• Title/Summary/Keyword: La

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A Study on the Dry Matter Yield and Nutritive Values of Wild Korean Lespedeza(Lespedeza Stipulacea Maxim.) (야생 코리언 레스페데자(Lespedeza stipulacea Maxim.)의 건물수량 및 사료가치에 관한 연구)

  • Lee, In D.;Lee, H.S.;Kim, D.S.
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.19 no.3
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    • pp.189-196
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    • 1999
  • This study was conducted to evaluate the dry matter yield, quality and utilization of nutrients of wild Korean lespedeza as a forage legume sources. Dry matter(DM) yield of stages, chemical composition and DM digestibility were observed, also DM intake, digestibility and utilization of nitrogen and energy by Korean native goats were determined. Experimental diets include three treatrnents ; mixture grass hay(GS), GS 80% + lespedeza(LA) 20% and GS 60% + LA 40%, respectively. The DM yield of Korean lespedeza(LA) with advancing the growing stage tended to significantly increase(P<0.05). The average DM yield was observed 7,336kg/ha. CP content of LA tended to decrease, but fiber content tended to increase at growing stage advanced(P<0.05). The tannin content of LA was highest in bud stage (54.5mg/g), but tended to decrease at growing stage advanced, lowest in seed ripe stage(26.8mg/g) (P<0.05). With increasing the level of LA supplementation, DM intake by Korean native goats slightly increased, but no differences were observed in all diets. The digestibility of DM, cellular constituents and NDF were slightly lower for GS 100% diets than LA 20% and 40% supplemented diets(P<0.05). Apparently digested N% was not detected significant differences in all diets, but retained N and biological value were higher for LA supplemented diets than for GS 100% diets (P<0.05). Utilization of DE and ME was not detected significant differences in all diets. Above the results, it could be suggested that LA have a potential to provide as forage legume sources considering the DM yield, DM digestibility and nitrogen utilization.

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Investigation of the La1-x(Ca or Sr)xCrO3x=0 and 0.25) Interconnect Materials for High Temperature Electrolysis of Steam (고온수증기전기분해용 La1-x(Ca or Sr)xCrO3(x=0 and 0.25) 연결재 재료 연구)

  • Jeong, So-Ra;Kang, Kyoung-Soo;Park, Chu-Sik;Lee, Yong-Taek;Bae, Ki-Kwang;Kim, Chang-Hee
    • Korean Chemical Engineering Research
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    • v.46 no.6
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    • pp.1135-1141
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    • 2008
  • The $La_{1-x}(Ca\;or\;Sr)xCrO_3$(x=0 and 0.25) interconnect materials for high temperature electrolysis of steam were investigated in views of sinterability and electrical conductivity. $LaCrO_3$, $La_{0.75}Ca_{0.25}CrO_3$ (LCC), and $La_{0.75}Sr_{0.25}CrO_3$ (LSC) powders were synthesized by coprecipitation method. Crystal structure was confirmed by X-ray diffraction (XRD). The sintering characteristics were analyzed by relative density and scanning electron microscopy. The electrical conductivity was measured by a DC four probe method. From the analyses of relative densities, it was found that the doped $LaCrO_3$ showed better sinterability than $LaCrO_3$ and the those sinterability increased with decrease of those particle sizes. The XRD results at different sintering temperatures for LCC and LSC revealed that the sinterability is closely related to the second phase transformation, that is, the second phase melting above $1,300^{\circ}C$ for LCC and $1,400^{\circ}C$ for LSC significantly promotes the sinterability. In case of electrical conductivities of LCC and LSC, which had a similar relative density, LCC showed better electrical conductivity than LSC.

