• 멤브레인
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• 제24권5호
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• pp.367-374
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• 2014

본 연구에서는 LSCF/GDC (20 : 80 vol%) 복합 분리막 표면에 LSC/GDC (50 : 50 vol%) 활성층을 코팅한 후 활성층의 열처리 온도, 두께, 침투법을 이용한 STF 도입이 산소투과 특성에 미치는 영향을 고찰하였다. 활성층 도입은 복합 분리막의 산소 투과 유속을 급격히 증진시켰으며 이는 활성층 성분인 LSC/GDC (50 : 50 vol%)가 전자 전도성 및 표면 산소 분해 반응을 증진시켰기 때문이었다. 활성층의 열처리 온도가 $900^{\circ}C$에서 $1000^{\circ}C$로 증가한 경우, 산소 투과 유속은 증가하였고 이는 분리막과 활성층 사이 그리고 활성층의 결정입간 접촉이 증진하여 산소이온과 전자 흐름을 증진시켰기 때문으로 설명되었다. 코팅층의 두께가 약 $10{\mu}m$에서 약 $20{\mu}m$로 증가한 경우, 산소 투과 유속은 오히려 감소하였는데 이는 코팅층의 두께가 증가할수록 기공을 통한 공기 중의 산소 유입이 어려워지기 때문으로 설명되었다. 또한, 코팅층에 침투법을 이용하여 STF를 도입한 경우가 STF를 도입하지 않은 경우 보다 높은 산소 투과 유속을 보였는데 이는 도입된 STF가 산소 분해하는 표면 반응 속도를 촉진시키기 때문이다. 본 연구로부터 LSC/GDC (50 : 50 vol%) 활성층 코팅 및 특성 제어는 LSCF/GDC (20 : 80 vol%) 복합 분리막의 산소투과 증진에 매우 중요함을 확인하였다.

• 대한금속재료학회지
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• 제47권7호
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• pp.423-432
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• 2009

In the galvanizing coating process, the effects of the silicon content on the coatability and wettability of molten zinc were investigated on Dual-Phase High Strength Steels (DP-HSS) with various Si contents using the galvanizing simulator and dynamic reactive wetting systems. DP-HSS showed good coatability and a well-developed inhibition layer in the range of Si content below 0.5 wt%. Good coatability was the results of the mixed oxide $Mn_{2}SiO_{4}$, being formed by the selective oxidation on the surface, with a low contact angle in molten zinc and a large fraction of oxide free surface that provided a sufficient site for the molten zinc to wet and react with the substrate. On the other hand, with more than 0.5 wt%, DP-HSS exhibited poor coatability and an irregularly developed inhibition layer. The poor coatability was due to the poor wettability that resulted from the development of network-type layers of amorphous ${SiO}_{2}$, leading to a high contact angle in molten zinc, on the surface.

• Current Optics and Photonics
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• 제5권5호
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• pp.576-582
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• 2021

Dichroic beam-splitter (DBS) with polarization-maintaining took an important role in the free space quantum telecommunication tests on the Micius satellite of China. In this presentation, we designed and prepared a 50 layer polarization-maintaining DBS coating by a dual ion beam sputtering deposition (Dual-IBS) method. In order to solve a stress problem, an 18 layer special anti-reflection (AR) coating with similar physical thickness ratio was deposited on the backside. By stress compensation, the surface flatness RMS value of the DBS sample decreased from 0.341 λ (@632.8 nm) to 0.103 λ while beam splitting and polarization maintaining properties were almost kept unchanged. Further, we discussed the mechanism of film stress and stress compensation by equation deduction and found that total stress had a strong relationship with the total physical thickness and the ratio of layer materials.

• 한국전자파학회논문지
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• 제23권5호
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• pp.598-605
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• 2012

본 논문에서는 이중 모드 공진기 간의 개구 결합을 이용한 적층형 이중 대역 대역 통과 여파기를 제안하였다. 이중 모드 공진기 사이에 위치한 두 개의 개구를 통해 두 개의 결합 경로가 형성된다. 이를 이용하여 공진기의 모양에 변형을 주지 않고 개구의 크기 조절만으로 결합량을 조절할 수 있다. 또한, 이중 모드 공진기의 스터브 사이의 개구를 이용하여 두 번째 대역의 대역폭을 첫 번째 대역에 영향을 주지 않으면서 추가적으로 조절할 수 있다. 개구를 통한 결합 방법에 대해 이론적인 해석을 하였다. 제안된 구조를 이용하여 2.4 GHz WLAN, 3.5 GHz WiMax에서 동작하는 여파기를 설계 및 제작하였다. 제작된 여파기는 각각 2.45 GHz, 3.5 GHz의 중심을 기준으로 9 %, 8 %의 대역폭을 갖는다.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2001년도 종합학술발표회 논문집 Vol.11 No.1
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• pp.165-168
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• 2001

