• Journal of the Korean Ceramic Society
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• v.36 no.10
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• pp.1056-1061
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• 1999

Phase formation and oxygen ion conduction of La(Ba)Ga(Mg)O3-$\delta$ system was studied, BaLaGa3O7 and BaLaGaO4 formed as a secondary phase above the solubility limit of Ba2+ in La3+ sites. The oxygen ionic conductivity of La(Ba)Ga(Mg)O3-$\delta$ was 0.1 S/cm 80$0^{\circ}C$ The activation energy of the oxygen ion conduction was dependent on temperature. This value was higher at low temperature than at high temperature.

• 한국전기화학회:학술대회논문집
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• 2002.07a
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• pp.271-276
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• 2002

고체산화물 연료전지의 구성요소인 전해질의 $(La_{1-x}Sr_x)(Ga_{1-y}Mg_y)O_{3-\delta}$계의 결정상 및 미세구조특성을 연구하였다. Mg의 첨가량이 증가할수록 Sr의 고용량도 증가하였으며 Sr의 함량이 많으면 2차상인 $LaSrGa_3O_7$상이 생성되었으며 Mg의 첨가량이 증가함에 따라서는 $LaSrGaO_4$상이 생성되었다. $LaSrGaO_4$상이 생성된 경우에는 낮은 전도도를 나타내었으며 $LaSrGa_3O_7$상의 경우에는 전기전도도에 큰 영향을 미치지 않았다. 또한 Sr과 Mg 첨가량의 증가는 grain 성장을 억제하였으며 $(La_{0.8}Sr_{0.2})(Ga_{0.8}Mg_{0.2})O_{3-\delta}$는 $1000^{\circ}C$에서 0.1S/cm 정도의 전기전도도를 나타내었다.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1495-1498
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• 2005

Due to an efficient red emission, $Eu^{+3}$ ions have doped in various host materials. Eu-doped $LaPO_4/LaPO_4$ core/shell nanophosphor which emits red light in visible range, was synthesized by using a solution system. The mean size of the nanoparticle observed by TEM was about 7-8 nm. In this core/shell system, the thickness of $LaPO_4$ shell was optimized on the basis of relative PL emission intensity. In addition, the luminescent properties of $LaPO_4:Eu/LaPO_4$ core/shell particle have been compared with Eu-doped $LaPO_4$ bulk particle and nanoparticle.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.11a
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• pp.21-23
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• 1994

By adding La₂O₃ 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 SiO₂ by 4-12wt% La₂O₃. As La₂O₃ 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 La₂O₃ and transmittance region was enlarged by increasing the La₂O₃ in IR region. Also, fabricate core fiber at 820℃ and severy the optical loss we could fact that La₂O₃ composition added 12wt% showed the minimum optical loss.

• Journal of Magnetics
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• v.2 no.2
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• pp.46-49
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• 1997

This paper reports the first success in enhancement of the magneto-optic figure of merit of garnet films in blue wavelengths. The maximum of the absolute value of the Faraday rotation angle observed at about 500 nm for the films with no La substitution shifted toward shorter wavelength as La content increased, that leads the increase of the absolute value of the Faraday rotation angle in the wavelengths shorter than about 480 nm. The optical absorption coefficient at the wavelengths shorter than 500 nm decreased as La content increased. As a result the magneto-optic figure of merit increased in the wavelengths shorter than 470 nm as La content increased and was about two times larger for the film with La content of 0.6 in formular unit compared to that of the film without La substitution. This might be attributed to the shift of the centers of the charge transfer and crystal field transitions by La substitution.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.670-671
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• 2006

We report on the mechanical and structural properties of nanocrystalline 8% and 10% mol yttria stabilized zirconia (YSZ) obtained using mechanical alloying (MA). The as-milled powders show a body-centered cubic structure with grain sizes in the nanometer scale. After uniaxial pressing and sintering the compacts exhibit good mechanical properties. We discuss the correlation of these enhanced properties with the microstructural changes induced by heat treatment.

• Bulletin of the Korean Chemical Society
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• v.9 no.5
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• pp.283-288
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• 1988

The titled properties on reduction of the perovskite $LaBO_3$ (B = Fe, Co, Ni) have been investigated by means of temperature-programmed reduction, isothermal reduction and X-ray diffraction methods. Nominal composition of $LaFeO_{3.18},\;LaCoO_{3.00}\;and\;LaNiO_{2.92}$ are determined. Reduction reaction of these mixed oxides differed according to B-site transition metal and thermal stability on reduction decreased as following order: $LaFeO_{3.18}$ > $LaCoO_{3.00}$ > $LaNiO_{2.92}$. From the results of isothermal reaction, kinetics on reduction of the perovskite has been discussed in detail.