Mössbauer Studied of Multiferroic Bi2/3La1/3FeO3 Nanoparticles (Multiferroic Bi2/3La1/3FeO3 나노입자의 Mössbauer 연구)

  • Lee, Seung-Wha
    • Journal of the Korean Magnetics Society
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    • v.16 no.1
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    • pp.28-33
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    • 2006
  • La substituted perovskite $BiFeO_3$ have been prepared by a sol-gel method. Magnetic and structural properties of the powders were characterized with Mossbauer spectroscopy, XRD, SEM, and TG-DTA. The crystal structure is found to be a rhombohedrally distorted perovskite structure with the lattice constant $\alpha=3.985{\AA}\;and\;\alpha=89.5^{\circ}.\;Bi_{2/3}La_{1/3}FeO_3$ powders that were annealed at and above $600^{\circ}C$ have a single-phase perovskite structure. However, powders annealed at $900^{\circ}C$ have a typical perovskite structure with small amount of $Bi_2O_3$ phase. The Neel temperature of $Bi_{2/3}La_{1/3}FeO_3$ is found to be $680\pm3K$. The isomer shift value at room temperature is found to be 0.27 mm/s relative to the Fe metal, which is consistent with high-spin $Fe^{3+}$ charge states. Debye temperature far$Bi_{2/3}La_{1/3}FeO_3$ is found to be $305\pm5K$. The average hyperfine field $H_{hf}(T)$ of the $Bi_{2/3}La_{1/3}FeO_3$, shows a temperature dependence of $[H_{hf}(T)-H_{hf}(0)]/H_{hf}(0)=-0.42(T/T_N)^{3/2}-0.13(T/T_N)^{5/2}$ for $T/T_N<0.7$ indicative of spin-wave excitation.

Effects of Different Dietary Fats and Fibers on the Lipid Concentrations of Liver and Serum and Biochemical Index in Rats (흰쥐의 간장 및 혈청 지질농도와 임상생화학적 지표에 미치는 식이섬유 및 식이지방 급원을 달리한 식이 투여의 영향)

  • 차재영;홍상식;조영수;김대진
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.8
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    • pp.1377-1384
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    • 2003
  • This study investigated the effects of different types of dietary fats and fibers on the concentrations of serum and liver lipids and biochemical index in male Sprague-Dawley rats for 6 weeks. The experimental groups were divided into three groups; 5% corn oil +5% cellulose (CO group),10% corn oil +10% psyllium husk (CO +PH group) and 10% lard +10% psyllium husk (LA+ PH group). Body weight gain and FER (food efficiency ratio%) decreased significantly in the LA+PH group and decreased slightly in the CO+PH group compared with the CO group. Food intake and tissue weights were not significantly different among the dietary groups. Concentrations of serum total cholesterol decreased significantly in the CO + PH group compared with the CO group, but no significant different in the LA + PH group. Concentrations of serum triglyceride and phospholipid decreased significantly in the CO+PH and the LA+PH groups compared with the CO group. Liver cholesterol concentration was significantly decreased in the LA+PH group compared with the CO and the CO+PH groups. Glutamic pyruvic transaminase activity was significantly increased in the LA + PH group compared with the CO and the CO + PH groups. However, lactate dehydrogenase and blood urea nitrogen was significantly decreased in the LA+ PH group compared with the CO and the CO +PH groups. The others biochemical parameters, total protein, albumin, glucose, glutamic oxaloacetic transaminase, alkaline phosphatase were not significantly different among the dietary groups. These results showed that the lowering effect of dietary psyllium husk on serum lipid concentrations was more pronounced in the corn oil -feeding group than in the lard-feeding group as dietary fat source.

The effect of Thermal Distribution on $LaSc_3(BO_3)_4$ Crystal Growth by Cz Method ($LaSc_3(BO_3)_4$ 단결정 성장조건)

  • 장영남;배인국
    • Korean Journal of Crystallography
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    • v.9 no.1
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    • pp.21-29
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    • 1998
  • The rare-earth orthoborate family, RM3(BO3)4 is known to be the most promising material for the microlaser host. To grow LaSc3(BO3)4 single crystal, the phase relation of the system LaBO3-ScBO3 was investigated by DTA method. LaSc(BO3)4 was the unique intermediate compound in the binary system the peritectic reaction point of which was 1495 ±2℃. Owing to the peritectic behavior of the compound, the crystal growth of the rare-earth Sc-borate was carried out by pulling from the melt-soultion of La1+xSc3-x(BO3)4. The optimal conditions for the growth of LaSc3(BO3)4 were determined by traditional CZ method : pulling speed 0.7mm/hr, rotation speed 7-10 rpm under reduction condition. Pt and Ir crucibles could be used for about 8-10 times of growth. The effect of thermal configurations on the temperature distribution was investigated. A special two-coordinate manipulator was made for the precise movement of thermocouples from the melt to the top of the furnace for several thermal configurations. The radial gradient on the melt surface depends strongly on the construction of the afterheater. On the other hand, the axial gradient was mainly propotional to both the opening degree of baffle plate and the mutual positions of crucible and heater.

