• Title/Summary/Keyword: EU school

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Luminescence Wavelength Control of $CaAlSiN_3:Eu^{2+}$ by Ca-replacing: Computational and Experimental Study

  • Onuma, Hiroaki;Suehiro, Takayuki;Suzuki, Ai;Tsuboi, Hideyuki;Hatakeyama, Nozomu;Endou, Akira;Takaba, Hiromitsu;Kubo, Momoji;Sato, Tsugio;Miyamoto, Akira
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.290-293
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    • 2009
  • We both theoretically and experimentally investigated the luminescence wavelength control of the $Eu^{2+}$-doped $CaAlSiN_3$ (CASN:$Eu^{2+}$). To modify emission wavelength, Na-doped and Mg-doped CASN:$Eu^{2+}$ (NCASN:$Eu^{2+}$ and MCASN:$Eu^{2+}$) have been studied. According to quantum chemistry calculation result, we synthesized NCASN:$Eu^{2+}$ and MCASN:$Eu^{2+}$. NCASN:$Eu^{2+}$ and MCASN:$Eu^{2+}$ showed shorter emission wavelength than that of CASN:$Eu^{2+}$.

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Apoptotic Effects of Eugenol-loaded Nanoemulsions in Human Colon and Liver Cancer Cell Lines

  • Majeed, Hamid;Antoniou, John;Fang, Zhong
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.21
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    • pp.9159-9164
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    • 2014
  • Background: In this study eugenol (EU) loaded nanoemulsions (NEs) emulsified with modified starch were prepared and their apoptotic potential against liver and colon cancer cells was examined in comparison with bulk EU. Materials and Methods: We prepared stable EU loaded NEs whcih were characterized by dynamic light scattering, centrifugation and gas chromatography. Furthermore, cell viability was determined using MTT assay, and apoptosis and cell cycle analysess by flow cytometry. Results: HB8065 (liver) and HTB37 (colon) cells when treated with EU:CA NEs demonstrated greater apoptotic cells percentages as evidenced by microscopic images and flow cytometric evaluations. It was observed that EU and EU:CA NE induced apoptosis in both cell lines via reactive oxygen species (ROS) generation. Conclusions: The present study demonstrated that ROS plays a critical role in EU and EU:CA NE induced apoptosis in HB8065 and HTB37 cells. This is the first report on the antiproliferative mechanisms of EU loaded NE.

Expression of EuNOD-ARP1 Encoding Auxin-repressed Protein Homolog Is Upregulated by Auxin and Localized to the Fixation Zone in Root Nodules of Elaeagnus umbellata

  • Kim, Ho Bang;Lee, Hyoungseok;Oh, Chang Jae;Lee, Nam Houn;An, Chung Sun
    • Molecules and Cells
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    • v.23 no.1
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    • pp.115-121
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    • 2007
  • Root nodule formation is controlled by plant hormones such as auxin. Auxin-repressed protein (ARP) genes have been identified in various plant species but their functions are not clear. We have isolated a full-length cDNA clone (EuNOD-ARP1) showing high sequence homology to previously identified ARP genes from root nodules of Elaeagnus umbellata. Genomic Southern hybridization showed that there are at least four ARP-related genes in the genome of E. umbellata. The cDNA clone encodes a polypeptide of 120 amino acid residues with no signal peptide or organelle-targeting signals, indicating that it is a cytosolic protein. Its cytosolic location was confirmed using Arabidopsis protoplasts expressing a EuNOD-ARP1:smGFP fusion protein. Northern hybridization showed that EuNOD-ARP1 expression was higher in root nodules than in leaves or uninoculated roots. Unlike the ARP genes of strawberry and black locust, which are negatively regulated by exogenous auxin, EuNOD-ARP1 expression is induced by auxin in leaf tissue of E. umbellata. In situ hybridization revealed that EuNOD-ARP1 is mainly expressed in the fixation zone of root nodules.

