• Title/Summary/Keyword: Deposition reduction

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EPA's Research Activities & Strategies for the Reduction of Atmospheric Deposition of Air Pollutants (미국의 대기침적현상 규명을 위한 접근방법 및 대응방안)

  • 정장표
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 1999.10a
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    • pp.331-337
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    • 1999
  • 대기침적은 대기중으로 방출된 오염물질의 이동과 그 영향을 조절하는 중요한 기작으로서, 현상론적인 형태에 따라 습성침적 및 건성침적으로 구분된다. 이러한 대기침적 현상은 수질의 악화, 건강 및 생태학적 악영향을 초래하는 중요한 요소로 작용할 뿐만 아니라, 최근 우리나라를 비롯한 동북아시아지역에서의 대기오염물질의 장거리 이동현상의 정확한 규명을 하기 위한 노력의 일환으로 그 관심이 모아지고 있다.(중략)

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Estimation for the Reduction of Atmospheric Deposition of Air Acid Pollutions in Silla Culture Region (신라문화권 지역에서 산성대기오염물질 침적량 추정)

  • 이승일
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2002.11a
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    • pp.79-80
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    • 2002
  • 경주시는 신라 천년의 고도로서 신라의 역사와 문화가 아직도 곳곳에 남아 있는 국내 최대의 역사도시이자 유적도시로 잘 알려져 있으며, 세계적으로 역사적인 문화가치를 인정받아 유네스코에 의해 세계문화유산으로 지정된 불국사, 석굴암, 남산 및 고분군 등의 문화재가 분포하고 있다. 특히, 경주시 지역에는 다보탑, 석가탑, 석굴암 및 불상 등 세계적으로 유명한 석조문화재가 고 밀도로 분포되어 있다. (중략)

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Surface Properties of ITO Thin Film by Planarization (광역평탄화에 따른 투명전도박막의 표면특성)

  • Choi, Gwon-Woo;Lee, Woo-Sun;Seo, Yong-Jin
    • Proceedings of the KIEE Conference
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    • 2006.10a
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    • pp.95-96
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    • 2006
  • ITO thin film is generally fabricated by various methods such as spray, CVD, evaporation, electron gun deposition, direct current electroplating, high frequency sputtering, and reactive DC sputtering. However, some problems such as peaks, bumps, large particles, and pin-holes on the surface of ITO thin film were reported, which caused the destruction of color quality, the reduction of device life time, and short-circuit. Chemical mechanical polishing (CMP) process is one of the suitable solutions which could solve the problems.

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The Analysis of Sediment Reduction Effect by Installing Check Dams at Domestic Multi-Purpose Dams (국내 다목적 댐의 저사댐 설치에 따른 퇴사저감 효과 분석)

  • Choi, Gye-Woon;Kim, Kwang-Nam;Han, Man-Shin;Yun, Yong-Jin
    • Journal of the Korean Society of Hazard Mitigation
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    • v.11 no.3
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    • pp.183-189
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    • 2011
  • In this study sediments reduction effects on dam have been analyzed in the case of check dam installation in the upstream. Analyzed sediment reduction effects of 27 points conducted for 10 multi-purposes dam, which is target of this study. According to regression analysis result, Sediment reduction effect by installing check dam has shown inclination which increase as area ratio rises. According to analysis result, sediment reduction effect was greatest in Geum-river point at Daecheong-dam. The life-time is estimated to increases about 60% by installing check dams. When Area ratio increases, it was deduced through regression analysis that rise Sediment Reduction Effect by installing check dam. This study can be useful for the management and design plans like the dam's site or priority for placing. Furthermore, it would be able to construct an efficient sand depositing dam if complementary is provided by being considered catchment area and lucrative property.

A Study on Contact Resistance Reduction in Ni Germanide/Ge using Sb Interlayer

  • Kim, Jeyoung;Li, Meng;Lee, Ga-Won;Oh, Jungwoo;Lee, Hi-Deok
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.2
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    • pp.210-214
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    • 2016
  • In this paper, the decrease in the contact resistance of Ni germanide/Ge contact was studied as a function of the thickness of the antimony (Sb) interlayer for high performance Ge MOSFETs. Sb layers with various thickness of 2, 5, 8 and 12 nm were deposited by RF-Magnetron sputter on n-type Ge on Si wafers, followed by in situ deposition of 15nm-thick Ni film. The contact resistance of samples with the Sb interlayer was lower than that of the reference sample without the Sb interlayer. We found that the Sb interlayer can lower the contact resistance of Ni germanide/Ge contact but the reduction of contact resistance becomes saturated as the Sb interlayer thickness increases. The proposed method is useful for high performance n-channel Ge MOSFETs.

