著者

圷 亮輔 慶本 天謹 金川 哲也 内山 祐介

出版者

日本混相流学会

雑誌

混相流 (ISSN:09142843)

巻号頁・発行日

vol.34, no.1, pp.166-179, 2020-03-15 (Released:2020-04-02)

参考文献数

28

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Two types of weakly nonlinear propagations of plane progressive pressure waves in an initially quiescent compressible liquid uniformly containing many spherical gas bubbles are theoretically investigated. The treatment of two types of propagations corresponds to an extension of our previous result (Yoshimoto & Kanagawa, Jpn. J. Multiphase Flow, 33 (2019), 77) to a generic form. The main assumptions are as follows: (i) The incident wave frequency is much larger than an eigenfrequency of single bubble oscillations; (ii) The compressibility of the liquid phase, which has long been neglected and induces the high speed propagation mode, is considered; (iii) The wave propagates with a large phase velocity exceeding the speed of sound in pure water. From the method of multiple scales with two types of appropriate choices of three nondimensional parameters, we can systematically derive two types of nonlinear Schrödinger (NLS) equations with some correction terms in a unified way. These two equations can describe high-speed propagation of pressure waves in compressible bubbly liquids.

著者

前田 泰希 金川 哲也

出版者

日本混相流学会

雑誌

混相流 (ISSN:09142843)

巻号頁・発行日

vol.34, no.1, pp.140-147, 2020-03-15 (Released:2020-04-02)

参考文献数

20

被引用文献数

2

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Weakly nonlinear propagation of plane pressure waves in a flowing water uniformlycontaining many spherical microbubbles is theoretically investigated. At the initial state, the gas and liquid phases have different flow velocity distributions as a small nonuniform effect in bubbly flows. The basic equations based on a two-fluid model are utilized to describe velocity distributions of gas and liquid phases. By using the method of multiple scales and the determination of size of three nondimensional ratios, we can systematically derive two types of nonlinear wave equations describing long-range propagation of waves. i.e., the Korteweg-de Vries-Burgers (KdVB) equation and the nonlinear Schrödinger (NLS) equation with variable coefficients. As a result, initial velocity distributions affect an advection effect of waves induced by a relative velocity between gas and liquid phases and a moving bubble.

著者

亀井 陸史 金川 哲也

出版者

日本混相流学会

雑誌

混相流 (ISSN:09142843)

巻号頁・発行日

vol.34, no.1, pp.148-157, 2020-03-15 (Released:2020-04-02)

参考文献数

20

被引用文献数

2

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This study theoretically clarifies an effect of the liquid viscosity and the thermal conductivity on weakly nonlinear propagation of pressure waves in a liquid containing many spherical microbubbles. As in our preceding paper (Kamei et al., J. JSCE, Ser. A2, 75 (2019), 499) focusing on a long wave, by the use of the method of multiple scales, a nonlinear Schrödinger equation describing the long-range propagation of an envelope wave of short carrier wave is derived from the basic equations incorporating the liquid viscosity and the thermal conductivity. As a result, as in our preceding long wave case, the liquid viscosity and the thermal conductivity affect the dissipation effect, and a nonlinear effect in the adiabatic process decreases in comparison with the previous study (Kanagawa et al., J. Fluid Sci. Technol., 6 (2011), 838). On the other hand, unlike in our preceding long wave case, a dispersion effect in the adiabatic process decreases in comparison with the previous study.

著者

鮎貝 崇広 金川 哲也

出版者

日本混相流学会

雑誌

混相流 (ISSN:09142843)

巻号頁・発行日

vol.34, no.1, pp.158-165, 2020-03-15 (Released:2020-04-02)

参考文献数

13

被引用文献数

7

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Oscillation of gas bubbles in a bubbly liquid induces dissipation and dispersion effectsof waves into a nonlinear evolution of pressure waves. Long-range propagation of pressure waves with a moderately small amplitude is described by the KdV-Burgers (KdVB) equation. This paper numerically solves the KdVB equation via a spectral method to predict the nonlinear evolution of waves in bubbly liquids. Focusing on the waveform, and the nonlinear, dissipation and dispersion terms, the following results are obtained: (i) An initially sinusoidal waveform satisfying a periodic boundary condition is firstly distorted due to the nonlinear effect; (ii) Wave distortion is suppressed by increasing the dissipation and dispersion effects; (iii) A break-up due to the dispersion effect appears; (iv) A balance between the nonlinear and dispersion effects is accomplished and then a pulse wave satisfying a feature of soliton is formed. As a result, the initial bubble radius and the initial void fraction strongly contribute the dissipation and dispersion effects, respectively.

