• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.675-678
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• 2004

Ozone is usually generated from oxygen gas using a silent discharge apparatus and its concentration is less then 10 mol%. An ozone condensation system is constructed for metal oxide thin film fabrication. Ozone is condensed by the adsorption method, which is widely used for the growth of oxidation thin films such as superconductor. Highly condensed ozone is analyzed by three methods; ultraviolet absorption, thermal decomposition and Q-mass analyzing methods. Thermal decomposition method is most effective in the highly condensed ozone region and its method is superior to Q-mass analyzer for determining ozone concentration because of the simplicity of the method.

• Journal of Environmental Impact Assessment
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• v.14 no.1
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• pp.17-24
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• 2005

This study was performed to evaluate the adsorption rate of phosphate corrosion inhibitor and reaction rate constant in drinking water distribution systems. The optimum concentration of corrosion inhibitor would vary depending on the quality of water, pipe materials, and condition of metal surfaces. The current adsorption study indicated that the residual phosphate concentration of the corrosion inhibitor decreased with the time as it adsorbed on the surface of pipe material. As time went by, the residual phosphate concentration became constant. It means that the formation of the corrosion protection film on metal surfaces is completed.

• Bulletin of the Korean Chemical Society
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• v.22 no.3
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• pp.288-292
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• 2001

The kinetic mechanism of Hafnia alvei aspartase in the amination direction has been determined in the absence of metal. The initial velocity pattern obtained by varying the concentration of fumarate at several fixed concentrations of NH4+ , shows an intersection on the left of the ordinate at pH 7.0, indicating that the kinetic mechanism is a sequential mechanism in which substrate inhibition by fumarate is observed. The dead-end inhibition pattern by varying the concentration of NH4+ at several fixed concentration of succinate shows an intersection on the left of the ordinate. These data are consistent with random addition of NH4+, or fumarate. The Haldane relationship gives a Keq of 1.18 ${\times}$10-3 M at pH 7.0, which is in agreement with the values obtained from the direct determination of reaction concentrations at equilibrium (6.0 $\pm0.2$ ${\times}$10-3 M).

• ALGAE
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• v.26 no.3
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• pp.265-275
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• 2011

This study examined the bioaccumulation of the heavy metals copper (Cu) and zinc (Zn) by the giant kelp, Macrocystis pyrifera, by exposing meristematic kelp tissue to elevated metal concentrations in seawater within laboratory aquaria. Specifically, we carried out two different experiments. The first examined metal uptake under a single, ecologically-relevant elevation of each metal (30 ppb Cu and 100 ppb Zn), and the second examined the relationships between varying levels of the metals (i.e., 15, 39, 60, 120, 240, and 480 ppb Cu, and 50, 100, 200, 300, 500, and 600 ppb Zn). Both experiments were designed to contrast the uptake of the metals in isolation (i.e., when only one metal concentration was elevated) and in combination (i.e., when both metals' concentrations were elevated). Following three days of exposure to the elevated metal concentrations, we collected and analyzed the M. pyrifera tissues using inductively coupled plasma atomic emissions spectroscopy. Our results indicated that M. pyrifera bioaccumulated Cu in all treatments where Cu concentrations in the seawater were elevated, regardless of whether Zn concentrations were also elevated. Similarly, M. pyrifera bioaccumulated Zn in treatments where seawater Zn concentrations were elevated, but this occurred only when we increased Zn alone, and not when we simultaneously increased Cu concentrations. This suggests that elevated Cu concentrations inhibit Zn uptake, but not vice versa. Following this, our second experiment examined the relationships among varying seawater Cu and Zn concentrations and their bioaccumulation by M. pyrifera. Here, our results indicated that, as their concentrations in the seawater rise, Cu and Zn uptake by M. pyrifera tissue also rises. As with the first experiment, the presence of elevated Zn in the water did not appear to affect Cu uptake at any concentration examined. However, although it was not statistically significant, we observed that the presence of elevated Cu in seawater appeared to trend toward inhibiting Zn uptake, especially at higher levels of the metals. This study suggests that M. pyrifera may be useful as a bio-indicator species for monitoring heavy metal pollution in coastal environments.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.1
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• pp.35-41
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• 2006

