• 대한전기학회논문지:전력기술부문A
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• 제48권10호
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• pp.1349-1355
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• 1999

A power distribution facility map is drawn on cadastral map. Besides, grid lines are added on the map for sectionalization. For automatic recognition of the map, we first extract recognizing regions. In this paper, we propose an extraction method of recognizing regions by partially extending thinned image. The proposed method is consist of three phases, binarization phase, thinning phase and partial extending phase. The first phase generate a binary image using threshold value which is obtained by histogram analysis. The binary image contains many part of recognizing regions, but not all. The second phase generate thinned image which is generated by appling thinning operator to the binary image. And the third phase extends thinned image from terminal point until satisfying termination condition. The proposed method is tested on several power distribution facility maps, and the results are presented.

• Bulletin of the Korean Chemical Society
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• 제34권1호
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• pp.139-142
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• 2013

A study was carried out to evaluate the solid phase micro-extraction (SPME) for formaldehyde emission analysis of uncoated plywood. In SPME, formaldehyde was on-fiber derivatized through headspace extraction and analyzed by gas chromatography coupled with mass spectrometry (GC/MS). The SPME was compared with desiccators (DC-JAS 233), small-scale chamber (SSC-ASTM D6007) and liquid-liquid extraction (LLE-EPA 556) methods which were performed in accordance with their respective standards. Compared to SSC (RSD 4.3%) and LLE (RSD 5.0%), the SPME method showed better repeatability (RSD 1.8%) and not much difference from DC (RSD 1.4%). The SPME has proven to be highly precise (at 95% confidence level) with better recovery (REC 102%). Validation of the SPME method for formaldehyde quantitative analysis was evidenced. In addition, the SPME by air sampling directly from plywood specimens (SPME-W) correlated best with DC ($r^2$ = 0.983), followed by LLE ($r^2$ = 0.950) and SSC ($r^2$ = 0.935).

• Bulletin of the Korean Chemical Society
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• 제34권8호
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• pp.2330-2334
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• 2013

A highly selective molecularly imprinted polymer (MIP) for sarcosine, a cancer marker, was prepared and its use as solid-phase extraction (SPE) sorbent material was demonstrated. The MIP was prepared by a very simple procedure using methacrylic acid as functional monomer and a mixture acetonitrile/water (4/1, v/v) as porogen, overcoming in this way the problems usually related to the imprinting of biological polar compounds. The MIP was tested in batch experiments in order to evaluate its binding properties and then used as SPE sorbent for the selective clean-up and pre-concentration of sarcosine. The extraction protocol was successfully applied to the direct extraction of sarcosine from spiked human urine indicating that the MIP allowed sarcosine to be pre-concentrated while simultaneously interfering compounds were removed from the matrix.

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1463-1464
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• 2011

• 한국축산식품학회지
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• 제24권1호
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• pp.80-85
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• 2004

본 연구에서는 역미셀을 이용한 단백질 추출공정에서 적극적으로 활용되지 못했던 양이온 계면활성제에 의한 단백질 추출 가능성을 제시하였으며 초유로부터 IgG의 분리를 위한 반응조건을 조사하였다. IgG의 분리에 적합한 조건은 반응 수용액상의 경우 pH 8, 50 mM KCl었으며 유기용매상의 계면활성제(CDAB) 농도는 100 mM로 나타났다. 위의 조건에서는 초기시료에 존재하는 IgG의 90%이상이 회수되었으며 회수된 단백질의 93%가 IgG로 나타났다. 또한 본 연구는 기존의 역미셀을 이용한 일반적인 단백질 추출공정인 정추출 및 역추출 공정을 이용하지 않고 정추출 공정만을 이용함으로써 추출과정을 단순화하였다.

• Journal of Microbiology and Biotechnology
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• 제24권12호
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• pp.1690-1698
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• 2014

Partial purification of glucoamylase from solid-state fermentation culture was, firstly, investigated by reverse micellar extraction (RME). To avoid back extraction problems, the glucoamylase was kept in the original aqueous phase, while the other undesired proteins/enzymes were moved to the reverse micellar organic phase. The individual and interaction effects of main factors (i.e., pH and NaCl concentration in the aqueous phase, and concentration of sodium bis-2-ethyl-hexyl-sulfosuccinate (AOT) in the organic phase) were studied using response surface methodology. The optimum conditions for the maximum recovery of the enzyme were pH 2.75, 100 mM NaCl, and 200 mM AOT. Furthermore, the optimum organic to aqueous volume ratio ($V_{org}/V_{aq}$) and appropriate number of sequential extraction stages were 2 and 3, respectively. Finally, 60% of the undesired enzymes including proteases and xylanases were removed from the aqueous phase, while 140% of glucoamylase activity was recovered in the aqueous phase and the purification factor of glucoamylase was found to be 3.0-fold.

