• 자원환경지질
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• 제31권2호
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• pp.111-125
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• 1998

Dispersion, migration and enrichment of environmental toxic elements from the Samkwang Au-Ag mine area were investigated based upon major, minor and rare earth element geochemistry. The Samkwang mine area composed mainly of Precambrian granitic gneiss. The mine had been mined for gold and silver, but closed in 1996. According to the X-ray powder diffraction, mineral composition of stream sediments and soils were partly variable mineralogy, which are composed of quartz, orthoclase, plagioclase, amphibole, muscovite, biotite and chlorite, respectively. Major element variations of the host granitic gneiss, stream sediments and soils of mining and non-mining drainage, indicate that those compositions are decrese $Al_2O_3$, $Fe_2O_3$, MgO, $TiO_2$, $P_2O_5$ and LOI with increasing $SiO_2$ respectively. Average compositional ranges (ppm) of minor and/or environmental toxic elements within those samples are revealed as As=<2-4500, Cd=<1-24, Cu=6-117, Sb=1-29, Pb=17-1377 and Zn=32-938, which are extremely high concentrations of sediments from the mining drainage (As=2006, Cd=l1, Cu=71, Pb=587 and Zn=481 ppm, respectively) than concentrations of the other samples and host granitic gneiss. Major elements (average enrichment index=6.53) in all samples are mostly enriched, excepting $SiO_2$, $Na_2O$ and $K_2O$, normalized by composition of host granitic gneiss. Rare earth element (average enrichment index=2.34) are enriched with the sediments from the mining drainage. Minor and/or environmental toxic elements within all samples on the basis of host rock were strongly enriched of all elements (especially As, Br, Cu, Pb and Zn), excepting Ba, Cr, Rb and Sr. Average enrichment index of trace elements in all samples is 15.55 (sediments of mining drainage=37.33). Potentially toxic elements (As, Cd, Cr, Cu, Ni, Pb, and Zn) of the samples revealed that average enrichment index is 46.10 (sediments of mining drainage=80.20, sediments of nonmining drainage=5.35, sediments of confluent drainage=20.22, subsurface soils of mining drainage=7.97 and subsurface soils of non-mining drainage=4.15). Sediments and soils of highly concentrated toxic elements are contained some pyrite, arsenopyrite, sphalerite, galena and goethite.

• 자원리싸이클링
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• 제26권3호
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• pp.79-91
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• 2017

수소연료전지자동차(FCV)의 핵심은 고분자고체형연료전지(Polymer Solid Fuell Cell: PEFC)이고 전지 중에서 전기화학적 전기를 발생하는 핵심 소재는 백금촉매이다. 백금은 남아프리카와 러시아 등에 편재되어있고, 백금의 세계생산량은 연간 약 178톤이고 고가이므로 리싸이클링 한다. 현재 PEFC에 Pt를 사용하는 양은 $0.2{\sim}0.1mg/cm^2$인데, 전지의 가격을 줄여서 FCV보급을 확대하기 위하여 사용하는 Pt양을 $0.05{\sim}0.03mg/cm^2$까지 감소시키는 것을 목표로 하여 각국이 연구 개발하고 있다. 나노배금 제조기술은 건식법과 습식법으로 크게 나누며 습식환원법을 중심으로 제조하는 방식이 Pt를 제조하는데 유리하다. 나노Pt를 이용하여 폴리올법, 개량형 Cu-UPD/Pt 치환법 및 나노캡슐법 등에 의해 $Pt-Pd/Al_2O_3$, Pt/C, Pt/GCB, Pt/Au/C, PtCo/C, PtPd/C 등의 Pt촉매가 연구 개발되고 있으며, Pt촉매의 활성향상 및 안정화 기술 등이 보고되고 있다. 본고는 나노Pt와 나노Pt촉매의 제조기술 및 폐 촉매의 리사이클링 및 Pt촉매의 응용기술 경향을 조사 분석하였다.

• 한국지구과학회:학술대회논문집
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• 한국지구과학회 2005년도 추계학술발표회 논문집
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• pp.136-141
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• 2005

