研究者詳細 - 安田　啓司

論文 - 安田　啓司

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ハイブリッド型超音波反応器による有害物質の分解と除去招待有り

安田啓司

超音波TECHNO 29 巻 ( 6 ) 頁： 32-36 2017年12月

Dependence of cavitation, chemical effect, and mechanical effect thresholds on ultrasonic frequency 査読有り Open Access

Nguyen, TT; Asakura, Y; Koda, S; Yasuda, K

ULTRASONICS SONOCHEMISTRY 39 巻頁： 301 - 306 2017年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Ultrasonics Sonochemistry

Cavitation, chemical effect, and mechanical effect thresholds were investigated in wide frequency ranges from 22 to 4880 kHz. Each threshold was measured in terms of sound pressure at fundamental frequency. Broadband noise emitted from acoustic cavitation bubbles was detected by a hydrophone to determine the cavitation threshold. Potassium iodide oxidation caused by acoustic cavitation was used to quantify the chemical effect threshold. The ultrasonic erosion of aluminum foil was conducted to estimate the mechanical effect threshold. The cavitation, chemical effect, and mechanical effect thresholds increased with increasing frequency. The chemical effect threshold was close to the cavitation threshold for all frequencies. At low frequency below 98 kHz, the mechanical effect threshold was nearly equal to the cavitation threshold. However, the mechanical effect threshold was greatly higher than the cavitation threshold at high frequency. In addition, the thresholds of the second harmonic and the first ultraharmonic signals were measured to detect bubble occurrence. The threshold of the second harmonic approximated to the cavitation threshold below 1000 kHz. On the other hand, the threshold of the first ultraharmonic was higher than the cavitation threshold below 98 kHz and near to the cavitation threshold at high frequency.

DOI： 10.1016/j.ultsonch.2017.04.037

Production of Liposome from Sphingomyelin by Ultrasonic Device under Supercritical Carbon Dioxide 査読有り

C. Uemori, T. Katsube, S. Machmudah, Wahyudiono, H. Kanda, K. Yasuda and M. Goto

Asian Journal of Applied Sciences 5 巻 ( 5 ) 頁： 1042-1048 2017年10月

Removal of Silicic Acid in Geothermal Water by a Combination of Ultrasonication and Silica Gel Seed

Nguyen, TT; Takahashi, Y; Asakura, Y; Yasuda, K

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN 50 巻 ( 7 ) 頁： 542 - 547 2017年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：公益社団法人化学工学会

A combination of ultrasonication and silica gel seed was studied as a silica scale prevention method in geothermal water. The effects of ultrasonic frequency, initial monosilicic acid concentration, pH, concentration, particle diameter and pore size of the silica gel on the removal ratio of silicic acid were examined. For comparison, stirring without and with silica gel, and ultrasonication with the addition of hydrogen peroxide or t-butanol were performed. Ultrasonication enhances the removal of silicic acid by silica gel seed. Ultrasonication at 500 kHz was more effective for the removal of silicic acid than ultrasonication at 28 kHz and stirring. The removal ratio of silicic acid increased with an increase in silica gel concentration. The small seed particle diameter of 60 μm and large seed pore size of 7 nm performed well in the removal of silicic acid. When the initial concentration of monosilicic acid was 1.1 g/L and the silica gel concentration was 1.5 g/L, the removal ratio of silicic acid was highest at pH 6 because the reaction between polymer and polymer is dominant. However, in the case of an initial monosilicic acid concentration of 0.5 g/L, the removal ratio was highest at pH 9 because reaction between polymer and monomer is dominant. The polymerization rate of monosilicic acid was increased by the addition of hydrogen peroxide due to a higher formation rate of hydroxide radicals. In contrast, the addition of t-butanol lowered the polymerization rate of monosilicic acid because the hydroxide radicals were scavenged. The frequency switching from 500 kHz to 28 kHz at 90 min for each ultrasonication enhanced the removal ratio of silicic acid.