• KSBB Journal
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• 제18권3호
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• pp.202-206
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• 2003

역미셀과 가압이산화탄소를 이용한 난백 lysozyme의 추출실험에서 일정한 압력의 이산화탄소를 유기용액에 가하였을 때 lysozyme의 추출율과 그 때 형성되는 역미셀의 크기, 즉 역미 셀 내부의 수분함량 ($W_{0}$)를 알아보았다. 이산화탄소로 가압된 상태에서도 수용액에서 유기용액으로의 lysozyme의 추출 경향은 실험조건인 수용액의 이온강도, pH, 유기용액의 계면활성제의 농도를 달리 하였을 때 기존의 다른 연구와 유사한 경향을 나타내었으며, 이산화탄소의 압력을 102 bar까지 증가시켰을 때 가장 높은 추출율을 나타내었다. 또한 이때 역미셀 내부의 수분함량 ($W_{0}$)을 측정한 결과, lysozyme의 추출율과 역미셀 내부의 수분함량은 비례함을 확인할 수 있었다.

• 공업화학
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• 제8권6호
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• pp.967-972
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• 1997

접촉분해경유(LCO)와 dimethylsulfoxide(DMSO)수용액의 평형추출로부터 얻어진 추출상을 원료로 사용한 역추출에 의해 추출상중의 방향족의 회수를 검토했다. 역추출 용매의 선정을 위해, Benzene, Toluene, m-Xylene(mX), n-Hexane(Hx)과 n-Octane(Ot)을 용매로 사용하여 추출상-용매간의 분배평형을 측정한 결과, 추출상중의 방향족의 회수면에서 Hx이 가장 적절한 용매이었다. 또, Hx을 용매로 사용하여 평형 역추출을 행해 방향족의 회수에 대한 조작인자의 영향을 검토했다. 방향족에 대한 분배계수는 용매/원료(추출상) 질량비(S/F)(S/F를 변화시켜 얻어진 추잔상 혹은 추출상중의 질량분율)에 관계없이 일정했으나 수율은 S/F가 증가함에 따라 증가했다. 조작온도는 방향족의 분배계수와 수율에 영향을 미치지 못했다. 나프탈렌류 성분(탄소수:10~12)간에는 탄소수가 많을수록 분배계수 및 수율이 컸다. 또한, 회분 교반조를 사용하여 역추출을 행해 방향족 성분의 물질이동 속도를 측정했다.

• 자원리싸이클링
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• 제18권6호
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• pp.3-9
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• 2009

본 총설은 용매추출(또는 액-액 추출)에 대한 일반적인 원리와 추출제별 용매추출 공정의 기초 원리를 소개하고 있다. 용매추출은 서로 섞이지 않는 두 상(phase)간에 화합물이 한 상(phase)에서 다른 상으로 이동하는 현상을 이용하는 공정이다. 초기에는 분석화학 분야에서 용매추출의 간편성, 신속성 및 넓은 적용성 때문에 많이 사용되었으며, 분액깔데기와 같은 간단한 도구로 수분내에 추출실험을 완료할 수 있다는 장점이 있다.

• 분석과학
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• 제13권3호
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• pp.399-402
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• 2000

To determine the concentrations of microcystins present in lake water or in tap water using high performance liquid chromatography, it is necessary to concentrate a large volume of water samples (about 20 L) into very small volume (0.1-0.3 mL). Concentration can be conveniently done when disc type solid phase extraction (SPE) apparatus is used. Using this apparatus we have investigated the recovery rates of three kinds of microcystins, RR, YR, LR. The recovery rates were relatively low and the reproducibilities were not good either. It is expected, however, that the appropriate selection of the disc conditioning and eluting solvents and reproducible reconcentration process after SPE will improve both the recovery rates and the reproducibilities.