Study on Reliability Improvement of Voltage Transformers by Increasing Voltage Factor

Tae‑Sik Kong,Hee‑Dong Kim,Hung‑Sok Park,Soo‑Hoh Lee,Soon‑Yong Kim,Pil‑Bum Joung,Jin‑Yeub Park 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.3

Voltage transformers (VTs) must be highly reliable as they are essential components of the electric power industry. VT failures can cause a signifcant impact for important facilities such as nuclear power plants. In fact, VTs which passed the international standard, were damaged and sometimes resulted in the shutdown of the nuclear power plants. In order to improve the reliability, VTs with various iron core was studied. The electromagnetic feld simulation, a saturation characteristics test, and an overvoltage breakdown test were conducted. The result shows that the magnetic fux density signifcantly afects the reliability of VTs. To increase the reliability of VTs, it is required to reduce the magnetic fux density by increasing the knee-point and voltage factor. Owing to limited installation space, increasing the size of the iron core is difcult. Instead, VT by decreasing the thickness of the conductor and increasing the number of turns, it was possible to reduce the magnetic fux density without the size change. Therefore, improved VTs were obtained by decreasing the thickness of the conductor and increasing the number of turns, and the improved reliability was verifed through a comparison test with existing VTs. The fabricated VTs shows a signifcantly higher saturation voltage and breakdown time than existing VTs. Thus, by proposed VTs can contribute the stable operation of the nuclear power plant and improve the manufacturer’s quality.

한국산 약용식물의 화장품천연소재로서 응용에 관한연구

안봉전,이진태,이순애,곽재훈,박정미,이진영,박태순,손준호 경산대학교 생명자원개발연구소 2003 생명자원과 산업 Vol.7 No.-

Biological activities and application of sanguisorbae officinalis L. were investigated. In the enzymological physiological activities, the electron donating ability(EDA) was 54.92% in 10 ppm and it was over 90% over 50ppm and SOD-like activity was high as 65.36% in 1000 ppm, it was gradual increased. As inhibitory effect of xanthine oxidase, it was 17.90% in 200 ppm and a little low as 36.89% in 500 ppm and inhibitory effect of tyrosinase, it was a little low as 20.45% below 1000 ppm. As the result of measuring the lipid oxidation, all the concentrations of medical ion treatments had the ability to keep it from acidification and metal ion blocking effects about the lipid oxidation promoting factors(Fe^(2+) and Cu^(2+)), Fe^(2+) was better than Cu^(2+) and all concentrations of medical ion treatments was 40% in 50ppm. When it was applied into normal skin-softener it showed safe effect so that we can expect that as the natural material of cosmetics.

천안지역 일부 다중이용시설의 포름알데히드 농도에 관한 연구

전혜리(Hye-li Jeon),조수연(Su-yeon Jo),조혜란(Hye-ran Jo),조태진(Tae-Jjn Cho),박종안(Jong-an Park),손부순(Bu-soon Son) 대한환경위생공학회 2009 대한환경위생공학회지 Vol.24 No.2

This study was conducted at a Terminal, a Parking Lot, an Underground shopping center, a Funeral hall and a Hospital waiting room of Cheon An area in August 2008 to examine the concentration level of HCHO(formaldehyde). The concentration level of the remodeled sites were 39.4 ± 12.0 ㎍/㎥ in the terminal, 32.7 ± 7.3 ㎍/㎥ in the parking, and 97.8 ± 29.4 ㎍/㎥ in the underground shopping center. The underground shopping center had the highest level and followed by the terminal and the parking. On the contrary, the site remodeling had the level of 17.7 ± 12.4 ㎍/㎥ in the funeral hall and 17.9 ± 0.6 ㎍/㎥ in the hospital waiting room. The funeral hall had highest level than that of the hospital waiting room. Both the remodeled sites and the not remodeled site had concentration level of HCHO below the standard level, but it was higher in the remodeled sites. There were no relations among the HCHO, the temperature and the humidity in facilities of Cheon An area.

