• Analytical Science and Technology
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• v.11 no.5
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• pp.386-393
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• 1998

A new analytical luminescence method for the $Dy^{3+}$ ion was studied using the luminescence enhancement by the treatment of the o-phenanthroline on the TLC plate. Compared to the specific emission intensities of the ion in water solution, if the ion solution is spotted on the TLC plate, the luminescence intensities were extremely enhanced. There was additional enhancement effect of the luminescence intensities of the ions on the TLC plate, if the ion on the TLC plate is treated with o-phenanthroline. Based on the luminescence enhancement, the detection limit was improved by more than 4 order of magnitude compared to that of solution sample. The dynamic ranges and correlation coefficients of the calibration curves near the detection limit were 102 order and ~0.99, respectively. The energy-transfer mechanism was explained for the theoretical back ground of the luminescence enhancement.

• Journal of the Korean Geotechnical Society
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• v.21 no.5
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• pp.187-196
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• 2005

Since the allowable bearing capacities of piles in weathered/fractured rock are mainly governed by settlement, the load-displacement behavior of pile should be known accurately. To predict pile head settlement at the design stage, the exact understanding of the load-transfer mechanisms is essential. Therefore, in this research, the load-transfer mechanism of drilled shaft socketed into weathered rock was investigated. For the investigation, five cast-in-place concrete piles with diameters of 1,000 mm were socketed into weathered gneiss. The static axial load tests and the load-transfer measurements were performed to examine the axial resistant behavior of the piles. A comprehensive field/laboratory testing program on weathered rock at the Held test sites was also performed to describe the in situ rock mass conditions quantitatively. And then, the effect of rock mass condition on the load transfer mechanism was investigated. The f-w (side shear resistance-displacement) curve of the pile in moderately weathered rock reached to yielding point at a for millimeter displacements, and after yielding point, the rate of resistance increment dramatically decreased. However, the f-w curve in the highly/completely weathered rock did not show the obvious yielding point, and the resistance gradually increased showing the hyperbolic pattern until relatively high displacement (>15 mm). The q-w (end bearing resistance-displacement) curves showed linear response at least until the base displacement of approximately 10 mm, regardless of rock mass conditions.

• Publications of The Korean Astronomical Society
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• v.12 no.1
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• pp.1-21
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• 1997

We have obtained theoretical calibration curves to convert the amount of polarization into the strength of magnetic field, by a numerical calculation of radiation transfer for the polarized spectral line of FeI $6303{\AA}$. In our calculation, three kinds of atmospheric models (VAL-C, penumbra, umbra) have been used to make a proper calibration for an active region composed of quiet, penumbral and umbral areas. It was found that firstly, the results of our calculation depend highly on a kind of atmospheric model rather than on any other input parameters used in a model. Secondly, observed line profile showed m solar spectrum atlas proved to be very similar to the calculated profiles obtained by using a penumbra model. Finally, another method except this calibration curve should be developed to estimate correctly the distribution of magnetic field in solar active region from the observation of polarized spectral line.

• Journal of the Korean Chemical Society
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• v.45 no.2
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• pp.138-160
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• 2001

In this study we measured oxidation potentials and current densities for poly(vinylcholride) (PVC) and poly(carbonate)(PC) in nonaqueous solutions, in order to find out how corrosion (oxidation) potentials depend on temperature, pH, enzyme, or added salts. The Tafel's slopes were determined from the Tafel plots of polarization curves. The transfer coefficients (${\alpha}$) wre evaluated from the slope(1-${\alpha}$)nF/2.3 RT, and the electrode reactions appeared irreversible under all conditions.

• Journal of the Korean Applied Science and Technology
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• v.17 no.2
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• pp.83-88
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• 2000

The VOCs(Volatile Organic Compounds) is one of the major cause for the atmosphere pollution. Breakthrough behavior of benzene and toluene in adsorption bed packed with activated carbon was experimentally studied. Composition and temperature of the gas flowing in the bed was measured and breakthrough curves for each component was obtained. Breakthrough time of benzene was earlier than that of toluene due to relatively weak adsorptivity. The relationship between breakthrough time and flow rate was obtained. The shape of temperature change with time was dependent on the position in the bed. Temperature changed faster and sharper in the inlet than in the outlet. It was noted that breakthrough behavior could be affected by the heat transfer properties.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.118-121
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• 1995

Fabrication and a new analytical expression for the capacitance characteristics of hydrogenerated amorphous silicon thin film transistors(a-Si:H TFTs) is presented and experimentally verified. The results show that the experimental capacitance characteristics are easily measeured. Measured transfer and DC output characteristic curves of a-Si:H TFT are similar to those of the standard MOSFET-IC. The capacitances on bias voltages are in good agreement with experimental data. This capacitance characteristics is suitable for incorporation into a circuit simulator and can be used for computer-aided design of a-Si thin film transistor integrated circuits.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.10 no.S_1
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• pp.47-53
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• 2001

We carroed our to measure the variations of potential with current density (polarization curves) for poly(ethyleneterephthalate). The results were particularly examined to identify the influences on corrosion potential and corrosion rate of various factors including temperature, pH, exposure time, salt, and enzyme. The Tafel slope for anodic dissolution was determined by the polarization effect depending on these conditions. The optimum conditions were established for each case. The second anodic current density peak and maximum passive current density were designated as the relative corrosion sensitivity$(I_r/I_f)$. The mass transfer coefficient value$(\alpha)$ was determined with the Tafel slope for anodic dissolution based on the polarization effect with optimum conditions.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.664-666
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• 2008

Low-temperature curable organic insulator was prepared through blending of polyimide type base resin and cross-linking agent. The newly developed resin can be formed into films using a wet process and cured at $130^{\circ}C$. Using the low temperature cured film as the gate dielectric layer, the field effect mobility of $0.15\;cm^2/V{\cdot}s$ was obtained from a pentacene field effect transistor in the saturation regime and no hysteresis behavior was observed in transfer curves.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.371-374
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• 2003

The degree of changes in mechanical properties of fire-damaged reinforced concrete column depends mostly on sectional geometry, duration exposed to fire, and moisture containment. In order to reasonably assess the deterioration of structural capacity of fire-damaged reinforced concrete column, it is necessary to develop a theoretical model predicting column behavior based on nonlinear heat transfer equation in addition to the traditional mechanics. This research focuses on the development of theoretical model to predict moment-curvature relations of fire-damaged reinforced column. The model is used for the assessment of structural capacity of fire-damaged column in terms of moment-curvature relations and PM interaction curves.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.383-384
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• 2008

In this paper, we extract interface trap density with treatment of gate dielectric of OTFT's. Interface trap densities in this paper were extracted from transfer curves. We obtained interface trap densities in pentacene / PVP interface Non-treated device has $1.4{\times}10^{12}cm^{-2}eV^{-1}$ Dit and treated device has $1.1{\times}10^{12}cm^{-2}eV^{-1}$ Dit.