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탄소강의 부식억제제로서 Amine Alcohol의 치환기에 의한 흡착 특성의 영향에 관한 연구
孫太源,閔丙喆,權東赫,金亨培 弘益大學校 科學技術硏究所 1991 科學技術硏究論文集 Vol.1 No.-
The inhibitive effect of monethanolamine, N-methylethanolamine and on carbon steel S.S.41 in the 3.5% NaCl solution has been studied using polarization test method. A significant retardation of corrosion rate was observed in the 3.5% NaCl solution containing the inhibitors. The adsorption characteristic of inhibitor was studied and the adsorption heat(???)was calculated by molecular interaction value f. The results obtained from polarization test method revealed that the efficiency of corrosion inhibition was effected by molecular interactions of adsorption complex on metal surface. Using Frumkin adsorption isotherm, which was most favorable isotherm to the experimental data, molecular interaction of adsorption(f) for MEA, and NMEA on carbon steel surface were calculated to be -8.77, and -8.25 Kcal/mole, respectively. From these results, the heat of adsorption were estimated to be 16.77 and 12.18Kcal/mole, respectively. From the activation energy values, it was known that mechanism of corrosion had been changed by the addition of corrosion inhibitors.
A. 高校 科學 (生物·地球科學) 및 數學科 探究學習의 評價模型 定立과 評價紙 開發
李相協,權炳奎,林在圭,孫文求,吳岱燮,楊洪準,梁承榮,姜用熙,林成圭,金正遠,金吉民,兪正在 경북대학교 과학교육연구소 1982 科學敎育硏究誌 Vol.6 No.-
Currently the evaluation of high school science and mathematics learning has been too much knowledge-centered without concerning the inquiring ability or scientific attitude. This study, therefore, was made for the purpose of establishing of evaluation model for high school science (biology and earth science) and mathematics learning and its evaluation items. In this paper, the research was done about three fields, biology, earth science and mathematics. 1. For the biology, the evaluation methods of inquiry learning were studied with the foreign references, and proper evaluation items were suggested. 2. For the earth science, after analizing 5 kinds of earth science textbook of current using in high school, essential 19 items were selected. 5 of them were tested in test group and control group, then, the results were analized. 3. For the mathematice, the teaching elements of「Set」and「Flow chart」in mathematics (Ⅰ) were selected and structured. Detailed teaching objects were established and evaluation items were introduced.
기반 기술 : DNP3 프로토콜 보안 현황 및 공격 탐지 방안
권성문 ( Sung Moon Kwon ),유형욱 ( Hyung Uk Yoo ),이상하 ( Sang Ha Lee ),손태식 ( Tae Shik Shon ),권성문 ( Sung Moon Kwon ),유형욱 ( Hyung Uk Yoo ),이상하 ( Sang Ha Lee ),손태식 ( Tae Shik Shon ) 한국항행학회 2014 韓國航行學會論文誌 Vol.18 No.4
과거의 제어 시스템은 제어 시스템의 망을 외부의 망과 분리함으로써 외부의 접근을 원천 차단하여 외부공격에 대한 보안을 보장받았다. 그러나 제어 시스템의 디바이스들이 다양해지고 디바이스 간의 상호 운용이 필요해짐에 따라 효율적인 관리 시스템이 필요해 졌으며 이는 제어 시스템 또한 외부의 망과 연결되는 요인이 되었다. 따라서 효율적인 관리는 용이해졌으나 보안 사항이 포함되지 않은 다수의 제어 시스템의 프로토콜이 각종 사이버 공격의 위험에 놓이게 되어 각 프로토콜에 대한 보안 기능 추가 및 공격 탐지에 관한 연구가 활발히 진행 되어 왔다. 본 논문에서는 컨트롤 센터와 변전소간 통신에 쓰이는 DNP(distributed network protocol)3 프로토콜을 중점으로 다루며 프로토콜의 특징과 보안 현황 분석 및 현재까지 공개된 취약점 분석과 취약점을 이용한 공격 탐지 방안을 제시한다. In the past, security on control system was guaranteed by isolation of control system networks from external networks. However as devices of the control systems became more various and interaction between the devices became necessary, effective management system for such network emerged and this triggered connection between control system networks and external system networks. This made management of control system easier but also made control system exposed to various cyber attack threats, Therefore researches on appending security measures on each protocols are in progress. This paper focused on DNP(distributed network protocol)3 protocol which is used for communication between control center and substations. It describes characteristics of DNP3 protocol and research on adding security elements to the protocol. It also analyzed known vulnerabilities of DNP3 protocol and proposed data mining methodology for detecting such vulnerabilities.
