• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.587-596
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• 2014

A new ${\pi}$-stacked donor-acceptor (D-A) system, [Ru(1-([2,2'-bipyridine]-6-yl-methyl)-3-(2-cyclohexa-2',5'-diene-1,4-dionyl)-1H-imidazole)(2,2':6',2"-terpyridine)]$[PF_6]_2$ (ImQ_T), has been synthesized and characterized. Similar to its precedent, [Ru(6-(2-cyclohexa-2',5'-diene-1,4-dione)-2,2':6',2"-terpyridine)(2,2':6',2"-terpyridine)]$[PF_6]_2$ (TQ_T), this system has a cofacial alignment of terpyridine (tpy) ligand and quinonyl (Q) group, which facilitates an electron transfer through ${\pi}$-stacked manifold. Despite the presence of lowest-energy charge transfer transition from the Ru-based-HOMO-to-Q-based-LUMO (MQCT) predicted by theoretical calculations by using time-dependent density functional theory (TD-DFT), the experimental steady-state absorption spectrum does not exhibit such a band. The selective excitation to the Ru-based occupied orbitals-to-tpy-based virtual orbital MLCT state was thus possible, from which charge separation (CS) reaction occurred. The photo-induced CS and thermal charge recombination (CR) reactions were probed by using ultrafast visible-pump/mid-IR-probe (TrIR) spectroscopic method. Analysis of decay kinetics of Q and $Q^-$ state CO stretching modes as well as aromatic C=C stretching mode of tpy ligand gave time constants of <1 ps for CS, 1-3 ps for CR, and 10-20 ps for vibrational cooling processes. The electron transfer pathway was revealed to be Ru-tpy-Q rather than Ru-bpy-imidazol-Q.

• 대한두경부종양학회:학술대회논문집
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• 2009.11a
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• pp.187-189
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• 2009

• Bulletin of the Korean Chemical Society
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• v.27 no.7
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• pp.1009-1014
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• 2006

Density functional theory calculations are applied to investigate the intramolecular proton transfer in the tautomers of thymine radical cation and its hydrated complexes with one water molecule. The optimized structures and energies for 6 tautomers and 6 transition states of thymine radical cation are calculated at the B3LYP/6-311++G(d,p) level. It is predicted that the order of relative stability for the keto and enol tautomers of thymine radical cation is the same with that of the neutral thymine tautomers, though the enol tautomers are more stabilized with respect to the di-keto form in the radical cation than in the neutral state. A new channel of proton transfer from >C5-$CH_{3}$ of thymine is found to open and have the lowest energy barrier of other proton transfer processes in thymine radical cation. The roles of hydration are also investigated with thymine-water 1 : 1 complex ions. The presence of water significantly lowers the barrier of the proton transfer, which clearly shows the assisting role of hydration even with one water molecule

• Journal of Technology Innovation
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• v.10 no.2
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• pp.149-163
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• 2002

In order to manage technology transfer properly, it is important to judge whether the technology transfer is successful or not, and to find out the reason of the conclusion. The study aims to find out the relationship between successfulness of technology transfer and reasons or basis of the conclusion. Empirical investigation was carried out for Korean small and medium size firm in machinery and material field with statistical analysis on questionnaire and intensive interview. Result of the analysis is identified and compared with the other. It is shown that Korean firms feel their technology transfer is successful when it meet functional objectives and to get enough knowledge to further utilization from external source. Realization of benefit do not affect much the successfulness of technology transfer even though it is final objectives of technology transfer.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.1
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• pp.17-27
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• 2009

Water jet impingement cooling is used to remove heat from high-temperature surfaces such as hot steel plates in the steel manufacturing process (thermo-mechanical cooling process; TMCP). In those processes, uniform cooling is the most critical factor to ensure high strength steel and good quality. In this study, experiments are performed to measure the heat transfer coefficient together with the inverse heat conduction problem (IHCP) analysis for a plate cooled by planar water jet. In the inverse heat transfer analysis, spatial and temporal variations of heat transfer coefficient, with no information regarding its functional form, are determined by employing the conjugate gradient method with an adjoint problem. To estimate the two dimensional distribution of heat transfer coefficient and heat flux for planar waterjet cooling, eight thermo-couple are installed inside the plate. The results show that heat transfer coefficient is approximately uniform in the span-wise direction in the early stage of cooling. In the later stage where the forced-convection effect is important, the heat transfer coefficient becomes larger in the edge region. The surface temperature vs. heat flux characteristics are also investigated for the entire boiling regimes. In addition, the heat transfer rate for the two different plate geometries are compared at the same Reynolds number.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1561-1565
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• 2012

