• Title/Summary/Keyword: pHi

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Synthesis and Characterization of a New PPV Derivative Containing a Sterically Hindered 2,5-Dimethylphenyl Group

  • Kim, Yun-Hi;Lee, Hyun-Ouk;Lee, Ki-Suk;Kwon, Soon-Ki
    • Macromolecular Research
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    • v.11 no.6
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    • pp.471-475
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    • 2003
  • A new poly[2-(2',5'-dimethylphenyl)-1,4-phenylenevinylene] (PDMPPV) that features a bulky 2',5'-dimethylphenyl substituent, which can induce steric hindrance between the PPV backbone and the methyl groups, was designed and synthesized. The polymer structure having no TBB defects was confirmed by $^1$H-NMR and $\^$13/CNMR spectroscopy. The polymer showed good thermal stability with high T$\_$g/. The polymer film showed a maximum absorption at 415 nm with an absorption onset at 480 nm. The maximum emission peak showed at ca. 515 nm, with a shoulder at 530 nm. The turn-on voltages of ITO/PEDOT/PDMPPV/Al and ITO/PDMPPV/Al devices were 8 and 10 V, respectively. The electroluminescence spectrum from the device showed a maximum peak at 510 nm with a shoulder at ca. 535 nm.

Purification and Characterization of a Novel 21 kD Calcium Binding Protein from Dunaliella salina

  • Ko, Jae-Heung;Lee, Sun-Hi
    • Journal of Plant Biology
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    • v.39 no.3
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    • pp.173-177
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    • 1996
  • A novel calcium binding protein (CaBP) was purified to electrophoretic homogeneity from Dunaliella salina. In the course of purification experiment, this CaBP was identified as a monomer and its molecular weight was about 21 kDand isoelectric point (pI) value was about 4.1 using isoelectrofocusing. This CaBP was able to bind Ca2+ even in the pressence of an excess MgCl2 and KCI both in solution. In the SDS-PAGE, the Ca2+-bound form was slower than the Ca2+-free form in the nondenaturing PAGE. This means that the CaBP undergoes conformational change in the Ca2+-bound condition. Furthermore, UV absorption spectrum and fluorescence intensity of this CaBP was investigated. UV absorption peak was appeared at about 258 nm and decreased somewhat in Ca2+-bound condition. In the measurement of fluorescence, maximum intensity was appeared at 303 nm and decreased in Ca2+-bound state, similarly as UV absorption spectrum. These show distinct changes upon Ca2+-binding, which indicate of structural and/or dynamic changes largely reminiscent of other members of the EF-hand Ca2+-binding protein family.

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The Short Channel Effect Immunity of Silicon Nanowire SONOS Flash Memory Using TCAD Simulation

  • Yang, Seung-Dong;Oh, Jae-Sub;Yun, Ho-Jin;Jeong, Kwang-Seok;Kim, Yu-Mi;Lee, Sang Youl;Lee, Hi-Deok;Lee, Ga-Won
    • Transactions on Electrical and Electronic Materials
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    • v.14 no.3
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    • pp.139-142
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    • 2013
  • Silicon nanowire (SiNW) silicon-oxide-nitride-oxide-silicon (SONOS) flash memory devices were fabricated and their electrical characteristics were analyzed. Compared to planar SONOS devices, these SiNW SONOS devices have good program/erase (P/E) characteristics and a large threshold voltage ($V_T$) shift of 2.5 V in 1ms using a gate pulse of +14 V. The devices also show excellent immunity to short channel effects (SCEs) due to enhanced gate controllability, which becomes more apparent as the nanowire width decreases. This is attributed to the fully depleted mode operation as the nanowire becomes narrower. 3D TCAD simulations of both devices show that the electric field of the junction area is significantly reduced in the SiNW structure.

