• Korea-Australia Rheology Journal
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• 제18권2호
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• pp.103-107
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• 2006

Organic-inorganic composite of polyaniline and barium titanate (PANI-$BaTiO_3$) was synthesized via an in-situ oxidation polymerization of aniline in the presence of barium titanate ($BaTiO_3$) nanoparticles dispersed in an acidic medium. Barium titanate has large electric resistance and relatively high dielectric constant which is one of the essential properties for its electrorheological (ER) applications. The microstructure and composition of the obtained PANI/$BaTiO_3$ composite were characterized by SEM, FT-IR and XRD. In addition, we also employed a rotational rheometer to investigate the rheological performance of the ER fluids based on both pure PANI particle and PANI/$BaTiO_3$ composite. It was found that the composite materials possess much higher yield stresses than the pristine PANI due to unique dielectric properties of the inorganic $BaTiO_3$ particles. Finally, we also examined dynamic yield stress by analyzing its extrapolated yield stress data as a function of electric field strengths. Using the critical electric field strengths deduced, we further found that the universal yield stress equation collapses their data onto a single curve.

• Journal of Pharmaceutical Investigation
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• 제22권4호
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• pp.281-287
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• 1992

Omeprazole (OMZ) is very unstable in acidic solution, which selectively inhibit the release of the gastric juice in the gastric mucosa, In order to stabilize (OMZ) in oral solid dosage form, the enteric-coated microcapsules and compression-coated OMZ tablets containing lysine or arginine as stabilizer were prepared and their dissolution and stability test were performed. The haif life of OMZ microcapsules containing arginine was 194 days at $30^{\circ}C$ and OMZ was completely released in 60 min. The half-lives of enteric coated and non-coated compression-coated OMZ tablets with lysine were 292 and 95 days at $30^{\circ}C$, respectively. The half-lives of enteric coated and non-coated compression-coated tablets with arginine were 1752 and 293 days at $30^{\circ}C$, respectively, and OMZ were released completely in 20 min in the 2nd fluid of K.P.VI. Consequently, the enteric-coated compression-coated OMZ tablets with arginine as stabilizer provided a good formulation for oral solid dosage form.

• Journal of Yeungnam Medical Science
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• 제11권1호
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• pp.30-34
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• 1994

염산 lidocaine의 피하 주입시 발생되는 고통을 감소시키기 위하여 8.4% sodium bicarbonate로 중화시켜 사용해 보았다. 지원자를 대상으로한 실험군의 100%에서 예상된 효과를 얻을 수 있었다.

• 한국식물병리학회지
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• 제10권4호
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• pp.305-313
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• 1994

Typically susceptible lesions were developed on pepper (cv. Hanbyul) leaves inoculated with the compatible strains Ds 1 of Xanthomonas campestris pv. vesicatoria. The lesions appeared first water-soaked and then turned yellow with a chlorotic area. In contrast, the leaves inoculated with the incompatible strain 81-23 initially turned yellow and then developed local necrosis. Multiplication of x. c. pv. vesicatoria in pepper leaves also were distinctly different between the two strains. The strain Ds 1 multiplied more greatly than did the strain 81-23 in the infected leaves. X. c. pv. vesicatoria infection of pepper leaves induced the synthesis of soluble proteins, especially more greatly in the compatible than in the incompatible interactions. Some pathogenesis-related (PR) proteins were detected in the intercellular washing fluid (IWF) and extracts of the infected pepper leaves. In particular, the 32 kDa protein on SDS-PAGE gels appeared intensely in the incompatible interaction. In contrast, some proteins with moluecular masses of 65, 71, and 75 kDa disappeared in the infected pepper leaves. Isoelectric focusing could identify the pIs of soluble proteins in infected pepper leaves. The accumulation of the IWF from infected leaves was more conspicuous in the incompatible than the compatible interaction. These results suggest that some extremely acidic and basic proteins were induced and accumulated in the intercellular spaces of infected pepper leaves.

• 한국식품영양과학회지
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• 제29권2호
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• pp.198-203
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• 2000

A highly viscous biopolymer from Bacillus coagulans CE-74 was purified and its rheological properties were studied The rheological properties of biopolymers produced by Bacillus coagulans CE-74 were studied at the temperature ranges with 20~8$0^{\circ}C$, at the concentration of 0.5~4.0%, at the pH ranges from 3 to 1 and at the shear rate fo 7.34~73.38 sec-1. The apparent viscosity of biopolymer was decreased with increasing shear rate, and thereby biopolymer showed pseudoplastic characteristics. Biopolymer solution showed a characteristic of non-Newtonian fluid properties. At the concentration of 1%, the consistency index and the flow behavior index were shown at 2.64 poise. sec11 and 0.8571, respectively. All dispersions were pseudoplastic fluids described accurately by Herschel-Bulkley model. The change of the biopolymer viscosity on pH showed the highest value at the pH 7.0 and it showed lower at acidic conditon that at alkaline condition comparatively.

