• 제목/요약/키워드: Component Effects

검색결과 2,767건 처리시간 0.029초

홍삼 추출물 투여가 생쥐간에서 항산화 효소 활성과 지질과산화에 미치는 효과 (Effects of Red Ginseng Component on the Antioxidative Enzymes Activities and Lipid Peroxidation in the Liver of Mice)

  • 성금수;전철;권용훈;김경현;장재철
    • Journal of Ginseng Research
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    • 제24권1호
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    • pp.29-34
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    • 2000
  • 홍삼 사포닌의 항산화 작용을 나타내는 활성성분을 screening하기 위하여 홍삼 추출물(물 추출물, 알코올 추출물, 지용성분획, 총 사포닌, PD 및 PT)이 항산화 효소(SOD, catalase)의활성도 변화와 $H_2O$$_2$ 및 MDA의 함량 변화에 미치는 영향을 조사하였다. 항산화 효소인 SOD의 활성도를 조사해 본 결과 지용성 추출물, PD, 알코올 추출물 투여군 순으로 활성도를 높이는 것으로 조사되었으며, SOD에 의한 중간 생성물인 $H_2O$$_2$의 함량을 조사한 결과 모든 추출물 투여군에서 감소하였으며, 그 중에서도 PT 알코올 추출물 및 PD투여군이 유의성있게 감소하였다. catalase 활성도는 지용성 추출물 투여군이 가장 높았고, 그 다음으로 총 사포닌, 알코올 추출물 투여군 순으로 조사되었다. 유리기에 의해 생성된 지질과 산화의 최종산물인 MDA의 함량은 모든 추출물 투여군에서 유의성(p<0.01) 있게 감소하였으며, 그 중에서도 지용성 추출물, 알코올 추출물, PD투여군 순으로 가장 많이 감소하였다. 이와 같은 홍삼 사포닌의 항산화 효과는 SOD및 catalase와 같은 항산화 효소의 직접적인 작용과 홍삼의 특정 성분들이 생체내에서 내인성 항산화 물질의 합성능력을 강화시킴으로서 산화적 손상에 대한 방어기전을 향상시키는 결과로 생각되며, 그중에서 지용성 추출물과 PD분획물이 가장 효과적인 성분으로 생각된다.

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브랜드명성수준에 따른 브랜드 스토리텔링의 효과 (The Effect of Brand Storytelling in Brand Reputation)

  • 최수아;정효선;황윤용
    • 유통과학연구
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    • 제12권4호
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    • pp.55-63
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    • 2014
  • Purpose - Brands and products often play key roles in enabling consumers to experience a good attitude, resulting in mentally enacting a specific prototype and reliving the experience by retelling a specific story. Brand storytelling can function as an important tool for managing the brand. To successfully apply a firm's brand storytelling, it is important to prove the effectiveness of storytelling. Therefore, by utilizing the research of Escalas (1998) and Fog et al. (2005), a list of measurements for storytelling component quality (SCQ) was applied. In addition, customer attitudes toward brand storytelling were tested. In particular, if customers encounter a dynamic and interesting story, although the brand is not widely known, they can be in communion with the brand and establish an emotional connection (Hill, 2003). Thus, brand reputation was divided into two levels (high vs. low), and the difference in effectiveness between storytelling component quality and consumers' advertisement attitude, brand attitude, and purchasing intention was examined. Research design, data, and methodology - By using the measurement list used in Choi, Na, and Hwang (2013), 12 categories in the level of message quality, conflict quality, character quality, and plot quality were measured. In addition, categories of brand reputation, advertisement attitude, brand attitude, and purchasing intention were measured. The study was based on 181 final survey samples targeting undergraduate and graduate students in Gwangju Metropolitan City. Results - Consumer responses toward storytelling were researched in the context of brand characteristics or product attributes, such as brand reputation, differentiated from extant simple effects of storytelling. Some brands with high reputation enjoy a halo effect due to prior learning, while other brands with comparatively low reputation have trouble generating positive responses despite attempts to enhance the level of reputation or induce favorable attitudes. Although not all due to the component quality of storytelling, the case of brands with low reputation exerted more positive impact on consumer attitudes than did brands with high reputation. As mentioned earlier, consumer evaluation of the component quality of storytelling was categorized into advertising attitudes, brand attitudes, and purchase intention for this study; this provides managerial implications in other ways. The results imply that an effective application of storytelling could be an important emotional tool for the development of both brands with low brand awareness and of well-known brands. Finally, this study serves to increase consumers' understanding and ability in interpreting brand stories that marketers tell about themselves, as well as to highlight differential experiences with products by level of brand hierarchy. Conclusions - This research aimed to provide an objective guideline for storytelling component quality while considering brand awareness. Thus, brand reputation was considered for proving the baseline effectiveness of storytelling, and this study provided directions for strategic establishment of storytelling. Based on this, we conclude that in further studies, it will be necessary to systematically manage brand story by considering other situation variables and various story patterns, and studying their differences.

