• Membrane Journal
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• v.22 no.1
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• pp.62-71
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• 2012

In this study, for preparation of gas separation membrane with high permeability, hydroxy polyimide was synthesized using 6FDA and APAF. Synthesis of HPI was confirmed by H-NMR and FT-IR, thermal property of membrane was characterized by Differential scanning calorimetric (DSC) and thermogravimetric analyzer (TGA). Especially, the synthesized HPI can possible to search conversion to PBO at $450^{\circ}C$. To obtain the membrane having high permeability, ternary system consist of polymer, solvent and non-solvent additive was introduced, asymmetric HPI flat sheet membrane was prepared by phase inversion method. Finally, the change of morphology with each component was observed through FE-SEM.

• Journal of IKEEE
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• v.23 no.2
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• pp.594-598
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• 2019

We demonstrate an alternative alignment process using transferring process on solution driven HfZnO film. Parallel pattern is firstly fabricated on a silicon wafer by laser interference lithography. Prepared HfZnO solution fabricated by sol-gel process is spin-coated on a glass substrate. The silicon wafer with parallel pattern is placed on the HfZnO film and annealed at $100^{\circ}C$ for 30 min. After transferring process, parallel grooves on the HfZnO film is obtained which is confirmed by atomic force microscopy and scanning electron microscopy. Uniform liquid crystal alignment is achieved which is attributed to an anisotropic characteristic of HfZnO film by parallel grooves. The liquid crystal cell exhibited a pretilt angle of $0.25^{\circ}$ which showed a homogeneous alignment property.

• Applied Chemistry for Engineering
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• v.32 no.3
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• pp.260-267
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• 2021

In this study, a carboxylate-based anionic surfactant SLEC-3 was prepared from coconut oil and the structure was elucidated by using FT-IR, ¹H-NMR and ¹³C-NMR analysis. Measurements of interfacial properties such as critical micelle concentration, static and dynamic surface tensions, emulsification index, and foam stability have shown that SLEC-3 is better in terms of interfacial activity and more effective in lowering interfacial free energy than those of SLES, which has been widely used as a conventional anionic surfactant in the detergent industry. Biodegradability, acute oral toxicity and dermal irritation tests also revealed that SLEC-3 surfactant possesses excellent mildness and low toxicity, indicating the potential applicability in detergents and cleaner products formulation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6C
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• pp.219-229
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• 2010

Slope failure in South Korea generally occurs by the localized heavy rain in a rainy season and typhoon, and it annually causes huge losses of both life and property because nearly 70% of territory in South Korea is covered with mountains. It is required to measure the risk of slope failure quantitatively before proper prevention methods are provided. However, there is no way to estimate the risk based on realtime rainfall, geological characteristics, and geotechnical engineering properties. This study presents the development of digital terrion model to predict slope stability using infinite slope stability theory combined with temporal groundwater change. Case studies were performed to investigate factors to affect slope stability in Japan.

• Textile Coloration and Finishing
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• v.27 no.1
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• pp.35-49
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• 2015

This paper investigated optimum process conditions of coating yarn for awning fabric. For this purpose, the simulation for processability and yarn quality using SPSS statistics package was carried out, and PP/TPO and PET/PVC coating yarns specimens were made with variation of extruder temperature and feed speed of core yarn on the yarn coating machine for examining simulation result. It was revealed that optimum coating conditions of PP/TPO 1000d coating yarn were extruder temperature $150^{\circ}C$, and core yarn feed speed 400~500m/min. Mechanical property and thermal shrinkage of PP/TPO coating yarn made at this conditions were best and core evenness rates of these coating yarns by yarn compression tester were also superior, which was certified by SEM photograph. In addition, these experimental results were coincided with simulation results. It was found that, in PET/PVC coating yarn, yarn physical properties between 1500d and 1200d coated yarns were not shown any difference, and core evenness rates of these coating yarns were superior. It revealed and concluded that these simulated coating conditions are applicable to production field.

