축압축을 받는 CFRP 적층부재의 에너지흡수특성과 파괴모드에 관한 연구

김정호,정회범,전형주 한국산업안전학회 2002 한국안전학회지 Vol.17 No.3

The object of this paper is to investigate collapse characteristics of CF/Epoxy(Carbon Fiber/Epoxy resin)composite tubes on the change of interlaminar number and fiber orientation angle of outer and to evaluate reappearance of collapse characteristics on the change of tension strength of fibers under static and impact axial compression loads. When a CF/Epoxy composite tube is crushed, static/impact energy is consumed by friction between the loading plate and the splayed fronds of the tube, by fracture of the fibers, matrix and their interface. In general, CF/Epoxy tube with 6 interlaminar number(C-type) absorbed more energy than other tubes(A, B, D-types). The maximum collapse load seemed to increase as the interlaminar number of such tubes increases. The collapse mode depended upon orientation angle of outer of CF/Epoxy tubes and loading status(static/impact). Typical collapse modes of CF/Epoxy tubes are wedge collapse mode, splaying collapse mode and fragmentation collapse mode. The wedge collapse mode was shown in case of CF/Epoxy tubes with 0˚ orientation angle of outer under static and impact loadings. The splaying collapse mode was shown in only case of CF/Epoxy tubes with 90˚ orientation angle of outer under static loadings, however in impact tests those were collapsed in fragmentation mode. So that, CF/Epoxy tube with 6 interlaminar number and 90˚ outer orientation angle presented to the optimal collapse characteristics.

SHS법에 의한 TiB_2-AI계 복합체의 합성 및 특성 연구

김시회,강석원,이형복 明知大學校 産業技術硏究所 2002 産業技術硏究所論文集 Vol.22 No.-

Abstract - The composite of TiB_2-A1 system was sintered by SPS and the microstructure and mechanical properties of activated powders prepared by mechanical alloying method. Mechanical alloying was performed in a planetary ball mill for 120~180min with 350rpm under vacuum. activated powders were sintered at 1400℃ for 4min with 60MPa under vacuum. As a result, TiB_2-Al composites showed the mechanical properties which is a much higher than that of monolithic TiB_2. The relative density and flexural strength of composition added Al 0.3mol were 98%, 847MPa and the hardness of 19.6GPa in the 0.1mol A1 addition composition was the highest.

3원계 화합물 반도체의 에너지 밴드 구조와 전기적 특성 연구

김철회,김형관,한백형 漢陽大學校 基礎科學硏究所 1994 基礎科學論文集 Vol.13 No.-

Empirical pseudopotential 방법을 이용하여 아연 화합물 반도체의 에너지 밴드 구조를 구하였다. ??의 에너지 간격은 InSb의 조성비에 따라 ??=0.606χ²-0.727χ+0.361를 얻었고 전자이동도는 χ=0.6, 합금산란 포텐셜이 0.82eV, 온도가 77。K, 불순물 농도가 ??일때 6.7 × 10⁴cm/V-s을 얻었다. Energy band structure of zinc-blende semiconductors is calculated by the empirical pseudopotential method using the adjustable parameter. Energy gap of ?? with InSb mole fraction is ??=0.606χ²-0.727χ+0.361 and its electron mobility is found to be a high value of 6.7 × 10⁴cm/V-s with mole fraction x=0.6, alloy scattering potential ΔU=0.82eV, Temperature T=77。K, and impurity concentration ??.

