• 한국지하수토양환경학회지:지하수토양환경
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• 제16권6호
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• pp.46-57
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• 2011

In this study, analytical solution of multip-species transport equations coupled with a first-order reaction network under constant concentration boundary condition or total flux boundary condition is obtained using similarity transformation approach of Clement et al. (2000). The study shows the schematic process about how multi-species transport equations with first-order sequential reaction network is transformed through the similarity transformation approach into independent and uncoupled single species transport equations with first-order reaction. The analytical solution was verified through the comparison with popular commercial programs such as 2DFATMIC and RT3D. The analytical solution can be utilized in nuclear waste sites where radioactive contaminants and their daughter products occur and in industrial complex cities where chlorinated solvent such as PCE, TCE, and its biodegradation products produces. In addition, it can help the verification of the developed numerical code.

• 한국지하수토양환경학회지:지하수토양환경
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• 제29권1호
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• pp.63-71
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• 2024

Hydrothermal Reaction (HTR) was applied for the stabilization of contaminated soil with heavy metals, and then the test determined the optimal conditions for HTR. After HTR, the concentration of heavy metals in the contaminated soil increased. However, it was observed that the leachability potential significantly decreased as determined by TCLP and SPLP tests. This decrease was attributed to a decline in fractions 1-2 and an increase in fractions 3-4 as revealed by sequential extraction procedure. Due to the mineralogical characteristics of the dredged soil, distinct changes were not evident in the five-stage fraction. Therefore, it is deemed necessary to understand the chemical and mineralogical characteristics of the target soil for HTR application in order to selectively address contaminants. Comparison among operating conditions determined the optimal condition to be at 240℃ for one hour.

• 한국미생물·생명공학회지
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• 제19권1호
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• pp.100-108
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• 1991

Molecular characteristics and improving methods for thermal stability of enzyme have been considered. Intrinsic and extrinsic stabilizing mechanisms are two governing principles for enhanced thermal stability of enzyme in molecular basis. Factors contributing to the former and the latter mechanisms may be involved in the enhanced thermal stability of enzyme complementarily. Also, the methods for improving thermal stability of enzyme which comprise reaction in organic solvent system, chemical modification, immobilization, sequential unfolding and refolding, gene manipulation techniques and enzyme-antibody complexing are reviewed.

• Bulletin of the Korean Chemical Society
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• 제23권9호
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• pp.1285-1290
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• 2002

Various nitrobenzaldehydes were simultaneously allylated and reduced using indium in the presence of HCl in aqueous media to give compounds having both functionality of homoallylic alcohol and aromatic amine. Sequential protection of the amino gro up and oxidation of the anilinyl homoallylic alcohol provided useful precursors of heterocyclic compounds such as dihydroindolones and dihydroquinolones, which could be efficiently synthesized through intramolecular cyclization reaction.

• Bulletin of the Korean Chemical Society
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• 제26권2호
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• pp.229-230
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• 2005

• 약학회지
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• 제47권5호
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• pp.271-275
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• 2003

Easy and efficient synthetic route of novel 4'-C methyl branched carbocyclic nucleosides is described. The installation of alkyl and aryl groups at 4'-position of carbocyclic nucleosides were successfully made via sequential [3,3]-sigmatropic rearrangement and ring-closing metathesis (RCM) starting from simple ketones such as acetol. Adenine and uracil were coupled via Pd(0) catalyzed reaction, followed by desilylation to give novel compounds 13 and 14, respectively.

• Journal of Microbiology and Biotechnology
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• 제6권3호
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• pp.162-166
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• 1996

The protein coding sequence of the 4-aminobutyrate aminotransferase was amplified by polymerase chain reaction (PCR) from a previously cloned cDNA of pig brain using a pair of primers based on the published sequence. The amplified DNA was introduced into a T7 expression vector. Recombinant 4-aminobutyrate aminotransferases were overexpressed in Escherichia coli. The inclusion bodies were formed when enzyme was overexpressed. The unfolded, overproduced proteins were purified by chromatography with hydroxyapatite and refolded by a sequential dialysis method. The renatured 4-aminobutyrate aminotransferase regained the catalytic activity. However, the purified mutant protein did not show the catalytic function of 4-aminobutyrate aminotransferase.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1992년도 춘계학술대회 논문집 92
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• pp.177-200
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• 1992

A thermo-viscoplastic finite element program was developed to analyze the compression molding of SMC process. Deformation of the material was modelled by using the flow-rule. Heat balance during the process was coupled to the deformation. In the cure study, a kinetic model was adopted to describe the cure behavior. The numerical kinetic model was integrated with the thermo-viscoplastic numerical analysis by adding heat generation due to the chemical reaction of the workpiece in the heat transfer analysis. The integrated finite element program can simulate a whole sequential molding process including deformation, heat transfer, and chemical reaction. A practical SMC molding process with T-shaped substructure was simulated. The simulated results showed good agreements with experiments.

• 한국대기환경학회지
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• 제2권2호
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• pp.51-59
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• 1986

Hydrodesulfurization of dibenzothiophene (DBT) dissolved in n-heptane was studied over sulfided $Ni - W/\gamma - Al_2O_3$ catalyst at temperature ranges from 513 to 573 K and at pressure ranges from 20 to 60 x $10^5$ Pa. Hydrogenation of biphenyl (BP) and cyclohexylbenzene (CHB) observed in products were also run. The products were almost biphenyl and cyclohyxylbenzene, and the conversion of DBT was very sensitive to temperature. Concerning the products distribution while the formation of biphenyl decreased, the formation of cyclohexylbenzene increased in the range of high pressure. The reaction network was found to be sequential reaction which formed cyclohexybenzent through the intermediate of biphenyl. The disappearances of DBT and biphenyl were the first order with respect to DBT and biphenyl and their activation energys were 24.3 and 13.6 Kcal/mol, respectively.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.418-418
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• 2012

We fabricated a new type of hybrid film using molecular layer deposition (MLD). The MLD is a gas phase process analogous to atomic layer deposition (ALD) and also relies on a saturated surface reaction sequentially which results in the formation of a monolayer in each sequence. In the MLD process, polydiacetylene (PDA) layers were grown by repeated sequential surface reactions of titanium tetrachloride and 2,4-hexadiyne-1,6-diol with ultraviolet (UV) polymerization under a substrate temperature of $100^{\circ}C$. Ellipsometry analysis showed a self-limiting surface reaction process and linear growth of the hybrid films. Polymerization of the hybrid films was confirmed by infrared (IR) spectroscopy and UV-Vis spectroscopy. Composition of the films was confirmed by IR spectroscopy and X-ray photoelectron (XP) spectroscopy. The titanium oxide cross-linked polydiacetylene (TiOPDA) hybrid films exhibited good thermal and mechanical stabilities.