• Title/Summary/Keyword: Internal flow control

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Effects of Pinelliae Rhizoma on immunocyte and cytokine production in asthma model mouse (반하(半夏)가 천식모델 생쥐의 면역세포 및 사이토카인에 미치는 영향)

  • Song, Jae-Jin;Park, Yang-Chun
    • The Journal of Internal Korean Medicine
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    • v.26 no.1
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    • pp.156-168
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    • 2005
  • Objective : The purpose of this research is to examine the effects of Pinelliae Rhizoma (PR) extract on immune cells and cytokines in ovalbumin (OVA)-induced asthmatic mice. Methods : In vivo, C57BL/6 mice were sensitized and handicapped by OVA for 12 weeks. During this experiment, the one group was then treated with PR extract for the 8 weeks (3 times per week) and analyzed by ELISA and flow cytometer. Results : In vivo, there were significant decreases in eosinophils, IL-4, IL-5, IL-13, IgE in BALF (bronchoalveolar lavage fluid) compared with that of control group. However, $IFN-{\gamma}$ in BALF of GS group increased significantly, compared with that of control group. Additionally, the population of $CD3e^-/CCR3^+,\;CD69^+/CD3e^+,\;IgE^+/B220^+,\;CD11b^+/Gr-l^+$ cells in the PR group decreased, compared with that of control group. Conclusion : The results of this study support a role for PR as an effective treatment for asthma in its experimental success in significantly decreasing inflammation and asthma reactions, and in increasing $IFN-{\gamma}$, which helps prevent such reactions.

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Numerical simulation of thermo-fluid flow in the blast furnace (고로내 열유동 현상의 수치해석 사례(I))

  • Jin, Hong-jong;Choi, Sang-Min
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.2038-2043
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    • 2007
  • Analysis of the internal state of the blast furnace is needed to predict and control the operating condition. Especially, it is important to develop modeling of blast furnace for predicting cohesive zone because shape of cohesive zone influences on overall operating condition of blast furnace such as gas flow, temperature distribution and chemical reactions. Because many previous blast furnace models assumed cohesive zone to be fixed, they can't evaluate change of cohesive zone shape by operation condition such as PCR, blast condition and production rate. In this study, an axi-symmetric 2-dimensional steady state model is proposed to simulate blast furnace process using the general purpose-simulation code. And Porous media is assumed for the gas flow and the potential flow for the solid flow. Velocity, pressure and temperature distribution for gas and solid are displayed as the simulation results. The cohesive zones are figured in 3 different operating conditions.

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The Effects of Yukmijihwang-tang, Taeksa-tang, Silbi-um on Mesangial cell Proliferation, Fibronectin Synthesis, MHC-class II Expression (육미지황탕(六味地黃湯),택사탕(澤瀉湯), 실비음(實脾飮)이 메산지움세포 증식, Fibronectin 합성 및 MHC-class II 발현에 미치는 영향(影響))

  • Ahn, Sae-Young;Doo, Ho-Kyung;Lee, Jin-Sin
    • The Journal of Internal Korean Medicine
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    • v.21 no.3
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    • pp.433-441
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    • 2000
  • Objective : To analyze the effects of Yukmijihwang-tang, Taeksa-tang, Silbi-um on mesangial cell proliferation, fibronectin synthesis and MHC-class II expression. Methods : Laboratory studies were performed with the method of surface enzyme immunoassays or flow cytometry after addition of peripheral blood mononuclear cells(PBMC) supernatants treated with medications using the cultured human mesangial cells. Results : 1. Silbi-um produces more suppressive effect than control group and hydrocortisone group on the mesangial cell proliferation. In Yukmijihwang-tang, Taeksa-tang and Silbi-um, mesangial cell proliferation significantly decreased than in hydrocortisone group 2. In the 'without fetal bovine serum' study, Yukmijihwang-tang take more suppressive effect than Control group on the fibronectin synthesis. In the 'with fetal bovine serum' study, Yukmijihwang-tang, Taeksa-tang, Silbi-um all have suppressive effect, but it hasn' t any statistical significance. 3. Yukmijihwang-tang, Taeksa-tang, Silbi-um all have a suppressive effect on the MHC-class II expression. Conclusions : Herb medicine generally show a suppressive effect on the suppression of the mesangial cell proliferation, fibronectin synthesis and MHC-class II expression.

