• 제목/요약/키워드: SRO

검색결과 34건 처리시간 0.025초

Characterization of SrRuO3 Conducting Thin Films Grown on p-Si (100) Substrates by Metalorganic Chemical Vapor Deposition

  • Cuong Nguyen Duy;Yoon, Soon-Gil
    • Transactions on Electrical and Electronic Materials
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    • 제6권1호
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    • pp.14-17
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    • 2005
  • The SrRuO_{3}$ films for application of the bottom electrode were deposited on p-Si (001) substrates by metalorganic chemical vapor deposition (MOCVD). The films are characterized by various deposition parameters. The optimum deposition condition for SRO films is the deposition temperature of $500{\circ}C$, Sr/Ru input mol ratio of 1.0, and a flow rate of precursors of 15 ml/h. The films deposited by an optimum condition exhibited a single phase of SrRuO_{3}$, an rms roughness of 8 nm, and a resistivity of approximately $900{\mu}{\Omega}{\cdot}cm$. The high resistivity of the films for application of a bottom electrode should be improved through a characterization of an interface.

Processing of $Si_3N_4/SiC$ and Boron-Modified Nanocomposites Via Ceramic Precursor Route

  • Lee, Hyung-Bock;Rajiv S. Mishra;Matt J. Gasch;Han, Young-Hwan;Amiya K. Mukherjee
    • The Korean Journal of Ceramics
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    • 제6권3호
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    • pp.245-249
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    • 2000
  • Consolidation of amorphous powders is emerging as a route for synthesis of high strength composite materials. Diffusion processes necessary for consolidation are expected to be more rapid in amorphous state(SRO) than in the crystalline state(LRO). A new synthesis technique of exploiting polymeric ceramic precursors(polysilazane and polyborosilazane) is derived for Si$_3$N$_4$/SiC and boron-modified nanocomposites for extremely high temperature applications up to 200$0^{\circ}C$. The characterization methods include thermal analysis of DTA, and XRD, NMR, TEM, after pyrolysis, as a function of time and temperature.

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원자력발전소 시뮬레이터 기술규제 고찰 (Investigation of the Regulatory Requirements for Nuclear Power Plant Simulators)

  • 홍진혁
    • 한국시뮬레이션학회:학술대회논문집
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    • 한국시뮬레이션학회 1999년도 추계학술대회 논문집
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    • pp.299-307
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    • 1999
  • 원자력 발전소 시뮬레이터는 고도의 안전성과 정밀성을 바탕으로 운전원이 실제 상황과 동일한 환경하에서 실습할 수 있도록 모의 훈련장치로서 발전소 운전원 운전능력 배양, 운전절차서 검증 및 개발, 제어기법 사전 점검 및 안전도 분석, 운전방법 개선 등을 가능케 하고 있다. TMI 사고이후 원자력발전소 시뮬레이터의 중요성이 강조되어 운전원 훈련의 필수요건으로 추가되고 있으며, NRC 등에 의해 인허가된 시뮬레이터를 운전원 시험 (RO, SRO 시험)에 사용토록 하고 있다. 우리나라에서는 아직 인허가를 요구하고 있지 않지만 조만간 시뮬레이터에 대한 규제가 예상되고 있다. 그러나 현재 시뮬레이터에 대한 규제요건 분석이 제대로 이루어지지 않고 있는 실정이다. 이를 위해 본 논문에서는 시뮬레이터에 대한 미국 등 외국의 규제 방침, 기준 및 요건 등을 분석하고 있으며, 향후 기존 시뮬레이터 개정 및 신규 시뮬레이터 개발시 규제요건 만족에 상당한 도움을 줄 수 있을 것이다.

