• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.393-393
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• 2011

We investigated the electronic structures of a poly sodium 4-styrensulfonate intercalated graphite oxide (PSSGO) electrode and a precursor graphite oxide (GO) electrode using X-ray absorption spectroscopy (XAS). Both electrodes were obtained from electrochemical cells. We found that in the C K-edge XAS spectra the ${\pi}^*$ state intensity originating from the sp2 hybridization of graphite decreases predominantly in the graphite oxide and PSSGO electrodes. This indicates that the negatively charged electrolyte ion (BF4-) is absorbed onto the electrodes and is transferred to the ${\pi}^*$ state of the both electrodes. The analysis of their F K-edge spectra reveals that more BF4- ions were found in the PSSGO electrode than in the graphite oxide electrode. This indicates that more electrolyte ions are absorbed in the PSSGO than in the graphite oxide electrode. We argue that this is the main reason why PSSGO cells have higher capacitance, higher energy density, and higher power density when compared to the graphite oxide cells. We also found that BF4- is the primary working ion that can be inserted into the interlayers of the PSSGO electrode.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1379-1382
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• 1997

Diamond-like carbon(DLC) thin films are produced by using a filtered cathodic vacuum arc(FCVA) deposition system. Different magnetic components, namely steering, focusing, and filtering plasma-optic systems, are used to achieve a stable arc plasma and to prevent the macroparticles from incorporating into the deposited films. Effects of magnetic fields on plasma behavior and film deposition are examined. The carbon ion energy is found to be varied by applying a negative (accelerating) substrate bias voltage. The deposition rate of DLC films is dependent upon magnetic field as well as substrate bias voltage and at a nominal deposition condition is about $2{\AA}/s$. The structural properties of DLC films, such as internal stress, relative fraction of tetrahedral($sp^3$) bonds, and surface roughness have also been characterized as a function of substrate bias voltages and partial gas($N_2$) pressures.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.06a
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• pp.291-296
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• 2007

We measured potential waveform of load, displacement, micro electric signal generated by rock and mortar fracture using PXI A/D Converter. The rock type used for measurement was used granite, limestone and sandstone, and mortar specimen. we made measuring equipment of physical properties to confirm basic information of physical properties, measured physical properties of rock engineering, electric resistivity and seismic velocity. Potential waveform system was built using PXI A/D Converter and measured potential waveform of load, displacement, micro-electric signal generated using this during uniaxial compressive test by the specimen finished such test of physical properties. Using the saturated rock and mortar specimen, micro electric signal increased, and It didn't increase a signal in dried rock and mortar specimen according as load and strain rate increases. But signal also increased in saturated or dried specimen in case of sandstone. It was possible to check the close correlation relationship the signal and fracture behavior by a compressive load as the signal of fracture position was increased bigger than the other position. It was also possible to check the correlation relationship between physical properties and micro geo-electric signal.

• Journal of the Korean Chemical Society
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• v.29 no.1
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• pp.38-44
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• 1985

Photoreaction path for the monocyanochromium (Ⅲ) ion was inferred from the experimentally observed product ratio and theoretical analysis. The angular overlap model was used to analyze the d-orbital of various intermediates along a selected reaction coordinate and to determine quartet state energy level. A loss of equatorial ammine leads to pentacoordinated square pyramid with CN- ligand in an equatorial position. The SP(CNeq) intermediate undergoes a rearrangement by the N-Cr-CN bending. This process leads to a trigonal bipyramidal intermediate in which the CN- ligand is located in equatorial position. The subsequent association with a solvent molecule should probably proceed by lateral attack an one edge of the equatorial triangle. The assumption adopted above was consistent with experimental results.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.6
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• pp.148-155
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• 2008

In this paper, we constructed the noise robust content-based music retrieval system in mobile environment. The performance of the proposed system was verified with ZCPA feature which is blown to have noise robust characteristic in speech recognition application. In addition, new indexing and fast retrieval method are proposed to improve retrieval speed about 99% compare to exhaustive retrieval for large music DB. From the computer simulation results in noise environment of 15dB - 0dB SNR, we confirm the superior performance of the proposed system about 5% - 30% compared to MFCC and FBE(filter bank energy) feature.

• Bulletin of the Korean Chemical Society
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• v.33 no.12
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• pp.4079-4083
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• 2012

The mechanism of the cycloaddition reaction between singlet state dichlorosilylene germylidene ($Cl_2Si=Ge:$) and acetone has been investigated with B3LYP/6-$31G^*$ and B3LYP/6-$31G^{**}$ method, from the potential energy profile, we predict that the reaction has one dominant reaction pathway. The presented rule of the reaction is that the two reactants firstly form a Si-heterocyclic four-membered ring germylene through the [2+2] cycloaddition reaction. Because of the 4p unoccupied orbital of Ge atom in the Si-heterocyclic four-membered ring germylene and the ${\pi}$ orbital of acetone forming a ${\pi}{\rightarrow}p$ donor-acceptor bond, the Si-heterocyclic four-membered ring germylene further combines with acetone to form an intermediate. Because the Ge atom in the intermediate hybridizes to an $sp^3$ hybrid orbital after the transition state, then, the intermediate isomerizes to spiro-heterocyclic ring compound involving Si and Ge (P4) via a transition state.

