• Nuclear Engineering and Technology
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• 제28권4호
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• pp.366-372
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• 1996

The simulated spent PWR fuel pellet which is corresponding to the turnup of 33,000 MWD/MTU is prepared by adding 11 fission-product elements to UO$_2$. The simulated spent fuel pellet is treated at 40$0^{\circ}C$ in air (oxidation), at 110$0^{\circ}C$ in air (high-temperature treatment), and at $600^{\circ}C$ in hydrogen (reduction). The product is treated through additional addition and reduction up to 3 cycles. Pellets are completely pulverized by the first oxidation, and the high-temperature treatment causes particle and crystallite to grow and surface to be smooth, and thus particle size significantly increases and surface area decreases. The reduction following the high-temperature treatment decreases much the particle size by means of the formation of intercrystalline cracks. The particle size decreases a little during the second oxidation and reduction cycle and then remains nearly constant during the third and fourth cycles. Surface area of pounder increases progressively with the repetition of oxidation and reduction cycles, mainly due to the formation of Surface cracks. The degradation of surface area resulting from high-temperature treatment is restored by too subsequent resulting oxidation and reduction cycles.

• 유기물자원화
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• 제20권2호
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• pp.44-52
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• 2012

본 연구에서는 고유가 시대의 대안으로 정부에서 추진하고 있는 농촌형 녹색마을에 재생에너지를 도입하는 경우 $CO_2$ 저감효과를 분석하고, 재생에너지의 보급 활성화 방안을 제시하고자 하였다. 전라북도 G시에 조성하고 있는 소규모 농촌형 녹색마을의 에너지 잠재량을 조사한 결과 태양에너지를 이용하면 연간 6.73 GWh의 전력생산이 가능하고, 바이오매스로는 연간 134.06 GWh의 전략생산이 가능한 것으로 분석되었다. 따라서 전체 전력생산량은 연간 233.19 GWh로서 대상지역에서 연간 사용하고 있는 총 에너지 소비량 705.80 GWh의 33%를 부담할 수 있는 것으로 판단되었다. 한편 이산화탄소 감축잠재량을 산정한 결과 농산부산물은 1,891 ton_$CO_2$, 축산폐기물은 43,635 ton_$CO_2$, 도시폐기물은 395 ton_$CO_2$, 임산부산물은 50,324 ton_$CO_2$로 분석되었으며, 바이오매스로 인한 효과는 연간 총 96,245 ton_$CO_2$ 으로 나타났다. 또한 태양광에너지 2,251 ton_$CO_2$, 태양열에너지 1,383.3 ton_$CO_2$로 태양에너지로 인한 효과는 3,634 ton_$CO_2$이었으며, 총 99,879 ton_$CO_2$의 배출을 감축할 수 있는 것으로 나타났다.

• 펄프종이기술
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• 제36권2호
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• pp.17-23
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• 2004

The effects of refining consistency and plate gap on the specific energy consumption and physical properties of liner were investigated. Higher refining consistency and narrower plate gap brought about the reduction of specific energy consumption to decrease the freeness. Refining consistency and plate gap did not affect the bulk, Taber stiffness and compression index. The reduction of freeness and/or the increase of specific energy consumption caused the decrease of bulk and Taber stiffness, but increased the compression index. The effect of grammage on bulk was not observed, but Taber stiffness and compression index were increased with grammage. The bulk was decreased with the reduction of freeness rapidly at the above 400 mL CSF, and then levelled off. It is expected that the reduction of energy consumption could be obtained from the application of higher refining consistency and narrower plate gap during refining.

• 한국태양에너지학회 논문집
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• 제28권5호
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• pp.14-20
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• 2008

As the number of buildings that use the transparent permeation materials as the outer wall is on the increase, the coming amount of the light rays is a lot, and thus the increase in the cooling load and the radiant heat of high temperature may cause the residents to discomfort. In order to reduce such influences, this paper analyzed the installation effects of the sunshade BIPV. The inner temperature of the room installed the sunshade BIPV or otherwise was measured, and compared and analyzed the effects of reducing the cooling load by the incoming light rays. The sample space of the third floor of S university installed the sunshade BIPV has two rooms on the same conditions, and for five sunny days selected in August, the researcher measured the air temperature and the temperature of the fittings with closing the windows to minimize the movement of air without operating the coolers. The maximum cooling load measured by the incoming light rays in the room where the sunshade BIPV was not installed was examined as 459.13kcal/h. It can be understood as the effect of reducing the cooling load according to the incoming rays of the room with sunshade BIPV. Even though the effect of cooling load reduction is not so great in a room, the total reduction in cooling room for the 32 rooms installed the sunshade BIPV was estimated to be 40442.27kcal/day, which will be able to bring the maximum reduction effect of 17.1kW in energy and reduce the investment cost owing to the reduction in cooling load when initially designing the building.

