• Journal of Conservation Science
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• v.27 no.4
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• pp.357-369
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• 2011

The Bongamsa Jeongjindaesa Wonotap Pagoda (Treasure No. 171) constructed in the 10th century composed mainly of leucocratic granite with feldspar phenocryst. The major rock-forming minerals are quartz, orthoclase, plagioclase and some biotite. This pogoda is highly damaged physical weathering which are break-out, flakes, exfoliation and cracks. As a result of the infrared thermography on the surface of the pagoda, internal exfoliations occurred to cracks. Also, P-XRF analysis showed that Fe, S, Ca and Mn of concentration were so high in the discoloration parts. The coated part of red pigment has a high five times in Fe content than the fresh rock surface. This result suggests that material of red pigment is hematite. Ultrasonic velocity of the stone properties were from 831 to 2,457 m/s, but it measured velocity of less than 1,000m/s in part of damaged area. Therefore, we suggest for safety conservation for weathered parts of the pagoda, that is in want of rejoin and consolidation treatment about serious damage parts.

• Journal of Conservation Science
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• v.37 no.5
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• pp.579-589
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• 2021

Five waterlogged wood artefacts were excavated from Suyeong-ri site in Hwaseong, South Korea. The aim of the present study was to identify the species and estimate the date of manufacture and the manufacturing method of these artefacts. The study also aimed to conserve the original shapes of waterlogged wood artefacts by using the vacuum freeze drying method. The two large waterlogged woods were identified as Ulmus spp. and Morus spp., whereas one of the three small waterlogged woods was identified as Abies spp. and the other two as hard pine. Radiocarbon dating using wiggle match dated the manufacturing of these wooden artefacts between BCE 8520-8490 or BCE 8470-8290 in the Neolithic age, and a similar period was also confirmed for seed excavated from a place close to the location where the waterlogged wood artefacts were excavated. The surface of waterlogged wood artefacts had several traces of manufacturing processes - traces of tearing and chopping - were observed. Based on these observations, it was confirmed that stone adz was used to make these wooden artefacts. Thereafter, the waterlogged wood samples were conserved by immersing them into PEG#4,000 of concentration in water from 10% to 40% at room temperature(15~25℃) and subjecting them to vacuum freeze drying. However, the internal moisture was not completely removed in some thick parts of waterlogged woods by applying the general schedule such as raising the shelf temperature as the surface temperature rises. Therefore, additional study is required using the schedule-method for vacuum freeze drying of large waterlogged wood.

• Conservation Science in Museum
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• v.15
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• pp.122-137
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• 2014

The National Museum of Korea own a historical document box ^K976 that was once used to store Joseon Wangjo Sillok ^{Annals of the Joseon Dynasty} of the Joseon Dynasty. The rectangular box has a lid, and the entire surface is varnished with black lacquer. The wood of the box had become warped and the upper part of the wooden frame had been damaged. In some areas, the paint was flaking off, exposing the underlying wood, and an iron ring that connected the lid to the body of the box was missing. Thus, in 2013, Conservation Science Department in National Museum of Korea began to repair and restore the Joseon document box. Before the treatment, analyses were conducted to examine the box's structure, damaged parts, species of wood, and lacquering techniques. The wood was found to be that of a linden tree. As for the lacquering technique, the surface of the box was first coated with a layer of lacquer and bone ash, and then covered with Korean traditional paper. Next, the box was painted with a layer of mud and ashes, followed by a layer of black pigment mixed with soot, and then varnished again with lacquer.

• The Journal of the Petrological Society of Korea
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• v.23 no.3
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• pp.239-247
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• 2014

The (U-Th)/He dating utilizes the production of alpha particles ($^4He$ atoms) during natural radioactive decays of $^{238}U$, $^{235}U$ and $^{232}Th$. (U-Th)/He age can be determined from the abundances of the parent nuclides $^{238}U$, $^{235}U$ and $^{232}Th$ and the radiogenic $^4He$. Because helium is one of the noble gases (non-reactive) with a relatively small radius, it diffuses rapidly in many geological materials, even at low temperatures. Therefore, ingrowth of $^4He$ during radioactive decay competes with diffusive loss at elevated temperatures during the geologic time scale, determining the amount of $^4He$ existing today in natural samples. For example, He diffusion in apatite is known to be very rapid compared to that in most other minerals, causing a significant diffusive loss at ${\sim}80^{\circ}C$ or higher. At ${\sim}40^{\circ}C$, He diffusion in apatite becomes slow enough to preserve most $^4He$ in the sample. Thus, an apatite's (U-Th)/He age represents the timing when the sample passed through the temperature range of $80-40^{\circ}C$. The crustal depth corresponding to this temperature range is called a "partial retention zone." Normal closure temperatures for a typical grain size and cooling rate are ${\sim}60-70^{\circ}C$ for apatite and ${\sim}200^{\circ}C$ for zircon and titanite. Because the apatite He closure temperature is lower than that of most other thermochronometers, it can provide critical constraints on relatively recent or shallow-crustal exhumation histories.

• Journal of Conservation Science
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• v.32 no.3
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• pp.345-352
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• 2016

The purpose of this study is to analyze on the textile used for book covers of "Gukgiboksiksoseon" and "Boepboksajeolboksaek", and slipcase of these books kept in the Oryundae Korean Martyrs Museum in Busan. These records are estimated to be written by Gyeongbin Kim(1831-1907), who was a royal concubine of 24th King Heonjong (reign 1834~1849) of the Joseon Dynasty. The cover textile of slipcase and two books are investigated to be silks by the FT-IR. The cover textile of slipcase is flower patterned satin with silver thread and the cover textile of two books are green and red with Su characters and bat patterned satin. The blackish part of pattern of slipcase is investigated by silver thread by FE-SEM-EDAX. Moreover, by the dye analysis, berberine, brazilin, and carthamin are detected from the cover textile of "Boepboksajeolboksaek". It is indicated that it was dyed with an amur cork-tree, a sappanwood, and a safflower. And rutin which is the main dyestuff of the sophora flower of the pagoda tree was detected from the yellow thread of the cover textile of slipcase.

