• Nuclear Engineering and Technology
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• v.49 no.7
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• pp.1451-1456
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• 2017

Finding technical issues associated with equipment scale-up is an important subject for the investigation of pyroprocessing. In this respect, electrolytic reduction of 1 kg $UO_2$, a unit process of pyroprocessing, was conducted using graphite as an anode material to figure out the scale-up issues of the C anode-based system at pilot scale. The graphite anode can transfer a current that is 6-7 times higher than that of a conventional Pt anode with the same reactor, showing the superiority of the graphite anode. $UO_2$ pellets were turned into metallic U during the reaction. However, several problems were discovered after the experiments, such as reaction instability by reduced effective anode area (induced by the existence of $Cl_2$ around anode and anode consumption), relatively low metal conversion rate, and corrosion of the reactor. These issues should be overcome for the scale-up of the electrolytic reducer using the C anode.

• Korean Journal of Environment and Ecology
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• v.29 no.6
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• pp.936-946
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• 2015

This study is aimed to analyze the reduction performance of building energy consumption according to planting base types of panel-type green walls which can be applied to existing buildings. The performance was compared to the general performance of green walls that have demonstrated effects of improving the thermal environment and reducing building energy consumption in urban areas. The number of planting base types was 4 in total, and simulations were conducted to analyze the thermal conductivity, thermal transmittance, and overall building energy consumption rate of each planting base type. The highest thermal conductivity by the planting base type was Case C (0.053W/mK), followed by Case B (0.1W/mK) and Case D (0.17W/mK). According to the results of energy simulation, the most significant reduction of cooling peak load per unit area was Case C (1.19%), followed by Case B (1.14%) and Case D (1.01%) when compared to Case A to which green wall was not applied; and the most significant reduction of heating peak load per unit area was estimated to be Case C (2.38%), followed by Case B (1.82%) and case D (1.50%) when compared to Case A. The amount of yearly cooling and heating energy use per unit area showed 3.04~3.22% of reduction rate. The amount of the 1st energy use showed 5,844 kWh/yr of decrease on average for other types when compared to Case A. The amount of yearly $CO_2$ emission showed 996kg of decrease on average when compared to Case A to which the green wall was not applied. According to the results of energy performance evaluation by planting location, the most efficient energy performance was eastward followed by westward, southward and northward. According to the results of energy performance evaluation by planting location by green wall ratio, it was found that as the ratio of green wall increased, the energy performance displayed better results, showing approx. double reduction rate in energy consumption at 100% of green wall ratio than the reduction rate at 20% to 80% of green wall ratio.

• Journal of the Korean Solar Energy Society
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• v.28 no.6
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• pp.70-77
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• 2008

The purpose of this study evaluates a feasibility and economical efficiency of new renewable energy. According as weather change is serious problem now days, every people make attention to the reduction of greenhouse gas. The revitalization of new renewable energy creates the variety of energy source, stability of energy supply and reduction of greenhouse gas. In this study evaluates a feasibility and economical efficiency from new renewable energy of various photo voltaics, wind power, small hydro and biogas. Feasibility does in standard of technical characteristic, politic support, marketability, establishment present condition and development aim. Economical efficiency does in standard of developmental unit cost, utilization factor, equipment life, politic support cost, interest ratio. The results of this study were as follows photo voltaics, wind, small hydropower, biogas in order feasibility is high. Developmental unit cost, utilization factor, equipment life, politic support cost and analyzed the relationship of interest ratio fluctuation and economical efficiency. From all new renewable energy the utilization factor most is important in economical efficiency but necessary utilization factor is difficult because environmental problem.