The K Ar ages, whole rock geochemistry and Sr Nd Pb isotopes have been determined for the submarine basalts dredged from the P2 and P3 segments of the Antarctic-Phoenix Ridge (APR), Drake Passage, Antarctica, for better understanding on temporal variation of magma chemistry in association with extinction of seafloor spreading. The fossilized APR is distant from the known hot spots, and consists of older N-MORB prior to extinction of spreading and younger E-MORB after extinction. The older N-MORB (3.5-6.4 Ma) occur in the southeast flank of the P3 segment (PR3) and the younger E-MORB (1.4-3.1 Ma) comprise a huge seamount at the P3 segment (SPR) and a big volcanic edifice at the P2 segment (PR2). The N-type PR3 basalts have higher Mg#, K/Ba, and CaO/Al2O3 and lower Zr/Y, Sr, and Na8.0 with slight enrichment in incompatible elements and almost flat REE patterns. The E-type SPR and PR2 basalts are highly enriched in incompatible elements and LREE. The extinction of spreading occurring at 3.3 Ma seems to have led to a temporal magma oversupply with E-MORB signatures. Geochemical signatures such as Ba/TiO2, Ba/La, and Sm/La suggest heterogeneity of upper mantle and formation of E-MORB by higher contribution of enriched materials to mantle melting, compared to N-MORB environment. E-MORB magmas beneath the APR seem to have been produced by low melting degree (up to 1% or more) at deeper low-temperature regime, where metasomatized veins consisting of pyroxenites have preferentially participated in the melting. The occurrence of E-MORB at the APR is a good example to better understand what kinds of magmatism would occur in association with extinction of spreading.

• 자원환경지질
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• 제28권1호
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• pp.53-67
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• 1995

Geochemical characteristics of iron-related Ulsan granite was studied in comparison with the Cretaceous granitoids from the metallogenic provinces of copper, lead-zinc and lead-zinc/molybdenum in the Gyeongsang Basin, and the variation of cheminal compositions at the Ulsan granite/serpentinite contact was investigated. Ulsan granite is plotted in the regions of granite and granodiorite of Streckeisen's diagram. It shows differentiation trend of calc-alkali magma, and the magmatic evolution from granodiorite to granite is consistant with the general crystallization path of the Cretaceous the granitoids in Gyeongsang Basin. Differentiation index(D.I.) of Ulsan granite is 86~95, which is higher than those of Jindong granites (D.I.=45~70) and Onjongri granites (D.I.=67~84), and there are differences in the content of some major and trace elements between Ulsan granite and other Cretaceous granitoids. At the Ulsan granite/serpentinite contact $SiO_2$, $K_2O$, $Na_2O$, $Al_2O_3$, Rb, Sr, Ba which are abundant in Ulsan granite decrease toward serpentinite, while T.Fe, MgO, Ni, Cr which are abundant in serpentinite decrease toward Ulsan granite. Therefore, the geochemical characteristics of Ulsan granite is applicable to distinguish iron province from different metallogenic provinces where other Cretaceous granitoids occur in the Gyeongsang Basin, and it is possible to find serpentinite which was intruded by granite on the basis of chemical variations.

• 한국재료학회지
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• 제28권4호
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• pp.201-207
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• 2018

Infrared(IR) heating has many advantages, such as energy efficiency, reduced heating time, cleanliness, equipment compactness, high drying rate and easy automation. These features of IR heating provide widely industrial applications, such as surface heat treatment in semiconductor fabrication, thermoforming of polymers, drying and disinfection of food products, heating to metal forging, and drying of wet materials. In this study, the characteristics of a protected gold mirror were examined by spectrophotometer and the lifetime of the coating layers were evaluated by a cross-cutting method and salt spray test. The effects of manufacturing conditions on the protected gold mirror were seen and remedies for these effects were noted in order to improve the properties of the protected gold mirror in the drying process. The reflectance and lifetime of the protected gold mirror was influenced by manufacturing conditions, such as surface roughness and forming conditions of the anti-oxide layer, the adhesion layer, the reflecting layer and the protection layer. The results of this study showed that the protected gold mirror manufactured using a buffing method for pre-treatment resulted in the most effective reflectance. In addition, $Al_2O_3$ coating on an Al substrate as an anti-oxide layer was more effective than the anodizing process in the test of reflectance. Furthermore, the protected gold mirror manufactured by layers forming of various materials resulted in the most effective reflectance and lifetime when coated with $Al_2O_3$ as the anti-oxide layer, coated Cr as the adhesion layer, and coated $MgF_2$ as the protection layer.

• 한국광물학회지
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• 제9권1호
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• pp.26-34
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• 1996

The white leather-like playgorskite occurs as a vein in the Cretaceous sedimentary rocks in the Yeongsan area, Kyeongnam, Korea. It has been investigate by means of XRD, TEM, DTA-TG, IR and chemical analysis. The palygorskite vein is composed mostly of well-crystallized palygorskite. The wall rock of the vein is altered to smectite along both sides of the vein. According to TEM observation the palygorskite shows a fibrous habit. The sizes offibers are quite variable, ranging from 0.1 to 3.0 micron in length. From XRD data, the palygorskite has orthorhombic unit cell with a=12.726$\AA$, b=17.796$\AA$, c=5.1666$\AA$. The chemical formula of the palygorskite was calculated as [Si7.93Al0.07](Al1.91Fe+30.11Mg1.96)Ca0.01O20(OH)4(OH2)2.

