• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.313-316
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• 2002

Effect of Pluronic F-68, a nonionic surfactant, on the extracellular production of hGM-CSF in transgenic Nicotiαna tabacum cell suspension culture was investigated. The addition of 5 g/L Pluronic F-68 did not affect the cell growth but increased the extracellular production of hGM-CSF by two-fold. This may be due to the enhanced permeability of the cell membrane by the interaction between the Pluronic F-68 and the cell membrane.

• KSBB Journal
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• v.22 no.4
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• pp.185-190
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• 2007

Productivity of secreted recombinant protein depends largely on its stability in the extracellular environment with protease. Most hGM-CSF produced by transgenic tobacco cell cultures and secreted to the medium was confirmed to be rapidly degraded by protease in medium. To increase the productivity, therefore, various protein stabilizers such as gelling agents such as carrageenan and alginate, polymers, polyols, and amino acids have been tested. The stability of hGM-CSF in spent medium without cells was improved by the presence of gelling agents. However, the reason for the enhanced production by the addition of gelling agents may be due to the increased expression level and permeability rather than stability. The addition of DMSO inhibited the cell growth, but improved specific yield. The others were not effective for stability as well as hGM-CSF production.

• Journal of the Korean Electrochemical Society
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• v.9 no.2
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• pp.89-94
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• 2006

Nafion/poly(ether(amino sulfone)) acid-base blend polymer electrolyte membranes were prepared and their proton conductivity and dimethyl ether permeability were investigated. Characteristics of direct dimethyl ether fuel cell (DDMEFC) performance using prepared blend membrane were studied. The increase of amine groups in the base polymer in composite membranes resulted in the decrease in dimethyl ether permeability. The proton conductivity of the blend membranes gradually increased as increasing temperature. The conductivity of Nafion/PEAS-0.6 (85:15) blend membranes was measured to be $1.42\times10^{-2}S/cm\;at\;120^{\circ}C$ which was higher than that of the recast Nafion. The performance of direct dimethyl ether fuel cell (DDMEFC) using the Nafion/PEAS blend membranes was higher than that using $Nafion^(R)115$ membrane. Enhanced performance of direct dimethyl ether fuel cells using Nafion/PEAS blend membrane was explained by reducing dimethyl ether (DME) crossover through the electrolyte membrane and maintenance of the proton conductivity at high temperature.

• Journal of the Korean GEO-environmental Society
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• v.12 no.12
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• pp.47-54
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• 2011

Consolidation behavior of soft clay is generally to be affected by its compressibility and deformation characteristics. Especially, soil permeability depends on soil characteristics including its type of anisotropy. Coefficient of permeability of soft clay is mostly estimated by using laboratory(Oedometer test) and in-stiu piezocone test. The permeability characteristics of soft clay is estimated by excess pore pressure dissipation test results. In this study, the tests were performed to find out the validity of the existing theoretical formula in clay by pore pressure dissipation test and laboratory test results. After grasping of variation the coefficient of permeability ratio(${k_{h}/k_{v}}$) in different clay soils, it was found out adequate solution of in-stiu permeability ratio(${k_{h}/k_{v}}$). Piezocone tests and laboratory tests were performed at the site of pilot project of ground improvement at Yangsan-Mulgeum, Gyeongsangnam-do. Comparisons of the estimated values of ${k_{h}/k_{v}}$ using piezocone tests results and those from laboratory consolidation tests were carried out. Test results show that values of ${k_{h}/k_{v}}$ by piezocone test result(5.85) is similar of it's laboratory test(5.28).

