• Title/Summary/Keyword: K doping

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Effect of Doping Elements on Superconducting Characteristics in Bi-system Ceramics (Bi계 세라믹에서 초전도체 특성에 미치는 도우핑 원소의 영향)

  • 양승호;박용필;김용주
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.198-203
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    • 2000
  • This paper investigated the effects of doping elements on the Bi-Sr-Ca-Cu-O ceramics. The doping elements can be classified into four groups depending on their superconducting characteristics in the Bi-Sr-Ca-Cu-O structure. The first group of doping elements(Co, Fe, Ni and Zn) substitute into the copper site and can reduce the critical temperatures of the 2223 and 2212 phases. The second group of doping elements(Y and La) substitute into the Ca site and cause the disappearance of the 2223 phase and increase the critical temperatures in the 2212 phase. The third group of doping elements(P and K) have a tendency to decompose the superconducting phase and reduce the optimal sintering temperature. The fourth group of doping elements(B, Si, Sn and Ba) almost unaffected the superconductivity of the 2223 and 2212 phase.

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Deping characteristics of the Bi-Sr-Ca-Cu-O ceramics (Bi-Sr-Ca-Cu-O 세라믹의 도우핑 특성)

  • 박용필;김영천;황석영
    • Electrical & Electronic Materials
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    • v.9 no.1
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    • pp.1-8
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    • 1996
  • We investigated the effects of doping elements on the Bi-Sr-Ca-Cu-O ceramics. The doping elements can be classified into four groups depending on their supeconducting characteristics in the Bi-Sr-Ca-Cu-O structure. The first group of doping elements(Co, Fe, Ni and Zn) substitute into the copper site and can reduce the critical temperatures of the 2223 and 2212 phases. The second group of doping elements(Y and La) substitute into the Ca site and cause the disappearance of the 2223 phase and increase the critical temperatures in the 2212 phase. The third group of doping elements(P and K) have a tendency to decompose the superconducting phase and reduce the optimal sintering temperature. The fourth group of doping elements(B, Si, Sn and Ba) almost unaffected the superconductivity of the 2223 and 2212 phase.

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Effect of Recombinant Bovine Somatotropin (${\gamma}$ bST) Administration on bST Levels in Milk of Cows

  • Park, Jeongeun;Park, Myung-Ja;Jaeho Chin;Park, Jongsei;Kim, Jooho
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1995.04a
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    • pp.127-127
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    • 1995
  • The present study was conducted to examine the effect of recombinant bovine somatotropin(${\gamma}$ bST), which was administered to cow to promote milk production, on bST levels in milk. Fourteen cows were divided into two groups: 1) control cows received neither y bST nor vehicle, 2) treated cows were administered twice at two-week interval with 500mg ${\gamma}$ bST each cow by subcutaneous injection. Milk samples were taken on day 0 (prior to injection), day 7 (7 days after 1st injection), day 21 (7 days after 2nd injection) and day 35 (21 days after 2nd injection).

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Molecular Analysis using High Performance Capillary Electrophoresis

  • Yoo, Young Sook;Ban, Eun Mi;Kim, Young Sook;Han, Yeosun;Park, Jongsei
    • Analytical Science and Technology
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    • v.8 no.4
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    • pp.881-886
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    • 1995
  • Several forms of gangliosides have been separated from various types of biological matrices using cyclodextrin-modified capillary zone electrophoresis (CZE). Quantitative analysis of phospholipids from biological fluids was achieved by micellar electrokinetic capillary chromatography (MECC) using 35mM sodium dodecyl sulfate. Phosphorylation, one of the most important post-translational modifications of proteins at serine, threonine and tyrosine residues in small peptides were identified and quantitative analyses of phosphopeptides were performed. Seven different neuropeptides which are relative the pain reachanism in the vertebrate central nervons system were also separated by CZE.

