• 제목/요약/키워드: Research Process

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리싸이클 CFRP 적용 C/C 복합재료 제조 및 특성 연구 (Study of Manufacturing Process and Properties of C/C Composites with Recycled Carbon Fiber Reinforced Plastics)

  • 김세영;한인섭;방형준;김수현;성영훈;이슬희
    • Composites Research
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    • 제35권4호
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    • pp.242-247
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    • 2022
  • 본 연구는 기존의 폐CFRP를 재활용하여 얻은 재생 탄소섬유를 다시 CFRP 제조에 활용하는 대신 탄소를 모재로 구성하는 탄소/탄소 (Carbon/Carbon, C/C) 복합소재를 제조하는 원료로 활용하기 위한 것이다. 먼저 일반적으로 많이 활용되는 에폭시수지 복합재료의 열분해 공정에 산화-불활성 분위기 변환 기술을 적용하여 1~2% 수준의 잔탄률을 19%까지 향상시켰으며, 이를 통해 에폭시수지 활용 C/C 복합재료 제조 가능성을 확인하였다. 다만, 산화-불활성 분위기 제어를 통한 열분해 공정으로 얻은 탄소의 경우 산소결합도가 높아 추후 개선 연구가 필요한 것으로 나타났다. 또한, 폐CFRP를 열분해 열처리 후 파쇄 및 해쇄 공정을 통해 단섬유 C/C 복합재료 시험편을 제조하였으며 이에 대한 기계적 물성 평가를 통해 최적 공정 조건을 도출하였다.

Dependence of Stress-Induced Leakage Current on Low Temperature Polycrystalline Silicon TFTs

  • Chen, Chih-Chiang;Chang, Jiun-Jye;Chuang, Ching-Sang;Wu, Yung-Fu;Sheu, Chai-Yuan
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.622-625
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    • 2003
  • The dependence of stress-induced leakage current on LTPS TFTs was characterized in this study. The impacts of poly-Si crystallization, gate insulator, impurity activation, hydrogenation process and electrostatic discharge damage were investigated. It was observed more TFTs instable characteristic under those process-assisted processes. According to the LTPS roadmap, smaller geometric and low temperature process were the future trend and the stress-induced leakage current should be worthy of remark.

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Development of Treatment Process for Residual Coal from Biosolubilization

  • Rifella, Archi;Shaur, Ahmad;Chun, Dong Hyuk;Kim, Sangdo;Rhim, Young Joon;Yoo, Jiho;Choi, Hokyung;Lim, Jeonghwan;Lee, Sihyun;Rhee, Youngwoo
    • 청정기술
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    • 제24권2호
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    • pp.119-126
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    • 2018
  • This study introduced a treatment process that was developed to treat Indonesian low-rank coal with high-ash content, which has the same characteristics as residual coal from the biosolubilization process. The treatment process includes separation of ash, solid-liquid separation, pelletizing, and drying. To reduce the ash content, flotation was performed using 4-methyl-2-pentanol (MIBC) as frother, and kerosene, waste oil, and cashew nut shell liquid (CNSL) as collectors. The increasing amount of collector had an effect on combustible coal recovery and ash reduction. After flotation, a filter press, extruder, and an oven drier were used to make a dried coal pellet. Then another coal pellet was made using asphalt as a binder. The compressive strength and friability of the coal pellets were tested and compared.

지역사회 건강증진 협력 개발 연구의 지향 과제 (Health Promotion Research on Community Collaboration and Partnership Building: Current Emphases and Directions)

  • 유승현
    • 보건교육건강증진학회지
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    • 제26권4호
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    • pp.83-90
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    • 2009
  • Objectives: As collaboration for community health promotion is much emphasized, the concept and process of community collaboration for health needs to be discussed. This paper discusses varying types of collaboration and collaboration building processes and suggests directions for enhancing community collaboration research and practice. Methods: Leading literature on community partnership building and community health development and current community partnership research program information were reviewed. Results: Although the term collaboration is used interchangeably with cooperation, partnership, network, or coalition, conceptual differences need to be acknowledged in order to develop and reinforce the processes of collaboration. Collaboration building goes in hand with community-based participatory research and systems thinking, which should be supported by long-term, systematic planning and evaluation research. Conclusion: Collaboration for community health promotion needs to be defined and agreed conceptually, thus collaboration process can be developed. Effective collaboration building will be facilitated by systematic thinking and participatory research. Research support system should appreciate the time-intensive, process-oriented nature of collaboration building by providing long-term research funding and emphasizing process and long-term evaluation.

