• Bulletin of the Korean Chemical Society
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• 제31권10호
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• pp.2797-2800
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• 2010

For the purpose of developing advanced new absorbents for carbon dioxide, ionic liquids (ILs) are considered as alternative materials due to their superior properties to conventional organic solvents. Since low $CO_2$ solubility in ionic liquids is a major concern for their application as absorbents, it is essential to focus on improving $CO_2$ absorbing capability of ILs. In this paper, strongly basic ionic liquids, namely [$C_n$-mim]OPh (n = 2, 4, 6), have been synthesized and studied over a wide range of temperature and pressure changes. [$C_n$-mim]OPh can be easily synthesized from corresponding [$C_n$-mim]Cl and sodium phenoxide and has been found to be good $CO_2$ absorbents.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표대회 논문집(III)
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• pp.797-802
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• 1998

Fiber reinforcement can significantly improve the properties of concrete. Particulary, toughness or energy-absorbing ability of fiber reinforced concrete is frequently higher than that of unreinforced concrete. Toughness is a measure of energy absorption capacity and used to characterized fiber reinforced concrete's ability to resist fracture when subjected to static, dynamic and impact loads. However, the current standard methods of characterizing the toughness of fiber reinforced concrete have proven to be some inadequate and problems and have caused a great deal of dissent and confusion. This study research some of the inadequate and problems with these toughness measurement methods and proposes the evaluation method for Fiber Reinforced Concrete toughness.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1998년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Spring 1998
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• pp.180-187
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• 1998

One of the major difficulties in the seismic analysis of a dam-reservoir system is the treatment of the energy radiation in the upstream direction of the reservoir. In this paper a new transmitting boundary is presented that can model properly the radiation of energy in the far field direction of a semi-infinite reservoir with constant depth. In the newly developed method, effects of surface wave motion are taken into account and the reservoir-foundation interaction is approximately accounted for with an absorbing boundary condition. If a dam has vertical upstream face and the infinitely long reservoir maintains constant depth, then the proposed transmitting boundary can be directly coupled with the model of dam body. In present study, the dam body is assumed to behave elastically and modeled by finite element method. Seismic responses of a dam model are investigated using the newly developed transmitting boundary.

• 한국수소및신에너지학회논문집
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• 제11권4호
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• pp.171-177
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• 2000

Metal hydride used as hydrogen storage material usually needs the activating process to store the hydrogen at high temperature or high pressure. In general as the particle size of metal hydride becomes smaller, approached to the micro, furthermore, nano scale, storage ability and reaction kinetics are reported to be increased, because the specific surface is extremely increased. But the experimental results demonstrated that the optimum particle size is existed for the best absorbing performance, opposite to the usual expectation. This results from the particles to be come amorphous with their approaching to micro and nano scale, in the storage site within the metal hydride lattice is decreased, which is proved by XRD and SEM.

• 한국수소및신에너지학회논문집
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• 제14권2호
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• pp.146-154
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• 2003

The hybrids of zeolite and metal hydride were prepared to improve the absorption properties as media for hydrogen storage. The zeolites which was deposited on the surface by metal hydride vapor showed excellent absorption properties and sodalite was proved to be better than zeolite-A in the reaction velocity and hydrogen storage capacity. This suggests the metal hydride could be used effectively as catalytic active material for enhancing the hydrogen storage in zeolite containing $\alpha$-cages and furthermore the hydrogen molecules have preference tobe occluded in their cavities containing $\alpha$-cages more effectively than that containing a and $\beta$-cages.

• Nuclear Engineering and Technology
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• 제45권4호
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• pp.553-564
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• 2013

This study evaluates the local damage of a turbine in an auxiliary building of a nuclear power plant due to an external impact by using the LS-DYNA finite element program. The wall of the auxiliary building is SC structure and the material of the SC wall plate is high manganese steel, which has superior ductility and energy absorbance compared to the ordinary steel used for other SC wall plates. The effects of the material of the wall, collision speed, and angle on the magnitude of the local damage were evaluated by local collision analysis. The analysis revealed that the SC wall made of manganese steel had significantly less damage than the SC wall made of ordinary steel. In conclusion, an SC wall made of manganese steel can have higher effective resistance than an SC wall made of ordinary steel against the local collision of an airplane engine or against a turbine impact.

