• Journal of Environmental Science International
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• v.11 no.11
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• pp.1157-1163
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• 2002

The effective removal of microcystins by chlorination was investigated on a laboratory scale. With an initial chl.a concentration of more than 1,000 $\mu\textrm{g}$/ℓ, the required chlorine dose for the effective removal of microcystins from the raw water was more than 8.0 mg/ℓ. Whereas, a chlorine dose of 3.0 mg/ℓcould effectively remove microcystins from raw water containing a chl.a concentration of less than 1,000 $\mu\textrm{g}$/ℓ. The microcystin removal was more effective below pH 8.0, plus the optimum pH range was unrelated to the concentration of toxic algal material. Although chlorination is one of the most effective methods for reducing the toxin from blue-green algae, it causes cell lysis and toxin release. However, it was demonstrated that the released cell lysates and toxins could be effectively removed by a higher dose of the oxidant. The highest removal efficiency of dissolved microcystins(initial concentration: 280 $\mu\textrm{g}$ L$\^$-1/) was with a chlorine dose of 5.0 mg/ℓ.

• Membrane Journal
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• v.2 no.1
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• pp.33-48
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• 1992

OSRO process was developed and it was confirmed more effective in ethanol concentrating process comparing to reverse osmosis process. It may be industrialized if more effective membrane for OSRO and reverse osmosis, which indicate the value greater than zero, it was shown that OSRO process was more effective than reverse osmosis for the ethanol concentration process. The decrease of feed concentration and flow rate and the increase of applied pressure made more effective operating conditions in OSRO process to concentrate ethanol. From the numerical esults for the multi-plates, theoretical DC values of reverse osmosis and OSRO process was increased as the umber of stages increased. DC values were increased with the increase of applied pressure in same number of stages. The theoretical values of DC by numerical calculation were corresponded to the experimental values within 15% tolerance. DC value was increased proportional to applied pressure and osmotic sink solution flow rate but it was decreased proportional to feed concentration and flow rate. The numerical calculation over the wide ranges inclading experimental condition was proposed in this study.

• Journal of the Korean Society of Visualization
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• v.15 no.2
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• pp.26-32
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• 2017

Hypochlorous acid(HOCl) is a chemical that is a safe sanitizer and disinfectant approved by the Food and Drug Administration as a food additive, exhibiting strong sterilizing power with low effective chlorine concentration of pH 5.0-6.5 and effective chlorine concentration 10-80 ppm. To apply to fishery industries, we develope the HOCl ice for store or delivery of fishery products. However when HOCl is being frozen, the contained HOCl are expelled out from the ice due to the molecular structures of ice; there is no space to contain HOCl inside. To increase chlorine containing amount in ice, we develop the alginate particles containing HOCl which is bio comparable since alginate is a natural polymer extracted from the brown algae and it is widely used for drug delivery and containing substances, etc. We produce HOCl with water as base solution suppressing osmotic flow from fishery products, and mix it with the developed alginate particles and made HOCl-alginate ice and checked the remaining amount of HOCl. We measure the change of pH and chlorine concentration optimizing the best concentration of alginate particles. Finally, we produce the alginate particle HOCl ices with respect to the alginate's optimal concentration.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.6
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• pp.757-765
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• 1999

Lagrangian particle dispersion model(LPDM) is an effective tool to calculate the dispersion from a point source since it dose not induce numerical diffusion errors in solving the pollutant dispersion equation. Fictitious particles are released to the atmosphere from the emission source and they are then transported by the mean velocity and diffused by the turbulent eddy motion in the LPDM. The concentration distribution from the dispersed particles in the calculation domain are finally estimated by applying a particle count method or a Gaussian kernel method. The two methods for calculating concentration profiles were compared each other and tested against the analytic solution and the tracer experiment to find the strength and weakness of each method and to choose computationally time saving method for the LPDM. The calculated concentrations from the particle count method was heavily dependent on the number of the particles released at the emission source. It requires lots fo particle emission to reach the converged concentration field. And resulting concentrations were also dependent on the size of numerical grid. The concentration field by the Gaussian kernel method, however, converged with a low particle emission rate at the source and was in good agreement with the analytic solution and the tracer experiment. The results showed that Gaussian kernel method was more effective method to calculate the concentrations in the LPDM.

• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.762-766
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• 2006

To improve water resistance of paperboard used to manufacture the corrugated boxes, effect of surface coating of the liner- board with Na-alginate was investigated by determining the optimum processing conditions such as a optimum alginate concentration for surface coating, plasticizer content, concentration of divalent cations their immersion times, For the surface coating of the liner-board, 2.5% Na-alginate solution was found to be the optimum concentration, and the concentration of glycerol used as plasticizer was effective when 35% alginate concentration was use was Used Immersion of the alginate coated paperboard for 3 min in a $CaCl_2$ solution improved the water resistance properties. As a divalent cation for the insolubilization of the alginate films, $Cu^{2+}$ was found to be as effective as $Ca^{2+}$. Among the platicizers tested, sorbitol was the most effective in reducing water vapor permeability and water solubility of alginate coated paperboard.

