• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.430-433
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• 2003

Nitrogen pollution in urban and rural groundwater is a common problem and poses a major threat to drinking water supplies based on groundwater. In this work, the kinetics of nitrification-denitrification coupled reactions are modeled and new reaction modules for the RT3D code describing the fate and transport of nitrogen species, dissolved oxygen, dissolved organic carbon, and biomass are developed and tested. The proposed nitrogen transformations and transport model showed very good match with the results of other public codes.

• Applied Chemistry for Engineering
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• v.10 no.4
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• pp.581-585
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• 1999

The surface treated hydroxypropyl methylcellulose(HPMC) which could adjust the soluble time was synthesized when 40 wt % glyoxal solution and $KH_2PO_4$ were sprayed and reacted. And also, the solution dynamic at different ratios of two adding agents were identified If the surface of HPMC was treated with only glyoxal, the dispersion characteristics at different ratios of two adding agents were identified If the surface of HPMC was treated with only glyoxal, the dispersion was observed in the neutral solution and the viscosity was increased after directly dissolved as the solution become alkali condition. But the fine-powder type of HPMC which reacted with glyoxal and $KH_2PO_4$ was dispersed regardless of pH of solution and observed that it was dissolved and its viscosity increased after elapsing some time. With increasing amount of glyoxal and $KH_2PO_4$, the soluble time was delayed. The reaction condition was about 60 min at $75{\sim}85^{\circ}C$. Especially, the removal process of organic solvent after reaction was not required due to reaction under water solution without organic during glyoxal and $KH_2PO_4$ treatment. And also, the HPMC which could adjust the soluble rate in water or organic solvent by changing the degree of substitution of HPMC was synthesized.

• Journal of Ginseng Research
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• v.3 no.2
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• pp.134-143
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• 1979

It order to extract the soluble organic substances of Korean ginseng effectively, the ginseng extract have been made by using amylase. The investigation on the optimum condition of enzyme reaction was carried out, and the amounts of gained extract and its saponin pattern were compared among the ethanol extract, water extract and enzyme extract. The results obtained are summerized as follows. 1. The gaining ratio or ginseng extract was the highest value when the raw ginseng and dried ginseng were extracted in the concentration of 7.5% and 5% with 0.3%∼0.6% enzyme for 25 hour. 2. The amounts of ethanol extract, water extract and enzyme extract were 9.14%, 17.23% and 23.73% in case of raw ginseng and 64.09%, 72.52% and 74.36% in case of dried ginseng, respectively. The amount of enzyme extract was increased as much as 6∼14% in case of raw ginseng, and 2∼10% in case of dried ginseng compared with that of ethanol and water extract. 3. The absolute content of saponin was nearly constant in spite of the different extraction method and all of the ginseng saponin pattern of thin-layer chromatograms were almost same.

• Journal of Environmental Science International
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• v.16 no.5
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• pp.623-632
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• 2007

The objective of this study is analysis of Andong-Dam lake water quality with water quality model. Model parameters of the WASP applied to Lake Andong-Dam were estimated. The methodology is based on grouping water quality constituents and relevant parameters and successively estimating parameters by a trial-and-error procedure. Water qualify system for modeling consisted of BOD, DO, T-N, T-P. The results of water quality modelling using WASP. T-N was maximum affected by K71C(Organic nitrogen mineralization rate) parameter. T-P was maximum affected by K83C(Dissolved organic phosphorus mineralization) parameter, and It did not show a difference almost from the parameter of others and it omitted. BOD was maximum affected by Temperature parameter, it was visible of the reaction due to the KDC(Deoxygenation rate) in afterwords, and it did not show a difference from the parameter of others and it omitted. DO was maximum affect by Temperature parameter, and It did not show a difference almost from the parameter of others and it omitted. The parameter which it presumes from the this study uses a water quality modeling and Actual value and the result with which it compares, error rate the parameter presumption which is appropriate with 1% interior and exterior is investigated, It will reach and it uses and it will be able to apply to the suitable parameter in water quality modelling of the objective area which can be feeded by it becomes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.1151-1154
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• 2003

Ultraviolet rays, OH H O radical and $O_3$ produced by the streamer discharge in water are widely used to deactivate microorganisms and remove organic contaminants in water and the dominant factor of these decomposition is the oxidized reaction of hydrogen peroxide and dissolved $O_3$ in water. In this paper, the barrier discharge was used to create plasma in a gas, liquid and solid medium and the electrode with the reactor combined barrier with packed type(BPR) was made as noncontact way against water so that the effect of water characteristic change by the erosion of electrodes exposing in water should be minimized. The active radical and $O_3$ gas generated in plasma region were reacted into the water as electrode so that at the same time a dissolved $O_3$ and hydrogen peroxide were formed in water and The change of pH and conductivity were measured.