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Titre- l'économie trans libidinale-homo surplus (트랜스 리비도 경제학 - Homo surplus)

  • Yun, Ji-yeong
    • Journal of Korean Philosophical Society
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    • v.126
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    • pp.191-212
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    • 2013
  • Cet article consiste ${\grave{a}}$ critiquer $l'{\acute{e}}conomie$ libidinale, $subordonn{\acute{e}}e$ ${\grave{a}}$ l'ordre phallique qui coupe les flux libidinaux. La notion lacanienne du $d{\acute{e}}sir$ qui est $focalis{\acute{e}}e$ sur le manque, ne pourrait prendre en compte la dimension $cr{\acute{e}}ative$ et productive du $d{\acute{e}}sir$ qui est $li{\acute{e}}e$ ${\grave{a}}$ la perspective deleuzienne et guattarienne du $d{\acute{e}}sir$. La $possibilit{\acute{e}}$ de la $d{\acute{e}}rive$ et de la $d{\acute{e}}stratification$ des flux libidinaux pourrait se mener vers la notion du "homo surplus", laquelle est la notion $in{\acute{e}}dite$ que j'ai $cr{\acute{e}}e$. Le surplus est ce qui $d{\acute{e}}passe$ la logique phallogocentrique par son $immensurabilit{\acute{e}}$ et sa surabondance. Dans cette perspective, la critique virulente de la notion du plaisir $cantonn{\acute{e}}$ dans la partie $g{\acute{e}}nitale$, $s^{\prime}op{\grave{e}}re$ avec l'analyse de la jouissance qui est non phallique; Cette jouissance non phallique est $li{\acute{e}}e$ ${\grave{a}}$ l'agencement non $lin{\acute{e}}aire$ et multiple des pratiques sexuelles $in{\acute{e}}dites$ et radicales.

The Effect of La Concentration on The PLZT(x/30/70) Thin Films for NVRAM Memory Device (비휘발성 메모리 소자를 위한 PLZT(x/30/70) 박막에 대한 La 농도변화의 효과)

  • 김성진;윤영섭
    • Proceedings of the IEEK Conference
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    • 2000.06b
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    • pp.28-31
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    • 2000
  • In this paper, the effects of La addition of PLZT(x/30/70) thin films Prepared by sol-gel method are investigated for NVFRAM application. The tetragonality (c/a), the grain size, and the surface roughness of PLZT thin films decrease with an increase of La concentration. As the La concentration increases, the dielectric constants at 10 kHz increase from 450 to 600, while the loss tangent decrease from 0.075 to 0.025. Also, the leakage current density at 100kV/cm decrease from 5.83$\times$10$^{-7}$ to 1.38$\times$10$^{-7}$ 4/$\textrm{cm}^2$. In the results of hysteresis loops measured at $\pm$170kV/cm, the remanent polarization and the coercive field of PLZT thin films with La concentration from 0 to 10㏖% decrease from 20.8 to 10.5 $\mu$C/cm and from 54.48 to 32.12kV/cm, respectively. After a fatigue measurement by applying 10$^{9}$ square pulses with $\pm$5V, the remanent polarizations of PLZT thin films with 0 and 10㏖% La concentration decrease about 64 and 42 % from initial state. In the results of retention measurement after 10$^{5}$ s, PLZT thin films with 0 to 10mo1% La concentration show that the remanent polarization is decreased about 43% and 9% from initial state, respectively.