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.191-194
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• 2003

In this study, permeability tensor is computed for a three dimensional braided preform by applying a FVM to a unit cell. It is evident that resin will flow through the inter-tow and the intra-tow regions when pressure gradient is applied to the resin. The intra-tow region in the braided preform is regarded as not only an impermeable solid but also a permeable porous media. When the intra-tow region is excluded from domain of flow analysis in the case of the impermeable solid, the Stokes equation is computer for only inter-tow region. (omitted)

• Korean Journal of Microbiology
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• v.9 no.4
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• pp.149-154
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• 1971

Effect pf gibberellic acid (GA) on the growth rate, respiratory activity and solute uptake of Chlorella cells were measured and their correlation were discussed. Growth rate and respiratory activity of the algal cells are enhanced considerably by very samll amount (50 ppm) of GA treatment although they are suppressed by relatively higher concentration more than 100 ppm. Phosphate uptake of the algal cells, however, decreased even though lower concentration of GA is applied. Thereforem it is inferred that the growth enhancement of the algae by GA is not due to the increase of the permeability of the algal cells but expansion growth owing to the increase of osmotic pressure caused by the increase of hydrolase activity of the algae.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.3-5
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• 1997

Properties of a good drug include safety, efficacy, half-life and bioavailability. With the current approach to drug discovery based on receptor-based and cell-based screening methods, compounds are frequently moved into development with poor bioavailability. With low bioavailability, drug administration is typically limited to parenteral routes, thus limiting the potential wide-spread utility of these therapeutic agents. The first and most important factor limiting a drug's bioavailability is the intestinal membrane permeability which in turn determines the maximum fi:action of the dose administered that can be absorbed. We have recently utilized new intubation methods for performing permeability measurements in humans and establishing a fundamental human data base for correlating intestinal jejunal membrane permeabilities with permeabilities determined in other systems, e.g., animals, tissue culture, as well as physical chemical properties.

• Textile Coloration and Finishing
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• v.7 no.3
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• pp.38-43
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• 1995

To improve the biofunctional properties of silk fibroin membranes, 2-(methacryloyloxy)ethyl-2-(trimethylammonium)ethyl phosphate(MTP), which is a methacrylate with phospholipid polar groups grafted and poly(MTP-co-BMA) was coated on the surface of silk fibroin membranes. The permeability and biocompatibility of silk fibroin membranes with phosphoryl choline group were investigated. The permeability of a salt(NaCl) was increased with grafting by MTP. Futhermore, the poly(MTP-co-BMA)-coated silk fibroin membranes displayed less blood cell adhesion than the silk fibroin membranes.

• Textile Coloration and Finishing
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• v.26 no.4
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• pp.322-330
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• 2014

The phospholipid-based MPCE(2-Methacryloxyethyl Phosphoryl Chlorine) copolymer was mixed with wet polyurethane for coating of nylon fabrics. The substitution rate of water in coagulation bath with DMF was changed under control of the size of formed hydrophilic microporous cell enable to manufacture excellent breathable, anti-bacterial and moisture control fabrics. Biocompatible property, vapor permeability, hydrostatic pressure, moisture management and anti-bacterial property were investigated for treated nylon fabrics. In result, increased moisture transmission rates, decreased water resistance and outstanding moisture control property could be confirmed by enhanced hydrophilicity of wet-coated nylon fabric with MPCE copolymer.

• Journal of the Korean Geotechnical Society
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• v.17 no.4
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• pp.249-257
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• 2001

본 논문에서는 경남 양산지역의 퇴적층에서 채취한 불교란 시료를 이용하여 표준압밀시험($IL_{CON}$)과 일정변형률(CRS, Constant Rates of Strain) 압밀시험을 수행한 후 각각의 시험결과를 분석하여 양산점토의 투수특성을 고찰하였다. 이를 위하여 투수계수와 간극비의 관계를 Kozeny(1927)와 Carman(1956) 이후 제안된 많은 연구결과와 비교, 검토하였으며, 시료를 연직방향으로 성형하여 CRS 시험을 수행한 후 횡방향투수계수를 산정하여 양산점토의 투수계수의 이방성을 살펴보았다. CRS시험 결과, 직접적으로 정상류를 발생시켜 누수계수를 측정하는 Rowe cell 시험에 비하여 상대적으로 투수계수의 이방성이 과소평가되는 경향을 보였다. 또한 현장 투수계수에 영향을 미치는 요소들을 살펴보고, 깊이에 따른 투수계수를 고찰하였다.다.