
JOHN P. FORMBY ◽  
W. JAMES SMITH ◽  
DAVID SYKES
Keyword(s):  
Tax Progressivity ◽  
Concentration Curves

The asymptotic stage of longitudinal turbulent dispersion within a tube

1977 ◽  
Vol 80 (2) ◽  
pp. 293-303 ◽  
Author(s):  
R. Dewey ◽  
Paul J. Sullivan
Keyword(s):  
Turbulent Flows ◽  
Friction Velocity ◽  
Turbulent Dispersion ◽  
Time Interval ◽  
Longitudinal Diffusion ◽  
A Value ◽  
Discharge Velocity ◽  
Concentration Curves ◽  
Temporal Growth Rate ◽  
Short Times

This paper describes an experimental investigation of the conditions for which the asymptotic description of longitudinal dispersion given by Taylor (1954) would apply. At non-dimensional times following the release of a dye pulse that are significantly larger than those previously investigated, the integrated concentration curves were observed to be skewed. At relatively short times from release the concentration curves appear to be well described by the models presented by Sullivan (1971) and by Chatwin (1973). Some features of the asymptotic behaviour, namely the translation of the modal value of the integrated concentration curve at the discharge velocity and the constant temporal growth rate of the variance, are observed at the longest times following release. On the basis of these observations it is estimated that a non-dimensional time interval oftu*/d=O(105/R*), whereR*=u*d/v,u*is the friction velocity,vthe kinematic viscosity anddthe tube diameter, is required for the Taylor result to become applicable. Thus application of Taylor's theory is significantly restricted in turbulent flows, especially those with irregular boundaries and those that are not stationary. There the variations in the flow must be small with respect to an equivalent ‘development time’ if a value of the ‘local’ longitudinal diffusion coefficient is to have meaning.

Effects of finite impurity concentration in van Hove superconductors

1998 ◽  
Vol 58 (5) ◽  
pp. 2448-2451
Author(s):  
I. Tifrea ◽  
M. Crisan
Keyword(s):  
Impurity Concentration

scholarly journals Attractive Fermi polarons at nonzero temperatures with a finite impurity concentration

2018 ◽  
Vol 98 (1) ◽  
Author(s):  
Hui Hu ◽  
Brendan C. Mulkerin ◽  
Jia Wang ◽  
Xia-Ji Liu
Keyword(s):  
Impurity Concentration

The Vacancy Generation Influence on the Initial Stage of Ion Implantation

2015 ◽  
Vol 1097 ◽  
pp. 29-34
Author(s):  
E.S. Parfenova ◽  
Anna G. Knyazeva
Keyword(s):  
Surface Layer ◽  
Ion Implantation ◽  
Metal Surface ◽  
Impurity Concentration ◽  
Coupled Model ◽  
Irreversible Processes ◽  
Concentration Profiles ◽  
Thermodynamics Of Irreversible Processes ◽  
Vacancy Generation ◽  
Initial Stage

The coupled model is presented to describe the elements penetration into the surface layer of metal during the process of ion implantation. Mechanical stresses arising due to the interaction of particles with the surface affect the redistribution of the implanted impurity. In addition, the existence of vacancies in the metal surface and their generation under the stresses influence are taken into account. The kinetic law is written on the basis of the thermodynamics of irreversible processes. The solution had been found numerically. As a result, the distributions of impurity concentration and deformations have been obtained for various time moments. The comparison of the concentration profiles with vacancies and without their have been given.

Metastable Solid Solutions of Impurities in Silicon

1981 ◽  
Vol 7 ◽  
Author(s):  
J. S. Williams ◽  
K. T. Short
Keyword(s):  
High Resolution ◽  
Solid Solutions ◽  
Impurity Concentration ◽  
Rutherford Backscattering ◽  
Equilibrium Solubility ◽  
Furnace Annealing ◽  
Strain Effects ◽  
Crystal Boundary ◽  
Silicon Lattice ◽  
Supersaturated Solid Solutions

ABSTRACTHigh resolution Rutherford backscattering and channeling techniques have been used to investigate the formation and stability of supersaturated solid solutions of As, Sb, In, Pb, Tℓ and Bi implants in (100) silicon. In all cases nearsubstitutional solid solubilities far exceeding maximum equilibrium solubility limits can be achieved by furnace annealing at temperatures ≤ 600°C. Details of the recrystallisation process indicate that the maximum impurity concentration which can be incorporated onto silicon lattice sites may be controlled by impurity size and associated strain effects at the amorphous-crystal boundary during epitaxial regrowth.

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