Mg₂SiO₄ : La, Ho 열형광선량계에서 활성제 농도가 글로우 커브에 미치는 영향 La, Ho TLD on Activation Concentration

김영국,손인호,채건식,노경석,오재근,이은숙 경남대학교 신소재연구소 1996 論文集 Vol.6 No.-

본 연구에서는 Mg₂SiO₄에 활성화 물질로 La, Ho를 첨가하여 열형광체를 제작하였고 불순물의 농도를 1wt.% ∼5 wt.%까지 변화시키면서 열평광강도의 glow curve를 측정하였다. 도한 열형광체의 glow curve를 peak shape법으로 분석해서 TL특성에 대한 포획 매개변수와 활성화 에너지, 발광차수, 선량의존성등을 조사하였으며, 그 물리적 특성을 조사하고 선량계로서 타당성과 실용성을 확인하였다. The Mg₂SiO₄: La, Ho thermoluminescent phospher has been prepared by sintring Mg₂SiO₄after doping the transition elements La and Ho. The heating rate is 10℃/sec at this thermoluminescent phospher are heated. The maximum peaks are found in the measured Mg₂SiO₄: La and Ho. TL glow curve at 229℃ and 345 C when the 1 wt.%-5 wt.%. The glow curve of TLD increased TL intensity and temperature of peak appears to the high temperature when the heating rate is l0℃/sec-25℃/sec. The activation energy of the main peak has been estimated by the peak shape method. The estimated activation energies are 1.77 eV. 1.52 eV respectively. The thermoluminescence process in Mg₂SiO₄: La and Ho are found to the 2nd order when the main peak of the glow curve is analyzed by peak shape method. The dose responses of Mg₂SiO₄: La and Ho TLD are linear up to intensity of X-ray.

ERK1/2 activation in quercetin-treated BEAS-2B cell plays a role in Nrf2-driven HO-1 expression

이윤진,Jun-Hwan Song,Myung-Ho Oh,Yong-Jin Lee,김용배,Jae-Hyuk Im,이상한 대한독성 유전단백체 학회 2011 Molecular & cellular toxicology Vol.7 No.4

Quercetin, a member of the flavonoids,has been heralded as chemopreventive agent, generally because of its free radical-scavenging and antiproliferative activities. In this process, NF-E2-related factor-2 (Nrf2) plays a role in protecting cells from oxidative damage; however, the exact mechanisms in which bronchial epithelial cells respond to quercetin by activating Nrf2 are not fully understood. Here, we report the role of extracellular signal-regulated kinase (ERK) activation in response to quercetin. Quercetin treatment decreased the viability of human bronchial epithelial BEAS-2B cells in a dose- and time-dependent manner. ERK1/2 was activated within 10 min of quercetin addition and then remained increased above control level throughout 48 h, whereas AKT phosphorylation was suppressed from the first 1 h of quercetin treatment. Inhibition of Erk1/2 phosphorylation attenuated quercetin-induced loss of cell viability. Nrf2levels in both nuclear and whole cell lysates increased after quercetin treatment and was accompanied by the increase of heme oxygenase-1 (HO-1) protein level,indicating that increased HO-1 expression is Nrf2-mediated. Activation of the Nrf2/HO-1 system after quercetin treatment was suppressed by the pretreatment with MEK inhibitor, PD98059. Also, silencing Nrf2 with siRNA decreased cell viability and augmented cytotoxic effect of anticancer drug LBH589. Overall, our results indicate that quercetin induces the up-regulation of Nrf2-mediated HO-1 expression, at least in part, via MEK/ERK1/2 signaling, as an adaptive mechanism which may provide advantages for cell proliferation and enhance survival despite endogenous and/or exogenous oxidative insults.

Anti-Inflammatory and Cytoprotective Effects of TMC-256C1 from Marine-Derived Fungus <i>Aspergillus</i> sp. SF-6354 via up-Regulation of Heme Oxygenase-1 in Murine Hippocampal and Microglial Cell Lines

Kim, Dong-Cheol,Cho, Kwang-Ho,Ko, Wonmin,Yoon, Chi-Su,Sohn, Jae Hak,Yim, Joung Han,Kim, Youn-Chul,Oh, Hyuncheol MDPI AG 2016 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.17 No.4

