• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.131.2-131.2
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• 2010

서부 발전 태안화력발전소에 건설 예정인 IGCC Demo plant의 설계 자료를 근거로 석탄 가스화기의 정상 상태 전산모사를 PRO/II를 사용하여 수행하였다. 석탄을 PRO/II가 받아들일 수 있는 성분으로 바꾼 후 가스화기를 버너와 가스화기 본체의 두 부분으로 나누어 모델링하였다. 버너는 단열조건의 Gibbs Reactor로 모델링하였다. 모사 결과 산소가 완전 소진될 때까지 반응이 진행되는 것을 확인하였다. 가스화기는 char gasification 반응은 kinetic reaction equation으로, gas phase reaction은 equilibrium reactor로 모사하는 알고리듬을 개발 하였으나 PRO/II의 기능에 한계가 있어 간단한 Gibbs Reactor로 모사하였다. 가스화기는 membrane wall에 의하여 냉각되는 것을 고려하여 $1550^{\circ}C$의 균일한 온도에서 반응이 일어나는 것으로 고려하였다. 전산 모사 결과 주요 성분의 조성이 실제 syngas의 조성과 5% 정도 오차가 있는 것으로 나타났다.

• Membrane Journal
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• v.31 no.4
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• pp.253-261
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• 2021

Solutions to water pollution, global warming, and climate change have been currently discussed. Pressure retarded osmosis (PRO) using a difference in salt concentration between two fluids is proposed to meet the demand for clean water and produce eco-friendly energy. Although PRO has been researched continuously, it has not been commercialized yet due to limitations such as lack of technology and the high price of membranes. Meanwhile, the membrane is one of the most significant parts of the PRO engine and salinity gradient power (SGP) technology. Research continues to technologically develop graphene oxide membranes and nanocomposite membranes used in salinity gradient power generation. Studies on efficient membranes, solvents, and solutes are active to enable high energy efficiency of the osmotic heat engine even at low temperatures of waste. Studies have been conducted on reducing internal concentration polarization and increasing power density by using membranes with balanced permeability and selectivity. In this review, dealing with these studies, we discuss the types of PRO membranes, theoretical modeling of technologies through efficient membranes, and other technologies to develop the process efficiency.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.20-21
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• 2003

Insulin-like growth factors (IGFs) are mitogenic peptide hormones that regulate embryonic development, postnatal growth and cellular differentiation in vertebrates IGFs are initially translated as pre-pro-peptides and then proteolytically processed to yield the mature IGFs and E-peptides. Like the C-peptide of pro-insulin, the E-peptides of pro-IGFs are generally believed to possess little or no biological activity other than their potential roles in the biosynthesis of the mature IGFs. Like human IGF-1, previous studies in our laboratory showed that the recombinant trout Ea4-peptide of pro-IGF-1 exhibited a dose-dependent mitegenic activity in cultured BALB/3T3 fibroblasts and other non-oncogenic transformed cells (Tian et al., 1999) We have also shown by in vitro and in vivo studies that Ea4-peptide possessed novel anti-tumor activities (Chen et al., 2002, Kuo and Chen, 2002; Kuo and Chen 2003). Recent results of studies conducted in chorionicallantoic membrane of developing chicken embryos revealed that Ea4-peptide of trout pro-IGF-1 also possesses a dose-dependent antiangiogenic activity. Together these results raised the question whether Ea4-peptide of trout pro-IGF-1 may affect heart and blood vessel development and hematopoiesis in fish embryos. (중략)

• Water for future
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• v.51 no.4
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• pp.59-65
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• 2018

• Journal of Korean Society of Water and Wastewater
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• v.30 no.3
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• pp.271-278
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• 2016

Recently, reverse osmosis (RO) is the most common process for seawater desalination. A common problem in both RO and thermal processes is the high energy requirements for seawater desalination. The one energy saving method when utilizing the osmotic power is utilizing pressure retarded osmosis (PRO) process. The PRO process can be used to operate hydro turbines for electrical power production or can be used directly to supplement the energy required for RO desalination system. This study was carried out to evaluate the performance of both single-stage PRO process and two-stage PRO process using RO concentrate for a draw solution and RO permeate for a feed solution. The major results, were found that increase of the draw and feed solution flowrate lead to increase of the production of power density and water permeate. Also, comparison between CDCF and CDDF configuration showed that the CDDF was better than CDCF for stable operation of PRO process. In addition, power density of two-stage PRO was lower than the one of single-stage. However, net power of two-stage PRO was higher than the one of single-stage PRO.

