• Membrane Journal
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• v.19 no.2
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• pp.145-149
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• 2009

The aim of this paper is to investigate removal of salts in hydrolyzed sericin solution by a prepared nanofiltration membrane. The nanofiltration membrane was prepared by the interfacial polymerization method, and then compared with commercialized nanofiltration membrane in terms of salts removal. The sericin solution was hydrolyzed by a protease. The molecular weight distribution of the hydrolyzed sericin was determined by electrophoresis method. Relative flux measurements were carried out to investigate membrane fouling.

• Current Photovoltaic Research
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• v.7 no.2
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• pp.33-37
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• 2019

In this paper, we compared the performance of $Cu(In,Ga)(S,Se)_2$ (CIGSSe) thin film solar cell with CdS buffer layer deposited by irradiating 365 nm UV light with 8 W power in Chemcial Bath Deposition (CBD) process. The effects of UV light irradiation on the thin film deposition mechanism during CBD-CdS thin film deposition were investigated through chemical and electro-optical studies. If the UV light is irradiated during the solution process, the hydrolysis of Thiourea is promoted even during the same time, thereby inhibiting the formation of the intermediate products developed in the reaction pathway and decreasing the pH of the solution. As a result, it is suggested that the efficiency of the CdS/CIGSSe solar cell is increased because the ratio of the S element in the CdS thin film increases and the proportion of the O element decreases. This is a very simple and effective approach to control the S/O ratio of the CdS thin film by the CBD process without artificially controlling the process temperature, solution pH or concentration.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.183-186
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• 1998

This paper deals with 28, 56, 91 days age compressive strength and ratio of weight when OPC and Low-Heat cement mortar immersed in chemical solution. As a result of experiment, the resistance of Low-Heat Cement motar in chemical attack is more effective than that of OPC, because of lower $C_3$A content and Pozzolanic reactions. Especially in long term age compressive strength, Low-Heat cement mortar shows higher strength in all kind of chemical solution compared with compressive strength of OPC motar.

• Journal of the Korean Chemical Society
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• v.15 no.5
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• pp.223-228
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• 1971

In the electrolytic preparation of persulphate from sulphate solution, the current efficiency decrease with temperature increase at the platinum anode. But in case of electrodeposited lead peroxide anode, the current efficiency increase with temperature of the solution. The reason seems to be that the ozone formation is faster in platinum anode than in lead peroxide as temperature increase.

• Korean Journal of Materials Research
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• v.16 no.2
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• pp.123-128
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• 2006

[ $BaMgAl_{10}O_{19}:Mn^{2+}$ ](BAM:Mn) phosphor particles with spherical shape were prepared by spray pyrolysis from colloidal solution with silica. The phosphor particles prepared by spray pyrolysis from aqueous solution had irregular morphology after high temperature post-treatment. On the other hand, the phosphor particles prepared from spray solution with colloidal silica had spherical shape after post-treatment. Colloidal silica used as additive improved the spherical shape and filled morphology of the precursor particles prepared by spray pyrolysis. The precursor particles with filled structure produced the BAM:Mn phosphor particles with spherical shape and non-aggregation characteristics after post-treatment at $1400^{\circ}C$ under reducing atmosphere. The phosphor particles prepared from colloidal solutions formed the crystal structure of BAM:Mn phosphor irrespective of the silica contents. The BAM:Mn phosphor particles prepared from aqueous and colloidal solutions had similar photoluminescence intensities under vacuum ultraviolet.

