• Membrane Journal
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• v.30 no.5
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• pp.307-318
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• 2020

Conventional perfluorinated sulfonic acid membrane, Nafion is widely used for vanadium redox flow battery (VRFB). It is desired to prevent vanadium ion permeation through a membrane to retain the capacity, and to keep the cell efficiency of a VRFB. Highly proton conductive and chemically stable Nafion membranes, however, suffer from high vanadium permeation, which induce the reduction in charge and discharge capacity by side reactions of vanadium ions. In this study, to resolve the issue, silica nanoparticles, which are functionalized with 3-aminopropyl group (fS) are introduced to enhance the long-term performance of a VRFB by lowering vanadium permeation. It is expected that amine groups on silica nanoparticles are converted to positive ammonium ion, which could deteriorate positively charged vanadium ions' crossover by Gibbs-Donnan effect. There is reduction in proton conductivity may due to acid-base complexation between fS and Nafion side chains, but ion selectivity of proton to vanadium ion is enhanced by introducing fS to Nafion membranes. With the composite membranes of Nafion and fS, VRFBs maintain their discharge capacity up to 80% at a high current density of 150 mA/㎠ during 200 cycles.

• Korean Journal of Biological Psychiatry
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• v.7 no.1
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• pp.64-73
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• 2000

There are several candidate genes in genetic study of alcoholism. Among them, allelic associations have been reported between MAOA CA repeat polymorphism and alcohol dependence, recently. And also, several studies have been investigated genotype-phenotype relationships between MAOA CA repeat polymorphism and clinical manifestations. The authors tried to identify differences in allelic frequency of MAOA CA repeat polymorphism between alcohol dependence and controls, and in behavioral trait and clinical characteristics according to MAOA CA repeat polymorphism. We also tried to investigate genotype-phenotype relationships between MAOA CA repeat polymorphism and behavioral trait such as aggression. We examined 49 male patients with alcohol dependence(DSM-IV) who had been admitted in Yong-In Mental Hospital from June 1st 1998 to October 31th 1998. We performed semistructured interview for demographic and clinical characteristics. Self-report questionnaire for BDHI(Buss-Durkey Hostility Inventory) was given to all subject at least 4weeks later after admission. Using polymerase chain reaction and polyacrylamide gel electrophoresis, MAOA CA repeat polymorphism were observed in 52 male controls and 49 male patients with alcohol dependence. We devided alcoholic patients into two groups according to allelic length of MAOA CA repeat polymorphism ; alcoholics with short alleles(${\leq}$119bp, N=20) and alcoholics with long alleles(${\geq}$123bp, N=29). T-test, ${\chi}^2$-test and Fisher exact probability test were used for statistical analysis. There were no significant differences in frequency of each allele and short and long alleles of MAOA CA repeat polymorphism between alcoholics and controls. But there were significant differences in clinical symptoms and behavioral trait between alcoholics with short and long alleles. In clinical symptoms, alcoholics with long alleles used alcohol more frequently during one month before admission, had much more maximum amount of beer drinking and reported withdrawal seizure more frequently than with short alleles. In contrary, alcoholics with short alleles expressed depressed mood and guilty feeling more frequently and wanted complete abstinence as a treatment goal more frequently than with long alleles. In behavioral trait, alcoholics with long alleles had higher total aggression score and showed much more self-assertive attitude(subscale of expression of aggression) than with short alleles. Allelic length of MAOA CA repeat polymorphism was correlated with self-assertive attitude and accounted for 9% of the variance of self-assertive attitude. And also, predictable variables of allelic length of MAOA CA repeat polymorphism were drinking frequency and self-assertive attitude. Our findings suggest that MAOA CA repeat polymorphism may provide some behavior modifying role especially in self-assertive attitude and indirect symptom modifying role in Korean male alcoholics.

