• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집D
• /
• pp.715-720
• /
• 2001

The main reason for applying positive pressure variable clearance packing in fossil power plant is high efficiency and energy saving movement in the government. This study intends to analyze the turbine efficiency through the shaft packing improvement in thermal power plant and makes its comparison to that of the used packing.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
• /
• pp.195-198
• /
• 1996

The control objective of drum level of boiler in thermal power plant is to maintain drum level at constant setpoint regardless of disturbance such as main steam flow. The initial response of the drum level loop process is in a direction opposite to the final response. The drum level loop shows inverse response when the power is changed abruptly. We adopt fuzzy controller using knowledge base considering system dynamics for controlling drum level. Finally, the simulation result using the digital simulator for boiler system in Seoul Power Plant Unit 4 shows the validity of fuzzy controller.

• 한국에너지공학회:학술대회논문집
• /
• 한국에너지공학회 2003년도 춘계 학술발표회 논문집
• /
• pp.371-376
• /
• 2003

원자력 발전소에서 격납건물 계통의 건전성 유지는 냉각재상실사고(Loss of Coolant Accident: LOCA) 및 주증기관 파단(Main Steam Line Break : MSLB) 사고와 같은 설계기준사고 시 격납건물의 최대 온도/압력을 평가하는 격납건물 성능 평가는 격납용기 내에 방사능 물질을 효율적으로 가두어 방사능 피해로부터 공공의 안전을 확보할 수 있느냐 하는 관건이다.(중략)

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 2005년도 춘계학술발표회
• /
• pp.641-642
• /
• 2005

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
• /
• pp.127-128
• /
• 2013

Off-gas power plant is a renewable energy power plant which generate electrical energy using the low calorie FOG and BFG as main fuel. This combined cycle power plant is comprised of gas turbines, gas compressors, steam turbines, generators, and auxiliary equipment such as gas mixer, mixing tank, and gas cooler. In this paper, a off-gas power plant and development of its several equipment using CFD are introduced.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2013년도 추계학술대회 논문집
• /
• pp.868-869
• /
• 2013

• Natural Product Sciences
• /
• 제16권4호
• /
• pp.259-264
• /
• 2010

The essential oil fraction was obtained from the underground parts o of Ligusticum chuanxiong (Umbelliferae) by steam distillation, and its main components, Z-ligustilide and butylidene phthalide, were isolated by column chromatography. Its essential oil fraction and the isolated main components were examined for effects on their anti-inflammatory properties in RAW 264.7 macrophage cells to develop a new natural anti-inflammatory drug. The results showed that the L. chuanxiong essential oil fraction and its main components, Z-ligustilide and butylidene phthalide, inhibited the production of nitric oxide significantly in lipopolysaccharide (LPS)-treated RAW 264.7 cells. LPS-induced interleukin-$1{\beta}$ (IL-$1{\beta}$), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-$\alpha$) production was also decreased in a dose-dependent manner. In addition, western blot analysis revealed that the L. chuanxiong essential oil fraction and also its main components, Z-ligustilide, and butylidene phthalide reduced the expression levels of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS).

• 약학회지
• /
• 제55권5호
• /
• pp.398-403
• /
• 2011

Ligusticum chuanxiong (Umbelliferae) is a perennial herb that has been used for invigoration of blood in Korean traditional medicine. It is especially important in gynecological therapy of amenorrhea and dysmenorrhea. In this study, the essential oil of L. chuanxiong was obtained by steam distillation and its main components of L. chuanxiong, Z-ligustilide and butylidene phthalide, were isolated by silica gel column chromatography. We investigated the cytotoxic effects of the essential oil fraction of L. chuanxiong and its main components on MCF-7, HeLa and SK-Hep-1 cell lines by measuring the number of surviving cancer cells after treatment through direct cell counting and MTT analysis, and by examining the morphological changes under the microscope. The essential oil from the rhizomes of L. chuanxiong and its main components showed significant cytotoxic activities for all three tested cell lines. We also observed morphological changes of shrinking and blebbing in the membranes of the three cell lines, depending on the concentration of L. chaunxiong oil or its main components.

