Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Significant loss of mechanical strength in archeological oak from the 17th century Vasa ship: correlation with cellulose degradation
KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
Vise andre og tillknytning
(engelsk)Artikkel i tidsskrift (Fagfellevurdert) Submitted
Identifikatorer
URN: urn:nbn:se:kth:diva-32819OAI: oai:DiVA.org:kth-32819DiVA, id: diva2:412091
Merknad
QC 20110420Tilgjengelig fra: 2011-04-20 Laget: 2011-04-20 Sist oppdatert: 2011-11-09bibliografisk kontrollert
Inngår i avhandling
1. Effects of Cell Wall Structure on Tensile Properties of Hardwood: Effect of down-regulation of lignin on mechanical performance of transgenic hybrid aspen. Effect of chemical degradation on mechanical performance of archaeological oak from the Vasa ship.
Åpne denne publikasjonen i ny fane eller vindu >>Effects of Cell Wall Structure on Tensile Properties of Hardwood: Effect of down-regulation of lignin on mechanical performance of transgenic hybrid aspen. Effect of chemical degradation on mechanical performance of archaeological oak from the Vasa ship.
2011 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

Wood is a complex material and the mechanical properties are influencedby a number of structural parameters. The objective of this study has been toinvestigate the relationship between the structure and the mechanical propertiesof hardwood. Two levels were of special interest, viz. the cellular structureand morphology of the wood, and the ultra-structure of the cell wall. In thenext step, it was of interest to examine how the mechanical properties ofhardwood change with spontaneous/induced changes in morphology and/orchemical composition beyond the natural variation found in nature.

Together, this constituted the framework and basis for two larger projects,one on European aspen (Populus tremula) and hybrid aspen (Populus tremulax Populus tremuloides), and one on European oak (Quercus robur). Amethodology was developed where the concept of relative density and compositemechanics rules served as two useful tools to assess the properties ofthe cell wall. Tensile testing in the longitudinal direction was combined withchemical examination of the material. This approach made it possible to revealthe mechanical role of the lignin in the cell wall of transgenic aspen trees,and investigate the consequences of holocellulose degradation in archaeologicaloak from the Vasa ship.

The study on transgenic aspen showed that a major reduction in lignin inPopulus leads to a small but significant reduction in the longitudinal stiffness.The longitudinal tensile strength was not reduced. The results are explainableby the fact that the load-bearing cellulose in the transgenic aspen retained itscrystallinity, aggregate size, microfibril angle, and absolute content per unitvolume. The results can contribute to the ongoing task of investigating andpinpointing the precise function of lignin in the cell wall of trees.

The mechanical property study on Vasa oak showed that the longitudinaltensile strength is severely reduced in several regions of the ship, andthat the reduction correlates with reduced average molecular weight of theholocellulose. This could not have been foreseen without a thorough mechanicaland chemical investigation, since the Vasa wood (with exception fromthe bacterially degraded surface regions) is morphologically intact and witha micro-structure comparable to that of recent oak. The results can be usedin the ongoing task of mapping the condition of the Vasa wood.

sted, utgiver, år, opplag, sider
Stockholm: KTH Royal Institute of Technology, 2011. s. viii, 67
Serie
Trita-CHE-Report, ISSN 1654-1081 ; 2011:14
Emneord
tensile strength, transgenic hybrid aspen, lignin down-regulation, the Vasa ship, chemical degradation, longitudinell draghållfasthet, transgen hybridasp, ligninnedreglering, Vasaskeppet, kemisk nedbrytning
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-32190 (URN)978-91-7415-914-1 (ISBN)
Disputas
2011-04-29, F3, Lindstedtsvägen 26, Stockholm, 13:00 (engelsk)
Opponent
Veileder
Merknad
QC 20110420Tilgjengelig fra: 2011-04-20 Laget: 2011-04-08 Sist oppdatert: 2011-04-26bibliografisk kontrollert

Open Access i DiVA

Fulltekst mangler i DiVA

Personposter BETA

Berglund, Lars

Søk i DiVA

Av forfatter/redaktør
Bjurhager, IngelaBerglund, Lars
Av organisasjonen

Søk utenfor DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric

urn-nbn
Totalt: 419 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf