• 제목/요약/키워드: VAC

검색결과 225건 처리시간 0.052초

Influence of Shrinkage and Stretch During Drying on Paper Properties

  • Torbjorn Wahlstrom
    • 펄프종이기술
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    • 제31권5호
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    • pp.31-46
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    • 1999
  • A drying paper strives to shrink due to the shrinkage of the individual paper fibres. Laboratory results show that a reduction of the shrinkage or an imposed stretch leads to a large increase in tensile stiffness and a large decrease in strain at break. In c cylinder drying section the water in the web is repeatedly heated on the drying cylinder and evaporated in the free draw. To evaluate the drying process regarding influence on paper properties these sub-processes, or drying phases, have to be studied separately. The effect of the conditions on the drying cylinder and on the VacRoll is investigated in pilot trails. Both the fabric tension on the drying cylinder and on the VacRoll reduces the shrinkage of the paper. The laboratory results are used as input to a numerical simulation of the conditions in the free draw. If the web width is increased or the length of the free draw is reduced the mean shrinkage of the paper web is reduced . However, the difference in shrinkage between the middle and the edge of the web is increased.

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선천성 영아 섬유육종 (Congenital Infantile Fibrosarcoma)

  • 김태형;정재희;송영택
    • Advances in pediatric surgery
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    • 제10권1호
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    • pp.52-55
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    • 2004
  • A newborn male baby was transferred to our hospital with a left inguinal mass. The mass was huge measuring $10{\times}10cm$, engorged, and dark-blue colored as a result of internal hemorrhage. Unstable vital signs were combined with DIC and acute renal failure. Emergency operation was performed because of the suspicion of bowel perforation. The peritoneal cavity was full of ascitis and the distal jejunum had a 0.5 cm perforation. Segmental resection of the jejunum and incisional biopsy of the inguinal mass were performed. On pelvic and thigh MRI, the mass protruded into pelvic cavity and encircled large vessels and nerves of the thigh. Pathologic diagnosis was congenital infantile fibrosarcoma. Fifteen days after operation, primary tumor excision was undertaken. The second look operation, performed after 6 times VAC chemotherapy, revealed no remained malignant cell on microscopic section. The baby has been followed closely for the last eight months.

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RTGC의 연료절감을 위한 전압 보상 컨버터에 관한 연구 (A Study on the Voltage Compensation Converter to decrease fuel consumption of RTGC)

  • 바이사;류지수;한동화;이영진;이상호;최규하
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2011년도 전력전자학술대회
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    • pp.280-282
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    • 2011
  • This paper presents a development of voltage compensation dc/dc converter to decrease fuel consumption of RTGC system. We used 3-phase interleaved converter, which has the same structure as the commercially available three-phase inverter, is used. RTGC system is supplied the power from diesel-engine generator. According to power demand, engine speed is varying 20~60Hz, and voltage is varying 210Vac ~ 480Vac. When idle mode or low power operation dc/dc converter operates by constant output voltage control. The perpormance of converter is evaluated through several experiments with a real RTGC. Proposed system can cut down fuel consumption by 36% at idle mode operation.

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무접점 베터리 충전 장치용 Half-Bridge 직렬 공진 컨버터 분석 및 설계 (Analysis and Design of Half-Bridge Series Resonant Converter for Non-Contact Battery Charger)

  • 김창균;유정식;박종후;조보형;서동현
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 F
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    • pp.2508-2511
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    • 1999
  • A non-contact battery charger which transfers energy using magnetic field without any electrical contacts is designed using half-bridge series resonant converter. This converter utilizes series resonance to reduce the undesirable effect of large leakage inductance of the non-contact transformer and ZVS operation can reduce switching losses. In this paper. analysis and design procedure of half-bridge series resonant converter with non-contact transformer is presented. Input voltage is 85VAC ${\sim}$ 270VAC, output voltage and current is 4.1V and 800mA, respectively. Furthermore, a method for calculating the secondary current of the transformer to control battery charging current in constant current charging mode which is required for litium-ion battery is proposed and the performance is verified from experiments.

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Model-on-demand Predictive Control of Polymerization Reactor Systems

  • Hur, Su-Mi;Park, Myung-June;Rhee, Hyun-Ku
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.97.2-97
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    • 2001
  • This work is concerned with the improvement of the productivity and the product quality in the polymerization reactors by using model-on-demand predictive control(MoDPC). This technique is applied to a continuous styrene polymerization reactor and a semibatch methyl methacrylate (MMA)/vinyl acetate(VAc) copolymerization reactor. The regress is constructed with the most influential variables the conversion and the jacket inlet temperature for the styrene polymerization reactor, and the free volume and the reactor temperature for the MMA/VAc copolymerization reactor through open loop operations. From the simulation results for setpoint tracking and disturbance rejection problems, it is demonstrated that the MoDPC shows ...

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고주파링크 전력계통 연계형 PCS (High Frequency Link PCS for Interfacing with Power Utility System)

  • 정봉근;윤광호;이광호;김은수;차인수
    • 전력전자학회논문지
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    • 제15권1호
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    • pp.60-68
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    • 2010
  • 최근 PCS(Power Conditioning System)는 고효율, 고 전력밀도 및 고 기능화를 통해 고집적화 추세에 있다. 이러한 요구를 만족시키기 위해 LLC 공진인버터와 LF 사이클로 컨버터로 구성된 회로를 제안했다. 동작분석 및 1kW 시제품을 제작하여 110Vac, 60Hz 전원계통연계실험 통해 적용 가능함을 보였으며 이에 대한 실험결과를 서술하였다.

대형 교통신호용 LED 구동 SMPS 설계 (Design of LED Driving SMPS for Large Traffic Signal Lamp)

  • 신현용
    • 한국전자통신학회논문지
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    • 제4권2호
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    • pp.123-129
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    • 2009
  • 본 연구에서는 철도 및 공항 등 대형 교통수단의 표시등으로 사용하기 위한 LED 신호등 구동회로를 설계하고 제작된 SMPS의 전기적 특성을 측정하였다. 입력전압 8~12VAC 및 8~16VDC에 대하여 출력전압, 출력전류 및 전력효율은 각각 6VDC, 1.85ADC 및 >70%이었다. 또한 규정한 AC 입력전압에 대하여 측정한 역률은 모두 0.75 이상의 값을 얻었다.

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