• 보존과학연구
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• s.11
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• pp.87-105
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• 1990

Chemical and micro morphological changes of archaeological waterlogged woods from shipwrecked materials in marine situations were investigated which were submerged in seabed for over 900 years. Tested Wood species were Pinusdensiflora, Zelkova serrata, Quercus acutissima and Camellia japonica. The obtained results were summarized as follows; Chemical analysis showed that lignin content was increased, whereas the amout of holocellulose was heavily decreased in the degraded archaeological lwoods(DAW), when compared to the recent woods. The amount of alkalineextractives in the DAW was extremley high. IR spectra showed that disappearance of absortion band at $1,730㎝^-1$ intensity increase at 1,600, 1,500 and $1,270㎝^-1$ and the emergence of single band around $1,050㎝^-1$.Microscopic investigation showed that cell wall of latewood tracheids and fiber in the DAW were severely degraded while, early wood tracheids less degraded. Degradation in the cell wall was mainley occurred in $S_2$layer, while the middle lamella was the least degraded. The micro morphological characteristics of DAW were separation of secondary wall from middle lamella, cavities aligned with micro fibril angle in $S_2$layer and granular appearance of secondary wall by the bacterial attack.

• Journal of Conservation Science
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• v.32 no.2
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• pp.155-165
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• 2016

This study aimed at verifying the effect of hydroxypropyl cellulose(HPC) treatment on polyethylene glycol(PEG)-treated waterlogged wood for surface stabilizing. This research investigated macroscopic and microscopic appearance, color change, weight change, and dimensional change. And effect of HPC was verified through variance analysis (ANOVA) and least significant difference test(LSD). HPC formed thin layer on the surface of wood specimen, and blocked the pore of tracheid and the gap between the crack. Specimens without deterioration showed no invisible change except HPC 1,000,000 treatment group. Whitening was appeared at the sound surface of HPC 1,000,000 treated wood. Specimens with deterioration showed a little color difference change by external moisture adsorption. Thin layer of HPC on the surface of wood specimen was maintained after the deterioration, and this HPC layer significantly suppressed the weight and dimensional change by moisture adsorption.

• Journal of Conservation Science
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• v.6 no.2 s.8
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• pp.126-140
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• 1997

There were some cases in the past that waterlogged wooden finds were neglected and damaged severely because adequate methods of conservation processing could not be found. However, since a wooden ship unearthed in Anapji of Kyongju was processed by poly(ethylene glycol) (PEG) impregnation method in 1975, most of waterlogged wooden finds have been processed by diverse scientific methods. Most commonly-used conservation processing methods of waterlogged wooden finds in Korea are PEG impregnation method, alcohol-ether-resin method and vacuum freeze-drying method. New methods developed recently in Europe and Japan such as sucrose method, sugar-alcohol method and higher alcohol method are also being studied here. The most important task in conservation processing of waterlogged wood is to find good impregnation materials suitable to Korean climate and environments and develop their application methods. For efficient conservation processing, it is important to know the natures of finds and impregnation materials and relation between impregnation and drying condition. To achieve it, many experiments and studies are needed.

• 한국문화재보존과학회:학술대회논문집
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• 2003.03a
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• pp.31-31
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• 2003

• 한국문화재보존과학회:학술대회논문집
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• 2003.09a
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• pp.48-54
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• 2003

• 한국문화재보존과학회:학술대회논문집
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• 2007.05a
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• pp.31-32
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• 2007

• 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 Conservation Science
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• v.16 s.16
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• pp.110-118
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• 2004

In order to evaluate two-step treatment of PEG-freeze drying for highly-degraded waterlogged ash woods (Fraxinus PP.; ca. 5,700 BP), which were excavated from peat lands in western Korea, dimension stability was examined during 45 months after complete treatment. The samples pre-treated with PEG in water solution showed better dimensional stabilities than the ones with PEG in t-butanol(TBA) solution. It suggests that TBA reduced the flexibility of wood cells and overflying by TBA induced micro-checks during freeze drying. Micro-checks results in fragile wood structures and consequently, large shrinkage by moisture absorbances of high PEG contents during exposure in humid condition. The results suggest that PEG in water-solution treatment is better than PEG in t-butanol as pretreament for freeze drying of highly-degraded waterlogged ash woods.

• Journal of Conservation Science
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• v.23
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• pp.67-72
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• 2008

This study was conducted to examineboth the type of wood decay and the degree of degradation for the waterlogged woods (Alnus spp. and Fraxinus spp., about 5,700~5,900 year old), which were excavated at Higokri, Pyungteak in the west-coastal region of Korea. The transmission electron microscope (TEM) observation indicated the degradations by soft rot and bacteria were common in both woods. Erosion bacteria attacked gradually and irregularly from the secondary layer to compound middle lamella and often produced the cavity which was similar to soft-rot cavity but much smaller ones. Tunneling bacteria decomposed mainly $S_2$ layer. Though of highly degraded walls, the cells almost kept the original form with intact lignin-rich middle lamella, which were saturated by water. No marine borer's trace indicated that the sealine rise in the western coast of Korean peninsula during the climate optimum period in the holocene might not be high enough to submerge the Higokri area which locates about 2 km from the present sealine.

• Conservation Science in Museum
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• v.11
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• pp.49-52
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• 2010

A wooden Comb excavated at Shinchang-dong wetland site was treated with cetylalcohol as a reinforcing agent. The conservation process was done by freeze drying the wooden artifact after substituting it with no.3 butyl alcohol and impregnating with 40wt% cetylalcohol solution. Consequently there was no noticeable surface damage. Also it showed 54% of remaining weight and a shrinkage of length 3.3%, width 2.1% and thickness 3.1%. Therefore using cetylalcohol for conservation of waterlogged archeological wood was effective dimensional stability and remaining weight.