• Journal of the Korean Solar Energy Society
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• v.23 no.3
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• pp.73-80
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• 2003

The purpose of this study was to analyze daylighting performance in a semi-infinite size office space for lighting energy conservation. DOE2.1E was used for simulations for the model space of $12\times12\times2.6m$. Nomographs were developed which could simulate work plane illuminance, glare index, energy consumption rate and energy reduction rate for daylighting design. Major results of simulations are as follows ; 1) When blinds facing south were installed, 43% of workplane illuminance diminished, but the flare index didn't exceed the recommended max-glare value. 2) In a semi-infinite office space facing south. energy consumption rate in the case space of 500 lux workplane illuminance is larger then case space of 300 lux workplane illuminance. Therefore, energy reduction rate is increased when the semi-infinite office faces south and naintains 300 lux workplane illuminance level.

• Journal of Energy Engineering
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• v.26 no.1
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• pp.45-53
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• 2017

The best practices of energy efficiency were selected by reviewing cases collected from the results of IEA research and prior studies, and then by evaluating the correspondence of each case for four attributes including economic performance, synergy, political adjustment, and marketability. The selected best practices included 36 cases in 6 fields such as governance, finance, utility, home, transportation, and industry/small and medium-sized businesses. The reduction of energy costs has brought countries implementing best practices of energy efficiency a variety of benefits, including higher rate of return, the reduction of incidental expenses, the increase of productivity, and the improvement of accessibility to energy. To have similar effects, other countries need to adjust these best practices before applying to their situations.

• Nuclear Engineering and Technology
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• v.48 no.4
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• pp.997-1001
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• 2016

Conductive ceramics are being developed to replace current Pt anodes in the electrolytic reduction of spent oxide fuels in pyroprocessing. While several conductive ceramics have shown promising electrochemical properties in small-scale experiments, their long-term stabilities have not yet been investigated. In this study, the chemical stability of conductive $La_{0.33}Sr_{0.67}MnO_3$ in $LiCl-Li_2O$ molten salt at $650^{\circ}C$ was investigated to examine its feasibility as an anode material. Dissolution of Sr at the anode surface led to structural collapse, thereby indicating that the lifetime of the $La_{0.33}Sr_{0.67}MnO_3$ anode is limited. The dissolution rate of Sr is likely to be influenced by the local environment around Sr in the perovskite framework.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2000.04a
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• pp.153-157
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• 2000

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.97-98
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• 2018

• Journal of the Korean Solar Energy Society
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• v.31 no.5
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• pp.126-133
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• 2011

The current world wide interest in environmental issues has moved from energy conservation to $CO_2$emission reduction. Recently, according to the increase in demand for water resources, insufficient potable water circumstance is supposed, unless there are corresponding in crease in water conservation and water recycling. This study has attempted to analyze $CO_2$emission reduction by water saving strategies like installation water saving devices, rain water harvesting and grey water system. To do this, this research investigates applicable water conservative strategies by literature review and calculated total water saving. The results show that (1) firstly, the water usage and $CO_2$ emission could be reduced up to 44%, (2) $CO_2$ emission reduction by water saving devices and rainwater harvesting system is about 47.7%, and (3) water usage and $CO_2$ emission reduction by grey water system is about 66%. In the future, this paper will be utilized for water management from the early design stage to maintenance stage of water glutton building.

• KIEAE Journal
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• v.13 no.2
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• pp.93-100
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• 2013

Many countries have made their best to protect the earth from global warming and to find solutions for the reduction of carbon dioxide emittion and energy consumption. Especially, buildings have emitted over 40% of carbon dioxide against whole quantities emitted to the earth. Therefore, the reduction of carbon dioxide emitted from buildings require to save the earth environment. Energy consumption of buildings in Korea has reached 24% of total energy quantities, and energy consumption of collective housing has been continuously increasing. So, Korea government has also executed the Green Building Certification Criteria(GBCC). The GBCC evaluates the 8 types of buildings - collective housing, office, school, etc - to certificate the green building. In this paper, the evaluation items of collective housing in GBCC were reviewed to be used as the reference data for future revisions by the case studies. According to the results of this study, current version of GBCC requires additional revisions about the evaluations of energy consumption monitoring, commissioning and existing building.