• Journal of the Mineralogical Society of Korea
• /
• v.30 no.2
• /
• pp.71-81
• /
• 2017

Rock properties and the effects of chemicals that were used for conservation were studied for effective conservation treatment of Seated Buddha rock carving, which is composed of grayish white tuff, at Golguram Hermitage, Gyeongju. The rocks contain 3-5% montmorillonite, a swelling mineral and reacting with water, the d spacing of swelling minerals was increased (1.54-2.69%). On the one hand, the physical properties of the rock samples, such as surface hardness, water absorption rate, and porosity improved after the application of ethyl silicate-based stone strengthener. On the other, the interlayer of swelling minerals decreased and greater the of swelling mineral content, the greater is the extent of swelling (4.23-12.12%). When the ethyl silicate-based stone strengthener was applied after pretreatment with a swelling inhibitor, the physical properties were similar to those of the stone strengthener alone. There was no interlayer spacing change of swelling minerals due to swelling inhibition treatment; however, when the stone strengthener was applied after the swelling inhibitor, interlayer changes were similar to those when only the stone strengthener was treated (4.10-11.85%). Though the peak intensity of swelling minerals in X-ray diffraction pattern decreased, the effect of the swelling inhibitor was almost negligible. Therefore, it is not appropriate to use ethyl silicate-based stone strengthener for Golgulam rock containing swelling minerals and supplementing them with a swelling inhibition system is not effective. Because weathering rapidly progresses when swelling minerals contact moisture, for now, measures to prevent water contact, such as expansion of the canopy, are needed in the lower and side parts of the carving.

• Journal of Conservation Science
• /
• v.24
• /
• pp.13-22
• /
• 2008

The identification of species, hygroscopic property, and ability of ethylene gas absorption of 23 ancient charcoals excavated from wooden coffin burials and roof-tile kilns of Chudong-ri cultural site were investigated. All of the 12 charcoals excavated from wooden coffin burials were broad-leaved trees. Among the total 12 samples, 9 samples were Lepidobalanus and others were Celtis spp.. On the other hand, other 11 charcoals from roof-tile kilns were needle-leaved tree, Pinus spp.(hard pine). The broad-leaved tree charcoals from wooden coffin burials showed a higher moisture absorption capacity than needle-leaved tree charcoals from roof-tile kilns. The ethylene gas absorption was greater in the Lepidobalanus charcoal than that of Celtis spp. and Pinus spp. (hard pine) charcoal. The broad-leaved tree charcoal having high absorption ability of substances was due to a large microporous and specific surface area. Therefore, it was estimated that broad-leaved tree charcoals were filled in order to make favorable condition in tomb. The wood quality of pine is soft and easy to burn because of low specific gravity, as well as high calorific value by resin in wood. We could assume that the pine wood was used as fuel for roof-tile kilns because of easy control of heating and thermal power.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.21 no.2
• /
• pp.109-121
• /
• 2003

Lots of various utilities are buried under the surface. The effective management of underground utilities is becoming the very important subject for the harmonious administration of the city. Ground Penetrating Radar(GPR) survey including other various underground survey methods, is mainly used to detect the position and depth of buried underground utilities. However, GPR is not applicable, under the circumstances of shallow depth and places, where subsurface materials are inhomogeneous and are composed of clay, salt and gravels. The aim of this study is to overcome these limitations of GPR and other underground surveys. High-frequency electromagnetic (HFEM) method is developed for the non-destructive precise deep surveying of underground utilities. The method is applied in the site where current underground surveys are useless to detect the underground big pipes, because of poor geotechlical environment. As a result, HFEM survey was very successful in detecting the buried shallow and deep underground pipes and in obtaining the geotechnical information, although other underground surveys including GPR were not applicable. Therefore this method is a promising new technique in the lots of fields, such as underground surveying and archaeology.

• Journal of the Mineralogical Society of Korea
• /
• v.31 no.3
• /
• pp.149-159
• /
• 2018

The Gyeongju Bunhwangsa Stone Brick Pagoda, which was built with bricks of andesite, is the oldest brick stone pagoda of Silla period. The damage patterns in the stone pagoda are pollutants such as white crust, black crust, discoloration, soil adsorption, and microorganisms, and repair materials. The damage pattern of structural factors in the Stone Brick Pagoda is a bulging phenomenon. According to the X-ray diffraction analysis, white crust are mainly consist of calcite ($CaCO_3$) and thermonatrite ($Na_2CO_3{\cdot}H_2O$) that evaporite finds in nature. Damage pattern varies depending on location of stone pagoda. The pollutants are first story body of pagoda. The microorganisms are confirmed at base, lion statues, first and second story capstone, and repair materials observed at base. The bulging phenomenon appeared on the first story body of the pagoda. Occupancy rates by damage type were higher in the order of microorganisms, pollutants, repair material, bulging phenomenon, and peeling. The highest percentage of individual damage patterns were black microorganisms (39.3%), followed by lichen (17.9%), discoloration (8.0%), white crust (5.5%), cement mortar (5.1%) and peeling (3.1%).

