• Title/Summary/Keyword: ${\kappa}-{\varepsilon}$

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Effects of Douchi Hataedock Treatment on Induction of Allergic Rhinitis in Obese Induced NC/Nga Mice (두시 하태독법이 시행된 비만 생쥐에서 Th2 분화조절을 통한 알러지성 비염 유발 감소 효과)

  • Ahn, Sang Hyun;Kim, Ki Bong
    • The Journal of Pediatrics of Korean Medicine
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    • v.32 no.2
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    • pp.1-10
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    • 2018
  • Objectives This study investigated the effects of Hataedock treatment with Douchi on induction of allergic rhinitis in obese induced NC/Nga mice. Methods NC/Nga mice were divided into control group (Ctrl), allergic rhinitis induced obese mice group (ARE), and allergic rhinitis induced obese mice group with Douchi Hataedock treatment (FGT). The 3-week-old mice of the FGT group were given one 10 mg/kg dose of Douchi Hataedock extract and sensitized with allergic antigens at weeks 4, 5, and 6. After 1 week of final sensitization, allergic rhinitis was induced primarily in mice nasal cavities for five days. After one week of the completion with the first induction, the second induction was introduced by the same method. After 1 week, few samples of the nasal mucosal tissues of each group were prepared. The factor of Th2 differentiation and inflammation control such that IL-4, STAT6, CD40, $Fc{\varepsilon}RI$, substance P, MMP-9, $NF-{\kappa}B$ p65, p-IkB, iNOS and COX-2 were observed by immunohistochemistry. Also, the difference in nasal mucosal injury was observed by histochemical method (PAS staining). Results The FGT group showed that reduced IL-4 production, STAT6 expression and CD40 expression by regulating excessive Th2 differentiation. Also, production of substance P and MMP-9 and activity of $Fc{\varepsilon}RI$ in mast cells were decreased. Inhibition of $NF-{\kappa}B$ p65 activity was induced by inhibition of p-IkB, and the production of inflammatory enzymes iNOS and COX-2 were decreased. In addition, the damage of intramural respiratory epithelium was low and excessive mucin secretion in goblet cells was low. Conclusions This study confirmed the possibility of controlling the allergic rhinitis in obese children who are expected to have an overactive inflammation.

Ginsenoside Rc from Panax ginseng exerts anti-inflammatory activity by targeting TANK-binding kinase 1/interferon regulatory factor-3 and p38/ATF-2

  • Yu, Tao;Yang, Yanyan;Kwak, Yi-Seong;Song, Gwan Gyu;Kim, Mi-Yeon;Rhee, Man Hee;Cho, Jae Youl
    • Journal of Ginseng Research
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    • v.41 no.2
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    • pp.127-133
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    • 2017
  • Background: Ginsenoside Rc (G-Rc) is one of the major protopanaxadiol-type saponins isolated from Panax ginseng, a well-known medicinal herb with many beneficial properties including anticancer, anti-inflammatory, antiobesity, and antidiabetic effects. In this study, we investigated the effects of G-Rc on inflammatory responses in vitro and examined the mechanisms of these effects. Methods: The in vitro inflammation system used lipopolysaccharide-treated macrophages, tumor necrosis $factor-{\alpha}/interferon-{\gamma}-treated$ synovial cells, and HEK293 cells transfected with various inducers of inflammation. Results: G-Rc significantly inhibited the expression of macrophage-derived cytokines, such as tumor necrosis $factor-{\alpha}$ and $interleukin-1{\beta}$. G-Rc also markedly suppressed the activation of TANK-binding kinase $1/I{\kappa}B$ kinase ${\varepsilon}/interferon$ regulatory factor-3 and p38/ATF-2 signaling in activated RAW264.7 macrophages, human synovial cells, and HEK293 cells. Conclusion: G-Rc exerts its anti-inflammatory actions by suppressing TANK-binding kinase $1/I{\kappa}B$ kinase ${\varepsilon}/interferon$ regulatory factor-3 and p38/ATF-2 signaling.

