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 most common wood species in Sweden, and one of the most important renewable raw materials in Northern Europe, is Norway spruce (Picea abies). Today, it is utilized mainly for sawed timber and the production of pulp and paper. A modern kraft pulp mill that produces bleached pulp has a material efficiency of about 40-45%, and the final product contains mainly cellulose. The other components o...

to evaluate the nutritive value in some lignocellulosic materials, 3 sets of experiments were conducted on aspen, and grape woods. to enhance the digestibility, the woods were treated with 5% naoh. throughout the first trial, chemical composition and digestibility coefficients of dry matter, organic matter and ndf of experimental feeds, ph of rumen, as well as palatability were evaluated while ...

In Cactaceae, wood anatomy is related to stem morphology in terms of the conferred support. In species of cacti with dimorphic wood, a unique process occurs in which the cambium stops producing wide-band tracheids (WBTs) and produces fibers; this is associated with the aging of individuals and increases in size. Stem support and lignification have only been studied in fibrous tree-like species,...

Properties of heat-treated wood have been studied extensively in recent years. However, study on wood that has been treated in pressurized steam is limited, as most wood heat treatments are carried out in atmospheric steam. The main purpose of this study was to explore the influence of steam pressure on chemical changes of heat-treated wood. Wet chemical analysis, elemental analysis, and FTIR a...

A series of comparable specimens of hornbeam wood were submitted to pretreatments by white-rot fungi, by alkali alone, or by alkali and oxidizing agents. The pretreatments caused weight loss of wood and modified its physical properties and chemical composition. All pretreatments reduced markedly axial permeability of the test specimens in the wet state (w > FSP). The chemical pretreatments of t...

A quantitative evaluation of wood chemical components for some tree species in a forest area from east-northern Romania is presented here, through a comparative study from 1964 to 2000. Investigation upon the wood tree-rings in a Quercus robur L. tree species, as a dominant species, as regards its chemical composition and structure of the natural polymer constituents cellulose and lignin was al...

INTRODUCTION. THE somewhat arbitrary classification of the wood decays caused by fungi into " brown " and " white " rots has in recent years been the subject of controversy, as it has been suggested that more accurate classification can be based on strictly chemical evidence regarding the effects of the various wood-rotting fungi on wood substance. So far as "brown" rots are concerned a suffici...

In this work, the effect of temperature on charcoal structure and chemical composition is investigated for four tree species. Wood charcoal carbonized at various temperatures is analyzed by mid infrared spectroscopy coupled with multivariate analysis and by thermogravimetric analysis to characterize the chemical composition during the carbonization process. The multivariate models of charcoal w...

Methylolurea and carbamide were used to impregnate eucalyptus wood to improve its physical and chemical properties. The physical properties and dimensional stability were examined. TGA was used to evaluate the thermal stability of the wood. FTIR was used to state the changes of functional groups. The changes of wood structure were observed by SEM. The results showed the bending strength and com...