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Image based methods for nondestructive detection of compression wood in sawn timber
Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
1999 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Compression wood is an anomaly in wood formed by the living softwood tree to compensate for excessive, asymmetric loads by developing special fibres. Compression wood has special properties that are unwanted in the utilisation of sawn wood products and is thus desirable to detect and reject in an early stage. It is difficult to detect manually and there are no commonly used nondestructive methods for automatic detection of compression wood today. This thesis is based on work reported in four papers that describe development, evaluation and comparison of four different methods for nondestructive detection of compression wood. Spectral and colour scanning both utilises differences in the spectral composition of light reflected from the wood surface to bring out contrast between normal wood and compression wood. X-ray scanning detects radiation transmitted through the wood. Absorption of x-rays is closely related to the density, which is higher for compression wood than normal wood. Tracheid-effect scanning utilises the direction oriented light-scattering properties of wood fibres, which is less pronounced in compression wood. The methods have been developed and evaluated using material with biological variations and different moisture content. Classification of compression wood in real-time is considered and discussed, with industrial implementation of the methods in mind.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 1999. , 7 p.
Series
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757 ; 1999:34
National Category
Other Mechanical Engineering
Research subject
Wood Technology
Identifiers
URN: urn:nbn:se:ltu:diva-26603Local ID: f29a23f0-e1e5-11db-b0f8-000ea68e967bOAI: oai:DiVA.org:ltu-26603DiVA: diva2:999769
Note

Godkänd; 1999; 20070403 (ysko)

Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-24Bibliographically approved

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CiteExportLink to record
Permanent link

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Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
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  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
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