• Title/Summary/Keyword: V.K.T.

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Analysis of Insulator Failures Altar Installation of Arcing Horns in 154kV Transmission Lines (154kV 송전선로 Arcing Horn 적용에 따른 애자련 사고분석)

  • Cho, S.B.;Lee, H.K.
    • Proceedings of the KIEE Conference
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    • 1998.07e
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    • pp.1743-1745
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    • 1998
  • Insulators of 154kV T/L have been frequently damaged by fault currents. Arcing horn is a very effective and economic method for protection of insulators from the flashover. We developed arcing horns for 154kV T/L in order to protect insulators from the arc[1]. This paper analyzes the status of insulator failures in 154kV T/L after installation of the arcing horns.

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A study on thermally stimulatede current in semi-insulating GaAs (반절연성 GaAs에서 열자극 전류에 관한 연구)

  • 배인호;김기홍;김인수;최현태;이철욱;이정열
    • Electrical & Electronic Materials
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    • v.7 no.5
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    • pp.383-388
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    • 1994
  • Deep levels in semi-insulating GaAs were observed by thermally stimulated current(TSC) measurement In the temperature ranges of 100-300K Tl(E$\_$c/-0.18eV), T2(E$\_$c/-0.20eV), T3(E$\_$c/-0.31eV), T4(E$\_$c/-0.40eV), and T5(E$\_$c/-O.43eV) traps have been observed. The TI, T2, and T5 traps seem to be related to the V$\_$As/, V$\_$Ga/-complex, and As$\_$Ga/$\^$++/ respectively. T4 trap is considered with respect to V$\_$Ga/-V$\_$As/ complex.

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MAGFET Hybrid IC with Frequency Output (주파수 출력을 갖는 MAGFET Hybrid IC)

  • Kim, Si-Hon;Lee, Cheol-Woo;Nam, Tae-Chul
    • Journal of Sensor Science and Technology
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    • v.6 no.3
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    • pp.194-199
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    • 1997
  • When voltage or current gets out of the magnetic sensor as it is, we have often faced the problems such as introduction of noise and loss of voltage. In order to reduce these problems, a 2 drain MAGFET operating in the saturation region and fabricated by CMOS process, the system of I/V converter, VCO with operational amplifier, and V/F conversion circuits with Schmitt Trigger are designed and fabricated in one package. The absolute sensitivity of magnetic sensor shows 1.9 V/T and the product sensitivity is $3.2{\times}10^{4}\;V/A{\cdot}T$. The characteristic of V/F conversion is very stabilized and has the value of 190 kHz/T.

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Effects of Trichosanthes kirilowii Maxim and Scutellaria baicalensis Georgi on $IL-1{\beta}-induced$ GnT-III and V in Melanoma B-16 (Melanoma B-16에서 $IL-1{\beta}$ 유발 GnT-III, V 활성에 대한 과루인(瓜蔞仁), 황금(黃芩) 추출물의 영향(影響))

  • Seo, Woon-Gyo;Jeong, Ji-Cheon
    • THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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    • v.5 no.1
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    • pp.103-118
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    • 1999
  • The activity of N-acetylglucosamitnyltransferase(GnT) III and V on a Melanoma B-16 was examined after incubation with interleukin 1 (IL-1). While augumenting cell proliferation, IL-1 resulted in a decrease of GnT-III activity and an increase of GnT-V activities. Consistant with this, Melanoma B-16 cultured with IL-1 showed increased affinlity to Daturam stramonium lectin, which recognizes asialo-tri- and asialeo-tetra-antenery N-linked oligosaccharides. These results indicate that IL-1 modulate glycosyltransferase activity and the oligosaccharide structure of target cells. On the other hand, to investigate whether or not TKM-SG affect GnT-V gene expression in lung metastatic carcinoma, we used RT-PCR methods. TKM-SG treated cell lines showed low levels of secretion of GnT-V mRNA transcription as elucidated by RT-PCR. Thus, with together lower GnT-V activity levels in the medium, TKM-SG was highly effective for lung cancer metastasis treatment and it was concluded that the medicine can be used as a potent anti-lung cancer metastasis medicine.

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Water Treatment Characteristics by Const ucted Wetland with Different Vegetation - Open Water Arrangements (식생습지와 개방수역의 배열에 따른 인공습지의 수처리 특성)

  • Jang, Jeong-Ryeol;Choi, Sun-Hwa;Kwun, Soon-Kuk
    • Journal of Korean Society on Water Environment
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    • v.23 no.1
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    • pp.122-130
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    • 2007
  • This study was conducted to evaluate water treatment characteristics according to vegetated wetland(V) and open water(O) arrangements in free water surface constructed wetland. Three pilot-scale wetlands, V-V, O-V and V-O, were built and operated. $BOD_5$ was a slightly reduced at all the arrangements because the influent concentration was so low as background concentration of constructed wetlands. While T-N and T-P removal efficiency showed higher than 50% for all cases. The O-V arrangement showed the highest removal efficiency: 20% for $BOD_5$, 56% for SS, 59% for T-N and 72% for T-P. Effluent concentration of the O-V were significantly low compared with those from the V-O. O-V arrangement would be beneficial in the light of pollutant removal efficiency as well as construction cost.