• Journal of the Korean Chemical Society
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• v.55 no.3
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• pp.478-485
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• 2011

Merocyanine derivatives transformed from spiropyran-containing compounds by irradiating the light of ultraviolet (UV) include zwitterion of phenolate anion and amine cation. Complexation of this phenolate anion on merocyaninemodified surface and Ni ion among metal ions led to a change of surface charge and it was measured with kelvin prove force microscopy (KFM). We found that the resultant surface potential decreased linearly as UV-exposed time increased, and finally were saturated. Also it was analyzed through XPS the immobilized amount of Ni ions was increased according to increase of UV-exposed time. It is considered that these properties could be applied for detection and a quantitative control of different metal ions. Further research is to aim construct specific scaffold/matrix which enable high selective, high sensitive and, especially, a quantitative immobilization of metal ions-binding biomaterials such as proteins and cells.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.71.2-71.2
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• 2011

300MW 급 태안 IGCC 가스화 플랜트 및 기존 발전소에 CCS 를 설치할 경우에 대해 기술 타당성 검증을 목적으로 CCS 모델링을 수행하였다. CCS Case Studies 는 플랜트 운전부하에 따른 $CO_2$ 제거율, $H_2S$ 제거율, 소모동력 범위 등 플랜트 성능을 예측할 수 있다. Case Studies 결과를 활용하여 설계된 CCS 설비 용량이 운전범위에 적합한지를 판단할 수 있고 과잉 설계되었을 경우 플랜트 건설비를 절감할 수 있다. IGCC 가스화 플랜트에서 생산되는 합성가스의 $CO_2$ 분압, 목표 $CO_2$ 제거율, 경제성을 기준으로 적합한 CCS 공정을 판단한 결과 Selexol 공정이 선정되었다. Selexol 공정은 고압, 고농도의 산성가스 제거에 적합하며 다른 물리적 용매인 Rectisol 공정에 비해 건설비용이 경제적이고 화학 흡수제인 아민과 비교하여 운전 온도 범위가 넓다. CO, $H_2O$ 를 $CO_2$, $H_2$ 로 전환하는 Water Gas Shift Reaction (WGSR) 공정은 Co/Mo 촉매 반응기로 구성되었고 Selexol 공정은 $H_2S$ Absorber, $H_2S$ Stripper, $CO_2$ Absorber, $CO_2$ Flash Drum 로 구성되었다. WGSR+Selexol 모델링은 Wet Scrubber 후단의 합성가스 (40.5 bar, $136{\sim}139^{\circ}C$) 를 대상으로 하였다. WGSR+Selexol 공정 운전 조건 변화 [Process Design Case(PDC), Equipment Design Case(EDC), Turndown Design Case(TDC)] 에 따른 플랜트 모델링 결과를 비교분석 하였다. 주요 분석 내용은 WGSR 설비에서의 CO 의 $CO_2$ 전환 효율, Selexol 설비에서 $CO_2$ 제거 효율, $H_2S$ 제거 효율이다. 모델링 결과 WGSR 설비에서의 CO 의 $CO_2$ 로의 전환율 99.1% 이상, Selexol 설비에서 $CO_2$ 제거율은 91.6% 이상, $H_2S$ 제거율 100%이었다. CCS 설비 설치에 따른 플랜트 성능 영향을 분석하기 위해서 CCS 설비의 Chiller, Compressor, Pump 소비동력을 계산하였다. 모델링 결과 Chiller 는 2.6~8.5 MWth, Compressor 는 3.0~9.6 MWe, Pump 는 1.4~3.0 MWe 범위 이었다. 플랜트 로드가 50%인 TDC 소모동력은 플랜트 로드가 100%인 PDC 소모동력의 절반 수준이었다. 합성가스를 WGS+Selexol 공정을 통해 수소가스로 전환시키면 가스터빈 연료가스의 Lower Heating Value (LHV) 값이 평균 11.5% 감소하였다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.2
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• pp.149-154
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• 1999