This Paper presents the design method and performance characteristics of a dual band balun. The design method for dual balun is based on the lumped element eqiuvalent circuit of quater-wave transformaer. By employing the proposed configuration and the derived formulas, dual band balun are designed and simulated and manufactured. The proposed design method and equivalent circuit can make it easy to adapt to designing of ceramic multi-layer chip type dual band balun. The dual band will find applications in wireless communication circuits.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.95.2-95.2
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• 2011

In order to achieve high performance and low cost for commercial applications, the development of membrane electrode assemblies (MEA), in which the electrochemical reactions actually occur, must be optimized. Expensive platinum is currently used as an electrochemical catalyst due to its high activity. Although various platinum alloys and non-platinum catalysts are under development, their stabilities and catalytic activities, especially in terms of the oxygen reduction (ORR), render them currently unsuitable for practical use. Therefore, it is important to decrease platinum loading by optimizing the catalysts and electrode microstructure. In this study, we prepared several different MEAs (non-uniform Nafion$^{(R)}$ ionomer loading electrode) which have dual catalyst layers to find the optimal Nafion$^{(R)}$ ionomer distribution in the electrodes. We changed Nafion$^{(R)}$ ionomer content in the layers to find the ideal composition of the binder and Pt/C in the electrode. For MEAs with various ionomer contents in the anodes and cathodes, the electrochemical activity (activation overpotential) and the mass transport properties (concentration overpotential) were analyzed and correlated with the single cell performance. The dual catalyst layers MEA showed higher cell performance than uniformly fabricated MEA, especially at the high current density region.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1103-1106
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• 2006

We have presented a comprehensive study on threshold voltage $(V_{th})$ control of organic thin-film transistors (OTFTs) with dual-gate structure. The fabrication of dual-gate pentacene OTFTs using plasma-enhanced atomic layer deposited (PEALD) 150 nm thick $Al_2O_3$ as a bottom gate dielectric and 300 nm thick parylene or PEALD 200 nm thick $Al_2O_3$ as both a top gate dielectric and a passivation layer is reported. The $V_{th}$ of OTFT with 300 nm thick parylene as a top gate dielectric is changed from 4.7 V to 1.3 V and that with PEALD 200 nm thick $Al_2O_3$ as a top gate dielectric is changed from 1.95 V to -9.8 V when the voltage bias of top gate electrode is changed from -10 V to 10 V. The change of $V_{th}$ of OTFT with dual-gate structure has been successfully understood by an analysis of electrostatic potential.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.288-291
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• 2004

Due to the charge compensation effect, SOI(Silicon-On-Insulator) LIGBT with dual-epi layer have been found to exhibit both low forward voltage drop and high static breakdown voltage. In this paper, electrical characteristics of the SOI LIGBT with dual-epi structure is presented. Trenched anode structure is employed to obtain uniform current flowlines and shorted anode structure also employed to prevent the fast latch-up. Latching current density of the proposed LIGBT with $T_1=T_2=2.5{\mu}m,\;N_1=7{\times}10^{15}/cm^3,\;N_2=3{\times}10^{15}/cm^3$ is $800A/cm^2$ and breakdown voltage is 125V while latching current density and breakdown voltage of the conventional LIGBT is $700A/cm^2$ and 55V.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.707-710
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• 2004

We have proposed on dual-drive & -emission (DDE) panel based on organic light-emitting diodes (OLEDs). The device is composed on independent operation of two OLED structures with two transparent electrodes for data signals and an intermediate reflective electrode for common scan signal. Typical device structure is ITO / organic electroluminescent layer (1) /intermediate reflective electrode / organic electroluminescent layer (2) /transparent electrode. Symmetric bright emission could be obtained by applying AlNd as the intermediate reflective electrode and $MoO_3$ as a hole injection layer for upper device structure. The proposed panel is useful for emissive face-to-face panel exhibited for different images.

• IEIE Transactions on Smart Processing and Computing
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• 제4권5호
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• pp.318-323
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• 2015

We present a new way to create a thermally stable, highly strained germanium (Ge) optical resonator using a novel Ge-on-dual-insulators substrate. Instead of using a conventional way to undercut the oxide layer of a Ge-on-single-insulator substrate for inducing tensile strain in germanium, we use thin aluminum oxide as a sacrificial layer. By eliminating the air gap underneath the active germanium layer, we achieve an optically insulating, thermally conductive, and highly strained Ge resonator structure that is critical for a practical germanium laser. Using Raman spectroscopy and photoluminescence experiments, we prove that the novel geometry of our Ge resonator structure provides a significant improvement in thermal stability while maintaining good optical confinement.