Analysis for Combustion Characteristics of Hybrid Rocket Motor (하이브리드 로켓의 연소특성 해석)

  • 김후중;김용모;윤명원
    • Journal of the Korean Society of Propulsion Engineers
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    • v.6 no.1
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    • pp.21-29
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    • 2002
  • Hybrid propulsion systems provide many advantages in terms of stable operation and safety. However, classical hybrid rocket motors have lower fuel regression rate and combustion efficiency compared to solid propellant rocket motor. The recent research efforts are focused on the improvement of volume limitation and regression rate in the hybrid rocket engine. The present study has numerically investigated the combustion processes in the hybrid rocket engine. The turbulent combustion is represented by the eddy breakup model and Hiroyasu and Nagle and Strickland-Constable model are used for soot formation and soot oxidation. Radiative heat transfer is modeled by finite volume method. To reduce the uncertainties for convective heat transfer near solid fuel surface having strong blowing effect, the Low Reynolds number $\kappa-\varepsilon$ turbulent model is employed. Based on numerical results, the detailed discussion has been made for the turbulent combustion processes in the vortex hybrid rocket engine.

Computing turbulent far-wake development behind a wind turbine with and without swirl

  • Hu, Yingying;Parameswaran, Siva;Tan, Jiannan;Dharmarathne, Suranga;Marathe, Neha;Chen, Zixi;Grife, Ronald;Swift, Andrew
    • Wind and Structures
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    • v.15 no.1
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    • pp.17-26
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    • 2012
  • Modeling swirling wakes is of considerable interest to wind farm designers. The present work is an attempt to develop a computational tool to understand free, far-wake development behind a single rotating wind turbine. Besides the standard momentum and continuity equations from the boundary layer theory in two dimensions, an additional equation for the conservation of angular momentum is introduced to study axisymmetric swirl effects on wake growth. Turbulence is simulated with two options: the standard ${\kappa}-{\varepsilon}$ model and the Reynolds Stress transport model. A finite volume method is used to discretize the governing equations for mean flow and turbulence quantities. A marching algorithm of expanding grids is employed to enclose the growing far-wake and to solve the equations implicitly at every axial step. Axisymmetric far-wakes with/without swirl are studied at different Reynolds numbers and swirl numbers. Wake characteristics such as wake width, half radius, velocity profiles and pressure profiles are computed. Compared with the results obtained under similar flow conditions using the computational software, FLUENT, this far-wake model shows simplicity with acceptable accuracy, covering large wake regions in far-wake study.

Redeveloping Turbelent Boundary Layer after Separation-Reattachment(II) -A Consideration on Turbulence Models- (박리-재부착 이후의 재발달 난류경계층 II -난류 모델들에 관한 고찰-)

  • 백세진;유정열
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.13 no.5
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    • pp.999-1011
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    • 1989
  • A consideration on the trubulence models for describing the redeveloping turbulent boundary layer beyond separation-reattachment in the flow over a backward-facing step is given through experimental and numerical studies. By considering the blance among the measured values of respective terms in the transport equations for the turbulent kinetic energy and the turbulent shear stress, the recovering process of the redeveloping boundary layer from non-equilibrium to equilibrium has been investigated, which takes place slowly over a substantial distance in the downstream direction. In the numerical study, the standard K-.epsilon. model and the Reynolds stress model have been applied to two kinds of flow regions, one for the entire downstream region after the backward-facing step and another for the downstream region after reattachment. Then the results are compared to a meaningful extent, with the experimental values of the turbulent kinetic energy k, the turbulent energy production term P, the dissipation term K-.epsilon. model, a necessity for a new modelling has been brought forward, which can be also applied to the case of the nonequlibrium turbulent flow.

