흰 민들레 추출물의 항산화능 및 항균활성

박명수, 라만, 임우종, 김기윤, 우성만, 이선미, 사동민 忠北大學校 農業科學硏究所 2011 農業科學硏究 Vol.27 No.4

-본문참고-

LCC 技法을 利用한 低層 商街建物(5~6層)의 所要 費用 豫測 및 初基工事費와 渾營管理費 比較에 關한 硏究

김용수,김동현 中央大學校 建設環境硏究所 1998 環境科學硏究 Vol.9 No.1

For the purpose of analyzing life cycle costs of small-size commercial buildings, 5 buildings are selected. They are all located in Anyang, Kyunggi-do, Life cycle cost data for the analysis were collected from building owners, building users and maintenance experts specializing in small-size commercial buildings by interviewing with them. The collected data are initial construction cost, operation and maintenance costs, replacement cost and demolition cost. In this research, conclusions are as follows : 1) The mean operation and maintenance costs will be needed approximately 650,000won/㎡ in 1996 constant cost terms and 230,000won/㎡ in 1996 discounted cost terms when the stydy period is 60 years ; and 2) Through the analysis between construction costs and running costs, it is investigated that the buildings which had higher initial construction costs show less running costs.

UV/Cl₂(g)에 의한 Si-wafer 표면금속 오염물의 건식세정에 관한 연구

손동수,정광진,최성호,천희곤,조동율 울산대학교 1998 공학연구논문집 Vol.29 No.2

본 연구에서는 실리콘 웨이퍼 표면에 존재하는 미량의 Zn, Fe, Ti 금속 오염물들이 UV-excited chlorine radical을 이용한 건식세정 방법으로 제거되는 반응과정을 연구 하였다. 실리콘 웨이퍼 상에 진공증착법으로 원형패턴이 있는 Zn, Fe, Ti 박막을 증착시켜 상온 및 200℃에서 UV/CI₂세정하였을 때, 염소 래디컬(CI*)이 Fe, Zn, Ti와 반응하여 제거되는 것을 반응 전후 광학현미경과 SEM을 통해 표면 형상 변화를 관찰하였고, in-line으로 연결된 XPS를 통해서 반응 후 웨이퍼 표면에 남아있는 화합물의 화학적 결합상태를 관찰하였으며, UV/CI₂세정 후 실리콘 기판이 손상받는 정도를 알기 위해 AFM으로 표면 거칠기를 측정하였다. 광학현미경과 SEM의 분석에 의하면 Zn와 Fe는 쉽게 제거되는 반면 염화물을 형성하기 보다는 휘발성이 적은 산화물을 형성하는 경향이 강한 Ti은 약간만 제거되는 것을 확인하였다. XPS 분석을 통해서 이들 금속 오염물들이 chlorine radical과 반응하여 웨이퍼 표면에 금속 염화물을 형성하고 있는 것을 확인하였고, UV/CI₂세정처리를 하였을 때 실리콘 웨이퍼의 표면 거칠기가 약간 증가하는 것을 알 수 있었다. 지금까지의 결과를 통해 볼 때, 습식세정과 UV/CI₂건식세정을 병행하면 플라즈마 및 레이저를 사용하는 다른 건식세정 방법에 비하여 보다 저온에서 실리콘 기판의 큰 손상 없이 비교적 용이하게 금속 오염물을 제거할 수 있음을 알수 있었다. The reaction mechanisms of dry cleaning of Zn, Fe and Ti trace contaminants on the Si wafer using UV/CI₂ have been studied by SEM, AFM and XPS analyses. The patterned Zn, Fe and Ti films were deposited on the Si wafer surface by thermal evaporation and changes in the surface morphology after dry cleaning using CI₂and UV/CI₂at 200℃ were studied by optical microscopy and SEM. In addition changes in surface roughness of Si wafer by the cleaning was observed by AFM. The chemical bonding states of the Zn, Fe and Ti deposited silicon surface were observed with in-line XPS analysis. Zn and Fe were easily cleaned in the form of volatile zinc-chloride and iron-chloride as verified by the surface morphology changes. Ti which forms involatile oxides was not easily removed at room temperature but was slightly removed by UV/CI₂at elevated temperature of 200℃. It was also found that the surface roughness of the Si wafer increased after CI₂and UV/CI₂cleaning. Therefore, the metallic contaminants on the Si wafer can be easily removed at lower temperature by continuous processes of wet cleaning followed by UV/CI₂dry cleaning.

