• Journal of Korean Society of Environmental Engineers
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• v.30 no.6
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• pp.616-620
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• 2008

The aim of this study was to investigate the influence of phosphate on the adhesion of Escherichia coli to porous media. Column experiments were performed to examine the effect of phosphate on bacterial adhesion to quartz sand and iron-coated sand. Results showed that bacterial mass recovery in quartz sand decreased from 74.5 to 35.4% as phosphate concentration increased from 0 to 16 mg/L. This indicated that bacterial adhesion to quartz sand was enhanced with increasing phosphate concentration. This phenomenon is due to the increase of ionic strength. In contrast, the mass recovery in the coated sand increased from 2.9 to 26.0% as phosphate concentration increased. This indicated that bacterial adhesion to the coated sand was reduced with increasing phosphate concentration, due to the preoccupation of favorable adsorption sites and competitive adsorption by phosphate.

• Journal of the Korean Chemical Society
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• v.25 no.3
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• pp.160-165
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• 1981

Radical copolymerization of the complexed 2-vinylpyridine with vinyl acetate and divinylbenzene initiated by azobisisobutyronitrile was carried out in N, N-dimethylformamide in presence of barium chloride at $98{\circ}C$. In the preparation of 2-vinylpyridine-vinylacetate-divinylbenzene terpolymer, the optimum reaction conditions were studied by means of various temperatures and times. 2-vinylpyridine-vinylalcohol-divinybenzene resin was prepared by transesterificating 2-vinylpyridine-vinylacetate-divinylbenzene terpolymer with a 1% methanolic sodium hydroxide solution. 2-Vinylpyridine-vinylphosphate-divinyldenzene was prepared by phosphorylating 2-vinylpyridine-vinylalcohol-divinylbenzene resin with phosphoric acid and urea. The compositions of each synthetic resin were identified by means of infrared absorption spectroscopy. The ion exchange capacities of each 2-vinylpyridine-vinylalcohol-divinylbenzene and 2-vinylpyridine-vinylphosphate-divinylbenzene terpolymer was 3.69 meq/g and 5.38 meq/g.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.680-688
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• 1998

The macroreticular (MR) type glycidylmethacrylate (GMA)-divinylbenzene (DVB) copolymer (polyglycidylmethacrylate) beads (RG) were prepared by a suspension polymerization using 0~100 vol % of 2,2,4-trimethylpentane (TMP) as a diluent. Macroreticular type cation exchange resins containing phosphoric acid groups (RGP) were prepared by the reaction of GMA-DVB copolymer and poly (glycidyl methacrylate) bead (RG) with phosphoric acid in the presence of benzene. In this study, the effect of degree of crosslinking and the amount of the diluent on physical properties and adsorbability of uranium of RGP resins were investigated respectively. The chemical and physical properties of RGP resins were affected by both of the amount of the diluent and the degree of crosslinking. The effect of degree of crosslinking on the adsorbed amount of uranium for RGP resins were decreased in the order of $$RGP-10(50){\sim_=}RGP-1(50)>RGP-2(50)>RGP-5(50)>RGP-0$$. The effect of the diluent amount were as follows RGP-2(100)>RGP-2(75)>RGP-2(50)>RGP-2(30)>RGP-2(0). The crosslinking degree effect on uranium adsorbability depended on pore structure, cation exchange capability and swelling ratio. On the other hand, the effect of the diluent amount were relied on surface area and pore structure raher than cation exchange capability.

• Korean Chemical Engineering Research
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• v.52 no.4
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• pp.481-485
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• 2014

The applicability of the dipping, ultrasonic-assisted, heating methods to the extraction of useful components from Zostera marina was investigated. For the increase of the extraction yield of caffeic acid and rosmarinic acid from Zostera marina, ionic liquids and DES were used as additives in the extraction solvent. The optimum extraction conditions were found: dipping extraction, methanol as extraction solvent, 0.005 g of freeze-dried material powder, 5 mL methanol, 30 min and 0.5 g of DES-3 ($Et_4NCl$ and phenol) as additive. As a result, 0.19 mg/g of caffeic acid and 8.48 mg/g of rosmarinic acid were obtained. This method is simple and sensitive, and has been applied successfully to determine the component of caffeic acid and rosmarinic acid in Zostera marina and these results indicate that DES were used as additives is more suitable than traditional extraction for the extraction of useful components from Zostera marina.

