• Journal of the Korean Vacuum Society
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• v.3 no.2
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• pp.234-238
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• 1994

전자스핀 공명(ESR)으로 측정된 수소화된 비정질 게르마늄(a-Ge:H)의 D-센터에 대한 스핀밀도 의 온도의존성이 77∼350K의 온도범위에서 보고된다. a-Ge:H의 D-센터에 대하여 이 온도범위에서 온 도가 증가함에 따라스핀밀도의 감소가 관측되었으며, 그 결과는 전자상관에너지와 열적이온화효과에 근 거하는 결함 모델들의 예상치와 비교되었다. a-Ge:H에서의 스핀밀도의 감소는 전자상관에너지 모델로서 는 이해될수 없었고 상온에서의 결함계의 열적 이온화에 기인할 수 있는 것으로 생각된다.

• Journal of the Korean Vacuum Society
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• v.5 no.4
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• pp.365-370
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• 1996

Electrochromic $WO_3$ films were prepared by using an electron-beam deposition method. The dependence of the chemical stability of film on the substrate temperature was studied. From the experimental results, The optical property and chemical stability of as-deposited films strongly depended on the substrate temperature. The $WO_3$ film prepared at a substrate temperature of $80^{\circ}C$ was found to be the most stable when subjected to repeated coloring and bleaching cycles in an organic 0.6M $LiClO_4$ solution.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.538-544
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• 1996

A highly viscous biopolymer from alkali-tolerant Bacillus sp. was purified and its rheological properties were studied. 1% (w/v) solution of purified biopolymer showed pseudoplastic fluid behavior with the yield stress similar to those of xanthan and guar gum, and its consistency index was exponentially dependent on concentration and temperature. The concentration dependency of consistency index exhibited two rectilinear plots with different slopes at 1% concentration and pseudoplastic property increased with the increase of biopolymer concentration. The biopolymer solution exhibited a low temperature dependency and the activation energy of flow was 1.16 kacl/g mol. The apparent viscosity was very dependent on the change of pH and the addition of salt. However, no organic solvent effects were observed effects of viscosity synergism with the addition of viscosifier were not observed.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2010.05a
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• pp.221-222
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• 2010

• Korean Journal of Crystallography
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• v.12 no.3
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• pp.157-161
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• 2001

The observe relaxation phenomena and freezing behavior in Pb(Mg/sub ⅓/Nb/sub ⅔/O₃, relaxor ferroelectrics, weak electric-field properties as well as strong electric-field properties were investigated. The temperature dependence of the dielectric properties obtained using the low electric-field of 1 V/w was investigated. The dielectric properties obtained from the slope of the dielectric hysteresis loop and the temperature dependence of the pyroelectric properties were also investigated. When fitting all the experimental data with the Vogel-Filcher relation, a close agreement between the experimental data and equation was observed. The freezing temperature could be consistently calculated by the various methods.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.8 s.251
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• pp.949-956
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• 2006

The method of Greenwood and Williamson is extended to obtain a solution to the coupled non-linear problem of steady-state electrical and thermal conduction across a crack in a conductive layer, for which the electrical resistivity and thermal conductivity are functions of temperature. The problem can be decomposed into the solution of a pair of non-linear algebraic equations involving boundary values and material properties. The new mixed-boundary value problem given from the thermal and electrical boundary conditions for the crack in the conductive layer is reduced in order to solve a singular integral equation of the first kind, the solution of which can be expressed in terms of the product of a series of the Chebyshev polynomials and their weight function. The non-existence of the solution for an infinite conductor in electrical and thermal conduction is shown. Numerical results are given showing the temperature field around the crack.

• Korean Journal of Optics and Photonics
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• v.29 no.6
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• pp.241-246
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• 2018

In this paper, a low-cost optical temperature sensor is implemented, using a fiber Bragg grating (FBG) as the temperature probe and a low-cost VCSEL with temperature-dependent output wavelength as the light source. To analyze the wavelength of the reflected light from the FBG, an interrogation was applied using a method of referring to the internal temperature according to the output wavelength of the VCSEL. When the temperature of the VCSEL was adjusted from 14 to $52.2^{\circ}C$, the output wavelength varied from 1519.90 to 1524.25 nm. The degree of wavelength tuning according to temperature was $0.114nm/^{\circ}C$. The variable wavelength repeatability error according to temperature was ${\pm}0.003nm$, and the temperature measurement error was ${\pm}0.18^{\circ}C$. As a result of measuring the temperatures from 22.3 to $194.2^{\circ}C$, the value of the internal temperature change of the light source according to the applied temperature ${\Delta}T$ was $0.146^{\circ}C/{\Delta}T$, the change in reflected wavelength of the temperature probe according to applied temperature ${\Delta}T$ was measured at $16.64pm/^{\circ}C$. and the temperature measurement error of the sensor was ${\pm}1^{\circ}C$.

• Proceedings of the Korean Magnestics Society Conference
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• 1991.05a
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• pp.49-50
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• 1991

• Proceedings of the Korean Magnestics Society Conference
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• 1999.04a
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• pp.130-131
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• 1999

• Proceedings of the Optical Society of Korea Conference
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• 2007.07a
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• pp.345-346
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• 2007