Determination of subsurface structure parameters of a sample using secondary electrons energy spectrums

2006 ◽  
Author(s):  
S. S. Borisov ◽  
S. I. Zaitsev ◽  
A. Bloshenko ◽  
T. Misutina
Keyword(s):  
Structure Parameters ◽  
Subsurface Structure ◽  
Secondary Electrons

Subsurface imaging with electrokinetically-induced seismoelectric signals generated by low-frequency seismic waves

2020 ◽  
Author(s):  
Dmitry Alekseev ◽  
Mikhail Gokhberg ◽  
Aleksandra Pliss ◽  
Aleksey Goncharov ◽  
Ilya Veklich
Keyword(s):  
Rayleigh Waves ◽  
Seismic Waves ◽  
Low Frequency ◽  
Basic Research ◽  
Structure Parameters ◽  
Subsurface Imaging ◽  
Subsurface Structure ◽  
Macroscopic Description ◽  
Basic Research Project

<p>In this study we focus on the coupled macroscopic description of the second-kind seismo-electric (SE) effect in the subsurface structure arising due to low-frequency seismic waves. Starting with the Biot poroelasticity model, we derive the equations of the coupled geomechanical-electromagnetic problem assuming mechanical excitation in the form of seismic waves (primarily Rayleigh waves), and create code for seismoelectric field simulation. We present the results of the feasibility study showing the promising possibilities for determination of non-uniform subsurface structure parameters and allowing a subsurface imaging in terms of rock elastic constants, conductivity and permeability.</p><p>The study was supported by the Russian Foundation for Basic Research (Project No. 20-05-00691).</p>

VESTA 3for three-dimensional visualization of crystal, volumetric and morphology data

2011 ◽  
Vol 44 (6) ◽  
pp. 1272-1276 ◽  
Author(s):  
Koichi Momma ◽  
Fujio Izumi
Keyword(s):  
Search Algorithm ◽  
Voronoi Tessellation ◽  
Three Dimensional ◽  
Structure Parameters ◽  
Volumetric Data ◽  
Complex Molecules ◽  
Visualization System ◽  
Performance Improvements ◽  
Significant Performance

VESTAis a three-dimensional visualization system for crystallographic studies and electronic state calculations. It has been upgraded to the latest version,VESTA 3, implementing new features including drawing the external morphology of crystals; superimposing multiple structural models, volumetric data and crystal faces; calculation of electron and nuclear densities from structure parameters; calculation of Patterson functions from structure parameters or volumetric data; integration of electron and nuclear densities by Voronoi tessellation; visualization of isosurfaces with multiple levels; determination of the best plane for selected atoms; an extended bond-search algorithm to enable more sophisticated searches in complex molecules and cage-like structures; undo and redo in graphical user interface operations; and significant performance improvements in rendering isosurfaces and calculating slices.

Laboratory Stopped-Flow XAFS Apparatus. Structure Determination of the Short-Lived Peroxochromium Intermediate Formed during Reduction Process of Chromate(VI) Ion by Hydrogen Peroxide

1997 ◽  
Vol 52 (6) ◽  
pp. 711-718 ◽  
Author(s):  
Y. Inada ◽  
S. Funahashi
Keyword(s):  
Hydrogen Peroxide ◽  
Fine Structure ◽  
Water Molecule ◽  
Reduction Process ◽  
Stopped Flow ◽  
Structure Parameters ◽  
X Ray ◽  
Reaction Intermediate ◽  
X Ray Absorption

In order to determine the structure parameters of the reaction intermediate formed during the reduction process of chromate(VI) ion by hydrogen peroxide, a laboratory stopped-flow X-ray absorption fine structure (XAFS ) apparatus, which was constructed by a rotating anode X-ray generator, an energy scanning spectrometer, a stopped-flow assembly, and X-ray detectors, was newly developed. Using the apparatus, the Cr K -edge XAFS spectrum of the reaction intermediate was measured. One oxo group, two peroxo groups, and one water molecule are coordinated to the Cr(VI) center in the intermediate, CrO(O2)2(H2O ) , with Cr - O bond lengths of 157, 168, and 193 pm, respectively. The geometry around the Cr(VI) center is probably 6-coordinate pentagonal pyramidal.

scholarly journals Determination of porous structure parameters of coal particles to describe thermal conversion processes

2019 ◽  
Vol 109 ◽  
pp. 00101
Author(s):  
Oleksandr Topal ◽  
Iryna Holenko ◽  
Inna Diakun
Keyword(s):  
Porous Structure ◽  
Gas Adsorption ◽  
Thermal Conversion ◽  
Structure Parameters ◽  
Adsorption Method ◽  
Coal Particles ◽  
Different Temperatures ◽  
Char Reactivity ◽  
Determination Of Parameters

The results of determination of parameters of porous structure of coal and char particles are presented. They were determined using gas adsorption method and thermal decomposition of particles in air oxygen. The porous structure parameters allow predicting char reactivity change at different temperatures as well as during conversion in accordance with Random Pore Model (RPM-model).

Determination of Thickness and Composition of Thin AlxGa1-xAs Layers on GaAs by Total Electron Yield (TEY)

1994 ◽  
Vol 38 ◽  
pp. 127-137
Author(s):  
Maria F. Ebel ◽  
Robert Svagera ◽  
Horst Ebel ◽  
Robert Hobl ◽  
Michael Mantler ◽  
...  
Keyword(s):  
Quantitative Information ◽  
X Rays ◽  
Total Electron Yield ◽  
Secondary Electrons ◽  
Total Electron ◽  
Surface Charging ◽  
Electron Yield ◽  
Low Energy Electrons ◽  
X Irradiation

The measurement of the total electron yield (TEY) emitted from a solid specimen when irradiated by monochromatic x-rays is used for quantitative information on the specimen. For this purpose one has to determine the increase of TEY in the course of a variation of the photon energy from below to above the absorption edges of the specimen elements. These increases are the analytical quantities and are correlated with the composition of the specimen. The detected electrons are photo, Auger and secondary electrons. Most of them lost some of their original kinetic energy due to inelastic collisions along their path from the atom of origin to the surface. Low energy electrons are especially found in the secondary electron peak with electron energies of less than 20eV. Electrically nonconductive specimens under x-irradiation tend to positive surface charging.

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