• Economic and Environmental Geology
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• v.29 no.3
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• pp.395-405
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• 1996

The Donjin deposits which is located in the Chinan Basin, are emplaced along $N10{\sim}40^{\circ}E$ trending fissure sets. So it is a sort of fissure-filling ore deposits. The results of paragenetic studies suggest two stages of hydrothermal mineralization; stage I: base-metal sulfides stage, stage II: late base-metal sulfides, electrum and silver-bearing sulfosalts stage. Au: Ag ratios of the electrums show that Ag atomic% are higher than that of Au. The temperature and salinity of the Donjin deposits estimated from fluid inclusion and sulfur isotope geothermometry are as follows; stage I: $240{\sim}315^{\circ}C$, 2.4~7.1 NaCl eq. wt.%, stage II: $190{\sim}268^{\circ}C$, 4.6~8.4 NaCl eq. wt.%. The estimated oxygen and sulfur fugacity during first stage mineralization, based on phase relation of associated minerals, range from $10^{-35}{\sim}10^{-39.7}$ atm. and$10^{-11}{\sim}10^{-13.4}$ atm., respectively. All these evidences suggest that the Dongjin deposits are polymetallic meso-epithermal ore deposits.

• Journal of The Korea Institute of Healthcare Architecture
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• v.26 no.1
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• pp.29-37
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• 2020

Purpose: The purpose of the research is to find difficulty levels of LEED credits in each LEED level based on credits achievement in order to find important of LEED-HC credits to gain LEED-HC. Methods: The individual credits of LEED-HC v.2009 scorecards from USGBC website are analyzed. With achieved scores rate of LEED credits per each Level, all credits are reassembled in 4 different ranges (A~D); easy (A), easy-moderate (B), moderate-hard (C) and hard (D) to achieve scores. Results: 1) Achieved point rate in LEED-HC specific credits are low. These credits need to be reviewed carefully. 2) In 88 projects, 37 projects are gained Silver level which is more than projects in certification level. In order to encourage to gain LEED-HC level, Average Achieved rate to earn Certificate level needs to be risen. 3) Credits in range D rarely affect to gain platinum level. EAc1 (24 points) are critical to gain Silver and Gold level. However, EAc1 points are not effective to achieve Certificate level. Implications: This research will provide a fundamental back data to set up Korean Green building rating system for Healthcare.

• Bulletin of the Korean Chemical Society
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• v.15 no.12
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• pp.1042-1045
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• 1994

A thin film of silver ferricyanide (Ag$_3$Fe(CN)$_6$) on a platinum or gold substrates can be reduced electrochemically to the salt of silver ferrocyanide in potassium nitrate solution. The color of these films are orange and these films are shown to be electrochromic. The voltammogram is shown the asymmetry of the oxidation compared to the reduction wave under various supporting electrolytes. The standard heterogeneous electron-transfer rate for these films and bare Pt electrode were 0.49 ${\times}$ l0$^{-2}$ and 1.30 ${\times}$ l0$^{-2}$ cm/s, respectively, obtained using a rotating disc electrode. Rough D$_0$ values, evaluated from the Levich equation, for Fe(CN)$_6^{3-/4-}$ at both SF thin film and a bare Pt disc electrode were shown as 1.2l ${\times}$ l0-6 and 0.94 ${\times}$ l0$^{-6}$ cm$^2$/s, respectively. The conductivities, as determined from the slops of the i-V curves for a ca. 1 mm sample for dried SF potassium rich and deficient bulk samples pressed between graphite electrodes, were 9.34 ${\times}$ l0$^{-9}$ and 5.80 ${\times}$ l0$^{-9}$ (${\Omega}$${\cdot}$cm)$^{-1}$, respectively.

