• Journal of the Korean Applied Science and Technology
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• v.32 no.2
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• pp.339-347
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• 2015

This study is to evaluate moisturizing effect and durability of UV A/B blocking activity with multiple (W/O/W) emulsion system. Most of the sun protective products come to be hot issue having both high SPF and long-lasting activity as using special products when is going out, mountain climbing and sports. Also, many consumers prefer the products which have the excellent waterproofing activity of sun care cosmetics as well as the non-sticky feeling that carried out the study of the sensorial science and texture preference. Therefore, development of the specific formulation using this multiple (W/O/W) emulsion technology, it has O/W type hydro skin feel having soft and moist texture when it is treated on the skin. Finally, this formulation is instantly changed to W/O type feel after adsorbed into the skin. The purpose of this study is to get high SPF lasting effect having high water resistance tactivity with high functional multiple (W/O/W) emulsion cream. We used major ingredients, UV-B absorbers were selected with ethylhexyl methoxycinnamate, isoamyl-p-methoxycinnamate, ethylhexylsalicylate, and octocrylene, UV-A absorbers were selected with butylmethoxydibenzoylmethane, bis-ethylhexyloxyphenol methoxy phenyltriazine. SPF effect of O/W type cream was 34.1. SPF effect of W/O/W type cream was 40.6 (increased about 19%). Water resistance effect after 4 hours, SPF effect of O/W type cream was 3.6 (quickly drop down). SPF effect of W/O/W type cream having 81.0 % waterproofing effect was 32.7 (decreased about SPF 7.9). Moisturizing effect of O/W cream at first was superior comparing multiple emulsion. But after 3 hours quickly was drop-down. Moisturizing effect of multiple emulsion was high comparing O/W type and other sun block creams after 4 hours was constantly maintaining water-content.

• Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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• v.6
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• pp.345-365
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• 2002

In diesem Aufsatz wired versucht, eine Mikrostruktur $f\"{u}r$ ein elektronisehes Detusch-Koreanisehes $W\"{o}rterbueh$ zu entwerfen. Bei gedruekten $W\"{o}rterb\"{u}ehern$ sind die lexikographischen Daten und die $W\"{o}rterbuch­strukturen$ mehr oder weniger standardisiert, dagegen bei elektronischen $W\"{o}rterb\"{u}ehern$ strikt formalisiert. Im Laufe der letzten 50 Jahre sind zwar viele gedruekte, jedoch kaum auf Elektronik basierte zweisprachige $W\"{o}rterb\"{u}cher\;f\"{u}r$ Deutseh-Koreanisch ersehienen. Elektronische $W\"{o}rterb\"{u}cher$ haben mehre Vorteile und sind in diesem Informationszeitalter als Hilfsmittel $f\"{u}r$ den Fremdspraeherwerb unabdingbar. Die Festlegung der logischen Struktur des $W\"{o}rterbuehs\;ist\;f\"{u}r\;die\;W\"{o}rterbucharbeit\;unerl\"{a}{\ss}lich$ und $f\"{u}r$ die Herstellung elektronischer $W\"{o}rterb\"{u}cher$ von Bedeutung, wird jedoch in der koreanischen Praxis oft $vemachl\"{a}{\ss}igt$. Daher weisen die meisten koranischen $W\"{o}rterb\"{u}cher$ keine konsistente Form in der Struktur von $W\"{o}rterbuehdefinitionen$ auf. Aus diesen $Gr\"{u}nden$ schlage ich eine formale logisehe Struktur $f\"{u}r$ ein elektronisches Deutsch-Koreanisches $W\"{o}rterbuch$ vor. $Zun\"{a}chst$ werden grundlegende lexikalische Begriffe $eingef\"{u}hrt,\;anschlie{\ss}end$ wird auf die Analyse der lexikalischen $Eintr\"{a}ge\;f\"{u}r$ ein Deutsch-Koreanisches $W\"{o}rterbuch$ eingegangen. In diesem Beitrag wird keine fertige Miktostruktur $pr\"{a}sentiert$, sondern eine Anregung zur weiteren Diskussion zu einer Mikrostruktur gegeben. Als logisehe Struktur $f\"{u}r$ das elektronische Deutsch-Koreanische $W\"{o}rterbuch$ wird eine glattalphabetische Makrostruktur aufgenommen, die Mikrostruktur als semiintegriert. Die lexikographische Arbeit ist $zeitaufw\"{a}ndig$ und braucht viele $Fachkr\"{a}fte$. Deshalb ist die Festlegung einer konsistenten und objektiven Mikrostruktur eine Voraussetzung der $W\"{o}rterbuchherstellung$. Sie regt auch dazu an, die lexikalischen Informationen im Artikel genauer zu analysieren. Erst dadurch wird ein effektives elektronisches $W\"{o}rterbuch\;m\"{o}glich$, das eine Weiterbenutzung der klassifizierten Informationen $unterst\"{u}tzt$.

