4방향성 탄소/탄소 복합재의 함침거동 특성

주혁종,맹학영,최돈묵,진영학 忠南大學校 産業技術硏究所 1996 산업기술연구논문집 Vol.11 No.2

For the preparation of 4-directional carbon fiber reinforced carbon composites(4D CFRCs) which have good thermal stability and high mechanical properties under the high temperature, pressure impregnation, carbonization and graphitization processes were performed after fabrication of 4D preform using the pultruded rod and weaving method. Due to the good compactability of pitch matrix precursor and reinforcement, carbon matrix was infiltrated effectively into the pore and crack of 4D CFRCs during the densification process. Carbon yield of matrix pitch was high level by adapting of the pressure impregnation and carbonization process. Rod network type 4D preform was more easily densified than weaving type 4D preform.

Lifted versions of robust D-stability and D-stabilisation conditions for uncertain polytopic linear systems

Lee, D. H.,Park, J. B.,Joo, Y. H.,Lin, K. C. IET 2012 IET control theory & applications Vol.6 No.1

<P>This study aims at developing new linear matrix inequality (LMI) conditions for robust κ-stability and κ-stabilisation of linear time-invariant uncertain systems in polytopic domains. An existing LMI condition for robust κ-stability is lifted into those of larger dimensions that are given as functions of a certain integer κ. Based on the consequent conditions, new sufficient conditions for the existence of a state-feedback control law ensuring the robust κ-stability of the closed-loop system is proposed in terms of LMIs. Finally, examples are given to illustrate the benefit of the proposed methods.</P>

Development of the new KSTAR helium distribution box

Lee, Y.J.,Kwag, S.W.,Song, N.H.,Park, D.S.,Chang, Y.B.,Moon, K.M.,Kim, N.W.,Joo, J.J.,Lee, C.H.,Kim, K.P.,Song, J.I.,Park, S.H.,Kim, H.T.,Ahn, H.J.,Kim, Y.S. Elsevier 2017 Fusion engineering and design Vol.123 No.-

<P><B>Abstract</B></P> <P>KSTAR project has required the new helium distribution box named upgraded distribution box (DBU) for the operation of the cryogenic components such as in-vessel cryo-pump (CPI), super-sonic molecular beam injector (SMBI), and deuterium pellet injection system (PIS). Two CPIs are inserted into the tokamak vacuum vessel and these components shall be operated at 90K for the liquid nitrogen thermal shields and 4.5K for the hydrogen cryo-panel. One hydrogen PIS was newly mounted on the tokamak for the 2016 KSTAR campaign. Liquid nitrogen shall be supplied to the one SMBI. For the operation of above mentioned 3 kinds of cryogenic components, a helium refrigerator, which had been used for the R&D in the KSTAR facility construction phase (2002–2013), was moved and inserted into the KSTAR 9kW helium facility room. The cooling capacity of the refrigerator at 4.5K is 1kW and it was manufactured from the Linde Kryotechnik before 2002. After some maintenances in warm compressor, electrical power supply, oil-filter, and so on, commissioning of the refrigerator up to 4.5K was accomplished successfully. From the beginning of 2015, design and fabrication of the DBU was started. It shall control the liquid nitrogen for the SMBI and CPI thermal shields whereas liquid helium for the CPI cryo-panel and PIS. To minimize the temperature of the liquid nitrogen to be supplied to SMBI and CPI, a thermal damper tank was inserted into the distribution box. Nitrogen return gases are to be warmed up to room temperature at the heater in the distribution box. A 1000l of liquid helium vessel is located nearby the PIS to supply cold gas helium (∼5K). Because the CPI cryo-panel requires regeneration up to 90K, complex regeneration and re-cool down scenario was developed and applied to the DBU. Including operational results, details of the DBU progresses will be reported in this paper.</P> <P><B>Highlights</B></P> <P> <UL> <LI> There has been progresses in the construction and 1st operation of DBU in 2016 KSTAR plasma experiments. </LI> <LI> Two in-vessel cryopumps (CPIs) cool-down to 4.5K and observed pumping speed was 3.0E4l/s. </LI> <LI> Manual CPI regeneration tests were accomplished regarding future automatic control. </LI> <LI> Production of the D<SUB>2</SUB> pellets were successful and there has been lots of injection tests. </LI> </UL> </P>

