• Title/Summary/Keyword: HFA

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Optical Properties of $Yb(HFA-D)_3$ Complex for Laser Material (레이저 매질로서의 $Yb(HFA-D)_3$ 착물의 광학적 특성)

  • 김정호;박용필
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2000.11a
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    • pp.129-132
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    • 2000
  • Perdeuterated hexaflouroacetyIacetonato-ytterbium $[Yb(HFA-D)_3]$ complexes were synthesized by the keto-en01 tautomerism reaction of $Yb(HFA-D)_3$ in methanol-$d_4$ in order to reduce the radiationless transition to the ligands. The luminescence properties of $Yb(HFA-D)_3$ complex were measured in the following anhydrous deuterated organic solvents ; Acetone-$d_6$, Methanol -$d_4$, THF-$d_6$, PO$(OHC_3)_3$ and DMSO-$d_6$. The intensity, lifetime and quantum efficiency of the luminescence in DMSO-$d_6$ were superior to those in other deuterated solvents. It was suggested that the anhydrous DMSO-$d_6$ might be the most appropriate solvent for the liquid laser material of $Yb(HFA-D)_3$ complex.

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Optical Properties of $Yb(HFA-D)_{3}$ Complex for Laser Material (레이저 매질로서의 $Yb(HFA-D)_{3}$ 착물의 광학적 특성)

  • 김정호;박용필
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.129-132
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    • 2000
  • Perdeuterated hexafluoroacetylacetonato -ytterbium [$Yb (HFA -D)$_3$_3$] complexes were synthesized by the koto-enol tautomerism reaction of $Yb(HFA-H)_3$ in methanol-$d_4$, in order to reduce the radiationless transition to the ligands. The luminescence properties of $Yb(HFA-D)_3$ complex were measured in the following anhydrous deuterated organic solvents : Acetone-$d_6$, Methanol-$d_4$, THF-$d_8$, $PO(OC$H_3$)_3$ and DMSO-$d_6$. The intensity, lifetime and quantum efficiency of the luminescence in DMSO-$d_6$ were superior to those in other deuterated solvents. It was suggested that the anhydrous DMSO-d$_{6}$ might be the most appropriate solvent for the liquid laser material of $Yb(HFA-D)_3$ complex.x.

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Development of Yb(HFA-D)$_3$Complexes for Liquid Laser Material (액체 레이저 매질로서의 신물질 Yb(HFA-D)$_3$착물의 개발)

  • 김정호;박용필
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.12
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    • pp.1045-1050
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    • 2000
  • Perdeuterated hexaflouroacetylacetonato-ytterbium [Yb(HFA-D)$_3$]complexes were synthesized by the keto-enol tautomerism reaction of Yb(HFA-H$_3$) in methanol-d$_4$in rder to reduct the radiationless transition to the ligands. The luminescence properties of Yb(HFA-D)$_3$complex were measured in the following anhydrous deuterated organic solvents ; Methanol-d$_4$, THF-d$_{8}$, PO(O$CH_3$)$_3$and DMSO-d$_{6}$. The intensity, lifetime and quantum efficiency of the luminescnce in DMSO-d$_{6}$ were superior to those in other deuterated solvents. It was suggested that the anhydrous DMSO-d$_{6}$ might be the most appropriate solvent for the liquid laser material of Yb(HFA-D)$_3$complex.complex.

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Synthesis and Characterization of Volatile and Thermally Stable Europium β-Diketonate Complexes

  • 강성주;정영숙
    • Bulletin of the Korean Chemical Society
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    • v.18 no.1
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    • pp.75-80
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    • 1997
  • Preparation and properties of Eu(hfa)3·L (Hhfa = hexafluoroacetylacetone, L = bis(2-methoxyethyl)ether, diglyme, and 2, 2':6', 2"-terpyridine, tpy), which are potential CVD precursors for europium, were investigated. The reaction of the Eu2O3 with Hhfa in the presence of tridentate neutral ligand yielded the nine-coordinated Eu(hfa)3·L. Eu(hfa)3·diglyme is air- and moisture-stable and most importantly has good volatility and thermal stability. Eu(hfa)3·tpy shows no sublime intact. The complex Eu(hfa)3·diglyme has been characterized by an X-ray structure determination; monoclinic P21/n, a=10.252(1), b=16.051(6), c=19.392(8) Å, β=96.10(2)°, V=3173(2) Å3. The europium atom in Eu(hfa)3·diglyme adopts a square-antiprismatic geometry with the ninth coordinating oxygen atom capping one of the square faces. All the adducts have been characterized by IR, TGA/DTA.

