著者

国本 隆 池田 栄三 西邑 弘

出版者

一般社団法人 軽金属学会

雑誌

軽金属 (ISSN:04515994)

巻号頁・発行日

vol.1953, no.7, pp.59-65, 1953-05-31 (Released:2008-10-30)

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We found that the aluminum surface was blackened in the boiling natural-water. Then, we examined the condition in which this discolouration occurred. As the experiments, aluminum and its alloys (1S, 2S, 52S, 61S, 17S) which were variously treated were boiled in the well-water, the distillated water and the well-water which was controlled PH. Table 1-11 and Photo. 1-11 show the results of these experiments. Summarizing these results, we have determined the conditions in which the discolouration occurres as follows.(1) There should be neither oxid film nor other films which prevent the direct contact of the water on the aluminum surface before boiling in the natural water.(2) Thc Tcmperature of water should be more than 80°C and the aluminum surface should be laid in the condition in which the oxid film is formed.(3) The water should have any metallic ions and these ions should be in the condition in which they are able to act sufficiently.The discolouration above mentioned seems to illustrate one of the delicate action of bare aluminum surface and to give us the kye with which we may be able to unlock the tightly closed door of the aluminum surface problems, for instance, activity and oxidation of aluminum surface and corrosion resistance of aluminum and its alloys, etc.

著者

佐野 晴洋 山下 節義 川西 正祐 井口 弘 吉永 侃夫 小城 勝相 塚本 幾代 藤田 博美 岡本 浩子 加藤 伸勝 宮本 宣博 浮田 義一郎 山根 秀夫 森 律 池田 栄三 乾 修然 藤岡 惇 阿部 醇吉

出版者

日本衛生学会

雑誌

日本衛生学雑誌 (ISSN:00215082)

巻号頁・発行日

vol.37, no.2, pp.566-579, 1982-06-30 (Released:2009-02-17)

参考文献数

32

被引用文献数

1 3

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An epidemiological survey and clinical investigations were carried out on 162 retired workers from manganese mines and ore grinders, who were the residents of the Tamba district of Kyoto Prefecture. Most of the workers had been employed in small industrial factories with less than five employees under very poor working conditions. Fifty-five percent of them had worked in the mines and factories for longer than 11 years. Forty-six percent had been retired for 11-20 years, whereas 27% for longer than 21 years. A group of 124 people living in the same region but who had not been exposed to manganese served as the control group.The incidence of subjective symptoms associated with chronic manganese poisoning such as emotional instability, psychomotor irritability and neurologic abnormalities was apparently high in the experimental group and it increased with the period of exposure to manganese dust. Twenty-eight percent of the workers reported the subjective symptoms while they were employed, but 45% of them reported as late as six years after they retired.Of the retired workers, five (3.1%) had parkinsonism, three (1.9%) showed symptoms of hemiparkinsonism, and fifteen (9.3%) showed neurological symptoms including maskedlike, gait unbalance, slurred speech and imparied fine movements. Forty-five percent of these patients recognized these abnormalities for more than five years after they had left the contaminated workings. It is noteworthy that 39% of the retired workers were diagnosed as having pneumoconiosis.Some of the problems encountered in diagnosing manganese poisoning after exposure has been terminated is also discussed here.