著者

北澤 和也 阿部 積 風間 守 工藤 雅孝

出版者

日本法科学技術学会

雑誌

日本法科学技術学会誌 (ISSN:18801323)

巻号頁・発行日

vol.20, no.2, pp.185-189, 2015 (Released:2015-07-17)

参考文献数

5

被引用文献数

1

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The influence of liquid cleaners on the inner wall coating of aluminum bottle cans was examined by a combination of 20 cleaners and 21 bottles. The bottle cans were classified into three types by their inner resin coatings. The coatings were an epoxy resin, another type of epoxy resin and a polyester resin. After a small portion of liquid cleaners were dropped on the epoxy resin inner coatings of bottles, one of the cleaners generated hydrogen bubbles but the other 19 cleaners caused no effect. This phenomenon was not observed even after about twenty hours when using other liquid cleaners. A mixture of alkalis (NaOH and KOH) and a solvent (diethylene glycol mono-n-butyl ether) in the components of the liquid cleaner in question brought the same phenomenon, and the concentration of the solvent and the time taken to start bubbling were correlated. Therefore, we concluded that because the solvent denatured the inner resin coating of aluminum bottle cans, the alkalis were made accessible to aluminum and generated hydrogen bubbles as a result.

著者

工藤 雅孝 風間 守 阿部 積

出版者

日本法科学技術学会

雑誌

日本法科学技術学会誌 (ISSN:18801323)

巻号頁・発行日

vol.14, no.2, pp.93-98, 2009 (Released:2009-08-25)

参考文献数

8

被引用文献数

1 1

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The blast wave caused by the explosion of the explosive and so on shows the refractive index which is different from that of ambience because the wave is accompanied by the density change of the medium. The Schlieren method is often used as a technique to observe the behavior of fluid using the difference of refractive index. However, it is difficult to apply to outdoor experiments because the method requires arrangements of some optical equipments around the subject. In this study, the visualization of the blast wave in a convenient method from the digital frame images which had been taken by a digital high-speed camera in a past outdoor experiment without any optical equipment was tested. This method was a subtraction of images, and a processed image was produced by difference of gradations between two original frame images before and after the explosion. In a part of the background which resulted in a mottled pattern having minute bright and dark parts, the blast wave was possible to be visualized in every frame image. The main blast wave and reflected blast wave from the ground were observed in the processed images. The equivalent ratio to other conventional explosives was derived from the propagation of the blast wave clarified by the processed images. Consequently, this method can be used for estimation of the power of explosion.