• Korean Journal of Pharmacognosy
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• v.47 no.1
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• pp.18-23
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• 2016

This study was conducted to investigate the tyrosinase inhibitory and melanin production inhibitory activity of the distilled water extract of Dendropanax morbifera leaf (DMW) and the fermented extract by Lactobacillus plantarum (DMF). DMF was prepared by inoculation of L. plantarum after the extraction procedure with distilled water. Fermentation for 48 hours at $37^{\circ}C$ is the most effective condition in this study. In DPPH radical scavenging ability, $SC_{50}$ values of the fermented DMF was $37.9{\mu}g/ml$ as a result of more effective than DMW extract ($52.6{\mu}g/ml$). Moreover, tyrosinase inhibitory activity of DMF showed higher activity than DMW. In nontoxic concentration range, DMF showed strong melanin production inhibitory effect in ${\alpha}$-melanocyte stimulating hormone-stimulated B16F10 cell. As a result, the fermentation of the distilled water extract of D. morbifera leaf by L. plantarum could be applicable to functional materials production for skin-whitening agents.

• Textile Coloration and Finishing
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• v.15 no.4
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• pp.8-16
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• 2003

Poly(trimethylene terephthalate)(PTT) fiber was pretreated with organic solvent/water solution of various compositions. The organic solvents used in this experiment were benzyl alcohol, n-buthanol, and N,N-dimethylformamide(DMF). Density of the fibers were investigated as a measure of crystallite region. The dye uptake increased in the order of pretreatment with hot water < untreated < 5% benzyl alcohol < 100% benzyl alcohol < 90% benzyl alcohol; hot water < untreated $\risingdotseq$ 5% butanol < 100% beutanol < 90% butanol; hot water $\risingdotseq$ 5% DMF < untreated < 90% DMF < 100% DMF. The dye uptake increases with increase of crystallinity. It seems likely that the recrystallization process during the pretreatment with organic solvent/water solutions leads to an increase in the microvoid and then a large increase in the dye uptake. Also the dyeing rate increased and the dyeing transition temperature decreased with the pretreatments. The results obtained are corresponds with the plasticization of the fiber structure formed during the pretreatrnent.

• Rapid Communication in Photoscience
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• v.3 no.4
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• pp.85-87
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• 2014

We studied the characteristics of emissive state of the first (p-G1) and second (p-G2) generation of phenylacetylene dendrimers bearing stilbene as a core by using time-resolved fluorescence spectroscopy in cyclohexane (c-Hex) and N, N-dimethylformide (DMF), which are nonpolar and polar solvents, respectively. Time-dependent red-shift of emission spectra p-G2 both in c-Hex and DMF was observed in comparison with p-G1. Besides, the time constant of red-shift of spectra was found to be larger in DMF than in c-Hex. This indicates that the emissive state of p-G2 has a polar character in DMF as a result of charge delocalization from core to peripheral dendrons followed by stabilization of emissive state.

• The International Journal of Costume Culture
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• v.6 no.2
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• pp.134-146
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• 2003

Polyester of linear homopolymer poly(ethylene terephthalate)(PET) was chemically modified through the formation of branched copolymer to improve the undesirable properties of fiber. Photo-induced graft copolymerization of the acrylic monomers acrylic acid (AA) and methyl acrylate (MA) in the liquid and vapor phase, respectively, onto N,N-dimetylformamide (DMF)-pretreated PET fibers was carried out. The effect of various synthesis conditions and DMF pretreatment of the PET on the graft yield was investigated. Grafting mechanism was analysed. The grafting was promoted by increasing DMF pretreatment temperature and amount of DMF retention in the fiber. The increasing biacetyl and monomer flow time, and irradiation time enhanced the grafting up to a certain amount and thereafter it decreased.

• Bulletin of the Korean Chemical Society
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• v.35 no.8
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• pp.2419-2422
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• 2014

The syntheses and crystal structures of a three-dimensional (3D) coordination network $[Zn_4(2-mBIM)_5-(C_2H_6NCOO)(HCOO)({\mu}-OH)]{\cdot}DMF$ ($1{\cdot}$DMF; 2-mBIM = 2-methylbenzimidazolate) and a two-dimensional (2D) layer $[Zn_2(2-mBIM)_3(HCOO)(H_2O)]{\cdot}DMF$ ($2{\cdot}DMF$) are reported. Different structures were produced depending on the ratio of reactants. Structurally, 1 illustrates the formation of a unique framework based on a 2-mBIM bridge with the side group on an imidazole ring, while 2 possesses a honeycomb layer built up purely from imidazolates. For gas sorption, $CO_2$ is adsorbed on the activated phase of 1 but $N_2$ is not taken up.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.5
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• pp.1-13
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• 1995

In this paper, we evaluated the mean acquisition time and it's variance of the rapid synchronization system using the DMF(Digital Matched Filter) under the DS/CDMA system which uses the long period PN code. And we implemented the synchronization system that satisfies the specification demanded by the proposed EIA/TIA Interim Standard of Qualcomm Company. We showed that the state of the PN spreading code was estimated using the DMF(Digital Matched Filter) and then exact and fast chip synchronization could be achieved by the early-late tracking loop in the multiple channel environment. And we suggested the possibility that this synchronization system could be useful in the emerging digital cellular DS/CDMA system.

• Proceedings of the Membrane Society of Korea Conference
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• 1999.10b
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• pp.23-26
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• 1999

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.431-433
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• 2005

• Bulletin of the Korean Chemical Society
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• v.30 no.1
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• pp.27-28
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• 2009

• Membrane Journal
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• v.27 no.3
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• pp.273-283
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• 2017

Polysulfone (PSF) is one of an important polymer that has been widely used in the manufacture of asymmetric microfiltration (MF) membranes. PSF membrane is considered as hydrophobic membrane that easily fouled during membrane operation process. The blending method is an effective method for improving the fouling resistance of PSF membranes. sPES (sulfonated polyethersulfone) is one of the useful polymers that can be used in PSF polymer blend method to improve hydrophilicity of PSF membranes. In this study, microfiltration polymer membranes were prepared by using PSF/sPES/PVP/BE/DMF casting solution and water coagulant. The morphology of MF membranes was changed by addition of a small amount of sPES in casting solution. The morphology of the sPES added membranes was changed into a highly asymmetric structure. The active layer grew and mean pore size was decreased by addition of sPES. However, the water flux of PSF/sPES/DMF/PVP/BE membrane was higher than that of PSF/DMF/PVP/BE membrane.