• Journal of Microbiology and Biotechnology
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• v.24 no.3
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• pp.379-385
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• 2014

The purpose of this study was to compare the ability of an engineered Escherichia coli to degrade chlorpyrifos (Cp) using an organophosphorus hydrolase enzyme, encoded in both Flavobacterium sp. ATCC 27551 or Pseudomonas diminuta, by employing the Lpp-OmpA chimera and the N-terminal domain of the ice nucleation protein as anchoring motifs. Tracing of the expression location of the recombinant protein using SDS-PAGE showed the presentation of OPH by both anchors on the outer membrane. This is the first report on the presentation of OPH on the cell surface by Lpp-OmpA under the control of the T7 promoter. The results showed cell growth in the presence of Cp as the sole source of energy, without growth inhibition, and with higher whole-cell activity for both cells harboring plasmids pENVO and pELMO, at approximately 10,342.85 and 10,857.14 U/mg, respectively. Noticeably, the protein displayed by pELMO was lower than the protein displayed by pENVO. It can be concluded that Lpp-OmpA can display less protein, but more functional OPH protein. These results highlight the high potential, of both engineered bacteria, for use in the bioremediation of pesticide-contaminated sources in the environment.

• Bulletin of the Korean Chemical Society
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• v.20 no.1
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• pp.42-48
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• 1999

We have performed a quantum-chemical investigation on the conformations and electronic properties of a variety of methoxy-substituted poly(p-phenylenevinylenes) (PPVs) to elucidate the effects of alkoxy substitution. Geometrical parameters for the polymers were fully optimized through Austin Model I (AM I) semi-empirical Hartree-Fock (HF) band calculations. Electronic properties of the polymers were obtained by applying the AM I optimized structures to the modified extended Huckel method. To confirm validity of the AM I conformational results, we also carried out ab initio HF calculations with the 6-31G (d) basis set for a variety of methoxy-substituted divinylbenzenes. It is found that the potential energy surfaces of alkoxy-substituted PPVs are quite shallow around the planar conformations, suggesting that the prepared films possess a variety of conformations with different torsion angle in the solid state, depending on the synthetic conditions. When two alkoxy groups are concurrently substituted at the adjacent sites in the phenylene ring, these groups are subject to rotating around the C(sp2)-O bonds by 70-80° to avoid the strong steric repulsion between them. Consequently, the overlap between the π-type p orbital of oxygen and the π molecular orbitals of the polymer decreases. This leads to a wide gap and a high oxidation potential for tetramethoxy-substituted PPV, compared to those of dialkoxy-substituted PPV.

• Electronic Materials Letters
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• v.14 no.6
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• pp.733-738
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• 2018

Undoped and Mn-doped $In_2O_3$ films were prepared by radiofrequency magnetron sputtering technique. The effects of Mn doping on the structural and optical properties of as-prepared films were investigated using X-ray diffraction, X-ray photoelectron spectroscopy and ultraviolet-visible spectroscopy. Mn doping can enhance the intensity of (222) peak in Mn-doped $In_2O_3$ thin film, indicating Mn dopant promotes preferred orientation of crystal growth along (222) plane. XPS analyses revealed that the doped Mn ions exist at + 2 oxidation states, substituting for the $In^{3+}$ sites in the $In_2O_3$ lattice. UV-Vis measurements show that the optical band gap $E_g$ decreases from 3.33 to 2.87 eV with Mn doping in $In_2O_3$, implying an increasing sp-d exchange interaction in the film. Our work demonstrates a practical means to manipulate the band gap energy of $In_2O_3$ thin film via Mn impurity doping, and significantly improves the photoelectrochemical activity.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.5
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• pp.63-71
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• 2011

In this paper, we propose a new real time image retargeting method which preserves the contents of an image. Since the conventional seam carving which is the well-known content-based image retargeting technology uses the dynamic programming method, the repetitive update procedure of the accumulation minimum energy map is absolutely needed. The energy map update procedure cannot avoid the processing time delay because of many operations by the image full-searching. The proposed method calculates the diffusion region of each seam candidates in the accumulation minimum energy map in order to reduce the update processing time. By using the diffusion region, several seams are extracted at the same time and the update number of accumulation energy map is reduced. Therefore, although the fast processing is possible, the quality of an image can be analogously maintained with an existing method. The experimental results show that the proposed method can preserve the contents of an image and adjust the image size on a real-time.