• 제목/요약/키워드: molybdenum(Mo)

검색결과 455건 처리시간 0.027초

반도체 제조공정에서 발생하는 혼산폐액으로부터 고순도 인산 회수 (Recovery of phosphoric acid from the waste acids in semiconductor manufacturing process)

  • 박성국;노유미;이상길;김주엽;신창훈;안재우
    • 한국자원리싸이클링학회:학술대회논문집
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    • 한국자원리싸이클링학회 2006년도 춘계임시총회 및 제27회 학술발표대회
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    • pp.90-94
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    • 2006
  • 액정(LCD)과 반도체 제조공정에서 발생하는 인산, 질산, 초산, Al, Mo 등이 혼재하고 있는 인산계 혼산폐액을 액정제조공정에서 사용할 수 있는 고순도 에칭액으로 재활용하기 위해서 용매추출법, 진공 증발법, 확산투석법 및 이온교환법의 각각의 기술적 특성을 살린 혼합 처리공정을 이용하여 고순도 인산 회수 기술을 확립하고 상용화 시스템을 개발하고자 하였다. 시험 결과 진공증발에 의해 질산과 초산을 100% 제거할 수 있었고, TOP를 사용한 용매추출에서도 추출 4단, 탈거 6단, 상비 1/3으로 완벽하게 제거할 수 있었다. 이온교환의 전단계로 적용한 확산투석에서 Al 97%, Mo 75% 제거할 수 있었고 이온교환공정에서 Al 및 Mo를 각각 1ppm 이하로 정제할 수 있었다.

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Active-Matrix Field Emission Display with Amorphous Silicon Thin-Film Transistors and Mo-Tip Field Emitter Arrays

  • Song, Yoon-Ho;Hwang, Chi-Sun;Cho, Young-Rae;Kim, Bong-Chul;Ahn, Seong-Deok;Chung, Choong-Heui;Kim, Do-Hyung;Uhm, Hyun-Seok;Lee, Jin-Ho;Cho, Kyoung-Ik
    • ETRI Journal
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    • 제24권4호
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    • pp.290-298
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    • 2002
  • We present, for the first time, a prototype active-matrix field emission display (AMFED) in which an amorphous silicon thin-film transistor (a-Si TFT) and a molybdenum-tip field emitter array (Mo-tip FEA) were monolithically integrated on a glass substrate for a novel active-matrix cathode (AMC) plate. The fabricated AMFED showed good display images with a low-voltage scan and data signals irrespective of a high voltage for field emissions. We introduced a light shield layer of metal into our AMC to reduce the photo leakage and back channel currents of the a-Si TFT. We designed the light shield to act as a focusing grid to focus emitted electron beams from the AMC onto the corresponding anode pixel. The thin film depositions in the a-Si TFTs were performed at a high temperature of above 360°C to guarantee the vacuum packaging of the AMC and anode plates. We also developed a novel wet etching process for $n^+-doped$ a-Si etching with high etch selectivity to intrinsic a-Si and used it in the fabrication of an inverted stagger TFT with a very thin active layer. The developed a-Si TFTs performed well enough to be used as control devices for AMCs. The gate bias of the a-Si TFTs well controlled the field emission currents of the AMC plates. The AMFED with these AMC plates showed low-voltage matrix addressing, good stability and reliability of field emission, and good light emissions from the anode plate with phosphors.

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초절전형 Schottky barrier rectifier의 제조 및 그 특성 (Fabrication and Characteristics of ultra power-saving Schottky barrier rectifier)

  • 김준식;최영호;박근영;최시영
    • 대한전자공학회논문지SD
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    • 제39권4호
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    • pp.35-40
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    • 2002
  • 일함수가 낮은 바나듐과 몰리브덴을 장벽금속으로 사용하여 초절전형 SBR을 제조하였다. 일함수가 낮은 장벽금속을 사용함으로서 나타나는 역방향 누설전류를 감소시키기 위해 n-Si층에 아르곤 이온을 1×10/sup 14/ ion/㎠, 40 keV로 주입하였다. 제조된 소자의 전기적 특성은 60 A/㎠의 동일한 전류밀도에서 Mo-SBR의 V/sub F/는 0.39 V이고 V-SBR은 0.25 V로서 매우 낮은 V/sub F/를 나타내었다. 이에 따라 아르곤 이온주입에 의해 제조된 Y-SBR의 역방향 누설전류는 일반적인 V-SBR과 비교하여 20㎂ 이상 감소됨을 확인할 수 있었다. 또한, 아르곤 이온주입으로 인한 소자의 특성저하는 나타나지 않았다.