<P>In the course of searching for bioactive secondary metabolites from marine fungi, TMC-256C1 was isolated from an ethyl acetate extract of the marine-derived fungus <I>Aspergillus</I> sp. SF6354. TMC-256C1 displayed anti-neuroinflammatory effect in BV2 microglial cells induced by lipopolysaccharides (LPS) as well as neuroprotective effect against glutamate-stimulated neurotoxicity in mouse hippocampal HT22 cells. TMC-256C1 was shown to develop a cellular resistance to oxidative damage caused by glutamate-induced cytotoxicity and reactive oxygen species (ROS) generation in HT22 cells, and suppress the inflammation process in LPS-stimulated BV2 cells. Furthermore, the neuroprotective and anti-neuroinflammatory activities of TMC-256C1 were associated with upregulated expression of heme oxygenase (HO)-1 and nuclear translocation of nuclear factor-E2-related factor 2 (Nrf2) in HT22 and BV2 cells. We also found that TMC-256C1 activated p38 mitogen-activated protein kinases (MAPK) and phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathways in HT22 and BV2 cells. These results demonstrated that TMC-256C1 activates HO-1 protein expression, probably by increasing nuclear Nrf2 levels via the activation of the p38 MAPK and PI3K/Akt pathways.</P>

複合組織鋼의 摩擦 熔接部의 疲勞破壞特性에 관한 硏究

吳世旭,姜鎬珉,兪在煥,林東哲 東亞大學校 1988 東亞論叢 Vol.25 No.1

This study has been carried out to investigate the characteristics of fatigue crack of welded zone and heat affected zone of friction welded dual phase steel. The results obtained from the experiments are summarized as follows. Microstructure of welded zone is changed to ferrite and pearlite from ferrite and martensite by wel-ding heat. Micro-vickers hardness of welded zone is higher than that of base metal zone and heat affec-ted zone. Micro-vickers hardness of heat affected zone is lower than that of welded zone and microstructure of heat affected zone is changed to fine martensite and ferrite by heating cycle of welding. Fatigue limits of heat affected zone is a little higher than that of welded zone and base metal zone. There are no difference of fatigue limit of base metal zone and welded zone. Fatigue strength of welded zone is similar to that of base metal zone. At high △K region(△K>19MPa·??), fatigue crack propagation velocity of heat affected zone is slower than that of welded zone and base metal zone, and the difference of fatigue crack propagation velocity is smaller than that of high △K region. The crack occurs to the notch in heat affected zone first, but the final fracture surface is the surface of welded zone. It is abvious that heat affected zone of friction welded dual phase steel superior to welded zone and base metal zone in fatigue strength and resistance of fatigue crack propagation. The above mentioned facts are contrary to theory that heat affected zone of general metals is weaker than welded zone and base metal zone.

人工海水에 의한 複合組織鋼의 表面腐蝕이 疲勞破壞强度에 미치는 影響

吳世旭,姜鎬珉,李悅宰 東亞大學校 大學院 1986 大學院論文集 Vol.11 No.-

The influence of seawater corrosion on fatigue life at low stress level appears to be larger than that at high stress level about M.E.F. dual phase steel. Especially, the variation-range between high stress level and low stress level is large in the sea bottom corrosion of 250 hours and 1000 hours about S-N curves. According to corrosion time and corrosion conditon the amount of reduction of fatigue limit and fatigue life is varied. Fatigue limit and fatigue life for sea surface corrosion condition is lower than those for sea bottom corrosion condition and the influence of sea surface corrosion of fatigue life is large. It is appeared the relation between fatigue length and the number of cycle is depended on stress level, corrosion time and corrosion condition and corrosion pits occurred by seawater corrosion are become the cause of micro-crack. The variation-range of the crack propagation rate for low stress level is larger than that for high stress level. Portions of these fracture surface don't occur plastic deformation by S.E.M observation. However, these are found quasi-cleavage fracture that occur seperate fracture.

Cu량에 따른 Bi₂Sr₂Ca₂Cu₃O_(x)화합물의 특성에 관한 연구

오재근,주유환,손인호 경남대학교 환경문제연구소 2003 환경연구 Vol.26 No.-

We have grown Bi₂Sr₂Ca₂Cu₃O_(x) compound by improved directional solidification method with changing a quantity of Cu from 3.0 to 4.0 in order to examine substitution effect. The highest critical temperature arising in the Cu3.4 sample is about 110K. The critical temperatures of Cu3.2 sample and Cu3.8 sample are found to be about 80K. The Cu3.0 and Cu4.0 samples do not show the superconductivity. From the experiment we understand that the Cu3.4 sample is Bi-2223 phase and the other sample is a mixture of the Bi-2212 and some other phases.

