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Danvind, Jonas
Publications (10 of 13) Show all publications
Danvind, J. & Ekevad, M. (2006). Local water vapor diffusion coefficient when drying Norway spruce sapwood (ed.). Paper presented at . Journal of Wood Science, 52(3), 195-201
Open this publication in new window or tab >>Local water vapor diffusion coefficient when drying Norway spruce sapwood
2006 (English)In: Journal of Wood Science, ISSN 1435-0211, E-ISSN 1611-4663, Vol. 52, no 3, p. 195-201Article in journal (Refereed) Published
Abstract [en]

In this article, a one-dimensional and a two-dimensional approach to the evaluation of local diffusion coefficients for Norway spruce sapwood from measured moisture content (MC) values are presented. A studied wood sample was dried from the initial green condition to about 15% mean MC, but here only the diffusive part of the drying process between approximately 25% and 15% mean MC was treated. Measured local MC values were based on nondestructive X-ray computed tomography data. Finite element calculations were performed with two alternative diffusion coefficients to test the appropriateness of the diffusion coefficients that were evaluated from the measured MC values. The evaluated diffusion coefficients show interesting dependence on MC and distance from the evaporation surface. The advantage of using the methods presented is that the diffusion coefficient is calculated on a local level without having to define a function for the diffusion coefficient's dependency on other parameters

National Category
Bio Materials Other Mechanical Engineering
Research subject
Wood Physics; Wood Technology
Identifiers
urn:nbn:se:ltu:diva-5622 (URN)10.1007/s10086-005-0753-4 (DOI)000237966100002 ()2-s2.0-33744532133 (Scopus ID)3c65f9b0-bb52-11db-b560-000ea68e967b (Local ID)3c65f9b0-bb52-11db-b560-000ea68e967b (Archive number)3c65f9b0-bb52-11db-b560-000ea68e967b (OAI)
Note
Validerad; 2006; 20061016 (cira)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Eriksson, J., Johansson, H. & Danvind, J. (2006). Numerical determination of diffusion coefficients in wood using data from CT-scanning (ed.). Paper presented at . Wood and Fiber Science, 38(2), 334-344
Open this publication in new window or tab >>Numerical determination of diffusion coefficients in wood using data from CT-scanning
2006 (English)In: Wood and Fiber Science, ISSN 0735-6161, Vol. 38, no 2, p. 334-344Article in journal (Refereed) Published
Abstract [en]

The radial moisture diffusion coefficient in Fick's law for a sample of Norway spruce (Picea abies) under isothermal drying conditions was determined in a parameterization of Arrhenius' equation type. Using X-ray CT-scanning, the wood density and moisture content distributions were obtained in the radial direction for the wood sample. An optimization scheme, based on finite element computation, was then applied to find the parameter values such that the difference between observed and computed moisture content was minimized. The combined numerical and experimental technique was developed to reduce known disadvantages of similar approaches, and a specific algorithm to determine diffusion coefficients was presented. A comparison of the calibrated diffusion coefficient with those given in the literature showed a good fit. The computed moisture content based on the obtained diffusion coefficient and the observed moisture content agreed well. Finally, the effect of measurement errors on the computed material parameter was found to be small

National Category
Bio Materials
Research subject
Wood Physics
Identifiers
urn:nbn:se:ltu:diva-8667 (URN)733be8a0-bb52-11db-b560-000ea68e967b (Local ID)733be8a0-bb52-11db-b560-000ea68e967b (Archive number)733be8a0-bb52-11db-b560-000ea68e967b (OAI)
Note
Validerad; 2006; 20061016 (cira)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Eriksson, J., Johansson, H. & Danvind, J. (2005). A mass-transport model for drying wood under isothermal conditions (ed.). In: (Ed.), (Ed.), Proceedings: 9th International IUFRO Wood Drying Conference. Paper presented at International IUFRO Wood Drying Conference : 21/08/2005 - 26/08/2005. : Nanjing Forestry University