• 한국산학기술학회논문지
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• 제22권5호
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• pp.118-127
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• 2021

최근 대기환경에 대한 국민의 관심이 증대하고 있으며, 미세먼지 등으로 인하여 국민 건강이 위협 받고 있다. 또한 정부는 대기오염물질에 대한 모니터링을 확대하고, 환경기준을 강화하는 등 대기질 개선을 위한 노력을 지속하고 있다. 한반도 지역에 따라 대기질이 상이하기 때문에 원인 파악과 영향요인 탐색이 필요한 실정이다. 본 연구에서는 충남권에 위치한 도시의 대기환경과 지역적 차이를 탐색하였다. 연구방법으로 충남 3개 도시의 대기질 현황을 확인하고, 기온, 풍속, 강수, 계절 등의 기상조건과 SO₂, NO₂, CO, PM₁₀, PM_2.5, O₃ 등의 대기오염물질과 입자상 물질에 포함된 Pb, Cd, Cr, Cu, Ni, As, Mn, Fe, Al, Ca, Mg 등의 중금속 성분을 대상으로 회귀분석을 수행하였다. 분석결과 PM₁₀ 농도의 경우, 천안은 Mn(0.4884), 당진은 CO(0.3329), 서산은 Mg(0.5691) 농도에 의한 기여도가 높았다. PM_2.5의 경우, 천안 NO₂(0.4759), 당진 CO(0.4128), 서산 NO₂(0.3715)에 의한 영향이 크게 나타났다. 종합하면 대기질 측면에서 충남 지역별 영향요인이 상이하고, 기여도에 분명한 차이가 존재함으로 이를 고려한 정부의 지역별 대기질 관리가 요구 된다고 판단된다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 춘계학술대회 논문집
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• pp.1-2
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• 2009

The high critical current ($I_c$, A) of SmBCO coated conductor in a magnetic field, the high production rate and the high material yield are promising for applications. The inhomogeneity of Ie at the long length coated conduct is very important problem for electric application. So we researched the reason of inhomogeneity of $I_c$ at long length tape prepared by batch type co-evaporation system called by EDDC. The long length SmBCO coated conductors were developed on $LaMnO_3/IBAD-MgO/Y_2O_3/Al_2O_3$/Hastelloy C276 template. The distribution of $I_c$ are from 0 to 397 A/cm at 77 K and self field. We have studied the microstructures of these films by using SEM, EDS and X-ray diffraction. The XRD and composition by EDS results of SmBCO film reveals subtle difference. But, the microscopic observation by SEM show the microcrack at the sample with low $I_c$.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.499-502
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• 2008

고정층반응기에서 니켈이 치환된 하이드로탈사이트($Ni_3Mg_3Al_2(CO_3)(OH)_{{16}{\cdot}n}H_2O$ ; n=3$\sim$5)를 합성하고 여기에 세리아를 첨가 후 소성하여 얻은 촉매를 사용하여($Ce_xNi_3$-HTlc ; x=0.3$\sim$1.2) 메탄의 부분산화 반응실험을 수행하였다. 세리아가 첨가되지 않은 촉매는 반응 초기 활성이 세리가가 소량 첨가된 ($Ce_{0.3}Ni_3$-HTlc) 촉매보다 우수하였으나 장시간 반응에서는 차차 활성이 저하되었으나, $Ce_{0.3}Ni_3$-HTlc의 활성은 30시간까지 일정하게 유지 되었다. 세리아 함량이 많아 질수록 촉매 활성은 점차 저하되었으며, $Ce_{1.2}Ni_3$-HTlc 는 촉매활성이 매우 낮았다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2012년도 추계총회 및 학술대회 논문집
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• pp.179-180
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• 2012

Aluminum alloys are widely known as non-ferrous metal with light weight and high strength. Consequently, these materials take center stage in the aircraft and automobile industry. The Al7075 aluminum alloy is based on the Al-Zn-Mg-Cu and one of the strongest wrought aluminum alloys. Aluminum nitride has ten times higher thermal conductivity($319W/m{\cdot}K$) than Al2O3 and also has outstanding electric insulation($1{\times}1014{\Omega}{\cdot}cm$). Furthermore, it has high mechanical property (430 MPa) even though its co-efficient of thermal expansion is less than alumina For these reasons, it has great possibilities to be used for not only the field which needs high strength lightweight but also electronic material field because of its suitability to be applied to the insulator film of PCB or wafer of ceramic with high heat conduction. This paper investigates the mechanical properties and corrosion behavior of aluminum alloy Al7075 deposited with aluminum nitride thin films To improve the surface properties of Al7075 with respect to hardness, and resistance to corrosion, aluminum nitride thin films have been deposited by pulsed DC reactive magnetron sputtering. The pulsed DC power provides arc-free deposition of insulating films.