• Title/Summary/Keyword: Inductive effect

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A Study on the Reclosing Overvoltage in 345 [kV] Transmission Line (345kV 계통 재투입과 전압 해석)

  • Yoon, Jae-Young;Park, Dong-Wook;Whang, Chi-Woo
    • Proceedings of the KIEE Conference
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    • 1990.11a
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    • pp.166-169
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    • 1990
  • The purpose of the circuit breaker on power system is to disconnect the faulty part from the system and to maintain the integrity of the system. With switching overvoltages are generated. When the system voltages become higher, switching overvoltage is important factor in insulation co-ordination. Since the no-load reclosing overvoltage with inductive source is severe, this paper deals with the reclosing overvoltage and the effect of closing resistor. This reclosing overvoltage of 27-bus model system with and without closing resistor is analyzed by using EMTP (Electro-Magnetic Transients Program) for both deterministic and Stochastic model.

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Design and Implementation of Wideband Microstrip Antenna with Resistive and Inductive Loading (저항성 및 유도성 부하를 가진 평판형 광대역 안테나의 설계 및 제작)

  • Jeon, Sang-Bong;Ahn, Chang-Hoi
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.6
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    • pp.1111-1116
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    • 2007
  • Antennas of the near field detection radar require little distortion in time domain caused by multi reflections between feed and open ends of the antenna, so that help to discriminate the target signal from the clutters. The resistive loading techniques have been used to reduce the late time distortions in order to prevent masking of target. In this paper, we design a microstrip antenna with two arms having sloted lines, which have inductance loading effect. Implemented antenna shows better performance on reducing late-time ringing, and the peak value of the received signal becomes 45% greater than the one by the antenna with two non-sloted lines.

Studies on Inhibition Factors and the Role of Phytochrome in the Floral Induction in Short-day Plants (단일식물의 개화유도를 조절하는 개화억제요소의 규명과 Phytochrome의 역할에 관한 연구)

  • 맹주선
    • Journal of Plant Biology
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    • v.19 no.1
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    • pp.14-18
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    • 1976
  • Inhibition of flowering in Lemna perpusilla 6746 by 30 mM sucrose was reversed by the addition of acetylcholine (>$10^{-4}M) supplemented with 10^{-4}M$ ascorbic acid to 1/10-strength Hunter's growth medium. The reversible effect of acetylcholine was found to be greater at early stages of flowering than in the later period. Promotive effects of both acetylcholine ($10^{-3}M) and eserine(10^{-5}M$) on flowering in the short-day plant under various photoperiodic conditions were studied. It was indicated that the application decreased length of the critical dark period for the floral induction, and it was also shown that the endogenous status of acetylcholine was involved in the floral response which had a correlation with phytochrome. Interruption of inductive dark periods by red irradiation (1min) immediately followed by far-red light (1 min) completely inhibited flowering, while the addition of acetylcholine and eserine to the medium under the same condition slightly promoted flowering, indicating possible involvement of phytochrome system in acetylcholine activity for photoperiodic sensitivity of floral response in Lemna perpusilla 6746.

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Screening bonding wire and the wideband characterization to reduce crosstalk between high density bonding wires (고밀도 본딩와이어간의 혼신감소를 위한 차폐 본딩왕이어 및 광대역 해석)

  • 이상동;이해영
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.7
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    • pp.92-98
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    • 1996
  • parallel bonding wires separaated with a screeing bonding wire are proposed and characterized in order to redue mutual coupling and parasitics of high-speed and high-density device packaging. The mehtod of moments (MoM) with the incorporation of the ohmic loss has been used in a wide range of frequencies. From the calculated results, we have found that the screening bonding wire effectively reduces inductive and capacitive crostalk levels more than 3dB. the parasitic self inductance is also reduced more than 12% by the screening effect. Therefore, for a general VLSi package, the packaging density can be increased more than 30% using the screening bonding wire. This screeing bonding wire and the analysis can be effectively used to reduce crosstalk and increase packaging density of high density devices.

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Electrical Characteristics of Langmuir-Blodgett Ultra Thin Films (Langmuir-Blodgett 초박막의 전기적 특성)

  • You, D.S.;Kang, H.;Choi, M.K.;Jeong, S.W.;Shon, B.C.;Kang, D.Y.
    • Proceedings of the KIEE Conference
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    • 1989.07a
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    • pp.374-376
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    • 1989
  • Ultra Tihn Film of 100 angstrom-order is fabricated by Langmuir-Blodgett technique. The conductivity of this this measured by the direction of either vertical or horizontal axis is results in a quite different value. Specific inductive capacity and effect of time variation of LB films are also considered.