DOI： 10.1252/jcej.16we262

Web of Science

Scopus

CiNii Research

Effect of ultrasonic cavitation on measurement of sound pressure using hydrophone 査読有り

Nguyen, TT; Asakura, Y; Okada, N; Koda, S; Yasuda, K

JAPANESE JOURNAL OF APPLIED PHYSICS 56 巻 ( 7 ) 頁： 07JE061-07JE065 2017年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics

Effect of ultrasonic cavitation on sound pressure at the fundamental, second harmonic, and first ultraharmonic frequencies was investigated from low to high ultrasonic intensities. The driving frequencies were 22, 304, and 488 kHz. Sound pressure was measured using a needle-type hydrophone and ultrasonic cavitation was estimated from the broadband integrated pressure (BIP). With increasing square root of electric power applied to a transducer, the sound pressure at the fundamental frequency linearly increased initially, dropped at approximately the electric power of cavitation inception, and afterward increased again. The sound pressure at the second harmonic frequency was detected just below the electric power of cavitation inception. The first ultraharmonic component appeared at around the electric power of cavitation inception at 304 and 488 kHz. However, at 22 kHz, the first ultraharmonic component appeared at a higher electric power than that of cavitation inception.

DOI： 10.7567/JJAP.56.07JE06

Web of Science

Scopus

A05 ウルトラファインバブルを利用した超音波反応器の開発

松島穂高, 朝倉義幸, 安田啓司

ソノケミストリー討論会講演論文集 26 巻 ( 0 ) 頁： 11 - 12 2017年

P17 ウルトラファインバブルの生成・消滅に及ぼす超音波条件の影響

朝倉義幸, 松島穂高, 安田啓司

ソノケミストリー討論会講演論文集 26 巻 ( 0 ) 頁： 53 - 54 2017年

P05 超音波とウルトラファインバブルを用いた金ナノ粒子の合成

佐藤智史, 安田啓司, 朝倉義幸

ソノケミストリー討論会講演論文集 26 巻 ( 0 ) 頁： 29 - 30 2017年

超音波反応器の開発とソノプロセスの応用招待有り

安田啓司

23 巻 ( 383 ) 頁： 236-242 2016年7月

Simulation of the Formation and Characteristics of Ultrasonic Fountain 査読有り

Z. Xu, K. Yasuda, X-J. Liu

Ultrasonics Sonochemistry 32 巻頁： 241-246 2016年3月

ファインバブルの資源・環境分野への活用招待有り

安田啓司

混相流 30 巻 ( 1 ) 頁： 37-44 2016年3月

Quantitative Calculation of Reaction Performance in Sonochemical Reactor by Bubble Dynamics 査読有り

Z. Xu, K. Yasuda and X-J. Liu

Chinese Physics B 24 巻 ( 10 ) 頁： 1043011-1043017 2015年8月

Dispersion and Coalescence of Oil Droplets by Ultrasound and Application for Solvent Extraction of Gallium 査読有り

K. Yasuda, T. T. Nguyen, R. Okura, S. Nakayama, J. Jin and Y. Asakura

Japanese Journal of Applied Physics 54 巻 ( 7S1 ) 頁： 07HE031-07HE035 2015年5月

超音波霧化の特性とアルコールの分離招待有り

安田啓司

日本ソノケミストリー学会誌 9 巻 ( 1 ) 頁： 17-22 2015年3月

Separation of Oil Droplets from Oil-in-water Emulsion Using a Microbubble Generator 査読有り

K. Yasuda and K. Haneda

Journal of Chemical Engineering of Japan 48 巻 ( 3 ) 頁： 175-180 2015年3月

ファインバブルとテトラヒドロフランを用いたメタンハイドレートの合成招待有り

安田啓司

日本エネルギー学会誌 93 巻 ( 11 ) 頁： 1031-1037 2014年11月

Influence of Orifice Shape on Reaction Rate by Hydrodynamic Cavitation 査読有り

K. Yasuda, T. Kaji and Z. Xu

Applied Mechanics and Materials 625 巻頁： 718-721 2014年8月

Separation Characteristics of Alcohol from Aqueous Solution by Ultrasonic Atomization 査読有り

K. Yasuda, M. Mochida, Y. Asakura and S. Koda

Ultrasonics Sonochemistry 21 巻 ( 6 ) 頁： 2026-2031 2014年7月

地熱水中ケイ酸重合に及ぼす超音波の影響

安田啓司, 高橋優太

超音波TECHNO 26 巻 ( 4 ) 頁： 46-49 2014年7月

Effect of Ultrasonic Irradiation on Behavior of Silica Polymerization in Geothermal Water 査読有り

K. Yasuda, Y. Takahashi and Y. Asakura

Japanese Journal of Applied Physics 53 巻 ( 7S ) 頁： 07KE081-07KE083 2014年6月

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