Journal of the Japanese Society of Snow and Ice
Online ISSN : 1883-6267
Print ISSN : 0373-1006
Search
Advanced search
OR
Browse
Search
Volume 21, Issue 6
Displaying 1-5 of 5 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
  • The rate of sliding and the analysis of friction on snow Part II
    MASAKI SHINBO
    1959 Volume 21 Issue 6 Pages 171-177
    Published: 1959
    Released on J-STAGE: July 23, 2009
    DOIhttps://doi.org/10.5331/seppyo.21.171
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    In the previous paper, we described the method of measuring the friction of snow and obtainning the accurate value of its friction without any influence of front drag and scale effect due to size limitation by our rotational friction tester though this effect could not be escaped even in model ski or sledge method, and proved that the degree of accuracy of μS and μK fell within the limit of ±0.05. Also we proved that μS and μK took constant value within cedtain pressure range (2166g/cm2) and that μK took constant value within certain sliding speed range (0.0057.2m/sec.)
    In this paper, we have described the result of the measurement of friction of plastics on snow and we proved that μS was affected by air tempeeature, snow temperature, watercontent of snow, the kind of plastics, its water absorption and roughness of its surface, and that μK was affected by air temperature, snow temperature, water-content of snow, sliding speed, the kind of plastics and water absorption. But it was not affected by the roughness of its surface. Accordingly there are some factors which are not common in them.
    Furthermore, we proved that, when the watercontent of snow increased, μK increased abnormally and μS decreased on the flat sliding surface, and consequently μK>μS.
    As this abnormal phenomenon would be due to interaction of water and smooth sliding surface, we have overcome this with rough sliding surface.
    As for the relation between the nature of plastics and μK on snow, we proved that μS showed fairly large value when the contact angle of plastics with water was larger, μK on snow showed different value when the method of synthesis gave difference of hydrophillic properties. As for mechanism of this phenomenon, we will report in near future.
    View full abstract
    Download PDF (1062K)
  • Snowgage of high catching rate
    R. INOUE, M. ANZAI
    1959 Volume 21 Issue 6 Pages 178-181
    Published: 1959
    Released on J-STAGE: July 23, 2009
    DOIhttps://doi.org/10.5331/seppyo.21.178
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    The catching characteristics of conventional snow gages are quite unsatisfactory.
    Yoshida and Saito observed the catching rate C of various snow gages and found that C was given by the following empirical formula,
    C=1/(1+mv)
    where v is the wind velocity in m/s near the gages orifice and m is the constant for certain snow gage. For J.M. A. standard 20-cm standpipe snowgage m was 0.449.
    In order to secure high catching rate, it is neccesary to undisturb the air current above the orifice.
    The authers designed a snowgage which had the funnel-shaped head connected to an U-tube. The funnel and it's side of the U-tube is filled with kerosene and the other side is filled with water. The whole system is heated to a certain temperature above 0°C. When the snowflakes enter in the oil, they melt and fall down as waterdrops into this U-tube, and the same mass of water of these drops must overflow from the opening of the water side of the U-tube. The overflown water is measured by the jar for raingage.
    From the analysis of the results of field tests, the catching rate of this snowgage is presumed to be shown by the following formula.
    C=1/(1+0.24v)
    View full abstract
    Download PDF (6416K)
  • On the strength of the defence forest tree and defence pile
    MASAYUKI KANATA
    1959 Volume 21 Issue 6 Pages 182-185
    Published: 1959
    Released on J-STAGE: July 23, 2009
    DOIhttps://doi.org/10.5331/seppyo.21.182
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    To protect from the damages caused by the avalanche, the Japan National Railway forests the defence forest and builds the defence pile on the slope where an avalanche is threatened.
    To find out the bending strength of the defence forest tree and the defence pile agains the pressure of the snow cover on the slope, the trees were classified according to the size of diameter while the defence pile was classified according to the material, and then each of them was pulled by a wire rope in parallel with the slope and the maximum bending strength just before its break was observed.
    View full abstract
    Download PDF (2914K)
  • [title in Japanese]
    [in Japanese]
    1959 Volume 21 Issue 6 Pages 186-189
    Published: 1959
    Released on J-STAGE: January 20, 2010
    DOIhttps://doi.org/10.5331/seppyo.21.186
    JOURNAL FREE ACCESS
    Download PDF (728K)
  • [title in Japanese]
    [in Japanese]
    1959 Volume 21 Issue 6 Pages 190
    Published: 1959
    Released on J-STAGE: July 23, 2009
    DOIhttps://doi.org/10.5331/seppyo.21.190
    JOURNAL FREE ACCESS
    Download PDF (217K)
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top