효율적 인력물자 운반용 적·하화대의 개발 및 활용

황춘수,장통일,임현교 한국안전학회 2003 한국안전학회지 Vol.18 No.2

In recent years, the Korean Army made use of fork-lifters or conveyors when loading and/or unloading military material in order to prevent accidents and to promote efficiency of military material handling activities. However, in troops smaller than battalions, manual material handling activities are still committed for many reasons. In this thesis, a brand new loading/unloading device for efficient military material handling for manual workers was developed, and its validation study was conducted through objective assessment based on electromyography, subjective assessment based on Body-Map technique developed by Corlett and Bishop, and finally work performance comparison. The results of EMG analysis showed that muscular workload improved by 24% when using the device compared to manual work without the device, and complain of each body part was remarkably reduced. In addition, remarkable effectiveness enhancement was observed in the work performance. Consequently, it could be concluded that ergonomic devices like one developed in this research should he studied further in the ergonomic sense as well as in the economical sense.

Alloxan 유도 당뇨병상태에서 과산화지질생성에 미치는 Brazilin의 효과

안영수,길이룡,소동수,창동신,김진형,박광식,문창규 한국환경독성학회 1996 환경독성보건학회지 Vol.11 No.2

Brazilin was tested for its ability to inhibit alloxan induced lipidperoxidation. Lipid peroxide contents in liver, kidney and serum were measured by the TBA method. ICR mice receiving alloxan at a dose of 43mg/kg via the tail vein after a 24hrs starvation showed significantly increased lipid peroxide contents as compared to untreated control. Lipid peroxide contents in liver, kidney and serum of alloxan-induced diabetic mice were dose-dependently decreased by the treatment of brazilin at a dose of 10mg/kg, 50mg/kg, 100 mg/kg for 5 days.

FC-25계 회주철의 Boro-Nitriding 복합 표면처리에 따른 표면특성과 고온산화거동에 관한 연구

허인창,손근수,윤재홍,조동율,박봉규,김현수,김인수 대한금속재료학회 2005 대한금속·재료학회지 Vol.43 No.2

Surface properties and oxidation behavior were studied for FC-25 gray cast iron (GCI), ion nitrided CCI (N CCI), powder boronized CCI (B GCI) and powder boronized N CCI (B-N GCI). A boride (Fe2B and FeB) layer with a tooth shape was formed by boronizing GCI at 650℃. The thickness and hardness of the layer were proportional to boronizing temperature and time. The hardness was decreased as the depth of the boronized layer increased. The activation energy for boride formation was about 74 kJ/mol. The thickness of the graphite layer formed by boronizing was increased by increasing temperature and time. A silicon layer insoluble to borides accumulated beneath the boride layer. The major phases were Fe4N, Fe3N and FeN in the nitride layer formed by ion nitriding. The thickness and hardness of the layer increased with increasing nitriding temperature and time under the Fe4N decomposition temperature of 680℃. The hardness was maximum at the surface and decreased with increasing nitrided depth on B-N GCI at 700℃, above the Fe4N decomposition temperature. Hardness of B-N GCI at the layer depth of 10 μm was 1000 Hv, which was lower than that of the B GCI at the same condition. Also the layer thickness was 50 gm; 10 μm deeper than that of B GCI. The reason was that the nitrogen gas given off by the decomposition made the layer porous and facilitated the diffusion of oxygen and other reactants. The samples were oxidated at 800℃ for 48hrs under atmospheric air. Oxidation rate was in decreasing order of N GCI, GCI, B GCI and B-N GCI. Oxidation rates were greatly influenced by the diffusion of nitrogen gas formed by Fe4N decomposition over the decomposition temperature of 680℃ and the oxidation barrier of the less corrosive boride layer. (Received October 29, 2004)