Effects of Oxygen and Alkaline Earth Atoms on Emission Wavelength of $Eu^{2+}$-doped Oxide Phosphor: A Computational Chemistry Study

  • Onuma, Hiroaki;Yamashita, Itaru;Serizawa, Kazumi;Suzuki, Ai;Tsuboi, Hideyuki;Hatakeyama, Nozomu;Endou, Akira;Takaba, Hiromitsu;Kubo, Momoji;Miyamoto, Akira
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.294-297
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    • 2009
  • We computationally investigated the effects of oxygen and alkaline-earth on the emission wavelength of the $Eu^{2+}$-doped oxide phosphor. Using QSPR method, we found that the oxygen and alkaline-earth atom around the Eu atom increase and decrease the emission wavelength, respectively. We also investigated the $Eu^{2+}$-doped sulfide, nitride, and oxynitride phosphors.

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Optimization red emission of SrMoO4: Eu3+ via hydro-thermal co-precipitation synthesis using orthogonal experiment

  • Tan, Yongjun;Luo, Xuedan;Mao, Mingfu;Shu, Dehua;Shan, Wenfei;Li, Guizhi;Guo, Dongcai
    • Current Applied Physics
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    • v.18 no.11
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    • pp.1403-1409
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    • 2018
  • In the present study, the $SrMoO_4:Eu^{3+}$ phosphors has been synthesized through hydro-thermal co-precipitation method, and single factor and orthogonal experiment method was adopted to find optimal synthesis condition. It is interesting to note that hydro-thermal temperature is a prominent effect on the luminescent intensity of $SrMoO_4:Eu^{3+}$ red phosphor, followed by co-precipitation temperature, calcining time, and the doping amount of $Eu^{3+}$. The optimal synthesis conditions were obtained: hydro-thermal temperature is $145^{\circ}C$, co-precipitation temperature is $35^{\circ}C$, the calcining time is 2.5 h, and the doping amount of activator $Eu^{3+}$ is 25%. Subsequently, the crystalline particle size, phase composition and morphology of the synthesized phosphors were evaluated by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The results show that these phosphors possess a scheelite-type tetragonal structure, and the particle size is about $0.2{\mu}m$. Spectroscopic investigations of the synthesized phosphors are carried out with the help of photo-luminescence excitation and emission analysis. The studies reveal that $SrMoO_4:Eu^{3+}$ phosphor efficiently convert radiation of 394 nm-592 and 616 nm for red light, and the luminescence intensity of $SrMoO_4:Eu^{3+}$ phosphors is improved. $SrMoO_4:Eu^{3+}$ phosphors may be a potential application for enhancing the efficiency of white LEDs.

Luminescence of $Eu^{3+}$ and $Sm^{3+}$ Doped Potassium Tungstate Phosphor

  • Lee, Gwan-Hyoung;Kim, Tae-Hyung;Kang, Shin-Hoo
    • Journal of Information Display
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    • v.6 no.2
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    • pp.25-29
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    • 2005
  • The luminescent properties of $Eu^{3+}$ and $Sm^{3+}$ doped potassium tungstate phosphor are investigated. The $K_{4-3x}(WO_4)_2:Eu^{3+}\;_x,Sm^{3+}\;_y$ phosphor is produced by firing the mixed precursors, followed by re-firing with a flux. The re-firing process results in the defect-free surface and uniform growth of the particles. The strong absorption in the region of ultra violet light is observed due to the 4f-4f electron transitions of the $Eu^{3+}$ and $Sm^{3+}$ ions. The doping concentration of europium into potassium tungstate is relatively high, compared to other host materials. It is revealed that the crystal structure is a monoclinic with space group, C2/c. This crystal structure facilitated the $Eu^{3+}$ ions to be located with the Eu-Eu distance larger than 5 ${\AA}$ so that concentration quenching does not occur even at high doping concentration. The excitation spectrum could be adjusted by the introduction of the samarium. A small amount of the $Sm^{3+}$ ions that acts as a sensitizer increases the energy absorption peak around 405 nm.

