• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.7
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• pp.382-386
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• 2004

A study has been made of surface modification of organic materials by ion implantation to increase the surface electrical properties. The substrate used were PET(polyethylene teraphtalate). N$^{＋}$, Ar$^{＋}$ implantation was peformed at energies of 40 keV and 50 keV with fluences from $5{\times}10^{15}$, $1{\times}10^{16}$,$7{\times}10^{16}$, $1{\times}10^{17}$/ ions/$cm^2$. UV/Vis, FT-IR and XPS spectroscopy measured for surface structure changes. Surface resistance decrease of implanted polymers was affected by ion implantation energy, ion species and ion dose rate. Surface conductivity of PET increased $2{\times}10^{9}$/∼$2{\times}10^{10}$/$\Omega$/sq by ion implantation. Result of various spectroscopy analysis, the cause of increasing PET surface conductivity was expected to breaking C=O bonds. It was formation carbon network structure by promote cross-linking and create C-C, C=C bonds.

• Journal of the Korean Ceramic Society
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• v.37 no.11
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• pp.1051-1057
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• 2000

TiO$_2$와 CeO$_2$박막을 Si 위에 증착한 후 MOCVD법에 의해 PbTiO$_3$박막을 증착하여 MFIS 구조를 형성하였다. 절연층의 후열처리가 절연층 및 MFIS 구조의 전기적 특성에 미치는 영향을 관찰하기 위해 산소분위기와 $600^{\circ}C$~90$0^{\circ}C$의 온도범위에서 후 열처리를 행하였고, C-V 특성 및 누설전류 특성을 분석하였다. CeO$_2$와 TiO$_2$박막의 유전상수는 증착 직후 6.9와 15였으며, 90$0^{\circ}C$ 열처리를 행한 후 약 4.9와 8.8로 감소하였다. 누설전류밀도 역시 증착 직후 각각 7$\times$$10^{-5}$ A/$ extrm{cm}^2$와 2.5$\times$$10^{-5}$ A/$\textrm{cm}^2$에서 90$0^{\circ}C$ 열처리를 거친 후에 약 4$\times$$10^{-8}$ A/$\textrm{cm}^2$와 4$\times$$10^{-9}$ A/$\textrm{cm}^2$로 감소하였다. Ellipsometry 시뮬레이션을 통해 계산된 계면층의 두께는 90$0^{\circ}C$에서 약 115$\AA$(CeO$_2$) 및 140$\AA$(TiO$_2$)까지 증가하였다. 계면층은 MFIS 구조에서 강유전층에 인가되는 전계를 감소시켜 항전계를 증가시켰고, charge injection을 방지하여 Al/PbTiO$_3$/CeO$_2$(90$0^{\circ}C$, $O_2$)/Si 구조의 경우 $\pm$2 V~$\pm$10 V의 측정범위에서 memory window가 계속 증가하는 것을 보여주었다.

• Textile Coloration and Finishing
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• v.19 no.3
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• pp.18-25
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• 2007

The fixing behaviors of anthraquinone disperse dyes containing dimethylamino substituent, such as C. I. Disperse Violet 26(D.V.26) and C. I. Disperse Blue 14(D.V.14), or containing diamino substituent, such as C. I. Disperse Blue 73(D.B.73), and monochlorotriazinyl azo reactive dyes, such as C. I. Reactive Orange 13(R.O.13), C. I. Reactive Red 3(R.R.3). C. I. Reactive Yellow 2(R.Y.2) on polyester/cotton blend(P/C) fabrics were examined for the one-step printing of P/C fabrics. The high temperature steaming of $175^{\circ}C$ is the most satisfactory fixing method for P/C one-step printing with above disperse and reactive dyes among the four different fixing methods: $175^{\circ}C$ steaming, $102^{\circ}C$ steaming${\rightarrow}175^{\circ}C$ steaming, $190^{\circ}C$ thermosol, $102^{\circ}C$ steaming${\rightarrow}190^{\circ}C$ thermosol. $190^{\circ}C$ thermosol is unfit to fix R.R.3 and R.Y.2 whose heat stability is poor. It was found that D.V.26 and D.B.14 containing dimethylamino substituent are unstable for heat and alkali, but D.B.73 is stable for them to print P/C blend fabrics with R.O.13 which is also stable for heat. Therefore we found that D.B.73, R.O.13 and a pair of D.B.73 and R.O.13 were very suitable for one-step printing of P/C blend fabrics.

• Korean Journal of Optics and Photonics
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• v.7 no.4
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• pp.341-347
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• 1996

The photocount distribution from a quasi-thermal light source, a moving ground glass disk (surface roughness; 9 ${\mu}{\textrm}{m}$) illuminated by a well-stabilized He-Ne laser, is measured by a photon counting system, and analyzed with theoretical calculations. The distribution approaches the Poisson distribution for the long coherence time ${\tau}_c$ compared to the measuring time T. The coherence time ${\tau}_c$ of the quasi-thermal source can be changed by controlling the velocity v of the motor driving the glass disk. By the comparison of experimental results and theory for the condition of T/ ${\tau}_c$ >>1, the coherence time ${\tau}_c$ of the quasi-thermal source is turned out to be in the range of 31.43 $mutextrm{s}$~2.48 $mutextrm{s}$ according to the circumferential velocity of the disk, and compared with the simple calculation of $\sigma$/v.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.8
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• pp.652-657
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• 2001

Vanadate glasses containing 10~20mol% glass former, P$_2$O$_{5}$ were prepared by melting the batch in platinum crucible and quenching on the copper plate. Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ glass-ceramics having LiV$_3$O$_{8}$ were obtained by heat-treatment of this glass in crystallization temperature. The glass-ceramics showed singnificantly good capacity and long cycles life according to heating condition. In this paper, we described electrochemical properties during crystallization process and found the best crystallizaton condition of Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ glass as cathode material. Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ glass-ceramics heat-treated at 233$^{\circ}C$ for 3 hors showed good rechargeable capacity of 220mAh/g in the cycling range between 2.0 and 3.9V.en 2.0 and 3.9V.