Effect of Hataedock Method with Coptidis Rhizoma and Glycyrrhiza Uralensis in Allergic Rhinitis-induced Obese Mice (비만 유발 생쥐에서 Th2분화조절을 통한 황련-감초 하태독법의 알레르기성 비염 발현 억제효과)

  • Ahn, Sang Hyun;Jung, A Ram;Kim, Ki Bong
    • The Journal of Pediatrics of Korean Medicine
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    • v.33 no.2
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    • pp.22-31
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    • 2019
  • Objective This study is to learn the effects of Hataedock method using Coptidis rhizoma and Glycyrrhiza uralensis mixed extract on inflammatory response in allergic rhinitis-induced obese NC/Nga mice. Materials and Methods The mice were fed with high fat-diet to be obese, and were divided into 3 groups as follows; allergic rhinitis-induced obese mice group with Hataedock method (CGT, n=10), no treatment group (Ctrl), allergic rhinitis elicited obese mice group (ARE). To induce allergic rhinitis, NC/Nga mice of 3 weeks age were sensitized on 7, 8 and 9 weeks by ovalbumin antigen in intraperitoneal space. After 7 days of final sensitization, allergic rhinitis was initially induced in mice through nasal cavities for 5 days. After 1-week, allergic rhinitis was induced again by the same method. Histological examination was used to identify distribution of IL-4, CD40, STAT6, $Fc{\varepsilon}RI$, substance P, MMP-9, NF-${\kappa}B$ p65, iNOS and COX-2. Results Hataedock method significantly reduced IL-4, STAT6 and CD40 response (p<0.05). In CGT, the inhibition of Th2 differentiation decreased inflammatory mediators such as $Fc{\varepsilon}RI$, substance P, MMP-9, NF-${\kappa}B$ p65, iNOS and COX-2 (all p<0.05). The immunological improvement led reduction of respiratory epithelial damage and mucin secretion in goblet cell. Conclusion The results of this study show that the Hataedock method suppresses the expression of allergic rhinitis by decreasing the inflammatory mediators through the regulation of Th2 differentiation even when the inflammation reaction is increased by obesity. Therefore, Hataedock may have potential preventive measure of allergic rhinitis accompanied by obese.

An Analytical Study on the Condensation of Submerged Vapor Jets in Subcooled Liquids (과냉수에서의 증기응축제트에 대한 해석적 연구)

  • 김기웅;이계복;김환열
    • Journal of Energy Engineering
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    • v.8 no.2
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    • pp.333-340
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    • 1999
  • A numerical study of turbulent condensing vapor jet submerged in subcooled liquids has been conducted. A physical model of the process is presented employing the locally homogeneous flow approximation of two phase flow in conjunction with a $\kappa$-$\varepsilon$-g model of turbulence properties. In this model the turbulence is represented by differential equations for its kinetic energy and dissipation. A differential equation for the concentration fluctuations is solved and a clipped normal probability distribution function is proposed for the mixture fraction. Effects of steam mass flux, pool temperature and nozzle internal diameter on the condensing vapor jet are also analyzed. The model is evaluated using existing data for turbulent condensing vapor jets. The agreement between the predictions and the available experimental data is good.

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Development of Simulation Model for Diffusion of Oil Spill in the Ocean 1 -Three Dimensional Characteristics of the Circulation in the Nearly Closed Bay- (해양유출기름의 확산 시뮬레이션 모델 개발I- 폐쇄만에서의 3차원 흐름특성분석 -)

  • Lee, J.W.;Kim, K.C.;Kang, S.Y.;Doh, D.H.
    • Journal of Korean Port Research
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    • v.11 no.2
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    • pp.241-255
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    • 1997
  • Three dimensional numerical model is used to simulate the circulation patterns in the Gamcheon Bay located in Pusan, Korea and compared with the observed data. The model is forced by winds, tidal elevation at open boundaries, and warm water discharged from the outfall of power plant, Turbulence mixing coefficients are calculated according to a ${\kippa}-{\varepsilon}$ turbulence closure submodel. Temperature, salinty and current are measuted extensively and these measuted data are compared with the simulation results. Eddy-like features exist both in observed data dna simulation results. These eddies are the results of interaction with the weak tidal current, wind driven current and warm water discharges. Compensational deeects are also found to exit such that while surface current is strong, bottom current tends to weaken and vice versa.

