• Title/Summary/Keyword: flow contraction

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General Pharmacology of PEG-Hemoglobin SB1

  • Kim, Eun-Joo;Lee, Rae-Kyong;Bak, Ji-Yeong;Choi, Gyu-Kap
    • Biomolecules & Therapeutics
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    • v.7 no.2
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    • pp.170-177
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    • 1999
  • PEG-hemoglobin SB1 (SB1), which is a hemoglobin-based oxygen carrier, is intended to use as a safe blood substitute against brain ischemia and stroke. The general pharmacological profiles of SB1 were studied. The doses given were 0, 5, 10, 20 ml/kg and drugs were administered intravenously. The animals used for this study were mouse, rat and guinea pig. SB1 showed no effects on general behavior, motor coordination, spontaneous locomotor activity, hexobarbital sleeping time, anticonvulsant activity, analgesic activity, blood pressure and heart rate, left ventricular peak systolic pressure, left ventricular end diastolic pressure, left ventricular developing pressure, double product, heart rate, coronary flow rate, smooth muscle contraction using guinea pig ileum, gastrointestinal transport, gastric secretion, urinary volume and electrolyte excretion at all doses tested except the decrease of body temperature. These findings demonstrated that SB1 possesses no general pharmacological effects at all doses tested.

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Development of an integrative cardiovascular system model including cell-system and arterial network (세포-시스템 차원의 혈류역학적 심혈관 시스템 모델의 개발)

  • Shim, Eun-Bo;Jun, Hyung-Min
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.542-546
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    • 2008
  • In this study, we developed a whole cardiovascular system model combined with a Laplace heart based on the numerical cardiac cell model and a detailed arterial network structure. The present model incorporates the Laplace heart model and pulmonary model using the lumped parameter model with the distributed arterial system model. The Laplace heart plays a role of the pump consisted of the atrium and ventricle. We applied a cellular contraction model modulated by calcium concentration and action potential in the single cell. The numerical arterial model is based upon a numerical solution of the one-dimensional momentum equations and continuity equation of flow and vessel wall motion in a geometrically accurate branching network of the arterial system including energy losses at bifurcations. For validation of the present method, the computed pressure waves are compared with the existing experimental observations. Using the cell-system-arterial network combined model, the pathophysiological events from cells to arterial network are delineated.

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A Study on The Relation of O-mi(五味) and Sam-Eum-Sam-Yang(三陰三陽) (오미(五味)와 삼음삼양(三陰三陽)의 관계에 대한 고찰(考察))

  • Baik, You-Sang
    • Journal of Korean Medical classics
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    • v.20 no.4
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    • pp.81-90
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    • 2007
  • From the study on the relation of O-mi(五味) and Sam-Eum-Sam-Yang(三陰三陽), the conclusion is as follows. The system of Sam-Eum-Sam-Yang(三陰三陽) in human body expresses a kind of inner images[象] of continuous life, that implies many complex view-points, in both inside and out-side according to time flow. Besides, O-mi(五味) is one of very important native properties of all existences, that is accepted from the state they have been located in, and it includes the principles of real nature. Based on understanding of Sam-Eum-Sam-Yang(三陰三陽), when we investigate properties of O-mi(五味) for practical use, the concepts of contraction and extension[收散], softening and hardening[軟堅], and slowing and fastening[緩急], referred in Naegyeong(內經), directly express the images of Sam-Eum-Sam-Yang(三陰三陽).

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?Experimental Study on the Effects of Zanthoxyli Fructus and Fagarae mandshuricae Fructus (천초(川椒) 및 산초(山椒)의 효능(?能)에 관(關)한 실험적(實驗的) 연구(硏究))

  • O, Han-Gyun;Won, Jong-Hun;Jeong, Gyu-Man
    • The Journal of Pediatrics of Korean Medicine
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    • v.4 no.1
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    • pp.1-17
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    • 1990
  • ?In order to investigate effects of Zanthoxyli Fructus (Sample-A) and Fagarae mandshuricae Fructus (Sample-B), experimental study was performed through observation on isolated - ileum analgesic, hypothermal, anti-pyretic, anti-inflammatory, capillary permeability, blood flow rate, blood pressure and respiratory works. The results were as follows; 1. In spontaneous movement of mice isolated-ileum, both samples were noted to have strong inhibitory action after temporary contraction, and to show antagonism against acetylcholine chloride and barium chloride. 2. Both samples were showed to have antihistamin work on guinea pig isolated-ileum 3. In analgesic work by the acetic acid method, only Fagarae mandshuricae Fructus was proved to have significant analgesic effect in mice. 4. Both sample groups indicated anti-pyretic and anti-inflammatory effect. 5. Both samples were noted to have inhibitory effect against capillary permeability ?rise in mice. ?6. Both samples were noted to have dose-dependent falling effect on blood pressure in rabbits.