ZnO-Co3O4-Cr2O3-La2O3 세라믹스의 결함과 입계 특성에 미치는 CaCO3의 영향 (Effects of CaCO3 on the Defects and Grain Boundary Properties of ZnO-Co3O4-Cr2O3-La2O3 Ceramics)

  • 홍연우;하만진;백종후;조정호;정영훈;윤지선
    • 한국전기전자재료학회논문지
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    • 제31권5호
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    • pp.307-312
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    • 2018
  • Liquid phases in ZnO varistors cause more complex phase development and microstructure, which makes the control of electrical properties and reliability more difficult. Therefore, we have investigated 2 mol% $CaCO_3$ doped $ZnO-Co_3O_4-Cr_2O_3-La_2O_3$ (ZCCLCa) bulk ceramics as one of the compositions without liquid phase sintering additive. The results were as follows: when $CaCO_3$ is added to ZCCLCa ($644{\Omega}cm$) acting as a simple ohmic resistor, CaO does not form a secondary phase with ZnO but is mostly distributed in the grain boundary and has excellent varistor characteristics (high nonlinear coefficient ${\alpha}=78$, low leakage current of $0.06{\mu}A/cm^2$, and high insulation resistance of $1{\times}10^{11}{\Omega}cm$). The main defects $Zn_i^{{\cdot}{\cdot}}$ (AS: 0.16 eV, IS & MS: 0.20 eV) and $V_o^{\bullet}$ (AS: 0.29 eV, IS & MS: 0.37 eV) were found, and the grain boundaries had 1.1 eV with electrically single grain boundary. The resistance of each defect and grain boundary decreases exponentially with increasing the measurement temperature. However, the capacitance (0.2 nF) of the grain boundary was ~1/10 lower than that of the two defects (~3.8 nF, ~2.2 nF) and showed a tendency to decrease as the measurement temperature increased. Therefore, ZCCLCa varistors have high sintering temperature of $1,200^{\circ}C$ due to lack of liquid phase additives, but excellent varistor characteristics are exhibited, which means ZCCLCa is a good candidate for realizing chip type or disc type commercial varistor products with excellent performance.

방사선 조사에 의한 DNA Double Strand Breaks의 생성 및 회복에 미치는 인삼 알칼로이드 분획의 효과 (The Effects of Alkaloid Fraction of Korean Ginseng on the Radiation-Induced DNA Strand Breaks)

