著者

上田 義勝 徳田 陽明 谷垣 実 赤松 重則 秦 隆志

出版者

公益社団法人 日本表面真空学会

雑誌

表面と真空 (ISSN:24335835)

巻号頁・発行日

vol.66, no.11, pp.654-659, 2023-11-10 (Released:2023-11-10)

参考文献数

23

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The paper presents the results of electrical property measurements for submicron-scale bubbles (Ultra Fine Bubble, UFB) as a property that includes correlation with water. The relationship between the concentration of UFBs and average size and the electrical conductivity of water is shown, confirming that the presence of UFBs generated by oxygen gas decreases the electrical conductivity of water. In addition, the internal pressure was directly detected using the perturbation angle correlation method, and a lower internal pressure (about 3.4 atmospheres) than theoretical was measured. We proposed the use of ultrasonic waves as a simple detection method for bubbles, including the distinction between UFBs and impurities, and are still measuring the bubbles.

著者

刈谷 未来 山脇 直也 奥村 勇人 赤松 重則 西内 悠祐 秦 隆志

出版者

日本ソノケミストリー学会

雑誌

ソノケミストリー討論会講演論文集 27 (ISSN:24241512)

巻号頁・発行日

pp.47-48, 2018-11-19 (Released:2022-09-20)

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In this study, for the evaluation of ultrafine bubbles (UFB) which is important in fine bubble research, a method to use hydroxyl (OH) radicals or luminescence phenomenon (sonoluminescence) generated by the collapse of UFB when applying ultrasonic wave to UFB as an indicator was verified. Electron spin resonance method and potassium iodide (KI) method were used for the evaluation of OH radicals, and photomultiplier tubes were used for the evaluation by sonoluminescence. OH radicals by the collapse of UFB were observed from the result of OH radical measurement by ESR. And, even in the KI method which is a simple OH radical evaluation, it was shown that the same evaluation can be made from the difference in absorbance when ozone is used for the inclusion gas. On the other hand, in the sonoluminescence measurement, it was confirmed that the luminescence intensity in water to which inorganic particles of the same amount as that of UFB was added was smaller than in the case of UFB water.

著者

赤松 重則 上田 義勝

出版者

日本混相流学会

雑誌

混相流 (ISSN:09142843)

巻号頁・発行日

vol.36, no.1, pp.20-27, 2022-03-15 (Released:2022-03-31)

参考文献数

21

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Bubbles with a diameter less than 1μm are called ultrafine bubbles (UFB). And UFB is expected to be applied in the environment, agriculture and medical treatment. In this study, we will examine the possibility by using ultrasonic waves and ultrapure water (UPW), also the attenuation characteristics of UFB water, to analyze the properties of UFB. The attenuation characteristics of UFB water in broadband ultrasound waves up to 32.5 MHz were investigated. In the 1.5-2.5 MHz ultrasonic band, the attenuation coefficient in the near-field was relatively close to the theoretical value calculated from the bubble density measurement results. For the 32.5 MHz ultrasound, there was a clear difference in the attenuation coefficient for the bubble density distribution between the UPW and the UFB water. In addition, the change in the number density distribution of bubbles and the change in the attenuation coefficient were observed depending on the elapsed days after UFB generation. It is possible that the change is related to the increase in the bubble diameter of the UFB.