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1992 Fiscal Year Final Research Report Summary

Development of a new method to measure moisture content for wood with moisture gradients with ultrasonic method.

Research Project

Project/Area Number 03660162
Research Category

Grant-in-Aid for General Scientific Research (C)

Allocation TypeSingle-year Grants
Research Field 林産学
Research InstitutionNiigata University (1992)
The University of Tokyo (1991)

Principal Investigator

MISHIRO Akiyoshi  Niigata University Faculty of Agriculture Associate Professor, 農学部, 助教授 (90012004)

Project Period (FY) 1991 – 1992
KeywordsUltrasonic velocity / Moisture gradient / Moisture content / Law of composite / Grain angle / Density / Water-saturated / Drying
Research Abstract

The properties of ultrasonic velocity through wood were examined to estimate moisture content of wood with moisture gradients by ultrasonic method.Following results were obtained.
1)The simple and good bonding methods were devised to get an accurate ultrasonic velocity. 2) When moisture gradient exists against the forward direction of ultrasound,the law of composite was applicable. When moisture gradient exists parallel to the forward direction of ultrasound, ultrasonic velocity was more dependent on the parts with the faster velocity. 3) Below the fibersaturation, ultrasonic velocity increased curvilinealy as moisture content decreased and the change percentage in ultrasonic velocity per unit moisture content was much more in the longituidnal direction than in the radial. The patterns of ultrasonic velocity-moisture content curves on a graph in a longitudinal and a radial for vapor-saturated specimens during drying were not so different with species. The patterns of ultrasonic velocity-moisture content curves in a longitudinal and a radial for water-saturated specimens during drying depended on the species,and could be divided into three groups. Consider the wood during drying as a composite material of woods with different moisture contents and the law of composite was applied,and the calculations agreed with measured valued. 4) In the LR and LT planes, ultrasonic velocity decreased as grain angle increased in softwoods and hardwoods,but in the RT plane the tendency of ultrasonic velocity on the annual rings in softwoods was different from that in hardwoods. 5) Ultrasonic velocity in a longitudinal was directly proportional to density in some speices, and in some it was inversely proportional to density, and in some no correlation was found between them.

  • Research Products

    (10 results)

All Other

All Publications (10 results)

  • [Publications] Akiyoshi MISHIRO: "Ultrasonic velocity of wood and its moisture content." Proceedings of All-Division 5 Conference,IUFRO. 2. 525 (1992)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 三城 昭義: "木材中の超音波伝播速度と含水率との関係" 木材学会誌.

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 三城 昭義: "木材中の超音波伝播速度に及ぼす水分傾斜(水分分布)の影響" 木材学会誌.

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 三城 昭義: "木材中の超音波伝播速度に及ぼす木理角の影響" 木材学会誌.

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 三城 昭義: "木材中の超音波伝播速度に及ぼす比重の影響" 木材学会誌.

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Akiyoshi Mishiro: "Ultrasonic velocity of wood and its moisture content" Proceedings of All - Division 5 Conference,IUFRO. 2. 525 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Akiyoshi Mishiro: "Relationship between ultrasonic velocity and moisture content of wood during drying."

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Akiyoshi Mishiro: "Effect of moisture gradients on the ultrasonic velocity of wood."

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Akiyoshi Mishiro: "Effect of grain angle on the ultrasonic velocity of wood."

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Akiyoshi Mishiro Akiyoshi: "Effect of specific gravity on the ultrasonic velocity of wood"

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 1994-03-24  

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