• 한국가스학회지
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• 제11권1호
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• pp.9-12
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• 2007

본 연구에서는 디젤기관에서 배출되는 배출가스의 저감을 위하여 경유와 천연가스의 혼합비율이 서로 다르게 연료의 분사량을 조절 전부하 운전시의 토크값을 4:0, 3:1, 2:2및 1:3의 4종류로 설정 디젤기관의 연소특성을 살펴보았다. 엔진회전수의 변화에 의한 배출가스의 변화를 알아보기 위하여 회전수를 1500, 2000, 2500 및 3000 rpm으로 설정 NOx, 흑연, 일산화탄소 및 탄화수소의 배출농도값을 측정하였다. 그 결과 디젤연료만을 사용하였을 경우보다 천연가스를 혼합하였을 경우 NOx, 일산화탄소 및 탄화수소의 배출농도는 다소 증가하였으나, 흑연의 배출농도는 감소하는 경향을 나타내었다.

• BMB Reports
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• 제31권4호
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• pp.399-404
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• 1998

In order to gain further insight on the relationship between structure and function of glutathione S-transferase (GST), the six active-site mutants, R13T, K44T, Q51A, Q64A, S65A, and D98A, of human GST P1-1 were expressed in Escherichia coli and purified to electrophoretic homogeneity by affinity chromatography on immobilized GSH. The active-site mutants showed marked differences in substrate specificity. The substitution of Gln51 with threonine resulted in a drastic decrease in the specific activities to <10% of the wild-type value. The substitution of Arg13 with threonine resulted in more decreased specific activity toward cumene hydroperoxide and in the $I_{50}$ values of S-(2,4-dinitrophenyl) glutathione and benanstatin A. These results suggest that the substitution of Arg13 with threonine changes the conformation of the active site to increase the affinity for the product or electrophilic substrate. Lys44 seems to be in the vicinity of the H-site of hGST P1-1 or may contribute to some extents to the electrophile binding.

• 복식
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• 제41권
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• pp.117-138
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• 1998

This study can be divied into three major sections: 1. Background on the 1980s : The 1980s can be characterized as a era of rising expectations over the quality of life. Interest in art, history, culture, and new technology increased to appeal to a greater audience. In fashion, these changes led to greater focus on quality and unique stylishness as fashion represented a medium through which luxury and refined tastes could be expressed. 2. Textile Trends of the 80s Divided into 4 Periods : The period of 1980-82 saw the mixture of natural lines with constructive lines. The textiles used in fashions in this period can be characterized by natural materials, mannish materials of the 1950s, feminine materials of the 1920s and 30s, and spoty materials of the 1960s. The period of 1983-85 was an avante garde period which used rustic avante-garde materials and art craft materials. The period of 1986-87 can be described as minimalistic and neo-classical which incorporated materials which represents a metropolitan feel, retro decorative materials and sporty, futuristic mat-erials. Lastly, the period of 1988-89 produced ethnic and natural fashions which relied on traditional British materials, country elegant and innocent look fabrics, ethinic and ecology-minded materials, in addition to comfortable and sports casual materials. 3. Characteristrics and methods of expression for textiles in the 1980s, : In the 1980s, the development of textiles have can be divided into 4 distinct patterns: decorative materials, sporty materials. In generals textiles have increased in their decorative nature-especially decoration by texure. Textile have also incorporated the mixture of contrasting themes in order to create new fabrics.

• 한국생산제조학회지
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• 제20권4호
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• pp.427-433
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• 2011

Chassis part in automotive body is affected by fatigue load at driving on the ground. Universal joint on this part is influenced extremely by the fatigue load. Fatigue life, damage and natural frequency are analyzed at universal joint under nonuniform fatigue load. The york part at universal joint is shown with the maximum equivalent stress and displacement of 60.755 MPa and 0.21086 mm as strength analysis. The possible life in use in case of 'SAE bracket' is the shortest among the fatigue loading lives of 'SAE bracket', 'SAE transmission' and 'Sine Wave'. The damage at loading life of 'SAE transmission' is the least among 3 types. The frequency of damage in case of 'Sine Wave' is 0.7 with the least among 3 fatigue loading life types but this case brings the most possible damage as 80% at the average stress of 0. Natural vibration at this model is analyzed with the orders of 1'st to 5'th and maximum frequency is shown as 701.73 Hz at 5'th order. As the result of this study is applied by the universal joint on chassis part, the prevention on fatigue damage in automotive body and its durability are predicted.

• Ocean and Polar Research
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• 제24권1호
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• pp.63-71
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• 2002

This preliminary study on the changes of macrobenthic assemblages in experimental sediment fences was conducted as a part of tidal marsh restoration project. Intertidal sediment fences were designed to increase the efficiency of trapping sediments on unvegetated tidal flats in order to raise sediment elevation and to allow colonization of intertidal vegetation. Although increment of soil surface level was not observed over the first three months of the study, it was possible to obtain some effects of the sediment fence. Three months later, the particle sizes of the surface sediment at experimental plots became much finer compared to unfenced areas on the natural mudflats located in the same tide level as that of the plots. The difference was much greater on the plot with drainage canals than on the plot without ones. Species diversity of the experimental plots became much higher than that of natural sites. Perinereis aibuhitensis and Glauconome chinensis which were absent from initial community appeared with high density in the plot with drainage canals. Those species were significantly different in abundance between the experimental plot and the natural mudflat. Changes in species composition were not detected in another experimental plot without drainage canals.