• Journal of Nutrition and Health
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• v.32 no.4
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• pp.353-368
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• 1999

This study was performed to investigate the effects of Korean native plant diets on lipid and cadmium (Cd) metabolisms and also antioxidative enzyme activities in rats. Seventy male Sprague-Dawley rats weighing 210.3$\pm$2.7g were blocked into ten groups according to body weight. Rats were raised for four weeks with diets containing 0 or 0.04%(w/w) cadmium chloride and 5%(w/w) plant powder-Ssook(Artemisia princeps var. orientalis HARA), Chamchwi(Aster scaber THUNB), Gomchwi(Lingularia fischeri TUBCZ). or Solbeerum (Portulaca oleracea LINNE). Food intake, weight gain, food efficiency ratio, and weights of liver, kidney, spleen and epididymal fat were significantly lower in Cd-exposed groups, food efficiency ratio, and weights of liver, kidney, spleen and epididymal fat were significanlty lower in Cd-exposed groups. Plasma total lipid level, liver total lipid, cholesterol and triglycerde concentrations, and fecal total lipid, cholesterol and triglyceride excretions were decreased by Cd administration. Total lipid and triglyceride concentration in plasma and liver were lower in Chamchwi groups together with increased fecal total lipid and triglyceride excretions. Cholesterol concentration in plasma and liver were lower in Gomchwi groups with increased fecal cholesterol excretions. Activities of red-blood-cell superoxide dismutase(SOD), and liver catalase, SOD and glutathione peroxidase (GSH-px) were decreased significantly by Cd administration. Thiobarbituric acid reactive substance(TBARS) concentrations of plasma and liver were increased by Cd administration. Thiobarbituric acid reactive substance(TBARS) concentration of plasma and liver were increased by Cd administration. Administration of plant diets decreased plasma and liver catalase, SOD and GSH-px activities in Cd-free diet groups and increased them in Cd-administered groups. Plasma and liver TBARS concentrations were decreased in animals fed plant diets, with Chamchwi showing the most effective antioxidative capacity. The concentration of Cd accumulated in blood and tissue decreased in Cd-exposed groups fed plant diets. Liver Cd concentration were lower in the Chamchwi and Gomchwi groups, and kidney Cd levels were lower in the Ssook and Chamchwi groups. Among them, Chamchwi was the most effective in Cd detoxification. In conclusion, Chamchwi and Gomchwi were effective in lowering tissue lipid levels, with Chamchwi having the greatest antioxidative and detoxifying effects.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.5
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• pp.201-206
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• 2004

In order to investigate the optimum conditions for the effective ozone formation in a dielectric barrier discharge, measurements of ozone concentration were carried out for various conditions such as the gap length, the dielectric material and the operating gas. It was found that the optimum discharge conditions differed exceedingly in the types of operating gases and dielectric materials. In dry air, dielectric material with low dielectric constant and thermal conductivity, which might contribute to the restriction of the gas temperature rise in the discharge region, proved effective in obtaining both high ozone yield and concentration. The optimum gap length was considered to be in the range of 600-800 mm. In oxygen, using a quartz glass disk as a dielectric material, the required condition to obtain the high ozone yield and concentration was expanded.

• The Korean Journal of Ecology
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• v.27 no.5
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• pp.301-306
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• 2004

The sensitivity to Cd of three ectomycorrhizal fungi, Paxillus involutus, Suillus bovinus and Rhizopogon subcaerulescens, was assessed and compared in terms of radial growth and dry mass production, using both agar and liquid culture. The radial growth of S. bovinus and R. subcaerulescens was significantly reduced at the lowest concentration (0.1mg Cd/L). The 50% effective concentration (EC$_{50}$) values calculated from radial growth rates of the ectomycorrhizal fungi showed that the sensitivity of the fungi to Cd was greatest in S. bovinus and lowest in R. subcaerulescens. Cadmium addition also significantly decreased dry mass production of the ectomycorrhizal fungi. The sensitivity of the fungi to Cd in terms of dry mass production, was greatest in S. bovinus and lowest in P. involutus. Higher growth rates of P. involutus and melanisation of R. subcaerulescens appeared to contribute to reduced Cd toxicity.

• Journal of Environmental Science International
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• v.16 no.8
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• pp.985-994
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• 2007

To investigate the effect of NOx and VOCs(volatile organic compounds) on the generation of high ozone episode, examined the hourly variations of ozone, NOx and VOCs concentrations, and calculated the ozone isopleth about maximum ozone concentrations using OZIPR which was presented by U. S. EPA at three sites in Busan. There was some difference by the sites, but decreasing VOCs concentration was effective for reduction of ozone at 22 July, the episode day of 2005. In the year 2006, the episode day was 8 August and the variations of NOx and VOCs concentration was little than variation of ozone. So it was estimated that the photochemical production of ozone was low than transportation of ozone. And the result of the OZIPR modeling was that decreasing VOCs concentration was effective for reduction of ozone.

• Geotechnical Engineering
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• v.13 no.2
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• pp.17-28
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• 1997

In this study sodium chloride solution is employed for chemicals, and several cylindrical triaxial tests are performed on the sand-bentonite mixtures saturated with sodium chloride solution. Deformation(elastic modulus, E) and strength(cohesion, c', and angle of friction, f') parameters are obtained from the triaxial tests as functions of confining pressure and sodium chloride solution concentrations. The results here indicate an increase in the value of effective cohesion with increase in the concentration of NaCl solution, which can be explained by using the Gouy-Chapman model. The value of the effective angle of shearing resistance does not show significant change with the increase in concentration of NaCl solution. The Young's modulus also increases with the increase in concentration of NaCl solution.