Novel X-ray Method for In Situ Determination of Gelator Strand Structure: Polymorphism of Cholesteryl Anthraquinone-2-carboxylate

1996 ◽  
Vol 35 (12) ◽  
pp. 1324-1326 ◽  
Author(s):  
Emanuele Ostuni ◽  
Peter Kamaras ◽  
Richard G. Weiss
Keyword(s):  
Ray Method ◽  
X Ray

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

Global X-Ray Method for the Determination of Stress Profiles

2002 ◽  
Vol 404-407 ◽  
pp. 19-24 ◽  
Author(s):  
Jean Michel Sprauel ◽  
H. Michaud
Keyword(s):  
Ray Method ◽  
X Ray ◽  
Stress Profiles

scholarly journals Analysis of diagnostic possibilities of radio- logic and CT examination for pelvic injuries in children

1996 ◽  
Vol 3 (2) ◽  
pp. 45-48
Author(s):  
E. M. Kil’dyushov ◽  
I. V. Buromsky ◽  
V. M. Rozinov ◽  
L. E. Kuznetsov
Keyword(s):  
Comparative Analysis ◽  
Morphological Data ◽  
Ray Method ◽  
Diagnostic Reliability ◽  
X Ray ◽  
Ct Examination ◽  
Radiologic Examination ◽  
Pelvic Injuries

The purpose of this report is the determination of the diagnostic reliability of routine radiologic and CT examinations for pelvic injuries in children. The comparative analysis of these examinations and postmortem morphologic studies of pelvic spesimens was performed in 10 children, aged 2-12 years. It was shown that the X-ray method allowed to diagnose only 47.37% and CT method - 76.32% of all real pelvic injuries (by morphological data) in those children. However, the detectability of damage of the structures that formed the anterior pelvic semi-ring was 50% by radiologic examination, and 60% by CT examination, while for the structures forming posterior pelvic semi-ring it was 44.44% and 94.44%, respectively.

Determination of the crystal structure of magnesium perchlorate hydrates by X-ray powder diffraction and the charge-flipping method

2010 ◽  
Vol 66 (6) ◽  
pp. 579-584 ◽  
Author(s):  
Kevin Robertson ◽  
David Bish
Keyword(s):  
Crystal Structures ◽  
Powder Diffraction ◽  
Fundamental Parameter ◽  
Magnesium Perchlorate ◽  
Space Group ◽  
X Ray ◽  
Partial Pressures ◽  
Dehydration Reactions

X-ray powder diffraction (XRD) data were used to solve the crystal structures of phases in the magnesium perchlorate hydrate system, Mg(ClO4)2·nH2O (n = 4, 2). A heating stage and humidity generator interfaced to an environmental cell enabled in-situ XRD analyses of dehydration reactions under controlled temperatures and partial pressures of H2O (P_{{\rm H}_2{\rm O}}). The crystal structures were determined using an ab initio charge-flipping method and were refined using fundamental-parameter Rietveld methods. Dehydration of magnesium perchlorate hexahydrate to tetrahydrate (348 K) results in a decrease in symmetry (space group = C2), where isolated Mg2+ cations are equatorially coordinated by four H2O molecules with two [ClO4]− tetrahedra at the apices. Further dehydration to the dihydrate (423 K) leads to bridging of the isolated packets to form double corner-sharing chains of octahedra and polyhedra (space group = C2/m).

EVALUATION OF THE STRESSED DEFORMED STATE OF MAIN GAS PIPELINES RUNNING IN PERMANENTLY FROZEN GROUNDS

2020 ◽  
pp. 58-63
Author(s):  
M. M. Sidorov ◽  
N. I. Golikov ◽  
R. P. Tihonov
Keyword(s):  
Experimental Data ◽  
Calculated Data ◽  
Gas Pipeline ◽  
Loss Of Stability ◽  
Portable Equipment ◽  
Ray Method ◽  
X Ray ◽  
Deformed State ◽  
Pipeline Monitoring

The work evaluates the stress deformed state of the section of the interfield gas collecting main, running in permanently frozen grounds. The object of research is a section of a pipeline with an arched discharge formed as a result of loss of stability as a result of thermal erosion of permanently frozen grounds to disturbance of the vegetation cover. The determination of stresses was carried out by the X-ray method using portable equipment. The experimental data were analyzed with the calculated. The calculated data were obtained by measuring the spatial position of the gas pipeline section. The obtained values of the acting stresses and the estimates of the critical indicators of the gas pipeline monitoring section made it possible to reasonably estimate the stress state. The methodology for determining the acting stresses of pipelines using portable X-ray equipment can be successfully applied to estimate the stressed-deformed state of pipeline systems running in the zone of permafrost.

Residual Stresses and Differential Deformation of Electroplated Structures

1989 ◽  
Vol 33 ◽  
pp. 161-169
Author(s):  
G. Sheikh ◽  
I. C. Noyan
Keyword(s):  
Residual Stresses ◽  
Lattice Parameter ◽  
Stress Profile ◽  
X Ray ◽  
Residual Stress Profile ◽  
Cyclic Loading And Unloading ◽  
Nickel Substrates ◽  
Loading And Unloading

AbstractWe report the results of a recent study where nickel substrates electroplated with chromium were loaded in-situ on an x-ray diffractometer. This technique allows determination of lattice spacings in the vicinity of the interface for both the film and the substrate as a function of the applied load. We used such lattice parameter data, SEM observations of the surface and x-ray peak breadth data to study the partitioning of deformation between the film and the substrate. The data indicates progressive loss of adhesion between the film and the substrate with increasing deformation. We observe significant effect of electroplating residual stresses on the mechanical behavior of the system. The loss of adhesion between the film and the substrate coupled with the initial residual stress profile causes an apparent 'negative Poisson's ratio' for the film during initial stages of the loading. This effect disappears with cyclic loading and unloading.

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