• 한국도로학회논문집
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• 제16권5호
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• pp.39-47
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• 2014

PURPOSES : This study aimed to analyze economic effect of recycled aggregate production on job-site airport pavement. METHODS : The validation of site recycling for waste concrete as economic efficiency is analyzed through the case study of site recycling at an O airport pavement construction. The break-even point for the cost of site recycling was estimated according to two different waste concrete processing methods such as job-site recycling and processing on commission (or plant). RESULTS : Job-site recycling cost decreases as the use rate of job-site recycled concrete aggregate increases, or the amount of concrete waste increases, but transporting distance decreases. It was shown in an O airport case that as the use rate of job-site recycled concrete aggregate exceeds 61.4 %, the job-site recycling cost is cheaper than the processing cost on commission. CONCLUSIONS : The results of this study can utilize basic data of feasibility for site recycling of waste concrete on airport pavement construction.

• KSBB Journal
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• 제8권1호
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• pp.17-22
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• 1993

$1.96{\times}10^{-5}$(IU/cell/hr) of specific scu-PA production rate was obtained from HEK cells in maintaining ca. $8{\times}10^{5}$(cells/ml) of maximum roll density at 10(ml/hr) of perfusion rate with recycling 20% serum free conditioned media. It can be compared to $4{\times}10^{6}$(cells/ml) of maximum cell density and $4.56{\times}10^{-4}$(IU/cell/hr) of specific production rate in cultivating cells with 1% serum containing medium. Thc conversion ratio of scu-PA to tc-UK increased up to 55% as the recycling ratio increased; however, recycling the used medium seemed to have least negative effect on cell growth. It also showed that the recycling process had definitive advantage of using serum free medium in perfusion cultivation of HEK cell line.

• Industrial Engineering and Management Systems
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• 제13권1호
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• pp.52-66
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• 2014

Promotion of a closed-loop supply chain requires disassembly systems that recycle end-of-life (EOL) assembled products. To operate the recycling disassembly system, parts selection is environmentally and economically carried out with non-destructive or destructive disassembly, and the recycling rate of the whole EOL product is determined. As the number of disassembled parts increases, the recycling rate basically increases. However, the labor cost also increases and brings lower profit, which is the difference between the recovered material prices and the disassembly costs. On the other hand, since the precedence relationships among disassembly tasks of the product also change with the parts selections, it is also required to optimize allocation of the tasks in designing a disassembly line. In addition, because information is required for such a design, the recycling rate, profit of each part and disassembly task times take precedence among the disassembly tasks. However, it is difficult to obtain that information in advance before collecting the actual EOL product. This study proposes and analyzes an optimal disassembly system design using integer programming with the environmental and economic parts selection (Igarashi et al., 2013), which harmonizes the recycling rate and profit using recyclability evaluation method (REM) developed by Hitachi, Ltd. The first stage involves optimization of environmental and economic parts selection with integer programming with ${\varepsilon}$ constraint, and the second stage involves optimization of the line balancing with integer programming in terms of minimizing the number of stations. The first and second stages are generally and mathematically formulized, and the relationships between them are analyzed in the cases of cell phones, computers and cleaners.

• 한국산림과학회지
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• 제97권5호
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• pp.530-539
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• 2008

The study evaluates the greenhouse gas (GHG) reduction potential of paper recycling by paper industry in South Korea and determines the positive impact on global warming by conserving the world's forests through decreasing pulp wood use. South Korea is one of the leading countries in the world thai recycle papers with a collection rate of 71.8 percent and a recycling rate of 74.4 percent in 2005. Greenhouse gas emission reduction potential in terms of carbon dioxide ($CO_2$) equivalent from paper recycling was assessed scientifically by the use of Life Cycle Assessment (LCA). Three types of papers including newsprint, container-board, and white-board were used for assessment in this study. Results of this study indicate that $CO_2$ emission reduction potential of recycling paper varies according to its types and recycling rates. Greenhouse gas emission reduction factor of 0.74869 $tCO_2$ per ton of recycled paper was derived from this study. In applying this factor. it was found out that the South Korean paper industry reduced GHG emission of around 6,364,550 $tCO_2$ by recycling paper in 2005. With this. the country's paper industry could claim that by recycling in thai particular year. approximately $23.8million\;m^3$ of woods were not harvested and thus 212,500 ha of world's forests were estimated to be saved in that particular year. Overall. it could be concluded that the Korean paper industry was able to reduce $CO_2$ emission and was able to conserve world's forests by its high rates of paper recycling.

• 청정기술
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• 제15권1호
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• pp.23-30
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• 2009

EU의 WEEE 지침에서는 전기전자제품의 생산자들이 반드시 달성하여야 하는 재활용률과 재생률의 목표치를 설정해 놓았다. 하지만 어떻게 재활용률과 재생률을 계산해야 하는지는 규정하지 않았다. 생산자의 입장에서는 설계단계에서 제품의 폐기단계에서의 재활용률과 재생률을 예측하고 결과를 설계의 개선에 반영하기 위하여 제품의 재활용가능률과 재생가능률을 산정해 볼 수 있는 표준방법이 필요하다. 본 연구에서는 전기전자제품의 생산자들이 개발되는 제품의 재활용가능률 및 재생가능률을 산정할 수 있는 방법들을 조사하고 폐기단계에서의 재활용률과 재생률과 유사한 결과를 얻을 수 있는 재활용가능률과 재생가능률의 산정방법을 개발하였다. 개발된 방법은 여러 가지 종류의 가전제품에 적용하여 결과를 검정해 보았다.

