• Journal of the Korean Ceramic Society
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• v.38 no.12
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• pp.1097-1103
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• 2001

TiO$_2$anchored on a porous clay ceramic support (PCS) for use in lightweight photocatalyst were synthesized by the dropping precipitant method. A PCS of macro and micro pore size of around several mm~${\mu}{\textrm}{m}$ in diameter were prepared by the rapid heat treatment at, 1,15$0^{\circ}C$ for 10 min from low grade of clay. The change in pH of reaction solution due to the different addition rate of NH$_4$HCO$_3$as a precipitant, the reaction temperature and the concentration of TiCl$_4$had a pronounced effect on the nature of precipitated TiO$_2$particles on the surface of a PCS and the crystal structure of precipitated TiO$_2$particles. At an addition rate of 0.8 ml/min of NH$_4$HCO$_3$and pH=6 of reaction solution, homogeneous precipitation of TiO$_2$particles on a PCS was achieved. TiO$_2$particles with anatase phase was precipitated on the surface of a PCS at the low concentration of TiCl$_4$, the high addition rate of NH$_4$HCO$_3$and the high reaction temperature.

• Korean Journal of Chemical Engineering
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• v.35 no.11
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• pp.2256-2268
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• 2018

Hydrophilic and hydrophobic polyethersulfone (PES)-zinc oxide (ZnO) sublayers were prepared by loading of ZnO nanoparticles into PES matrix. Both porosity and hydrophilicity of the hydrophilic sublayer were increased upon addition of hydrophilic ZnO, while these were decreased for the hydrophobic sublayer. In addition, the results demonstrated that the hydrophilic membrane exhibited smaller structural parameter (S value or S parameter or S), which is beneficial for improving pure water permeability and decreasing mass transfer resistance. In contrast, a higher S parameter was obtained for the hydrophobic membrane. With a 2 M NaCl as DS and DI water as FS, the pure water flux of hydrophilic TFN0.5 membrane was increased from $21.02L/m^2h$ to $30.06L/m^2h$ and decreased for hydrophobic TFN0.5 membrane to $14.98L/m^2h$, while the salt flux of hydrophilic membrane increased from $10.12g/m^2h$ to $17.31g/m^2h$ and decreased for hydrophobic TFN0.5 membrane to $3.12g/m^2h$. The increment in pure water permeability can be ascribed to reduction in S parameter, which resulted in reduced internal concentration polarization (ICP). The current study provides a feasible and low cost procedure to decrease the ICP in FO processes.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.831-838
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• 2009

In order to evaluate a removal characteristic of diclofenac, ibuprofen and naproxen by oxidizing agents, $Cl_2,\;O_3$ and $O_3/H_2O_2$ are used as oxidants in this study. In case of that $Cl_2$ is used for oxidizing pharmaceuticals, ibuprofen is not removed entirely at $Cl_2$ dose range of 0.5~5.0 mg/L for 60 minutes, however, removal tendency of diclofenac and naproxen are so obviously at $Cl_2$ dose higher than 0.5 mg/L. In addition, as $Cl_2$ dose and contact time are increased, the removal rate of diclofenac and naproxen is enhanced. When $O_3$ is used as oxidizing agent, ibuprofen is not eliminated at $O_3$ dose range of 0.2~5.0 mg/L. On the contrary, 72~100% of diclofenac and 49~100% of naproxen are removed at $O_3$ dose of 0.2~5.0 mg/L. From experiments using $O_3/H_2O_2$ as an oxidant, we can find that $O_3/H_2O_2$ is much more effective than $O_3$ only for removal of diclofenac and naproxen. Moreover, the efficiency is raised according to increase of $H_2O_2$ dose, however, experiments using $O_3/H_2O_2$ show that oxidation of pharmaceuticals is less effective as $H_2O_2$ to $O_3$ ratio increased to above approximately 1.0. On reaction rate constant and half-life of diclofenac, ibuprofen and naproxen depending on $Cl_2$, $O_3$ and $O_3/H_2O_2$ dose, an oxidation of pharmaceuticals by $Cl_2$ and $O_3$ particularly has a comparatively high reaction rate constant and short half-life comparing $O_3/H_2O_2$. From above results, we can fine that diclofenac and naproxen can be easily eliminated in oxidation processes.

