New Method to Acquire Chemomechanical Parameters of Diverse Chemical Reactions

2011 ◽  
Author(s):  
Roman Boulatov ◽  
Charles Lee
Keyword(s):  
Chemical Reactions ◽  
New Method

scholarly journals Uranium Decontamination from Waste Soils by Chlorination with ZrCl4 in LiCl-KCl Eutectic Salt

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Junhyuk Jang ◽  
Tack-Jin Kim ◽  
Sungbin Park
Keyword(s):  
Cyclic Voltammetry ◽  
Chemical Reactions ◽  
Contaminated Soil ◽  
Contaminated Soils ◽  
New Method ◽  
Dissolution Behavior ◽  
Salt Mixture ◽  
Natural Soils ◽  
Eutectic Salt ◽  
Obvious Change

The dissolution behavior of U, contained in the soils, was examined through chlorination with ZrCl4 to reduce the U concentration to clearance levels. Natural soils, composed of Si, Al, and approximately 2 ppm U, acted as surrogates for the contaminated soils. A salt mixture of LiCl-KCl-ZrCl4 was prepared in an Al2O3 crucible at 500°C, and SiO2 or natural soils were loaded for the chemical reactions. The reaction of SiO2 and Al2O3 with ZrCl4 was monitored by cyclic voltammetry, and no obvious change was observed. The results showed that SiO2 and Al2O3 were stable against ZrCl4. The reaction of natural soils with ZrCl4 indicated that the U content decreased from 2 to 1.2 ppm, while ∼0.4 ppm U appeared in the salt. Thus, the U, in the soils, dissolved into the salt by chlorination with ZrCl4. Therefore, based on these results, a new method to remediate U-contaminated soil wastes by chlorination with ZrCl4, followed by electrorefining of U, is suggested.

scholarly journals A new method for determining stoichiometric coefficients using minors of a matrix

2022 ◽  
Author(s):  
Rainier Lombaard
Keyword(s):  
Linear Algebra ◽  
Chemical Reactions ◽  
Inverse Method ◽  
Reduction Reaction ◽  
New Method ◽  
Complex Structures ◽  
Traditional Methods ◽  
Matrix Inverse ◽  
Spinel Materials

Spinel materials often have complex structures and as a result, balancing of reactions with these compounds by traditional methods become very time consuming. A method to calculate the stoichiometric coefficients for chemical reactions using first a modified matrix-inverse method and then an optimised method is proposed. Both methods are explored using linear algebra and the result demonstrated using a typical chromite reduction reaction.

Alumina powders via a controlled precipitation of aluminum acetate

1989 ◽  
Vol 4 (4) ◽  
pp. 967-971 ◽  
Author(s):  
A. Ayral ◽  
J. C. Droguet
Keyword(s):  
Thermal Decomposition ◽  
Ir Spectroscopy ◽  
Chemical Reactions ◽  
Thermal Evolution ◽  
New Method ◽  
Alumina Powder ◽  
Alkoxide Precursor ◽  
Aluminum Acetate ◽  
Controlled Precipitation

A new method of producing alumina powder is described. Aluminum basic acetate is first synthesized from alkoxide precursor. The chemical reactions which control the precipitation of this salt are followed, using IR spectroscopy. Alumina powder is obtained by further thermal decomposition, and the thermal evolution of the precipitate is studied.

scholarly journals A new method for determining stoichiometric coefficients using minors of a matrix

2021 ◽  
Author(s):  
Rainier Lombaard
Keyword(s):  
Chemical Reactions ◽  
Matrix Algebra ◽  
Inverse Method ◽  
Reduction Reaction ◽  
New Method ◽  
Complex Structures ◽  
Metallothermic Reduction ◽  
Mathematical Basis ◽  
Matrix Inverse ◽  
Spinel Materials

The motivation of this study was the investigation into the metallothermic reduction of chromite ores. Spinel materials have complex structures and as a result, balancing of the reduction reactions by traditional methods become very time consuming. A method to calculate the stoichiometric coefficients for chemical reactions using first a modified matrix-inverse method and then a new optimised method is proposed. The mathematical basis of both methods is explored using matrix algebra and then demonstrated using a typical chromite reduction reaction.

