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Volume 10, Issue 3-4
Displaying 1-7 of 7 articles from this issue
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Shyôgo MATSUSHIMA1957 Volume 10 Issue 3-4 Pages 113-122
Published: December 25, 1957
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSIn this paper, creep tests made on granite specimens under a uniaxial compressional pressure are reported. It has been found, as previously inferred, that the flow rate in lateral direction becomes larger than that in axial direction with increasing load. Near or in the fracture range, the lateral flow becomes some hundred times as large as the longitudinal one. This result conforms in tendency to the variation of Poisson's ratio with load which was reported in the previous paper.
Referring to the recovery and stress-strain curves, it is suggested that granites show different behaviors simultaneously in different directions under a uniaxial compression; that is elastic in the direction of the applied stress and plastic in the direction perpendicular to it.View full abstractDownload PDF (770K) -
Shôshichirô KATÔ1957 Volume 10 Issue 3-4 Pages 123-140
Published: December 25, 1957
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSAssuming the fluid motion of vT1°-type (expression (3.1) in §3), we have studied here the time characteristics of self-exciting fluid dynamos. As a result of theoretical calculations, it has been found that three magnetic fields expressed by three surface spherical harmonics Ymn-1, Ymn and Ymn+1((n, m)-harmonics in §3) can coexist independently of other magnetic fields. These three magnetic fields oscillate concurrently in intensity quasi-periodically with time, the frequency being proportional to order m, fluid velocity and depth of the fluid layer. The westward drift of the earth's magnetic field and also the reversal of the magnetic field of the sun may be well explained by the above results. The periodical dynamo presented here may also be appropriate as a model for magnetic variable stars.View full abstractDownload PDF (1328K) -
Reflection and Transmission of Elastic Waves at a Discontinuity with an Intervenient Transient LayerRyôsuke SATÔ1957 Volume 10 Issue 3-4 Pages 141-153
Published: December 25, 1957
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSReflection and refraction of elastic waves at a discontinuous boundary in transmitting medium have been studied by many authors since 1899. Most of them have assumed that density or elastic constant of the medium vary discontinuously (mathematically) at the boundary. While there can be little doubt that very sharp discontinuities exist in the earth, it will be better to consider that physical properties of materials in the immediate vicinity of the “discontinuity” vary continuously in actual cases. In such cases, the most pertinent transfer of energy among the waves concerned takes place near the boundary, say, within a few wave-lengths from it, and no theory can be adequate without referring to the sharpness of discontinuity as compared with the wave-length.
K. Sezawa and K. Kanai, in 1935, and A. Wolf, in 1937, are the only two who investigated the effect of sharpness of discontinuity on reflection and refraction phenomena. Their studies, however, were confined only to vertical incidence of waves, (although, in the latter, some qualitative statements were made about the general case), with simplifying assumptions that densities are the same everywhere and rigidity or velocity in the intervenient layer varies linearly with depth.
In this paper, the present writer has investigated reflection and transmission of elastic waves at “discontinuity” for the incidence of SH-waves with various glancing angles, supposing that there is an invervenient layer of thickness H between two different media. In the intervenient layer, both density and rigidity vary continuously but steeply from the corresponding values of the upper medium to those of the lower one. He has found that the reflected wave is considerably affected by the existence of the intervenient layer if the wave-length of incident wave is very small compared with the thickness of the layer, but the transmitted wave is not affected very much.View full abstractDownload PDF (859K) -
Ziro SUZUKI1957 Volume 10 Issue 3-4 Pages 154-160
Published: December 25, 1957
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSA complete expression of dynamical characteristics for electromagnetic seismographs with no electric amplifier has been derived by Tazime. In this paper the same expression is deduced in another way, which is more familiar to seismologists. The method is conducive to easy understanding of physical meanings of the expression. Further, the expression is reduced to one of practical convenience. The new expression is written in terms of usual constants for galvanometer, i. e., period, coil resistance, critical damping resistance, and sensitivity.View full abstractDownload PDF (475K) -
Akeo KATAOKA, Mikio OGURI1957 Volume 10 Issue 3-4 Pages 161-162
Published: December 25, 1957
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSDownload PDF (250K) -
Tokutarou YABASHI1957 Volume 10 Issue 3-4 Pages 162-164
Published: December 25, 1957
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSDownload PDF (406K) -
Ziro SUZUKI, Haruko ISHIDA1957 Volume 10 Issue 3-4 Pages 164-165
Published: December 25, 1957
Released on J-STAGE: March 11, 2010
JOURNAL FREE ACCESSDownload PDF (268K)
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