• Title/Summary/Keyword: Equilibrium investigation

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Theoretical Model for the Electrical Resistance of Skin (피부의 전기적 저항에 대한 이론적 모델)

  • Oh, Seaung-Youl
    • Journal of Pharmaceutical Investigation
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    • v.26 no.3
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    • pp.207-213
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    • 1996
  • The kinetic change of electrical resistance of hairless mouse skin as a function of ionic strength of the bathing medium was determined from impedance measurements. After increasing (decreasing) the ionic strength of the bathing medium, resistance decreased (increased) continuously with time, finally reaching an equilibrium value. We have modelled this process, using nonsteady-state diffusion kinetics. The results show semi-quantitative correlation between theoretically derived and experimentally obtained values. Overall, this work provides further mechanistic insight into ion-conduction through the skin.

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Interaction of Beta-cyclodextrin with Some Pharmaceuticals (Beta-cyclodextrin과 의약품(醫藥品)과의 상호작용(相互作用))

  • Kim, Shin-Keun
    • Journal of Pharmaceutical Investigation
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    • v.4 no.1_2
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    • pp.13-18
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    • 1974
  • Data are present for the interaction of beta-cyclodextrin with 7 pharmaceuticals in aqueous solution. By means of the solubility method of analysis, definite interaction were found to occur with all the compounds tested. The amount of these pharmaceuticals in equilibrium with their respective solid phase increased progressively with beta-cyclodextrin. A concentration of 1.5 g of beta-cyclodextrin per 100 ml of water increased the solubility of most compounds tested (except one) by 15-120%. Hydrolysis in alkali solution of chrolothiazide was retarded in the presence of beta-cyclodextrin.

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Adsorption of Nalidixic Acid to Human Erythrocytes and Plasma (Nalidixic Acid의 혈구(血球) 및 혈장(血漿)에 대(對)한 흡착(吸着))

  • Kim, Shin-Keun
    • Journal of Pharmaceutical Investigation
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    • v.4 no.1_2
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    • pp.25-30
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    • 1974
  • The adsorption of nalidixic acid on human erythrocytes was found to expressed by Freundlich's isotherm. The amount of adsorption of nalidixic acid on erythrocytes increased with an increase of pH. The adsorption of nalidixic acid on human plasma was found to expressed at Scatchard's equation by the equilibrium dialysis method. An influence of pH on adsorption of nalidixic acid to human plasma proteins was studies at pH 4-10. It was found that the degree of adsorption increase with the increase of pH from 4-6, but descreased above pH 9.

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Small Signal Modeling for the PWM Series Resonant Converter (PWM-SRC) (펄스-폭 변조방식의 직렬공진 컨버터의 소신호 모델링)

  • Choi, Hyun-Chil
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.11
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    • pp.1441-1447
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    • 1999
  • A discrete time domain modeling is presented for the pulse-width modulated series resonant converter (PWM-SRC) with a discontinuous current mode. This nonlinear system is linearized about its equilibrium state to obtain a linear discrete time model for the investigation of small signal performances such as the stability and transient response. The usefulness of this small signal model is verified through the dynamic simulation.

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Binding of Nalidixic Acid with Plasma Protein -On the Species Difference in Binding- (Nalidixic Acid와 혈장단백(血漿蛋白)과 결합(結合)에 관(關)한 연구(硏究) -동물(動物)의 종속차(種屬差)에 대(對)하여-)

  • Kim, Shin-Keun
    • Journal of Pharmaceutical Investigation
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    • v.6 no.1
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    • pp.14-17
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    • 1976
  • Binding of nalidixic acid with plasma of male and female rats, dogs, and rabbits was studied in vitro using the method of equilibrium dialysis in 1/15 mole phosphate buffer (pH 7.4). Rat plasma had the most extensive binding capacity followed by dog and rabbit plasma, and the plasma of female had more extensive capability than male in rat and rabbit but it was reversed in dog.