Selective Sampling and Orientation of Non-Homogeneous Tissues

1968 ◽  
Vol 26 ◽  
pp. 98-99
Author(s):  
C. C. Clawson ◽  
L. W. Anderson ◽  
R. A. Good
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Random Sampling ◽  
New Method ◽  
Microscope Examination ◽  
Small Areas ◽  
Selective Sampling ◽  
Large Numbers ◽  
Specific Orientation

Investigations which require electron microscope examination of a few specific areas of non-homogeneous tissues make random sampling of small blocks an inefficient and unrewarding procedure. Therefore, several investigators have devised methods which allow obtaining sample blocks for electron microscopy from region of tissue previously identified by light microscopy of present here techniques which make possible: 1) sampling tissue for electron microscopy from selected areas previously identified by light microscopy of relatively large pieces of tissue; 2) dehydration and embedding large numbers of individually identified blocks while keeping each one separate; 3) a new method of maintaining specific orientation of blocks during embedding; 4) special light microscopic staining or fluorescent procedures and electron microscopy on immediately adjacent small areas of tissue.

Surface reactions observed by photoemission electron microscopy (PEEM)

1992 ◽  
Vol 50 (1) ◽  
pp. 286-287
Author(s):  
H.H. Rotermund
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Work Function ◽  
Chemical Reactions ◽  
Reaction Diffusion ◽  
Dynamic Processes ◽  
Clean Surface ◽  
Crystal Surfaces ◽  
Single Crystal Surfaces ◽  
Photoemission Electron

Chemical reactions at a surface will in most cases show a measurable influence on the work function of the clean surface. This change of the work function δφ can be used to image the local distributions of the investigated reaction,.if one of the reacting partners is adsorbed at the surface in form of islands of sufficient size (Δ>0.2μm). These can than be visualized via a photoemission electron microscope (PEEM). Changes of φ as low as 2 meV give already a change in the total intensity of a PEEM picture. To achieve reasonable contrast for an image several 10 meV of δφ are needed. Dynamic processes as surface diffusion of CO or O on single crystal surfaces as well as reaction / diffusion fronts have been observed in real time and space.

Microwaves: Application in Electron Microscopy

1990 ◽  
Vol 48 (3) ◽  
pp. 140-141
Author(s):  
Anthony S-Y Leong ◽  
David W Gove
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Chemical Reactions ◽  
Electromagnetic Waves ◽  
Tissue Fixation ◽  
Primary Method ◽  
Dipolar Molecules ◽  
Wide Range ◽  
Time Required ◽  
Cryostat Sections

Microwaves (MW) are electromagnetic waves which are commonly generated at a frequency of 2.45 GHz. When dipolar molecules such as water, the polar side chains of proteins and other molecules with an uneven distribution of electrical charge are exposed to such non-ionizing radiation, they oscillate through 180° at a rate of 2,450 million cycles/s. This rapid kinetic movement results in accelerated chemical reactions and produces instantaneous heat. MWs have recently been applied to a wide range of procedures for light microscopy. MWs generated by domestic ovens have been used as a primary method of tissue fixation, it has been applied to the various stages of tissue processing as well as to a wide variety of staining procedures. This use of MWs has not only resulted in drastic reductions in the time required for tissue fixation, processing and staining, but have also produced better cytologic images in cryostat sections, and more importantly, have resulted in better preservation of cellular antigens.

Fine structure and properties of defects in naturally occurring silicates and oxides

1990 ◽  
Vol 48 (4) ◽  
pp. 460-461
Author(s):  
David R. Veblen
Keyword(s):  
Chemical Reactions ◽  
High Resolution Electron Microscopy ◽  
Extended Defects ◽  
Single Chain ◽  
Naturally Occurring ◽  
Resolution Electron ◽  
Fine Structures ◽  
Image Simulations ◽  
Similar Crystal Structure

Extended defects and interfaces control many processes in rock-forming minerals, from chemical reactions to rock deformation. In many cases, it is not the average structure of a defect or interface that is most important, but rather the structure of defect terminations or offsets in an interface. One of the major thrusts of high-resolution electron microscopy in the earth sciences has been to identify the role of defect fine structures in reactions and to determine the structures of such features. This paper will review studies using HREM and image simulations to determine the structures of defects in silicate and oxide minerals and present several examples of the role of defects in mineral chemical reactions. In some cases, the geological occurrence can be used to constrain the diffusional properties of defects.The simplest reactions in minerals involve exsolution (precipitation) of one mineral from another with a similar crystal structure, and pyroxenes (single-chain silicates) provide a good example. Although conventional TEM studies have led to a basic understanding of this sort of phase separation in pyroxenes via spinodal decomposition or nucleation and growth, HREM has provided a much more detailed appreciation of the processes involved.

A new method for the determination of nitrates

1960 ◽  
Vol 23 ◽  
pp. 227-232 ◽  
Author(s):  
P WEST ◽  
G LYLES
Keyword(s):  
New Method
Sign in / Sign up

Export Citation Format

Share Document