• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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• pp.25-28
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• 2004

The capillary number is used to represent the mobilization potential of organic phase trapped within porous media. The capillary number has been defined by three different forms, according to types of flow velocity and viscosity used in the definition of capillary number. This study evaluated the suitability of the capillary number definitions for representing TCE mobilization by constructing capillary number-TCE saturation relationships. The results implied that the capillary number should be correctly employed, according to interest of scale and fluid flow behavior. This study suggests that the pore-scale capillary number may be used only for investigating the organic-phase mobilization at the pore scale because it is defined by the pore-velocity and the dynamic viscosity. The Newtonian-fluid capillary number using Darcy velocity and the dynamic viscosity may be suitable to quantify flood systems representing Newtonian fluid behavior. For viscous-force modified flood systems such as surfactant-foam floods, the apparent capillary number definition employing macroscopic properties (permeability and potential gradient) may be used to appropriately represent the desaturation of organic-phases from porous media.

• 전기화학회지
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• 제7권4호
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• pp.179-182
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• 2004

The aim of this study is to investigate the initiation and propagation of crevice corrosion for ferritic stainless steel in artificial crevice based on micro capillary tube method. The 430 stainless steel in artificial crevice is potentiostatically polarized in different sodium chloride solutions. Potentiodynamic and potentiostatic polarization data were measured in situ. The potentials in the crevice were measured by depth profile using the 0.04 mm diameter micro capillary tube inserted in the crevice. The potentials in the crevice ranged from -220 mV to -360 mV vs SCE from opening to bottom of crevice, which are lower than the external surface potential, -200 mV vs SCE. Such a potential drop induced the change of the metal surface state from passive to active. The surface of metal is located in passive state in -200 mV but the inner surface keeps active state below -220 mV, Thus these results show that the It drop mechanism in the crevice was more objective for evaluation and the method was easier to reproduce. Therefore the potential drop is one of the reasons for crevice corrosion by measuring the potentials in narrow crevice with a new micro measuring system.

• 한국광물학회지
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• 제9권1호
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• pp.17-25
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• 1996

Usual experimental adsorption isotherms as a function of relative humidity were constructed from adsorbed water contents in soils, which were kept more than 2 days in vacuum desiccators with constant humidities controlled by sulfuric acids of various concentrations. From the experimental data, the adsorption surface areas were calculated on the basis of the existing adsorption theory, such as Langmuir, BET, and Aranovich. Based on the Gibbs function describing chemical potential of perfect gas, the relative humidities in the desiccators were transformed into their chemical potentials, which were assumed to be the same as the potentials of equilibratedly adsorbed water in soils. Moreover, the water potentials were again transformed into the equivalent capillary pressures, heads of capillary rise, and equivalent radius of capillary pores, on the basis of Laplace equation for surface tension pressure of spherical bubbles in water. Adsorption quantity distributions were calculated on the profile of chemical potentials of the adsorbed water, equivalent adsorption and/or capillary pressures, and equivalent capillary radius. The suggested theories were proved through its application for the prediction of temperature rise of sulfuric acid due to hydration heat. Adsorption heat calculated on the basis of the potential difference was dependant on various factors, such as surface area, equilibrium constants in Langumuir, BET, etc.

• 분석과학
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• 제12권4호
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• pp.341-345
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• 1999

The separation and determination of inorganic cations by a capillary zone electrophoresis was studied. Cations were separated by the capillary column and detected by indirect UV method. The running buffer of 0.03 M creatinine and 0.02 M-hydroxy isobutylic acid solution (pH 4.8) was used to improve the mobility of ions in the column. A potential of 18 kV was applied at anode. A complete separation of cations ranged within 15 min and detection limits were between 0.1 and 1.0 ppm. The applicability of the method for real samples was demonstrated.

• 전기화학회지
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• 제6권4호
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• pp.250-254
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• 2003

본 연구는 전기화학적 실험측정으로 페라이트계 430스테인레스강 시험편에 인위적으로 틈을 형성시켰다. 부식용액은 IN $H_2SO_4+0.1N\;NaCl$ 전해액을 사용하였고, 각 시험편의 틈의 크기를 달리하였다. 전기화학적 평가방법은 -600mV/5CE에서 정방향으로 +1,200mV/SCE까지 주사속도 600mV/hr로 동전위 분극시험을 실시하여 부식전위, 부동태 전류밀도 등의 부식거동을 분석하였다. 그리고 정전위 분극시험을 실시하여 부동태 구간 전위 -200mV/SCE를 일정하게 인가 한 후, 틈내에 부동태 전류밀도와 틈부식 발생시간을 계측하였다 실험방법에 있어 Microcapillary tube(MCT)를 이용한 방법으로 틈내 각 지점의 전위를 틈 깊이에 따른 틈내부의 전위강하(IR Drop)에 주목하고, 575 430 스테인레스강 금속에 대한 분극특성과 연계하므로써 틈부식의 발생 원인을 '전위의 이동'의 관점에서 규명 하였다.

