• 한국환경과학회지
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• 제21권9호
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• pp.1043-1051
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• 2012

Coagulation, flocculation, and dissolved air flotation (DAF) experiments were performed with humic acid to evaluate the influence of operational conditions on removal efficiencies. We investigated coagulation, flocculation, and flotation conditions of humic acid removal using a laboratory-scale DAF system. This paper deals with coagulant type (aluminum sulfate and PSO-M) and the most relevant operational conditions (velocity gradients for coagulation and flocculation, retention time and recycle ratio and flotation time). Results showed that optimal conditions for removing humic acid, yielding CHA removal efficiencies of approximately 85 %, are a recycle ratio of 40 %, coagulant dosages of 0.15 - 0.20 gAl/gHA as aluminum sulfate and 0.03 - 0.12 gAl/gHA as PSO-M, coagulation($400s^{-1}$ and 60s), flocculation($60s^{-1}$ and 900s or more), and flotation(490 kPa or more and at least 10 min).

• 산업경영시스템학회지
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• 제30권1호
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• pp.48-58
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• 2007

For a sustainable development, the resources circulation system should be established and required alternative logistics area of enterprises. In this paper, we are to suggest a direction through analysis effects, and reduce, recycle, reuse factor of transportation, material handling, packing, information, management in logistics function, and effects of logistics organization on Firm Performance. We found significant correlations between the constructs extracted above, and between the constructs and firm's performance. This study was conducted with the subjects of manufacturing enterprises with concurrent reviews of literature and statistical analysis, and the meaning of this study would be the analysis of the influencers of the resources circulation system.

• Journal of Electrical Engineering and Technology
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• 제8권4호
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• pp.911-919
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• 2013

This paper reports the development of test bed with the energy recovering technique using two-step boost converter. The device is utilized for LDC aging test of Hyundai Motor's LPI AVANTE HEV in mass production. The developed power recycle type test bed is designed as 1.5 kW class to test up to the maximum load power of LDC and is also designed to supply scant power supply up to 500 W after power recycle. The theoretical design analysis and operational characteristics analysis results of test bed are reported, and its practicality and reliability are verified through the test result. Also, the finally developed test bed confirms approximately 79~85 % energy saving effect compared to the usual traditional aging test system.

• 자원리싸이클링
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• 제6권2호
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• pp.60-69
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• 1997

PS수지(polystyrene)는 수지강도가 높고 열안정성, 접착성, 도장성 등 2차가공성이 우수하여 가전제품, 사무용기기, 구조부품, 일용잡화 등 다방면에 적용되고 있으며 1995년도의 수요량은 약 52만톤에 이르고 잇다. PS수지중 단열재와 각종 포장, 완충재로 사용되고 있는 발표 PS(EPS)수지는 98%가 공기로 구성되어 있고 프레온 등의 환경저해물질을 사용하지 않아 연소시 유독가스를 발생시키지 않고 골판지에 비해 적은 비중으로 완충작용을 하므로 자원절약적이고 환경친화적인 소재로서 95년도의 국내수요는 21만톤에 이르고 있다. 용도별로는 단열재로 70%, 가전, 농수산물 포장재로 약 30%가 사용되고 있으며 95년도 재활용실적은 약 26%에 달하고 있으며 이중 재생수지로 66.5%, 경량콘크리트에 21.1%, 접착제 및 기타 용도로 12.3%가 사용되었다.

• 자원리싸이클링
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• 제6권2호
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• pp.12-21
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• 1997

Plastics waste constitutes approximately 23% by volume of the municipal solid waste(MSW) generated in the U.S. each year, and have slow rate of degradation in the environment. Therefore, there is a great deal of public pressure to recycle plastics, and more than 100 million people participate in the curbside recycling programs. Despite the high level of public interest, only 3.5% of the plastic are recycled, which is substantially lower than the recycle rates of other materials such as paper fibers, glass, and iron. Although a large part of the reason is due to the low price of virgin polymers, which in turn is due to the low price of oil, it is possible to make the plastics recycling as a profitable business by developing advanced technologies. In this communication, various methods of separating pplastics from metals and from each other are discussed.

• 한국포장학회지
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• 제30권1호
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• pp.31-42
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• 2024

This review paper provides a detailed analysis of PET (polyethylene terephthalate) bottle recycling in Japan. Japan is a global leader in PET bottle recycling due to its advanced regulatory framework and proactive industry initiatives. Japan's success attributes to the widespread adoption of bottle-to-bottle recycling, driven by the beverage industry's commitment to sustainability. By utilizing post-consumer PET bottle recovery and food-grade mechanical recycling technologies, Japan has achieved significant milestones in PET bottle recycling. This paper examines regulatory frameworks, collection systems, reprocessing facilities, and food safety assessments to highlight Japan's innovative approaches to PET bottle recycling and their impact on global sustainability efforts. Drawing parallels with Korea's early stages of PET recycling, it suggests involving major beverage companies and re-evaluating regulations to promote bottle-to-bottle recycling. The focus is on the implications for Korea to promote circular economy principles in plastic recycling.