• Journal of Food Hygiene and Safety
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• v.32 no.4
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• pp.336-340
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• 2017

The present study evaluated the antibacterial effect of Flos syzygii Aromatici methanolic extracts (FSAE). In addition, the effectiveness of FSAE against Escherichia coli O157:H7 infection was studied using ICR female mice. At 24 h after incubation of E. coli O157:H7, FSAE at the concentration of 0.269 (p < 0.05), 0.538 (p < 0.001) and 1.075 mg/mL (p < 0.001) significantly inhibited the growth of E. coli O157:H7 compared to the control group. After single challenge with E. coli O157:H7, forty female ICR mice were divided into four experimental groups which were orally administered with saline (control), 0.538 (group 1), 1.075 (group 2) and 2.15 mg/mL (group 3) of FSAE, respectively. On the 3rd day, the number of fecal E. coli O157:H7 in group 2 (p < 0.05) and group 3 (p < 0.01) was significantly decreased compared to that in the control group. On the 7th day post-treatment, the number of fecal E. coli O157:H7 in all FSAE-treated groups was significantly decreased compared to that in the control group (group 1, p < 0.05; group 2 and 3, p < 0.001). According to the results of the present study, administration of FSAE to mice can reduce the severity of E. coli O157:H7 infection. Therefore, the current study suggests that FSAE could be a good candidate for the treatment of enteric infections in domestic animals.

• Journal of the Korean Ceramic Society
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• v.36 no.12
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• pp.1390-1395
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• 1999

Zr(Y,Ce)O2 TZP ceramics were prepared by sintering compacts of 3 mol% Y2O3-TZP(3Y-TZP) powders with different amount of 12 mol% CeO2-TZP(12Ce-TZP) in air at 140$0^{\circ}C$ for 2 h. The phase changes microstructure and mechanical properties of Zr(Y. Ce)O2 TZP after hydrothermal aging(20$0^{\circ}C$ 5h) were investigated. Although an addition of 12Ce-TZP accelerated the grain growth of Zr(Y, Ce)O2 TZP it restrained the transformation of tetragonal to the monoclinic phase during aging. The degradation in mechanical properties of sintered bodies was governed by the formed monoclinic phase and chemical composition. Induced Vickers indentation crack was propagated intergranually. From SEM observation of the fracture surfaces the pull-out of individual grain was confirmed.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.965-970
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• 2009

Oleuropein content of olive leaf extracts (OLE; ethanol extract) was evaluated by high performance liquid chromatography analysis. Oleuropein contents were $4.21{\pm}0.57$, $3.92{\pm}0.43$, $0.32{\pm}0.03$, $5.76{\pm}0.32$, and $32.47{\pm}0.25$ mg/100 g for ethanol extract, and hexane, chloroform, ethyl acetate, and butanol fraction, respectively. The removal of DPPH free radical increased in OLE and all 5 fractions of OLE in a concentration dependent manner. In order to investigate the antioxidant effect of OLE in vitro, 80%(v/v) ethanol OLE, $H_2O_2$, or combined treatment of 80%(v/v) ethanol OLE and $H_2O_2$ were applied on mouse embryonic fibroblast (MEF) cells. Cells were damaged by oxidative stress decreased their viability followed by increasing concentration of $H_2O_2$, but co-treatment of OLE and $H_2O_2$ showed an increase in cell growth about 20% compare to the cells treated with $H_2O_2$. OLE suppresses cytotoxicity induced by $H_2O_2$ in dose dependent manner. OLE treatment on MEF cells was also examined by analyzing cell cycle and apoptotic rate using flow cytometry. Apoptotic and necrotic cell accumulation was decreased in addition of OLE to $H_2O_2$ compare to the oxidative damaged cells. Taken together, these results demonstrated that OLE suppresses cytotoxicity induced by $H_2O_2$ and protect cells against oxidative stress on MEF cells.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.7
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• pp.4095-4099
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• 2013

Oxidative stress induces apoptosis in many cellular systems including glioblastoma cells, with caspase-8 activation was regarded as a major contribution to $H_2O_2$-induced cell death. This study focused on the role of the autophagic protein p62 in $H_2O_2$-induced apoptosis in U87MG cells. Oxidative stress was applied with $H_2O_2$, and cell apoptosis and viability were measured with use of caspase inhibitors or autophagic mediators or siRNA p62, GFP-p62 and GFP-p62-UBA (del) transfection. We found that $H_2O_2$-induced U87MG cell death was correlated with caspase-8. To understand the role of p62 in MG132-induced cell death, the levels of p62/SQSTM1 or autophagy in U87MG cells were modulated with biochemical or genetic methods. The results showed that the over-expression of wild type p62/SQSTM1 significantly reduced $H_2O_2$ induced cell death, but knockdown of p62 aggravated the process. In addition, inhibition of autophagy promoted p62 and active caspase-8 increasing $H_2O_2$-induced apoptosis while induction of autophagy manifested the opposite effect. We further demonstrated that the function of p62/SQSTM1 required its C-terminus UBA domain to attenuate $H_2O_2$ cytotoxity by inhibition of caspase-8 activity. Our results indicated that p62/SQSTM1 was a potential contributor to mediate caspase-8 activation by autophagy in oxidative stress process.

