The determination of layer charge by curve-fitting of Lorentz- and polarization-corrected X-ray diagrams

Clay Minerals ◽  
1986 ◽  
Vol 21 (2) ◽  
pp. 183-190 ◽  
Author(s):  
H. Stanjek ◽  
R. Friedrich
Keyword(s):  
Charge Distribution ◽  
Curve Fitting ◽  
Clay Fraction ◽  
Layer Charge ◽  
Confidence Limits ◽  
High Charge ◽  
X Ray ◽  
Symmetrical Distribution

AbstractThe clay fraction from the B horizon of a Psammentic Hapludalf containing vermiculite and smectite was treated with n-alkylammonium chloride ranging from nc = 6 to nc = 16. X-ray data were obtained by step-scanning, stored in a computer, corrected with the Lorentz and polarization factors and then fitted with a deconvolution programme. The layer charge was determined from the uncorrected, the corrected and the fitted diagrams, respectively. The evaluated confidence limits of ξ decreased in the same order revealing the vermiculite to be a high-charge type. The computed charge distribution of the smectite changed from an unlikely bimodal to a nearly symmetrical distribution.

scholarly journals Advanced Research of the Triassic Clay from the Baltic Region

2012 ◽  
Vol 51 (4) ◽  
pp. 376-382
Author(s):  
J. Karasa ◽  
J. Kostjukovs ◽  
A. Palaša ◽  
A. Actiņš
Keyword(s):  
Solid State ◽  
Quantitative Determination ◽  
Organic Molecules ◽  
Clay Fraction ◽  
Solid State Reactions ◽  
Baltic Region ◽  
X Ray ◽  
Smectite Clays ◽  
The Baltic

A procedure of smectite containing clay enrichment has been optimized, and the process of sedimentation has been studied. The new enrichment based method for quantitative determination of clay fraction in smectite containing sediment was developed. A new method for obtaining organoclays from enriched smectite clays has been investigated. The method is based on solid-state reaction between smectite and organic compounds, where organic molecules can be intercalated in dried clay mineral (montmorillonite) by solid-state reactions, without or with use of solvents. The enriched clay and the obtained organoclay samples were characterized with X-ray powder diffraction (PXRD).

scholarly journals Least squares curve fitting in Mo3d X-ray photoelectron spectra for determination of oxidation states of supported molybdenum catalysts.

1989 ◽  
Vol 38 (2) ◽  
pp. 65-71
Author(s):  
Natsuo FUKUMOTO ◽  
Isao KOJIMA ◽  
Masayasu KURAHASHI ◽  
Hiromichi SHIMADA ◽  
Akio NISHIJIMA
Keyword(s):  
Least Squares ◽  
Curve Fitting ◽  
Photoelectron Spectra ◽  
Oxidation States ◽  
X Ray ◽  
Molybdenum Catalysts ◽  
Least Squares Curve Fitting ◽  
Fitting In

scholarly journals LAYER CHARGE AND CHARGE DISTRIBUTION OF SMECTITES: A PARAMETER WHICH CONTROLS IMPORTANT PHYSICAL PROPERTIES OF BENTONITES

2007 ◽  
Vol 40 (2) ◽  
pp. 690
Author(s):  
G. E. Christidis
Keyword(s):  
Physical Properties ◽  
Rheological Properties ◽  
Charge Distribution ◽  
Classification Scheme ◽  
Lower Layer ◽  
Structural Formula ◽  
New Method ◽  
Layer Charge ◽  
Formula Method

The new method of Christidis and E beri (2003), which determines the layer charge and charge distribution of dioctahedral smectites in bentonites is presented and is compared to the existing methods for determination of layer charge and charge distribution, namely the structural formula method and the alkylammonium method. The new method is based on the comparison ofXRD traces of K-saturated, ethyleneglycol solvated smectites with simulated XRD-traces calculated for three-component interlayering. Applications of the method include modeling of the evolution of smectite layers towards illite during diagenesis, and study of the influence of layer charge and charge distribution of smectites on important physical properties of bentonites such as rheological properties (viscosity, gel strength, yield point and thixotropy) and swelling. Smectites with layer charge between -0.425 and-0.47 to - 0.48 equivalents phfu affect rheological properties in a different way compared to smectites with higher or lower layer charge than this layer charge interval. Based on these observations a new classification scheme for smectites has been proposed according to their layer charge. In this classification scheme the term smectites with intermediate layer charge has been introduced.

