• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.57-61
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• 2001

일반적으로 Asphaltene은 원유뿐만 아니라 화석연로원(Fessil Fuel Sources)에도 포함되어 있는 것으로 알려져 있으며 난분해성으로 탄화수소(Hydrocarbon)와 Heterocyclic 또는 N-, S-, 산소를 포함하는 화합물이다. 그리고 금속성 물질이 Asphaltene Fraction에 농축되어 있는 것으로 알려져 있다. 한편 이러한 metallo-complex는 Asphaltene의 구조화합물중 방향족계 sheet 사이에 Self-association 상태로 존재한다. Asphaltene의 분해는 일반 TPH나 BTEX계 유류의 분해 기작과는 매우 상이하며 현재까지 Asphaltene으로 오염된 토양의 복원 기술을 매우 미미한 것으로 알려져 있다. 따라서 본 연구는 Asphalteme으로 오염된 토양의 복원 기숙을 개발하기 위한 전단계로 Asphaletene의 구성물질과 저분자화 작용기작을 구명하여 효과적 복원기술 개발을 위하여 Arabian Light Oil에서 Oil 자체와 Oil에서 분리해낸 Asphaltene을 사용하여 용매조건과 처리제별로 저분자화 과정을 조사하였다.

• Journal of the Korean Ceramic Society
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• v.47 no.1
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• pp.71-74
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• 2010

We have investigated protonic conduction in highly dense (>98%) polycrystalline Y-doepd $BaZrO_3$ (BYZ) ceramic with an average grain size of ~85 nm. It is observed that the protonic conductivity across the grain boundaries in this nano-crystallilne BYZ (n-BYZ) is significantly higher than the microcrystalline counterpart. Such a remarkable enhancement in grain boundary conductivity results in high overall conductivity that may allow this chemically stable protonic conductor to serve as a solid electrolyte for low-temperature solid oxide fuel cell applications.

• Journal of the Korean Ceramic Society
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• v.47 no.1
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• pp.47-53
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• 2010

Ceramics with perovskite-type structure are interesting functional materials for several energy conversion processes due to their flexible structure and a variety of properties. Prominent examples are electrode materials in fuel cells and batteries, thermoelectric converters, piezoelectrics, and photocatalysts. The very attractive physical-chemical properties of perovskite-type phases can be modified in a controlled way by changing the composition and crystallographic structure in tailor-made soft chemistry synthesis processes. Improved thermoelectric materials such as cobaltates with p-type conductivity and n-type manganates are developed by following theoretical predictions and tested to be applied in oxidic thermoelectric converters.

• International Journal of Concrete Structures and Materials
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• v.7 no.2
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• pp.111-117
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• 2013

Heavy oil fly ash (HOFA) is a byproduct generated by the burning of heavy fuel oil. Chemical analysis showed that HOFA is mainly composed of unburned carbon with a significant amount of heavy metals. Due to toxicity, management of this waste poses a challenge to the industry personal. The present study investigates the possible use of HOFA as a black pigment or admixture in cement mortar aiming to produce ornamental brick. In order to investigate the change of cement mortar strength when HOFA is added, the standard compressive strength test with 50 mm cubes was performed. The results showed that the addition of 2-5 % of HOFA in cement mortar does not affect its strength. The leaching behavior of trace elements within HOFA and HOFA mixed mortar were investigated through laboratory batch leaching experiments. The results confirmed that HOFA can be utilized as a black pigment in ornamental brick, which is environmentally safe and provides good balance between color and brick properties.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.253-256
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• 2006

Most heater being used in vehicles has been used to a cabin heating by being supplied from a heat loss of the engine coolant for heat source efficiency. Recently, the heat loss is reduced by high efficiency in the engine. It becomes to require the combustion heater that directly bums the heater used in vehicles to provide heat source of the heater. The purpose of this study is to research a burner which will applicate combustion heater by the numerical analysis. There are the 5 different types of burners, which is designed by differently each design of the swirler. N-DODECANE by used the burner fuel is performed by numerical analysis in every 5 burner. The burner's efficiency testing is evaluated on the basis of the Exhaust gas temperature.

• 한국전산유체공학회:학술대회논문집
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• 2008.03a
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• pp.302-307
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• 2008

The development technology for the helicopter is improved by the increasing of computing power and advanced test facilities. The increasing efficiency of fuel consuming by the developing of improved lift-to-drag rotor system is the major issue, the noise reduction for ecology(civil area) and increase of survivability to reduce noise detection(battlefield) also are important. This investigation shows the classification of helicopter external noise and requirements, the noise flight test methods, the numerical modeling method for aero-acoustic of rotor blade and the result of CAA(Computational Aero-Acoustic) for main rotor blade.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.710-714
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• 2000

Present study deals with combustion characteristics and performance of U type radiation tube burner which combustion capacity is 30,000kcal/he and the maximum capacity of supply fuel is $3.0N m^3/hr$. Temperature range of radiation tube is maximum $170^{\circ}C$ and minimum $150^{\circ}C$ and this displays relatively small temperature range. And thermal efficiency is satisfactory as $75{\sim}80%$. Also, radiative efficiency of radiation tube is $52{\sim}63%$.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1690-1696
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• 2003

A two-dimensional direct numerical simulation is performed to investigate the flame structure of $CH_4/N_2$-Air counterflow nonpremixed flame interacting with a single vortex. The detailed transport properties and a modified 16-step augmented reduced mechanism based on Miller and Bowman's detailed chemistry are adopted in this calculation. The results show that an initially flat stagnation plane, where an axial velocity is zero, is deformed into a complex-shaped plane, and an initial stagnation point is moved far away from vortex head when the counterflow field is perturbed by the vortex. It is noted that the movement of stagnation point can alter the mechanism of reactants (fuel and oxidizer) fluxes into the flame surface, and then can alter the flame structure.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.5
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• pp.35-41
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• 2012

Liquified hydrogen peroxide as a monopropellant is drawing an attention as a power generating energy source for a machine requiring simple and light weight structure. The liquified hydrogen peroxide is attracted due to its outstanding applicability because it doesn't require an oxidizer and discharge a hazardous product. For the further industrial applications, however, a feasibility study should be carried out carefully in the aspect of the specific power density. In this study, a prototype of vane motor driven by the liquified hydrogen peroxide with high density of upper 95% was developed and its performance characteristic such as a specific power density was estimated via measuring pressure and rotation speed of the vane motor. The specific power density obtained by numerical simulation using FSI analysis supported by experimental results was up to $0.02kW/kg_{f}$, which reaches at the level of the latest developed fuel cell.

• 한국전산유체공학회:학술대회논문집
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• 2008.10a
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• pp.302-307
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• 2008

The development technology for the helicopter is improved by the increasing of computing power and advanced test facilities. The increasing efficiency of fuel consuming by the developing of improved lift-to-drag rotor system is the major issue, the noise reduction for ecology(civil area) and increase of survivability to reduce noise detection(battlefield) also are important. This investigation shows the classification of helicopter external noise and requirements, the noise flight test methods, the numerical modeling method for aero-acoustic of rotor blade and the result of CAA(Computational Aero-Acoustic) for main rotor blade.