• Title/Summary/Keyword: complex fluids

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Studies on Dissolution of Fentiazac from ${\beta}-Cyclodextrin$ Inclusion Complex (${\beta}$-씨클로덱스트린 포접화합물로부터 펜티아작의 용출)

  • Yoon, Hyung-Joong;Back, Un-Bong;Seo, Seong-Hoon;Kim, Soo-Uck
    • Journal of Pharmaceutical Investigation
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    • v.20 no.3
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    • pp.153-159
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    • 1990
  • To increase the solubility of fentiazac which is used widely as a non-steroidal antiinflammatory drug, its inclusion complex and suppositories were prepared and studied. Inclusion complexes of fentiazac with ${\beta}-cyclodertin$ $({\beta}-CyD)$ were prepared by four diffrent methods; coprecipitation method, kneading method, solvent evaporation method, freeze drying method. Suppositories of $fentiazac/{\beta}-CyD$ with PEG 1500 and Witepsol H-15 were prepared by solvent evaporation method and freeze drying method. Inclusion complex formation of fentiazac with ${\beta}-CyD$ was ascertained by powder X-ray diffractometry, differential scanning calorimetry and IR spectroscopy. The dissolution rate of fentiazac from the inclusion complex increased in distilled water and KP 2nd disintegration test fluids (pH 6.8) but extemly decreased in KP 1st disintegration test fluid (pH 1.2). Inclusion complexes prepared by freeze drying method and solvent evaporation method were similar. Freeze drying method seemed to be suitable for preparation of complex with most higher dissolution rate but coprecipitation method seemed not to be suitable. The dissolution rate of fentiazac increased markedly by ${\beta}-CyD$ complexation. The release rates of suppositories increased in the following order. Complex prepared by freeze dying method in PEG 1500 > complex prepared by solvent evaporation method in PEG 1500 > fentiazac in PEG 1500 > complex prepared by freeze dying method in Witepsol H-15 > complex prepared by solvent evaporation method in Witepsol H-15 > fentiazac in Witepsol H-15.

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Flow Characteristics in a Multistage Axial Turbine (다단 축류형 터빈의 유동 특성 해석)

  • Um InSik;Park Jun Young;Baek Je Hyun
    • 한국전산유체공학회:학술대회논문집
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    • 2000.10a
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    • pp.149-154
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    • 2000
  • The flows through a turbomachinery tend to be extremely complex due to its inherent unsteady and viscous phenomena. A good analysis of the flows associated with rotor/stator interactions in turbomachinery will be great help in design stage. In this investigation, unsteady viscous flow structurts through one and half stage of UTRC large scale rotating axial turbine are analysed. The numerical data was compared with experimental data and showed good agreement.

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Development of a Three Dimensional Mesh Generation Program for CFD Simulations (CFD 해석을 위한 3차원 격자생성 프로그램의 개발)

  • Chang J.;Kim S.-R.;Hur N.
    • 한국전산유체공학회:학술대회논문집
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    • 2001.10a
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    • pp.157-163
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    • 2001
  • In the present study a mesh generation program is developed for three dimensional flow analyses with complex geometry. By the present program one can define vertices using various coordinate systems and cells for finite volume approach. Rendered display of the generated mesh can be also available in both orthographic and perspective projection modes. Through perspective projection mode, one can check the quality of generated mesh by moving around inside the mesh like a virtual reality. The examples of the program execution is given in the paper.

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Determination of enalapril in human blood by high-performance liquid chromatography mass spectrometer.

