会议名称：2013世界木材日研讨会(2013 World Wood Day Symposium)
会议时间：2013年3月19-20日
会议地点：Karimjee Hall, Dar es Salaam, Tanzania
报 告 人： Misao Yokoyama
　　　　　Researcher of Kyoto University

Abstract
Wood has always played a major role in Japanese traditional culture. More than 90% of buildings listed as a National property or a nationally important cultural property of Japan are constructed with wood. In the ancient capitals Kyoto and Nara, many traditional wooden buildings were inscribed as World Cultural Heritage of the UNESCO. The most famous and the world’s oldest wooden construction still standing is Horyu-ji temple from the latter half of the seventh century.
Wood is present in many cultural heritage objects thanks to its capacity to resist over long period of time. However, the evolution of its properties in regular use remains insufficiently known. The present study on the effect of wood aging takes advantage of the Japanese context where building traditions have been maintained for centuries.
One major difficulty for the research on “aging of wood” is the gathering of suitable samples, with well-defined origin, certified dating and permission of publication by conservation administration. The Japanese context, where traditional uses of wood have been maintained for more than 1600 years, offers a unique opportunity to address the question of wood aging.
The matching of specimens from different origins is another typical obstacle. Wood is a variable material due to genetic variations and dependency on growing conditions of the trees. To discuss property changes due to aging, a recent reference is required. However, it is difficult and sometimes impossible to obtain recent wood that closely matches a given old wood sample. To overcome the difficulty, thermally treated wood as an accelerated aging can be used to produce corrections that will allow comparing data from slightly mismatched samples. Thermally treatment ware performed at 90, 120, 150, and 180℃ for various periods on new hinoki wood from Kiso area.
This paper deals with mechanical characteristics of aged hinoki (Chamaecyparis obtuse Endl.) wood from Japanese historical buildings. It is not only for the basic science study on aging of wood by using unique and indigenous Japanese hinoki wood, but also for the commonality and universality of worldwide wooden cultural assets. This research will have a positive role on preservation and conservation of wooden cultural properties in the world.

Speaker Profile
Misao Yokoyama holds a Doctor of Philosophy degree in Agriculture from the Kyoto University in Japan. Since completing her PhD thesis she has been working as a researcher at the Research Institute for Sutainable Humanosphere. She specialises in aging of wood conducting scientific studies on mechanical properties of varied wood species, particularly, unique indigenous Japanese wood. Her research has an application in the preservation of world-wide collections of wooden objects, and she has a positive role in study group of wooden cultural properties in the Japan Wood Research Society.