| Project/Area Number |
08556023
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
林学
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| Research Institution | Tokyo University of Agriculture and Technology |
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Principal Investigator |
WATANABE Naoaki Tokyo Univ.of Agric and Technol.Fac.of Agric.Assist Prof., 農学部, 助手 (10143637)
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| Co-Investigator(Kenkyū-buntansha) |
KANIWA Masanori Hibiya Amenis Co. Aeboric.Lab., Assist.Manger, 室長代理
IWAI Kunio Showa Electronic Institute Co.Kanto Branch, Manager, 所長
SATO Keiichi Tokyo Univ.of Agric and Technol.Fac.of Agric.Assoc Prof., 農学部, 助教授 (90178723)
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| Project Period (FY) |
1996 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥17,000,000 (Direct Cost: ¥17,000,000)
Fiscal Year 1998: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1997: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1996: ¥14,800,000 (Direct Cost: ¥14,800,000)
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| Keywords | tree diagnosis / acoustic emission chracteristics / standing tree / ultrasonic computed tomography / non-destructive inspection / ultrasonic propagation characteristics / 音波伝播特性 / 超音波CTスキャナー / アコースティック・エミッション |
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| Research Abstract |
To diagnose tree health and evaluate hazard trees, acoustic emission(AE) detection in the xylem of shoot and stem and ultrasonic measurement were made on several tree species using same sensors at one time. The AE generation of the healthy seedlings in the control was concentrated at the initiation or maximum of the solar irradiance. Total AE generation in a day were different among species. Ring-porous wood species, such as Zelkova, Quercus and Fraxinus generated many AE counts, but diffuse porous wood species, Fagus generated few. While healthy seedlings scarcely generated any AE in a night and in rain, stressed ones often generated AE in dark. AE measurements of nine species during drying to death revealed that stressed seedlings were distinguished from healthy and wilted ones by AE pattern and quantity. So, AE monitoring can be used for watering management of seedlings and street trees.
Ultrasonic computed tomography(CT) scanning device was developed for internal decay detection using tone burst wave. Artificial cavity was detected up to 30cm logs in diameter. Ultrasonic propagation characteristics in wood was measured in the cross sectional direction. Ultrasonic pulse was transmitted most quickly in the radial direction passing through pith, when pulsar and sensor were set at the angle of 120-240ﾟ At other angle, pulse took the shortest course to sensor. These results improve CT program in data processing.
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