Equilibria in the transport epitaxial formation of indium phosphide and arsenide

1986 ◽  
Vol 51 (6) ◽  
pp. 1213-1221 ◽  
Author(s):  
Ivo Braun ◽  
Přemysl Klíma ◽  
Josef Stejskal ◽  
Čestmír Černý ◽  
Petr Voňka ◽  
...  
Keyword(s):  
Indium Phosphide ◽  
Indium Arsenide ◽  
Theoretical Calculations ◽  
Equilibrium Mixture ◽  
Pure Liquid ◽  
Gaseous State ◽  
First Case ◽  
Other Substances ◽  
The Ideal ◽  
Ideal Gaseous State

From the data available in literature, equilibria were calculated of the reactions which come into consideration in the preparation of indium phosphide and indium arsenide. In the first case it was supposed that indium phosphide was formed as a pure solid substance, that indium might exist either as a pure liquid, or as a gas and that the remaining 16 components in the equilibrium mixture were in the ideal gaseous state. In the second case, the formation of pure solid indium arsenide and the existence of 18 other substances in the equilibrium mixture, also in the ideal gaseous state, were supposed. The results of these theoretical calculations for indium phosphide were compared with the experimental deposition temperatures and reasonable agreement has been found.

Studies on rotational barriers in alkyl halogenides by means of vibrational spectroscopy

1980 ◽  
Vol 45 (4) ◽  
pp. 984-996 ◽  
Author(s):  
Michal Bureš ◽  
Čestmír Černý
Keyword(s):  
Simple Model ◽  
Internal Rotation ◽  
Infrared Spectra ◽  
Conformational Transitions ◽  
Gaseous State ◽  
Rotational Barriers ◽  
Halogenated Alkanes ◽  
Kinetics Of ◽  
The Ideal ◽  
Ideal Gaseous State

A simple model describing the influence of the neighbouring molecules on the mechanism of the internal rotation in a given molecule has been proposed which allows the calculation of the barrier hindering the internal rotation in the ideal gaseous state from the temperature dependencyof the infrared spectra. To ascertain its adequacy, the kinetics of conformational transitions in seven halogenated alkanes has been investigated, and values of the activation enthalpies accompanying the internal rotation in a solution as well as the rotational barriers in the ideal gaseous state have been determined.

EFFECTS OF SULFUR SUBSTITUTIONAL IMPURITIES ON ZnO STRUCTURE USING DENSITY FUNCTIONAL THEORY

2011 ◽  
Vol 10 (03) ◽  
pp. 381-390
Author(s):  
MANUEL ALBERTO FLORES-HIDALGO ◽  
DIANA BARRAZA-JIMÉNEZ ◽  
DANIEL GLOSSMAN-MITNIK
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Structural Changes ◽  
Theoretical Calculations ◽  
Plane Waves ◽  
Crystal Form ◽  
Functional Theory ◽  
Substitutional Impurity ◽  
Gap Energy ◽  
Other Substances

Zinc oxide ( ZnO ) electrical properties can be modified by addition of impurities or defects such as vacancies or other substances. We use sulfur ( S ) as a substitutional impurity and present a theoretical study on the characteristics of ZnO structures in its crystal form containing S in substitution of O . For theoretical calculations we used Density Functional Theory (DFT) with pseudopotentials and plane waves. ZnO in crystal form with S in substitution of O at heavy percentage was studied by analyzing properties like lattice characteristics, total energy, and gap energy. Lattice parameters a, b, c, and c/a ratio increase with the S -substituent percentage while the crystal stability decreases. Variation of gap energy shows a decreasing trend with increasing amount of substitution. In this paper, we provide a detailed data useful to identify the effects on ZnO in its crystal form when O is replaced by S that will help to predict if the structural changes on the modified ZnO structures may be suitable for applications in opto-electronics.

scholarly journals The Spermicidal Powers of Chemical Contraceptives: II. Pure Substances

1931 ◽  
Vol 31 (2) ◽  
pp. 189-214 ◽  
Author(s):  
John R. Baker
Keyword(s):  
Saline Solution ◽  
Potassium Cyanide ◽  
Standard Technique ◽  
The Body ◽  
Hydrogen Ions ◽  
Prussic Acid ◽  
Other Substances ◽  
Reduce Surface Tension ◽  
Pure Substances ◽  
The Ideal

