• Economic and Environmental Geology
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• v.17 no.1
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• pp.17-34
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• 1984

The Ordovician limestone and dolomite was mineralized by the intrusion of quartz porphyry to form hydrothermal ore deposit along the fault shear zone, which trends $N30^{\circ}-40^{\circ}W$ dipping $60^{\circ}-70^{\circ}SW$. The primary manganese carbonates in the upper part of the deposit were oxidized to form supergene manganese ore deposits. The quartz porphyry is plotted mainly in granite region of the triangular diagram of normative composition. The granite phase contains more copper and lead, but less zinc, nickel and chromium than the granodiorite phase which occupies the northwestern part of the quartz porphyry. The content of copper, lead, zinc, nickel and chromium in the quartz porphyry is lower compared with the granitic rocks from the copper province in the Gyeongsang basin. But the granitic rocks from the lead-zinc province has lower content of copper and nickel than the quartz porphyry. The primary distribution pattern of trace elements in the country rock of limestone and dolomite has close relation with the hydrothermal mineralization, showing anomalous or high content near the fault shear zone. The secondary distribution pattern of trace elements in soils shows close relation with the solubility of the carbonates of the elements under weathering condition.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.10
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• pp.1314-1319
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• 2007

This study is to compare food components and the sensory properties of common and functional Porphyra yezoensis, Pyroligneous liquor, Salicornia herbacea L. and Salicornia herbacea L. treated with oak charcoal. The samples used in this study were provided by a local manufacturer. We analyzed their proximate composition, mineral content, heavy metal content and amino acids. We conducted the sensory evaluation before and after grilling Porphyra yezoenis. Common components are more plentiful in functional Porphyra yezoenis than in common except for carbohydrate and crude fiber. In the case of mineral content, generally functional Porphyra yezoensis contains much more mineral than common except for magnesium and zinc. Especially Salicornia herbacea L. treated with oak charcoal contains abundant iron. Also, Salicornia herbacea L. contains a lot of calcium potassium, copper and sodium. There is a little more heavy metal except for chromium, cadmium and lead in Salicomia herbacea L. treated with oak charcoal than in common that contains a lot of chromium, cadmium and lead, although a wide difference was not discovered between them. In the case of composed amino acid, there are much glutamic acid, glycine, isoleucine and phenylalanine in both Porphyra yezoensis. Especially alanine and phenylalanine are trebled in functional Porphyra yezoensis. Also, there are far more serine and lysine in Salicornia herbacea L. and Salicornia herbacea L. treated with oak charcoal than in common Porphyra yezoensis and Pyroligneous liquor. In the case of the sensory properties, there isn't a big difference before grilling Porphyra yezoensis; however, after grilling, most functional Porphyra yezoenis had good sensory properties results, especially Salicornia herbacea L. were better than Pyroligneous liquor.

• Applied Chemistry for Engineering
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• v.26 no.4
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• pp.432-438
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• 2015

In this work, activated carbon fibers (ACFs) were oxyfluorinated and their adsorption ability for the low concentration of hexavalent chromium in an aqueous solution was investigated. The pore structure and surface properties of ACFs were examined by BET and X-ray Photoelectron Spectroscopy (XPS), respectively. Due to the oxyfluorination treatment, the content of (C-O) bond on ACFs surface which influences the adsorption capacity for heavy metal ions increased largely, resulting that $Cr^{6+}$ adsorption equilibrium reached quickly within 10 min. In addition, the maximum removal efficiency at the initial $Cr^{6+}$ concentration of 20 ppm was observed, which is a 100% improvement compared to that of non-treated ACFs. These results suggest that the oxyfluorination of ACFs can be applied as a good surface treatment for the effective adsorption of the low concentration of $Cr^{6+}$.

