• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.4
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• pp.159-168
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• 2015

Forty-four surface sediments from Doam Bay were analyzed for total organic carbon (TOC), total nitrogen (TN), total metal (Al, Fe, Mn, Cr, Cu, Ni, Pb, Zn) and further chemical partitioning of metals were carried out in some samples. The TOC (0.32~3.10%) and TN (0.03~0.26%) values of the samples were similar to those of other coastal area. The C/N ratios ranged from 7.9 to 11.9 with an average 9.3 which revealed that contribution of terrestrial organic matters was relatively rare. Contents of analysed metals showed a level lower than threshold effects level (TEL) in sediment quality guidelines. Based on the chemical speciation of metals, the lattice fractions were found in the order Cr > Cu > Ni > Zn > Pb > Mn, while Mn and Pb are the ratio of the non-lattice fractions accounted for more than 50%. The average baseline values were obtained relative cumulative frequency curves and linear regression analysis. The respective baseline concentrations for Cu, Ni, Pb, Zn, Cr and Mn were 11.8, 23.1, 26.8, 76.6, 56.7, 585 mg/kg, respectively. Based on geoaccumulation index ($I_{geo}$) with a baseline values of Mn showed that face the contamination phase from estuarine stations. However, in case of Zn and Pb, although there is no sign of contamination, it could be release from sediment when there is a change in the environment, which is caused from the high ratio of non-lattice fractions.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.6
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• pp.69-78
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• 2010

As part of preliminary study for development of 1,200 N-class bipropellant rocket engine with the concentrated hydrogen peroxide, bipropellant engine elements were designed and experimentally tested. The catalysts of $MnO_2$ and $MnO_2$ added Pb as an additive were compared to achieve high decomposition performance and the catalytic reactor with $MnO_2$ added Pb was designed and its decomposition efficiency of 97.2% was achieved. The autoignition tests of kerosene by decomposed hydrogen peroxide were carried out under various equivalence ratios to ignite without additional ignition sources. Autoignition were achieved in all experimental conditions and $C^*$ efficiencies at each condition were at or above 90%. From the measured thrust results, the highest value was 830 N which is in corresponds with 1,035 N at vacuum level assuming $C^*$ efficiency equals $I_{sp}$ efficiency.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2005.11a
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• pp.78-79
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• 2005

Effects of dietary lactose or killed Salmonella on the performance, immune response and anti-oxidant system was studied in chicks innoculated with Salmonella typhimurium. In 27 days of age broiler, dietary lactose decreased performance, while dietary lactose and killed Salmonella elevated plasma peroxidase activity and IL-1 level in supernatant of PBMC stimulated with LPS. When broiler chicks innoculated with Salmonella, performance, activities of erythrocyte MnSOD and plasma peroxidase were enhanced after 7 days of the innoculation. Dietary lactose and killed Salmonella increased activity of erythrocyte MnSOD, plasma peroxidase, proliferation of PBMC stimulated with LPS and IL-1 level in the supernatant after 15 days of the innoculation. The result indicated that dietary lactose and killed Salmonella have modulated innate immune response and antioxidant system in broiler chicks innoculated with Salmonella typhimurium.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.156-164
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• 2010

As part of preliminary study for development of 1,200 N-class bipropellant rocket engine with the concentrated hydrogen peroxide, bipropellant engine elements were designed and experimentally tested. The catalysts of $MnO_2$ and $MnO_2$ added Pb as an addictive were compared to achieve high decomposition performance and the catalytic reactor with $MnO_2$ added Pb was designed and its decomposition efficiency of 97.2% was achieved. The autoignition tests of kerosene by decomposed hydrogen peroxide were carried out under various equivalence ratios to ignite without additional ignition sources. Autoignition were achieved in all experimental conditions and $C^*$ efficiencies at each condition were at or above 90%. From the measured thrust results, the highest value was 830 N which is in corresponds with 1,035 N at vacuum level using 94.1% theoretical $I_{sp}$.

• Resources Recycling
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• v.9 no.3
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• pp.3-12
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• 2000

A Study on the cementation for the recovery of Cu, Ni and Co with Mn metallic powders in leaching solution from the manganese nodule that have removed Fe ions was studied. The results showed that the recovery efficiencies of metal ions with Mn powders increased when the temperature, pH and the concentration of chloride ions were increased in mixed solution. And the recovery efficiencies of Cu was 98% and not changed with the addition amounts of Mn powders but, in case of Co and Ni, the recovery efficiencies were increased with the addition amounts. The particle size of precipitate was about $5\mu\textrm{m}$. From the results of experiment we proposed the two-step cementation process for the recovery of Cu, Ni and Co with Mn powders.

