• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1978.04a
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• pp.96.2-96
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• 1978

Commerial naringinase from Aspergillus niger was partially purified by various methods, and was immobilized to porous alkylamine silica of 30~40 mesh and 400 $\AA\pm10％$ pore diameter that had been activated with 2.5％ glutaraldehyde. About 50~70％ of initial naringinase activity was recovered after the immobilization process. Some enzymatic properties of the immobilized naringinase was investigated and compared with those of the native enzyme. The optimal temper-ature had moved from $40^{\circ}C$ to $55^{\circ}C$ and the heat stability of the immobilized enzyme was better than that of the native naringinase. But no signi-ficant diference in the pH effect on activity was detected. The activation energy of reaction, Ea, was markedly decreased from 14.9 to 8.64 (Kcal/mole) by immobilization.

• Journal of the Korean Applied Science and Technology
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• v.22 no.3
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• pp.228-233
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• 2005

Langmuir-Blodgett(LB) technique can speak the best candidate of the future molecular electronic devices. But, precursor as molecular ultrathin film devices require the bulk property that are influenced by the molecular orientation. So, this device is one of current interest in molecular electronic device development of new materials. In this study, quantitative evaluation of molecular orientation in LB films of polyamic acid alkylamine salt was performed analysis experiment comparing the absorption or transmission intensity of the FT-IR spectrometer and reflection or absorption spectra with UV-visible absorption spectra. It could find that the polar angle(${\theta}$) of the dipole moment appears in about $68^{\circ}$ and the tilting angle of the alkyl chain is about $11.5^{\circ}$.

• Journal of the Korean Applied Science and Technology
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• v.28 no.4
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• pp.438-448
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• 2011

Chitosan is widely used in cosmetics and medical fields. Special emphasis has been put on the chemical modification of chitosan to explore its full potential. We have described the synthesis and biological activity of novel peptide amino acid derivatives. The polyamino acid derivatives were synthesized by introducing alkylamine functional group on chitosan at C-6. The poor aqueous solubility of chitosan derivatives hinder both pharmacological studies and pharmaceutical development. To make amino acid coupled chitosan derivatives with improved biological effect and solubility, some attempts have been taken to consist of amino peptide group like aspartic acid and phenylalanine-aspartic acid derivatives onto chitosan C-6. The resultingly substituted chitosan was characterized by solubility in various solvents. We measured chitosan derivatives with $^1H$-NMR and $^{13}C$-NMR. Also, We were investigated on the physical properties and biological activities of these products.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.277-280
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• 1997

It is important to investigate the molecular arrangement and the orientational distribution in the study of LB films. Polarized UV/visible absorption spectra make it possible to reveal the molecular arrangement and the orientational distribution. It is clarified that the PAAS LB films have specific directions in the molecular arrangement and the orientational distribution, which art different in intensity corresponding to the surface pressure. Unpolarized UV/visible absorption spectra reveal that the surface pressure is proportional to the finn thickness and is related to the molecular orientation. Current-Voltage(I-V) measurements provide that the current decreases as the surface pressure increases and there are certain phenomena called switching phenomena. Switching effort indicates that the current flows in high conductivity during on-state and suddenly decreases into low conductivity during off-state.

• Elastomers and Composites
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• v.52 no.1
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• pp.59-68
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• 2017

The effect on the hydrolysis resistance properties by the addition of maleic anhydride grafted EMDM (MA-g-EPDM) and PP (MA-g-PP) to a PA66/GF composite was investigated with respect to the mechanical properties, thermal properties, and morphology. The degree of hydrolysis of the PA66/GF composite was measured using py-GC/MS analysis. When compared to the PA66/GFcomposite in MEG/water solution, the composites where MA-g-EPDM and MA-g-PP were added to PA66/GF showed a higher degree of hydrolysis resistance, impact strength, and thermal properties, whereas their tensile strength, tensile modulus, flexural strength and flexural modulus decreased. As immersion time in the solution increases, the rate of tensile strength drop of the MA-g-PP added composite appeared lower than that of the PA66/MA-g-EPDM/GF and PA66/GF composites. The py-GC/MS analysis confirmed the formation of PA66 hydrolysis reaction by products such as carboxylic acid and alkylamine with increasing immersion time.

