X-Ray Diffraction Patterns for Quantitative Analysis of Coastal Sediments in Between Mandapam And Vembar, Gulf of Mannar Coast, South India

2020 ◽  
Vol V9 (04) ◽  
Author(s):  
R. Karikalan ◽  
S. Bangaru Priyanga ◽  
S. Rakkiannan ◽  
Keyword(s):  
Quantitative Analysis ◽  
South India ◽  
Coastal Sediments ◽  
Gulf Of Mannar ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns

Qualitative and Quantitative Analysis of Stacking Disorder in α-and β-SiC by X-ray Diffraction and Structure Modeling

1995 ◽  
Vol 410 ◽  
Author(s):  
Bogdan Palosz ◽  
Svetlana Stel'makh ◽  
Stanislaw Gierlotka
Keyword(s):  
Quantitative Analysis ◽  
Model Parameters ◽  
Qualitative And Quantitative Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Qualitative And Quantitative ◽  
Poisson Function ◽  
Diffraction Patterns ◽  
Computer Generation ◽  
Stacking Disorder

ABSTRACTA method of analysis of disordering in α- and β-SiC polycrystals by numerical modeling, and a simulation of X-ray diffraction profiles are presented. The diffraction patterns of nonperiodic structures were simulated for models of 2000 layer fragments of the structure. Computer generation of the models was based on the Poisson function describing the size distribution of the domains of basic polytypes and faults. The models were quantified by a set of input probability parameters describing relative frequencies of the occurrence of the domains of polytypes and faults. Implementation of a correlation parameter that characterizes coherence of sequential domains of a given polytype assures a good reproducibility of the simulated diffraction profiles obtained for the same set of the model parameters. Based on this method, a quantitative analysis of disordering in polycrystals of SiC annealed in the temperature range 1100–2200 °C was performed.

X-Ray Diffraction Analysis of Prehistoric Pottery

1973 ◽  
Vol 38 (3) ◽  
pp. 339-344 ◽  
Author(s):  
John W. Weymouth
Keyword(s):  
Quantitative Analysis ◽  
Relative Abundance ◽  
Preliminary Report ◽  
Quantitative Method ◽  
Chemical Elements ◽  
X Ray Diffraction ◽  
Qualitative Information ◽  
X Ray ◽  
Prehistoric Pottery ◽  
Diffraction Patterns

AbstractThis is a preliminary report on a quantitative method for grouping prehistoric pottery using x-ray diffraction techniques. Of the various analytical methods that have been applied to the analysis of pottery, x-ray diffraction techniques have been among the least used, and then usually to obtain qualitative information. Most analytic methods measure the relative abundance of chemical elements, but diffraction patterns give information on the crystalline substances in the pottery. In this study, attention is directed to the crystalline components of the temper rather than the clays or their derivatives. The method groups pottery according to the relative concentrations of such minerals as quartz, calcite, and the feldspars. Thus, success depends on reasonable consistency in the use of tempering materials by pottery makers at one time and place. I have examined a number of sherds from different sites in Iowa and Missouri supplied by Dale R. Henning, University of Nebraska. The results so far indicate that it is possible to group prehistoric pottery by a quantitative analysis of the x-ray diffraction pattern of the temper in the pottery.

FULLPAT: a full-pattern quantitative analysis program for X-ray powder diffraction using measured and calculated patterns

2002 ◽  
Vol 35 (6) ◽  
pp. 744-749 ◽  
Author(s):  
Steve J. Chipera ◽  
David L. Bish
Keyword(s):  
Quantitative Analysis ◽  
Matrix Effects ◽  
Internal Standard ◽  
Solid Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Phases ◽  
Quantitative Analysis Method ◽  
Diffraction Patterns ◽  
User Intervention

FULLPATis a quantitative X-ray diffraction methodology that merges the advantages of existing full-pattern fitting methods with the traditional reference intensity ratio (RIR) method. Like the Rietveld quantitative analysis method, it uses complete diffraction patterns, including the background. However,FULLPATcan explicitly analyze all phases in a sample, including partially ordered or amorphous phases such as glasses, clay minerals, or polymers. Addition of an internal standard to both library standards and unknown samples eliminates instrumental and matrix effects and allows unconstrained analyses to be conducted by direct fitting of library standard patterns to each phase in the sample. Standard patterns may include data for any solid material including glasses, and calculated patterns may also be used. A combination of standard patterns is fitted to observed patterns using least-squares minimization, thereby reducing user intervention and bias.FULLPAThas been coded into MicrosoftEXCELusing standard spreadsheet functions.

Evaluation of Freezing Methods by Low Temperature X-Ray Diffraction

1977 ◽  
Vol 35 ◽  
pp. 330-333
Author(s):  
T. Gulik-Krzywicki ◽  
M.J. Costello
Keyword(s):  
Biological Materials ◽  
Molecular Organization ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
X Ray ◽  
Rate Dependent ◽  
Before And After ◽  
Freeze Etching ◽  
Diffraction Patterns ◽  
Set Up

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.

