• Smart Structures and Systems
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• 제20권2호
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• pp.163-173
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• 2017

Structural health monitoring (SHM) of civil infrastructure using fiber Bragg grating sensor networks (FBGSNs) has received significant public attention in recent years. However, there is currently little research on the health-monitoring technology of high-piled wharfs in coastal ports using the fiber Bragg grating (FBG) sensor technique. The benefits of FBG sensors are their small size, light weight, lack of conductivity, resistance corrosion, multiplexing ability and immunity to electromagnetic interference. Based on the properties of high-piled wharfs in coastal ports and servicing seawater environment and the benefits of FBG sensors, the SHM system for a high-piled wharf in the Tianjin Port of China is devised and deployed partly using the FBG sensor technique. In addition, the health-monitoring parameters are proposed. The system can monitor the structural mechanical properties and durability, which provides a state-of-the-art mean to monitor the health conditions of the wharf and display the monitored data with the BIM technique. In total, 289 FBG stain sensors, 87 FBG temperature sensors, 20 FBG obliquity sensors, 16 FBG pressure sensors, 8 FBG acceleration sensors and 4 anode ladders are installed in the components of the back platform and front platform. After the installation of some components in the wharf construction site, the good signal that each sensor measures demonstrates the suitability of the sensor setup methods, and it is proper for the full-scale, continuous, autonomous SHM deployment for the high-piled wharf in the costal port. The South 27# Wharf SHM system constitutes the largest deployment of FBG sensors for wharf structures in costal ports to date. This deployment demonstrates the strong potential of FBGSNs to monitor the health of large-scale coastal wharf structures. This study can provide a reference to the long-term health-monitoring system deployment for high-piled wharf structures in coastal ports.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.567-571
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• 2008

PEM Fuel Cell operation mode can be classified into dead-end mode or open mode by whether the outlet port is blocked or not. Generally, dead-end type fuel cell has some merits on the pressure drop and system efficiency because it can generate more power than the open type fuel cell due to high operating pressure condition. However, the periodic purging process should be done for removing water which is formed as product of a reaction in the gas diffusion layer. In this study, cathode side dead-end type operation has been conducted. Moreover, pulsating flow generator at the outlet of cathode side has been suggested for increasing the period to purge the formed water because the pulsating flow can make formed water scattered uniformly over the whole channel. As a result, the purging period with pulsation increased by 1.5-2 times longer than that without pulsating.

• 분석과학
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• 제15권6호
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• pp.496-501
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• 2002

Electrolyte cathode atomic discharge (ELCAD)는 용액 중에 포함된 미량 중금속을 연속 자동적으로 측정하기 위한 새로운 광학 측정기로서 플라스마에 의한 중금속들의 방출 강도를 측정하는 원자방출 분광법의 하나이다. 특히 이 방법은 검액을 전처리하지 않고 직접 분석할 수 있기 때문에 온라인 (on-line) 현장분석이 가능하다. ELCAD에서는 분위기 가스로 공기를 이용하고, 양극부분에 백금 전극을 사용하며, 음극에서는 연속적으로 전해질 시료를 주입하면서 플라스마를 형성하면서 미량의 중금속을 분석할 수 있다. 액상 글로우 방전의 기초 특성 연구로는 철의 원자 방출선 세기를 구한 다음 Einstein-Boltzmann식을 사용하여 플라스마 온도를 구한 다음 구리, 납, 철 및 니켈의 미량 분석 및 간섭 현상에 대해서 연구하였고, 검출 한계를 구하였다.

• 한국수소및신에너지학회논문집
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• 제29권6호
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• pp.549-558
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• 2018

The overall efficiency depend on the overpotential of the oxygen evolution reaction in alkaline water electrolysis. Therefore, it is necessary to research to reduce the oxygen evolution overpotential of electrodes. In this study, Ni-Zn-Fe electrodes were prepared by electroplating and the surface area was increased by Zn leaching process. Electroplating variables were studied to optimize the plating parameters(electroplating current density, pH value of electroplating solution, Ni/Fe content ratio). Ni-Zn-Fe electrode, which is electroplated in a modified Watts bath, showed 0.294 V of overpotential at $0.1A/cm^2$. That result is better than that of Ni and Ni-Zn plated electrodes. As the electroplating current density of the Ni-Zn-Fe electrode increased, the particle size tended to increase and the overpotential of oxygen evolution reaction decreased. As reducing pH of electroplating solution from 4 to 2, Fe content in electrode and activity of oxygen evolution reaction decreased.

• 공업화학
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• 제22권3호
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• pp.235-242
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• 2011

본 총설은 전극표면과 수용액 사이의 계면에서의 산화 및 환원반응을 이용하여 수용액 내 존재하는 유해한 유기화합물, 중금속 이온 등을 처리 가능한 최근의 전기화학기술에 대해서 정리 요약한 것이다. 수처리에 사용 가능한 전기화학기술은 일반적으로 고온, 고압을 요구하지 않으므로 비용면과 안정성면에서 장점을 지니고 있으며, 또한 높은 시스템 효율로서 다양한 성분을 포함한 폐수를 동시에 처리 가능하다는 것을 소개하고자 한다. 무엇보다 중요한 것은 전극소재의 선택과 사용이다.

