• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.499-502
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• 2002

We synthesized Y$\sub$1.8/Ba$\sub$2.4/Cu$\sub$3.4/O$\sub$x/(Y123+Y211+1wt% CeO$_2$) powders using Polymeric Complex method and used raw materials; Y$_2$O$_3$, BaCO$_3$, CuO and CeO$_2$. It was formed by calcination at 850 $^{\circ}C$ for 24h in air. In comparison of solid-state method, sol-gel method etc., synthesis temperature decreased up to 100$^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.32 no.2
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• pp.197-208
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• 1995

${\gamma}$-LiAlO2 fibers for fiber reinforced molten carbonate fuel cell (MCFC) matrix have been produced from LiAlO2 complex polymeric sols using the sol-gel process. The stable and spinnable LiAlO2 sols could be synthesized by mixing LiNO3 alcohol solutions in aluminum complex polymeric sols prepared through the condensationpolymerization reaction of 1 more of aluminum tri-sec-butoxide with 0.55 mole of mixed chelates (mole ratio of acetylaceton/triethanolamine=0.25/0.3). It was found that the viscosity range for fiber-spinning should be higher than 30 poise. The defect-free flexible ${\gamma}$-LiAlO2 fibers with the average tensile strength of 350 MPa could be obtained when the spinned fibers were heat-treated to 120$0^{\circ}C$ on the specified heating schedule after dried at room temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.482-485
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• 2002

We synthesize a (Y,Sm)BCO(its composition is (Y/Sm123+0.4Y/Sm211)+1wt%CeO$_2$) powders using polymeric complex method. (Y,Sm)BCO powders are prepared as heated at 970$^{\circ}C$. For measurement of this characterization, We measure XRD and SEM. We use TSMG method for fabricatlon of (Y,Sm)BCO single crystal. The manufactured VBCO single crystal is measured by a magnetic distribution device using 0.5 Tesla magnet. As the result of this measurement, we find that a trapped magnet fields are 550 Gauss.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.05a
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• pp.224-233
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• 2002

A common YBCO powder has been made from a mixture of Y123 and Y211 that heated at different temperatures, respectively. The synthesis temperature of Y211 is lower than Y123. If Y211 has been heated as a synthesis temperature of Y123, a particle size of it may be very coarse. It exist as one of main defects for superconductor. But We simultaneously synthesize a YBCO(its composition is (Y123+0.4Y211)+$lwt%CeO_2$) using polymeric complex method. In the YBCO, the Y123 is synthesized lower temperature than other methodes, and its crystal structure is orthorombic. For measurement of these superconducting properties, we fabricated a YBCO single crystal. The manufactured YBCO single crystal is measured a magnetic distribution device using 0.5Tesla magnet and trapped magnet fields in it are 0.2Tesla.

• Journal of the Korean Society of Safety
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• v.8 no.1
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• pp.29-34
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• 1993

Two major hazardous gases. SOx and NOx. are emissioned from fossile fuels. SOx has been removed when oil is refined but NOx hasn't. So NOx is very serious problem in air pollution now There are several technologies to remove NOx. e.g. cooling method. scrubbers method. combustion method, polymer membrane method and adsorbent methods. Polymer membrane and adsorbent methods have good economic merit in removal systems of low content hazard gases. Traditional absorbents are porous silicas, aluminas. active carbon and zeolites. But these absorbents act only physisorption which has less removal performance than chemisorption. In this study. polymeric absorbent which has chemisorption as well as physisorption was analyzed about chemical structure and experimented about optimum operation conditions. The results showed that the chemical structure of the polymeric absorbent was expected as polystyrene having -N-CH$_2$COOH absorbent was revealed about 310$m^2$/g. The molar ratio of absored NO to charged NO in absorption experiments was shown 60% of the polymeric absorbent and 45% of zeolite absorbent at 3$0^{\circ}C$.

