TEMPERATURE AND PRESSURE DEPENDENCE OF ELASTIC PROPERTIES OF EARTH’S LOWER MANTLE COMPONENTS

1996 ◽  
Vol 10 (15) ◽  
pp. 697-703 ◽  
Author(s):  
S.S. BEDI ◽  
M.S. BHANGOO
Keyword(s):  
Elastic Properties ◽  
Pressure Dependence ◽  
Lower Mantle ◽  
Thermal Phonon ◽  
Simple Method ◽  
Body Interaction ◽  
Temperature And Pressure ◽  
Three Body ◽  
Derivatives Of ◽  
Good Agreement

The expressions for the temperature and pressure derivatives of Second Order Elastic (SOE) constants of elements of earth’s lower mantle i.e. CaO, MgO and SrO have been obtained using a simple method of direct differentiation of expressions of SOE constants which have been suitably modified taking into account three body interaction and thermal phonon pressure. The method provides a direct check to the already known expressions of pressure derivatives of SOE constants using Thurston and Brugger relation. The results obtained at 300° K are found to be in reasonably good agreement with the experiment.

scholarly journals THEORETICAL PREDICTION OF ELASTIC CONSTANTS FOR MgO

2013 ◽  
Vol 22 ◽  
pp. 24-27
Author(s):  
B. K. PANDEY ◽  
ANJANI K. PANDEY ◽  
CHANDRA KUMAR SINGH
Keyword(s):  
High Pressure ◽  
Theoretical Prediction ◽  
Elastic Properties ◽  
Pressure Dependence ◽  
Lower Mantle ◽  
Close Agreement ◽  
Elastic Parameter ◽  
Shearing Stress ◽  
Pressure Condition ◽  
Precise Knowledge

Precise knowledge of the elastic properties of MgO periclase, under high-pressure condition is therefore crucial for constructing the accurate mineralogical model of the Earth's lower mantle. In present work an attempt has been done to calculate the pressure dependence elastic properties such as isothermal bulk modules (KT), Young's modulus of elasticity Y and shearing stress G for geophysical MgO by using three deferent phenomenological EOS viz. the Born-Mayer EOS, Murnaghan EOS and Birch EOS. The result shows that the value of elastic parameter as calculated by using Murnughan EOS and Birch EOS shows close agreement with each other while Born-Mayer EOS shows deviation in calculated values.

Relaxation Behavior in Polystyrene Near and Above the Glass Transiton Studied by Ultrasonic Technique

1995 ◽  
Vol 407 ◽  
Author(s):  
A. Sahnoune ◽  
L. Piché
Keyword(s):  
Relaxation Time ◽  
Pressure Dependence ◽  
Relaxation Behavior ◽  
Ultrasonic Technique ◽  
The Real ◽  
Kauzmann Temperature ◽  
Temperature And Pressure ◽  
Fragility Parameter ◽  
Fragile Glass ◽  
Good Agreement

ABSTRACTWe report measurements of the temperature and pressure dependence of ultrasonic modulus in polystyrene between 340 and 550 K and applied pressures up to 775 bar. The real and imaginary parts of the modulus are analyzed within the Havriliak-Negami model and very good agreement is found over the entire temperature and pressure ranges. Using the Vogel-Tammann-Fulcher equation for the relaxation time, the Kauzmann temperature TK and the fragility parameter D of polystyrene were determined. The value of D indicates that polystyrene is a fragile-glass former.

Three-body interaction and fluorite structure: Elastic properties of CaF2, SrF2, and BaF2

1984 ◽  
Vol 30 (12) ◽  
pp. 7255-7260 ◽  
Author(s):  
Subinay Dasgupta ◽  
A. N. Basu ◽  
A. Basu
Keyword(s):  
Elastic Properties ◽  
Fluorite Structure ◽  
Body Interaction ◽  
Three Body

Structural and elastic properties of barium chalcogenides (BaX, X=O, Se, Te) under high pressure

Open Physics ◽  
2008 ◽  
Vol 6 (2) ◽  
Author(s):  
Purvee Bhardwaj ◽  
Sadhna Singh ◽  
Neeraj Gaur
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Elastic Constants ◽  
Structural Phase ◽  
Transition Pressure ◽  
Phase Transition Pressure ◽  
Cscl Structure ◽  
Three Body ◽  
Derivatives Of ◽  
Good Agreement

AbstractIn the present paper we have investigated the high-pressure, structural phase transition of Barium chalcogenides (BaO, BaSe and BaTe) using a three-body interaction potential (MTBIP) approach, modified by incorporating covalency effects. Phase transition pressures are associated with a sudden collapse in volume. The phase transition pressures and associated volume collapses obtained from TBIP show a reasonably good agreement with experimental data. Here, the transition pressure, NaCl-CsCl structure increases with decreasing cation-to-anion radii ratio. In addition, the elastic constants and their combinations with pressure are also reported. It is found that TBP incorporating a covalency effect may predict the phase transition pressure, the elastic constants and the pressure derivatives of other chalcogenides as well.

