• Nuclear Engineering and Technology
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• v.51 no.3
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• pp.746-754
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• 2019

Vitrification of radioactive liquid waste (RLW) provides a feasible solution for isolating radionuclides from the biosphere for an extended period. In vitrification, base glass and radioactive waste are added simultaneously into the melter. Determination of heat and mass transfer rates is necessary for rational design and sizing of melter. For obtaining an assured product quality, knowledge of reaction kinetics associated with the thermal decomposition of waste constituents is essential. In this study Thermogravimetry (TG) - Differential Thermogravimetry (DTG) of eight kinds of nitrates and two oxides, which are major components of RLW, is investigated in the temperature range of 298-1273 K in the presence of base glasses of five component (5C) and seven component (7C). Studies on thermal behavior of constituents in RLW were carried out at heating rates ranging from 10 to $40\;K\;min^{-1}$ using TG - DTG. Thermal behavior and related kinetic parameters of waste constituents, in the presence of 5C and 7C base glass compositions were also investigated. The activation energy, pre-exponential factor and order of the reaction for the thermal decomposition of 24% waste oxide loaded glasses were estimated using Kissinger method.

• Journal of the Korean Society of Costume
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• v.39
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• pp.271-281
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• 1998

The purposes of this study were to deter-mine the dimensions of the housewives' cloth-ing behavior for the environmental protection and the identify the effective variables. The results of this study was intended to provide fundamental material for the establishment of clothing behavior guidelines for the environmental protection. This study was conducted by reference analysis and empirical study. To develop theoreti-cal framework study. To develop theoreti-cal framework of dimensions of environmental protection behavior, references concerned were analyzed. The results of reference analy-sis showed that the dimensions of environmental protection bahavior were resource and energy saving, sold waste reduction, resource reuse or recycle, and green product purchase. The dimensions of housewives' clothing behavior for environmental protection were identified by use of self-administered questionnaires. The results of enpirical study showed that the dimensions of clothing behavior for the environmental protection wre clothing resource reuse or recycle, clothing management resource saving, clothing consumption resource saving, green product purchase, and clothing management resource saving was the highest and that of resource reuse or recycle was the lowest. Environmental consciousness, taking environmental education or not, residing place, clothing seperate-collectiong at residing place were effective variables on clothing behavior for environmental protection.

• Journal of Environmental Science International
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• v.22 no.4
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• pp.425-433
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• 2013

A mass balance of process was calculated by using the analysis of basic unit and environmental assessment of all the processes of Busan fashion color industry cooperative that operates a combined heat and power plant and a bio treatment plant. The mass balance for the combined heat and power plant was done, based on boiler and water treatment processes while each unit reactor was used for the bio treatment plant. From the results above, a resource recycle network, a treatment flowchart for food waste water/wastewater treatment and a carbon reduction program were established.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.235-237
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• 2007

Concerns on environmental issues and global warming are increasing worldwide. Environmental regulations such as Tokyo Protocol, RoHS, WEEE are also getting harder and harder and used as trade barriers. Different from other manufacturing industries, information and communication industry is basically environment friendly-low emission of harmful materials and little consumption of energy. But information and communication industry can contribute to world environment by recycle articles in disuse and properly process discarded trash. Furthermore, by using more renewable energy, it can reduce the $CO_2$ emission, one of the major the green house gas.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 1994.10a
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• pp.31-38
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• 1994

The purpose of paper is to suggest directions of sustainable Architecture for dwelling planning. It deals with foreign example regading recycling Architecture in the point of using natural reources and energy effectively and minimizing environmental wastes. The methods which can be applied to Korean dwelling planning are as follows : 1) To use the underground space of apartments as pubilc energy-saving facility 2) To use conservatory passive solar systems at south-facing balconies of apartments 3) To flow daylight into the staircase of single-family house 4) To construct compactly doors and windows which have high-level insulation with high insulated walls and ventilation systems 5) To recycle materials such as steel, wood and soil 6) To recycle space according to the change of uses 7) To make users participate actively when we plan for dwelling.

• Membrane and Water Treatment
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• v.4 no.4
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• pp.251-263
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• 2013

The internal reflux effect on dialysis through the retentate phase of a countercurrently cross-flow rectangular module is investigated. Theoretical analysis of mass transfer in cross-flow devices with or without recycling is analogous to heat transfer in cross-flow heat exchangers. In contrast to a device without reflux, considerable mass transfer is achievable if cross-flow dialyzers are operated with reflux, which provides an increase in fluid velocity, resulting in a reduction in mass-transfer resistance. It is concluded that reflux can enhance mass transfer, especially for large flow rate and feed-concentration operated under high reflux ratio.

