• Title/Summary/Keyword: j factor

검색결과 2,559건 처리시간 0.031초

Hormonal Regulation of Insulin-Like Growth Factor Binding Protein Secretion by a Bovine Mammary Epithelial Cell Line

  • Kim, W.Y.;Chow, J.C.;Hanigan, M.D.;Calvert, C.C.;Ha, J.K.;Baldwin, R.L.
    • Asian-Australasian Journal of Animal Sciences
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    • 제10권2호
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    • pp.233-239
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    • 1997
  • A mammary epithelial cell line (MAC-T) established as a model for lactation was utilized to identify and characterize effects of various hormones upon insulin-like growth factor binding protein secretion. Ligand and immunoblot analyses of conditioned media indicated that insulin-like growth factor binding protein-2 was secreted by MAC-T cells. Insulin-like growth factor-I stimulated insulin-like growth factor binding protein-2 secretion in a dose-dependent manner, but prolactin and bovine somatotropin did not alter insulin-like growth factor binding protein-2 secretion. Insulin increased and cortisol decreased insulin-like growth factor binding protein-2 secretion. Effects of insulin-like growth factor-I on insulin-like growth factor binding protein-2 secretion support previous studies using primary cultures of bovine mammary cells and bovine fibroblasts. Effects of cortisol and insulin on insulin-like growth factor binding protein-2 secretion may be explained by changes in protein synthesis. In addition, supraphysiological doses of insulin can cross-react with the insulin-like growth factor-I receptor and stimulate insulin-like growth factor binding protein-2 secretion. MAC-T cells provide a model system to study mechanisms that regulate local insulin-like growth factor-I bioactivity.

천연가스 사용설비 오염물질 배출특성 연구 (A Study on Characteristics of Pollutants from LNG Facilities)

  • 이중성;이현찬;유현석;한정옥
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
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    • pp.223-226
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    • 2004
  • The thesis examined the charactcri:stlC of pollutants exhausted from LNG facilities. So, combustion gas and concentration of greenhouse gas exhausted from gas boiler for home use, furnace facilities, electric power facilities, boiler for industrial use and boiler for heating fueled LNG is measured. And the exhaust factor of pollutants is produced by classify of pollutants in detail. And this exhaust factor is compared and investigated with data of a foreign nations.

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Transcription factor NF-kB as a potential biomarker of oxidative stress to evaluate antioxidant effects

  • Berg, Robin van den;Sierksma, Aafje;Hendriks, Henk F.J.;Vaes, Wouter H.J.
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2003년도 춘계학술대회 논문집
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    • pp.25-26
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    • 2003
  • There is increasing interest in the involvement of transcription factors, such as of the transcription factor NF-kB (nuclear factor-kB), in the pathogenesis of various diseases. The involvement ofNF-kB is especially of interest as it is activated by oxidative stress and its activation can be modulated by antioxidant compounds. (omitted)

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복합 전열 촉진 핀이 적용된 핀-관 열교환기의 성능에 대한 실험적 연구 (An Experimental Study on Air-Side Performance of Fin-and-Tube Heat Exchangers Having Compound Enhanced Fins)

  • 김내현
    • 한국산학기술학회논문지
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    • 제16권7호
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    • pp.4364-4374
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    • 2015
  • 본 연구에서는 복합 전열 촉진 핀 열교환기의 열전달 및 압력손실에 대하여 실험적으로 검토하였다. 비교를 위하여 널리 사용되는 루버 핀 열교환기에 대한 실험도 수행하였다. 핀 피치(1.5mm~1.7mm)와 열수(1열~3열)를 변화시키며 열전달 및 압력손실에 미치는 영향을 검토하였다. 실험범위에서 핀 피치가 j와 f 인자에 미치는 영향은 크지 않았다. 열수가 증가하면 j 인자는 감소하고 f 인자는 열수와 무관하였다. 루버 핀의 j와 f 인자가 복합 전열 촉진 핀의 값들보다 크게 나타났다. 1열의 경우 평균 j 인자와 f 인자는 23%, 27% 크고, 2열에서는 11%, 8%, 3열에서는 10%, 9% 크게 나타났다. 하지만 동일 압력 손실 대비 전열 성능은 복합 전열 촉진 핀 열교환기가 1열에서 6.4%, 2열에서 11.1%, 3열에서 13.6% 크게 나타났다. 기존 루버 핀 상관식은 j 인자를 과대 예측하고 f 인자를 과소 예측하였다.