THERMOELASTIC BEHAVIOUR OF FLUORITE SOLIDS USING THREE-BODY FORCE SHELL MODEL

1992 ◽  
Vol 06 (19) ◽  
pp. 3179-3188 ◽  
Author(s):  
S. S. BEDI ◽  
MAJOR SINGH ◽  
JASPAL SINGH
Keyword(s):  
Shell Model ◽  
Elastic Constants ◽  
Body Force ◽  
Thermal Phonon ◽  
Third Order ◽  
Third Order Elastic Constants ◽  
Three Body ◽  
Body Potential ◽  
Derivatives Of ◽  
Theoretical Results

The expressions for the second and third order elastic constants of fluorite lattice are derived using Lundqvist three-body potential incorporating thermal phonon pressure and inter-sublattice displacement through the shell model. Theoretically calculated values of the third order elastic constants are compared with the theoretical results of other workers and experiments. First order pressure derivatives of the second order elastic constants calculated using Thurston and Brugger relations for Ca 1-x Sr x F 2 and Sr 1-x Ba x F 2 are found to be in agreement with the experiment.

scholarly journals Investigation of Structural Phase Transition of PbS

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Purvee Bhardwaj
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Elastic Properties ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Three Body ◽  
Body Potential ◽  
Model Phase ◽  
Sudden Collapse ◽  
Good Agreement

The high-pressure structural phase transition of semiconductor PbS has been investigated, using the three body potential (TBP) model. Phase transition pressures are associated with a sudden collapse in volume. The phase transition pressures and related volume collapses obtained from this model show a generally good agreement with available results. Moreover, the elastic properties of PbS are also investigated.

scholarly journals One-Pot Synthesis of Novel Furochromone and Oxazocine Derivatives as Promising Antitumor Agents with Their Molecular Docking Studies

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Rita M. Borik
Keyword(s):  
Molecular Docking ◽  
Antitumor Agents ◽  
Docking Studies ◽  
One Pot ◽  
Simple Method ◽  
Standard Drug ◽  
Molecular Docking Studies ◽  
Benzoic Acid Derivatives ◽  
Derivatives Of ◽  
Good Agreement

One-pot efficient synthesis of novel chromone derivatives 4a–h and that of 5a–h were described in a simple method via four-component reaction between furochromone carbaldehyde, amine, isocyanate derivatives, and benzoic acid derivatives or nicotinic acid, respectively. Also, oxazocine derivatives 7a, b were prepared via reaction of visnagine carbaldehyde, ethyl acetoacetate and isocyanate derivatives 2a, b. The obtained derivatives of novel furochromone and oxazocine derivatives were evaluated as promising antitumor agents against panel of two human cell lines, hepatocellular carcinoma (HEPG2) and breast carcinoma (MCF7). The antitumor results suggested that furochromone derivatives 5a–h have activity against MCF7 in comparison with doxorubicin as the standard drug. Furthermore, the molecular docking studies of these novel derivatives of furochromone and oxazocine showed good agreement with the biological results when their binding pattern and affinity towards the active site of EGFR was investigate.

scholarly journals Absolute Pressure Dependence of the Second Ionization Level of EL2 in GaAs

1989 ◽  
Vol 163 ◽  
Author(s):  
D.E. Bliss ◽  
W. Walukiewicz ◽  
D.D. Nolte ◽  
E.E. Haller
Keyword(s):  
Pressure Dependence ◽  
Emission Rate ◽  
Uniaxial Stress ◽  
Absolute Pressure ◽  
Pressure Derivative ◽  
Effective Masses ◽  
The Difference ◽  
P Type ◽  
Derivatives Of ◽  
Good Agreement

AbstractWe report the results of DLTS experiments under uniaxial stress on the second ionization level of EL2(++/+) in p-type GaAs. We measured the shift in the hole emission rate as a function of stress applied in the [100] and [110] directions. By modeling the valence band with two independently displacing bands and appropriately derived effective masses, we obtain a small absolute hydrostatic pressure derivative for the defect, 39 ±15 meV GPa-1. The shear contribution is negligible. This result is very different than for the first ionization level, EL2(+/o) with a emission energy pressure derivative of 90 ±15 meV GPa-1. The difference can be accounted for by the pressure dependence of the electron capture barrier of EL2(+/o), 49 ±15meV GPa-1. The absolute pressure derivatives of the two levels are then comparable and in good agreement with simple theory for Ga site point defects.

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