• Journal of Hydrogen and New Energy
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• v.27 no.4
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• pp.441-446
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• 2016

Alcohols are particularly attractive as alternative fuels because they are a renewable resource. This paper describes the performance and emission characteristics of ethanol and methanol gasoline blended fuels in a spark ignition engine. This experimental results showed that alcohol gasoline blended fuels decreased the torque, brake mean effective pressure, and brake power decreased when alcohol blended fuels were applied to a gasoline engine and also CO, HC and NOx emissions were reduced in accordance with the contents of alcohol contents.

• Journal of Hydrogen and New Energy
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• v.28 no.3
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• pp.246-251
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• 2017

To fabricate a hydrocarbon polymer electrolyte composite membrane incorporated with Pt nanoparticle, the polymer electrolyte membrane made of a sulfonated-fluorinated hydrophilic-hydrophobic block copolymer (SFBC) and sulfonated poly (ether ether ketone) (SPEEK) blend in the wight ratio of 1 : 1 was synthesized, and a simple drying process was used in order to incorporate Pt nanoparticle into the SFBC/SPEEK film by reducing platinum (II) bis (acetylacetonate), Pt $(acac)_2$. The distribution of the Pt nanoparticles was observed by transmission electron microscopy (TEM), and mechanical and thermal properties were tested by universal testing machine (UTM) and thermogravimetry analyzer (TGA). Cation conductivity, ion exchange capacity (IEC) and I-V characteristics were estimated.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.610-610
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• 2013

그래핀을 구성하는 탄소 원자는 모두 표면에 존재하기 때문에, 맞닿아 있는 물질에 따라 그래핀의 물리적 특성에 민감한 영향을 미치기도 한다. 본 연구에서는 라만분광법과 원자 힘 현미경(atomic force microscopy, AFM)을 이용하여 통상적인 열처리 조건에서 그래핀에 탄화수소가 흡착될 수 있는 가능성을 탐구하였다. 산소가 없는 조건에서 열처리된 그래핀으로부터 D, G, 2D 봉우리와 겹쳐지는 폭이 넓은 새로운 라만 봉우리들이 관찰되었다. 열처리 시간, 온도 및 진공도에 따른 라만 스펙트럼의 변화와AFM에 의해 확인된 표면의 구조 변화로부터 새로이 관찰된 라만 봉우리는 탄화수소의 탄화에 의해 그래핀의 표면에 형성된 비결정성 탄소물질(amorphous carbon)임을 확인하였다. 기계적 박리법과 화학기상증착법으로 시료를 준비할 때 사용된 폴리머 잔유물이 열처리 과정에서 탄화수소를 배출하는 것으로 판단된다. 이 연구는 그래핀 소자의 작동에 있어서 환경적인 효과를 이해하고 탄화에 의해 그래핀 표면에 만들어진 비결정질 탄소를 정량화하는데 도움을 줄 것이다.

• Journal of Hydrogen and New Energy
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• v.27 no.6
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• pp.721-726
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• 2016

Alcohols are particularly attractive as alternative fuels because they are a renewable resource. This paper describes the performance and emission characteristics of ethanol and diesel blended fuels in a compression ignition engine. This experimental results showed that ethanol diesel blended fuels decreased the torque and brake mean effective pressure. And experimental results indicated that using ethanol-diesel blended fuel, smoke, CO and HC emissions decreased as a result of the ethanol addition.

• Journal of Hydrogen and New Energy
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• v.15 no.3
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• pp.235-243
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• 2004

A number of potential applications of aluminum foams are being identified and renewed interest in these engineering materials is also reflected by several current research projects. One of the key issues for industrial exploitation of aluminum foams is the development of cost-effective manufacturing strategies facilitating, preferably, net shape production of foams with controlled porosity and cell size, and minimized structural imperfection. Especially, melt route to aluminum foam production based on the foaming agents offer attraction of low cost and the potential for good microstructure. The present paper is focused mainly on foaming agents of melt-foam aluminum such as $TiH_2$ or $TiH_2-Al$ mixture. For the purpose of economical manufacturing, we are proposed to hydrogen induced mechanical alloying (HIMA) process. Thermo-physical properties of particles synthesized are compared with conventional methods. Specimens synthesized are characterized by scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), thermo- gravimetry-differential scanning calorymetry (TG-DSC), pressure-composition-isotherm. (PCI).

