• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.11
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• pp.740-744
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• 2017

Herein we studied the electrical and optical properties of indium tin oxide ITO/Ag/ITO multilayer thin films for application in transparent conducting electrodes. The ITO and Ag thin films were deposited onto soda lime glass (SLG) using radiofrequency and DC-sputtering methods, respectively. The as-synthesized ITO/Ag/ITO multilayer thin films were analyzed using 4-point probe, UV-Visible spectroscopy, and Hall measurement. We observed a rapid increase in electron concentration with increasing Ag thickness. However, electron mobility decreased with increasing Ag thickness. Finally, ITO/Ag/ITO multilayer thin films showed a characteristic low sheet resistance of $18{\Omega}/sq$ and high optical transmittance value (80%) with variation of Ag thickness (5~10 nm).

• Transactions on Electrical and Electronic Materials
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• v.10 no.6
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• pp.185-188
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• 2009

The effects of the growth temperature on the properties of ZnO thin films were investigated by using X-ray diffraction, scanning electron microscopy, ultraviolet-visible spectrophotometry, and Hall measurements. The ZnO films were deposited by rf magnetron sputtering at various growth temperatures in the range of 100-$400{^{\circ}C}$. A strong c-axis preferred orientation is observed for all of the samples. As the growth temperature increases, the crystalline orientation of the ZnO (002) plane is not changed, but the full width at half maximum gets smaller. The dependence of the electron concentration, mobility, and resistivity on the growth temperature exhibits that the ZnO films have a higher electron concentration at higher temperatures, thus giving them a low resistivity. The optical transmittance and band gap energy, calculated from the spectra of optical absorbance, show a significant dependence on the growth temperature. As for the sample grown at $100{^{\circ}C}$, the average transmittance is about 90% in the visible wavelength range and the band gap is estimated to be 3.13 eV.

• The Korean Journal of Community Living Science
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• v.16 no.2
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• pp.11-16
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• 2005

The purpose of this study was to investigate the antioxidant properties of unripened apple extracts. The amount of total flavonoids in the peel and 5/30 samples were 2.7times and 5.0 times higher than the flesh and 6/30 samples, respectively. The degree of angintensin I converting enzyme (ACE) inhibition activity in hot water extracts was higher than the other extracts. In the 5/30 sample, a $0.1\%$ concentration of unripened apple powder showed almost the same electron-donating ability with a $0.5\%$ concentration of the 6/30 sample. More than $90\%$ of the electron-donating ability was observed from the peel extracts regardless of solvents used for extraction. The nitrite-scavenging effects of acetone and methanol extracts of the 5/30 sample were the strongest at pH 1.2, and especially the $80\%$ methanol extracts exhibited a powerful scavenging effect of more than $90\%$ at pH 3.0.

• Journal of the Korean Electrochemical Society
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• v.7 no.1
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• pp.44-48
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• 2004

The two-component type enzyme amplified amperometric DNA assay is described to use an ambient $O_2$ of the substrate of the DNA labeling enzyme. Although the assay detects DNA only at > 0.5M concentration, a concentration $\~10^6$ fold higher than the sandwich-type enzyme amplified amperometric DNA assay, it can be run with an always available substrate. The assay utilizes screen-printed carbon electrodes (SPEs) which were pre-coated by a co-electrodeposited film of an electron conducting redox hydrogel and a 37-base long single-stranded DNA sequence. The DNA in the electron conducting film hybridizes and captures, when present, the 37-base long detection-DNA, which is labeled with bilirubin oxidase (BOD), an enzyme catalyzing the four-electron reduction of $O_2$ to water. Because the redox hydrogel electrically connects the BOD reaction centers to the electrode, completion of the sandwich converts the film from non-electrocatalytic to electrocatalytic for the reduction of $O_2$ to water when the electrode is poised at 200 mV vs. Ag/hgCl. The advantage or the assay over the earlier reported sandwich type enzyme amplified amperometric DNA assay, in which the amplifying enzyme was horseradish peroxidase, is that it utilizes ambient $O_2$ instead of the less stable and naturally unavailable $H_2O_2$.

