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Volume 8 (1952)
- Issue 4 Pages 163-
- Issue 3 Pages 115-
- Issue 2 Pages 55-
- Issue 1 Pages 1-
Volume 8, Issue 2
Displaying 1-13 of 13 articles from this issue
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[in Japanese]Article type: Article
1952 Volume 8 Issue 2 Pages 55-56
Published: June 30, 1952
Released on J-STAGE: June 02, 2017
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[in Japanese]Article type: Article
1952 Volume 8 Issue 2 Pages 57-58
Published: June 30, 1952
Released on J-STAGE: June 02, 2017
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Jun'ichi SaneyoshiArticle type: Article
1952 Volume 8 Issue 2 Pages 59-65
Published: June 30, 1952
Released on J-STAGE: June 02, 2017
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Soichro KurokiArticle type: Article
1952 Volume 8 Issue 2 Pages 66-70
Published: June 30, 1952
Released on J-STAGE: June 02, 2017
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Toshihiko Ohno, Heiji KawaiArticle type: Article
1952 Volume 8 Issue 2 Pages 71-75
Published: June 30, 1952
Released on J-STAGE: June 02, 2017
JOURNAL FREE ACCESSThe absolute threshold value of bone-conduction hearing has been measured by observing the force transmitted from an electro-magnetic vibrator on the head skin by BaTiO_3 ceramic between the vibrator and the skin. The thresholds on the mastoid(excited area 1cm^2)with the open auricle were about 800dynes at 100cps, 30dynes at 500cps, 25dynes at 1000cps, 3dynes at 2000cps and 20dynes at 4000 cps, respectively. The distinctive nodal lines were observed at about 250, 400 and 600cps, due to the resonance of skull. In the case of the closed auricle, the decrease of threshold value was about 25 db at 100 cps, 35 db at 150cps, 20db at 200cps, 10db at 400cps, and 0 db at 800cps, respectively. The above phenomena could be explained by assuming the ear-drum to be mass(19. 6mg)and resistance(3. 24g/sec)View full abstractDownload PDF (465K) -
Jobu AwataniArticle type: Article
1952 Volume 8 Issue 2 Pages 75-79
Published: June 30, 1952
Released on J-STAGE: June 02, 2017
JOURNAL FREE ACCESSThis Paper describes a research on the diffraction effect in the case when a plane sound wave train impinges on a prolate spheroid in the direction of its long axis The sound pressures at the various points on its surface, that is, the diffraction coefficients are calculated, and these are compared with those by a sphere and a circular plate.View full abstractDownload PDF (456K) -
Jobu AwataniArticle type: Article
1952 Volume 8 Issue 2 Pages 79-82
Published: June 30, 1952
Released on J-STAGE: June 02, 2017
JOURNAL FREE ACCESSEmploying a Rayleigh disc and a torsion vane placed in the same sound field, the particle velocity of the medium(air), from which the mean energy density E of the wave calculated, and the radiation pressure W on a circular plate were measured respectively. The values of the ratio W/E thus obtained for the various frequencies were compared with the theoretical values calculated by the present author. The experimental result pointed out that the radiation pressures by the waves of equal intensity very remarkably according to the frequency and the property of the sound field. The frequency range of this experiment was from 1 kc. to 12kc. and the diameter of the circular plate 3. 2cm.View full abstractDownload PDF (466K) -
Akira Odashima, Junkichi SohmaArticle type: Article
1952 Volume 8 Issue 2 Pages 83-87
Published: June 30, 1952
Released on J-STAGE: June 02, 2017
JOURNAL FREE ACCESSWe measured the ultrasonic velocity(frequency 444kc)in the polystyrene-benzene solution by the interferometer method. The molecular weight of the used polystyrene sample was about 446, 000. First, the dependence of velocity on concentration was observed. We found that the velocity increased with increase of concentration in diluted solution up to the concentration of 0. 03gr/cc, in which the velocity attained 1339m/sec, but in concentrated solutions above that the velocity was approximately constant. This suggests that, also in the high frequency region there are two different states in high polymer solutions, as in dicated by static measurements of viscosity and specific volume. And the boundary concentration between these two states obtained by this measurement is of the same order of magnitude as obtained from static ones. We calculated the velocity of this diluted solution by employing a model analogous to Eyring's free volume model, and velocity values obtained are in good agreement with the experimental ones. We calculated the adiabatic compressibility of this solution in various concentrations from the velocity and density data. Next, we observed the temperature dependence of velocity in concentrated solutions with various concentration. In each concentration, the abrupt increasement of velocity in the neighbourhood of the melting point of benzene were observed. This suggests that the concentrated polymer solution might have some transition region in this temperature region.View full abstractDownload PDF (542K) -
