• 제목/요약/키워드: R&D team

검색결과 1,474건 처리시간 0.031초

노즐 용삭을 고려한 복합 소호형 차단기의 압력 상승 계산 (Calculation of Pressure Rise of Self-blast Circuit Breaker considering Nozzle Ablation)

  • 배채윤;안희섭;정영우;최종웅;오일성
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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    • pp.677-678
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    • 2006
  • Pressure risc is an important design factor and affects significantly on the characteristics of gas circuit breakers. For self-blast circuit breakers, the nozzle ablation plays important role in pressure-building up and should be properly considered for the accurate calculation. In this paper, the nozzle ablation is treated as a boundary condition and the pressure is calculated from mass fractions of PTFE and SF6. The amount of the ablated mass of a nozzle is assumed to be proportional to the are energy and the area of nozzle surface that directly touches arc. The calculation result is compared with measured data and shows good agreement with it.

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인덕션 쿡탑 기구물 형상변경이 Heatsink 및 Coil 냉각성능에 미치는 영향에 대한 연구 (Study on the Cooling Performance of Heatsink for Induction Cooktop using Computational Fluid Dynamics)

  • 박동호;권명근;이동범;서응렬;박용종
    • 한국유체기계학회 논문집
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    • 제18권3호
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    • pp.33-37
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    • 2015
  • A numerical study on the IPM/Bridge Diode cooling and coil cooling has been performed. Results are presented as plots of thermal resistance, temperature drop and RPM-ratio. CFD analysis for conventional cooling system has been performed as a reference case. As the RPM-Ratio was increased, heatsink thermal resistance and coil temperature were decreased. IPM/Bridge Diode thermal resistance and temperature of the coil is tended to be trade-off. The temperature of coil closest to the AC-motor fan showed the most significant change in accordance with duct design. The temperature of coil located at the top of DC-motor fan showed the most significant variation as the cooling air passes the heatsink fin area.

유채 전초 추출물 유래 항산화 및 항염 활성 성분 (Anti-oxidative and Anti-inflammatory Constituents from the Extracts of Brassica napus L. Whole Plant)

  • 조연정;현주미;강지미;김창윤;이남호
    • 생약학회지
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    • 제53권3호
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    • pp.125-132
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    • 2022
  • In this study, we investigated anti-oxidative and anti-inflammatory efficacy, and identified their constituents from Brassica napus L. (Korean name: Yuchae) whole plant. Upon the anti-oxidative activities screening, the ethanol extract exhibited potent DPPH and ABTS+ radical scavenging activities. On the anti-inflammation studies using LPS-induced RAW264.7 cells, the extract inhibited the production of NO and pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) effectively. To identify major constituents of B. napus extract, further purification was performed and led to isolation of two compounds; isorhamnetin 3,7-O-diglucoside(1) and isorhamnetin 3-O-glucoside(2). Quantitative analysis by high pressure liquid chromatography (HPLC) determined the flavonoid 1 as the major constituent. Isolated compounds showed DPPH radical scavenging effects and decreased NO levels without causing cell toxicities. These results indicate that the extract of Yuchae, a rich plant resource in Jeju Island, could be potentially applicable as an anti-oxidative and/or anti-inflammatory ingredients.

145kv GIS용 스프링 조작기 부품 해석의 신뢰성 향상에 관한 연구 (A Study on the Reliability Improvement of Part Analysis in a Spring Operating Mechanism for 145kv GIS)

  • 김승오;석호일;한동영;임동수;최원호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.6-8
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    • 2005
  • 스프링 조작기는 초고압 GIS, GCB 등의 개폐장치를 구동시키는 조작 장치로서 동작 중 부품에 큰 충격력 및 힘이 작용하여 파손되는 경우가 발생한다. 이에 개발 설계 단계에서 스프링 조작기의 구조적 건전성 확보를 위해 각 부품에 작용하는 힘을 예측하여 평가, 검증하는 해석 및 시험 기술이 요구된다. 본 논문에서는 145kV GIS용 스프링 조작기를 ADAMS로 다물체 동역학 해석을 수행하여 추출한 부품의 조인트 반력을 이용하여 응력 해석을 수행하였다. 그리고 그 결과와 응력측정 시험 데이터와의 비교를 통해 해석의 신뢰성을 검증할 수 있었다. 여기서는 한 예로 커넥팅 로드에 대한 신뢰성 평가를 시행하였다.

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전기로를 위한 하이브리드 STATCOM에 대한 연구 (Research on Hydrid STATCOM for Electric Arc Furnaces)

  • 김상현;김동환;권병기
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2014년도 추계학술대회 논문집
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    • pp.173-174
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    • 2014
  • STATCOM은 전기로와 같은 무효전력 부하원에서 전원 안정화를 목적으로 산업응용분야에 널리 적용되고 있다. 하지만 시스템 비용 절감 등의 이유로 커패시터 뱅크와 함게 운용되는 Hybrid STATCOM의 적용이 요구되어 왔다. 본 논문에서는 포스코ICT에서 개발한 5Mvar Hybrid STATCOM(static synchronous compensator)에 대해 기술하였다.

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Driving technologies for AMOLEDs

  • Matsueda, Yojiro;Kim, Hong-Kwon;Chung, Ho-Kyoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.393-398
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    • 2006
  • This paper classifies driving technologies for AMOLEDs by the driving TFT conditions in pixels. A saturation region operation type driving TFT circuit provides good stability of OLED because of constant current drive. However, complicated compensation circuits are necessary to avoid effect of the TFT characteristics deviation. On the other hand, a linear region operation type driving TFT circuit provides better uniformity of the display image and lower power consumption. However, the stability of OLED is critical because of constant voltage drive.

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