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Akaki T.,Miyazaki Prefectural Wood Utilization Research Center | Maehara H.,Kumamoto University | Tooyama M.,Forestry Research and Instruction Station of Kumamoto Prefecture
Journal of Wood Science | Year: 2012

For making efficient use of waste wood ash emitted from wood biomass plant, the wood and wood ash-based hydroxyapatite (HAp) composite was produced and their flammability characterization was studied by thermogravimetric (DTA-TG) analysis, oxygen index (OI) measurement and cone calorimeter test. The results show that the exothermic and weight loss peaks in DTA-TG combustion profiles due to their significant thermal decomposition were weakened by the HAp agent impregnation. In addition, the OI value of HAp composites was increased by the HAp combining and the OI showed a correlation with the HAp contents. Also, the cone calorimeter study revealed that the heat release rates were decreased with increasing amount of HAp injection and accordingly their total heat release has an inverse relationship to the HAp contents. These results indicate that the treatment with wood ash-based HAp agents can enhance the flame retardancy of the treated woods. © 2012 The Japan Wood Research Society.

Jensen J.L.,University of Auckland | Nakatani M.,Miyazaki Prefectural Wood Utilization Research Center | Quenneville P.,University of Auckland | Walford B.,Scion Research
Construction and Building Materials | Year: 2012

A simple model based on quasi non-linear fracture mechanics is presented for estimating the withdrawal failure load of screws embedded in wood. The model takes into account major geometrical parameters such as the shank diameter, the length of the threaded area of the screw, the thread projection, and the pitch, and material properties such as the modulus of elasticity of the wood and the screw, the shear strength, and the fracture energy of the wood. Damage caused to the wood when driving the screw into the wood may be taken into account by assuming the presence of either initial shear stresses or an initial crack. The initial shear stress or the initial crack length is used as an empirically determined fitting parameter. Theoretical predictions are compared with experimental results of lag screws placed parallel to grain in end wood and subjected to withdrawal. © 2011 Elsevier Ltd. All rights reserved.

Nakatani M.,Miyazaki Prefectural Wood Utilization Research Center | Mori T.,Kyoto University
AIJ Journal of Technology and Design | Year: 2016

A moment resisting joint with lagscrewbolts shows good mechanical performance and aesthetic view due to not exposing the connectors to the outside. However, the beam and column joints rarely showed a brittle shear failure at the panel zone of the column surrounded by the lagscrewbolts. In this research, a joint system reinforced by long wood screws was confirmed to improve the strength properties and prevent from the failure at the early stage. As the results, the maximum shear strength and stiffness increased with increasing the number of the screws embedded with a comfortable space between each lagscrewbolts and edge distance.

Yanaga K.,Tottori University | Sotome K.,Tottori University | Suhara H.,Miyazaki Prefectural Wood Utilization Research Center | Maekawa N.,Tottori University
Mycoscience | Year: 2015

A new basidiolichen species, Lepidostroma asianum (Agaricomycetes, Lepidostromatales, Lepidostromataceae), is described based on basidiomata collected from red clay in southwestern Japan. This is the first report of a species in the genus Lepidostroma from Asia. The species is characterized by producing pale orange to reddish-orange, cylindrical to slightly fusiform basidiomata that taper toward the apex and by cylindrical to suballantoid basidiospores measuring 7.0-10.0 × 3.5-5.0 μm. In addition, it is associated with a green alga and forms a film-like thallus. Lepidostroma asianum differs from all previously-described species in its unique combination of these characteristics. Phylogenetic analyses of partial nuclear large subunit and small subunit rRNA gene sequences also differentiated it from other species. The cultural features of a Lepidostroma species are also provided for the first time. © 2014 Published by Elsevier B.V. on behalf of the Mycological Society of Japan.

Arima T.,Miyazaki Prefectural Wood Utilization Research Center
11th World Conference on Timber Engineering 2010, WCTE 2010 | Year: 2010

Wooden construction is referred as an "urban forest". The volume of wood presently occupying the wooden structures of Japan account for 48% of the wood in the country's plantation forests and 20% of the total volume of all forests in Japan. The amount of energy saved by substituting wood for the other materials and the effect of biomass energy use on carbon dioxide emission reduction are to be quantitatively analyzed. When looked at in this way, areas which are populated with wooden housing and wooden construction can be very appropriately called a "forest". Naturally, the purpose of calling wooden construction a "forest" alludes to the "Sustainable Society " which should be strived for and would be unthinkable without the connection between the forests and the city.

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