채널 간격 변화에 따른 해수냉난방용 판형 열교환기의 열전달과 압력강하에 대한 수치해석적 연구 (A numerical study on heat transfer and pressure drop of plate heat exchanger using at seawater air conditioning with the variation of channel spaces)

  • 김현주;이호생;윤정인;손창효;정영권
    • Journal of Advanced Marine Engineering and Technology
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    • 제38권6호
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    • pp.704-709
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    • 2014
  • 판형열교환기는 해양온도차와 해수냉난방 시스템과 같은 해양플랜트 및 화학공업의 분야에 사용되어 왔다. 본 연구의 목적은 판형열교환기의 채널 간격과 같은 설계 변수를 결정하기 위해서 판형열교환기 내 열전달과 압력강하 특성을 분석하는 것이다. 본 논문에서는 판형열교환기의 채널 간격 변화에 따른 열전달 성능을 수치적으로 연구하였다. 수치적 분석 결과로부터 해수 유량 변화와 함께 j factor는 선형적으로 감소하였다. 판형열교환기 채널 간격 변화에 따라 유량이 증가할수록 j factor는 선형적으로 감소하였다. 그리고 유량의 증가와 함께 f factor는 선형적으로 감소하였다. 물측과 해수측의 열전달 특성과 압력강하 특성을 각각 더하여 비교한 결과, 열전달 성능은 2.4-2.4 mm가 가장 우수하므로, area goodness factor가 가장 우수함을 알 수 있었다.

J-적분과 균열선단개구변위에 관한 구속계수 m의 평가 (An Estimation of Constraint Factor on the ${\delta}_t$ Relationship)

  • 장석기
    • Journal of Advanced Marine Engineering and Technology
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    • 제24권6호
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    • pp.24-33
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    • 2000
  • This paper investigates the relationship between J-integral and crack tip opening displacement, ${\delta}_t$ using Gordens results of numerical analysis. Estimation were carried out for several strength levels such as ultimate, flow, yield, ultimate-flow, flow-yield stress to determine the influence of strain hardening and the ratio of crack length to width on the $J-{\delta}_t$ relationship. It was found that for SE(B) specimens, the $J-{\delta}_t$ relationship can be applied to relate J to ${\delta}_t$ as follows $J=m_j{\times}{\sigma}_i{\times}{\delta}_t$ where $m_j=1.27773+0.8307({\alpha}/W)$, ${\sigma}_i:{\sigma}_U$, ${\sigma}_{U-F}={\frac{1}{2}} ({\sigma}_U+{\sigma}_F$), ${\sigma}_F$, ${\sigma}_F}$ $Y=({\sigma}_F+{\sigma}_Y)$, ${\sigma}_Y$

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파형개선을 위한 방전등 안정기 개발 (Development of discharge lamp ballast for wave improvement)

  • 이오걸;송달섭;김태우;이준탁;송호신;김종기
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 학술대회 논문집 전문대학교육위원
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    • pp.85-88
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    • 2000
  • This paper was development a discharge lamp ballast in order to wave improvement of high power factor and high efficiency. The discharge lamp ballast consists of a power factor correction circuit and a correction circuit on switching frequency of inverter. Instead of passive power factor circuit, active power factor circuit is adopted. Because it has the advantage of size, weight, total harmonic distortion, out DC voltage regulation, and power factor. The power factor circuit with MG34262 is controlled by variable frequency discontinuous mode. Results experiments, discharge lamp ballast is showed to have excellent for the proposed electronic ballast's operation and characteristics.

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