• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1463-1469
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• 2013

Portland cement used as binding material in combination of ferrous iron for reductive dechlorination of chlorinated organics is already widely studied topic by several researchers. However there is no clear evidence about the component solely responsible in cement for trichloroethylene (TCE) dechlorination. Many researchers suspect that the ettringite, monosulfate phases associated with hydration of cement are responsible active agents for TCE dechlorination. This study deals with synthesizing different pure crystalline minerals like ettringite and monosulfate phases of cement hydration and check individual phase's TCE dechlorinating capacity in combination with ferrous iron. The results indicated that the synthesized minerals showed no reduction capacity for TCE. The findings in the present study is significant as it shows that ettringite and monosulfate phases which were suspected minerals by previous researchers for TCE dechlorination are not reactive. Hence it is suspected that some other mineral or mineral form in cement phase could be responsible for TCE degradation.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.16 no.4
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• pp.169-179
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• 2011

To investigate the controlling factor and accumulation of trace metal concentrations in Chun-su Bay sediments, grain-size, specific surface area, organic carbon content, calcium carbonate content, and concentration of Al, Fe, Na, K, Mg, Ca, Ti, Mn, P, S, Ba, Sr, Li, Co, Cr, Ni, Cu, Zn, As, Cd, Cs, Sc, V, Sn were analyzed. Controlling factors of metals were quartz-dilution, calcium carbonate and coarse sand or K-feldspar. Although the distribution of V, Co, Cr, Ni, Cu, Zn, Sn, and Cd concentration was explained by grain-size effiect, Mn and As showed the similar importance of grain-size effect and coarse sand or K-feldspar factors. By virtue of enrichment factor and 1 M HCl experiment, there were little enrichment in all the trace metals in bay sediments, which were explained well by geochemical properties of sediments. Since the concentration levels of As in coarse sand were high as much as those in fine-grained sediments and it was combined with Mn oxide (1 M HCl leached) and K-feldspar (residual), it was suggested that when the enrichment of As in sediments would be assessed, it is necessary to separate the coarse sand from bulk sediments or to use only sediments with higher than 10% in < $16{\mu}m$ fraction.

• Korean Journal of Environmental Biology
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• v.36 no.2
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• pp.124-130
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• 2018

Paralichthys olivaceus (mean length, $13.3{\pm}1.6cm$; mean weight, $25.6{\pm}3.7g$) were exposed to waterborne hexavalent chromium at different concentrations (0, 0.5, 1.0, and $2.0mg\;L^{-1}$) for 10 days. Hematological parameters such as hemoglobin and hematocrit of P. olivaceus were significantly decreased after waterborne chromium exposure. There were no significant alterations in inorganic plasma components, calcium, or magnesium after waterborne chromium exposure. Organic plasma components such as glucose and cholesterol levels were significantly increased after exposure to chromium at concentration over $1.0mg\;L^{-1}$. However, significant change in total protein was not observed. Enzymatic plasma components such as aspartate aminotransferase (AST), alanine aminotransaminase (ALT), alkaline phosphatase (ALP) levels were significantly increased after chromium exposure. Results of this study indicate that waterborne chromium exposure can cause significant alterations in hematological parameters and plasma components of P. olivaceus. Such changes in parameters could be used as reliable indicators for toxic effects of waterborne chromium exposure.

• Journal of the Korean Chemical Society
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• v.14 no.1
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• pp.65-74
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• 1970

Formation of the complexes of alkaline earths with citrate ions in aqueous, acetone-water and ethanol-water solutions was studied at room temperature by the equilibrium exchange technique. This technique involved the measurements of distribution of radioactivity between cation exchange resin and solution phase after the radioactive metal ions were equilibriated with the cation exchange resin in the presence of citrate ions ($Cit^{3-}$) of varying concentrations. The pH of the solutions was controlled to 7.2-7.5, and the ionic strength of the solutions was kept at 0.10-0.12. The present study revealed that both barium and strontium ions formed the one to one citrate complexes, $[M Cit]^-$ in all solvent systems examined. It was also observed that calcium ions formed the one to one citrate complex in aqueous solution. In acetone-water and ethanol-water solutions, however, calcium ions were observed to form both one to one and one to two complexes, $[Ca Cit]^-$ and $[Ca\;Cit_2]^{4-}$. The results of the present study indicated also that relative stabilities of the complexes increased in the order; $Ba^{++}\;<\;Sr^{++}\;<\;Ca^{++}$, and in the order of increasing concentration of the organic components in the mixed solvent systems.

• Culinary science and hospitality research
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• v.19 no.5
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• pp.100-109
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• 2013

This study aims to analyze 19 kinds of mineral contents in hair targeting 311 people in Seoul who suffer from hair loss. The results are as follows: 1. The average contents of all kinds of minerals were within the standards. 2. Sodium, potassium, and selenium were more detected in men than in women; calcium, magnesium, copper, and manganese were more detected in women than in men; toxic elements, mercury, antimony, and arsenic were more detected in men than in women, which was statistically significant. 3. As the age increased, potassium (p<.05), iron (p<.01), manganese (p<.05), chromium (p<.01), and mercury (P<0.01) increased gradually, which was statistically significant. In particular, the content of mercury exceeded its standard in those over fifty. 4. Selenium (p<.01), lead (p<.05), aluminum (p<.05), and arsenic (p<.01) were more detected in natural hair than in permanent or colored hair. Calcium (p<.001), magnesium (p<.001), and manganese (p<.01) were more detected in permanent or colored hair than in natural hair. They were all statistically significant.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.9 no.2
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• pp.63-71
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• 2011

