Experimental and Theoretical Studies on the Stability of Induction Pumps at Large Rm Numbers

1989 ◽  
pp. 325-331 ◽  
Author(s):  
J. Rapin ◽  
Ph. Vaillant ◽  
F. Werkoff
Keyword(s):  
Theoretical Studies ◽  
The Stability ◽  
Experimental And Theoretical Studies

Intrinsic Defects in GaAs - the Case of El2

1987 ◽  
Vol 104 ◽  
Author(s):  
H. J. Von Bardeleben ◽  
D. Stievemard
Keyword(s):  
Electronic Structure ◽  
Stable Configuration ◽  
Theoretical Studies ◽  
Absorption Bands ◽  
Teller Distortion ◽  
Jahn Teller ◽  
The Stability ◽  
Additional Support ◽  
Jahn Teller Distortion ◽  
Experimental And Theoretical Studies

ABSTRACTThe arsenic antisite-arsenic interstitial pair model for the stable configuration of the EL2 defect in GaAs has stimulated new experimental and theoretical studies, the results of which lead to additional support for this model. Recent theoretical studies, taking into account the effect of a Jahn Teller distortion of the T2 Asi levels have given an insight into the stability and the electronic structure of the defect pair. Further, ODENDOR studies have directly confirmed this model and allowed one to specify the lattice location and the charge state of the Asi ion. The pair structure of this defect implies a reconsideration of the charge states of the EL2 defect, as well as the origin of the optical absorption bands for which transitions on the Asi ion and intracenter bands have also to be considered. The model leads further to a description of the metastable configuration : an arsenic molecule at the gallium vacancy site, the electronic structure of which is calculated. The vacancy related defects, known from electron irradiation studies, are not detected in LEC grown GaAs as native defects.

scholarly journals AX2: Type of compounds and an overview of theoretically investigated TiO2

2020 ◽  
Vol 9 (2) ◽  
pp. 79-87
Author(s):  
Dušica Jovanović ◽  
Jelena Zagorac ◽  
Branko Matović ◽  
Aleksandra Zarubica
Keyword(s):  
Band Gap ◽  
Wide Band ◽  
Theoretical Studies ◽  
Chemical Bonds ◽  
Wide Band Gap ◽  
Specific Temperature ◽  
Temperature And Pressure ◽  
The Difference ◽  
The Stability ◽  
Experimental And Theoretical Studies

AX 2-type compounds can be ionic, covalent or molecular types of structure, which depends on the size of atoms and the polarization properties. The materials of such type of the structure have different properties that can find the application in various areas of science and industry. Titanium dioxide, as a material of AX 2-type of the structure is a wide band gap semiconductor that has been widely investigated due to its photocatalytic properties and applicability for various purposes, such as the production of solar cells, decontamination of pollutants, elimination of microorganisms, suppression of cancer cells, etc. Experimental and theoretical studies of this metal oxide can give different data on the stability of individual crystalline modifications and their transitions. This study has presented an overview of theoretically examined TiO 2 modifications and current problems that can be encountered (such as various band gap values obtained by different methods and functionals; the difference between the stability of modifications examined on ab initio level and experimentally; the character of chemical bonds and transitions at the specific temperature and pressure conditions…) and overrun by optimal corrections added in calculations.

MONITORING THE STABILITY OF VERTICAL SHAFT FOR POTASSIUM MINES

2020 ◽  
Vol 3 (1) ◽  
pp. 304-317
Author(s):  
N.M. KACHURIN ◽  
◽  
I.A. AFANASIEV ◽  
V.S. PESTRIKOVA ◽  
P.P. STAS ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Rock Mass ◽  
Strain State ◽  
Theoretical Studies ◽  
Vertical Shaft ◽  
Support Material ◽  
Safe Operation ◽  
Predictive Assessment ◽  
The Stability ◽  
Experimental And Theoretical Studies

As a result of experimental and theoretical studies, the regularities of the interaction of vertical shafts of potash mines with the rock mass were clarified, which allows predictive assessment of the consequences of violations of construction geotechnology projects and to develop effective measures to restore lining and ensure safe operation of shafts. At the same time, during the construction of vertical shafts, deviations from projects occur without modeling the possible consequences of such violations of projects. However, for a predictive assessment of the consequences of violations of construction geotechnology projects and the development of effective recommendations for the restoration and ensuring the safe operation of shafts, it is necessary to use a system of control and measuring monitoring of the support material, and mathematical modeling of its stress-strain state.

On the Magic Character of Al6Au-

2007 ◽  
Vol 72 (2) ◽  
pp. 185-196 ◽  
Author(s):  
Michele L. Kimble ◽  
Albert W. Castleman ◽  
Jose U. Reveles ◽  
Shiv N. Khanna
Keyword(s):  
Flow Reactor ◽  
Experimental Studies ◽  
Gold Clusters ◽  
Laser Vaporization ◽  
Theoretical Studies ◽  
Triangular Face ◽  
Stable Species ◽  
The Stability ◽  
Experimental And Theoretical Studies ◽  
Homo Lumo

Joint experimental and theoretical studies have been carried out to identify the stability of aluminum gold clusters. The experimental studies where the AlnAu- clusters are generated via laser vaporization in a flow reactor and subsequently reacted with oxygen indicate that Al6Au- is an exceptionally stable species that is not only resistant to etching by oxygen but also grows in intensity when AlnAu- clusters are exposed to oxygen. Theoretical studies indicate that the six aluminum atoms in Al6Au- form an octahedron and that the Au atom occupies a hollow site above the triangular face of the octahedron. It is shown that it takes much larger energy to remove an Al or a Au atom compared to that for neighboring sizes, and this accounts for its resistance to oxygen. The special stability is rooted in the electronic spectrum that is marked by a large HOMO-LUMO gap of 1.38 eV, and the system is best described as a nearly free electron gas of 20 electrons.

Size-dependent phase transitions and phase reversal at the nanoscale

2017 ◽  
Author(s):  
Amanda S. Barnard
Keyword(s):  
Phase Transitions ◽  
Size Range ◽  
Solution Chemistry ◽  
Physical Parameters ◽  
Theoretical Studies ◽  
Phase Reversal ◽  
Size Dependent ◽  
The Stability ◽  
Experimental And Theoretical Studies ◽  
Phase Relationships

This article investigates size-dependent phase transitions and phase reversal at the nanoscale. In general, the crystallization of a nanomaterial into a particular structure is kinetically driven. However, the choice of which structure occurs in a specific size range is often a result of thermodynamics. These size-dependent phase relationships may be explored by analyzing the free energy and enthalpy of formation. This article considers the size-dependent phase stability of nanomaterials based on experimental and theoretical studies of zirconia and titania. It describes the use of bulk phase diagrams to capture important information on the stability of materials. It also highlights some of the physical parameters that influence phase transitions and phase reversal at the nanoscale, including temperature, pressure, shape, solution chemistry, surface chemistry and surface charge.

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