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        검색결과 54

        23.
        1996.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        silica의 precursor로 TMOS를 사용하여 autoclave 내에서 supersritical drying으로 투명한 TiO2-SiO2 이성분계 aerogle을 얻을 수 있었다. 반응성이 뛰어난 titanium alkoxide의 중축합반응을 억제할 수 있는 강한 산성 영역에서 투명한 Aerogel을 얻을 수 있었으며, 물을 직접 첨가하지 않고 silicon alkoxide의 축합반응의 부산물인 물을 이용하여 titanium alkoxide의 반응성을 제어했을 때 투명성이 더욱 증진되었다.
        4,200원
        25.
        2018.10 서비스 종료(열람 제한)
        Background : Coffee is one of the favorite brewed drink in the world where is distributed in Latin America, Southeast Asia, Southern Asia and Africa. Coffee has an effective antioxidant ability and reported about that. In this study, it was analyzed by using high performance liquid chromatography (HPLC) to establish the method about content of caffeine, chlorogenic acid, caffeic acid and p-coumaric acid in coffee. Methods and Results : Coffee was extracted with 70% EtOH in room temperature and evaporated at 45℃. All standard and sample extract were melted and diluted with 15% MeOH. Mobile phase was prepared using water with 0.01% phosphoric acid and MeOH. All standard and sample were analyzed with gradient elution (0 min : 15% MeOH, 35 min : 30% MeOH). The chromatograms were monitored at 272 and 320 ㎚. HPLC reported linear equation that based on the calibration curve for each standard compound (caffeine : Y = 1.04e + 004X – 3.21e + 003, R2 = 0.999890. chlorogenic acid : Y = 2.86e + 004X – 8.24e + 003, R2 = 0.999891. caffeic acid : Y = 2.07e + 004X – 1.21e + 004, R2 = 0.999894. p-coumaric acid : Y = 3.24e + 004X – 1.10e + 004, R2 = 0.999897). Standard compounds were determined with qualitative and quantitative analysis. The retention time of each peak of standard compounds were separated by chromatogram. Conclusion : In this study, we determined that the analysis method of compounds in coffee. In addition, we have confirmed that separation about the retention time of each peak of caffeine and chlorogenic acid in different solvent condition depending on acid buffer. This method can be use to determine standard compound in coffee.
        26.
        2018.10 서비스 종료(열람 제한)
        Background : Oplopanax elatus Nakai. is distributed in Korea and China. In this study, we have used high performance liquid chromatography (HPLC) to compare the internal standards contents [uracil, adenosine, protocatechuic acid, syringin (eleutheroside B) and scoparone (6,7-dimethoxycoumarin)], and compared the antioxidant activity. Methods and Results : Samples were prepared two different temperature conditions (90℃ and 100℃). Total phenolic contents and total flavonoid contents were analyzed while gallic acid and quercetin were used as standard. Anti-oxidant activities were measured by determination of DPPH and reducing power assay. HPLC was reported as five standard compounds equivalent using the following linear equation based on the calibration curve. According to the results, the anti-oxidant effects of Korean O. elatus Nakai. stem extracts in 90℃ water showed more activity than that of Chinese in DPPH assay. However, the amount of internal compounds was higher in Chinese O. elatus Nakai.. The anti-oxidant effects of Korean O. elatus Nakai. stem extracts in 90℃ water showed more activity than Korean O. elatus Nakai. stem extracts in 100℃ water in DPPH assay. In this study, we had found that, at over the 100℃ temperature all the anti-oxidant effects of O. elatus Nakai. extracts were reduced. However, all five standard compounds were detected at similar value. Conclusion : These results suggests that Korean O. elatus Nakai. has higher anti-oxidant activities which can be use for bioactivity assay.
        27.