• 한국포장학회지
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• 제26권3호
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• pp.133-138
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• 2020

As HMR (home meal replacement) food market grows rapidly, a new packaging with more HMR specialized functions is highly required to promote consumers' convenience. A susceptor is defined as a material generating heat by absorbing electromagnetic energy such typically as radiofrequency or microwave radiation. In microwave cooking, susceptors are made of conductive metal thin film deposited on paper or plastic sheet and have generally been used to help crispen or brown foods by converting microwave energy into heat. This mini review article deals with current status of microwave susceptor packaging including commercial products, technical theory, types of susceptor and a test method for heating performance.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.162-169
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• 2009

In summer electrical energy is consumed in very high rate. It is used to operate conventional air conditioning system. Hot and humid air can germinate mould spores, encourage ill health, and create physiological stress (discomfort). Dehumidifier solar cooling effect is the one alternative solution saving electrical energy. We use surplus heat energy in the summer, to get cooling effect and then to get human reach to comfort condition. These devices have two system, dehumidifier and regeneration system. This paper will be focus in dehumidifier system. Dehumidifier system use for absorbing moisture in the air and decreasing air temperature. When the liquid desiccant as strong solution contact with the vapor air in the packed tower, it works. The heat and mass transfer performances of flow pattern in the packed tower of dehumidifier are analyzed and compared in detail. In this experiment was introduced, the flow patterns are parallel flow and counter flow. The performance of these flow patterns will calculate from air side. Which is the best flow pattern that gave huge mass transfer rate? The proposed dehumidifier flow pattern will be helpful in the design and optimization of the dehumidifier solar cooling system.

• 한국정밀공학회지
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• 제20권6호
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• pp.222-229
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• 2003

The purpose of this study is to evaluate the mechanical properties of 6061 Al foams, which were fabricated by P/M and multi-step induction heating method, and to build the database, which is needed for computer aided modeling or foam components design. Aluminium foams, consisting of solid aluminium and large quantities of porosities, is widely used in automotive, aerospace, naval as well as functional applications because of its high stiffness at very low density, high impact energy absorption, heat and fire resistance, and greater thermal stability than any organic material. In this study, 6061 Al foams were fabricated for variation of fraction of porosities (%) according to porosities (%)-final heating temperature ( $T_{a3}$) curves. Mechanical properties such as compressive strength, energy absorption capacity, and efficiency were investigated to evaluate the feasibility of foams as crash energy absorbing components. Moreover, effect of the surface skin thickness on plateau stress and strain sensitivity of the 6061 Al foams with low porosities (%) were studied.d.

• Composites Research
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• 제13권6호
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• pp.30-38
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• 2000

본 연구에서는 낙추충격 시험시스템을 제작하여 낙추의 응력파 전파 현상을 고려한 CFRP적층판의 충격흡수특성 및 충격강도를 평가하였으며, 초음파 C-스캔너를 이용하여 내부손상영역을 관찰하여 시험편의 손상면적과 흡수에너지의 상관관계를 규명하였다. 적층배향이 다른 직교이방성 시험편이 의사등방성 시험편의 충격에너지와 흡수에너지 수준을 보면 의사등방성 시험편이 흡수에너지가 높게 나타났지만, 충격에너지와 박리면적의 크기는 별 차이가 나타나지 않았으며 계면수가 많은 시험편이 충격에너지를 많이 흡수하였다. 적층수 및 적층방향이 동일한 경우, GFRP 프리프레그를 삽입한 시험편이 그렇지 않은 시험편보다 흡수에너지가 높게 나타났다.