• Journal of Food Hygiene and Safety
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• v.15 no.3
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• pp.209-218
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• 2000

This study was conducted to determine the content of trace metals in crops cultivated in Han-riverside, Anyang stream, Tan stream, and Jungryang stream. Trace metals (Pb, Cr, Cd, Fe, Zn, Cu, Hg) were detected in 36 crops, 285 samples by Atomic Absorption Spectrophotometer and Mercury Analyzer. The average concentration of trace metals in crop samples was in the order of Fe (34.592 ppm)>Mn (11.071 ppm)$\geq$Zn(8.853 ppm)>Cu(1.795 ppm)>Cr(0.237 ppm)>Pb(0.100 ppm)>Cd(0.011 ppm)>Hg(0.003 ppm). In crop samples, the contents of Fe, Cu, Mn, and Zn, which ranges were 0.004-203.083 ppm, 0.017~22.727 ppm, 0.000~74.373 ppm, 0.080~37.166 ppm, respectively, were relatively higher than those of Pb, Cd, Cr, and Hg, which ranges were 0.000~0.654 ppm, 0.000~0.270 ppm, 0.000~l.229 ppm, 0.000~0.037 ppm, respectively. The concentration of trace metals in crop samples was in the order of leafy vegetables > stem vegetables > root vegetables > fruity vegetables. In the root vegetables, such as radish, the content of Pb was leaf(0.055 ppm)>root(0.035 ppm), that of Cr, leaf (0.118 ppm)>root(0.031 ppm), that of Cd, leaf(0.004 ppm)>root(0.001 ppm), that of Hg, leaf(0.004 ppm)>root(0.001 ppm). As the results, it could be thought that root is the organ which doesn't accumulate the heavy metal ions, but absorb them.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.1
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• pp.56-72
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• 1999

Airborne concentrations of welding fumes in which 13 different metals such as Al, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Si, Sn, Ti, and Zn were analyzed were measured at 18 factories including automobile assembly and manufactures, steel heavy industries and shipyards. Air samples were collected by personal sampler at each worker's worksite(n=339). Blood levels of Cd, Cu, Fe, Mn, Pb and Zn were also measured from samples taken from 447 welders by atomic absorption spectrometry and compared with control values obtained from 127 non-exposed workers. The results were as follows ; 1. Among various welding types, $CO_2$ welding 70.2 % were widely used, shielded metal arc welding(SMAW) 22.1 % came next, and rest of them were metal inert gas(MIG) welding, submerged arc welding(SAW), spot welding(SPOT) and tungsten inert gas(TIG) welding. 2. Welding fume concentration was $0.92mg/m^3$($0.02{\sim}15.33mg/m^3$) at automobile assembly and manufactures, $4.10mg/m^3$($0.02{\sim}70.75mg/m^3$) at steel heavy industries and $5.59mg/m^3$($0.30{\sim}91.16mg/m^3$) at shipyards, respectively, showing significant difference among industry types. Workers exposed to high concentration of welding fumes above Korean Permissible Exposure Limit(KPEL) amounted to 7.9 % and 12.5 %, in $CO_2$ welding and in SMAW at automobile assembly and manufactures and 62.7 % in $CO_2$ welding, and 12.5 % in SMAW at shipyards, and 66.2 % in $CO_2$ welding and 70.6 % in SMAW at steel heavy industries. 3. Geometric mean of airborne concentration of each metal released from welding fumes was below one 10th of KPEL in all welding types. Percentage of workers, however, exposed to airborne concentration of metals above KPEL amounted to 16.8 % in Mn and 7.6 % in Fe in $CO_2$ welding; 37.5 % in Cu in SAW, 30 % in Cu in TIG; and 25 % in Pb in SPOT welding. As a whole, 76 Workers(22.4%) were exposed to high concentration of any of the metals above KPEL. 4. There were differences in airborne concentration of metals such as Al, Cd, Cr, Cu. Fe. Mn, Mo, Ni, Pb, Si, Sn, Ti and Zn by industry types. These concentrations were higher in shipyards and steel heavy industries than in automobile assembly and manufactures. Workers exposed to higher concentration of Pb above KPEI amounted to 7.4 % of workers(7/94) in automobile assembly and manufactures. In shipyards, 19.2 % of workers(19/99) were over-exposed to Mn and 7.1 % (7/99) to Fe above KPEL. In steel heavy industries, 14.4 %(21/146), 7.5 %(11/146) and 13 %(19/146) were over-exposed to Mn, Fe and Cu, respectively. As a whole, 76 out of 339 workers(22.4%) were exposed to any of the metals above KPEL. 5. Blood levels of Cd, Cu, Fe, Mn, Pb, and Zn in welders were $0.11{\mu}g/100m{\ell}$, $0.84{\mu}g/m{\ell}$, $424.4{\mu}g/m{\ell}$, $1.26{\mu}g/100m{\ell}$, $5.01{\mu}g/100m{\ell}$ and $5.68{\mu}g/m{\ell}$, respectively, in contrast to $0.09{\mu}g/100m{\ell}$, $0.70{\mu}g/m{\ell}$, $477.2{\mu}g/m{\ell}$, $0.73{\mu}g/100m{\ell}$, $3.14{\mu}g/100m{\ell}$ and $6.15{\mu}g/m{\ell}$ in non-exposed control groups, showing significantly higher values in welders but Fe and Zn.

