• Journal of the Earthquake Engineering Society of Korea
• /
• 제19권1호
• /
• pp.13-19
• /
• 2015

This paper presents the performance improvement of an EQS (Eradic Quake System) device applied to a nuclear power plant. For the nuclear facility, the EQS device needs to be ensured to have high quality, flexibility of design and reliability. To improve the reliability of the design, the hysteresis of the device must be exactly predicted. The friction coefficient of PTFE (PolyTetraFluoroEthylene) and the stiffness of the MER-Spring are considered as the factors influencing the hysteresis curve. In this paper, those factors are analysed to predict the behavior of the device and to improve the equipment of the EQS device. The results of the improved EQS device have been verified via a tests to be comparable with the predicted results. The estimation results indicate that considering those factors is more appropriate than the results of the previous design and method.

• Journal of Environmental Science International
• /
• 제2권1호
• /
• pp.49-56
• /
• 1993

This study identified the fumes produced from the cooking of the seasoned meats containing various condiments such as garlic, onion, pepper, soy sauce, and sesame oil. Concentrations, at the breathing zone of the cook, of volatile organic compounds (VOCs) and aldehydes included in the cooking fumes of seasoned meats were identified. Many chloro- and fluoro-aliphatic hydrocarbons, aromatic hydrocarbons, ketones, and aldehydes, which could be carcinogen suspecting chemicals, were producing from the cooking fumes of the seasoned meats. This study also identified the ventilation efficiencies of the cooking fumes of the six exhaust ventilation systems, which were widely being used in the general apartments, houses, and small-food factories. For a comparison of the ventilation efficiencies of the systems, acetaldehyde was chosen as a marker pollutant and its concentrations at the breathing zone of the cook were identified. The laboratory fume hood showed the best ventilation efficiency of the six ventilation systems studied, and then the lateral hood ventilation and the down draft ventilation followed the laboratory fume hood. Finally, this study identified that both a wall factor nearby pollutant sources and a distance factor between the hood face and pollutant sources should be also considered for an effective local exhaust ventilation system design.

• Journal of Electrical Engineering and Technology
• /
• 제4권1호
• /
• pp.93-97
• /
• 2009

The nanoporous $F:SnO_2$ materials have been prepared through the controlled hydrolysis of fluoro(2-methylbutan-2-oxy)di(pentan-2,4-dionato)tin followed by thermal treatment at $400-550^{\circ}C$. The main IR features include resonances at 660, 620 and 540 cm-1. From the TG-DTG result, three main mass losses of 6.5, 13.3 and 3.8 at 81, 289 and $490^{\circ}C$ are observed between 50 and $650^{\circ}C$ yielding a final residue of 76.0%. The size of Sn $O_2$ nanoparticles rose from 5 nm to 10-12 nm as the temperature of thermal treatment is increased from 400 to $550^{\circ}C$.

• Journal of Microbiology and Biotechnology
• /
• 제16권10호
• /
• pp.1634-1639
• /
• 2006

Hepatitis C virus (HCV)-encoded nonstructural protein 5B (NS5B) possesses RNA-dependent RNA polymerase activity, which is considered essential for viral proliferation. Thus, HCV NS5B is a good therapeutic target protein for the development of anti-HCV agents. In this study, we isolated two different kinds of nuclease-resistant RNA aptamers with 2'-fluoro pyrimidines against the HCV NS5B from a combinatorial RNA library with 40 nucleotide random sequences, using SELEX technology. The isolated RNA aptamers were observed to specifically and avidly bind the HCV NS5B with an apparent $K_d$ of 5 nM and 18 nM, respectively, in contrast with the original RNA library that hardly bound the target protein. Moreover, these aptamers could partially inhibit RNA synthesis of the HCV subgenomic replicon when transfected into Huh-7 hepatoma cell lines. These results suggest that the RNA aptamers selected in vitro could be useful not only as therapeutic agents of HCV infection but also as a powerful tool for the study of the HCV RNA-dependent RNA polymerase mechanism.

• Journal of the Korea Institute of Military Science and Technology
• /
• 제20권4호
• /
• pp.543-550
• /
• 2017

Various chemical properties including density and heat of formation of 1-substitued trinitroimidazoles (TNIs) were estimated by using density functional theory (DFT). Using chemical properties estimated by DFT, explosive performance and sensitivity of 1-substitued TNIs were analyzed by following the ADD Method-1 procedure. The results were displayed on two-dimensional performance-sensitivity plot, and were compared with those of explosive molecules commonly used in many military systems. Different 1-substituents of TNI made that both explosive performance and impact sensitivity were changed significantly. Methyl substituted TNI became moderately insensitive and slightly less powerful. Amino, fluoro, picryl, and difluoroamino substituted TNIs were highly powerful like RDX and HMX, but greatly sensitive. Nitro substituted TNI was predicted to be extremely sensitive to be handled as a secondary explosive.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 한국전기전자재료학회 2005년도 춘계학술대회 논문집 디스플레이 광소자 분야
• /
• pp.189-192
• /
• 2005

We have investigated the EO characteristics generation of pretilt angle for a nematic liquid crystal (NLC) alignment with photoalignment method on three kinds of photopolymer surfaces using polymer substrates. The LC homogeneous alignment were observed on the PMI3CA (N-(phenyl)maleimide with 3-carbon chain cinnamoyl group) and PMIF (N-(phenyl)maleimide including fluoro cinnamoyl group). However, the homeotropic alignment on the PMI5CA(N-(phenyl)maleimide with 5-carbon chain cinnamoyl group) was obtained. Also, EO characteristics of the flexible photoaligned TN-LCD using PMIF surface are better than that of the flexible TN-LCD using PMI3CA surface. Also, the stable EO performances of flexible photoaligned VA-LCD using the PMI5CA surface was observed.

