scholarly journals Quantitative measurements of density in shock-compressed silver up to 330 GPa using x-ray diffraction

2022 ◽  
Vol 131 (1) ◽  
pp. 015901
Author(s):  
Amy L. Coleman ◽  
Saransh Singh ◽  
Cara E. Vennari ◽  
Raymond F. Smith ◽  
Travis J. Volz ◽  
...  
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
Quantitative Measurements

A furnace and environmental cell for thein situinvestigation of molten salt electrolysis using high-energy X-ray diffraction

2011 ◽  
Vol 19 (1) ◽  
pp. 39-47 ◽  
Author(s):  
Mark J. Styles ◽  
Matthew R. Rowles ◽  
Ian C. Madsen ◽  
Katherine McGregor ◽  
Andrew J. Urban ◽  
...  
Keyword(s):  
Molten Salt ◽  
Inert Anode ◽  
High Energy ◽  
X Ray Diffraction ◽  
Molten Salt Electrolysis ◽  
X Ray ◽  
Quantitative Measurements ◽  
Materials Used ◽  
Characterization Of Materials

This paper describes the design, construction and implementation of a relatively large controlled-atmosphere cell and furnace arrangement. The purpose of this equipment is to facilitate thein situcharacterization of materials used in molten salt electrowinning cells, using high-energy X-ray scattering techniques such as synchrotron-based energy-dispersive X-ray diffraction. The applicability of this equipment is demonstrated by quantitative measurements of the phase composition of a model inert anode material, which were taken during anin situstudy of an operational Fray–Farthing–Chen Cambridge electrowinning cell, featuring molten CaCl2as the electrolyte. The feasibility of adapting the cell design to investigate materials in other high-temperature environments is also discussed.

The structure of the α-keratin microfibril

1983 ◽  
Vol 3 (6) ◽  
pp. 517-525 ◽  
Author(s):  
R. D. B. Fraser ◽  
T. P. MacRae
Keyword(s):  
Diffraction Pattern ◽  
Intermediate Filaments ◽  
Chemical Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Quantitative Measurements ◽  
Surface Lattice ◽  
Starting Point ◽  
Electron Microscopical

Quantitative measurements of the intensity of the meridional reflections in the X-ray-diffraction pattern of α-keratin are shown to be consistent with a microfibril structure in which a surface lattice with an axially projected period around 200 Å is subject to a periodic interruption with an axially projected period of 470 Å. Taken in conjunction with recent evidence on the chemical structure of α-keratin and other inter-mediate filaments this finding enables an elaboration to be made of a model proposed earlier by RDB Fraser, TP MacRae, & E Suzuki (3. Mol. Biol. 108, 435–452, 1976.) for the α-helical framework of the microfibrii. The disposition and connectivity of the helical segments suggested here provides a straightforward explanation of a number of recent physicochemical and electron-microscopical observations on intermediate filaments and provides a starting point for the development of models for the framework of other intermediate filaments.

scholarly journals X-ray structure and elastic strains in copper

1940 ◽  
Vol 176 (966) ◽  
pp. 398-411 ◽  
Keyword(s):  
Applied Stress ◽  
Cold Work ◽  
X Ray Diffraction ◽  
Atomic Lattice ◽  
X Ray ◽  
Permanent Strain ◽  
Quantitative Measurements ◽  
Lattice Strains ◽  
Extension Curve ◽  
Elastic Lattice

An X-ray examination of copper has been undertaken whilst the metal has been actually under tensile stress, and the X-ray structure investigated at a systematic series of points on the load-extension curve and during unloading and reloading from selected points on the curve. It is shown that the permanent strain is associated with the breakdown of the grains into the crystallite formation and that this change is essentially irreversible. The elastic strain of the metal is accompanied by reversible changes in dimensions of the atomic lattice which take place without leaving in the lattice any permanent distortion, as shown by the observation that the X-ray diffraction rings, including rings of the diffuse type, contract and expand under the action of the applied stress without any change in the degree of diffusion. The lattice changes are distinguished in this way from certain lattice strains or lattice distortions permanently imposed on the lattice as a result of deformation by cold-work. Quantitative measurements are made on the elastic lattice strains exhibited by the (400) and (331) planes in a direction perpendicular to the axis of the applied stress, and these are compared with the equivalent external elastic constants. These measurements show that marked difference in rate of strain may take place in neighbouring grains subjected to the same external stress, and on this difference is based an explanation of the extensive breakdown of the grains into components of widely varying orientations which characterizes the structure of a polycrystalline metal after deformation beyond the yield point.

