• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.12
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• pp.764-768
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• 2016

To investigate excess $Na^+$ effect, $Bi_{0.5}(Na_{0.78+x}K_{0.22})_{0.5}TiO_3$ ($0{\leq}x{\leq}0.05$) (BNKT) ceramics were prepared by using a conventional solid-state reaction method. The structure and ferroelectric properties of BNKT ceramics were characterized by XRD (X-ray diffraction) and polarization dependence by external electric field. Also, the temperature dependence of dielectric constant and loss were studied. From these results, it was found that appropriate excess $Na^+$ into BNKT ceramics compensate the volatility and induce dense ceramics. The enhanced piezoelectric coefficient (158 pC/N) and depolarization temperature ($202^{\circ}C$) were obtained for the x=0.01 composition.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.4
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• pp.384-388
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• 2001

In order to investigate regional variation of food component in the top shells, Omphalius pfeifferi capenteri, caught from Jeju, Sogwipo, Hallim and Songsan, Jeju island, Republic of Korea, food sanitary (heavy metal and volatile basic nitrogen), nutritional (mineral, total amino acid contents, fatty acid composition), taste (extractive nitrogen) components and sensory evaluation (color, texture and taste) were measured. From the result of the contents of heavy metal and volatile basic nitrogen, the top shell might not invoke health risk in using food source, The extractive nitrogen contents of top shell were $343.0\~385.4\;mg/100\;g$. The amounts of total amino acids were $12.5\~13.2\;g/100\;g$, and the major compound among them were glutamic acid, proline and aspartic acid. The major compound among mineral were sodium, calcium, potassium and magnesium. In fatty acid composition, polyenes with essential component or healthy functionality such as 20:4n-6, 20: 5n-3 and 22: 5n-3 were the major components. But, lipid content was extremely small. Judging from the results of chemical and sensory evaluation described a above, food components were not different among top shells caught from various area.

• Journal of the Korean Ceramic Society
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• v.28 no.10
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• pp.803-809
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• 1991

Microstructure, room temperature resistivity and temperature coefficient of resistance of BaTiO3 ceramics were characterized and measured in this study. The basic composition of the BaTiO3 cremics was formed by adding 0.25 mol% Dy2O3 and 0.07 mol% MnO2 to the BaTiO3 composition. Samples of the BaTiO3 ceramics were prepared by adding various amounts of the TiO2, SiO2 and Al2O3 to the basic composition. An addition of 1 mol% TiO2, 2 mol% SiO2 and 0.5 mol% Al2O3 to the basic composition resulted both the values of the room temperature resistivity and the temperatured coefficient being maxium. Meanwhile, an addition of 1 mol% TiO2 and 1 mol% Al2O3 to the basic composition resulted the value of the room temperature resistivity maxium and the temperature coefficient minimum. The temperature coefficient showed a maximum value as well as a minimum value when the three kinds of the additives were added together to the basic composition of the BaTiO3 ceramics. Maxed phases of BaTi3O7, BaTiSiO5 and BaAl2Si2O8 were present at the grain boundary.

• The Korean Journal of Community Living Science
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• v.15 no.3
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• pp.107-112
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• 2004

Many studies have showen that Letinus edodes have a reducing effects on blood pressure and lipid levels in animals with high blood pressure and hyperlipidemia. But the only cap has been on the market as goods and the stipe has been wasted. The price is very variable and is based on harvest time and the part of the plant currenty, there is not much information about the nutritional composition and bio-fuctional effects of Letinus edodes based on harvest time and part. Some farmers have been selling the powder seasoning by drying and pulverizing Letinus edodes including stipe to develop value added, late harvested Letinus edodes and its stipe these days. This study was conducted to investigate and compare the nutritional composition of Letinus edodes harvested at different times (early: E, late: L) and separated by part (cap: C, stipe: S). The 4 kinds of materials were named as early harvested cap (EC) and stipe (ES), and late harvested cap (LC) and stipe (LS) samples were obtained from Mungyeong City Agricultural Technology & Extension Center. The composition analysis of the nutrients in the 4 materials was conducted by using the AOAC method. The proximate components (moisture, protein, fat, fiber, ash, and carbohydrates), minerals and vitamin content were measured. Nutritional composition of Lentinus edodes did not show any significant difference between early and late harvested mushrooms. Nutritional compositions were different according to part. The results demonstrate that the late harvested stipe can also be used as a quality food material.

