• Journal of the Korean Chemical Society
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• v.42 no.4
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• pp.391-397
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• 1998

The geometry of furan, relevant to the binding of bis-furan lexitropsin that contains this ring to the base pair of minor groove of DNA, is optimized by semiempirical (MNDO) and ab initio (Hartree-Fock) methods. The proton affinity and electronic structure are evaluated at the 6-31G and $6-31G^{\ast}$ level of theory for the optimized geometry. The proton affinities are also studied for various substituted furans with the electrondonating and -withdrawing groups to estimate the substituent effect on the proton affinity of furans. It has been found that the electron-donating substituents increase the proton affinity of furan, whereas the electron-withdrawing substituents decrease it. This result can be explained with atomic charge and electron density at oxygen of substituted furans.

• Journal of the Korean Chemical Society
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• v.51 no.1
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• pp.7-13
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• 2007

The oxazole plays an important role in the binding of lexitropsin to the guanine-cytosine base pair from minor groove of DNA. The geometry optimization is performed with DFT calculations for the two possible conformations of the protonated oxazole. The proton affinities are calculated at B3LYP level of theory with 6-31G* basis set for the optimized geometry. It is found that the proton affinites of the conformations in which the oxazole nitrogen is the protonation center are greater than that of the conformations in which the oxazole oxygen is the protonation center. This result is in good agreement with molecular electrostatic potential (MEP) contour map. The proton affinities are also studied for various substituted oxazoles with the electron-donating and -withdrawing groups to estimate substitutent effect on the proton affinity at the hydrogen bonding site of the oxazoles. it is shown that the electron-donating substituents increase the proton affinity of oxazole, while the electron-withdrawing substituents decrease it.

• Journal of the Korean Chemical Society
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• v.38 no.1
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• pp.21-25
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• 1994

The proton affinities of substituted imidazoles, relevant to the binding of lexitropsins that contain imidazole ring to the base pair (G-C sequence) of minor groove of DNA, are studied with the aid of EHT calculations. It is shown that proton affinity of imidazole substituted at position $\alpha$ to the basic nitrogen is slightly larger than that of imidazole substituted at N for the methylimidazole. Proton affinities of N-substituted imidazoles are found to be larger than those of imidazoles substituted at position ${\alpha}$ for a selected set of the other derivatives. As predicted the proton affinity increases when electron-donating group is attached at position N of imidazole.

• Journal of the Korean Chemical Society
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• v.39 no.7
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• pp.493-500
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• 1995

The geometry optimization of oxazole, relevant to the binding of lexitropsin that contains this ring to the base pair (G-C sequence) of minor groove of DNA, is performed with the aid of MM+ and ab initio (Hartree-Fock) calculations. The proton affinity and electronic structure are calculated at the 6-31G and $6-31G^{\ast}$ level for the optimized geometry. The proton affinities are also studied for various substituted oxazoles with the electron-donating and -withdrawing groups to estimate the substituent effect on the proton affinities of oxazoles. It is shown that the electron-donating substituents increase the proton affinity of oxazole, while the electron-withdrawing substituents decrease it. This result can be explained with atomic charge and electron density at oxygen of substituted oxazoles.

• Journal of the Korean Chemical Society
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• v.42 no.1
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• pp.1-8
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• 1998

Molecular electrostatic potential (MEP) of the thiazole, relevant to the binding of lexitroposin that contains thiazole ring to the base pair of minor groove of DNA is obtained from the results of ab initio calculation. The geometry optimization for the two possible conformations of protonated thiazoles is performed with the aid of MNDO and ab initio calculations. The proton affinities are calculated at the 6-31G and 6-31G basis set for the optimized geometry. The proton affinities are also studied for various substituted thiazoles with the electron-donating and electron-withdrawing groups to estimate substituent effect on the proton affinity of thiazoles. It is found that the thiazole with nitrogen atom aligned inward to the DNA minor groove exhibit higher proton affinity and electron-donating substituents increase the proton affinity of thiazoles.ĀȀꃏ?⨀缾ĀȀ會ĀȀ?⨀ꖓĀĀȀ會ĀȀ僐?⨀聥ꖓĀĀȀ會ĀȀ꣐?⨀聐缾ĀȀ會ĀȀÑ?⨀ၑ缾ĀȀ會ĀȀ壑?⨀ꁑ缾ᨀĀꀏ會Āꀏ냑?⨀⡒缾᐀Āꀏ會Āꀏ࣒?⨀끒缾ᰀĀꀏ會Āꀏ惒?⨀ꁩꖓȀĀꀏ會Āꀏ룒?⨀⡪ꖓሀĀꀏ會Āꀏდ?⨀ᤐ돀삺?⨀塨?⨀飣?⨀돐룣?⨀偠잖⨀샣?⨀줏덐탣?⨀젏ꠏܞ
Ȍ蠀
ᥲ⴯