• Proceedings of the Korean Vacuum Society Conference
• /
• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
• /
• pp.149.2-149.2
• /
• 2013

친 환경적 소재인 ETFE (Ethylene Tetra Fluoro Ethylene)는 내화학성과 단열성을 가지며 탁월한 빛투과성, 자정효과 및 초경량 소재의 특성을 가진 열가소성 불소수지로서 서울시 신청사, Water Cube라고 많이 알려진 베이징 올림픽 수영 경기장 같은 대형 건축물의 외벽에 사용될 만큼 최근 세계 각국의 건축가들에게 각광을 받고 있다. 본 실험에서는 영구자석을 이용한 고밀도 플라즈마로 높은 점착성과, 균일한 박막 및 대면적 공정이 가능한 RF-magnetron sputtering방법으로 기판인 Slide glass위에 ETFE를 증착하여 접촉각의 변화와 구조적 및 광학적 특성에 대하여 측정하였다. 접촉각 측정결과 35w에서 $15^{\circ}$ 이하의 친수 특성을 나타내었고, 자외선 파장에서의 투과율 측정 결과 87% 이상의 높은 투과율을 나타내었다. AFM (Atomic Force Microscope) 측정결과 35 W에서 1.6 nm의 RMS (Root mean square)값이 측정 되었다. ETFE 특성은 비가 오면 자동으로 이물질이 씻겨 내려 주기적으로 청소를 해줘야하는 유리보다 유지관리비가 적게 될 것으로 사료되고, 높은 자외선 투과율을 보임으로 온실에서 균형 잡힌 식물 성장을 위한 화학약품의 소모를 줄여 줄 것으로 사료된다.

• Journal of Veterinary Clinics
• /
• 제33권2호
• /
• pp.138-141
• /
• 2016

The aim of this study was to diagnose the fertility of a female western lowland gorilla kept in Seoul Zoo, in accordance with age by analyzing the fecal sex hormone metabolites. The study was conducted in two period of times, when the animal was from 35 to 37 years old and when the animal was from 40 to 42 years old. Non-invasive method by using fecal samples was used for safe and efficient fertility diagnosis. We collected the feces from the enclosure at least three times a week. Then $17{\beta}$-estradiol and progesterone, which are fecal sex hormone metabolites, were measured by time-resolved fluoro-immunoassay to compare the menstruation cycle and the annual reproductive cycle. For the duration of the primary study (when the animal was 35~37 years old), irregular menstruation and high concentrations of estradiol and progesterone were observed. However, menstruation was hardly observed and the concentrations of both hormones were statistically very low in the period of secondary study (when the animal was 40~42 years old). This observed phenomenon in our study was very comparable to menopause in adult women; therefore, it was confirmed that our female gorilla has reached menopause because of the natural aging, as they become older.

• Biomolecules & Therapeutics
• /
• 제7권3호
• /
• pp.216-220
• /
• 1999

A chemosensitivity assay with small replicate Mm5mt/cl C3H mammary tumor cell cultures was developed to determine whether changes in viral antigen expression and release into culture fluids could be utilized as an in vitro measure of modulating drug effect. The 52,000 MW viral envelope glycoprotein (gp52) of the mouse mammary tumor virus (MMTV) was measured in culture fluids of control and drug-treated cultures while cell density was simultaneously determined by cell staining and OD 664 nm determination. While extra-cellular gp52 levels and cell density progressively increased over 72 hours for control cultures, declines in both parameters provided dual measures of effect for combination [N(phophonacetyl-L-aspartic acid)+5-fluorouracil], combination 〔N(phophonacetyl-L-aspartic acid )+5-fluoro-5'-deoxyuridine〕and single component treatment of this combination. At each treated time point, thesecombinations begin to produce a greater decline in both cell density and gp52 levels as compared to single drug treatments. These results indicate that N(phopho-nacetyl-L-aspartic acid) in combination can enhance the effectiveness of single drug.

• Journal of The Korean Society of Inherited Metabolic disease
• /
• 제13권2호
• /
• pp.89-97
• /
• 2013

Purpose: We retrospectively investigated individuals who hadbeen identified by neonatal screening as potential galactosemia patients to determine the etiology of galactosemia. Methods: One hundred fifty-three patients referred to Korea Genetics Research Center due to high galactose level detected by neonatal screening test between February 2005 and May 2013 were examined. Galactose and galactose-1-phosphate levels were measured by using a fluoro metric microplate reader. Lactose free diet was initiated immediately after confirmed by urine Clinitest. If reducing sugar was negative, we employed abdominal sonogram and echocardiogram to check for possible porto-systemic shunt. Results: Fifteen patients were diagnosed with galactosemia. One patient had galactokinase (GALK) deficiency; four had UDP galactose-4-epimerase (GALE) deficiency; two had citrin deficiency; and four had porto-systemic shunt. Two had unknown causes of galactosemia. Conclusion: In addition to genetic defects of GALT, GALK and GALE, citrin deficiency or porto-systemic shunt could also cause galactosemia. It is crucial to carry out differential diagnosis to determine the cause of galactosemia.