• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.264-267
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• 2004

[ $Bi_{3.25}La_{0.75}Ti_3O_{12}$ ] (BLT) thin films were prepared by using metal organic decomposition method onto the $LaNiO_3$ (LNO) bottom electrode. Both the structure and morphology of the films were analyzed by x-ray diffraction (XRD) and atomic force microscope (AFM). Even at low temperatures ranging from 450 to $650^{\circ}C$, the BLT thinfilms were successfully deposited on LNO bottom electrode and exhibited (117) orientation. The BLT thin films annealed as low as $600^{\circ}C$ showed excellent ferroelectricity, higher remanent polarization and no significant degradation of switching charge at least up to $5{\times}10^9$ switching cycles at a frequency of 100 kHz and 5 V. For the annealing temperature of $600^{\circ}C$, the remanent polarization Pr and coercive field were $23.5\;C/cm^2$ and 120 kV/cm, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.81-81
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• 2010

Growth of TiO2 films prepared by atomic layer deposition (ALD) was studied on C fiber. Moreover, adsorption and photocatalytic decomposition of methylene blue on TiO2 thin films were studied. Preferential growth of TiO2 on steps of C surfaces could be identified by scanning electron microscopy (SEM). X-ray Photoelectron Spectroscopy (XPS) showed thickness-dependent positive core level shift of Ti, which can be interpreted in terms of enhanced final state charging for thicker films. Adsorption and photocatalytic behaviors of TiO2 thin films will be discussed in this poster.

• Analytical Science and Technology
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• v.8 no.4
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• pp.419-425
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• 1995

A method has been investigated for the determination of selenium and tellurium in Ginseng, Ganoderma and Garlic using hydride generation atomic absorption spectrometry(HG-AAS). The concentration effects of hydrochloric acid and sodium tetrahydroborate on the hydride generation for the determination of selenium and tellurium were investigated. The method of sample decomposition was also investigated using various mineral acids, such as nitric, perchloric and sulfuric acid in the closed system, and foreign ion effects containing in the samples were studied. The calibration curves of selenium and tellurium were obtained in the range of 0~40 ppb. The detection limits(S/N=2) of selenium and tellurium are 0.1 and 0.2 ppb. Analytical data of selenium and tellurium in Garlic, Ganoderma and Ginseng are 289, 296 and 198 ng/g for selenium and 146, 127 and 110 ng/g for tellurium, respectively.

• International Journal of Safety
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• v.5 no.1
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• pp.29-32
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• 2006

There has been an increasing need for substitute energy development due to the dry up of the fossil fuel and environmental problems. Among the substitute energy under consideration, producing hydrogen from water without the accompanying release of carbon has become a promising technology. Also, Iodine-Sulfur (IS) thermochemical water decomposition is one of the promising processes that can produce hydrogen efficiently using the high temperature gas-cooled reactor (HTGR) as an energy source capable of supplying heat at over 1000. In this study, to effect an initiating events identification of the IS process, Master Logic Diagram (MLD) was used and 9 initiating events that cause a leakage of the chemical material were identified.

• Journal of the Chungcheong Mathematical Society
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• v.31 no.4
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• pp.487-509
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• 2018

The Truncated Moment Problem (TMP) entails finding a positive Borel measure to represent all moments in a finite sequence as an integral; once the sequence admits one or more such measures, it is known that at least one of the measures must be finitely atomic with positive densities (equivalently, a linear combination of Dirac point masses with positive coefficients). On the contrary, there are more general moment problems for which we aim to find a "signed" measure to represent a sequence; that is, the measure may have some negative densities. This type of problem is referred to as the General Truncated Moment Problem (GTMP). The Jordan Decomposition Theorem states that any (signed) measure can be written as a difference of two positive measures, and hence, in the view of this theorem, we are able to apply results for TMP to study GTMP. In this note we observe differences between TMP and GTMP; for example, we cannot have an analogous to the Flat Extension Theorem for GTMP. We then present concrete solutions to lower-degree problems.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.5
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• pp.165-170
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• 2016

We have synthesized $Pt_xNi_y$ alloy nanodendrites by a thermal decomposition method. The structure and composition of the as-prepared samples were characterized by field-emission transmission electron microscopy (FE-TEM), energy dispersive X-ray (EDX) spectroscopy, and X-ray diffraction (XRD). The growth mode of the $Pt_xNi_y$ alloy samples synthesized as a function of an intended atomic fraction of Ni was likely to be strongly affected by and reduction (or oxidation) potentials and surface energy.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.663-666
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• 2000

Laser direct writing of micro-patterned copper lines has been achieved by pyrolytic decomposition of copper formate films (Cu(HCOO)$_2$$.$4H$_2$O), as a precursor, using a focused Ar$\^$+/ laser beam ($\lambda$= 514 nm) on PCB boards and glass substrates. The linewidth and thickness of the lines were investigated as a function of laser power and scan speed. The profiles of the lines were measured by scanning electron microscope (SEM), surface profiler (${\alpha}$-step) and atomic force microscopy (AFM). The electrical resistivities of the patterned lines were also investigated as a function of laser parameter using probe station and semiconductor analyzer. we compared resistivities of the patterned lines with that of the Cu bulk, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.525-528
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• 1997

In this study, Eu(TTA)$_3$(phen) was synthesized and its films were prepared by vapor deposition method. Its films were characterized by UV-Vis absorption spectroscopy, Atomic Force Microscopy(AFM) and Photoluminescence(PL) measurements. Their electroluminescent(EL) characteristics were investigated by PL measurements, where a cell structure of glass substrate/ITO/Eu(TTA)$_3$(phen)/Al was employed. It was found that its films were well prepared without any decomposition and the film thickness could be controlled by adjusting the amount of Eu(TTA)$_3$(phen) in a boat. The EL spectrum of these films was almost the same as that of PL spectrum of these films.

• Nuclear Engineering and Technology
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• v.39 no.3
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• pp.221-230
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• 2007

Wavelet theory was applied to detect a singularity in a reactor power signal. Compared to Fourier transform, wavelet transform has localization properties in space and frequency. Therefore, using wavelet transform after de-noising, singular points can easily be found. To test this theory, reactor power signals were generated using the HANARO(a Korean multi-purpose research reactor) dynamics model consisting of 39 nonlinear differential equations contaminated with Gaussian noise. Wavelet transform decomposition and de-noising procedures were applied to these signals. It was possible to detect singular events such as a sudden reactivity change and abrupt intrinsic property changes. Thus, this method could be profitably utilized in a real-time system for automatic event recognition(e.g., reactor condition monitoring).

• Applied Chemistry for Engineering
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• v.9 no.6
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• pp.884-888
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• 1998

Effects of heating time under high temperature on the thermal and mechanical properties of neutron shielding materials based on modified (KNS-102), hydrogenated(KNS-106) bisphenol-A type epoxy resin and phenol-novolac(KNS-611) type epoxy resin for radioactive material shipping casks have been investigated. At early stages, the initial decomposition temperatures of the shielding materials of KNS-102, KNS-106 and KNS-611 increased with the heating time under high temperature, but it was rarely affected by the heating time in the later stages. In addition, the thermal conductivities of KNS-102 and KNS-106 decreased with heating time, but that of KNS-611 increased with the heating time. On the contrary, the thermal expansion coefficients of neutron shielding materials decreased with increase of heating time. At the high temperature, the tensile strength and flexural strength of the shielding materials of KNS-102 and KNS-611 increased with heating time, but those of KNS-106 decreased with increase of heating time. And the heating time under high temperature on the neutron shielding materials did not show measurable loss of weight and hydrogen content.