• 제목/요약/키워드: Deposition reduction

검색결과 493건 처리시간 0.032초

Analysis and Estimation of Reservoir Sedimentation Using Remote Sensing and GIS

  • Sungmin Cho
    • International Journal of Internet, Broadcasting and Communication
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    • 제15권4호
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    • pp.199-204
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    • 2023
  • Periodic assessment of reservoir capacity is essential for better water resources management and planning for the future water use. Reservoirs and water storage structures raised on the rivers are subjected to sedimentation and he sedimentation is caused by deposition of eroded sediment particles carried by the streams. Knowledge of reservoir sedimentation is important to estimate avaliable storage capacity for optimum reservoir operation and scheduling water release. In recent years, remote sensing and GIS techniques have emerged as an important tool in carrying out reservoir capacity analysis and water management. The reduction in storage capacity as compared to the original capacity at the time of reservoir impounding is indicative of sediment deposition. In this study, the application of GIS and remote sensing techniques were applied to assess the sediment deposition, losses in the reservoir storage and the revised cumulative capacity. Satellite images covering Pyodongdong reservoir were analyzed using Erdas Imagine and ArcGIS softwares.Cumulative capacities at different levels were also calculated and we estimated that the revised live storage was 84.2Mft3 in 2021 and 64.3Mft3 in 2022 while the original capacity was 22.8 and 53.6Mft3 in 2021 and 2022.

Dielectric properties of ZrTiO4 thin films deposited by DC magnetron reactive sputtering

  • Kim, Taeseok;Park, Byungwoo;Hong, Kug-Sun
    • Journal of Korean Vacuum Science & Technology
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    • 제3권2호
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    • pp.130-133
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    • 1999
  • Paraelectric ZrTiO4 thin films were synthesized on a Si(100) substrate using DC magnetron reactive sputtering. Films deposited above-400$^{\circ}C$ exhibited crystalline characteristics. The dielectric constants ($\varepsilon$) and dielectric losses (tan$\delta$) of as-deposited and annealed films were measured in the 1 MHz range using a Pt upper electrode and a phosphorous-doped si bottom electrode. Preliminary data showed that as the deposition temperature increased, the dielectric losses decreased while the dielectric constants did not change significantly. similar trends for dielectric losses were observed when the as-deposited samples were annealed at 800$^{\circ}C$. The reduction of dielectric losses at high-deposition temperatures and post annealing correlated well with the x-ray diffraction peak widths.

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Spray and Atomization Technologies in Pesticides Application: A Review

  • No, Soo-Young
    • 한국분무공학회지
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    • 제6권4호
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    • pp.1-13
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    • 2001
  • In the pesticides sprays, spray and atomization technologies to increase the deposition and reduce the drift are briefly reviewed. Further research is needed to deduce a measure of drift risk in sprays with different structures, velocity profiles. For flat fan nozzles, the data of breakup length and thickness of liquid sheet are essential to understand the atomization processes and develop the transport model to target. In the air-assisted spray technology to reduce drift, further works on the effect of application height on drift and air assistance on droplet size should be followed. In addition, methods for quantifying included air in the air inclusion techniques are required. A few researches on the droplet size of fallout can be found in the literature. A combined technology with electrostatic method into one of method for the reduction of drift may be an effective strategy for increasing deposition and reducing drift.

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PM OLED Fabrication with New Method of Metal Cathode Deposition Using Shadow Mask

  • Lee, Ho-Chul;Kang, Seong-Jong;Yi, Jung-Yoon;Kim, Ho-Eoun;Kwon, Oh-June;Hwang, Jo-Il;Kim, Jeong-Moon;Roh, Byeong-Gyu;Kim, Woo-Young
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.987-989
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    • 2006
  • 1.52" $130(RGB){\times}130$ full color PM OLED device with $70\;{\mu}m{\times}210\;{\mu}m$ of sub-pixel pitch was fabricated using shadow mask method for metal cathode deposition. Instead of conventional patterning process to form cathode separator via photolithography, regularly patterned shadow mask was applied to deposit metal cathode in this OLED display. Metal cathode was patterned via 2-step evaporation using shadow mask with shape of rectangular stripe and its alignment margin is $2.5\;{\mu}m$. Technical advantages of this method include reduction of process time according to skipping over photolithographic process for cathode separator and minimizing pixel shrinkage caused by PR cathode separator as well as improving lifetime of OLED device.

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Effects of pH on Preparation of Au-Coated $TiO_2$ Nanoparticles by Deposition-Precipitation Method

  • Nguyen, Dung The;Kim, Dong-Joo;Kim, Kyo-Seon
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2009년도 춘계학술대회 논문집
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    • pp.150-150
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    • 2009
  • We prepared the Au-coated $TiO_2$ (Au/$TiO_2$) nanoparticles by deposition-precipitation (DP) method with and without bases (urea or NaOH) and investigated the effects of pH on the preparation of Au/$TiO_2$ nanoparticles for various kinds of bases. For the DP method without bases, the Au nanoparticles in the diameter of about 50 nm were generated in the solution by the reduction reaction with trisodium citrate and they did not deposit on the surface of $TiO_2$. For the DP method with bases, Au precursors deposited on the surface of $TiO_2$ and then reduced to the Au nanoparticles in the diameter of 4-5 nm on the surface of $TiO_2$ by the reaction with trisodium citrate.