• Journal of the Korean Ceramic Society
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• v.55 no.5
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• pp.480-491
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• 2018

Calcium phosphates (CaP) were prepared by a wet chemical method. Micro-crystalline dicalcium phosphate (DCPD) was precipitated at $37^{\circ}C$ and pH 5.0 using $Ca(OH)_2$ and $H_3PO_4$. The precipitated DCPD solution was kept at $37^{\circ}C$ for 96 h. Artificial bone cement was composed of DCPD, $Ca(H_2PO_4)_2{\cdot}H_2O$ (MCPM), and $CaSO_4{\cdot}1/2H_2O$, $H_2O$ and aqueous poly-phosphoric acid solution. The wet prepared CaP powder was used as a matrix for the bone cement recipe. With the addition of aqueous poly-phosphoric acid, the cement hardening reaction was started and the CaP bone cement blocks were fabricated for the mechanical strength measurement. For the tested blocks, the mechanical strength was measured using a universal testing machine, and the microstructure phase analysis was done by field emission scanning electron microscopy and X-ray diffraction. The cement hardening reaction occurred through the decomposition and recrystallization of MCPM and $CaSO_4{\cdot}1/2H_2O$ added on the surface of the wet prepared CaP, and this resulted in grain growth in the bone cement block.

• Journal of the Korean Chemical Society
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• v.55 no.4
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• pp.570-574
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• 2011

Large colorless single crystals of analcime with diameters up to 0.20 mm have been synthesized from gels with the composition of $3.00SiO_2$ : $1.50NaAlO_2$ : 8.02NaOH : $454H_2O$ : 5.00TEA. The fully $Na^+$-exchanged analcime have been prepared with aqueous 0.1 M NaCl (pH adjusted from 6 to 11 by dropwise addition of NaOH). The single-crystal structure of hydrated $|Na_{0.94}(H_2O)|[Si_{2.06}Al_{0.94}O_6]$-ANA per unit cell, a=13.703(3) ${\AA}$, has been determined by single-crystal X-ray diffraction technique in the orthorhombic space group Ibca at 294 K. The structure was refined using all intenties to the final error indices (using only the 1,446 reflections for which $F_o$ > $4{\sigma}(F_o))R_1/wR_2$ = 0.054/0.143. About 15 $Na^+$ ions are located at three nonequivalent positions and octahedrally coordinated. The chemical composition is $Na_{0.94}(H_2O)Si_{2.06}Al_{0.94}O_6$. The Si/Al ratio of synthetic analcime is 2.19 determined by the occupations of cations, 14.79, in the single-crystal determination work.

• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.400-406
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• 1999

In an effort to obtain high efficiency in gas fired absorption chillers, a new working fluid has been developed with thc addition of the component of $LiNO_3$, LiCl and LiI to the conventional solution of $LiBr-H_2O$. The solubility and vapor pressure of the 4 component working fluid developed in this work were measured and compared to the results of $LiBr-H_2O$ solution. It was observed that there exists an optimal mole ratio of the inorganic salts in terms of solubility. The mole ratio of LiBr, $LiNO_3$ and LiCl was found to be around 5:1:1~2 in the $LiBr-LiNO_3-LiCl-H_2O$ mixture, and in the case of $LiBr-LiO_3-Lil-H_2O$ and $LiBr-Lil-LiCl-H_2O$ mixtures, the mole ratio of LiBr, $LiNO_3$ and Lil/ LiBr, LiI and LiCl were found to be around 5:1:1 and 5:1:0.5~1 respectively. The vapor pressure of the 4 component working fluid of the optimal mole ratio was increascd with adding the component of $LiNO_3$, LiCl and LiI except for $LiBr-LiNO_3-LiCl-H_2O$ mixture. The absorption capacity of $LiBr-LiNO_3-LiCl-H_2O$ mixture was obtained higher than that of $LiBr-H_2O$ mixture.