LiNbO3의 스트레인광학형 광도파로를 이용한 세기 광 변조기와 광 파워 분배기 (Optical power splitters and optical intensity modulators utilizing Strain-Optic Waveguides of LiNbO3)

  • 정홍식
    • 한국광학회지
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    • 제14권1호
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    • pp.38-43
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    • 2003
  • $LiNbO_3$의 스트레인광학효과와 ~l.4$\mu\textrm{m}$ 두께 이상으로 증착된 Mo(molybdenum)/Pt(platinum) 금속 박막으로부터 발생되는 압축스트레인을 이용하여 채널 광도파로 제작 공정을 개발하였다. 제작된 광도파로는 단일모드로 관찰되었으며, 삽입 손실이 TE, TM 입사 편광모드 각각에 대해서 6.2, 7.7 dB/cm로 측정되었다. 전극 길이와 간격이 11 mm, 21 $\mu\textrm{m}$인 광변조기를 스트레인광학형 광도파로 구조를 이용하여 제작하였으며, $V_{\pi}$= 16.1 V와 100% 변조 깊이가 1.55$\mu\textrm{m}$ 파장 영역에서 측정되었다. 또한 1$\times$2광 파워 분리기를 제작한 결과 0.63$\mu\textrm{m}$ 파장 영역에서 on/off 특성이 $\pm$25V에서 관찰되었다.

AMOUNT AND DISTRIBUTION OF DIETARY MINERALS IN SELECTED PHILIPPINE FORAGES

  • Serra, S.D.;Serra, A.B.;Ichinohe, T.;Harumoto, T.;Fujihara, T.
    • Asian-Australasian Journal of Animal Sciences
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    • 제9권2호
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    • pp.139-147
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    • 1996
  • Eight Philoppine forages were studied to obtain the following: 1) nutrient concentrations and digestibility, 2) distribution of the various minerals in fiber fractions through mineral analyses of neutral detergent fiber(NDF) and acid detergent fiber(ADF) residues, and 3) correlation coefficients among the factors affecting forage quality and mineral concentrations. These Philippine forages were paragrass [Brachiaria mutica (Forsk.) Stapf], stargrass (Cynodon plectostachyum Pilger), napiergrass (Pennisetum purpureum Schumach.) calopo (Calopogonium muconoides Desv.), centrocema (Centrocema pubescens Benth.), gliricidia [Gliricidia sepium (Jacq.) Walp.] leucaena [Leucaena leucocephala (Lam.) de Wit.] and sesbania [Sesbania grandiflora (L.) Poir]. Species differences(p<0.01) were observed on various nutrient fractions including mineral composition and digestibility. The cell wall(NDF) fraction, prepared by boiling in neutral detergent solution, contained the following proportions of the total mineral originally present (%): calcium (Ca), 0.7; phosphorus(P), 14.3; magnesium(Mg), 1.9; potassium(K), 3.7; copper(Cu), 16.4; zinc(Zn), 2.9; molybdenum(Mo), 9.3; cobalt(Co), 16.2; manganese(Mn), 5.6, and iron(Fe), 81.3. The ligno-cellulose(ADF) fraction, prepared by boiling in acid detergent solution, contained the following proportions of the total mineral originally present(%): Ca, 0.2; P, 4.4; Mg, 0.7; K, 2.8; Cu, 32.3; Zn, 1.1; Mo, 8.9; Co, 4.7; Mn, 5.4; and Fe, 36.8. Correlation coefficients among the factors affection forage quality and mineral concentrations were also observed. Evidently, 75 and 45% of the minerals in grasses and legumes was positively correlated to CP and IVDMD, respectively. Moreover, 55, 80 and 75% of the forage minerals was negatively correlated to NDF, ADF and ADL fraction, respetively, implying that most of the minerals reside in the non-structural cell components.

슈퍼 오스테나이트계 스테인리스강의 시그마상 특성에 따른 부식거동 분석 (Analysis of the Corrosion Behavior According to the Characteristics of Sigma Phase Formed in Super Austenitic Stainless Steel)

  • 김예은;박진성;조동민;홍승갑;김성진
    • Corrosion Science and Technology
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    • 제19권4호
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    • pp.203-210
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    • 2020
  • The corrosion behavior of super austenitic stainless steel was studied by examining the characteristics of the sigma phase formed in the steel. A range of experimental and analytical methods was employed, including potentiodynamic polarization tests, critical pitting temperature tests, transmission electron microscopy, and energy-dispersive spectroscopy. Three steel samples with different sigma phase levels were obtained by intentionally adjusting the manufacturing process. The results showed that the corrosion resistance of the samples was strongly dependent upon the size and distribution of the sigma phase precipitated in the samples. The larger the size of the sigma phase, the higher the Mo content in the sigma phase and the higher the depletion level of Mo at the interface between the matrix/sigma phase, the more samples with a coarse-sized sigma phase were susceptible to localized pitting corrosion at the interface. These results suggest that various manufacturing processes, such as welding and the post-heat treatment of the steel, should be optimized so that both the size and fraction of the sigma phase precipitated in the steel are small to improve the resistance to localized corrosion.

