• Korean Journal of Materials Research
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• v.11 no.8
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• pp.685-689
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• 2001

We carried out these experiments to examine the effects of element substitution of Co and La-Co for Sr-ferrite. The calcined properties of Co and La-Co element substitution were examined, and also the sintered magnetic properties were measured with the stoichiometric condition. The magnetic properties of $(La-Co)_{0.3}-SrM$ composition are as follows; $(M_s)$: 71.08 emu/g, $iH_c$: 4.38 kOe and $B_r$ : 4.18 kG, $iH_ c$ :4.35 kOe, $BH_{max}$: 4.3 MGOe. The $BH_{max}$ value was increased up to 10 % compared with conventional values. Our results imply that the magnetic properties of Sr-ferrite can be improved by the substitution of those elements.

• Journal of the Korean Ceramic Society
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• v.51 no.6
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• pp.527-532
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• 2014

$0.97Bi_{0.5+x}(Na_{0.78}K_{0.22})_{0.5-3x}TiO_3-0.03LaFeO_3$ lead-free piezoelectric ceramics were fabricated by a solid state reaction method. $LaFeO_3$ additives were added to $Bi_{0.5}(Na_{0.78}K_{0.22})_{0.5}TiO_3$ for volatile compensation of bismuth and sodium ions in the sintering process. To create A-site vacancies, the mole ratio and charge valence of A-site ions ($Bi^{3+}$, $Na^+$ and $K^+$) were controlled. The improved piezoelectric properties were observed by addition of $LaFeO_3$ and control of A-site vacancies. In particular, a $d_{33}^*(S_{max}/E_{max})$ value of 614pm/V and an electric field induced strain of 0.33% was observed in $0.97Bi_{0.505}(Na_{0.78}K_{0.22})_{0.485}TiO_3-0.03LaFeO_3$ ceramic.

• Journal of the Korean Magnetics Society
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• v.11 no.6
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• pp.256-261
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• 2001

These experiments were carried out to examine the effects of element substitution of Zn and La-Zn for Sr-ferrite. The calcined properties of Zn and La-Zn element substitution were examined, and also the sintered magnetic properties were compared with the stoichiometric condition. The magnetization properties of calcined SrM materials is as follows; M$\_$s/ : 61.06 emu/g. Also, the magnetization properties of calcined Zn$\_$0.3/-SrM materials is as follows; M$\_$s/ : 66.90 emu/g. The sintered magnetic properties of (La-Zn)$\_$0.3/-SrM composition is as follows; B$\_$r/ : 4.21 kG, BH$\_$max/: 4.19 MGOe.

• Korean Journal of Environmental Agriculture
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• v.30 no.2
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• pp.196-201
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• 2011

BACKGROUND: Bioavailability enhancement by solubilization of lipophilic drugs in nano-emulsion has been reported and it may be useful in pharmaceutical and nutraceutical products. This study was performed to compare in vivo bioavailability of nano-emulsion formulation with that of the general product as control. METHODS AND RESULTS: The pharmacokinetics assessment of Vitamin A, D and E complex of nanoemulsion formulation (LaVita), in comparison to the general product, was performed in the male rat plasma by a single oral dose at 20 mL/kg body weight (n=3/group). For nano-emulsion formulation (LaVita), $C_{max}$ of vitamin A and E in plasma were much higher and the area under the curve (AUC) of vitamin A, D and E were 14-63% higher, and the half-life of vitamin E was 2-fold longer than the general product. According to statistical analysis, each $C_{max}$ of vitamin A, D & E was significantly higher (p<0.01, 0.05 and 0.01, respectively) than that of general product. Half-life of vitamin A was significantly higher (p<0.01) and AUC of vitamin A and D were also significantly higher than the general product. CONCLUSION(s): Considering significant increment of $C_{max}$ and AUC, LaVita made of nano-emulsion could be more effective the absorption rate and extent for bioavailability of vitamin A, D & E than those of general product.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.30 no.3
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• pp.103-109
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• 2020

The effect of La₂O₃ addition on the crystalline phase, microstructure, and dielectric properties of BaTiO₃ has been studied as a function of the amounts of La₂O₃. 0.3 mol% TiO₂-excess BaTiO₃ powder was synthesized by solid-state reaction, and then the powder compacts with various amounts of La₂O₃ were sintered at 1250℃ for 2 hours. Room temperature XRD showed changes in the lattice parameters and a decrease of tetragonality (c/a) as the amounts of La₂O₃ increased. It can be explained that the phase transition from tetragonal to cubic phase occurred because La³⁺ replaced Ba²⁺ site, which increased the instability of the tetragonal phase. As La₂O₃ was added over 0.1 mol%, the critical driving force for growth (Δg_c) increased over maximum driving force (Δg_max). As the result, the grain size decreased with La₂O₃ addition. Dielectric constant decreased as the amounts of La₂O₃ increased, which was analyzed with crystal structure and microstructure.