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Numerical Simulation of Viscoelastic Fluid Flow Through 4:1 Axi-symmetric Contraction Using Type-dependent Difference Method (형식에 따른 차분법을 이용한 축대칭 4:1 수축을 지나는 점탄성유동의 수치모사)

  • 유정열
    • The Korean Journal of Rheology
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    • v.7 no.2
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    • pp.110-119
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    • 1995
  • 본 연구에서는 Upper Convected Maxwll 유체 및 Leonov-like-Giesekus 유체모형 을 이용하여 축대칭 4:1수축을 지나는 점탄서유체의 유동을 수치해석하였다. 이러한 점탄성 유체의 대한 지배방정식이 타원형-쌍곡선형으로 형식변화되므로 이를 적절히 고려할수 있 는 형태의 와도방정식을 이용하여 수치해석을 수행하였다. 와도방정식의 수치해석에서는 형 식에 따른 차분법을 도입하였다. 두 유체모형에 대해서 Weissenberg수를 증가시키면서 탄 성의 효과가 모서리와류의 크기, 응력의 분포 지배방정식의 형식변화에 미치는 영향을 살펴 보았다. 수치해석결과 탄성의 효과가 증가할수록 모서리와류가 커지며, 평면유동의 경우보다 훨씬 큰 모서리와류가 관찰되어 기존의 실험결과와 잘 일치하는 것을 볼수 있었다. 또한 수 치해석 결과로부터 와도방정식의 형식변화를 확인할수 있었다.

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Response Analysis of the Coronary Circulation Under the T-PLS Operation via a Lumped System Model (집중시스템 모델을 이용한 이중박동 생명보조장치 작동하의 관상순환계 반응해석)

  • Ko, Hyung-Jong;Park, Jong-Cheon;Shim, Eun-Bo
    • Journal of the Korean Society of Industry Convergence
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    • v.12 no.1
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    • pp.27-33
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    • 2009
  • In this paper, a computational analysis using a lumped system model is performed to investigate the hemodynamics of coronary circulation under the operation of T-PLS relevant to the cardiac arrest cases. The coronary circulation system is assumed to be comprised of three compartments: coronary arteries, coronary capillaries, and coronary veins. The effect of myocardial muscle contraction or relaxation is represented by temporal variations in the bias pressure. To verify the present method, we analyzed the coronary circulation for normal case and then compared the results with the existing data. Numerical results on the cardiac arrest model showed that T-PLS can increase LAD flow significantly.

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Optimal Design and Test of Fuel-Rich Gas Generator

  • Lee, Changjin;Kwon, Sun-Tak
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2004.03a
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    • pp.560-564
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    • 2004
  • The optimal design and combustion analysis of the gas generator for Liquid Rocket Engine (LRE) were performed. A fuel-rich gas generator in open cycle turbopump system was designed for 10ton$_{f}$ in thrust with RP-1/Lox propellant. The optimal design was done for maximizing specific impulse of main combustion chamber with constraints of combustion temperature and power matching required by turbopump system. Design variables were selected as total mass flow rate to gas generator, O/F ratio in gas generator, turbine injection angle, partial admission ratio, and turbine rotational speed. Results of optimal design show the dimension of length, diameter, and contraction ratio of gas generator. Also, the combustion test was conducted to evaluate the performance of injector and combustion chamber. And the effect of the turbulence ring was investigated on the mixing enhancement in the chamber.r.

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Study on Design Parameters of Supersonic Ejectors to Simulate High Altitude Engine Test (고고도 엔진 성능모사를 위한 2차 노즐 목을 갖는 초음속 이젝터의 설계 인자 연구(Ⅱ))

  • Yoon, Si-Kyung;Yeom, Hyo-Won;Sung, Hong-Gye;Shin, Wan-Soon
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.11a
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    • pp.353-356
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    • 2008
  • The effects of design parameters of supersonic ejector system under the assumption of constant pressure mixing; such as mass flow rate ratio, area ratio, Primary mach number on ejector system performance were investigated by theoretical formulations. And for a given design condition and working fluid, Computational Fluid Dynamics was conducted.

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Hydrodynamic performance of a vertical slotted breakwater

  • George, Arun;Cho, Il Hyoung
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.12 no.1
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    • pp.468-478
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    • 2020
  • The wave interaction problem with a vertical slotted breakwater, consisting of impermeable upper, lower parts and a permeable middle part, has been studied theoretically. An analytical model was presented for the estimation of reflection and transmission of monochromatic waves by a slotted breakwater. The far-field solution of the wave scattering involving nonlinear porous boundary condition was obtained using eigenfunction expansion method. The empirical formula for drag coefficient in the near-field, representing energy dissipation across the slotted barrier, was determined by curve fitting of the numerical solutions of 2-D channel flow using CFD code StarCCM+. The theoretical model was validated with laboratory experiments for various configurations of a slotted barrier. It showed that the developed analytical model can correctly predict the energy dissipation caused by turbulent eddies due to sudden contraction and expansion of a slotted barrier. The present paper provides a synergetic approach of the analytical and numerical modelling with minimum CPU time, for better estimation of the hydrodynamic performance of slotted breakwater.

System Dynamics Approach to Progress Payment Regulations

  • JeongHoon Lee;Moonseo Park;Hyun-Soo Lee;Sungjoo Hwang
    • International conference on construction engineering and project management
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    • 2013.01a
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    • pp.181-187
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    • 2013
  • The construction market condition is getting worse because of global constructions slow down, low profit, market contraction and so on. For these reason, most construction companies depend on public construction projects which possible to protect construction fee, known as progress payment, by laws. Despite this law, problems of progress payment are constantly occurring and it has been main factors that hinder the construction cost's cash-flow in construction project. To solve this problem, many researchers suggested various solutions but most of solutions were focused on specific target as owner, general contractor, and subcontractor. So, most of solutions were insufficient consider about interaction between contractors. Because of these reasons, it was hard to reflected policy. This research aimed to use system dynamics to develop the model for the application and payment based on the regulations and papers. Also, performed a developed model's verification based on progress payment regulation's basic objectives.

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