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

1)利用超声超声对受涝木材进行无损检测：在本课题中，我们试图通过超声图像处理来估计受涝木材任何特定部分横截面上的相对硬度。此外，我们还发现，在聚乙二醇浸渍过程中，最麻烦的部分出现了异常收缩，显示出显著的非均匀超声回声。这些结果为湿渍木制品的保护提供了有用的信息。2)采用传质理论处理方法研究了湿渍木材的保护：本课题研究了木材种类、聚乙二醇乙二醇酯浓度和温度对湿渍木材浸渍率的影响。并估算了径向、纵向和轴向三个维度的聚乙二醇浸渍速率的差异。3)淹水木材中滞留微生物的调查：本研究发现两种类型木材的滞留微生物有显著差异。在日本柳杉的浸渍木材中，我们发现主要是革兰氏阴性微生物，而在七叶树中，除了革兰氏阴性微生物外，还发现了几种微生物，尽管这两种木材长期浸泡在同一水罐中。

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.