Otohiko Nomoto, Tadashi Kishimoto, Takuro IkedaArticle type: Article
1952 Volume 8 Issue 2 Pages 88-92
Published: June 30, 1952
Released on J-STAGE: June 02, 2017
JOURNAL FREE ACCESSMeasurements were performed on the absorption and dispersion of ultrasonic waves in castor oil and the result was discussed from the standpoint of the relaxation theory of viscosity. Absorption measurement was performed by the pulse technique at three frequencies 1. 43Mc/sec, 2. 86Mc/sec and 7. 6Mc/sec, and at temperatures between -4°and+35°C. The observed absorption coefficients proved to be lower than the classical values given by the Stokes'formula. Velocity values were obtained at five frequencies between 0. 47Mc/sec and 7. 7Mc/sec by ultrasonic interferometry and revealed a dispersion of about 20m/sec between these frequency limits. This dispersion is of approximately twice the amount to be expected from the relaxation theory by empoloying the static value of the viscosity coefficient.View full abstractDownload PDF (464K) -
Otohiko Nomoto, Tadashi KishimotoArticle type: Article
1952 Volume 8 Issue 2 Pages 93-96
Published: June 30, 1952
Released on J-STAGE: June 02, 2017
JOURNAL FREE ACCESSMeasurement was performed on the velocity of ultrasonic waves in concentric solutions of NaCl, KCl, KBr, Kl and MgSO_4 at temperatures of 15°〜55°and at various frequencies, but no dispersion was observed between the limits of the frequencies emplpyed:NaCl(1. 43〜12. 87Mc/sec), KCl(0. 47〜12. 87Mc/sec), KBr(4. 29〜12. 87Mc/sec), Kl(4. 29〜12. 87Mc/sec), MgSO_4(0. 47〜2. 86Mc/sec). The method of ultrasonic interferometry was employed for velocity determination at frequencies between 0. 47 and 2. 86 Mc/sec, and the method of the diffraction of light by ultrasonic waves at frequencies between 1. 43 and 12. 87Mc/sec.View full abstractDownload PDF (414K) -
Cotoji Satta, Atsuo Sugawara, Yutaka KohasiArticle type: Article
1952 Volume 8 Issue 2 Pages 97-103
Published: June 30, 1952
Released on J-STAGE: June 02, 2017
JOURNAL FREE ACCESSThe authors studies the body wall vibration(especially at the back of the nose)by phonation with a crystal pick-up to search the corelation among the amplitude of the wall vibration(μ), voice pressure(μbar)and the quantity of the nasal respiration(cc). It was found useful to decide the degree of nasalization from the ratio of the amplitude of wall vibration and the voice pressure, which was named by the authors as "vibration proportion". Comparison was made with Japanese vowels and nasal sounds uttered by 40 persons(9 male, 12 female, 5 singers and 14 patients of nasal speech). (A)Normal persons:1. The amplitude of wall vibration of nasal sounds is greatest in speech sounds. Yhe vowels "i"and "u" have greater amplitudes than others and "a" the smallest. 2. In average, the amplitude is greater in male voice than in female voice. In male voice the amplitude is great in low vocal range and in female voice it is great in high vocal range. It is very interesting to think of vocal difference by sex. 3. When nasopharynx is closed, the amplitude is smaller than when it is opened and this fact coincides with the degree of nasalization by acoustical examination. 4. The measured values slightly change sometimes on the same person(with same vocal range, voice intensity and speech sound). Accordingly, it is found that articulation is not always constant. 5. The vibration of nose wall increases with the nasalization and the relation between them, which is one of main objects of this study, is made more clear by "vibration proportion". Namly it is possible to know the degree of nasalization of a person from the "vibration proportion". (B)Singers(by singing voice):Difference between speech sounds which we perceived generally in normal persons decreases by singers and the vibration becomes more uniform. There is no wonder that it is the results of practice of singing method. (C)Patients of nasal speach:The amplitude of nose wall vibration is larger than normal extent(sometimes several times larger than normal). Therefore it is possible to know the degree of nasal speech by measurement of the wall viblation.View full abstractDownload PDF (747K) -
Yutaka Kohashi, Yasuo TokitaArticle type: Article
1952 Volume 8 Issue 2 Pages 104-
Published: June 30, 1952
Released on J-STAGE: June 02, 2017
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Sakae MoritaArticle type: Article
1952 Volume 8 Issue 2 Pages 105-
Published: June 30, 1952
Released on J-STAGE: June 02, 2017
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