• Environmental Engineering Research
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• 제21권1호
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• pp.69-73
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• 2016

Generation of food waste is a serious issue that needs to be addressed worldwide. Developing suitable treatment methods while generating energy (methane) is a common practice for sustainable treatment of waste. In this study, methane generation by food waste was investigated in mesophilic and thermophilic regimes at various hydraulic retention times (HRTs) and organic loading rates (OLR). In temperature regimes, influent concentrations and HRTs ranged from 30 to 110 g COD/L and 18 to 30 days, respectively, which corresponding to an OLR of 1.0 to $6.1kg\;COD/m^3-d$. Better methane production and organic removal was observed under thermophilic conditions because of the enhanced hydrolysis of complex polymers and microbial activity at higher temperature. The peak methane productivities attained in thermophilic and mesophilic regimes were 1.30 and $0.99m^3/m^3-d$, respectively. The maximum methane yields were achieved at 50 g COD/L and HRT of 24 d in both cases, and the values were 264 and $221m^3/ton$ COD, respectively. The results of this study will facilitate the development of sustainable methane production technologies using food waste as a feedstock.

• Nuclear Engineering and Technology
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• 제56권3호
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• pp.1100-1107
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• 2024

The nuclear waste attributes of near-term deployable SMRs were assessed using established nuclear waste metrics, which are the DU mass, SNF mass, volume, activity, decay heat, radiotoxicity, and decommissioning LLW volumes. Metrics normalized per unit electricity generation were compared to a reference large PWR. Three SMRs, VOYGR, Natrium, and Xe-100, were selected because they represent a range of reactor and fuel technologies and are active designs deployable by the decade's end. The SMR nuclear waste attributes show both some similarities to the PWR and some significant differences caused by reactor-specific design features. The DU mass is equivalent to or slightly higher than the PWR. Back-end waste attributes for SNF disposition vary, but the differences have a limited impact on long-term repository isolation. SMR designs can vary significantly in SNF volume (and thus heat generation density). However, these differences are amenable to design optimization for handling, storage, transportation, and disposal technologies. Nuclear waste attributes from decommissioning vary depending on design and decommissioning technology choices. Given the analysis results in this study and assuming appropriate waste management system and operational optimization, there appear to be no major challenges to managing SMR nuclear wastes compared to the reference PWR.

• 대한지역사회영양학회지
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• 제24권5호
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• pp.422-432
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• 2019

Objectives: The purposes of the study were to assess wastes generated in school foodservice and to identify factors influencing the generation of plate waste. Methods: A survey was administered from November 18-30 in 2015 to dietitians and nutrition teachers that were employed in schools located in Gyeonggi province. A questionnaire file and on-line survey site link were sent to the dietitians and nutrition teachers by e-mail. A total of 622 dietitians and nutrition teachers responded and 594 responses were used for data analysis after excluding 28 responses with significant missing data. Results: Plate waste was the major part of food waste generated in school foodservice. Vegetable menus and soup/stews were discarded the most as plate waste. The dietitians and nutrition teachers perceived students' unbalanced diet and lack of appreciation of food as causes of the plate waste. Regarding waste management, they were concerned about environmental contamination by food waste and felt uncomfortable about discarding food. No plate waste day was the most frequently used plate waste reduction activity, followed by newsletters on plate waste reduction. Difficulty in getting teachers' support for dietary education during meal time was rated the greatest barrier to implementing the activities. To reduce plate waste, they perceived that students should understand the importance of environment conservation, teachers should supervise students' eating during meal time, students should be educated about proper portion, and foodservice staff should improve food quality. Conclusions: To improve students' intake and reduce plate waste in school foodservice, foodservice staff need to involve students in school foodservice and improve the palatability of meals, especially vegetable dishes. School nutrition teachers and dietitians should educate students about healthy eating and environment conservation and the school community needs to understand and support plate waste reduction and healthy eating in schools.