• Kyungpook Mathematical Journal
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• v.17 no.2
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• pp.227-233
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• 1977

• The Korean Journal of Ceramics
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• v.3 no.4
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• pp.263-268
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• 1997

RuO$_3$ thin films were deposited on Si(100) substrate at low temperatures by hot-wall metalorganic chemical vapor deposition. Bis(cyclopentadienyl) ruthenium, Ru$(C_5H_5)_2$, was used as the precursor RuO$_2$single phase was obtained at a low deposition temperature of 25$0^{\circ}C$ and the crystallinity of RuO$_2$thin films improved with increasing deposition temperature. RuO$_2$thin films grow perpendicularly to the substrate and show the columnar structure. The grain size of RuO$_2$films drastically increases with increasing the deposition temperature. The resistivity of the 180 nm-thick RuO$_2$thin films deposited at 27$0^{\circ}C$ was 136 $\mu$$\Omega$-cm and increased with decreasing film thickness. SrBi$_2Ta_2O_4$ thin films deposited by rf magnetron sputtering on the RuO$_2$bottom electrodes showed a fatigue-free characteristics up to ~10$^10$ cycles under 5 V bipolar square pulses and the remanent polarization, 2 P$_r$ and the coercive field, 2 E, were 5.2$\mu$C/$\textrm{cm}^2$ and 76.0 kV/cm, respectively, for an applied voltage of 5 V The leakage current density was about 7.0$\times$10$^{-6}$ A/$\textrm{cm}^2$ at 150 kV/cm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.190-195
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• 2000

The electrical properties and stability of ZPCE varistors consisted of $ZnO-Pr_6O_{11}-CoO-Er_2O_3$ ceramics were investigated. $ZnO-Pr_6O_{11}-CoO-Er_2O_3$ based ceramics were sintered at $1300^{\circ}C$ and $1350^{\circ}C$, respectively, without and with 0.5 mol% $Er_2O_3$. The varistors sintered at $1300^{\circ}C$ exhibited a better nonlinearity than that $1350^{\circ}C$. The varistors with $Er_2O_3$ of 0.5 mol% exhibited a high nonlinear exponent of 52.8. However, they easily degraded due to the low density below 85% of TD. On the other hand, the varistors sintered at $1350^{\circ}C$ without $Er_2O_3$ exhibited an extremely poor nonlinearity, but the varistors with $Er_2O_3$ of 0.5 mol% exhibited a relatively good nonlinearity, which the nonlinear exponent is 34.8 and the leakage current is $7.4\;{\mu}A$ Morever, they exhibited a very high stability, which the variation rate of varistor voltage, nonlinear exponent, and leakage current are -0.9%, -2.9%, and +2.7%, respectively, under the third stress $(0.80 V_{1mA}/90^{\circ}C/12h)$ + $(0.85 V_{1mA}/115^{\circ}C/12h)$ + $(0.90 V_{1mA}/120^{\circ}C/12h)$. Consequently, it was estimated that $ZnO-Pr_6O_{11}-CoO-Er_2O_3$ ceramics will be usefully applied to develop the advanced $Pr_6O_{11}$-based ZnO varistors.

• The Korean Journal of Pesticide Science
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• v.2 no.2
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• pp.90-96
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• 1998

The purpose of this study is to investigate the liquid culture conditions for mass production of Metarhizium anisopliae var. majus ARS 978 which is a potential microbiological pesticide. The temperature and pH range for optimal cultivation were $28^{\circ}C$ and pH 7.0, respectively. For M. anisopliae ARS 978, 1.0 %(v/v) molasses, 1.0 %(w/v) distiller's dry solubles, and 0.3 %(w/v) $CaCO_{3}$ were found to be the proper nutrients, considering cell mass, enzyme activities and spore concentration.

• Journal of the Korean Magnetics Society
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• v.13 no.3
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• pp.109-114
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• 2003

The purpose of this study Is to investigate the effect of $V_2$O$_{5}$ addition on the microstructures and magnetic properties of 7.7${\times}$4.5${\times}$1.0 mm sized multi-layer chip inductors prepared by the screen printing method using 0∼0.5 wt％ $V_2O_{5}$-doped NiCuZn ferrite pastes. With increasing the $V_2O_{5}$ content, the exaggerated grain growth of ferrite layers was developed due to the promotion of Ag diffusion and Cu segregation into the grain boundaries oi ferrites, which affected significantly the magnetic properties of the chip inductors. After sintering at $900^{\circ}C$, the inductance at 10 MHZ of the 0.5 wt％ $V_2O_{5}$-doped chip inductor was 3.7 ${\mu}$H less than 4.2 ${\mu}$H of the 0.3 wt% $V_2O_{5}$-doped one, which was thought to be caused by the residual stress at the ferrite layers increased with the promotion of Ag diffusion and Cu segregation. The quality factor of the 0.5 wt% $V_2O_{5}$-doped chip inductor decreased with increasing the sintering temperature, which was considered to be caused by the electrical resistivity of the ferrite layer decreased with the promotion of Ag/cu segregation at the grain boundaries and the growth of the mean grain size of ferrite due to exaggerated grain growth of ferrite layers.