• BMB Reports
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• v.32 no.6
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• pp.561-566
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• 1999

CA(1-8)-ME(1-12) [CA-ME], composed of cecropin A(1-8) and melittin(1-12), is a synthetic antimicrobial peptide having potent antibacterial and antitumor activities with minimal hemolytic activity. In order to investigate the effects of the flexible hinge sequence, Gly-Ile-Gly, of CA-ME on antibiotic activity, CA-ME and three analogues, CA-ME1, CA-ME2, and CA-ME3, were synthesized. The Gly-Ile-Gly sequence of Ca-ME was deleted in CA-ME1 and replaced with Pro and Gly-Pro-Gly in CA-ME2 and CA-ME3, respectively. CA-ME1 and CA-ME3 showed a significant decrease in antitumor activity and phospholipid vesicle-disrupting ability. However, CA-ME2 showed similar antitumor and vesicle-disrupting activities, as compared with CA-ME. These results suggest that the flexibility or ${\beta}$-turn induced by Gly-Ile-Gly or Pro in the central part of CA-ME may be important in the electrostatic interaction of the N-terminus cationic ${\alpha}$-helical region with the cell membrane surface and the hydrophobic interaction of the C-terminus amphipathic ${\alpha}$-helical region with the hydrophobic acyl chains in the cell membrane. CA-ME3 exhibited lower antitumor and vesicle-disrupting activities than CA-ME and CA-ME2. This result suggests that the excessive ${\beta}$-turn structure caused by the Gly-Pro-Gly sequence in CA-ME3 seems to interrupt ion channel/pore formation in the lipid bilayer. We concluded that the appropriate flexibility or bilayer. We concluded that the appropriate flexibility or ${\beta}$-turn structure provided by the central hinge is responsible for the effective antibiotic activity of the antimicrobial peptides with the helix-hinge-helix structure.

• BMB Reports
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• v.33 no.1
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• pp.49-53
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• 2000

PMAP-23 is a 23-residue antimicrobial peptide derived from porcine myloid cells. In order to investigate the effects of two Pro residues at positions 12 and 15 of PMAP-23 on antibiotic activity, two analogues in which Ala was substituted for Pro residue at position 12 or 15 were synthesized. $Pro^{12}{\rightarrow}Ala$ (PMAPl) or $Pro^{15}{\rightarrow}Ala$(PMAP2) substitution in PMAP-23 caused a significant reduction on antitumor and phospholipid vesicle-disrupting activities, but did not cause a significant effect on antibacterial activity. PMAP-23 displayed the type I ${\beta}-turn$ structure with a negative ellipticity at near 205 om in SDS micelle, whereas PMAP1 and PMAP2 had a somewhat ${\alpha}-helical$ propensity in TFE solution, as compared to PMAP-23. These results suggest that two Pro residues of positions 12 and 15 in PMAP-23 play important roles in the formation of ${\beta}-turn$ structure on lipid membrane and its ${\beta}-turn$ structure may be essential for antibiotic activity including phospholipid vesicle-disrupting property.

• Proceedings of the Membrane Society of Korea Conference
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• 2005.11a
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• pp.178-180
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• 2005

• 한국유가공학회:학술대회논문집
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• 1997.05a
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• pp.23-34
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• 1997

Calcium-stimulated ATPase ($Ca^{2+}$-ATPase) which has optimal pH value at 7.0 was found in the membrane fraction of human milk, and its enzymatic properties were studied. The purified $Ca^{2+}$-ATPase required 0.45 mM Ca ion for maximal activity. Among the nucleosides, $Ca^{2+}$-ATPase showed a higher substrate specificity to ATP and UTP than to CTP and GTP. $Ca^{2+}$-ATPase had apparent Km value of 0.065, and V max of 7.63 mol ATP hydrolyzed/mg pro-tein per min, respectively. $Ca^{2+}$-ATPase was potently inhibited by lanthanide, vanadate, and p-chloromercuribenzoate, and inactivated by EDTA, and CDTA and EGTA, but were unaffected by N-ethylmaleimide, $NaN_3$, ouabain, or oligomycin, and was completely inactivated by heating at $60^{\circ}C$ for 10 min. This enzyme activity was concentrated in the membrane fraction of the cream and skim milk membrane, but not founded in bovine milk.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.9
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• pp.476-481
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• 2016

Pressure retarded osmosis (PRO) is a quite new technique for power generation using an osmotically driven membrane process. In the PRO process, water permeates through a semipermeable membrane from a low concentration feed solution to a high concentration draw solution due to osmotic pressure. This study carried out to evaluate the performance of the 8 in spiral wound membrane module using reverse osmosis concentrate for a draw solution and reverse osmosis permeate for a feed solution. Three different flowrates of draw and feed solution, such as 2.4 L/min, 5.0 L/min, and 10.0 L/min were used to estimate the power density and water flux under various range of hydraulic pressure differences between 5 bar and 30 bar. In addition, the effects of feed and draw solution concentration, flowrate, and mixing ratio on 8 in spiral wound PRO membrane module performance were investigated in this study. As major results, increases of the draw solution concentration lead to the improvement of power denstiy, and water flux. Also, increase of flowrate resulted in the improvement of power density and water flux. In addition, optimal mixing ratio of draw and feed solution inlet flowrate was found to be 1:1 to attain a maximum power denstiy.