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Describing non-Fickian water-vapour sorption in wood

Wadsö, Lars LU (1994) In Journal of Materials Science 29(9). p.2367-2372
Abstract
Moisture transport and sorption in wood may not be accurately described by Fick's law of diffusion. The problem of making a model of non-Fickian behaviour (NFB) for wood is discussed. Some measurements in which NFB in wood is clearly seen are also reviewed. Four criteria, which must be satisfied by a model describing sorption in wood cell walls, are presented: (1) the model should not only describe the response to step changes in vapour pressure; (2) it should be able to predict sorption with more than one time scale; (3) the sorption rate should not depend on the thickness of the cell wall; (4) small rapid changes in vapour pressure should give slower fractional weight change than large rapid changes. A review of models of NFB in... (More)
Moisture transport and sorption in wood may not be accurately described by Fick's law of diffusion. The problem of making a model of non-Fickian behaviour (NFB) for wood is discussed. Some measurements in which NFB in wood is clearly seen are also reviewed. Four criteria, which must be satisfied by a model describing sorption in wood cell walls, are presented: (1) the model should not only describe the response to step changes in vapour pressure; (2) it should be able to predict sorption with more than one time scale; (3) the sorption rate should not depend on the thickness of the cell wall; (4) small rapid changes in vapour pressure should give slower fractional weight change than large rapid changes. A review of models of NFB in synthetic polymers indicates that there is presently no model of NFB which fulfills the above criteria. More measurements of the sorption behaviour of the cell wall are needed to construct such a model for wood. This model can then probably be used, together with a Fickian diffusion model, to model the sorption behaviour of whole wood. (Less)
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author
organization
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type
Contribution to journal
publication status
published
subject
in
Journal of Materials Science
volume
29
issue
9
pages
2367 - 2372
publisher
Springer
external identifiers
  • scopus:0028429421
ISSN
0022-2461
DOI
10.1007/BF00363428
language
English
LU publication?
yes
id
15c5edbf-34ce-41e2-86e7-10c27fbac833 (old id 1034470)
date added to LUP
2008-02-19 08:29:39
date last changed
2017-10-08 04:20:14
@article{15c5edbf-34ce-41e2-86e7-10c27fbac833,
  abstract     = {Moisture transport and sorption in wood may not be accurately described by Fick's law of diffusion. The problem of making a model of non-Fickian behaviour (NFB) for wood is discussed. Some measurements in which NFB in wood is clearly seen are also reviewed. Four criteria, which must be satisfied by a model describing sorption in wood cell walls, are presented: (1) the model should not only describe the response to step changes in vapour pressure; (2) it should be able to predict sorption with more than one time scale; (3) the sorption rate should not depend on the thickness of the cell wall; (4) small rapid changes in vapour pressure should give slower fractional weight change than large rapid changes. A review of models of NFB in synthetic polymers indicates that there is presently no model of NFB which fulfills the above criteria. More measurements of the sorption behaviour of the cell wall are needed to construct such a model for wood. This model can then probably be used, together with a Fickian diffusion model, to model the sorption behaviour of whole wood.},
  author       = {Wadsö, Lars},
  issn         = {0022-2461},
  language     = {eng},
  number       = {9},
  pages        = {2367--2372},
  publisher    = {Springer},
  series       = {Journal of Materials Science},
  title        = {Describing non-Fickian water-vapour sorption in wood},
  url          = {http://dx.doi.org/10.1007/BF00363428},
  volume       = {29},
  year         = {1994},
}