• Journal of Conservation Science
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• v.31 no.1
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• pp.21-27
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• 2015

The Phoenix-shaped Glass Ewer, which is No. 193 National Treasure, was seriously damaged by a unique form of green glass pieces when excavated among a number of burial accessories of Hwangnamdaechong known to have been formed in the 5th century. While it has long been exhibited at the National Museum of Korea since its treatment for conservation treatment at conservation science laboratory in 1984, the existing adhesive materials seriously deteriorated for the 30 years, and the condition was quite unstable. The epoxy resin used as a restorative materials turned yellowing due to the light and heat so much that it was no longer able to exhibit it in a stable and effective manner. As a result, a re-treatment for conservation was conducted lately. This study focuses on the three pieces of Gold wires used to carefully wrap up the handle of the Phoenix-shaped Glass Ewer broken into three pieces, which has not been studied so far. As for the analysis method for Gold wires, SEM-EDS and Stereo Microscope were used for nondestructive analysis. First of all, the result of the SEM-EDS analysis shows that the composition was Au 91.9 wt.%-Au 92.8 w.t% and Ag 5.9 wt.%-Ag 6.5 wt.%, which indicates that it was an alloy made of Au and Ag. The production technique of Gold wires was also observed by means of optical microscopes. In general, Gold wires were manufactured by a drawing process in which a lump of gold was beaten or pulled out of a hole or by a process of twisting a gold plate. However, Gold wires separated from the handle of the Phoenix-shaped Glass Ewer did not involve any trace of twisting on the surface. Rather, fine vertical stripes were observed with the sections filled up. Hence, it is thought that this Ewer went through a drawing process and then was mended. As a result, no certain relation with the golden mending material used for the Phoenix-shaped Glass Ewer was verified. The findings above indicate that most of the existing researches on Gold wires recognized them, not as separate remains, but merely as a component of other golden remains. Thus, there has been little systematic study on the manufacturing techniques of Gold wires. The future study on Gold wires may verify the correlation between the Gold wires used to fix the handle of the Phoenix-shaped Glass Ewer, which is examined in this study, with that of golden remains in the Silla era.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.6
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• pp.279-290
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• 2016

The performance of upflow anaerobic bioelectrochemical reactor (UABE), equipped with electrodes (anode and cathode) inside the upflow anaerobic reactor, was compared to that of upflow anaerobic sludge blanket (UASB) reactor for the treatment of acidic distillery wastewater. The UASB was stable in pH, alkalinity and VFAs until the organic loading rate (OLR) of 4.0 g COD/L.d, but it became unstable over 4.0 g COD/L.d. As a response to the abrupt doubling in OLR, the perturbation in the state variables for the UABE was smaller, compared to the UASB, and quickly recovered. The UABE stability was better than the UASB at higher OLR of 4.0-8.0 g COD/L.d, and the UABE showed better performance in specific methane production rate (2,076mL $CH_4/L.d$), methane content in biogas (66.8%), and COD removal efficiency (82.3%) at 8.0 g COD/L.d than the UASB. The maximum methane yield in UABE was about 407mL/g $COD_r$ at 4.0 g COD/L.d, which was considerably higher than about $282mL/g\;COD_r$ in UASB. The rate limiting step for the bioelectrochemical reaction in UABE was the oxidation of organic matter on the anode surface, and the electrode reactions were considerably affected by the pH at 8.0 g COD/L.d of high OLR. The maximum energy efficiency of UABE was 99.5%, at 4.0 g COD/L.d of OLR. The UABE can be an advanced high rate anaerobic process for the treatment of acidic distillery wastewater.