| Project/Area Number |
09650791
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Material processing/treatments
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| Research Institution | Yamaguchi University |
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Principal Investigator |
KUMADA Makoto Yamaguchi University, Faculty of Engineering, Professor, 工学部, 教授 (60284262)
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| Co-Investigator(Kenkyū-buntansha) |
YAMADA Takahiro Yamaguchi Prefectual Industrial Technology Institute, Group Manager, 産業技術センター, 主任(研究職)
FUJITA Sakae NKK Materials & Processing Research Center, Group Manager, 福山・材料研究センター, 室長(研究職)
KOBUCHI Shigetoshi Yamaguchi University, Center for Collaborative Research, Associate Professor, 工学部・地域共同研究開発センター, 助教授 (30225560)
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| Project Period (FY) |
1997 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 1999: ¥100,000 (Direct Cost: ¥100,000)
Fiscal Year 1998: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1997: ¥3,200,000 (Direct Cost: ¥3,200,000)
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| Keywords | Acid Rain / Corrosion Damages / Air Pollutants / pH / Carbon Steel / Rust / UV Irradiation / Photocatalystic Effect |
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| Research Abstract |
(1) We investigated acid rain corrosion damages of structures and cultural assets, and forest decline in western Japan which has became a serious problem. It has been found a damage of cultural assets that gold plated HAKKAKU TORO made of copper in DAIBUTSUDEN OF NARA-TODAIJI was corroded by chlorinic species due to pollution combustion and by acid rain due to sulfuric oxides. A great number of dead pine trees have been found along high ways in Okayama, Hiroshima and Yamaguchi Prefectures. Prof. Nakane of Hiroshima University proposes an thought that acid falls adherent to pine leaves and air pollutants solved into fog and dew drops decrease the function of photosynthesis and that declined pine trees are easily attacked by a few harmful insects.
(2) We measured pH values of rain at several points in Yamaguchi Prefecture. pH values were 4.38 to 6.25 at Faculty of Engineering of Yamaguchi University, 4.72 at a point in Shyuho Town and 4.38 to 5.79 at a point in Heki Town. Acidification of rain was remarkable in Heki Town near Japan Sea.
(3) We investigated the photocatalystic effect of rust on acid rain corrosion of a carbon steel. Ultra-Violet(UV) light was irradiated to the carbon steel in artificial acid rain. Corrosion loss of the rusted carbon steel increased 20 to 40% due to UV irradiation and the photocatalystic effect of rust on corrosion became larger with immersion time. Electrochemical anodic polarization curves confirmed the photocatalystic effect of rust. Porarization to 0 mV induced 0.3 mA/? of light response current density. From the results, we proposed a enhacement mechanism of the photocatalystic effect of rust on acid rain corrosion of a carbon steel.
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