• Journal of the Korean Applied Science and Technology
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• v.11 no.2
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• pp.147-150
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• 1994

Ultra thin films of HDSM-CuPc(Tetra-3-hexadecylsulphamoylcopperphthalocya-nine) were formed on various substrates by Langmuir-Blodgett method, where HDSM-CuPc was synthesized by attaching long-chain alkylamine(hexa-decylamine) to CuPc. The reaction product was identified with FT- IR, UV-visible absorption spectroscopies, elemental analysis and thin layer chromatography. The formation of ultrathin films of HDSM-CuPc was confirmed by FT-IR and UV-visible spectroscpies.

• Journal of the Korean Applied Science and Technology
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• v.11 no.2
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• pp.151-155
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• 1994

Polyamic acid alkylamine (N, N-dimethylhexadecylamine)(PAAS)염을 합성하여 그 합성여부를 확인하였으며 PAAS염의 Langmuir막의 ${\pi}-A$ 등온선 및 표면 전위 특성 등을 조사 하였다. Langmuir-Blodgett법에 의하여 PAAS염의 LB막을 여러종류의 기관에 누적하였으며 누적여부를 자외선 흡수 스펙트럼 및 적외선 투과 스펙트럼을 이용하여 조사하였다. 그리고 PAAS LB막을 열처리에 의하여 이미드(imide)화시켜 폴리이미드 LB막을 제조하였으며 그 이미드화 여부를 자외선 및 적외선 스펙트럼을 이용하여 조사하였다.

• YAKHAK HOEJI
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• v.40 no.1
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• pp.19-24
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• 1996

The 6,7-dichloroquinolone-5,8-dione(I) was reacted with ethyl acetoacetate in the presence of sodium ethoxide to yield 6-(${\alpha}$-acetyl-${\alpha$-ethoxycarbonyl-methyl)-7-chloro-quin oline-5,8-dione(II). When this compound II was reacted with some alkylamine (methylamine, ethylamine, propylamine, isopropylamine, cyclopropylamine, methoxyethylamine, ethanolamine, benzylamine, furfurylamine), 1N-alkyl-2-methyl-3-ethoxycarbonyl-pyridino(2,3f)-indole-4,9-dione(IIIa-i) were obtained via intramolecular cyclization.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.222-224
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• 1994

This paper describes the optimum conditions for depositing PAAS(polyamic acid alkylamine salts) Langmuir-Blodgett (LB) films, which are a precursor of polyimide LB films. The optimum conditions were studied by $\pi$-A isotherma with a varication of temperatures, spreading amounts or solution, compression speeds, and etc. Transfer ratio was also measured depending on the type of LB films.

• Journal of the Korean Applied Science and Technology
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• v.11 no.1
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• pp.71-77
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• 1994

In order to review industrial application of amphoteric surfactants, new types of hydroxy sulfobetaine, 3-(N, N-dimethyl N-dimethyl-N-alkylammonio)-2-hydroxy-1-propane sulfonate and 3-(N, N-dimethyl N-acylammonio)-2-hydroxy-1-propane sulfonate were prepared by the reaction of quaternized sodium 1-chloro-2-hydroxy-3-propane sulfonate with N, N-dimethyl-N-alkylamine and N, N-dimethyl N-acylamido propylamine that have a straight chain radical of 12, 18 carbon atoms respectively in the presence of alkali catalyst. All the reaction products could be separated by means of column and thin layer chromatography, and the yields of all products ranged in $85{\sim}90%$, the structure of them could be confirmed from IR and $^{1}H$-NMR spectra.