• 한국재료학회지
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• 제13권5호
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• pp.285-291
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• 2003

The nanosized silver and gold particles are prepared by ERC method in which metal vapors with high temperature is rapidly quenched by coolants such as liquid nitrogen or liquid argon. In order to monitor the crystal structural changes on the internal and the surface of the nanosized noble metal particles, lattice parameter, internal strain and Debye-Waller factor are investigated, and the calculation of X-ray diffraction scattering intensity is performed. The lattice parameters of silver and gold particles agree with those of bulk materials, and crystal internal strain of the metal particles is not changed by rapid cooling. The Debye-Waller factor of gold particles is increased with decreasing particle size because of the surface softening phenomenon of nanosized particles, but the crystal structural change on the surface of the particles is not detected from the comparison the calculated X-ray diffraction profile with the experimental profile on gold particles with the particle size of 4 nm.

• 대한자원환경지질학회:학술대회논문집
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• 대한자원환경지질학회 2003년도 춘계 학술발표회 논문집
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• pp.178-179
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• 2003

Mesothermal, tellurium-bearing gold-silver vein mineralization of the Yuryang mine was formed in mineralogically complex quartz-sulfide veins that filled the fault fractures in Precambrian gneiss within Gyeonggi Massif. Ore grades average 179 g/ton gold with a gold/silver ratio of 1.5 : 1. Ore mineralization was deposited in single stage. Major ore mineralization can be divided into two mineralization phases with increasing paragenetic time: Fe-sulfide and base-metal mineralization phase $\rightarrow$ telluride mineralization phase. (omitted)

• 한국표면공학회지
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• 제14권4호
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• pp.209-214
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• 1981

Electrolytic recovery of gold and silver from diluted solutions has at first been applied nearly 100 years ago. Compared with other recovery techniques electrolytic treatment offers several advantages. But to achieve high space-time yields special constructions of electrolytic cells for improved mass transfer are necessary. Ex-tended cathode surface areas and vigorous agitation are important features. Gold and silver recovery by use of newly developed electrolytic cell constructions - rotating tubular bed reactor and impact rod reactor - has been described. Calculations based on industrial application during several years are confirming that electrolytic recovery of precious metalss from diluted solutions has been operated in a very economic way.

• 한국광물학회지
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• 제16권3호
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• pp.265-280
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• 2003

인리형 분지인 백악기 음성분지와 단층 접촉하는 무극 광화대는 백악기 흑운모 화강암을 모암으로 하여 배태된 금$.$은광상들로 구성된다. 무극 광화대내 금$.$은광상들은 북측의 무극광산으로부터 남측의 태극광산까지 서로 다른 금$.$은 품위비, 광석광물의 종류 및 산출 빈도 등을 보이며 열수변질대 분포 특성에 있어서도 상이한 공간적 분포특성을 보인다. 비교적 높은 금$.$은 품위비를 보이는 금봉광산은 복성맥의 구조를 보이며 석영맥으로부터 견운모대 \$\longrightarrow$ 아견운모대 \$\longrightarrow$ 프로필리틱대 \$\longrightarrow$ 아프로필리틱대의 열수변질대가 수평적으로 발달하는 특징을 보인다. 광화대 최남단에 위치하는 태극광산은 상대적으로 낮은 금$.$은비를 보이며 망상 세맥을 중심으로 프로필리틱대 \$\longrightarrow$ 아프로필리틱대의 순서로 열수변질대가 발달한다. 열수변질대의 수직적 변화는 대체로 변질대 하부에서 견운모대가 우세하나, 상부에서는 프로필리틱대가 광범위하게 분포하며, 점토대가 불연속적으로 중첩되는 특징을 보인다. 이러한 열수변질대의 상이한 수평$.$수직적 분포 특성은 각 광산의 열수계의 차이를 반영한 것으로, 금봉광산은 비교적 고온$.$고염도와 물-암석 상호반응이 진행된 광화 유체로부터 견운모대가 형성되었으며, 태극광산은 상대적으로 저온 저염도와 물-암석 상호반응이 미약한 광화 유체에 의하여 프로필리틱대가 형성된 것으로 해석된다. 이런 열수계의 차이는 각 광산이 열수계의 열적 중심(무극광산)에 위치하는지 또는 외곽부(태극광산)에 위치하는지에 따라 열수변질대 분포 양상과 금$.$은비 분포 양상의 차이를 유도한다. 따라서 무극 지역 탐사시 열적 중심부에 해당하는 고온의 지온 구배가 형성되는 지역과 물-암석 상호반응에 의한 견운모 변질작용이 우세한 지역을 고품위대 탐사 지침으로 제시할 수 있다.

