• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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• pp.51-51
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• 2003

• 조명전기설비학회논문지
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• 제23권9호
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• pp.17-23
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• 2009

자외선 살균기술을 바탕으로 한 수처리 분야에 대한 관심이 최근 증가하고 있다. 수처리분야에서 살균처리방식의 효율은 유체 살균챔버나 살균강도 그리고 미생물의 불활성역학에 따라 수처리 성능이 결정된다. 광산화법에 이용되는 빛은 주로 자외선이 이용되며 매우 깨끗하고 높은 에너지를 가지고 있어 화학살균방법에 비해 잔류물이 없고 높은 안정성으로 최근 관심이 높아지고 있다. 그러나 자외선살균방식은 조사시간과 조사량에 직접적인 영향을 받아 이를 위한 최적의 설계가 이루어져야 한다. 본 연구에서는 유수살균장치의 챔버 내의 자외선 램프와 유수에 대한 3D-CFD discrete ordinates model 모델을 제시하고 이를 시뮬레이션을 통해 설계방식의 최적화 여부를 검증하고 향후 유수형 자외선살균방식의 시뮬레이션방법을 제안하고자 한다.

• 한국지능시스템학회논문지
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• 제19권5호
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• pp.713-719
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• 2009

본 논문은 비선형 특성을 내재한 물 수요예측을 위하여 기존의 시계열 자기회귀 알고리즘과 다층신경망 학습방법을 결합한 단기 물 수요 예측 알고리즘을 개발하였다. 제시된 방법을 검증하기 위한 사례연구로 2007년도와 2008년도 전북지역의 광역상수도 A정수장에서 취득된 데이터를 활용하여 알고리즘 구축 및 제안 방법의 정확도를 분석하였다. 실험 결과 다중회귀모델은 MAPE가 5.1%, AR모델은 3.8%, 제안된 방법인 AR+MLP 모델은 3.6%로 나타나 성능이 우수한 것으로 나타났다. 따라서 제안된 방법을 사용할 경우 정수장에서 단기 물 수요예측에 유용하게 활용할 수 있음을 보였다.

• Nuclear Engineering and Technology
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• 제51권7호
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• pp.1799-1804
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• 2019

The concept of a new method, the CARBEX (CARBonate EXtraction) process, was proposed for reprocessing of spent uranium oxide fuel. The proposed process is based on use of water solutions of $Na_2CO_3$ or $(NH_4)_2CO_3$ and solvent extraction (SE) by the quaternary ammonium compounds for selective recovery and purification of U from the fission products (FPs). Applying of SE allows to reach high degree of purification of U from FPs. Carrying out the processes in poorly aggressive alkaline carbonate media leads to increasing safety of SNF's reprocessing and better selectivity of separation of lanthanides and actinides. Moreover carbonate reprocessing media allows to carry out a recycling and regeneration of reagents. We have been done laboratory scale experiments on the extraction components of simulated voloxidated spent fuel in the solutions of NaOH or $Na_2CO_3-H_2O_2$ and recovery of U from carbonate solutions by SE method using carbonate of methyltrioctylammonium in toluene. It was shown that the purification factors of U from impurities of simulated FPs reached values $10^3-10^5$. The received results support our opinion that CARBEX after the further development can become more safe, simple and profitable method of spent fuel reprocessing.

• Advances in environmental research
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• 제9권3호
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• pp.215-232
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• 2020

Crude oils are essential source of energy. It is majorly found in geographical locations beneath the earth's surface and crude oil is the main factor for the economic developments in the world. Natural crude oil contains unrefined petroleum composed of hydrocarbons of various molecular weights and it contains other organic materials like aromatic compounds, sulphur compounds, and many other organic compounds. These hydrocarbons are rapidly getting degraded by biosurfactant producing microorganisms. The present study deals with the isolation, purification, and characterization of biosurfactant producing microorganism from oil-contaminated soil. The ability of the microorganism producing biosurfactant was investigated by well diffusion method, drop collapse test, emulsification test, oil displacement activity, and blue agar plate method. The isolate obtained from the oil contaminated soil was identified as Bacillus subtilis. The identification was done by microscopic examinations and further characterization was done by Biochemical tests and 16SrRNA gene sequencing. Purification of the biosurfactant was performed by simple liquid-liquid extraction, and characterization of extracted biosurfactants was done using Fourier transform infrared spectroscopy (FTIR). The degradation of crude oil upon treatment with the partially purified biosurfactant was analyzed by FTIR spectroscopy and Gas-chromatography mass spectroscopy (GC-MS).

• 약학회지
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• 제54권4호
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• pp.316-321
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• 2010

Adefovir dipivoxil which was originally developed by Gilead Sciences has been used as treatments of HIV and HBV, especially a therapeutics for HBeAg positive and negative chronic patients. We developed highly efficient purification method using reverse phase column chromatography for mass production and a stable amorphous Adefovir dipivoxil using solid dispersion method. Reverse phase column chromatography led to highly pure product, more than 99.7% by HPLC and can be used for mass production compared with normal column chromatography. Solid dispersion method containing watersoluble polymer and Isomalt showed improved stability of amorphous Adefovir dipivoxil against heat and moisture.