• The Journal of the Korean dental association
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• v.9 no.12
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• pp.819-822
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• 1971

For this investigation, author isolated Streptococcus mitis strain SD-9 from the bacterial flora in the human dental plaque, which was incubated in brain-heart infusion media containing 5% sucrose at 37℃ for 24 hours. For the cytochemical demonstration of polysaccharide produced by this strain, a modified thiosemicarbazide osmium method (Critchley et al., 1967) was used. After fixation with this reagent, the harvested cells was suspended in 1% agar for the higher concentration of cells(Kellenberger et al., 1964). And they were dehydrated in the various concentration of ethanol, and embedded in Epon 812(Luft, 1961). Sectioning was done with the Sorvall MT-2 Porter Blum ultramicrotome by means of a glass knife, and the sections were stained with saturated uranyl acetate and lead citrate (Raynolds, 1963). All preparations were examined in a electron microscope, Hitachi HU-ll E-1 type. The morphological features of extracellular polysaccharide produced by Streptococcus mitis strain SD-9 were appeared in 3 structurally different forms, those are, electron dense fibrillar material linearly arranged adjacent to the outer surface of cell wall, highly electron dense globular material adjacent to the outer surface of cell wall, and strutureless fluffy meshwork of possible very fine filament.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.04a
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• pp.76-77
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• 2009

In this paper, We have studied Electron Transport Layer(ETL) in the New Organics applied to Red phosphorescent organic light-emitting devices. The structure of ITO/2-TNATA(15nm)/CBP;$Ir(piq)_3$/DPVBi(30nm)/New ETL(60nm)/LiF(0.5nm)/Al(100nm) has been used, measured changing doping concentration of EML. The results of OLED turn-on voltage at 2.2V, and Maximum Luminance at 2.8V was $1000cd/m^2$. This high luminance at low voltage results from a high electron. conduction of the new electron transport layer.

• Journal of Microbiology and Biotechnology
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• v.11 no.3
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• pp.406-411
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• 2001

In a bacterial denitrification test with Pseudomonas sp. and anaerobic consortium, more nitrates and less substrate were consumed but less metabolic nitrite was produced under an anaerobic $H_2$ condition rather than under $N_2$ condition. In a bioelectrochemical denitrification test with the same organisms, the electrochemically reduced neutral red was confirmed to be a substitute electron donor and a reducing power like $H_2$. The biocatalytic activity of membrane-free bacterial extract, membrane fraction, and intact cell for bioelectrochemical denitrification was measured using cyclic voltammetry. When neutral red was used as an electron mediator, the electron transfer from electrode to electron acceptor (nitrate) via neutral red was not observed in the cyclic voltammogram with the membrane-free bacterial extract, but it was confirmed to gradually increase in proportion to the concentration of nitrate in that of the membrane fraction and the intact cell of Pseudomonas sp.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.994-997
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• 2002

We have synthesized novel Diphenoquinone(DQ) derivatives. Electron drift mobility of DQ series was measured and electron affinity$(E_a)$ of them is estimated 3.7~3.9eV by CV. Electron drift mobility$(\mu)$ of electric field dependence by time of flight(TOF) technique is $1.76{\times}10^{-5}cm^2/V{\cdot}s$(DQ5) at the concentration of 10wt% verse poly(4,4'-cyclohexylidene diphenylcarbonate)(Pc-Z) and $1.66{\times}10^6V/cm$.

• Nuclear Engineering and Technology
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• v.52 no.2
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• pp.373-380
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• 2020

This study was carried out to convert the hydrophobic characteristics of PVDF to hydrophilic. Poly(-vinylidene fluorine) (PVDF) was grafted by electron beam irradiation and sulfonated. The grafting degree of modified PVDF increased with the monomer concentration, but not the conversion degree. From the results of FTIR and XPS, it was shown that the amount of converted sulfur increased with the grafting degree. The radiation-induced graft polymerization led to decrease fluorine from 35.7% to 21.3%. Meanwhile, the oxygen and sulfur content increased up to 8.1% and 3.2%. The pore size of modified membranes was shrunken and the roughness sharply decreased after irradiation. The ion exchange capacity and contact angle were investigated to show the characteristics of PVDF. The enhanced ion exchange capacity and lower contact angle of modified PVDF showed that the hydrophilicity played a role in determining membrane fouling. Electron beam irradiation successfully modified the hydrophobic characteristics of PVDF to hydrophilic.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2182-2187
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• 2007

The relative contributions of phonon and electron to the thermal conductivity of silicon film with varying doping density are evaluated from the modified electron-phonon interaction model, which is applicable to the micro/nanoscale simulation of energy transport between energy carriers. The thermal conductivities of intrinsic silicon layer thicknesses from 20 nm to 500 nm are calculated and extended to the variation in n-type doping densities from 1.0 ${\times}$ $10^{18}$ to 5.0 ${\times}$ $10^{20}$ $cm^{-3}$, which agree well with the experimental data and theoretical model. From simulation results, the phonon and electron contributions to thermal conductivity are extracted. The electron contribution in the silicon is found to be not negligible above $10^{19}$ $cm^{-3}$, which can be classified as semimetal or metal by the value of its electrical resistivity at room temperature. The thermal conductivity due to electron is about 57.2% of the total thermal conductivity at doping concentration 5.0 ${\times}$ $10^{20}$ $cm^{-3}$ and silicon film thickness 100 nm.