• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.1
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• pp.80-85
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• 2007

We report the electro-optical properties of the sensory rhodopsin II using a near-field scanning microwave microscope(NSMM). Rhodopsin was known as a photoreceptor pigment with a retinal as a chromophore via a protonated Schiff base and consists of seven ${\alpha}-helical$ transmembrane segments. The sensory rhodopsin II, expressing E. coli UT5600 with endogenous retinal biosynthesis system and purified with $Ni^{-2}-NTA$ affinity chromatography in the presence of 0.02 % DM (Dodecyl Maltoside) from Natronomonas pharaonis. We measured the absorption spectra and the transients difference of sensory rhodopsin II from Natronomonas pharaonis using a UV/VIS spectrophotometer with Nd-Yag Laser (532 nm). The absorption spectra of NpSR II showed a typical rhodopsin spectrum with a left shoulder region and the photointermediates spectra of NpSR II-ground state (${\lambda}max=498\;nm$), NpSR II-M state (${\lambda}max=390\;nm$), and NpSR II-O state (${\lambda}max=550\;nm$) during the photocycle. The observed photocycle reaction was confirmed by measuring the microwave reflection coefficient $S_{11}$ at an operating frequency of f=3.93-3.95 GHz and compared with the results of a photocycle of NpSR II.

• Korean Journal of Materials Research
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• v.19 no.4
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• pp.179-185
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• 2009

We fabricated thermally evaporated 30 nm-Ni/(20 nm or 60 nm)a-Si:H/Si films to investigate the energy-saving property of silicides formed by rapid thermal annealing (RTA) at temperatures of $350^{\circ}C$, $450^{\circ}C$, $550^{\circ}C$, and $600^{\circ}C$ for 40 seconds. A transmission electron microscope (TEM) and a high resolution X-ray diffractometer (HRXRD) were used to determine the cross-sectional microstructure and phase changes. A UVVIS-NIR and FT-IR (Fourier transform infrared spectroscopy) were employed for near-IR and middle-IR absorbance. Through TEM and HRXRD analysis, for the nickel silicide formed at low temperatures below $450^{\circ}C$, we confirmed columnar-shaped structures with thicknesses of $20{\sim}30\;nm$ that had ${\delta}-Ni^2Si$ phases. Regarding the nickel silicide formed at high temperatures above $550^{\circ}C$, we confirmed that the nickel silicide had more than 50 nm-thick columnar-shaped structures with a $Ni_{31}Si_{12}$ phase. Through UV-VIS-NIR analysis, nickel silicide showed almost the same absorbance in the near IR region as well as ITO. However, in the middle IR region, the nickel silicides with low temperature showed similar absorbance to those from high temperature silicidation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.5
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• pp.813-820
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• 1998

This study was performed as a part of comparative biochemical studies of carotenoid pigment for the fresh water fish. Carotenoids in integument of Korean dark sleeper, Odontobutis platycephala, and dark sleeper, Odontobutis odontobutis interrupta, which are all the Korean native fresh water fish, were separated by thin layer chromatography, column chromatography and HPLC. The separated carotenoid were then reduced and isomerized by NaBH4 and I2 respectively to investigate UV-Vis spectrophotometeric patterns and chracterized by IR, 1H-NMR and Mass spectrum. The content of total carotenoids in the integument of Korean dark sleeper was 3.01mg% in April, but it was increased to 3.74mg% in September at the near of spawning period. The carotenoid isolated in April consisted of $\beta$-carotene(25.6%), lutein(18.5%) and zeaxanthin(12.0%) as major carotenoids and also contained isocryptoxanthin, diatoxanthin, tunaxanthin, cynthiaxanthin, canthaxanthin and $\alpha$-cryptoxanthin as minor carotenoids. Similarly, in September the carotenoid consisted of $\beta$-carotene(16.5%), zeaxanthin(13.7%) and cynthiaxanthin(13.6%) as major carotenoids and also contained lutein, isocryptoxanthin, tunaxanthin, $\alpha$-cryptoxanthin, diatoxanthin and canthaxanthin as minor carotenoids. At the near of spawning period, the content of cynthiaxanthin and $\alpha$-cryptoxanthin were increased. The content of total carotenoids in the integument of spawning period. T도 carotenoid isolated in April and September consisted of $\beta$-carotene(24.9%, 27.5%), zeaxanthin(14.4%, 20.9%) and lutein(12.6%, 11.4%) as major carotenoids and also contained cynthiaxanthin, tunaxanthin, diatoxanthin, isocryptoxanthin, $\alpha$-cryp-toxanthin and canthaxanthin as minor carotenoids. At the near of spawning period, the content of zeaxanthin was increased, indicating that the carotenoid composition were dependent upon their living conditions and their integument colors. Both Korean dark sleeper and dark sleeper contained high amount of cynthiaxanthin and diatoxanthin which are found as rare carotenoids in the other of fresh water fish. It is interes that they also contained tunaxanthin which is a specific carotenoid in marine fishes.