  • 조철구;김태환;류성렬;고경환;김미숙;김정희;김성호;윤형근;지영훈
    • Radiation Oncology Journal
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    • 제13권2호
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    • pp.113-120
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    • 1995
  • Purpose : To investigate the effect of alkaloid fraction from Korean ginseng on radiation-induced DNA double strand breaks (dsb) formation and repair in murine lymphocytes Materials and Methods : We used the neutral filter elution technique to assay $^{60}Co\;{\gamma}$ ray-induced DNA double strand breaks formation and repair in C57BL/6 mouse spleen lymphocytes for evaluating the dose-response relationship in the presence of alkaloid fraction as a radioprotective agent. The lymphocytes were stimulated with Phytohemagglutinin (PHA, 2 u g/ml) to label $^3[H]-thymidine.$ Isotope-labelled lymphocytes in suspension were exposed to 100 Gy at $0^{\cdot}C$ in the alkaloid fraction-treated group and elution procedure was performed at PH 9.6. The extents of formation of radiation-induced DNA double strand breaks and repair were compared respectively via strand scission factor (SSF) and relative strand scission factor (RSSF). Results: Alkaloid fraction reduced the formation of double strand breaks with dose modification factor of 2 15, compared to control group Rejoining of DNA dsb appeared to take place via two components. The first fast component was completed within 20.4 minutes, but the second slow component was not completed until 220.2 minutes after irradiation. About $30\%$ of dsb formed by irradiation was ultimately unrejoined despite the administration of alkaloid fraction. The administration of alkaloid fraction had a great effect on the second slow component of repair; the half-time of fast component repair was not changed, but that of slow component was 621.8 minutes. Conclusion: Neutral filter elution assay Proved to be a very effective method to quantitate the extents of DNA dsb formation and its repair. By using this technique, we were able to evaluate the efficiency of alkaloid fraction from Korean ginseng as a valuable radioprotector. Alkaloid fraction can be used prophylactically to prevent or ameliorate the severe radiation damages in workers and neighbors around the atomic power plants. For more refined study, however, more advanced purification of alkaloid fraction wil be needed in the near future.

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Bi0.5(Na0.78K0.22)0.5TiO3 세라믹스의 A-site 비화학양론이 유전 및 전기적 특성에 미치는 영향 (A-site Non-stoichiometric Effects of Bi0.5(Na0.78K0.22)0.5TiO3 Ceramics on the Dielectric and Electrical Properties)

  • 박정수;이규탁;윤지선;조정호;정영훈;백종후
    • 한국전기전자재료학회논문지
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    • 제27권12호
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    • pp.803-808
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    • 2014
  • $Bi_{0.5+x}(Na_{0.78}K_{0.22})_{0.5-3x}TiO_3$ ceramics with an excess $Bi^{3+}$ and a deficiency of $Na^+$ and $K^+$ were synthesized by a conventional solid state reaction method. The structure and morphology of $Bi_{0.5+x}(Na_{0.78}K_{0.22})_{0.5-3x}TiO_3$ ceramics were characterized by X-ray diffraction and field emission scanning electron microscopy. The electric polarization and mechanical strain induced by external electric field, and the temperature dependence of dielectric constant were investigated. These results demonstrated that an ergodic relaxor phase can be induced by controls of the mole ratio of $Bi^{3+}$, $Na^+$ and $K^+$. A phase boundary between non-ergodic and ergodic relaxor phases can be observed at ambient temperature. The ergodic relaxor phase can be transferred to the ferroelectric phase by application of the electric field. The stability of the induced ferroelectric phases strongly depends on the mole ratio of $Bi^{3+}$, $Na^+$ and $K^+$. The maximum strain of 0.31% was observed in $Bi_{0.51}(Na_{0.78}K_{0.22})_{0.47}TiO_3$ ceramics sintered at $1,150^{\circ}C$ for 2 h.