토끼에서 근육주사시 입자 크기에 따른 amoxicillin의 비교 약물동태학

박승춘,윤효인,오태광,장범수,배순이,조준형,정상희,이내경,김민규 충남대학교 수의과대학 동물의과학연구소 1998 動物醫科學硏究誌 Vol.6 No.-

To investigate the pharmacokinetic difference between the two amoxicillin (AMX) particles in rabbits after intramuscular injection (i.m.), both of AMX-S (particle size: 10 ㎍) and AMX-L (particle size: 100 ㎍) were injected into New Zealand White rabbits (1.2±0.3 ㎏) at a dose rate of 10 ㎎/㎏ of body weight. In this study, serum AMX concentrations were detected by microbiological assay with E. coli BE 1186 which shows high antibiotic sensitivity. After i.m. administration, AMX-S and AMX-L were best fitted as 1-compartment model with the absorption and elimination phase. The biological half-life (T_1/2, _k10) of AMX-S is 4.06±1.09 h and that of AMX-L 4.76±0.69 h. The serum maximal concentration time (T_max) of AMX-S and AMX-L were 0.88±0.17 h and 0.77±0.11 h, respectively. Maximal AMX concentration (C_max) (AMX-S: 5.71±0.62 ㎍/㎖, AMX-L: 5.04±0.25 ㎍/㎖) in serum showed a significant difference (p<0.05). In terms of bioequivalance, however, there was no difference between the two AMX's after i.m. injection in the basis of C_max and AUC.

중심관이 있는 고효율 축상 유입식 싸이클론 집진기 수치해석적 연구

박지영,장동순,엄태인 忠南大學校 産業技術硏究所 1994 산업기술연구논문집 Vol.9 No.2

A numerical study has been performed in order to investigate the performance of two different shapes of axial-vane type cyclones. The first is a standard type and the other is the one with a central body of the form of an annular tube. Numerical calculations are made using a well-known Patanker's methodology. That is, a control-volume based finite difference method is employed together with the power-law scheme for the descretization of the convection term appeared in governing equation. The pressure-velocity coupling is resolved by the use of the revised version of SIMPLE, say SIMPLEC. The Reynolds stresses are closed using the standard k-ε model. The general pattern of fluid motion is resolved together with the particle trajectory behavior for 8 different particle sizes as a function of swirl strength and central body. The calculation data are in good agreement with the empirical knowledge, for instance, the effect of swirl intensity. The cyclone with a central body shows a high removal efficiency of particulate but more pressure drop than a standard one. Further discusstions are made in detail.