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Process Design to Prevent Internal & External Defects of Cold Extruded Products with Double Ribs (이중 리브를 가진 냉간 압출품의 내.외부 결함 방지를 위한 공정 설계)

  • 김동진;김병민
    • Transactions of Materials Processing
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    • v.8 no.6
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    • pp.612-619
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    • 1999
  • Internal and external defects of an inner pulley for automobile air conditioner are investigated in this study. Inner pulley is a part of compressor clutch assembly of automobile air conditioner. In cold forging of inner pulley, the design requirement are to keep the same height of the inner rib and outer one and to make uniform distribution of hardness in the forged product. At the end of the forging of inner pulley, the piping defect as an external defect begins to form at the back center of the billet. The internal crack as an internal defect also occur at the adiabatic shear band which usually has maximum ductile fracture value. It is important to predict when the internal and external defects occur during the deformation process, in order to minimize the amount of discard that is generated. The finite element simulations are applied to analyze the defects. The validity of the computational results are examined by experiments. These computational results are in good agreement with the experimental ones.

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A Review of Acupuncture for the Treatment of Raynaud's Disease (레이노병의 침치료에 대한 연구동향)

  • Jeon, Sang-woo;Kim, Ho;Jeong, Min-jeong;Jang, In-soo
    • The Journal of Internal Korean Medicine
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    • v.38 no.4
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    • pp.433-442
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    • 2017
  • Objectives: The purpose of this study was to assess the effectiveness of acupuncture for the treatment of Raynaud's disease. Methods: This review was conducted using nine electronic databases (CINAHL, CiNii, CNKI, EMBASE, J-STAGE, NDSL, OASIS, PubMed, and WANFANG) and the keywords "Raynaud's disease", "Raynaud disease", "acupuncture", and "needling". Only randomized controlled trials (RCTs) using acupuncture for Raynaud's disease were included, and the methodological quality of the trials was assessed using the Cochrane risk-of-bias tool. Results: After screening, six RCTs were selected among 67, and the total effective rate and peripheral blood flow were used as evaluation methods. In five studies, the total effective rate was significantly higher in the intervention group than in the control group. In three studies, peripheral blood flow was higher in the intervention group than in the control group, with two studies being statistically significant and the remaining study not being statistically significant. Conclusions: Acupuncture could be a suitable treatment without adverse effects for Raynaud's disease because it improves peripheral blood flow. However, further studies, including randomized, placebo-controlled, double-blind methods, and clear evaluation criteria are needed.

Study on Spray characteristics of Dual-Manifold Injector with Various Tangential Entries (이중 매니폴드 분사기에서 접선방향 유입구의 변화에 따른 분사특성 연구)

  • Lee, Ingyu;Jeong, Seokgyu;Yoon, Jungsoo;Park, Gujeong;Yoon, Youngbin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.10
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    • pp.868-874
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    • 2015
  • Thrust variation is an essential parameter in a space mission such as landing on an atmosphereless planet or docking a spacecraft. In order to achieve the thrust variation control, using throttleable injector is a representative and general method. A dual-manifold injector, one of throttleable injectors, was used to control mass flow rate. Five kinds of injectors were designed and investigated in order to compare the spray characteristics of the dual-manifold injector with various tangential entries. Spray angles and patterns were measured to determine external flow characteristics and film thicknesses were measured in order to investigate the internal flow patterns.

