|
Accession number;99A0924153
|
| Title;Internal Friction of Ice Crystals at Low Frequencies. III. Internal Friction Measured in the Frequency Range from 0.1 to 200Hz. |
| Author;
OGURO MITSUGU
(Hokkaidokyodai Asahikawako)
KISO NAOKICHI
(Asahikawa Natil. Coll. of Technol.)
|
Journal Title;Journal of Hokkaido University of Education. Natural Science
|
Journal Code:L3615A
|
ISSN:1344-2570
|
|
VOL.50;NO.1;PAGE.37-47(1999)
|
| Figure&Table&Reference;FIG.7, REF.24 |
| Pub. Country;Japan |
| Language;Japanese |
| Abstract;The internal friction of as-grown and annealed ice single crystals was measured by an inverted torsion pendulum between -10 to -15.DEG.C.. An inverted torsion pendulum was used for forced vibrations from 0.1 to 20Hz and for resonance vibrations from 27 to 200Hz. Specimens were cut from unoriented pure ice single crystals grown by the Bridgman method and then were annealed for 14 to 20 days at approximately -2.DEG.C.. There were two type of peaks in as-grown specimens: (a) the well-known peak due to the orientation of water molecules caused by intrinsic Bjerrum defects and (b) a loss peak at a lower temperature than (a) peak. The peak at high temperature predominated at higher frequencies, but the height of the peak decreased with decreasing frequency and the dominant peak changed to the lower temperature peak. A new broadened peak at lower temperatures appeared in well-annealed specimens instead of the latter peak. The logarithmic plot of relaxation time against the reciprocal temperature of the Debye-type peak was linear at temperatures higher than 210K and these data lay on the extension line of our previous experiment. The average activation energy was estimated as 0.55eV. The slope at temperatures lower than 210K decreased. The activation energy ranges of two loss peaks observed at low temperatures were estimated as 0.26eV to 0.34eV and 0.26eV to 0.38eV, respectively. The origins of two peaks at lower temperatures were compared with the experimental results of mechanical and electrical measurement of other investigators and are attributed to lattice defects such as dislocation in ice. (author abst.) |
|
|
|
Related Articles;
|
