• 제목/요약/키워드: J300

검색결과 1,088건 처리시간 0.028초

고주파특성 측정을 통한 barium titanate의 주파수센서 및 온도센서 연구 (Microwave Characteristics of Barium Titanate for Frequency Sensor and Temperature Sensor)

  • 김진옥;한만흥
    • 센서학회지
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    • 제5권1호
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    • pp.9-14
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    • 1996
  • $WO_{3}$가 첨가된 $BaTiO_{3}$를 고상법으로 제작하여 상온에서 $160^{\circ}C$의 온도 범위와 300 kHz - 300 MHz의 주파수 범위에서 회로망분석기를 이용하여 2포트 S-파라메터 방법으로 고주파 저항, 리액턴스 및 임피던스를 측정하여 $130^{\circ}C$ 이하에서 주파수 및 온도센서로서의 가능성을 진단하였다.

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300 kN 현수애자의 설계를 위한 전계해석에 관한 연구 (A Study on Electric Field Analysis for 300 kN Suspension Insulator Design)

  • 김익수;최재구;문인욱;장원률;주병수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 E
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    • pp.2047-2050
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    • 1999
  • This paper presents some of the results of current research on 300 kN Suspension Insulator Design. In this paper, authors first used 2-dimensional field calculation to solve the electric field distribution of an insulator unit and insulator strings, and then 3-dimensional field calculation in order to overcome the shortcomings of 2-dimensional field calculation in which an axis-symmetrical coordinate has been used. And, it was found that the environmental configuration of 300 kN Suspension Insulator String gives great roles to the field distribution of the insulators.

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Hole-Trapping in Iodine-Doped Pentacene Films at Low Temperatures

  • Yun, W.J.;Cho, J.M.;Lee, J.K.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.70-73
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    • 2006
  • Pentacene films, grown on polyethylene terephthalate (PET) substrates, were doped with Iodine. ESR measurements were made for the films in the temperature range of 100-300 K. Two regimes of doping stages were discernible: a light (intercalation) doping regime and a heavy doping regime. The light doping regime was concluded to be dominated by localized holes that were trapped at low temperatures, which indicated trap states near the valence band edge.

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SA 508C-3강의 고온에서 J-R Curve 및 Tmat의 평가 (Evaluation of J-R Curve and Tmat of SA 508C-3 Steel at Elevated Temperature)

  • 임만배;차귀준
    • 한국해양공학회지
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    • 제12권3호통권29호
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    • pp.60-67
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    • 1998
  • In this study, the J-Resistance Curve and material tearing modulus of SA508-C3 steel, which is one of the used nuclear pressure vessel steel, are measured ar room temperature, $200^{circ}C$ and $300^{circ}C$ according to load ratio analysis and ASTM E813, ASTM E1152, respectively. It is observed that J-R curve and Tmat value decrease as the temperature level increase. Applicability of $T_j$ proposed by Paris et al as instability parameter for ductile material is investigated. It is concluded that results are the $T_j$ parameter may be used as a crack instability parameter.

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IGBT를 적용한 300kVA급 대용량 무정전전원장치 개발 (Development of the 300kVA Large Capacity IGBT UPS)

  • 변영복;김태진;조기연;박성준;김철우
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 F
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    • pp.2057-2059
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    • 1998
  • In order to maintain a high quality output voltage, conventional UPS systems use complex filters with large passive components. To overcome this drawback, real time feedback control schemes have been invested. However, these techniques require a high inverter switching frequency to dynamically adapt to changing load conditions reduce harmonics of the output voltage, thereby rendering the system inadequate for high power applications. This paper presents real time digital signal processor(DSP) control of a large capacity UPS system feeding nonlinear loads to provide a sinusoidal inverter output voltage, unity input power factor, low bus voltage ripple, and excellent transient response.

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Effects of Rapid Thermal Anneal on the Magnetoresistive Properties of Magnetic Tunnel Junction

  • Lee, K.I.;Lee, J.H.;K. Rhie;J.G. Ha;K.H. Shin
    • Journal of Magnetics
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    • 제6권4호
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    • pp.126-128
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    • 2001
  • The effect of rapid thermal anneal (RTA) has been investigated on the properties of an FeMn exchange-biased magnetic tunnel junction (MTJ) using magnetoresistance and I-V measurements and transmission electron microscopy (TEM). The tunneling magnetoresistance (TMR) in an as-grown MTJ is found to be ∼27%, while the TMR in MTJs annealed by RTA increases with annealing temperature up to 300$\^{C}$, reaching ∼46%. A TEM image reveals a structural change in the interface of A1$_2$O$_3$layer for the MTJ annealed by RTA at 300$\^{C}$. The oxide barrier parameters are found to vary abruptly with annealing time within a few ten seconds. Our results demonstrate that the present RTA enhances the magnetoresistive properties of MTJs.

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In Vitro Evaluation of Three Positional Isomers of mono-PEGylated Salmon Calcitonin

  • Jung, J.Y.;Youn, Y.S.;Oh, S.H.;Hong, S.T.;Lee, J.E.;Lee, S.O.;Lee, K.C.
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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    • pp.300.1-300.1
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    • 2003
  • Salmon calcitonin (sCT) is a therapeutic polypeptide hormone consisting of 32 amino acids (3432 Da). As with other bioactive peptide therapeutics, however, therapeutic use of sCT has been limited due to the problems of short circulating half-life and rapid proteolytic degradation. To get over this problem, the three positional isomers of mono-PEGylated sCT were prepared and among these, the best drug candiate for nasal application was chosen. (omitted)

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Selection of working fluid for cryosurgical probe considering biological heat transfer

  • Hwang, Gyu-Wan;Jeong, Sang-Kwon
    • 한국초전도ㆍ저온공학회논문지
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    • 제9권4호
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    • pp.46-49
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    • 2007
  • This paper describes the sensitive cooling performance change of J-T refrigerator for cryosurgical probe due to its working fluid. The analytical results of using 50 bar nitrous oxide are compared with the case of 300 bar argon. Bio-heat equation is numerically solved to investigate the effect of the probe temperature and the cooling power of the J-T refrigerator. The refrigerator using 50 bar nitrous oxide has larger cooling power above 185 K than the one with 300 bar argon, which enables fast cooling at early stage of cryosurgery, but the biological tissue away from the probe tends to be cooled slowly after the probe reaches its lowest operating temperature. When the repeated freeze-thaw cycle is employed for main tissue destruction mechanism, using high pressure nitrous oxide is more advantageous than argon if the freezing operation is within 2-3 minutes. The probe with high pressure argon is more suitable for the case of longer freeze-thaw cycle with fewer repetitions.