• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.3
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• pp.265-265
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• 1998

The phase behavior of chlorinated hydrocarbon/mixed surfactants/water microemulsion systems were investigated for dry cleaning solvent properties. With appropriate surfactant mixtures, Winsor type I-III-II microemulsions were generated which is the same as hydrocarbon systems. For perchloroethylene(PCE) with mixed Tween systems, the optimum salinity(S*) decreases and the optimum solubilization parameter(o*) increases with decreas- ing HLB. For PCE with mixed Aerosol MA and ethoxylated alcohol systems, S* and o* both increase with increasing ethylene oxide moles. For dichlorobenzene(DCB) with mixed Aerosol MA and ethoxylated or propoxylated sulfate systems, S* and o* both increase with increasing ethylene oxide moles or propylene oxide moles.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.3
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• pp.365-373
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• 1998

The phase behavior of chlorinated hydrocarbon/mixed surfactants/water microemulsion systems were investigated for dry cleaning solvent properties. With appropriate surfactant mixtures, Winsor type I-III-II microemulsions were generated which is the same as hydrocarbon systems. For perchloroethylene(PCE) with mixed Tween systems, the optimum salinity(S*) decreases and the optimum solubilization parameter(o*) increases with decreas- ing HLB. For PCE with mixed Aerosol MA and ethoxylated alcohol systems, S* and o* both increase with increasing ethylene oxide moles. For dichlorobenzene(DCB) with mixed Aerosol MA and ethoxylated or propoxylated sulfate systems, S* and o* both increase with increasing ethylene oxide moles or propylene oxide moles.

• Polymer(Korea)
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• v.36 no.1
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• pp.1-8
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• 2012

In this study, we employed hydroxypropyl-${\beta}$-cyclodextrin (HP-${\beta}$-CD) as an excipient to produce poly(lactic-$co$-glycolic acid) (PLGA) fine particles by a supercritical fluid process, called aerosol solvent extraction system (ASES), and investigated the effect of HP-${\beta}$-CD content on the morphology of the particles. The influence of HP-${\beta}$-CD on the drug release characteristics of paclitaxel-loaded PLGA particles was also evaluated. Fine particles were obtained when the HP-${\beta}$-CD content in PLGA/HP-${\beta}$-CD mixtures was greater than 40% and 30%, respectively, for PLGA(75:25) and PLGA(50:50), whereas a film-like precipitate was obtained for lower HP-${\beta}$-CD content. The release rate for paclitaxel loaded PLGA(75:25)/HP-${\beta}$-CD particles was found to increase with HP-${\beta}$-CD content.

• Particle and aerosol research
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• v.11 no.4
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• pp.107-113
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• 2015

SBA-16 (Santa Barbara Amorphous) was synthesized over supported $TiCl_4/MgCl_2$. Due to its high surface area and excellent morphological performance, it was expected to form the bi-supported catalytic system and be used for ethylene polymerization. Polymerization of ethylene was carried out at atmospheric pressure using hexane as solvent and triethylaluminium as cocatalyst. ICP, FTIR, DSC, TG-DTA were used to characterize polyethylene and catalyst product. Optimum conditions for ethylene polymerization were found to be 100 mL hexane, Al/Ti molar ratio of 160 and 1 h polymerization at $60^{\circ}C$. The activity of 396.76 kg PE/mol Ti.h.atm was achieved. Melting point of the obtained polymer was in the range of $132-135^{\circ}C$ and the highest degree of crystallization was 46%.

• Particle and aerosol research
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• v.7 no.1
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• pp.31-44
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• 2011

The hourly volatile organic compounds(VOCs) concentrations between 2005 and 2008 at Bulgwang photochemical assessment monitoring station were investigated to establish a method for quality assurance and quality control(QA/QC) procedure. Systematic error, erratic error, and random error, which was manifested by outlier and highly fluctuated data, were checked and removed. About 17.3% of the raw data were excluded according to the proposed QA/QC procedure. After QA/QC, relative standard deviation for representing 15 species concentrations decreased from 94.7-548.0% to 63.4-125.8%, implying the QA/QC procedure is proper. For further evaluation about the adequacy of QA/QC procedure, principal components analysis(PCA) was carried out. When the data after QA/QC procedure was used for PCA, the extracted principal components were different from the result from the raw data and could logically explain the major emission sources(gasoline vapor, vehicle exhaust, and solvent usage). The QA/QC procedure based on the concept of errors is inferred to proper to be applied on VOCs. However, an additional QA/QC step considering the relationship between species in the atmosphere needs to be further considered.

