scholarly journals Self-preservation and structural transition of gas hydrates during dissociation below the ice point: an in situ study using Raman spectroscopy

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Jin-Rong Zhong ◽  
Xin-Yang Zeng ◽  
Feng-He Zhou ◽  
Qi-Dong Ran ◽  
Chang-Yu Sun ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Gas Hydrates ◽  
Structural Transition ◽  
In Situ Study

In situ study on the structural transition in YBO3 through Raman spectroscopy

2011 ◽  
Vol 131 (1-2) ◽  
pp. 274-277 ◽  
Author(s):  
G.X. Gu ◽  
D. Wang ◽  
X.S. Lv ◽  
S.M. Wan ◽  
J.L. You ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Structural Transition ◽  
In Situ Study

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

scholarly journals A new high-pressure cell for systematic in situ investigations of micro-scale processes in gas hydrates using confocal micro-Raman spectroscopy

2020 ◽  
Vol 91 (11) ◽  
pp. 115103 ◽  
Author(s):  
Judith M. Schicks ◽  
Mengdi Pan ◽  
Ronny Giese ◽  
Mathias Poser ◽  
Nur Aminatulmimi Ismail ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
Gas Hydrates ◽  
High Pressure Cell ◽  
Micro Scale ◽  
Micro Raman Spectroscopy ◽  
Pressure Cell

Occupation and Release Behavior of Guest Molecules in CH4, CO2, N2, and Acetone Mixture Hydrates: An In Situ Study by Raman Spectroscopy

2014 ◽  
Vol 53 (14) ◽  
pp. 6179-6184 ◽  
Author(s):  
Youngrok Seo ◽  
Sulki An ◽  
Jeong-Woo Park ◽  
Byeong-Soo Kim ◽  
Takeshi Komai ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Release Behavior ◽  
Guest Molecules ◽  
In Situ Study

scholarly journals In-situ study of the kinetics of phosphoric acid interaction with calcite and fluorapatite by Raman spectroscopy and flotation

2021 ◽  
Vol 162 ◽  
pp. 106729
Author(s):  
Lev O. Filippov ◽  
Inna V. Filippova ◽  
Oumar B. Kaba ◽  
Daniel Fornasiero
Keyword(s):  
Raman Spectroscopy ◽  
Phosphoric Acid ◽  
Acid Interaction ◽  
In Situ Study ◽  
Kinetics Of
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