• Journal of Pharmaceutical Investigation
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• v.35 no.1
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• pp.33-38
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• 2005

Recently increasing attention has been focused on solid lipid nanoparticles (SLN) as a parenteral drug carrier due to its numerous advantages that can come from both polymeric particle and fat emulsions, together with the possibility of controlled release and increasing drug stability. Lipophilic drugs such as paclitaxel, cyclosporin A, and all-trans retinoic acid have been successfully entrapped in SLN but the incorporation of hydrophilic drugs in SLN is very limited because of their very low affinity to the lipid. Therefore, as a new approach to improve the loading of hydrophilic drugs, a w/o/w emulsion technique has been developed. The primary objective of the current study was to improve the loading efficiency of a model hydrophilic drug, glycine (Log P = -3.44) into SLN. The proposed preparation process is as follows: A heated aqueous phase consisting of 0.1 ml of glycine solution in water (100 mg/ml), and poloxamer 188 (5 mg) were then added to a molten oil phase containing precirol (100 mg) and lecithin (5 mg). This mixture was dispersed by sonicator, leading to a w/o emulsion. A double emulsion (w/o/w) was formed after the addition of 2% poloxamer solution to the above dispersed system. After cooling the double emulsion, solid lipid nanosuspensions were successfully formed. The lipid nanoparticles had the mean particle size of 441.25 nm, and the average zeta potential of -20.98 mV. The drug loading efficiency was measured to be 8.54% and the drug loading amount was measured to be 0.92%. The w/o/w emulsion method showed an increased loading efficiency compared to conventional o/w emulsion method.

• Polymer(Korea)
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• v.38 no.1
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• pp.103-107
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• 2014

Poly(acrylonitrile-butadiene-styrene) (ABS) composite sheets containing titanium dioxide ($TiO_2$), barium sulfate ($BaSO_4$), calcium carbonate ($CaCO_3$) were prepared by using a co-rotating twin screw extruder, and the reflectance and flexural modulus of the composite sheets were measured. The fillers were well dispersed in ABS matrix. The reflectance of composite sheet was increased with increasing $TiO_2$ and $BaSO_4$ content. Sheet having $TiO_2$ 20 wt% composition, with 5~20 wt% $BaSO_4$ resulted in more than 95% of reflectance. The flexural modulus of composite sheet was increased from 1864 MPa for $ABS/TiO_2/BaSO_4$ 85/10/5 (w/w/w) to 3134 MPa for $ABS/TiO_2/BaSO_4$ 55/20/25 (w/w/w).

• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.3
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• pp.237-246
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• 2014

Multiple emulsions, called multiphase emulsions, include water-in-oil-in-water (W/O/W) type and oil-in-water-in-oil (O/W/O) type emulsions. In cosmetic industry, they are used to stabilize active ingredients but the applicability of the multiple emulsions is limited because of low stability and difficulty of manufacturing. In this study, we investigated a two-step emulsification process for a W/O/W type emulsion. We also investigated the change of stability using different emulsifiers and oil polarity. The results suggested that polyglyceryl-10 stearate, as a main emulsifier, played an important role in the stability and the formation of the multiple emulsions.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.2
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• pp.103-110
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• 2009

The objective of this study is to analyze the influences of fatty alcohols and fatty acids on rheological properties of oil in water (O/W) emulsions using viscosity and rheograms. As the chain length of fatty alcohols and fatty acids lengthened, the viscosity of emulsions was increased. The influence of fatty alcohols on viscosity enhancement was stronger than that of fatty acids. Both stearyl alcohol and cetearyl alcohol, which have carbon chain length similar to lipophilic portion of surfactant used in emulsion preparation, had showed the best increase in viscosity of O/W emulsions. O/W emulsions prepared with fatty alcohols and fatty acids were pseudo-plastic fluid and they showed shear thinning behaviour like as the common cosmetic emulsions. O/W emulsions prepared with cetyl alcohol, cetearyl alcohol and stearyl alcohol were thixotropic fluids and thixotropy increased with an increase in the concentration of fatty alcohols and fatty acids. Also O/W emulsions prepared with fatty alcohols were more thixotropic than those prepared with fatty acids. For the sake of viscosity increase related to O/W emulsions stability and spreadability enhancement related to payoff, it is thought that fatty alcohols are more useful than fatty acids in the O/W emulsions as the emulsion stabilizer.