著者

大阪産業大学学会 [編]

出版者

大阪産業大学学会

巻号頁・発行日

2007

著者

聖徳大学 [編]

出版者

聖徳大学

巻号頁・発行日

1990

著者

中村 七重

出版者

聖徳大学

雑誌

研究紀要 人文学部 = Bulletin of Seitoku University (ISSN:09166653)

巻号頁・発行日

vol.9, pp.97-103, 1998-12-14

著者

中村 七重

出版者

聖徳大学

雑誌

研究紀要 人文学部 = Bulletin of Seitoku University (ISSN:09166653)

巻号頁・発行日

vol.5, pp.141-146, 1994

著者

中村 七重

出版者

聖徳大学

雑誌

研究紀要. 第一分冊, 人文学部 (ISSN:09166653)

巻号頁・発行日

vol.5, pp.141-146, 1994

著者

蔵本 修 森脇 拓也 綾野 克紀 阪田 憲次

出版者

日本コンクリート工学協会

雑誌

コンクリート工学年次論文集 (ISSN:13477560)

巻号頁・発行日

vol.25, no.1, pp.503-508, 2003

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PC構造物における設計自由度の拡大,部材の軽量化,高耐久性などを目的として高強度コンクリートはますますその重要性を高めている。しかしながら,コンクリートの高強度化に伴い,若材令時の収縮によるひびわれが問題となっている。高強度コンクリートの収縮ひずみを予測する場合,自己収縮の影響が大きくなる。本研究では,高強度モルタルの自己収縮ひずみの挙動を把握し,高強度コンクリートにも適用できる収縮ひずみ予測手法を提案する。

著者

雪花山人 述

出版者

立川文明堂

巻号頁・発行日

1914

出版者

鐵道院

巻号頁・発行日

vol.明治42年3月末日, 1909

著者

岡崎 弘樹

出版者

日本中東学会

雑誌

日本中東学会年報 (ISSN:09137858)

巻号頁・発行日

vol.29, no.1, pp.67-95, 2013-07-15 (Released:2018-03-30)

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The purpose of this article is to examine the concept of “Just despot”, which was mentioned in 1899 by an Egyptian thinker Muhammad ‘Abduh. Although he was said to be an Islamic idealist, he was deeply aware of the harsh realities of the Egyptian society. Therefore, he emphasized the importance of a national leadership, whereas he understood the people who have internalized the oppression under the hierarchical system of despotism. In fact, his ideas were, to a great extent, influenced by the preceding ideas. First, the terminology of istibdād signified literally “decisiveness” it only began to be used in the sense of “despotism” in the mid-19th century. Second, the first generation of Nahda considered the despotism as a problem of the abuse of power until the 1860s. Third, in the late 1870s, Afghānī emphasized the necessity of a leader’s ability, whereas Isḥāq began to describe the despotism as a mechanism of reproduction of power. In short, the concept of “Just despot”, employed by ‘Abduh, was, in general, a product of his adaptation and development of these two points of view. He reached the meaning of a modern political concept following the efforts of their predecessors.

著者

孝岡 睦子

出版者

神戸大学美術史研究会

雑誌

美術史論集

巻号頁・発行日

no.6, pp.74-86, 2006-02

著者

石井 晋

出版者

学習院大学

雑誌

學習院大學經濟論集 (ISSN:00163953)

巻号頁・発行日

vol.38, no.1, pp.51-65, 2001-04

出版者

[EATCS]

巻号頁・発行日

0000

著者

須川 美知子

出版者

横浜創英短期大学

雑誌

横浜創英短期大学紀要 (ISSN:09174370)

巻号頁・発行日

vol.3, pp.55-83, 2002-03-31

著者

今西錦司

出版者

中央公論社

雑誌

サル

巻号頁・発行日

1965

被引用文献数

1

著者

小林 哲治

出版者

一般社団法人 日本機械学会

雑誌

年次大会

巻号頁・発行日

vol.2019, 2019

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<p>Recently the hardware & software technology is improved, many kinds of technologies are developed and adopted to NDT. Especially, in oversea country, the robotics technology is used positively for NDT work. The reason why these technologies are used in oversea is the convenience at first. The advantage of using robotics technology is that it can get the reliable inspection data, reduce outage time & costs for the project. And using robotics technology, it can access the location where an engineer cannot access with safety, for example, Confined spaces (Tank inside), Elevated pipes (pipes at the production facility). Additionally, other main reason is the manpower. Same as recent Japanese industrial market, the lack of manpower is big problem in oversea country. And more, the labor accident during the work at confined spaces, height location and hazardous environment is critical issue same as Japan. Although robotics technology is not perfect, the usage of robotics technology can solve many problems in the present industry. The following is example which the robotics technology is used for NDT work to do the plant maintenance.</p>

著者

中崎 昌雄 Masao Nakazaki

雑誌

中京大学教養論叢 = Chukyo University bulletin of the Faculty of Liberal Arts (ISSN:02867982)

巻号頁・発行日

vol.37, no.1, pp.87-127, 1996-06-28