• Korean Journal of Veterinary Research
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• v.33 no.1
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• pp.53-60
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• 1993

Anaerobic bacteria are suggested to be potential source for new antibiotics. In order to search for antibiotics from domestic origin, we collected 800 soil samples across Korean locations and could isolate as many as 989 anaerobic strains. Among them 10, strains were found to have good producing capacity of antibiotics. An anaerobe was finally selected due to secreting antibiotics having high antimicrobial activity towards multiple resistant microorganism(E coli JM 83) transformed by genetic engineering technique. Its morphological, physiological and biochemical charateristics were investigated, together with antimicrobial spectrum therefrom. On antimicrobial spectrum study, substance secreted from this strain, had no activities to fungus and yeast. The selected strain showed G(+) and coccal shape, on Gram, staining and electron scanning microscopy, respectively. Biochemically this strain utilized glucose, fructose lactose, sucrose, but did not arabinose, cellulose, rhamnose, sorbitol, trehalose, mannitol. Catalase test showed negative property. Optimal growth temperature was $37^{\circ}C$. The results obtained above suggest this strain Streptococcus faecium subspp. and we named it Streptococcus sp. An-21-1.

• Journal of the Korean Ceramic Society
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• v.44 no.1 s.296
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• pp.58-64
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• 2007

In this study, we investigated $Li_2ZrO_3$ membrane as a candidate material for high-temperature $CO_2$ separation and evaluated mechanical property. $Li_2ZrO_3$ powder was synthesized by solid state reaction of $Li_2CO_3\;and\;ZrO_2$. Then we fabricated $Li_2ZrO_3$ tape using tape casting method. Dense $Li_2ZrO_3$ membrane prepared by sintering at $1600^{\circ}C$ for 2 h after pressing $Li_2ZrO_3$ tape using lamination machine. Mechanical properties before and after $CO_2$ absorption of fabricated $Li_2ZrO_3$ membrane such as Hertzian indentation, Victors hardness and 3-point bending testing were evaluated.

• Genomics & Informatics
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• v.3 no.1
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• pp.24-29
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• 2005

TRPV2 is a non-specific cation channel expressed in sensory neurons, and activated by noxious heat. Particularly, TRPV2 has six transmembrane domains and three ankyrin repeats. TRPV2 has been cloned from various species such as human, rat, and mouse. Oocytes of Xenopus laevis - an African clawed frog ­have been widely used for decades in characterization of various receptors and ion channels. The functional property of rat TRPV2 was also identified by this oocyte expression system. However, no TRPV2 orthologue of Xenopus laevis has been reported so far. Hence, we have focused to clone a TRPV2 orthologue of Xenopus laevis with the aid of bioinformatic tools. Because the genome sequence of Xenopus laevis is not available until now, a genome sequence of Xenopus tropicalis - a close relative species of Xenopus laevis - was used. After a number of bioinformatic searches in silico, a predicted full-length sequence of TRPV2 orthologue of Xenopus tropicalis was found. Based on this predicted sequence, various approaches such as RT-PCR and 5' -RACE technique were applied to clone a full length of Xenopus laevis TRV2. Consequently, a full-length Xenopus laevis TRPV2 was cloned from heart cDNA.

• Journal of Ocean Engineering and Technology
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• v.12 no.2 s.28
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• pp.65-70
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• 1998

In this report, the creep properties and creep life estimation by Larson-Miller Parameter(LMP) Method for 2.25Cr1Mo steel to be used as power plant tubes or other components were presented at the high temperatures of 500, 550, and $600^{\circ}C$. It was confirmed experimentally and quantitatively that a creep life estimation equation at such various high temperatures was well derived by LMP and could be used very effectively within the creep life of 10$^3$ hours, but very unreliable and even dangerous for design in a long term of creep life such as 10$^4$ or $10^5$ hours.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.55-55
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• 2008

이차전지의 음극 중 $LiC_6$는 높은 용량을 보이나 완충하는 프로세스 동안에 금속리튬에 가까운 potential을 갖게 되어 조작에 어려움이 있다. 이러한 대용물질로서 $Li_4Ti_5O_{12}$ spinel은 가볍고 높은 에너지 밀도를 가지고 있고 낮은 전압영역이 가능하여 이차전지의 음극 물질로서 유용하다. 그러나 $Li_4Ti_5O_{12}$ 물질 자체가 insulation이며, 고상합성법을 사용하게 되면 좋은 특성을 나타내기가 어렵다. 이번 실험에서는 고상합성을 통하여 $Ba^{2+}$와 $Sr^{2+}$이온을doping한 후 전기화학적 특성이 어떻게 향상되었는가를 연구하였다. Ba와 Sr을 첨가한 $Li_4Ti_5O_{12}$는 첨가하지 않은 물질에 비하여 보다 안정적인 평탄구역을 갖게 되었으며 방전용량이 $40mAhg^{-1}$의 향상을 가져왔다. 또한 Li half cell에서 100cycle 진행하는 동안 보다 안정적인 전극구조를 유지하였다.