When people encounter wooden products, they tend to unthinkingly take them in their hands and evaluate them in a multisensory manner based on both visual and tactile cues. Using specimens made of four types of wood and finished with two types of coating, we investigated the process of sensory inspection to identify which of these two perceptions plays the paramount role in the formation of subjects' visual and tactile impressions of wooden specimens. A multiple regression analysis of the relationship between the combined visual-tactile perception and its constituent visual and tactile components revealed that although visual perception played the dominant role overall, information from tactile receptors in the form of perceptions of the specimens' temperature, roughness, and moistness had a significant effect on subjects' impressions. An investigation of the relationship between subjects' visual and tactile perceptions and the material properties of the specimens suggested that subjects' impressions of the wooden specimens were linked to tactile perceptions shaped by specimen roughness and visual perceptions shaped by specimen brightness.

A method for calculating plastic clamp force from tightening torque was presented by considering a bi-linear model obtained from experimental tightening torque-clamp force relationships. The practical applicability of the calculation method was verified by tightening tests of Cryptomeria japonica − bolted joints using metal washers of various sizes. Results were as follows : It was found that a ratio of side-length (diameter) to thickness of metal washers ranging from 7.8 to 16.0 did not affect the torque coefficient. In addition, the ratio of maximum plastic torque coefficient to maximum elastic torque coefficient, γ_max and the ratio of minimum plastic torque coefficient to minimum elastic torque coefficient, γ_min, which are elements of the calculation method, tended to increase depending on embedment into timber of metal washers in side-length (diameter) to thickness ratios of 10.0 (washer size : 32×t 3.2 mm), 10.9 (washer size : 35×t 3.2 mm) and 7.8 (washer size : 35×t 4.5 mm). Furthermore, calculated tightening torque values were verified by tightening tests using a digital torque wrench. As a result, plastic clamp force values obtained by experiment agreed with calculated values ranging from minimum clamp force F_min to maximum clamp force F_max. However, the method of reducing variation in γ_max and γ_min remained to be investigated.

In this study, we investigated the relationship between weight reduction and color change in torrefied wood chips. We heated Japanese cedar (Cryptomeria japonica D. Don) heartwood and sapwood specimens with dimensions of 29 mm × 29 mm × 5 mm at 200 °C, 230 °C, and 250 °C for 0 - 360 min and then obtained color data. We found correlations between L* and the oven-dry weight ratio after/before heating (W/W₀), L*+a* and W/W₀, and L*+b* and W/W₀. The values of L*, L*+a*, and L*+b* after torrefaction were suitable for accurately and simply estimating the weight reduction of the torrefied chips. Both heartwood and sapwood samples can be used for these estimations without the need to separate them because we found the relationships between the color data and W/W₀ for the heartwood to be very similar to those for the sapwood. However, it is necessary to separate the LR-, LT-, and RT-planes because their corresponding color data and W/W₀ were not similar. Although the torrefied chips become darkened, their grains remain visually distinguishable.