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Enhanced Photocatalytic Properties of Visible Light Responsive La/TiO2-Graphene Composites for the Removal of Rhodamin B in Water

  • Areerob, Yonrapach;Oh, Won-Chun
    • Journal of the Korean Chemical Society
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    • v.61 no.4
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    • pp.168-178
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    • 2017
  • $La/TiO_2$ - graphene composites were synthesized in this study, and applied to the photocatalytic degradation of Rhodamine B (RhB) under UV-visible light irradiation. X-ray diffraction (XRD), surface analysis, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), and Transmission electron microscopy (TEM) analysis demonstrated that $La/TiO_2$ nanoparticles were well distributed on the surface of graphene, and formed the heterostructure of $La/TiO_2$-graphene. Compared to the pure $TiO_2$, $La/TiO_2$-graphene composites displayed much higher photocatalytic activities in RhB degradation under UV-visible light irradiation. The photocatalytic data of $La/TiO_2$-graphene composites exhibit extended light absorption in the visible light region, and possess better charge separation capability than that of pure $TiO_2$. The high photocatalytic activity was attributed to the composite's high adsorptivity, extended light absorption, and increased charge separation efficiency, due to the excellent electrical properties of graphene, and the large surface contact between graphene and $La/TiO_2$ nanoparticles.

Synthesis and luminescence properties of lanthanum oxides/hydroxides nanorod bundles

  • Hussain, Sk. Khaja;Raju, G. Seeta Rama;Yu, Jae Su
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.171.2-171.2
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    • 2015
  • Nowadays, trivalent rare-earth ($RE^{3+}$) ions activated metal oxides have been proved to be excellent host materials due to their various applications. Facile wet-chemical technique have been considered as the best synthetic route due its intensive interest in the preparation of nanostructures. Europium ion doped lanthanum hydroxide ($La(OH)_3:Eu^{3+}$) phosphors were synthesized by the facile wet chemical method using the hexamethylenetetramine (HMTA) as a mediated surfactant. The thermal behavior for the $La(OH)_3:Eu^{3+}$ phosphors was investigated by thermogravimetric and differential thermal analysis method. The morphological studies were measured by scanning electron microscope and transmission electron microscope measurements, indicating three-dimensional (3D) flower-like $La(OH)_3:Eu^{3+}$ nanorod bundles. After subsequent annealing process, the lanthanum oxide ($La_2O_3:Eu^{3+}$) phosphor exhibited similar kind of morphology. The synthesized $La(OH)_3:Eu^{3+}$ and $La_2O_3:Eu^{3+}$ samples were characterized by X-ray powder diffraction and Fourier transform infrared spectroscopy. Furthermore, photoluminescence and cathodoluminescence properties were studied in details.

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Fabrication and characteristics of La1-xSrxMO3(M = Fe, Co, Mn) formaldehyde gas sensors (La1-xSrxMO3(M = Fe, Co, Mn) 물질을 이용한 포름알데히드 가스센서의 제조와 특성)

  • Kim, H.J.;Choi, J.B.;Kim, S.D.;Yoo, K.S.
    • Journal of Sensor Science and Technology
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    • v.17 no.3
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    • pp.203-209
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    • 2008
  • Thick film formaldehyde (HCHO) gas sensors were fabricated by using $La_1_{-x}Sr_xMO_3$ (M= Fe, Co, Mn) ceramics. The powders of $La_1_{-x}Sr_xMO_3$ (M=Fe, Co, Mn) were synthesized by conventional solid-state reaction method. By using the $La_1_{-x}Sr_xMO_3$ (M=Fe, Co, Mn) paste, the thick-film formaldehyde sensors were prepared on the alumina substrate by silkscreen printing method. The experimental results revealed that $La_1_{-x}Sr_xMO_3$ (M= Fe, Co, Mn) ceramic powder has a perovskite structure and the thick-film sensor shows excellent gas-sensing characteristics to formaldehyde gas (sensitivity of $La_{0.8}Sr_{0.2}FeO_3$, S= 14.7 at operating temperature of $150^{\circ}C$ in 50 ppm HCHO ambient).