• Membrane Journal
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• v.20 no.3
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• pp.210-216
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• 2010

The hydrogen permselective membrane were prepared by chemical vapor deposition (CVD) aiming at the applications to hydrogen iodide decomposition in the thermochemical IS process, and it was evaluated for the possibility as a separation membrane. An electron probe X-ray microanalyzer (EPMA) and SEM picture were used to analyze the morphology and structure of the prepared membranes. It was confirmed that Zr-Si-O layer exist in the surface of the prepared membrane using zirconia coated support. Single-component permeance to $H_2$ and $N_2$ were measured at $300{\sim}600^{\circ}C$. Hydrogen permeance through the Z-1 membrane at a permeation temperature of $600^{\circ}C$ was about $1{\times}10^{-7}\;mol{\cdot}Pa^{-1}{\cdot}m^{-2}{\cdot}s^{-1}$. The selectivities of $H_2/N_2$ at $600^{\circ}C$ were 5.0 and 5.75 for Z-1 and Z-2 membrane, respectively.

• Applied Biological Chemistry
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• v.25 no.3
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• pp.177-181
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• 1982

This experiment was carried out to investigate the stability of Dicofol solutions which were prepared with various organic solvents such as xylene, toluene, methylisobutyl ketone (M.I.B.K.), cyclohexanone, N.N.-dimetyl formamide (N.N.-D.M.F.) and isophorone under different temperature and storage period. The decomposition rate of Dicofol was increased in the order of cyclohexanone> N.N.-D.M.F.>W.P.>toluene, xylene, M.I.B.K. and isophorone. However, it was shown that precipitation was found in Dicofol solutions such as xylene, toluene and M.I..B.K. except isophorone. Therefore, isophorone was recognized as the best of organic solvents tested for Dicofol in the case of emulsifiable concentrate formulation with it.

• Applied Chemistry for Engineering
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• v.8 no.6
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• pp.1000-1005
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• 1997

The properties of ceramics by solid-state reaction with hydroxyapatite[$Ca_{10}(PO_4)_6(OH)_2$], which was isolated from tuna bone by wet milling process were investigated. The bulk density $2.93g/cm^3$ at $1350^{\circ}C$ was close to the calculated density $3.21g/cm^3$. On X-ray measurements, the major phases were identified as hydroxyapatite at below $1300^{\circ}C$, but the whitlockite [$Ca_3(PO_4)_2$] phases were appeared due to a decomposition of hydroxyapatite with temperature. The microstructures of sintering specimens were shown as small closed pores between grain boundaries. The mean bending strength of the sintered hydroxyapatite by solid-state reaction is about 58 MPa and this value is higher than that of the articular cartilage maximum strength, 40MPa.

• Applied Chemistry for Engineering
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• v.23 no.1
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• pp.77-85
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• 2012

Production process of the flexible ceramic foamed body through the complexation with the fiberous sepiolite and expanded pearlite was researched. The processing of fibrillation of the inorganic mineral fiber sepiolite is the most important whole processing for manufacturing of the ceramic foamed body consisting of the expanded perlite and sepiolite. The fibrous sepiolite and expanded pearlite are blended and becomes the slurry phase. And this slurry phase is converted to a massive foamed body through the low temperature heat treatment process less than $300^{\circ}C$. The heat-treatment process of the slurry phase composite has to be designed to include the evaporation step of the moisture remaining among the slurry composition, foaming step by the decomposition of the foaming agent, and resolution removal step of the organic material which was added in the composite remained after the foaming step. The heat treatment process should be considered as significant factors in design of total process. As to the condition of heat treatment process and foaming agent, there was the a correlation. An organic type foaming agent like DSS (dioctyl sodium sulfosuccinte) was effective in foaming of the slurry compound consisting of the expanded perlite and sepiolite fiber.

• Journal of Animal Environmental Science
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• v.15 no.1
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• pp.59-68
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• 2009

This study investigated the evaluation of maturity, stability, nutrient and heavy metal from rotating drum composter of food waste amended with poultry manure composting inoculated with effective microorganisms(EM). Composting were performed for the first, drying reactor($15m^3$) 3 hours and the second, composting reactor($30m^3$) 24 hours, and parameters monitored this period included moisture content, NaCl, pH, electrical conductivity(EC), C/N ratio, organic matter(OM), nutrient content and heavy metal. Changes in compost temperature during composting were maintained constantly in the range of $60{\sim}80^{\circ}C$ using firewood boiler(450 MJ/h). We examined physicochemical parameters and heavy metals in order to assess their effectiveness as stability and maturity, nutrient and harmful indicators such as seed germination rate<60%, potassium 1>%, dm and NaCl>1%, dm at the end of the final compost. The finished compost obtained after decomposition phase at the end of the 2nd composter could not be utilized for land improvement or reclamation.