서로 다른 제 2최근접 원자의 상호작용을 고려한 Ga Al AS의 에너지띠 연구

김철회,김형관,한백형 漢陽大學校 基礎科學硏究所 1994 基礎科學論文集 Vol.13 No.-

본 논문에서는 ??의 에너지 띠를 연구하기 위하여 tight-binding방법을 사용하였고 VCA(Virtual Crystal Approximation)방법을 개선하여, 서로 다른 제2최근접원자의 상호작용을 고려하였다. 간접갭에서 직접갭으로의 전환점은 AlAs의 조성비가 0.43일때였고, band gap은 0.0≤χ≤0.43에서 ??=0.22χ²+1.408χ+1.55, 0.43≤χ≤1.0에서는 ??=0.35χ²-0.084χ+2.03을 얻었고, 실험치와 잘 일치하였다. In this paper, the energy band structure of ?? is calculated by the tight-binding method, and the interactions of different kinds of the next-nearests are included in order to improve VCA(Virtual Crystal Approximation) method. Turning point from indirect band gap to direct band gap is found to be at AlAs mole fraction of 0.43. In 0.0≤χ≤0.43, the dependence of band gap on x is well fitted to ??=0.22χ²+1.408χ+1.55, and 0.43≤χ≤1.0, ??=0.35χ²-0.084χ+2.03.

추적조사를 중심으로 한 腰椎間板脫出症에 대한 蜈蚣藥鍼의 臨床的 硏究

최회강,소기숙,고강훈,박소영,김성남,이종덕,원경숙,문형철,김성철 大韓鍼灸學會 2003 대한침구의학회지 Vol.20 No.3

Objective : This study is performed for the purpose of examining the efficacy of the scolopendrid(Scolopendra morsitans L) which has been to low back pain as a folk remedy. Methods & Results : Seventy patints with H.I.V.D. treated with the scolopendrid aquacupuncture and examined 4 tests; D.I.T.I., physical test, Oswestry disability index, and self-conscious pain rate were studied. And we follow up after discharge, we evaluated the present state and recovery period. Or we evaluated by herniated type and duration of onset. There was 58~97% of efficacy rate in each tests. Moreover, statistically valuable change in all 7D.I.T.I. points and in disability index and in self-conscious pain rate was showed. Conclusion : The scolopendrid aquacupuncture is possible to be effective terating the H.I.V.D patients. so we suggest the possibility using this new remedy to the H.I.V.D. patients.

2차원 방사선 규격사진에서 하악골 상행지 고경의 보정분석에 관한 3차원 CT 영상 연구

황현식,김형민,이기헌,임회정 대한치과교정학회 2007 대한치과교정학회지 Vol.37 No.5

안면비대칭 환자의 진단 및 치료계획 수립 시 하악골 상행지 고경의 좌우 차이를 정확히 판정하는 것이 필요하다. 본 연구는 2차원 방사선사진에서 정면 상행지경사도 및 측면 상행지경사도를 이용하여 하악골 상행지 고경을 보정하는 방법이 비대칭 판정에 도움이 되는지 알아보고자 시행되었다. 이부 편위가 있는 안면비대칭자 40명을 대상으로 정모두부방사선규격사진을 촬영하고 좌우 각각의 하악골 상행지 고경을 측정하는 한편 정모 및 측모 방사선사진에서 계측된 정면 상행지 경사도 및 측면 상행지 경사도를 이용하여 상행지 고경을 3차원적 개념으로 보정한 후, 실제 3차원 영상에서의 비대칭 판정 결과와 비교 분석을 시행하였다. 측정결과, 정면 및 측면 상행지 경사도는 이부편위측에 비하여 반대측에서 크게 나타났으며 보정 후 상행지 고경의 좌우 차이는 증가하는 양상을 나타내었다. 보정 전 그리고 보정 후 각각에서 상행지 고경의 좌우비대칭 여부를 판정한 후, 3차원 영상에서의 판정을 기준으로 하여 보정에 따른 sensitivity, specificity 그리고 accuracy 변화를 살펴본 결과, specificity는 44%에서 22%로 감소하였으나 sensitivity는 74%에서 94%로 증가하는 것으로 나타났다. 아울러 accuracy가 보정 전 68%에서 보정 후 78%로 증가하는 것으로 나타나 정면 및 측면 상행지 경사도를 이용하여 상행지 고경을 3차원적 개념으로 보정할 경우, 이는 보다 정확한 비대칭 판정에 유용함을 보여주었다. Objective: Defining right and left side differences in mandibular ramus height is one of the key elements in the diagnosis of facial asymmetry. The purpose of the present study was to evaluate the effect of correction of ramus height with frontal and lateral ramal inclinations (FRI and LRI) in 2-dimensional cephalograms and observe how this affects the diagnostic accuracy of asymmetry. Methods: Frontal and lateral cephalograms were obtained in 40 individuals with chin deviation. FRI and LRI were measured on each side and ramus height measurement was corrected with these inclinations using Pythagorean's theorem. The results of diagnosis before and after correction on cephalograms were compared with the results in 3D CT images. Results: Both FRI and LRI showed greater values in the contralateral side than in the chin-deviated side and these contributed to an increase in the right and left side ramus height differences. After comparison of diagnostic results before and after correction on cephalograms with the results on 3D CT images, the sensitivity increased significantly (from 74 to 94 %) whereas the specificity decreased (from 44 to 22 %). Overall accuracy increased from 68 to 78% with the correction using FRI and LRI. Conclusions: The results of the present study indicate that correction of ramus height with FRI and LRI is useful for an accurate diagnosis of facial asymmetry on frontal cephalograms.

