Development of Radar Apparatus for Scanning of Wooden-Wall to Evaluate Inner Structure and Bio-Degradation Non-Destructively

A nondestructive and small FMCW radar apparatus for scanning of the wooden wall to evaluate inner structure and biodegradation progressed in the wall was developed, and the performance of the apparatus was investigated. The allocations and the properties of the construction members in the wall, such as wooden posts and beams, metal plate connectors and insulating materials was recognized as 2D and 3D images. The moist area of more than 50% in moisture content in the wall was also recognized, and this suggests that the area of potentiality of biodegradation such as fungal and insect attacks in the wall can be detected by this apparatus. The feasibility of the apparatus to evaluate of the loss in the wood substance caused by the bio-degradation was also confirmed.

Autohydrolysis of birch wood

Autohydrolysis of wood as a pretreatment stage before alkaline pulping is seen as an opportunity to approach the ideals of a forest biorefinery. In autohydrolysis the degradation products of primarily hemicelluloses and some other wood components are mainly dissolved (liquid phase) and they also escape partly as gas. In the present paper, birch was autohydrolysed at two intensity levels (characterised by P-factors of 200 and 1000) and the mass balances of autohydrolysis including solid, liquid, and gaseous phases were established. Approximately 10% and 25% of the total wood substance was transferred to the liquid phase at the two autohydrolysis intensities, respectively. In both cases about 50% of the degraded wood substance consisted of xylose-based material. The share of monomeric xylose was about 6% and 50% in the two samples, respectively. From the residual oligosaccharide fractions, 13% and 90% accounted for the DP2 to DP4 components in the P200 and P1000 samples, respectively. As expected, the weight-average molar mass of the components in the P1000 hydrolysate was substantially lower (0.4 kDa) than those in the corresponding P200 hydrolysate (2.1 kDa). Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) measurements revealed that relative to xylotriose the P1000 sample contained significantly fewer acidic pentosan fractions than the P200 sample. Xylooligosaccharides dissolved at both intensity levels remained highly acetylated, and some of these also carried 4-O-methylglucopyranosyluronic acid substituents.

Near-Infrared Spectroscopic Monitoring of the Diffusion Process of Deuterium-Labeled Molecules in Wood. Part II: Hardwood

Fourier transform near-infrared (FT-NIR) transmission spectroscopy was applied to monitor the diffusion process of deuterium-labeled molecules in hardwood (Beech). The results are compared with previous data obtained on softwood (Sitka spruce) in order to consistently understand the state of order in cellulose of wood. The saturation accessibility and diffusion rate varied characteristically with the OH groups in different states of order in the wood substance, the diffusants, and the wood species, respectively. The variation of saturation accessibility should be associated with the fundamental difference of the fine structure such as the microfibrils in the wood substance. The effect of the anatomical cellular structure on the accessibility was reflected in the variation of the diffusion rate with the wood species. The size effect of the diffusants also played an important role for the diffusion process in wood. Since the volumetric percentage of wood fibers and wood rays is relatively similar, the dichroic effects due to the anisotropy of the cellulose chains were apparently diminished. Finally, we proposed a new interpretation of the fine structure of the microfibrils in the cell wall by comparing a series of results from hardwood and softwood. Each elementary fibril in the hardwood has a more homogeneous arrangement in the microfibrils compared to that in the softwood.