• Journal of Powder Materials
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• v.20 no.2
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• pp.129-133
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• 2013

In this paper we have studied the effect of water droplet size on nano-particle size distribution using SMPS(Scanning Mobility Particle Sizer)system. It can be seen that the unknown peak at >100 nm was caused by water droplets which did not dry completely when DI water was used as a solvent in the SMPS system. Therefore, it is important to dry water droplets generated from atomizer in the SMPS system when measuring the particle size distribution using less than 100 nm nano-particles in diameter. From this study, It can be concluded that the napion was a useful material as dryer ones and using EAG(Electro Aerosol Generator) as a particle generator was the most effective in reducing the effect of water droplets.

• KSBB Journal
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• v.6 no.1
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• pp.105-109
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• 1991

In separating alkaline protease from the bacteria (Bacillus licheniformis) fermentation broth using reverse micelle, effects of various factors;ionic strength, pH and surfactant concentration, on separation efficiency were studied. KCl controls the ionic strength. The lower KCl concentration was in the feed solution, the more protein and activity was recovered. The higher KCl concentration was in the stripping solution, the more protein and activity was recovered. Using sodium-di-2-ethylhexyl sulfosuccinate(Aerosol-OT or AOT) as a surfactant, the higher AOT concentration in the solvent, the more activity and protein were recovered. 0.1N NaOH and IN HCl were used to adjust pH. Maximum recovery of protein mass and activity were obtained at feed solution of pH 5.3. Maximum activity was recovered at stripping solution of pH 7.5

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.4
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• pp.412-417
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• 2022

Capacitive-type humidity sensors with a high sensitivity and fast response/recovery times have attracted a great attention in non-contact respiration biological signal monitoring applications. However, complicated fabrication processes involving high-temperature heat treatment for the hygroscopic film is essential in the conventional ceramic-based humidity sensors. In this study, a non-toxic ceramic/metal halide (BaTiO₃(BT)/NaCl) humidity sensor was prepared at room temperature using a solvent-free aerosol deposition process (AD) without any additional process. Currently prepared BT/NaCl humidity sensor shows an excellent sensitivity (245 pF/RH%) and superior response/recovery times (3s/4s) due to the NaCl ionization effect resulting in an immense interfacial polarization. Furthermore, the non-contact respiration signal variation using the BT/NaCl sensor was determined to be over 700% by maintaining the distance of 20 cm between the individual and the sensor. Through the AD-fabricated sensor in this study, we expect to develop a non-contact biological signal monitoring system that can be applied to various fields such as respiratory disease detection and management, infant respiratory signal observation, and touchless skin moisture sensing button.

• KSBB Journal
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• v.21 no.2
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• pp.157-163
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• 2006

A supercritical fluid process, called aerosol solvent extraction system(ASES), is especially suitable to the pharmaceutical, cosmetic and food industries due to its environmentally-friendly, non-toxic and residual solvent-free properties. In particular, the application of the ASES process to the processing of thermo-labile bioactive compounds has received attention of many scientists and engineers because of its low-temperature operating conditions. Unstable substances such as Vitamin-C and Vitamin-A can be effectively protected from degradation during the preparation process, because the ASES process is free from oxygen and moisture. In this study, Vitamin-C was formulated with 2-hydroxypropyl-${\beta}$-cyclodextrin (HP-${\beta$-CD) for enhancement of Vitamin-C stability and bioavailability using the ASES process. To investigate the influence of the preparation process on the stability of Vitamin-C, Vitamin-C/HP-${\beta}$-CD inclusion complexes were prepared using both conventional solvent evaporation method and ASES process, and stored in a 50 mM phosphate buffer solution of pH 7.0 at $25^{\circ}C$ for 24 hours. From the experimental results, the stability of the Vitamin-C/HP-${\beta}$-CD inclusion complex prepared from the ASES process was found to be much higher than that of pure Vitamin-C and the Vitamin-C/HP-${\beta}$-CD inclusion complex prepared by the solvent evaporation method. The stability of Vitamin-C was observed to increase with the decrease of temperature at a constant pressure or with the increase of pressure at a constant temperature.

• Journal of Pharmaceutical Investigation
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• v.39 no.3
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• pp.167-171
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• 2009

Poly(lactic-co-glycolic acid) (PLGA) microspheres have been a useful tool as a controlled drug delivery system for peptides and proteins. Recently, porous microspheres have gained great attention as inhalation drug delivery system due to their low aerodynamic densities. Here, we report highly porous PLGA microspheres, which were prepared by using a single o/w emulsification/solvent evaporation method. Two types of porogen, i.e., (i) extractable Pluronic F127 and (ii) gas foaming salt of ammonium bicarbonate, were used to induce pores on the surface of PLGA microspheres. The respective preparation conditions on dp/cp ratio and porogen concentration were determined by the previous preliminary experiments, and other preparation factors were further optimized on the basis of PLGA Mw and porogen type. The morphological features examined by scanning electron microscope (SEM) show these porous microspheres have highly porous surface structure with a diameter range of 20${\sim}$30 ${\mu}$m. These highly porous PLGA microspheres, which have much lower density, would be a practical aerosol system for pulmonary drug delivery.