        2018.10 서비스 종료(열람 제한)
        Background : Hippophae rhamnoides L. are known for antioxidant, immunodeficiency, skin protection, influenza infection and prevention of heart disease. This study was carried out to confirm the possibility of functional food by changing the antioxidant effect using H. rhamnoides L. leaf extracts to the Gamju (sweet rice drink). Methods and Results : A total of 12 samples were made of different processes. Briefly, the H. rhamnoides L. leaf were extracted at 60℃ in two different conditions (EtOH 100%, water 100%). Gamju was fermented into three different koji (Aspergillus oryzae – red, yellow, black). In addition, The addition of H. rhamnoides L. leaf extracts were mixed in two ways (simultaneous saccharification, mixed after saccharification). Antioxidant activities were estimated by 2,2-diphenyl-1-picryl-hydrazil (DPPH) and reducing power assay. Total phenolic content (TPC) was determined by Folin-Ciocalteu method. In this study, we found that Gamju mixed with H. rhamnoides L. leaf increased antioxidant effects and TPC than the control (original Gamju). Moreover, the anti-oxidant effects of the mixed H. rhamnoides L. leaf with Gamju after saccharification exhibited more activity than simultaneous saccharification in DPPH assay. Conclusion : These results demonstrated that samples of added to the H. rhamnoides L. leaf could be use as functional food.
        28.
        2018.10 서비스 종료(열람 제한)
        Background : Arctium lappa L., Compositae plant, has been consumed as a vegetable and beverage in China, Taiwan, and Japan for a long time. Several studies have reported for the burdock to include antioxidant activity, hepato-protective efficacy, anti-inflammatory activity, anti-proliferative and apoptotic effects, anti-microbial and antiviral activity. Thus, A. lappa is considered a promising plant for the treatment of chronic diseases, such as cancer, diabetes, and AIDS and due to the increasing evidence of functional compounds contributions over a variety of health beneficial properties the A. lappa has received increasing scientific interest. The primary aim of the present study was determined antioxidant activities and analysis of standard compound in A. lappa. Methods and Results : There were five different solvent conditions (100% water, 30% EtOH, 50% EtOH, 70% EtOH, 100% EtOH), extract in the room temperature. Comparatively, 70% EtOH extract showed higher values of DPPH radical scavenging activity than others. As the increasing of EtOH percentage contents, we confirmed increase total phenol and flavonoid contents. The 2,4-di-tert- butylphenol as standard compound was detected by HPLC analysis based on the calibration curve: equation : Y = 8.17e + 003X – 1.43e + 005, R2 = 0.996227. The amount of standard compounds were similar in all each different solvent conditions, but not detected in water extract. Conclusion : These results showed that A. lappa could be used as potential materials of antioxidant, and should be need more study.
        29.
        2018.10 서비스 종료(열람 제한)
        Background : Forsythia suspensa Vahl (Oleaceae) is such an antioxidant source which is a slimbing plant widely distributed in China, Japan and Korea. The extracts of the dried fruits have been used for a long time as traditional Asian medicines to treat gonorrhea, erysipedas, inflammation and pharyngitis. It was also reported that F. suspensa was able to suppress vomiting, resist hepatic injure, inhibit of elastase activity, and exhibit diuretic, analgesic, antioxidant, anti-endotoxin and antiviral effects. This study was performed to investigate the antioxidant and whitening effect of F. suspensa extract and fractions. Methods and Results : Firstly, extract the dried F. suspensa by methanol three times at room temperature and fraction for each solvents (hexane, ethyl acetate, butanol and water). The DPPH radical scavenging activity was measured at 517 ㎚ by using a UV spectrophotometer. The gallic acid and quercetin were used as positive control of total phenol and flavonoid contents assay. Reducing power was conducted four concentration of samples and positive control, measured the absorbance at 700 ㎚. Ethyl acetate fraction showed the highest effect on DPPH radical scavenging activity, total phenol contents, and reducing power. On the other hand, the highest level of total flavonoid contents indicated in butanol fraction. The ethyl acetate fraction indicated the highest percentage of enzyme inhibition at the tested same concentration. Conclusion : These results suggest that F. suspensa extract and ethyl acetate fraction could be utilized as a antioxidant. Further biological and phytochemical study is needed.
        30.