• Journal of Powder Materials
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• v.25 no.2
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• pp.151-157
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• 2018

In this study, the compound $Li_3BO_3$ (LBO) is intended to be prepared by a polymeric complex method as a sintering aid for the densification of $Li_7La_3Zr_2O_{12}$ (LLZ) solid electrolyte. A polymeric precursor containing Li and B is heat-treated in an air atmosphere at a temperature range between $600^{\circ}C$ and $800^{\circ}C$. Instead of LBO, the compound $Li_{2+x}C_{1-x}B_xO_3$ (LCBO) is unexpectedly synthesized after a heat-treatment of $700^{\circ}C$. The effect of LCBO addition on sintering behavior and ion conductivity of LLZ is studied. It is found that the LCBO compound could lead to significant improvements in the densification and ionic conductivity of LLZ compared to pure LLZ. After sintering at $1100^{\circ}C$, the density of the LLZ-12wt%LBO composite is $3.72g/cm^3$, with a high Li-ion conductivity of $1.18{\times}10^{-4}Scm^{-1}$ at $28^{\circ}C$, while the pure LLZ specimen had a densify of $2.98g/cm^3$ and Li-ion conductivity of $5.98{\times}10^{-6}Scm^{-1}$.

• YAKHAK HOEJI
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• v.39 no.1
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• pp.48-54
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• 1995

Coupling of tetracycline(Tc) to dithiocarbamate chitosan(DTCC) via chelate bond was investigated varying reaction time, concentration, temperature, pH, and Ca(II)/Tc ratio. The amount of Tc bound to matrix increased to give a maximum and decreased as the reaction proceeded. The degree and rate of dissociation of Tc complex were affected by the reaction temperature, and pH. By running the reaction at low temperature and pH, the degree of dissociation was greatly diminished. Properties of drug-release from DTCC-Ca(II)-Tc complex were studied by batch- and flow-method and release of Tc and CA(II) by flow method followed nearly zero-order. DTCC-Ca(II)-Tc showed very prolonged antimicrobial activity compared to that of free Tc.

• Journal of the Korean Ceramic Society
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• v.31 no.11
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• pp.1271-1282
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• 1994

The surface of commercial alumina fibers used for reinforcing the MCFC matrix has been coated with ${\gamma}$-LiAlO2 being the same material as the matrix, by the sol-gel method in order to enhance the corrosion resistivity of alumina fibers. Stable LiAlO2 complex polymeric sols for coating was synthesized by mixing aluminum alkoxide polymeric sols with LiNO3 solution. It was found that the LiAlO2 polymeric sol prepared by adding the mixed chelate of acethylacetone and triethanolamine (the mole ratio of AA/TEA = 0.125/0.75) to the 1 mole of the aluminum alkoxide had the excellent stability and coating behavior. The crystalline structure of the dried gel from the ${\gamma}$-LiAlO2 sol was completely transformed into the ${\gamma}$-LiAlO2 at $600^{\circ}C$. The optimum viscosity of the sol for coating the alumina long fibers was 30~40 cP, while it was 12~20 cP in case of the short fiber coating. The ${\gamma}$-LiAlO2 coated alumina fibers without defects fully densified when heat-treated at 120$0^{\circ}C$.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.172-172
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• 2006

Molecular imprinting constitutes a valuable method of preparing polymeric materials with specific binding properties. The most conspicuous merit of molecular imprinting is that structurally three-dimensional recognition sites can be introduced into a polymer matrix with ease and low cost when compared with the complicated process of biological system for antigen and antibody. We used a thermally reversible bond for the preparation of the monomer-template complex, which allowed us to remove the template easily by means of a simple thermal reaction and to simultaneously introduce various functional groups into the cavity. This method is especially propitious for developing artificial receptors for molecules lacking strongly interactive groups.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.12 no.5
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• pp.229-233
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• 2002

Nano-sized ZnO particles were successfully synthesized at low temperatures by a polymerized complex method via an organochemical route. The polymeric precursors could be prepared using Zn nitrate hexahydrate and a mixed solution of citric acid and ethylene glycol as a chelating agent and a reaction medium. The polymeric precursors were calcined at temperatures from 300 to $700^{\circ}C$ for 3 h, and evaluated for degree of crystallization process, thermal decomposition, surface morphology and crystallite size. The thermal decomposition and crystallization process were analyzed by TG-DTA, FI-IR and XRD. The morphology and crystallite size of the calcined particles were evaluated by scanning electron microscopy (SEM), transmittance electron microscopy (TEM) and Scherrer's equation. Crystallization of the ZnO particles was detected at $300^{\circ}C$ and entirely completed above $400^{\circ}C$. Particles calcined between 400 and $700^{\circ}C$ showed a uniform size distribution with a round shape. The average particle sizes calcined at $400^{\circ}C$ for 3 hour were 30~40nm showing an ordinary tendency to increase with the temperatures.