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Volume 13, Issue 1
Displaying 1-6 of 6 articles from this issue
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Hitoshi TAKEUCHI, Naota KOBAYASHI1960 Volume 13 Issue 1 Pages 1-8
Published: March 30, 1960
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSThe variational calculus method used in a previous paper is applied in §. 4 to the study of Love waves propagating along a free surface of a semi-infinite elastic medium, in which the density and elasticities are changing exponentially with depth. The method is also applied to the study of Love (in §. 2) and Rayleigh (in §. 3) waves in a uniform superficial layer upon a uniform semi-infinite medium. In §. 5, is shown a trial function which is useful in the study of Love waves in the case when the substratum is perfectly rigid.View full abstractDownload PDF (505K) -
Bin OKAI1960 Volume 13 Issue 1 Pages 9-25
Published: March 30, 1960
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSWhen a layer of fluid is heated uniformly from below, a convection occurs in a regular cellular pattern for the values of the Rayleigh number in excess of a critical value. A perturbation method is presented here to determine the form and amplitude of this steady convection. The essential point is to expand functions describing the field (velocity and temperature) in a power series of a parameter ε, while the Rayleigh number is put as a product of its critical value times (1+ε2). A set of inhomogeneous equations thus obtained can be solved by the perturbation method used in non-linear oscillation problems. In the two-dimensional case the slope of heat transport curve steepens abruptly at the critical Rayleigr number. As another example which can be dealt with in this way, a convection in a sphere is studied. This is an extention of Chandrasekhar's linearized stability theory.View full abstractDownload PDF (1170K) -
Bin OKAI1960 Volume 13 Issue 1 Pages 26-36
Published: March 30, 1960
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSIn this paper, a theoretical investigation is made of the steady thermal convection in a two-dimensional fluid layer when it is heated uniformly from below under a simultaneous constraint of non-uniform temperature on its upper surface. Mathematically this is an extention of the method developed in the anthor's previous paper to a problem with inhomogeneous boundary conditions. It was found that the site of spontaneous convection cells is decided according to the surface temperature disturbance having the critical wave length. Surface disturbances having much larger or smaller wave length play very little part in this, while those having wave lengths close to the critical one are effective in determining the general feature of fluid motion.View full abstractDownload PDF (802K) -
Kennosuke OKANO1960 Volume 13 Issue 1 Pages 37-42
Published: March 30, 1960
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSTo find the origin of microseisms, it is important that arrival directions of microseismic waves should be clearly observed. For this purpose, the writer recorded orbital motions in UD-EW, UD-NS and EW-NS planes simultaneously by vector seismographs. He selected waves of the pure Rayleigh-type and investigated the frequency distribution of arrival directions of these waves. The results obtained are as follows. All directions found, with one exception, point toward the coast.
The frequency of the direction shows neither the equitable distribution nor the random one, but there is a constant pattern of distribution with respect to the coast regardless of the position of a center of Iow pressure.
The particle orbits suggest that microseismic waves do not always come continuously from definite directions.View full abstractDownload PDF (2252K) -
[in Japanese]1960 Volume 13 Issue 1 Pages 43-60
Published: March 30, 1960
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSDownload PDF (1671K) -
Bin OKAI1960 Volume 13 Issue 1 Pages 61-62
Published: March 30, 1960
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSDownload PDF (265K)
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