• Title/Summary/Keyword: basic research

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Ester Derivatives from Tannase-treated Prunioside A and Their Anti-inflammatory Activities

  • Jun, Chang-Soo;Yoo, Myung-Ja;Lee, Woo-Yiel;Kwak, Kyung-Chell;Bae, Moon-Sung;Hwang, Woo-Taek;Son, Dong-Hwan;Chai, Kyu-Yun
    • Bulletin of the Korean Chemical Society
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    • v.28 no.1
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    • pp.73-76
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    • 2007
  • Prunioside A, isolated from the methanol extract of Spiraea prunifolia var. Simpliciflora's root, is composed of coumaroyl, monoterpene-type, and glucosyl units. The esterase activity of tannase was used to remove the p-coumaroyl and glucopyranosyl groups. The enzymatically hydrolyzed compound was reacted with various acyl chlorides to synthesize its ester derivatives, which showed the inhibitory effects on NO production in murine machrophage?like RAW 264.7 cells stimulated with lipopolysaccharide and interferon-γ.

Ultra Thin Film Barrier Layer for Plastic OLED

  • Kopark, Sang-Hee;Oh, Ji-Young;Hwang, Chi-Sun;Yang, Yong-Suk;Chu, Hye-Yong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.44-47
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    • 2004
  • Fabrication of barrier layer on PES substrate and plastic OLED device by atomic layer deposition are carried out. Simultaneous deposition of 30nm of $AlO_x$ film on both sides of PES gives film MOCON value of 0.0615g/$m^2$.day (@38$^{\circ}C$, 100% R.H). Introduction of conformal $AlO_x$ film by ALD resulted in enhanced barrier properties for inorganic double layered film including PECVO $SiN_x$. Preliminary life time to 91% of initial luminance (1300 cd/$m^2$ ) for 100nm of PECVD $SiN_x$/30nm of ALD $AlO_x$ coated plastic OLED device was 260 hours.

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Effects of ZnS Insertion on the Characteristics of CaS:Pb Thin Film Phosphor

  • Park, Sang-Hee Ko;Kang, Seung-Youl;Kim, Kwang-Bok;Kim, Dong-Il;Yun, Sun-Jin
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.1071-1074
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    • 2003
  • The effects of ZnS insertion on the characteristics of CaS:Pb phosphor were investigated. The intensity of photoluminescence of ZnS inserted CaS:Pb excited by 347nm were increased while that excited by 254nm was unchanged, compared to those of CaS:Pb thin film. The electroluminescent display having ZnS inserted CaS:Pb showed lower threshold voltage and higher efficiency than those of CaS:Pb ELD device.

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Properties of Sequential Lateral Solidification (SLS) Crystallized Poly-Si Films and Melting Process Simulation

  • Kim, Yong-Hae;Sohn, Choong-Yong;Chung, Choong-Heui;Ko, Young-Wook;Lee, Jin-Ho
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.248-251
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    • 2003
  • The large size grain of poly-Si film is obtained above the upper limit of excimer laser energy at which the random nucleation occurs. We simulate the time dependent temperature profile of ${\alpha}-Si/SiO_2/Si$ substrate structure according to the excimer laser energy with $ANSYS^{\circledR}$ simulator. As the thickness is increased, the laser energy for the melting of ${\alpha}-Si$ film is increased.

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Sense Amplifier Design for A NOR Type Non-Volatile Memory

  • Yang, Yil-Suk;Yu, Byoung-Gon;Roh, Tae-Moon;Koo, Jin-Gun;Kim, Jongdae
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1555-1557
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    • 2002
  • We have investigated the precharge type sense amplifier, it is suitable fur voltage sensing in a NOR type single transistor ferroelectric field effect transistor (1T FeFET) memory read operation. The proposed precharge type sense amplifier senses the bit line voltage of 1T FeFET memory. Therefore, the reference celt is not necessary compared to current sensing in 1T FeFET memory, The high noise margin is wider than the low noise margin in the first inverter because requires tile output of precharge type sense amplifier high sensitivity to transition of input signal. The precharge type sense amplifier has very simple structure and can sense the bit line signal of the 1T FeFET memory cell at low voltage.

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A simultaneous wavelength tuning and stabilization scheme of a fiber-optic interferometer filter

  • Ahn, Joon-Tae;Lee, Hak-Kyu;Jeon, Min-Yong;Lim, Dong-Sung;Kim, Kyong-Hon
    • Journal of the Optical Society of Korea
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    • v.3 no.1
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    • pp.32-34
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    • 1999
  • We successfully demonstrated a stabilized fiber-optic Mach­Zehnder interferometer filter with continuous tunability. The tunable scheme was achieved with fine wavelength control of an 1.3${\mu}{\textrm}{m}$ tunable laser diode used as a stabilization light source. The transmission wavelength of the tunable filter was shifted linearly with respect to the wavelength change of the stabilization light source.

Optimization of Packaging Design of TWEAM Module for Digital and Analog Applications

  • Choi, Kwang-Seong;Lee, Jong-Hyun;Lim, Ji-Youn;Kang, Young-Shik;Chung, Yong-Duck;Moon, Jong-Tae;Kim, Je-Ha
    • ETRI Journal
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    • v.26 no.6
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    • pp.589-596
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    • 2004
  • Packaging technologies for a broadband and narrowband modulator with a traveling wave electro-absorption modulator (TWEAM) device were developed. In developing a broadband modulator, the effects of the device and packaging designs on the broadband performance were investigated. The optimized designs were obtained through a simulation with the result that we developed a broadband modulator with a 3 dB bandwidth of 38 GHz in the electrical-to-optical (E/O) response, an electrical return loss of less than -10 dB at up to 26 GHz, an rms jitter of 1.832 ps, and an extinction ratio of 5.38 dB in a 40 Gbps non-return to zero (NRZ) eye diagram. For analog application, the effect of the RF termination scheme on the fractional bandwidth was studied. The microstrip line with a double stub as a matching circuit and a laser trimming process were used to obtain an $S_{11}$ of -34.58 dB at 40 GHz and 2.9 GHz bandwidth of less than -15 dB.

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Ultra Thin Film Encapsulation of Organic Light Emitting Diode on a Plastic Substrate

  • Park, Sang-Hee;Oh, Ji-Young;Hwang, Chi-Sun;Lee, Jeong-Ik;Yang, Yong-Suk;Chu, Hye-Yong;Kang, Kwang-Yong
    • ETRI Journal
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    • v.27 no.5
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    • pp.545-550
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    • 2005
  • We have carried out the fabrications of a barrier layer on a polyethersulfon (PES) film and organic light emitting diode (OLED) based on a plastic substrate by means of atomic layer deposition (ALD). Simultaneous deposition of 30 nm $AlO_x$ film on both sides of the PES film gave a water vapor transition rate (WVTR) of $0.062 g/m^2/day (@38^{\circ}C,\;100%\;R.H.)$. Further, the double layer of 200 nm $SiN_x$ film deposited by plasma enhanced chemical vapor deposition (PECVD) and 20 nm $AlO_x$ film by ALD resulted in a WVTR value lower than the detection limit of MOCON. We have investigated the OLED encapsulation performance of the double layer using the OLED structure of ITO / MTDATA (20 nm) / NPD (40 nm) / AlQ (60 nm) / LiF (1 nm) / Al (75 nm) on a plastic substrate. The preliminary life time to reach 91% of the initial luminance $(1300 cd/m^2)$ was 260 hours for the OLED encapsulated with 100 nm of PECVD-deposited $SiN_x$ and 30 nm of ALD-deposited $AlO_x$.

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