        2018.10 서비스 종료(열람 제한)
        Background : Oplopanax elatus has many compounds such as essential oils, saponin, flavonoids, anthraquinones, and polyacetylenes etc. in all part of stems, roots, and leaves. In previous study, we isolated five compounds (uracil, adenosine, protocatechuic acid, syringin, and scoparone) from the water extract of in stems of O. elatus. In this study, we confirmed the variation of chemical constituents and antioxidant activity in leaves of O. elatus by different cultivation environment. Methods and Results : We analyzed three types of O. elatus in different cultivation environment (in vitro plant, in vivo plant and wild plant). We detected five compounds (uracil, adenosine, protocatechuic acid, syringin, and scoparone) in three types of plants by using HPLC. The contents of five compounds varied depending on the different cultivation environment. Syringin and adenosine were detected on all plants and showed different contents, respectively. We compared antioxidant activities such as total phenol contents (TPC), total flavonoid contents (TFC), DPPH and reducing power assay. The values of antioxidant activities (DPPH and reducing power) in leaves of in vitro plants were higher than other plants. Also TPC and TFC in leaves of in vitro plants showed the highest contents. Conclusion : These results could be basic data for cultivation methods about enhancement of syringin and adenosine compounds contents in leaves of O. elatus.
        31.
        2018.05 서비스 종료(열람 제한)
        Background : Mahonia nepalensis DC. has been used as folk medicine in Vietnam. However, its biological activities have not yet fully understood. In the present study, crude extract from Mahonia nepalensis DC. was fractionated with n-hexane, ethyl acetate and butanol (saturated of water). The extract and fractions of M. nepalensis DC., produced after a process of evaporating, were tested for anti-oxidative and anti-inflammatory activities. Methods and Results : Total phenolic, total flavonoid contents of M. nepalensis DC. were analyzed while gallic acid and quercetin were used as standard, respectively. The antioxidant free radical scavenging activities of its stem crude extract and fractions were also evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and reducing power assay. Results revealed that ethyl acetate (EtOAc) fraction showed the highest total phenolic content, as well as DPPH radical scavenging and reducing power. Briefly, the highest level of total phenolic content (122.94 ± 4.93 ㎎·GAE/g) and reducing power (absorbance of 0.815 at 1 ㎎/㎖) was indicated in EtOAc fraction. It also possessed activity in DPPH radical scavenging (IC50 = 48.93 ± 0.59 ㎍/㎖), which was better than butylated hydroxytoluene (BHT) (IC50 = 125.25 ± 0.8 ㎍/㎖) and other fractions. In an anti-inflammatory response, the potential inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS) - stimulated RAW264.7 cells were found in EtOAc and BuOH fractions. The NO production was below 20% at a dose manner of 100 ㎍/ ㎖. Results showed higher potential anti-inflammatory effect of M. nepalensis DC. than some plants. Hence, it could be developed as a useful agent for treating of inflammatory diseases. Conclusion : These results demonstrated the highly potential effect on anti-oxidative and anti-inflammatory activities of M. nepalensis DC. Therefore, further studies are necessary in order to explore the variety of M. nepalensis stem to be applied as a valuable natural material.
        32.
        2018.05 서비스 종료(열람 제한)
        Background : Eleutheroside E (Syringaresinol-di-O-glucoside), one of the internal standard in Eleutherococcus senticosus (Rupr. & Maxim.) Maxim., showed effects on the anti-inflammation of arthritis and the decline in blood sugar. In this study, it was analyzed by using high performance liquid chromatography (HPLC) to find out the optimum experimental condition which indicated the highest content of eleutheroside E. Methods and Results: In total of 15 different experimental conditions were used to extract samples. Briefly, there were three different conditions in the temperature (room temperature, 70℃ and 100℃) and five solvent conditions (100% water, 30% EtOH, 50% EtOH, 70% EtOH and 100% EtOH) were used. The extraction condition of all samples were extracted in every 4 hours and repeated three times with a reflux cooling system. The HPLC was reported as eleutheroside E standard equivalents using the following linear equation based on the calibration curve : equation : Y = 7.72e + 0.04X – 7.83e + 004, R2 = 0.999918. Among 15 conditions, eleutheroside E was obtained with the highest amount (10.36 ± 3.81 ㎎/g of extract) at 100% EtOH extracted and room temperature condition. In this study, the eleutheroside E content was increased with increasing of EtOH concentration. And it can be detected by heating at 100% water extraction condition. Conclusion : These results demonstrated that the experimental condition at room temperature in 100% EtOH could be used in further studies to obtain the highest content of eleutheroside E in Eleutherococcus senticosus (Rupr. & Maxim.) Maxim.
