In situ X-Ray Diffraction Method to Study Natural Gas Hydrates

1998 ◽  
Vol 278-281 ◽  
pp. 335-341 ◽  
Author(s):  
C.C. Tang ◽  
M.C. Miller ◽  
Robert J. Cernik ◽  
S.M. Clark ◽  
C.A. Koh ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Hydrates ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Natural Gas Hydrates

Properties and Dynamics of Bulk Subgrains Probed In-Situ Using a Novel X-Ray Diffraction Method

2007 ◽  
pp. 613-618
Author(s):  
Bo Jakobsen ◽  
Ulrich Lienert ◽  
Jon Almer ◽  
Wolfgang Pantleon ◽  
Henning Friis Poulsen
Keyword(s):  
Diffraction Method ◽  
X Ray Diffraction ◽  
X Ray

In Situ Three-Dimensional Orientation Mapping in Plastically-Deformed Polycrystalline Iron by Three-Dimensional X-Ray Diffraction

2014 ◽  
Vol 777 ◽  
pp. 118-123 ◽  
Author(s):  
Yujiro Hayashi ◽  
Yoshiharu Hirose ◽  
Daigo Setoyama
Keyword(s):  
Three Dimensional ◽  
Diffraction Method ◽  
Inverse Pole Figure ◽  
Coarse Grained ◽  
Uniaxial Tensile ◽  
X Ray Diffraction ◽  
Polycrystalline Iron ◽  
X Ray ◽  
Orientation Mapping

In situ three-dimensional crystallographic orientation mapping in plastically-deformed polycrystalline iron is demonstrated using a modified three-dimensional x-ray diffraction method. This voxel-by-voxel measurement method enables the observation of intragranular orientation distribution. The experiment is performed using coarse-grained ferrite with a mean grain size of ~ 60 μm and an incident x-ray beam with a beam size of 20 μm × 20 μm. Grains averagely rotate approximately toward the <110> preferred orientation of body-centered cubic uniaxial tensile texture. Intragranular orientation distributions are spread as the tensile strain increases to 10.7 %. Furthermore, intragranular multidirectional rotations are observed in grains near the <100> and <111> corners in the inverse pole figure.

Measurements of physical properties of gas hydrates and in situ observations of formation and decomposition processes via Raman spectroscopy and X-ray diffraction

2003 ◽  
Vol 81 (1-2) ◽  
pp. 351-357 ◽  
Author(s):  
T Uchida ◽  
S Takeya ◽  
L D Wilson ◽  
C A Tulk ◽  
J A Ripmeester ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Physical Properties ◽  
Gas Hydrates ◽  
Hydrate Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrate Layer ◽  
Decomposition Processes ◽  
In Situ Observations

Gas hydrate properties and phase transition kinetics were studied using Raman spectroscopic and X-ray diffraction methods. These techniques have the advantage of measuring physical properties such as crystal structure, gas composition, and cage occupancy of gas molecules without decomposing the sample. In situ observations using these techniques are indicative of formation and decomposition processes in gas hydrates. Raman spectroscopy is used for the analysis of gas concentrations and gas compositions of gas hydrates. The ν1 symmetrical C–H stretching vibration mode of methane molecules in the hydrate phase shows a doublet, and the relative intensity of the peaks determines the cage-occupancy ratio. However, as the Raman method is not standard for this application, we evaluated the method by analyzing the same methane hydrate sample using NMR and Raman scattering in a laboratory in Canada and also comparing the data with the Raman measurements made on the same sample in a laboratory in Japan. The data were consistent with all three measurements. In addition, in situ measurements of hydrate formation and decomposition were done by X-ray diffraction. The transformation of ice into CO2 hydrates occurred in two steps: at first a CO2 hydrate layer rapidly formed a coating on the ice surface and then the CO2 hydrate slowly grew according to the diffusion rates of CO2 and H2O molecules through the hydrate layer to the reaction sites. The same methods were used to observe the self-preservation effect of methane hydrates. PACS Nos.: 82.80Ch, 61.10Nz