음란물 접촉과 청소년의 성 가치관의 변화 : 서울 일개 중학교를 중심으로

김가영,김슬기,김지아,박다현,연현숙,오연경,주혜인,차근영 이화여자대학교 간호과학대학 2011 이화간호학회지 Vol.- No.45

This document's purposes are to give basic data in the viewpoint of nursing through investigation on the change of teenager's sexual values resulted from pornography experience. 150 middle school boy students who were in first, second and third grade were surveyed. Investigated place is limited only one school which is located in Seoul city. 123 Data was available among the 150 surveyed data. Collected data are statistically processed using SPSS program. To verify the reliability, Cronbach'a was applied and analysed using t- test, ANOVA. In short, the main results of this survey are as follows. 1. The general characteristics of surveyed students: Most of surveyed students were middle school 3rdgrade(42.5%) who had computer at their room ranked first (47.2%). The average using time of internet was more than 2 hours (35.4%, the highest rate). 76.6% of surveyed students answered that they had experience of watching the pornography. 2. 53.1% of surveyed students, which is the highest ratio, experienced pornography before they entered middle school. The curiosity rank first (57.%) about the question why they watch pornography. In case of students who had no experiences of pornography answered that they didn't watch pornography because they had no concern on pornography (51.6%). 3. On sexual values, the average scores of pornography non-experienced (3.77±0.46, full score: 5..0) are higher than those of pornography-experienced (3.53±0.51), showing statically significant difference against pornography -experienced group. 4. Findings of sexual values scores on general characteristics were as follows; The higher in grades, the lower in scores. Top-graded students gained higher scores of sexual values than low graded students showing statistically significant difference in both case of characteristics.

한탄 바이러스 genome RNA의 packaging mechanism에 대한 연구

박근용,주명수,박찬,주영란,이호동,최규리,이점규,최우영,남재환,유정희 국립보건연구원 2000 국립보건원보 Vol.37 No.-

선택적 레이저 용융 공정시 공정 변수가 적층형상에 미치는 영향

성민영(M. Y. Sung),주병돈(B. D. Joo),김은화(E. H. Kim),김수희(S. H. Kim),문영훈(Y. H. Moon) 한국소성가공학회 2010 한국소성가공학회 학술대회 논문집 Vol.2010 No.10

Selective laser melting (SLM) is a fast growing process of rapid production for metallic based parts. The influence of processing variables such as powder, laser output power, and scan rate on the densification. Therefore a study on fabrication Fe-Cr-Ni powder by selective laser melting has been performed. In this study, the effect of the process parameters on shape of the fabricated part in the selective laser melting process is investigated by analysis of variance such as the height, depth of the fabricated part. With energy density decrease, the height and depth were decreased. Although the conditions are of the same energy density, the shape is different by laser power and scan rate. The shapes according to laser parameters were divided into 3 groups. And the Type Ⅱ is obtained under the conditions as 50㎛ of spread powder height, more than 15㎛ of pulse width.

