• Korean Chemical Engineering Research
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• 제46권3호
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• pp.473-478
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• 2008

망간황화물이 NO의 선택적 촉매 환원에 미치는 영향을 반응성 및 속도론적평가와 TPR(Temperature Programmed Reduction), TGA분석을 통하여 고찰하였다. 망간산화물은 $200^{\circ}C$ 이하의 저온에서 우수한 질소산화물 전환을 보였으나, 망간황화물의 경우 황화정도에 따라 질소산화물 전환은 고온으로 전이하였다. 또한 질소산화물 전환율도 황화정도에 따라 감소하였다. TPR 실험결과 망간산화물들은 $160^{\circ}C$ 이하의 낮은 온도에서 환원이 시작되었으나 망간황화물은 $280^{\circ}C$ 이상의 온도에서 환원이 시작되었다. TPR 실험을 통한 환원 시작온도는 촉매의SCR 시작 온도와 관련이 있는 것으로 판단된다. 망간황화물의 활성화에너지는 다른 촉매에 비해 낮게 나타났으나 pre-exponential 상수 크기가 다른 촉매에 비해 1/1000배 만큼 작아 NO에 대한 활성이 낮게 나타났다. 천연망간광석은 함유된 다양한 금속산화물의 영향으로 순수한 망간산화물보다 낮은 온도에서 재생되었다.

• Nuclear Engineering and Technology
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• 제34권1호
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• pp.9-21
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• 2002

Recently each domestic NPP has achieved zero release in liquid effluent activity. However, when looking back past experiences in world nuclear power operation, it is thought that another maximum activity reduction in the released liquid effluent just prior to falling it into environment, if possible, will bring a good effect in PA viewpoint. As the intent of applying the safety concept of diversity to conducting the above activity reduction measure, a scheme passing that effluent through the Deposition Bed just before discharging it into ocean environment was divised. Both Zeolite and ＂the mixed ＂Anthracite-sand＂ were derived as the main activity adsorption medium used in the Deposition Bed, and the schematic drawings of this Bed were presented.

• BMB Reports
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• 제42권9호
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• pp.580-585
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• 2009

Dimethyl sulfoxide (DMSO) is widely used in chemistry and biology as a solvent and as a cryoprotectant. It is also used as a pharmaceutical agent for the treatment of interstitial cystitis and rheumatoid arthritis. Previous reports described DMSO as being reduced by methionine-S-sulfoxide reductase (MsrA). However, little is known about the DMSO reduction capability of methionine-R-sulfoxide reductase (MsrB) or its effect on the catalysis of methionine sulfoxide reduction. We show that mammalian MsrB2 and MsrB3 were unable to reduce DMSO. This compound inhibited MsrB2 activity but did not inhibit MsrB3 activity. We further determined that DMSO functions as an inhibitor of MsrA and MsrB2 in the reduction of methionine sulfoxides via different inhibition mechanisms. DMSO competitively inhibited MsrA activity but acted as a non-competitive inhibitor of MsrB2 activity. Our study also demonstrated that DMSO inhibits in vivo methionine sulfoxide reduction in yeast and mammalian cells.

• 한국식품영양과학회지
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• 제28권1호
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• pp.94-99
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• 1999

This study was carried out to determine the inhibitory effect of juice of garlic, onion, ginger and red pepper against Staphylococcus aureus, Salmonella enteritidis, Vibrio parahaemolyticus and Enterobacter cloacae which are food born disease organisms. It was found that 1~2.5%(wt/vol.) garlic juice showed strong antimicrobial action against growth of all test bacteria at 1/20$\times$10-6 dilution. Especially 1% garlic juice completly inactivated Vibrio parahaemolyticus but approximately 71.9~88% of reduction at same concentration in other bacteria was occurred. 2.5% onion juice had 28.5% antimicrobial activity on Sal. enteritidis, but 50% reduction was occurred on St.aureus and V. parahaemolyticus at same concentration. Antibacterial activity of ginger juice was similar to that of onion juice. 2.5% ginger juice showed approximately 50% reduction on Sal. enteritidis and V.parahaemolyticus, but less antimicrobial activity was occured on St. aureus and E. cloacae. Red pepper juice showed the least antimicrobial activity on food born disease organism compared to that of other juices. 2.5% red pepper juice showed 11.3%, 18.7% and 8.1% reduction on St. aureus, Sal. enteritidis and V.parahaemolyticus, respectively.

