In this paper stress relaxation of water-swollen wood was discussed with two conditions of temperature change, i.e. 1) specimens at 20°C were heated rapidly to 30-80°C, and 2) specimens at 30-80°C were cooled rapidly to 20°C. Stress relaxation was measured in the radial direction for 3 hours after the temperature had changed in 3 minutes. In addition, the fluidity of specimens was defined as the amount of change of the relative relaxation modulus (1-E_t /E₀). The results obtained are as follows :
1) When specimens at 20°C were heated rapidly to 30-80°C respectively, their fluidity clearly increased in comparison with the control specimens, which remained at constant temperature for a long time. Accordingly, It is clarified that an unstable state was incurred not only by cooling but also by heating.
2) Under cooling condition, the fluidity of specimens increased in proportion to the degree of cooling ; but under heating condition, the highest value of fluidity was at 50°C or 60°C. The reason for this is that the higher the temperature, the faster the dissolution speed of the unstable state.
3) The relaxation spectrum on a master curve basis shows that the peak of temperature history specimen was located at a short-time region in comparison with control specimen. The apparent activation energy was calculated from the relationship between the shift factor and the reciprocal of absolute temperature. The dates indicate that the value of control specimen was higher than that of temperature history specimen. Consequently, it is considered that the unstable structure was formed in the cell wall because of temperature elevation.

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In order to investigate the influence of alkali treatment on structural features and on hygroscopic properties, weight and dimensions were measured after wood samples (Picea jezoensis Carr.) were treated with aqueous solutions of various NaOH concentrations and conditioned at various relative humidity conditions.
In the oven-dry condition, volume and cross-sectional area of wood samples treated at NaOH concentrations ranging from 0 to 15% decreased, and at NaOH concentrations ranging from 15 to 20% they remained constant. Longitudinal contraction occurred in wood samples treated at NaOH concentrations ranging from 12 to 15%. These observations were due to both dissolution of wood components and wood structure deformation resulting from transformation of cellulose microfibrils.
The equilibrium moisture content of treated wood samples was larger than untreated wood samples except when the wood samples were treated with aqueous solutions of 5% NaOH concentration and conditioned below 71% RH. The water sorption isotherms of untreated and treated wood samples were analyzed by using the Hailwood & Horrobin equation. The number of sorption sites per 1 g of wood sample decreased in the NaOH concentration range of 0 to 5% and increased at the NaOH concentration of 20%. The equilibrium constant of formation of hydrated water increased in the NaOH concentration range above 10%. It was speculated that the hygroscopicity at low relative humidity was reduced due to dissolution of hemicellulose in the NaOH concentration range of 0 to 5% and increased due to increases in the proportion of amorphous components in the NaOH concentration range above 10%. Cluster size increased in the NaOH concentration ranges of 0-5% and 10-12% at high relative humidity. It is suggested that the changes in hygroscopicity at high relative humidity were due to increased void spaces as a result of dissolution of hemicellulose and of intermicellar and intramicellar swelling.

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Moisture adsorption properties of three typical bamboo species in Japan, namely madake (Phyllostachys reticulate), mousouchiku (Phyllostachys pubescens), and hachiku (Phyllostachys nigra MUNRO var. Henosis), were examined and analyzed on the basis of the Hailwood & Horrobin theory. The hygroscopicity of the three bamboos differ, and its ranking was madake<mousouchiku and hachiku, madake having been extracted with dilute alkaline solution. The hygroscopicity was greater in the inner than the outer portion of the cross section for all bamboo species. These differences were due to the extractives content in the bamboo substance, because they disappeared after extraction with 2% NaOH aqueous solution. It was presumed from the results of analysis based on Hailwood & Horrobin theory that the change in hygroscopicity following extraction with alkaline solution depended not only on the removal of extractives but also on the properties of regions newly created by the extraction which can swell with water adsoption.

