著者

向阪 保雄 野村 俊之 内藤 牧男

出版者

一般社団法人 粉体工学会

雑誌

粉体工学会誌 (ISSN:03866157)

巻号頁・発行日

vol.57, no.10, pp.526-529, 2020-10-10 (Released:2020-12-09)

参考文献数

5

被引用文献数

2

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Aerosol infection issues by COVID-19 were discussed from the viewpoint of particle technology, and the following conclusions were obtained: 1) Number of virus contained in a 10 μm droplet is very few, only 1 virus per 2000 droplets, whereas 0.5 virus in a 100 μm droplet, if 106 copies/mL of viral load in saliva is assumed. 2) Droplets larger than 100 μm can quickly settle down by gravity. 3) The possibility of aerosol infection is very low unless in unusual environments. 4) Mask is very effective, but the leakage from the space between mask and face has risk in heavy exhalation.

著者

内藤 牧男 堀田 禎 早川 修 篠原 伸広 植松 敬三

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.106, no.1236, pp.811-814, 1998-08-01

被引用文献数

9 13

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The effect of ball milling conditions on pulverization of the very small amount of large particles in silicon nitride powder was examined. In this paper, the wet sieve analysis and X-ray sedimentation method were used to measure the content of large particles in the ground powder which influence important properties of sintered ceramics such as fracture strength. As a result, it was made clear-that the wet sieve analysis would be a reliable method to measure the content of just a few large particles in the ground powder. By applying this analysis to the ball-mill grinding of silicon nitride powder, it was found that the processing conditions required to grind the large particles were different from those to obtain high specific surface area as well as small average size of particles. This is because the impact force exerted onto the particles by the media balls is more effective on grinding large particles.

著者

内藤 牧男

出版者

ホソカワミクロン株式会社

雑誌

粉砕 (ISSN:04299051)

巻号頁・発行日

vol.50, pp.47-51, 2006-10-30 (Released:2018-10-03)