Moisture diffusion coefficient of reaction woods: compression wood of Picea abies L. and tension wood of Fagus sylvatica L.

2011 ◽  
Vol 46 (1-3) ◽  
pp. 405-417 ◽  
Author(s):  
Asghar Tarmian ◽  
Romain Remond ◽  
Hadi Dashti ◽  
Patrick Perré
Keyword(s):  
Diffusion Coefficient ◽  
Picea Abies ◽  
Fagus Sylvatica ◽  
Tension Wood ◽  
Compression Wood ◽  
Moisture Diffusion ◽  
Moisture Diffusion Coefficient ◽  
Fagus Sylvatica L

Air permeability in longitudinal and radial directions of compression wood of Picea abies L. and tension wood of Fagus sylvatica L.

Holzforschung ◽  
2009 ◽  
Vol 63 (3) ◽  
Author(s):  
Asghar Tarmian ◽  
Patrick Perré
Keyword(s):  
Picea Abies ◽  
Fagus Sylvatica ◽  
Tension Wood ◽  
Compression Wood ◽  
Air Permeability ◽  
Normal Wood ◽  
Reaction Wood ◽  
Anatomical Point ◽  
Bordered Pits ◽  
The Difference

Abstract The air permeability in longitudinal and radial directions of compression wood in spruce (Picea abies) and tension wood in beech (Fagus sylvatica) was compared with that of the corresponding normal wood. The primary aim of the present study was to explain why the reaction woods dry more slowly than the normal woods in the domain of free water. A number of boards conventionally dried to an average final moisture content of 12% were chosen to perform the measurements. Bordered pits on the radial walls of longitudinal tracheids in the compression and normal wood and intervessel or intervascular pits in the tension and normal wood were also examined. The reaction wood of both species is less permeable than the normal wood, both in longitudinal and radial directions. The difference in permeability was more pronounced between compression and normal wood of spruce, especially in longitudinal direction. From an anatomical point of view, this is likely related to some differences in anatomical characteristics affecting the airflow paths, such as the pit features. Such results can explain the difference in drying kinetics of the reaction and normal woods in the capillary regime of drying.

Reaction wood drying kinetics: tension wood in Fagus sylvatica and compression wood in Picea abies

2008 ◽  
Vol 43 (1-2) ◽  
pp. 113-130 ◽  
Author(s):  
A. Tarmian ◽  
R. Remond ◽  
M. Faezipour ◽  
A. Karimi ◽  
P. Perré
Keyword(s):  
Picea Abies ◽  
Fagus Sylvatica ◽  
Tension Wood ◽  
Compression Wood ◽  
Drying Kinetics ◽  
Reaction Wood ◽  
Wood Drying

scholarly journals Evaluation of the Mass Diffusion Coefficient and Mass Biot Number Using a Nondominated Sorting Genetic Algorithm

Symmetry ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 260 ◽  
Author(s):  
Radosław Winiczenko ◽  
Krzysztof Górnicki ◽  
Agnieszka Kaleta
Keyword(s):  
Genetic Algorithm ◽  
Diffusion Coefficient ◽  
Biot Number ◽  
Moisture Diffusion ◽  
Absolute Error ◽  
Mass Diffusion ◽  
Precise Determination ◽  
Nsga Ii ◽  
Moisture Diffusion Coefficient ◽  
Nondominated Sorting

A precise determination of the mass diffusion coefficient and the mass Biot number is indispensable for deeper mass transfer analysis that can enable finding optimum conditions for conducting a considered process. The aim of the article is to estimate the mass diffusion coefficient and the mass Biot number by applying nondominated sorting genetic algorithm (NSGA) II genetic algorithms. The method is used in drying. The maximization of coefficient of correlation (R) and simultaneous minimization of mean absolute error (MAE) and root mean square error (RMSE) between the model and experimental data were taken into account. The Biot number and moisture diffusion coefficient can be determined using the following equations: Bi = 0.7647141 + 10.1689977s − 0.003400086T + 948.715758s2 + 0.000024316T2 − 0.12478256sT, D = 1.27547936∙10−7 − 2.3808∙10−5s − 5.08365633∙10−9T + 0.0030005179s2 + 4.266495∙10−11T2 + 8.33633∙10−7sT or Bi = 0.764714 + 10.1689091s − 0.003400089T + 948.715738s2 + 0.000024316T2 − 0.12478252sT, D = 1.27547948∙10−7 − 2.3806∙10−5s − 5.08365753∙10−9T + 0.0030005175s2 + 4.266493∙10−11T2 + 8.336334∙10−7sT. The results of statistical analysis for the Biot number and moisture diffusion coefficient equations were as follows: R = 0.9905672, MAE = 0.0406375, RMSE = 0.050252 and R = 0.9905611, MAE = 0.0406403 and RMSE = 0.050273, respectively.

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