• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.1
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• pp.39-45
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• 2004

Fine LaAlO$_3$ powders wore successfully synthesized from La$_2$O$_3$ and ${\gamma}$ $Al_2$O$_3$ powders milling for 10∼50 hours via the high energy milling technique (mechanochemical method) in room temperature and air. The particle size of LaAlO$_3$ powder were estimated from XRD patterns and SEM images to be 160∼180 nm. The LaAlO$_3$ ceramics arc derived for the synthesized powders (milling for 10, 30 and 50 hours) by sintering at 140$0^{\circ}C$ and 150$0^{\circ}C$. The micrographs of grains showed an agglomeration and the degree of agglomeration increased with the milling time. The LaAlO$_3$ made from synthesized powders milling for 50 hours can be sintered to 99.5％ of theoretical density at 150$0^{\circ}C$ for 1 hour. These ceramics exhibits a dielectric constant of 20, a dielectric loss of 0.0003 and a temperature coefficient of capacitance of 15 ppm/$^{\circ}C$ at 1 MHz.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.648-651
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• 2003

Fine $LaAlO_3$ powders were successfully synthesized from $La_2O_3$ and ${\gamma}-Al_2O_3$ powders milling for $10{\sim}50hrs$ via the high energy milling technique (mechanochemical methode) in room temperature and air. The particle size of $LaAlO_3$ powder were estimated from XRD patterns and SEM images to be $160{\sim}180nm$. The $LaAlO_3$ ceramics are derived for the synthesized powders (milling for 10, 30 and 50hrs) by sintering at $1400^{\circ}C$. The micrographs of grains showed a agglomeration and the degree of agglomeration increased with the milling time. The $LaAlO_3$ made from synthesized powders milling for 30hrs can be sintered to 98% of theoretical density at $1,400^{\circ}C$ for 4hrs.

• The Korean Journal of Ceramics
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• v.6 no.1
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• pp.21-26
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• 2000

Nanosized powders of trimetallic orthoferrites containing La and Sm in different ratios were synthesised by the thermal decomposition at low temperatures of the corresponding hexacyanocomplexes. The precursors and their decomposition products were analyzed by simultaneous thermogravimetric and differential thermal analysis (TG/DTA), x-ray diffraction (XRD) and Raman spectroscopy. Single phase trimetallic precursors and oxides were obtained. The crystal structure of the perovskitic oxides was orthorhombic, and the lattice parameters were affected by the ionic size of the rare earth elements present in the oxides. Raman spectroscopy showed a disorder effect in the vibrational bands with increasing the La content.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.7
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• pp.1065-1077
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• 2010

This study researchers the libretto and the original novel of the opera to propose fashion styles and stage costumes for the opera, "La $boh\grave{e}me$." This article studied the meanings of the $boh\grave{e}me$ in the 1830's France and the characteristics of the $boh\grave{e}me$ that appeared in the original novel, "$Sc\grave{e}nes$ de la vie de $boh\grave{e}me$." The characteristics of bohemian fashion styles in the $Sc\grave{e}nes$ de la vie de $boh\grave{e}me$ were not normal, not related with trends, and not new. Before presenting the new fashion styles, this study examined the stage costume problems of La $boh\grave{e}me$ with five existing performance materials. In conclusion, this study proposed new stage costume designs that reflect more dramatic fashion expressions of the characters, expression on the passage of time, and contemporary fashion records.

• Journal of the Korean institute of surface engineering
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• v.46 no.2
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• pp.87-92
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• 2013

Viscosities of $LaCl_3$-CsCl binary melts were measured by the capillary method over the range of their liquidus temperatures to about 1200 K. The cell constant were determined by using pure water. The results obtained are summerized as follows: Viscosities of melted $LaCl_3$ were decreased with the content of CsCl for all over the composition range of binary melts. Composition versus viscosity relation for the binary melt showed a non-linear relationship from the additivity line and the deviations showed a maximum value at about 60 mol% CsCl. This suggest the existence of the complex ion of $LaCl_4{^-}$ in the melt. Activation energy for the viscous flow of the binary melts decreased monotonously with the increasing content of CsCl after a few increasement till 40 mol% CsCl. All of these results were the resemble with the viscosities of $LaCl_3$-NaCl binary melts.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1985.01a
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• pp.21-23
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• 1985