A 16-week feeding trial was conducted to determine the amount of fish meal analogue (FMA) that can be replacing white fish meal (WFM) protein in Korean rockfish. Five experimental diets were formulated on isonitrogenous and isocaloric basis of $50\%$ crude protein and 15.6 KJ/g diet. The graded level of replacement of PM by Em on the basis of crude protein were as follows : Diet 1($100\%$ WFM), Diet 2($87.5\%$ WFM : $12.5\%$ FMA), Diet 3 ($75\%$ WFM : $25\%$ FMA), Diet 4($75\%$ WFM : $25\%$ FMA+2 EAAs), Diet 5 ($50\%$ WFM : $50\%$ FMA+2 EAAs). Methionine and Iysine were selected for 2 essential amino acids (EAA) to study the effect of adding EAA to the diets 4 and 5. Weight gain (WG), feed fed efficiency (FE) and protein efficiency ratio (PER) of fish fed diet 3, 4 and 5 were significantly lower (P< 0.05) than those of fish fed the control ($100\%$ WFM),while that of fish fed diet 2 was not significantly different diet(P>0.05) from those of fish fed the control diet. WG, FE and PER of fish fed diet 4 were significantly higher (P<0.05) than those of fish fed diet 3, but lower than those of fish fed the control diet. Therefore, these results indicated that FMA protein could substitute WFM protein up to $12.5\%$ without 2 EAAs supplementation in Korean rockfish. And, dietary supplementation of 2 EAAs could be benetficial when FMA is utilized as a fish meal replacer in juvenile Korean rockfish.

• Applied Chemistry for Engineering
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• v.22 no.1
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• pp.104-108
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• 2011

In the non-conductive adhesives (NCAs) for adhesion of micro electro mechanical system (MEMS), there are some problems such as delamination and cracking resulting from the large differences of coefficients of thermal expansion (CTE) between NCAs and substrates. So, the addition of inorganic particles such as silica and nano clay to the CTEs composit have been applied to reduce the CTEs of the adhesives. Additions of the flexibilizers such as siloxanes have also been performed to improve the flexibility of epoxy composite. Amino modified siloxane (AMSs) were used to improve compatibility between epoxy and siloxane. In this study, glass transition temperatures (Tg) and moduli of those composites were measured to confirm the effects of AMS with two different equivalents on thermal/mechanical properties of AMS/epoxy composites. Tg of KF-8010/epoxy composites decreased from 148 to $122^{\circ}C$ and those of X-22-161A/epoxy composites decreased from 148 to $121^{\circ}C$. Moduli of KF-8010/epoxy composites decreased from 2648 to 2143 MPa by adding KF-8010 and moduli of X-22-161A/epoxy composites decreased from 2648 to 2014 MPa. In short, using long Si-O chain AMS leads to a greater decrease in moduli. However, haven't showed significant differences in Tg's.

• Korean Journal of Organic Agriculture
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• v.18 no.4
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• pp.527-539
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• 2010

This study was conducted to determine the effect of probiotics as an alternative for antibiotics on growth performance, nutrient digestibility, noxious gas emission and fecal microbial population in growing piglets. A total of 96 piglets ($22.5{\pm}1.3$kg average body weight) were allotted to 3 different treatment groups and replicated 4 times with 8 piglets per replicate in randomized complete block design. Treatments were T1) (Control, basal diet+0.2% antibiotics), T2) 0.2% probiotics complex and T3) 0.3% Bacillus probiotics. During the whole experiment period, there were no differences (p>0.05) in average daily gain (ADG), average daily feed intake (ADFI) and feed efficiency. However, digestibility of dry matter, crude protein, ether extract, nitrogen free extract and crude ash were showed higher in probiotics groups (T2 and T3) than those of control. In noxious gas emission, ammonia, amine, hydrogen sulfide and mercaptan were significantly (p<0.05) reduced in T2 and T3 treatments compared to those in control. Moisture content of feces was not significantly different among treatments. The colony forming units (CFU) of total bacteria, E. coli and thermoduric bacteria in feces were significantly different among treatments. The CFU of total bacteria, E. coli and thermoduric bacteria in T3 treatment were reduced by feeding probiotics B. From this study, we suggest that probiotics A and B are likely able to improve the growth performance and nutrients digestibility, reduce noxious gas emission and change the fecal microbial composition in growing piglets.