신원방우황청심원액의 심혈관계에 관한 약효

조태순,이선미,김낙두,허인회,안형수,권광일,박석기,심상호,신대희,박대규 성균관대학교 약학연구소 1999 成均藥硏論文集 Vol.11 No.-

Abstract-In order to investigate the pharmacological properties of New Wonbang Woohwangchungsimwon Liquid (NSCL), effects of Wonbang Woohwangchungsimwon Liquid (SCL) and NSCL were compared. In isolated rat aorta, NSCL and SCL showed the relaxation of blood vessels in maximum contractile response to phenylephrine (10^-6 M) regardless to intact endothelium or denuded rings of the rat aorta. Furthermore, the presences of the inhibitor of NO synthase and guanylate cyclase did not affect the relaxing effect of NSCL and SCL. NSCL and SCL inhibited the vascular contractions induced by acetylcholine, prostaglandin endoperoxide or peroxide in a dose-dependent manner. In conscious spontaneously hypertensive rats (SHRs), NSCL and SCL significantly decreased heart rate. NSCL and SCL, at high doses, had a negative inotropic effect that was a decrease of left ventricular developed pressure and (-dp/dt)/(+dp/dt) in the isolated perfused rat hearts, and also decreased the contractile force and heart rate in the isolated rat right atria. In excised guinea-pig papillary muscle, NSCL and SCL had no effects on parameters of action potential such as resting membrane potential, action potential amplitude, APD_90 and V_max at low doses, whereas inhibited the cardiac contractility at high doses. These results suggested that NSCL and SCL have weak cardiovascular effects with relaxation of blood vessels and decrease of heart rate, and that this effect is no significant differences between cardiovascular effects of two preparations.

신원방우황청심원의 심혈관계에 관한 약효

조태순,이선미,김낙두,허인회,안형수,권광일,박석기,심상호,신대희,박대규 성균관대학교 약학연구소 1999 成均藥硏論文集 Vol.11 No.-

Abstract-In order to investigate the phamacological properties of New Wonbang Woohwangchungsimwon Pill (NSCH), effects of Wonbang Woohwangchungsimwon Pill (SCH) and NSCH were compared using various experimental models. In rat aorta, NSCH and SCH made the relaxation of blood vessels in maximum contractile response to phenylephrine (10^-6 M) regardless to endothelium containing or denuded rings of the rat aorta. Furthermore, the presence of the inhibitors of NO synthase and guanylate cyclase did not aftect significantly the relaxing effects of NSCH and SCH, NSCH and SCH inhibited the vascular contractions induced by acetylcholine, prostaglandin endoperoxide or peroxide in a dose-dependent manner. In conscious spontaneously hypertensive rats (SHRs). NSCH and SCH decreased significantly heart rate. These, at high doses, had a negative inotropic effect that was a decrease of left ventricular developed pressure and (-dp/dt)/(+dp/dt) in the isolated perfused rat hearts, and also decreased the contractile force and heart rate in the isolated rat right atria. In guinea-pig papillary muscle, these had no effects on parameters of action potential such as action potential amplitude (APA). V_max and resting membrane potential (RMP) at low doses, whereas inhibited the cardiac contractility at high doses. Furthermore, these had a significant inhibitory effects on palpitation of the heart in normotensive rats and SHRs. These results suggest that NSCH and SCH have weak cardiovascular effects, and that there is no significant differences between cardiovascular effects of two preparations.

