scholarly journals A PRELIMINARY STUDY OF THE COLEMANITE-RICH TUFF LAYER FROM THE SOURIDES AREA, KARLOVASSI BASIN, SAMOS ISLAND, HELLAS

2007 ◽  
Vol 40 (2) ◽  
pp. 769
Author(s):  
N. Kantiranis ◽  
A. Filippidis ◽  
M. Stamatakis ◽  
E. Tzamos ◽  
A. Drakoulis
Keyword(s):  
Chemical Composition ◽  
Light Microscopy ◽  
Powder Diffraction ◽  
X Ray ◽  
Atomic Adsorption ◽  
Atomic Adsorption Spectroscopy ◽  
Preliminary Study

Representative 3 kg sample of a colemanite-bearing tuffaceous layer from Sourides village of Samos Island have been investigated for its mineralogical and chemical composition using Light Microscopy, X-Ray Powder Diffraction and Atomic Adsorption Spectroscopy methods. The studied sample contains 68 wt. % colemanite, consisting of 31.1 wt. % B203 and 28.4 wt. % CaO. The mineralogical and chemical composition of the sample, after calcination could produce a concentrate containing 43-44 wt. % B203, fulfill at least one of the commercial specifications for the calcined colemanite concentrates.

X-ray powder diffraction and magnetic study of nominal Zn1-xNdxCr2Se4 – compounds (x = 0.05, 01)

2013 ◽  
Vol 28 (S2) ◽  
pp. S75-S85
Author(s):  
Izabela Jendrzejewska ◽  
Paweł Zajdel ◽  
Ewa Maciążek ◽  
Maria Sozańska ◽  
Tomasz Goryczka
Keyword(s):  
Chemical Composition ◽  
Solid State ◽  
Powder Diffraction ◽  
Magnetic Moments ◽  
Solubility Limit ◽  
Lattice Parameter ◽  
Antiferromagnetic Coupling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pure Matrix

Polycrystalline compounds in the Zn1-xNdxCr2Se4 system were prepared by solid state reaction using selenides (ZnSe, Cr2Se3) and pure elements (Nd, Se) as starting materials. The structural properties were determined by X-ray diffraction and the chemical composition confirmed by SEM-EDX. The observed symmetry is cubic, space group Fd3m, while the lattice parameter varies from 10.4955(7)Å to 10.4976(7)Å, and is larger than for the pure matrix. The solubility limit for the current synthesis route lies below x = 0.1. The magnetic moments, effective and saturation, increase with increasing amount of Nd ions. The Neel temperature TN and ΘCW drop, respectively, to 17.4K and 81K for x = 0.1, independently indicating that neodymium is incorporated into the spinel lattice and promotes antiferromagnetic coupling between the Cr3+ ions.

The use of reliability factors in analyzing powder patterns in Pt–Si sputtering targets and subsequent films

1998 ◽  
Vol 13 (6) ◽  
pp. 1517-1521 ◽  
Author(s):  
Abdul Rahman ◽  
Walter P. Lowe ◽  
Clayton W. Bates
Keyword(s):  
Powder Diffraction ◽  
X Ray ◽  
Planar Configuration ◽  
Preliminary Study

X-ray powder diffraction was used to characterize a Pt–Si sputtering target and subsequent films. The powder patterns of each sample indicated lines due to diffraction from different phases. We have initiated a preliminary study through which we have analyzed and characterized these films. The results presented for these samples corroborate with results observed for this system in the planar configuration.

scholarly journals X-Ray Powder Diffraction of Einsteinium Compounds

1978 ◽  
Vol 22 ◽  
pp. 101-107
Author(s):  
R. G. Haire ◽  
J. R. Peterson
Keyword(s):  
Chemical Composition ◽  
Powder Diffraction ◽  
Thermal Energy ◽  
Diffraction Data ◽  
Specific Activity ◽  
Radioactive Decay ◽  
High Specific Activity ◽  
X Ray ◽  
Transplutonium Elements ◽  
Xrpd Analysis

X-ray powder diffraction (XRPD) analysis has proven to be extremely valuable in the study of the transplutonium elements. The high specific activity and the thermal energy associated with the radioactive decay of einsteinium isotopes make XRPD analysis of einsteinium samples very difficult. The major problems are destruction of the samples crystallinity and alteration of their chemical composition. Blackening of the X-ray film also compromises the analyses. By applying certain guidelines given here, a limited amount of success has been achieved in obtaining diffraction data on einsteinium and some of its compounds.