• Journal of the Korean Society of Radiology
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• v.4 no.4
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• pp.5-10
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• 2010

The $Ca_2SiO_4$ phosphors doped by La with 0.1 wt%, 0.3 wt%, 0.5 wt%, and 1.0 wt% concentration were prepared by sintering at $1000^{\circ}C$ for 90 minutes in N2 atmosphere. The phosphors were ground in powdered form and were grouped in $100{\mu}m$ size, then the samples had been exposed to low energy X-ray and UV light. The TL glow curves were measured by heating the phosphors at $10^{\circ}C/s$ rate. There was no significantly meaningful correlation between the TL intensity and the doping level. The intensities of the TL peak measured from X-ray irradiated samples doped with 0.1 wt% were relatively strong. The activation energy and the frequency factor were 0.434 ~ 0.516 eV and 0.5 ~ 0.56, respectively. The intensities of the TL peak measured from UV irradiated samples doped with 0.3 wt% were relatively strong. The activation energy and frequency factor were 0.415 ~ 0.477 eV and 0.5 ~ 0.53, respectively. The TL process were found to be the 2nd order for both X-ray and UV irradiation. The TL intensity was increased linearly with the increase of the radiation dose. In summary, the $Ca_2SiO_4 phosphors developed in this study showed good TL characteristics at low energy X-ray and UV light. We believe they will be used as TLDs in near future for personal and environmental radiation detection dosimetry.

• Journal of Biosystems Engineering
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• v.15 no.1
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• pp.33-43
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• 1990

Spectral reflectance of paddy, brown rice, milled rice, greenish grain, yellow grain and denatured grain were measured over the range of 340 to 820 nm with "Double Beam Spectrophotometer(Model UV-180)". Variation in the reflectance depending on milling degree of milled rice appeared greatest over the range of 420 to 500 nm, and that between white rice and other rice samples appeared greatest near 500 nm. On the basis of the above results, a whiteness meter to measure milling degree of rice was manufactured using tungsten lamp, photodiodes and amplifier, and its performance was compared with the existing whiteness meters (KETT and Z-II optical sensor). There were very high correlations among those whiteness meters.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.72.1-72.1
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• 2015

We investigate black hole (BH) activities of 16 red active galactic nuclei (AGNs). The 16 red AGNs selected by red colors in optical through near-infrared (NIR) and radio detection. In order to derive BH activities of the red AGNs, we use $P{\beta}$ line with NIR spectra obtained by the SpeX on the IRTF. The $P{\beta}$ line suffers from dust extinction less than UV/optical BH mass estimators. We compared Eddington ratios of the red AGNs and "normal" AGNs, and the Eddington ratios of red AGNs are significantly higher than those of "normal" AGNs. The result is consistent with a scenario that red AGNs are the intermediate population between star forming galaxies and "normal" AGNs, and BHs of red AGNs are very active and grow rapidly in such a stage.

• Bulletin of the Korean Chemical Society
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• v.32 no.11
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• pp.3904-3908
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• 2011

A new octahedral Ru(III) complex with a tripodal tetraamine ligand, tpea = tris[2-(1-pyrazoyl)ethyl]amine, has been prepared and characterized. The single crystal X-ray crystallographic study of the complex revealed that the complex has a near octahedral geometry with the tetradentate ligand and two chloride ions. Peroxidase activity was examined by observing the oxidation of 2,2'-azinobis(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) with hydrogen peroxide in the presence of the complex. Amount of $ABTS^{+{\bullet}}$ generated during the reaction was monitored by UV/VIS and EPR spectroscopies. After the initiation of the peroxidase reaction, $ABTS^{+{\bullet}}$ concentration increases and then decreases after certain time, indicating that both ABTS and $ABTS^{+{\bullet}}$ are the substrates of the peroxidase activity of the Ru(III) complex.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.391-394
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• 2003

Laser direct writing process is developed 3rd harmonic Diode Pumped Solid State Laser with the near visible wavelength of 355 m sensitive polymer is irradiated by UV laser and developed using polymer solvent to obtain quasi-3D. It is important to reduce line width for image mode waveguides, so some investigations will be carried out in various conditions of process parameters such as laser power, writing speed, laser focus and optical properties of polymer. This process could be to fabricate a single mode waveguide without expensive mask projection method. Experimentally, the patterns of trapezoidal shape were manufactured into dimension of 8.4 mm width and 7.5 mm height. Propagation loss of straight waveguide measured 3 dB/cm at 1,550 nm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.05a
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• pp.47-49
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• 1995

We report the spectroscopic properties of column-III nitrifies of GaN, GaInN, and AlGaN. The column-III nitride semiconductors are promising materials to realize the current-injection-type blue-and ultraviolet (UV)-light-emitting devices with high performance. To acheive the lasing with low threshold, the devices are must constructed to double heterostructure by succesive epitaxial growth technique, and we must confine the carriers in the potential barrier and optical confinement in wave guide between barrier and active layers has different refractive index. The refractive index of column-III nitride semiconductors, however, are rarely reported. The measured refractive index was 2.9, and the observed characteristic peak near the enrgy gap was analysed using a dielectric function and may due to excitonic contribution.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.958-960
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• 1992

The fluorescence characteristics of near UV dye, BBQ pumped by Ar flashlamp have been studied for various electrical input energies applied to the flashlamp and argon fill pressures in the flash tube. The peak wavelength of fluorescence is about 380nm when the fluorescence intensity is at the peak value. The rise time of the fluorescence pulse is about 7 $\mu$sec and its FWHM is about 55$\mu$sec.