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This paper describes thermal properties of binder-less wood chip insulation panels, focusing especially on the effect of panel thickness and on comparisons with the glass wool and phenolic foam panels commonly used as insulation material for buildings. Insulation panels with a density of 100 kg/m³ and thicknesses ranging from 50 to 150 mm were manufactured using wood shavings derived from a wood processing factory. Our panels were measured for thermal conductivity and diffusivity by analyzing heat flux through a simple wall model under an unsteady temperature schedule. The results obtained are as follows : 1) Thermal conductivity of our panel was about 0.060 W/mK for the practical thicknesses of 100 to 150 mm. 2) Heat inflow to the wall with our insulation panel was less than that of the glass wool and phenolic foam panels when compared at the same thermal resistance level. 3) Thermal diffusivity of our panels (0.41 × 10^-6 m²/s) was about half the value of the glass wool and three quarters of that of the phenolic foam panels since our panels have higher density and specific heat than the others. The results characterize our panels as having thermal insulation capacity that can be superior to that of glass wool and phenolic foam panels due to greater heat storage capacity.

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Differences of the pharmacological effects of Agaricus blazei cultured by various materials were examined. Agaricus blazei mushrooms were prepared on culture media composed by the following five materials ; 1) tops of sugar cane shoots (stems and leaves), 2) rice straw 3) wheat straw, 4) broad leaf tree bark, and 5) used substrate after Pleurotus ostreatus cultivation. The pharmacological effects of this mushroom were examined by the following methods ; 1) anti platelet aggregation stimulated by PAF or arachidonic acid Na, 2) inhibition of IL-8 gene expression stimulated by TNF-α, 3) improvements of rough surfaces by using replica method.
In both anti platelet aggregation test and chemokine gene revelation control test, the A. blazei cultured on the top shoot of sugar cane medium showed the most effective results compared with that cultured on other media. In the test of the improvement of rough surfaces by using replica method, the effect of A. blazei cultured by the top shoot of sugar cane medium was also highest compared to that cultured on the control, the extracts of A. bisporus or the ion exchanged water. These results suggest that the A. blazei cultured on the top shoot of sugar cane medium can be expected to have the most effective pharmacological functions.

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This study examined growth and wood properties of sugi (Cryptomeria japonica D. Don) cutting cultivars planted in the Kyushu region. Sixteen cultivars (48 trees) which were identified based on MuPS (Multiplex-PCR of SCAR markers) types were used.
Each cutting cultivar showed peculiar growth. The intra-cultivar variations in green moisture content of heartwood were small whereas the inter-cultivar variation was large. There were statistically differences in the L^* and a^* values of the heartwood color between cultivars, and a negative correlation of the L^* value with green moisture content was found. There was also significant difference in wood density between cultivars, and the neutral and the late-growth type cultivars showed larger basic density than the precocious-growth type cultivars. A significant difference in dynamic Young's modulus was also found between cultivars, and there were two axial variation patterns. In one pattern the dynamic Young's modulus increased with stem height, and in the other it was almost constant except at the position of the butt log where it had the lowest value. The former was the neutral or late growth type and the latter was the precocious type. There was a significant difference in the bending load-deformation curve of clear test specimens between cultivars or growth types.

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Bark chips of Acacia mangium, which are produced as wood waste by an Indonesian pulp factory, were carbonized to powdered charcoal at a temperature range between 300∼400°C. The by-product, tar, was mixed with the powdered charcoal, molded, and formed into charcoal having uniform shape, sufficient strength, and constant ignition followed by stabilization and/or carbonization. The effects of the process-stabilization without carbonization and carbonizing temperatures-were also investigated from an environmental viewpoint, i.e., the conservation of energy. Only stabilization for 4 h or carbonization below 400°C without stabilization yielded sufficient hardness ; however, the faint odor of wood tar persisted. Stabilization followed by carbonization below 400°C or stabilization for 20 h without carbonization completely eliminated the odor with increasing hardness. The heating value of the molded charcoal that was carbonized at 600°C with or without stabilization was the highest, and its ignition temperature was also high. Despite a low heating value, the molded charcoal carbonized at 300°C without stabilization was considered to be suitable for ignition due to its lowest ignition temperature of 233°C. The molded charcoal, which was carbonized at 900°C after stabilization, was activated by steaming for 60 min at 900°C. The yield was 36 wt% and its surface area was 615 m²/g, which is rather moderate as compared with that of the activated carbons obtained from wood waste.

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