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천연물로부터 5 alpha-Reductase 활성억제 및 면포용해효과의 검색
최승만(Seung Man Choi),김창덕(Chang Deok Kim),이민호(Min Ho Lee),최영호(Young Ho Choi),랑문정(Moon Jeong Rang),안호정(Ho Jung Ahn),윤여표(Yeo Pyo Yun) 대한약학회 1999 약학회지 Vol.43 No.3
The antibacterial activity against Propionibacterium acnes (P. acnes), 5alpha-reductase inhibition and comedolytic effects are the important pharmacological target sites of antiacne drugs. We previously reported on the antibacterial activities against P. acnes by natural products. In the present study the screening of 5alpha-reductase inhibition and comedolytic effects from natural products were performed. Seven natural products such as Angelica koreana Sophora flavescens, Prunus persica, Bombyx mori, Areca catechu, Galla rhois and Gleditschia koraiensis perfectly inhibited the activity of 5alpha-reductase at the concentration of 0.01% (w/v). Sixteen natural products which were shown to have the potent antibacterial activities against P.acnes or 5alpha-reductase inhibition activities were assayed for the comedolytic test. In the results of comedolytic effects on experimentally-induced comedones (EIC), Sophora flavescens showed the strongest comedolytic effect on EIC, and Polygonum cuspidatum and Angelica koreana showed stronger comedolytic effects on EIC than azelaic acid used for a positive control at the concentration of 3% (w/v). These results suggest that several natural products including Sophora flavescens can be developed as noble antiacne agents.
최승만(Seung-Man Choi),장춘만(Choon-Man Jang),김광용(Kwang-Yong Kim) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.5
Performance characteristics of an axial flow fan having distorted inlet flow were investigated by numerical simulation and experiments. The distorted inlet flow was obtained by changing the shape of hub-cap installed upstream of the hub of the axial flow fan. Two types of the hub-cap shape were introduced to understand the effect of inlet flow distortion on the fan performance. Three-dimensional flow measurements upstream and downstream of the fan rotor were performed by a five-hole Pitot tube, and numerical analysis of the blade passage is performed by three-dimensional Reynolds-averaged Navier-Stokes equations. The distorted inlet flow invokes the increase of inlet flow angle due to the decrease of axial velocity, thus resulting in flow separation on the blade suction surface. The flow separation deteriorates fan performance near the hub. Detailed flow characteristics in the blade passage with relation to the different shape of a hub-cap were also analyzed.
Propionibacterium acnes에 대한 천연물의 항균효과 검색
최승만(Seung Man Choi),김민주(Min Joo Kim),최영호(Young Ho Choi),안호정(Ho Jung Ahn),윤여표(Yeo Pyo Yun) 大韓藥學會 1998 약학회지 Vol.42 No.1
Propionibacterium acnes is the pharmacological target site of antiacne drugs. We have examined the antiacne activity of ninety seven natural products which have been used as Korean traditional medicines in various skin disorders. The antibacterial activity of extracts from the natural products were evaluated against P. acnes ATCC 9616 by disc method. Twelve natural products showed the potent antibacterial activity against P. acnes, and were, selected for the minimal inhibitory concentration(MC) against P. acnes. MICs of nine extracts were below 0.3% (w/v) and Sophora flavescens showed the most potent activity with a MIC of less than 0.008%(w/v) against P. acnes. Thus, the results suggest that nine natural products including S. flavescens can be developed as sources of promising potent antiacne agents.
최승만(Seung-Man Choi),장춘만(Choon-Man Jang),김광용(Kwang-Yong Kim) 한국유체기계학회 2004 유체기계 연구개발 발표회 논문집 Vol.- No.-
In the present work, characteristics of an axial flow fan having distorted inlet flow produced by hub cap are investigated. The distorted inlet flow is generated by the shape of hub cap installed in front of the axial flow fan. Two different cases of hub cap geometry are analyzed to verify the influence of flow distortion. The flow fields are analyzed numerically by solving steady form of three-dimensional Reynolds-averaged Navier-Stokes equation and standard k-ε model is used for a turbulence closure. The results obtained from the numerical simulation are compared to those from experimental measurements. It is found that the overall performance of the axial flow fan is increased by reducing the flow distortion at the hub. Detailed characteristics of the flow fields of two different geometric conditions are also discussed.
축류 송풍기 허브측 불균일 유입유동 현상 및 성능 특성
장춘만(Choon-Man Jang),최승만(Seung-Man Choi),김광용(Kwang-Yong Kim) 한국유체기계학회 2005 유체기계 연구개발 발표회 논문집 Vol.- No.-
Performance characteristics of an axial flow fan having distorted inlet flow have been investigated using numerical analysis as well as experiment. Two kinds of hub-cap, round shape and right-angled front shape, are tested to investigate the effect of inlet flow distortion on the fan performance. In case of right-angled front shape, axisymmetric distorted inflow is induced by flow separation at the sharp edge of hub-cap, and the characteristics of the inflow depends on the distance between hub-cap and blade leading edge. Flow analysis of the blade passage is performed by solving the three-dimensional Reynolds-averaged Navier-Stokes equations. Numerical solutions are validated in comparison with experimental data measured by a five-hole probe downstream of the fan rotor. It is found from the numerical results that non-uniform axial inlet velocity profile near the hub results in the change of inlet flowangle. The changed inlet flow angle near the hub invokesa flow separation on the blade surfaces, thus deteriorating the fan efficiency. The effect of the distance between hub-cap and blade leading edge on the efficiency is also discussed.
서성진(Seoung-Jin Seo),최승만(Seung-Man Choi),김광용(Kwang-Yong Kim) 한국유체기계학회 2004 유체기계 연구개발 발표회 논문집 Vol.- No.-
This paper presents the response surface optimization method using three-dimensional Navier-Stokes Analysis to optimize the shape of a axial flow fan. Reynolds-averaged Navier-Stokes equations with k-ε turbulence model are discretized with finite volume approximations. Regression analysis is used for generating response surface, and it is validated by ANOVA. Five geometric variables, i.e., distribution of sweep angle at mean and tip, lean angle at mean and tip, and spanwise location of mean were employed to optimize the efficiency. The computational results are compared with experiment data. As a main result of the optimization, the efficiency was successfully improved.