• Title/Summary/Keyword: RPF Reduced Mechanism

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A DNS Study of Ignition Characteristics of Lean PRF/Air Mixtures under HCCI Conditions (HCCI 조건에 일어나는 희박 PRF/공기 혼합물의 점화특성에 관한 직접수치모사 연구)

  • Luong, Minh Bau;Yoo, Chun Sang
    • 한국연소학회:학술대회논문집
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    • 2012.11a
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    • pp.153-156
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    • 2012
  • Direct numerical simulations (DNSs) of ignition of lean primary reference fuel (PRF)/air mixtures under homogeneous charge compression ignition (HCCI) conditions are performed using 116-species reduced chemistry. The influence of variations in the initial temperature field, imposed by changing the variance of temperature, and the fuel composition on ignition of lean PRF/air mixtures is studied using the displacement speed analysis.

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Diuretic Action of Angiotensin II in Dog (Angiotensin Ⅱ의 이뇨작용(利尿作用))

  • Ko, Suk-Tai;Lee, Min-Jae;Hur, Young-Keun
    • YAKHAK HOEJI
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    • v.33 no.3
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    • pp.183-190
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    • 1989
  • Angiotensin II, adminstered (infused or injected) intravenously, elicited the antidiuretic action with the decreased parameters of renal function at a small dose ($0.01\;{\mu}g/kg/min$), whereas, at a large dose (0.03, $0.1\;{\mu}g/kg/min$ and $5.0\;{\mu}g/kg$), it produced the diuretic action accompanied the increased amounts of sodium and potassium excreted in urine ($E_{Na}\;and\;R_K$). At this time, glomerular filtration rates (GFR) were weakened slightly and renal plasma flows (RPF) were reduced markedly, and then filtration fractions (FF) were increased. Angiotensin II, infused into a renal artery, exhibited antidiuretic action at a small dose ($0.003\;{\mu}g/kg/min$), and diuretic action at a large dose ($0.01\;{\mu}g/kg/min$), only in infused (experimental) kidney. The mechanism of the action was similar to the cases of the intravenous angiotensin II. The above results suggest that angiotensin II of a large dose produced diuretic action due to mechanism inhibiting reabsorption of electrolytes in renal tubules, mainly in proximal tubule in dog.

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