Mariko Yamasaki

Learn More
Ninety-six bird and forty-seven mammal species are associated with the hemlock type in the northeastern United States. Of these species eight bird and ten mammal species are strongly associated with the hemlock type though none of these species are limited to it. Hemlock species richness appears to be lower than in other conifer or hardwood types. Avian(More)
A wooden mat to be used as heat-insulating/acoustic material was developed using wood shavings in their raw curled flake form as the primary material. This report discusses the influences of fabrication conditions on sound absorption and form retention. The results showed that the form retention was increased with kenaf composition. However, the normal(More)
Wood was treated with lasers of 349- and 355-nm wavelength and 5- and 12-ns pulse width. First, holes were drilled in the wood, and high aspect ratio holes of 20-µm diameter and 5-mm depth were obtained within several seconds at 80 mW of output. The diameter of the holes was relatively uniform in the depth direction. Incising was then conducted on the wood(More)
In this study, the potential of wood-only (metal-free) load-bearing walls was proposed and tested based on the idea of using the same type of material throughout wherever possible while improving basic properties such as strength, sound insulation, and heat insulation. Specifically, a technique was tested of combining pressure sensitive adhesive tape and(More)
Timber joints used in traditional Japanese constructions have no metal plates or fasteners. Because these joints resist external force by embedment to each member, they show high ductility. The ductile joints get much attention recently. Japanese “Watari-ago” joint used in horizontal structure is one such ductile joint. The joint consists of two beams with(More)
Heat insulating and acoustic absorbing materials were endued with fireproof performance and subjected to quantitative evaluations assuming a variety of uses and situations. Fireproofing was performed by spraying an aqueous solution of flame retardants on raw materials (wood shavings, kenaf bast fibers, and core-sheath-type fibers) during the fiber spreading(More)
Cutting of wood using short-wavelength (266-, 355-, 532-, and 1064-nm) lasers was carried out and wavelength dependence in relation to machining performance and post-processing appearance was investigated. We found that a 355-nm-wavelength laser achieves the greatest machining performance. The variation in machining performance between different wavelengths(More)
In this study sound insulation of walls was evaluated using wood insulation mat and plywood jointed with a combination of adhesive tape and wood dowels. Building of actual wall assembly test specimens and evaluating their sound insulation revealed that the sound transmission loss for jointing using a combination of adhesive tape and wood dowels was(More)
The mortise–tenon joint, which connects columns and beams of a wooden building, often creates a gap in contact part of members. This gap is considered to affect mechanical performance of the mortise–tenon joint. This study derived a method of theoretical estimation with a gap as parameter for the mechanical performance of mortise–tenon joint. In addition,(More)