To investigate the effects of circular sawing conditions and moisture content of workpieces on the mass concentration of airborne dust generated from circular sawing of sugi (Cryptomeria japonica), the mass concentration of airborne dust of diameter 7.07 µm or less during sawing was measured at a worker's breathing zone with a light-scattering type dust monitor at intervals of one second. The sawing parameters varied in this experiment were workpiece feed speed, circular saw revolution speed, and the feed per tooth. The geometric mean of mass concentration was more affected by the circular saw revolution speed than by specimen feed speed and feed per tooth, and increased with the circular saw revolution speed. This implies that the quantity of airborne dust that reached a worker's breathing zone increases with increasing peripheral circular saw speed. Although the geometric means for dust collector operation were lower than the occupational exposure limit (OEL), individual measurement values of mass concentration during sawing were sometimes larger than the OEL. The probability that the measurement value was larger than the OEL was 0.0 for 1500 rpm of circular saw revolution speed, and 0.03-0.18 for 2000 and 2500 rpm. The geometric standard deviation of mass concentration was not affected by the sawing conditions. There was a negative relationship between the geometric mean of mass concentration and workpiece moisture content, and a positive relationship between the geometric standard deviation of mass concentration and workpiece moisture content.

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Effects of activation temperature on yield, ash content, specific surface area and moisture absorption of activated carbon made from pruned apple branches with an air-based activation method were investigated, and these characteristics were compared with activated carbon from Cryptomeria japonica. The results are as follows: The yield at activation temperature of 900°C from pruned apple branches was lowest, and was lower than that of Cryptomeria japonica, while the ash yield was higher than that of Cryptomeria japonica. The specific surface area at activation temperature of 900°C from pruned apple branches was highest, and based on converted ash yield was higher than that of Cryptomeria japonica. Moisture adsorption of activated carbon from pruned apple branches increased with rising relative humidity and activation temperature, and based on converted ash yield was higher than that of Cryptomeria japonica.

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We investigated saccharification of xylan by Thermobacillus composti and its immobilization on a hydrophilic porous gel carrier. T.composti saccharified xylan at 50°C in aerobic condition and the product was used as carbon source for growth of T.composti. Xylose was detected in the culture of T. composti. Then T.composti was immobilized on the carrier. Scanning electron microscopy (SEM) showed that T.composti entered into the holes of the carrier and proliferated there well. Xylose was also detected in the culture of T.composti immobilized on the carrier. The immobilization did not inhibit the saccharification ability of T.composti.

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To investigate the visual and olfactory effects of an interior environment made of hiba (Thujopsis dolabrata Sieb. et Zucc.) wood in humans, we measured psychological and physiological responses. Four actual-size model rooms containing different proportions of hiba wood were constructed for this experiment. Subjects were 14 healthy male and female college students. Changes in psychological evaluations and physiological responses were examined after entering each of these rooms. As a result of an analysis of volatile compounds in the indoor air after the experiment, air concentration of sesquiterpenes was increased by increasing the amount of hiba wood in the interior environment. Odor intensity and acceptability were significantly increased by increasing the amount of hiba wood in the interior environment. A room with hiba wood used for the floor and walls felt significantly more “natural” and “traditional” than a room without hiba wood, and changes in the “fatigue” level on profile of mood states (POMS) were significantly less in a room with hiba wood used for the floor and walls than those in a room without hiba wood. Blood pressure and salivary alpha-amylase findings suggested that differences in the amount of hiba wood in the interior environment caused different levels of autonomic nervous activity. Therefore, there was no correspondence between psychological evaluations and physiological responses.

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The effect of visual stimulation from room interiors with different wood quantities on task efficiency during two-digit addition and subtraction was investigated. Four actual-size model rooms of interiors constructed with different quantities of sugi (Cryptomeria japonica D.Don) wood were used for this experiment. Subjects were twelve healthy males and females comprised of university students and other adults. After resting for five minutes in the test rooms, the calculation tasks were performed for sixteen minutes. Changes in psychological evaluations and physiological response were measured before and after each task. Concerning room interior images, the “comfort” and “atmosphere” images were significantly different among the four rooms. The rating of a “comfortable” feeling before the task was significantly different among the four rooms. However, the “comfortable” feeling after the task was evaluated as “uncomfortable” in all rooms, and there was no significant difference among the four rooms. Salivary alpha-amylase showed significant differences among the time points, but there was no significant difference among the four rooms. The number of answers and percentage of incorrect answers as an index of task efficiency were not significantly different among the four rooms. This study suggested that task efficiency during two-digit addition and subtraction was not affected by the differences in “comfort” and “atmosphere” images or the “comfortable” feeling before the task in each room.

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Terpenoid compounds obtained from the extractives of sound heartwood, rotten portions, and resinous exudates of a fallen branch of Joumon-sugi (a symbolic old tree of Cryptomeria japonica growing on Yakushima Island, Kagoshima, Japan, where it is listed as a World Natural Heritage, of 25.3m height and 16.4m girth at breast height) were analyzed. Some terpenoid compounds containing an aromatic group including cadalene were found in addition to δ-cadinene which was the major component in the neutral parts of hexane solubles of the sound heartwood. The proportions of sesquiterpenes and oxygen-containing sesquiterpenoids were higher in the components of sound heartwood terpenoids. On the other hand, sesquiterpenes were decreased, and diterpenoids and unidentified compounds occupied a large proportion of the components of rotten portion extractives. Main compounds in the exuded resin of the branch were α-pinene, 6, 7-dehydroferruginol, and ferruginol. The exudates contain less oxygen-containing sesquiterpenoids than the exuded resin from a 35-year-old planted yakusugi (a cultivar of sugi) tree that was injured with a pin from outside of the trunk to its sapwood.

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The three-dimensional molding method of wood veneer is one of the promising technologies that can increase the utilization ratio of domestic softwood. However, so far in this technology semi-fixed wood, which is the raw material of three-dimensional molding, is fabricated by compression only in the R direction. Therefore, only edge-grained veneers were obtained, and the products that could be made were limited to edge-grained patterns. In this study, fabrication of flat-grained semi-fixed wood was achieved by applying a 2-step compression method. Furthermore, speaker-cones were molded from both edge-grained veneer and flat-grained veneer by using the three-dimensional molding method. In the case of edge-grained veneer, a success ratio of 80% was obtained with 0.4 mm and 0.5 mm-thick veneers, and a success ratio of 50% was obtained in the case of flat-grained veneers. The frequency response of these products showed that they were comparable to commercial products.

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