筋小胞體의 ATPase Kinetics에 關한 硏究

朴映淳,李承兩,朴泰水,庾基洙,李 弘,金允坤 圓光大學校 1982 論文集 Vol.16 No.2

본 연구에서는 토끼 골격근 소포체에서 분리한 근소포체의 ATPase활성에 대한 일반적 특성과 수종의 2가 양이온(??)의 영향에 관한 연구를 하였다. ATPase활성과 Ca uptake에 미치는 2가 양이온의 저해 효과와 저해기작은 Dixon plot, Lineweaver-Burk plot, Hanes-Woolf plot, Woolf-Augustinsson-Hofstee plot, Eadie-Scatchard plot, Arrhenius plot등을 이용하여 분석하였으며 그 결과는 다음과 같다. 1. 근소포체의 ATPase는 ??과 ??의 존재하에서 활성화 되어지며 ??의 농도가 4mM일 때 ??의 최적 농도는 0.1mM이었다. 2. 근소포체의 ATPase는 ??-ATPase와 (??)-ATPase로 구성되어 있고 (??) - ATPase의 활성은 ??-ATPase의 활성보다 높았다. 3. ATPase의 활성화 에너지는 약 19Kcal/mol이었다. 4. ATPase 활성에 미치는 2가 양이온은 12.5㎛과 400㎛의 범위 내에서 이온 농도가 증가됨에 따라서 활성도는 점점 감소되었다. 5. ATPase활성율 50% 저해시키는데 2가 양이온의 농도는 Ki값과 같아서 ??, ??, ?? Pd ??에 대한 각각의 농도는 10㎛, 30㎛, 130㎛ 및 350㎛이었다. 특히 ??은 저 농도에서 (12.5-100㎛)는 활성제로, 고농도에서 (200-400㎛)는 저해제로 작용하는 것 같다. 6. 2가 양이온은 ATPase의 Km에는 변화를 주지 않으나 Vmax의 저하를 일으키는 것으로 보아 비경쟁 저해제임이 판정되었다. 7. 2가 양이온은 가역적 저해제임이 판명되었다. 8. Ca 吸收能에 대한 CuCl₂의 阻害는 50~500㎛의 CuCl₂농도에서 현저히 나타났으며 이 현상은 Ca 吸收能과 ATPase 活性과 밀접한 관계를 보여주는 것이다. General properties of the ATPase and the effects of the divalent cations (??) on the total ATPase activity of the fragmented sarcoplasmic reticulum (FSR) isolated from rabbit skeletal muscle were investigated in the present resent research. The inhibitory effect of divalent cations on the FSR ATPase activity and its mechanism were analyzed by various plots such as Dixon plot, Lineweaver-Burk plot, Hanes-woolf plot, Eadie-Scatchard plot and Arrhenius plot. The results obtained were as follows: 1. The FSR ATPase is activated by ?? and ??; the optimum concentration of is 0.1 mM in the presence of 4 mM MgCl₂. 2. The FSR ATPase could be distinguished as ??-ATPase and (??)-ATPase. The activity of (??)-ATPase predomiant over that of ??-ATPase. 3. The apparent energies of activation for total ATPase was approximately 19Kcal/mole. 4. The inhibitory effects of the divalent cations on the enzyme activity increased as the concentrations of the divalent cations increased in the concentrations between 12.5 and 400㎛. 5. Concentration of 50% inhibition for each divalent cation was almost identical with the inhibition constant (ki). The Ki's were 10,30,130, and 350㎛ for ??, ??, ??, and ??, respectively. ?? seemed to be anactivator at lower concentrations and an inhibior at higher concentratios. 6. The divalent cations did not change the Km but decreased the Vmax of the FRS ATPase, suggesting that they are noncompetitive inhibitors on the FSR ATPase. 7. The divalent cations were also found to be revesible inhibitors on the FSR ATPase. 8. The inhibitory effect of CuCl₂on a uptake increased as the concentration CuCl₂increased in the range between 50㎛.

하악에 발생한 양성골아세포종의 증례보고

박태원,이삼선,유동수,최순철 大韓口腔顎顔面 放射線學會 1993 Imaging Science in Dentistry Vol.23 No.1

소아 상악동 병변의 방사선학적 평가

박태원,최순철 大韓口腔顎顔面 放射線學會 1992 Imaging Science in Dentistry Vol.22 No.2

The authors evaluated the distribution of the antral pathologic conditions and their radiographic features on the Waters' radiographs of 151 children patients who had been radiographed at the department of Oral Radiology, Seoul National University Hospitals. The obtained results were as follows ; 1. The most common pathologic condition was inflammatory change(58%), Percentage of showing cystic lesion and fibro-osseous lesion were 25% and 11% respectively. 2. In cases of inflammatory change, odontogenic origins were 12 cases(13%) and bilateral occurrences were 37 cases(39%). 3. The most common radiographic feature of the inflammatory conditions was various types of mucosal thickenkng(78%). Percentage of cases showing totally increased radiopacity was 18%. 4. Intrinsic cystic lesions were 26 cases(65%) and dentigerous cyst was the most common exitinsic cyst. 5. Most of the fibro-osseous lesions(15 from 17 cases) were fibrous dysplasia. 6. Maxillary sinus hypoplasia(5 cases) and Burkitt's lyphoma(4 cases) were also observed.