• Journal of Acupuncture Research
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• v.19 no.5
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• pp.10-27
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• 2002

연구목적 : 면역억제와 활성 작용을 지닌 것으로 알려진 녹용약침(CPH)을 type II collagen 유발 관절염 (CIA) 백서와 인산이온 유발 연골세포의 세포사에 있어 보호활성 효과를 연구하였다. 연구방법 : 7주된 암컷 Sprague-Dawley 쥐를 collagen으로 관절염을 유발시킨 후 CPH의 효과를 관절염 점수, 체중감소 등의 평가기준으로 검정하였다. CPH는 일주일에 5번씩 각각 10, 20, 30 및 $100{\mu}g/kg/day$의 용량으로 양측 신수혈에 주입하였다. 연구결과 : 1. 300 mg/kg/day CPH처리로 관절염점수의 감소를 기초로 한 collagen 유발 관절염의 발생을 완전히 억제하였으며 관절염 점수상에서 CPH의 효과작인 용량은 64 mg/kg이었다. 2. CHP는 쥐의 간에 있는 DHO-DHase 활성을 $Ki=843{\pm}43{\mu}g/ml$의 비교적 높은 비활성으로 억제하였다. 3. 관절염관련 세포의 증식억제활성을 검정한 결과 CPH의 항 증식효과는 세포주기 S기에서 정지시키는 활성을 나타내었다. 4. 쥐의 늑연골로부터 완전히 최종 분화된 비대연골세포를 분리 배양하여 3~5mM/L Pi를 첨가함으로서 세포사멸을 측정하였다. $10{\mu}g/ml$ CPH 처리에 의한 보호(억제) 효과가 Pi-유발 연골세포의 세포사에 대한 Na-Pi cotransport의 경쟁적 저해제로 알려진 phosphonoformic acid(PFA)의 억제활성과 상응하는 수준으로 CPH의 활성을 확인하게 되었다.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.4
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• pp.361-368
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• 2021

The objective of this study was to establish technology for removing bacteria with human- and eco-friendly material. Staphylococcus aureus as an important component for balanced equilibrium among microbiomes, was cultured under various concentrations of phosphate. Experimental observation relating to physical properties was performed in an addition of phosphate buffer. Statistically minimum value of size and hardness using atomic force microscope was observed on the matured biofilm at 5 mM concentration of phosphate. As a result of absorbance for the biofilm tagged with dye, concentration of biofilm was reduced with phophate, too. To identify whether this reduction by phosphate at the 5 mM is caused by counter ion or not, sodium chloride was treated to the biofilm under the same condition. To elucidate components of the biofilm counting analysis of the biofilm using time-of-flight secondary ion mass spectrometry was employed. The secondary ions from the biofilm revealed that alteration of physical properties is consistent to the change of extracellular polymeric substrate (EPS) for the biofilm. Viscoelastic characterization of the biofilm using a controlled shear stress rheometer, where internal change of physical properties could be detected, exhibited a static viscosity and a reduction of elastic modulus at the 5 mM concentration of phosphate. Accordingly, bacteria at the 5 mM concentration of phosphate are attributed to removing the EPS through a reduction of elastic modulus for bacteria. We suggest that the reduction of concentration of biofilm induces dispersion which assists to easily spread its dormitory. In conclusion, it is elucidated that an addition of phosphate causes removal of EPS, and that causes a function of antibiotic.

