• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.3-8
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• 1989

Recent research activities for open and closed cycle MHD electrical power generations are reviewed. World first full scale 500MWe natural gas fired open cycle MHD is now under construction in USSR. Coal-fired open cycle MHD researches are in the stage of proof of concept and retrofitting of old coal power stations with MHD is planned in US and other countries. Basic research for closed MHD is most actively pursued in Japan, which potentially can provide a very high efficiency and a simple and reliable system.

• 환경위생공학
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• 제14권1호
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• pp.42-53
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• 1999

A study on the synthesis of zeolite from coal fly ash from power plant was carried out to reduce environmental problems and reuse industrial waste. The synthesized zeolite was proved to be Zeolite 4A type by means of the XRD and SEM analysis, and then the synthesized zeolite was used as an absorbent to remove the $NH_4^+$ ions in the wastewater and water. In the ion exchange of single $NH_4^+$ ions by the natural zeolite and the synthesized zeolite, the ion exchange reached equilibrium within 10 min. and 1hr, respectively. The amount of ion exchanged $NH_4^+$ to the unit weight of natural zeolite and zeolite 4A were 1.09 and 3.54 meq/g respectively, and the amount of $NH_4$ ion exchanged by the synthesized zeolite was higher than by the natural zeolite. The ion exchange kinetics fitted very well to the Feundlich and Langmuir isotherm. The effects of coexisting cations on the ion-exchange properties of zeolites were studied in order to apply them to water treatment. In the bisolute-system of the $NH_4^+-K^+$ and $NH_4^+-Na^+$ systems, the ion exchange capacity was smaller than the single $NH_4^+$ ion system. The effects of coexisting cations on the ion exchange system by the natural zeolite and the synthesized zeolite were found to be $K^+>Na^+$ and $Na^+>K^+>>Mg^{2+}>Ca^{2+}$, respectively.

• Composites Research
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• 제34권1호
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• pp.51-56
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• 2021

석탄 핏치의 전구체인 콜타르를 바인더 및 함침재로 이용하여 벌크흑연을 제조할 수 있는 가능성을 검토하고자 하였다. 충전재로 천연흑연을 이용하였으며, 천연흑연과 콜타르를 혼합 및 성형한 후 탄화 열처리를 실시하였다. 탄화 열처리 후 함침-재탄화를 5회 실시하여 밀도, 기공율, 압축강도, 그리고 이방성비를 측정하였다. 탄화체의 최고 밀도는 1.76 g/㎤였고, 기공율은 최소 15.6%로써 공정 제어에 의해 조절이 가능하였다. 압축강도는 최고 20.3 MPa이 얻어졌다. 탄화체의 이방비는 최대 0.34로써 강한 이방성 탄화체를 얻을 수 있었다. 따라서 콜타르를 바인더 및 함침재로 이용하여 벌크 형태의 인조흑연 제조가 가능하다는 것을 확인하였다. 또한 탄화체의 이방성을 조절하여 전기적, 기계적 방향 특성을 조절한다면 적절한 재료 설계를 통하여 다양한 분야에 응용할 수 있을 것이라 판단된다.

• 한국태양광발전학회지
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• 제4권2호
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• pp.45-53
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• 2018

Natural gas demand for power generation continued to increase until 2013 due to the expansion of large-scale LNG power plants after the black-out of 2011. However, natural gas demand for power generation has decreased sharply due to the increase of nuclear power and coal power generation. But demand for power generation has increased again as energy policies have changed, such as reducing nuclear power and coal power plants, and abnormal high temperatures and cold waves have occurred. If the gas pipeline pressure can be properly maintained by predicting these fluctuations, it can contribute to enhancement of operation efficiency by minimizing the operation time of facilities required for production and supply. In this study, we have developed a regression model with daily power demand and base power generation capacity as explanatory variables considering characteristics by day of week. The model was constructed using data from January 2013 to December 2016, and it was confirmed that the error rate was 4.12% and the error rate in the 90th percentile was below 8.85%.

• Journal of information and communication convergence engineering
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• 제3권2호
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• pp.63-66
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• 2005

In 2000, the EU set up an energy policy related renewables use for electricity demand up to $22\%$ on the purpose of preventing energy exhaustion and world climate exchange. Technology development and energy production policy on coal, oil and natural gas focus on how to minimize their environmental effects since the world energy system will continue to be dominated by fossil fuels with almost $90\%$ of total energy supply in 2030. In the long run, the EU drives expansion policy of the renewable energy. If related policies and programs will show successful operation in the near future and will be resulted in increase of budget, we could expect the possibility of expansion of renewable energy market in Korea in the future.

• 한국토양비료학회지
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• 제38권3호
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• pp.142-149
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• 2005

본 연구는 충남 보령시 청라면에 위치한 폐광산광미로부터 청라저수지 저니토에 이르기까지 토양에 존재하는 중금속과 자연방사능원소간의 발생과 분포에 대하여 조사하였다. 조사 결과 광미영향 지점과 비영향 지점간의 중금속과 자연방사능원소 함량에는 현저한 차이가 있었다. 중금속의 분포 특성은 Pb ($1.32-29.96mg\;kg^{-1}$, 평균 $10.44mg\;kg^{-1}$), Cd ($0.15-0.76mg\;kg^{-1}$, 평균 $0.51mg\;kg^{-1}$), Cu ($0.28-49.67mg\;kg^{-1}$, 평균 $12.43mg\;kg^{-1}$), Cr ($1.31-13.18mg\;kg^{-1}$, 평균 $4.87mg\;kg^{-1}$)으로 조사 되었다. 그리고 Pb와 Cu의 조사지점별 함량 변이는 다른 중금속에 비해 매우 높았다. 건조한 토양을 기준으로 한 자연방사능 함량은 Pb-210 ($4.87dpm\;g^{-1}$), Th-234 ($3.52dpm\;g^{-1}$), Ra-226 ($2.88dpm\;g^{-1}$), Ra-228 ($7.30dpm\;g^{-1}$), K-40 ($58.06dpm\;g^{-1}$) 순으로 나타났으나 핵실험 등의 낙진으로 인하여 대기로부터 유입되는 Cs-137은 발견되지 않았다. 이러한 결과를 기준으로 하여 석탄광미 자체에 포함된 자연방사능 함량과 조시지점에서 조사된 자연방사능 함량을 비교하였을 때 Pb-210 (4.41%), Th-234 (3.60%), Ra-226 (2.09%)로 매우 낮은 비율로 조사되었으나 Ra-228 (266%)과 K-40 (308%)은 석탄광미보다 광미장 외의 지점에서 더 높은 비율로 존재함을 알 수 있었다. 그리고 중금속과 자연방사능의 발생 정도 사이에는 상관관계가 낮았다.

