• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.335-335
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• 2012

높은 효율의 InGaN/GaN 전광소자는 현대 조명 산업에 필수적인 역할을 하고 있다. 전광소자의 효율을 높이는 데에는 여러가지 한계들이 있다. 예를 들면 높은 전류에서의 효율 저하, GaN의 전위결함에 의한 비발광 재결합의 발생 등이 있다. 이러한 한계를 극복하고자 InGaN/GaN 전광소자의 효율을 높이기 위해 사파이어 기판의 표면을 거칠게 바꾸는 방법, 무분극 전광소자, 표면 플라즈몬 등 여러가지 많은 방법들이 개발되고 있다. 본 실험에서는 유기금속화학증착 방법을 이용하여 사파이어 기판위에 Si이 도핑된 n-type GaN를 3.0 um 증착 하였고 그 위에는 9층의 양자 우물 층을 쌓았다. 마지막으로 위층은 Mg 이 도핑된 p-type GaN를 200 nm 증착 하여 소자를 형성하였다. 포토리소그래피 공정과 에칭공정을 통하여 7 um 인 선 패턴을 가진 시료를 완성하였다. 투과 전자 현미경의 측정 결과 맨 위층인 p-GaN의 에칭된 깊이는 175 nm 이였다. 금속박막을 증착하기 위해 열증착 방법으로 금과 은의 박막을 두께를 달리하여 0~40 nm증착 하였다. 금과 은의 두께에 따른 광발광 측정 결과 은(Ag)박막만 40 nm 일 경우 금속박막이 없는 시료보다 광발광 효율이 7배 증가하였고 금 10 nm와 은 30 nm 인 경우에는 3.5배 증가하였다. 또한 패턴의 폭에 따른 광발광 증가를 알아보고 광발광 증가가 일어나기 위한 최적의 패턴조건을 알고자 폭을 5, 10 um 달리하였고, 원자간 힘 현미경과 전자현미경을 이용하여 에칭된 패턴의 폭과 두께를 확인하였다. 본 실험을 통해 금과 은박막에 의한 표면플라즈몬 효과와 광발광 효율증대에 대해 토의할 것이다.

• Resources Recycling
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• v.27 no.6
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• pp.76-83
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• 2018

This article aims to summarize the scrap recycling status of gold, silver, platinum and palladium from foreign countries by courntires and industries in order to utilize the data for securing the raw materials of the domestic urbanmining industry. The amount of gold from scrap has shown a tendency to decrease in countries other than China, which is attributed to the large imports of scrap containing gold in China. The industry demand for gold is the highest in electronic products, but demand is decreasing. The amount of scrap recycling in silver has declined in other regions compared to those in Europe, indicating that the world's overall scrap recycling volume has declined. Production and demand from scrap of platinum and palladium are mostly for catalysts and have been steadily increasing until now. However, it is expected that the amount of waste catalysts in automobiles will decrease with the increase of electric vehicle use.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.3
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• pp.1-13
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• 2010

The aim of this study is to analyze gold-silver mineral potential in the Taebaeksan mineralized district, Korea using a Geographic Information System(GIS) and an artificial neural network(ANN) model. A spatial database considering Au and Ag deposit, geology, fault structure and geochemical data of As, Cu, Mo, Ni, Pb and Zn was constructed for the study area using the GIS. The 46 Au and Ag mineral deposits were randomly divided into a training set to analyze mineral potential using ANN and a test set to verify mineral potential map. In the ANN model, training sets for areas with mineral deposits and without them were selected randomly from the lower 10% areas of the mineral potential index derived from existing mineral deposits using likelihood ratio. To support the reliability of the Au-Ag mineral potential map, some of rock samples were selected in the upper 5% areas of the mineral potential index without known deposits and analyzed for Au, Ag, As, Cu, Pb and Zn. As the result, No. 4 of sample exhibited more enrichments of all elements than the others.

• 프린팅코리아
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• v.8 no.5
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• pp.52-57
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• 2009

금창연 출판문화학회 회장(동원대학 광고편집과 학과장)은 요즘 25시간이 부족하다. 학회장에 학교 학과장, 학보 주간교수 등을 맡고 있기 때문이다. 출판문화학회는 2008년 12월 금 회장의 각고의 노력으로 사단법인으로 등록되었다. 사단법인 출범과 함께 다양한 사업을 추진할 계획이어서 금 회장은 할 일이 더욱 많아졌다. 신학기를 맞아 학생들과의 상담이 줄을 잇고 강의와 학보 발간 때문에 인터뷰가 어렵다는 금 교수를 4월의 금요일 늦은 시간 동원대학 캠퍼스에서 만났다.

