The aim of the present study was to determine whether the radical reaction intermediates--reactive oxygen species (ROS) were formed during the laccase-catalyzed oxidation of wood fibers from Chinese fir (Cunninghamia lanceolata) and to quantify tentatively its production with electron spin resonance (ESR) spectrometry. To investigate the activation pathways triggered by laccase, ESR spin-trappi...

Qualitative and quantitative data are presented for 21 collections of Berberis and one each of Epimedium, Jeffersonia, and Nandina. Most species of Berberis have large numbers of narrow vessels ~ixed with vasicentric tracheids. Scalariform perforation plates are reported here only for Epimedium, m wh1ch they are occasional. Berberidaceae have living fibers (Berberis), fiber-tracheids plus livin...

Dynamic (or 2D) FT-IR spectroscopy in combination with polarized IR irradiation has been used in this work to study wood polymer orientation and interactions on the ultrastructural level in wood fibers in the native state as well as the effects of different pulping processes. The wood polymer interactions were studied under both dry and humid conditions. The matrix of lignin and hemicelluloses ...

Wood extractives cause pitch problems in pulp and paper manufacture. Extractives are low-molecular weight lipophilic components in wood consisting mainly of triglycerides, waxes, steryl esters, sterols, free long chain fatty acids and resin acids (Fengel and Wegener 1989a). The deposits of wood extractives associated with fibers, inorganic salts and additives, technically referred to as pitch, ...

This study is devoted to the morphological, chemical and physical characterization of raw material of the fruit of Luffa Cylindrica. By microscopic analysis, it can be observed that the fruit is composed of an assembly of dependent cords, where four parts are differentiated: external, internal wall, core and bond. Each cord consists of hollow and flexible cylindrical fibers.The external par...

Thermoplastic starch (TPS)/wood composites were prepared from starch plasticized with 36 wt% glycerol. The components were homogenized by dry-blending, extruded and injection molded to tensile bars. Tensile properties, structure, deformation, water adsorption and shrinkage were determined as a function of wood content, which changed between 0 and 40 vol% in 7 steps. The modification of TPS with...

The far-infrared properties of spruce wood are examined with a terahertz time-domain spectrometer. The solid wood is shown to exhibit both birefringence and diattenuation. The birefringence properties are sufficient for construction of a quarter-wave plate operating at 0.36 THz, and a half-wave plate operating at 0.71 THz. The origin of the birefringence is attributed to preferential fiber orie...

Vessels White oak cell types, fibers, rays, and vessels, were isolated from high-yield chemimechanical, neutral Rays sulphite semichemical (NSSC), and kraft pulps. Milled wood lignins (MWL) from NSSC fiber and ray Fibers cell fractions analyzed by ultraviolet and infrared spectroscopy were found to have similar syringyl/ Cell wall guaiacyl ratios. Methoxyl analyses of MWL’s were also similar an...

in this study, the effect of chemical modification of wood flour on the mechanical properties of polypropylene based composites was investigated using by dynamic mechanic thermal analysis. to meet this objective, the wood flour treated with chemical components including alkaline, acetic acid and benzoyl chloride, and then the chemically treated fibers were compounded with polypropylene at 180 °...