• Title/Summary/Keyword: Split-phase

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Estimation of Impurities from Commercially Available Glycyrrhizin Standards by the HPLC/ESI-MS (HPLC/ESI-MS에 의한 글리시리진 표준품의 불순물 추정)

  • Myung, Seung-Woon;Min, Hye-Ki;Kim, Myungsoo;Kim, Young Lim;Park, Seong-Soo;Cho, Jung Hee;Lee, Jong-Chul;Cho, Hyun-Woo;Kim, Taek-Jae
    • Analytical Science and Technology
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    • v.13 no.4
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    • pp.504-510
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    • 2000
  • The impurity profiles from the raw materials of glycyrrhizin were performed by the high performance liquid chromatography (HPLC)/electrospray ionization (ESI)- mass spectrometry (MS). For the HPLC experiment, a $C_{18}$($3.9{\times}300mm$, $10{\mu}m$) column was used and the mobile phase was acetic acid/$H_2O$ (1:10):acetonitrile=3:2 with a flow rate of 0.8 ml/min. The effluent was splitted into the ratio of 50:1 and went into the ESI-MS. Three to six impurities were found and informed of the identification of the structure of the impurities by ESI-MS. And the structures of impurities were suggested to a hydroxy-glycyrrhizin which is added with hydroxy group (-OH) in the glycyrrhetic acid moiety and a reduced-glycyrrhizin which the position of 12 of the glycyrrhetic acid moiety is reduced. The purities of the standard materials were about 90%.

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Analyzing the Phenomena of Hate in Korea by Text Mining Techniques (텍스트마이닝 기법을 이용한 한국 사회의 혐오 양상 분석)

  • Hea-Jin, Kim
    • Journal of the Korean Society for Library and Information Science
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    • v.56 no.4
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    • pp.431-453
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    • 2022
  • Hate is a collective expression of exclusivity toward others and it is fostered and reproduced through false public perception. This study aims to explore the objects and issues of hate discussed in our society using text mining techniques. To this end, we collected 17,867 news data published from 1990 to 2020 and constructed a co-word network and cluster analysis. In order to derive an explicit co-word network highly related to hate, we carried out sentence split and extracted a total of 52,520 sentences containing the words 'hate', 'prejudice' and 'discrimination' in the preprocessing phase. As a result of analyzing the frequency of words in the collected news data, the subjects that appeared most frequently in relation to hate in our society were women, race, and sexual minorities, and the related issues were related laws and crimes. As a result of cluster analysis based on the co-word network, we found a total of six hate-related clusters. The largest cluster was 'genderphobic', accounting for 41.4% of the total, followed by 'sexual minority hatred' at 28.7%, 'racial hatred' at 15.1%, 'selective hatred' at 8.5%, 'political hatred' accounted for 5.7% and 'environmental hatred' accounted for 0.3%. In the discussion, we comprehensively extracted all specific hate target names from the collected news data, which were not specifically revealed as a result of the cluster analysis.