• 한국가구학회지
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• 제18권4호
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• pp.275-281
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• 2007

This study was carried out to know bending process property of bentwood by treatment methods such as microwave and ammonia solution treatment. Bentwood processing was operated on bending-jig form with 60mm and 100mm radius of curvature (ROC). The species was used to Korean red pine (Pinus densiflora). No significant difference was shown in bentwood processing method on ROC. In treatment method, ammonia solution treatment for bentwood was better in dimensional stability and working ability than that of microwave treatment. However, bentwood stress was reduced with ammonia solution treatment. Color of bentwood surface appearance has a dark tendency in ammonia solution treatment. But it seems to beautiful effect of apparent annual ring is rising esthetically by ammonia solution treatment. To utilize wood as a exterior material for living amenity, it has to be closely examined from various angles including surface property, degree of swelling and shrinkage, drying state, retaining strength, durability, safety, and insect damage.

• 한국전기전자재료학회논문지
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• 제27권11호
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• pp.702-706
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• 2014

A comparative study has been attempted for microwave and conventional sintering of lead-free $Bi_{0.5}Na_{0.5}TiO_3(BNT)$-based multilayer ceramic actuators(MLAs). It was found that microwave sintering (MWS) could be successfully applied to the co-firing of piezoceramic/AgPd MLAs with a 10 times shorter firing cycle as well as $100^{\circ}C$ lower firing temperature ($850^{\circ}C$) for sufficient densification than conventional furnace sintering ($950^{\circ}C$). Furthermore, MWS-derived specimens showed better electric field-induced strain than that of CFS-derived specimens by effectively suppressing interdiffusions between ceramic and electrode layers.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.749-751
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• 2002

$(Pb_{1-x}Sr_x)TiO_3$ $(0.6{\leq}x{\leq}0.8)$ thin films were prepared by the MOD method for tunable microwave device application and their characteristics were investigated as a function of Sr content(x) and applied field. Thin films showed a homogeneous microstructure and the tetragonality(c/a) was slightly decreased with increasing Sr content. With increasing Sr content, Curie temperature of the thin films showed a decreasing tendency. For the PST thin films, the dielectric constant at room temperature, Tc, and $tan{\delta}$ were 750~1900, $-70^{\circ}{\sim}-30^{\circ}C$ and 0.025~0.04, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.605-608
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• 2002

In order to improve the microwave dielectric properties of ZnO+$TiO_2$ ceramic systems, we studied the relations among microstructures, phases, and microwave dielectric properties at various mole ratio and sintering temperatures. The optimum composition was found to be 0.2ZnO+0.8$TiO_2$ when sintered at $1100^{\circ}C$, at which we could obtain following results: $Q{\times}f_o$ = 22,500 GHz, ${\varepsilon}_r$ = 73, and $\tau_f=+210ppm/^{\circ}C$.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 추계 학술논문 발표대회
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• pp.27-28
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• 2011

This research aims to secure fundamental data for the development offire-retardant wood by soaking dried wood in fire-retardant liquid. To dry wood, optimal drying conditions for softwood usually used as structural material and hardwood usually used as finishing or furniture material were derived by varying the microwave outputs and heating times of microwave wood drying equipment. The research foundthat each specimen needs 8 to 15 minutes of heating time depending on water content and output. For softwood, fire-retardant liquid equivalent to about 10 percent of the total mass of the specimen infiltrated into the dried wood, of which the water content was reduced to 5~6 percent.

• 한국전기전자재료학회논문지
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• 제18권12호
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• pp.1129-1132
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• 2005

The purpose of this reserch is to establish the new design technology for microwave Coplanar structure. The components in microwave circuit are classified to transmission devices, EM devices, and quasi-TEM devices. After design of these devices, we analyzed these CPWs electromagnetically using FDTD method, and suggested optimum CPW structure. In oder to realize a CPW module up to 30 GHz-100 GHz band, we research on a technology of 3-dimensional microwave CPW, and GaAs substrate with Si layer for ohmic loss. As a result this research, we suppressed the leakage, resonance, coupling, and radiation of CPW EMI, and improved resonance quality of CPW.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.984-987
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• 2003

유기발광소자 안에 존재하는 비발광영역(dark spot)의 전압에 대한 영향을 근접장 마이크로파 현미경(near-field scanning microwave microscope)을 이용하여 관찰하였다. 유기발광소자는 glass/indiumtin oxide(ITO)/Cu-Pc/tris-(8-hydroquinoline)aluminum(Alq3)/aluminum(Al) 의 기본구조로 제작하였다. Dark spot은 ITO 기판을 부분적으로 에칭하여서 형성시켰다. Dark spot에 $0{\sim}l5 V$ 까지 전압을 인가시키면서 인가 전압에 따른 전기적 특성을 근접장 마이크로파 현미경 image의 변화와 반사계수인 $S_{11}$ 측정을 통하여 연구하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.439-442
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• 2004

The effects of sintering additives on the low-temperature sintering and microwave dielectric properties of $Mg_4Nb_2O_9$ dielectric ceramics were studied. When $3{\sim}20wt%$ of $0.242Bi_2O_3-0.758V_2O_5$ was added, the sintering temperature decreased from $1100{\sim}1300^{\circ}C$ to $950^{\circ}C$ and high density was obtained. When $Mg_4Nb_2O_9$ was sintered at $950^{\circ}C$ with 10wt% of sintering additive, the microwave dielectric properties of $Q{\times}f_0\;=\;80.035GHz,\;\epsilon_r\;=\;13.3\;and\;\tau_f\;=\;-12.9\;ppm/^{\circ}C$ were obtained.

• 한국세라믹학회지
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• 제29권3호
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• pp.177-182
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• 1992

The effect of heat-treatment temperature on the microwave absorbing properties was investigated in Ni0.8Zn0.2Fe2O4 specimens. The composite specimens were prepared by modling and curing the mixture of prereacted ferrite powder and silicone rubber. The measurement of complex permeability and permittivity was made by the reflection/transmission method. The most sensitive material constants with heat-treatment temperature is the imaginary (loss) component of permeability. The higher the heat-treatment temperature, the greater the magnetic loss. The composite specimens with high magnetic loss exhibited superior microwave absorbing properties. The quantitative estimation of microwave absorbing properties were made by plotting the observed material constants on the calculated solution map of impedance-matching.

• Carbon letters
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• 제1권3_4호
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• pp.143-147
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• 2001

Under the irradiation of radiofrequency wave, the dipole materials vibrate as microwave phase changes. This causes friction between adjacent molecules and enables an unique characteristics of interior heating of the materials. Using this principle, when harmful material pass through anthracite- bed which play a role as a absorber of radiofrequency wave, the material can be easily decomposed by the microwave energy. To remove benzene vapour and other solvents in the process of industry, we examined decomposition of benzene in this manner. It was found that benzene was decomposed to the methane, ethane, propane and butane, etc. during passing through the carbon-bed under the microwave impingement and distribution of methane in the products reached about 85 vol.%. The decomposition rate of benzene was high within 5 minutes from start of reaction. For a lower concentration of benzene gas, general cases in the field of industry, almost complete decomposition of benzene is believed possible and this method is surely expected to be useful for the prevention of air pollution and improvement of ambient condition.