• 한국수소및신에너지학회논문집
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• 제25권2호
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• pp.105-113
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• 2014

Performance tests on $Ni/Ce-ZrO_2/Al_2O_3$ catalysts with additives (MgO, $La_2O_3$) were investigated in the combined reforming processes (SCR, ATR, TRM) in order to produce hydrogen and carbon monoxide (it is called "syngas".). The catalyst characterization was conducted using the BET surface analyzer, X-ray diffraction (XRD), SEM, TPR and TGA. The combined reforming process was developed to adjust the syngas ratio depending on the synthetic fuel (methanol, DME and GTL) manufacturing processes. Ni-based catalysts supported on alumina has been generally recommended as a combined reforming reaction catalyst. It was found that both free NiO and complexed NiO species were responsible for the catalytic activity in the combined reforming of methane conversion, and the $Ce-ZrO_2$ binary support employed had improved the oxygen storage capacity and thermal stability. The additives, MgO and $La_2O_3$, also seemed to play an important role to prevent the formation of the carbon deposition over the catalysts. The experimental results were compared with the equilibrium data using a commercial simulation tool (PRO/II).

• 한국재료학회지
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• 제24권3호
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• pp.129-134
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• 2014

Pure $MgH_2$ was milled under a hydrogen atmosphere (reactive mechanical grinding, RMG). The hydrogen storage properties of the prepared samples were studied at a relatively low temperature of 423 K and were compared with those of pure Mg. The hydriding rate of the Mg was extremely low (0.0008 wt% H/min at n = 4), and the $MgH_2$ after RMG had higher hydriding rates than that of Mg at 423 K under 12 bar $H_2$. The initial hydriding rate of $MgH_2$ after RMG at 423 K under 12 bar $H_2$ was the highest (0.08 wt% H/min) at n = 2. At n = 2, the $MgH_2$ after RMG absorbed 0.39 wt% H for 5 min, and 1.21 wt% H for 60 min at 423K under 12 bar $H_2$. At 573 K under 12 bar $H_2$, the $MgH_2$ after RMG absorbed 4.86 wt% H for 5 min, and 5.52 wt% H for 60 min at n = 2. At 573 K and 423 K under 1.0 bar $H_2$, the $MgH_2$ after RMG and the Mg did not release hydrogen. The decrease in particle size and creation of defects by reactive mechanical grinding are believed to have led to the increase in the hydriding rate of the $MgH_2$ after RMG at a relatively low temperature of 423 K.

• 한국가스학회지
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• 제28권2호
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• pp.47-55
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• 2024

한국에는 2030년까지 100여 기의 액화수소 탱크가 도입될 것으로 전망된다. 액화수소는 -253 ℃ 상태로 진공단열구조 탱크에 저장되기 때문에 단열에 문제가 생기면 탱크가 파열되는 대재해의 가능성이 상존한다. 그래서 법령에서는 최후의 보루로 PRV를 설치하도록 규정하고 있다. 주의할 것은 액화수소의 경우 배관의 압력강하를 무시하고 용량을 잘못 계산하면 무용지물이 된다는 것이다. CGA S-1.3에서는 PRV 입·출구 압력강하율을 각각 3% 미만 및 10% 미만으로 하도록 하고 있다. 그러나 배관의 압력강하량과 유량 사이에 상호 의존성이 있어 이들 값을 단번에 계산하는 것이 불가능하다. 그래서 본 연구에서는 매트랩/시뮬링크를 이용하여 PRV시스템의 압력강하율을 계산하는 시뮬레이터를 개발하고, 설계 요소에 대한 압력강하율의 민감도를 평가하였다.

• 한국수소및신에너지학회논문집
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• 제27권2호
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• pp.176-181
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• 2016

Recent years, supercapacitors have been attracting a growing attention as an efficient energy storage, due to their long-lifetime, device reliability, simple device structure and operation mechanism and, most importantly, high power density. Along with the increasing interest in flexible/stretchable electronics, the supercapacitors with compatible mechanical properties have been also required. A eutectic gallium-indium (EGaIn) liquid metal could be a strong candidate as a soft electrode material of the supercapacitors because of its insulating surface oxide layer for electric double layer formation. Here, we report the electrochemical study on the charging/reaction process at the interface of EGaIn liquid metal and electrolyte. Numerical fitting of the charging current curves provides the capacitance of EGaIn/insulating layer/electrolyte (${\sim}38F/m^2$). This value is two orders of magnitude higher than a capacitance of a general metal electrode/electrolyte interface.