Dissociation of Natural Gas Hydrates Observed by X-ray CT Scanner

2006 ◽  
Vol 912 (1) ◽  
pp. 1011-1020 ◽  
Author(s):  
JUN MIKAMI ◽  
YOSHIHIRO MASUDA ◽  
TAKASHI UCHIDA ◽  
TOHRU SATOH ◽  
HIDEAKI TAKEDA
Keyword(s):  
Natural Gas ◽  
Gas Hydrates ◽  
Ct Scanner ◽  
X Ray ◽  
Natural Gas Hydrates

Evaluation of Tri-Axial Magnetostriction in Cube-Oriented Fe-Ga Single Crystal by Using X-Ray Diffraction Method

2017 ◽  
Vol 909 ◽  
pp. 300-305 ◽  
Author(s):  
Takehito Ikeuchi ◽  
Akihiro Koyama ◽  
Muneyuki Imafuku ◽  
Shun Fujieda ◽  
Yusuke Onuki ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Single Crystal ◽  
Volume Fraction ◽  
Diffraction Method ◽  
Diffraction Measurement ◽  
Magnetic Field Direction ◽  
Magnetic Domains ◽  
X Ray Diffraction ◽  
X Ray

We carried out in situ tri-axial magnetostriction analysis for cube-oriented Fe-18%Ga single crystal by X-ray diffraction measurement under magnetic field. Periodic change in tri-axial magnetostriction with applied magnetic field direction was clearly observed. However, those values in [100] and [010] directions were not equivalent. Theoretical calculation of magnetostriction considering domain structure revealed this is caused by the non-equivalent volume fraction of initial magnetic domains.

An in situ, energy-dispersive x-ray diffraction study of natural gas conversion by carbon dioxide reforming

1993 ◽  
Vol 97 (13) ◽  
pp. 3355-3358 ◽  
Author(s):  
A. T. Ashcroft ◽  
A. K. Cheetham ◽  
R. H. Jones ◽  
S. Natarajan ◽  
J. M. Thomas ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Natural Gas ◽  
Diffraction Study ◽  
Energy Dispersive ◽  
X Ray Diffraction ◽  
Carbon Dioxide Reforming ◽  
Natural Gas Conversion ◽  
X Ray ◽  
Gas Conversion

Study of The Hydrothermal Synthesis of Gallium Phosphates Using in Situ Time-Resolved X-Ray Diffraction

1998 ◽  
Vol 547 ◽  
Author(s):  
R.I. Walton ◽  
T. Loiseau ◽  
R.J. Francis ◽  
D. O'Hare ◽  
G. Férey
Keyword(s):  
Kinetic Data ◽  
Three Dimensional ◽  
Diffraction Method ◽  
Effect Of Temperature ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
Time Resolved ◽  
X Ray ◽  
Phosphorus Source

AbstractThe hydrothermal crystallisation (130-180 °C) of three-dimensional open-framework gallium and aluminium oxyfluoro-phosphates with the ULM-3 and ULM-4 structures have been studied in situ for the first time. The in situ energy-dispersive X-ray diffraction method has allowed the formation of the crystalline products to be observed under hydrothermal conditions The integrated areas of the strongest Bragg reflections has allowed quantitative kinetic data to be extracted. The effect of temperature, phosphorus source, templating agent have been investigated. The nature of phosphorus source in the reaction mixture has been found to affect dramatically the course of reaction for certain combinations of amine and temperature. Previously unobserved transient crystalline phases have been seen during the production of ULM-3 gallium phosphates when P2O5 or polyphosphoric acid are used. The formation of these intermediates affects the kinetics of product growth. In the case of the aluminium ULM-3 materials reaction always proceeds via a crystalline intermediate whatever phosphorus source is used. The ULM-4 framework materials are found to always crystallise directly with no evidence for any intermediates. Kinetic data for each system have been modelled using standard solid-state chemistry expressions, and these calculations indicate the reactions to be diffusion controlled.

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