• 제목/요약/키워드: F-V characteristics

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음극전극의 종류에 따른 유기발광소자의 특성에 관한 연구 (A Study on Characteristics of Organic Light-Emitting Device with Various Cathodes)

  • 노병규;김중연;오환술
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 추계종합학술대회 논문집(2)
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    • pp.37-40
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    • 2000
  • This paper has been studied on characteristics of organic light-emitting device with various cathode materials. These catode materials were Al:Li(5%), Al, Cu, CsF/Al. And in these devices, HTL(hole transfer layer) was TPD and EML(emitting layer) was Alq$\sub$3/. We studied the I-V characteristics for each device. And then, the turn-on voltage of device for Al-Li(5%), Al, Cu, CsF/Al cathode were 7, 9, 13, 3V respectively. So, the CsF/Al cathode is superior to other cathode materials for I-V characteristics.

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Electrical Properties of F16CuPC Single Layer FET and F16CuPc/CuPc Double Layer FET

  • Lee, Ho-Shik;Park, Yong-Pil;Cheon, Min-Woo
    • Transactions on Electrical and Electronic Materials
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    • 제8권4호
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    • pp.174-177
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    • 2007
  • We fabricated organic field-effect transistors (OFETs) based a fluorinated copper phthalocyanine ($F_{16}CuPC$) and copper phthalocyanine (CuPc) as an active layer. And we observed the surface morphology of the $F_{16}CuPC$ thin film. The $F_{16}CuPC$ thin film thickness was 40 nm, and the channel length was $50{\mu}m$, channel width was 3 mm. And we also fabricated the $F_{16}CuPc/CuPc$ double layer FET and with different $F_{16}CuPc$ film thickness devices. We observed the typical current-voltage (I-V) characteristics and capacitance-voltage (C-V) in $F_{16}CuPc$ FET and we calculated the effective mobility. From the double layer FET devices, we observed the higher drain current more than single layer FET devices.

V2F 난류모형을 이용한 초음속 램프유동의 해석 (Computation of Supersonic Ramp Flow with V2F Turbulence Mode)

  • 박창환;박승오
    • 한국전산유체공학회지
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    • 제8권2호
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    • pp.1-7
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    • 2003
  • The V2F turbulence model, which has shown very good performance in several test cases at low speeds, has been applied to supersonic ramp flow with 20. corner angle at the free stream Mach number of 2.79. The flow is known to manifest strong shock wave/turbulent boundary layer interactions. As a comparative study, low-Reynolds k-ε models are also considered. While the V2F model predicts wall-pressure distribution well, it relatively predicts larger separation bubble and higher skin-friction after the reattachment than the experimental data. Although the ellpticity of f equation is the characteristics of incompressible flows, the converged solutions are acquired in the compressible flow with shock waves. The effect of the realizability constraints used in the model is also examined. In contrast to the result of impinging jet flows, the realizability bounds proposed by Durbin deterioate the overall solutions of the supersonic ramp flow.

Effect of surgical castration treatments on blood parameters and behavioral characteristics in Korean native cattle (Hanwoo)

  • Kim, Byeong-Soo
    • 한국동물위생학회지
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    • 제39권4호
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    • pp.221-226
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    • 2016
  • The animal welfare issues in cattle breeding include breeding environment, elimination, and castration. Among these, castration is unavoidable because it decreases cattle aggressiveness, improves meat quality, and enhances feed efficiency. In this study, the degree of stress associated with various methods of castration treatment was investigated for animal welfare in Hanwoo breeding. Cortisol levels dramatically increased right after castration in both the SoF and SoV groups. However, the increase in the SoF group was significantly (P<0.05) higher than that in the SoV group, and the range of decrease was also smaller. Among the behavioral characteristics, standing was significantly (P<0.05) higher in the SoV ($374.93{\pm}21.51$) and SoF ($379.93{\pm}21.30$) groups based on the behavioral time (min/12 hours) compared to that in the NC group ($359.37{\pm}19.69$). The SoF and SoV groups did not show any significant (P<0.05) difference. In terms of behavioral frequency, the NC group demonstrated a significantly (P<0.05) high frequency of drinking, self-grooming, scratching, and rubbing, and a significantly (P<0.05) less frequency of fighting behavior. The feeding time significantly (P<0.05) decreased in the SoV and SoF groups, and their frequencies of pairwise grooming were significantly (P<0.05) less. Based on the results, the cattle experienced less stress during castration by a veterinarian than during treatment using a move-stop.

리브 간격 변화에 따른 열.유동 수치해석 및 압력 저하 특성 (Numerical Analysis of Thermal and Flow affected by the variation of rib interval and Pressure drop Characteristics)

  • 정한식;이경환;신용한;최순호;정효민
    • Journal of Advanced Marine Engineering and Technology
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    • 제35권5호
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    • pp.616-624
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    • 2011
  • 본 연구에서는 사각채널내에 주유속 방향에 가로지르게 배치된 반원 리브의 난류 유동에 대한 유동 특성과 열전달 증대에 관해 수치해석적으로 살펴보았다. 사각채널의 종횡비는 5이고, 수력직경 대비 리브 높이비는 0.07, 사각채널 높이 대비 리브 높이비는 0.117로서 리브 높이 대비 리브 피치비가 8~14인 리브를 주기적으로 배열하여 연구를 수행하였다. 난류 모델의 선정은 실제 현상과 근접한 벽 근처 유동 특성과 열전달을 위해 SST k-${\omega}$ 난류 모델과 v2-f 난류 모델을 이용하였다. 수치해석의 결과는 실험에 의 해 관찰된 난류 유동 특성, 열전달 및 마찰계수의 결과를 잘 예측함을 보여준다. 본 결과에서 난류 운동 에너지가 재순환류 영역의 확산과 밀접한 관련이 있음을 알 수 있고 v2-f 난류 모델이 SST k-${\omega}$ 난류 모델에 비해 실험결과를 더 잘 예측하였다.