• 생약학회지
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• 제53권3호
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• pp.119-124
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• 2022

Vaginal microbiome deeply influences vaginal health via production of messenger molecules. The healthy vaginal pH ranges between 3.5 and 4.5. However, dysbiosis of vaginal microbiome increases the pH level, leading to the incidence of vaginitis. The commensal vaginal bacterium Dermabacter vaginalis-which was isolated from the vaginal fluid of a Korean female-was incubated in acidic and neutral pH to simulate healthy and vaginitis conditions, respectively. The chemical profiles of the two different cultures were compared using HPLC. The compound showing distinctive difference between the two sets of data was presumed to be a chemical messenger, which was identified as cyclo(L-pro-L-met) by analysis of NMR, MS, and specific rotation data. Synthesis was achieved in three steps (overall yield 15%), enabling structure confirmation and antimicrobial evaluation against vaginal pathogens. Cyclo(L-pro-L-met) showed antifungal activity against Candida albicans, a major cause of vulvovaginal candidiasis.

• 자원환경지질
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• 제8권1호
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• pp.25-56
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• 1975

Most fluorite deposits of South Korea are distributed in three metallogenic zones namly as: Hwacheon, Hwangangni and Geumsan metallogenic zones. Fluorite deposits of each zone show The characteristic features owing to the geological setting, the structural patterns and their forming processes. deposits of the Hwacheon metallogenic zone are wholly fissure filling hydrothermal veins emThe bedded in shear fractures of the granite gneiss or schists of Precambrian age or in the cooling fractures of the granite and acidic hypabyssal rocks which are assumed to be a differentiated sister rock of the granite. Localization of most fluorite veins of the region is structurally controlled by NW and EW fracture systems and genetically related to the granite intrusion which ascertained as motivating rock of the fluorite mineralization. Fluorites are in most cases accompanied by quartz, chalcedony mainly and rarely agate, calcite, barite and sulphide base metals in some localities. The deposits of the Hwangangni metallogenic zone were formed at the last stage of hydrothermal polymineralization of W, Mo, Cu, Pb, Zn. The majority of the fluorite ore bodies were originated from replacement in limestone beds of Great Limestone Series or in calcareous interbeds of metasediments, whereas some cavity-filling ore bodies were embedded in phyllites and schists of the Ockcheon system and along the fissures in the replaced beds which were originated by volume decrease. The localization of fluorite deposits in this region is genetically related to the Moongyong granite which has been dated as middle Cretaceous, and controlled structurally by the $N20^{\circ}{\sim}50^{\circ}W$ extension fracture system or axial planes of folds, and by faults of NE direction that acted as paths of ore solution. The deposits of the Geumsan metallogenic zone are seemed to be formed through the similar process as that of Hwangangni metallogenic zone, but characteristic distinctions are in that they are more prevailing fracture filling veins and large number of the deposits are localized in roof-pendants or xenolithes of limestone in granites and porphyries. Igneous rocks that presumably motivated the mineraltzation are middle Cretaceous Geumsan granite and porphyries. Metallogenic epoch of the fluorite mineralization of South Korea are puesumably limited in early-middle Cretaceous. Studies of the fluid inclusions in fluorites of the region reveal that the homogenization temperature of the fluorite deposits are as follows: Hwacheon metallogenic zone : $95^{\circ}C{\sim}165^{\circ}C$; Hwangangni metallogenic zone : $97^{\circ}C{\sim}235^{\circ}C$; Geumsan metallogenic zone : $93^{\circ}C{\sim}236^{\circ}C$. Judging from the above results, the deposits of the Hwancheon region were formed at the epithermal stage, and those in the Hwangangni and Geumsan regions, were deposited at epithermal stage preceded by mesothermal mineralization of small scale in which some sulphide minerals were deposited. The analytical data of minor elements in the fluorites reveal that ore solutions of Hwangangni metallogenic zone seemed to be emanated in more acidic stage of magma differentiation than Hwacheon metallogenic zone did.