• The Korean Journal of Ecology
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• v.20 no.5
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• pp.385-391
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• 1997

To investigate the degrees of toxification in the serpentine areas, serpentinites and adjacent metamorphic rocks and soils from the serpentinite, metamorphic area and transitional area(mixed soil) between serpentinite and metamorphic rocks are collected from the Hongseong-Gun, Chungnam. A plant, Geochemically, the serpentinites are high in the nickel, chromium and cobalt content whereas the metamorphic rocks show high zinc, scandium, molybdenum and iron contents. The serpentine soils are high in the nickel, chromium and cobalt contents whereas the non-serpentine soils show high zinc and iron contents. Heavy metal contents in the G. oldhamiana are high in the serpentine soil relative to the mixed soil. Ratio of the iron to nickel contents for the G. oldhamiana are low in the serpentine soil(49) relative to the mixed soil(216). Of the G. oldhamiana, most of the heavy metal contents except zinc and molybdenum are high in the root relative to the aboveground vegetation. Comparing with rocks, the G. oldhamiana is low in the all of heavy metal contents relative to the serpentinite. Uptake of zinc by the G. oldhamiana is high in the serpentinites and metamorphic rocks whereas uptake of scandium and iron by the G. oldhamiana is very high in the serpentinite area.

• Nutrition Research and Practice
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• v.3 no.3
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• pp.212-219
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• 2009

This study was performed to investigate the association between hair mineral levels and nutrient intakes, age, and BMI in female adults who visited a woman's clinic located in Seoul. Dietary intakes were assessed by food frequency questionnaire and mineral levels were measured in collected hairs, and the relationship between these was examined. The average daily nutrient intakes of subjects were compared to those of the KDRIs, and the energy intake status was fair. The average intake of calcium in women of 50 years and over was 91.35% of KDRls and the potassium intake was greatly below the recommended levels in all age groups. In the average hair mineral contents in subjects, calcium and copper exceeded far more than the reference range while selenium was very low with 85.19% of subjects being lower than the reference value. In addition, the concentrations of sodium, potassium, iron, and manganese in the hair were below the reference ranges in over 15% of subjects. The concentrations of sodium, chromium, sulfur, and cadmium in the hair showed positive correlations (P < 0.05) with age, but the hair zinc level showed a negative correlation (P < 0.05) with age. The concentrations of sodium, potassium, chromium, and cadmium in the hair showed positive correlations (P < 0.05) with BMI. Some mineral levels in subjects of this study showed significant correlations with nutrient intakes, but it seems that the hair mineral content is not directly influenced by each mineral intake. As described above, some hair mineral levels in female adults deviated from the normal range, and it is considered that nutritional intervention to control the imbalance of mineral nutrition is required. Also, as some correlations were shown between hair mineral levels and age, BMI, and nutrient intakes, the possibility of utilizing hair mineral analysis for specific purposes in the future is suggested.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.897-900
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• 2008

Some substances of cement could make underestimate concentration of hexavalent chromium(Cr(VI)) as they reduce Cr(VI) to Cr(III) in acidic condition during the determination of Cr(VI) content in cement. The reduction of Cr(VI) increased with elapsed time after acidification in this study. The reduction rate varied with various cements. From our result, we can conclude that simultaneous additions of acid and DPC were required for the accurate measurement of Cr(VI) in cement. The high recovery rate of 94.3 to 106.7% with the simultaneous acid-DPC addition method can also support our conclusion.

• Corrosion Science and Technology
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• v.9 no.1
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• pp.20-28
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• 2010