        33.
        2018.05 서비스 종료(열람 제한)
        Background : Oplopanax elatus has many compounds such as essential oils, saponin, flavonoids, anthraquinones, and polyacetylenes etc. in all part of stems, roots, and leaves. It is traditionally used to treat asthma, depressive states, chronic fatigue syndrome, diabetes mellitus, rheumatism, arthritis, gastrointestinal disorders, and wounds. In this study, the evaluation of several factors affecting the variation of chemical constituents and antioxidant activity in stem of O. elatus. Methods and Results : Five compounds (uracil, adenosine, protocatechuic acid, syringin, and scoparone) were isolated from the water extract of in stems of O. elatus. We extracted stems of them with hot water by different temperature (85 and 100℃) and times (1, 4, and 7 hrs.) and analyzed contents of five compounds by HPLC and antioxidant activity such as DPPH, ABTS and reducing power assay. The contents of five compounds varied depending on the extraction time and extraction temperature, the contents of uracil and protocatechuic acid in extracts of stems reduced with times. However, there is no difference the amount of variation in chemical constituents in stems of O. elatus. The antioxidant free radical scavenging activities of its stem extracts in 85℃ water (IC50 = 34.56 ± 0.8 ㎍/㎖ of extracts) showed more activity than extracts in 100℃ water (IC50 = 39.58 ± 1.6 ㎍/㎖ of extracts) in ABTS assay. Conclusion : In conclusion, the contents of five compounds were not significantly affected by extraction time and extraction temperature. Therefore, these results could be basic data for the quality management of five compounds in stems of O. elatus extracted with hot water.
        34.
        2017.11 서비스 종료(열람 제한)
        도금산업은 국가 핵심역량 사업분야인 전기재료 및 전자 부품 산업등과 밀접한 관계를 가지고 있는 산업분야일 뿐만 아니라, 핵심 부품 및 소재의 기능적 특성과 부가가치를 향상시켜 가격을 결정하는 품질에 큰 영향을 미치는 기반 산업이지만 배출 폐수에는 중금속 이외에도 맹독성 물질인 시안화물과 주요 오염물질이 대량 포함되어 있어 주요 유해물질 배출 관리 대상 업종으로 분류되어 집중 관리되고 있는 실정이다. 이에 소규모 국내 도급업체는 공동 폐수처리장을 통해 폐수를 처리하고 있으나, 도금방법이나 폐수의 특성에 따라 분리 배출되어지지 않고 대부분 통합 배출되어짐으로 인해 처리공정이 복잡하고 처리시설이 방대해지며 많은 처리비용이 소요되고 있어 도급산업을 위축시키는 원인으로 지목되고 있다. 최근 이러한 문제의 해결을 통해 도금산업을 강화하고자 이온성 물질을 분리해 정제할 수 있는 전기투석 기술을 이용한 다양한 연구가 진행되고 있다. 본 연구에서는 전기투석 장치를 이용하여 도금폐수내 구리와 니켈의 제거성능을 평가하였다. 전기투석장치의 이온교환막은 Astom사의 NEOSEPTA를 이용하였고 총 5쌍의 음이온 교환막과 양이온 교환막으로 구성된 스택을 제작하였다. NaCl을 이용하여 TDS 4,000mg/L, 니켈과 구리의 농도를 각각 20mg/L로 제조한 합성폐수를 이용하여 실험한 결과, 한계전류 12v와 25분의 체류시간 조건에서 구리와 니켈은 모두 99%이상 제거되었다. 또한 동일조건에서 유량이 증가할수록 구리와 니켈의 제거효율도 증가하는 경향을 나타내었다. 이온교환막의 변경에 따른 처리성능을 평가한 결과, 이온교환막의 종류에 따라 처리성능에 차이를 나타내어 추가적인 연구가 필요한 것으로 판단된다.
        35.
