wood is a porous three dimensional, hydroscopic, viscoelastic, anisotropic bio-polymer composite composed of an interconnecting matrix of cellulose, hemicelluloses and lignin with minor amounts of inorganic elements and organic extractives. some, but not all, of the cell wall polymer hydroxyl groups are accessible to moisture and these accessible hydroxyls form hydrogen bonds with water. as the...

The effects of different management regimes on uneven-aged Douglas-fir stands in the Pacific Northwest of the United States were predicted with a simulation model. Management alternatives were defined by residual stand structure and cutting cycle. The residual stand structure was set by basal area–diameter-q-ratio (BDq) distributions, diameter-limit cuts (assuming concurrent stand improvement),...

Fiber dimensions and lignin and cellulose content of various highly productive, non-wood plants and agricultural residues were examined to assess their suitability for paper production. Plants like kenaf (Hibiscus cannabinus L.) and giant reed (Arundo donax L.) internodes gave very good derived values, especially slenderness ratio, which is directly comparable to some softwood and most hardwood...

Log prices can vary significantly by grade: grade 1 logs are often several times the price per unit of grade 3 logs. Because tree grading rules derive from log grading rules, a model that predicts tree grades based on tree and stand-level variables might be useful for predicting stand values. The model could then assist in the modeling of timber supply and in economic optimization. Grade models...

Recent molecular genetic data suggest that cellulose synthase (CesA) genes coding for the enzymes that catalyze cellulose biosynthesis (CESAs) in Arabidopsis and other herbaceous plants belong to a large gene family. Much less is known about CesA genes from forest trees. To isolate new CesA genes from tree species, discriminative but easily obtainable homologous DNA probes are required. Hyperva...

Thioacidolysis is a method used to measure the relative content of lignin monomers bound by β-O-4 linkages. Current thioacidolysis methods are low-throughput as they require tedious steps for reaction product concentration prior to analysis using standard GC methods. A quantitative thioacidolysis method that is accessible with general laboratory equipment and uses a non-chlorinated organic solv...

Abstract The correct characterisation of wood properties is fundamental for the best utilisation resources. In Europe, grading defined by strength classes that are determined based on either bending or tension tests. European standards give equations to estimate characteristic in from bending, and vice versa depending which was tested. These applied all softwoods. aim this paper empirically det...

Lignin characteristics are significantly affected by kraft processing and isolation conditions. In the studies carried out in this context, commercial lignins or isolated from industrial black solutions generally preferred. study, order to conduct more comprehensive research, three lignin samples were liquor obtained laboratory cooking trials of pine, poplar, wheat straw chips, representing sof...

To perform a non-destructive evaluation of wood, the Christoffel equation is frequently used to describe the relationship between the ultrasonic wave velocity and the mechanical parameters. In the context of acoustical tomography imaging of standing trees, the key contribution of this numerical study is to determine the influence of mechanical parameters of the wood radial-tangential plane on t...