A large volume of uranium electrokinetic leachate has been generated during the electrokinetic decontamination to remove uranium from contaminated soil. The treatment technology for the reuse of the uranium leachate was developed. The concentration of uranium in the generated uranium leachate was 180 ppm and concentrations of Mg(II), K(I), Fe(II), and Al(III) ions ranged from 20 ppm to 1,210 ppm. The treatment process for uranium leachate consisted mainly of mixing and cohesion, precipitation, concentration, and filtration. In order to obtain the pH=11 of a precipitate solution, the calcium hydroxide needs to be 3.0g/100ml and the sodium hydroxide needed to be 2.7g/100ml. The results of several precipitation experiments showed that a mixture of NaOH+0.2g alum+0.15g magnetite was an optimal precipitant for filtration. The average particle size of precipitate with NaOH+alum+0.15g magnetite was $600\;{\mu}m$. Because the total value of metal concentrations in supernatant at pH=9 was the smallest, sodium hydroxide should be added with 0.2g alum and 0.15g magnetite for pH=9 of leachate.

• Journal of the Korean GEO-environmental Society
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• v.12 no.7
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• pp.23-29
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• 2011

The oxidation slag has been widely used in civil engineering project, whereas the reduced slag from electric furnace has yet to be applied. Consequently in order to find out the recycling method in civil engineering field, the mineral compositions of the reduced slag were analyzed and some tests on water quality were performed to estimate the potential release of toxic compounds. Slag-soil mixtures of 0, 10, 20 and 30%(dry weight) soil were prepared in lysimeter columns and the effluents were collected with the period of one, two and four week options in closed system, respectively. The result from qualitative and quantitative analysis using X-ray Diffraction(XRD) and X-ray Fluorescence(XRF) indicates that the main mineral of the reduced slag is $Ca_2(SiO_4)$, a kind of calcium silicate. Also, the leaching medium analyzed by Inductively Coupled Plasma Optical Emission Spectroscopy(ICP-OES) showed that main heavy metals such as Al, Fe and Mn are included in the reduced slag due to the effect of steel production process. It can be seen that the leachate does not violate the regulation guide line of waste material of heavy metal. Also the pH levels were increased from pH 6.9 for 0% soil to pH 10 for 30% soil. However the influence on leachate circulation period of one through four weeks was negligible.

• Korean Journal of Materials Research
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• v.11 no.7
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• pp.609-614
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• 2001

This study was carried out to obtain a basic data on the production of the Nd-Fe-B system rare earth anisotropic bonded magnet by R-D & HDDR process. The reduction reaction of Nd$_2$O$_3$by metallic Ca and the diffusion reaction of Nd into Fe-B alloy powder were investigated for the production the Nd-Fe-B alloy powder. We concluded that a proper quantity of metallic Ca was about 1.3 times of theoretical equivalent from the yields of Nd and B after the R-D reaction at 100$0^{\circ}C$ for 1h. In the XRD analysis the diffusion reaction of Nd into the center of Fe-B alloy powder for the completed homogenization was required through about 45min at 110$0^{\circ}C$ for the R-D reaction, and also the maximum efficiency on the yield of Nd was obtained with such a condition. Residual Ca and oxygen contents of the final powder sample after washing were detected in 0.17wt% and 0.42wt% by ICP and oxygen analyzer, respectively.

• The Korean Journal of Pharmacology
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• v.24 no.1
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• pp.111-123
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• 1988

Neutrophil elastases were purified by a three step procedure consiting of one Sephadex G-75 and two HPLC elutions. The elastases cross-reacted with antibodies to human neutrophil elastase. Three bands with molecular weights between 26,000 and 29,700 were observed by gel electrophoresis. At each stage of purification the quantity of Zn increased, reaching molar ratio of 2:1 with elastase in the most purified samples. Calcium content. was seletively elevated during the earlier stages of purification but decreased to a ratio of 0.25 to 1 with elastase at the final step of purfication. Neutrophil elastase could be inhibited by EDTA, EGTA and 1,10-phenanthroline. EGTA inhbition was noncompetitive inhibition and reversible only if the time of preincubation was relatively short, indicating the instability of the apoenzyme. The concentration of chelator required to show significant inhibition of elastase was also dependent upon the stage of purity and the ionic strength of the reaction mixture. Inhibition by EGTA, followed by the removal of EGTA, could be reversed by Zn. In the presence of EGTA the enzyme could be returened to full activity by the addition of Zn, Mn and Ca, but not Mg or Na. All of the above evidence strongly supports human neturophil elastase could be a metalloenzyme as well as a serine protease.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.4
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• pp.384-388
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• 2001

In order to investigate regional variation of food component in the top shells, Omphalius pfeifferi capenteri, caught from Jeju, Sogwipo, Hallim and Songsan, Jeju island, Republic of Korea, food sanitary (heavy metal and volatile basic nitrogen), nutritional (mineral, total amino acid contents, fatty acid composition), taste (extractive nitrogen) components and sensory evaluation (color, texture and taste) were measured. From the result of the contents of heavy metal and volatile basic nitrogen, the top shell might not invoke health risk in using food source, The extractive nitrogen contents of top shell were $343.0\~385.4\;mg/100\;g$. The amounts of total amino acids were $12.5\~13.2\;g/100\;g$, and the major compound among them were glutamic acid, proline and aspartic acid. The major compound among mineral were sodium, calcium, potassium and magnesium. In fatty acid composition, polyenes with essential component or healthy functionality such as 20:4n-6, 20: 5n-3 and 22: 5n-3 were the major components. But, lipid content was extremely small. Judging from the results of chemical and sensory evaluation described a above, food components were not different among top shells caught from various area.