• Journal of Astronomy and Space Sciences
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• v.9 no.1
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• pp.120-125
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• 1992

The normalized line profiles of VV Cep have been calculated by integrating the equation of transfer. The Sobolev theory was adopted and the wind velocity distribution was assumed to be V(r) = V$\infty(1-R_c/r)^{1/2}$. The peaks of the line profiles for the phase 0.06 and 0.80 appear at near half maximum and zero velocity surface of the wind, respectively.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.5
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• pp.231-238
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• 2006

This paper analysed the induced current density inside human body of hot-line worker for 765kV double circuit transmission line according to locations of human body. Human model was composed of several organs and other parts, whose shapes were expressed by spheroids or cylinders. Organs such as the brain, heart, lungs, liver and intestines were taken into account. Applying the 3 dimensional boundary element method, we calculated induced current density in case a worker was located inside and outside a lowest phase of 765 kV transmission line in which a 60% current of maximum load flowed. As results of study, we found a maximum induced current density in all organs was less than $10mA/m^2$ when a wonder was outside. As one in brain and heart was higher than $10mA/m^2$ when a worker was inside, we propose a method for lowering current density.

• Korean Journal of Crystallography
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• v.13 no.3_4
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• pp.148-151
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• 2002

The molecular and crystal structure of metalaxyl C/sub15/H/sub21/NO₄, was determined by single crystal x-ray diffraction study. Crystallographic data for, title compound P2₁/c, a=7.849(4) Å, b=13.081(5) Å, c=15.100(3) Å, β=101.8(2)°, V= 1517.6(3) ų, Z=4. The molecular. Structure model was solved by direct method and refined by full-matrix least- squares. The final reliable factor, R, is 0.067 for 1694 independent reflections (F/sub o//sup 2/>4σ(F/sub o//sup 2/)). The molecular structure of title compound shows an intramolecular hydrogen bond: Cl2-Hl2A…O1.

• Journal of the Korean Chemical Society
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• v.34 no.5
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• pp.445-451
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• 1990

The catalytic ammoxidation of methylpyrazine into cyanopyrazine over a supported vanadium oxides catalyst on ${\gamma}$-alumina was studied in a continuous-flow fixed bed reactor. Various crystalline phases of vanadium oxides were obtained depending on reduction temperatures. And also the activities for the reaction of methylpyrazine into cyanopyrazine were affected by their major oxidation states of the corresponding crystalline phases. The 10${\%}$ vanadium oxides loaded ${\gamma}$-alumina catalyst, which was reduced at 600$^{\circ}C$ under the hydrogen flow for 2 hours, showed the highest activity and the highest selectivity on cyanopyrazine in the ammoxidation of methylpyrazine.Its major crystalline phase was V$_2$O$_3$ with the presence of V$_6$O$_{13}$ and V$_2$O$_4$(VO$_2$) together. And this coexistance seemed to enhance the activity.

• Korean Journal of Materials Research
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• v.8 no.12
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• pp.1110-1114
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• 1998

The crystallization behaviors and electrical conductivities of the glasses heat-treated at various times and temperatures in the CuO-Bi$_2$O$_3$-V$_2$O$_{5}$ glass system were investigated. Among glass samples with various compositions, the highest conductivity obtained in the 31CuO-14Bi$_2$O$_3$-55V$_2$O$_{5}$ (mol%) glass sample. The 31CuO-14Bi$_2$O$_3$-55V$_2$O$_{5}$ (mol%) glass sample crystallized by heat treatment at 358$^{\circ}C$ for 8h had 2.67$\times$10$^{-2}$ $\Omega$$^{-1}$ $cm^{-1}$ /, which was much high value as a solid electrolyte. Compared to the glass sample, the heat- treated glass sample was increased in conductivity by an order of 10$^3$-10$^4$due to the formation and growth of BiVO$_4$ and CuVO$_3$crystals.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.6 no.2
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• pp.220-228
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• 1996

CdTe single crystals were grown by vertical Bridgman method using double furnace with two siliconit heating elements. When the peak temperature of the upper furnace was fixed at $1150^{\circ}C$ and that of the lower furnace was $800^{\circ}C$, the temperature gradient was about $22.5^{\circ}C$/cm. The lattice constant $a_0$ was $6.482\AA$ from the X-ray diffraction and the band gap energy obtained from the optical absorption experiment at room temperature was 1.478 eV. PL spectrum showed that the bound exciton emission peak was resolved into ($A^0,X$) (1.5902, 1.5887 eV), ($h\;D^0$) (1.5918 eV) and ($D^0,X$ (1.5928, 1.5932 eV), and we have also calculated binding energy and ionization energy of the neutral donor and acceptor.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.1
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• pp.17-25
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• 1996