Precision of X-Ray Emission Measurements in the Determination of Low-Alloy Steels with an X-Ray Spectrograph*

1961 ◽  
Vol 5 ◽  
pp. 423-432
Author(s):  
Robert L. O'Neil ◽  
John B. Neuhardt ◽  
William P. Shulhof
Keyword(s):  
Quality Control ◽  
Control Method ◽  
Low Alloy Steels ◽  
Confidence Limits ◽  
Low Alloy Steel ◽  
X Ray ◽  
Quality Control Method ◽  
Alloy Steels ◽  
Future Work

AbstractA large amount of data has been treated statistically to determine daily and long-range variations which occur when replicate determinations are made on low-alloy steel samples. The experiment reported here was designed and run to evaluate the results obtained using an RCA Siemens X-ray spectrograph. As part of a quality-control method for the analysis of low-alloy steels, it was desirable to know the confidence limits for within-day and day-to-day replication. This paper reviews the results of this study and represents an outline of future work planned.

Alkylammonium characterization of smectite alteration in the Tertiary basins of southeast Korea

Clay Minerals ◽  
1998 ◽  
Vol 33 (2) ◽  
pp. 243-254 ◽  
Author(s):  
J. Ko ◽  
G. H. Lee ◽  
H.-S. Moon ◽  
Y. Song
Keyword(s):  
Volcanic Activity ◽  
Unit Cell ◽  
Layer Charge ◽  
Systematic Change ◽  
X Ray Diffraction ◽  
High Charge ◽  
X Ray

AbstractThe layer charge characteristics of smectite from the Tertiary basins in the Pohang area, Korea have been studied in detail using the alkylammonium method. On the basis of layer charges, the smectite in the Pohang area can be classed as normal and high-charge (hc) smectite. The layer charge of the normal smectite averages 0.3, and ranges from 0.25 to 0.38/half unit-cell. The hcsmectite collapses on K saturation to become illite-like material and shows 10 Åseries reflections on X-ray diffraction. The layer charge of the hc-smectite ranges from 0.5 to 1. The layer charges do not appear to be related to stratification or to basins of occurrence. The diagenetic trend that may have existed in the region was probably disturbed by later volcanic activity. A systematic change in layer charge and geochemistry of smectite in Waeup illustrates that the heat and solutions associated with the volcanic activity may have played a role in the development of layer charge.

Layer-charge evaluation of expandable clays from a chronosequence of podzols in Finland using an alkylammonium method

Clay Minerals ◽  
2001 ◽  
Vol 36 (4) ◽  
pp. 571-584 ◽  
Author(s):  
F. Gillot ◽  
D. Righi ◽  
M. L. Räisänen
Keyword(s):  
Clay Minerals ◽  
Lower Layer ◽  
Layer Charge ◽  
X Ray Diffraction ◽  
High Charge ◽  
X Ray ◽  
Effective Time ◽  
Smectite Clays ◽  
Experimental Alteration

AbstractSmectites from the E horizon of podzols dated at 1200–10,000 y in central and northern Finland were studied. Clay minerals in the fine (<0.1 μm) and coarse (0.1–2 μm) fractions were examined by X-ray diffraction. The distribution (octahedral or tetrahedral) and magnitude of the layer charge of expandable minerals were estimated using intercalation of alkylammonium ions (nC = 12) associated with the Hofmann & Klemen effect. In addition, charge alteration following desaturation (H+exchange) and autotransformation was investigated. Smectites from the E horizons of podzols are not homogeneous but constitute a mixture of several populations with various layer charges. Smectites with lower layer charge are present in podzols having a longer effective time of pedogenesis, suggesting alteration of the high-charge smectites with time. Experimental alteration of the smectites by autotransformation shows that a decrease of the layer charge is easily produced by desaturation of the smectite clays.

Lateral resolution of the electron microbeam analysis

1978 ◽  
Vol 36 (1) ◽  
pp. 542-543
Author(s):  
H.J. Dudek
Keyword(s):  
Quantitative Analysis ◽  
Depth Resolution ◽  
Lateral Resolution ◽  
Cylindrical Particle ◽  
Correction Procedure ◽  
X Ray ◽  
Element Concentrations ◽  
Microbeam Analysis ◽  
The Matrix

The chemical inhomogenities in modern materials such as fibers, phases and inclusions, often have diameters in the region of one micrometer. Using electron microbeam analysis for the determination of the element concentrations one has to know the smallest possible diameter of such regions for a given accuracy of the quantitative analysis.In th is paper the correction procedure for the quantitative electron microbeam analysis is extended to a spacial problem to determine the smallest possible measurements of a cylindrical particle P of high D (depth resolution) and diameter L (lateral resolution) embeded in a matrix M and which has to be analysed quantitative with the accuracy q. The mathematical accounts lead to the following form of the characteristic x-ray intens ity of the element i of a particle P embeded in the matrix M in relation to the intensity of a standard S

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