• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.318.2-318.2
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• 2014

The high contact resistance is still one of the major issues to be resolved in CdS/CdTe thin film solar cells. CdTe/Metal Schottky contact induced a high contact resistance in CdS/CdTe solar cells. It has been reported that the work function of CdTe thin film is more than 5.7 eV. There has not been a suitable back contact metal, because CdTe thin film has a high work function. In a few decades, some buffer layer was reported to improve a back contact problem. Buffer layers which are Te, $Sb_2Te_3$, $Cu_2Te$, ZnTe:Cu and so on was inserted between CdTe and metal electrode. A formed buffer layers made a tunnel junction. Hole carriers which was excited in CdTe film by light absorption was transported from CdTe to back metal electrode. In this report, we reported the variation of solar cell performance with different buffer layer at the back contact of CdTe thin film solar cell.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.3
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• pp.397-409
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• 2004

There has been few studies of either domestic or international to apply CCT-ICP-MS for the precise analysis of As and Cr components associated with airborne particulate matter. To date, the use of CCT-ICP-MS is strongly recommended for the accurate analysis of the toxic trace metals; this is because CCT-ICP-MS technique prevents polyatomic spectral interferences involved in the determination of As and/or Cr components. Taking advantage of CCT-ICP-MS technique, the measurements of about 20 metals were undertaken in this study. The standard reference material (NIST SRM 2783) was used for analytical quality control. To improve analytical accuracy and of acid efficiency, we selected nitric acid based on a test of three kinds of acid for microwave digestion method 1 ) nitric acid. 2) nitric acid and hydrogen peroxide. and 3) nitric acid and perchloric acid. When this method was employed, relative errors to SRM values of Al, As, Cr Fe, Mg, Mn, Pb, Sb, V, and Zn fell below 20%, while those or Ca, Si, and Ti were higher than 20%. The overall results of our study show that the concentrations of As and V determined by CCT-ICP-MS were satisfied with the certificated values within a relative error of 20e1c, whereas those determined by ICP-MS were 10 times higher than the certificated values.

• Journal of Conservation Science
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• v.1 no.1 s.1
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• pp.27-39
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• 1992

Metallurgical studies of the bronze artifacts excavated from Miruksa Temple were performed by chemical analysis and metallographic observation. Alloy systems of the bronze artifacts were classified into two groups of Cu-Sn and Cu-Sn-Pb, according to the items. The contents of impurities such as Sb, As, Ni and Fe in bronze artifacts are within the limiting range of the mod ern standard bronze castings. Chemical compositions of the kitchen utensils such as bronze vessels and dishes in the Unified Silla dynasty, are in the follow ing range, Cu : 74.8-79.4% and Sn : 18.6-21.1%. Chemical composition of the Buddha-image in Koryo dynasty are 820Cu-7.0Sn-10.3Pb, showing increased Pb content and decreased Sn content. The results of chemical analysis suggest that the chemical compositions were good controlled. Any casting defects such as voids and shrinkage holes are not found microscopically, indicating high casting skill. Zinc atoms are not contained in the all bronze artifacts of Miruksa Temple site. This is the common facts founded in the east asian bronze artifacts of Korea, China and Japan. It is comparable with the European bronze of Cu-Sn-Pb-Zn system, after the Middle Age.

• Environmental Engineering Research
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• v.18 no.1
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• pp.3-8
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• 2013

Collision cell technology-inductively coupled plasma-mass spectrometry (CCT-ICP-MS) was used to measure the concentrations of approximately 19 elements associated with airborne PM2.5 samples that were collected from a roadside sampling station in Daejeon, Korea. Standard reference material (SRM 2783, air particulate on filter media) of the National Institute of Standards and Technology was used for the quality assurance of CCT-ICP-MS. The elemental concentrations were compared statistically with the certified (or recommended) values. The patterns of distribution were clearly distinguished between elements with their concentrations ranging over four orders of magnitude. If compared in terms of enrichment factors, it was found that toxic trace elements (e.g., Sb, Se, Cd, As, Zn, Pb, and Cu) of anthropogenic origin are much more enriched in PM2.5 samples of the study site. To the contrary, the results of the correlation analysis showed that PM2.5 concentrations can exhibit more enhanced correlations with the elements (e.g., Fe, K, Si, and Ti) arising from earth's crust. The findings of strong correlations between PM2.5 and the elements of crustal origin may be directly comparable with the dominant role of those species by constituting a major fraction of even PM2.5 as well as PM10 at the roadside area.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.44-45
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• 2006