• Journal of Conservation Science
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• v.28 no.1
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• pp.87-94
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• 2012

This study was focused on digital restoration and surface depth modeling applying the three-dimensional laser scanning system of the Haeundae Stone Inscription. Firstly, the three-dimensional digital restoration carried out acquiring of point cloud using wide range and precision scanner, thereafter registering, merging, filtering, polygon mesh and surveyed map drawing. In particular, stroke of letters, inscribed depth and definition appearing the precision scanning polygon was outstanding compared with ones of the wide range polygon. The surface depth modeling completed through separation from polygon, establishment of datum axis, selection of datum point, contour mapping and polygon merging. Also, relative inscribed depth (5~17mm) and outline by the depth modeling was well-defined compared with photograph and polygon image of the inscription stone. The digital restoration technology merging wide range and precision scanning restored the total and detailed shape of the Stone Inscription quickly and accurately. In addition, the surface depth modeling visibly showed unclear parts from naked eye and photograph. In the future, various deteriorations and surrounding environment change of the Stone Inscription will be numerically analyze by periodic monitoring.

• Journal of the Korean Geophysical Society
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• v.4 no.1
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• pp.1-10
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• 2001

A number of tangible cultural properties have been left to suffering damage without any scientific conservation or maintenance. We conducted nondestructive geophysical explorations around the Western pagoda of the Iksan Mireuksa Temple for the purpose of preparing the counterplan of its conservation and maintenance and of utilizing the geophysical information for the design of repair. Geophysical image of the shallow subsurface around the construct resulting from electric resistivity, seismic refraction, and GPR methods carried out along 6 lines in the site was used to investigate the relationship between the foundation characteristics and the structural safety. Tilting of the pagoda southwest towards seems to result from the low resistivity zones found in the southwestern part. The GPR and seismic surveys revealed a boundary at depth of 3.3～3.5m dividing into two layers, compacted overlaid soil and the original ground. The boundary appears to dip southwest. The artificial layer as a foundation does not covers as much as the bottom area of the pagoda. This top soil dipping southwest seems to result in tilting of foundation southwestward towards. Our geophysical result suggests ground reinforcement in the western part of the survey area for the conservation of the construct.

• Journal of Conservation Science
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• v.19
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• pp.5-18
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• 2006

The Mireuksaji stone pagoda of the Iksan was built in Muwang King of Baekjae Kingdom and has maintained its present status through several rebuilding process. Recently, the structural unbalance of the pagoda has worsened, so for scientific maintenance recovery of its original pagoda form, the pagoda is under dismantling process. The original form of this pagoda is being presumed to be a plane square pagoda of nine stories, though only a portion of six stories remains until today. The destroyed part from collapse was liked in insecure pagoda form by Japanese in year of 1915. On the surface of the stone which has gone through the present time, efflorescence appeared as precipitation substance over crusted and due to this phenomenon, the structure and color of thee original stone haven't been preserved. Therefore, quantitative analysis on its kind, emitted status and contamination type of secondary inorganic contamination substance of the over crusted surface were analyzed. Also through reaction experiments, contamination type was defined and tests have been applied to find the requirements that will wash out the contaminants. The result of this study will provide the base of quantitative analysis on the kind of inorganic contamination of the surface of stone assets, and it shall also contribute to the application of scientific maintenance recovery of surface cleaner for efflorescence.

• The Journal of the Petrological Society of Korea
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• v.4 no.2
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• pp.153-167
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• 1995

Emplacement ages for the granite plutons of the Jurassic and the Cretaceous times in the central Ogcheom Fold Belt were determined by Rb-Sr whole rock and mineral isocheon methods. In addition mineral ages for the plutons were determined by K-Ar and fission track methods. In turn, thermal histories and uplifting rates of the granitic bodies are elucidated from the isotopic ages. The Jecheon(~203 Ma) and Mungyeong(at lest~200 Ma) granites of the Jurassic and the Muamsa, Wolagsan and Daeyasan granites(~110 Ma) of the Cretaceous show high strontium initial ratios [$(^{87}Sr/^{86}Sr)_1$0.7100],suggesting that the granitic magmas have been generated by partial melting of crustal materials (S-type), or by mixing of mantle and crustal materials. Only mineral ages of the Sogrisan and Hyeongjebong granites (~90 Ma) were determined by K-Ar method, and petrogenesis of them were not defined yet. The two Jurassic granite plutons were cooled rapidly down to $300^{\circ}C$, right after the plutons were slowly cooled down since then, due to their deep emplacment. During the Middle Cretaceous period, the Jurassic Mungyeong granitic pluton was intruded and thermally affected much by the surrounding Wolagsan and Daeyasan granites. Accordingly the Rb-Sr mineral age, K-Ar hornblende and biotite ages of the Mungyeong granite appear to be reduced or reset due to the thermal effects above their blocking temperatures. All the cretaceous granites have been cooled much ore simply and rapidly down than the Jurassic ones below $300^{\circ}C$, owing to their shallow emplacement.

• Journal of Gastric Cancer
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• v.9 no.2
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• pp.39-45
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• 2009

Endoscopic resection has been established as one of the treatment options for selected cases of early gastric cancer in Korea. Yet the indications, best treatment methods, management of complications and follow-up methods after the procedure are still uncertain. Some large-scale multicenter studies have recently been reported in Korea. In this review, I will provide an overview of the recent published articles and future directions for endoscopic resection of early gastric cancer.