• Iberoamérica
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• v.13 no.1
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• pp.255-286
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• 2011

Las fronteras de México. Guatemala y Belize se formaron cuando se indepedizaron desde España. Generalmente se adaptaron la división establecida durante la época colonial. Sin embargo, se han sucedido varios incidentes para alterarla. Uno de los incidentes más importantes fue 'la Guerra de Castas de Yucatán'. Los mayas aprovecharon esa oportunidad para expresar sus resentimientos que se formaron bajo el sistema colonial. Las rebeliones mayas ocuparon la parte oriente de la península y se formaron un país independiente que se duró más de 50 años. Para apacificar esta gran rebelión de los mayas indígenas, el gobierno mexicano dejó de perder el territorio de Belize que mantenía su soberania durante pasados tres siglos. Finalmente se formaron la frontera con Belize.

• Journal of the Korean Institute of Landscape Architecture
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• v.25 no.3
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• pp.66-88
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• 1997

There is no special law of Landscape architecture in Korea. So, examining the concept from the legal basis of LA with the viewpoint of a natural scientist not a jurist, this study was conducted to grasp the present condition of the name and the related text of the foreign laws in force which were connected with LA.. And those foreign laws were arranged in the name and the text and classified by nations of regional groups and it was considered to the mutual relation with lots of laws which are scattered with the various laws. Current domestic regulations to the various fields of LA are assembled with the many related rules. The governmental organization conducting those business is nonexistent up to now and it is generally known to except the dept. of LA from the office organization in Korea. Being at a disadvantage as mentioned above, this study was progressed under the necessity of the scientific basis for the expected organic law of LA proposed to establish it by every field of LA. Though feels inconvenience if the study for the items itself of LA had been proceeded prior to the study of laws relating to LA throughout the study, such a extensive study will be a subject to be attempted constantly hereafter by all part of landscape architects. The contents of the study are as follows ; 1. The present condition of the foreign laws connected with LA 1. The proposal & analysis of the problems and the solutions to the domestic laws connected with LA 3. The proposal of the reasonable application pklan in order to establish the organic law for LA. Among the items relating to LA such as engineer, contract, planning, design and supervision, construction, maintenance, plant and planting, open space, facilities, aesthetics and sight, park, land use and development planning, urban and regional planning, leisure space planning, environmental conservation and ecology, structural engineering of construction, administration, right and penal regulations, the laws dealing with the matter relating to LA directly or indirectly are prescribed dispersedly in the many other related laws and it is concluded to be impossible for the independent law of LA is likely to be establish with not only selecting and arranging the matter having closed connections to LA directly but also being recognized as the systematic equipment of the LA business. It was to be analyzed the present condition of the collected foreign laws relating to LA. After pointing out the problems to the domestic related laws being at issue, the remedies for it were presented through the questionnaire of the landscape specialist in which the supporting opinions to the recognition to the problems and the solutions were come to a major portion. Three types of application such as applicable, non-applicable, applicable after examination were presented to decide whether or not the foreign related laws were applied to the domestic one. The result of analysis shows that 42 statutes and 9 ordinances are applicable, 4 statutes and 7 ordinances are non-applicable, 1 constitution, 81 statutes and 48 ordinances are applicable after examination.

• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.145-149
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• 2015

The electrochemical behavior of $Nd_2O_3-La_2O_3-NiO$ mixed oxide including rare earth resources has been studied to synthesize $La_{0.5}Nd_{0.5}Ni_5$ alloy in a LiCl molten salt. The $Nd_2O_3-La_2O_3-NiO$ mixed oxide was converted to $NiNd_2O_4$ (spinel) and $LaNiO_3$ (perovskite) structures at a sintering temperature of $1100^{\circ}C$. The spinel and perovskite structures led a speed-up in the electrolytic reduction of the mixed oxide. Various reaction intermediates such as Ni, $NiLa_2O_4$ were observed during the electrochemical reduction by XRD analysis. A possible reaction route to $La_{0.5}Nd_{0.5}Ni_5$ in the LiCl molten salt was proposed based on the analysis result.