• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2005년도 연구개발 발표회 논문집
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• pp.89-93
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• 2005

In this work, perfusive particles are used to form a micro column in a microfluidic chip and flow properties of the micro column are investigated. The packing flow velocity and the column/particle size ratio are shown to be important parameters affecting the packing density of the micro column. Experimental results show that the effect of the column/particle size ratio on the flow resistance of the micro column is negligible. This contrasts with previous works on the effect of the column/particle size ratio on the total pressure drop across the column.

• 한국환경과학회지
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• 제5권5호
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• pp.561-567
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• 1996

31 종류의 유기 염소계 잔류 농약을 동시에 분석하는 기체 크로마토그래피 방법을 개발하기 위하여 본 연구를 수행하였다. 준비된 분석 시료를 ECD (electron capture detector)로 Ultra-2 column의 GC (gas chromatography)에 주입하였다. Column 충진 물질을 florisil과 alumina N으로 변화시키면서 잔류 용액을 column에 loading하고 용출 용매로는 ether . benzene(2 : 8) solution, hexane . benzene(1 . 1) solution, dichloromethane, acetone 및 methanol을 사용하였다. 분석 결과 column 충진 물질로 florisil을 사용하였을때 (첫째 조건) 6종류의 유기 염소(dichlorfluanid, captan, chlorofenvinfos, folpet, captafol과 dicofol)가 검출되지 않았다. 이 조건에서 dichloromethane과 methanol을 용출 용매로 첨가하였을때는 (둘째 조건) 첫째 분석 조건하에서 검출되지 않았던 6종류의 유기 염소가 검출되었고 thrin계 pesticides, 특히 captan과 captafol의 recovery가 증가하였다(첫째 조건에서와 마찬가지로 충진 물질로 florisil을 사용). 그러나 BHC(benzene hexachloride) 화합물의 recovery는 감 소하였다. 한편 alumina N을 column 충진 물질로 사용하였을 경우에는 dichlorfluanid, chlorofenvinfos, folpet 및 dicofol의 recovery가 증가하였으며 aldrin도 그러하였다. 하지만 captan과 captafol은 그렇지 못하였다. Thrin계 pesticides, captan 및 captafol을 동시에 검출하기 위하여 florisil과 alumina N을 충진 물질로 동시에 사용하고 n-hexane을 충진시켜 용출시킨 결과, captan과 captafol이 검출되지 않았는데 이는 column이 충분히 활성화되지 않았기 때문이라고 생각된다. Column(florisil과 alumina N을 충진 물질로 동시 사용)을 충분히 활성화시키고 여러가지 용출 용매를 사용하여 불순물을 제거하였을때 분석 결과가 가장 우수하였다(31 종류의 유기 염소계 잔류 농약이 sharp하게 검출되었고 높은 감도를 나타내었다).

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 춘계학술대회 논문집
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• pp.401-405
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• 2004

Column subtraction, originally proposed by Harche and Thompson(]994), is an exact method for solving large set covering, packing and partitioning problems. Since the constraint set of ship scheduling problem(SSP) have a special structure, most instances of SSP can be solved by LP relaxation. This paper aims at applying the column subtraction method to solve SSP which can not be solved by LP relaxation. For remained instances of unsolvable ones, we subtract columns from the finale simplex table to get another integer solution in an iterative manner. Computational results having up to 10,000 0-1 variables show better performance of the column subtraction method solving the remained instances of SSP than complex branch-and-bound algorithm by LINDO.

• 한국항해항만학회지
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• 제28권2호
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• pp.129-133
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• 2004

Column subtraction, originally proposed by Harche and Thompson(1994), is an exact method for solving large set covering, packing and partitioning problems. Since the constraint set of ship scheduling problem(SSP) have a special structure, most instances of SSP can be solved by LP relaxation This paper aim, at applying the column subtraction method to solve SSP which am not be solved by LP relaxation For remained instances of unsolvable ones, we subtract columns from the finale simplex table to get another integer solution in an iterative manner. Computational results having up to 10,000 0-1 variables show better performance of the column subtraction method solving the remained instances of SSP than complex branch and-bound algorithm by LINDO.

