scholarly journals Precise measurement of selenium isotopes by HG-MC-ICPMS using a 76–78 double-spike

2020 ◽  
Vol 35 (2) ◽  
pp. 320-330 ◽  
Author(s):  
Marie-Laure Pons ◽  
Marc-Alban Millet ◽  
Geoff N. Nowell ◽  
Sambuddha Misra ◽  
Helen M. Williams
Keyword(s):  
Precise Measurement ◽  
Geological Samples ◽  
Selenium Isotope ◽  
Selenium Isotopes ◽  
Isotope Measurements

A novel 76Se–78Se double spike allows for rapid and precise selenium isotope measurements in geological samples.

THERMODYNAMIC PROPERTIES AND GEOCHEMISTRY OF ISOTOPIC COMPOUNDS OF SELENIUM

1962 ◽  
Vol 40 (2) ◽  
pp. 367-375 ◽  
Author(s):  
H. R. Krouse ◽  
H. G. Thode
Keyword(s):  
Partition Function ◽  
Kinetic Isotope Effect ◽  
Chemical Reduction ◽  
Equilibrium Constants ◽  
Elemental Selenium ◽  
Exchange Reactions ◽  
Kinetic Isotope ◽  
Naturally Occurring ◽  
Selenium Isotope ◽  
Selenium Isotopes

Using "normal vibration equations" and statistical mechanics, the isotopic vibrational frequencies and the partition function ratios for various Se76- and Se82-containing compounds have been calculated. The equilibrium constants for selenium isotope exchange reactions derived from these partition function ratios indicate that noticeable fractionation of selenium isotopes can be expected in the laboratory and in naturally occurring processes.The Se82/Se76 ratios for 16 natural samples have been compared mass spectrometrically. Variations of up to 1.5% found in this ratio are discussed.A kinetic isotope effect of 1.5% found in a chemical reduction of selenite ion to elemental selenium is also discussed.

High precision titanium isotope measurements on geological samples by high resolution MC-ICPMS

2007 ◽  
Vol 262 (3) ◽  
pp. 247-255 ◽  
Author(s):  
Ingo Leya ◽  
Maria Schönbächler ◽  
Uwe Wiechert ◽  
Urs Krähenbühl ◽  
Alex N. Halliday
Keyword(s):  
High Resolution ◽  
High Precision ◽  
Geological Samples ◽  
Isotope Measurements

Bence-albee after 25 years: A new superior α-factor correction procedure for the quantitative analysis of oxides and silicates

1992 ◽  
Vol 50 (2) ◽  
pp. 1744-1745
Author(s):  
John T. Armstrong
Keyword(s):  
Quantitative Analysis ◽  
Electron Microprobe ◽  
Binary Systems ◽  
Correction Procedure ◽  
Geological Samples ◽  
The Past ◽  
Large Matrix ◽  
Computational Speed ◽  
Microprobe Data ◽  
Geological Sciences

One of the most cited papers in the geological sciences has been that of Albee and Bence on the use of empirical " α -factors" to correct quantitative electron microprobe data. During the past 25 years this method has remained the most commonly used correction for geological samples, despite the facts that few investigators have actually determined empirical α-factors, but instead employ tables of calculated α-factors using one of the conventional "ZAF" correction programs; a number of investigators have shown that the assumption that an α-factor is constant in binary systems where there are large matrix corrections is incorrect (e.g, 2-3); and the procedure’s desirability in terms of program size and computational speed is much less important today because of developments in computing capabilities. The question thus exists whether it is time to honorably retire the Bence-Albee procedure and turn to more modern, robust correction methods. This paper proposes that, although it is perhaps time to retire the original Bence-Albee procedure, it should be replaced by a similar method based on compositiondependent polynomial α-factor expressions.

Quantitative Analysis Of X-Ray Images From Geological Materials

1990 ◽  
Vol 48 (2) ◽  
pp. 244-245
Author(s):  
J. M. Paque ◽  
R. Browning ◽  
P. L. King ◽  
P. Pianetta
Keyword(s):  
Quantitative Analysis ◽  
Bulk Composition ◽  
Principal Component ◽  
Analytical Description ◽  
Bulk Sample ◽  
Geological Samples ◽  
X Ray ◽  
Software And Hardware ◽  
And Storage ◽  
Insight Into

Geological samples typically contain many minerals (phases) with multiple element compositions. A complete analytical description should give the number of phases present, the volume occupied by each phase in the bulk sample, the average and range of composition of each phase, and the bulk composition of the sample. A practical approach to providing such a complete description is from quantitative analysis of multi-elemental x-ray images.With the advances in recent years in the speed and storage capabilities of laboratory computers, large quantities of data can be efficiently manipulated. Commercial software and hardware presently available allow simultaneous collection of multiple x-ray images from a sample (up to 16 for the Kevex Delta system). Thus, high resolution x-ray images of the majority of the detectable elements in a sample can be collected. The use of statistical techniques, including principal component analysis (PCA), can provide insight into mineral phase composition and the distribution of minerals within a sample.

PRECISE MEASUREMENT OF ENERGY DISTRIBUTION IN Ga LMIS

1987 ◽  
Vol 48 (C6) ◽  
pp. C6-141-C6-146 ◽  
Author(s):  
M. Komuro ◽  
T. Kato
Keyword(s):  
Energy Distribution ◽  
Precise Measurement

Sparse Representation Based Dielectric Loss Angle Measurement

2015 ◽  
Vol 9 (1) ◽  
pp. 566-570
Author(s):  
Zhang Ji ◽  
Jianfeng Zheng
Keyword(s):  
Dielectric Loss ◽  
Power Systems ◽  
Sparse Representation ◽  
Precise Measurement ◽  
Angle Measurement ◽  
Measuring Error ◽  
Loss Angle ◽  
Analysis Method ◽  
Electric Capacity ◽  
Dielectric Loss Angle

Precise measurement of dielectric loss angle is very important for electric capacity equipment in recent power systems. When signal-to-noise is low and fundamental frequency is fluctuating, aiming at the measuring error of dielectric loss angle based on some recent Fourier transform and wavelet transform harmonics analysis method, we propose a novel algorithm based on sparse representation, and improved it to be more flexible for signal sampling. Comparison experiments describe the advantages of our method.

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