E-빔 증착된 Sn 전구체의 황화 열처리 온도 및 시간에 따른 SnSx 박막 성장 효과 (Effect of the Sulfurization Temperature and Annealing Time of E-Beam Evaporated Sn Precursors on the Growth of SnSx Thin Films)

  • 황팅지엔;김제하
    • 한국전기전자재료학회논문지
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    • 제30권11호
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    • pp.734-739
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    • 2017
  • We prepared $SnS_x$ thin films on both soda-lime glass (SLG) and molybdenum(Mo)/SLG substrates by a two-step process using a Sn precursor followed by sulfur reaction in rapid thermal annealing (RTA) at different sulfurization temperatures ($Ts=200^{\circ}C$, $230^{\circ}C$, $250^{\circ}C$, and $300^{\circ}C$) and annealing times ($t_s=10min$ and 30 min). The single SnS phase was dominant for $200^{\circ}C{\leq}T_s$<$250^{\circ}C$, while an additional phase of $SnS_2$ was appeared at $T_s{\geq}250^{\circ}C$ alongside SnS. The SnS grains in all the samples showed strong growth along the preferred [040] direction. The band-gap energy ($E_g$) of the films was estimated to be 1.24 eV.

Nitrogenase Derepression and Associated Metabolism in a Microaerophilic Cyanobacterium, Plectonema boryanum

  • Pandey, Kapil Deo;Sukla, Sarkar;Naz, Shaheen;Smita, Chaturvedi;Ajaikumar, Kashyap
    • Journal of Microbiology and Biotechnology
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    • 제11권2호
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    • pp.179-185
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    • 2001
  • Nitrate grown cells of cyanobacterium Plectonema boryanum, transferred to nitrogen stress, evolved nitrogenase catalyzed $H_2$ under microaerophilic condition. Nitrogen ($N_2$) in gs phase, low light intensity, and reducing substances in incubation phase stimulated $N_2$fixation ($H_2\;evolution$). Cyanobacterium grew slowly under microaerobic condition with a low intracellular ammonia pool. Nitrogen sources (${NO_3}^-,{NH_4}^+,\;and\;CH_3NH_3$) inhibited nitrogenase and glutamine synthetase (GS) transferase activity, and methylamine behaved like an ammonical nitrogen source. Depletion of molybdenum (Mo) and addition of tungsten (W) in the incubation medium inhibited $H_2$ evolution, Cyanobacterium was able to take up nitrate and expressed nitrate reductase (NR) activity under microaerophilic condition at an extremely slow rate.

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화력발전소 NOx 제거를 위한 SCR 촉매 특성 (Characteristics of SCR-Catalytic with de-NOx System in Thermal Power plants)

  • 고승재;김지현;김미정;조연배;박영구
    • 한국응용과학기술학회지
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    • 제30권3호
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    • pp.451-460
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    • 2013
  • NOx from the thermal power plants are NO and $NO_2$. This work investigated the chemical/physical characteristics and SCR efficiency of newly prepared catalysts including tungsten ($WO_3$), molybdenum ($MoO_3$) and antimony ($SbO_3$) based on vanadia($V_2O_5$) over titania($TiO_2$). As a result of the examination, the surface area of the catalysts promoted with additional metals was larger and the de-NOx efficiency also was enhanced with temperature. The most efficient catalytst was $V_2O_5/TiO_2-WO_3$(10%) at $200^{\circ}C$. Such a high efficiency could contribute to reduce the ammonia slip.

대기압 글로우 방전의 구현 및 안정화에 대한 실험적 연구 (An Experimental Study on the Implementation and Stabilization of Atmospheric Pressure Glow Discharge)

  • 최상원
    • 한국안전학회지
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    • 제23권4호
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    • pp.42-46
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    • 2008
  • Ionizers are essential in various areas of manufacturing industries to protect electrostatic hazards and to reduce inferior products. For ion sources used in the charge neutralizers, there are corona discharge, soft X-ray, ultraviolet and glow discharge. Glow discharge has lots of attractive properties, such as lower discharge sustaining voltage, no generation of ozone, and so on. In this paper, we did an experimental study to trace the mechanism and stabilization of atmospheric pressure glow discharge using the several size and shape of electrodes. As an experimental result, to sustain conditions of atmospheric pressure glow discharge is that discharge voltage is 360V, discharge current is 12mA, apply frequency is 1kHz between electrodes when positive electrode is molybdenum(Mo) and negative electrode is copper(Cu). We confirmed that the mechanism and stabilization of atmospheric glow discharge is deeply concerned with the shape and material of electrode for discharge. Especially, glow discharge in atmospheric pressure was well generated and sustained according with the physical properties used electrode materials, example melting point, thermal conductivity, and etc.