$CHF_3/C_2F_6$ 반응성이온 건식식각에 의한 실리콘 표면의 변형에 관한 연구

박형호,권광호,곽병화,이수민,권오준,김보우,성영권,Park, Hyeong-Ho,Gwon, Gwang-Ho,Gwak, Byeong-Hwa,Lee, Su-Min,Gwon, O-Jun,Kim, Bo-U,Seong, Yeong-Gwon 한국재료학회 1991 한국재료학회지 Vol.1 No.4

실리콘 산화막을 $CHF_{3/}C_2F_6$ 혼합가스를 사용하여 반응성이온 건식식각을 행할 때 실리콘 표면에 형성되는 잔류막과 손상층을 X-선 광전자 분광기(XPS)와 이차이온 질량 분석기(SIMS)를 사용, 연구하였다. 실리콘, 탄소, 산소 및 불소의 angle-resolved XPS분석기술을 이용한 비파괴적 화학결합상태의 깊이분포 분석을 통하여 잔류막의 표면부에 O-F 결합이 존재하며 잔류막은 주로 탄소와 불소의 결합체인 C-F 플리머로 구성되어져 있고 Si-O, Si-C 및 Si-F 결합 등이 존재함을 알았다. 손상층은 실리콘 표면에서 약 60nm 깊이까지 탄소와 불소의 침투에 의해 형성되어져 있음을 알았다. The effects of $SiO_2$ reactive ion etching (RIE) in $CHF_{3/}C_2F_6$ on the surface properties of the underlying Si substrate were studied by X-ray photoelectron spectroscopy(XPS) and secondary ion mass spectrometry(SIMS) techniques. Angle-resolved XPS analysis was carried out as non-destructive depth profile one for investigating the chemical bonding states of silicion, carbon, oxygen and fluorine. The residue layer consists of C-F polymer. O-F bond was found on the top of the polymer layer and Si-O, Si-C and Si-F bonds were detected between Si substrate and polymer film. A 60nm thick damaged layer of silicon surface mainly contains carbon and fluorine.

中國·소련의 體制改革과 韓國 北方政策의 方向

金永聲,裵相五 충남대학교 법률행정연구소 1988 논문집 Vol.16 No.-

완전탈구된 치아의 재식에 관한 치험례

최영철,권오연,김광철,이긍호 大韓小兒齒科學會 1993 大韓小兒齒科學會誌 Vol.20 No.2

Exarticulation includes all cases in which the tooth has been totally displaced out of its socket. The main etilogies in the permanent dentition are direct blows and traffic accident, while in the primary dentition are fall-downs. The prognosis of tooth which has been recieved endodontic treatment after replantation is better than received endodontic treatment before replantation. Ca(OH)₂as a initial canal filling material diminishes undesirable replacement root resorption, so in the cases of compelted and uncompleted root formation, the pulp is extirpated and then a Ca(OH)₂dressing is placed until optimal stage for final canal filling with gutta percha cones. Storage media and storage period of avulsed tooth is very important things for prognosis after replantation. A strong relationship has been found between dry storage or storage in non physiologic media (c.g tapwater) and root resorption. Physiologic saline and/or fresh milk is one of the best storage media.

Expansin 유전자를 이용한 담배의 형질전환과 형질전환체 선발

백승준, 김보미, 장종오, 엄유리, 석영선, 이이 충북대학교 연초연구소 2008 煙草硏究 Vol.21 No.-

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$\textrm{Al}_2\textrm{O}_3$를 함유하는 AIN세라믹스의 반응소결 및 열전도도

김영우,이윤복,박상희,오기동,박홍채,Kim, Yeong-U,Lee, Yun-Bok,Park, Sang-Hui,O, Gi-Dong,Park, Hong-Chae 한국재료학회 1998 한국재료학회지 Vol.8 No.1