FC-25계 회주철의 이온질화처리에 따른 표면특성과 고온산화거동에 관한 연구

허인창,손근수,윤재홍,조동율,박봉규,김현수,김인수 대한금속재료학회 2005 대한금속·재료학회지 Vol.43 No.4

Surface properties and high temperature oxidation behavior were investigated for FC-25 Gray Cast Iron(GCI) and the ion nitrided GCI(N-GCI). The GCI was pre-cleaned to improve hardness to the optimum pre-sputtering parameters with an Ar/H₂ ratio of 1/2, working pressure of 3 torr, working temperature of 550℃ and working time of 1hour. The optimum nitriding conditions for the maximum hardness of 560575 Hv were an N₂/H₂ ratio of 3/1, working pressure of 3 torr, and working temperature of 575℃. The thickness of graphite in the GCI was increased by increasing the working temperature from 525℃ to 595℃ for the nitriding time of 6-18hrs. XRD patterns showed FeO and Fe₂O₃ peaks for both the oxidized N-GCI and GCI at temperatures of 600℃ and 800℃ under atmospheric environment for both 24 and 60hours. At 800℃, above the Fe4N decomposition temperature of 680℃, the oxidation rate of N-GCI was greater than that of the GCI. The most abundant nitride, Fe4N, was decomposed and the nitrogen gas given off by the decomposition made the protective film porous by degassing through the film. But at 600℃, below the decomposition temperature, the degree of oxidation of N-GCI was lower than that of the GCI because the nitride film worked as protective barrier for oxidation. (Received October 29, 2004)

사염화탄소의 간독성에 대한 파두 다당류분획의 예방효과

이은경,길이룡,소동수,창동신,전선덕,정명규,문창규 한국환경독성학회 1996 환경독성보건학회지 Vol.11 No.2

In present study, we fractionated polysaccharides from Croton tiglium and investigated their hepatoprotective effects on CCI₄ intoxication. Polysaccharide fraction of which molecular weight is over 300,000(HP) showed the most potent hepatoprotective effects on CC1₄ intoxication. Lipid peroxidation, BAST and sALT were used as parameters to evaluate the liver damage. Glucose, xylose and arabinose were found to be monosaccharides composing sugar moiety of HP.

Dark-Blood Computed Tomography Angiography Combined With Deep Learning Reconstruction for Cervical Artery Wall Imaging in Takayasu Arteritis

Su Tong,Zhang Zhe,Chen Yu,Wang Yun,Li Yumei,Xu Min,Wang Jian,Li Jing,Tian Xinping,Jin Zhengyu 대한영상의학회 2024 Korean Journal of Radiology Vol.25 No.4

Objective: To evaluate the image quality of novel dark-blood computed tomography angiography (CTA) imaging combined with deep learning reconstruction (DLR) compared to delayed-phase CTA images with hybrid iterative reconstruction (HIR), to visualize the cervical artery wall in patients with Takayasu arteritis (TAK). Materials and Methods: This prospective study continuously recruited 53 patients with TAK (mean age: 33.8 ± 10.2 years; 49 females) between January and July 2022 who underwent head-neck CTA scans. The arterial- and delayed-phase images were reconstructed using HIR and DLR. Subtracted images of the arterial-phase from the delayed-phase were then added to the original delayed-phase using a denoising filter to generate the final-dark-blood images. Qualitative image quality scores and quantitative parameters were obtained and compared among the three groups of images: Delayed-HIR, Dark-blood-HIR, and Dark-blood-DLR. Results: Compared to Delayed-HIR, Dark-blood-HIR images demonstrated higher qualitative scores in terms of vascular wall visualization and diagnostic confidence index (all P < 0.001). These qualitative scores further improved after applying DLR (Dark-blood-DLR compared to Dark-blood-HIR, all P < 0.001). Dark-blood DLR also showed higher scores for overall image noise than Dark-blood-HIR (P < 0.001). In the quantitative analysis, the contrast-to-noise ratio (CNR) values between the vessel wall and lumen for the bilateral common carotid arteries and brachiocephalic trunk were significantly higher on Darkblood- HIR images than on Delayed-HIR images (all P < 0.05). The CNR values were significantly higher for Dark-blood-DLR than for Dark-blood-HIR in all cervical arteries (all P < 0.001). Conclusion: Compared with Delayed-HIR CTA, the dark-blood method combined with DLR improved CTA image quality and enhanced visualization of the cervical artery wall in patients with TAK.

Semisimple Artinian Rings of Fixed Rings

Lee,Tong-su 울산대학교 1984 연구논문집 Vol.15 No.2

G가 R위에 작용하는 automorphism군일 때 G가 고정시키는 R의 모든 원의 집합을 RG라 하면 RG가 semisimple Artinian 일 때 R도 semisimple Artinain이다. Let G be a finite group of automorphisms of the ring R, and RG be the ring of fixed points of G in R. Then if RG is semisimple Artinian, R is semisimple Artinian where R has no nlipotent ideals and no |G| torsion.