• The Journal of the Petrological Society of Korea
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• v.20 no.3
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• pp.141-149
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• 2011

Samples (two granites, marble, sandstone) were heated in an electric furnace at temperature $400^{\circ}C$ and $600^{\circ}C$ in order to investigate the change of physical properties of rocks depending on the heating temperature. Changes of Color and physical properties such as specify gravity, porosity, absorption, p-wave velocity are visible while mineralogical changes by using polarizing microscope are not pronounced. In addition, porosity and absorption increased while specific gravity and p-wave velocity decreased at a more higher temperature ($600^{\circ}C$). Although the open porosity does not indicate total porosity of the rock. but p-wave velocity can be used to evaluate the degree of damage Therefore, porosity and p-wave velocity should be compared in order to investigate the change of physical properties of rocks depending on the heating temperature.

• Korean Journal of Optics and Photonics
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• v.23 no.4
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• pp.159-166
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• 2012

We have developed a daytime measuring rotational Raman LIDAR system for temperature measurement. To decrease the background signal from sunlight, we have designed and installed narrow band (0.5 nm) and high rejection ($10^{-6}$) rate band pass filter system using a grating and an interference filter. We calibrated our system by comparing our horizontal temperature profile and KMA (Korea Meteorological Administration) data. We have found that our temperature profile has a good correlation with KMA data within our theoretically expected variance. And we have used these calibration values in obtaining a vertical temperature distribution. To check our system, we also have compared our vertical temperature data with US standard atmospheric temperature profile. We also have compared our temperature profile with sonde data.

• Journal of Conservation Science
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• v.30 no.2
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• pp.169-179
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• 2014

After occurrence of Cyanobacteria in 1997, Songsan-ri tombs located in Gonju have been investigated to monitor for biological damage. The room temperature of Tomb No.6 was $18.6{\sim}19.8^{\circ}C$ and the relative humidity was 94.3~99.9%. The temperature of Royal Tomb of King Muryeong was $17.3{\sim}18.53^{\circ}C$ and the relative humidity was 73.2~96.45%. The variation of relative humidity increased after setting up air vents. If the outside temperature increases, dew condensation occurs on the floor and the north side. When conditioning equipment operates, the maximum temperature differences between walls is $2.8^{\circ}C$. Bacteria from the air of the tomb and on the surface of the walls outnumbered fungi. 20 species of fungi including Alternaria sp., Aspergillus sp., Penicillium sp., and 19 species of bacteria including Pseudomonas sp., Arthrobacter sp., are identified. Microbes in the tombs may damage cultural heritage. The growth possibility of microbes should be estimated because the microbes in the tombs may damage mural painting. The interrelation between microenvironmental condition and biological damage of mural painting should be researched to come up with an long-term conservation method.

• 보존과학연구
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• s.22
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• pp.53-79
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• 2001

The scientific analysis and provenance study of potteries excavated from kiln site at Gyeongsang Nam-do were carried out using XRD, ICP-AES and NAA. We can summary the following Result :1. As a result of XRD analysis, it showed that soft potteries consisted of quartz, feldspar and clay minerals while hard potteries consisted of high temperature crystals such as mullite, tridymite, cristobalite.In case of firing temperature which are determined by XRD, potteries consisted of quartz, feldspar and clay mineral had very low firing temperature. While potteries having only cristobalite ranged above $1200^{\circ}C$.2. As a result of correlation analysis using trace element, the selected characteristic elements which was able to distinguish from each kiln site was Sm, Cs, Sc, Eu, Hf.3. Discriminant analytical showed that each kiln site were classified into 4-gruops;Kimhaeci Daesungdong, Hamangun Myosari, Changyounggun Yochori and one group mixed KimhaeciGuosandong, Kimhaeci Samgyeri. This suggests that there are no correlations between the raw materials used in each kiln sites except Kimhaeci Guosandong, Kimhaeci Samgyeri.

• 보존과학연구
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• s.21
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• pp.57-75
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• 2000

We performed the scientific analysis through composition analysis, micro-structure investigation, melting point and hardness test to the glass beads excavated at Naesanri in Gosung. Through this investigation, we could examine closely the characterization of raw materials and manufacture technique As a result of micro-structure investigation of glass beads, it appeared that the bubbles in glass beads have remained. Coloring agents of yellow glass bead was remained to the shape of inclusion. And on observing the transparent solid particle, we can know that these do not melt the raw materials because of low melting temperature of a crucible. The result of composition analysis of all glass beads using ICP, these were classified as $Na_2O_2$-$SiO_2$ type of glass. Also, these added to $AI_2O_3$ to improve the durability. The value of Vickers hardness of glass beads appeared the HV 490-530. The HV 1,440 of the transparent solid particle was much more than that of inner glass bead. This means that raw materials do not melt because of a low melting temperature of a crucible. The result of melting temperature analysis of glass beads using DSC/TGA, it was measured about $1,250^{\circ}C$.

