• 제목/요약/키워드: sulfidation

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HgCdTe 기판의 황화 처리에 따른 보호막 특성 향상 (Sulfide treatment of HgCdTe substrate for improving the interfacial characteristics of ZnS/HgCdTe heterostructure)

  • 김진상;윤석진;강종윤;서상희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.973-976
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    • 2004
  • The results of numerous studies in III-V semiconductors show that sulfur treatment improves the electrical parameters of III-V compound devices. In this article, we examine the effects of sulfidation of HgCdTe surface on the interfacial characteristics of metal-ZnS-HgCdTe structures. Different from sulfidation in III-V material, S can not be act as an impurity because II-S compounds (ZnS, CdS) generally used as passivant for HgCdTe. Our studies of sulfur-treatment on HgCdTe surface show that sulfur agent forms the S- S, II-S bonds at the surface layer. These bonds are very effective to improve the electrical properties of ZnS layer on HgCdTe by reducing the possibility of native oxides formation. After the sulfidation process, MIS capacitors of HgCdTe show great improvement in electrical properties, such as low density of fixed charge and reduced hystereisis width.

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황화수소 제거를 위한 칼슘계 고온탈황제의 황화반응속도에 관한 연구 (Kinetic study of high-temperature removal of $H_2S$ by Ca-based sorbents)

  • 김영식;전지환
    • 한국환경과학회:학술대회논문집
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    • 한국환경과학회 1998년도 봄 학술발표회 프로그램
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    • pp.144-153
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    • 1998
  • Sorbents of calcined limestone and oyster particles having a diameter of about 0.63mm were exposed to simulate fuel gases containing 5000ppmv H2S for temperatures ranging from 600 to 800C in a TGA. The reaction between CaO and H2S proceds via an unreacted shrinking core mechanism. The sulfidation rate is likely to be controlled primarily by countercurrent diffusion through the product layer of calcium sulfide(CaS) formed. The kinetics of the sorption of H2S by CaO is sensitive to the reaction temperature and particle size, and the reaction rate of oyster was faster than the calcined limestone.

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황화수소 제거를 위한 칼슘계 고온 탈황제의 황화반응속도 (Kinetic of High-Temperature Removal of $H_2S$ by Ca-based Sorbents)

  • 김영식;전지환;손병현;정종현;정덕영;오광중
    • 한국환경과학회지
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    • 제8권1호
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    • pp.125-133
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    • 1999
  • Sorbents of calcined limestone and oyster particles having a diameter of about 0.63mm were exposed to simulated fuel gases containing 5000ppm $H_2S$ for temperatures ranging from 600 to 80$0^{\circ}C$ in a TGA (Thermalgravimetric analyzer). The reaction between CaO and $H_2S$ proceeds via an unreacted shrinking core mechanism. The sulfidation rate is likely to be controlled primarily by countercurrent diffusion through the product layer of calcium sulfide(CaS) formed. The kinetics of the sorption of $H_2S$ by CaO is sensitive to the reaction temperature and particle size, and the reaction rate of oyster was faster than the calcined limestone.

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망만계 탈황제에 의한 황화수소 제거에 관한 연구 (A Study on the Removal of Hydrogen Sulfide by the Manganese Based Sorbents)

  • 손병현;최성원;김영식;정종현;조상원;오광중
    • 한국환경보건학회지
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    • 제22권4호
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    • pp.1-9
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    • 1996
  • Experiments have been made to test the practical feasibility of using calcined manganese ore to desulfurize hot reducing gas. In this study, the effects of particle size of sorbents, temperature of sulfidation, flow rate and sorbent characteristics on the $H_2S$ removal efficiency of calcined manganese ore were investigated. Experimental results showed that the removal efficiency of $H_2S$ was optimum when the temperature was about 800$\circ$C and that the smaller particle size the higher the $H_2S$ removal efficiency. When the temperature was above 800$\circ$C, the reactivity of sorbent has lowered because agglomeration of sorbent increased intraparticle transport resistance, and this phenomenon was confirmed by SEM photographs. As the temperature increases, capacity for the $H_2S$ removal was increased but the equilibrium concentration of $H_2S$ was not affective.

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Mineralogical characteristics of Se- and Te-bearing epithermal gold-silver deposits: Eunsan and Moisan veins

  • Kim, Chang-Seong;Park, Seon-Gyu;Yoo, Bong-Chul;Kim, Wan-Joong;Jun-Rovillos
    • 대한자원환경지질학회:학술대회논문집
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    • 대한자원환경지질학회 2003년도 춘계 학술발표회 논문집
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    • pp.180-183
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    • 2003
  • Epithermal deposits are an important class of hydrothermal deposits, that have recently seen an surge of exploration and research, principally as significant resources of gold and silver. Epithermal deposits form at shallow depths (surface to 1-2km) and temperatures less than 30$0^{\circ}C$ (Hayba et al., 1985), and encompass a variety of low-sulfidation (near-neutral pH, reduced fluid; LS) and high-sulfidation (acidic and oxidized fluid; HS) deposits (Sillitoe, 1993; White and Hedenquist, 1995). (omitted)

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Low-Sulfidation Epithermal Gold Deposits in East China: Characteristics, Types, and Setting

  • Mao, Jing-Wen;Li, Xiao-Feng;Zhang, Zuo-Heng
    • 대한자원환경지질학회:학술대회논문집
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    • 대한자원환경지질학회 2003년도 춘계 학술발표회 논문집
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    • pp.15-18
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    • 2003
  • We preliminarily describe the basic characteristics of the low-sulfidation epithermal gold deposits in East China. It can be divided into granite- and alkaline rock-related types. These gold deposits are structurally controlled by caldera, craters, diatremes and related faults, hosted in volcanic rocks, and characterized by alterations of adularia, chalcedony, quartz, sericite and calcite assemblages. The ore-forming ages are within three pulses of 180-188 Ma, 135-141 Ma, and ca. 120 Ma, which are geodynamically corresponding the collision orogenic process between North China and Yangtze cratons, transformation of the tectonic regime, and delamination of the lithosphere, respectively.

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