• Journal of the Korean Graphic Arts Communication Society
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• v.26 no.1
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• pp.73-85
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• 2008

We have manufactured a photoresist which has excellent dispersity and good applying property due to 330cps of viscosity for environment-friendly and economical maskless screen plate making. And the photoresist applied on the screen stretched was exposed without mask by beam projector with CRT light source. Then it was developed by air spray with $1.7kgf/cm^2$ of injection pressure. The pencil hardness and solvent resistance of curing photoresist film were worse than those of conventional photoresist film and the maximum resolution of line image formed by maskless screen plate making was 0.5 mm since the exposure system for maskless plate making has weak light intensity and the diffusion of light. But we could obtain maskless screen plate which has sharp edges of line image and confirm a possibility of dry development process by air spray method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.1241-1244
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• 2003

The materials showing high structure dispersity are developed on the natural quartz base and they are obtained by mechano-chemical technology. Depending on the processing conditions and subsequent applications the materials produced by mechano-chemical reaction (MCR) show concurrently magnetic, dielectric and electrical properties. The obtained magnetic-electrical powders classified by aggregate complex of their features as segnetomagnetics, contain a dielectric material as a carrying nucleus, particularly the quartz on that surface one or more layers of different compounds are synthesized having thickness up to $10{\sim}50nm$ and showing magnetic, electrical and other properties.

• Journal of the Korean Ceramic Society
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• v.14 no.2
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• pp.95-103
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• 1977

Characteristics of Ham Pyong clay and clay-organic complexes were investigated by means of geological exploration, chemical analysis, X-ray diffraction, differential thermal analysis, electron microscopy, thermal mechanical analysis, cation exchange capacity and viscosity measurement. The results are as follows; 1) This caly is a transported clay which has black and white colors, and the amounts of deposit are estimated about 1, 600, 000M/T. 2) The major mineral phases identified by X-ray diffraction are kaolinite, sericite and halloysite and the minor phases are quartz and feldspar, these mineral phases can be seperated very easily by the elutriation method. 3) It was supposed that the black colored clay involved a certain clay-organic complexs by the mechanism of intercalation as well as surface absorption. 4) The clay-organic complexes in clay seemed to improve dispersity, to increase the fluidity of clay-water slips, to decrease the firing shrinkage and to promote the thermo-chemical reaction at temperature range up to 50$0^{\circ}C$, but not to effect on the resulted firing color.

• Bulletin of the Korean Chemical Society
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• v.35 no.7
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• pp.2009-2012
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• 2014

An anionic surfactant, sodium dodecylbenzene sulfonate (SDBS), was introduced during the ultrasonication process for exfoliation of graphene. The surfactant plays the roles of exfoliator and stabilizer by binding to the graphene surface. The obtained modified graphene was characterized by Fourier-transform infrared spectroscopy (FT-IR) and solid state $^{13}C$ CP/MAS NMR to analyze the binding between molecules, and by X-ray diffraction (XRD) to characterize the bulk structure. The resulting graphene exhibited good dispersion stability in both water and organic solvents.

• Journal of Communications and Networks
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• v.5 no.3
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• pp.230-239
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• 2003

In this paper, we propose a framework to study how to route packets efficiently in multipath communication networks. Two traffic congestion control techniques, namely, flow assignment and packet scheduling, have been investigated. The flow assignment mechanism defines an optimal splitting of data traffic on multiple disjoint paths. The resequencing delay and the usage of the resequencing buffer can be reduced significantly by properly scheduling the sending order of all packets, say, according to their expected arrival times at the destination. To illustrate our model, and without loss of generality, Gaussian distributed end-to-end path delays are used. Our analytical results show that the techniques are very effective in reducing the average end-to-end path delay, the average packet resequencing delay, and the average resequencing buffer occupancy for various path configurations. These promising results can form a basis for designing future adaptive multipath protocols.

• Textile Coloration and Finishing
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• v.15 no.5
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• pp.327-332
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• 2003

In this study, the polyurethane microcapsules for non-aqueous dyeing containing iron oxide and disperse dyes were prepared by in-situ polymerization method using hexamethylene diisocyanate(HDI) with ethylene glycol(EG). And the size, shape, and particle size distribution of microcapsules prepared were investigated. The size and shape of microcapsule were observed by optical microscope and scanning elecron microscope. The particle size distribution was analyzed by particle size analyzer. The microcapsule size and its distribution were largely effected by the existance of surface active agent in the system. When a surfactant did not exist in the system, the size distribution of microcapsules prepared was much uneven. By adding a surfactant, this phenomenon was disappeared. And the size of microcapsule was also effeced by the hydrophobicity of core material(disperse dye). It was considered due to the difference of dispersity of core materials. And the size of microcapsule prepared was inversely proportional to the stirring speed.

• Journal of Dairy Science and Biotechnology
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• v.36 no.2
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• pp.121-124
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• 2018

Ellagic acid (EA) is a naturally occurring polyphenolic compound in vegetables, nuts, and fruits such as berries. EA has antioxidant, anticancer, anti-allergy, and anti-inflammatory activities. The objectives of this research were to investigate the physicochemical properties of nanoparticles before and after nano-encapsulation of EA in dairy protein and to develop a functional (anti-inflammatory) dairy protein-based beverage containing EA. A particle size analyzer was used to determine the physicochemical and morphological properties. High performance liquid chromatography was used to evaluate the entrapment efficiency of EA. The nanoparticles containing EA were 100 to 200 nm in diameter. The determined poly dispersity index value of 0.3 to 0.4 indicated that the nanoparticles were uniformly distributed with similar size. Zeta-potential values were also similar between the control groups. The entrapment efficiency of EA was nearly 90%. The results indicate the potential for development of nanoparticles containing EA beverage products with anti-inflammatory activity.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.585-587
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• 2002

The materials showing high structure dispersity are developed on the quartz base and they are obtained by mechano-chemical technology. Depending on the processing conditions and subsequent applications the materials produced by mechano-chemical reaction show concurrently magnetic, dielectric and electrical properties. The obtained magnetic-electrical powders classified by aggregate complex of their features as segnetomagnetics, contain a dielectric material as a canγing nucleus, particularly the quartz on that surface one or more layers of different compounds are synthesized having thickness up to 10~50 nm and showing magnetic, electrical and other properties.

• Transactions on Electrical and Electronic Materials
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• v.5 no.1
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• pp.29-33
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• 2004

The materials showing high structure dispersity have been developed on the quartz base by mechano-chemical technology. Depending on the processing conditions and subsequent applications, the materials produced by mechano-chemical reaction (MCR) showed concurrently magnetic, dielectric and electrical properties. The obtained magnetic-electrical powders classified by aggregate complex of their features as segneto-magnetics, contained a dielectric material as a carrying nucleus, particularly the quartz on that surface one or more layers of different compounds was synthesized having thickness up to 10∼50 nm and showing magnetic properties and etc.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.31-32
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• 2007

Oil-based nanofluids are prepared by dispersing spherical and fiber-shaped $Al_2O_3$ and AlN nanoparticles in transformer oil. Two hydrophobic surface modification processes are compared in this investigation. It is obvious that the combination of nanoparticle, surfactant and surface modification process is very important for the dispersity of nanofluids. For ($Al_2O_3$+AIN) particles with 1% volume fraction, the enhancement of thermal conductivity and convective heat transfer coefficient is nearly 11% and 30%, respectively, compared to pure transformer oil. The cooling effect of ($Al_2O_3$+AlN)-oil nanofluids on the heating element and oil itself is confirmed by a natural convection test using a prototype transformer.