• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.293-294
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• 2010

In this study, it was analyzed that autogenous expansion of MgO concrete was affected by W/B and curing temperature. Autogenous expansion test was performed for MgO concrete, which is mixed MgO of 0%, 5% of cement weight. With autogenous expansion based on long-term time variation was measured, it was observed an influence with W/B and curing temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.237-238
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• 2008

The films of Vanadium tungsten oxide, $V_{1.85}W_{0.15}O_5$, were grown on Pt/Ti/$SiO_2$/Si substrate by RF sputtering method. The $V_{1.85}W_{0.15}O_5$ thin films deposited on Pt/Ti/$SiO_2$/Si substrates by RF sputtering method exhibited fairly good TCR and dielectric properties. It was found that film crystallinity, dielectric properties, and TCR properties were strongly dependent upon the annealing temperature. The dielectric constants of the $V_{1.85}W_{0.15}O_5$ thin films annealed at $300^{\circ}C$ were 55, with a dielectric loss of 1.435, respectively. Also, the TCR values of the $V_{1.85}W_{0.15}O_5$ thin films annealed at $300^{\circ}C$ were about -3.6%/K.

• Archives of Metallurgy and Materials
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• v.67 no.4
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• pp.1507-1510
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• 2022

An optimum route to synthesis the W-based composite powders with homogeneous dispersion of oxide nanoparticles was investigated. The La₂O₃ dispersed W powder was synthesized by ultrasonic spray pyrolysis using ammonium metatungstate hydrate and lanthanum nitrate. The dispersion of Y₂O₃ nanoparticles in W- La₂O₃ powder was carried out by a polymer addition solution method using yttrium nitrate. XPS and TEM analyses for the composite powder showed that the nano-sized La₂O₃ and Y₂O₃ particles were well distributed in W powder. This study suggests that the combination processing of ultrasonic spray pyrolysis and polymeric additive solution is a promising way to synthesis W-based composite powders.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2001.11a
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• pp.16-16
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• 2001

• Journal of the Korean Ceramic Society
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• v.23 no.3
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• pp.53-61
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• 1986

A gas sensor which has been made by wet process had fabricated by coating each of the mixture on alumina tube and firing at 85$0^{\circ}C$ for 3hrs. A gas concentration such $H_2$, CO, $C_3H_8$, $C_2H_2$ and $CH_4$ vs its detection voltage characteristics has been in-vestigated on $SnO_2-In_2O_3-MgO$ system doped with PdO, $La_2O_3$, $ThO_2$, NiO and $Nb_2O_5$ The optimum sensitivity composition for various gases were 90w/o $SnO_2$-9w/o $In_2O_3$-1w/o MgO for $H_2$, $C_2H_2$ CO and $C_3H_8$ and 95w/o $SnO_2$-4w/o $In_2O_3$-1w/o MgO for $CH_4$. The sample which has been made by wet process than dry process had predominated sensitivity for each gases and particle size of the sample coprecipitated with PH=9 was 0.1${\mu}{\textrm}{m}$ The $SnO_2$-In2_O_3-MgO$ system doped with 2w/o $Nb_2O_5$ and NiO was the most sensitive for $H_2$ and $C_2H_2$ gas. In $SnO_2$-In2_O_3-MgO$ system doped with $ThO_2$ the sensitivity of $H_2$ gas was decreased but CO gas was in-creased when dopant con was increased.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.29 no.1
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• pp.135-150
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• 2003

This study is described the stabilizing technology of water-in-oil (w/o) emulsion and the mechanism of emulsification with quaternium-18 hectorite (Q-18 HTRT) by swelling action. When Q-18 HTRT is dispersed in oil, it swells and constructs card-house structure adding ethanol, and formation of water phase is caused by hydrogen bonding. The gelling activities of Q-18 HTRT were excellent such as mineral oil, squalane, cetostearyl isononanoate, isostearic acid, cetyl octanoate, octyl dodecanol and so on. Especially, when oil gel containing Q-18 HTRT passed one to three times by Roll mill. It made the W/O emulsion cream (W/O-ECRM) having 2.0 w/w% of Q-18 HTRT and also produced the control sample (control) including 3.0 w/w% of cetyl PEG/PPG- l0/l dimethicone. The stability of after 24 weeks, Hardness of W/O-ECRM dropped 7.48%, whereas hardness of control went down 57 71%. As a result of these test emulsification of W/O-ECRM is superior compared with control. In cosmetic, 0-18 HTRT can use as suspending agent, oil adsorbent, emulsifying agent, dispersing agent, viscosifier and pigment.