• Horticultural Science & Technology
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• v.17 no.2
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• pp.141-143
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• 1999

Genetic relationship of Calanthe discolor, C. sieboldii, and C. bicolor for elucidating the classification was investigated. Electrophoretic zymograms for either peroxidase or esterase isozymes indicated that bands of C. bicolor appear in the zone where those of C. discolor and C. sieboldii are located. Genetic relationship among the three Calanthe species using RAPD analysis showed that C. discolor and C. sieboldii are more distant each other than C. bicolor, demonstrating the genetic position of C. bicolor between the other two. It was assumed that C. bicolor is a natural hybrid between C. discolor and C. sieboldii.

• The Journal of the Petrological Society of Korea
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• v.23 no.1
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• pp.1-15
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• 2014

The Yeongam mineralized zone is located in the southwestern part of the Korean peninsula, including the Sangeun, Eunjeok and Baramjai mines. This zone is located in the northeastern part of the Mokpo-Haenam-Yeongam volcanic circular structure. The 13 sites of quartz vein with mineralization are developed in the Sangeun-Eunjeok-Baramjai area, within rhyolitic welded tuff, showing N-S or NNW trend with highly dipping to the west. The quartz veins occur as a single vein or a bundle of veins with width of 1-5 cm in each. The existence of faults parallel to the quartz veins indicates that the faulting occurred before and after the development of quartz veins and mineralization. The quartz veins and mineralized zone are displaced by NW-trending sinistral strike-slip faults. The extension of the Sangeun-Eunjeok mineralized belt is traced to the south, following a NNW-trending tectonic line, and the Au-Ag contents are analysed in the 12 sites of quartz veins. Contents of gold and silver are 12.3 g/t and 1,380.0 g/t in Eunjeok mine, 2.7 g/t, 23.5g in Sangeun mine, and <0.1 g/t, 5.7 g/t in Baramjai mine respectively. Therefore, a highly Ag-Au mineralized zone is not developed in the southern part of the studied area.

• Economic and Environmental Geology
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• v.55 no.2
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• pp.171-181
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• 2022

The Geochang Au-Ag deposit is located within the Yeongnam Massif. Within the area a number of hydrothermal quartz and calcite veins were formed by narrow open-space filling of parallel and subparallel fractures in the granitic gneiss and/or gneissic granite. Mineral paragenesis can be divided into two stages (stage I, ore-bearing quartz vein; stage II, barren calcite vein) by major tectonic fracturing. Stage I, at which the precipitation of major ore minerals occurred, is further divided into three substages (early, middle and late) with paragenetic time based on minor fractures and discernible mineral assemblages: early, marked by deposition of pyrite with minor pyrrhotite and arsenopyrite; middle, characterized by introduction of electrum and base-metal sulfides with minor sulfosalts; late, marked by hematite with base-metal sulfides. Fluid inclusion data show that stage I ore mineralization was deposited between initial high temperatures (≥380℃ ) and later lower temperatures (≤210℃ ) from H₂O-CO₂-NaCl fluids with salinities between 7.0 to 0.7 equiv. wt. % NaCl of Geochang hydrothermal system. The relationship between salinity and homogenization temperature indicates a complex history of boiling, fluid unmixing (CO₂ effervescence), cooling and dilution via influx of cooler, more dilute meteoric waters over the temperature range ≥380℃ to ≤210℃. Changes in stage I vein mineralogy reflect decreasing temperature and fugacity of sulfur by evolution of the Geochang hydrothermal system with increasing paragenetic time. The Geochang deposit may represents a mesothermal gold-silver deposit.