• 한국의류산업학회지
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• 제12권6호
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• pp.705-714
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• 2010

This study has the purpose of classifying the types of decoration techniques applied to the Korean traditional costume of modern style which are shown in relevant monthly magazines and analyzing the characteristics of the techniques. Findings of the study can be summarized as follows. The types of decoration techniques applied to the Korean traditional costume are classified into single and composite types according to decorative components. In the traditional costume of the former type, a quite many of gold and silver foils and embroideries are found. While, in that of the latter type, a combination of two different decorations, gold and silver foils and embroideries, embroideries and seonchigi or embroideries and stitches is usually used. These decoration techniques are usually applied to some parts of the costume like git, kkeutdong or cuffs, somae or sleeves, jacket or jeogori, the lower hem of the skirt and between joined parts in the skirt. More notably, Korean traditional costumes for women shown in monthly magazines released during the period as mentioned above were investigated to find that a part of the women's clothes, that is, skirt was in most cases decorated with brilliant embroideries. Used together with the techniques, patterns are usually applied onto embroideries and gold or silver foils. Most of the patterns are flower in shape. The main material of the Korean traditional costume is fabrics that have brilliant patterns on the surface and are commercially available irrespective of season. Consequently, since 2010, flower motive patterns which are important in modern fashion trend will be used in embroideries, gold and silver foils. Additionally, embroideries such as seakdong, applique, drawing made with modern style will be the main stream of new HanBok style.

• 자원환경지질
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• 제22권3호
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• pp.237-252
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• 1989

The Inseong gold-silver mine is located 3Km northwest of Suanbo, Choongcheongbugdo, Republic of Korea. The mine occurs in the shear zone formed by tension fractures within the Hwanggangri Formation of the Ogcheon metamorphic belt. Ore minerals found in the gold-silver bearing hydrothermal quartz vein composed mainly of pyrite, arsenopyrite, sphalerite, galena and minor amount of chalcopyrite, pyrrhotite, stannite, bismuthininte, native bismuth, chalcocite, electrum and tellurian canfieldite(?). The gangue minerals are quartz, calcite, chlorite and rhodochrocite. Wallrock alterations such as chloritization, silicitication, pyritization, carbonitization and sericitization can be observed in or around the quartz vein. According to the paragenetic sequence, quartz vein structure and mineral assemnlages, three different stages of ore formation can be recognized. The physico-chemical environment of ore formation in this deposit shows slight variation from stage to stage, but the condition of main ore deposition can be summarized as follows. Fluid inclusion, S-istope geothermometry and geothermometry based on mineral chemistry by use of arsenopyrite and chlorite show the ore was formed at temperature between 399 and $210^{\circ}C$ from fluids with salinities of 3.3-5.8 wt.% equivalent NaCl. It indicates that pressure during the mineralization is less than 0.6 Kb corresponding to a depth not greater than 1Km. S-isotope data suggests that thermal fluid may have magmatic origin wit some degree of mixing with meteoric water. In coclusion, the Inseong gold-silver deposit was formed at shallow depth and relatively high-temperature possibly with steep geothermal gradient under xenothermal condition.

• 자원리싸이클링
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• 제26권1호
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• pp.30-36
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• 2017

양극흙에 함유된 금과 은을 회수하기 위해 무기산(염산, 질산, 황산)과 thiourea 및 thiosulfate에 의한 침출실험을 수행했다. 산화제를 첨가하지 않은 조건에서 금은 무기산용액에 전혀 용해되지 않았다. 3종류의 무기산의 농도가 동일한 조건에서 황산용액에서 은의 침출율이 가장 높았으며, 염산의 농도가 증가함에 따라 $AgCl_2{^-}$의 형성에 따라 은의 침출율이 증가하였다. 한편 주석은 질산용액에 전혀 용해되지 않았으나, 구리, 니켈과 아연은 본 실험조건에서 모두 용해되었다. 황산과 thiourea의 혼합용액에서 금과 은은 모두 용해되었다. Thiosulfate용액에 은의 일부가 용해되었으나, 금은 전혀 용해되지 않았다.

