• Proceedings of the Korean Vacuum Society Conference
• /
• 2007.08a
• /
• pp.311-311
• /
• 2007

• Applied Microscopy
• /
• v.44 no.3
• /
• pp.105-109
• /
• 2014

The microstructure of as-quenched $Al_{70}Cu_{18}Mg_{12}$ alloy has been investigated in detail using transmission electron microscopy. Al nano-crystals about 5 nm with a high density are distributed in the amorphous matrix, indicating amorphous matrix nano-composite can be synthesized in Al-Cu-Mg alloy. The high density of Al nano-crystals indicates very high nucleation rate and sluggish growth rate during crystallization possibly due to limited diffusion rate of solute atoms of Cu and Mg during solute partitioning. The result of hardness measurement shows that the mechanical properties can be improved by designing a nano-composite structure where nanometer scale crystals are embedded in the amorphous matrix.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09b
• /
• pp.1211-1212
• /
• 2006

The electrophoretic deposition process of Ni nano-particles was employed for self-repairing of heat exchanger tubes. For electrophoretic deposition of Ni nano-particles on pitted Ni alloy specimen, a constant electric field of 100 V $cm^{-1}$ was applied to the specimen for 180 s in Ni-dispersed solution. It was found that as electrophoretic deposition proceeded, the size of the pit remarkably decreased due to the agglomeration of Ni nano-particles at the pit. This strongly suggests that the electrophoretic mobility of the charged particles is larger for the pit with a higher current value rather than outer surfaces with a lower current value.

• Journal of Dairy Science and Biotechnology
• /
• v.36 no.4
• /
• pp.187-195
• /
• 2018

Nano-delivery systems, such as nanoparticles, nanoemulsions, and nanoliposomes, are carriers that have been used to enhance the chemical as well as physical stability and bioavailability of bioactive compound. Food-grade nano-delivery system can be produced with edible biopolymers including proteins and carbohydrates. In addition to the low-toxicity, biocompatibility, and biodegradability of these biopolymers, their functional characteristics, such as their ability to bind hydrophobic bioactive compounds and form a gel, make them potential and ideal candidates for the fortification of bioactive compounds in functional dairy foods. This review focuses on different types of nano-delivery systems and edible biopolymers as delivery materials. In addition, the applications of food-grade nano-delivery systems to dairy foods are also described.

• Laser Solutions
• /
• v.17 no.2
• /
• pp.19-25
• /
• 2014

Optical embedded diffraction gratings with the bulk modification in BK-7 glass plates excited by tightly focused high-intensity femtosecond (130fs) Ti: sapphire laser (peak wavelength = 790nm) were demonstrated. The structural modifications with diameters ranging from 400nm to $4{\mu}m$ were photo-induced after plasma formation occurred upon irradiation with peak intensities of more than $1{\times}1013W/cm^2$. The graded refractive index profile was fabricated to be a symmetric around from the center of the point at which low-density plasma occurred. The maximum refractive index change was estimated to be $1.5{\times}10^{-2}$. The two optical embedded gratings in BK-7 glass plate were demonstrated with refractive index modification induced by the scanning of low-density plasma formation.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.9
• /
• pp.2542-2546
• /
• 2010

The objective of this paper was to investigate the effect of dextran gel on preparation of nano-liposomes loaded with ginkgolide. During preparation, Sephadex G75, G50 and G25 were added in the aqueous phase respectively. From the experiment, nano-liposomes prepared by dextran gels were found spherical and smooth. The result indicated that aperture of dextran gels were narrower, particle size of nano-liposomes was smaller (207.13 ~ 89.16 nm) and zeta potential was greater (-36.2 ~ -29.5 mV) in more negative. The study also revealed that differences of the entrapment efficiency and drug loading among the three types of nano-liposomes were not significant. In vitro drug release test demonstrated that nano-liposomes had a better controlled release. To conclude, by using dextran gel in the preparation of nano-liposome loaded with ginkgolide, the particle size could be effectively controlled and the drug stability could be improved.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.08a
• /
• pp.121-121
• /
• 2011

Graphene formed by chemical vapor deposition was exposed to the various plasmas of Ar, O2, N2, and H2 to examine its effects on the bonding properties of graphene to metal. Upon the Ar plasma exposure of patterned graphene, the subsequently deposited metal electrodes remained intact, enabling successful fabrication of field effect transistor (FET) arrays. The effects of enhancing adhesion between graphene and metals were more evident from O2 plasmas than Ar, N2, and H2 plasmas, suggesting that chemical reaction of O radicals induces hydrophilic property of graphene more effectively than chemical reaction of H and N radicals and physical bombardment of Ar ions. From the electrical measurements (drain current vs. gate voltage) of field effect transistors before and after Ar plasma exposure, it was confirmed that the plasma treatment is very effective in controlling bonding properties of graphene to metals accurately without requiring buffer layers.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2004.12a
• /
• pp.171-172
• /
• 2004

• Proceedings of the Korean Magnestics Society Conference
• /
• 2004.06a
• /
• pp.3-4
• /
• 2004

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.46 no.3
• /
• pp.394-399
• /
• 2017

To resolve environmental pollution caused by synthetic packaging materials, biodegradable films have been studied as an alternative. In this study, we prepared rockfish skin gelatin (RFG) and nano-clay (Cloisite $Na^+$ and Cloisite 10A) composite films to compare the effects of nano-clay on the physical properties of RFG film. Gelatin was extracted from rockfish skin and used to prepare RFG film with sorbitol as a plasticizer. Tensile strength (TS), water vapor permeability (WVP), and water solubility (WS) of the RFG film were 15.0 MPa, $2.70{\times}10^{-9}g\;m/m^2\;s\;Pa$, and 53.8%, respectively. Addition of nano-clay to the RFG film increased TS and decreased WVP and WS. The X-ray diffraction analysis and scanning electron microscopic results suggest that RFG/nano-clay composite films formed an exfoliated structure. These results indicate that RFG/nano-clay composite films can be applied as biodegradable packaging materials in the food industry.