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        검색결과 64

        21.
        2011.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        An isocratic high performance liquid chromatography (HPLC) method for routine analysis of deoxynivalenol in noodles was validated and estimated the measurement uncertainty. Noodles (dried noodle and ramyeon) were analyzed by HPLC-ultraviolet detection using immunoaffinity column for clean-up. The limits of detection (LOD) and quantification (LOQ) were 7.5 μg/kg and 18.8 μg/kg, respectively. The calibration curve showed a good linearity, with correlation coefficients r² of 0.9999 in the concentration range from 20 to 500 μg/kg. Recoveries and Repeatabilities expressed as coefficients of variation (CV) spiked with 200 and 500 μg/kg were 82 ± 2.7% and 87 ± 1.3% in dried noodle, and 97 ± 1.6% and 91 ± 12.0% in ramyeon, respectively. The uncertainty sources in measurement process were identified as sample weight, final volume, and sample concentration in extraction volume as well as components such as standard stock solution, working standard solution, 5 standard solutions, calibration curve,matrix, and instrument. Deoxynivalenol concentration and expanded uncertainty in two matrixes spiked with 200 μg/kg and 500 μg/kg were estimated to be 163.8 ± 52.1 and 435.2 ± 91.6 μg/kg for dried noodle, and 194.3 ± 33.0 and 453.2 ± 91.1 μg/kg for ramyeon using a coverage factor of two which gives a level of statistical confidence with approximately 95%. The most influential component among uncertainty sources was the recovery of matrix, followed by calibration curve.
        4,000원
        26.
        2009.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,000원
        30.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ceramic pigments were developed by using 4 kinds of Brass scraps. Each Brass scraps were mixed with same weight-ratio of Husk ash, and fine-ground by Rotate ring mill(RRG-120, Armstech industrial. co. Ltd, Korea) after firing at 900℃, 1000℃ and 1100℃. As a result, analysis of particle size of synthetic pigments by particle size analyser, they are 3μm as average. The resulting pigments were characterized by using XRD, FT-IR, SEM Structure of the crystals are Zn2SiO4,, and ZnO, Cu2O, CuO, and cristobalite are existed and particles' shape are plate or needle. As a result of analysis of chemical composition by XRF, synthetic pigments have high SiO2 and CuO content and have SnO2, ZnO and NiO, too. 1wt%, 3wt% and 5wt% pigments were added in each lime glaze, lime-barium glaze and lime-magnesia glaze, and fired at oxidation and reducing atmosphere to figure hue in glazes out. As a result of analysis of color, chroma and brightness by UV, colors of glazes fired at oxidation atmosphere turned into green from sky blue, and colors of glazes fired at reducing atmosphere turned into pink and red.
        4,000원
        31.
        2004.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 중학생을 대상으로 지속적인 음악청취가 발표불안에 미치는 영향을 밝히고자 하였다. 실험 참여자는 여중생 두 개 반을 대상으로 통제집단 33명, 실험집단 33명씩 총 66명이고, 음악처치를 받는 집단과 아무런 처치가 주어지지 않는 집단으로 나누었다. 처치 전, 처치 1주 후 및 2주 후에 자기보고식으로 이루어진 발표불안척도(SAS)와 교사의 평가로 이루어진 발표행동 평가척도(SBES)를 통하여 발표불안을 측정하였다. 결과는 음악처치를 받은 실험집단에서 발표불안이 의미 있게 감소하는 것으로 나타났다. 따라서 음악에 의한 감성 유발이 발표상황에서 받는 스트레스에 긍정적인 효과가 있었다.
        4,000원
        34.
        2001.05 구독 인증기관 무료, 개인회원 유료
        DESIGNIN AND OPERATION OF DIGITAL EVIDENCE MANAGEMENT SYSTEM APPLYING COMPUTER FORENSICS AND ELECTRONIC CERTIFICATION Digital evidence will be used as a term, which means the electronic form of information which is necessary to confirm or prove the factum of all kinds of behaviors committed through the devices which have data processing ability including computer. It is expected that there will be the increase of legal conflicts surrounding electronic commerce activities as well as the increase of cyber crimes, as the number of Internet users are getting bigger. In order to solve the problems of conflicts derived from electronic commerce, the factum of electronic commerce activities must be confirmed. In order to confirm the factum of electronic commerce activities, the evidence is prerequisite. Almost all evidences relating to the electronic commerce activities exist in digital form. For the reason that the digital evidence can be easily damaged and changed, special management is required to collect, analyze, and preserve the digital evidence. In order to meet this requirement, this study proposes a basic model of digital evidence management system applying computer forensics and electronic authentication.
        4,000원
        36.