A summary of KEPCO's 765kV substation design (한전 765kV 변전소의 기본설계 개요)

  • Kim, M.D.;Jung, S.H.;Kim, J.H.
    • Proceedings of the KIEE Conference
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    • 1999.07e
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    • pp.2139-2142
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    • 1999
  • 765kV substations which will be the core installation of the bulk power transmission system in Korea for the upcoming $21^{st}$ century, were designed of outdoor full GIS type to minimize required area. As principal equipment, main transformers of 2,000 MVA per bank and 50kA 8,000A gas insulated switchgears of up-to-date technology were adopted in designing substations to transmit bulk power of 10GW. Dual digital protective relay systems and distributed indication and control systems with fiber optic LAN were used.

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A Study on the Fabrication of CsI(T1) Radiation Sensor and its Spectroscopic Characteristics (CsI(T1) 방사선센서의 제작 및 분광특성 연구)

  • 권수일;신동호
    • Progress in Medical Physics
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    • v.13 no.1
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    • pp.44-50
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    • 2002
  • CsI(T1) single crystal was grown in a Bridgman growing apparatus, which has the diameter of 11 mm and the mole ratio of 0.001 mol%. Radiation sensors were made with CsITl)crystal and two photodiodes, and measured spectroscopic characteristics and linearity for gamma-ray and X-ray. The energy resolution of CsI(T1) radiation sensor has been measured with $^{22}$ Na, $^{137}$ Cs and $^{60}$ Co gamma standard sources. Also output linearity of CsITl) sensor was measured for diagnostic radiation region. The energy resolutions of CsI(T1) radiation sensor for 0.511MeV gamma-ray from Na-22 source, 0.662MeV from Cs-137 source, and 1.17MeV and 1.332MeV from Co-60 source were 13.2%, 8.3%, 6.7%, and 5.1% respectively. Also the output linearity up to 80mAs current for 60kVp, 80kvp, 100kVp, 120kVp tube voltages has been studied.

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Characterization of Dextran Produced by L. mesenteroides ATCC 13146

  • Yoo, Sun-Kyun
    • 한국생물공학회:학술대회논문집
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    • 2005.10a
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    • pp.358-362
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    • 2005
  • High molecular weight dextran (39% alcohol, v/v), less soluble dextran, eluted from this column between T 500 and T 2000, a commercial linear dextran, Soluble dextran (45% alcohol, v/v) eluted at between T 70 and T 150 dextran. The molecular weight average of total dextran (50% alcohol, v/v) was between 150,000 to 500,000. A few oligosaccharides were detected from hydrolyzates of less soluble dextran. The hydrolyzates of soluble dextran were a family of DP 1 to 6 isomaltooligosaccharides. Compounds greater than DP 4 were branched isomaltooligosaacharides.

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VIABILITY FOR SEMILINEAR DIFFERENTIAL EQUATIONS OF RETARDED TYPE

  • Dong, Qixiang;Li, Gang
    • Bulletin of the Korean Mathematical Society
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    • v.44 no.4
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    • pp.731-742
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    • 2007
  • Let X be a Banach space, $A:D(A){\subset}X{\rightarrow}X$ the generator of a compact $C_0-semigroup\;S(t):X{\rightarrow}X,\;t{\geq}0$, D a locally closed subset in X, and $f:(a,b){\times}C([-q,0];X){\rightarrow}X$ a function of Caratheodory type. The main result of this paper is that a necessary and sufficient condition in order that D be a viable domain of the semi linear differential equation of retarded type $$u#(t)=Au(t)+f(t,u_t),\;t{\in}[t_0,\;t_0+T],{u_t}_0={\phi}{\in}C([-q,0];X)$$ is the tangency condition $$\limits_{h{\downarrow}0}^{lim\;inf\;h^{-1}d(S(h)v(0)+hf(t,v);D)=0}$$ for almost every $t{\in}(a,b)$ and every $v{\in}C([-q,0];X)\;with\;v(0){\in}D$.

Kinetics and Mechanism of Mutant O-acetylserine Sulfhydrylase-A (C43S) from Salmonella typhimurium LT-2

  • Yoon, Moon-Young
    • BMB Reports
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    • v.29 no.3
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    • pp.210-214
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    • 1996
  • The pH dependence of the kinetic parameters of mutant O-acetylserine sulfhydrylase (OASS) from Salmonella typhimurium LT-2 has been determined in order to obtain information on the chemical mechanism. The initial velocity pattern obtained by varying the concentrations of OAS at several fixed concentrations of TNB, shows an intersection on the left of the ordinate at pH 7.0, indicating that the kinetic mechanism is a sequential mechanism in which substrate inhibition by OAS is observed while the wild type enzyme showed a ping pong mechanism. The values of $V/E_t$, $V/K_{OAS}E_{t}$ and $V/K_{TNB}E_{t}$ decreased by about 68%, 14% and 16% as compared with the wild type enzyme. The $V/K_{OAS}E_{t}$ is a pK of 6.5 on the acid side of the pH profile, and the $V/K_{TNB}$ is pH independent. As compared with the wild type enzyme, the pKs in the V/K profiles are shifted, reflecting that binding of the cofactor in free E:OAS is less asymmetric.

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