초고용량 캐패시터(Supercapacitor)는 이차전지와 더불어 차세대 전지로 분류되는 신형에너지 장치로서 충 방전 속도가 다르고 순간 전력공급이 가능하며 충 방전 수명이 반영구적으로 길고 고출력을 내기 때문에 이차전지가 갖지 못하는 영역에서 동력에너지원으로 사용된다. 본 연구에서는 초고용랑 캐패시터의 전극소재인 탄소계 재료를 대신하여 비탄소계 전극소재인 $Li_4Ti_5O_{12}$의 고상법 제조를 위한 Li/Ti의 최적 조성과 혼합 방법으로 Li-Ti 계에 $Fe_2O_3$, NiO, $Nb_2O_5$, $Sb_2O_3$ 그리고 ZnO와 같은 금속산화물로 치환시켜 합성된 Li -Ti계 금속산화물의 특성 및 충 방전 효과에 미치는 영향을 관찰하고자 하였다.

• Journal of the Korean Applied Science and Technology
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• v.27 no.3
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• pp.266-272
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• 2010

Natural Ginger extract was extracted from Ginger component using ethanol as a solvent, and we tested various pharmaceutical characteristics in this extract. Characteristics experiment to use natural Ginger extract tested antimicrobial experiment using microbe, and analyzed organic and inorganic component with analysis instrument. From the result of characteristics experiment, some conclusions are obtained as follow. In this experiment, natural Ginger extract was obtained about 22.50 g-Ginger extract(extraction ratio : 1.80%) as liquid state of some viscous yellow-brown color. The result of antimicrobial experiment with staphylococcus aureus and aspergillus niger in microbe decreased more and more according to passage of reaction time. This phenomenon could know that Ginger extract has influenced to antimicrobial effect. In the result of instrumental analysis, aromatic organic components of benzimidazole(1.283), propyl isothiocyanate or isothiocyanic acid(1.477) etcs from Ginger extract were detected with GC/MS and inorganic component of Ca(27.6 ppm), K(24.08 ppm), Mg(6.03 ppm), Na(1.02 ppm), Zn(1.02 ppm), Sb(0.711 ppm) and Li(0.079 ppm) etcs from Ginger extract were detected with ICP/OES.

• Economic and Environmental Geology
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• v.54 no.2
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• pp.213-232
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• 2021

Ore criteria at the Sheba Deposit indicate orogenic mineralization type. Rocks and mineral assemblages suggest low formation-temperature of green-schist facies. Pyrite found in two generations; Type1 is irregular grains, contains higher arsenic and gold contents, compared to the relatively younger phase Type2 pyrite, which is composed of euhedral grains, found adjacent to late quartz-carbonate veins or at rims of type1 pyrite. Two gold generations were identified; type1 found included in sulphides (mainly pyrite). The second gold type was remobilized (secondary) into free-lodes within silicates (mainly quartz). Gold fineness is high, as gold contains up to 95 wt. % Au, Ag up to 3.5 wt. %, and traces of Cu, Ni, and Fe. Pyrite type2 contains tiny mineral domains (rich in Al, Mn, Hg, Se, Ti, V, and Cr). Zoning, and replacement textures are common, suggesting multiple mineralization stages. The distribution and relationships of trace elements in pyrite type2 indicate three formation patterns: (1) Al, Mn, Hg, Se, Ti, V, Cr, and Sn are homogeneously distributed in pyrite, reflecting a synchronous formation. (2) As, Ni, Co, Zn, and Sb display heterogeneous distribution pattern in pyrite, which may indicate post-formation existence due to other activities. (3) Au and Ag show both distribution patterns within pyrite, suggesting that gold is found both in microscopic phases and as chemically bounded phase.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.2
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• pp.83-100
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• 2022