• Journal of Environmental Health Sciences
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• v.44 no.5
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• pp.433-443
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• 2018

Objectives: The purpose of this study was to examine the relationship between dietary habits and concentrations of urinary phthalate metabolite in elementary school children. Methods: This study was conducted in Seoul, South Korea. We collected urine samples from 156 children from a single school in September 2016. Information on dietary habits was obtained from the parents of the children. Five types of urinary phthalate metabolites were analyzed using a high-performance liquid chromatography tandem mass spectrometer. Multiple linear regression analysis was used to determine the factors affecting the concentrations of urinary phthalate metabolite. Results: Girls had a significantly lower concentration of urinary mono-n-butyl phthalate (MnBP) (p=0.006) than did boys. When the consumption of bean processed food and wrapped delivery food were more than once a week, urinary MnBP (p=0.021) and monobenzyl phthalate (MBzP) (p=0.032) concentrations were the highest, respectively. Conclusion: Several urinary phthalate metabolite concentrations were associated with demographic and dietary habits. Particularly, urinary MnBP and MBzP were associated with several processed foods. The findings of this study might be useful as basic data for establishing and educating on environmental health policy.

• Journal of Life Science
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• v.6 no.1
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• pp.6-13
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• 1996

The possible use of milk-wastewater as a fermentation media for the production of citric acid by Aspergillus niger has been investigated. The addition of Mn$^{2+}$ , Fe$^{2+}$ and Cu$^{2+}$ to the medium promoted citric acid production while only Mg$^{2+}$ decreased citric acid production. The concentrations of citric acid produced were marked up to 7.2g/l and 16.5g/l in a batch bioreactor by Aspergillus niger ATCC 9142 with 50g/l and 100g/l of reducing sugar concentration in milk-wastewater, respectively. A mathematical model was developed and simulating the predictability of cell growth, citric acid production and substrate consumption rate, and gave good agreement results with experimental data.

• Journal of Environmental Health Sciences
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• v.26 no.2
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• pp.41-48
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• 2000

This study has been carried out to determine the seasonal characteristics of concentration of various ionic (CI-, NO3-, SO42-, Na+, NH+, K+, Ca2+) and heavy metallic (Pb, Mn, Cu, Ni) species in Pusan from August 1997 to April 1998. The concentrations of CI-, Na+, K+ were higher during summer with 2.98 ${\mu}{\textrm}{m}$/㎥. Seasonal variation of total concentration of but the concentration of NH4+ was higher during winter with 2.46${\mu}{\textrm}{m}$/㎥. Seasonal variation of total concentration of heavy metals(Pb, Cu, Mn, Ni) were 186.0 ng/㎥ in summer, 222.6 ng/㎥ in autumn, and 135.83 ng/㎥ in winter. Over the seasons inspected, the concentration of Mn was higher in coarse particles than fine particles and concentration of Ni was higher in fine particles than coarse particles. during yellow sand period, the concentration of TSP was increased about two times than that of other period. SO42-, Ca2+ concentrations were higher than other ionic components because of soil particles. The concentration of Ni showed 94.62ng/㎥ was increased about 4~5 times than other period. Principal component of the yellow sand, SO42-, Ca2+ could be discreased by rainfall and washout effect of atmospheric aerosol was higher in coarse particles than fine particles. Results from PCA(principal component analysis) showed that major pollutant was NaCl by seasalt particulate and (NH4)2SO4.