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전자상자성공명법을 이용한 오가피나무추출물의 항산화효과에 대한 연구
최신욱 ( Shin Wook Choi ),김창수 ( Chang Su Kim ),최명수 ( Myoung Soo Choi ),김보현 ( Bo Hyeon Kim ),김학수 ( Hack Soo Kim ),최대성 ( Dae Sung Choi ) 대한화장품학회 2005 대한화장품학회지 Vol.31 No.1
본 연구는 천연물로부터 기능성화장품의 소재로 이용할 수 있는 새로운 항산화제를 개발하기 위하여 정선산 오가피나무 추출물의 항산화 효과를 측정하였다. 통상적 항산화력 평가기법인 DPPH 라디칼 소거능 평가 방법은 천연물의 항산화능을 평가하기에 가장 쉬운 방법중에 하나이나 생체내에서 발생되는 특정 라디칼에 대한 항산화능을 평가하기에는 부적합하여 본 연구진은 전사상자성공명법이라는 방법을 이용하여 특정 라디칼에 대한 오가피나무 추출물의 항산화능을 평가하였다. 전자상자성공명법을 이용한 항산화능 평가 결과 오가피나무의 추출물은 유해산소종 및 유해질소종에 대한 매우 우수한 항산화능을 가지고 있음이 밝혀졌으며, 이리한 결과로 보아 오가피나무 추출물은 새로운 항산화제 소재 및 피부내의 산화적 스트레스 방지목적의 기능성 화장품소재로서의 개발가능성이 매우 높음을 알 수 있었다. This work was carried out to investigate the antioxidative effects of Acanthopnax sessiliflorus from Jeongseon County for the purpose of development of a novel antioxidant from natural products. The antioxidant activity was determined by using electron paramagnetic resonance (EPR), not measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) which have bun used for antioxidant activity of natural sources. Although DPPH radical scavenging activity assay have been generally used for antioxidant activity, this assay is nut appropriated for determinating which radical is scavenged by extracts from natural products. Using EPR, we determinated whether A. sessiliflorus extracts from Jeongseon County scavenge specific radicals or not. On experiment of scavenging superoxide anion radical, hydroxyl radical, nitrogen dioxide and peroxinitrite. Extracts from A. sessiliflorus showed high antioxidant activities to reactive oxygen and nitrogen species. These result suggest that extracts from A. sessiliflorus act as an antioxidant by scavenging reactive oxygen and nitrogen species and used as new cosmetic ingredients for anti-oxidative stress in skin.
최성대(Seong-Dae Choi),정선환(Seon-Hwan Cheong),김잠규(Jam-Kyu Kim),최명수(Myoung-Su Choi),공병채(Byeong-Chae Gong) 한국기계가공학회 2009 한국기계가공학회 춘추계학술대회 논문집 Vol.2009 No.6
The complicated stress modes which are common in most machine structures and parts make the analysis of fracture mechanism The fracture mechanism which are common in most machine structures and parts shows mixed-mode stress. It is very difficult to analyze its behavior using numerical method. In this study, the experiment of fatigue crack growth as varying of stress ratio was carried out and its effects was analyzed. And existence of fatigue fracture closure was observed through fractured surface.
혼합모드(Ⅰ+Ⅱ)에서 피로균열진전에 미치는 응력비의 영향
공병채(Byeong-Chae Gong),최명수(Myoung-Su Choi),권현규(Hyun-Kyu Kwon),최성대(Seong-Dae Choi) 한국기계가공학회 2009 한국기계가공학회지 Vol.8 No.4
The loading condition of actual construction works is complex. The shear effect of mixed-mode load component are crack propagation mechanism in step larger than the crack initial mechanism. Therefore, in this study received a mixed-mode loading on fatigue crack stress ratio on crack propagation path and speed of progress to leam whether stress affects crack propagation. ? P a constant state of fatigue tests in Mode I, II give the same stress ratio, frequency 10㎐, sinusoidal waveform was used. A lower stress ratio fatigue crack propagation angle is small. This is less affected by the Mode II. Therefore, a mixed-mode fatigue crack propagation is to progress by the Mode. Stress ratio in a mixed mode crack in the path of progress and found a lot of impact.
혼합모드(Mode Ⅰ+Ⅱ)구현을 위한 2축 피로시험 JIG 설계
최성대(Seong-Dae Choi),정선환(Seon-Hwan Cheong),김기만(Gi-Man Kim),김잠규(Jam-Kyu Kim),최명수(Myoung-Su Choi),김우재(Woo-Jae Kim) 한국산업융합학회 2008 한국산업융합학회 논문집 Vol.11 No.2
Elements of a mechanical structure are getting from multi-axles stress. so fatigue characteristic experiment Shall execute in multi-axles stress state. it is very hard to apply according to forms of a testing machine and implementation. In this study, 2 axles fatigue testing machine did a design and Development. a new JIG developed to realize a mixed mode. a stress state in mixed mode of a specimen had each other comparison using the Finite element method to examine propriety of a new JIG.
최성대(Seong-Dae Choi),정선환(Seon-Hwan Cheong),김잠규(Jam-Kyu Kim),최명수(Myoung-Su Choi),공병채(Byeong-Chae Gong) 한국기계가공학회 2009 한국기계가공학회 춘추계학술대회 논문집 Vol.2009 No.6월
The complicated stress modes which are common in most machine structures and parts make the analysis of fracture mechanism The fracture mechanism which are common in most machine structures and parts shows mixed-mode stress. It is very difficult to analyze its behavior using numerical method. In this study, the experiment of fatigue crack growth as varying of stress ratio was carried out and its effects was analyzed. And existence of fatigue fracture closure was observed through fractured surface.