ͧ
Molecua及컲ࡔ
ȏᰗۊऀں
Molecular electrostatic potential (MEP) of the thiazole, relevant to the binding of lexitroposin that contains thiazole ring to the base pair of minor groove of DNA is obtained from the results of ab initio calculation. The geometry optimization for the two possible conformations of protonated thiazoles

• Composites Research
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• v.32 no.5
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• pp.222-228
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• 2019

The proton exchange membrane fuel cell (PEMFC) system has many potential uses as an environmentally friendly power source. Carbon fiber composite bipolar plates are highly corrosion resistant and have high specific strength and stiffness in acidic environments, however, the relatively low electrical conductivity is a major issue which reduces the efficiency of PEMFC. In this study, electrically conductive particles (graphite powder and carbon black) are applied to carbon-epoxy composite prepregs to reduce the electrical resistance of the bipolar plates. The electrical resistance and mechanical properties are measured using conventional test methods, and a unit cell performance evaluation of developed carbon composite bipolar plates is performed to compare with the conventional bipolar plate.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.07a
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• pp.209-210
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• 2013

본 연구의 목적은 공학에 대한 흥미, 태도, 성취가 낮은 여학생에게 공학 경험을 제공함으로써 공학 분야의 여성 인재를 양성할 수 있는 계기를 마련하기 위한 공학 중심 STEAM 프로그램의 틀을 설계하는 데 있다. 이를 위하여 여학생의 특성을 분석하고 여학생 친화적인 환경을 구축하였으며 여학생 친화적 환경에 부합하는 e-textile이라는 도구를 활용하여 STEAM 교육 프로그램을 설계하였다. 교육 프로그램은 학습자가 직접 참여할 수 있도록 Learning by Doing, Learning by Design의 전략을 사용하도록 하였으며 교육 프로그램 전 과정을 학습자 스스로 창의적인 사고를 바탕으로 문제를 해결해나가도록 하고 교사는 조력자, 안내자 역할을 할 수 있도록 하였다.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.117-123
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• 2015

본 연구에서는 DFT를 이용하여 Nucleophilicity와 Basicity의 연관성에 대한 계산화학적 분석을 수행하였다. Basicity는 선정된 모델 분자의 protonation 반응에서 생성물과 반응물의 enthalpy 변화량인 양성자 친화도(Proton affinity, PA) 값을 구하여 분석하였다. 계산한 결과는 실험을 통해 얻은 PA 결과와 경향성이 거의 일치함을 확인하였다. Nucleophilicity는 모델 분자들과 $CH_3Br$ (electrophile)의 $SN_2$반응에서 gibbs free energy of activation(${\Delta}G^{\ddag}$) 값으로 그 경향성을 분석하였다. 또한 용매의 종류를 다르게 하여 용매에 따른 ${\Delta}G^{\ddag}$ 값의 경향성도 확인하였다. 각 용매에 따라 구한 ${\Delta}G^{\ddag}$와 PA의 상관관계를 비교하였으나, 큰 연관성은 보이지 않았다. 이에 ${\Delta}G^{\ddag}$와 PA의 상관관계를 보여줄 수 있는 parameter를 찾기 위하여 각 모델 분자의 Electronegativity와 Polarizability를 계산하여 연관성을 비교해보았다. Polarizability를 적용했을 때 Nucleophilicity와 Basicity사이의 연관성을 나타낼 수 없었던 반면, Electronegativity를 적용하여 Basicity와 Nucleophilicity의 연관성 보일 수 있음을 이론적으로 규명하였다.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.7
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• pp.807-812
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• 2015

Lifelong education is a periodic keyword. For a lifelong learner friendly education, university should provide the adult learners with the efficient academic administrative service. A university should support them in learning a series of graded lifelong study and come up with the convenience of continuous learning, maintaining the educational operation as a lifelong education university. A local government induces the regional economy reinvigoration from setting the lifelong learning conditions of the city. In this paper, I suggest a policy management scheme for opening training courses of 3D printing and CAD professionals training module as a non-degree reeducation programs for the lifelong learners that reflects the industrial milieu of the local community.

• Journal of the Korean Chemical Society
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• v.47 no.2
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• pp.96-103
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• 2003

Density Functional Theory(DFT) calculations are performed to estimate the hydrogen bonding interaction energies in pyridine-water and amino-substituted pyridine-water complexes. Some equilibrium properties are also obtained for these complexes at B3LYP/aug-cc-pVDZ level. It is shown that the amino substitution increases the proton affinity of pyridine and stabilizes the hydrogen bond. The degree of stabilization upon formation of the complex varies with the number and the position of the amino groups.