• 헤리티지:역사와 과학
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• 제52권3호
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• pp.160-171
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• 2019

나주 정촌고분 1호 석실 출토 소환두도는 내부 별도 장식이 없는 오각형 환두도이다. 또한 모도와 자도 2자루로 구성된 모자대도이다. 정촌고분 소환두도는 환두부, 병부, 신부, 초미금구로 구성되었다. 소환두도 환두는 철지은장(鐵地銀裝)이지만 은(銀)이 염화은으로 부식되면서 연보라색을 띠며 내부 철제 심의 부식물이 표면에 형성되었다. 염화은은 염화이온이 용해된 매장 환경에서 은이 수분과 반응하여 생성되는데, 가루 형태로 부식되어 유물의 형태 보존을 어렵게 한다. 정촌고분에서 함께 출토된 다른 은제 유물도 유사한 부식 형태를 보여주고 있다. 정촌고분 소환두도의 X선 투과조사 및 CT 분석 결과, 철제 외환에 T자형 슴베를 만들고 신부의 슴베와 연결하였다. 소환두도의 자도를 참고하여 모도의 형태를 유추하면, 모도는 환두, 병두금구, 병연금구를 은판(銀板)으로 감싸고 금제 환과 은제 선으로 병부를 장식하였다. 환두 슴베와 신부 슴베의 연결 방식은 리벳 구멍이 확인되지 않아 단접(鍛接)한 것으로 판단되었다. 초미금구는 철판으로 형태를 만들고 끝단을 견직물로 감싸고 그 아래를 은판과 금제 환으로 장식하였다. 정촌고분 소환두도는 금 은 철제 금속을 다양하게 사용하였으며 백제, 신라, 가야의 여러 가지 요소가 복합적으로 구성되어 주변 유적 및 여러 문화권 영향을 받았음을 확인할 수 있었다.

• 자원환경지질
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• 제25권3호
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• pp.297-316
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• 1992

The Daebong gold-silver deposits is located in 8 km southwest of Cheongyang, Chungcheongnam-Do, Republic of Korea. The gold-silver-bearing hydrothermal quartz veins was formed within the Precambrian metasediments of Gyeonggi massif. Ore minerals occur as mainly of pyrite, sphalerite (0.78~6.19 wt.% Cd), galena, pyrrhotite and minor amounts of chalcopyrite, arsenopyrite, magnetite, ilmenite, chalcocite, electrum (55.00~89.55 wt.% Au) and argentite. The gangue minerals are quartz, calcite, chlorite, K-feldspar, biotite. Wall-rock alterations such as chloritization, silicification, pyritization, carbonatization and sericitization can be observed near the quartz veins. According to the mineral paragenetic sequence based on vein structure and mineral assemblages, three stage mineralizations can be recognized. Fluid inclusion, sulfur isotope and thermodynamic data show that the ore minerals were dominantly deposited at the between 388 and $204^{\circ}C$ from fluids with salinities of 8.1~0.3 wt.% equivalent NaCl, and sulfur isotope value 4.84 to 6.40 per mil of sulfides indicates igneous sources of sulfur in the hydrothermal system and fluid inclusion salinity data suggest that thermal fluids may have magmatic origin with some degree mixing of meteoric water.

• Restorative Dentistry and Endodontics
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• 제10권1호
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• pp.63-70
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• 1984

It was the purpose of this study to determine the galvanic current between a gold alloy inlay and four types of amalgam using the circuit through pulp chambers when the freshly extracted teeth with those restorations were brought into contact in a physiologic saline solution, and to investigate the effectiveness of cavity varnish or ammonated silver-nitrate on the surface of amalgam restoration in reducing galvanic current. The current was measured with current-to-voltage converter and recored on a physiograph 6630-257. The following results were obtained. 1. Generally, galvanic current decreased as the time elapsed. 2. Galvainc current decreased significantly in the first day and after then minimal change was observed until 30th day. 3. Initial galvanic current was 29.6 ${\mu}A$ in the cut amalgam and 24.5 ${\mu}A$ in Dispersalloy amalgam and after then the current was significantly decreased. 4. Initial galvanic current was 12.6 ${\mu}A$ in spherical amalgam (low copper amalgam) and 13.8 ${\mu}A$ in Tytin amalgam and the amount of change was lower in sperical amalgam and Tytin amalgam than that in lathe cut amalgam and Dispersalloy amalgam. 5. Painting ammoniated silver-nitrate or Copalite on the surface of amalgam resotration decreased initial galvanic current and ammoniated silver-nitrate is more effective in decreasing galvanic current than Copalite. 6. Galvanic current by contact between amalgam restoration and gold restoration increased abruptly and dropped rapidly becoming almost.