• Journal of the Korean Ceramic Society
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• v.49 no.4
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• pp.325-327
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• 2012

Europium-doped $LaSi_3N_5$ phosphor was synthesized from LaSi/Si/$Si_3N_4/Eu_2O_3$ mixture by nitridation at $1390^{\circ}C$ and additional annealing at $1650^{\circ}C$ for 4 h. The phosphor shows emissions in the green light region with a maximum at 560 nm. With increasing europium content in the general formula $La_{1-z}Eu_zSi_3N_{5-z}O_{1.5z}$ from z = 0.01 to 0.06 there was a maximum emission for z = 0.04 followed by concentration quenching for the highest europium content (z = 0.06).

• Journal of the Korean Ceramic Society
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• v.25 no.4
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• pp.321-328
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• 1988

The sintering phenomena, electrical resistivity, dielectric and piezoelectric properties of lead titanate ceramics modified by the partial substitution of La for Pb and Mn for Ti, (Pb1-1.5xLax)(Ti1-yMny)O3 ceramics, have been investigated. In (Pb1-1.5xLax)(Ti1-yMny)O3 system, with increasing lanthanum content, the realtive bulk density increased, but the Curie point and tetragonality (c/a) decreased. The tetragonal-to-cubic phase transition boundary existed in the range of 0.20

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.374-377
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• 2003

Sol-gel processing of BaTiO$_3$ ceramics doped with La(0.01-1.00 at.%) were prepared from metal barium, titanium n-butoxide and lanthanum isopropoxide. Characterization of the sol-gel-derived powder using XRD, SEM is also reported. The obtained results suggested that insulator to semiconductor transition for highly donor-doped barium titanate was closely related to the incorporation of donor into the grains and to the resultant grain size, which were significantly affected by the sinterability of BaTiO$_3$ powders and sintering conditions used.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.621-624
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• 2002

Lanthanum nickel oxide$(LaNiO_3)$ powders have been prepared via a mechanochemical processing without any additional heat treatment. When a mixed lanthanum and nickel oxide was mechanically activated for 6 hours with 450 rpm, a stable and single phase perovskite powder was successfully synthesized and its crystallite size of about 90 nm is calculated by using the Scherrer equation.

• Transactions on Electrical and Electronic Materials
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• v.1 no.1
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• pp.17-21
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• 2000

In order to investigate the dependence of a content in lead lanthanum titanate (PLT) films and heat treatment, sol-gel process has been used. Four types of PLT thin films with the chemical formula, Pb$\_$1-x/ La$\_$x/Ti$\_$1-x/4/O$_3$(X=18, 21, 24 and 28 mole %) have been fabricated on Pt/Ti/SiO$_2$/Si multi-layers and ITO/glass substrates, The post-annealing temperature in the range of 400~700 $\^{C}$ is applied for the formation of perovskite structure in PLT films. The structureal, electrical and optical properties of PLT film with the addition of La content are estimated. The films orientation and surface structure of films are studied by XRD (X-ray diffraction) and SEM(scanning electron microscopy). The P-E hysteresis loop become narrower with increasing La content. The average transmittance of the films is about 80%.

• Journal of Electrochemical Science and Technology
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• v.11 no.4
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• pp.421-429
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• 2020

This report describes the simultaneous detection of the two dyes most commonly used in food, tartrazine (TZ) and sunset yellow (SY), based on a microcomposite of carbon paste decorated with La₂O₃ and TiO₂. Anodic currents for SY-TZ were observed at 0.89-1.21 V by cyclic voltammetry (CV) separated with a ΔV of 0.32 V. The increased anodic peak currents compared to that of the unmodified carbon paste electrode were almost 50 and 41% for SY-TZ, respectively. The detection limits with the optimal amount of La₂O₃-TiO₂ were 0.02 and 0.03 µmol/L, respectively. The relative standard deviation (RSD) based on fifty measurements was less than 3%. The versatility and novelty of the sensor were tested with food samples containing these substances and other substances.

• Korean Journal of Optics and Photonics
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• v.13 no.6
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• pp.554-558
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• 2002

A new laser material, Nd:LSB $(Nd${3}:LaSc_3(BO_3)_4$, lanthanum scandium borate), of microchip type was grown by the Czochralski pulling method, and tested for optical and lasing properties. Nd:LSB, able to be highly doped with $Nd^{3+}$ ions while maintaining good optical, chemical, mechanical properties, was compared to another Nd-type laser material. The absorption and fluorescence spectra, and fluorescence lifetime were measured, and the crystal structure was analyzed. The lasing characteristics were investigated by using Ti:sapphire laser as a pumping light source.

• Bulletin of the Korean Chemical Society
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• v.30 no.3
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• pp.657-660
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• 2009

The surface of $Li[Ni_{0.8}Co_{0.15}Al_{0.05}]O_2$ cathode particle was modified by lanthanum based oxide to improve electrochemical property and thermal stability. The XRD pattern of surface layer was indexed with that of $La_4NiLiO_8$. The discharge capacity of modified electrode was higher than that of pristine sample, specially at fast charge-discharge rate and high cut-off voltage. In the DSC profile of the charged sample, the generation of heat by exothermic reaction was decreased by surface modification. Such enhancement may by attributed to the presence of stable lanthanum based oxide, which effectively suppressd the reaction between electrode and electrolyte on the surface of $Li[Ni_{0.8}Co_{0.15}Al_{0.05}]O_2$ electrode.

• YAKHAK HOEJI
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• v.43 no.6
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• pp.802-808
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• 1999

Vibrio vulnificus cytolysin has been incriminated as one of the important virulence determinants in V. vulnificus infection. In the present study, the effects of Vibrio vulnificus cytolysin on platelets were examined. Vibrio vulnificus cytolysin induced platelet aggregation and increased intracellular calcium concentration ($[Ca^{2+}]_i$) of rat platelets. These effects were abolished in $Ca^{2+}-free$ buffer (2 mM EGTA). Cytolysin also potentiated ADP-and collagen-induced platelet aggregation. Lanthanum (2 mM) inhibited cytolysin-diduced platelet aggregation. However, another $Ca^{2+}$ channel blockers, verapamil ($20{\;}{\mu}M$) or mefenamic acid ($20{\;}{\mu}M$) did not block cytolysin-induced platelet aggregation. Osmotic protectants, sucrose (50 mM) and raffinose (50 nM) suppressed platelet aggregation by 35.9% and 63.4%, respectively. V. vulnificus cytolysin increased membrane conductances of platelet membranes. These results suggest that cytolysin-induced platelet aggregation is mediated via lanthanum sensitive-calcium influx which resulted from the pore formation by V. vulnificus cytolysin.

• Journal of information and communication convergence engineering
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• v.1 no.1
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• pp.31-34
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• 2003

Sol-gel processing of $BaTiO_{3}$ ceramics doped with La (0.01∼1.00 at.%) were prepared from metal barium, titanium n-butoxide and lanthanum isopropoxide. Characterization of the sol-gel-derived powder using XRD, SEM is also reported. The obtained results suggested that insulator to semiconductor transition for highly donor-doped barium titanate was closely related to the incorporation of donor into the grains and to the resultant grain size, which were significantly affected by the sinterability of $BaTiO_{3}$ powders and sintering conditions used.