Control of Sound Pressure Inside a Flow Excited Resonator (유동가진 공명기 내부의 음압 제어)

  • Hwang, Cheol-Ho;Park, Jong-Beom
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.196-199
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    • 2005
  • Flow traveling over a cavity opening forms a vortex due to unstable shear layer and induces an aerodynamic pressure excitation from the diffusion of the vortex convecting out of the trailing edge of the opening. The interaction between the excitation force and the cavity response sustains resonance in the resonator(cavity) and locked-in vortex shedding at the leading edge of the opening. The aerodynamic excitation force can be described from the diffusion of the vortex over the trailing edge and the level of its diffusivity is related to the strength of vorticity seeded at the loading edge. In this study, the control scheme of the internal pressure oscillation was proposed from regulating the vorticity at the leading edge by use of an oscillating spoiler. It was found that the relative motion between the spoiler and the air mass at the cavity opening influenced vorticity strength and the control was achieved by direct feedback of the cavity pressure fluctuation to the actuator.

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Cryogenic Systems for HTS Power Cables

  • Yeom, Han-Kil;Koh, Deuk-Yong;Lee, Bong-Kyu;Kim, Ig-Seang
    • Progress in Superconductivity and Cryogenics
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    • v.5 no.1
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    • pp.133-135
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    • 2003
  • Cryogenic systems are requirement for the operation of HTS power cables. In general, HTS power cables require temperature below 77K, a temperature that can be achieved from the liquid nitrogen at latm or sub-cooled LN2 above latm. HTS power cable needs sufficient refrigeration to overcome its low temperature heat loading. This loading typically cones in two forms : (1) heat leaks from the surroundings and (2) internal heat generation. This paper explains the cooling test system of 10m HTS power cable. This system is composed of storage dewar, auto fill system, core cryostat and cold-box. Storage dewar is a LN2 storage tank and auto fill system is a LN2 supply device to the sub-cooler, Core cryostat is a LN2 flow line. Cold box is a control unit of temperature and flow rate. It is composed of control valve, flow meter, sub-cooler and circulation pump, etc..

A Study on the Noise Reduction through the Control of Internal Flow for a Slim Type External ODD (슬림타입 외장형 ODD 내부의 유동 안정을 통한 소음저감에 관한 연구)

  • Lee, Woo-Jin;Seo, Jun-Ho;Rhim, Yoon-Chul
    • Transactions of the Society of Information Storage Systems
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    • v.8 no.2
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    • pp.72-77
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    • 2012
  • The demand for the laptop computer has been increased day by day and most of users ask quiet computer and devices to work in comfortable environment. One of the devices which generate acoustic noise is an external ODD. Unlike the internal ODD, the external ODD is easy to emit noise because it runs outside of the computer and also it is packed with a thin plastic covers. As the disk rotates, vortex flow is generated inside of the cavity due to various and complicated mold parts of the cover. In addition, there is a gap between the disk tray and the upper/lower cases, through which the air flows as well as the noise leaks. In this study, we have proposed how to reduce the acoustic noise of an external ODD using numerical and experimental analysis. The pressure fluctuations and turbulent kinetic energy distributions are calculated for the developed model. The results show that the sound pressure level is reduced by 2.3dB through simple modifications of ribs of the top cover, which remove or suppress flow instabilities inside of the cavity.

Vibration Control of Flexible Structures by using Conveying Fluid Pipe (유동유체가 흐르는 파이프에 의한 유연 구조물의 진동제어)

  • 류시웅;김건희;공창덕;오경원
    • Journal of the Korean Society of Propulsion Engineers
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    • v.8 no.2
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    • pp.25-31
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    • 2004
  • This paper describes a new vibration-suppression technique for flexible cantilevered structures by using a pipe containing an internal flow. The stability and dynamic response are analyzed based on the finite element method. The flutter limit and optimum stabilizing fluid velocity are determined in root locus diagrams. The impulse responses of the system are studied by the mode superposition method to observe the damping rate of the motion. The stabilizing effect of an internal flow is demonstrated by impulse responses of the structures with and without an material damping. It is found that the response of the pipe with flow of liquid has a larger effect of, stabilizing than that with flow of gas.