• 태양에너지
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• 제19권3호
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• pp.1-11
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• 1999

Previous researchers have studied how to reduce a pumping power in order to save energy in the fluid transporting system. Especially, it has been studied a lot about reducing the pressure drop among parameters related to the energy saving for fluid transport. This study is to investigate the effect of a substantial drag reduction caused by the polymer(A611P, A601P) when the working fluids flow to the vertical and horizontal direction in the vertical cylindrical equipment of closed flow system. In this experiment, we mount a visualization equipment on the test section and take pictures. With using the PIV system, instrument and analyzing the movement of bubble for different polymer concentration are observed and some mechanism of the drag reduction effect is clarified.

• 자원ㆍ환경경제연구
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• 제9권5호
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• pp.925-945
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• 2000

This paper analyses the impact of energy-saving investment on Greenhouse gas emissions using a model of energy demand in Korea. SUR method was employed to estimate the demand equation. The econometric estimates provide information about the energy price divisia index, sector income, and energy saving-investment elasticities of energy demand. Except for energy price divisia, the elasticities of each variable are statistically significant. Also, the price and substitution elasticities of each energy price are similar to the results reported by the previous studies. The energy-saving investment is statistically significant and elasticities of each sector is inelastic. Using the coefficient of energy-saving investment and carbon transmission coefficient, the amount of reduction of energy demand and the reduction of carbon emissions can be estimated. The simulation is performed with the scenario that the energy-saving investment increase by 10~50%, keeping up with Equipment Investment Plan of 30% increase in energy-saving investment by 2000. The results show that the reduction of energy demand measured as 11.2% based upon 1995's level of the energy demand, in industrial sector. Accordingly, the carbon emissions will be reduced by 11.3% based upon 1995's level of the carbon emissions in industrial sector.

• 신재생에너지
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• 제16권3호
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• pp.27-34
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• 2020

This study involved a total budget analysis on the greenhouse gas (GHGs) emissions of landfills, focusing on surface emissions and the effect on emissions reductions of generating landfill gas (LFG) electricity from March 7, 2007 to December 31, 2018. The GHGs reduction effect from the electricity generation using 536.6 × 10³ tCO₂ of CH₄ was only 5.8% of the GHGs from surface emissions of 9,191 × 10³ tCO₂. In the total budget, the collection ratio should be over 95% if the reduction effect is greater than the surface emissions. The correlation coefficient for the relationship between the LFG collection ratio and GHGs reduction was -0.89. An additional effect of lowering CH₄ content may occur if the surface emitting flux of LFG decreased with an increase in the collection ratio. The unit reduction effect of GHGs by suppressing surface emissions was 4174 tCO₂/TJ. This was far greater than that of LFG power generated (54.3 tCO₂/TJ), demonstrating that surface emission control is the most important measure by which to mitigate GHGs emission.

• Carbon letters
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• 제1권1호
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• pp.17-21
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• 2000

Catalytic reduction and oxidation of NO over polyacrylonitrile based activated carbon fibers (PAN-ACF) under various conditions were carried out to develop removal process of NO from the flue gas. The effect of temperature, oxygen concentration and the moisture content for the reduction of NO with ammonia as a reducing agent was investigated. The reduction of NO increased with the oxygen concentration, but decreased with the increased temperature. The moisture content in the flue gas affects the reduction of NO as the inhibition of the adsorption of the other components and the reaction on the surface of ACE For the oxidation of NO to $NO_2$ over PAN-ACF without using a reducing gas, it showed the temperature and the oxygen concentration of the flue gas are the important factors for the NO conversion in which the conversion increased with oxygen concentration and decreased with the temperature increase and might be the alternative option for the selective catalytic reduction process.

• 에너지공학
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• 제19권4호
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• pp.203-214
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• 2010

본 논문은 한국의 원자력발전소 가동에 따른 온실가스 저감 기여도와 국민경제적 효과를 평가하였다. 한국의 2009년 원자력 발전량과 국가에너지기본계획에 의거한 추정 발전량에 온실가스 배출계수를 적용한 결과, 원자력발전이 온실가스 배출량의 저감과 전기요금의 인상억제, 화석연료의 수입대체 등에 긍정적으로 기여하고 있는 것으로 분석되었다. 향후 국가에너지의 안정적 경제적 조달과 기후변화에 대응하기 위하여 원자력발전의 비중이 확대될 필요가 있는 것으로 보인다.

• 한국자원식물학회지
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• 제13권3호
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• pp.249-254
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• 2000

태양열 집열판을 이용한 가온재배 실태를 조사 분석하고 그에 따른 문제점을 도출하여 해결방안을 모색, 향후 자연에너지 이용 기기제작 및 사용의 기초자료를 제공하고자 태양열 집열판을 이용한 20농가를 조사한 결과, 설치 비용은 18백만원/20a정도 소요되었으며, 주 재배작목은 토마토(30%)와 화훼(40%)였고, 포도, 고추, 오이, 상추 및 딸기 등도 일부 재배하고 있었다. 태양열이용 정보는 대부분 지도기관에서 얻고 있었으며, 연료절감 효과가 20%미만이라고 응답한 농가가 75%로 지도기관에서 조사한 대부분 20%이상과는 차이가 있었다. 연료절감 효과에 비하여 시설비의 과중과 시공업체의 기술부족이 문제점으로 나타나 이의 보완이 필요하였다.