측면 홈을 가지는 STS316 CT시험편의 정적 성장균열에 대한 프랙탈 기하학의 응용

윤유성,권오헌 한국산업안전학회 2002 한국안전학회지 Vol.17 No.4

The application of fractal concept provides an useful method in the study for the quantitative analysis of irregular variations like fracture surfaces and crack profiles. Fractal curves have characteristics that represents a self-similarity based on the fractal dimension. The fractal dimensions were obtained by the box counting method. In this report, we obtained the nearly stable fractal dimensions of fracture crack profiles for STS316 with CT specimens as the crack advances and the relationships between crack length and fractal dimension. Moreover fractal fracture parameter that corresponds to J-R curve is shown by the relationships between fractal dimension and crack extension. From the results, we concluded that the crack extension of high toughness material also shows the fractal characteristics, which can be used in order to evaluate the crack life precisely.

남자 노인에서 족관절 족저 굴곡근 신장운동이Functional Reach에 미치는 효과

권오윤,한명석,박동식 大韓再活醫學會 1999 Annals of Rehabilitation Medicine Vol.23 No.3

Chloroform 용매 중에서 Aniline과 Iodine간의 Charge Transfer Complex 형성 Mechanism에 대한 연구

권오윤,崔相元,金南政 여수대학교 1989 論文集 Vol.3 No.-

The formation of charge transfer complex between indine and aniline in chloroform solvent have been studied kinetically by using conductivity method. The initially formed outer charge transfer complex was transformed into a inner charge transfer complex. The pseudo first order rate constants and aitivation entropy are affected by aniline concentration. The second order rate constants for the decomposition of the outer charge transfer complex(first order in aniline and in the outer charge transfer complex) depend on the aniline concentration. The ease with which the transformation proceeds depends on the relative magnitudes of the enthalpy of formation of the outer charge transfer complex as well as dielectric properties of aniline.

20대 연령의 안정성 한계(Limits of Stability)에 대한 연구

권오윤,장정훈 원광보건전문대 1995 원광보건전문대학논문집 Vol.18 No.-

전하이동 착물형성에 따른 Mechanism 및 용매의 영향

權五윤,崔相元,徐鎬埈 여수대학교 1989 論文集 Vol.3 No.-

The formation of charge transfer complex between iodine and aniline in CHCl₃CHCl₄: CH₂Cl₂(1:1), CH₂Cl₂have been studied kinetically by using conductivity method. The initially formed outer charge transfer complex was transformed into a inner charge transfer complex. The pseudo first order rate constants and activation entropy are affected by solvent dielectric constant. The second order rate constants for the decomposition of the outer charge tranfer complex (first order in aniline and in the outer charge transfer complex) depend on the aniline concentration. The ease with which the transfermation proceeds depends on the relative magnitudes of the enthalpy of formation of the outer charge transfer complex as well as aniline concentration.

Ethanol중에서 Dodecylamine 의 Layered Silicate 층내 삽입 거동

권오윤 여수대학교 1998 論文集 Vol.13 No.2

Intercalation behaviors of dodecylamine into interlayer of layered silicic acids such as H+-magadiite, H+-kenyaite and H+-montmorilonite were investigated by X-ray powder diffraction method in ehanol solution. Well-crystallized dodecylamine-H+-montmorilonite intercalation compounds formed in 0.5M∼1.2M dodecylamine solution, but basal spacings showed a great increase from 26Å to 41.4Å between 0.9M and 1.2M dodecylamine solution. Dodecylamine-H+-magadiite intercalation compounds crystallized well with basal spacing of 48.0Å in 1.5M dodecylamine solution. Dodecylamine-H+-kenyaite intercalation compounds formed well with basal spacing of 52.8Å. These results indicate that an arrangement and adsorption amount of dodecylamine in intersurface have an affect on the increase of basal spacing.

Bacillus cereus에 있어서 Phospholipase C활량에 관한 몇가지 계면활성제의 영향

권오용,윤희주,한수자 충남대학교 자연과학연구소 1987 忠南科學硏究誌 Vol.14 No.2

This study demonstrates the effects of four detergents and three on the activity change of phospholipase C which is prepared from the cultural broth of Bacillus cereus. This assay of phospholipase C activity was carried out with phosphatidylcholine micelles which were mixed with the detergents and sterols, with increase a molar ratio of these compounds to phosphatidylcholine. Phospholipase C was highly activated at 0.5 molar ratio of Tween 80-mixed micelles. In the case of Triton X-100, it was activated at higher molar ratio indicated 1.0. Sodium dodecyl sulfate was more effective than that of the other detergents at lower molar ratio. However sodium deoxycholate-mixed micelles increased the activity more 7 times than that of the control group. This maximum activation was occurred at 2.5 molar ratio and the turbidity was gradually decreased. Cholesterol and ergosterol increased the activity until molar ratio reached up to 0.9. But the activity was higher at 0.3 molar ratio for stigmasterol. Consequently, it was indicated that phospholipase C was activated with the supplement of detergents until the mixed micelles made a number of small and spherical shape.

