• Journal of Sericultural and Entomological Science
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• v.31 no.1
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• pp.45-54
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• 1989

본 연구에서는 견에 대한 산성염료의 염착기구를 규명하기 위하여 전하수가 다른 산성염료에 의한 흡착실험을 수행하여, 견섬유와 피브로인막의 구조와 염료의 구조를 관련시켜서 산성염료의 흡착거동에 관한 해석을 하였다. 산성염료에 sulfonic acid group이 도입됨에 따라서 partition coefficient(Kp)는 감소하였지만 Langmuir type sorption constant(KL)는 증가하였고, 염욕의 pH와 온도의 증가에 따라서도 Kp, KL 값은 증가하였다. 전하수가 1, 2인 Dye I과 Dye II는 견섬유와 피브로인 막에 대하여 stoichiometric adsorption이 잘 적용될 수 있었으나 전하수가 3인 Dye III는 잘 적용되지 않았다. sulfonic acid group이 산성염료에 도입됨에 따라 각각의 sulfonic acid group의 표준친화력은 감소하였고, 모든 엔탈피 값은 음(-)으로 나타난 반면에 엔트로피 값은 양(+)으로 나타났다. 견섬유와 피브로인 막의 흡착 constant를 비교한 결과, 견 피브로인에 대한 산성염료의 흡착거동은 견 피브로인의 구조에 영향을 받는다는 것을 알 수 있다.

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.961-964
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• 2006

GDP-mannosyltransferase (GMT) is an enzyme responsible for the addition of a mannose to glucose ($\alpha$[1$\rightarrow$3]) during biosynthesis of the water-soluble branched polysaccharide acetan in Acefobacter species. In an effort to obtain a cellulose-overproducing bacterium, a mutant defective in GMT of Acetobacter xylinum KCCM 10100 was constructed by single crossover homologous recombination using part of the aceA gene encoding GMT amplified by polymerase chain reaction. The GMT-disrupted mutant produced 23% more cellulose, but 16% less water-soluble polysaccharide than those of the wild-type strain. Analysis of the sugar composition by gel permeation chromatography revealed that water-soluble polysaccharides produced by the GMT-defective mutant contained no mannose molecule.

• Proceedings of the Membrane Society of Korea Conference
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• 1995.09a
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• pp.73-85
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• 1995

The asymmetric hollow fiber membranes were prepared by the wet spining of polyetherimide dope solution and the effect of hollow fiber structures on the permeation characteristics of carbon dioxide and nitrogen gases through these membrane were investigated. As the concentration of the $\gamma$-butyrolactone (GBL) in dope solution, acting as a swelling agent was increased, the structure of hollow fiber was changed from the finger to sponge type. The permeabilities of gases (CO$_{2}$, N$_{2}$) through these membrane were measured over the wide range of pressure under different temperature. The effect of water vapor on the permeabilities of gases was also investigated. The measured permeabilities showed the different characteristics depending on the structure of membranes. It was found that the flow through the pores were dominant over the polymers matrix. Blocking effect by water vapor in the pores of skin layer greatly improved the ideal separation factor of carbon dioxide/nitrogen.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.237-240
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• 2002

Amino terminated polyetherimide(ATPEI) has been synthesized by bisphthalic anhydride arid m-phenylenediamine, after that characterized by differential scanning calorimetry(DSC), thermogravimetric analyzer(TGA). Fourier transform (FT-IR) spectroscopy and gel permeation chromatography(GPC). ATPEI was blend to improve the toughness of bisphenol-A type epoxy resin which was cured by nadic methyl anhydride(NMA). The fracture toughness and the molphology of the toughened epoxy resin was evaluated. The toughness of ATPEI modified epoxy resin was higher than that of the PEI modified epoxy resin. In addtion, carbon fiber/ATPEI modified epoxy resin composites were fabricated and the mechanical properties of the resulted composites were investigated.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.442-445
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• 1999

