• Title/Summary/Keyword: $Bi_2Te_{2.7}Se_{0.3}$

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Mineralogy and Geochemistry of Iron Hydroxides in the Stream of Abandoned Gold Mine in Kwangyang, Korea (광양 폐금광 수계에 형성된 철수산화물에 대한 광물학적 및 지구화학적 특성)

  • Park, Cheon-Young;Jeoung, Yeon-Joong;Kim, Seoung-Ku
    • Journal of the Korean earth science society
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    • v.22 no.3
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    • pp.208-222
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    • 2001
  • Geochemical investigations on suspended amorphous iron oxide material from the Kwangyang gold mine and its surrounding area, Cheonnam, Korea have been carried out. The sediments samples were collected from 11 location along Kwangyang mine area and were air dried and sieved to -80 mesh. These samples consist mainly of iron, silicon and alumina. The Fe$_2$O$_3$ contents ranges from 17.9 wt.% to 72.3 wt.%. The content of Fe$_2$O$_3$ increase with decreasing Si, Al, Mg, Na, K, Mn, and Ti, whereas the contents of Te, Au, Ga, Bi, Cd, Hg, Sb, and Se increase in the amorphous stream sediments. Amorphous stream sediments have been severely enriched for As (up to 54.9 ppm), Bi (up to 3.77 ppm), Cd (up to 3.65 ppm), Hg (up to 64 ppm), Sb (up to 10.1 ppm), Cu (up to 37.1 ppm), Mo (up to 8.86 ppm), Pb (up to 9.45 ppm) and Zn (up to 29.7 ppm). At the upstream site, the Au content (up to 4.4 ppm) in the amorphous stream sediments are relatively high but those contents decrease with distance of mine location. The content of Ag (up to 0.24 ppm) were low in upstream site but those contents increase significantly in the downstream sites. The X-ray diffraction patterns of the samples have virtually no sharp and discrete peaks, indicating that some samples are amorphous or poorly-ordered. The quartz, goethite, kaolinite and illite were associated in amorphous stream sediments. The infrared spectra for amorphous stream sediments show major absorption bands due to OH stretching, adsorbed molecular water, sulfate and Fe-O stretching, respectively.

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Quality characteristics and antioxidant capacities of oriental melon wine depending on pretreatments (전처리 방법에 따른 참외와인의 품질특성과 항산화능)

  • Hwang, Hee-Young;Ha, Hyoung-Tae;Ha, Se-Bi;Seong, Gi-Un;Hwang, In-Wook;Chung, Shin-Kyo
    • Food Science and Preservation
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    • v.22 no.3
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    • pp.421-427
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    • 2015
  • Oriental melon (Cucumis melo L. var. makuwa) has been widely consumed as various processed foods, such as dried products, jelly, wine, juice, and vinegar, in Asian countries. In fruit processing, blanching and pressure treatments affect its quality, such as antioxidant activities, sensory characteristics, and etc. This study was conducted to evaluate the effects of blanching and pressure pre-treatments on oriental melon wine-making (BP, blanching and pressure filtration; BNP, blanching and non-pressure filtration; NBP, non-blanching and pressure filtration; and NBNP, non-blanching and non-pressure filtration). Physicochemical properties and antioxidant capacities by ${\alpha}$, ${\alpha}$-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, ferric ion reducing antioxidant power (FRAP) assay, and total phenolic and total flavonoid contents were measured for comparison of the different pre-treatment methods. After the aging process, the alcohol contents and pH values showed no statistical differences, whereas the amount of soluble solids, reducing sugar, and titratable acidity were slightly different among the pre-treatments (p<0.05). The samples with blanching pre-treatment showed higher antioxidant capacities than those of other pre-treatments. In the sensory evaluation, the BNP was the best in overall acceptability. Thus, this study showed that the blanching treatment enhanced the antioxidant capacities and sensory qualities of the oriental melon wine.