• Journal of Applied Biological Chemistry
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• 제56권2호
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• pp.79-81
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• 2013

맹종죽(Phyllostachys pubescens) 수액의 저장성을 향상시키기 위하여 열처리 조건을 조사하였다. 수액을 $70^{\circ}C$에서 30분간 열처리한 후 $2^{\circ}C$에서 보관하면서 수액의 pH, 총 세균수, 관능특성을 경시적으로 분석하여 품질변화를 조사하였다. 그 결과, 맹종죽 수액의 품질 및 관능특성이 10일 동안 유지되었다.

• Journal of Microbiology and Biotechnology
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• 제9권1호
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• pp.62-69
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• 1999

In order to investigate the critical amino acid residues involved in the catalytic activities of $\beta$-cyclodextrin glucanotransferase ($\beta$-CGTase) excreted by Bacillus firmus var. alkalophilus, the amino acid residues in $\beta$-CGTase were modified by various site-specific amino acid modifying reagents. The cyclizing and amylolytic activities of $\beta$-CGTase were all seriously reduced after treatment with Woodward's reagent K (WRK) modifying aspartic/glutamic acid, N-bromosuccinimde (NBS) modifying tryptophan, and diethylpyrocarbonate (DEPC) modifying histidine residues. The roles of tryptophan and histidine residues in $\beta$-CGTase were further investigated by measuring the protection effect of various substrates during chemical modification, comparing protein mobility in native and affinity polyacrylamide gel electrophoresis containing soluble starch, and comparing the $K_m$ and $V_{max}$ values of native and modified enzymes. Tryptophan residues were identified as affecting substrate-binding ability rather than influencing catalytic activities. On the other hand, histidine residues influenced catalytic ability rather than substrate-binding ability, plus histidine modification had an effect on shifting the optimum pH and pH stability.

• Nutrition Research and Practice
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• 제5권6호
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• pp.495-502
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• 2011

In this study, antioxidant and free radical scavenging activities of the natural antioxidative compound, pyrogallol-phloroglucinol-6,6'-bieckol (PPB) isolated from brown algae, Ecklonia cava was assessed in vitro by measuring the radical scavenging activities (DPPH, alkyl, hydroxyl, and superoxide) using electron spin resonance (ESR) spectrometry, intracellular reactive oxygen species (ROS) scavenging activity, and DNA damage assay. According to the results of these experiments, the scavenging activity PPB against difference radicals was in the following order: DPPH, alkyl, hydroxyl, and superoxide radicals ($IC_{50}$; 0.90, 2.54, 62.93 and $109.05{\mu}M$). The antioxidant activities of PPB were higher than that of the commercial antioxidant, ascorbic acid. Furthermore, PPB effectively inhibited DNA damage induced by $H_2O_2$. These results suggest that the natural antioxidative compound, PPB, can be used by the natural food industry.

• 자연과학논문집
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• 제18권1호
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• pp.65-76
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• 2007

The purpose of this study is to examine residents' consciousness for urban parks and green spaces in the city of Daejeon. This work enables us to find new implementation factors to increase resident's satisfaction of urban parks and green spaces. This study surveyed 1005 residents from 80dongs(neighborhoods), of 5 Gu(districts) districts in Daejeon. The survey was conducted with a structurally organized questionnaire and objective materials. The data collected from participants of the survey were summarized as follows. Daejeon residents want more natural parks and neighborhood parks than other urban facilities as recreation facilities. The favorite places in which Daejeon residents visit are Bomun Mountain, Gap River, Geajock Mountain, and Yudeon River, in order. In landscape scenery of Daejeon, residents prefer Daedeck research complex area than others and they felt that urban landscape scenery is more improved than 5 years ago. Also they want to increase the area of park and green space about 4times more than present. The result shows that the importance index of park and green space is 8.7 and the satisfaction index is 5.42. These results suggests that the demand by residents for urban park and green spaces will improve as the urban structure is improved.

• Journal of Ginseng Research
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• 제14권3호
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• pp.379-384
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• 1990

In order to study the lipid peroxidation caused by light and the protective action it in biological memberane, reverse-phase evaporation liposome (REV) was employed as a model memberance and the effect of several antioxidants and ginseng water extracts were tested. In the presence of photosensitizer, liposome was oxidized easily and the oxidation index dut to the peroxidation was increased. The oxidation index of liposome was increased according to the increase in temperature. When dl-${\alpha}$-tocopherol, ${\beta}$-carotene or L-ascorbic acid was added into the reaction mixture, the photooxidation of liposome was inhibited. Ginseng water extract and crude saponin inhibited the rate of oxidation index of liposome in low concentration but increase in high concentration. On the other hand, when lipid hydroperoxide of liposome was tested by ferrothiocyanate method, ginseng water extract and crude saponin acted as antioxidants.