Characteristics of Silicon Carbide Nanowires Synthesized on Porous Body by Carbothermal Reduction

  • Kim, Jung-Hun;Choi, Sung-Churl
    • Journal of the Korean Ceramic Society
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    • v.55 no.3
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    • pp.285-289
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    • 2018
  • We synthesized silicon carbide (${\beta}-SiC$) nanowires with nano-scale diameter (30 - 400 nm) and micro-scale length ($50-200{\mu}m$) on a porous body using low-grade silica and carbon black powder by carbothermal reduction at $1300-1600^{\circ}C$. The SiC nanowires were formed by vapor-liquid-solid deposition with self-evaporated Fe catalysts in low-grade silica. We investigated the characteristics of the SiC nanowires, which were grown on a porous body with Ar flowing in a vacuum furnace. Their structural, optical, and electrical properties were analyzed with X-ray diffraction (XRD), transmission electron microscopy (TEM), and selective area electron diffraction (SAED). We obtained high-quality SiC single crystalline nanowire without stacking faults that may have uses in industrial applications.

Reduction of metal-graphene contact resistance by direct growth of graphene over metal

  • Hong, Seul Ki;Song, Seung Min;Sul, Onejae;Cho, Byung Jin
    • Carbon letters
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    • v.14 no.3
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    • pp.171-174
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    • 2013
  • The high quality contact between graphene and the metal electrode is a crucial factor in achieving the high performance of graphene transistors. However, there is not sufficient research about contact resistance reduction methods to improve the junction of metal-graphene. In this paper, we propose a new method to decrease the contact resistance between graphene and metal using directly grown graphene over a metal surface. The study found that the grown graphene over copper, as an intermediate layer between the copper and the transferred graphene, reduces contact resistance, and that the adhesion strength between graphene and metal becomes stronger. The results confirmed the contact resistance of the metal-graphene of the proposed structure is nearly half that of the conventional contact structure.

Phase Changes of Vanadium Oxide Thin Films (산화 바나듐 박막의 상변화)

  • 선우진호;신인하;고경현;안재환
    • Journal of the Korean institute of surface engineering
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    • v.25 no.6
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    • pp.293-298
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    • 1992
  • Various vanadium-oxide thin films were deposited by e-beam and thermal evaporation of V2O5, V2O3, and VO2 powders. Films with thickness of $2000\AA$ were subjected to annealing at $300^{\circ}C$~$450^{\circ}C$ in N2 atmosphere for the crystallization and desification purposes. For the films deposited from V2O5 and VO2 sources, sources, Magneli (VnO2n-1$ 4\leq$ $n\leq$ 8) and VO2 phase appeared at $300^{\circ}C$, respectively, but VO2 phase also transformed into Magneli phase at $450^{\circ}C$ by severe reduction. On the contrary, VO2/VO mixed phases resulted from congruent evaporation of V2O3 unchanged after the same annealing treatment due to the balanced reduction and oxidation of VO2 and VO whcih have different equilibrium O2 pressures. It is suggested that the annealing in the controlled oxidation atmosphere or the deposition using mixed oxide sources are necessary to get the film containing VO2 phase.

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저 염소 TiN필름 제조를 위한 CVD 반응기 내의 유동해석

  • 임익태;전기영
    • Proceedings of the Korean Society Of Semiconductor Equipment Technology
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    • 2003.12a
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    • pp.1-6
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    • 2003
  • Flow modulation chemical vapor deposition process has been reported as an alternative way to obtain low resistivity, low residual chlorine content and good step-coverage titanium nitride film. Flow and concentration characteristics in a vertical FMCVD reactor are analyzed by using computational fluid dynamics method. The results show that 1.0 second as Cl reduction period is too short and there is still $TiCl_4$ gas above the holder at the end of the period. Time variation of $TiCl_4$ gas concentration on the holder shows that at least 3.0 second is necessary as Cl reduction time for the sake of film characteristics.

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Initial Performance Degradation of Hydrogen-Fueled Ceramic Fuel Cell with Plasma-Enhanced Atomic Layer-Deposited Ultra-Thin Electrolyte (플라즈마 원자층증착 초박막전해질 수소 세라믹연료전지의 초기성능 저하)

  • JI, SANGHOON
    • Transactions of the Korean hydrogen and new energy society
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    • v.32 no.5
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    • pp.340-346
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    • 2021
  • The initial electrochemical performance of ceramic fuel cell with thin-film electrolyte fabricated by plasma-enhanced atomic layer deposition method was evaluated in terms of peak power density ratio, open circuit voltage ratio, and activation/ohmic resistance ratios at 500℃. Hydrogen and air were used as anode fuel and cathode fuel, respectively. The peak power density ratio reduced as ~52% for 30 min, which continually decreased as time increased but degradation rate gradually decreased. The open circuit voltage ratio decreased with respect time; however, its behavior was evidently different from the reduction behavior of the peak power density. The activation resistance ratio increased as ~127% for 30 min, which was almost similar with the reduction behavior of the peak power density ratio.