The Zhenzigou Pb-Zn deposit, which is one of the largest Pb-Zn deposit in the northeast of China, is located at the Qingchengzi mineral field in Jiao Liao Ji belt. The geology of this deposit consists of Archean granulite, Paleoproterozoinc migmatitic granite, Paleo-Mesoproterozoic sodic granite, Paleoproterozoic Liaohe group, Mesozoic diorite and Mesozoic monzoritic granite. The Zhenzigou deposit which is a strata bound SEDEX or SEDEX type deposit occurs as layer ore and vein ore in Langzishan formation and Dashiqiao formation of the Paleoproterozoic Liaohe group. White mica from this deposit are occured only in layer ore and are classified four type (Type I : weak alteration (clastic dolomitic marble), Type II : strong alteration (dolomitic clastic rock), Type III : layer ore (dolomitic clastic rock), Type IV : layer ore (clastic dolomitic marble)). Type I white mica in weak alteration zone is associated with dolomite that is formed by dolomitization of hydrothermal metasomatism. Type II white mica in strong alteration zone is associated with dolomite, ankerite, quartz and alteration of K-feldspar by hydrothermal metasomatism. Type III white mica in layer ore is associated with dolomite, ankerite, calcite, quartz and alteration of K-feldspar by hydrothermal metasomatism. And type IV white mica in layer ore is associated with dolomite, quartz and alteration of K-feldspar by hydrothermal metasomatism. The structural formulars of white micas are determined to be (K_0.92-0.80Na_0.01-0.00Ca_0.02-0.01Ba_0.00Sr_0.01-0.00)_0.95-0.83(Al_1.72-1.57Mg_0.33-0.20Fe_0.01-0.00Mn_0.00Ti_0.02-0.00Cr_0.01-0.00V_0.00Sb_0.02-0.00Ni_0.00Co_0.02-0.00)_1.99-1.90(Si_3.40-3.29Al_0.71-0.60)_4.00O₁₀(OH_2.00-1.83F_0.17-0.00)_2.00, (K_1.03-0.84Na_0.03-0.00Ca_0.08-0.00Ba_0.00Sr_0.01-0.00)_1.08-0.85(Al_1.85-1.65Mg_0.20-0.06Fe_0.10-0.03Mn_0.00Ti_0.05-0.00Cr_0.03-0.00V_0.01-0.00Sb_0.02-0.00Ni_0.00Co_0.03-0.00)_1.99-1.93(Si_3.28-2.99Al_1.01-0.72)_4.00O₁₀(OH_1.96-1.90F_0.10-0.04)_2.00, (K_1.06-0.90Na_0.01-0.00Ca_0.01-0.00Ba_0.00Sr_0.02-0.01)_1.10-0.93(Al_1.93-1.64Mg_0.19-0.00Fe_0.12-0.01Mn_0.00Ti_0.01-0.00Cr_0.01-0.00V_0.00Sb_0.00Ni_0.00Co_0.05-0.01)_2.01-1.94(Si_3.32-2.96Al_1.04-0.68)_4.00O₁₀(OH_2.00-1.91F_0.09-0.00)_2.00 and (K_0.91-0.83Na_0.02-0.01Ca_0.02-0.00Ba_0.01-0.00Sr_0.00)_0.93-0.83(Al_1.84-1.67Mg_0.15-0.08Fe_0.07-0.02Mn_0.00Ti_0.04-0.00Cr_0.06-0.00V_0.02-0.00Sb_0.02-0.01Ni_0.00Co_0.00)_2.00-1.92(Si_3.27-3.16Al_0.84-0.73)_4.00O₁₀(OH_1.97-1.88F_0.12-0.03)_2.00, respectively. It indicated that white mica of from the Zhenzigou deposit has less K, Na and Ca, and more Si than theoretical dioctahedral mica. Compositional variations in white mica from the Zhenzigou deposit are caused by phengitic or Tschermark substitution [(Al³⁺)^VI+(Al³⁺)^IV <-> (Fe²⁺ or Mg²⁺)^VI+(Si⁴⁺)^IV] substitution. It means that the Fe in white mica exists as Fe²⁺ and Fe³⁺, but mainly as Fe²⁺. Therefore, white mica from layer ore of the Zhenzigou deposit was formed in the process of remelting and re-precipitation of pre-existed minerals by hydrothermal metasomatism origined metamorphism (greenschist facies) associated with Paleoproterozoic intrusion. And compositional variations in white mica from the Zhenzigou deposit are caused by phengitic or Tschermark substitution [(Al³⁺)^VI+(Al³⁺)^IV <-> (Fe²⁺ or Mg²⁺)^VI+(Si⁴⁺)^IV] substitution during hydrothermal metasomatism depending on wallrock type, alteration degree and ore/gangue mineral occurrence frequency.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1996.04a
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• pp.57-64
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• 1996