• 유기물자원화
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• 제13권1호
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• pp.90-99
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• 2005

본 연구는 음식물류폐기물 발생에 관한 춘천시민의 의식을 조사하고자 하였다. 조사결과 춘천시민의 약 50%가 일주일에 $5{\sim}10{\ell}$의 생활폐기물을 배출하고 있었으며 배출자 대부분이 35세이하였다. 또한, 일주일간 가정에서 배출되는 생활폐기물 중 음식물류폐기물 비율이 10~30%이었고, 배출형태로는 '물기제거 후 규격봉투에 담아 배출한다'가 약 30%, '물기제거 후 일반쓰레기와 함께 배출한다'가 약 10%이었다. 음식물류폐기물의 발생은 필요이상의 식품구매와 과량의 조리가 주된 요인이었으며 집주변이나 골목에 버려진 음식물류폐기물로 인한 가장 심각한 문제점은 악취 및 해충인 것으로 나타났다. 음식물류폐기물의 감량을 위한 중점관리대상은 주로 소규모 개인음식점으로 나타났다. 춘천시민들은 음식물류폐기물 감량을 위해 노력해야 할 주체로 응답자의 절반이상이 '시민 개개인'이라 생각하면서도 '감량을 위한 노력은 하지 않고 있다'고 응답하였다. 또한, 춘천시민들은 '음식물류폐기물이 자원이라는 의식'이 부족하였고 '음식물을 남기는 것이 예의'라고 생각하는 시민들이 많아 이에 대한 개선책이 필요한 것으로 나타났다.

• Journal of Advanced Marine Engineering and Technology
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• 제28권2호
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• pp.367-375
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• 2004

We have developed a highly efficient boiler system using the 2,600cc Diesel engine. In this system, the co-generation concept is utilized in that the electric power is produced by the generator connected to the engine, and waste heat is recovered from both the exhaust gases and the engine itself by the shell-and-tube heat exchangers. The heat exchanger connected to the engine outlet is specially designed such that it not only recovers waste heat effectively from the exhaust gases, but significantly reduces an engine noise. It is found that the total efficiency(thermal efficiency plus electric power generation efficiency) of this system reaches maximum 96.3％ which is about 15％ higher than the typical Diesel engine boiler system currently being used worldwide.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.175-180
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• 2008

Thermoelectric materials convert temperature difference to electric power for power generation and vice versa for refrigeration. Recent advances in enhancing the thermoelectric figure-of-merit shed light on efficient power generation from the waste heat available in industries and vehicles. Nanoscale phenomena with both nanoscale constituent-embedded bulk samples and nanoscale materials proving enhanced thermoelectric performance have been widely reviewed. Bulk materials of crystal-orientation and nano-structured particle embedding seem to promise a higher thermoelectric figure-of-merit and an effective power generation application. As a preliminary study, Si-Ge nanocomposite was prepared with spark plasma sintering method and its properties were examined.

• 토지주택연구
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• 제5권1호
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• pp.41-51
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• 2014

국내 신축 공동주택 건설은 2002년 11% 이상의 증가를 기록한 후 매년 3~4% 대의 꾸준한 증가추세를 보이고 있다. 최근 공공부문의 아파트 신축공사 현장에서 폐기물 분리발주제도에 의한 최초 발주물량과 실제 발생물량의 과다한 차이가 발주자와 수급인 사이에서 빈번하게 논란을 일으키고 있다. 이에 대해서는 현장 환경관리 미흡, 초기 계약물량의 과소 등 다양한 원인이 제기되고 있으며, 특히 건설폐기물 수량 예측에 적용되는 발생원단위 기준에 대한 개정 요구가 갈수록 증가하고 있다. 대부분의 현행 원단위는 2000년대 초에 수립되어 기술 발전에 따라 새롭게 적용되는 자재와 공법으로 인한 폐기물 발생 유형과 수량의 변화를 반영하지 못한다는 문제점을 지니고 있다. 따라서 본 연구는 보다 정밀한 신축아파트 폐기물 발생 원단위를 개발하기 위한 기초작업으로서 현장의 공종별 폐기물 발생 유형과 수량 예측방법을 명확히 하고자 하였다. 이를 위해 2010년에서 2013년 사이에 착공한 신축 아파트 10개 현장의 건축공사 내역서를 확보하고, 건설폐기물 전문가와 현장 폐기물관리 담당자의 의견을 반영하여 각 내역항목에서 발생가능한 폐기물 유형과 실질 할증률을 검토하였다. 본 연구에서 가설공사부터 지급자재부문까지의 건축공사 내역항목별로 정리한 폐기물 발생여부와 유형, 수량예측 시 반영여부, 손실률 등의 자료는 향후 보다 현실적인 데이터에 근거한 간접추계방식의 원단위 개발에 기여할 것이다.