• Journal of Conservation Science
• /
• v.31 no.2
• /
• pp.105-114
• /
• 2015

In this study, an advanced epoxy putty which was as a multi-purpose restoration material being used to restore missing parts in the artifact preservation treatment process was developed. For the purpose of addressing the issues including the workability issue resulting from high strength, the drooping issue resulting from long hardening time during work process and the issue of contaminating the surface of artifact resulting from stained material on tools or gloves, a property comparison was conducted with existing materials to examine the properties of restoration materials in the form of epoxy putty currently being frequently used. For the purpose of addressing the issues of existing materials and allowing the developed epoxy putty to have similar properties, two types of hardeners with different properties were selected to conduct property experiments. As for the hardeners, mercaptan type hardener and aliphatic amine type hardeners in the total of two types were selected for the development. The result showed that the two types were both in the form of paste and their hardening time of 5-10 minutes were about 3-10 times shorter than that of existing materials, thereby improving the work convenience. In terms of abrasion rate to increase workability, it was improved by about 3 times to allow effective and convenient use. As for the issue of contaminating the artifact surface during the process, white micro-balloon was added as filler to address the issue to reduce the oil ingredient to develop multi-purpose restoration material with low shrinkage & high workability in coloring, light weight and cutting force.

• Journal of Conservation Science
• /
• v.32 no.4
• /
• pp.459-469
• /
• 2016

The goal of this study was to examine property changes induced by the choice of filler used with an epoxy resin that was developed in 2014 to restore cultural assets and consider the applicability of the resin as a restorative agent. The properties of putty mixed with 9 types of fillers and as-developed resins were compared with those of existing materials with regard to stability, superiority and applicability. The potential of the putty as an alternative material was also examined. The materials produced the best adhesiveness, color change and hardness results when mixed with lime. Micro balloon produced the best wear rates and hardening times, while diatomite produced the best tensile and compressive strengths. A plaster and white mineral pigment mixture produced the best specific gravity. Every material except for lime exhibited about 2.5-20 times higher wear rates than the existing material, which is thought to exhibit an excellent cutting force. The hardening time was enhanced by about 0.5-9 times to improve convenience. The stability of the relic was also ensured by improving hand staining without any shrinkage or deformation. The material exhibited about 0.5-27 times less yellowing. Thus, it is thought to be a material that can reduce property changes and reduce the degree of relic fatigue which occurs during reprocessing and sense of difference from relic.

• KOMUNHWA
• /
• no.70
• /
• pp.35-62
• /
• 2007

Songguk-ri site gained academic recognition by the excavation of stone coffin tomb with a bronze dagger in 1974. And it is confirmed that this site is epoch-making in Korean bronze age through the following excavation started in 1975. But the excavation reports published until now do not have even overall view of this site, thus it is difficult to get the whole picture of this site. Thus, in this paper the author reexamined all reports on this site and by making the map of overall view and distribution of archaeological features as a basic research. Moreover, I analyzed also artifacts from this site, and compared with the recent papers written by other researchers about the chronology and character. Songguk-ri site has livelihood domain which consists of dwelling pits, attached features, storage pits, pot-firing features, wood fence, abatises, buildings above ground, as well as cemetery which consists of stone-coffins, jar-coffins, pit tombs. Trace of making large terrace was also excavated. These features seem to belong to the same archaeological stage, dated about B.C.850-550, according to C14 dating. On the other hand, the intensification of wet-rice cultivation made this group more productive. Based on this financial strength, some influential group emerged they constructed defensive settlement to protect their products safely. Besides it seems that there were frequent occurrence of conflicts. However, we can know that they kept their stable life, through the expansion of living space. Consequently, Songguk-ri site played a role of the summit among some settlement in this area.