Open this publication in new window or tab >>A mass-transport model for drying wood under isothermal conditions
2005 (English)In: Proceedings: 9th International IUFRO Wood Drying Conference, Nanjing Forestry University , 2005Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Nanjing Forestry University, 2005
National Category
Bio Materials
Research subject
Wood Physics
Identifiers
urn:nbn:se:ltu:diva-31299 (URN)571cfa30-0641-11dc-b09b-000ea68e967b (Local ID)571cfa30-0641-11dc-b09b-000ea68e967b (Archive number)571cfa30-0641-11dc-b09b-000ea68e967b (OAI)
Conference
International IUFRO Wood Drying Conference : 21/08/2005 - 26/08/2005
Note
Godkänd; 2005; 20070519 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Scheepers, G., Danvind, J., Morén, T. & Rypstra, T. (2005). An investigation of fluid water movement in birch during drying through variation of wood sap surface tension and initial average moisture (ed.). In: (Ed.), (Ed.), Proceedings: 9th International IUFRO Wood Drying Conference. Paper presented at International IUFRO Wood Drying Conference : 21/08/2005 - 26/08/2005. : Nanjing Forestry University
Open this publication in new window or tab >>An investigation of fluid water movement in birch during drying through variation of wood sap surface tension and initial average moisture
2005 (English)In: Proceedings: 9th International IUFRO Wood Drying Conference, Nanjing Forestry University , 2005Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Nanjing Forestry University, 2005
National Category
Bio Materials
Research subject
Wood Physics
Identifiers
urn:nbn:se:ltu:diva-26901 (URN)029f6140-0642-11dc-b09b-000ea68e967b (Local ID)029f6140-0642-11dc-b09b-000ea68e967b (Archive number)029f6140-0642-11dc-b09b-000ea68e967b (OAI)
Conference
International IUFRO Wood Drying Conference : 21/08/2005 - 26/08/2005
Note
Godkänd; 2005; 20070519 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Danvind, J. (2005). Analysis of drying wood based on nondestructive measurements and numerical tools (ed.). (Doctoral dissertation). Paper presented at . Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Analysis of drying wood based on nondestructive measurements and numerical tools
2005 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Improved understanding of moisture and mechanical behaviour is a general objective for wood drying research. The main objective of this doctoral thesis was to develop nondestructive experimental methods suitable for collecting valuable response data related to the moisture behaviour and mechanical behaviour of drying wood and to refine this information into modelling parameters. A method for simultaneous noncontact measurement of two-dimensional surface deformations and interior densities was developed. This was done using Digital Speckle Photography (DSP) and X-ray Computed Tomography (CT). Displacements and densities were used for calculation of strain and of moisture content. Experimental tests of the measurement method were done on cross sections of Scots pine. The following accuracy was stated for different properties: A typical calculated displacement error of approximately 10 micrometre was found. Strains derived from the displacements had a maximal error of 1.11 mstrain. Moisture content measuring accuracy was estimated to +-1.8% moisture content at a significance level of 0.05 in a measuring volume with the approximate size 2 x 2 x 1.5 mm3. A similar noncontact technique based only on X-ray CT scanning was developed. Displacements were then estimated from boundary movements of an object in CT images. The estimated standard deviation of the measured moisture content error for this method was 0.04% moisture content. The mean error was unknown. Two different approaches to determining moisture diffusion coefficients