원전 구조물-기기 상호작용이 기기 지진응답에 미치는 영향 연구 (A Study on the Effects of Nuclear Power Plant Structure-Component Interaction in Component Seismic Responses)

  • 곽신영;임승현;정광섭;정재욱;최인길
    • 한국전산구조공학회논문집
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    • 제35권2호
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    • pp.83-91
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    • 2022
  • 원자력발전소 기기 내진설계 및 지진해석은 비연계모델을 대상으로 수행된다. 그러나 이러한 비연계해석은 실제 구조물-기기 간 상호작용 등의 실제 현상을 모사할 수 없기 때문에 연계해석에 비하여 정확하지 못한 결과를 발생시키게 된다는 한계를 가진다. 이러한 배경 아래 이 연구는 실제 원전 격납건물 구조물 및 관련 부계통을 대상으로 질량비와 고유진동수비를 고려하여 지진 연계해석과 비연계해석을 수행하고, 이를 바탕으로 부계통에서의 응답을 비교 분석하였다. 결과적으로 지진 연계해석 결과가 비연계해석 결과보다 대다수 작은 값을 주는 것을 확인하였다. 이러한 결과는 기존 연구인 단순한 연계모델에 대한 해석 결과와 유사하지만, 부계통 응답 차이는 훨씬 더 두드러지게 나타나는 것을 확인하였다. 또한, 이는 지진파의 입력 주파수의 영향보다는 부계통의 설치위치에 영향을 받는 것으로 확인되었다. 마지막으로 비연계 및 연계 지진해석의 차이가 부계통의 질량비가 크고, 고유진동수가 거의 일치하는 영역에서 발생하는 이유는 이 영역에서 주계통과 부계통 동적 상호작용이 크게 나타나기 때문인 것으로 보인다.

r면 사파이어 위에 HVPE로 성장된 a면 GaN 에피층의 성장온도 효과 및 1000℃에서의 V/III족 비의 효과 (The effects of growth temperatures and V/III ratios at 1000℃ for a-plane GaN epi-layer on r-plane sapphire grown by HVPE)

  • 하주형;박미선;이원재;최영준;이혜용
    • 한국결정성장학회지
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    • 제25권2호
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    • pp.56-61
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    • 2015
  • Ga source 채널의 HCl flow가 700 sccm, 그리고 V/III족 비가 10으로 고정되었을 때, r-면 사파이어 위에 HVPE로 성장된 a-면 GaN 에피층 특성에 대한 성장 온도 영향을 연구하였다. 추가적으로 성장온도가 $1000^{\circ}C$, 그리고 Ga source 채널의 HCl flow가 700 sccm으로 고정되었을 때, 공급가스에 대한 V/III족 비 영향에 대하여 연구하였다. 성장온도가 높아지면서, a-면 GaN 에피층에 대한 (11-20) 면의 Rocking curve(RC)의 반치폭 값이 감소하였고 a-면 GaN 에피층의 성장두께는 증가하였다. $1000^{\circ}C$에서 V/III족 비가 높아짐에 따라, (11-20) 면의 RC의 반치폭 값이 감소하였고, a-면 GaN 에피층의 성장두께가 증가하였다. $1000^{\circ}C$와 V/III족 비=10에서 성장된 a-면 GaN 에피층이 (11-20) 면에서 가장 낮은 RC 반치폭인 734 arcsec을 보이며, RC측정을 통한 (11-20) 면의 방위각 가장 작은 영향을 보여준다.

사장 케이블 진동에 의한 보강형의 전단력 변화 (Shear Force Variation of Stiffening Girder caused by Vibration of Stay Cable)

