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Volume 70 (2008)
- Issue 6 Pages 561-
- Issue 5 Pages 477-
- Issue 4 Pages 423-
- Issue 3 Pages 357-
- Issue 2 Pages 97-
- Issue 1 Pages 3-
Volume 70, Issue 5
Displaying 1-3 of 3 articles from this issue
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Seiji KAMIMURA , Shingo HOSHINO2008 Volume 70 Issue 5 Pages 477-485
Published: 2008
Released on J-STAGE: April 09, 2021
JOURNAL OPEN ACCESSIn general, ice growth during industrial manufacturing of ice is governed by heat conduction and/or heat convection. Although radiation cooling is observed in nature, e.g., ice formation on roads under cold conditions, radiation cooling has not been employed in the manufacture of ice. The aim of this research is to investigate ice growth under radiation cooling. First of all, an experimental setup is developed and tested. The experimental apparatus consists of a low-temperature heat source, a water tank, and an insulation box. The insulation box is placed between the cold heat source and the water tank in order to prevent conduction and convection of heat between them. The formation of frost on the cold heat source is prevented by reducing the pressure inside the insulation box. Experiments are carried out in a low-temperature room in which the temperature maintained at approximately 2℃. The ice formed is photographed at various stages of its growth using a CCD camera. The first crystal forms spontaneously several hours after the cooling is started. The ice growth rate is almost constant along the vertically direction, and the ice formed is approximately 20-mm thick after 40 h. The average growth rate of ice is found to be 0.56 mm h -1 . The ice formed appears to be almost perfectly transparent with no bubbles. A cross section of 50 mm × 50 mm of the ice is found to be composed of a single crystal with the c-axis along the vertical direction. The growth rate of ice under conduction cooling reduces with increasing ice thickness, although it under radiation cooling is maintained almost constant. Involving bubbles inside of the ice under radiation cooling is smaller than them under conduction cooling.View full abstractDownload PDF (7570K) -
Sento NAKAI , Satoru YAMAGUCHI, Yukari TAKEUCHI2008 Volume 70 Issue 5 Pages 487-498
Published: 2008
Released on J-STAGE: April 09, 2021
JOURNAL OPEN ACCESSCharacteristics of anomalies of surface meteorological elements during the winter of 2007/2008 are described. The normalized maximum snow depth (z2008) in Honshu Island tends to be negative at altitudes below 200 meters and close to zero at higher stations. The z2008 was above normal in many stations below altitudes of 50 meters on Hokkaido Island. The z2008, which was much lower than normal, was concentrated locally in some areas of a 100-km scale. Characteristic periods of the winter of 2007/200 were defined in the following time series of temperature anomalies: I) warm period from December through the first half of January; II) cold period from the last half of January to the end of February; and III) very warm period in March. The anomalies in snow depth was negative regardless of the amount of precipitation anomaly in period I. The anomalies in snow depth was close to zero in the last half of the period II at stations where it snowed heavily enough to compensate for the negative anomaly in snow depth in period I. Large positive temperature anomalies in period III suggests a significant nationwide snowmelt. Even a period-mean temperature anomaly of about K could cause a large change in the rain/snow ratio, and also in the melting speed, to affect the seasonal variation of the anomaly of snow depth.View full abstractDownload PDF (11164K) -
Konosuke SUGIURA, Shuhei TAKAHASHI, Takao KAMEDA , Hiroyuki ENOMOTO , ...2008 Volume 70 Issue 5 Pages 499-506
Published: 2008
Released on J-STAGE: April 09, 2021
JOURNAL OPEN ACCESS
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