کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1754306 | 1522659 | 2007 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Changes of acoustic emission and strain in hard coal during gas sorption–desorption cycles Changes of acoustic emission and strain in hard coal during gas sorption–desorption cycles](/preview/png/1754306.png)
The cylindrical coal samples were subjected to three successive cycles of sorption–desorption processes of a single gas (CO2, CH4). Acoustic emission (AE) and strains were simultaneously recorded during the sorption and desorption processes.Tests were conducted on medium-rank coal from the Upper Silesia Basin, Poland. Follow-up tests for gas sorption–desorption consistently showed significant changes of AE characteristics for re-runs on the same sample. The AE level decreased in each successive test. The most spectacular differences were observed between AE generated during the first cycle of gas sorption and the subsequent cycle. This phenomenon could be due to structural changes in the coal taking place substantially on its first exposure to the sorbate. The AE results indicate, that each cycle of gas sorption–desorption was run on the same coal though with a somewhat different structure.In those tests, the swelling of coal by CO2 or/and CH4 was anisotropic (greater in the direction perpendicular to the bedding plane than parallel) in each cycle of the gas sorption–desorption process.
Journal: International Journal of Coal Geology - Volume 70, Issue 4, 1 May 2007, Pages 305–312