• 자원환경지질
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• 제30권2호
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• pp.81-87
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• 1997

전남 및 경상점토열수변질지역은 백악기 유천층군의 화산암지대내 분포한다. 전남 변질지역의 모암은 산성화산암류이며 경상 변질지역의 모암은 산성 및 중성화산암류이나 중성화산암류가 우세하다. 두 변질지역의 열수변질작용을 비교 하였을 때 중요한 차이는 열수용액의 기원으로 생각된다. 경상 열수변질지대는 마그마수가 열수의 주 기원으로서 고온성 변질광물인 엽납석이나 홍주석이 우세하게 산출되며 마그마수에서 특징적인 붕소 함유 광물인 듀모티어라이트와 전기석의 산출이 특징적이다. 이에 반해서 전남 열수변질지역은 천수와 열수의 혼합용액이 열수의 주 기원으로 천수가 중요한 역할을 하였으며, 저온성 광물인 카오린, 명반석 등이 우세하게 산출된다. 또 다른 중요한 차이는 pH 와 같은 열수용액의 화학성 차이이다. 전남 열수변질지역의 명반석-카오런-석영 변질광물군은 저온의 강산성 열수용액으로서 "산-황산염형" 으로 특징되며 이에 반해 경상 열수변질지역의 견운모-석영 변질광물군은 "석영-견운모형" 에 해당되며 고온의 중성 내지 약산성 열수용액에 의한 변질특성을 나타낸다. 또한 두 지역은 열수변질대 모암인 화산암류의 지질구조 환경에서 차이를 찾아 볼 수 있다. 전남 열수변질지역은 산성암질 돔과 성인적으로 관련되나 경상 열수 변질지역은 칼데라와 관련된 특성을 보인다.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1988년도 학술대회지
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• pp.28-32
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• 1988

에피네프린은 지방분해를 촉진하고 인슈린은 지방생성을 촉진한다는 것은 잘 알려져 있다. 최근에 한국홍삼분말 중에는 에피네프린으로 유도된 지방분해를 억제하며 인슐린이 매개하는 당으로부터의 지방합성을 촉진하는 아데노신과 산성펩티드 성분이 존재함이 밝혀졌다. 산성펩티드의 화학구조는 Glu-Glu-Glu-Glu-Glu-Glu-Glucose인 것으로 밝혀졌다. 한국홍삼으로 부터 추출된 이러한 물질들은 흰쥐 지방세포에서 반대의 대사경로를 통하여 지방분해를 억제하는 반면 지방합성을 촉진하기도 하는 선택적 조절작용을 나타낸다. 최근에 우리는 여러가지 악성종양을 가진 환자의 복수액으로부터 toxohormone-L로 명명된 독성물질을 분리하였다. Toxohormone-L은 흰쥐 지방세포에서 지방분해를 촉진하고 흰쥐에서 식욕감퇴를 유발했다. Toxohormone-L의 이러한 작용은 한국홍삼에서 분리된 진세노사이드 $Rb_2$에 의해서 억제됨이 발견되었다. 한국홍삼에서 발견된 이러한 물질의 생리학적 유의성을 언급하고자 한다.

• Corrosion Science and Technology
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• 제4권4호
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• pp.140-146
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• 2005

Fossil fired power plant produces the electric energy by using a thermal energy by the combustion of fossil fuels as like oil, gas and coal. The exhausted flue gas by the combustion of oil etc. contains usually many contaminated species, and especially sulfur-content has been controlled strictly and then FGD (Flue Gas Desulfurization) facility should be installed in every fossil fired power plant. To minimize the content of contaminations in final exhaust gas, high corrosive environment including sulfuric acid (it was formed during the process which $SO_2$ gas combined with $Mg(OH)_2$ solution) can be formed in cooling zone of FGD facility and severe corrosion damage is reported in this zone. These conditions are formed when duct materials are immersed in fluid that flows on the duct floors or when exhausted gas is condensed into thin layered medium and contacts with materials of the duct walls and roofs. These environments make troublesome corrosion and air pollution problems that are occurred from the leakage of those ducts. The frequent shut down and repairing works of the FGD systems also demand costs and low efficiencies of those facilities. In general, high corrosion resistant materials have been used to solve this problem. However, corrosion problems have severely occurred in a cooling zone even though high corrosion resistant materials were used. In this work, a new technology has been proposed to solve the corrosion problem in the cooling zone of FGD facility. This electrochemical protection system contains cathodic protection method and protection by coating film, and remote monitoring-control system.