The structures of the four lowest alanine conformers, along with their radical cations and the effect of ionization on the intramolecular proton transfer process, are studied using the density functional theory and MP2 method. The energy order of the radical cations of alanine differs from that of the corresponding neutral conformers due to changes in the basicity of the $NH_2$ group upon ionization. Ionization favors the intramolecular proton transfer process, leading to a proton-transferred radical-cation structure, [$NH_3{^+}-CHCH_3-COO{\bullet}$], which contrasts with the fact that a proton-transferred zwitterionic conformer is not stable for a neutral alanine in the gas phase. The energy barrier during the proton transfer process is calculated to be about 6 kcal/mol.

• Archives of Reconstructive Microsurgery
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• v.21 no.1
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• pp.27-33
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• 2012

We studied the results of the immediate microsurgical reconstruction of the distal digit injury with short vascular pedicled partial toe transfer. Thirteen patients with amputation or crush injury of the distal digit who underwent partial toe transfer at the authors' institute over 8-year period were reviewed. Delay between initial injury and reconstruction ranged from 1 to 9 days. All flaps were harvested on a short vascular pedicle, with anastomoses performed at a proximal interphalangeal joint level on the fingers and metacarpophalangeal joint level on the thumbs. Good to excellent cosmetic and functional results were obtained in all cases, with nearly normal-looking fingertip. The mean static two point discrimination was 10 mm. Immediate reconstruction with short vascular pedicled partial toe transfer is an excellent option for the reconstruction of the compostie defect of the distal digit.

• Journal of Korea Technology Innovation Society
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• v.2 no.2
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• pp.233-248
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• 1999

For the last several decades, it has been recognized that technology is a key factor in becoming an ADC and an advanced firm. So many countries and individual firms have been increasing investments on technology development. Especially LDCs including Korea choose technology transfer and transaction as an important alternative of their own technology development. To activate technology transaction and transfer, it is necessary to establish an technology transaction system, namely a Technomart that will make good connections between technology suppliers and technology buyers, and efficient functional linkages of supporting infrastructures including organizations and laws related with technology transactions. Therefore this study reviewed both the characteristics of technology transfer and transaction and a conceptual structure of a Technomart through a literature review. And then, the study analyzed the Technomart related laws including an intellectual property right, a copyright, a patent right, and electric transaction related laws. In conclusion the study proposed the development directions of the Technomart related laws.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.3-7
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• 2002

In vitro embryo culture techniques provide significant contributions not only for a basic research of fertilization and early embryogenesis, but also for a low cost mass production of bovine embryos for transfer, embryo diagnosis, nuclear cloning and the production of transgenic cows. This presentation introduces newly developed serum-free media (IVD101 and IVMD101) that are effective far high yields of transferable embryos of excellent quality from in vitro-matured and fertilized oocytes. Both serum-free media are superior to a conventional serum-containing medium on the increased rates of blastocyst formation, post-thaw embryo viability, and pregnancy after transfer. Furthermore, reduced risks of calf mortality and large calf syndrome are also observed for the serum-free-derived embryos. Serum-derived embryos contain a large number of lipid droplets and immature mitochondria in their cytoplasm that may account for the lower production of transferable embryos and poor embryo quality.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.186.1-186.1
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• 2014

Graphene, which is a 2-dimensional carbon material, has been attracting much interest due to its unique properties and potential applications. So far, many interesting experimental and theoretical works have been done concerning the electronic properties of graphene on various substrates. Especially, there are many experimental reports about doping in graphene which is caused by interaction between graphene and its supporting substrates. Here, we report the study of charge transfer between graphene and oxide substrates using density functional theory (DFT) calculations. In this study, we have investigated the charge transfer related with graphene considering various oxide substrates such as SiO2(0001) and MgO(111). Details in charge transfer between graphene and oxides are analyzed in terms of charge density difference, band structure and work function.