• Conservation Science in Museum
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• v.7
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• pp.69-73
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• 2006

This study is the investigation of the tree type of six waterlogged archaeological wood excavated from the remains related to Yun Sundo in Bogildo, Wando Island; the remains had been excavated and surveyed by Jeonnam Cultural property Research Center. The identification result was four Pinus sp. (hard pine), one loquat and one Symplocaceae. All the identified tree types are subtropical ones and they are common in Bogildo, Wando Island.

• Journal of Conservation Science
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• v.5 no.2 s.6
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• pp.51-56
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• 1996

This paper deals with the restoration of ancient wooden bridge foundation which excavated in Seta river Shiga Prefecture, Japan. Shiga Archeological Research started a marine archeological investigation of the bridge foundation in 1987. The bridge foundation stricture excavated and have since then recovered about a lots of woods and another materials. The bridge foundation structure constructed log, timbers and stones. The species of those waterlogged wood were identified as two types, hardwood and softwood. Hardwood(log : Cyclobalanopsis) was used for below foundation and softwood (timber' Chamaecyparis obtusa Endl. Cupreessaceae) was used for base structure. One of those timber sample dated by dendrochronology, we asked Dr. Misutani*. The softwood gave a felling date of 567 A.D. In result, the ancient Seta bridge foundation structure had constructed between Asuka and Nara period. We healed the news that ancient bridge foundation excavated at Woljyongyo site in Kyongju, Korea 1987. The bridge foundation Setakarahashi is similar in plane and structure to Woljyongyo structures. The Woljyongyo site report had be of value for reference. We had planning to restore those woods. Hardwood log was got serious damage. The water content varies from 400 to $600\%$. The other timbers water content varies about $200\%$. In the Shiga Center for Archaeological Operations and the Azuchi Castle Archaeological Museum, we set up the PEG impregnation tank. Those wooden objects treated by PEG method. PEG with a molecular weight of 4000. The treatment results may be considered satisfactory. The ancient wooden Seta bridge was reconstructed in Biwako Museum which established in Oct. 1996. We must take care of indoor exhibition environments. (*Nara National Cultual Properties Research Institute).

• Journal of Conservation Science
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• v.36 no.3
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• pp.225-235
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• 2020

The present study aimed to monitor changes in the amount of PEG free-flowing back from PEG-treated woods and compressive strength changes with change in relative humidity from 90% to 30%. The change in the relative humidity was done 3 times. For the current study, water-logged wood (Prinus group) was used and the wooden blocks cut out of it were subjected to 3 different impregnation methods combined with different drying conditions as follows: 1) impregnating with 80% PEG#4000 followed by drying in nature (hereafter PEG80), 2) impregnating with 40% PEG#4000 and then drying in vacuum freeze drying equipment (hereafter PEG40), and 3) impregnating with 40% PEG#4000 in t-butanol, followed by drying in the vacuum freeze drying equipment (hereafter TB40). It was verified that most of the PEG was free-flowing back from the PEG-treated woods; however, a small amount of left PEG was observed on the lumen surface. The amount of PEG free-flowing back from the PEG-treated woods increased whenever the relative humidity changes from 90% to 30%. The compressive strengths of PEG80 and TB40 were increased whenever the relative humidity changed from 90% to 30%, whereas PEG40 decreased. The current study showed how to control the relative humidity to effectively manage PEG-treated waterlogged woods.

• Journal of the Korean Applied Science and Technology
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• v.29 no.1
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• pp.108-115
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• 2012

Archaeological waterlogged woods found under the sea, in lakes, or in swamp environments are generally weak and fragile. If waterlogged wood materials were taken out of the water and left without modification, they would collapse and lose their original dimensions completely. Conservation is performed to replace the water with chemical agents and to give dimensional stabilization and durability. EDTA and PEG are the most commonly used in the preservation of wood. pH control-precipitation method is used for recovery of EDTA from waste fluid of archeological waterlogged wood conservation treatment. The black substance is eliminated from wood as Fe-EDTA complex are formed and EDTA is separated and precipitated from Fe-EDTA complexes at pH 2.68 or less. The result of analysis of the precipitated products and the commercial EDTA by FT-IR and FE-SEM showed that precipitated product by pH adjusted was not a type of Fe-EDTA complex, but pure EDTA. Waste fluid produced in PEG treatment shows the black color and has an offensive odor by organic matter extracted from wood. Color of waste fluid is decolored with oxidation reaction by peroxy hydrate. In FT-IR and SEM-EDX of PEG after freeze-drying process, no significant change of functional groups induced from oxidation is observed, and any metal ion does not exist in the solid PEG specimen. The molecular weight of PEG is measured using GPC and viscometry. Properties of PEG before and after preservation treatment, and after oxidation with $H_2O_2$ were not changed. Consequently, the peroxidation with $H_2O_2$ is a reasonable and simple method to decolor the used PEG solution.