• 한국산학기술학회논문지
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• 제15권11호
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• pp.6890-6897
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• 2014

본 전기로 환원슬래그는 팽창성 물질이 함유되어 불안정한 상태이므로 건설용 재료로 그대로 사용하기에는 다소 무리가 있다. 그러나 전기로 환원슬래그에는 $11CaO{\cdot}7Al_2O_3{\cdot}CaF_2$와 ${\beta}-C_2S$ (calcium aluminate compounds) 물질이 함유되어 있으므로 적절한 성분 보조제를 혼합하여 사용한다면 콘크리트용 혼화재료로서 사용이 가능할 것으로 판단된다. 이에 본 연구에서는 콘크리트 혼화재료서 전기로환원슬래그 미분말의 사용 가능성을 검토하고자 한다. 전기로 환원슬래그 미분말의 치환율별 모르타르 강도특성과 응결특성을 검토 결과, 최적 치환율은 30% 수준으로 나타났다. 최적 치환율에 석고 첨가에 따른 응결시간 및 강도특성을 파악한 결과, 전기로환원슬래그 미분말 치환율 30%인 배합에 이수석고를 8% 혼입하였을 경우 압축강도 발현 성상 및 응결특성이 OPC와 유사한 결과를 나타내었다.

• 한국의료질향상학회지
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• 제6권1_2호
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• pp.150-160
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• 1999

Background : Because hospitals had to faced with financial hardship, we have to have more effective hospital management. In this study, we tried to improve job performance and to reduce cost maintaining safety in fields of patients care. Methods : Central Supply Room(CSR) staffs taught strategy of material cost reduction to middle level managers and staffs 14 times. All staffs and voluntary service workers, working in 33 nursing units, participated in this activity. We developed questionnaire to check the degree of participate in cost reduction activity and job performance in CSR, and quality improvement in the wards. Two hundred questionnaires were distributed and 197 returned. Results : Because CSR staffs developed new items and every item was managed at each department, stocks of each department were reduced. Overall, by comparing before and after cost reduction activity, almost 1.2 billion won reduced for one year. Staffs' loyalty and spirits of cost reduction were improved by changing clothes and duty environment. Furthermore, these activity improved patients' satisfaction. Conclusion : We suggest that CSR activity in a university hospital contributes to improve job performance and to reduce cost without any problem in patient care.

• KEPCO Journal on Electric Power and Energy
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• 제5권4호
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• pp.331-335
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• 2019

In this study we investigate catalytic activity and selectivity of mixture of Ag and ketjenblack according to their ratios by product analysis and electrochemical experiments, such as cyclic voltammetry, linear sweep voltammetry and chronoamperometry. We reveal that catalytic activity toward CO₂ reduction to CO is improved by simple mixing Ag nanoparticle and ketjenblack because addition of ketjenblack suppresses aggregation of Ag nanoparticles and brings increase in electrochemical active surface area. However, excess amount of ketjenblack rather inhibit the CO₂ reduction to CO. These observations provide clues to develop highly active Ag catalyst or electrode toward electrochemical reduction of CO₂.

