• Title/Summary/Keyword: waste reduction

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Mechanochemical Approach for Oxide Reduction of Spent Nuclear Fuels for Pyroprocessing

  • Kim, Sung-Wook;Han, Seung Youb;Jang, Junhyuk;Jeon, Min Ku;Choi, Eun-Young
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.19 no.2
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    • pp.255-266
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    • 2021

  • Solid-state mechanochemical reduction combined with subsequent melting consolidation was suggested as a technical option for the oxide reduction in pyroprocessing. Ni ingot was produced from NiO as a starting material through this technique while Li metal was used as a reducing agent. To determine the technical feasibility of this approach for pyroprocessing, which handles spent nuclear fuels, thermodynamic calculations of the phase stabilities of various metal oxides of U and other fission elements were made when several alkaline and alkali-earth metals were used as reducing agents. This technique is expected to be beneficial, not only for oxide reduction but also for other unit processes involved in pyroprocessing.

  • https://doi.org/10.7733/jnfcwt.2021.19.2.255 인용 PDF KSCI

Properties of Lightweight Foamed Concrete with Waste Styrofoam and Crude Steel Cement (폐스티로폼과 조강시멘트를 혼입한 경량기포콘크리트의 특성)

  • Park, Chae-Wool;Lee, Sang-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.06a
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    • pp.77-78
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    • 2020

  • In Korea, more than 30,000 tons of waste Styrofoam are produced every year. Styrofoam is spent more than 500 years decomposing during the reclamation process, so it needs to be recycled. The recycling rate of waste styrofoam continues to be the third highest in the world, but it is lower than that of Germany and Japan. Therefore, measures are needed to increase the recycling rate of waste Styropol. Another problem is that cement is mainly used in existing lightweight foam concrete. However, large amounts of CO2 from cement-producing processes cause environmental pollution. Currently, Korea is increasing its greenhouse gas reduction targets to cope with energy depletion and climate change, and accelerating efforts to identify and implement reduction measures for each sector. In 2013 alone, about 600 million tons of carbon dioxide was generated in the cement industry. Therefore, this study replaces CO2 generation cement with furnace slag fine powder, uses crude steel cement for initial strength development of bubble concrete, and manufactures hardening materials to study its properties using waste styrofoam. As a result of the experiment, the hardening agent replaced by micro powder of furnace slag was less intense and more prone to absorption than cement using ordinary cement. Further experiments on the segmentation and strength replenishment of furnace slag are believed to contribute to the manufacture of environmentally friendly lightweight foam concrete.

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A Study on the Perception and Attitude towards Food Waste Reduction by the Elementary School Pupils (부산지역 초등학생들의 음식물쓰레기 감량에 대한 인식 및 태도 연구)

  • 김소희;류은순
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.31 no.6
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    • pp.1155-1162
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    • 2002

  • Food waste in school foodservices is an important factor in managing expense or evaluating the acceptance of served meals and a serious environmental hazard factor in all countries. In this study, the perception and attitude towards food waste reduction and the recognition of environmental pollution of students from elementary school foodservices in Busan, Korea were investigated. The questionnaire was responded by 519 students (boy: 255, girl: 264) in the third and sixth grades. School lunch programs were proved to contribute to the improvement of students' food intake habits. The perception and attitude towards food waste reduction of the third grade students (3.61/3.73) were significantly higher than those of the sixth grade students (3.46/3.59) (P<0.01). Food waste education made a significant impact on the perception and attitude on food waste (p<0.01). When dislike food was supplied the students having the higher perception and attitude towards food waste reduction ate it more than those having the lower perception and attitude. The major reason for plate waste was shown to be influenced by the taste and amount of foods supplied in school lunch programs. Most of students recognized that food waste pollution (4.22) was one of the severest problems among the environmental pollutions, followed by air (4.13), tap water (4.09) soil (3.78), noise (3.55) pollution. The students separated the garbage in the house (72.6%) better than in school and the outside (55.2%). The perception of food waste was positively correlated with the attitude toward reduction of food waste and the recognition of environmental pollution (p<0.01). The attitude toward reduction of food waste was also positively correlated with meal quantity taken (p<0.01).

  • https://doi.org/10.3746/jkfn.2002.31.6.1155 인용 PDF KSCI