• Journal of the Korean Ceramic Society
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• v.51 no.5
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• pp.392-398
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• 2014

$Al_2O_3$-SiC composites reinforced with SiC whisker ($SiC_w$) were fabricated using three different methods. In the first, $Al_2O_3-SiC_w$ starting materials were used. In the second, $Al_2O_3-SiC_w$-SiC particles ($SiC_p$) were used, which was intended to enhance the mechanical properties by $SiC_p$ reinforcement. In the third method, reaction-sintering was used with mullite-Al-C-$SiC_w$ starting materials. After hot-pressing at $1750^{\circ}C$ and 30 MPa for 1 h, the composites fabricated using $Al_2O_3-SiC_w$ and $Al_2O_3-SiC_w-SiC_p$ showed strong mechanical properties, by which the effects of reinforcement by $SiC_w$ and $SiC_p$ were confirmed. On the other hand, the mechanical properties of the composite fabricated by reaction-sintering were found to be inferior to those of the other $Al_2O_3$-SiC composites owing to its relatively lower density and the presence of ${\gamma}-Al_2O_3$ and ${\gamma}-Al_{2.67}O_4$. The greatest hardness and $K_{1C}$ were 20.37 GPa for the composite fabricated using $Al_2O_3-SiC_w$, and $4.9MPa{\cdot}m^{1/2}$ using $Al_2O_3-SiC_w-SiC_p$, respectively, which were much improved over those from the monolithic $Al_2O_3$.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.262-262
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• 2006

Biodegradable and amphiphilic di-block and tri-block copolymers, prepared with monomethoxy poly ethylene glycol (MPEG) and ${\varepsilon}-caprolactone\;({\varepsilon}-CL)$, were used for the application of W1/O/W2 multi- emulsion capsules. The effects of topology and the ratio of hydrophilic moiety of PCL-based polymers on the encapsulation efficiency of the $W_{1}/O/W_{2}$ multi-emulsion capsules containing Ascorbic Acid-2-Glucoside (AA-2-G) were investigated. The ratio of PEG and PCL was 1:0.5, 1:0.75, 1:1, and 1:1.25. PEG-PCL block copolymers were added to the first step of the preparation of $W_{1}/O$ emulsions. The dispersion stability, the particle size, the morphology of the $W_{1}/O/W_{2}$ multi-emulsion capsules were observed using an on-line turbidity meter, dynamic light scattering (DLS), a confocal microscopy (with FITC) and an optical microscopy. Biodegradable behavior of the PEG-PCL block copolymers and release behavior of AA-2-G were also observed by Gel Permeation Chromatography (GPC) and High Performance Liquid Chromatography (HPLC).

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.985-1001
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• 2018

In this study, we tried the various experiments using the emulsifier, electrolyte, stabilizer and gelling agent in order to improve a stability of low viscosity W/O emulsion. As a result, when we used polyglyceryl-4 diisostearate/polyhydroxystearate/sebacate as a main emulsifier, PEG-30 dipolyhydroxystearate and cetyl PEG/PPG-10/1 dimethicone as a co-emulsifier for stable emulsification system, 0.5 % sodium chloride as an electrolyte, 1 % distearyldimonium chloride as a stabilizer, 0.5 % glyceryl behenate/eicosadioate as an oil gelling agent, emulsion particle is the best. Also, we got the stable and low viscosity W/O emulsion maintained at a constant viscosity at 2,000 cps or less. In addition, we were able to examine the possibility of development of low viscosity fluids type sunscreens with excellent feeling and stability through the application of inorganic sunscreen agents.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.3
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• pp.227-236
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• 2014

In this study, O/W and W/S emulsions were prepared by combining oils having different required hydrophilic lipophilic balance (HLB) values under the diverse conditions of HLB values composed of a hydrophilic surfactant and a lipophilic surfactant and their stability was investigated. Results showed that the higher the viscosity of O/W emulsions was as the lower the HLB value of emulsifier and emulsion particle showed a tendency to be a smaller and compact and stabler in centrifugal filtration. W/S emulsions also showed a similar tendency to be a smaller and compact as HLB values of emulsifier was higher and stabler in centrifugal filtration. However, the viscosity of W/S emulsion tended to get lower in HLB conditions of all emulsifiers as the time passed. This indicated that the emulsions had an unstable feature in long-term stability. In conclusion, the results showed opposite to the known theory that O/W emulsion is proper to be applied by nonionic surfactant with a high HLB value and W/S emulsion to be applied by nonionic surfactant with a low HLB value and provide useful information for the cosmetics research and related areas.