• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.3
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• pp.65-73
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• 2011

기후변화는 에너지 수지와 물 수지의 변화를 초래하여 육상 생물권에 영향을 미칠 것이다. 기온과 강수량의 변화와 대기중의 탄산가스 농도 변화는 작물의 생육환경을 크게 변화시킬 것이다. 본 연구에서는 FAO AquaCrop 모형을 이용하여 기온과 강수량의 변화와 대기중 탄산가스 농도의 변화가 짐바브웨의 옥수수 수확량에 미치는 영향을 분석하였다. 미래 기후 값은 HadCM3 모형 예측 값을 change factor 기법으로 상세화 하였다. 배출 시나리오는 A2와 B2를 선정하였으며 시간대는 2020s, 2050s 및 2080s의 30년 기간을 선정하였다. 기준작물 증발산량은 Penman-Monteith 식으로 산정하였다. 관개용수 공급이 충분한 것으로 가정하고 전통적인 보충관개를 실시하였을 때 기준년도 (1970s)에 비해 옥수수 증발산량은 최대 26 %, 옥수수 잠재 수확량은 최대 93 %까지 증가할 것으로 예측되었으며 물의 생산성은 최대 53 %까지 증가할 것으로 예측되었다.

• KIEAE Journal
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• v.10 no.3
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• pp.103-110
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• 2010

Carbonation is one of the major deterioration factors for concrete. So. lots of researchers have proposed the equations for determining carbonated depth and the initial time of steel corrosion due to carbonation to predict the service life of concrete structures. However, there are large gaps among the equations for predicting carbonation because each researcher has different considering factors to predict carbonation depth. So, in this study, we calculated the deviations of the proposed equations for carbonation, and we calculated each researcher different corrosion initiation time. However, it has a lot of deviation. Therefore, we evaluated the probability of steel corrosion considering each deviation using MCS, an analysis method based on probability theory. In the results, we have proposed much advanced information for determining service life of reinforced concrete structures due to carbonation.

• Electrical & Electronic Materials
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• v.9 no.8
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• pp.831-835
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• 1996

The molten carbonate fuel cell has conspicuous features and high potential in being used as an energy converter of various fuels to electricity and heat. However, the MCFC which use strongly corrosive molten carbonate at 650[.deg. C] have many problem. Systematic investigation on corrosion behavior of Fe-based Cr has been done in ($62{\times}38$)mol % (Li+K)$CO_3$ melt at 923K by using steady state polarization and electrochemical impedance spectroscopy method. It was found that the corrosion current of these Fe-based alloys decreased with increasing Cr content, and this was attributed to the formation of $LiCrO_2$ layer at the surface .

• Journal of the Korean Chemical Society
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• v.54 no.3
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• pp.295-299
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• 2010

An experimental rig was constructed in order to study the inhibitory effects of two thermal inhibitors namely; stone and calcium carbonate, on Liquefied Petroleum Gas -air flames. This was achieved by measuring the flammability limits of the combustible mixtures before and after the addition of these inhibitors. It was found that calcium carbonate has superior inhibitory effect on the combustible mixture under investigation while, Stone has a lower inhibitory effect than that of calcium carbonate.

• Transactions of the Korean hydrogen and new energy society
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• v.15 no.1
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• pp.54-61
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• 2004

Temperature characteristics in a stack of molten carbonate fuel cell (MCFC) have been investigated with simulation based on the computational fluid dynamics (CFD) codes and experimental way. The MCFC has generally two stack structures when the natural gas is used as fuel; one is the external reforming type and the other is internal reforming type. Computer simulation at the external reforming stack suggests that the maximum temperature in the stack depends on the gas flow length. The 2 kW MCFC stack with 25 cm gas flow length showed about $675^\circ{C}$ of maximum temperature.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.5
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• pp.447-454
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• 2009

Electrolyzed reduced water was known as an alkaline solvent than piped water, natural water and mineral water etc. By means of reduction property, electrolyzed reduced water could dissolve a solute than other kinds of water without chemicals. In this study, serpentine dissolution in electrolyzed reduced water was investigated as a novel pre-treatment of serpentine which was a minerals for carbon dioxide sequestration. The elements (Ca, Si, Mg etc.) of serpentine were dissolved rapidly at early in the dissolvation then after some minutes the solubilities of serpentine elements showed stable state without abrupt changes. In spite of serpentine elements dissolution, chemical bondings and crystallographic structure of serpentine were not changed. It was explained that the dissolution mechanism of serpentine occurred from surface in electrolyzed reduced water and bulk structure sustained without collapse.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.245-246
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• 2009

This paper presents the development of lightweight aggregate self-consolidating concrete using lightweight aggregates. Lightweight concrete is known for its advantage of reducing the self-weight of the structures, reducing the areas of sectional members as well as making the construction convenient. Thus the construction cost can be saved when applied to structures such as long-span bridge and high rise building. Therefore experimental tests were performed as such mechanical properties and carbonation of self-consolidating concrete using lightweight aggregates.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.229-230
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• 2010

The Carbonation, one of the main deterioration factors of concrete, reduces capacity of members with providing rebar corrosion environment. Consequently it suggested standards of all countries of world, carbonation depth prediction equation of respective researchers and time to rebar corrosion initiation. As a result of carbonation depth prediction equation calculation, difference of time to rebar corrosion initiation is 149 years and difference of carbonation depth prediction equation is 162 years when water cement ratio is 50%. So a study on rebar corrosion with carbonation depth will need existing reliable data and verifications by experiment.

• 한국전기화학회:학술대회논문집
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• 2001.06a
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• pp.231-236
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• 2001

용융탄산염 연료전지용 anode의 creep 현상을 개선하기 위해 $Ni-5wt.\%Al$ green sheet를 사용하여 다양한 소결조건을 적용, $Al_2O_3$를 형성시킨 전극을 제조하고 그 $Al_2O_3$의 형태에 따른 creep 특성에 대해 연구하였다. 소결은 각각 환원분위기, 완전산화-환원분위기, 부분 산화-환원분위기의 서로 다른 분위기에서 진행하였는데, 부분산화-환원분위기로 소결한 경우 Ni-Al 고용체 네트워크를 깨드리지 않고 $A1_2O_3$를 미세한 입자형태로 분산시킬 수 있었다. 그리고, 상기의 방법으로 제조된 anode를 $650^{\circ}C$에서 100psi로 가압하면서 creep test를 실시한 결과 약 $2.3\%$의 변형율을 나타내었다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.2
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• pp.78-81
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• 2004

The nacre of imaged abalone pearls was obtained as a calcium carbonate of aragonite type. This result was same the nacre of natural abalone pearl. From the observation of SEM for the nacre adhered on the pearl nucleus, it was known that the layers of calcium carbonate and conchiolin were stratified. The growth rate of nacre was found to be 0.0056∼0.0074 mm/day, which is twice faster than that of traditional method used shells. The pendant and brooch were manufactured using the imaged abalone pearls.