• 보존과학연구
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• s.24
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• pp.215-227
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• 2003

The gilt-bronze Sarira Reliquary was discovered when repairing three-stories east stone pagoda (Treasure No. 395) at Seungju-eup in Suncheon city in Jeollanam-do Province in August, 1986. Then it was appointed as Treasure in 1988. The Sarira Reliquary had been held in Seonamsa temple, but deterioration on the surface and corrosion had appeared affecting its surface detail. Consequently, the conservation treatment was carried out from November 2002 to March 2003.The corrosion and dirt on the surface of the Sarira Reliquary were cleaned with ethyl alcohol and Benzotriazole was applied to prevent further corrosion. Finally, NAD-10(Paraloid NAD-10), acrylic resin, was used to consolidate the structure. Moreover, after non-destructive analysis to confirm element of alloy, copper, gold, silver and mercury were discovered and this result tells us that it was plated with gold by amalgam. Fibers at the pedestal were examined under the microscope and identified as silk. The total height of this Sarira Reliquary is 6.0cm, the height of lotus pedestal and the roof is 2.7cm and 1.8cm, respectively. The roof and body are joined together, and the lotus pedestal can be separated, on which the octagonal reliquary is impaled. The pedestal consists of 3layers of petals and the surface is decorated with flower pattern. The reliquary is presumed to be created in the 14th century, and it becomes valuable historical material to reveal the secret of metal work in the late Goryeo Dynasty.

• Advances in materials Research
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• v.1 no.1
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• pp.1-12
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• 2012

There have been many efforts on the generating metal nanocrystals enclosed by high-index facets for the use as highly active catalysts. This paper describes a facile synthesis of Au trisoctahedra with high-index facets. In brief, the Au trisoctahdra were prepared by reduction of $HAuCl_4$ in N,N-dimethylformamide (DMF) containing poly (vinyl pyrrolidone) (PVP) and trace amount of $AgNO_3$. The Ag ions in the reaction solution played a critical role in controlling the trisoctahedral shape of the final product by underpotential deposition (UPD) on the Au surfaces. The as-prepared Au trisoctahedra were single crystal and enclosed by high-index {441}, {773} and {331} facets.

• Conservation Science in Museum
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• v.21
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• pp.53-66
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• 2019

This study describes the processes undertaken for the conservation treatment of metal artifacts excavated in Hasong-ri, Yeongwol, Gangwon-do and the results of the related surface composition analysis. X-ray fluorescence analysis (XRF) was applied to analyze the surface composition of a small gilt-bronze wind chime, two clappers, and a small gourd-shaped bronze bottle. The gourd-shaped bronze bottle was investigated using radiography to examine its internal structure. The wind chime and clappers were excavated from the same location. A gilt layer was identified on the wind chime, but surface corrosion made it difficult to identify any such layers on the clappers. The element analysis revealed that the wind chime was made of bronze in a Cu-Sn-Pb ternary system and was gilt-plated using mercury amalgam. The clappers were made from copper with a small amount of gold detected, but did not show any evidence of mercury. Since a thick corrosion layer was affixed to the surface of each clapper, it was impossible to identify the surface composition and determine if the clappers had been gilded. It is possible that the gold detected from the clappers was a foreign substance or had detached from the giltbronze wind chime buried alongside them. The small gourd-shaped bronze bottle was investigated through surface element analysis and radiography to verify if it was a type of silver bottle used as currency during the Goryeo dynasty. The radiography photography identified that a small hole in the middle of the base had been stopped up. The general surface analysis did not detect silver, which suggests that the bottle was made of bronze instead and was not one of the silver bottles used as a means of currency.

• Economic and Environmental Geology
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• v.32 no.5
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• pp.445-454
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• 1999

The Sanjeon Au-Ag deposit consists of three subparallel hydrothermal quartz-calcite veins which filled fault-related fractures (generally $N20^{\circ}$ to 35"W-trending and $70^{\circ}$ to $80^{\circ}$ SW-dipping) within quartz porphyry. The vein mineralization shows an apparent variation of mineral assemblages with paragenetic time: (1) early, white quartz + pyrite + arsenopyrite + brown sphalerite, (2) middle, white (vein) to clear quartz (vug) + base-metal sulfides + electrum + argentite, (3) late, calcite + pyrite + native silver. Mineralogic and fluid inclusion data indicate that gold-silver minerals were deposited at temperatures from 2l $0^{\circ}$ to $250^{\circ}$ with salinities of 4 to 5 wt. % equiv. NaCl and log fS2 values from -14.0 to -12.2 atm. The linear relationship between homogenization temperature and salinity data indicates that gold-silver deposition was a result of meteoric water mixing. Ore mineralization occurred at pressure conditions of about 70 bars, which corresponds to the mineralization depths of about 260 m to 700 m. There is a remarkable decrease of the calculated 1)180 values of water from 1.3 to -9.7%0 in hydrothermal fluid with increasing paragenetic time. This indicates a progressive increase of meteoric water influx in the hydrothermal system at the Sanjeon deposit. Oxygen-hydrogen, sulfur, and carbon isotope values of hydrothermal fluids indicate that the ore mineralization was formed largely from meteoric waters with the contribution of sulfur and carbon from a deep igneous source.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.213-219
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• 2006