By adding La$_2$O$_3$ to optical multicomponent glass composition, after making mother glass and core fiber that enable to enlarge the infrared transmittance region, then surveyed the optical properties. Through thermal analysis of the glass abstained by melt-quenching after selecting stable basic composition on devitrification and replace SiO$_2$ by 4-12wt% La$_2$O$_3$. As La$_2$O$_3$ increases up to l2wt% transition temperature, refractive index, density, deformation temperature increased, whereas thermal expansion coefficient decreased. As a result of inspectig transmittance in UV/VIS/IR region, visable region indicated the decrease of transmittance by increasing the La$_2$O$_3$ and transmittance region was enlarged by increasing the La$_2$O$_3$ in IR region. Also, fabricate core fiber at 820$^{\circ}C$ and severy the optical loss we could fact that La$_2$O$_3$ composition added 12wt% showed the minimum optical loss.

• Korean Journal of Microbiology
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• v.36 no.4
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• pp.312-315
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• 2000

Paecilomyces tenuipes DGUM 32001, an entomopathogenic fungus, was examined to evaluate in vitro cytotoxicity against several human cancer cells. The fruiting bodies of P. tenuipes were extracted with methanol and fractioned with some organic solvents i.e. chloroform, ethyl acetate, and butanol. The methanol extracts of P. tenuipes showed significant cytotoxicity against human cancer cell lines; HeLa, HeLa S3, and A-431. Among the fractions tested, the ethyl acetate fraction had the highest cytotoxicity against three cancer cell lines. The $IC_{50}$ values of ethyl acetate fraction against HeLa, HeLa S3, and A-431 were 13, 35, and 30 $\mu$g/ml, respectively. However, cytotoxicity might not be due to apoptosis. The methanol extract of cultured mycelia showed high cytotoxicity against HeLa cell lines.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1114-1115
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• 2006

The preparation of single-phase $CuLaO_2$ with delafossite-type structure by means of the solid-state reaction method was investigated using X-ray diffraction. The results showed that notwhistanding the fact that there was a trace of metallic copper, nearly single-phase $CuLaO_2$ was obtained by using $La(OH)_3$ as a lanthanum source and by firing the mixed powder with nonstoichiometric composition ratio of $La(OH)_3:Cu_2O=1:1.425$ in a vacuum at 1273 K for 10 h. The measurement of electrical conductivity and Seebeck coefficient showed that $CuLaO_2$ thus obtained was a p-type semiconductor and had a Seebeck coefficient of approximately $70{\mu}V/K$.

• Journal of the Korean Ceramic Society
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• v.36 no.1
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• pp.50-54
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• 1999

We have measured the x-ray photoemission spectroscopy of cation deficient La0.970Mn0.970O3 as a function of temperature. Detailed results on the chemical shifts and changes in Mn 2p and Lp 3d core levels due to variation of temperature have been obtained. The Mn 2p 3/2 and 1/2 main peaks and La 3d core spectrum shift to lower binding energy levels with increasing temperature. This XPS behavior is correlated with the strength of localization of Mn3+. The Jahn-Teller effect due to Mn3+ besides the conventional random potential effects is likely to localize charge carriers in La-.970Mn0.970O3.

• Journal of the Korean Chemical Society
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• v.33 no.1
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• pp.82-89
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• 1989

The fluorescence of $Eu^{3+},\;Tb^{3+}$ substituted for $La^{3+}$ in Lanthanum Oxychloride (LaOCl) has been studied. The fluorescence intensity of the $Eu^{3+},\;Tb^{3+}$ in LaOCl excited by Ultra-violet light were investigated on its activator concentration and discussed as the energy transfer process. The energy transfer from $Tb^{3+}\;to\;Eu^{3+}$ take place in the $Eu^{3+}\;and\;Tb^{3+}$ codoped LaOCl crystal. This process was confirmed to the change of concentration and the measurement of fluorescence decay time.