• Journal of Food Hygiene and Safety
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• v.26 no.1
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• pp.76-81
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• 2011

The protease produced by a Bacillus pumilus CN8 strain was purified by DEAE-Cellulose-52 ion exchange. It has a molecular weight of approximately 96,920 Dalton. In the present study, this protease showed strong activity over a broad range of pH (6.5-9.5) and temperature from $40^{\circ}C$ to $60^{\circ}C$, and the protease performed the maximal activity at pH 7.3 at $42^{\circ}C$. The effect of metal ions on protease activity showed that $K^+$ could slightly increase the protease activity, and other ions such as $Zn^{2+}$, $Fe^{2+}$, $Na^+$, $Ca^{2+}$, $Mg^{2+}$ had no significant activation or inhibition to the protease (P> 0.05), and the more important is that $Cu^{2+}$, $Mn^{2+}$, $Sn^{2+}$, $Cd^{2+}$ had a strong inhibitory effect on the protease activity.

• Elastomers and Composites
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• v.37 no.2
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• pp.124-133
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• 2002

Waste PBT powder was depolymerized by saponification under the mild temperature conditions($80{\sim}110^{\circ}C$) and atmospheric pressure. In depolymerization of PBT, sodium hydroxide was more effective than potassium hydroxide. The depolymerization increased with increasing reaction temperature and decreasing particle size. The reaction kinetics of depolymerization could be expressed by the shrinking unreacted core model without product layer, in which the surface reaction was a rate determining step. The activation energy was 98.1 KJ/mol. The recovery ratio of the TPA obtained from the depolymerized PBT particles of 85.1 and $105{\mu}m$ for 6 hours was about 95%.

• Journal of the Korean Chemical Society
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• v.41 no.12
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• pp.645-652
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• 1997

Hydride complexes Cp*Ru(CO)(PR3)H (Cp*=η5-C5Me5, PR3=PMe3, PEt3, PMePh2, PPh3, PCy3)(4a-4f) were synthesized by the reaction of the corresponding chloro complex Cp*Ru(CO)(PR3)Cl (3a-3f) with various hydridic reagent (NaBH4, LiAlH4, LiBEt3H) or NaOMe. Irradiation of Cp*Ru(CO)(PCy3)H (5e) in C6D6 solution with UV light caused H/D exchange reaction between coordinated Cp*, PCy3 and/or Ru-H ligand proton and a deuterium of the deuterated aromatic solvent through a series of inter- and intramolecular C-H activation. The proposed mechanism was described.

• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.46-46
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• 2003

Salviae Miltiorrhizae Radix has been used for treatment of cardiovascular diseases in oriental medicine. To investigate the possible involvement of cardiac ion channel in this effect, we examined electrophysiological effects of the extract of Salviae Miltiorrhizae Radix on action potentials and ionic currents in rat ventricular myocytes. The extracts of Salviae Miltiorrhizae Radix were fractionated into nine fractions, and the effect of each fraction on action potential was tested. The fraction containing monomethyl lithospermic acid-A (LSA-A) induced a significant prolongation of action potential duration (APD). LSA-B which is a major component of Salviae Miltiorrhizae Radix, however, did not cause a significant effect. In voltage clamp experiments, the effects of LSA-A on K currents, Ca currents and Na currents were tested. Neither K currents nor L-type Ca currents were affected by LSA-A. On the contrary, LSA-A significantly slowed down the inactivation kinetics of the Na current with no effect on the fast component of the inactivation process. The amplitude of the peak current and the voltage-dependence of activation were not changed by LSA-A. The effect of LSA-A on Na current was abolished when high concentration of $Ca^{2+}$ buffer (10 mM BAPTA) was included in the pipette solution or when Ca2+ current was blocked by nicardipine (1 $\mu$M) in the bath solution.n.

• Journal of the Korean Applied Science and Technology
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• v.17 no.1
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• pp.49-53
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• 2000

For decompose carbon dioxide, manganese oxide was synthesized with $0.25M-MnSO_{4}{\cdot}nH_{2}O$ and 0.5M-NaOH by coprecipitation. We made magnetite deoxidized manganese oxide by hydrogen reduction for 1hour at $330^{\circ}C$. We investigated characteristics of catalyst, hydrogen reduction degree and decomposition rate of carbon dioxide. The structure of the hausmannite certified spinel type. The specific surface area of synthesized hausmannite and deoxidized hausmannite were $22.36m^{2}/g$, $33.56m^{2}/g$ respectively. The decomposition rate of $CO_{2}$ of deoxidized hausmannite was 57%.