In this work, to detect of hydrogen in DI water in the generator area of nuclear power plants was fabricated Pd/Pt gate MISFET sensor using Pd membrane. $H_2$ permeation through Pd accounts for external mass transfer, surface adsorption and desorption, transitions to and from the bulk metal, and diffusion within the metal. The identification of pinholes in the generator area of plant is an important safety consideration, as hydrogen build-up gives rise to explosion. For this type of application the sensor needs to be isolated in DI water, accordingly, a Pd membrane was used to separate the DI water. The hydrogen in the DI water was then absorbed on the Pd thin film and diffused into the oil through the thin film. The Pd/Pt gate MISFET sensor, encapsulated by oil, will thereby detect permeated hydrogen.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.82-88
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• 2005

Ethnic Korean onggi earthenwares were fabricated using different clay formulations and glazing treatments. Their permeability properties against oxygen, carbon dioxide, and moisture were measured at $20^{\circ}C$ and examined from the aspect of food preservation. Onggi walls consisted of micropores that offered higher gas and moisture permeation rates when compared with other food packaging materials. Earthenware walls were unique in having $CO_2/O_2$ permeability ratios of 0.60-1.00. Gas and moisture permeabilities were lower, with wall structure having lower porosity and surface glazing. Results revealed onggi jar packages of grape fruits could attain wide range of $O_2$ and $CO_2$ concentrations. Onggi containers present good opportunity to obtain optimum packaging conditions for respiring or ripening products, depending on commodity type.

• Archives of Pharmacal Research
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• v.17 no.2
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• pp.57-59
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• 1994

The effect of sodium taurodihydrofusidate (STDHF) on drug permeation across nasal mucosa was studied in vitro using Ussing type diffusion chamber. Disodium cromoglicate (DSCG, M.W.5123) and fluorescein isothiocyanate-dextran (FD) of different molecular wieghts (M.W. 4400-71200) were used as model drugs. Pemeation profiles of DSCG and FDs showed a typical pseudo steady-state curve with short lag time. The pemeability coefficient of FD (M.W. 9400) sigmodially increased with increasing STDHF concentration. It also enhanced the DSCG pemeation. Interestingly the enhancement efficacy was independent of molecular weight of penetrants.

• The Korean Journal of Zoology
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• v.35 no.4
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• pp.466-473
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• 1992

Storage protein-1 (SP-1) of Gallerio mellonella was identified in hemolvmph and fat body by electrophoresis. SP-1 was purified from hemolvmph by KBr density gradient ultracentrifugation , DEAE-cellulose (DE52) ion-exchange chromatography, and gel permeation chromatography (Sephadex G-200). Purity of SP-1 was confirmed by Non-SDS PAGE and electron microscope. SP-1 is 9.4 nm in diameter and regular octahedron in shape. SP-1 has isoelectric point of 5.7 and native molecular weight of 365 K dalton and is composed of one type of subunit with molecular weight of 82 K dalton. Ttiacylslvcerol and phospholipid were found to be maior lipid components in SP-1.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.3
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• pp.438-443
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• 1996

The effect of plasma polymerization conditions on the structure of the plasma polymerized styrene were investigated by using Fourier Transform Infrared Ray(FT-IR), Differential Scanning Calorimetry (DSC), Gel Permeation Chromatography(GPC). Plasma polymerized thin film was prepared using an interelectrode inductively coupled gas-flow-type reactor. We show that polymerization parameters of thin film affect sensitivity and etching resistance of plasma polymerized styrene is 1.41~3.93, and deposition rate of that are 32~383[.angs./min] with discharge power. Swelling and etching resistance becomes more improved with increasing discharge power during plasma polymerization. (author). 11 refs., 10 figs., 1 tab.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.488-490
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• 2003

As aluminum becomes more widely used in power distribution systems, so the corrosion caused by bimetallic contacts of aluminum and copper becomes more serious problem. In particular, the poor contact of the commonly used compression type bimetal connections may bring about the disastrous interruption of the power supply resulted from the increased corrosion within the joints, which is accelerated by the permeation of water and electrolyte into the interface. In this paper, the corrosion characteristics of aluminum and copper are investigated to improve the reliability of Al-Cu connectons.