• Title/Summary/Keyword: 화학효율

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차세대 연료전지 기술 국가기술지도 [NTRM]

  • 한종희;임태훈
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 2003.05a
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    • pp.121-139
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    • 2003
  • 기술분석, 기술적 극복과제 도출 및 해결방안, 경제성 분석(환경 cost 고려), 단계별 개발목표의 정량화, 목표달성 방안(추진 시나리오), 기술의 정의 : 연료의 화학에너지를 전기화학반응에 의해 전기에너지로 직접 변환하는 발전 장치로서, 기존의 발전 기술보다 높은 발전효율로 그리고 공해물질 배출은 줄이면서 전기와 열을 동시에 생산하는 기술(중략)

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POLICY & ISSUES 기획특집_3 - 제품 유해물질규제 현황 및 사업장 대응시스템 구축방안

  • Park, Baek-Su
    • Bulletin of Korea Environmental Preservation Association
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    • s.405
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    • pp.17-21
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    • 2013
  • 범세계적으로 강화되고 있는 화학물질 및 유해화학물질 함유제품 규제에 대한 기업의 체계적이고 효율적 대응 대책 마련이 시급하다. 이률 위해서는 우선적으로 제품에 함유된 규제 물질을 확인하고 제조공정 유입 및 사용을 차단하기 위한 공급망내 물질정보 생산 관리 전달을 통합 관리하는 사업장 대응시스템 구축이 필요하다.

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Technology of Titanium Powder Materials (티타늄 분말재료 기술)

  • 김용진
    • Journal of Powder Materials
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    • v.11 no.3
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    • pp.265-270
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    • 2004
  • 티타늄 및 티타늄합금은 강도/밀도 비가 높고, 내열성, 내부식성, 피로강도가 높기 때문에 지금까지 항공, 우주, 해양 및 화학 장치용 소재로서 많이 사용되어 왔다. 최근, 자동차 산업과 레저용 제품 등의 성능과 효율향상을 위해 항공ㆍ우주 산업이나 특수화학장치 산업에 한정되어 사용되고 있던 티타늄소재를, 이들 산업으로 확대하여 응용하고 있다. (중략)

A Study on Remediation of Diesel-Contaminated Soil by Biosurfactant- Enhanced Soil Washing (생물계면활성제를 이용한 디이젤 오염토양세척기술에 관한 연구)

  • 문혜준;임영경;김윤관;주춘성;방기연;정욱진;이승우
    • Journal of Soil and Groundwater Environment
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    • v.7 no.2
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    • pp.13-22
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    • 2002
  • Soil washing by surfactants is a technology to enhance mobilization and subsequent degradation of oil pollutants by reducing the surface tension of pollutants which is combined with soil. In this study, biosurfactant, rhamnolipid was produced from Pseudomonas aemginosa ATCC 9027 which had an excellent biodegradable activity in soil without causing secondary pollution. Effects of chemical surfactants on the removal of diesel from diesel-contaminated soil were compared to those of biosurfactants including rhamnolipid. Diesel removal efficiency by rhamnolipid extracted from P. aeruginosa culture broth was over 95% in both batch and column washing test in 5,000ppm diesel-contaminated soil with 1% surfactants after washing for 24 hours. On the contrary, the results of chemical surfactants were below 50∼80%, The chemical surfactants with HLB value(8∼15) showed more then 75% efficiency of diesel removal. But, when the HLB values were below 8 or over 15. their efficiency were observed as less then 60% of diesel removal. Rhamnolipid, biologically produced surfactants, may also be promising agent for enhancing diesel removal from contaminated soil.

Effective Chemical Treatment of Biologically Treated Distillery Wastewater in Industrial Scale (생물학적으로 처리한 주정폐액의 효율적인 화학적 처리방법)

  • Nam, Ki-Du;Chung, In;Hur, Daniel;Park, Wan
    • Journal of Life Science
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    • v.9 no.6
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    • pp.692-697
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    • 1999
  • For further removal of non-biodegradable CODs and color in biologically treated distillery waster water, we selected a chemical treatment with Fe(III) and cationic polymers and then another chemical treatment with Fenton reagent. We developed Pregenerated Bubble Flotation(PBF) to effectively remove the chemical sludge from each chemical reaction process. The flotation unit was constructed with hydraulic loading rate, 7 ㎥/$m^2$.hr. The CODMn and suspended solids (SS) in biologically treated distillery waste water were reduced by the first PBF from 310-1096 mg/L to 141-303 mg/L and from 160-990 mg/L to 48-385 mg/L, respectively. Again, after the Fenton reaction process, floated SS was skimmed off at the top of the flotation unit and the final effluent was directly discharged without any tap water dilution. The quality of final effluent can be below 40 mg/L-CODMn but IISan Distilery has been maintained effluent quality of 73 mg/L-CODMn and 10-80 mg/L-SS. The chemical cost was saved by more than 30% as compared with that of prior process.