5-64.3mol% AI$_{2}$O$_{3}$를 함유하는 AIN(1wt% $Y_{2}$O$_{3}$)의 1650-190$0^{\circ}C$ 상압소결에 따른 치밀화 거동, 미세구조, 열전도도가 검토 되었다. XRD 분석결과, AION(5NIN \ulcorner9 AI$_{2}$O$_{3}$ ), 27R AIN다형, AIN이 소결체의 주상으로서 동정되었다. AI$_{2}$O$_{3}$ 의 함량이 증가할수록 소결체의 부피밀도는 증가 하였다. AION을 기지상으로 하는 물질($\geq$ 30mol% AI$_{2}$O$_{3}$ )인 경우는 175$0^{\circ}C$ 소결에서 최대의 부피밀도를 나타내었으며, AIN을 기지상으로 하는 경우(5mol% AI$_{2}$O$_{3}$ ) 는 소결온도가 증가할수록 밀도가 감소하였다. $Y_{2}$O$_{3}$의 존재하에서 주로 185$0^{\circ}C$이상에서 AI$_{2}$O$_{3}$ 와 AIN의 반응에 으해서 액상이 생성되었다. AION을 기지로 하는 물질의 치밀화는 주로 액상의생성 및 AION의 입성장에 의해서 지배되었으나, AIN을 기지로 하는 물질에 있어서는 1$650^{\circ}C$에서 액상이 생성되었고, 소결온도가 190$0^{\circ}C$까지 상승할 동안 AIN의 입성장은 크게 일어나지 않았다. AI$_{2}$O$_{3}$ 함량이 증가할수록 낮은 열도도를 갖는 다량의 AION 및 액상의 생성으로 인하여 소결체의열전도도는 감소 하였다. 5mol% AI$_{2}$O$_{3}$ 를 함유한 190$0^{\circ}C$ 소결체가 최대의 열전도도(77.9W/(m\ulcornerk))를 나타내었다.

액상침투법을 이용한 $Al_2O_3/TZP$ 복합체의 제조 및 특성

양태영,이윤복,김영우,오기동,박홍채,Yang, Tae-Yeong,Lee, Yun-Bok,Kim, Yeong-U,O, Gi-Dong,Park, Hong-Chae 한국재료학회 2000 한국재료학회지 Vol.10 No.5

다공성 알루미나 소결체내부로 3Y-TZP 및 12Ce-TZP 전구체를 각각 액상침투시킴으로써 2종류의 $Al_2O_3/TZP$복합체를 제조하였다. 소량의 (~11.0 wt%) TZP의 첨가는 Al2O3소결체 ($1600^{\circ}C$, 2시간)의 강도 (19~59%)와 파괴인성(14~157%)을 증가시켰다. 3Y-TZP의 첨가는 복합체의 강도의 향상에 12Ce-TZP의 첨가는 인성의 향상에 보다 효과적이었다. 침투도니 TZP는 복합체의 내부보다 표면에 집중되었으며, 그 결과 이곳에서의 입성장에 빨랐고 $Al_2O_3$의입성장 억제효과도 상대적으로 뛰어났다. 입계 및 입내균열전파가 일어났으나 $Al_2O_3/12Ce-TZP$의 경우가 $Al_2O_3/3Y-TZP$에 비하여 입계파괴가 우세하였다 Two kinds of $Al_2O_3/TZP$ composites were prepared using the liquid infiltration of 3Y-TZP and 12Ce-TZP precursors into hte sintered porous $Al_2O_3$. Small TZP additions(~11.0wt%) had increased the strength(19~59%) and fracture toughness(14~157%) of the sintered Al2O3 material($1600^{\circ}C$, 2h). The addition of 3Y-TZP was effective on case of the strength. By the way, in case of the fracture toughness that of 12Ce-TZP was effective. Infiltrated TZP was concentrated on the surface where its grain growth was enhanced and $Al_2O_3$ grain growth was effectively inhibit-ed, when compared to the inner region of the composite. The indentation crack was propagated through both intergranular modes and transgranular and the proportion if intergranular fracture was the larger in $Al_2O_3/12Ce-TZP$.