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The Effect of Douchi Hataedock Treatment for Dermatophagoides Farinae-Induced Atopic Dermatitis-like Skin Lesions by Controlling IL-4 Activity (두시 하태독법의 IL-4 활성 조절이 D. farinae 유도 아토피유사피부염 발병 조절에 미치는 효과)

  • Ahn, Sang Hyun;Kim, Jae Kyu;Cheon, Jin Hong;Kim, Ki Bong
    • The Journal of Pediatrics of Korean Medicine
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    • v.31 no.1
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    • pp.43-51
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    • 2017
  • Objectives Hataedock method is a Korean medical therapy which removes fetal toxin by orally administering herbal decoction to neonates. This study was to observe skin damage and anti-inflammatory effect via regulating IL-4 activity in NC/Nga mice which were induced atopic dermatitis (AD)-like skin lesion by Dermatophagoides (D.) farinae after applying Douchi Hataedock method. Methods NC/Nga mice with 3 weeks of gestational age were used. Each 10 mice were allocated to the control group (Ctrl), the AD-induced group (AE), and the group which induced AD after administering Douchi extract (GT). After 4 weeks from administering Douchi extract to the mice, the primary AD was induced by applying D. farinae extract 6 times per week for 3 weeks and then the secondary AD was induced by the same method after 1 week from the primary AD induction. To identify the skin damage and anti-inflammatory effect, we observed LxR, IL-4, Fc ${\varepsilon}$ receptor, substance P, and $NF-{\kappa}B$. Results The GT group showed alleviation of skin injury and decrease in capillary angiogenesis. Stratum corneum damage, epithelial cell hyperplasia, lymphocyte infiltration, and capillary distribution relatively decreased in the GT group. LxR-positive reaction in the GT group were increased by 53% than that of the AE group. IL-4 production, $Fc{\varepsilon}$ receptor activity, and substance P-positive reaction in the GT group were decreased by 82%, 42%, and 82% respectively compare to those of the AE group. $NF-{\kappa}B$-positive reaction in the GT group were decreased by 15% compare to that of the AE group. Conclusions Hataedock method with Douchi extract alleviated AD via reducing inflammatory cytokines secreted at the early stage of AD. Thus, Douchi Hataedock method has a beneficial effect for the prevention and treatment of AD.

PREDICTION OF A HEAT TRANSFER TO CO2 FLOWING IN AN UPWARD PATH AT A SUPERCRITICAL PRESSURE

  • Cho, Bong-Hyun;Kim, Young-In;Bae, Yoon-Yeong
    • Nuclear Engineering and Technology
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    • v.41 no.7
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    • pp.907-920
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    • 2009
  • This study was performed to evaluate the prediction capability of a commercial CFD code and to investigate the effects of different geometries such as a 4.4 mm tube and an 8/10 mm annular channel on the detailed flow structures. A numerical simulation was performed for the conditions, at which the experimental data was produced by the test facility SPHINX. A 2-dimensional axisymmetric steady flow was assumed for computational simplicity. The RNG $\kappa-\varepsilon$ turbulence model (RNG) with an enhanced wall treatment option, SST $\kappa-\omega$ (SST) and low Reynolds Abid turbulence model (ABD) were employed and the numerical predictions were compared with the experimental data generated from the experiment. The effects of the geometry on heat transfer were investigated. The flow and temperature fields were also examined in order to investigate the mechanism of heat transfer near the wall. The local heat transfer coefficient predicted by the RNG model is very close to the measurement result for the tube. In contrast, the local heat transfer coefficient predicted by the SST and ABD models is closer to the measurement for the annular channel.