• Nuclear Engineering and Technology
• /
• 제38권2호
• /
• pp.163-174
• /
• 2006

The $Ph{\acute{e}}bus$ FP project is an international reactor safety project. Its main objective is to study the release, transport and retention of fission products in a severe accident of a light water reactor (LWR). The FPT4 test was performed with a fuel debris bed geometry, to look at late phase core degradation and the releases of low volatile fission products and actinides. Post Test Analyses results indicate that releases of noble gases (Xe, Kr) and high-volatile fission products (Cs, I) were nearly complete and comparable to those obtained during $Ph{\acute{e}}bus$ tests performed with a fuel bundle geometry (FPT1, FPT2). Volatile fission products such as Mo, Te, Rb, Sb were released significantly as in previous tests. Ba integral release was greater than that observed during FPT1. Release of Ru was comparable to that observed during FPT1 and FPT2. As in other $Ph{\acute{e}}bus$ tests, the Ru distribution suggests Ru volatilization followed by fast redeposition in the fuelled section. The similar release fraction for all lanthanides and fuel elements suggests the released fuel particles deposited onto the plenum surfaces. A blockage by molten material induced a steam by-pass which may explain some of the low releases. The revaporisation testing under different atmospheres (pure steam, $H_2/N_2$ and steam /$H_2$) and up to $1000^{\circ}C$ was performed on samples from the first upper plenum. These showed high releases of Cs for all the atmospheres tested. However, different kinetics of revaporisation were observed depending on the gas composition and temperature. Besides Cs, significant revaporisations of other elements were observed: e.g. Ag under reducing conditions, Cd and Sn in steam-containing atmospheres. Revaporisation of small amounts of fuel was also observed in pure steam atmosphere.

• Journal of the Korean Wood Science and Technology
• /
• 제33권1호통권129호
• /
• pp.77-86
• /
• 2005

표고버섯 폐골목의 대체에너지 자원으로서의 가능성을 살펴보기 위하여 폐골목을 사용연수별로 구분하고 동일 수종의 정상재와 함께 화학적, 물리적 성상을 비교, 조사하였다. 또한 폐골목에 잔존하는 효소에 의한 전처리 효과를 살펴보기 위하여 기존의 전처리 방법인 폭쇄처리법과 비교하였다. 사용연수에 따른 화학적 성상의 변화는 회분, 수용성 추출물, alkali 추출물, 유기용매 추출물 함량 모두 뚜렷한 경향을 나타내진 않았지만 균주를 접종한 직후 폐골목에서 정상재보다 높은 함량을 나타내었다. Holocellulose 함량은 큰 폭으로 감소하였고 다른 주성분인 lignin 함량은 균주 접종 전후에 큰 변화를 보여주지 않았지만 cellulose 함량이 큰 폭으로 감소한 것을 고려하면 균주에 의해 상당량의 lignin 분해가 진행되었다. 부후정도는 균주 접종 후 점차 증가하는 모습을 보였지만, 결정화도는 급격히 감소하였다. 폭쇄처리에 의한 화학적, 물리적 성상의 변화로서 수용성 추출물, alkali 추출물, 유기용매 추출물 함량은 큰 폭으로 증가하였고, holocellulose 함량도 소폭 상승하였지만 lignin 함량은 특별한 경향을 나타내지 않았다. 그러나 다른 추출물의 함량이 급격히 증가한 것을 고려하면 holocellulose와 lignin 모두 감소하였다고 생각된다. 폭쇄처리에 의한 결정화도의 감소는 균주 접종 후의 감소폭과 비슷한 결과를 나타내었고, 인위적으로 부후시킨 재료에 대한 lignin 함량은 폐골목의 함량보다 감소하여 잔존 효소에 의한 전처리 가능성을 나타내었다. 이상의 결과로 미루어 보아 폐골목은 대체에너지 자원으로서 충분한 가능성을 갖고 있다고 사료된다.