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SCFL Application for Reducing Fault Current (고장전류 저감을 위한 초전도 한류기 적용)

  • Kim, Hak-Man;Kim, Jong-Yul;Choi, Sang-Bong;Moon, Young-Hwan;Sung, Ki-Chul
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.206-208
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    • 2002
  • The transmission system is designed to be protected by 40 kA rate of circuit breaker fer 345 tV system and 31.5 kA and 50 kA rate of circuit breaker for 154 kV system. The short circuit current shows the tendency of exceeding circuit breaker duty for some substations and the tendency will continue if an appropriate countermeasure will not be applied to. In order to solve this problem from the viewpoint of system operation, the 154 kV system is under reconfiguration to be radial systems. This paper presents application effect of resistive and inductive SCFL (Superconducting Fault Current Limiter to Korea power systems. An algorithm of SCFL site decision is suggested.

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Determination Times for Induction of Adventitious Shoots, Roots, Trichomes, and Calli from Segments of Arabidopsis thaliana by NAA and BA (애기장대(Arabidopsis thaliana)잎 절편에서 NAA와 BA에 의한 신초, 부정근, 모용 및 캘러스 형성 결정 시기)

  • Kim, Song-Lim;Han, Tae-Jin
    • Journal of Plant Biotechnology
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    • v.30 no.2
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    • pp.161-165
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    • 2003
  • The effect of NAA and Benzyladenine(BA) for determination times on the formation of adventitious shoots, roots trichmoes and calli in MS basal medium was investigated in leaf segments from ecotype 'Nosses' of Arabidopsis thalliana. Adventitious shoots, roots, trichomes and calli were formed fromed from leaf segments in a wede range of NAA and BA. The optimal combination of hormones for adventitious shoots formation, 20mg/L NAA for trichome formation, 100mg/L for callus formation. Inductive times for formation of adventitious shoots, roots, trichomes and calli were determined at 14, 4, 6 and 18 days respectively by periodical transfer of leaf segments from hormines containing media to hormone free medium.

Carbon nanotube antennas analysis and applications: review

  • El-sherbiny, Sh.G.;Wageh, S.;Elhalafawy, S.M.;Sharshar, A.A.
    • Advances in nano research
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    • v.1 no.1
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    • pp.13-27
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    • 2013
  • Carbon nanotube characterized by additional inductive effect as compared with the traditional conductors like copper wires of the same size. Consequently, carbon nanotubes have high characteristic impedance and slow wave propagation in comparison with traditional conductors. Due to these characteristics, carbon nanotubes can be used as antenna. In view of this, we describe and review the present research progress on carbon nanotube antennas. We present different analysis models and results which are developed to investigate the characteristics of CNT antennas. Then we conclude by summarizing the characteristics of CNT antennas and specifying the operating frequency limit.

Substituent Effects on the Binding Energies of Benzyl Alcohol-H2O Clusters: Ab initio Study

  • Ahn, Doo-Sik;Lee, Sung-Yul
    • Bulletin of the Korean Chemical Society
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    • v.23 no.2
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    • pp.262-266
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    • 2002
  • Computations are presented for the ortho- and para-substituted benzyl alcohol-$H_2O$ clusters. A variety of conformers are predicted, and their relative energies are compared. Binding energies of the clusters are computed, and detailed analysis is presented on the effects of substitution on the strength of the hydrogen bond in the clusters. F- and $NH_2-$ substituted clusters are studied to analyze the effects of electron-withdrawing and electron-pushing groups. In para-substituted clusters, the inductive effects are dominant, affecting the binding energies in opposite way depending on whether the hydroxyl group is proton-donating or -accepting. For ortho-substituted clusters, more direct involvement of the substituting group and the resulting geometry change of the hydrogen bond should be invoked to elucidate complicated pattern of the binding energy of the clusters.

The Structural distortion by a Substituent : Monosubstituted Benzene Derivative cases

  • Mhin, Byung-Jin
    • The Journal of Natural Sciences
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    • v.15 no.1
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    • pp.47-56
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    • 2005
  • The substituent dependence of geometric distortion through the two independent electronic substituent effects is analyzed for mono-substituted benzene derivatives of $C_{2v}$. Based on resonance structures, quantitative relationships expressing the resonance and field/inductive contribution terms in bond distortions are derived. The calculated field-effect parts of $C_{ipso}$_$C_{ortho}$ ring bonds increase and decrease compared to benzene for electropositive and electronegative substituents respectively. The nonbonded axial distance, $C_{ipso}$....$C_{para'}$ decreases for electronegative substituents and increases for electropositive substituents. As the electronegativity increases, the distance $C_{ortho}$....$C_{ortho'}$ increases. With the $\pi$-donors, $C_{meta}$....$C_{meta'}$ nonbonded distances are shorter compared to the ones of benzene, and for $\pi$-acceptors, the are longer. Our model based on valence bond approach predicts that the average bond length determined the area of ring, and the sum of the angles <$C_{ortho}$_$C_{ispo}$_$C_{ortho}$ and <$C_{meta}$_$C_{para}$_$C_{meta}$ determines the axial distance.

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