• Journal of the Korean Geographical Society
• /
• v.33 no.3
• /
• pp.447-454
• /
• 1998

As a widespread tephra erupted 24 to 25 KA, Aira-Tn Ash, or AT, provides an invaluable datum for stratigraphic study of late Pleistocene in Northeast Asia. AT can be identified from their tonal characteristic and morphology (the so­called bubble-wail feature), as well as typical refractive index. First reported in 1983, its presence was confirmed from many palaeolithic deposits distributed throughout Korea. It forces us to reconsider the age of prominent Pleistocene deposits. At the famous archaeological site of Chon-gok-ni, presence of AT lends a firm support that sedimentation and deposition of lithic assemblage were in fact a late Upper Pleistocene event, thus, throwing a new question at archaeologists to explain why such archaic-looking tools were continued to be made. Discovery of AT at Chongdongjin is more surprising, since the coastal terrace has been regarded by many as an early Lower Pleistocene eustatic feature. It implies strongly that we need to devise a new scheme for Quaternary stratigraphy. In the absence of reliable datum and marker for Quaternary research, efforts must be given to search for and identify AT and other widespread tephras.

• Journal of the Korean Society of Costume
• /
• v.61 no.10
• /
• pp.72-88
• /
• 2011

This study is about the costume relics that were excavated from M10 of the 6th site, M13 and M14 of the 8th site among all the Runghai(龍海) ancient tomb sites that were known as the royal family's tombs of Balhae, which were built from the late 8th century to the early 9th century. These costume relics were also introduced in the academic journal of Chinese archaeology(考古) 6 in 2009. The summary of the results that focused on finding features of the costume relics and its meaning were as follows: 1. Male and female statues, both of which were excavated from the Runghai ancient tomb sites, had the shape and composition of the government official's costumes such as the Danryeong(團領), Bokdu, and Gwadae. The female's hairstyle and accessories were quite similar to other costume relics of Balhae. In particular, the male statues wearing the Danryeong and Bokdu were considered as the normal figures of government officials of Balhaeafter the mid 8th century. 2. The female statue wearing the male attire is considered as a maid, and we can confirm that women dressing up like a man was a popular trend in Tang(唐), and this trend was introduced to Balhae. 3. The back flap(垂脚) of Bokdu that the male statue is wearing in M10 of the 6th site, has a shape that has not been found in the ancient relics of both Balhae and Tang. Therefore, it is considered as a unique shape of Bokdu of Balhae. However, it needs to be observed more and discussed in the future. 4. In regards to the Gwadae, the outside of the Gwadae is decorated with jade and has an embossed carving that is gold inside. The Gwadae of the Runghaisites has a unique design and it is distinguished from other ancient relics. 5. The gold trefoil crown and the leather conical hat that were found in M14 of the 8th site can be seen as the basic composition of official's hats in ancient Korea. Also, the motif of the gold trefoil is closely related to Anthemion that is often seen in the relics of the Three Kingdom period. Thus, we can assume according to this important finding that the style of ancient Korea official's hats came from either the king or a royal family of Balhae after the mid 8th century.

• Journal of Adhesion and Interface
• /
• v.16 no.4
• /
• pp.137-145
• /
• 2015

This study aimed to develop epoxy putty as a multi-purpose connection and restoration material that can be used for material-specific restoration work such as metal, wood, ceramics, earthenware and stone artifacts by replacing synthetic resins currently being used for preservation treatment of cultural assets. Existing synthetic resins have the issue of cutting force resulting from high strength, deflection resulting from long hardening time, contaminating the surface of artifacts through staining on tools or gloves and need for re-treatment resulting from material discoloration. Accordingly, paste type restoration material most widely being used in the field of cultural assets preservation treatment was selected and examined the property to select it as an object of comparison. Based on such process, epoxy putty was developed according to the kind of agent, hardener and filler. For the purpose of solving the issues of existing material and allowing the epoxy putty developed to have similar property, property experiments were conducted by selecting agents and hardeners with different characteristics and conditions. The study findings showed that both kinds are paste type that improved work convenience and deflection issue as a result of their work time of within 5~10 minutes that are about 3~10 times shorter than that of existing material. In regards to wear rate for increasing cutting force, it improved by about 3 times, thereby allowing easy molding. For the purpose of improving the issue of surface contamination that occurs during work process, talc and micro-ballon were added as filler to reduce the issue of stickiness and staining on hand. Furthermore, a multi-purpose restoration material with low shrinkage, low discoloration and high cutting force was developed with excellent coloring, lightweight and cutting force features.