from the studied data were presented. The first was based on minimizing the difference between measured and computed values through an optimization scheme. This approach required an initial assumption of the functional form of the diffusion coefficient. The second approach calculated diffusion and mass transfer coefficients through direct finite difference calculations on measured moisture content data. Results on Norway spruce showed interesting local variations of the diffusion coefficient, especially near the evaporation surface. Comparisons between measured and FEM simulated data showed good results. An example showed that a multivariate method of analysis could be an effective and easy-to-use tool for untangling relationships between variables and for generating information from data. Finally, it could be stated that the methods presented will be of use to improve the understanding of the behaviour of drying wood, with the focus on moisture and mechanical properties.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2005. p. 32
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544 ; 2005:23
National Category
Bio Materials
Research subject
Wood Physics
Identifiers
urn:nbn:se:ltu:diva-18059 (URN)6a1ee9c0-5225-11db-9592-000ea68e967b (Local ID)6a1ee9c0-5225-11db-9592-000ea68e967b (Archive number)6a1ee9c0-5225-11db-9592-000ea68e967b (OAI)
Note
Godkänd; 2005; 20061002 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Larsson, R., Danvind, J., Imbaud, O. & Morén, T. (2005). Prediction modelling of colour changes on boards of Norway Spruce and Scots Pine during low temperature drying (ed.). In: (Ed.), (Ed.), Proceedings: 9th International IUFRO Wood Drying Conference. Paper presented at International IUFRO Wood Drying Conference : 21/08/2005 - 26/08/2005. : Nanjing Forestry University
Open this publication in new window or tab >>Prediction modelling of colour changes on boards of Norway Spruce and Scots Pine during low temperature drying
2005 (English)In: Proceedings: 9th International IUFRO Wood Drying Conference, Nanjing Forestry University , 2005Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Nanjing Forestry University, 2005
National Category
Bio Materials
Research subject
Wood Physics
Identifiers
urn:nbn:se:ltu:diva-27754 (URN)14aa2200-0640-11dc-b09b-000ea68e967b (Local ID)14aa2200-0640-11dc-b09b-000ea68e967b (Archive number)14aa2200-0640-11dc-b09b-000ea68e967b (OAI)
Conference
International IUFRO Wood Drying Conference : 21/08/2005 - 26/08/2005
Note
Godkänd; 2005; 20070519 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Danvind, J., Eriksson, J. & Johansson, H. (2004). Calibration of a constitutive model for diffuse moisture transport in wood using data from X-ray CT-scanning and digital speckle photography (ed.). Paper presented at International conference of COST Action E15 Wood drying : 21/04/2004 - 22/04/2004. Paper presented at International conference of COST Action E15 Wood drying : 21/04/2004 - 22/04/2004.
Open this publication in new window or tab >>Calibration of a constitutive model for diffuse moisture transport in wood using data from X-ray CT-scanning and digital speckle photography
2004 (English)Conference paper, Oral presentation only (Refereed)
National Category
Bio Materials
Research subject
Wood Physics
Identifiers
urn:nbn:se:ltu:diva-35065 (URN)97297d70-9f24-11dc-9810-000ea68e967b (Local ID)97297d70-9f24-11dc-9810-000ea68e967b (Archive number)97297d70-9f24-11dc-9810-000ea68e967b (OAI)
Conference
International conference of COST Action E15 Wood drying : 21/04/2004 - 22/04/2004
Note
Godkänd; 2004; 20071130 (cira)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Danvind, J. & Morén, T. (2004). Using X-ray CT scanning for moisture and displacement measurements in knots and their surroundings (ed.). Paper presented at International conference of COST Action E15 Wood drying : 21/04/2004 - 22/04/2004. Paper presented at International conference of COST Action E15 Wood drying : 21/04/2004 - 22/04/2004.