신원방우황청심원액의 심혈관계에 관한 약효

조태순,이선미,김낙두,허인회,안형수,권광일,박석기,심상호,신대희,박대규 충남대학교 약학대학 의약품개발연구소 1999 藥學論文集 Vol.15 No.-

In order to investigate the pharmacological properties of New Wonbang Woohwangchungsimwon Liquid (NSCL), effects of Wonbang Woohwangchungsimwon Liquid (SCL) and NSCL were compared. In isolated rat aorta, NSCL and SCL showed the relaxation of blood vessels in maximum contractile response to phenylephrine (10^-6M) regardless to intact endothelium or denuded rings of the rat aorta. Furthermore, the presences of the inhibitor of NO synthase and guanylate cyclase did not affect the relaxing effect of NSCL and SCL. NSCL and SCL inhibited the vascular contractions induced by acetylcholine, prostaglandin endoperoxide or peroxide in a dose-dependent manner. In conscious spontaneously hypertensive rats (SHRs), NSCL and SCL significantly decreased heart rate. NSCL and SCL, at high doses, had a negative inotropic effect that was a decrease of left ventricular developed pressure and (-dp/dt)/(+dp/dt) in the isolated perfused rat hearts, and also decreased the contractile force and heart rate in the isolated rat right atria. In excised guinea-pig papillary muscle, NSCL and SCL had no effects on parameters of action potential such as resting membrane potential, action potential amplitude, APD_90 and V_max at low doses, whereas inhibited the cardiac contractility at high doses. These results suggested that NSCL and SCL have weak cardiovascular effects with relaxation of blood vessels and decrease of heart rate, and that this effect is no significant differences between cardiovascular effects of two preparations.

신우황청심원액의 심혈관계에 관한 약효연구

조태순,이선미,김낙두,허인회,안형수,권광일,박석기,심상호,신대희,박대규 충남대학교 약학대학 의약품개발연구소 1997 藥學論文集 Vol.13 No.-

In order to investigate the pharmacological properties of New Woohwangchungsimwon Liquid (NCL), efects of Woohwangchungsimwon Liquid (CL) and NCL were compared. In isolated rat aorta, NCL and CL showed the relaxation of blood vessels in maximum contractile response to phenylephrine (10^6M) without regard to intact endothelium or denuded rings of the rat aorta. Furthemore, the presences of the inhibitor of NO synthase and guanylate cyclase did not affect the relaxation of NCL and CL. NCL and CL inhibited the vascular contractions induced by acetylcholine, prostaglandin endoperoxide or peroxide in a dosedependent manner. In conscious spontaneously hypertensive rats (SHRs), NCL and CL significantly decreased heart rate. NCL and CL, at high doses, had a negative inotropic effect that was a decrease of LVDP and (-dp/dt)/(+dp/dt) in the isolated perfused rat hearts, and also decreased the contractile force and heart rate in the isolated rat right atria. In excised guinea-pig papillary muscle, NCL and CL had no efects on parameters of action potential at low doses, whereas inhibited the cardiac contractility at high doses. These results suggested that NCL and CL have weak cardiovascular effects with relaxation of blood vessels and decrease of heart rate, and that this effect is no significant differences between two preparations.