• Journal of the Korean Ceramic Society
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• v.37 no.6
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• pp.559-563
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• 2000

To decompose carbon dioxide, magnetite was synthesized with 0.2M-FeSO4$.$7H2O and 0.5 M-NaOH by coprecipitation. The deoxidized magnetite was prepared from the magnetite by hydrogen reduction for 1, 1.5, 2 hr. The degree of hydrogen reduction and the decomposition rate of carbon dioxide were investigated with hydrogen reduction time. The crystal structure of the magnetite was identified spinel structute by the X-ray powder diffractions. After magnetite was reduced by hydrogen, magnetite reduced by hydrogen become new phae(${\alpha}$-Fe2O3, ${\alpha}$-Fe) and spinel type simultaneously. After decomposing of carbon dioxide at 350$^{\circ}C$, new phse(${\alpha}$-Fe2O3, ${\alpha}$-Fe) were removed and the spinel type only existed. The specific surface area of the synthesized magnetite was 46.69㎡/g. With the increase of the hydrogen reduction time, the grain size, the hydrogen reduction degree and the decomposition rate of carbon dioxide was increased.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.433-436
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• 2005

The Fly-ash makes an Alumino-silicate gel when it mixes an alkali or a silicate solution. This Alumino-silicate gel is produced to the activation of an alkali silicate. And this act to the binder and makes a combine of particles. This study involved mechanical strengths of an Alumino-silicate Gel based the Fly-ash with an alkali solution. NaOH, KOH were utilized to an alkali solution. The alkali solution concentration was varied from 6 to 12M and the some added also the Meta-kaolin, Waterglass so that it made high the mechanical performance. Based on the experimental result, the compressive strengths increased as the quantity of the Meta-kaolin increased. And a mechanical strengths appeared according to the concentration of an alkali solution so that it was different. XRD, FT-IR have been used to characterize mechanical performance.

• Textile Coloration and Finishing
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• v.4 no.4
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• pp.90-96
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• 1992

In the PAN-based ACF manufacturing system stabilization step was improved with chemical treatment (preoxidation) in order to yield higher carbon content and to avoid excessive fragmentation during carbonization and activation process. The optimal condition of preoxidation was at 18$0^{\circ}C$ for 4 minutes in sodium glyceroxide in glycerine (concentration of NaOH was 0.02 meq/g). To investigate low temperature stabilization effect, preoxidized PAN fiber heated 22$0^{\circ}C$ to 26$0^{\circ}C$ as a function of treatment time and oxidative gas atmosphere, and analysed by infrared spectrum and TGA. As a results of IR and TGA, it was clear that impregnated[preoxidative] PAN had 14% higher residual than untreated PAN at 100$0^{\circ}C$ and the optimal condition of stabilization was at 26$0^{\circ}C$ for 3.5 hours within $N_2$ atmosphere.

• Proceedings of the Korean Society for Information Management Conference
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• 2014.08a
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• pp.187-190
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• 2014

현재 공공도서관에서는 홈페이지를 통한 이용자 교육 프로그램이 미비한 실정으로, 이 연구에서는 현재 도서관 홈페이지에서 제공하는 이용자 교육관련 항목들을 분석하여 향후 공공도서관 홈페이지를 이용한 이용자 교육 프로그램의 발전을 위한 제언을 제시하였다. 이를 위해 기존 문헌에서의 평가 기준과 전문가의 자문을 통하여 공공도서관 홈페이지의 이용자 교육관련 항목에 대한 분석기준을 확립하고, 이에 따라 공공도서관 홈페이지의 이용자 교육관련 항목들을 분석하였다. 이를 바탕으로 공공도서관 홈페이지 이용자 교육에서 필요한 사항들에 대해 제언하고자 한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.359-361
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• 2023

관광산업은 뉴 노멀(New Normal) 시대에 언택트에서 온택트(On-tact)형식의 메타버스(Metaverse)로의 새로운 관광 패러다임 전환을 맞이하고 있다. 이에 이 연구는 뉴 노멀 시대에 직면하여 관광산업의 변화방향에 대한 문제의식을 가지고서 지역의 관광활성화 방안 중에서도 체류형 지역 관광 활성화를 위한 방안으로 메타버스를 활용한 관광 홍보마케팅에 대한 효율적인 방안들에 대해 제안한다.