Examination of Rabbit Fc Crystals

1968 ◽  
Vol 26 ◽  
pp. 140-141
Author(s):  
J. P. Robinson ◽  
P. G. Lenhert
Keyword(s):  
Molecular Weight ◽  
Flat Plate ◽  
Phosphate Buffer ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Neutral Ph ◽  
Small Crystals ◽  
Carbon Coated ◽  
Diffraction Patterns

Crystallographic studies of rabbit Fc using X-ray diffraction patterns were recently reported. The unit cell constants were reported to be a = 69. 2 A°, b = 73. 1 A°, c = 60. 6 A°, B = 104° 30', space group P21, monoclinic, volume of asymmetric unit V = 148, 000 A°3. The molecular weight of the fragment was determined to be 55, 000 ± 2000 which is in agreement with earlier determinations by other methods.Fc crystals were formed in water or dilute phosphate buffer at neutral pH. The resulting crystal was a flat plate as previously described. Preparations of small crystals were negatively stained by mixing the suspension with equal volumes of 2% silicotungstate at neutral pH. A drop of the mixture was placed on a carbon coated grid and allowed to stand for a few minutes. The excess liquid was removed and the grid was immediately put in the microscope.

Control of the phase composition of advanced calcium phosphates using an x-ray diffractometer with a curved position-sensitive detector

2020 ◽  
Vol 86 (6) ◽  
pp. 29-35
Author(s):  
V. P. Sirotinkin ◽  
O. V. Baranov ◽  
A. Yu. Fedotov ◽  
S. M. Barinov
Keyword(s):  
Phase Composition ◽  
Calcium Phosphates ◽  
Position Sensitive Detector ◽  
Sensitive Detector ◽  
X Ray Diffraction ◽  
X Ray ◽  
Impurity Phases ◽  
Position Sensitive ◽  
Diffraction Peaks ◽  
Diffraction Patterns

The results of studying the phase composition of advanced calcium phosphates Ca10(PO4)6(OH)2, β-Ca3(PO4)2, α-Ca3(PO4)2, CaHPO4 · 2H2O, Ca8(HPO4)2(PO4)4 · 5H2O using an x-ray diffractometer with a curved position-sensitive detector are presented. Optimal experimental conditions (angular positions of the x-ray tube and detector, size of the slits, exposure time) were determined with allowance for possible formation of the impurity phases during synthesis. The construction features of diffractometers with a position-sensitive detector affecting the profile characteristics of x-ray diffraction peaks are considered. The composition for calibration of the diffractometer (a mixture of sodium acetate and yttrium oxide) was determined. Theoretical x-ray diffraction patterns for corresponding calcium phosphates are constructed on the basis of the literature data. These x-ray diffraction patterns were used to determine the phase composition of the advanced calcium phosphates. The features of advanced calcium phosphates, which should be taken into account during the phase analysis, are indicated. The powder of high-temperature form of tricalcium phosphate strongly adsorbs water from the environment. A strong texture is observed on the x-ray diffraction spectra of dicalcium phosphate dihydrate. A rather specific x-ray diffraction pattern of octacalcium phosphate pentahydrate revealed the only one strong peak at small angles. In all cases, significant deviations are observed for the recorded angular positions and relative intensity of the diffraction peaks. The results of the study of experimentally obtained mixtures of calcium phosphate are presented. It is shown that the graphic comparison of experimental x-ray diffraction spectra and pre-recorded spectra of the reference calcium phosphates and possible impurity phases is the most effective method. In this case, there is no need for calibration. When using this method, the total time for analysis of one sample is no more than 10 min.

Infrared spectroscopic study of the YPO4-YCrO4 system

1985 ◽  
Vol 50 (10) ◽  
pp. 2139-2145
Author(s):  
Alexander Muck ◽  
Eva Šantavá ◽  
Bohumil Hájek
Keyword(s):  
Spectroscopic Study ◽  
Infrared Spectra ◽  
Point Of View ◽  
Mixed Crystals ◽  
Crystal Symmetry ◽  
Infrared Spectroscopic Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Infrared Spectroscopic ◽  
Diffraction Patterns

The infrared spectra and powder X-ray diffraction patterns of polycrystalline YPO4-YCrO4 samples are studied from the point of view of their crystal symmetry. Mixed crystals of the D4h19 symmetry are formed over the region of 0-30 mol.% YPO4 in YCrO4. The Td → D2d → D2 or C2v(GS eff) correlation is appropriate for both PO43- and CrO43- anions.

scholarly journals Deep learning for visualization and novelty detection in large X-ray diffraction datasets

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Lars Banko ◽  
Phillip M. Maffettone ◽  
Dennis Naujoks ◽  
Daniel Olds ◽  
Alfred Ludwig
Keyword(s):  
Thin Film ◽  
Crystal Structure ◽  
Artificial Intelligence ◽  
Deep Learning ◽  
Novelty Detection ◽  
Structural Similarity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Post Hoc

AbstractWe apply variational autoencoders (VAE) to X-ray diffraction (XRD) data analysis on both simulated and experimental thin-film data. We show that crystal structure representations learned by a VAE reveal latent information, such as the structural similarity of textured diffraction patterns. While other artificial intelligence (AI) agents are effective at classifying XRD data into known phases, a similarly conditioned VAE is uniquely effective at knowing what it doesn’t know: it can rapidly identify data outside the distribution it was trained on, such as novel phases and mixtures. These capabilities demonstrate that a VAE is a valuable AI agent for aiding materials discovery and understanding XRD measurements both ‘on-the-fly’ and during post hoc analysis.

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