• BMB Reports
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• 제45권4호
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• pp.233-238
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• 2012

We present a top down separation platform for yeast ribosomal proteins using affinity chromatography and capillary electrophoresis which is designed to allow deposition of proteins onto a substrate. FLAG tagged ribosomes were affinity purified, and rRNA acid precipitation was performed on the ribosomes followed by capillary electrophoresis to separate the ribosomal proteins. Over 26 peaks were detected with excellent reproducibility (<0.5% RSD migration time). This is the first reported separation of eukaryotic ribosomal proteins using capillary electrophoresis. The two stages in this workflow, affinity chromatography and capillary electrophoresis, share the advantages that they are fast, flexible and have small sample requirements in comparison to more commonly used techniques. This method is a remarkably quick route from cell to separation that has the potential to be coupled to high throughput readout platforms for studies of the ribosomal proteome.

• 설비공학논문집
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• 제14권5호
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• pp.359-364
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• 2002

A popular type of residential air conditioner is the split system which has two separate units: indoor and outdoor units During field installation of the split system, the potential exists for not setting the charge exactly to the manufacturer´s specifications. The objective of this study is to investigate the effects of the refrigerant charge on the performance of the air conditioner. An air conditioner with capillary tube expansions was tested for various refrigerant charges. The results indicated that the more charge resulted in the more flowrate of the refrigerant. The flowrate of the refrigerant was one of the most important factors to understand the e(sects of the charge on the performance of the air conditioner with capillary tube expansions. Under-charge results in wide region of superheated vapor of the refrigerant in the evaporator, while over-charge results in high temperature of the liquid refrigerant in the evaporator.

• 분석과학
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• 제11권3호
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• pp.213-221
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• 1998

Bromide, chloride, fluoride, nitrite, nitrate, sulfite, sulfate, perchlorate, chlorate 및 chlorite가 포함된 시료를 capillary zone electrophoresis(CZE)와 indirect UV detection 방법으로 분리하였다. 음이온류의 분리는 running buffer로 5 mM ammonium dichromate, 10 mM ammonium acetate, 20 mM diethylenetriamine, 10% methanol(pH 9.3)을 사용하였으며 전압은 cathode에 15 kV를 공급하였다. 또한 최초로 CZE에서 음이온의 정량이 가능하도록 각 이온들에 대한 regression과 detection limit를 결정하였고, 이 분석방법은 톨루엔을 흡입한 사람의 뇨, 부검 혈액, 폐수 및 폭약 등 시료에 적용하였으며, 음이온의 함량을 ion chromatograph(IC)와 비교 검토하였다.

• Journal of the Korean Wood Science and Technology
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• 제25권3호
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• pp.66-74
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• 1997

Liquid permeabilities of red oak and several softwoods were measured by the pressure bomb method and a modified liquid permeability method in order to investigate their efficacy. The effect of preboiling and prefreezing on wood permeability were also examined for both green and resaturated specimens. Regardless of some disadvantages these two methods were revealed as a handy tool for quick evaluation of the permeability of an unknown species. The permeabilities of the resaturated specimens increased when preboiled. but decreased when prefrozen. For green specimens, however, pre freezing increased permeability. The discrepancy of the pre freezing effect on two specimens partially attributes to their difference of initial permeabilities. For all species except radiata pine heartwood, the radii of the effective capillary pores, derived from the water potential equation, distribute from $0.42{\mu}m$ to $7.2{\mu}m$. Those of radiata pine heartwood are below $0.46{\mu}m$.

• 대한화학회지
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• 제35권3호
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• pp.219-225
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• 1991

고도로 효율적인 분석방법인 모세관 전기영동 시스템을 최적의 감도를 갖는 상태의 기기로 국내에서 제작하였다. 50 ${\mu}m$ 내경을 가진 모세관을 완충용액으로 채워준 후 모세관의 양끝에 20∼35 kV의 전압을 걸어주는 이 분석방법은 20분 이내에 10 nl 이하의 소량의 시료를 이론단수가 20∼50만 정도가 되도록 분리할 수 있는 매우 좋은 분리능으 가지고 있다. 모세관 전기영동법의 분리능과 분리도를 증가시키는데 영향을 주는 요소들을 알아보기 위하여 catecholamine과 adenine 유도체를 분석하였다.