간헐포기를 이용한 고도처리공정에서 SRT와 인제거의 상관관계

신응배,주봉현,박주섭,이두진,김연권,이미경 漢陽大學校 環境科學硏究所 2001 環境科學論文集 Vol.22 No.-

생물학적 하·폐수처리에서 고형물 체류시간(Solid Retention Time, SRT)은 공정내에서 적절한 미생물량과 성장상태를 유지하기 위한 중요한 운전 인자들 가운데 하나이다. 특히 고도처리 공정에서 생물학적 인제거는 궁극적으로 잉여슬러지의 폐기를 통해 이루어지므로, 미생물의 성장률에 영향을 미치는 SRT와 폐기되는 슬러지내의 인 함유량은 매우 중요한 의미를 지닌다. 본 연구에선 lab scale의 간헐포기공정을 이용하여 SRT의 변화에 따른 인제거 효율 평가, 슬러지내 인 함유량 변화 및 미생물 분포에 대한 예측으로 SRT에 따른 인제거 특성을 살펴보았다. 반응기의 SRT를 15, 20 및 30일로 운전하여 인제거 효율을 평가한 결과, 인제거 효율은 각각 78.4%, 93.3% 및 84.0%로 나타나 SRT 20일이 가장 높았으나, 슬러지내의 인 함유량은 5.41%, 5.88%로서 SRT가 증가할수록 인 함유량이 증가하였다. SRT가 30일인 경우가 슬러지내 인 함유량이 가장 높았음에도 불구하고, SRT 20일로 운전한 경우의 인제거율이 가장 높았던 이유는 잉여슬러지로 폐기되는 인부하량이 가장 많았기 때문이다. SRT의 변화에 따라 미생물의 분포 변화를 살펴보기 위해 일반 표준활성슬러지와 SRT 15, 20, 30일로 운전된 본 반응기의 슬러지를 대상으로 호기성 소화실험을 실시하였다. 일반 표준활성슬러지는 소화실험 초기에 급격한 VSS의 감소를 보였으나, 인 방출량은 매우 적어, 슬러지내에 phosphate accumulating organisms(PAOs)가 거의 존재하지 않는다는 것을 확인할 수 있었으며, 고도처리 슬러지의 경우 SRT가 긴 슬러지 일수록 VSS의 감소율은 작아지지만, 인 용출량은 증가하여 슬러지내에 PAOs가 우점화되어 있는 것으로 조사되었다. The solid retention time (SRT) is one of the important control parameters in biological phosphorus removal. In this study, the lab scale biological nutrient removal (BNR) reactor using intermittent aeration was operated at various SRTs to evaluate the phosphorus removal efficiency. At SRTs of 15, 20, and 30 days, the phosphorus removal efficiencies were 78.4%, 93.3%, and 84.0%, respectively, giving an optimal SRT at 20 days and phosphorus contents in the biomass were 5.41%, 5.88%, and 6.26%, respectively. The amount of phosphorus removed by wasting excess sludge was estimated as 87.78 mgP/d, 114.03 mgP/d, and 90.90 mgP/d respectively. Aerobic digestion experiments were also carried out to investigate the behavior of the phosphate accumlating organisms (PAOs) in biomass produced at different reactors. An activated sludge from the BNR process showed slower volatile suspended solids (VSS) destruction rate and higher amount of phosphorus release, compared to the conventional activated sludge (CAS), suggesting the CAS had little PAOs compared to the activated sludge from the BNR process Also slower destruction rate and higher amount of phosphorus release in the sludge at 30 days SRT compared to the sludge at 15 days SRT. suggested PAOs were more predominant at longer SRT.

Designing thermal and electrochemical oxidation processes for d-MnO2 nanofibers for high-performance electrochemical capacitors

Lee, J. H.,Yang, T. Y.,Kang, H. Y.,Nam, D. H.,Kim, N. R.,Lee, Y. Y.,Lee, S. H.,Joo, Y. C. Royal Society of Chemistry 2014 Journal of Materials Chemistry A Vol.2 No.20

Comparison of Live Performance and Meat Quality Parameter of Cross Bred (Korean Native Black Pig and Landrace) Pigs with Different Coat Colors

Hur, S.J.,Jeong, T.C.,Kim, G.D.,Jeong, J.Y.,Cho, I.C.,Lim, H.T.,Kim, B.W.,Joo, S.T. Asian Australasian Association of Animal Productio 2013 Animal Bioscience Vol.26 No.7

Five hundred and forty crossbred (Korean native black pig${\times}$Landrace) F2 were selected at a commercial pig farm and then divided into six different coat color groups: (A: Black, B: White, C: Red, D: White spot in black, E: Black spot in white, F: Black spot in red). Birth weight, 21st d weight, 140th d weight and carcass weight varied among the different coat color groups. D group (white spot in black coat) showed a significantly higher body weight at each weigh (birth weight, 140th d weight and carcass weight) than did the other groups, whereas the C group (red coat color) showed a significantly lower body weight at finishing stage (140th d weight and carcass weight) compared to other groups. Meat quality characteristics, shear force, cooking loss and meat color were not significantly different among the different coat color groups, whereas drip loss was significantly higher in F than in other groups. Most blood characteristics were not significantly different among the different groups, except for the red blood cells.

원전 압력용기 용접부 초음파탐상, 결함크기 평가 및 결함 수리 경험

주영상,김병철,박대영,이종포,임형택 한국비파괴검사학회 1991 한국비파괴검사학회지 Vol.11 No.1

The importance and role of preservice and inservice inspection(PSI/ISI) for nuclear power plant components are intimately related to plant design, safety, reliability and operation etc.. The Korea Atomic Energy Research Institute(KAERI) has been performing PSI/ISI in Korea since the PSI of Kori nuclear power plant, unit 1 had been performed in 1977. KAERI has localized PSI/ISI technology and has done much experience in ultrasonic flaw detection, evaluation and its excavation on the weldments of large pressure vessels. The results of flaw estimation using ultrasonic examination are compared with the actual flaw sizes revealed by field excavation. KAERI's experience regarding PSI/ISI was described and some discussions were added.