The results identified for bacterial flora 174, Vibrio spp.132, and coliform group 183 strains isolated from the areas of last China Sea and Yosu coastal sea during from August 6th. to 14th. 1992 were as follow: 40 strains among the 74 strains of bacteria flora isolated from fast China sea area were Pseudomonas spp.$(54\%)$ and 60 strains among the 100 strains isolated from Yosu sea area were Enterobacteriaceae $(60\%)$. Four strains were Vibrio alginoliticus and one strain of V, parahaemolyticus among 5 strains of genus Vibrio isolated from last China Sea. While 54 strains were V. alginolyticus $(43\%)$ and V, parahaemolyticus $(17\%)$ among 127 strains genus Vibrio isolated from Yosu coastal sea area. Seventy nine strains among the 156 strains of coliform group isolated from Vosu sea area were Escherichia coli I $(51\%)$ and each one strain Citrobacter freundii I and II. 3 strains among 27 strains isolated from last China sea area were E. coli$(11\%)$ and 1 strain of C. freundii I. Coliform group was grouped into 16 types by IMViC system, $44^{\circ}C$, gelatin liquefaction test.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.362-364
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• 2016

본 논문에서는 MOS(Metal Oxide Semiconductor) Capacitor의 산화막내에 다양한 원인에 의해 존재하는 비이상적인 전하들 중 Fixed Oxide Charge가 소자의 문턱전압에 어떤 영향을 주는지 분석했다. 분석한 결과 n+ polysilicon Gate를 가지고, 산화막인 $SiO_2$의 두께가 3nm이고, 도핑농도가 $10^{18}cm^{-2}$인 P형 실리콘 기판으로 이루어진 MOS Capacitor에서 Fixed Oxide Charge Density가 $C/cm^2$ 이상일 때 문턱전압을 0.01V 이상 감소시키고 $C/cm^2$ 이하일 때 문턱전압을 0.01V 이상 증가시켰다.

• Journal of Korean Vacuum Science & Technology
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• v.4 no.1
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• pp.6-10
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• 2000

Ferroelectric YMnO$_3$ thin films were deposited on $Y_2$O$_3$/si(100) substrates by metalorganic chemical vapor deposition. The YMnO$_3$ thin films annealed in vacuum ambient (100 mTorr) above 75$0^{\circ}C$ show hexagonal structured YMnO$_3$. However, the film annealed in oxygen ambient shows poor crystallinity, and the second phase as $Y_2$O$_3$ and orthorhombic-YMnO$_3$ were shown. The annealing ambient and pressure on the crystallinity of YMnO$_3$ thin films is very important. The C-V characteristics have a hysteresis curve with a clockwise rotation, which indicates ferroelectric polarization switching behavior. When the gate voltage sweeps from +5 to 5 V, the memory window of the Pt/YMnO$_3$/Y$_2$O$_3$/Si gate capacitor annealed at 85$0^{\circ}C$ is 1.8 V. The typical leakage current densities of the films annealed in oxygen and vacuum ambient are about 10$^{-3}$ and 10$^{-7}$ A/cm$^2$ at applied voltage of 5 V.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.263-266
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• 2001

In this paper, we investigated dielectric properies for BST thin films that was deposited on MgO/Si substrates using RF magnetron sputtering. In here, MgO film was used to perform that a diffusion b arrier between the BST film and Si substrate and a buffer layer to assist the BST film growth. A d eposition condition for MgO films was RF Power of 50W, substrate temperature of room temperature and the working gas ratio of Ar:O$_2$ were varied from 90:10 to 60:47. Finally we manufactured the cap acitor of Al/BST/MgO/Si/Al structure to know electrical properties of this capacitor through I-V, C-V measurement. In the results, C-V aha racteristic curves was shown a ferroelectric property so we measured P-E. A remanent poliazation and coerceive electric field was present 2$\mu$C/cm$^2$ and -27kV/cm respectively at Ar:O$_2$=90:10. And a va clue of dielectric constant was 86 at Ar:02=90:10.