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Effect of deep eutectic solvent (DES) on the extraction of asiaticoside and madecassoside from Centella asiatica (병풀(Centella asiatica)로부터의 asiaticoside와 madecassoside의 추출효율에 미치는 DES의 영향)

  • Jaeyeong Choi;Yuim Jeon;Sung Ho Ha
    • Analytical Science and Technology
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    • v.36 no.3
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    • pp.128-134
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    • 2023
  • Centella asiatica (C. asiatica) extracts, including asiaticoside and madecassoside, are used in ointments to treat the wound and atopic dermatitis due to their antibacterial and skin-regenerating effects in Asia. Therefore, research on the cultivation and extraction efficiency of C. asiatica is being actively conducted to increase commercialization efficiency. In this study, various deep eutectic solvents (DESs) were prepared and used as the extraction solvents according to the mole ratio between the hydrogen bond acceptor (HBA) and hydrogen bond donor (HBD). And then, the extraction yields in distilled water (DW) and methanol (MeOH), commonly used extraction solvents for C. asiatica, were compared and analyzed by HPLC in the optimized operating condition. As a result, a mixture of DW and DES at a ratio of 3:7 showed about 1.4 times higher extraction efficiency than MeOH only. Conversely, the extraction efficiency in a mixture of MeOH and DES at a ratio of 3:7 was about 6 % lower than that in MeOH only.

Air-Processed Efficient Perovskite Solar Cell via Antisolvent Additive Engineering (안티솔벤트 첨가제 공정에 의한 대기 중 고효율 페로브스카이트 태양전지 제작)

  • Se-Yeong Baek;Seok-Soon Kim
    • Applied Chemistry for Engineering
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    • v.35 no.2
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    • pp.128-133
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    • 2024
  • Although antisolvent-assisted crystallization is one of the promising processes to produce high-quality perovskite films, general antisolvents such as chlorobenzene (CB) have toxic and volatile properties. In addition, CB is not suitable to control the crystallization of perovskite in the atmospheric air. In this work, isopropyl acetate (IA) is used as an eco-friendly antisolvent to demonstrate air-processed perovskite solar cells, and ethyl-4-cyanocinnamate (E4CN) with a cyano group, carbonyl group, and aromatic ring is introduced in IA to improve the performance and stability of devices. Defects at the surface and grain boundaries of the perovskite layer, such as un-coordinated Pb2+ and iodine, can be decreased resulting from the interaction of E4CN and perovskite, and thus reduced recombination and enhanced carrier transport can be expected. As a result, the perovskite device with E4CN achieves a high maximum power conversion efficiency (PCE) of 18.89% and outstanding stability, maintaining 60% of the initial efficiency for 300 h in the air without any encapsulation.

고효율 색소결합 유-무기 하이브리드 레이저 재료의 제조와 특성평가

  • Gwak, Seung-Yeon;Yang, Seung-Cheol;Kim, Jae-Hong;Lee, Gang-In;Lee, Jong-Hun;Bae, Byeong-Su
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2010.05a
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    • pp.57.1-57.1
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    • 2010
  • 레이저 색소 분자간의 회합을 막음으로써 높은 레이저 효율을 갖는 고체 색소 레이저를 제조하기 위해 레이저 색소인 DCM을 유-무기 하이브리드 재료에 화학적으로 결합시켰다. 수산화기를 기능기로 갖는 DCM을 합성하여 이를 솔-젤반응의 전구체로 활용하였다. 유기실란을 DCM과 함께 솔-젤반응을 시킴으로써 DCM이 결합된 유무기 하이브리드 재료를 제조하였다. DCM이 결합된 유-무기 하이브리드 재료는 유기물과 무기물의 특성을 각각 갖고 있기 때문에 용액공정을 통해 고체 색소 레이저를 단시간에 제작할 수가 있을 뿐만 아니라 열적 및 광학적으로 우수한 특성을 보여주었다. Nd:YAG 레이저를 여기광으로 이용하여 DCM이 결합된 유-무기 하이브리드 재료의 레이저 효율을 측정하여 DCM을 유기용매에 녹인 색소 레이저의 레이저 효율과 비교하였다. DCM이 결합된 유-무기 하이브리드 재료는 DCM의 농도가 높아질 수록 유기용매를 이용한 색소 레이저에 비해서 더 높은 레이저 효율을 가지는 것을 관찰하였다. 이는 DCM이 결합된 유-무기 하이브리드 재료에 각각의 DCM 분자가 실록산 망목구조와 화학적으로 결합이 되어있기 때문에 하이브리드 재료에 안정적으로 존재할 수 있게 되고 망목구조에 둘러쌓여 분자간의 회합이 방지되는 효과를 가지게 되기 때문이다.

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