• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04b
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• pp.152-156
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• 2000

Bi-thin films are fabricated by an ion beam sputtering, and sticking coefficients of the respective elements are evaluated. The sticking coefficient of Bi element exhibits a characteristic temperature dependence : almost a constant value of 0.49 below $730^{\circ}C$ and decreases linearly with temperature over $730^{\circ}C$. This temperature dependence can be elucidated from the evaporation and sublimation rates of bismuth oxide, $Bi_2O_3$, from the film surface. It is considered that the liquid phase of the bismuth oxide plays an important role in the Bi(2212) phase formation in the co-deposition process.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.372-375
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• 2006

SOFC is a high temperature fuelcell with many advantages, but it also have several demerits. One of the Issues is cathode poisoning of Cr coming from stainless steel interconnects. Diffusion process of Cr evaporated from the surface of interconnect steel was calculated by using CFD technique to understand factors for Cr deposition. It has been cleared that factors concerned in Cr deposition and how they affect Cr deposition. Major variables for Cr deposit ion are diffusion coefficient, air velocity and temperature If diffusion coefficient decreases, Cr concentration increases in the air but decreases on the cathode surface. Increasing in air velocity, Cr concentration decreases in the air and on the cathode surface. Increase in temperature leads to rising Cr concentration on the cathode surface because of diffusion coefficient increment.

• Nuclear Engineering and Technology
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• v.9 no.3
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• pp.125-137
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• 1977

The temperature coefficient has been investigated on the Wolsung nuclear power reactor, in which fuel is natural uranium dioxide and moderator heavy water. The numerical computations are carried out in terms of changes of the effective neutron multiplication factor with respect to fuel, moderator, and coolant temperatures. Those results are compared with the computed values of temperature coefficient based on the LATREP computer code.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1346-1348
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• 2001

Generally, Invar alloy shows very low thermal expansion characteristics, lower than $2{\times}10^{-6}$/K approximately. To apply Fe-Ni-Co-C Invar alloy as a core material for large ampacity transmission line we studied the effects of magnetic properties on coefficient of thermal expansion. The coefficient of thermal expansion(CTE) suddenly decreases with addition of a little carbon(0.08%), increases with the increasing carbon and has a constant value at the composition over than 1.0%C. The trend of Curie temperature change with carbon is similar with that of CTE. Therefore, the CTE has a linear relationship with Curie temperature. However, the CTE linearly decreases with the ratio of saturation magnetization and Curie temperature(${\sigma}_s/T_c$).

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1584-1589
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• 2003

This work applies the equilibrium molecular dynamics simulation method to study a Lennard-Jones liquid thin film suspended in the vapor and calculates diffusion coefficients by Green-Kubo equation derived from Einstein relationship. As a preliminary test, the diffusion coefficients of the pure argon fluid are calculated by equilibrium molecular dynamics simulation. It is found that the diffusion coefficients increase with decreasing the density and increasing the temperature. When both argon liquid and vapor phases are present, the effects of the system temperature on the diffusion coefficient are investigated. It can be seen that the diffusion coefficient significantly increases with the temperature of the system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.10a
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• pp.59-63
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• 2000

BSCCO thin films are fabricated via a co-deposition process by an ion beam sputtering with an ultra-low growth rate, and sticking coefficients of the respective elements are evaluated. The sticking coefficient of Bi element exhibits a characteristic temperature dependence : almost a constant value of 0.49 below $730^{\circ}C$ and decreases linearly with temperature over $730^{\circ}C$ This temperature dependence can be elucidated from the evaporation and sublimation rates of bismuth oxide, $Bi_2O_3$, from the film surface. It is considered that the liquid phase of the bismuth oxide plays an important role in the Bi(2212) phase formation in the co-deposition process.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.300-303
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• 2001

BSCCO thin films are fabricated via a co-deposition process by an ion beam sputtering with an ultra-low growth rate, and sticking coefficients of the respective elements are evaluated. The sticking coefficient of Bi element exhibits a characteristic temperature dependence : almost a constant value of 0.49 below $730^{\circ}C$ and decreases linearly with temperature over $730^{\circ}C$. This temperature dependence can be elucidated from the evaporation and sublimation rates of bismuth oxide, $Bi_{2}O_{3}$, from the film surface. It is considered that the liquid phase of the bismuth oxide plays an important role in the Bi 2212 phase formation in the co-deposition process.

• Journal of the Korean Ceramic Society
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• v.43 no.5 s.288
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• pp.284-292
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• 2006

$MgTiO_3{\cdot}CaTiO_3{\cdot}SrTiO_3$ system ceramics (MCST) were synthesized to study the effect of Ca addition amount and Sr substitution on temperature coefficient of resonance sequency. Temperature coefficient of resonance frequency was slightly increased by small amount ($i.e.{\sim}5%$) of Sr substitution. In case of 50% to 75% addition amount of $MgTiO_3$, decrease of quality factor was not observed with increasing dielectric constant.

• Fire Science and Engineering
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• v.23 no.5
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• pp.196-205
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• 2009

Electric mosquito repellent mats can be ignited by damage of cables, partial disconnection, overload. tracking and so on. In this study, we examined the structure of mosquito repellent mat, positive temperature coefficient(PTC) thermistor, used for heating element and phenomenological characteristics of remains, obtained on the scene of fires. After reappearance ignition test of PTC thermistors, we did comparison analysis them. And we could confine that the feature of heating plate and the shape of bursting were same.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.4
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• pp.136-141
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• 1996

In this paper, a new CMOS on-chip current reference circit for memory, operational amplifiers, comparators, and data converters is proposed. The reference current is almost independent of temeprature and power-supply variations. In the proposed circuit, the current component with a positive temeprature coefficient cancels that with a negative temperature coefficient each other. While conventional curretn and voltage reference circuits require BiCMOS or bipolar process, the presented circuit can be integrated on a single chip with other digiral and analog circits using a standard CMOS process and an extra mask is not needed. The prototype is fabricated employing th esamsung 1.0um p-well double-poly double-metal CMOS process and the chip area is 300um${\times}$135 um. The proposed reference current circuit shows the temperature coefficient of 380 ppm/.deg. C with the temperature changes form 30$^{\circ}C$ to 80$^{\circ}C$, and the output variation of $\pm$ 1.4% with the supply voltage changes from 4.5 V to 5.5 V.