• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.400-407
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• 2016

A unicellular green alga, Chlorella vulgaris KNUA027, was isolated from the roots of Panax ginseng seedlings and its biotechnological potential was investigated. The results of GC/MS analysis showed that C. vulgaris KNUA027 was rich in nutritionally important polyunsaturated fatty acids (PUFAs) such as alpha-linolenic acid (C_18:3 ω3, 45.8%, 50.8 mg/g) and hexadecatrienoic acid (C_16:3 ω3, 11.8%, 13.1 mg/g). Therefore, this Korean indigenous microalga may have potential as a source of omega-3 PUFAs. It was also found that the saturated palmitic acid (C_16:0, 37.1%, 41.2 mg/g), which is suitable for biodiesel production, was one of the major fatty acids produced by strain KNUA027. The proximate analysis showed that the volatile matter content was 88.5%, and the ultimate analysis indicated that the higher heating value was 19.8 MJ/kg. Therefore, the results from this research with C. vulgaris KNUA027 may provide the basis for the production of microalgae-based biofuels and biomass feedstock.

• Journal of Conservation Science
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• v.32 no.2
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• pp.189-202
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• 2016

To figure out the material characteristics about slag and raw materials which are founded in iron product sites in Seosan area, we used XRF, EDS to analysis chemical compositions. Also we observe the microstructure by microscope and SEM. To identify the mineral component, XRD analysis was used and to assume the provenance of the raw material, lead isotope ratio analysis was used. From the results, we figure out that slags are non-ferrous created when metal was refined. Also, main tissue of slags were Fayalite, Galena, Magnetite, and raw materials were identified as mineral of Galena, Anglesite, Pyrite etc. From the result about lead isotope ratio analysis, we found out most samples are classified as the Western Gyeonggi massif in South Korea. Especially three of raw materials and slag samples which collected in the Seosan Doseongri was presumed to be the provenance. We figure out that slags we analyzed were made in non-ferrous metal smelting process and especially that were more likely to smelt from Seosan Doseongri. If various slags in this area are analysed by someone, It will contribute understanding non-ferrous metal refining process as well as metal refining which are composed.

• Journal of Conservation Science
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• v.36 no.3
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• pp.152-161
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• 2020

The purpose of this study was to compare the chemical properties of white soil and refined clay sediment, which are produced early in the refining process. The characteristics of the white wares made at the kiln site in Goseong-ri, Chuncheon were also examined. Three groups of materials were examined: white wares excavated from the white wares kiln, raw material from white soil collected from the surface, and a refined clay sediment group. There were also three analysis methods, which were a main components analysis, a trace components analysis, and a mineral analysis. The main components analysis found that the white wares clay was in the RO₂4.04~4.28 and the RO + R₂O 0.30~0.31 mole areas, which were similar to the results for the refined clay sediment. However, the refining process used to produce better quality white wares meant that the large differences in the early white soil raw material appeared in the refined sediment. The mineral phase analysis showed that the crystals detected in the early white soil raw materials and refined clay sediment were almost identical. However, quartz and mullite mineral phases, which can occur above a certain temperature, were detected in the excavated white wares clay. Rare earth elements that were not affected by the pottery making process and the weathering of clay materials were found to have the same origin in all three groups.

• Analytical Science and Technology
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• v.14 no.1
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• pp.88-93
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• 2001

To measure the levels of dioxins in food selling at local markets, meat was analyzed by high resolution gas chromatography/high resolution ass spectrometry (HRGC/HRMS). The food samples were obtained from 5 large cities of Seoul, Chunchon, Daejon, Kwangju and Busan in Korea. All the samples were minced and extracted with Soxhlet extractor for 18 hours. After extraction, extracts were cleaned up by sulfuric acid impregnated silica gel, purified on a series of silica gel, alumina, carbon column chromatography and then analyzed by HRGC/HRMS. The contaminated levels were calculated as the TEQs by multiplying with the corresponding WHO-TEFs for each congeners. The overall recoveries were ranged from 80% to 153% and the limit of detection was about 0.01 ppt at S/N>3. The levels of PCDD/Fs for beef, pork and chicken were 0.018, 0.008 and <0.001 pgTEQ/g, respectively. In addition, the levels of non-ortho-co-planar PCBs for beef, pork and chicken were 0.008, 0.002 and 0.001 pgTEQ/g, respectively. Among food samples analyzed, chicken showed the lowest level of dioxin-like compounds. Regarding congener pattern, OCDD and PCB #77 were the highest contributing congeners.

• Ecology and Resilient Infrastructure
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• v.4 no.3
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• pp.180-185
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• 2017

Restoration of min-impacted arable land is often performed through stabilization of trace elements by amendment treatment combined with (clean) soil covering on the surface. Recently, soil loss problem from sloping remediated agricultural lands has risen as an emerging concern. In this study, efficacy of aggregation formation was assessed by single and binary treatments of four potential amendments (bentonite, lime, organic matter, and steel slag) applied on three cover soils having different clay contents (9.4, 14.7, and 21.2% for A, B, and C soils respectively). In results of single treatments, 5% organic matter for A soil and 5% lime for B and C soils were found most effective for the aggregation formation compared to the respective controls (without amendments). Among nine binary treatments, 3% organic matter + 1% lime for A soil and 1% organic matter + 3% lime for both B and C soils led to the highest formation of aggregation (30.4, 25.0, and 36.5% for A, B, and C soils). For a site-application, the soil erodibility difference between the cover soils (0.045, 0.051, and 0.054 for A, B, and C soils, respectively) and the national average of arable land (0.032) was assumed to be compensated by amendment addition, which is equivalent to 29.1% aggregation formation. To achieve the aggregation goal, 5% lime for A and B soils and 3% lime for C soil were best in the consideration of benefit/cost, thereby effectively and economically reducing soil loss from sloping remediation site. Soil alkalinity induced by lime treatment was not considered in this work.