The steel foundries with electric arc furnaces handling metal scraps have recently gained an attention as a potential source of dusts. The present study focuses on the analysis of dust emissions and removals during furnace charging and melting processes by commercial CFD software named FLUENT. A body fitted grid system consisting of 880,000 meshes was first generated by Gambit for the electric arc furnace with the capacity of 60 ton/cycle and then FLUENT was invoked to solve the corresponding NavierStokers equation for the momentum, temperature and dust concentration. The entire processes from metal charging to metal melting were simulated to investigate the unsteady behaviors of fluid flows and dust concentrations. The model simulation results showed that as the top of the electric arc furnace opened for metal charging, hot plumes bursted out from the furnace rose strongly by buoyance and escaped mostly through the main hood. Therefore, the capacity of main hoods determined the vent efficiency in the metal charging process. As the furnace was closed after the metal charging and the metal melting processes was followed, the hot flow stream stretching from the furnace to the main hood was dissipated fast and the flow from the inlet of the bottom of the left hand side to the main and monitoring hoods constituted the main stream. And there was only a slow flow in the right hand side of the furnace. Therefore, the dust concentrations were calculated higher in the left hand side of the furnace, which was consistent with observations.

• Journal of the Korean Chemical Society
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• v.40 no.1
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• pp.50-58
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• 1996

In the presence of metal ions(Co(Ⅱ), Ni(Ⅱ), Sr(Ⅱ), Cu(Ⅱ), Fe(Ⅲ), U(Ⅵ)), the sedimentation of humic acid was increased at constant pH with increasing metal concentration and the strength was increased in the following order: Sr < Ni < Co < Cu < Fe < U. At constant metal concentration, Cu(Ⅱ), Ni(Ⅱ), and Co(Ⅱ) ions caused an increase in sedimentation of humic acid as the solution pH increased, whereas Fe(Ⅲ) and U(Ⅵ) ions caused a decrease. Sr(Ⅱ) ions did not affect the sedimentation even with the variation of pH. The analysis of FT-IR spectra for the sediments prepared from the reaction between humic acid and metal ions showed that metal ions were bound to humic acid to form complexes, suggesting that the metal complexation plays an important role in the sedimentation of humic acid.

• Journal of Environmental Science International
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• v.14 no.2
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• pp.185-192
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• 2005

The concentration of heavy metal were studied for the estimation of quality in herbal medicines which is Bupleuri Radix, Paeoniae Radix, Dioscoreae Rhizoma and Astragali Radix in products of north Gyeongbuk area Also, we collected soils from several area in Gyeongbuk, and determined heavy metal concentration of soils by ICP. We compared with herbal medicines in products of Gyeongbuk and their soils. The average levels of heavy metal of herbal medicines in Gyeongbuk area are as follows: Mercury is 0.037mg/kg, Chromium is 0.093 mg/kg, Nickel is 0.108mg/kg, Copper is 0.475mg/kg, Zinc is 3.14mg/kg, Manganese is 1.52mg/kg, Iron is 7,83mg/kg, and Cadmium, Lead and Arsenic is not detected. It was very lower in concentrations than those of average Korea area. For the heavy metals contents of Gyeongbuk area, in Gong Jung Ri, represented the higher level, it may be due to a near the road. The Cd contents in soil was not a wide difference. For the As and Pb contents in soil, Song Sa Ri (Bupleuri Radix) represented the higher level(0.68mg/kg, 1523mg/kg). Correlation coefficients of heavy metal contents in cultured herbal medicines and their soils did not give reproducible results. But the degree of correlation between a few heavy metal contents of Dioscoreae Rhizoma and their soil showed the good transfer from the soil.