PDAT1 genome editing reduces hydroxy fatty acid production in transgenic Arabidopsis

  • Mid-Eum Park;Hyun Uk Kim
    • BMB Reports
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    • v.57 no.2
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    • pp.86-91
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    • 2024
  • The fatty acids content of castor (Ricinus communis L.) seed oil is 80-90% ricinoleic acid, which is a hydroxy fatty acid (HFA). The structures and functional groups of HFAs are different from those of common fatty acids and are useful for various industrial applications. However, castor seeds contain the toxin ricin and an allergenic protein, which limit their cultivation. Accordingly, many researchers are conducting studies to enhance the production of HFAs in Arabidopsis thaliana, a model plant for oil crops. Oleate 12-hydroxylase from castor (RcFAH12), which synthesizes HFA (18:1-OH), was transformed into an Arabidopsis fae1 mutant, resulting in the CL37 line producing a maximum of 17% HFA content. In addition, castor phospholipid:diacylglycerol acyltransferase 1-2 (RcPDAT1-2), which catalyzes the production of triacylglycerol by transferring HFA from phosphatidylcholine to diacylglycerol, was transformed into the CL37 line to develop a P327 line that produces 25% HFA. In this study, we investigated changes in HFA content when endogenous Arabidopsis PDAT1 (AtPDAT1) of the P327 line was edited using the CRISPR/Cas9 technique. The successful mutation resulted in three independent lines with different mutation patterns, which were transmitted until the T4 generation. Fatty acid analysis of the seeds showed that HFA content decreased in all three mutant lines. These findings indicate that AtPDAT1 as well as RcPDAT1-2 in the P327 line are involved in transferring and increasing HFAs to triacylglycerol.

Synthesis and Characterization of the Thermally Stable Ho(hfa)3(tme)

  • Kang, Seong-Joo
    • Bulletin of the Korean Chemical Society
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    • v.25 no.8
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    • pp.1207-1210
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    • 2004
  • Holmium $\beta$ -diketonate complexes, Ho(hfa)$_3$(tme), has been prepared and characterized by IR, TGA, MS, and single-crystal X-ray analyses. This complex is air- and moisture-stable and most importantly has good volatility and thermal stability. Holmium atom binds to nine oxygen atoms, contributed by six oxygen atoms of three hfa ligands and three oxygen atoms of the tme ligand. The coordination polyhedron of Ho can be described as a distorted tricapped trigonal prism. Crystal data for $Ho(hfa)_3(tme)$; orthorhombic $P2_12_12_1$, a = 15.415(4), b = 13.17(2), c = 17.291(3) $\AA$, V = 3496(1) ${\AA}^3$.

Utilizing Prosodic Information on the Sentence Comprehension in Children with High Functioning Autism

  • Chung, Chan-Hee;Lee, Hee-Ran;Kim, Jin-Dong
    • Biomedical Science Letters
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    • v.23 no.4
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    • pp.362-371
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    • 2017
  • The purpose of this study is to investigate difficulties in using prosodic information to identify the meaning of ambiguous sentences in children with high functioning autism (HFA). Fifteen high functioning autistic children and fifteen children who matched their chronological age (CA) participated in this study. We compared the performance of the two groups by conducting syntactically and affectively ambiguous sentence comprehension (SASC and AASC) tasks. The results of this study show that in both tasks, the difference between the two groups was statistically significant at each condition and the performance of high functioning autistic children was significantly lower. In a correlation analysis of major variables, children who matched CA showed a correlation between prosody-only (PO) and AASC, while children with HFA showed a correlation between PO and MO (morpheme-only). Children with HFA used grammatical morpheme information to understand general sentences. We found that the ability to use prosodic information in children with HFA is significantly lower than that of normally developed children. Considering the relevance of prosody to linguistic, non-linguistic and emotional aspects of communication, improving prosodic perception is thought to be a way to mediate deficits in the comprehension of ambiguous sentences in children with HFA.

Synthesis and Characterization of Holmium Complexes Containing $\beta$-Diketonate Ligands

  • 이정해;정영숙;손윤수;강성주
    • Bulletin of the Korean Chemical Society
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    • v.19 no.2
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    • pp.231-235
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    • 1998
  • Two holmium β-diketonate complexes, Ho(hfa)3(H2O)2 (1) and [Ho(hfa)3(H2O)2](triglyme) (2), have been prepared and characterized by IR, TGA, and single-crystal X-ray analyses. These complexes show polymeric chains by the intermolecular hydrogen bondings. The donor atoms of the intermolecular hydrogen bonding in both complexes are hydrogen atoms of the coordinated water molecules. The acceptor atoms in 1 are the carbonyl oxygen atoms of β-diketonate ligands whereas those in 2 are oxygen atoms of the triglyme ligand. While compound 1 decomposes cleanly to Ho2O3, compound 2 sublimes intact. Crystal data for 1 and 2 are as follows: Ho(hfa)3(H2O)2 triclinic P1, a=10.158(4), b=11.628(2), c=12.579(6) Å, α=67.02(3)°, β=73.95(4)°, γ=76.12(2)°, V=1299.8(8) Å3. [Ho(hfa)3(H2O)2](triglyme), monoclinic P21/c, a=12.559(3), b=19.111(2), c=16.789(6) Å, β=110.59(4)°, V=3772(2) Å3.