• Journal of Technologic Dentistry
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• v.10 no.1
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• pp.177-183
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• 1988

This paper aims to examine ceramic shade prescriptions for work authorizations in all its aspectclincal information, recording information, technical considerations, extended application, practical applications. The results are as follows : 1. The basic application provides essential data for ceramic veneer fabrication. 2.Three-dimensional information divides the space for body and enamel components. 3. The second body shade selection improves shade matching in the middle one-third of the tooth and enhences the appearance of the enamel component. 4. Ceramists are encouraged to recognize the influence each component has upon the total shade composition. 5. A format is established for recording clinical information. 6. The use of available ceramic systems is seemingly unlimited. The method presented provides flexisility for recording the most detailed shade information in simple graphic and verbal terms. 7. Technical simplification is a by-product of complete, precise work information.

• Transactions of the Korean hydrogen and new energy society
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• v.16 no.3
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• pp.209-218
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• 2005

To find a suitable metal component in oxygen carrier particles for chemical-looping hydrogen generation system(CLH), oxygen transfer capacities of metal components were compared and Ni has been selected as the best metal component. The proper operating conditions to achieve high hydrogen generation rate have been investigated based on the chemical-equilibrium composition analysis for water splitting reactor. Moreover, suitable compositions of syngas from gasifier of heavy residue to achieve high energy efficiency have been investigated by calculation of heat of reaction. Based on the selected operating conditions, the best configuration of two interconnected fluidized beds system for the chemical-looping hydrogen generator has been investigated as well.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.111-111
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• 2012

In this talk, we represent a novel approach to investigating intra-nanorod surface plasmon coupling with control over block compositions. The multi-component rod-like nanostructures, which consist of optically active components (Au and Ag) and optically less active component (for example, Ni) in UV-vis-NIR spectral window, showed interesting optical response depending on each block length and the total length of the structure. By controlling the composition and relative lengths of the blocks that comprise these structures, we can tailor the overall optical properties. Depending on the relative fraction of Au and Ag blocks, the intensity of the transverse modes varied without noticeable peak shifts. However, the strong intraparticle surface plasmon coupling resulted in the collective appearance of longitudinal LSP modes, including higher-order modes. The experimental observations were confirmed by theoretical calculation, using a discrete dipole approximation method. In addition, we will briefly discuss how single nanorod solar cells can be synthesized by using by using electrochemical deposition and AAO hard templates.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.586-590
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• 2001

In this paper, a novel control scheme compensating source voltage unbalance and harmonic currents for hybrid active power filters is proposed, where no low/high-pass filters are used in compensation voltage composition. The phase angle and compensation voltages for source harmonic current and unbalanced voltage components are derived from the positive sequence component of the unbalanced voltage set, which is simply obtained by using digital all-pass filters. Since a balanced set of the source voltage obtained by scaling the positive sequence components is used as reference values for source current and load voltage, it is possible to eliminate the necessity of low/high-pass filters in the reference generation. Therefore the control algorithm is much simpler and gives more stable performance than the conventional method. In addition, the source harmonic current is eliminated by compensating for the harmonic voltage of the load side added to feedback control of the fundamental component.

• Journal of the Korean Ceramic Society
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• v.15 no.2
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• pp.66-71
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• 1978

The cobalt blue spinel stains (main composition; CoO:$Al_2O_3$=1 : 1) in CoO-NiO-$Al_2O_$3 and $CoO-Al_2O_3-Cr_2O_3$ system were prepared by the calcination of each component oxides to be adequate for the factory. The color development, the change of the lattice constnat of the spinel and its application to colored glazes were studied. The results were summarized as follows. 1) In CoO-Al_2O_3$ spinel, the excess addition of each component hardly made any variation in lattice constantand alumina-rich spinel specimens caused the brilliant blue color fade. 2) An increase of $Ni^{2+}$ in $CoO-NiO-Al_2O_3$ system, made the lattice constnat of the $CoO-Al_2O_3$ spinel smaller, and an increase of $Cr^{3+}$ in $CoO-Al_2O_3-Cr_2O_3$, larger. 3) Glazed stains under lead glaze were colored nearly same dark blue color fade.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.140-143
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• 2004

Heat of hydration of concrete under different curing temperatures can be characterized with knowledge of the thermal activity, the heat rate at the reference temperature, and the total heat of hydration of the mixture. The so-called multi-component hydration model incorporates the effect of following variables: cement chemical composition, cement fineness, secondary cementitious powders, mixture proportions, and concrete properties. However, the model does not consider the use of silica fume as a secondary cementitious powder. Therefore, the model that quantifies the heat of hydration due to the use of silica fume is needed. In this thesis, the effects of silica fume on heat of hydration are evaluated and the influence on the heat of hydration are also quantified to be included in the model, so that the analysis using modified multi-component hydration model for silica fume concrete provides more accurate results than normal concrete.