• YAKHAK HOEJI
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• v.35 no.2
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• pp.99-110
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• 1991

This study was initiated to investigate the effects of organic germanium on cadmium and mercury intoxication. The effect was determined by the metallothionein induction in liver and kidney. Male rats (Sprague-Dawley) were treated with CdCI$_{2}$ (2mg/kg), HgCI$_{2}$ (1 mg/kg) and organic germanium (GE-132) (100 mg/kg) in single and in combination via intraperitoneal injection or intragastric administration every other days for 17 days. Experimental animals were sacrificed after 7, 12 and 17 days treatment. The serum transaminase activities (SGOT, SGPT), concentration of metal and metallothionein, metal-binding capacity of metallothionein in liver and kidney were determined and pathomorphological observations were undertaken. The combined treatment of GE-132 and CdCI$_{2}$ significantly decreased the increment of serum transaminase activities in rats treated with CdCI$_{2}$ only, but the combined treatment of GE-132 and HgCI$_{2}$ did not affect to activities of transaminases induced by mercury only. The concentration of metals (Cd and Hg) except Ge in the liver and kidney of rats increased with the time of treatment. Mercury concentration in kidney of rat treated with HgCI$_{2}$ only was significantly higher than the combined treatment of GE-132 and HgCI$_{2}$. The combined treatment of GE-132 and CdCI$_{2}$ significantly increased the concentration of metallothionein in liver compared to the CdCI$_{2}$ only, although the concentration of cadmium in liver were not significantly different between two groups. This indicates that GE-132 decreased toxicity of cadmium in liver by promoting metallothionein induction. There were no significant differences in metallothionein concentration in liver and kidney of rats between the combined treatment of GE-132 and HgCI$_{2}$ and HgCI$_{2}$ only. Metal-binding capacity of metallothionein varied with each time intervals in liver and kidney of metals treated rats except the liver of the combined treatment of GE-132 and CdCI$_{2}$. This finding explains the concentration of metallothionein in liver keeps abreast with the concention of metal. Furthermore, the combined treatment of GE-132and CdCl$_{2}$ revealed pathologically less changes in liver tissue than CdCl$_{2}$ only; the damages of liver cell, such as lobular necrosis and portal inflammation, were relieved and appeared more later. From the above results, organic germanium is considered to have some beneficial effect on the protection of liver from the cadmium intoxication.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.187-190
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• 2002

Reductive dechlorination of endosulfans was studied with zero valent metals (ZVMs) and bimetals in aqueous batch reactors. The effect of surfactants was evaluated. Endosulfan was successfully dechlorinated with zero valent iron. However, a bimetal, palladium coated iron (Pd/Fe) showed a highly enhanced reactivity for both endosulfan I and II indicating palladium act as a dechlorination catalyst on the iron. The effect of surfactants on degradation with ZVM has been very controvertible. Variable concentration of a nonionic surfactant, Triton X-100 and an anionic surfactant, SDS were added into the reactor with ZVM. The reaction rates of endosulfan were increased with both surfactants. In the case of Triton X-100, the reaction rate was increased with the increasing surfactant concentration up to 400 mg/L. Addition of small amount of surfactant under the CMC, the reaction rate was increased. However, the enhancing effect was diminished when a higher concentration of surfactant (1,000 mg/L) was used. Current study implicate that the surfactant adsorbed on the metal surface might increase the surface concentration of endosulfan resulting in the increased reaction rate. However, partitioning of endosulfan into the micelle formed at the high concentration of surfactant diminish the enhancing effect by reducing the contact chance between target compound and the metal surface.

• The Korean Journal of Mycology
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• v.19 no.4
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• pp.282-284
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• 1991

The yeast, Hansenula anomala B-7, isolated from the $Cd^{2+}$ rich soils and determined to be tolerant in the high concentration of $Cd^{2+}$ were employed in this work. Its intact cells grown in high concentration of $Cd^{2+}$ were observed to be Iysed at the early stage when transferred to a cadmium deficient broth. Its intact cells found to be not Iysed and grow well under the high concentration of $Cd^{2+}$. The Iysis of the intact cells grown at the high concentration of $Cd^{2+}$ ion was not found when the metal ions were replaced with $Cd^{2+}$ ion in the same concentration. This result indicated that Iysis of yeast cells, at least in this isolate, would be related to cell osmosis with the mineral ions added.