Kwon, Young-Min,Lee, Sung-Dong,Kang, Hyun-Sook,Cho, Mu-Gung,Hong, Soon-Sun,Park, Chae-Kyu,Lee, Jong-Tae,Jeon, Byeong-Seon,Ko, Sung-Ryong,Shon, Hyun-Joo,Choi, Dal-Woong The Korean Society of Ginseng 2008 Journal of Ginseng Research Vol.32 No.4
For evaluating the quality of ginseng, simple and fast analysis methods are needed to determine the ginsenoside content of the ginseng products. The aim of this study was therefore to optimize conditions for fast analysis of the ginsenosides, the active ingredients in extracts of Korean red ginseng. When tandem HPLC mass spectrometry (HPLC-MS/MS) was used, four forms of ginsenoside, Rb1, Rb2, Rc, and Re, were readily separated in seven minutes using a gradient mobile phase (acetonitrile and water containing acetic acid). This is the shortest separation time reported among the studies of major ginsenoside analysis. When gradient HPLC with UV detection was used, the detection limit was high, but separation of these four ginsenosides required 25 minutes using acetonitrile and water containing formic acid as a mobile phase. HPLC-MS/MS was able to separate ginsenoside Rg1 easily regardless of the mobile phase condition, but the HPLC-UV could not separate Rg1 because acetonitrile concentration in the mobile phase had to be maintained below 20%. Ginsenoside peaks were clearer and had more sensitive detection limits when Korean red ginseng extract was analyzed by the HPLC-MS/MS, but the UV detection was useful for chromatographic fingerprinting of all four major ginsenosides of the extract: Rb1, Rb2, Rc, and Re. Extracts were found to contain 2.17 mg, 1.51 mg, 1.29 mg, and 0.46 mg of ginsenoside Rb1, Rb2, Rc, Re, respectively, per gram weight. The ratios of each ginsenoside in the extracts were 1.0 : 0.7 : 0.6 : 0.2, respectively. Taken together, the results indicate that HPLC-MS/MS spectrometry could be the most useful method for rapid analysis of even small amounts of major ginsenosides, while HPLC with UV detection could also be used for rapid analysis of major ginsenosides and for quality control of ginseng products.
Shon, Byung Hoon,Jung, Chung Woo,Kwon, Oh Jin,Choi, Chang Kyoung,Tae Kang, Yong Elsevier 2018 INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER - Vol.122 No.-
<P><B>Abstract</B></P> <P>Refrigerants have been continuously developed to improve their thermal performances and to deal with relevant environmental issues. Recently, regulations on refrigerants are being intensified due to the global warming. To meet the enhanced environmental standards, low global warming potential (GWP) refrigerants have been developed. In this study, experimental studies are conducted to investigate the characteristics of condensation heat transfer and frictional pressure drop for R-1233zd(E). The experiments are carried out under partial condensation conditions in a plate heat exchanger to measure temperature, pressure and mass flow rate. Heat transfer coefficients and frictional pressure drops with respect to mean vapor qualities are yielded. During the partial condensation process, the heat transfer coefficients increases as the mass and heat fluxes increase. However, no significant change in frictional pressure drop is observed when the heat flux changes. It is concluded that other correlations for Nusselt number and pressure drop from the literature cannot be applied for the low GWP refrigerant, R-1233zd(E), and the present experimental correlations agree well with the experimental results with the error bands of ±20%.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The condensation heat transfer and pressure drop in PHE with R-1233zd(E) are experimentally tested. </LI> <LI> No significant change in frictional pressure drop is observed when the heat flux changes. </LI> <LI> The present experimental correlations agree well with the experimental results with the error bands of ±20%. </LI> <LI> Other correlations from the literature cannot be applied for the low GWP refrigerant, R-1233zd(E). </LI> </UL> </P>
Vacuum In-line Sealing Technology of the Screen-printed CNT-FEA
Kwon, Sang-Jik,Kim, Tae-Ho,Shon, Byeong-Kyoo,Cho, Euo-Sik,Lee, Jong-Duk,Uh, Hyung-Soo,Cho, Sung-Hee,Lee, Chun-Gyoo The Korean Infomation Display Society 2003 Journal of information display Vol.4 No.3
We have fabricated a carbon nanotube field emission display (CNT-FED) panel with a 2-inch diagonal size by using a screen printing method and vacuum in-line sealing technology. The sealing temperature of the panel was around 390$^{\circ}C$ and the vacuum level was obtained with 1.4x$10^{-5}$torr at the sealing. When the field emission properties of a fabricated and sealed CNT-FED panel were characterized and compared with those of the unsealed panel which was located in a test chamber of vacuum level similar with the sealed panel. As a result, the sealed panel showed similar I-V characteristics with unsealed one and uniform light emission with very high brightness at a current density of 243 ${\mu}A/cm^2$, obtained at the electric field of 10 V/${\mu}m$.