• Title/Summary/Keyword: 고상진

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MICROSTURCTURE AND MAGNETIC PROPERTY OF NiZn-FERRITES NANO-POWDER SYNTHESIZED AT A LOW TEMPERATURE (저온 합성 NiZn계 페라이트 나노 분말의 미세구조 및 자기 특성)

  • 남중희;박상진;정상진
    • Proceedings of the Korean Magnestics Society Conference
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    • 2002.12a
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    • pp.38-39
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    • 2002

  • 일반적인 세라믹스 분말 합성방법으로서 고상법과 침전법 등은 성분 원소들간의 균일한 혼합이 어렵고, 대부분 최종 생성물의 합성 온도가 높아서 다성분계에 대하여 단일 상을 유지하면서 미세한 분말을 얻기가 힘들다. 그러나, 최근 들어 이러한 단점을 보완하기 위한 방법으로서 비정질 citrate법, 무기 금속염을 이용한 sol-gel법 등과 같이 비교적 공정이 단순하면서 입도 분포가 좁고 재현성이 우수한 구형의 초미립 또는 나노 분말의 제조에 적합한 방법들이 많이 연구되고 있다[1]. (중략)

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A simple method to determine lycopene in solid supplementary food preparations using saponification and liquid chromatography (비누화 및 액체크로마토그래프를 활용한 고상 건강기능식품 중 라이코펜 분석법 개발)

  • Young Min Kim;Ye Bin Shin;Min Kyeong Kwon;Jin Hwan Kim;Ji Seong Kim;Dong-Kyu Lee;Myung Joo Kang;Yong Seok Choi
    • Analytical Science and Technology
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    • v.36 no.3
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    • pp.105-112
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    • 2023

  • Lycopene, a carotenoid hydrocarbon is known to have effects on reducing cardiovascular risk factors, blood lipids, and blood pressure. Thus, a lot of supplementary foods with lycopene in several dosage forms like soft capsule filled with liquid and hard capsule filled with powder are available in a market. Recently, however, our research group found that the lycopene assay in Supplementary Food Code of South Korea is only valid for oily lycopene preparation. Thus, here, we developed a simple method to determine lycopene in solid preparations for Supplementary Food Code of South Korea using saponification and liquid chromatography with an absorbance detector. The method was validated following Ministry of Food and Drug Safety guidelines. All validation parameters observed in this study were within acceptable criteria of the guidelines (selectivity, linearity of r2 ≥ 0.991, lower limit of quantification of 0.0149 mg/mL, accuracy as recovery (R) between 92.70 and 97.18 %, repeatability as relative standard deviation (RSD) values of R between 0.85 and 1.59 %, and reproducibility as the RSD value of interlaboratory R of 3.70 %). Additionally, the practical sample applicability of the validated method was confirmed by accuracy between 98.81 and 101.59 % observed from its lycopene certified reference material (CRM) analyses. Therefore, the present method could contribute to fortify the supplementary food safety management system in South Korea.

  • https://doi.org/10.5806/AST.2023.36.3.105 인용 PDF HTML

The Synthesis and Hydraulic properties of Calcium Sulfo Aluminate(CSA) derived from Secondary Refining Slag. (제강 2차 정련 슬래그를 재활용한 칼슘설포알루미네이트(CSA) 합성 및 수화 특성)

  • Seo, Chang Woo;Kim, Seon-Hyo;Ko, Sang Jin;Kim, Sang Hyun;Jo, Kyu Young
    • Korean Journal of Metals and Materials
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    • v.46 no.7
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    • pp.437-442
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    • 2008

  • The synthesis and hydration of Calcium Sulfo Aluminate[$3CaO{\cdot}3Al_2O_3{\cdot}CaSO_4(C_4A_3{\overline{S}})$, CSA cement utilizing secondary steelmaking refining slags is studied for recycling the discarded steel plant wastes to meet the environmental requrations imposed on the steel industry. Raw materials of secondary refining slag, lime sludge, gypsum and bauxite were prepared to be sintered at $1,250^{\circ}C$. The sintered samples were hydrated for 1, 3 and 7 days to evaluate the mineralogical and physico-mechanical properties. The hydration products evaluated with the aid of SEM and XRD analyses confirmed the formation and the continuing growth of ettringite phase with the further hydration times, which plays a role in developing the early strength and the expansion properties of cements. The physico-mechanical properties of hydrated CSA products employing the recycled steelmaking refining slags determined in terms of compressive strength and linear expansion of hydrated products are found to be superior to those of the Ordinary Portland Cement(OPC) or the other commercial CSA cements.

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