This study aimed to clarify the effects of differences in the wood subflooring and finishing on the physiology and psychology of walking barefoot. We measured surface electromyography (EMG) at six lower limb locations during walking on four different model floors, combining two types of flooring base materials with different stiffness and two types of floor finishes with different surface properties. We then conducted a psychological evaluation of the walking feelings. The 24-mm thick high-stiffness plywood subflooring had a significantly lower integrated EMG for the biceps femoris muscle while walking than the low-stiffness joist and 15-mm thick plywood subflooring, indicating less stress on the feet. Surface consolidated Japanese cedar, sugi (Cryptomeria japonica) wood finishing with the rough surface tended to have a lower surface integrated EMG during walking than ceramic-coated Japanese cypress, hinoki (Chamaecyparis obtusa) wood finishing with a smooth surface. Smooth finishing materials were rated as easier to walk on in the impression evaluation, which was contrasted with the surface EMG results. EMG is considered to be better suited for predicting the accumulation of fatigue due to prolonged walking, which is difficult to recognize after a short period of walking.

Uncaria rhynchophylla clone plants were harvested five times in summer and autumn for two consecutive years in Japan, and the contents of alkaloids, the ingredients for crude drug, in different tissue parts such as branches and leaves were determined. The results indicated that the contents in the branches with hooks (secondary branches) were more than 0.03% on dried sample weight, which are required for usage as crude drug material by Japanese Pharmacopoeia. In addition, less alkaloids contents in the leaves than in the secondary branches and the tip parts of the base branches from which the secondary branches ramified, and higher content in summer than autumn in every tissue part were also known. Quantitative differences in the extractives (useful compound) other than alkaloids between leaves (non-materials for crude drug) and branches with hooks harvested from the identical plants in August for two consecutive years were also investigated. The results indicated that the leaves contained more vitamin Es (tocopherols), especially α- and β-tocopherols which have higher bioactivities, than the branches with hooks did, and contained comparable amounts of sterols which were commonly known as bioactive compounds with the branches with hooks.

In this study, the position and shape of internal checks in boxed-heart square timber were analyzed to acquire basic knowledge for internal checks caused by high-temperature drying. Sugi (Cryptomeria japonica) boxed-heart square timbers with a cross-sectional dimension of 105×105 mm supplied from 9 prefectures in Japan were used. The timbers were dried at high temperatures. The 16947 internal checks were extracted from 978 transverse-sectional images containing internal checks. Internal checks with large areas and lengths were unevenly distributed near the diagonal of the square timber. This result supports the experience knowledge. The method was considered proper for approximating the internal check as a diamond when calculating the area from the width and length.

Fire retardant-treated (FRT) wood with a series of phosphoric acid and amino resin (leach-resistant type) or a mixture of phosphoric acid and boric acid (indoor use type) was weathered for up to 10 years at three places in Japan. Test results showed that FRT wood with a series of phosphoric acid and amino resin had high chemical retention and fire retardancy after 10 years compared with FRT wood with a mixture of phosphoric acid and boric acid. From 5 to 10 years, Decrease in fire retardancy of uncoated FRT wood treated with each fire-retardant was slower than up to 5 years. Fire retardancy of FRT woods with each fire retardant after 10 years, increased by coating with combination of fluorine resin-based and polybutadiene-based paint. FRT wood with a series of phosphoric acid and amino resin might keep initial fire retardancy for 10 years, if coated with the above paint. For uncoated and coated FRT wood with a mixture of phosphoric acid and boric acid, it showed that fire retardancy after 10 years was influenced by weathering sites. The condition for setting up the weathering rack was considered the reason for the influence of the weathering site on fire retardancy of weathered FRT wood.

Approximately 50 years ago, the Forestry and Forest Products Research Institute (FFPRI) conducted field tests (stake tests) to assess the natural durability of heartwood of various wood species. FFPRI examined the damage of heartwood stakes during the testing period and determined the average service life of each stake. The natural durability of each species was classified according to the average service life, and this classification has influenced the Japan Agricultural Standards for sawn lumber (JAS 1083) and the Housing Quality Assurance Law. However, inspection of the classification process revealed ambiguity because the durability of wood species was determined only by their average service lives. Differences in the number of stakes and variations in service lives in each species were not considered. Hence, we applied survival analysis to this existing data and evaluated the classification more precisely to consider these factors. The evaluation showed that there are differences in the tendency of deterioration depending on the wood species, i.e., there are species in which the durability of all stakes is low, ones in which this value is high, and others in which this value depends on the stake. The re-evaluation of the durability by a survival analysis revealed that the durability of kouyamaki is higher than that of Japanese cypress and hiba, both of which are considered to be highly durable. It also revealed that differences in the durability of species considered durable, such as Japanese cedar and Japanese larch, and that of species considered highly durable, such as hinoki and hiba, are not significant.

Anthraquinone (AQ) had attracted attention as an additive of alkali cooking since 1972, but International Agency for Research on Cancer reported that AQ had mutagenic or carcinogenic possibilities in 2012. In order to utilize bamboo as a non-wood paper resource and to find a safe and efficient cooking method of bamboo pulp, this study clarified the effects of using 2-methyl anthraquinone (2-MAQ), which was not mutagenic, on bamboo soda cooking and the residual content of 2-MAQ in the pulp. The addition of 0.06% 2-MAQ to soda cooking of bamboo chips increases the pulp yield by 3.0% at the same kappa number around 17 compared with no addition, which implies benefits of saving forest resources and fossil energy in paper industry. Analytical data shows that one kg of the unbleached bamboo pulp contained 0.02–0.11mg 2-MAQ as a very low quantity, and that the quantity transferred from packaging-paper and paperboard produced using the soda 2-MAQ pulp to food should not cause the carcinogenicity.