scholarly journals Quantitative determination of mineral matter in lignite by X-RAY spectrometry, using the Compton effect.

2016 ◽  
Vol 47 (4) ◽  
pp. 1645
Author(s):  
V. Perdikatsis
Keyword(s):  
Organic Matter ◽  
Absorption Coefficient ◽  
Quantitative Determination ◽  
Calorific Value ◽  
Matter Content ◽  
Compton Effect ◽  
Mineral Matter ◽  
X Ray ◽  
Mineral Phases

For the evaluation of lignite quality, apart from the calorific value, it is necessary to determine the mineral phases, which are deposited simultaneously with the organic matter during the formation of peat or formed epigenetically during the coalification stages. The mineral matter content is usually expressed as ash, after the combustion of lignite, and its determination is a quite time consuming process. In this paper an attempt is made for a fast and easy quantitative determination of mineral matter in lignite samples with unknown concentrations, with the use of an X-ray spectrometer and in particular the Compton effect of the X-ray tube. The intensity of the Compton peak is a function of the mass absorption coefficient of the lignite sample, which in turn depends on the type and amount of the mineral matter contained. Using this property of the Compton Effect, the percentage of mineral matter of lignite was determined. The method was verified by analyzing lignites with known concentrations of inorganic mater. The results of this study showed, that the mineral matter content can be determined, by the proposed method, fast and accurately without lignite combustion.

Quantitative Determination of some Carbonate Minerals in Greenschist Facies Meta-volcanic Rocks

1972 ◽  
Vol 9 (1) ◽  
pp. 36-42 ◽  
Author(s):  
Calvert C. Bristol
Keyword(s):  
Standard Deviation ◽  
Quantitative Determination ◽  
Volcanic Rocks ◽  
Internal Standard ◽  
Greenschist Facies ◽  
Carbonate Mineral ◽  
Mineral Contents ◽  
X Ray ◽  
Fine Grained

X-ray powder diffraction methods, successful in quantitative determination of silicate minerals in fine-grained rocks, have been applied to the determination of calcite, dolomite, and magnesite in greenschist facies meta-volcanic rocks. Internal standard graphs employing two standards (NaCl and Mo) have been determined.Carbonate mineral modes (calcite and dolomite) for 6 greenschist facies meta-volcanic rocks obtained by the X-ray powder method have been compared to normative carbonate mineral contents calculated for the same rocks. This comparison showed a maximum variation of 7.7 wt.% between the X-ray modes and the normative carbonate mineral contents of the rocks. Maximum standard deviation for the X-ray modes of these rocks was equivalent to 4.4 wt.%.

Microstructure and composition of the periderm of conulariids

2016 ◽  
Vol 90 (3) ◽  
pp. 389-399 ◽  
Author(s):  
Robert C. Ford ◽  
Heyo Van Iten ◽  
George R. Clark
Keyword(s):  
Organic Matter ◽  
Organic Matter Content ◽  
Matter Content ◽  
Mineral Matter ◽  
Upper Ordovician ◽  
The Core ◽  
Critical Point Drying ◽  
Thin Walled ◽  
Electron Imaging ◽  
Aperture Closure

AbstractTransmitted light and scanning electron imaging of sectioned specimens ofConulariaandParaconularia, prepared using HCl etching and critical point drying, revealed that their periderm is composed of extremely thin (approximately 0.5–3 µm), variably distinct microlamellae that are alternately organic poor and organic rich. Organic-rich microlamellae are cross-connected by slender strands of organic matter originally embedded in calcium phosphate, which in etched specimens has been dissolved. Microlamellae may be organized in thicker (approximately 5–75 µm) layers, or macrolamellae, that vary in color and organic matter content, possibly owing to changes in the ambient paleoenvironment. Thickening of the periderm to form transverse ribs and internal carinae was achieved through gradual thickening of individual microlamellae. In the core of the transverse ribs and internal carinae the distinction between organic-rich and organic-poor microlamellae may be reduced, owing to organic material becoming dominant over (former) mineral matter or vice versa. Combined with observations of plicated aperture closure in thin-walled conulariids, includingArchaeoconularia slateri(Reed, 1933) (Upper Ordovician, Scotland) showing smooth folding of midline carinae through angles greater than 90°, these results suggest a structure and original flexibility in the organic-rich biocomposite forming the conulariid periderm that supports its homology to the chitinous lamellar periderm of coronate scyphozoans.

Quantitative Determination of Lateral Concentration and Depth Profile of Histidine-Tagged Recombinant Proteins Probed by Grazing Incidence X-ray Fluorescence

2013 ◽  
Vol 117 (17) ◽  
pp. 5002-5008 ◽  
Author(s):  
Alexander Körner ◽  
Wasim Abuillan ◽  
Christina Deichmann ◽  
Fernanda F. Rossetti ◽  
Almut Köhler ◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Recombinant Proteins ◽  
Depth Profile ◽  
Grazing Incidence ◽  
X Ray

scholarly journals Accuracy improvement in XRF analysis for the quantification of elements ranging from tenths to thousands μg g−1 in human tissues using different matrix reference materials

2020 ◽  
Vol 35 (12) ◽  
pp. 2920-2927
Author(s):  
Jorge Machado ◽  
Patrícia Miguel Carvalho ◽  
Ana Félix ◽  
Delfin Doutel ◽  
José Paulo Santos ◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Reference Materials ◽  
Fluorescence Spectrometry ◽  
Human Tissues ◽  
Accuracy Improvement ◽  
External Calibration ◽  
X Ray ◽  
Xrf Analysis ◽  
Calibration Approach

In this work, we aim at achieving the most accurate quantitative determination of elements in human tissues by means of X-ray fluorescence spectrometry using the external calibration approach.

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