• Environmental Engineering Research
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• 제25권4호
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• pp.462-469
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• 2020

This study is proposing a System Dynamics Model for estimating Greenhouse Gas (GHG) emission from treating Municipal Solid Waste (MSW) in South Korea for years 2000 to 2030. The government of country decided to decrease the total GHG emission from waste sector in 2030 as per Business-as-usual level. In context, four scenarios are generated to predict GHG emission from treating the MSW with three processes i.e., landfill, incineration and recycling. For prior step, MSW generation rate is projected for present and future case using population and waste generation per capita data. It is found that population and total MSW are directly correlated. The total population will increase to 56.27 million and total MSW will be 21.59 million tons in 2030. The methods for estimating GHG emission from landfill, incineration and recycling are adopted from IPCC, 2006 guidelines. The study indicates that Scenario 2 is best to adopt for decreasing the total GHG emission in future where recycling waste is increased to 75% and landfill waste is decreased to 7.6%. Lastly, it is concluded that choosing proper method for treating the MSW in country can result into savings of GHG emission.

• 한국포장학회지
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• 제25권2호
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• pp.23-29
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• 2019

The volume of parcel delivery is steadily increasing with the rapid growth of the global online e-commerce market. However, a large amount of packaging materials used for these parcel delivery is finally causing environmental problems as waste. The rapid increase of these packaging waste has been making many countries to research ways to reduce the generation of distribution packaging waste. In this study, we have measured the empty space ratio for 131 packagings of parcel delivery purchased through the several domestic online stores in order to investigate the present situation in connection with the degree of excessive or overpack in korean parcel delivery packagings, so that 64 packagings were exceeded 50% in the empty space ratio. And we have suggested ways to reduce the generation of distribution packaging waste raised by e-commerce-based parcel delivery through analyzing the previous research and case studies ; one is to optimize and minimize the packaging design by safe transit test(field-to-lab test), another is to develop a reusable & returnable transport packaging and system applicable in the domestic supply chain, the other is to regulate directly with a policy.

• 자원리싸이클링
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• 제30권1호
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• pp.92-101
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• 2021

국내 도시광산업체의 해외진출을 장려하기 위해 유럽 32개국과 일본, 미국의 폐기물 발생 및 재활용 현황을 정리하였다. 그 결과 EU(European Union) 32개국 중 독일의 물질소비량과 폐기물 발생량이 가장 많았고, EU의 폐기물 조성 중 광산폐기물이나 흙 등 무기물이 가장 많은 부분을 차지하고 있었다. 폐기물 처리방법으로서 매립과 재활용이 각각 39%와 38%으로 아직까지 재활용할 여지가 많은 것으로 판단되었다. 일본의 전체 폐기물 발생은 최근 4억톤 이하로 감소하고 있는 추세이며, 제조업에서 가장 많은 폐기물이 발생하였다. 폐기물 중 재활용되는 비율은 50%를 조금 넘는 수준이나, 금속스크랩의 경우 90%를 상회하고 있으며, 폐플라스틱의 경우 60%로 나타났다. 미국의 폐기물발생량은 최근 2억6천5백만톤을 상회하고 있으며, 폐기물 중 52.1%가 매립되고 있고 재활용은 25.1%정도에 불과하여 향후 재활용산업에 진출할 여지가 높다고 판단된다.