Takuro Mori

Wood anatomical selectivity of drywood termite in the nest-gallery establishment revealed by X-ray tomography

Termite nest architecture has important biological attributes, as the whole structure represents a morphological expression of the sum of behavioral patterns which relate to a better understanding of their feeding ecology. The nest-gallery system of the western drywood termite, Incisitermes minor, inside naturally infested wood was visualized by X-ray computed tomography. Drywood termites are considered one-piece nesters; therefore, studying the anatomical properties of wood could increase the insight into those factors that influence the mechanisms used when the nest-gallery system is established. The interactions between the I. minor colony and environment, represented by the wood’s anatomical properties of fibers and growth rings, generate a distinctive and unique foraging pattern, which lead to selective excavation of the nest-gallery system. The results indicated that drywood termites exhibited continual adaptation to their environment as well as self-organization, similar traits of foraging and nesting biology can also be found in intermediate and separate nesters, however, at a different ecological scale.

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.

Propose Alternative Design Criteria for Dowel Type Joint with CLT

The load carrying capacity of dowel type joint in Cross Laminated Timber (CLT) was derived based on the Johansen’s yield model. The steel plate inserted drift pin joint with CLT (5 layered; thickness of laminae were same in one CLT, all of laminae were orthogonally arranged) was chosen as the specimen. Stiffness and nonlinear load - deformation relationships were calculated by numerical analysis using Rigid Body Spring Model (RBSM). Estimation showed the good agreement with the tensile test results on the joints.

Effects of salinity on the nail-holding power of dimension lumber used in light-frame wood building

We studied the effect of salinity on nail-holding power in wood construction. In saline solution, the holding power of nails was less than in purified water. With the increase of salt concentration, the surface and side nail-holding power of the wood specimens both declined, but the differences between salinity treatments were not significant. However, compared to the surface and side nail-holding power, the power on the edge was generally less and the difference was not obvious in different salt concentrations. In the same salt concentration, with the extension of the processing cycle, the performance of holding power of nails showed a downward trend, expect the temporary rise in the middle.