• 유기물자원화
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• 제11권1호
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• pp.138-148
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• 2003

본 연구에서는 폐플라스틱의 재활용 현황을 조사한 후 재활용을 저해하는 요인들을 분석하였다. 폐플라스틱의 재활용율을 저해하는 요인들은 토지와 인력확보의 어려움, 플라스틱의 종류별 재질표시 미흡, 경제적 유인책인 예치금과 부담금의 요율의 부적합 등으로 나타났다. LCA 방법을 통한 폐플라스틱의 재활용성을 분석하기 위하여 PET 재질의 물질 재활용 공정에 대한 LCA를 수행하였다. PET를 처녀원료로만 제조하는 것보다 재생 PET원료를 함께 사용했을 때의 환경영향은 오존층 파괴를 제외한 나머지 영향범주에서 (-)값으로 나타나 보다 환경친화적임이 밝혀졌다. 특히 지구온난화 영향의 범주에서 환경삭감 효과(avoided impact)가 크게 나타났다. 폐플라스틱의 재자원화를 활성화 하려면 먼저 재활용품에 대한 분리수거 제도가 확립되어야 하고 재활용 가능표시가 명확해야 하며 소비자들이 이를 쉽게 이해할 수 있어야 한다. 또한 생산자 예치금 및 소비자 예치금의 요율이 합리적이어야 하며 재활용에 대한 인프라구축, 정보체계 확립, 공공교육을 통한 시민들의 협조가 필요하다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1244-1247
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• 2004

In the last year, the number of registered vehicles in Korea surpassed the 14 million mark, and increase in number continuously. Nowdays, this tendency has raised some problems inevitably in the view of expansion of ELV and earth environment pollution resulted from it. Currently, the domestic recycle rate of ELV is about 75％. the reason of the row rate of it is due to that dismantling company can not obtain the needed recycling technology. State of art for recycling technology of ELV in domestic & foreign was introduced.

• Journal of the Korean Wood Science and Technology
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• 제17권3호
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• pp.45-51
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• 1989

A major problem in the enzymatic hydrolysis of lignocellulosic substrates is the very strong bonding of cellulase to lignin and even cellulose in the hydrolysis residues. This phenomenon inhibits recycle of the cellulase which is a major expense of the enzymatic hydrolysis process. In this paper, autohydrolyzed wood was delignified by two-stage with a 0.3% Na OH extraction and oxygen-alkali bleaching and was subjected to enzymatic hydrolysis with cellulase. Also, an improved almost quantitative recycle process of cellulase enzyme was discussed. In enzyme recovery by affinity method. the first recycling showed relatively high hydrolysis rate of 97.4%. Even at the third recycle. hydrolysis rate was 86.7 percents. In the case of cellulase recovery by ultrafiltration method, first 2 recycling treatments resulted very high hydrolysis rate(97.0-97.7%). Even the third recycling showed about 94.2%. Authoydrolysis of oak wood followed by 2-stage delignification with alkali and oxygen-alkali produced a substrate for enzymatic hydrolysis that allowed almost quantitative recycle of cellulase.

• 한국포장학회지
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• 제29권2호
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• pp.73-78
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• 2023

The cosmetics industry faces a significant challenge in addressing the decreased recycling rate of cosmetic containers due to the composite materials used to meet consumers' aesthetic satisfaction. To address thees issues, eco-friendly packaging solutions such as refill packaging and single-material use have been developed. However, the market for eco-friendly cosmetics packaging requires a product that meets consumers' demands for aesthetics, sensitivity, and eco-friendliness while also performing as well as existing products. This study presents a solution to the challenge of the decreased recycling rate of cosmetic containers by developing a new cosmetic packaging product for cream formulations. The product features an easily separable and dischargeable internal refill container, while maintaining the design aesthetics of the external container. Through various tests, the product was shown to be of equivalent quality and performance to existing cream cosmetic packaging, with no leakage or defects observed. Furthermore, the use of a single-material polypropylene refill container is expected to contribute to the improvement of the plastic recycling rate.

• 자원리싸이클링
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• 제23권4호
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• pp.58-68
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• 2014

2010년 기준 전 세계 자동차 등록대수는 약 10억 대에 이르며, 약 4천만 대의 폐 자동차가 발생하였다. 이에 EU를 비롯한 선진국들은 2015년까지 폐 자동차의 재활용률을 95%까지 높일 것을 요구하고 있다. 우리나라도 '전기 전자제품 및 자동차의 자원순환에 관한 법률'을 제정하여 폐 자동차의 95% 재활용을 목표로 하고 있다. 이러한 요구조건을 충족시키기 위해 현재 충분히 재활용되지 못하고 파쇄잔재물의 형태로 매립되고 있는 플라스틱, 비철금속 등의 처리 문제가 중요한 과제로 부상하고 있다. 본 연구에서는 폐 자동차 처리 선진국의 재활용 현황 조사의 일환으로, EU 폐차처리규정 설정 방향과 EU의 ELVs & SLF/ASR 처리 현황에 대한 조사를 수행하여, ELVs & SLF/ASR 처리의 세계적인 흐름을 확인하였다.