• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.41-44
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• 1998

Dual mode resonators were fabricated using high temperature superconductor. The deposited material was $Y_1Ba_2Cu_3O_{7-x}$(YBCO) on MgO(100) substrate using pulsed laser deposition. Dual mode resonators were patterned by standard photolithography process and wet etching. At the back-side of the substrate, the ground plane with the metal layer of Ti and Ag was fabricated. The transition temperatures of YBCO films were 85-88 K, and network analyzer was used for testing the performance of the resonators. The input/output feedline angles of each resonator were $60^{\circ}$and $100^{\circ}$. The resonant frequency of resonators was 10 GHz. In this paper, dual mode resonator was fabricated for the application of satellite communication.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.04a
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• pp.361-363
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• 2006

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.04a
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• pp.150-151
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• 2006

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2007.10a
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• pp.517-519
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• 2007

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2010.04a
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• pp.275-276
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• 2010

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.10a
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• pp.111-113
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• 2006

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.43-44
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• 2001

산업의 발달과 함께 화석연료의 소비가 증가하면서 산성강하물(Acid precipitation)에 대한 관심이 증가하여 왔다. 산성강하물은 주로 화석연료의 연소를 통해 대기로 배출된 질소와 황 산화물들로, 산화ㆍ환원, 산ㆍ염기 중화반응 등 다양한 변환과정을 거쳐 비나 눈과 같은 습성과정이나 가스나 입자상 물질과 같은 건성과정을 통해 다시 토양과 호수 등에 침적되어 이들을 산성화시키는 원인이 된다. 따라서 산성강하물에 대한 이해를 위해서는 강수의 화학조성과 아울러 가스와 입자상으로 존재하는 질소와 황화합물에 대한 관측이 필수적이다. (중략)

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.7
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• pp.1-8
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• 2019

The primary purposes of this study are to understand a fundamental effects of electro-deposition on reinforcing steel in saturated Ca(OH)2 electrolyte, and evaluate the corrosion rates of rebars under cyclic 3wt.%NaCl immersion and dry corrosion environment. The three cement mortar specimens with cover thickness 5, 10 and 30mm, were prepared in the experiment. To monitor the corrosion rates of rebars in mortar, the three cement mortar specimens were exposed to 110 wet-drying cycles(8-hour-immersion in 3wt.%NaCl and 16-hour-drying in a room temperature) in the laboratory. During the wet-dry cycles, the polarization resistance, Rp, and solution resistance, Rs, were continuously measured. The instantaneous corrosion rates of rebars on the effect of electro-depositing with sat. Ca(OH)2 electrolyte were estimated from obtained R-1p and degrees of wetness were estimated from Rs values. From the experimental results, the corrosion rates of rebars were greatly accelerated by wet/dry cycles. During the mortars exposed to drying condition, the large increases in the corrosion rates were showed at all rebar surfaces in three mortar specimen, attributed from the accelerated reduction rates of dissolved oxygen in drying process. However, the corrosion rates on rebar surface electrochemically deposited with sat. Ca(OH)2 electrolyte showed the clear decreases, caused by calcium deposits in the porous rust layer.

• Korean Journal of Materials Research
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• v.27 no.8
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• pp.403-408
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• 2017

We investigated the effect of ZnO buffer layer on the formation of ZnO thin film by ultrasonic assisted spray pyrolysis deposition. ZnO buffer layer was formed by wet solution method, which was repeated several times. Structural and optical properties of the ZnO thin films deposited on the ZnO buffer layers with various cycles and at various temperatures were investigated by field-emission scanning electron microscopy, X-ray diffraction, and photoluminescence spectrum analysis. The structural investigations showed that three-dimensional island shaped ZnO was formed on the bare Si substrate without buffer layers, while two-dimensional ZnO thin film was deposited on the ZnO buffer layers. In addition, structural and optical investigations showed that the crystalline quality of ZnO thin film was improved by introducing the buffer layers. This improvement was attributed to the modulation of the surface energy of the Si surface by the ZnO buffer layer, which finally resulted in a modification of the growth mode from three to two-dimensional.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05b
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• pp.62-65
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• 2002

Transparent conducting aluminum-doped Zinc oxide films (ZnO:Al) were prepared by rf magnetron sputtering on glass (Coming 1737) substrate as a variation of the deposition condition. After deposition, the smooth ZnO:Al films were etched in diluted HCl (0.5%) to examine the electrical and surface morphology properties as a variation of the time. The most important deposition condition of surface-textured ZnO films by chemical etching is the processing pressure and the substrate temperature. In low pressures (0.9mTorr) and high substrate temperatures $({\leq}300^{\circ}C)$, the surface morphology of films exhibits a more dense and compact film structure with effective light-trapping to apply the silicon thin film solar cells.