Pspice를 이용한 RL 회로 해석

오재근,박영국,박찬성,정영호 內務部 國立科學搜査硏究所 2001 國立 科學 搜査 硏究所 年報 Vol.33 No.-

Banana 栽植樣式이 生育과 收量에 미치는 影響

吳現道,朴才昊,金龍湖 濟州大學校 亞熱帶農業硏究所 1987 亞熱帶農業硏究 Vol.4 No.-

本 試驗은 1985年 3월 부터 1986年 3月에 걸쳐 栽植樣式이 生育과 收量에 미치는 影響을 究明하기 위하여 濟州大學校 亞熱帶農業硏究所 plastic film house에서 遂行되었다. 그 結果를 要約하면 다음과 같다. 바나나의 草長, 葉數, 葉幅, 葉長, 果掌數, 果房重은 栽植樣式에 따라 影響을 받지 않았으나 假莖長, 假莖直徑, 抽穗期, 成熟期는 有意性이 인정되어 正方形, 三角形, 長方形, 栽植樣式 順으로 假莖長과 假莖直徑이 增加하였고 抽穗期와 成熟期도 短縮되었다. 果掌當 果指數와 果掌重은 栽植樣式에 따라 1段에서 差異가 있었고 長方形, 三角形 栽植樣式에서 2段에서는 현저하게 감소하였으나 3段 이후부터는 緩慢하게 감소되는 傾向을 나타내었다. 果掌當 果指長과 果指直徑은 1段에 比해 2段에서 增加하였는데 長方形, 正方形, 栽植樣式에서 1段∼2段 差가 컸으며 果指直徑의 變化는 栽植樣式 및 果掌間에 따라서 差異가 크게 나타났다. 正方形, 三角形 栽植樣式에서 1段에 比해 2段 果指重이 增加하였으나 3段 이후부터는 감소되는 경향을 나타내고 栽植樣式 및 果掌間에 따라 差異가 컸다. This experiment was carried out to elucidate the influence of spatial arrangement at planting on the growth and yield in bananas (Musa cavendish Lambert 'Dwarf Cavendish') from March, 1985 to March, 1986 in the plastic film house at Research Institute for Subtropical Agriculture, Cheju National University, Cheju, Korea. The results obtained are summarized as follows. Plant height, no. of leaves, leaf width, leaf length, no. of hands, and bunch weight, were little affected by planting pattern. However, pseudostem length and diameter were greater and date of emergence and maturity were earlier in the order of regular, triangular, rectangular planting. The number of fingers/hand and hand weight were significantly affected by planting pattern in 1st hands and decreased remarkably in 2nd hand of the rectangular and triangular planting, but tended to be decreased slowly from 3rd hand. Finger length and diameter/hand were greater in 2nd hand than in 1st hand and more significant in the difference of 1-2 hands in rectangular and regular planting than that of triangular planting, finger diameter/hand were afected remarkably by planting pattern or hands. Finger weight/hand were increased in 2nd hand against 1st at regular and triangular planting, but tended to be decreased from 3rd hand and affected by planting pattern or hands.

GMAHN 환경에서의 TCP 프로토콜 성능 분석

吳世德,金玄旭,李光培,張良根,裵振勝,金在浩 明知大學校 産業技術硏究所 2007 産業技術硏究所論文集 Vol.26 No.-

Recently, GMAHN that provides interface between MANET and Wired Network has been focused in Mobile Communication. It is necessary that The technology provide reliable data transmission technology between mobile node and wired network in MANET environment that varing by the node movement. In this paper, using the TCP protocol(Tahoe, Reno, Vegas, SACK)that increases reliability between source and destination, we applied the TCP protocol mechanism to various environment, and compared result, and also proposed the efficient TCP mechanism by comparing each mechanism.

SAW를 이용한 ZnSe의 TAV 연구

오재근,손인호,채건식,김영국 경남대학교 환경문제연구소 1993 환경연구 Vol.15 No.-

The energy gap in ZnSe sing1e crystal epilayer have been studied by measuring Transverse Acoustoelectric Voltage(TAV). The energy gap of ZnSe was 2.6eV at room temperature. Trap levels were calculated by Heating rate, Peak shape and Initial rise methods respectively. Also we can calculated cross section of ZnSe.