• Journal of the Korean Ceramic Society
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• v.52 no.4
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• pp.237-242
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• 2015

$Bi_{0.5}(Na_{0.78}K_{0.22})_{0.5}TiO_3$ (BNKT) lead-free piezoelectric ceramics modified by $LaMnO_3$ (LM) were fabricated by conventional solid-state method. The crystal structure and the morphology of the lead free ceramics were analyzed by XRD (X-ray diffraction) and FE-SEM (Field Emission Scanning Electron Microscopy). The LM modified BNKT ceramics have a phase transition from ferroelectric tetragonal to non-polar pseudo-cubic. Despite decreases in the remnant polarization ($P_r$) and coercive field ($E_c$) in the P-E hysteresis loops, the electric-field induced strain properties were significantly enhanced by the LM modification. The highest value of $S_{max}/E_{max}=412pm/V$ at an applied electric field of 5 kV/mm was found in BNKT-0.01LM ceramic.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.11a
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• pp.31-33
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• 1992

This paper is studies the addition effects of $La_2O_3$ on the magnetic properties of Sr ferrite. Compositions were chosen according to the formula $[SrO{\cdot}nFe_2O_3]_{100-x}(La_2O_3)_x$. where n was varied between 5.8~6.1 and x between 0~3. The composition of the best value $(BH)_{max}$=1.48MGOe was n=6(stoichiometric composition) and x=2 at $La_2O_3$ addition. This value was higher than that of ordinary isotropic strontium ferrite.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.604-608
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• 2007

The INM simulation program is used to estimate the condition of the exposed area to the noise near a military airport in Korea. $WECPNL_k$, the evaluation unit of korean airport noise, is different from the ICAO $WECPNL_I$ that is used in the simulation program. Therefore, it is inappropriate to compare these units each other directly. This study presents method of comparison between them by using $LA_{MAX}$. The aircraft events are classified into three classes, as departure, overfly and approach. In result, the measurement and simulation seemed to be similar at departure and approach pattern. However, overfly pattern had higher errors between measurement and simulation. Finally, it is necessary to examine the method to determine flight events and duration for the $WECPNL_k$ application.

• Trans-
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• v.6
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• pp.35-42
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• 2019

Un jour, à la fin d'un symposium autour du célèbre film « La Bataille d'Alger » de Pontecorvo, quelqu'un a dit que l'histoire véridique était trop difficile à retrouver (à savoir ce qu'il s'était vraiment passé), il fallait donc la créer (dans le sens d'inventer). J'étais si surpris par cette conclusion anti-historique que je n'ai pu répondre. Nous pouvons faire l'histoire au présent par nos actions, mais ce qui a été fait est fait, et restera historique autant que possible dans la mesure où des historiens sérieux et libres pourront faire leur travail. Max Stirner a dit « Nous ne pouvons être libre de tout, mais nous pouvons tenter de faire nos écrits aussi libres que nous sommes ». Si nous rapportons cette idée à l'Histoire, cela veut dire que ce n'est pas parce que l'histoire est le résultat des recherches faites par des humains qu'elle doit être faussée. L'homme est faillible mais il est aussi perfectible. En tant qu'historien du cinéma, les questions importantes sont de savoir ce qui constitue une archive, (le Mal d'archive de Derrida, qui développe la pensée sur la constitution de la connaissance selon Foucault, intervient très à propos, ici) et comment les utiliser, dans les films en particulier, fiction ou documentaire.

• Progress in Superconductivity and Cryogenics
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• v.15 no.1
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• pp.6-10
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• 2013

We investigate the electrical and thermal transport properties of a sesquicarbide superconductor $La_2C_3$, including electrical resistivity, thermoelectric power, and thermal conductivity. The electrical resistivity exhibits a typical metallic character with a saturation behavior at high temperatures. The thermoelectric power shows a metallic behavior with pronounced phonon-drag effect, comparable with pure metals. The broad peak of the thermal conductivity is observed in the superconducting state, which is rapidly suppressed by magnetic fields. These observations suggest that the electron-phonon scattering is significant in $La_2C_3$, which is relevant with the relatively high-$T_c$ in $La_2C_3$ through strong electron-phonon coupling with low frequency phonon modes.