• Journal of the Mineralogical Society of Korea
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• v.18 no.2
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• pp.117-125
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• 2005

It is common to find lots of organic and inorganic precipitates inside of industrial cooling system. Analytical instruments including ICP-AES, IC, XRD, and SEM were used to investigate the effects of application of Mg on reaction among coolant, precipitates and suspended matters within chiller system. Magnesium (Mg) has a decreasing effect on total dissolved material in the coolant suggesting a significant improvement of quality of coolant. Disappearance of most organic materials in the cooling devices also suggests an inhibitive effect on the growth of organic matters.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.394-394
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• 2009

Water solubility of conjugated polymers may offer many applications. Potential applications of water-soluble conjugated polymers include the polymer light-emitting diode and new materials for nano and micro hollow-capsules, and bio- or chemo-sensors. We synthesized neutral polyfluorenes containing bromo-alkyl groups by the palladium catalyzed Suzuki coupling reaction. Bromo-alkyl side groups in neutral polyfluorenes were quaternized by tri-methyl amine solution. The electrochemical and optical properties of water-soluble conjugated polymers are discussed. This novel synthesized water-soluble conjugated polymers were used as a interfacial dipole layer between active layer and metal cathode in polymer solar cell for enhancement of open-circuit voltage (Voc), which is one of the most critical factors in determining device characteristics. We also investigated the device performance of polymer solar cell with different metal cathode such as Al, Ag, Au and Cu. In polymer solar cell, novel cationic water-soluble conjugated polymers were inserted between active layer and high-work function cathode (Al, Ag, Au and Cu).

• Membrane Journal
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• v.17 no.2
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• pp.99-111
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• 2007

It is impossible to remove toxic organic substances that are recognized as a cancer caused suspicious element in drinking water using the conventional water purification method. This study introduces groundwater into a reaction chamber as an effective amount of water to process this water using a mixed method of AOP oxidation and M/F membrane and purifies it as a desirable level by artificially mixing such toxic substances in order to effectively process the water. Based on this fact, this study configures an optimal operation condition. The VOCs existed in toxic substances was investigated as a term of phenol and toluene, and agricultural chemicals were also investigated as a term of parathion, diazinon and carbaryl. The experiment applied in this study was performed using a single and composite soolution. In the operation condition applied to fully dissolve and remove such substances, the amount of $H_2O_2$ injected in the process was 150 mL of a fixed quantity, the value of pH was configured as $5.5{\sim}6.0$, the temperature was controlled as a range of $12{\sim}16^{\circ}C$, the dissolved amount of ozone was applied more than 5.0 mg/L, the reaction time was determined as an optimal condition, such as $30{\sim}40$ minutes, and the segregation membrane in the same reactor was determined for acquire water drinking of large quantity using a pore size of $0.45{\mu}m$ M/F membrane.

• Journal of Environmental Science International
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• v.10 no.1
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• pp.13-19
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• 2001

An on-line digestion system based on the flow injection analysis technique was presented for the determination of total phosphorus. The system converts condensed and organic phosphoruses into orthophosphate that can be analyzed spectrophotometically. The reaction between orthophosphate and ammonium molybdate in a strong acid medium forms the yellow complex of phosphomolybdate which is next reduced to a molybdic blue complex by stannous chloride. The quantitation of orthophosphate is based on the absorbance of the molybdic blue. To determine total phosphorus, the digestion system was installed between the sample injector and the reaction coil with the added lines of digestion solution(potassium persulfate+sulfuric acid) and the $H_2O$ carrier. The system has shown that the digestion efficiencies were greater than 95% for the typical condensed and organic phosphoruses. When tripolyphosphate standards were used, the calibration data showed that the linear dynamic range extended to a concentration of 1.5ppm with the detection limit of 25ppb total phosphorus. The typical relative standard deviation was less than 2%. The proposed system was successfully applied to lake water, wastewater, and streamwater. The analytical variables such as digestion efficiency, analysis time, and reproducibility were evaluated and compared with the manual digestion method.

• Journal of Environmental Health Sciences
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• v.21 no.3
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• pp.102-106
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• 1995

This study was performed to examine factors affecting the decompostion of nondegradable polluants(trichloroethylene(TCE), phenol) using ultrasonic irradiation. The TCE and phenol, which are major hazard compounds causing environmental pollution, were not decomposable pollutants by conventional treatment. The results show that the oxidation and reduction reaction of ultrasound produced $H_2O_2$, $H^+$ and $OH^-$ radical, which decomposed pollutants of TCE and phenol in water. It was confirmed that the ultrasonic irradiation showed an excellent removal efficiency for the nondegradable pollutants than any other processes, utilized in the treatment of organic compounds in the industrial wastewater. Conclusively, these results suggest that ultrasonic irradiation may be highly useful for the treatment of wastewaters contaminated organic pollutants, which is difficult to treat economically by conventional process.