• 대한화학회지
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• 제61권3호
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• pp.89-96
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• 2017

This study proposed adsorption of Pb(II) ions from aqueous solution using activated carbon prepared from areca catechu shell (ACS AC) using Timphan Method. The effects of independent variables on adsorption kinetic and isotherm have been investigated by conducting experiments in batch mode at neutral pH. The structural characterization of adsorbent was done by FT-IR and SEM analysis. The Pb(II) adsorption was correlated very well with the pseudo second-order kinetic (PSOKM) and Langmuir isotherm models (LIM). Increasing NaOH mass for activation and adsorption temperature increased weakly all the parameters of adsorption kinetic and isotherm. The Pb(II) ions adsorption capacity of the ACS AC at 27 and $45^{\circ}C$ was 50.51 and 55.25 mg/g, respectively. Thermodynamic parameters were determined, and the results confirmed the Pb(II) ions adsorption should be endothermic and spontaneous process, and both physical and chemical adsorption should be taken place.

• 한국응용과학기술학회지
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• 제24권4호
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• pp.383-392
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• 2007

This paper is studied on the efficient purification process of dimethyl carbonate (DMC) from the melt layer crystallization combining crystallization process, sweating process and distillation recovery process. Purity and yield of DMC crystal depended mainly on the crystallization temperature, cooling rate, sweating termperature sweating rate. Through the optimization of crystallization and sweating operation, DMC crystal can be upgraded to very high purity over 99.9% and high yield over 85%.

• 청정기술
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• 제24권1호
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• pp.1-8
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• 2018

환경 오염에 대한 사회적 요구가 증가하고 염색 공정 폐수 배출에 대한 규제가 강화되면서 기존 수계 염색에서 발생하는 다량의 폐수와 에너지 낭비를 근본적으로 해결하기 위한 대안으로 초임계 염색 공정이 주목 받고 있다. 초임계 염색 공정에서는 기존 수계 염색에서 염색 용매인 물 대신 이산화탄소만을 사용하기 때문에 발생하는 폐수가 전혀 없고 미 고착 염료와 이산화탄소를 재사용 할 수 있다는 점에서 친환경적이다. 또한 염색 이후 추가적인 건조공정 없이 건조된 섬유를 얻을 수 있어 에너지 소비를 줄일 수 있다. 본 논문에서는 먼저 초임계 염색 공정의 발전배경과 현재 우리나라에서의 연구를 정리하였으며 초임계 염색의 원리와 기존 수계염색과의 장단점을 비교 설명하였다. 원리를 보다 자세히 설명하기 위해 초임계 이산화탄소와 염료 사이의 용해도를 비롯해 초임계 이산화탄소와 섬유에서 염료의 분배계수 및 물질전달 연구를 정리하였고, 현재 연구의 한계점과 연구방향을 제시하였다. 또한 초임계 염색 설비 내에서의 염료의 동적거동에 대하여 토의하였으며 전 세계적으로 개발된 초임계 염색 설비를 정리하였다. 마지막으로 현재 초임계 염색 공정의 최적화와 폴리에스터를 제외한 다른 합성섬유와 천연섬유에 적용하기 위해 필요한 연구개발 방향을 제시하였다.

• 한국가스학회:학술대회논문집
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• 한국가스학회 2002년도 추계학술발표회 논문집
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• pp.137-142
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• 2002

• Bulletin of the Korean Chemical Society
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• 제35권7호
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• pp.2183-2185
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• 2014

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권6호
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• pp.371-374
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• 2002

Production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)［P(3HB/V)］, by fed-batch culture of recombinant Escherichia coli harboring a plasmid containing the Alcaligenes latus polyhy-droxyalkanoate (PHA) biosynthesis genes, was examined in two pilot-scale fermentors with air supply only, In a 30 L fermentor having a XLa value of 0.11 S­$^1$, the final P(3HB/V) concentration and the P(3HB/V) content obtained were 29.6 g/L and 70.1 wt%, respectively giving a productivity of 1.37 g P(3HB/V)/L-h. In a 300 L fermentor having a XLa of 0.03 S­$^1$, the P(3HB/V) concentration and the P(3HB/V) content were 20.4 g/L and 69 wt%, respectively giving a productivity of 1.06g P(3HB/V)/L-h. These results suggest that economical production of P(3HB/V) is possible by fed-batch culture of recombinant E. coli in a large-scale fermentor having low KLa value.