        1998.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        한국에서 주로 섭취되고 있는 주요 식이섬유질원으로서 장내 유익균의 생육을 촉진한다고 알려진 사과, 미역, 쑥, 머위를 천연 형태로 건조분말화하여 식이내에 5%, 15%가 되게 첨가한 후 노화가 진행된 흰쥐에게 4주간 급여하였다. 그 결과 β-glucuronidase는 셀를로스군과 미역 15% 첨가군에서 가장 낮은 활성을 나타냈으며 β-glucuronidase의 경우는 쑥 15% 첨가군에서 유의적으로 현저한 증가를 보였다. 부패산물인 인돌 함량 변화는 쑥 섭취군에서 현저하게 낮은 경향을 보여 β-glucuronidase와는 다른 양상을 보였다. 수분함량은 미역섭취군과 쑥5%, 머위15% 섭취군에서 높았으며 pH는 쑥 15% 섭취군이 가장 낮은 값을 보여주었다. 쑥 15% 섭취군이 장내균총 조성을 개선시킬 수 있을 것으로 보고되어 그 유의성을 밝히고자 하였으나 본 실험에서는 부패산물, 유해효소등과 장내균총의 조성과의 뚜렷한 관계는 발견하지 못하였다.
        4,000원
        37.
        1996.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Klebsiella sp. L-10 의 N-methyl-N`-nitro-N``-nitrosoguanidine 변이주인 Klebsiella sp. L-10 NTG-50으로부터 생산된 고점성의 히알우론산 복합체를 이상계 추출법으로 정제하여 물리화학적 성질을 조사하였다. 정제된 히알우론산 복합체의 점도는 온도와 염농도가 높아짐에 따라 낮아졌고 pH 5.0 이하와 11.0 이상에도 매우 낮았다. 정제된 히알우론산 복합체의 굳기(hardness)는 1.20kg, 응집성(cohesiveness)은 1.92, 점착성(adhesiveness)은 0.62 이었다. 또한 보수력은 g당 6.9ml이었다.
        4,000원
        38.
        1991.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to investigate the extraction mechanism of barley tea in cylindrical packed column, pilot plant scale packed column was designed and constructed. And extraction conditions for steady flow in the packed column were searched. The main results of this study are as follows : 1. Circulation of the stock barley tea before the extraction running was indispensable in consideration of inequality, gas, particles existed in packed bed. Solid-liquid equilibrium was initially maintained after the circulation. 2. Flow direction of solvent must be up-flow for maintaining the constant bed height and flow rate during the extraction. Paessure drop in pucked bed was similar to decrease ratio of extract concentration. 3. The porosity of packed bed was in the range of 0.24∼0.36 according to the particle size. And it was decreased as the particle size became smaller.
        4,000원
        39.
        2023.06 KCI 등재 서비스 종료(열람 제한)
        In this study, we investigated the characteristics of Volatile Organic Compounds(VOCs) emission from painting and printing facilities in the Pyeongdong industrial complex in Gwangju. In addition, the objective was to understand the distribution characteristics of VOCs in the ambient air in industrial complexes affected by painting and printing facilities. The painting facility mainly emitted toluene, acetone, butyl acetate, 4-methyl-2-pentanone, ethyl acetate, 1-butanol, methyl ethyl ketone, m,p-xylene, o-xylene, 4-ethyltoluene, ethylbenzene, 3-ethyltoluene, and 1,2,4-trimethylbenzene. The main emission components in printing facilities were methyl ketone, ethyl acetate, acetone, 2-propanol, toluene, heptane, and butyl acetate. Ethyl acetate, toluene, 2-butanone, acetone, butyl acetate, 2-propanol, xylenes, and 4-methyl-2-pentanone were detected in the ambient air of the Pyeongdong industrial complex, consistent with the VOCs emitted by painting and printing facilities. The average concentration of seasonal TVOCs followed an order of winter > fall > spring > summer, whereas the concentrations of daytime and nighttime TVOCs were generally higher at night than those during the day, and the wind speed was greater during the day than it was at night. Based on a factor analysis of VOCs in the ambient air of Pyeongdong industrial complex, it is considered that organic solvents used in coating, printing, and electronics manufacturing facilities, as well as diesel vehicle emissions played a major role.
        40.
        2018.02 KCI 등재 서비스 종료(열람 제한)
        Background: To obtain useful safflower resources for breeding and research of functional materials, the present study was conducted to determine fatty acid compositions and antioxidant activities of 281 safflower accessions collected from East Asia including South Korea. Methods and Results: Lipid contents and fatty acids compositions were evaluated using soxhlet extraction and gas chromatography, respectively. A antioxidant activities were analyzed using a spectrophotometer. The evaluation range of safflower accessions showed very wide variation. In terms of lipid contents, the China accessions were higher than the collection from other regions, whereas antioxidant activities did not differ among regions. The result of the principal component analysis showed that the first and second principal component cumulatively explained 90.6% of the total variation. In clustering the safflower accessions, the tree showed four major clades. Group II (16 accessions) was high in lipid content, oleic acid and linoleic acid, whereas group III (50 accessions) exhibited higher antioxidant activities than other groups. Conclusions: It was recommended that the China collections be utilized as a useful resource for research on functional oil materials. These results provided valuable information for safflower breeders and researchers of functional food.
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