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Doping Control in ZnO Nanowires Employing Hot-Walled Pulsed Laser Deposition (Hot-Walled PLD를 이용한 ZnO 나노와이어의 도핑 제어)

  • Kim, Kyung-Won;Lee, Se-Han;Song, Yong-Won;Kim, Sang-Sig;Lee, Sang-Yeol
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.5-5
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    • 2008
  • We design and demonstrate the controled doping into ZnO nanowires (NWs) adopting self-contrived hot-walled pulsed laser deposition (HW-PLD). Optimized synthesis conditions with the diversified dopants guarantee the excellent crystalinity and morphology as well as electrical properties of the NWs. Proprietary target rotating system in the HW-PLD fuels the controlled formation and doping of the NWs. Prepared NWs sensitive to the environment are systematically characterized, and the doping mechanism is discussed.

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Simultaneous Determination of Synthetic Phosphodiesterase-5 Inhibitors in Dietary Supplements by Liquid Chromatography-High Resolution/Mass Spectrometry

  • Kim, So-Hee;Kim, Ho-Jun;Son, Jung-Hyun;Jeon, Byoung-Wook;Jeong, Eun-Sook;Cha, Eun-Ju;Lee, Jae-Ick
    • Mass Spectrometry Letters
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    • v.3 no.2
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    • pp.50-53
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    • 2012
  • After success of sildenafil for the treatment of erectile dysfunction, a large number of its analogues have been approved from FDA. Recently, the illegal dietary supplements which include sildenafil, vardenafil, tadalafil, or analogues of these drugs as ingredient have been widely distributed. Therefore, the determination of the residue of synthetic phosphodiesterase- 5 (PDE-5) inhibitors in dietary supplements is highly required due to indiscriminate and unintentional overdose caused nausea, chest pains, fainting and irregular heartbeat. In this paper, we report a rapid and sensitive analytical method for the simultaneous determination of nine phosphodiesterase-5 inhibitors by liquid chromatography-high resolution mass spectrometry. The present method was found to be accurate and reproducible with 40 ${\mu}g$/g of the limit of quantification for the nine PDE-5 inhibitors. The developed method can be successfully applied to the analysis of the seven illegal dietary supplements.

Performance Characteristic of the β-Human Chorionic Gonadotropin Assay on the Access 2 for Its Use in Doping Control

  • Kang, Min-Jung;Lee, Hye-Im;Shin, Sang-Mi;Yoo, Hye-Hyun;Kwon, Oh-Seung;Jin, Chang-Bae;Chung, Bong-Chul
    • Bulletin of the Korean Chemical Society
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    • v.31 no.10
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    • pp.2889-2892
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    • 2010
  • The objective of this study was to validate performance characteristics of the Access 2 (Beckman coulter) system for hCG assays for use as a confirmation test for doping control. The Access 2 assay was linear up to 500 IU/L. The correlation coefficient was higher than 0.999, and the sensitivity of the linearity was 0.82. There were no false positive or false negative cases. LOD was 0.59 IU/L. The method was robust when performed by different people. Repeatability and reproducibility were below 7%. We compared reproducibility and recoveries of Access 2 and Elecsys 2010. Access 2 demonstrated higher reproducibility than Elecsys 2010. Recoveries (accuracy) of Access 2 were between 85 and 105%. Recoveries for Elecsys 2010 were between 91 and 104%.

Fluorine-Doping Effect on Structural and Optical Properties of ZnO Nanorods Synthesized by Hydrothermal Method

  • Yoon, Hyunsik;Kim, Ikhyun;Kang, Daeho;Kim, Soaram;Kim, Jong Su;Lee, Sang-Heon;Leem, Jae-Young
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.204.1-204.1
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    • 2013
  • Fluorine, the radius of which is close to that of oxygen, could be an appropriate anion doping candidate. A lower lattice distortion could be expected for F doping, compared with Al, Ga, and In doping. F-doped ZnO (FZO) and undoped ZnO nanorods were grown onto glass substrate by the hydrothemal method. The doping level in the solution, designated by F/Zn atomic ratio of was varied from 0.0 to 10.0 in 2.0 steps. To investigate the effects of the structure and optical properties of FZO nanorods were investigated using X-ray diffraction, UV-visible spectroscopy and photoluminescence (PL). For the PL spectra, the maximum peak position of NBE moves to higher energy, from 0 to 4 at.%. As the doping concentration increases, the maximum peak position of NBE gradually moves to lover energy, from 4 to 10 at.%.

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