신 청소율 검사(Renal Clearance Study)를 이용하여 진단한 Gitelman씨 증후군 2예

기주영 ( Gi Ju Yeong ),김혜영 ( Kim Hye Yeong ),임정묵 ( Im Jeong Mug ),오광식 ( O Gwang Sig ),박영선 ( Park Yeong Seon ),권순길 ( Kwon Sun Gil ),신종성 ( Sin Jong Seong ),김미성 ( Kim Mi Seong ),지정훈 ( Ji Jeong Hun ),엄재호 ( E 대한신장학회 2001 Kidney Research and Clinical Practice Vol.20 No.6

We have experienced two patients who had hypokalemic metabolic alkalosis as well as hypomagnesemia and hypocalciuria with elevated plasma renin activity. We have performed renal clearance study after water loading, administration of furosemide and thiazide in two patients and two normal controls. Maximal free water clearance per 100 mL glomerular filtration rate(C_(H2O) ) and distal fractional chloride reabsorption[ C_(H2O) /(C_(H2O) +C_(Cl))] in our patients were reduced than the controls. Chloride clearance(C_(Cl)) was increased after furosemide administration but not after thiazide administration. Distal fractional chloride reabsorption[C_(H2O) /(C_(H2O) +C_(Cl))] was dramatically decreased by furosemide administration in our patients, whereas thiazide had little effect on it. Fractional excretion of sodium, chloride, magnesium, calcium was increased by furosemide administration, whereas thiazide administration had little effect on this parameters. These findings suggested the presence of a defect in the distal convoluted tubule rather than in the thick ascending loop of Henle. Herein, we report two cases of Gitelman`s syndrome diagnosed by renal clearace study after water loading, administration of furosemide and thiazide.

Mycelial Culture of Lentinus edodes Alleviates Rat Liver Toxicity Induced by Carbon Tetrachloride and Ethanol

Yeong L. Ha(하영래),Young S. Kim(김영숙),Chae R. Ahn(안채린),Jung M. Kweon(권정민),Cherl W. Park(박철우),Young K. Ha(하영권),Jeong O. Kim(김정옥) 한국생명과학회 2010 생명과학회지 Vol.20 No.1

LED의 간 보호 기능을 연구하기 위하여 CCl₄ 및 ethanol로 SD rat에 간독성을 유발한 다음, LED를 처리하였다. LED의 간 기능 보호효과는 간장치료제인 Silymarin과 비교하였다. CCl₄로 간 독성을 유발한 경우, LED는간의 항산화효소인 SOD, catalase, GSH peroxidase 효소활성의 항진을 유도하였고, 산화물인 TBARS의 함량을 감소시켰다. 또한 간 손상의 지표인 혈장의 GOT, GPT 및 LDH의 활성을 감소시켰다. Ethanol로 간 독성을 유발한 경우 LED는 간의 SOD, catalase, GSH preoxidase 효소활성 및 GSH 함량을 항진시켰고, 총 cholesterol, triglyceride 및 TBARS의 함량을 감소시켰다. 또한 ethanol 대사에 관여하는 ADH 효소 활성을 증진시켰고, ROS 생성에 관여하는 CYP2E1 효소의 발현을 감소시킴으로써, 혈장의 GOT, GPT 및 LDH 효소활성이 감소되었다. 또한 LED는 DPPH 및 mouse liver mitochondrial system에서 항산화효과를 보였다. 이러한 결과로 미루어 볼 때 LED는 in vitro와 in vivo에서 항산화효과에 의한 간 기능 보호효과를 갖는 것으로 추정된다. The protective effect of a mixed powder from solid-cultured and liquid-cultured Lentinus edodes mycelia (2:1, w/w) (designate LED) on the carbon tetrachloride (CCl₄)- and ethanol-induced hepatotoxicity of male Sprague-Dawley (SD) rat was investigated. In the CCl₄-induced rat hepatotoxicity experiment, rats of 4 groups (6 rats/group) were administere with Normal (0.2 ml distilled water), Control (0.2 ml distilled water), LED (LED 200 ㎎/㎏ BW + 0.2 ml distilled water), and Silymarin (200 ㎎/㎏ BW + 0.2 ml distilled water), p.o., daily for 2 weeks. Afterwards, all groups except for the Normal group were subjected to abdominal injection with CCl₄ (CCl₄: corn oil, 1:1 v/v; 0.5 ml/㎏ BW). For the ethanol- induced rat hepatotoxicity experiment, rats were divided into 5 groups (5 rats/group): Normal; Pair-fed control (PFC); Control (ethanol); LED (ethanol + LED 200 ㎎/㎏ BW); and Silymarin (ethanol + silymarin 200 ㎎/㎏ BW). Rats of the Normal and PFC groups were fed a basal liquid diet, and rats of the Control, LED, and Silymarin groups were fed a liquid ethanol diet containing LED or Silymarin. Eight weeks later, blood and liver samples were collected to analyze biomarkers. In CCl₄-induced SD rats, LED elevated hepatic superoxide dismutase (SOD), catalase, and glutathione peroxidase (GSH peroxidase) activities and thiobarbituric reactive substances (TBARS) were reduced, resulting in the reduction of glutamate-oxalate transaminase (GOT), glutamate-pyruvate transaminase (GPT) and lactic dehydrogenase (LDH) activities in plasma. Similar results of these enzymes and biochemical markers in both liver tissues and plasma were seen in ethanol-induced hepatotoxicity of SD rats. In addition, elevated alcohol dehydrogenase (ADH) activity and reduced expression of cytochrome p450 mixed monooxygenase enzyme (CYP2E1) were seen in liver tissues from ethanol-treated rats by LED treatment. These effects of LED were similar to those of Silymarin. In in vitro experiments, LED showed antioxidant activity in a 2,2-diphenyl-1-picrylhydrazyl (DPPH) system and mouse liver mitochondria system induced by NADPH/Fe<SUP>2+</SUP> and cumine hydroperoxide (CuOOH). These results indicate that LED protected SD rat hepatotoxicity, induced by CCl₄ and ethanol, through its antioxidative activity and might be useful as a material for protection from hepatoxicity in humans.