Optical Birefringence in Solid Nitrogen

1973 ◽  
Vol 51 (14) ◽  
pp. 1590-1592 ◽  
Author(s):  
D. J. Gannon ◽  
J. A. Morrison
Keyword(s):  
Upper Bound ◽  
X Ray Diffraction ◽  
Optical Birefringence ◽  
Cubic Symmetry ◽  
X Ray ◽  
Β Phase ◽  
Quantitative Measurements ◽  
Α Phase ◽  
Solid Nitrogen ◽  
Solid Phases

Quantitative measurements have been made of optical birefringence in two solid phases (α and β) of nitrogen. For the β phase (T > 35.6 °K), the observed birefringence is consistent with the structure determined by X-ray diffraction (P63/mmc) and it fixes the c/a ratio of the lattice accurately. While the measurements do not distinguish between the two structures (Pa3 and P213) that have been proposed for the α phase (T < 35.6 °K), they place a strict upper bound on the possible distortion that might arise from displacement of the nitrogen molecules from sites of cubic symmetry.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Ribosome Structural Organization

1974 ◽  
Vol 32 ◽  
pp. 332-333
Author(s):  
James A. Lake
Keyword(s):  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Small Subunit ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Specific Antibodies ◽  
X Ray ◽  
E Coli ◽  
Complete Sequences

The understanding of ribosome structure has advanced considerably in the last several years. Biochemists have characterized the constituent proteins and rRNA's of ribosomes. Complete sequences have been determined for some ribosomal proteins and specific antibodies have been prepared against all E. coli small subunit proteins. In addition, a number of naturally occuring systems of three dimensional ribosome crystals which are suitable for structural studies have been observed in eukaryotes. Although the crystals are, in general, too small for X-ray diffraction, their size is ideal for electron microscopy.

Electron Microscopy of Human Gallstones

1971 ◽  
Vol 29 ◽  
pp. 296-297
Author(s):  
C. Wolpers ◽  
R. Blaschke
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Bile Pigment ◽  
X Ray Diffraction ◽  
Triclinic Crystal System ◽  
X Ray ◽  
Follow Up Study ◽  
Infra Red ◽  
Main Components

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

Electron Microscopy of Shock Loaded Polycrystalline Beryllium

1974 ◽  
Vol 32 ◽  
pp. 506-507 ◽  
Author(s):  
J. M. Galbraith ◽  
L. E. Murr ◽  
A. L. Stevens
Keyword(s):  
Electron Microscopy ◽  
Wave Propagation ◽  
Structural Change ◽  
Single Crystal ◽  
Diffraction Pattern ◽  
Shock Loading ◽  
Slip Systems ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray

Uniaxial compression tests and hydrostatic tests at pressures up to 27 kbars have been performed to determine operating slip systems in single crystal and polycrystal1ine beryllium. A recent study has been made of wave propagation in single crystal beryllium by shock loading to selectively activate various slip systems, and this has been followed by a study of wave propagation and spallation in textured, polycrystal1ine beryllium. An alteration in the X-ray diffraction pattern has been noted after shock loading, but this alteration has not yet been correlated with any structural change occurring during shock loading of polycrystal1ine beryllium.This study is being conducted in an effort to characterize the effects of shock loading on textured, polycrystal1ine beryllium. Samples were fabricated from a billet of Kawecki-Berylco hot pressed HP-10 beryllium.

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