1. A technique for comparing the spermicidal powers of pure substances is described in detail. It is hoped that this may be accepted as the standard technique for the purpose.2. The killing concentration of each substance is determined by this technique. The killing concentration is defined as the lowest concentration, in the series 2, 1, ½, ¼ per cent., etc., which suffices to kill every guinea-pig sperm suspended in glucose-saline solution in half an hour at the temperature of the body in four consecutive experiments, the majority of the control sperms being moderately or very active.3. 36 substances have been graded by this technique.4. Mercuric chloride and formaldehyde were found to be the most spermicidal substances. The killing concentration of each per cent.5. Hexyl resorcin kills at per cent., soaps at per cent.6. Formaldehyde and hexyl resorcin, among other substances, seem likely to be useful as contraceptives.7. The significance of the high spermicidal power of soaps is discussed.8. Quinine bisulphate and chinosol, which are perhaps more commonly used as contraceptives than any other substances, only kill at ½ per cent.9. Certain very poisonous substances have very slight spermicidal powers. This applies to potassium cyanide, prussic acid and strychnine hydrochloride.10. Foaming mixtures, consisting of acids and sodium bicarbonate, could probably be used alone as contraceptives.11. The acrosome is the part of the sperm most vulnerable to spermicides. It tends to swell up and burst.12. Sperms are very susceptible to changes in osmotic pressure.13. It is the hydrogen ions and not the anions of acids that kill sperms.14. The suggestion that tribasic acids would be found to be more spermicidal than dibasic, and dibasic than monobasic, is not substantiated.15. Substances which reduce surface tension are often effective spermicides.16. The characters of the ideal chemical contraceptive are discussed.17. The need for co-operation in research in chemical contraception is stressed.

STRUCTURAL AND DYNAMICAL PROPERTIES OF LIQUID PD–AG ALLOYS

2004 ◽  
Vol 18 (16) ◽  
pp. 2257-2269 ◽  
Author(s):  
H. H. KART ◽  
M. TOMAK ◽  
M. ULUDOĞAN ◽  
T. ÇAĞIN
Keyword(s):  
Liquid Metals ◽  
Theoretical Calculations ◽  
Dynamics Simulation ◽  
Pure Liquid ◽  
Many Body ◽  
Self Diffusion ◽  
Dynamical Properties ◽  
Effects Of Temperature ◽  
Potential Parameters ◽  
Good Agreement

Structural and dynamical properties of Pd, Ag pure liquid metals and especially Pd x Ag 1-x alloys are studied by the molecular dynamics simulation. The effects of temperature and concentration on the liquid properties of Pd x Ag 1-x are analyzed. Sutton–Chen (SC) and Quantum Sutton–Chen (Q–SC) many-body potentials are used as interatomic interactions. The calculated diffusion constants and viscosities are in good agreement with the available experimental data and theoretical calculations. The coefficients of Arrhenius equation are also presented to calculate the self-diffusion coefficient and shear viscosity of Pd–Ag alloys at the desired temperature and concentration. We have shown that Q–SC potential parameters are more reliable in determining physical properties of metals and their alloys studied in this work.

Comment on the paper ‘On the influence of the Hall effect on the spectrum of the ideal magnetohydrodynamic cylindrical pinch’ by U. Schaper

1984 ◽  
Vol 31 (1) ◽  
pp. 173-175 ◽  
Author(s):  
A. Lifshitz ◽  
E. Fedorov ◽  
U. Schaper
Keyword(s):  
Eigenvalue Problem ◽  
Hall Effect ◽  
Distributional Sense ◽  
General Properties ◽  
First Case ◽  
Ideal Magnetohydrodynamic ◽  
Image Position ◽  
The Continuum ◽  
The Ideal

General properties of the eigenvalues of Schaper (1983), concerning the continuum of eigenvalues on p. 7, needs correction. The solutions in the distributional sense of the eigenvalue problem (5.3), will be given for two cases. The first case has been solved by A. Lifshitz and E. Fedorov and concerns continuous eigenvalues. In the second case, the solution for the points of accumulation of discrete eigenvalues is discussed.

Theoretical Calculations of the Ideal Strength of Ni, NiAl and Ni3Al in Tension and Shear

2018 ◽  
Vol 10 (10) ◽  
pp. 1420-1426 ◽  
Author(s):  
Zhiqin Wen ◽  
Yuhong Zhao ◽  
Huijun Li ◽  
Yongmei Zhang ◽  
Shuo Wang ◽  
...  
Keyword(s):  
Theoretical Calculations ◽  
Ideal Strength ◽  
The Ideal
Sign in / Sign up

Export Citation Format

Share Document