Open this publication in new window or tab >>Using X-ray CT scanning for moisture and displacement measurements in knots and their surroundings
2004 (English)Conference paper, Oral presentation only (Refereed)
National Category
Bio Materials
Research subject
Wood Physics
Identifiers
urn:nbn:se:ltu:diva-28272 (URN)20435e70-9f23-11dc-9810-000ea68e967b (Local ID)20435e70-9f23-11dc-9810-000ea68e967b (Archive number)20435e70-9f23-11dc-9810-000ea68e967b (OAI)
Conference
International conference of COST Action E15 Wood drying : 21/04/2004 - 22/04/2004
Note
Godkänd; 2004; 20071130 (cira)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Danvind, J. (2003). Measuring strain and moisture content in a cross section of drying wood using Digital Speckle Photography and Computerised X-ray Tomography (ed.). In: (Ed.), Frank C. Beall (Ed.), Proceedings of the 13th International Symposium on Nondestructive Testing of Wood: August 19-21, 2002, University of California, Berkeley Campus, California, USA. Paper presented at International Symposium on Nondestructive Testing of Wood : 19/08/2002 - 21/08/2002. Madison, Wis.: Forest Products Society
Open this publication in new window or tab >>Measuring strain and moisture content in a cross section of drying wood using Digital Speckle Photography and Computerised X-ray Tomography
2003 (English)In: Proceedings of the 13th International Symposium on Nondestructive Testing of Wood: August 19-21, 2002, University of California, Berkeley Campus, California, USA / [ed] Frank C. Beall, Madison, Wis.: Forest Products Society, 2003Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Madison, Wis.: Forest Products Society, 2003
National Category
Bio Materials
Research subject
Wood Physics
Identifiers
urn:nbn:se:ltu:diva-38185 (URN)c7f7d190-0799-11dc-b09b-000ea68e967b (Local ID)1-892529-31-9 (ISBN)c7f7d190-0799-11dc-b09b-000ea68e967b (Archive number)c7f7d190-0799-11dc-b09b-000ea68e967b (OAI)
Conference
International Symposium on Nondestructive Testing of Wood : 19/08/2002 - 21/08/2002
Note
Godkänd; 2003; 20070521 (cira)Available from: 2016-10-03 Created: 2016-10-03 Last updated: 2017-11-25Bibliographically approved
Danvind, J. (2002). Methods for collecting and analysing simultaneous strain and moisture data during wood drying (ed.). (Licentiate dissertation). Paper presented at . Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Methods for collecting and analysing simultaneous strain and moisture data during wood drying
2002 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Improved understanding of moisture and mechanical behaviour is an international objective for wood drying research. The main objective of this licentiate thesis work was to develop an experimental method suitable for collecting valuable response data related to the moisture and mechanical behaviour of drying wood. Another objective was to provide an example on how multivariate methods can be used to analyse response data. A method for simultaneous non contact measuring of two dimensional surface deformations and interior densities have been developed. This was done using Digital Speckle Photography, DSP, and X-ray Computerised Tomography (CT). Displacements and densities were used for calculation of strains and moisture contents using a custom software developed in Matlab. Experimental tests of the measuring method were made on cross sections of Scots pine. The following accuracy was stated for different properties: - Displacements measured with DSP could be measured with a random error down to 0.01 pixels. A more typical calculated displacement error of approximately 10 micrometres, was found in paper I. - Strains derived from the displacements had a maximal error of 1.11 mstrain in an experimental test in paper II. - Accuracy in density measurements was expected to be less than +-6 kg/m3 for wet wood with moisture contents ranging from 6-100% and less than +-2 kg/m3 in dry wood, at a significance level of 0.05. This was estimated for a 2x2x1.5 mm3 measuring volume. - Moisture content measuring accuracy was estimated by simulations in paper II, which resulted in a measuring accuracy of +-1.8% moisture content at a significance level of 0.05 in a measuring volume with the approximate size of 2x2x1.5 mm3. A multivariate analysing method has been used to present an example on multivariate modelling of shrinkage behaviour in Radiata pine. The method was found to be an easy-to-use tool and useful for valid prediction of radial, tangential, longitudinal and volume shrinkage in the moisture range between 0% and 22% moisture content of the studied wood. The method also proved to be effective for untangling relationships between variables and generating information out of data. Finally, it can be stated that the developed measuring technique and the tested multivariate analysing method will be of use to improve the understanding of the behaviour of drying wood, focusing on moisture and mechanical properties.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2002. p. 22
Series
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757 ; 2002:05
National Category
Bio Materials
Research subject
Wood Physics
Identifiers
urn:nbn:se:ltu:diva-17677 (URN)49a0a5b0-c2ac-11db-9ea3-000ea68e967b (Local ID)49a0a5b0-c2ac-11db-9ea3-000ea68e967b (Archive number)49a0a5b0-c2ac-11db-9ea3-000ea68e967b (OAI)
Note
Godkänd; 2002; 20070222 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
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