• Korean Chemical Engineering Research
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• 제61권1호
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• pp.89-96
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• 2023

동적 선형 블록과 정적 비선형 블록이 직렬로 연결되어 있는 Wiener형 비선형 모델은 여러 화학 공정의 동특성을 묘사하는데 널리 사용되는데, Wiener형 비선형 공정의 모델 확인은 다소 긴 공정 활성화 데이터가 필요하다. 본 연구는 이러한 단점을 보완하기 위하여 단일 계단 응답으로부터 Wiener형 비선형 공정 모델을 찾아낼 수 있는 새로운 모델 확인 방법을 제안한다. 제안된 방법은 계단 응답의 초기 응답으로부터 선형 동적 블록의 예측 응답을 얻어 선형 동적 블록의 모델을 확인하고, 이어서 비선형 정적 블록의 모델을 확인한다. 본 방법은 단일 계단 응답만을 사용하여 공정 모델 확인을 위해 필요한 공정 응답을 얻는 과정에서 시간과 비용적으로 큰 이득을 얻을 수 있다. 제안된 공정 확인 방법의 성능은 대표적인 Wiener형 비선형 공정인 pH 적정 공정과 액위 공정을 대상으로 검증되었다.

• 상하수도학회지
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• 제29권1호
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• pp.133-138
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• 2015

Pressure retarded osmosis (PRO) process is one of membrane processes for harvesting renewable energy by using salinity difference between feed and draw solutions. Power is generated by permeation flux multiplied by hydraulic pressure in draw side. Membrane fouling phenomena in PRO process is presumed to be less sever, but it is inevitable. Membrane fouling in PRO process decreases water permeation through membrane, resulting in significant power production decline. This study intended to investigate the effect of hydraulic pressure in PRO process on alginate induced organic fouling as high and low hydraulic pressures (6.5 bar and 12 bar) were applied for 24 h under the same initial water flux. In addition, organic fouling in draw side from the presence of foulant (sodium alginate) in draw solution was examined. As major results, hydraulic pressure was found to be not a significant factor affecting in PRO organic fouling as long as the same initial water flux is maintained, inidicating that operating PRO process with high hydraulic pressure for efficient energy harvesting will not cause severe organic fouling. In addition, flux decline was negligible from the presence of organic foulant in draw side.

• 융복합기술연구소 논문집
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• 제2권2호
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• pp.30-34
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• 2012

The SI thermochemical cycle process accomplishes water splitting through distinctive three chemical reactions. We focused on thermodynamic models applicable to the process. Recently, remarkable models based on the assumed ionic species have been developed to describe highly nonideal behavior on the liquid phase reactions. ElecNRTL models with ionic reactions were proposed in order to provide reliable process simulation results for phase equilibrium calculations in Section II and III. In this study, the current thermodynamic models of SI thermochemical cycle process were briefly described and the calculation results of the applied ElecNRTL models for phase equilibrium calculations were illustrated for binary systems.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1996년도 The 9th KACG Technical Annual Meeting and the 3rd Korea-Japan EMGS (Electronic Materials Growth Symposium)
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• pp.494-496
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• 1996

The purpose of this study is to investigate the effect of process conditions on pore distribution in porous silicon layer prepared by electrochemical reaction. Porous silicon layers formed on p-type silicon wafer show the network structure of fine porse whose diameters are less than 100${\AA}$. In n-type porous silicon, selective growth was found on the pore surface by wet etching process after PR patterning. And numerical method showed high current density on the pore tip. With this result we confirmed that pore formation has two steps. First step is the initial attack on the surface and second step is the directional growth on the pore tip.