  • 김현겸;황재웅;이명재
    • 대한토목학회논문집
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    • 제29권1A호
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    • pp.1-8
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    • 2009
  • 사장교에 사용되는 팽팽한 경사 케이블은 풍우현상에 의하여 진동에 쉽게 노출된다. 더욱이 보편적으로 알려진 풍우현상 이외의 이상현상에 의한 과도한 진동이 발생할 여지도 항상 존재한다. 급증한 동적변위는 케이블과 보호관에 과도한 인장력을 발생시키고 정착구와 댐퍼에 피로손상을 발생시키며 보강형의 설계에서 고려하지 않았던 추가적인 전단력 변화를 발생시킨다. 본 연구는 사장 케이블의 자유장에 발생된 동적변위에 의한 케이블의 동적장력 변화와 보강형의 전단력 변화를 분석 할 수 있는 해석적인 기법을 기술하고, 이로 인해 발생될 수 있는 사장교의 동적문제를 간략히 언급한다. 이것을 실현시키기 위해 사장 케이블이 진동하여 법선방향 변위를 발생시킬 때 나타나는 변화를 현방향 장력과 법선방향 장력으로 분리하여 물리적인 현상을 미분방정식으로 표현한 후 전개한 해를 풍우현상에 적용하여 케이블의 동적장력 변화와 보강형의 전단력 변화를 산정하였다. 주목할 것으로 CIP Recommendations(2002)에서 제시하는 방법론에 본 연구의 일부사항을 반영하여 산정하면 본 연구와 매우 유사한 결과를 제시하지만 CIP Recommendations에서 제시하는 방법론을 그대로 따라서 산정하면 10% 이상의 오차를 제시함을 확인하였다. 이것은 국제적으로 활용도가 매우 높은 설계지침에서 조차도 본 연구에서 논의하는 주제에 관한 조치가 없었음을 의미하는 것이다. 여기에 관한 검증은 사장 케이블의 진동형상을 만족하도록 외적하중을 재하시킨 탄성현수선 요소를 이용한 유한요소해석을 통하여 수행하였다.

Effects of sheds and cemented joints on seismic modelling of cylindrical porcelain electrical equipment in substations

  • Li, Sheng;Tsang, Hing-Ho;Cheng, Yongfeng;Lu, Zhicheng
    • Earthquakes and Structures
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    • 제12권1호
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    • pp.55-65
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    • 2017
  • Earthquake resilience of substations is essential for reliable and sustainable service of electrical grids. The majority of substation equipment consists of cylindrical porcelain components, which are vulnerable to earthquake shakings due to the brittleness of porcelain material. Failure of porcelain equipment has been repeatedly observed in recent earthquakes. Hence, proper seismic modelling of porcelain equipment is important for various limit state checks in both product manufacturing stage and detailed substation design stage. Sheds on porcelain core and cemented joint between porcelain component and metal cap have significant effects on the dynamic properties of the equipment, however, such effects have not been adequately parameterized in existing design guidelines. This paper addresses this critical issue by developing a method for taking these two effects into account in seismic modelling based on numerical and analytical approaches. Equations for estimating the effects of sheds and cemented joint on flexural stiffness are derived, respectively, by regression analyses based on the results of 12 pieces of full-scale equipment in 500kV class or higher. The proposed modelling technique has further been validated by shaking table tests.

Binary Mixture Toxicity of AROCLOR 1248, Oleic Acid, and Elemental Sulfur to Vibrio fischeri Luminescence

  • Kalciene, Virginija;Dabkeviciene, Daiva;Cetkauskaite, Anolda
    • 한국환경과학회지
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    • 제24권11호
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    • pp.1541-1546
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    • 2015
  • The objective of this research was to evaluate the toxicity of the industial xenobiotic Aroclor 1248 (A) and natural origin substances~elemental sulfur (S80) and oleic acid (OA) and their binary mixtures to V. fischeri bioluminescence during the prolonged exposure time (up to 60 min). The bioluminescence quenching test was used to determine the toxic effects. Full factorial experiment design and multiple regression analysis and the comparison of binary mixture effect with the sum of effects of individual chemicals were used for the evaluation of combined effects of toxicants. The analysis of general trend of mixture toxicity to bioluminescence showed that mixture toxic effects were reversible up to 60 min. Data analysis revealed different joint effects, which were depended on mixture composition. S80 enhanced toxic effect of A and acted additively with synergistic interaction. Hydrophobic OA in mixture with A acted antagonistically and in mixture with sulfur caused an additive effect with antagonistic component of interaction. It was concluded that low concentrations of natural toxic substances present in environmental samples as mixtures of chemicals can define the toxicodynamic character of industrial xenobiotics.