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A Theoretical Investigation of FCO and $FCO^+$

  • Sung, Eun-Mo;Lee, Ho-Soon
    • Bulletin of the Korean Chemical Society
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    • v.11 no.6
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    • pp.511-515
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    • 1990
  • Ab initio calculations with MP3 and CISD method were performed for the FCO and $FCO^+$. The equilibrium geometry of FCO shows the reasonable agreement with experimental values. $FCO^+$ has a linear geometry with $R_{CF}=1.213\;and\;R_{CO}=1.118{\AA}$. The quadratic force constants of $FCO^+$ are 23.21 md ${\AA}^{-1}$ for CO stretch and 12.38 md ${\AA}^{-1}$ for CF stretch. The cubic force constants and the other molecular constants are also calculated.

Analytical Investigation of Water Transport

  • Um, Suk-Kee;Lee, Kwan-Soo;Jung, Hye-Mi
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.2250-2254
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    • 2007
  • Comprehensive analytical models focusing on the anode water loss, the cathode flooding, water equilibrium, and water management strategy are developed for polymer electrolyte fuel cells. Analytical solutions presented in this study are compared with two-dimensional computational results and shows a good agreement in predicting those critical characteristics of water. General features of water concentration profile as a function of membrane thickness and current density are presented to illustrate the net effect of the back-diffusion of water from the cathode to anode and the water production by the cathode catalytic reaction on water transport over a fuel cell domain. As one of practical applications, the required humidity level of feed streams for full saturation at the channel outlets are investigated as a function of the physical operating condition. These analytical models can provide good understanding on the characteristic water

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Investigation and Design of Underground Cavern for Oil Storage in Korea (국내원유비축지하공동의 조사 및 설계)

  • Kim Chee Whan;Lee Seok Chun
    • Explosives and Blasting
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    • v.12 no.1
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    • pp.32-38
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    • 1994
  • This study Is to summarize the contents for the investigation and design of the construction for oil storage. Since underground caverns are large scale, in their construction one should consider the mechanical stability of cave·rns and the economic view of construction. On the basis of them, cavern's section and layout were determined and water curtains were designed to maintain hydraulic equilibrium so that gases were sealed tightly. Also the supporting criteria for rock bolt and stotcrete were determined by means of the classification of rock masses and the results of finite element method. The criteria of grouting reinforcement were presented according to the results of injection test in the pilot holes of working face.

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Investigation and Design of Underground Cavern for Oil Storage in Korea (국내 원유 비축 지하공동의 조사 및 설계 사례)

  • 김치환
    • Tunnel and Underground Space
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    • v.2 no.2
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    • pp.190-198
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    • 1992
  • This study is to summarize the contents for the investigation and design of the construction for oil storage. Since underground caverns are large scale, in their construction one should consider the mechanical stability of caverns and the economic view of construction. On the basis of them, cavern's section and layout were determined and water curtains were designed to maintain hydraulic equilibrium so that gases were sealed tightly. Also the supporting criterial for rock bolt and stotcrete were determined by means of the classification of rock masses and the results of finite element method. The criteria of grouting reinforcement were presented according to the results of injection test in the pilot holes of working face.

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Numerical Investigation on the Thermal and Flow Characteristics of Combustion Heater for Commercial Vehicle (차량용 연소식 난방기의 열 및 유동특성에 대한 수치연구)

  • Hwang, Chang-Hwan;Baek, Seung-Wook
    • Journal of the Korean Society of Combustion
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    • v.16 no.2
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    • pp.40-46
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    • 2011
  • The diesel pre-heater has being used in cabin heating and coolant heating of engine to reduce the engine warm up time for commercial vehicle. The pre-heaters are classified as diesel spray combustor and it forms diffusion flame. By using swirler, a recirculation flow of hot product gases is established near the fuel nozzle and it helps the maintaining of diffusion flame. The design difference of swirler can affect on reaction characteristics and temperature distribution inside pre-heater. The purpose of this study is the investigation of the effect of swirler configuration on combustion characteristics. To solve spray combustion problem, the Euler-Lagrange approach discrete model is used to track droplet trajectory and evaporation history. The PDF equilibrium model is used for chemical reaction model. These models are implemented into the FLUENT code.