n-Hexane에서 Aniline, N,N-dimethylaniline, Pyridine과 Iodine간의 Complex 형성에 따른 열역학적 성질에 대한 연구

권오윤,김응렬 漢陽大學校 基礎科學硏究所 1988 基礎科學論文集 Vol.7 No.-

n-Hexane 중에서 aniline, N,N-dimethylaniline, pyridine과 iodine간의 charge transfer complex 형성에 따른 열역학적 성질을 constant activity method를 이용해서 조사하였다. 용액중 iodine, activity를 일정하게 유지하기 위하여 tetramethyl ammonium pentaiodide를 사용하였으며, 이들 complex에 대한 isosbestic point를 분광학적인 방법으로 측정한 결과 aniline, N,N-dimethylaniline 및 pyridine에 대하여 각각 495, 513.5, 478nm 이었다. 25℃에서 aniline, N,N-dimethylaniline 및 pyriod과 iodine각의 complex 형성에 대한 평형상수는 각각 3.1, 30.86, 118.91·??이었으며, 속도 상수는 ??,??,??로 나타났다. 그리고 열역학적 parameter, ΔG는 -0.672, -2.030, ?? 이며, ΔS는 각각 -24.7, -34.3, ??, ΔH는 8.02, 12.26, ??이었다. The thermodynamic properties of iodine complexes with aniline, N,N-dimethy laniline, pyridine in n-hexane were studied by constant activity method. To maintain constant iodine activity in solution, we made use of ??(tetramethylammonium-pentaiodide) Isosbestic points measured by spectroscopic method were aniline:495nm, N,N-dimethylaniline:513.5nm, pyridine:478nm, respectively. Spectroscopic measurement was done at these iosbestic spoint, and experimental results for each iodine complexes with aniline, N,N-dimethylaniline, pyridine are following; equilibrium constant:3.11, 30.86, ??, rate constant :??, ??, ??, and thermodynamic parameters, ΔG:-0.672, -2.030, ??, ΔS:-24.7, 34.3, ??, and ΔH:8.02, 12.26, ??.

승객용 승강기의 재해예방에 관한 연구

윤유성,권오헌,고성석 한국산업안전학회 2002 한국안전학회지 Vol.17 No.2

Recently the car and elevator accidents as well as the fire, explosion and collapse increased. The passenger elevator accident from 1993 year to 2001 has about 56.7% of total accidents and the human victims of 180according to the Korea Elevator Safety Institute. Accident cause and prevention were investigated for the elevator having the fall, impact and narrowness accident types. The prevention and protection methods of the elevator accident from analysis results were suggested by comparing and analogizing the accident statistics about the accident investigation of the passenger elevator according to the elevator accidents.

테이핑이 발목의 관절가동범위와 고유수용성감각에 미치는 영향

김창인,권오윤,이충휘 한국전문물리치료학회 2001 한국전문물리치료학회지 Vol.8 No.3

This study was designed to determine the effect of ankle taping and short period of walking on the treadmill on the range of motion (ROM) and proprioception at the ankle joint. Twenty healthy male subjects (mean age=24.2 yr) participated in this study. Goniometry and videotape replaying method were used to measure the ankle ROM. Passive sagittal and frontal plane motions were measured. The difference in degree between the stimulus point and the reproduced point was defined as an angular error. The measurements were performed at four different phases: pre-taping (PRT), post-taping immediately (POT), post-5 minute walking with taping (P5M), and post-10 minute walking with taping (P10M). The ankle of dominant limb was taped by a certified athletic trainer using a closed basket weave technique. Participants walked on the treadmill at 2.5 mph. The results showed that the mean of the sagittal plane motion at PRT, POT, P5M, and P10M was 53.0, 30.5, 36.2, and 40.2 degrees, respectively. The frontal plane motion at PRT, POT, P5M, and P10M was 33.6, 13.9, 15.7, and 18.6 degrees, respectively, The angular error at PRT, POT, P5M, and P10M was 5.5, 1.6, 1.8, and 1.9 degrees, respectively. After 10 minutes of walking, the sagittal plane motion and frontal plane motion was increased by 9.7 and 4.7 degrees compared with POT, respectively. The proprioception was significantly improved alter the application of ankle taping. Both the restriction of frontal plane motion and proprioception improvement at the ankle joint may contribute to ankle stability during walking.