• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1998년도 춘계 학술발표회 논문집
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• pp.221-228
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• 1998

2차원 노심핵설계 코드 HELIOS를 이용하여 $^{7}$ LiF-BeF$_2$-ThF$_4$-$^{233}$ UF$_4$ 용융염 핵연료와 흑연(Graphite) 감속재로 구성된 AMBIDEXTER(Advanced Molten-salt Break-even Inherently-safe Dual-mission EXperimental and TEst Reactor) 원자로의 육각주형 로심격자에 대해 핵적 자활성 요건의 설계해석을 수행하였다. AMBIDEXTER 원자로는 액체 핵연료의 유동성을 이용한 온라인 핵연료 정화ㆍ처리ㆍ재생의 연속공정을 도입하여 노내의 잔류 핵분열 생성물질의 포화양을 최소로 유지시키고 중성자 경제성을 극대화하므로 높은 전환율을 얻는 설계이다. 핵연료 내에 잔류하는 핵분열생성물질의 포화농도에 대응하는 연소도를 등가연소도로 정의할 때, 열출력 250MW$_{th}$ AMBIDEXTER 원자로의 등가연소도 374MWD/TeH.E.의 평형 로심 모델에 대해 핵적 자활성을 지배하는 주요 핵설계 인자로서 용융염 핵연료의 $^{233}$ U Mole 분율, 흑연-대-용융염의 체적비, 노심격자 간격 및 출력 밀도의 변화에 따른 임계도 및 전환율을 평가하였다. 그 결과, $^{233}$ U Mole 분율과 혹연-대-용융염 체적비를 좌표축으로 하는 2차원상공간에서 핵적 자활성 요건 상태함수는 각 노심격자간격에 대해 완만한 선형 함수로 표현할 수 있음을 확인하였다.

• 한국대기환경학회지
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• 제30권1호
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• pp.68-76
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• 2014

The present study has evaluated the $CO_2$ adsorption amount of activated carbon pellets (AC). Coconut shell based test AC were modified with surface impregnation of glycine, glycine metal salts and monoethanolamine for low level $CO_2$ (3000 ppm) adsorption. Physical and chemical properties of prepared adsorbents were analyzed and the adsorbed amount of $CO_2$ was investigated by using pure and 3,000 ppm $CO_2$ levels. The impregnation of nitrogen functionalities was verified by XPS analysis. The adsorption capacity for pure $CO_2$ gas was found to reach upto 3.08 mmol/g by AC-LiG (Activated carbon-Lithium glycinate), which has the largest specific surface area ($1026.9m^2/g$). As for low level $CO_2$ flow the primary amine impregnated adsorbent showed 0.26 mmol/g of adsorption amount, indicating the highest selectivity. An adsorbent with potassium-glycine salts (AC-KG, Activated carbon-Potassium glycinate) instead of amine presented with 0.12 mmol/g of adsorption capacity, which was higher than that of raw activated carbon granules (0.016 mmol/g).

• Journal of Photoscience
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• 제10권3호
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• pp.219-223
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• 2003

Phloxine B (2,4,5,7-tetrabromo-4,5,6,7-tetrachlorofluorescein disodium salt), also referred as D&C red dye no. 28, is phototoxic to many insects such as Tephritidae fruit flies. Sunlight photolysis of phloxine B in aqueous solutions was a first order kinetic reaction at low concentrations. But it turned to be more complex reactions with the increase of phloxine B concentration. The half-lives of phloxine B (6-120 ${\mu}$M) were 18-41 and 52-289 hours in oxygenated and deaerated distilled water, respectively. The photolysis rate constants increased as the phloxine B concentrations increased. The singlet oxygen formation positively correlated with the concentrations of phloxine B and humic acid in oxygenated distilled water. The formation of singlet oxygen did not stop even after the complete degradation of phloxine B, which suggested an involvement of photoproduct-mediated reactions. The results showed that singlet oxygen mediated photooxidation was a dominant reaction for phloxine B dissipation in an aqueous solution, and the self-sensitized and photoproduct-mediated reactions were also involved at the higher concentrations. Iodide and bromide ions significantly decreased phloxine B photolysis rate constants, which were in relation to the decrease of singlet oxygen formation.

• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.469-472
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• 2003

A method that effectively precipitates capsular polysaccharide of Haemophilus influenzae type b (polyribosylribitol phosphate, PRP) conjugated to tetanus toxoid (TT), PRP TT in a liquid vaccine has been developed to measure free PRP present in TT-conjugate vaccine. The method involves adding anti-TT antibody and ammonium sulfate to precipitate PRP-TT conjugate and measuring free PRP in tile supernatant. This new method provides a complete precipitation of the total PRP-TT, and provides an accurate and reproducible measurements of free PRP. The accuracy of the assay was confirmed by spiking known amounts of unconjugated PRP to PRP-TT conjugate, and the new method was found to have no effect on free PRP while precipitating PRP-TT. The published acid precipitation method did not produce reproducible results due to incomplete precipitation of PRP-TT, especially when the vaccine is formulated in a salt-buffered solution.

• Journal of Microbiology and Biotechnology
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• 제30권7호
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• pp.1082-1091
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• 2020

Microbial transglutaminases (MTGs) are widely used in the food industry. In this study, the MTG gene of Streptomyces sp. TYQ1024 was cloned and expressed in a food-grade bacterial strain, Bacillus subtilis SCK6. Extracellular activity of the MTG after codon and signal peptide (SP Ync M) optimization was 20 times that of the pre-optimized enzyme. After purification, the molecular weight of the MTG was 38 kDa and the specific activity was 63.75 U/mg. The optimal temperature and pH for the recombinant MTG activity were 50℃ and 8.0, respectively. MTG activity increased 1.42-fold in the presence of β-ME and 1.6-fold in the presence of DTT. Moreover, 18% sodium chloride still resulted in 83% enzyme activity, which showed good salt tolerance. Cross-linking gelatin with the MTG increased the strength of gelatin 1.67 times and increased the thermal denaturation temperature from 61.8 to 75.8℃. The MTG also significantly increased the strength and thermal stability of gelatin. These characteristics demonstrated the huge commercial potential of MTG, such as for applications in salted protein foods.

• The Korean Journal of Physiology
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• 제25권2호
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• pp.159-170
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• 1991

In the rabbit renal artery, mechanisms of contraction by sodium depletion were investigated. The helical strips of isolated renal artery were immersed in the Tris-buffered salt solution. The contractions were recorded isometrically using a strain-gauge transducer. Na-free solution (Na was substituted by Li, choline or sucrose) produced contractions which were dependent on the nature of the Na substitutes. Na-free solution (choline) produced the contraction in ouabain-pretreated artery (Na loaded artery) even in the presence of verapamil. The amplitude of the contraction was dependent on the duration of the pretreatment with ouabain $(10\;^5M)$. Monensin potentiated the effect of ouabain on the contraction. Removal of Ca from bathing solution abolished the contraction and the substitution of Sr for Ca produced the contraction. Divalent cations such as Mg, Mn blocked the depolarization-induced contraction, while they had little effect on the Na-free contraction in Na loaded artery. These results suggest that the contraction induced by Na removal is dependent on the cellular Na content and may be caused by Ca influx via the Na-Ca exchange carrier.

• Bulletin of the Korean Chemical Society
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• 제32권2호
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• pp.590-594
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• 2011

An aminocarboxy aspartic acid-bonded silica (Asp-Silica) stationary phase was synthesized using L-aspartic acid as ligand and silica gel as matrix. The standard protein mixtures were separated with prepared chromatographic column. The effects of solution pH, salt concentration and metal ion on the retention of proteins were examined, and also compared with traditional iminodiacetic acid-bonded silica (IDA-Silica) column. The results show that Asp-Silica column exhibited an excellent separation performance for proteins. The retention of proteins on Asp-Silica stationary phase was consistent with electrostatic characteristic of cation-exchange. The stationary phase displayed typical metal chelate property after fixing copper ion (II) on Asp-Silica. Under competitive eluting condition, protein mixtures were effectively isolated. Asp ligand showed better ion-exchange and metal chelating properties as compared with IDA ligand.

