• Journal of the Korean Chemical Society
• /
• v.49 no.3
• /
• pp.255-260
• /
• 2005

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
• /
• 2005.09a
• /
• pp.63-67
• /
• 2005

Pentacene channel OTFT(organic thin film transistor)을 SiOC 절연박막 위에서 film by thermal evaporation 방법을 이용하여 성장시켰다. CVD 방법으로 증착시킨 SiOC 절연막은 조성비에 따라 특성이 달라지므로 절연막 위에서의 펜타센의 화학적 반응을 조사하기 위해서 inorganic-type인 $O_2/(BTMSM\;+\;O_2)$ = 0.5의 비율을 갖는 SiOC 박막을 사용하였다. 팬타센 분자의 말단에서 SiOC 표면에서 Diels-Alder 반응에 의한 이중결합이 깨어지면서 안정된 성장을 하지만 온도가 높아감에 따라 표면에서의 $SN_2$(bimolecular nucleophilic substitution) 반응과 연쇄적인 화학반응에 의해 팬타센의 성장을 방해하는 것으로 나타났다.

• Journal of the Korean Chemical Society
• /
• v.65 no.1
• /
• pp.9-14
• /
• 2021

In this study, the DFT calculation was performed using the B3LYP/6-31G(d,p) basis sets for the reaction process in which phenanthrene decomposes due to the chain reaction of two OH radicals on phenanthrene in the gaseous state of 298 K at 1 atm. As a result of the calculation, even when two OH radicals act on phenanthrene in a chain, the reaction for producing phenanthren-9-ol is predicted to be more advantageous than the reaction for producing phenanthren-1-ol. On the other hand, it was predicted that the OH addition process at room temperature would be advantageous for the priority of the OH addition and H abstraction process.

• Journal of the Korean Chemical Society
• /
• v.33 no.2
• /
• pp.168-176
• /
• 1989

Theoretical analysis of HF chemical laser models are performed through chemical reaction kinetics, gain process and stimulated emission process. A chemical laser of F+$H_2$ nonchain reaction is investigated through V-R transitions of excited HF for vibrational levels up to v = 3 and rate equations including nonchain pumping and deactivation. On this analysis, harmonic and anharmonic vibrational levels are considered separately and the results of the corresponding power calculations are showed very small difference between the two. Output powers are calculated with variation of temperature and initial concentrations of $H_2$. A HF chemical laser of $H_2$+$F_2$ chain reaction is also simulated with a premixed initial condition. Results of present model calculations are satisfactory through comparison with detailed calculations reported by others.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.10 no.1
• /
• pp.76-83
• /
• 2002

Mathematically and chemically simplified reaction scheme for n(heptane that simulates autoignitions of the end gases in spark ignition engines has been developed and studied computationally. The five(equation model is described, to predict the essential features of hydrocarbon oxidation. This scheme has been calibrated against autoignition delay times measured in rapid compression machines. The rate constants, activation temperatures, Ta, Arrhenius pre-exponential constants, A, and heats of reaction for stoichiometric nheptane/air has all been optimized. Comparisons between computed and experimental autoignition delay times have validated the present simplified reaction scheme. The influences of heat loss and concentration of chain carrier at the beginning of compression upon autoignition delay times have been computationally investigated.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.11 no.3
• /
• pp.13-19
• /
• 2003

Mathematically simplified reaction scheme that simulates autoignitions of the end gases in spark ignition engines has been studied computationally. The five equation model is described, to predict the essential features of hydrocarbon oxidation. This scheme has been calibrated against autoignition delay times measured in rapid compression machines. The rate constants, activation temperatures, Ta, Arrhenius preexponential constants, A, and heats of reaction for stoichiometric n-heptane/air, iso-octane/air, and their mixtures have all been optimised. The optimisation has been guided by Morley's correlation of the ratio of chain branching to linear termination rates with octane number. Comparisons between computed and experimental autoignition delay times have validated the Present simplified reaction scheme and the influences of octane number upon autoignition delay times have been computationally investigated. It has been found that both cool flame and high temperature direct reactions can have an effect on autoignition delay times.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.43 no.2 s.344
• /
• pp.13-17
• /
• 2006

Pentacene channel for organic thin film transistor was deposited on the SiOC film by thermal evaporation. The growth of pentacene is related with the Diels-Alder reaction and the nucleophilic reaction by the thermal induction. The surface is an important factor to control the recursive Diels-Alder reaction for growing of pentacene on SiOC far The terminal C=C double bond of pentacene molecule was broken easily as a result of attack of the nucleophilic reagents on the surface of SiOC film. The nucleophilic reaction can be accelerated by increasing temperature on surface, and it maks pentacene to grow hardly on the SiOC film with a flow rate ratio of $O_2/(BTMSM+O_2)=0.5$ due to its inorganic property. The nucleophlic reaction mechanism is $SN_2(bimolecular nucleophilic substitution)$ type.

• Journal of the Korean Chemical Society
• /
• v.49 no.6
• /
• pp.537-545
• /
• 2005

• Journal of the korean academy of Pediatric Dentistry
• /
• v.37 no.3
• /
• pp.275-287
• /
• 2010

Deep caries may induce pulpitis and the pulpal tissue interacts with microbial invasion. The immune response to protect the pulpal tissue can be mediated by cellular signal molecules produced by the pulpal cells. The understanding of these processes is important to find future therapeutic method for the diseased pulp. The pulp tissue from sound teeth was set as control group (n=30) and the pulp tissue from decayed teeth was set as test group (n=30). Total RNA was extracted from the pulp of each group and it was used for cDNA microarray and reverse transcriptase-polymerase chain reaction(RT-PCR). The expression of TGF-${\beta}1$ was studied by immunohistochemistry. The results were as follows: 1. cDNA microarray analysis identified 520 genes with 6-fold or greater difference in expression level with 143 genes more abundant in health and 377 genes more abundant in disease. 2. The RT-PCR analysis was done for randomly selected 14 genes and the results supported the result of cDNA microarray assay. 3. TGF-${\beta}1$ was highly expressed in the carious pulp and it was found in odontoblast by immunohistochemistry. In conclusion, many cytokines were found to be significantly changed their expression in the diseased pulp(/M/>1.6).

• Journal of the Korean Chemical Society
• /
• v.47 no.2
• /
• pp.127-132
• /
• 2003

We have developed a direct polymerase chain reaction (PCR) and electrophoresis method for the diagnosis of bovine theileriosis from whole blood DNA analysis without DNA extraction. The technique empolyed a FoLT (formamide, low temp.) technique and was utilized in the diagnosis of bovine theileriosis. Formamide solubilize the blood cells, and the lowered incubation temperatures reduced protein coagulation. 100-200 nL of whole blood and PCR reagents were introduced directly into a PCR tube. After the amplification, the PCR product (816-bp DNA) was introduced into the electrophoresis system. The results of this analysis were consist with those obtained using purified DNA.