• Journal of Pharmaceutical Investigation
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• v.28 no.3
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• pp.159-164
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• 1998

The O/W and W/O emulsions containing Scutellariae Radix extract(SRE) which is very slightly soluble in oil phases and sparingly soluble in water phases, were prepared by homogenizing water and oil phases with emulsifier. The diameters of emulsion were ranged from 100 to $300\;{\mu}m$. The viscosity of W/O emulsion was higher than that of O/W emulsion. W/O emulsion was more stable than O/W emulsion which was gradually degraded when tested by centrifuge method and temperature tolerance method at $50^{\circ}C$. The antibacterial activity of two emulsions was not significantly different from that of aqueous solution of SRE, and showed similar MIC and bacterial growth inhibition rate.

• Journal of the Korean Applied Science and Technology
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• v.27 no.3
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• pp.370-377
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• 2010

This study evaluated SPF (Sun Protection Factor) of various quntity and kind of sunscreen ingredients which is used in O/W and W/O emulsion by systematic and quantitative approach. Octylmethoxycinnamate(OMC), Buthylmethoxydibenzoylmethan (BMDM), Octocrylene (OC), Octylsalicylate(OS), Octyl Triazone (OT), Titanium dioxide (TD) are used for the experiment. As a result, when different chemical sunscreen ingredients are added to OMC, the synergy effect of SPF was high in order of BMDM, OC, OS, OT. There was no significant difference in O/W and W/O emulsions. It can be a guide to use sunscreen ingredients effectively when the relation between the results of in vitro SPF and in vivo SPF is comprehended.

• The Korean Journal of Food And Nutrition
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• v.37 no.1
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• pp.48-56
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• 2024

Effects of glutamic acid (Glu) and monosodium glutamate (MSG) on oxidative stability of oil-in-water (O/W) emulsions with different emulsifier charges during riboflavin (RF) photosensitization were evaluated by analyzing headspace oxygen content and conjugated dienes. Cetyltrimethylammonium bromide (CTAB), Tween 20, and sodium dodecyl sulfate (SDS) were used as cationic, neutral, and anionic emulsifiers, respectively. Glu acted as an antioxidant in CTAB- and Tween-20-stabilized O/W emulsions during RF sensitization, whereas Glu acted as prooxidants in SDS-stabilized O/W emulsions in the dark. However, adding MSG did not have a constant impact on the degree of oxidation in O/W emulsions irrespective of the emulsifier charge. In RF-photosensitized O/W emulsions, the emulsifier charge had a greater influence on antioxidant properties of Glu than on those of MSG.

• Bulletin of the Korean Chemical Society
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• v.18 no.10
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• pp.1090-1093
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• 1997

The solvent effects on the isotropic NMR shifts in conformationally rigid ligands such as quinuclidine, pyridine, and 4-aminopyridine coordinated to the paramagnetic polyoxometalate, [SiW11CoⅡO39]6- (SiW11Co), are reported. For these complexes the ligand exchange is slow on the NMR time scale and pure 1H NMR signals have been observed at room temperature. The signals for the SiW11Co complexes are shifted upfield whe dimethyl sulfoxide-d6 (DMSO) is added to a D2O solution. The isotropic shifts are separated into contact and pseudocontact contributions by assuming that the contact shifts are proportional to the isotropic shifts of the same ligands coordinated to [SiW11NiⅡO39]6-. It is shown that both the contact and pseudocontact shifts decrease (the absolute values of the pseudocontact shifts increase), when D2O is replaced by DMSO. It is suggested that D2O, a strong hydrogen bond donor, withdraws electron density from [SiW11CoⅡO39]6-, increasing the acidity of the cobalt ion toward the axial ligand. When D2O is replaced by DMSO, the acidity of the cobalt ion in SiW11Co decreases, weakening the Co-N bond. Then both the contact and pseudocontact shifts are expected to decrease in agreement with the observed solvent effects.