scholarly journals Experimental Determination of Phase Equilibria in the Na2O-SiO2-WO3 System

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2014
Author(s):  
Baojun Zhao ◽  
Kun Su ◽  
Xiaodong Ma
Keyword(s):  
Phase Equilibria ◽  
Electron Probe ◽  
Sodium Metasilicate ◽  
Primary Phase ◽  
Phase Equilibrium Data ◽  
X Ray ◽  
Sodium Disilicate ◽  
Phase Fields ◽  
Equilibrium Data

The present study investigated phase equilibria in the Na2O-SiO2-WO3 system experimentally using high-temperature equilibration, quenching, and electron probe X-ray microanalysis (EPMA). New thermodynamic information on the Na2O-SiO2-WO3 system was derived based on the newly obtained experimental results and data from the literature. The primary phase fields of sodium metasilicate, sodium disilicate, and tridymite were determined along with the isotherms at 1073, 1173, and 1273 K. The solubilities of WO3 in SiO2, Na2Si2O5, and Na2SiO3, and the solubility of SiO2 in Na2WO4 were accurately measured using EPMA. Comparisons between the existing and newly constructed phase diagram were carried out and the differences are discussed. The phase equilibrium data will be beneficial to the future development of sustainable tungsten industries and thermodynamic modelling in WO3 related systems.

Reduction of Potassium in Kidney Proximal Tubules to Aid in Electron Probe X-Ray Microanalysis of Calcium

1985 ◽  
Vol 43 ◽  
pp. 474-475
Author(s):  
A. LeFurgey ◽  
P. Ingram ◽  
L.J. Mandel
Keyword(s):  
Smooth Muscle ◽  
Proximal Tubule ◽  
Electron Probe ◽  
Clinical Applications ◽  
Proximal Tubules ◽  
Rabbit Kidney ◽  
Target Cells ◽  
X Ray ◽  
Freeze Dried

For quantitative determination of subcellular Ca distribution by electron probe x-ray microanalysis, decreasing (and/or eliminating) the K content of the cell maximizes the ability to accurately separate the overlapping K Kß and Ca Kα peaks in the x-ray spectra. For example, rubidium has been effectively substituted for potassium in smooth muscle cells, thus giving an improvement in calcium measurements. Ouabain, a cardiac glycoside widely used in experimental and clinical applications, inhibits Na-K ATPase at the cell membrane and thus alters the cytoplasmic ion (Na,K) content of target cells. In epithelial cells primarily involved in active transport, such as the proximal tubule of the rabbit kidney, ouabain rapidly (t1/2= 2 mins) causes a decrease2 in intracellular K, but does not change intracellular total or free Ca for up to 30 mins. In the present study we have taken advantage of this effect of ouabain to determine the mitochondrial and cytoplasmic Ca content in freeze-dried cryosections of kidney proximal tubule by electron probe x-ray microanalysis.

Electron Probe Microanalysis of Zinc-Bearing Hexagonal Ferrites

1965 ◽  
Vol 9 ◽  
pp. 304-313
Author(s):  
J. R. Shappirio
Keyword(s):  
Electron Probe ◽  
Hexagonal Ferrites ◽  
Structural Units ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Layer Structures ◽  
Cell Data ◽  
Unit Cell Data ◽  
The Ideal

AbstractThe electron probe is shown to be an effective tool for the analysis of the series of ferrimagnetic oxides referred to as the hexagonal ferrites. This series of compounds) containing barium, Fe3+, and a divalent metal cation, is formed by an ordered stacking of basic structural units in varying ratios. The ideal, complex stoichiornewy of these polytype-like mixed-layer structures can be computed from X-ray unit cell data; the various structures and their predicted stoichiometry are reviewed. Results of electron probe analysis of zinc-bearing single-crystal hexagonal ferrites are compared with theoretical values, the various correction procedures applied to the probe data are presented, and the limitations of the method in the analysis of hexagonal ferrites are discussed. The information obtained from this study has laid the groundwork for the determination of chemistry in substituted members of the hexagonal ferrite group, and will contribute significantly to the interpretation of the magnetic properties exhibited by these compounds.

scholarly journals Phase Equilibria in the In2O3-WO3 System

2002 ◽  
Vol 756 ◽  
Author(s):  
Annette P. Richard ◽  
Doreen D. Edwards
Keyword(s):  
Phase Equilibria ◽  
Binary Oxide ◽  
X Ray Diffraction ◽  
Subsolidus Phase ◽  
X Ray ◽  
Temperature Range ◽  
Oxide Phases ◽  
Phase Relationships

ABSTRACTThe subsolidus phase relationships in the In2O3-WO3 system at 800 – 1400°C were studied by X-ray diffraction. Two binary oxide phases – In2(WO4)3 and In6WO12 – are stable in air over the temperature range of 800 – 1200°C. Preferential volatilization of WO3 prevented the determination of phase equilibria above 1300°C.