• Microbiology and Biotechnology Letters
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• v.29 no.4
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• pp.227-233
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• 2001

To maximize astaxanthin (3,3'-dihydroxy-$\beta\beta$'carotene-44'-dione) production by high density Haematococcus pluvialis cultures, various, media were examined Among tested media, \`Hong Kong Medium and Modified Bolds Basal Medium showed the best result for cell growth ( $2.0$\times$10^{ 6}$cells /mL) and for astaxanthin content per cell (9.7 mg astaxanthin mg/g cell), respectively, Maximum astasanthin concentration of 6.1mL was obtained at pH 7.5, $20^{\circ}C$~$25^{\circ}C$ Deficiencies of nitrogen source($NaNO_3$ and proteose-peptone) found to simulate astaxanthin formation Relatively low light inten- sity of $60\mu$E ($\m^2$s) was sutiable for vegetative cell growth while higher light intensity was required for higher astaxanthin accumulation.

• Journal of the Korean Society for Marine Environment & Energy
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• v.3 no.4
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• pp.56-64
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• 2000

Behavior of trace metals in Masan Bay, Korea was studied in August 1998 when the oxygen deficient condition occurred. Dissolved Cd and Zn concentration in the surface waters decreased with increasing distance from Masan Harbor. Dissolved concentrations of Cd, Cu Pb and Zn in the surface waters were higher than bottom waters. Particulate(acid-teachable fraction) concentrations of Cu, Cd and Pb in the surface waters of Masan Bay decreased with increasing distance from Masan Harbor. Bottom waters contained higher concentrations of particulate Cd, Cu, Pb and Zn than surface waters. Distribution coefficients between dissolved and particulate phase (K/sub d/) of Cu and Cd decreased with the increasing distance from the Harbor, possibly due to reaction of these elements with sewage-derived particulate matter Al, Zn, Cu, Cd, and Pb in the surface sediment showed relatively high concentration in the inner Masan Bay.

• Applied Biological Chemistry
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• v.49 no.1
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• pp.77-81
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• 2006

This study was carried out to investigate the chemical components, and antioxidative and $anti-{\alpha}-glucosidase$ activities of Equisetum arvense extracts. In Equisetum arvense extracts were composed of 53.20% of crude fiber, 20.42% of crude ash, 15.32% of crude protein and 2.21% of crude fat. Potassium was the most predominant mineral and followed by phosphorus, calcium, magnesium, and sodium. The contents of the unsaturated fatty acids, such as linolenic acid, linoleic acid, and palmitic acid, were higher than those of saturated fatty acids. Seventy percent ethanol extract exhibited antioxidative activity with $IC_{50}$ of $168.1\;{\mu}g/ml$. The Seventy percent methanol extract showed higher ${\alpha}-glucosidase$ inhibitory activity than other solvent extracts.

• Analytical Science and Technology
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• v.7 no.3
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• pp.315-320
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• 1994

Li-GICs as a high performance energy storager were synthesized as a function of the Li content by the admixture and add-pressure method. The characteristics of these prepared compounds have been determined from the studies by X-ray diffraction, UV-VIS spectrometry and CHN analysis. It follows from the results of X-ray diffraction that the lower-stage intercalation compounds are formed as the Li contents increase, however the mixed stages in these compounds are also observed. In the case of the $Li_{40wt%}$, the compound with the structure of stage 1 has been predominently, but the structure of only stage 1 is not obtained. The $d_{001}$ value of stage 1 was determined to be ca. $3.70{\AA}$. An analysis of spectrometric data shows that each of the compounds gives distingushible energy state spectra. It is seen from the spectra that the positions of $R_{min}$ values, with increase in the Li contents, are shifted in the region of higher energy state. Such a result can be attributed to the formation of stable stages. The results of CHN analysis allow us to find the mixing state related to chemical compositions of the intercalated compounds and the superiority to admixture and add-pressure method. From the results determined, it reveals that $Li_{10wt%}$-GIC and $Li_{20wt%}$-GIC can be utilized for an anode of rechargable battery.

• Journal of Conservation Science
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• v.30 no.4
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• pp.345-351
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• 2014

Chemical and Pb isotope analysis were performed in order to determine the origin of bronze artefacts excavated from the Inyongsaji site in South Korea. The result of ICP-MS shows that they are tin bronzes in which lead was not intentionally added during production. Pb isotope data analyzed by TIMS are plotted in the southern region of Korea and China of the distribution map drawn by Mabuchi(1985). On the other hand, the identical isotope data are plotted in the Taebaek basin and the Olcheon metamorphic belt correspondent to zone2 and zone3 respectively. It is believed that the isotope data on the tin bronzes which have very low lead content can be used to trace the origin of copper ore rather than those of either lead or tin ore. Pb istope analysis allows diverse interpretation as it can be applied to any object containing trace amounts of lead. In addition, accumulation of isotope data as well as further studies will improve reliability of the provenance studies.