벼 기계이앙 1회용 종이 육묘상자 개발

박성태,황정동,김상열,문헌팔,양세준,김순철,유남진 한국국제농업개발학회 2003 韓國國際農業開發學會誌 Vol.15 No.3

벼 기계이앙 육묘에 주로 사용하고 있는 플라스틱 육묘상자의 문제점을 개선하고 친환경 농업 실현에도 기여할 수 있는 벼 기계이양 종이 육묘상자개발 및 육묘시험 결과를 요약하면 다음과 같다. 1. 폐지 등 혼합물을 고열압착한 종이 육묘상자는 내부 길이가 가로 58㎝, 세로 28㎝, 높이는 2㎝이고 무게는 250g이다. 2. 종이 육묘상자 모의 파종 후 10일~30일 묘소질은 플라스틱 육묘상자 모에 비하여 초장이 1.1~1.8㎝ 짧고 본당 건물중은 0.3~3.7㎎이 떨어졌으나 엽수와 모 충실도는 비슷하였다. 3. 종이 육묘상자 모의 파종 후 30일(중묘) 이앙 시 결주율은 3.3%로 플라스틱 육묘상자 모 결주율 3.2%와 거의 같았고, 출수기, 벼 생육특성 및 수량도 플라스틱 육묘상자와 비슷하였다. 4. 종이 육묘상자의 이점은 플라스틱 육묘상자에 비하여 육묘상자 비용이 약 20% 절감되고 파종 후 운반, 치상 등 작업이 용이하며, 이앙 후 회수, 세척 및 보관관리 노력이 생략된다. 그리고 이앙 후는 논에서 유기물화되므로 친환경농업에도 부합된다. A light and bio-degradable paper tray for seedling raising in machine transplanting rice was developed for the first time and a possibility for rice seedling growth was evaluated. The paper tray was made of mixture of recycling paper and sawdust, and molded under high temperature and pressure. The tray was 58㎝ length x28㎝ width x2㎝ height in size and 250g in weight per tray. The seedling height and dry weight per plant grown at the paper tray were generally 1.1 to 1.8㎝ shorter and 0.3 to 3.7㎎ lighter than those grown at the conventional plastic tray, respectively. However, other characters such as leaf number, seedling health score, missing hill, heading date, panicle and spiketlet number, and milled rice yield were similar to those in the plastic tray. Based on the result of research, the paper tray had following advantages in comparison of the plastic tray. The paper tray could be reduced seedling raising cost by 20% as compared with the plastic tray. Since the paper tray was of lightness even after seedbed soil fill-up, it was more handy and convenient to carry over. Labor input for collecting, washing, and storing the empty tray after seedling transplanting was not needed as the plastic tray. The paper tray was also bio-degraded and transformed into an organic matter, once it was incorporated into soil, which was considered as an environmentally- safe cultivation technology.

비용편익분석기법을 이용한 최적 낙석방지공법 평가 연구

박태순,노순미 서울産業大學校 2005 논문집 Vol.54 No.2

This study applied the cost-benefit theory in order to evaluate the financial reasonability of several methods relevant to the rockfall mitigation. The railroad line for the financial analysis is four lines having risks of rockfall, which are Young-dong line, Jung-sun line, Tae-baek line, and Joong-ang line. The significant conditions of study are 20m' section about each line based on the rockfall energy from 50kJ to lOOOkJ. This study has carried out the economical analysis such as Benefit-Cost Ratio(B/C), Net Present Value(NPV)', and Internal Rate of Return (IRR) through above mentioned conditions when various methods of the rockfall prevention including fences, walls, tunnels, and ring nets were constructed. As a result, this result shows what is the most efficient way in the aspects of economical efficiency. 본 연구는 낙석 저감에 관련된 여러 방법에서 경제적 합리성을 평가하기 위해 비용-편익 이론을 적용하였다. 경제성 분석을 위한 철도노선은 영동성, 정선선, 태백선, 중앙선으로 낙석의 위험을 갖고 있는 4개의 노선을 대상으로 하였다. 연구를 위한 중요한 조건은 50KJ에서 1000KJ의 낙석에너지를 갖고 있으며, 각 노선의 20m구간을 적용하였다. 낙석방지책, 낙석방지 옹벽, 피암터널과 링네트공법 등의 다양한 낙석방지공법이 실행될 때, 위에서 언급한 조건을 통해 편익-비용비(B/C), 순현재가치(NPV), 내부할인율(IRR)과 같은 경제성 분석을 수행하였다. 본 연구는 경제적인 효율성 측면에서 어떤 공법이 가장 효율적인 공법인지를 보여준다.