• Korean Journal of Food Science and Technology
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• v.15 no.4
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• pp.404-408
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• 1983

Some properties of malic enzyme (EC 1.1.1.40) prepared from malate-decomposition yeast, Schizosac-charomyces japonicus var. japonicus St-3 were investigated. The activity of malic enzyme was maximum when it was cultured for 24 hours. The optimum conditions for the enzyme reaction were pH 10.0 and temperature of $25^{\circ}C$. The crude enzyme was very stable at the range of pH 7.0-8.4, and almost 50 percent of enzyme activity was lost by heating at $60^{\circ}C$ for 10 minutes. The malic enzyme activity was enhanced by the addition of $Mn^{++}$. But the enzyme activity was not affected by the addition of organic acids, amino acids and ethanol, respectively.

• Analytical Science and Technology
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• v.13 no.6
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• pp.759-765
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• 2000

A study on the separation of Zr metal from $LiF-BeF_2-ZrF_4$ (67-27-6 mol%) molten salt was carried out using electrowinning. The decomposition potentials of the $LiF-BeF_2$ (72-28 mol%) and the $LiF-BeF_2-ZrF_4$ (67-27-6 mol%) molten salts were measured to be -1.55 and -1.35 volt, respectively. The Zr separation voltage from the salt were found to be in a range of -1.4 -1.5 volt. As increasing applied current, the deposition of molten salt on a cathode increases but the current efficiency decreases. In addition, the deposition and current efficiency decreases with increasing temperature.

• Analytical Science and Technology
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• v.23 no.6
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• pp.560-565
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• 2010

Perchlorate ion ($ClO_4^-$) has been widely used as oxidizing agent in military weapon system such as rocket and missile fuel propellant. So it has been challenging to remove the pollutant of perchlorate ion. nanoscale zero valence iron (nZVI) particles are widely employing reduction catalyst for decomposition of perchlorate ion. nZVI particles has increasingly been utilized in groundwater purification and waste water treatment. But it have strong tendency of aggregation, rapid sedimentation and limited mobility. In this study, we focused on reduction of perchlorate ion using nZVI particles immobilized in alginate polymer bead for stabilization. The stabilized nZVI particles displayed much greater surface area, and much faster reaction rates of reduction of perchlorate ion. In this study, an efficient way to immobilize nZVI particles in a support material, alginate bead, was developed by using $Ca^{2+}$ as the cross-linking cations. The efficiency and reusability of the immobilized Fe-alginate beads on the reduction of perchlorate was tested at various temperature conditions.

• Applied Chemistry for Engineering
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• v.16 no.4
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• pp.496-501
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• 2005

The thermal degradation of ABS in the presence of iron-based metal catalysts has been studied by thermogravimetric analysis (TGA). The reaction of iron-based metal catalysts (ferric nitrate nonahydrate, ammonium ferric sulfate dodecahydrate, iron sulfate hydrate, ammonium ferric oxalate, iron(II) acetate, iron(II) acetylacetonate and ferric chloride) with ABS has been found to occur during the thermal degradation of ABS. In a nitrogen atmosphere, char formation was observed, and at $600^{\circ}C$ approximately 3~23 wt% of the reaction product was non-volatile char. The resulting enhancement of char formation in a nitrogen atmosphere has been primarily due to the catalytic crosslinking effect of iron-based metal catalysts. On the other hand, char formation of ABS in air at high temperature by iron-based metal catalyst was unsuccessful due to the oxidative degradation of the char.

• Applied Chemistry for Engineering
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• v.1 no.1
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• pp.73-82
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• 1990

Rosin-maleic anhydride adduct (RMA) was synthesized from rosin and maleic anhydride. The polyamideimides were obtained by reacting the adduct with two aromatic diisocyanates using sodium methoxide as catalyst. The yield and the inherent viscosity of polymers obtained by the reaction in NMP solvent were low because of the possible reaction of NMP solvent with diisocyanate monomer. The polymers were synthesized in solvent mixture of NMP and cosolvents such as xylene, acetophenone, benzonitrile, and nitrobenzene in order to minimize the side reaction of NMP with diisocyanates. The yield of polymer obtained by the reaction in NMP-nonpolar cosolvent mixtures was about 70% and that obtained by the reaction in NMP-polar cosolvent mixtures was over 90%, respectively. The polymers were either amorphous or poorly cystalline, and soluble only in highly polar solvents. The inherent viscosity of polymers ranges from 0.12-0.26dl/g. The results of thermal analysis showed that the polymer had good thermal stability with initial decomposition temperature over $330^{\circ}C$.