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흉부단층촬영시(胸部斷層撮影時) 피폭선량(被曝線量)의 저감(低減)에 관(關)한 연구(硏究) (A Study on Reduction of Exposure Dose in Tomography of the Chest)

  • 반야유;이만구;임태랑;석전유치;전전미향;앵정달야;박영희;김창남;신동식
    • 대한방사선기술학회지:방사선기술과학
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    • 제17권2호
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    • pp.29-35
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    • 1994
  • Tomographic examination requires several times of exposure usually, therefore, reduction of radiation dose per exposure without loss of image quality proves of great benefit to patient. We compared the exposure doses under the following experimental conditions, A and B. A is the combination of SRO 380(rare earth screen) and SRH(high contrast film) with additional Cu filters or without. B is the widely used combination which is BH-III and Cronex-4 without additional filter. As a result, comparing with the condition B, the condition A with additional filter of Cu 0.15 mm + Al 0.7 mm, Cu 0.4 mm+ Al 0.4 mm and Cu 0.8 mm showed better Image quality and lower surface dose, 44 %, 31 % and 24 % of the condition B, respectively.

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플라즈마를 이용한 FGR 기반 저 NOx 연소 타당성 연구 (Feasibility Study of Low NOx Combustion based on FGR using Plasma Reformer)

  • 김관태;이대훈;차민석;길상인;윤진한;김동현;송영훈
    • 한국연소학회지
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    • 제12권3호
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    • pp.1-7
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    • 2007
  • A combined hydrogen generator of plasma and catalytic reformer was developed, and was applied to stabilize unstable flame of 200,000 Kcal/hr LPG combustor. The role of the plasma reformer was to generate hydrogen in a short period and to heat-up the catalytic reformer during the start-up time. After the start-up period, the catalytic reformer generates hydrogen through steam reforming with oxygen (SRO) reactions. The maximum capacity of the hydrogen generator was enough 100 lpm to stabilize the flame of the present combustor. In order to reduce NOx and CO emissions simultaneously, 1) FGR (Flue Gas Recirculation) technique has been adopted and 2) the hydrogen was added into the fuel supplied to the combustor. Test results showed that the addition of 25% hydrogen and 30% FGR rate lead to simultaneous decrease of CO and NOx emissions. The technique developed in the present study showed good potential to replace $NH_3$ SCR technique, especially in the small-scale combustor applications.

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저 NOx 연소를 위한 플라즈마 개질기 (Plasma Reformer for Low NOx Combustion)

  • 김관태;이대훈;차민석;길상인;윤진한;송영훈
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2007년도 제34회 KOSCO SYMPOSIUM 논문집
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    • pp.187-190
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    • 2007
  • A combined hydrogen generator of plasma and catalytic reformers has been developed, and has been applied to stabilize unstable flame of 200,000 Kcal/hr LPG combustor. The role of the plasma reformer is to generate hydrogen in a short period and to heat-up the catalytic reformer during the start-up time. After the start-up period, the catalytic reformer generates hydrogen through steam reforming with oxygen (SRO) reactions. The maximum capacity of the hydrogen generator is 100 lpm that is sufficient to be used to stabilize the flame of the present combustor. In order to reduce NOx and CO emissions simultaneously, 1) FGR (Flue Gas Recirculation) technique has been adopted and 2) the hydrogen has been added into the fuel supplied to the combustor. Test results shows that 25 % addition of hydrogen and 30 % FGR rate lead to simultaneous decrease of CO and NOx emissions. The technique proposed in the present study shows good potential to replace $NH_3$ SCR technique, especially in the case of small-scale combustor applications.

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차량진동 및 Rotor 내구특성을 고려한 Brake System 의 최적설계 (Optimal Design of Brake System considering Vehicle Vibration and Durability of Rotor)

  • 김봉수;김희열;김강욱;손영균;이동근;박관흠
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집A
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    • pp.764-769
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    • 2001
  • Brake-induced vibrations of a vehicle such as brake judder are determined by the excitation of brake torque variations and by their transfer to the driver's contact points via suspension, body and steering system. The formation of brake torque variation is mainly determined by static and dynamic disk thickness variations. The vibration transfer from the excitation by brake torque variation to the perception by the driver depends on the kinematic and dynamic behaviour of the components in the transfer path. Optimization of the judder performance can be achieved either by minimizing the excitation or by reduction of the judder sensitivity of the vehicle. In this paper, the optimization process of a front rotor is suggested to reduce brake judder considering the cooling performance of the rotor, the judder sensitivity of the vehicle and durability of the rotor.