Stereoselective Inhibitors Based on Nonpolar Hydrocarbons for Polar Organic Crystals

Kim, Jun-Yeong,Lee, Seung-Heon,Choi, In Young,Choi, Jae-Young,Lee, Seung-Chul,Jazbinsek, Mojca,Kim, Woo-Sik,Kwak, Sang Kyu,Huh, Yun Suk,Kang, Jeong Won,Kwon, O-Pil The American Chemical Society 2016 CRYSTAL GROWTH AND DESIGN Vol.16 No.11

<P>Nonpolar aliphatic hydrocarbons are usually regarded as solely antisolvents in solution crystallization processes of polar organic crystals, because of their very weak interactions with the surfaces of polar crystals compared to polar solvent interactions. Here we show that such weak interfacial interactions induced by nonpolar aliphatic hydrocarbons can be additionally used for controlling the morphology of polar organic pi-conjugated crystals. Various hydrocarbons, such as n-hexane, n-octane, and n-decane, act as stereoselective inhibitors for highly polar 2-(3-(4-hydroxystyryl)-5,5-dimethylcyclohex-2-enylidene) malono nitrile (OH1) crystals having large nonlinear optical and fluorescent activities. In the presence of hydrocarbons, a significant morphologic change of OH1 crystals is observed; OH1 crystals grown in conventional polar solvents exhibit a diamond-shaped plate morphology, while in the presence of nonpolar hydrocarbons, a belt-shaped morphology with an extremely large aspect ratio is obtained. The origin of the unusual stereoselective interfacial interactions on specific surfaces of OH1 crystals inducing the morphological change is investigated with molecular dynamics simulations. The theoretically predicted morphology is well matched with the experimental morphology.</P>

Analysis on GPS PDOP Peaks in Signal-Blockage Simulations

Yeong-Guk Kim,박관동,Mi-So Kim,Chang Seok Yoo,Joon Sung Bae,Jun O Kim 사단법인 항법시스템학회 2020 Journal of Positioning, Navigation, and Timing Vol.9 No.2

We determined Global Positioning System (GPS) satellite visibilities in signal-blockage simulations and then analyzed Position Dilution of Precision (PDOP) fluctuations obtained from those simulated satellite geometries. PDOP values under harsh signal-blockage simulation conditions become very high compared to those calculated with real observations. Especially when the number of observed satellites is four, which is the minimum requirement for GPS positioning, PDOP values instantaneously reached several hundreds or even several tens of thousands. It was also found that the volume of the tetrahedron composed with four satellites decreases significantly. When the correlation of the tetrahedron volume and PDOP was analyzed, we reached the following conclusions: PDOP values less than 4 can be acquired when the volume is larger than 103.2 × 1019 m3, and PDOP values increase beyond 50 when the volume is less than 6.0 × 1019 m3.