MEA 흡수제를 이용한 이산화탄소 포집 공정 모사 (Simulation on CO2 capture process using an Aqueous MEA solution)

  • 우대식;남성찬;정순관;윤여일
    • 한국산학기술학회논문지
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    • 제13권1호
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    • pp.431-438
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    • 2012
  • 아민 수용액을 이용한 이산화탄소 포집기술은 현재 가장 넓게 연구되는 분야이다. 전체 공정은 선택적 이산화탄소 흡수를 위한 흡수탑과 흡수제를 재생하고 고순도 이산화탄소를 얻기 위한 재생탑으로 이루어져있다. 공정 성능에 영향을 미치는 복잡한 설계 변수들이 존재하기 때문에 상업적으로 신뢰할만한 공정을 설계하기 위해서는 모델링을 통한 공정 해석과 최적화가 필요하다. 본 연구에서는 공정의 수렴문제를 고려하여 분해방법을 사용하였고, 아민계 흡수제를 이용하는 이산화탄소 포집 공정의 변수들에 대한 민감도 분석을 수행하였다. 현실적인 설계 결과를 얻기 위해 비평형 모델을 사용하였고 95% 이상의 순도로 90%의 이산화탄소를 회수할 수 있는 최적화된 공정을 설계할 수 있었다.

습식 화학 공정에 의한 태양전지로부터 고순도 실리콘 회수 및 이를 이용한 태양전지 재제조 (Photovoltaic Performance of Crystalline Silicon Recovered from Solar Cell Using Various Chemical Concentrations in a Multi-Stage Process)

  • 노민호;이준규;안영수;여정구;이진석;강기환;조철희
    • 한국재료학회지
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    • 제29권11호
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    • pp.697-702
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    • 2019
  • In this study, using a wet chemical process, we evaluate the effectiveness of different solution concentrations in removing layers from a solar cell, which is necessary for recovery of high-purity silicon. A 4-step wet etching process is applied to a 6-inch back surface field(BSF) solar cell. The metal electrode is removed in the first and second steps of the process, and the anti-reflection coating(ARC) is removed in the third step. In the fourth step, high purity silicon is recovered by simultaneously removing the emitter and the BSF layer from the solar cell. It is confirmed by inductively coupled plasma mass spectroscopy(ICP-MS) and secondary ion mass spectroscopy(SIMS) analyses that the effectiveness of layer removal increases with increasing chemical concentrations. The purity of silicon recovered through the process, using the optimal concentration for each process, is analyzed using inductively coupled plasma atomic emission spectroscopy(ICP-AES). In addition, the silicon wafer is recovered through optimum etching conditions for silicon recovery, and the solar cell is remanufactured using this recovered silicon wafer. The efficiency of the remanufactured solar cell is very similar to that of a commercial wafer-based solar cell, and sufficient for use in the PV industry.

무결정결함영역을 유지하면서 에너지를 절감하는 초크랄스키 실리콘 단결정 성장로 수냉관 최적 설계 (Optimal Water-cooling Tube Design for both Defect Free Process Operation and Energy Minimization in Czochralski Process)

  • 채강호;조나영;조민제;정현준;정재학;성수환;육영진
    • Current Photovoltaic Research
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    • 제6권2호
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    • pp.49-55
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    • 2018
  • Recently solar cell industry needs the optimal design of Czochralski process for low cost high quality silicon mono crystalline ingot. Because market needs both high efficient solar cell and similar cost with multi-crystalline Si ingot. For cost reduction in Czochralski process, first of all energy reduction should be completed because Czochralski process is high energy consumption process. For this purpose we studied optimal water-cooling tube design and simultaneously we also check the quality of ingot with Von mises stress and V(pull speed of ingot)/G(temperature gradient to the crystallization) values. At this research we used $CG-Sim^{(R)}$ S/W package and finally we got improved water-cooling tube design than normally used process in present industry. The optimal water-cooling tube length should be 200mm. The result will be adopted at real industry.

간헐포기 활성슬러지 중수처리공정의 현장적용 연구 (A Study on the Field Application of Intermittently Aerated Activated Sludge Process for Water Reuse System)

  • 서인석;김병군;박승국;권선웅
    • 한국물환경학회지
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    • 제16권4호
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    • pp.513-521
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    • 2000
  • Intermittently aerated activated sludge process was applied as a water reuse process of $70m^3/day$ for the upgrade of organic, nitrogen and phosphorus removal efficiency and clarifier performance. After application of the intermittently aeration, removal efficiency of BOD, SS, T-N and T-P were achieved 95%, 90%, 80% and 60%, respectively. Removal efficiencies in intermittently aerated process were considerably increased. comparing to those of continuously aerated activated sludge process. Also sludge rising problem in clarifier was improved. Average concentration of supplied reusing water were BOD 5 mg/L, turbidity 4 NTU and after chlorination, residual chlorine 0.4 mg/L, coliform 0 MPN/100mL. Intermittently aerated activated sludge process could be one of the best alternative process for the retrofit of conventional activated sludge process for the removal of nutrient in water reuse system.

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