According to the bipolar model, ion selectivity of some species in the passive film is important factor to control the passivation. An increase of cation selectivity of outer layer of the passive film can stabilize the film and improves the corrosion resistance. Therefore, the formation and roles of ionic species in the passive film should be elucidated. In this work, two types of solution (hydrochloric or sulfuric acid) were used to test high N and Mo-bearing stainless steels. The objective of this work was to investigate the formation of oxyanions in the passive film and the roles of oxyanions in passivation of stainless steel. Nitrogen exists as atomic nitrogen, nitric oxide, nitro-oxyanions (${NO_x}^-$), and N-H species, not nitride in the passive film. Because of its high mobility, the enriched atomic nitrogen can act as a reservoir. The formation of N-H species buffers the film pH and facilitates the formation of oxyanions in the film. ${NO_x}^-$ species improve the cation selectivity of the film, increasing the oxide content and film density. ${NO_x}^-$ acts similar to a strong inhibitor both in the passive film and at active sites. This facilitates the formation of chromium oxide. Also, ${NO_x}^-$ can make more molybdate and nitric oxide by reacting with Mo. The role of Mo addition on the passivation characteristics of stainless steel may differ with the test environment. Mo exists as metallic molybdenum, molybdenum oxide, and molybdate and the latter facilitates the oxide formation. When nitrogen and molybdenum coexist in stainless steel, corrosion resistance in chloride solutions is drastically increased. This synergistic effect of N and Mo in a chloride solution is mainly due to the formation of nitro-oxyanions and molybdate ion. Oxyanions can be formed by a 'solid state reaction' in the passive film, resulting in the formation of more molybdate and nitric oxide. These oxyanions improve the cation selectivity of the outer layer and form more oxide and increase the amount of chromium oxide and the ratio of $Cr_2O_3/Cr(OH)_3$ and make the film stable and dense.

• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.180-186
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• 2005

This paper discusses the development of mixtures for silica fume as a stabilization/solidification agent and a binder for industrial wastewater residue containing organic and heavy metal contaminants. The UCS (unconfined compressive strength) gradually increased to 66.7% as the silica fume content increased to 15%. The leaching of TOC (total organic carbon) and chromium decreased as more OPC (Ordinary Portland Cement) was substituted with the silica fume. When a mixture had 5% silica fume, it retained about 85% TOC, and chromium leached out 0.76 mg-Cr/g-Cr in acidic solution. Also, microstructural studies of the solidified analysis showed that the silica fume caused an inhibition to the ettringite formation which did not contrilbute to setting but coated the cement particles and retarded the setting reactions. The results indicated that the incorporation of silica fume into the cement matrix minimized the detrimental effects of organic materials on the cement hydration reaction and the contaminant leachability.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.1
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• pp.40-49
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• 2023

Objectives: The handling of carcinogenic, mutagenic or reproductive toxic (CMR) materials in paint-related products used by automobile maintenance companies in Busan was investigated and its characteristics were analyzed. Methods: MSDS for paint-related chemical products used by automobile repair companies in Busan were collected and the manufacturers, product uses, names of chemical substances in each component, CAS numbers, content, and more were listed. Results: As a result of collecting MSDS on 4,800 kinds of products handled in the painting process of automobile repair companies in Busan and comparing them with the latest toxic information database, 60 out of a total of 438 substances were found as CMR materials. Seven carcinogens (1A), including quartz, benzene, formaldehyde, and hexavalent chromium, were present. Two reproductive toxic 1A substances were included: hexavalent chromium in paint pigments and lead. Conclusions: Most of the products (95.5%) were found to contain at least of one CMR component, so it was judged that a study on exposure assessment of CMR substances by automobile maintenance workers is needed in the future.

• Analytical Science and Technology
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• v.21 no.1
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• pp.1-8
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• 2008

This study was conducted to investigate the characteristics of the leaching of metal components from CCA-treated wood during outdoor exposure. CCA-treated wood specimens were placed horizontally or buried vertically into the soil, and then exposed to the natural environment for a year. Wood samples were collected from the side of the horizontal wood specimens using a drill and saw dust samples were collected at the end of the exposure. Soil samples were also obtained around the wood specimens and at different depths of the posts. Wood and soil samples were analyzed for metals using an atomic absorption spectrometer. Monthly metal concentrations varied greatly and more metals were released when wood specimens were exposed vertically than horizontally. Arsenic was released from the wood by 80 % of the intial content. In addition, more leaching was observed from the zone below the ground than above the ground, and soil around the posts was contaminated with metals released from CCA-treated wood.