• Composites Research
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• v.35 no.4
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• pp.242-247
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• 2022

This study has a different direction from the existing technology of applying recycled carbon fiber obtained by recycling waste CFRP to CFRP again. A study was conducted to utilize recycled carbon fiber as a raw material for manufacturing a carbon/carbon (C/C) composite material comprising carbon as a matrix. First, it was attempted to recycle a commonly used epoxy resin composite material through a thermal decomposition process. By applying the newly proposed oxidation-inert atmosphere conversion technology to the pyrolysis process, the residual carbon rate of 1~2% was improved to 19%. Through this, the possibility of manufacturing C/C composite materials utilizing epoxy resin was confirmed. However, in the case of carbon obtained by the oxidation-inert atmosphere controlled pyrolysis process, the degree of oxygen bonding is high, so further improvement studies are needed. In addition, short-fiber C/C composite material specimens were prepared through the crushing and disintegrating processes after thermal decomposition of waste CFRP, and the optimum process conditions were derived through the evaluation of mechanical properties.

• Journal of Biosystems Engineering
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• v.16 no.3
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• pp.248-262
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• 1991

Simulation model was developed to analyze drying process for tray type red pepper dryer and validated by experiments. This model could predict satisfactorily temperatures and moisture contents of red pepper and temperatures of drying air during drying. Optimize algorithm was developed to search control valiables (drying air temperature, air recycle ratio and air flow rate) of red pepper dryer based on a criterion of minimizing energy consumption under the constraint conditions that statisfied carotenoid retension of at least 210mg per 100g dry matter, the moisture content of bottom layer of 15% (d.b) and drying time of less than 35 hours. Step changes in drying air temperature and air recycle ratio were considered in the optimization. In single step in control variables, the difference of the moisture content between top layer and bottom layer was great and more fan power was required. As the drying trays were exchanged when the moisture content of bottom layer reached to 100% (d.b), fifty percent of energy was saved and the difference of moisture content was little. In double step changes in control variables, optimal conditions were found by changing the step when the moisture content of bottom layer reached to 100% (d.b) (about 19.8 hours from starting drying). Optimum air flow rate was $18.1cmm/m^2$. Optimum drying air temperature and air recycle ratio in the first step was $55.8^{\circ}C$ and 0.80, and in the second step $65.6^{\circ}C$ and 0.88, respectively. In triple step changes in control variables, the optimal conditions were found by changing the steps when the moisture content of bottom layer reached to 250% (d.b) and 150% (d.b). Optimal air temperatures were $66.2^{\circ}C$, $58.4^{\circ}C$ and $66.9^{\circ}C$, and optimal air recycle ratios were 0.778, 0.785, 0.862 at each step, respectively. Optimal air flow rate was $18.9cmm/m^2$. The best operating mode was triple step mode considering energy consumption, drying time, fan power, and quality of dried red pepper. When the triple step mode was used to dry the red pepper, the energy consumption was about 16.5%~57.2% less than that of the single step mode and the drying time was 6.6 hours shorter than that of the double step mode.

• Journal of the Korean Professional Engineers Association
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• v.33 no.3
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• pp.35-36
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• 2000

The waste management system has become social problem all over the world since it is too much to control the waste generated during the economic development. Therefore Human being should minimize the dispersion of useful materials on the earth which is limited by means of recycle and reuse, and should maximize the use of solar energy which is almost infinite.

• Nuclear Engineering and Technology
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• v.55 no.7
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• pp.2662-2669
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• 2023

For the precise measurements of special nuclear materials (SNM) including Pu and Am isotopes, we have used phoswich detector combination of two single crystal scintillators of Gd₃Ga₃Al₂O₁₂:Ce and CsI:Tl. High detection efficiency and sensitivity along with high figure of merit for the discrimination of these phoswich detectors ensures the detection and discrimination of thermal neutrons and gammas from spontaneous fission of Pu and other isotopes in presence of high gamma background. Using this detector, the low energy gammas, which is stopped completely in 1mm thick disc of GGAG, can be also discriminated from high energies gamma and shows linearity in wide range of sample quantities. By changing only the appropriate shielding, the similar setup was used for thermal neutron detection and shows a very good linearity over wide range. The quantity of a test sample was also calculated accurately by using the measured calibrated plot.