A sample preparation for quantitative determination of magnesium in individual lymphocytes by electron probe X-ray microanalysis

1986 ◽  
Vol 141 (1) ◽  
pp. 69-78 ◽  
Author(s):  
Gregory R. Hook ◽  
Ronald J. Elin ◽  
Jeanette M. Hosseini ◽  
Carol Swyt ◽  
Charles E. Fiori
Keyword(s):  
Sample Preparation ◽  
Quantitative Determination ◽  
Electron Probe ◽  
X Ray

The Determination of the Efficiency of Energy Dispersive X-Ray Spectrometers by a New Reference Material

2006 ◽  
Vol 12 (5) ◽  
pp. 406-415 ◽  
Author(s):  
Marco Alvisi ◽  
Markus Blome ◽  
Michael Griepentrog ◽  
Vasile-Dan Hodoroaba ◽  
Peter Karduck ◽  
...  
Keyword(s):  
Reference Material ◽  
Electron Probe ◽  
Detection Efficiency ◽  
Calibration Procedure ◽  
Energy Dispersive ◽  
X Ray ◽  
Line Intensities ◽  
Operator Assistance ◽  
Scanning Electron

A calibration procedure for the detection efficiency of energy dispersive X-ray spectrometers (EDS) used in combination with scanning electron microscopy (SEM) for standardless electron probe microanalysis (EPMA) is presented. The procedure is based on the comparison of X-ray spectra from a reference material (RM) measured with the EDS to be calibrated and a reference EDS. The RM is certified by the line intensities in the X-ray spectrum recorded with a reference EDS and by its composition. The calibration of the reference EDS is performed using synchrotron radiation at the radiometry laboratory of the Physikalisch-Technische Bundesanstalt. Measurement of RM spectra and comparison of the specified line intensities enables a rapid efficiency calibration on most SEMs. The article reports on studies to prepare such a RM and on EDS calibration and proposes a methodology that could be implemented in current spectrometer software to enable the calibration with a minimum of operator assistance.

Absorption Correction Curves Obtained from Measurements of the Production of X-Rays as a Function of Depth

1972 ◽  
Vol 16 ◽  
pp. 198-205
Author(s):  
J.D. Brown ◽  
L. Parobek
Keyword(s):  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
X Rays ◽  
Matrix Elements ◽  
X Ray ◽  
Absorption Correction ◽  
Correction Equations

AbstractMeasurements of x-ray production as a function of depth in a sample (ϕ(ρz) curves) are fundamental to the determination of the quantitative equations for relating x-ray intensity to composition in electron probe microanalysis. These ϕ(ρz) curves have been measured for four different voltages and a number of different tracers in aluminum, copper, silver arid gold as matrix elements. From these ϕ(ρz) curves the absorption correction curves (f(x) curves) can be calculated. Such curves have been obtained and comparison is made with the absorption correction equations of Philibert. The effect of a tilted sample on the absorption correction is also discussed.

Correction for Non-Linearity of Proportional Counter Systems in Electron Probe X-Ray Microanalysis

1965 ◽  
Vol 9 ◽  
pp. 208-220 ◽  
Author(s):  
Kurt F. J. Heinrich ◽  
Donald Vieth ◽  
Harvey Yakowitz
Keyword(s):  
Theoretical Basis ◽  
Electron Probe ◽  
Dead Time ◽  
Pulse Height ◽  
The Other ◽  
Time Effects ◽  
X Ray ◽  
Electron Probe Microanalyzer ◽  
Intensity Measurements

AbstractWhile the theoretical basis for the correction of non-linearity of detector systems is well known, methods for the determination of dead-time effects must be adapted to electron probe microanalyzer systems. Two such methods, one employing both X-ray and current measurements and the other employing simultaneous X-ray measurements on two spectrometers, are described. The effect of pulse-height shrinkage at high counting rates on the linearity of the detector system is discussed. When the proposed corrections for the dead-time of X-ray detector systems employing proportional counters are applied to the X-ray intensity measurements obtained with the electron probe microanalyzer, count rates as high as 50,000 counts/sec can be used.

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