Non-destructive survey on the internal hardness of waterlogged archeological woods and its application to conservation of the waterlogged woods.

本研究涉及以下三个主题，以保护水浸木制文物。1)超声对浸水木材的无损检测：本课题通过超声图像处理，试图估计浸水木材任意特定部位横截面上分布的相对硬度。此外，我们还发现在PEG浸渍过程中出现异常收缩的最麻烦的部位，超声回波表现出明显的异质性。这些结果为我们提供了保存浸水木器的有用信息。2)应用传质理论处理对浸水木材的保护研究：本课题研究了木材种类、PEG浓度和温度对浸水木材浸渍率的影响。并从径向、向向和轴向三个维度估算了聚乙二醇浸渍率的差异。在此基础上，通过理论处理研究了浸水木材的风干速率。3)水淹木材中常驻微生物的调查：本课题发现两种木材的常驻微生物存在显著差异。在柳杉（Cryptomeria japonica D.Don）浸水木材中，主要发现革兰氏阴性微生物，而在马尾木块（Aesculus turbinata Bl）中，尽管这两种木块长期浸泡在同一容器中，但除了革兰氏阴性微生物外，还发现了几种微生物。

This research is concerned with following three subjects for conservation of waterlogged wooden cultural property.1) Non-destructive investigations on the waterlogged woods by ultrasound echography : In this subject we tried to estimate degree of relative hardness distributed in the cross section of the any particular parts of those woods by image processing of ultrasound echograms. Further we found the most troublesome parts, which shrinked abnormally in the PEG impregnation process, revealed remarkable heterogeneous ultrasound echoes. These results give us useful informations for conservation of waterlogged wooden objects.2) Investigations on the conservation of waterlogged woods applying theoretical treatment of mass transer : In this subject we investigated the influences of wood species, PEG concentration and temperature on impregnation rate of waterlogged woods. And we estimated difference of the PEG impregnation rates for three dimensions, such as radial, tandential and axial rate. Further we investigated by theoretical treatments on the rate of air drying for watelogged woods.3) Investigations on the resident microorganisms in the waterlogged woods : In this subject we found remarkable difference of resident microorganisms between two type of wood species. In the waterlogged wood of Cryptomeria japonica D.Don, we found mainly gram negative microorganisms, however, in the Aesculus turbinata Bl, found several species of microorganisms beside gram negative one in spite of these two type of wood blocks had been immersed for long term in a same water vessel.