• Title/Summary/Keyword: Transfer Center

Search Result 2,745, Processing Time 0.034 seconds

Synthesis, Photophysical and Electrochemical Properties of Novel Conjugated Donor-Acceptor Molecules Based on Phenothiazine and Benzimidazole

  • Zhang, Xiao-Hang;Kim, Seon-Ho;Lee, In-Su;Gao, Chun-Ji;Yang, Sung-Ik;Ahn, Kwang-Hyun
    • Bulletin of the Korean Chemical Society
    • /
    • v.28 no.8
    • /
    • pp.1389-1395
    • /
    • 2007

  • Two series of new organic fluorophores such as asymmetrical 3-(benzimidazol-2-yl)-10-hexylphenothiazine derivatives 1 and symmetrical 3,7-bis(benzimidazol-2-yl)-10-hexylphenothiazine derivatives 2 have been synthesized. Electronic absorption, fluorescence, and electrochemistry measurements reveal that the electron withdrawing benzimidazole subunit directly connected to the phenothiazine core facilitates the charge transfer characters which were also verified by the theoretical calculations. Various substituents on the benzimidazole moieties can allow a fine-tuning of the LUMO energy levels of the molecules without significantly affecting the HOMO energy levels. The method provides a new route for designing ambipolar molecules whose energy levels are well-matched with the Fermi levels of the electrodes to facilitate the electron or hole injection/transfer in OLED devices.

  • https://doi.org/10.5012/bkcs.2007.28.8.1389 인용 PDF KSCI

In Vitro Development of Interspecies Nuclear Transfer Embryos using Porcine Oocytes with Goat and Rabbit Somatic Cells

  • Quan, Yan Shi;Naruse, Kenji;Choi, Su-Min;Kim, Myung-Youn;Han, Rong-Xun;Park, Chang-Sik;Jin, Dong-Il
    • Reproductive and Developmental Biology
    • /
    • v.32 no.4
    • /
    • pp.249-253
    • /
    • 2008

  • Interspecies somatic cell nuclear transfer (iSCNT) is a valuable tool for studying the interactions between an oocyte and somatic nucleus. The object of this study was to investigate the developmental competence of in vitro-matured porcine oocytes after transfer of the somatic cell nuclei of 2 different species (goat and rabbit). Porcine cumulus oocytes were obtained from the follicles of ovaries and matured in TCM-199. The reconstructed embryos were electrically fused with 2 DC pulses of 1.1kV/cm for $30{\mu}s$ 0.3M mannitol medium. The activated cloned embryos were cultured in porcine zygote medium-3 (PZM-3), mSOF or RDH medium for 7 days. The blastocyst formation rate of the embryos reconstructed from goat or rabbit fetal fibroblasts was significantly lower than that of the embryos reconstructed from porcine fetal fibroblast cells. However, a significantly higher number of embryos reconstructed from goat or rabbit fetal fibroblasts cultured in mSOF or RDH, respectively, developed to the morular stage than those cultured in PZM-3. These results suggest that goat and bovine fetal fibroblasts were less efficacious than porcine-porcine cloned embryos and that culture condition could be an important factor in iSCNT. The lower developmental potential of goat-porcine and porcine-bovine cloned embryos may be due to incompatibility between the porcine oocyte cytoplasm and goat and bovine somatic nuclei.

  • PDF KSCI

Experimental Study of Evaporative Heat Transfer Characteristics of R-134a with Channel-Bending Angle in Microchannel Heat Exchangers (마이크로채널 열교환기에서 채널 굽힘 각도에 따른 R-134a의 증발열전달 특성에 관한 연구)

  • Lee, Hae-Seung;Jeon, Dong-Soon;Kim, Young-Lyoul;Kim, Seon-Chang
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.34 no.6
    • /
    • pp.635-642
    • /
    • 2010

  • Experimental investigations have been carried out to examine the evaporative heat transfer characteristics of R-134a with the channel-bending angle (CBA) in microchannel heat exchangers. In this study, we examined the effects of evaporation temperature and Reynolds number of R-134a on the evaporative heat transfer characteristics of R-134a in microchannel heat exchangers with CBAs of $120^{\circ}$, $150^{\circ}$, and $180^{\circ}$ under counterflow conditions. Experimental results show that the evaporative heat transfer rate and evaporative heat transfer coefficient increased with an increase in the Reynolds number of R-134a. Further, the evaporative heat transfer rate corresponding to CBAs of $120^{\circ}$ and $150^{\circ}$ increased to values greater than the evaporative heat transfer rate corresponding to $180^{\circ}$ by approximately 17.1% and 13.3%, respectively, for evaporating temperatures in the range $4.9-14.9^{\circ}C$. The evaporative heat transfer coefficient was affected by the channel angle with increasing evaporative heat transfer coefficient at small channel bending angle.

  • https://doi.org/10.3795/KSME-B.2010.34.6.635 인용 PDF KSCI