석탄중에는 미량원소(trace elements)가 포함되어 있으며 이들의 농도는 석탄의 종류나 산지에 따라 크게 다르다. 석탄중의 미량원소를 제거하는 것은 그동안 크게 문제가 되지 않았으나 최근 환경문제가 점차 고조되면서 이에 대한 관심이 높아지고 있다. 일반적으로 사람의 건강 및 환경에 유해한 원소중에서 화석연료 사용과 관련이 있는 원소는 비소(As), 카드늄(Cd), 납(Pb), 구리(Cu), 수은(Hg), 니켈(Ni), 셀레니움(Se) 및 아연(Zn) 등 8개 원소이다. 그러나 그외에도 배출규제의 대상이 되는 원소는 코발트(Co), 염소(Cl), 안티모니(Sb), 베릴리움(Be), 크롬(Cr)과 망간(Mn)이며 이중 망간은 석탄사용과 직접적인 관련이 있다. 따라서 Mn을 포함한 9개 원소가 석탄의 사용에 따른 중금속 방출과 관련이 있는 것으로 간주되고 있다. 본 연구에서는 발전용 석탄에 대한 물리적 전처리 공정을 적용하여 석탄중의 광물질등을 미리 제거하므로서 연소 후 배출되는 배기가스중의 중금속 저감 가능성을 관찰하였다. 본 연구결과 전처리 공정의 석탄중의 Trace elements양을 감소시키므로서 연소 후 중금속의 배출량을 크게 줄일 수 있음을 확인하였다. 발전소에 적용하고 있는 ESP가 배출가스중 As, Cu, Zn, Mn등의 중금속을 제거하는데 효율적이기는 하나 가스상으로 존재하는 Hg, Se등을 제거하는데는 효율적이지 못하다. 전처리공정 전후 회분중에 함유된 미량원소를 분석한 결과, 국내 무연탄이나 해외 유연탄 모두 중금속 제거에 있어서 유사한 경향을 보여주었으며, Pb, Zn, Mn 등은 50∼70%, 특히 Hg 배출량은 80% 이상 저감이 가능하였다. 전반적으로 년간 총 중금속 배출량도 50∼60%가 감소하여 전처리 공정이 석탄중의 중금속을 줄이는데 크게 기여함을 확인하였다.을 선택할 수 있는 메뉴 그리고 계산 결과를 파일로 혹은 프린트로 출력할 것을 선택할 수 있는 메뉴가 있다. 사용자는 해당되는 데이타를 입력한후 마우스로 원하는 작업의 메뉴를 선택하면 된다. 방법을 타액과 혈청내 testosterone 농도 측정에 응용하여 RIA의 결과와 비교하여 본 바 상관관계가 타액에서 r=0.969, 혈청에서 r=0.990으로 두 결과가 잘 일치하였다. 본 실험에서 측정된 한국인 여성의 타액내 testosterone농도는 107.7$\pm$12.0 pmol／l이었고, 남성의 타액내 농도는 274.2$\pm$22.1 pmol／l이었다. 이상의 결과로 보아 본 연구에서 정립된 EIA 방법은 RIA를 대신하여 소규모의 실험실에서도 활용할 수 있을 것으로 사려된다.또한 상실기 이후 배아에서 합성되며, 발생시기에 따라 그 영향이 다르고 팽창과 부화에 관여하는 것으로 사료된다. 더욱이, 조선의 ${\ulcorner}$구성교육${\lrcorner}$이 조선총독부의 관리하에서 실행되었다는 것을, 당시의 사범학교를 중심으로 한 교육조직을 기술한 문헌에 의해 규명시켰다.nd of letter design which represents -natural objects and was popular at the time of Yukjo Dynasty, and there are some documents of that period left both in Japan and Korea. "Hyojedo" in Korea is supposed to have been influenced by the letter design. Asite- is also considered to have been "Japanese Letter Jobcheso.

• Economic and Environmental Geology
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• v.24 no.2
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• pp.131-150
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• 1991

The Weolseong diatreme was temporally and spatially related to the intrusion of the Gadaeri granite, and was -mineralized by meteoric aqueous fluids. In the Nokdong As-Zn deposit, pyrite, aresenopyrite and sphalerite are the most abundant sulfide minerals. They are associated with minor amount of magnetite, pyrrhotite, chalcopyrite and cassiterite, and trace amounts of Pb-Sb-Bi-Ag sulphosalts. The AsZn ore probably occurred at about $350^{\circ}C$ according to fluid inclusion and compositional data estimated from the arsenic content of arsenopyrite and iron content of sphalerite intergrown with pyrrhotite + chalcopyrite + cubanite. Heating studies of fluid inclusions in quartz indicate a temperature range between 180 and $360^{\circ}C$, and freezing data indicate a salinity range from 0.8 to 4.1 eq.wt % NaCl. The coexisting assemblage pyrite + pyrrhotite + arsenopyrite suggests that $H_2S$ was the dominate reduced sulfur species, and defines fluid parameter thus: $10^{-34.5}$ < ${\alpha}_{S_2}$ < $10^{-33}$, $10^{-11}$ < $f_{S_2}$ < $10^{-8}$, -2.4 < ${\alpha}_{S_2}$ < -1.6 atm and pH= 5.2 (sericte stable) at $300^{\circ}C$. The sulfur isotope values ranged from 1.8 to 5.5% and indicate that the sulfur in the sulfides is of magmatic in origin. The carbon isotope values range from -7.8 to -11.6%, and the oxygen isotope values from the carbonates in mineralized wall rock range from 2 to 11.4%. The oxygen isotope compositions of water coexisting with calcite require an input of meteoric water. The geochemical data indicate that the ore-forming fluid probably was generated by a variety of mechanisms, including deep circulation of meteoric water driven by magmatic heat, with possible input of magniatic water and ore component.