• 한국지반환경공학회 논문집
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• 제9권2호
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• pp.23-29
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• 2008

고농도 입자성 유기 폐수를 대상으로 기존 혐기성 공정인 CSTR과 UASB공정으로 처리 시 불량한 상징수질, 불안정한 운전 특성과 같은 문제점이 제시되었다. 이에 본 연구는 새로운 개념의 ADEPT(Anaerobic Digestion Elutriated Phased Treatment) 공정을 주정폐수에 적용하여 처리 가능성을 평가하였다. CSTR과 ADEPT의 성능 비교 결과 ADEPT공정에서 gas 발생량은 약 2배였으며, 유기물 제거 효율과 고형물 제거 효율 역시 더 높은 효율을 보여주었다. 또한 ADPET는 비교적 짧은 HRT에서도 휘발성 지방산 생성으로 인한 pH 저하의 영향을 받지 않았으며, 안정적으로 pH를 유지하였다. ADEPT의 recycle ratio를 6Qin과 2Qin으로 변화를 주어 운전 시 6Qin의 운전 기간 동안 높은 처리 효율을 보여주었다. 따라서 ADEPT는 짧은 HRT로 인한 경제성 향상과 메탄 발생을 이용한 에너지 회수, 또한 산 생성조에서 생성되는 유기산을 최대로 생산, BNR 공정의 유기 탄소원으로 활용 가치가 있다고 판단된다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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• pp.145-148
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• 2003

Recently, the recycle of CMP (chemical mechanical polishing) slurries have been positively considered in order to reduce the high COO (cost of ownership) and COC (cost of consumables) in CMP process. Among the composition of slurries (buffer solution, bulk solution, abrasive particle, oxidizer, inhibitor, suspension, antifoaming agent, dispersion agent), the abrasive particles are one of the most important components. Especially, the abrasive particles of slurry are needed in order to achieve a good removal rate. However, the cost of abrasives, is still very high. In this paper, we have collected the silica abrasive powders by filtering after subsequent CMP process for the purpose of abrasive particle recycling. And then, we have studied the possibility of recycle of reused silica abrasive through the analysis of particle size and hardness. Also, we annealed the collected abrasive powders to promote the mechanical strength of reduced abrasion force. Finally, we compared the CMP characteristics between self-developed KOH-based silica abrasive slurry and original slury, As our experimental results, we obtained the comparable removal rate and good planarity with commercial products. Consequently, we can expect the saving of high cost slurry.

• 한국환경교육학회지:환경교육
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• 제11권1호
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• pp.151-164
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• 1998

Conclusion and the improvement plan according to the survey on recycling wastes in 'the program of woman and environmental education' mainly for the chairwomen of the women's association of the apartment house in City and County of Chungchongnamdo during the first half of 1998 (from March tp April) are as follows. 1. Conclusion 1) It showed that the rate of recognition for recycle has no difference by regional groups and the rate of recognition is 57.4% but they mainly know vaguely or they do not know. 2) It showed that the rate they do not know how the separated wastes are recycled is 30.4% and the scope of their knowledge is approximative.(52.6%) 3) It showed that it is the housewives who mainly do the separate garbage collection (72.7%) and 19.1% of the people have no interest in the separate discharge. 4) It showed that the rate they filter the garbage or remove water from the garbage at house is 53.1%. And 20% of the people in the urban region dump untreated wastes but 8.5% of the people in the rural region do the same, so the rate of using garbage in the rural region is higher than that in the urban region. 5) It showed that the separate state of the garbage is 29.2% for the removal of toothpick and paper and 47.4% for the removal of vinyl and stopper. 6) It showed that 66.7% of the motive for recycling waste is the education activity for environment by the women's association and SAEMAEUL association and 34.5% of that is the influence of TV and radio. 7) It showed that the rate of making compost and feed using garbage in the rural region is higher than that in the urban region and in some urban regions, the rate they sprinkle the garbage in provisional compost state on the floor garden is high. 8) It showed that the recognition rate for the material of separately collected garbage corresponding to the separate waste system of 5-6 classification is 12.5% 9) It showed that the major variable which has an effect on the recycle is the education activity for environment by the neighborhood meeting(P<0.05) and by the women's association of saemaeul activity(P<0.05)

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 제5회 학술대회 논문집 일렉트렛트 및 응용기술연구회
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• pp.109-112
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• 2003

Recently, CMP (Chemical mechanical polishing) technology has been widely used for global planarization of multi-level interconnection for ULSI applications. However, COO (cost of ownership) and COC (cost of consumables) were relatively increased because of expensive slurry. In this paper, we have studied the possibility of recycle of reused silica slurry in order to reduce the costs of CMP slurry. Also, we have collected the silica abrasive powders by filtering after subsequent CMP process for the purpose of abrasive particle recycling. And then, we annealed the collected abrasive powders to promote the mechanical strength of reduced abrasion force. Finally, we compared the CMP characteristics between self-developed KOH-based silica abrasive slurry and original slurry. As our experimental results, we obtained the comparable removal rate and good planarity with commercial products. Consequently, we can expect the saving of high cost slurry.