        2016.08 KCI 등재 서비스 종료(열람 제한)
        한국의 〈바리공주의 전설〉은 스토리와 캐릭터 창작에서 「바리데기」 저승신화를 대부분 수용하면서 레이스형 시나리오 구조를 지니고 있다. 〈바리공주의 전설1: 지옥의 탄생수〉에 이 어, 〈바리공주의 전설2: 왕의 부활〉을 출시했다. 일본에서 〈페르소나4〉는 현대사회를 무대 로 하여 「이자나기·이자나미」 저승신화를 변용하고 있다. 기존의 페르소나 시리즈의 스토리와 요소들을 포함시켜 ‘이식작(移植作)’과 ‘외전(外典)’ 방법을 통해 여러 장르의 게임을 개발했다. 이는 연속적인 부가 트랜스미디어 콘텐츠를 개발하는데 성공한 사례라고 하겠다. 게임 콘텐츠 를 더 풍부하게 개발하여 부가가치를 높일 수 있는 방안을 다양하게 모색해가야 할 것이다.
        36.
        2016.04 서비스 종료(열람 제한)
        The safety of SOC facilities is constantly under threat by the globally increasing abnormal climate. Responding to disasters requires prompt decision-making such as suggesting evacuation paths. For this, spatio-temporal information with convergence of disaster information and SOC facility information must be utilized. Such information is being collected separately by the government or related organizations, but not collectively. Through this study, the disaster and SOC facility-related data, which are being managed separately, can be collected and standardized. The integrated information required for the estimation of facility importance, risk, and damage can be provided. The suggested system is expected to be used as a decision-making tool for proactive disaster response.
        37.
        2015.02 서비스 종료(열람 제한)
        최근 SOC 시설물 안전 위협에 가장 이슈가 되고 있는 태풍, 호우, 지진 등의 자연재해는 유관기관의 지속적인 정보 수집에 의해 예측되고 있으며, 이러한 재해에 대응하기 위해 수집된 정보들을 융합하여 유관기관의 재해대응 의사결정이 이루어지고 있다. 또한 복합적 자연재해는 SOC 시설물의 구조 손실 및 설치 목적에 따른 역할 수행이 불가하게 되어 국가 발전에 직간접적인 영향을 끼친다. 수집된 정보는 수집방법 및 관리 주체가 달라 각각 다른 방식으로 관리되고 있기 때문에 신속한 재해대응을 하기에 불리하다. 신속한 재해대응 및 SOC 시설물 안전관리를 위해서는 분산된 정보를 통합하는 것이 필요하며, 이러한 통합된 정보를 관리하기 위한 인벤토리의 구축이 필요한 실정이다. 이렇게 통합된 인벤토리에서 정보를 활용할 수요자에게 전달할 경우 정보 제공의 신속성 및 신뢰도가 향상 될 것으로 판단된다. 정보가 통합 될 경우 분산 관리되고 있던 관리 방식을 표준화 할 수 있으며, 지속적으로 수집되는 정보를 인벤토리 내부에 확보할 수 있어 정보 획득 및 사용에 있어서 신속성, 정확성, 객관성을 유지할 수 있다. 재난·재해 대응 및 SOC 시설물 유지관리를 위한 인벤토리 구축을 위해서는 지속적으로 수집되는 정보의 송·수신 및 통합관리가 가능하여야 하며, 이를 위한 통합 시스템 구축이 필요하다. 본 시스템을 통해 연계·관리되는 인벤토리는 신속한 재해대응 의사결정 지원을 위한 정보제공이 가능하며, SOC 시설물의 중요도, 위험도, 피해도 등 목적별 평가를 위한 기초 자료로 활용이 가능할 것으로 판단된다.
        39.
        2014.10 서비스 종료(열람 제한)
        This report is contained to the repair guidelines of water-leakage crack and the standardization of performance evaluation testing method studied and reviewed to register to the domestic construction technique as the international standard, and to the introduction to the it’s research contents lasted three years between 2010 and 2013.
        40.
        2014.10 서비스 종료(열람 제한)
        This study is necessity for waterproofing construction using a Life Cycle Cost(LCC). On the purpose of expanding the technology to build and optimize leakage prevention design reasonable selection of center performance evaluation system and possible economic evaluation system.
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