• 한국수소및신에너지학회논문집
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• 제31권6호
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• pp.530-545
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• 2020

This paper reviews and summarizes the fuel-cell-related studies those have been recently published in major Korean Citation Index journals, aiming at analyzing the research trend in fuel cell technologies. Six major journals are selected for the literature survey; 57 papers are chosen for the detailed analysis through a screening examination on the total 1,040 papers published during between 2018 and 2020. Papers are classified into six technical categories, such as i) electrode, ii) electrolyte, iii) bipolar plate and stack, iv) fuel cell system, v) balance of plant, and vi) diagnosis-related studies, and summarized by the experts in the relevant area. Through this paper, we provide a comprehensive review on the recent trends and progress in fuel-cell-related research work in Korea.

• 한국수소및신에너지학회논문집
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• 제35권3호
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• pp.249-256
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• 2024

The cement industry emits a large amount of greenhouse gases compared to other industries, with about 60% of CO₂ emissions from the decarbonation of limestone and about 40% from the combustion of fossil fuels. Therefore, the cement industry needs to reduce greenhouse gases through carbon capture, utilization, and storage technology. Capturing CO₂ and synthesizing it into methanol is feasible and also useful as raw material for the chemical industry and as marine fuel. In this study, We aimed to produce methanol from syngas produced by capturing CO₂ emissions. Process simulations were performed under various conditions such as syngas ratio, temperature, and pressure for the production of synthesis gas and methanol, and the results showed that the optimal amount of methanol production at a synthesis gas ratio of 2.03.

• 한국수소및신에너지학회논문집
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• 제22권1호
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• pp.83-91
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• 2011

We investigated the effect of composition of a sulfur electrode with MWNT on the discharge behavior and cycling property of a Li/S cell. The MWNT content of a 60wt.% sulfur electrode varied from 10 wt.% to 30 wt.%. The optimum content of MWNT is 20wt.%, which shows the best cycling property. The first discharge capacity is 1166 mAh/g and decrease to the 542 mAh/g after 30th cycle. The homogeneous distribution of MWNT is an important factor for cycling properties.

• 한국수소및신에너지학회논문집
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• 제12권1호
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• pp.29-38
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• 2001

Zr-Mn-Ni 3성분계 합금으로서 $ZrMn_2Ni_x$ (x=0.0, 0.3, 0.6, 0.9 and 1.2) 합금을 제작하여 이들의 수소저장특성과 전기화학적 특성을 조사한 결과 $ZrMn_2Ni_x$ 모든 조성에서 C14 Laves phase가 형성되었다. 여러 합금 중에서 $ZrMn_2Ni_{0.6}$ 합금이 비교적 활성화가 빨리 이루어졌고(약 11회 싸이클 후), 방전용량이 가장 컸다(최대 45mAh/g). 모든 합금에서 6M KOH 전해질에 Zr이 가장 잘 용해되었다. $ZrMn_2Ni_{0.6}$ 합금은 다른 합금들에 비해 Mn과 Ni이 더 많이 용해되었다. $ZrMn_2Ni_{0.6}$ 합금이 비교적 활성화가 빨리 이루어지고 방전용량이 컸는데, 이에 따른 활발한 충 방전으로 인하여 Zr, Mn, Ni이 많이 용해되어 나온 것으로 사려된다.

• 정보학연구
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• 제10권2호
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• pp.37-45
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• 2007

The multiple-ability which the structure and the physical properties which the carbon or scull tube are unique show the applicability is superior in the plane indication element which is an indispensability of information communications apparatus, the stubbornness memory element, 2nd change of air and the rough copy dosage [khay] plaque seater, the hydrogen store material and the chemical sensor back and it has the possibility which will pass over the limit which the element of existing has. from the present paper it compared in the steel and only 10 the boat it did and it analyzed against an energy storage space voluntary application and developmental apply the carbon or scull tube trend in order about under researching the effective energy storage element it could be appeared, the technique of the strong carbon nano tube. 1. The hazard which embodies the energy storage element which uses the carbon or scull tube it follows in the function which stands and CNT of the structure which is various is necessary. 2. CNT fabrications of each one must precede possible not only must be each Cabinet conference circumstances quality gain and loss. 3. The structural control of syntheses, length controls, diameter controls and the metal - CNT junction control backs of quality CNT must precede. Applies the hereafter carbon or the scull tube in the various element with the primary preceding base technique for the structural plan technique of the carbon or scull tube to be certainly established, it does, secondarily the various element functional control technique which uses the carbon or scull tube is researched and will do.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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• pp.43-43
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• 2003

Carbon nanotubes(CNTs) have many application points, which are field emission devices, composites, hydrogen storage, nanodevices, supercapacitor and secondary battery. The most promising application point is emitter tip mays of field emission devices. Furthermore, it may be also useful as a vacuum device for high frequency and high power. But, there are some obstacles to fabricate carbon nanotube field emission device. One is that CNTs grown by CVD method has weak adhesion with substrate and the other is non-uniform length of them. These problems are very crucial in aging property and reliability of device in the field emission.