• Journal of Hydrogen and New Energy
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• v.21 no.2
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• pp.81-88
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• 2010

Hydrogen energy applications have recognized clean materials and high energy carrier. Accordingly, Hydrogen energy applies for fuel cell by Mg and Mg-based materials. Mg and Mg-based materials are lightweight and low cost materials with high hydrogen storage capacity. However, commercial applications of the Mg hydride are currently hinder by its high absorption/desorption temperature, and very slow reaction kinetics. Therefore one of the most methods to improve kinetics focused on addition transition metal oxide. Addition to transition metal oxide in $MgH_x$ powder produce $MgH_x$-metal oxide composition by mechanical alloy and it analyze XRD, EDS, TG/DSC, SEM, and PCT. This report considers kinetics by transition metal oxide rate and Hydrogen pressure. In this research, we can see behavior of hydriding/dehydriding profiles by addition catalyst (transition metal oxide). Results of PCI make a excellent showing $MgH_x$-5wt.% Sc2O3 at 623K, $MgH_x$-10wt.% $Sc_2O_3$ at 573K.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.41-41
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• 2003

비정질 실리콘 박막은 단결정 실리콘에 비해 저가이고 저온형성이 가능하여, 대면적/고효율의 실리콘 박막 태양전지 제작에 응용되고 있다. 태양전지에 적용하기 위해서는 우수한 암전류 및 광전류 특성을 나타내야 하고, 광학적 밴드 갭 특성 또한 중요하다. 본 연구에서는 HDP(High Density Plasma) PECVD 장비를 이용하여 나노결정립 및 비정질 실리콘 박막을 형성하고, 각 박막의 전기적, 광학적 특성을 측정, 평가하였다. 나노결정립 및 비정질 실리콘 박막의 전기적 특성은 Keithley 4200을 이용하여 암전류를 특성을 측정하였고, Solar Simulator를 이용하여 AM1.5, 100mW/$\textrm{cm}^2$ 조건에서 광전류 특성을 측정하였다. 또한, Spectrometer를 이용하여 박막의 투과율을 측정하여 Tauc Plot을 통해 광학적 밴드 갭을 계산하였다. 본 연구에서 형성된 비정질 실리콘 박막은 -$10^{6}$의 우수한 Photoresponse($\sigma$$_{ph}$ $\sigma$$_{d}$) 특성을 나타내었다. 또한, 비정질 실리콘 박막 내에 나노결정립이 형성됨에 따라 암전류는 증가하고, 광학적 밴드 갭도 증가하는 것을 알 수 있었다. 이렇게 밴드 갭이 증가된 나노결정립 실리콘 박막은 태양전지의 Window 층에 적용하면 효율 증가에 크게 기여할 것으로 판단된다.

• Journal of Energy Engineering
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• v.19 no.4
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• pp.221-227
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• 2010

In this study, we consider gas generation characteristics on pyrolysis of eco-fuel which were made by mixing of Pitch Pine and Lauan sawdust as biomass and polyethylene, polypropylene, polystyrene as municipal plastic wastes with catalyst in fixed bed reactor. From the result of higher heating value(HHV) measurement and of ultimate analysis, the heating value of plastic wastes and a hydrogen content in plastic sample are higher than biomass. An activation energy was reduced by a catalyst addition. However the catalyst content influence over 5 wt% was insignificant. The yield of hydrogen from gasification of biomass containing plastic wastes such as polyethylene, polypropylene and polystyrene were obtained higher than that of sole biomass. The high temperature and mixture ratio of catalyst conditions induced to high hydrogen yield in most of the samples. As the influence of catalyst, the hydrogen yield by catalytic reaction was higher than non-catalytic reaction. We confirmed that Ni-$ZrO_2$ catalyst is more active in increasing the hydrogen yield in comparison with that of carbonate catalyst. The maximum hydrogen yield was 65.9 vol.%(Pitch Pine / polypropylene / 20 wt.% Ni-$ZrO_2$(1:9) at $900^{\circ}C$).

• KSBB Journal
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• v.21 no.5
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• pp.353-359
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• 2006

The purpose of this study is to search the optimal solubilization technology which could be applied to sewage sludge, and is to find the characteristics of biological hydrogen production when the sludge treated by optimal method was used as a sole substrate. As a result of the test, treatment technology mixed with alkali and ultrasonic treatment was very powerful tool for treating sewage sludge with high solubilization, and its ratio and elution rate of organic material was 0.9 and 0.076 $min^{-1}$, respectively. When the sludge treated by above optimal technology was used, 4.4 ml $H_2/g$ VSS of hydrogen was produced. Finally, When the sludge treated by above optimal technology was used, 13.4 ml $H_2/g$ VSS of hydrogen was produced under optimum pH.

• Proceedings of the Korean Magnestics Society Conference
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• 2010.06a
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• pp.25-26
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• 2010