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펄스 레이저 증착법으로 $SrRuO_3$/Si 구조위에서 증착된 강유전체 $Pb(Zr_{0.2}Ti_{0.8})O_3$ 박막 (The ferroelectric $Pb(Zr_{0.2}Ti_{0.8})O_3$ thin film growth on $SrRuO_3$/Si structure by pulsed laser deposition)

  • 함성길;윤순길
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.302-302
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    • 2007
  • The $SrRuO_3$/Si thin film electrodes are grown with (00l) preferred orientations on SrO buffered-Si (001) substrates by pulsed laser deposition. The optimum conditions of SrO buffer layers for $SrRuO_3$ preferred orientations are the deposition temperature of $700^{\circ}C$, deposition pressure of $1\;{\times}\;10^{-6}\;Torr$, and the thickness of 6 nm. The 100nm thick-$SrRuO_3$ bottom electrodes deposited above $650^{\circ}C$ on SrO buffered-Si (001) substrates have a rms roughness of approximately $5.0\;{\AA}$ and a resistivity of 1700 -cm, exhibiting a (00l) relationship. The 100nm thick-$Pb(Zr_{0.2}Ti_{0.8})O_3$ thin films deposited at $575^{\circ}C$ have a (00l) preferred orientation and exhibit $2P_r$ of $40\;C/cm^2$, $E_c$ of 100 kV/cm, and leakage current of about $1\;{\times}\;10^{-7}\;A/cm^2$ at 1V.

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Hyperspectral Image Classification using EfficientNet-B4 with Search and Rescue Operation Algorithm

  • S.Srinivasan;K.Rajakumar
    • International Journal of Computer Science & Network Security
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    • 제23권12호
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    • pp.213-219
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    • 2023
  • In recent years, popularity of deep learning (DL) is increased due to its ability to extract features from Hyperspectral images. A lack of discrimination power in the features produced by traditional machine learning algorithms has resulted in poor classification results. It's also a study topic to find out how to get excellent classification results with limited samples without getting overfitting issues in hyperspectral images (HSIs). These issues can be addressed by utilising a new learning network structure developed in this study.EfficientNet-B4-Based Convolutional network (EN-B4), which is why it is critical to maintain a constant ratio between the dimensions of network resolution, width, and depth in order to achieve a balance. The weight of the proposed model is optimized by Search and Rescue Operations (SRO), which is inspired by the explorations carried out by humans during search and rescue processes. Tests were conducted on two datasets to verify the efficacy of EN-B4, with Indian Pines (IP) and the University of Pavia (UP) dataset. Experiments show that EN-B4 outperforms other state-of-the-art approaches in terms of classification accuracy.

여수산단 대기 중 휘발성유기화합물질 농도 경향 (Trends of Volitile Organic Compounds in the Ambient Air of Yeosu Industrial Complex)

  • 전준민;허당;김동술
    • 한국대기환경학회지
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    • 제19권6호
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    • pp.663-677
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    • 2003
  • The concentrations of volatile organic compounds (VOCs) in the ambient air were measured at three sites (Samil-dong, SRO and EFMC) in Yeosu industrial complex during September 2000 to August 2001. Air samples were collected for 24 hours in Silicocan canister (6l) with constant flow samplers every 6 days and analyzed using a cryogenic preconcentration system and a GC/MS. At each site, we identified 35 species known as on both the carcinogenic and mutagenicity by the EPA US (TO-14 manual). No relationship was found between YOCs concentration at three sampling points. Furthermore, the result shows that there appears to be a variety distribution of the concentration. BTX, vinyl chloride and high concentrations of 1,2-dichloroethane were observed at the sampling sites. Especially, high concentration of toxic VOCs, such as vinyl chloride, chloroform, 1,2-dichloroethane and benzene were shown at environmental facilities management cooperation (EMFC) site. They seem to be emitted from the facility of wastewater treatment in Yeosu industrial complex. It was difficult to tell the seasonal variation of total VOCs concentration. Nevertheless, the concentration in winter was typically higher than in summer The concentrations of toxic VOCs contents in Yeosu industrial complex were generally lower than those in Ulsan complex, although those were similar or less than in Seoul and Daegu. Whereas, toluene and styrene emitted from Yeosu industrial complex were higher than those of Edmonton industrial complex in Canada. Especially, toluene was third times higher than those observed from Texas, USA.