• Proceedings of the Membrane Society of Korea Conference
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• 2003.07a
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• pp.107-114
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• 2003

This study investigated the effect of 2-methoxy ethanol (2-Me) non-solvent as additive included in casting solution. Macroporous polymer membranes were prepared by using polyethersufone (PES)/N-methyl-2-pyrrolidone (NMP)/2-Me casting solution and water coagulant. The phase separation co-process of the vapor-induced phase separation (VIPS) and liquid-induced phase separation (LIPS) were used by means of membrane preparation method. The pore size and pore size distribution were controlled with additive (non-solvent), and measured with Automated Perm Porometer. By increasing additive (non-solvent) in the casting solution, the membranes produced changed from finger structure to sponge structure. That is due to the different diffusion rates. At slow diffusion process, sponge-like structure was formed and at fast diffusion process, finger-like structure was formed. Also relative humidity, evaporation time, temperature of casting solution and coagulation bath etc. had effects on the pore size distribution and the porosity of the membrane.

• Journal of Pharmaceutical Investigation
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• v.34 no.4
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• pp.305-310
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• 2004

This study was to prepare the anionic liposomes which were to release anticancer drug (doxorubicin) at the hyperthermia temperature $({\sim}42^{\circ}C)$ and to stabilize in bovine serum solution at $37^{\circ}C$. The vesicle size and zeta potential of liposomes in Tris-HCl buffered solution (pH 7.4) were measured by an electrophoretic light scattering spectrophotometer. To estimate the stability of liposomes, liposome size was measured in bovine serum solution at $37^{\circ}C$ for 72 h. The release of doxorubicin from liposome was determined by measuring the fluorescence intensity using fluorescence spectrophotometry with temperature and time. The size of liposomes was from 120 to 160 nm and zeta potential was from $-33.3{\pm}2.4$ to $-75.6{\pm}6.9\;mV$. Anionic liposome was stabilized in bovine serum solution at $37^{\circ}C$ within 72 h. Additionally, the release transition temperature of doxorubicin from liposomes was increased by increasing mole % of anionic phospholipid.

• Journal of the Korean Applied Science and Technology
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• v.25 no.2
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• pp.232-239
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• 2008

Separation of naphthalene from naphthalene and 2-methylnaphthalene mixture has been studied by layered melt and solution crystallization using ethylalcohol. Purity and yield of naphthalene depended mainly on the cooling rate: The effective distribution coefficient ($K_{eff}$) as the degree of impurity removal was observed to decrease with the decreasing in cooling rate. Purity of naphthalene can be enhanced to $5{\sim}7%$ by melt crystallization using 90% naphthalene and the purity of naphthalene can be obtained to be 99% up by solution crystallization.

• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.157-162
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• 2009

In this paper, the density, viscosity and solubility are measured to know the physical properties of dye. By changing the concentration of dye solution, the density change of the dye solution was very small and the viscosity of the dye solution was increased. Also, by changing the temperature of dye solution, the density change of the dye solution was increased but the viscosity of the dye solution was decreased. Solubility of dye conducts under the changing the salt and concentration of dye. In 20 wt% of dye and 15 wt% KCl, the amount of dye crystal is maximal. Also, batch salting-out experiments were performed with various conditions to know the optimal operating conditions of dye crystal. Under the various experiments, optimal operating condition was found based on amount of dye; added 15 wt% KCl, $25^{\circ}C$ temperature, 100 RPM, added at once.

• Korean Chemical Engineering Research
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• v.46 no.6
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• pp.1052-1056
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• 2008

Crystal mean size and shape change of calcium carbonate crystal was investigated by the temperature change and addition of PAA solution in the soda process. At low temperature($30^{\circ}C$, $60^{\circ}C$), calcite particles were made by. But at high temperature($80^{\circ}C$), aragonite particles were made by. At $30^{\circ}C$ and $80^{\circ}C$, Crystal shape were not changed by adding PAA solution. At moderate temperature($60^{\circ}C$), aragonite was obtained by adding PAA aqueous solution. Crystal shape was changed by adding PAA molecules. The higher concentration of PAA solution is, the more aragonite particles were observed. Incase of calcite and aragonite, mean size of calcium carbonate crystals were increased by higher molecule weight and higher concentration of PAA solution. But in the shape change region, the molecule weight of PAA was the main parameter of increasing mean crystal size.