• Archives of Pharmacal Research
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• 제28권11호
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• pp.1293-1301
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• 2005

Flavonoids, a group of low molecular weight phenylbenzopyrones, have various pharmacological properties including antioxidant, anticancer, bactericidal, and anti-inflammatory. We carried out anti-herpetic assays on 18 flavonoids in five classes and a virus-induced cytopathic effect (CPE) inhibitory assay, plaque reduction assay, and yield reduction assay were performed. When flavonoids were applied at various concentrations to Vero cells infected by HSV-1 and 2, most of the f1avonoids showed inhibitory effects on virus-induced CPE. Among the flavonoids, EC, ECG (flavanols), genistein (isoflavone), naringenin (flavanone), and quercetin (flavonol) showed a high level of CPE inhibitory activity. The antiviral activity of flavonoids were also examined by a plaque reduction assay. EC, ECG, galangin, and kaempferol showed a strong antiviral activity, and catechin, EGC, EGCG, naringenin, chrysin, baicalin, fisetin, myricetin, quercetin, and genistein showed moderate inhibitory effects against HSV-1. In these experiments, flavanols and flavonols appeared to be more active than flavones. Furthermore, treatment of Vero cells with ECG and galangin (which previously showed strong antiviral activities) before virus adsorption led to a slight enhancement of inhibition as determined by a yield reduction assay, indicating that an intracellular effect may also be involved.

• 패션비즈니스
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• 제9권3호
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• pp.22-36
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• 2005

This research is to classify psychological risk perceptions in purchases process at counterfeit at fashion luxury brands, into a risk perception on purchase activity itself and a risk perception on the post-purchase situation, and to analyze types and characteristics at risk reduction behaviors to reduce each risk perception. In this research a qualitative method was employed, and research-related data were collected and analyzed through in-depth interviews. Results were shown that risk reduction behaviors at psychological risk perception on purchase activity itself included rationalization of purchase, accompanied purchase, reduction and discontinuance of purchase, and that risk reduction behaviors of psychological risk perception on the post-purchase situation included information search, establishment of selection criteria, establishment of marginal limit, selective purchase, planned and compared purchase, and reduction and discontinuance of purchase. Previous researches suggested brand loyalty, selection of famous brands, utilization of information agents by marketers, pre-purchase usage and guaranteed purchase, but these risk reduction methods were not utilized, this probably being interpreted as a result of characteristics of counterfeit. In addition, risk reduction behavior of one type tended to reduce risk perception of several other types, and risk reduction behaviors of various types were utilized to reduce a certain type's risk perception. Not only types of risk perception but also levels of risk perception appeared to have exerted influence to risk reduction behaviors.

• Archives of Pharmacal Research
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• 제22권4호
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• pp.335-339
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• 1999

The oxidation-reduction potentials of cosmetic raw materials, showing tyrosinase inhibitory action, and phenolic compounds structurally similar to L-tyrosine were determined by cylcic voltammetry. The voltammograms obtained could be classified ito 4 patterns (patterns 1-4). Patterns 1, characterized by oxidation and reduction peaks as a pair, was observed with catechol, hydroquinone or phenol, and pattern 2 exhibiting another oxidation peak in addition to oxidation and reduction peaks as a pair was found with arbutin, kojic acid, resorcinol, methyl p-hydroxybenzoate and L-tyrosine as the substrate of tyrosinase. Pattern 3 with an independent oxidation peak only was expressed by L-ascorbic acid, and pattern 4 with a reduction peak only at high potentials, by hinokitiol. The tyrosinase inhibitory activity of these compounds was also evaluated using the 50% inhibitory concentration ($IC_{50}$) and the inhibition constant (Ki) as parameters. Hinokitiol, classified as patterns 4, showed the highest inhibitory activity (lowest $IC_{50}$ and Ki). Hydroquinone showing the second highest activity belonged to pattern 1, which also included compounds exhibiting pattern 2 was relatively low with Ki values being in the order of 10-4 M. Although there was no consistent relationship between oxidation-reduction potentials and tyrosinase inhibitory action, the voltammetry data can be used as an additional index to establish the relationship between the structure and the tyrosine inhibitory activity.