• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.415-415
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• 2012

ZnO nanostructures were synthesized by a vapor phase transport process in a single-zone furnace within a horizontal quartz tube with an inner diameter of 38 mm and a length of 485 mm. The ZnO nanostructures were grown on Au-catalyzed Si(100) substrates by using a mixture of zinc oxide and graphite powders. The growth of ZnO nanostructures was conducted at $800^{\circ}C$ for 30 min. High-purity Ar and $O_2$ gases were pushed through the quartz tube during the process at a flow rate of 100 and 10 sccm, respectively. The sequence of ON/OFF cycles of the Ar gas flow was repeated, while the $O_2$ flow is kept constant during the growth time. The Ar gas flow was ON for 1 min/cycle and that was OFF for 2 min/cycle. The structure and optical properties of the ZnO nanostructures were investigated by field-emission scanning electron microscope, X-ray diffraction, temperature-dependent photoluminescence. The preferred orientation of the ZnO nanostructures was along c-axis with hexagonal wurtzite structure.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.78-83
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• 2009

In general, Light-hardening polymer was used UV nanoimprint technology. A light-hardening polymer was had the problem of poor hardness, durability. In order to overcome the problem of polymer, inter change optical glass. However glass is very manufacture and a lowering of standars transmittance. In order to glass recover was necessary polishing process. The process is magnetorheological fluids polishing. MR polishing has been developed as a new precision finishing technique to obtain a fine surface. Hence, Magnetorheological fluids has been used for micro polishing to get micro parts. This polishing process guarantees high polishing quality by controlling the fluid density electrically. The applied material in experiments is fused silica glass. Fused silica glass is widely used in the optical field because of high degree of purity. For MR polishing experiments, MR fluid was composed with DI-water, carbonyl iron and nano slurry ceria. The wheel speed and electric current were chosen as the variables for analyzing the characteristics of MR polishing process. Outstanding surface roughness of Ra=1.58nm was obtained on the fused silica glass specimen. And originally glass transmittance was recover on the fused silica glass.

• Bulletin of the Korean Chemical Society
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• v.27 no.3
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• pp.377-380
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• 2006

The semiconductor PbS nanobelts (width 50-120 nm and length over 3 $\mu$m) were self-assembled in a simple reverse micelle solvent system containig the surfactant of polyoxyethylene (9) dodecy ether $(C_{12}E_9)$. The nanobelts synthesized were found to possess cube galena poly-crystal structure with high purity when analyzed by ED and X-ray diffraction. Significant “blue shift” from bulk material was observed on the PbS nanobelts using photoluminescence and UV-Vis spectroscopy. A mechanism involving the possible formation of nanobelts based on surfactant template was also proposed.

• The Research Journal of the Costume Culture
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• v.6 no.4
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• pp.13-25
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• 1998

This study focuses on the visual effects of various neckline-haristyle combinations on the perception of face image and type. The study employed a model with oval face and examined 35 combinations made up of five necklines and seven hairstyles. Looking at various face images depending upon different necklines, in case of round, V, boat square, and high necklines, long wave hair and medium wave hair produced a feminine image of marked individuality; long straight hair that covers the forehead and medium straight hair gave an image of charm and purity as well as an image of neatness; and long straight hair short cut hair showed an intellectual image. Regarding the perceptual type of face depending upon the different necklines of round, V, square, and high, the long straight hair covering the forehead and medium wave hair had the effect of an optical illusion that made the face look short and round; and short cut hair made the face line look distinct and the face look oval and slender.

• Journal of Microbiology and Biotechnology
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• v.8 no.6
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• pp.601-605
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• 1998

For the resolution of L-carnitine from DL-carnitine, resting cells of Enterobacter sp. NH-104, which had a higher capacity of D-carnitine decomposition, were harvested at maximal specific activity of D-carnitine decomposition of 47.05 unit/mg cell. The cells were frozen at $-80^{\circ}C$ to assess functions as enzyme sources. Optimal concentration of cells and DL-carnitine were 17 g/$\ell \; and \; 20 g/\ell$, respectively, and reaction buffer was best at 75 mM of Tris. HCl. Optimal temperature and pH were $36^{\circ}C$ and 8.2, respectively. When the reaction at optimal conditions was carried out for 14 h, the optical purity was 98.21 %, and the quantity and yield of remaining L-carnitine were 4.432 g/$\ell$ and 44.32%, respectively.

• Current Optics and Photonics
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• v.2 no.1
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• pp.96-100
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• 2018

A tunable low-phase-noise microwave generation structure that utilizes an optoelectronic oscillator (OEO) and a fiber Bragg grating (FBG) is proposed and experimentally demonstrated in this article. This structure has no particular requirement for the band width of the laser, and its tunability is realized through adjusting the central frequency of the tunable FBG. A detailed theoretical analysis is established and confirmed via an experiment. A high-purity microwave signal with a frequency tunable from 6 to 12 GHz is generated. The single-sideband phase noise of the generated signal at 10.2 GHz is -117.2 dBc/Hz, at a frequency offset of 10 kHz.

• Journal of the Korean Chemical Society
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• v.3 no.1
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• pp.31-35
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• 1954

Upon the basis of the results obtained hitherto in the studies of the stereochemical reaction mechanisms, the author has concluded that the stereospecificity of enzymes has essentially a relative character. And the author has pointed out the possibility of the occurrence of a new enzyme "inverskinase", which catalyses the reversible inversions such as D-compound ${\leftrighyarrow}$ L-compound in living organisms, and considered the stereospecificity of enzymes and the optical purity of components of living organism from this new standpoint.

• Journal of the Korean Ceramic Society
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• v.45 no.2
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• pp.87-89
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• 2008

A nano structured silica aerogel thin film was manufactured from inexpensive sodium silicate (water glass) using an ambient pressure drying method. High purity silicic sol was prepared by passing a water glass solution through an ion exchange resin, and the gel films were prepared on a modified glass substrate via dip coating. The dip coating conditions, such as coating time and solvent, were optimized. The optical and physical properties of the obtained silica aerogel thin film were characterized using a UV-visable spectrometer and a scanning electron microscope.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1469-1472
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• 2006

We investigated the electrical and optical properties of ZnO:Al thin films as a function of the thermal process conditions. The film was prepared by RF magnetron sputtering followed by annealing in a box furnace in air. An ZnO:Al (98:2) alloy with the purity of 99.99% (3 inch diameter) was used as the target material. The electrical properties of the transparent electrode, exhibited surface oxidation as a result of rapid oxygen absorption with increasing annealing temperature. The processed ZnO:Al films and commercial ITO(indium-tin-oxide) were applied to an OLED stack to investigate the current density and luminescence efficiency. The efficiency of the device using the ZnO:Al electrode was higher than that from the device using the ITO electrode.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.810-813
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• 2003

Application of inorganic silica-neodymia alloy films grown by sputtering technology to the dielectric layer of plasma display panel (PDP) is presented. The experimental results reveal that dielectric constant of the alloy films increases with neodymia concentration. Also, the alloy films act as band rejection color filter owing to sharp absorptions originating in the intratransition within the 4f shell of the $Nd^{3+}$ ion. In the optical band pass region, the transmittances of the alloy films show higher than those of commercial glass-like dielectrics. As a result, the luminance of PDP device with the alloy dielectric layer is higher than that of device with conventional dielectrics, indicating wider color gamut and higher color purity.