Luminescence characterization of $YVO_4$: $Eu^{3+}$, $Bi^{3+}$ red phosphor by rapid microwave heating synthesis (급속 microwave 열처리 방법으로 합성한 $YVO_4$: $Eu^{3+}$, $Bi^{3+}$ 적색 형광체의 발광 특성)

  • Park, W.J.;Song, Y.H.;Moon, J.W.;Yoon, D.H.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.18 no.4
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    • pp.169-173
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    • 2008
  • $Eu^{3+}$ and $Bi^{3+}$ co-doped $YVO_4$ phosphors were produced by a microwave heating process. When the microwave heating method was synthesized,. the particle size was very small and the particles tended to agglomerate. However, as the heating time increased, the particle size increased and the agglomeration decreased. The emission spectrum exhibited a weak band for $^5D_0{\longrightarrow}^7F_1$ at 594.91 and 602.3 nm and strong sharp peaks at 616.7 and 620.0 nm due to the $^5D_0{\longrightarrow}^7F_2$ transition of $Eu^{3+}$. Microwave heating synthesis can provide a product without long time heating as well as good homogeneous distribution of activators.

Asymmetry Ratio and Emission Properties of YVO4:Eu3+ Red Phosphors Synthesized by Solid-state Reaction Method (고상법으로 합성한 YVO4:Eu3+ 적색 형광체의 비대칭비와 발광 특성)

  • Jang, Jae-Young;Ahn, Se-Hyeok;Bang, Jun-Hyuk;Ma, Kwon-Do;Kim, Choon-Soo;Cho, Shin-Ho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.4
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    • pp.298-303
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    • 2012
  • $Y_{1-x}VO_4:Eu_x^{3+}$ red phosphors were synthesized with changing the mol ratios of $Eu^{3+}$ ions by using the solid-state reaction method. The crystalline structure of phosphors was found to be a tetragonal system with the maximum diffraction intensity at $25.02^{\circ}$. The grain particles showed the truncated hexagonal patterns with a very homogeneous size distribution at 0.05 mol of $Eu^{3+}$ ion. The excitation spectra of the phosphor ceramics were composed of a broad band centered at 303 nm and weak narrow multilines peaked in the range of 360-420 nm. The dominant emission spectrum was the strong red emission centered at 619 nm due to the $^5D_0{\rightarrow}^7F_2$ electric dipole transition. The experimental results suggest that the optimum doping mol ratio of $Eu^{3+}$ ions for preparing the red phosphors is 0.10 mol with the asymmetry ratio of 5.21.

A Study on EU Anti-dumping Law (EU 반덤핑법에 관한 소고)

  • Kim, Do-Hyoung
    • Management & Information Systems Review
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    • v.21
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    • pp.77-98
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    • 2007
  • This thesis is related with Anti-dumping law about Korea's export in EU. Indeed, Korea' export to EU market is how related to EU's Anti-dumping law this study was intended to reveal from a legal point of view. For this purpose from EU's Anti-dumping law's institution at present to application historical channel was examined and is showed Anti-dumping law's application procedure briefly. Throughout this study what we could get are EU's Anti-dumping law based on a statute, EU's Anti-dumping law's institution background and the law's application procedure & effects.

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A Comparative Study of EU and Japan ETS for Activation in Korean GHG Emission Trading System (한국형 온실가스 배출권 거래제도 활성화를 위한 EU 및 일본 사례 비교 연구)

  • Lee, Jeong Eun;Cho, Yongsung;Lee, Soo-Cheol
    • Journal of Climate Change Research
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    • v.6 no.1
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    • pp.11-19
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    • 2015
  • This study has aimed to compare an emission trading system (ETS) in the EU and Japan that introduced the scheme prior to Korea and provided the latter with a benchmarking model. Especially, the EU has a reputation for its well-organized and evolving system, and Japan has also successfully established the system despite its similar condition with Korea, such as an industrial structure and the degree of energy dependence. However, there are noticeable differences between the EU and Japan in their ETS. Whereas Japan has focused on securing certifications in CDM as the implementation of Kyoto protocol, EU has shown a tendency to transform the trading market from a parallel structure of EUA and CER transaction to only the EUA transaction after ending of 1st commitment period of the Kyoto Protocol. Since the differences were mainly caused by not only in a design of the system but also in internal governance and their national circumstance, it is meaningful to analyse the Korean case with a similar framework. This study may contribute to designing an appropriate system for emission trading in Korea through the comparison of the EU and Japanese case.