• Journal of the Korean Wood Science and Technology
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• v.50 no.2
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• pp.81-92
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• 2022

To analyze the relationship between climatic factors (mean monthly temperature and total precipitation) and tree-ring growths of Pinus densiflora S. et Z. from National Parks (according to region) of the Korea, 20 trees were sampled from 13 National Parks. Only trees that were successfully cross-dated were used for dendrochronological analysis, and at least 11 trees were included. The tree-ring chronology of Mt. Bukhan (covering the shortest period of 1917 - 2016 [100 years]) was assessed, as well as that of Mt. Seorak (covering the longest period of 1687 - 2017 [331 years]). After cross-dating, each ring width series was double-standardized by first fitting a logarithmic curve and then a 50-year cubic spline. The relationships between climate and tree-ring growth were calculated with response function analysis. The results show a significant positive correlation between a given year's February-March temperature, May precipitation levels, and tree-ring growth. It indicates that a higher temperature in early spring and precipitation before cambium activity are important for radial growths of Pinus densiflora in the Korea.

• Journal of Conservation Science
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• v.37 no.5
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• pp.567-578
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• 2021

In this study, the physicochemical properties of 21 wall fragments and rooftile pieces excavated from Jeseoksa Dump-site were analyzed, and the possibility of heat exposure, such as the fire reported in the literature, was investigated by estimating the firing temperature. From the results, it was estimated that the rooftiles were composed of refined materials, and the walls were composed of materials having different particle sizes depending on the layer. Unlike ordinary rooftiles and walls, they exhibited an uneven surface with traces of bloating phenomenon in the cross section. It was estimated from the blackening of some portions that firing was not performed in a controlled state in a constant firing environment. In addition, the estimated firing temperature showed that the non-overfired rooftiles had endured a firing temperature of 900℃ or less, but the over-fired samples were subjected to a temperature of 1,000℃ or higher and were fired at a temperature higher than the manufacturing temperature at that time. Additionally, the rooftiles probably became defective during firing or molding at the time of production, but the non-overfired rooftiles exhibited an intact shape and showed the possibility of heat exposure due to fire. Therefore, the analytical results of this study confirm that the defective architectural components damaged by the fire, as reported in the literature, were discarded in the Jeseoksa dump-site.

• The Korean Journal of Food And Nutrition
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• v.6 no.4
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• pp.287-293
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• 1993

This study was carried out to investigate the influences of cultural conditions of koji on the production of organic acid during rice-koji making by Aspergillus awamori var. kawachii which is now widely used as koji-mold in brewing Takju and Yakju in Korea. The optimum temperature for the germination of the conidia of the mold was 35'8, and the time required for germination at this temperature was 8 hours. Rapid germination occurred when the water content of steamed rice was above 40%, but germination retardation occurred markedly below 35%. The optimum cultural temperature for the production of organic acid was 32$^{\circ}C$, and the production of organic acid was markedly restricted at 36$^{\circ}C$ and 4$0^{\circ}C$. It was effective for the high production of both saccharogenic amylase and organic acid to shift the cultural temperature from initial 36$^{\circ}C$ to 32$^{\circ}C$ after 20~25 hours of cultivation. Initial water content suitable to the production of organic acid was 40% in steamed rice, but its production was markedly restricted below 30% of water content. When the quantity of conidial inoculation was too small, the production of organic acid was low in initial phase, but it was retrived at later period. Acid production was markedly restricted together with the increase in koji thickness.

• Journal of Conservation Science
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• v.31 no.2
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• pp.87-94
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• 2015

Plastic artwork can be appeared crack, change of color and whitening event by various environment conditions. A large scale plastic artwork often exhibits in outside it will be directly degraded by physical and chemical degradation factor such as strong sunlight, high humidity and rainfall. We should know degradation characteristic of plastics to prevent these damages. In this study, we studied degradation characteristic of plastics (5 types of wide use plastics; polypropylene, polystyrene, polyethylene, polyvinyl chloride, polyurethane) depending on various artificial degradation conditions such as high temperature, ultraviolet and these complex conditions (high temperature and ultraviolet). As a result, polypropylene, polystyrene and polyethylene show the most visible change especially polypropylene, polystyrene. Polypropylene didn't show a great change degree of tensile strength and contact angle, on the other hand polystyrene did. Polypropylene and polystyrene weakened by photo degradation, polyvinyl chloride and polyurethane had relatively good light stability. Also the high temperature and complex conditions were most degradation characteristic. High temperature worked for degradation catalyst because its energy can not enough worked for cut off binding energy of plastics while ultraviolet condition effected as directly degradation condition. Though following results, we expect it can be applied to investigation of degradation factor depending on plastic artwork materials and basic result of plastic artworks conservation.

• Korean Journal of Heritage: History & Science
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• v.45 no.3
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• pp.194-211
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• 2012

Pung-nap mudcastle has brought wide attention to archaeologists since scientific studies were carried out on the various types of building sites and excavated potteries related to A period of Baekje Kindom when it sat Hansung as the capital. It is identified that clay from Ra-No.19 site of Pung-Nap mudcastle has different from compositions that of residential soil. From archaeological point of view, it is believed that the the soil was a source material for potteries due to the appropriate viscosity and inclusions. Mineralogical and geochemical studies show that the compositions between the source material and randomly chosen two potteries from the same site are similar. Behavior pattern classification of major, trace and rare elements provides also very similar result. Artificial specimen has been made at different temperature in order to estimate firing temperature of the potteries by means of various kinds of instrumental application. As a result of the study, it is believed that the firing temperature of the red and brown pottery was $550{\sim}600^{\circ}C$ and $900{\sim}1,000^{\circ}C$ respectively.