Electron microscopic and electron probe x-ray microanalysis (EPXMA) of prostatic intraluminal “crystalloids”

1992 ◽  
Vol 50 (1) ◽  
pp. 608-609
Author(s):  
H.X. Bui ◽  
A. delRosario ◽  
M. Abdulla ◽  
C.E. Sheehan ◽  
R.J. Emerson ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Light Microscopy ◽  
Electron Probe ◽  
Prostatic Adenocarcinoma ◽  
Electron Microscopic ◽  
X Ray ◽  
Significant Potential ◽  
Well Differentiated ◽  
Benign Prostate

Prostatic intraluminal “crystalloids” are intensely eosinophilic, non-birefringent crystalline-like structures readily identified with light microscopy. Well documented to be associated with prostatic adenocarcinoma, these rhomboidal, hexagonal, triangular, polyhedral, or needle-like structures are almost exclusively confined to well differentiated prostatic adenocarcinomas and may occasionally be seen in adjacent benign glands bordering the tumors. Although of significant potential as a signal of nearby cancer in a limited biopsy of benign prostate, these “crystalloids” are poorly defined and their chemical composition has not been determined.

Microanalytical techniques for phenotyping secondary xylem

IAWA Journal ◽  
2020 ◽  
Vol 41 (3) ◽  
pp. 356-389
Author(s):  
Nadeeshani Karannagoda ◽  
Antanas Spokevicius ◽  
Steven Hussey ◽  
Gerd Bossinger
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Wall ◽  
Chemical Composition ◽  
Light Microscopy ◽  
Secondary Xylem ◽  
Laser Scanning Microscopy ◽  
X Ray ◽  
Secondary Tissue ◽  
Scanning Electron

Abstract The products of secondary xylem are of significant biological and commercial importance, and as a result, the biology of secondary growth and how intrinsic and extrinsic factors influence this process have been the subject of intense investigation. Studies into secondary xylem range in scale from the cellular to the forest stand level, with phenotypic analyses often involving the assessment of traits relating to cell morphology and cell wall chemical composition. While numerous techniques are currently available for phenotypic analyses of samples containing abundant amounts of secondary tissue, only a few of them (microanalytical techniques) are suitable when working with limiting amounts of secondary tissue or where a fine-scale resolution of morphological features or cell wall chemical composition is required. While polarised light microscopy, scanning electron microscopy, field emission-scanning electron microscopy and X-ray scattering and micro-tomography techniques serve as the most frequently used microanalytical techniques in morphotyping, techniques such as scanning ultraviolet microspectrophotometry, X-ray photoelectron spectroscopy, gas chromatography, Fourier-transform infrared spectroscopy and matrix-assisted laser desorption ionisation mass spectrometry serve as the most commonly used microanalytical techniques in chemotyping. Light microscopy, fluorescence microscopy, confocal laser scanning microscopy, transmission electron microscopy and Raman spectroscopy serve as dual micro morphotyping and chemotyping techniques. In this review, we summarise and discuss these techniques in the light of their applicability as microanalytical techniques to study secondary xylem.

