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Volume 72 (2010)
- Issue 6 Pages 377-
- Issue 5 Pages 311-
- Issue 4 Pages 237-
- Issue 3 Pages 157-
- Issue 2 Pages 115-
- Issue 1 Pages 3-
Volume 72, Issue 3
Displaying 1-3 of 3 articles from this issue
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Kunio WATANABE, Yosuke OOMORI, Tomomi WAKE, Masaru SAKAI2010 Volume 72 Issue 3 Pages 157-168
Published: 2010
Released on J-STAGE: July 31, 2022
JOURNAL OPEN ACCESSUnderstanding the water amount, solute concentration, and thermal properties of a soil is essential task in order to evaluate any mass transfer process during the soil freezing and thawing. Noborio et al., (1996) had developed a TDR probe, with ability to simultaneous measurement of water content and the soil thermal properties (thermo-TDR). In this study, the thermo-TDR method was applied for investigation of frozen sand and silt loam samples variably saturated with saline water. Experimental results of relative permittivity, electric conductivity, and apparent thermal conductivity were adequate for the both soils at a range from -20 to 20 degree Celsius. The data were used for evaluation of four thermal conductivity models. In addition, the cubic function for calibrating unfrozen water content from relative permittivity was modified by using the ice content because of the observed di erences in the relation “relative permittivity-ice amount” in silt loam. Finally, the total water contents estimated as a function of the unfrozen water amount and the thermal properties showed a good agreement with the measured ones at below -2 degree Celsius range. To improve the measurement accuracy and to apply it in a field conditions are issues for themo-TDR in the future.View full abstractDownload PDF (10093K) -
Katsutoshi TUSIMA, Rumi TANAKA2010 Volume 72 Issue 3 Pages 169-179
Published: 2010
Released on J-STAGE: July 31, 2022
JOURNAL OPEN ACCESSIn order to analyze the regelation process, the concept of equivalent water film δ was introduced. It is supposed that the thermal conductivity of a water film is the same as that of a wire; however, the thickness of water film d is adjusted on the basis of the ratio of the thermal conductivity the wire to that of water, i.e., (λ/λw)d. An isothermal line is a line that is perpendicular to the z-axis. The lines can exchange by drawing from equivalent film δ to actual water film d. Heat flows perpendicular to the exchanged isothermal lines on actual film. Heat flow refracts at the interface between the wire and water. The thickness of the water film can be calculated from the measured regelation velocity. It is estimated to be 4～11μm as shown in Table 1. On the other hand, when the thermal conductivity of the wire replaced to water’s one, the equivalent diameter of the wire can be determined. These figures (Fig.5) give a comparison among the regelation rates of different wires.View full abstractDownload PDF (9362K) -
Norikazu MAENO2010 Volume 72 Issue 3 Pages 181-189
Published: 2010
Released on J-STAGE: July 31, 2022
JOURNAL OPEN ACCESS
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