  • Chang, Dong-Jin;Shim, Chang-Koo;Chung, Suk-Jae
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.418.3-419
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    • 2002
  • Enalapril. a prodrug. is the ethyl ester of a long-acting angiotensin converting enzyme inhibitor. enalaprilat. Because enalapril does not contain any appreciable chromophore. detection of the drug in a complex matrix (e.g.. biological fluids) has been problematic with conventional detection systems in high-performance liquid chromatography (HPLC). As a result. determination of enalaprillevel in blood samples has been typically carried out using HPLC-MS/MS in the literature. (omitted)

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Numerical Simulation on Flows inside an Engine Room with Radiator and Cooling Fan Models (방열기 및 냉각팬을 고려한 엔진룸 내부유동 해석)

  • Kim S. L.;Lee S. C.;Lee K. H.;Hur N.
    • 한국전산유체공학회:학술대회논문집
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    • 1995.10a
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    • pp.70-75
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    • 1995
  • Recently, for the thermal system design in an engine room, the importance of the numerical analysis on the heat and fluid flow has been recognized. In the present study, the flow inside an engine room with complex geometry was analysed by use of TURBO-3D program being developed in KIST. Radiator and Cooling fan were simulated by porous media and momentum sources, and the result shows a good agreement with our expectation.

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Numerical Simulation and Visualization of The Flow Around Savonius Rotor

  • Miyashita Kazuko;Kawamura Tetuya
    • 한국전산유체공학회:학술대회논문집
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    • 2003.10a
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    • pp.258-259
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    • 2003
  • Flow around Savonius rotor is studied by means of the numerical simulation. Three-dimensional incompressible Navier-Stokes equations are solved numerically. Overgrid system is employed in order to enable the flow calculation of complex geometry. The basic equations in each region are solved by using the standard MAC method. The physical quantities such as the velocity and the pressure among each region are transferred through the overlapping region which is common in each region. Some numerical results of static and rotating rotor will be presented.

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Large Eddy Simulation of Turbulent Combustion Flow Based on 2-scaler flamelet approach

  • Oshima, Nobuyuki;Tominaga, Takuji
    • 한국전산유체공학회:학술대회논문집
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    • 2006.10a
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    • pp.18-21
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    • 2006
  • This paper investigates LES of turbulent combustion flow based on 2-scalar flamelet approach, where a G-equation and a conserved scalar equation simulate a propagation of premixed flame and a diffusion combustion process, respectively. The turbulent SGS modeling on these flamelet combustion approach is also researched. These LES models are applied to an industrial flows in a full scale gasturbine combustor with premixed and non-premixed flames. The numerical results predict the characteristics of experiment temperature profiles. Unsteady features of complex flames in combustor are also visualized.

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An Upwind Meshfree Method for the Supersonic Flow

  • Ahn, Mu-Young;Chang, Keun-Shik
    • 한국전산유체공학회:학술대회논문집
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    • 2006.10a
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    • pp.74-75
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    • 2006
  • Recently much attention has been drawn to meshfree method since conventional methods such as FDM, FVM and FEM have suffered from difficulty with mesh generation for complex geometry and deformable bodies. In this paper, an upwind point collocation meshfree method developed by the authors is applied to two shock wave diffraction problems. One is the shock diffraction over a 90-degree corner and the other is the single Mach reflection on a ramp. The scheme showed stability and the results showed accuracy.

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Steady Stokes flow analysis using Axial Green's Function Formulation (축그린함수법을 이용한 정상상태의 스톡스유동해석)

  • Kim, D.W.
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.256-258
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    • 2011
  • Using the axial Green's function method for Steady Stokes flows, we introduce a new pressure correction formula to satisfy the incompressibility condition, in which the pressure is related to the integral of the second order derivatives of the velocity. Based on this formula, we propose the iterative method for solving the Stokes flows in complicated domains. Even if the domain is complex, this method maintains the second order of convergence for the velocity.

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Assay development and HTS on microfluidic Lab-on-a-chip

  • Yang, Eun-Gyeong
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2002.07a
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    • pp.73-78
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    • 2002
  • Microfluidic lab-on-a-chip (LOC) systems have enabled a new generation ofassay technologies in chemical and biomedical sciences. Caliper's microfluidic LOC systems contain a network of microscopic channels through which fluids and chemical are moved in order to perform experiments. The main advantages of these continuous-flow devices are integration and automation of multiple steps in complex analytical procedures to improve the reproducibility of the results, and eliminated the manual labor, time and pipetting errors involved in analyses. The present talk is devoted to give a brief introduction of microfluidic basics and to present in applying continuous-flow microchips to drug screening with model enzyme assays.

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