• (The)Study of the Eastern Classic
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• no.73
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• pp.361-384
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• 2018

This paper aims to introduce Park Seon-su's ShuowenJiezi YIzheng from the perspective of Epigraphy, and incorporate it into the fields of Korean Epigraphy. Korean Epigraphy, which now categorized as a study since Kim Jeong-hee's powerful work in 19th century, can be listed either by studies published before and after Kim Jeong-hee's and by name of influential writers who have successfully presented each study and strive for the development of Korean Epigraphy. Earlier studies show that Korean Epigraphy has more books of data collection rather than the books of research on the epigraph. Regardless of the nationality of the author, all books containing Korean epigraph were counted as Korean Epigraphy, and those books made for religious reasons were not excluded from Korean Epigraphy as well. This indicates how wide the scope of Korean Epigraphy is. In this The reason Park Seon-su's research is ignored at present time, which was assessed as excellent in the late Chosun Dynasty, may come from lack of understanding on the ShuowenJiezi YIzheng. His book, ShuowenJiezi YIzheng, focuses on graphology but more broadly it includes translation of Epigraph and Epigraphy which leads to interpretation of scriptures. Such Park- Seonsu's great work must be presented in Korean Epigraphy studies to broaden its scope, also it is important to look for yet unfound pieces on the fields of Epigraphy.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.355-355
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• 2011

이론적으로 단일벽 탄소나노튜브(SWNT)는 무산란 전도가 가능하여 실리콘을 대체할 차세대 나노소자의 기본소재로서 많은 각광을 받아왔다. 이러한 SWNT의 전기전자적 특성을 좌우하는 주요인자로는 직경과 비틀림도(chirality)가 있으며, 이를 제어하기 위한 많은 방법들이 제시되어왔다. 특히, SWNT 합성 시 필요한 촉매 나노입자의 크기와 튜브직경과의 연관성이 제기된 후부터, 합성단계에서 촉매 나노입자의 형태(또는 크기)를 제어함으로써 SWNT의 직경을 제어하고자 하는 직접적인 방법들도 주요방법의 한 축으로 이어지고 있다. 한편, SWNT의 합성촉매로는 철, 코발트, 니켈 등의 전이금속이 주로 사용되어 왔으나, 최근에는 금, 은, 루테늄, 팔라듐, 백금 등의 귀금속에서부터 다양한 금속산화물 나노입자에 이르기까지 그 범위가 확장되었다. 본 연구에서는, 촉매 나노입자의 크기제어를 통하여 SWNT의 직경을 제어할 목적으로, 전이금속에 비해 상대적으로 융점이 낮아 비교적 낮은 온도의 열처리를 통해서도 입자의 크기를 제어할 수 있는 금 나노입자를 선정하여 SWNT의 합성거동을 살펴보았다. 합성은 메탄을 원료가스로 하는 CVD방법을 이용하였고, 합성되는 SWNT의 다발화(bundling) 등을 방지하기 위하여 수평배향 성장을 도모하였으며, 이를 위하여 퀄츠 웨이퍼를 사용하였다. 우선, 콜로이드상인 금 나노입자의 스핀코팅 조건을 최적화하여 퀄츠 위에 단분산(monodispersion) 된 금 나노입자를 얻었으며, 열처리 온도 및 시간의 제어를 통하여, 1~5 nm 범위 내에서 특정 직경을 갖는 금 나노입자를 얻는 것이 가능하게 되었다. 합성 후 금 나노입자의 크기와 합성된 SWNT 직경과의 관계를 면밀히 조사한 결과, 튜브보다 나노입자의 크기가 약간 큰 것을 확인할 수 있었으며, 금 나노입자의 크기에 따라 SWNT의 합성효율이 크게 좌우되는 것을 확인하였다.

• Journal of the Korean Chemical Society
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• v.54 no.2
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• pp.228-233
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• 2010

Recently, nanoparticles of gold and silver has been applied to various fields due to antimicrobial property. This study added Ag and Au nanoparticles in HEMA (2-hydroxyethylmethacrylate), NVP (N-vinyl pyrrolidone) and MMA (methylmethacrylate) and copolymerized the solution by heating at $70^{\circ}C$ for 40 minutes, $80^{\circ}C$ for 40 minutes, and finally, $100^{\circ}C$ for 40 minutes. Using the polymer produced through the copolymerization process, and measured the physical characteristics which showed water content of 28.43% ~ 35.27%, refractive index of 1.429 ~ 1.440, visible transmittance of 79.2% ~ 86.5% and tensile strength of 0.125 kgf ~ 0.201 kgf. We judged that we made the copolymer with antimicrobial and physical properties which is suitable for conventional contact lens.