• Korean Chemical Engineering Research
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• 제48권5호
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• pp.668-671
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• 2010

증류시스템 검증용 소형 다단 증류 장치에 활용할 수 있는 소형 충전물을 사용하여 실험실 규모의 증류실험을 실시하였다. 직경 6.7 mm의 실린더형 스테인레스 스틸 충전물을 이용하여 충분한 겉보기 표면적을 얻었고, 액의 체류량과 체류 속도도 양호한 결과를 얻었다. HYSYS를 이용한 이론단수의 계산치와 증류실험치를 비교하여 27 cm 충전층에 대해서는 7 cm이고, 45 cm 충전층에 대해서는 8 cm의 충전층이 이론단 1 단에 해당함을 알았다. 상업용 일정구조 배열의 충전탑에서 8 cm의 충전층이 이론단 1 단에 해당함과 비교하면 유사한 증류효율을 얻을 수 있음을 보여 주었다. 이러한 결과는 증류관의 보온이 완벽할 때 가능하였으며, 실험실에서의 증류 실험에서는 보온이 중요함을 입증하였다. 본 실험 결과로부터 실험실에서도 실제 현장에서 사용하는 증류탑과 유사한 증류 시스템의 시험이 가능함을 보여 준다.

• 한국해양공학회지
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• 제2권2호
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• pp.130-137
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• 1988

This thesis introduced that character of a treatment technique for a mading synthetic resin Hifiow-Ring. The material system of packings make an experiment air$NH_{3}$/air$H_{2}SO_{4}$, $SO_{2}$-air/NaOH, $NH_{3}$-air/$/H_{2}SO_{4}$ under general conditions. Lattices packing compared with conventional packings was proved low pressure loss and high separation efficiency for high loading per trans unit. And an inflow materal tested for absorption and rectification, it made an experiment under a range regular temperature, low energy and small amount of money. That made possible in simple equation, volume material tranfer coefficient$\beta_{L}$ . a by absorption or $\beta_{V}$ .a calculated in all range loading. The peculiarity pressure loss $\Delta\;P/NUT_{ov}$ for Hiflow-ring contributed to a fall cost of energy, a grade number of a vacuum rectification and absorption calculation.

• 한국환경과학회지
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• 제16권10호
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• pp.1147-1155
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• 2007

The applicability of in situ biobarrier or microbial filter technology for the remediation of groundwater contaminated with chlorinated solvent was investigated through column study. In this study, the effect of packing materials on the reductive dechlorination of PCE was investigated using Canadian peat, Pahokee peat, peat moss and vermicompost (or worm casting) as a biobarrier medium. Optimal conditions previously determined from a batch microcosm study was applied in this column study. Lactate/benzoate was amended as electron donors to stimulate reductive dechlorination of PCE. Hydraulic conductivity was approximately $6{\times}10^{-5}-8{\times}10^{-5}\;cm/sec$ and no difference was found among the packing materials. The transport and dispersion coefficients determined from the curve-fitting of the breakthrough curves of $Br^-$ using CXTFIT 2.1 showed no difference between single-region and two-region models. The reductive dechlorination of PCE was efficiently occurred in all columns. Among the columns, especially the column packed with vermicompost exhibited the highest reductive dechlorination efficiency. The results of this study showed the promising potential of in situ biobarrier technology using peat and vermicompost for the remediation of groundwater contaminated with chlorinated solvents.

• 융복합기술연구소 논문집
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• 제5권2호
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• pp.33-36
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• 2015

In this paper, the development history of random packings for several generations was briefly introduced. We demonstrate the application of 3D printing to the fabrication of Pall rings, directly using computer aided design (CAD) models. The CAD was used to design Pall rings with different number of blades. The models were then printed by using UV curing of acrylonitrile-butadiene-styrene (ABS) resins. The results show that 3D printing is a promising method for producing precisely controlled packing materials. It is also expected that 3D printing is helpful for the fundamental studies of highly efficient packing materials with complex geometrical shapes.

• Bulletin of the Korean Chemical Society
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• 제35권1호
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• pp.45-50
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• 2014

A fully packed capillary electrochromatographic (CEC) microchip with an on-column micro-solid phase extraction (SPE) bed for the preconcentration and separation of organic analytes was prepared. A linear microchannel with monodisperse colloidal silica packing was formed on a cyclic olefinic copolymer microchip with two reservoirs on both ends. Silver-cemented silica packing frit structure was formed at the entrance of the microchannel by electroless plating treatment as a base layer. A gold coating was formed on it by reducing $Au^{3+}$ to gold with hydroxylamine. Finally micro-SPE bed was formed by self-assembly adsorption of 1-dodecanethiol on it. Micro-SPE beds were about 100-150 ${\mu}m$ long. Approximately $10^3$ fold sensitivity enhancements for Sulforhodamine B, and Fluorescein in nM concentration levels were possible with 80 s preconcentration. Basic extraction characteristics were studied.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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• pp.1101-1106
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• 2000

When top down method is used, it could be a construction method trouble in column joint, between the former concrete and the latter. It could bring a void and weak concrete in column. The purpose of this study is to find a solution of removing void and air, way to exhaust air in top down column. through specimen concrete placing experiment.