• 공업화학
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• 제34권6호
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• pp.567-575
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• 2023

물의 전기 분해는 효과적인 그린 수소를 생산하기 위한 유망한 기술 중 하나로서 활발한 연구가 이루어지고 있다. 수전해 시스템의 원료로 해수를 직접 사용하게 되면 지구상에 있는 물의 약 97%를 해수가 차지하고 있으므로, 기존 담수 원료의 제한성에 대한 문제를 해결할 수 있다. 동시에 풍부한 부생 원료를 얻을 수 있는데, 그 성분과 pH 환경에 따라 전기 분해 과정에서 생성되는 Cl₂, ClO^-, Br₂ 및 Mg(OH)₂ 등이 대표적이다. 성공적인 해수 수전해 시스템 개발과 이에 필수적인 산소발생반응(oxygen evolution reaction, OER)과 수소발생반응(hydrogen evolution reaction, HER) 촉매를 개발하기 위해서는 해수 환경에서 일어나는 반응의 원인과 결과에 대해 파악할 필요가 있다. 따라서 본 논문에서는 해수 수전해 시스템의 반응 메커니즘과 특징 및 애노드와 캐소드 전극에 사용되는 전기화학 촉매들의 연구 개발 동향에 대해 살펴보고자 한다.

• 자원리싸이클링
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• 제33권1호
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• pp.15-21
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• 2024

전기차용 리튬이온배터리의 수요가 증가함에 따라 향후 발생할 폐리튬이온배터리 중의 유가금속 회수가 필요하다. 본 연구에서는 리튬이온배터리의 NCM계 양극재를 수소환원과 수침출에 의해 리튬을 수산화리튬으로 회수할 때의 회수율에 미치는 반응온도의 영향을 조사하였다. 반응온도가 상승함에 따라 수소에 의한 NiO, CoO의 환원에 의해 무게 감소율이 반응초기부터 급격하게 증가하였으며 동시에 H₂O 발생량도 증가하였다. 602 ℃ 이상에서는 양극재 중의 Ni, Co가 전부 환원되어 금속상으로 존재하였다. 그리고 수소환원 온도의 상승과 함께 Li 회수률도 증가하였으나 704 ℃ 이상에서는 약 92 % 이상의 유사한 수준을 나타내었다. 따라서 폐Li이온 배터리의 전처리로 수소환원하는 것에 의해 리튬만 사전에 회수하고 잔사를 재처리하면 효율적으로 유가금속을 분리하여 회수할 수 있을 것으로 기대된다.

• International Journal of Korean Welding Society
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• 제4권1호
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• pp.15-22
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• 2004

Metal transfer behavior of three shielded metal arc welding electrodes, AWS El1018, E6013 and E6010, were investigated through the characterization of size distribution of droplets and measurement of arc voltage signals. Of the three electrodes, Ell018 electrode showed the largest droplet size with the smallest amount of spatter, while E6010 electrode showed the smallest droplet size with the largest amount of spatter. Even though Ell0l8 electrode showed a good agreement between the frequencies of voltage drop in FFT processed voltage signals and the transfer rate of droplets, E6013 and E6010 electrodes showed weaker correlation because of their dominant explosive transfer behavior. The type of cathode used and electrode baking time also influenced the metal transfer behavior. Compared to bead-on-plate welding using steel plate as a cathode, welding on a water-cooled copper pipe showed less short-circuiting and higher melting rate in all electrodes because of higher arc potential and/or anode drop. When baked for a long time, E6010 electrode showed much more stable arc with less short-circuiting and explosion due to the loss of gas formation ingredients.

• 한국재료학회지
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• 제13권3호
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• pp.191-194
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• 2003

The influence of on ion beam irradiation to the indium tin oxide (ITO) substrate on the performance of the organic light-emitting diodes (OLEDs) was studied. ITO films were used as the transparent anode of OLEDs with poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV) as a hole-injection/transport layer. Oxygen and argon plasma treatment of ITO resulted in a change in the work function and the chemical composition. For plasma treated ITO anodes, the device efficiency clearly correlated with the value of the work function. We also discussed the implications of our experimental study in relation to the modification of the ITO surface composition, transmittance, reflectance, and water contact angle (WCA).

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.80.2-80.2
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• 2010

The development of high temperature-proton exchange fuel cell (HT-PEFC) is a key in solving the problem of carbon monoxide poisoning of the platinum at anode as well as water management in PEFCs operated below $90^{\circ}C$. In order to overcome these main issues, PEFCs must be operated at high temperature above $120^{\circ}C$. Ionic liquids are available for HT-PEFC due to exhibiting non-volatility and thermal stability. Ionic liquids are however leached out from polymeric matrix resulting in the increase of gas permeability. In this study, we have prepared and characterized the composite membranes with the ionic liquids consisting of 1-(4-vinylbenzyl)-3-butyl imidazolium chloride immobilized by the cross-linkers in pore-filling membrane to prevent to be leached out from the membrane. We confirmed that cross-linked ionic liquids were not leached out from the composite membranes through the various characteristic analyses. It was also verified that the prepared membranes are thermally stable from the result of TG analysis. The pore-filling membranes with the immobilized ionic liquids have a high proton conductivity over $10^{-2}$ S/cm at high temperature (> $120^{\circ}C$).