The Yongjang mine is located in Masan City, Gyeongsangnamdo, which consists of a black shale possessing quartzite veins with othercompositions such as gold, silver, and sublimated sulfur. The average width of the veins is $9{\sim}17cm$ and the average degrees of the gold and silver are 3.6 g/t and 113.6 g/t respectively. A regional and a detailed scale electrical resistivity surveys are conducted to determine the existence of the mineralization zones and the linear structures in the study area. In addition, surveys of a several different array methods are conducted such as dipole-dipole array in the surface and borehole-to-surface array, surface-to-borehole array, and dipole-dipole array in the borehole. The method of element division can be applied to the region in which the borehole is curved, inclined or the distance between the electrodes is shorter than that of nodal points, because the coordinate of each electrode cannot be assigned directly to the nodal point if several electrodes are in an element. Yongjang vein is extended longer under the subsurface than on the surface in the images reconstructed from the 3D inversion. Therefore, it is recognized that the 3-D interpretation of the electrical resistivity survey is a very useful method to figure out the existence of strike and extension direction because the mineralization zones and the linear structures are shown in each depth.

• Economic and Environmental Geology
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• v.39 no.5 s.180
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• pp.567-581
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• 2006

The Au-Ag lode deposits in South Korea are closely associated with the Mesozoic granitoids. Namely, the Jurassic deposits formed in mesozonal environments related to deep-seated granitoids, whereas the Cretaceous ones were developed in porphyry-related environments related to subvolcanic granitoids. The time-space relationships of the Au-Ag lode deposits in South Korea are closely related to the changing plate motions during the Mesozoic. Most of the Jurassic auriferous deposits (about $165{\sim}145$ Ma) show fluid characteristics typical of an orogenic-type gold deposits, and were probably generated in a compressional to transpressional regime caused by an orthogonal to oblique convergence of the Izanagi Plate into the East Asian continental margin. On the other hand, strike-slip faults and caldera-related fractures together with subvolcanic activity are associated with major strike-slip faults reactivated by a northward (oblique) to northwestward (orthogonal) convergence, and probably have played an important role in the formation of the Cretaceous Au-Ag lode deposits (about $110{\sim}45$ Ma) under a continental arc setting. The temporal and spatial distinctions between the two typical Mesozoic deposit styles in South Korea probably reflect a different thermal episodes (i.e., late orogenic and post-orogenic) and ore-forming fluids related to different depths of emplacement of magma due to regional changes in tectonic environment.

• Economic and Environmental Geology
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• v.21 no.2
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• pp.149-164
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• 1988

Electrum-sulfide mineralization of the Samgwang and Sobo mines of the Cheongyang Au-Ag area was deposited in two stages of quartz and calcite veins that fill fault zones in granite gneiss. Radiometric dating indicates that mineralization is Early Cretaceous age (127 Ma). Fluid inclusion and sulfur isotope data show that ore mineralization was deposited at temperatures between $340^{\circ}$ and $180^{\circ}C$ from fluids with salinities of 1 to 8 wt. % equiv. NaCl and a ${\delta}^{34}S_{{\sum}S}$ value of 2 to 5 per mil. Evidence of fluid boiling (and $CO_2$ effervescence) indicates a range of pressures from < 200 to $\approx$ 700 bars, corresponding to depths of ${\approx}1.5{\pm}0.3\;km$ in a hydrothermal system which alternated from lithostatic toward hydrostatic conditions. Au-Ag deposition was likely a result of boiling coupled with cooling. Meaured and calculated hydrogen and oxygen isotope values of ore-forming fluids indicate a significant meteoric water component, approaching unexchanged paleometeoric water values. Comparison of these values with those of other Korean Au-Ag deposits reveals a relationship among depth, Au/Ag ratio and degree of water-rock interaction. All investigated Korean Jurassic and Cretaceous gold-silver-bearing deposits have fluids which are dominantly evolved meteoric waters, but only deeper systems (${\geq}1.5\;km$) are exclusively gold-rich.