• 제목/요약/키워드: S-245

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SPMSM을 이용한 '245kV 40kA GIS' 조작기 개발 (Development of drive mechanism for 245kV 40kA high-voltage Gas Insulated Switchgear(GIS) using SPMSM)

  • 정균하;서경보;김정배;서인영
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 제39회 하계학술대회
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    • pp.980-981
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    • 2008
  • Mechanical spring and hydraulic pressure operated mechanisms are applied in most of today's High Voltage Gas Insulated Switchgear(GIS)s. This paper proposes a new type of operation mechanism for GIS circuit breakers rated at 245kV and 40kA. The Motor-Direct-Drive-Mechanism (MDDM) has many advantages compared to conventional operating mechanisms. It has a very simple structure with only one moving part, low mechanical stress and audible noise. It also allows monitoring, operation speed control and self-diagnosis functions.

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SPMSM을 이용한 245kV 40kA GIS 조작기 개발에 관한 연구 (A study on of drive mechanism for 245kV 40kA high-voltage Gas Insulated Switchgear(GIS) using SPMSM)

  • 정균하;오영진;여창호;서인영
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2007년도 하계학술대회 논문집
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    • pp.114-116
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    • 2007
  • Mechanical spring and hydraulic pressure operated mechanisms are applied in most of today's High Voltage Gas Insulated Switchgear(GIS)s. This paper proposes a new type of operation mechanism for GIS circuit breakers rated at 245kV and 40kA. The Motor-Direct-Drive-Mechanism (MDDM) has many advantages compared to conventional operating mechanisms. It has a very simple structure with only one moving part, low mechanical stress and audible noise. It also allows monitoring, operation speed control and self-diagnosis functions.

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Cytotoxic and Antitumor Constituents from Scutellaria indica

  • Bae, Ki-Hwan;Min, Byung-Sun;Ahn, Byung-Zun
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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    • pp.245-245
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    • 1994
  • From the active fraction, cytotoxic constituents 1-5 were isolated and identified to be 2(S)-5,7-dihydroxy-8,2'-dimethoxyflavanone (1), wogonin (5,7-dihydroxy-8-methoxyflavone, 2), 5,7-dihydruxy-8,2'-dimethoxyflavone (3), 2(5) -5,7,2'-trihydroxy-8-methoxyflavanone (4), 2(S) - 5,2',5'-trihydroxy-7,8-dimethoxyflavanone (5), respectively, with those of specimens$\^$1-2)/

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NOTES ON γ-OPEN SETS DEFINED BY γ-OPERATION ON A SUPRATOPOLOGICAL SPACE

  • Kim, Young Key;Min, Won Keun
    • 충청수학회지
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    • 제32권2호
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    • pp.245-250
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    • 2019
  • In this paper, the notion of ${\gamma}$-operation on a supratopological space is introduced. We found that the ${\gamma}$-operation induces a supratopology (topology) containing a given supratopology. We also introduce the notions of (${\gamma}$, S)-continuous function and almost ${\Gamma}$-supracompact defined by ${\gamma}$-operation on a supratopological space and investigate some properties for such notions.

R245fa 냉매를 이용한 배열회수 히트펌프 시스템 성능에 관한 실험적 연구 (Experimental Study on the Performance of Heat Recovery Heat Pump System using R245fa Refrigerant)

  • 김현택;김용찬;차동안;권오경
    • 설비공학논문집
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    • 제28권10호
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    • pp.408-413
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    • 2016
  • The objective of this study is to investigate the performance of a heat recovery heat pump dryer using a R245fa refrigerant experimentally. In this study, the main components of the heat pump dryer were an evaporator, a compressor, a condenser, and an expansion valve. As a result, when the amount of refrigerant varied from 15 kg to 16 kg, the hot air outlet temperature in the condenser and the heat transfer rate were almost kept constant. Therefore, the amount of refrigerant at 16 kg was considered to be a suitable amount in the heat pump. As the air inlet velocity varied from 0.5 m/s to 1.5 m/s, the highest temperature in the condenser could be obtained when the air inlet velocity was 0.5 m/s. The heat transfer rate, system (COP), and hot air outlet temperature were 5.6 kW, 3.4, and $102.5^{\circ}C$, respectively, when the bypass ratio and water temperature were 0% and $60^{\circ}C$.

NEW LAPLACE TRANSFORMS FOR THE GENERALIZED HYPERGEOMETRIC FUNCTION 2F2

  • KIM, YONG SUP;RATHIE, ARJUN K.;LEE, CHANG HYUN
    • 호남수학학술지
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    • 제37권2호
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    • pp.245-252
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    • 2015
  • This paper is in continuation of the paper very recently published [New Laplace transforms of Kummer's confluent hypergeometric functions, Math. Comp. Modelling, 55 (2012), 1068-1071]. In this paper, our main objective is to show one can obtain so far unknown Laplace transforms of three rather general cases of generalized hypergeometric function $_2F_2(x)$ by employing generalized Watson's, Dixon's and Whipple's summation theorems for the series $_3F_2$ obtained earlier in a series of three research papers by Lavoie et al. [5, 6, 7]. The results established in this paper may be useful in theoretical physics, engineering and mathematics.