Determination of the Concentrations of Cation and Anion Vacancies in Solid Potassium Chloride

1950 ◽  
Vol 18 (1) ◽  
pp. 72-74 ◽  
Author(s):  
Carl Wagner ◽  
Paul Hantelmann
Keyword(s):  
Potassium Chloride ◽  
Anion Vacancies ◽  
Cation And Anion Vacancies

Self-Diffusion, Conductivity and Transport Numbers in Alkali Halide Single Crystals

1971 ◽  
Vol 26 (5) ◽  
pp. 915-921 ◽  
Author(s):  
Franqois Beniere ◽  
Michelle Beniere ◽  
Marius Chemla
Keyword(s):  
Diffusion Coefficients ◽  
Correlation Effect ◽  
Einstein Relation ◽  
Transport Numbers ◽  
Self Diffusion ◽  
Anion Vacancies ◽  
Cation And Anion Vacancies ◽  
Complete Set ◽  
And Migration

Abstract The self-diffusion coefficients of the anions and cations have been measured in pure and doped NaCl and KCl crystals, together with the ionic conductivity. The experimental results give evidence for migration mechanisms via free cation and anion vacancies and vacancy pairs. Analysis of the complete set of diffusion data leads to the determination of the entropy and enthalpy of formation and migration of these defects. In a second part, the diffusion coefficients via free vacancies are compared with the conductivity data in order to investigate the validity of the Nernst-Einstein relation. This relation is found to be verified within 2%, in NaCl as well as in KCl, no appreciable correlation effect being detected.

Void-Lattice Formation in Natural Fluorite by Electron Irradiation

1976 ◽  
Vol 34 ◽  
pp. 614-615 ◽  
Author(s):  
L.E. Murr
Keyword(s):  
Electron Microscope ◽  
Electron Irradiation ◽  
Heavy Ion ◽  
High Energy ◽  
Stoichiometric Ratio ◽  
Direct Observations ◽  
Transmission Electron ◽  
Anion Vacancies ◽  
Cation And Anion Vacancies ◽  
Lattice Formation

The production of void lattices in metals as a result of displacement damage associated with high energy and heavy ion bombardment is now well documented. More recently, Murr has shown that a void lattice can be developed in natural (colored) fluorites observed in the transmission electron microscope. These were the first observations of a void lattice in an irradiated nonmetal, and the first, direct observations of color-center aggregates. Clinard, et al. have also recently observed a void lattice (described as a high density of aligned "pores") in neutron irradiated Al2O3 and Y2O3. In this latter work, itwas pointed out that in order that a cavity be formed,a near-stoichiometric ratio of cation and anion vacancies must aggregate. It was reasoned that two other alternatives to explain the pores were cation metal colloids and highpressure anion gas bubbles.Evans has proposed that void lattices result from the presence of a pre-existing impurity lattice, and predicted that the formation of a void lattice should restrict swelling in irradiated materials because it represents a state of saturation.

scholarly journals Analysis of operating variables for Yerba mate leaves supercritical carbon dioxide extraction

2018 ◽  
Vol 24 (3) ◽  
pp. 231-238 ◽  
Author(s):  
Branislava Teofilovic ◽  
Nevena Grujic-Letic ◽  
Strahinja Kovacevic ◽  
Sanja Podunavac-Kuzmanovic ◽  
Slobodan Gadzuric
Keyword(s):  
Potassium Chloride ◽  
Current Source ◽  
Economic Feasibility ◽  
Superior Performance ◽  
Yerba Mate ◽  
Operating Variables ◽  
Carbon Dioxide Extraction ◽  
Increasing Demand ◽  
Positive Results

Given the increasing demand for potassium in Brazil, the mining and use of carnallite is becoming increasingly important, because the current source of potassium, sylvinite, is being depleted and there is a risk of shortages. Based on theoretical and practical data available in existing literature, this work describes the development, simulation, and economic feasibility of a process for dissolution and crystallization of potassium chloride from carnallite ore. Positive results were obtained following the application of the Hoffman diagram and determination of the corresponding equation. The proposed process provided over 85% potassium chloride crystallization, demonstrating its superior performance, compared to existing procedures.

Gas Chromatographic Determination of Residues of Organophosphorus Pesticides with a Modified Flame Ionization Detector

1967 ◽  
Vol 50 (3) ◽  
pp. 601-604
Author(s):  
Joseph H Ford ◽  
Morton Beroza
Keyword(s):  
Potassium Chloride ◽  
Organophosphorus Pesticides ◽  
Chromatographic Determination ◽  
Ionization Detector ◽  
Carrier Gas ◽  
Flame Ionization ◽  
Phosphorus Containing ◽  
Carrier Gases ◽  
Chloride Coating

Abstract The effect of various salt coatings, metals, and carrier gases was investigated in an attempt to improve the Giuffrida thermionic detector for residues of phosphorus-containing pesticides. As reported recently hy Giuffrida et al., the highest sensitivity to phosphorus (with insignificant response to halogen) was obtained with a potassium chloride coating. The use of helium as the carrier gas produced an 8-fold enhancement in response to phosphorus over that obtained with nitrogen, and the response to halogen remained nil. Substrate interference was very low with the KCI detector and helium carrier gas, and analyses were possible at the subnanogram level

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