Synthetic Mn-Kilchoanite—a new development in polymorphism of melilite

1986 ◽  
Vol 50 (357) ◽  
pp. 511-515 ◽  
Author(s):  
Mitsuyoshi Kimata
Keyword(s):  
High Temperature ◽  
Chemical Composition ◽  
Powder Diffraction ◽  
Ionic Radius ◽  
Structure Type ◽  
Temperature Structure ◽  
Ir Absorption ◽  
X Ray ◽  
New Development ◽  
High Temperature Structure

AbstractTwo compounds with the chemical composition Ca2.32Mn0.68Si2.00O7 were synthesized from a molten carbonating silicate with the melilite composition. The synthetic samples were subsequently characterized by X-ray powder diffraction, IR absorption and EPMA, and they proved to be the anhydrous phases isomorphous with kilchoanite Ca3Si2O7 and åkermanite Ca2MgSi2O7 respectively, and to be polymorphous with each other. Their crystallochemical properties suggest that Mn-åkermanite is a high-temperature structure type of Mn-kilchoanite. Substitution of Mn2+ with an intermediate ionic radius between those of Mg2+ and Ca2+ cations establishes the polymorphic relationship between åkermanite Ca2MgSi2O7 and kilchoanite Ca3Si2O7.

X-ray powder diffraction data for CuFeSe2

1994 ◽  
Vol 9 (2) ◽  
pp. 108-110 ◽  
Author(s):  
J. A. Henaoa ◽  
J. M. Delgado ◽  
M. Quintero
Keyword(s):  
Crystal Structure ◽  
Chemical Composition ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Crystal Structure Data ◽  
Powder Diffraction Data ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Tetragonal System

Recent X-ray single-crystal diffraction studies have shown that CuFeSe2 crystallizes in the tetragonal system with space group P2c [, No. 112], Z = 4, with a =5.530(1) Å and c = 11.049(2) Å, c/a = 1.998. This material had been reported as pseudocubic with a =5.53 Å. The purpose of this paper is to present new X-ray powder diffraction data for CuFeSe2 and to compare the results with those reported for eskebornite, a mineral with ideal chemical composition CuFeSe2, and with those obtained from single-crystal structure data.

scholarly journals X-Ray powder diffraction of mineralogical samples by X-Ray goebel mirrors

2001 ◽  
Vol 34 (3) ◽  
pp. 883 ◽  
Author(s):  
V. PERDIKATSIS ◽  
V. PSYCHARIS
Keyword(s):  
Surface Roughness ◽  
Chemical Composition ◽  
Powder Diffraction ◽  
Comparative Studies ◽  
High Intensity ◽  
X Ray ◽  
Main Drawback ◽  
Irregular Shapes ◽  
Careful Preparation ◽  
Variable Chemical

Comparative studies are presented on a series of standard and mineralogical samples with X-ray powder diffraction methods, which have been made with a diffractometer possessing the traditional Bragg-Brentano geometry and a second one equipped with a parabolic Goebel mirror (parallel optics). The diffractometers with the Bragg-Brentano geometry are used extensively for the analysis of polycrystalline samples, the main drawback of which is the high expertise needed by the user in order to maintain an instrument in perfect alignment and the careful preparation of the studied samples. Samples measured with a Goebel mirror in parallel optics are free from displacement errors caused by the displacement of the surface or by the surface roughness of the samples. The advantages of the parallel optics are valuable in the case of study of mineralogical samples with the same structure and variable chemical composition (feldspars, amphiboles, pyroxenes, clays etc.) or samples with irregular shapes. Another advantage of Goebel mirrors is the high intensity.

Synthesis of potassium manganese oxides under hydrothermal conditions

1974 ◽  
Vol 39 (305) ◽  
pp. 559-563 ◽  
Author(s):  
T. Endo ◽  
S. Kume ◽  
M. Shimada ◽  
M. Koizumi
Keyword(s):  
Chemical Composition ◽  
Diffraction Pattern ◽  
Potassium Permanganate ◽  
Powder Diffraction ◽  
Manganese Oxides ◽  
Hexagonal Cell ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Temperature And Pressure ◽  
New Phase

SummaryA 1 M solution of potassium permanganate was sealed in a gold capsule and was treated under conditions of temperature and pressure up to 800 °C and 2·5 kb. Different kinds of products were produced under different conditions of synthesis, and potassium manganate, birnessite, cryptomelane, hausmannite, manganosite, and a new phase appeared. The chemical composition of the new phase was determined as K2Mn4O9 and its X-ray powder diffraction pattern was indexed on a hexagonal cell with a 11·295 and c 21·870 Å.

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