• 한국대기환경학회지
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• 제2권2호
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• pp.9-18
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• 1986

For identification and apportionment of sources emitting particulate matters in environment, the multi-elemental characterization of size-density fractionated particulate matters was carried out. Eight types of samples were tested; soil, flyash released from burning of bunker-Coil, diesel oil, coal, and soft coal, urban road-way dust, urban dust fall, and airborne particulate matter. The fractions of particulate matters obtained by heavy liquid separation methos with a series of dichloromethane-bromoform were then analyzed using atomic absorption spectrophotometry for Ni, Cr, Cu, An, Fe, Al, and Mg. Each sample showed a different concentration profile as a function of density, and a number of useful conclusions concerning characterization of elemental distribution were obtained. From the density distributions of elements in soil, the maximum value was found for all elements in the density range of 2.2 $\sim 2.9g.cm^{-3}$, including the density of $SiO_2$. However, the distribution of metallic compounds with the density lower than $2.2g.cm^{-3}$ was prevalent in urban roadway dust, urban dust fall, and airborne particulate matter. And the density distribution curves of these urban dusts also have the higher distribution at the density of 2.2 - 2.9g.cm^{-3}$, including the density of wind-blown silica. This tendency generally was prevalent in the natural source elements, such as Al, Fe, Mn, and Mg. The maximum values were found in the density ranges of 1.3 $\sim 2.2g.cm^{-3}$ from the density distribution of elements in oil fired flyash. These distributions of anthropogenic source elements, such as Zn, Ni, Cu, and Cr were higher predominately than those of natural source elements. And the higher distribution was found in the density range of $2.2 \sim 2.9g.cm^{-3}$ from the density distribution of elements in coal and soft-coal fired flyash. These distributions showed similar patterns to soil. But anthropogenic source elements somewhat predominated at the density ranges of $1.3 \sim 2.2g.cm{-3} and 2.9g.cm^{-3}$ to soil. Therefore the higher distribution of anthropogenic source elements in the density ranges of $1.3 \sim 2.2g.cm^{-3} and 2.9g.cm^{-3}$ was considered as anthropogenic origin.

• 한국가스학회지
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• 제19권2호
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• pp.37-44
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• 2015

본 연구에서는 CBM의 1차 생산뿐 아니라 $CO_2$나 $N_2$ 주입을 통한 ECBM, 혹은 지중저장을 목적으로 석탄층에 $CO_2$를 주입할 때 발생할 수 있는 암체의 부피변화 영향을 고려하여 기존의 Langmuir 흡착 관계식을 개선하였다. 본 모델의 검증을 위해 $CO_2$나 $CH_4$, $N_2$의 단일성분 흡착실험 데이터에 기존 Langmuir 모델값과 본 모델의 결과값을 비교하였다. 그 결과, 기존 모델에서는 흡착용량이 큰 석탄일수록, 흡착친화도가 큰 가스일수록 실험값과 모델값 사이의 오차가 커지는 경향이 나타났지만 본 모델에서는 모든 조건에서 실험결과를 잘 묘사하였고 본 모델을 통해 예측한 부피변형률 역시 실험값과 유사함을 확인하였다. 이렇게 개선된 단일성분 흡착모델을 혼합가스의 흡착모델인 IAS 모델에 적용하여 부피변화가 고려된 IAS모델로 개선하였다. 그 결과 혼합가스에 대한 흡착거동 역시 기존 모델에 비해 정확도를 높였고 이는 Hall 등(1994)이 수행한 혼합가스의 흡착실험결과와의 매칭을 통해 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.246-248
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• 2005

The power plants have a loading dock and unloading device for the diverse kinds of fuel such as the bituminous coal and natural gas imported by the sea from all over the world. To unload the coal in the ship not only in the environment-friendly manner but also in the cost-effective way, the new type of heavy equipment loaded with additional features as well as excavator and the remote controller to maneuver this equipment are developed. This heavy equipment, which can be used to unload the coal in the ship in conjunction with CSU (Continuous Ship Unloader), and the remote controller are endorsed by the related code and laws. With the remote controller, the field workers can operate the unloading equipment at the remote place far from the equipment as well as in the cabin for themselves without tile remote controller.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.1017-1022
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• 2003

The hydraulic structures such as aqueduct tunnels and the drainage canal of the hydroelectric power plant in Japan are almost old. Therefore, the concrete surface of the aqueduct tunnel has received damage by wear-out and the crack, etc. This study was to develop repair mortar mixed a coal ash coarse powder by using two kinds of high early strength cements. As a result, the repair mortar was obtained by substituting the EF cement (maid in Japan) and the MT cement (maid in South Korea) at a rate of 60:40, and substituting the coal ash 30% and the mixing rate 35% of the artificial aggregate for natural fine aggregate.