SPMSM의 센서리스 V/f 운전 시 MTPA 제어 기법 (A MTPA Control Method for Sensorless V/f Operation of SPMSMs)

  • 김원재;김상훈
    • 전력전자학회논문지
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    • 제23권4호
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    • pp.240-246
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    • 2018
  • In this paper, a sensorless V/f control based on maximum torque per ampere (MTPA) operation for PMSMs is proposed. Given that the MTPA operation is not considered in the conventional sensorless V/f control, efficient PMSM drives cannot be achieved. Therefore, this paper proposes an improved technique based on the d-axis current control to enable the MTPA operation in the V/f control for PMSMs. A stabilization technique is also proposed to improve the dynamic characteristics and stability against load variation. The effectiveness of the proposed technique is verified by conducting experiments with a 250 W SPMSM for driving a blower.

$CaSiN_2$를 모체로 하는 형광체의 개발 및 발광 특성 (Development and Luminescent Characteristics of $CaSiN_2$ Based Phosphors)

  • 이순석;임성규
    • 전자공학회논문지D
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    • 제36D권10호
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    • pp.31-36
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    • 1999
  • 질소 화합물의 새로운 형광체를 개발하기 위하여 $CaSiN_2:Eu,\;CaSiN_2:Tb$ 형광체를 합성한 후, 빛 발광 (photoluminescence, PL) 및 전계 발광(electroluminescence, EL) 특성을 평가하였다. $Ca_3N_2$, $Si_3N_4$$EuF_3$ 또는 $TbF_3$의 미분말을 혼합, 성형 및 소결하여 질소 화합물 형광체를 합성하였다. 합성된 $CaSiN_2:Eu,\;CaSiN_2:Tb$ 형광체의 PL 특성이 각각 Eu, Tb 이온에 의한 고유한 발광 파장과 일치하여 형광체로의 활용 가능성을 확인하였다. 스퍼터링 방법으로 제작된 $CaSiN_2:Eu$ 박막 전계 발광(thin-film electroluminescence, TFEL) 소자의 문턱 전압과 280 V에서의 발광 휘도는 각각 90 V, 1.62 $cd/m^2$ 임을 알 수 있었다. 또한 change-voltage(Q-V) 및 transferred charge-phosphor Field($Q_t-F_p$)의 전기적 특성도 함께 측정되었다.

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말레에이트계 유기초박막의 가스 반응 특성 분석 (Analysis of Gas Response Characteristics of Maleate Organic Ultra-thin Films)

  • 최용성;김정명;김도균;권영수
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제48권6호
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    • pp.442-450
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    • 1999
  • In this paper, we have fabricated Langmuir-Blodgett(LB) films by LB technique and evaluated the deposited status of LB films by UV-vis absorbance. It was found thatthe thickness of LB films per a layer are $27~30[{\AA}]$ by ellipsometry. The responeses between LB films and organic gases were investigated using by I-V characteristics of LB films and F-R diagram of quartz crystal. The response orders between LB films and organic gases observed by I-V characteristics were as following ; chloroform, methanol, acetone and ethanol in the order of their short chain length. The response mechanism between LB films and organic gases observed by F-R diagram of quartz crystal could be modeled on adsorption at surface, penetration, desorption at surface and inside.

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$F_{16}CuPC$를 활성층으로 사용한 유기전계효과트랜지스터의 바이폴라 특성연구 (Bipolar Characteristics of Organic Field-effect Transistor Using F16CuPc with Active Layer)

  • 이호식;박용필;천민우;김태곤;김영표
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 하계학술대회 논문집
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    • pp.303-304
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    • 2009
  • We fabricated organic field-effect transistors (OFETs) based a fluorinated copper phthalocyanine. ($F_{16}CuPc$) as an active layer. And we observed the surface morphology of the $F_{16}CuPc$ thin film. The $F_{16}CuPc$ thin film thickness was 40nm, and the channel length was $50{\mu}m$, channel width was 3mm. We observed the typical current-voltage (I-V) characteristics and capacitance-voltage (C-V) in $F_{16}CuPc$ FET and we calculated the effective mobility.

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연료용 알콜의 고온생산을 위한 고온성 효모 Saccharomyces cerevisiae F38-1의 분리 (Isolation of Saccharomyces cerevisiae F38-1, a Thermotolerant Yeast for Fuel Alcohol Production at Higher Temperature)

  • 김재완;진익렬;서정훈
    • 한국미생물·생명공학회지
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    • 제23권5호
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    • pp.617-623
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    • 1995
  • A new thermotolerant yeast strain was siolated, and its characteristics have been studied. The strain was identified and named Saccharomyces cerevisiae F38-1. This strain could grow not only at high temperature, but also in high concentrations of sugar and ethanol. S. cerevisiae F38-1 could grow in a medium containing 50% glucose. The isolate produced ethanol at 43$\circ$C, but didn't grow at 40$\circ$C in the presence of 8% ethanol. Fermentation studies showed that the isolate ferments 20% glucose to 9.8% (V/V) ethanol at 40$\circ$C in the presence of 0.2%, yeast extract.

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