• Clean Technology
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• v.15 no.4
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• pp.253-257
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• 2009

The waste solution discharged form the LCD(Liquid Crystal Display) manufacturing process contains phosphoric acid, nitric acid, acetic acid and metal ions such Al and other impurities. In this study, vacuum evaporation and diffusion dialysis was developed to commercialize an efficient system for recovering the high-purity phosphoric acid and manufacturing monoammonium phosphate. By vacuum evaporation, almost 99% of nitric and acetic acid was removed. Also, by diffusion dialysis, about 97.5% of Al was removed. Monoammonium phosphate was manufactured from purified phosphoric acid and ammonium hydroxide. In order to get the optimum manufacturing condition, the molar ratio of ammonium hydroxide and phosphoric acid, pH and temperature was controlled. Using this optimum condition, we obtained the recovery rate of monoammonium phosphate of about 90%.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.3
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• pp.159-164
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• 1991

A field microplot(D 20cm, L 85cm) experiment filled with Bonryang sandy loam soil (Typic Udifluvents) was conducted to obtain quantitative information on the movement of applied nutrients under diffetent soil moisture regimes and ladino clover cultivation. Chloride moved rapidly with soil water. When soil moisture tension was maintained at loer than 0.2 bar most of the Cl appeared to move outside the microplot 4 month after the microplot installation. Regardless of soil moisture condition, Cl was not detected in the soil due to the fast movement of the Cl beyond the microplot after 5.5 months Although large amount of P and water were applied to the soil of high available P during the field experiment, movement of P was negligible and most of P remained in thc place where applied due to the low solubility of the fused and superphosphate. Phosphate in the soil extracted by Bray No.1 solution and taken up by plant increased with soil moisture. Under the condition of irrigation at 0.2 bar, plant took up 23% of the applied P, and 24% of the P was extracted by Bray NO.1 solution, while plant took up 14% and 13% of the P was turned out to be Bray No.1 P. at thc nonirrigated condition after final harvest.

• Journal of the Korean Electrochemical Society
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• v.15 no.4
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• pp.207-215
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• 2012

Soft carbons are prepared by heat-treatment of cokes with different amounts of phosphoric acid (2, 4.5, and 10 wt% vs. cokes) at $900^{\circ}C$ to be used as anode materials for lithium ion batteries. From electrochemical measurements combined with structural analyses, we confirm that abundant nano-pores are existed in the microstructure of soft carbons prepared with the phosphoric acid, which are responsible for further lithium ion storage. Significant increase in reversible capacity of soft carbon is attained in proportion to added amount of the phosphoric acid. We also demonstrate the effect of structural modification with phosphoric acid on electrochemical performance of soft carbon to elucidate the origin of additional capacity.

• Applied Biological Chemistry
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• v.47 no.3
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• pp.344-350
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• 2004

This study was conducted to develop and assess the applicability of mixed-bed ion exchange resin capsules for water quality monitoring in small agricultural watershed. Recoveries of resin capsules for inorganic N and P ranged from 96 to 102%. The net activation energies and pseudo-thermodynamic parameters, such as ${\Delta}G^{o\ddag},\;{\Delta}H^{o\ddag},\;and\;{\Delta}S^{o\ddag}$ for ion adsorption by resin capsules, exhibited relatively low values, indicating the process might be governed by chemical reactions such as diffusion. However, those values increased with temperature coinciding with the theory. The reaction reached pseudo-equilibrium within 24 hours for $NH_4-N\;and\;NO_3-N$, and only 8 hours for $PO_4-P$, respectively. The selectivity of resin capsules were in the order of $NO_3\;^-\;>\;NH_4\;^+\;>\;PO_4\;^{3-}$, coinciding with that of encapsulated Amberlite IRN-150 resin. At the initial state of equilibrium, the resin adsorption quantity was linearly proportional to the mass of ions in the streams, but the rate of movement leveled off, following Langmuir-type sorption isotherm. The overall results demonstrated that the resin capsule system was suitable for water quality monitoring in small agricultural watershed, judging from the reaction mechanism(s) of the resin capsule and the significance of model in field calibration.