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Volume 37, Issue 1
Displaying 1-6 of 6 articles from this issue
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Yasushi KAWAKAMI, Hajime NISHIMURA1981 Volume 37 Issue 1 Pages 1-8
Published: March 30, 1981
Released on J-STAGE: June 17, 2011
JOURNAL FREE ACCESSBacterial degradation of the hydrocarbons of lubricating oils was investigated by mass spectrometric analysis which gives both total amount and the composition of hydrocarbon types of residual oil. An unused lubricating oil, which mainly consisted of hydrocarbon types with only a small percentage of n-alkanes, was degraded by marine Bacillus sp. and Pseudomonas sp. with 55% and 25% decreases in 10 days, respectively. Susceptibility of respective hydrocarbon types to biodegradation was in the following order: alkanes>noncondensed cycloalkanes, mono-aromatics>condensed cycloalkanes. A used lubricating oil of different brand showed a larger decrease than the unused oil. Both species of bacteria degraded large portions of alkane fraction of Arabian light crude oil.View full abstractDownload PDF (1273K) -
Paimpillil S. JOSEPH, Sanshiro KAWAI, Yoshiaki TOBA1981 Volume 37 Issue 1 Pages 9-20
Published: March 30, 1981
Released on J-STAGE: June 17, 2011
JOURNAL FREE ACCESSThe present study is a modification of the wave prediction model presented in the first paper of this title (KAWAI et al., 1979) based on the Toba's (1978) single parameter equation of the wind wave growth. The introduction of a grid method reduces the two defects pointed out in KAWAI et al., i.e., the absence of the prediction of certain instants at fixed points, and the concentration of wave energy at certain points in the wind direction, arising from the lack of treatment of the lateral spreading of wave energy around the wind direction. The new model is applied to the same set of data. The results shows overall improvements, such as the elimination of certain overestimate in the first study and the coincidence of the predicted maximum with the measured one. The swells are separately hindcasted and a very good agreement with measurement is obtained.View full abstractDownload PDF (2002K) -
Yutaka NAGATA, Kimie YONEMURA, Hideo NISHIDA1981 Volume 37 Issue 1 Pages 21-30
Published: March 30, 1981
Released on J-STAGE: June 17, 2011
JOURNAL FREE ACCESSEvidence for the applicability of GEK (Geomagnetic Electrokinetograph) measurements to shallow water regions is provided from observations in the shelf region of the East China Sea. The reason for the effectiveness of GEK measurements in this case is investigated theoretically, and it is shown to be attributable to the existence of a thick conductive sedimentary layer. In addition, it is shown that low conductive basement rock can be regarded as a good conductor for GEK measurements if the current width is broad enough and if the ratio of current width to water depth is larger than the resistivity ratio of basement rock to sea water. This implies that barotropic tidal currents can be measured with GEK in any ocean on the earth if they have significant magnitudes.View full abstractDownload PDF (1514K) -
Sei-ichi KANARI, Toshihiko TERAMOTO1981 Volume 37 Issue 1 Pages 31-48
Published: March 30, 1981
Released on J-STAGE: June 17, 2011
JOURNAL FREE ACCESSBottom current conditions due to tidal currents in the area of the Bashi Channel, Luzon Strait, are examined using a scaled hydraulic model in a uni-directional flow channel. The geometrical model is scaled in both the similitude of Froude's Number and the similitude of the four-thirds power law of eddy viscosity.
The currents obtained from the experiment seem to be consistent in order of magnitude with the estimated currents based on observations made by Offshore Environmental System Ltd. In a quasi-steady tidal phase, formation of a strong core flow is found in the Bashi Channel. It can be explained by a simple theoretical model in which the formation of the strong current is attributed to the submarine topography of the Luzon Strait.View full abstractDownload PDF (3266K) -
Akira HARASHIMA, Yukio OONISHI1981 Volume 37 Issue 1 Pages 49-59
Published: March 30, 1981
Released on J-STAGE: June 17, 2011
JOURNAL FREE ACCESSThe Coriolis effect on frontogenesis in the transitional region between the inner bay and the outer ocean is studied by running several three-dimensional numerical experiments. The aim is to clarify what external parameters, including the transverse scale of the basin, control the phenomena. The characteristics of the front in each case are described by defining three diagnostic quantities, namely, the sharpness of the front, the intrusion of the front, and the buoyancy difference between the minimum buoyancy region and the surrounding part, as the existence of the minimum buoyancy region is closely related to frontogenesis. The three quantities are shown to depend on two nondimensional numbers, Rof (=f-1L-2/3Fb1/3: defined as flux Rossby number) and Ref (=ν-1vL-2/3Fb1/3H2: defined as flux Reynolds number).View full abstractDownload PDF (2013K) -
1981 Volume 37 Issue 1 Pages 60
Published: 1981
Released on J-STAGE: June 17, 2011
JOURNAL FREE ACCESSDownload PDF (63K)
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