• Journal of Microbiology and Biotechnology
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• 제19권11호
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• pp.1470-1474
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• 2009

This paper describes the development a of direct multiplex reverse transcription-nested polymerase chain reaction (PCR) method, devised for simultaneous detection and typing of influenza viruses. This method combines the direct reverse transcription reaction without RNA purification with the enhancement of sensitivity and specificity of nested PCR. The method successfully detected three major human influenza viruses: influenza virus A subtype 1 (H1N1) and subtype 3 (H3N2), and influenza B virus (B). The minimum number of virus particles (pfu/ml) necessary for detection in spiked saliva samples was 200 (H1N1), 140 (H3N2), and 4.5 (B). The method's sensitivity and simplicity will be convenient for use in clinical laboratories for the detection and subtyping of influenza and possibly other RNA viruses.

• 한국산학기술학회논문지
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• 제17권6호
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• pp.9-17
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• 2016

Alcalase와 protamex의 두 가지 단백질 분해효소를 사용하여 홍어연골로부터 콘드로이틴 황산을 분해추출하고, 몇가지 물리화학적 공정을 적용하여 고순도의 콘드로이틴 황산을 얻기 위한 정제방법을 검토하였다. 2% alcalase로 홍어연골을 가수분해하고 $40^{\circ}Brix$로 농축한 추출물의 수율은 23.3%이었으나, 에탄올로 1회 및 2회 추가 정제한 경우 각각 8.47%, 3.37%로 얻어졌다. 1% alcalase와 1% protamex로 혼합 사용하여 추출분해하고, $40^{\circ}Brix$로 농축한 다음 1회 에탄올 정제한 경우는 추출수율이 16.62%로 측정되어 단백질 분해효소를 혼합한 경우가 더 높은 수율을 보였다. 추출된 콘드로이틴 황산의 함량은 에탄올 용매비에 따라 39.88~45.08%의 범위로 측정되었으며, alcalase만 사용시에는 용매비 1:1에서 42.92%로 가장 높게 측정되었고, alcalase와 protamex를 혼합 사용한 경우에는 용매비 1:2에서 45.08%로 가장 높았으며, 에탄올에 의한 농축물의 정제시 교반 시간은 2시간이 효과적이었다. 콘드로이틴 황산의 GPC (Gel Permeation Chromatography) 측정 결과 alcalase와 protamex를 혼합 사용한 경우 에탄올 정제 횟수에 따라 콘드로이틴 황산의 분자량과 순도는 각각 11만~31만 Da.과 24.87%~49.92%의 범위로 측정되었으며, 한외여과를 통하여 분자량 약 11만 Da., 최고 순도 53.93%의 콘드로이틴 황산을 얻을 수 있었다. 콘드로이틴 황산의 냄새 강도는 에탄올 정제만으로는 33%, 활성탄 처리와 에탄올 정제를 병행한 경우 38%의 감소효과가 얻어졌으며, 활성탄 처리와 2회의 에탄올 정제시 암모니아는 52.1%, TMA (trimethylamine)는 37.89%의 탈취효과가 있었으나, 냄새성분의 충분한 제거를 위해서는 추가적인 물리화학적 처리가 요구되었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권6호
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• pp.465-468
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• 2000

Methyl mercaptan oxidase was successfully induced from Rhodococcus rhodochrous IGTS8 using methyl mercaptan gas and purified to homogeneity for the detection of mercaptans. The purification procedure involved DEAE-Sephacel and Superose 12 column chromatography with recovery yields of 85.8 and 83.3%, and a specific activity of 92.7 and 303.4 units/mg-protein, respectively. The molecular weight of purified methyl mercaptan oxidase was determined to be 64.5 kDa by SDS-PAGE. The extract from gel filtration chromatography oxidizes methyl mercaptan to produce formaldehyde, which can be easily detected by the purpald-coloring method. Optimum temperature for activity was achieved at 60$^{\circ}C$. This enzyme was inhibited by both K$_2$SO$_4$and NaCl at concentration of less than 100mM and recovered to original activity at concentration of 200mM. In the presence of methanol, the activity decreased by 33%.

• Journal of Microbiology and Biotechnology
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• 제21권1호
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• pp.43-49
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• 2011

As a rare sugar alcohol, L-arabitol can be used in food and can prevent extra fat deposits in the intestinal tract. Commercially, L-arabitol is prepared from pure L-arabinose by hydrogenation, which needs a high temperature and high pressure, leading to a high production cost for Larabitol. Therefore, this study describes a novel L-arabitol production method based on biological purification from the xylitol mother liquor, a cheap and readily available raw material that contains a high concentration of Larabitol. First, a novel Bacillus megaterium strain was screened that can utilize xylitol, sorbitol, and mannitol, yet not L-arabitol. The isolated strain was inoculated into a medium containing the xylitol mother liquor under formulated culture conditions, where a high L-arabitol yield (95%) and high purity (80%) were obtained when the medium was supplemented with 50 g/l of xylitol mother liquor. Upon further purification of the fermentation broth by ion exchange and decolorization, L-arabitol was crystallized with a purity of 98.5%.