• 한국염색가공학회지
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• 제8권4호
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• pp.42-51
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• 1996

Alkaline hydrolysis to improve the hand of PET/acetate union fabric was studied in relation to skin saponification and retarding effect of salts on the alkaline hydrolysis of cellulose acetate fiber, accelerating effect of salts on the alkaline hydrolysis of PET fiber, and changes of total hand value(T.H.V) of PET/acetate union fabric treated with alkali/salt solution. It was found that the rate of saponification of acetate was delayed by the addition of salts such as LiCl, NaCl and CH$_{3}$COONa into NaOH solution below 10 minutes. The rate of shrinkage of acetate fabric treated with 5g/l NaOH solution at 9$0^{\circ}C$ and 60 minutes showed 20 % but it was decreased 8% by. the addition of 120g/l Concentration of inorganic salts. We could know that the rate of alkaline hydrolysis of filament yarn treated with alkali solution at 9$0^{\circ}C$ and 60 minutes was delayed about 3 % using 2,000T/M of hard twist yarn, especially acetate filament treated with alkali solution at 9$0^{\circ}C$ and 10 minutes was delayed about 10%. T.H.V. of PET/acetate union fabric was increased from 2.77 to 3.04~3.18 by the addition of salts into alkali solution.

• Bulletin of the Korean Chemical Society
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• 제23권6호
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• pp.845-851
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• 2002

The synthesis of the intramolecular donor - stabilized silyl and germyl complexes of the type ($Cab^c.p) MMe_2X$ (2a:M=Si, X=Cl;2b;M= Ge, X=Cl;2e;M=Si,X=H) was achieved by the reaction of $LiCab^c,p$ (1) with $Me_2SiClX$ and $Me_2GeCl_2$ respectively. The intramolecular M←P interacion in 2a-2c is provided by $^1H$, $13^C.$, $31^P$ and $29^Si$ NMR spectroscopy. The salt elimination reactions of dichlorotetramethyldisilane and -digermane with 1 afforded the $bis(\sigma-carboranylphosphino)disilane$ and disgermane [$(Cab^C.P)MMe_2]_2(4a;M$ = Si;4b: M=Ge). The oxidative addition reaction of 4a-4b with $pd_2(dba)_3CHCl_3afforded$ the bis(silyl)-and bis(germyl)-palladium complexes. The chloro-bridged dipalladium complexes were obtained by the reaction of 2a-2b with $pd_2(dba)_3CHCl_3$ The crystal structures of 5a and 7b were determined by X-ray structural studies.

• Macromolecular Research
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• 제16권8호
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• pp.734-740
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• 2008

A new crosslinked, poly(acrylic acid)-based, dehydrating agent was synthesized through solution polymerization. The Taguchi method, a robust experimental design, was adopted to optimize the synthetic conditions based on the moisture and water absorbing capacities of the dehydrating agent. The method applied for the experiment was a standard L27 ($3^8$) orthogonal array with eight parameters and three levels. By analyzing the variance of the test results, the most effective parameters to control the moisture absorbing capacity (MAC) and its rate were the kind of alkaline base (LiOH, NaOH, or KOH) used as a neutralizing agent of the acrylic acid monomer and the degree of neutralization: The maximum MAC of 40% was achieved at only 2 hat $32^{\circ}C$ and 50% RH when KOH was used as a base and the degree of neutralization was 90%, respectively. However, the water absorbing capacity (WAC) of the resulting dehydrating agent was very low at 158 g/g, indicating that WAC is unaffected by MAC and its rate in this system. The surface morphologies of the agents were examined using scanning electron microscopy (SEM).