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Pyrosol법에 의한 ZnO투명전도막의 전기적 광학적 특성 (Electrical and Optical Properties of ZnO Transparent Conducting Thin Films by Pyrosol Deposition Method)

  • 조우영;송진수;강기환;윤경훈;임경수
    • 대한전기학회논문지
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    • 제43권6호
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    • pp.965-970
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    • 1994
  • ZnO transparent conducting oxide thin films have been prepared by Pyrosol deposition method and the effects of the different experimental variables on the electrical resistivity and optical transmittance of the prepared films have been investigated in details. The best film with a resistivity of about 8 X 10S0-2TΩcm and transmittance about 80% has been obtained at the substrate temperature of 4$25^{\circ}C$ by using HS12T+CHS13TOH(1:3) solvent and NS12T carrier gas after annealing at 20$0^{\circ}C$ for 40 minutes in vacuum. Furthermore, We have also found the effect of substrate temperature on crystallographic orientation and surface morphology. Annealing of the as-deposited film in vacuum leads to a substantial reduction in resistivity without affecting the optical transmittance and crystallographic orientation.

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플라즈마 CVD에 의한 고전압 비정질 실리콘 박막 트랜지스터의 제작 (Fabrication of High Voltage a-Si:H TFT Plasma Chemical Vapor Deposition)

  • Lee, Woo-Sun;Kang, Young-Chul;Kim, Hyung-Gon
    • 대한전기학회논문지
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    • 제43권2호
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    • pp.312-317
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    • 1994
  • We studied the fabrication and electrical characteristics of high voltage hydrogenerated amorphous silicon thin film transistor using plasma enchanced chemical vapor deposition(PECVD). The device shows 2500${\AA}$ SiOS12T, 400-1500${\AA}$ a-Si tickness, 350V output voltage and 9.55${\times}$10S04T average on/off current ratio. We found that the leakage current of high voltage TFT occurred 0-70V drain voltage. As the leakage current depend on the a-Si thickness, the leakage current of high voltage TFT decreased by reduction of the a-Si thickness.

Non-electrolytic Deposition of Silver on Tungsten Powders for Functionally Gradient Composite Powder

  • Lee, Jae-Ho;Change, Gun-Ho
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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    • pp.1225-1226
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    • 2006
  • Particles of high strength material when coated with silver offer a means of obtaining desirable electrical properties and high strength. The coating process employed aqueous ammoniacal silver-nitrate electrolytes with a formaldehyde solution as the reductant. Modifying additives were also applied. The reduction and subsequent deposition of silver occurred selectively on the surface of the tungsten particles. The morphologies of the coated particles were assessed by SEM imaging. The silver was uniformed coated on tungsten powder and its thickness was estimated to be approximately 100nm on the basis of a mass account.

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얕은 소오스/드레인 접합깊이가 deep submicron CMOSFET 소자 특성에 미치는 영향 (Dependence of deep submicron CMOSFET characteristics on shallow source/drain junction depth)

  • 노광명;고요환;박찬광;황성민;정하풍;정명준
    • 전자공학회논문지A
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    • 제33A권4호
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    • pp.112-120
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    • 1996
  • With the MOsES (mask oxide sidewall etch scheme)process which uses the conventional i-line stepper and isotropic wet etching, CMOSFET's with fine gate pattern of 0.1.mu.m CMOSFET device, the screening oxide is deposited before the low energy ion implantation for source/drain extensions and two step sidewall scheme is adopted. Through the characterization of 0.1.mu.m CMOSFET device, it is found that the screening oxide deposition sheme has larger capability of suppressing the short channel effects than two step sidewall schem. In cse of 200.angs.-thick screening oxide deposition, both NMOSFET and PMOSFET maintain good subthreshold characteristics down to 0.1.mu.m effective channel lengths, and show affordable drain saturation current reduction and low impact ionization rates.

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펄스 레이저 증착법에서 증착 각도 변화에 따른 ZnO 박막 형성 메카니즘 (Investigation on formation mechanism of ZnO thin films deposited by pulsed laser deposition depending on plume-substrate angles)

  • 김재원;강홍성;이상렬
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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    • pp.200-202
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    • 2004
  • ZnO thin films were grown at different plume-substrate angles by pulsed laser deposition(PLD). From the X-ray diffraction(XRD) result, all ZnO thin films were found to be well c-axis oriented and c-axis lattice constant approached the value of bulk ZnO as plume-substrate(P-S) angle decreased. The grain size of ZnO thin films measured by atomic force microscopy increased and the UV intensity of ZnO thin films investigated by photoluminescence increased as P-S angle decreased. It is found that the improvement of structural and optical properties mainly comes from the reduction of the flux of ablated species arriving on a substrate per a laser shot by tilting a substrate parallel to the plume propagation direction.

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