Stress Dependence of Thermal Stability of Nickel Silicide for Nano MOSFETs

  • Zhang, Ying-Ying;Lim, Sung-Kyu;Lee, Won-Jae;Zhong, Zhun;Li, Shi-Guang;Jung, Soon-Yen;Lee, Ga-Won;Wang, Jin-Suk;Lee, Hi-Deok
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.15-16
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    • 2006
  • The thermal stability of nickel silicide with compressively and tensilely stressed nitride capping layer has been investigated in this study. The Ni (10 nm) and Ni/Co/TiN (7/3/25 nm) structures were deposited on the p-type Si substrate. The stressed capping layer was deposited using plasma enhanced chemical vapor deposition (PECVD) after silicide formation by one-step rapid thermal process (RTP) at $500^{\circ}C$ for 30 sec. It was found that the thermal stability of nickel silicide depends on the stress induced by the nitride capping layer. In the case of Ni (10 nm) structure, the high compressive sample shows the best thermal stability, whereas in the case of Ni/Co/TiN (7/3/25 nm) structure, the high compressive sample shows the worst thermal stability.

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Increase in Hepatic DT-Diaphorase Activity by Chronic Administration of Panax ginseng Extract to Mice (생쥐에서의 인삼추출액의 장기간 투여에 의한 간장 DT-Diaphorase 활성의 증가)

  • Lee, Kang-Mee;Wie, Myung-Bok;Song, Dong-Keun;Kim, Yong-Sik;Kim, Yung-Hi
    • Journal of Ginseng Research
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    • v.17 no.2
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    • pp.123-126
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    • 1993
  • Effects of chronic administration of ginseng extracts (30 or 150 mg/kg/day for 52 days, p.o.) to mice on the activities of DT-diaphorase and glutathione S-transferase (GST) in the liver and the brain were studied. The DT-diaphorase activity in the liver was increased over 2-fold at the dose of both 30 and 150 mg/kg/day, while there was no change in the activity of the enzyme in the brain. The GST activity in the liver was increased in a dose-dependent fashion up to 142% of the control value at the dose of 150 mg/kg/day. while there was no change in the activity of the enzyme in the brain. The ginseng-induced increase in the activities of these hepatic phase II drug-metabolizing enzymes which are involved in the detoxification of carcinogens, is suggested to underlie, at least in part, the anticarcinogenic activity of Panax ginseng.

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An Electrochemical Study on the New Black Chrome Bath Solution for the Electrodeposited Solar Selective Surface (흑크롬 태양광 선택흡수막 제조용 도금액의 개발 및 전기화학적 고찰)

  • Lee, Tai-Kyu;Cho, Suh-Hyun;Chea, Young-Hi;Auh, P.Chung-Moo
    • Solar Energy
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    • v.10 no.1
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    • pp.92-97
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    • 1990
  • The electrochemical approach to the characteristics of black chrome solar selective coatings has been reviewed. Based on the formula of the ChromOnyx bath solution manufactured by Harshaw Company, the chromic acid-propionic acid bath solutions have been prepared by KIER. Comprehensive review of the black chrome electrodeposition mechanism also has been performed on the role played by constituents in the bath solution during electrodeposition. The optical properties such as absorption and emittance of electrodeposited black chrome coatings obtained from the new formula and their surface analysis will be reported in detail.

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Estimation of Cattle Wastewater Treatment using Singang Advance Biology Reactor (SAB) (SAB 고율미생물반응기를 이용한 축산폐수처리의 성능 평가)

  • Lim, Bongsu;Kim, Doyoung;Park, Sungsoon
    • Journal of Korean Society on Water Environment
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    • v.25 no.5
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    • pp.727-734
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    • 2009
  • This study was carried out to evaluate the high rate biological reactor such as lab scale reactor before the application in site, and to get the basic data for possibility using liquid fertilizer with the effluent from biological reactor when the centrifugal machine was applied. The total volume of this reactor in 6 L, in composted of anoxic reactor (2 L), aerobic reactor (2 L), and nitification reactor (2 L). BOD removal efficiency rates when centrifugal machine was applied after effluent from biological reactor are over than 95%. This biological reactor was required post process to satisfy the effluent standards, and was need centrifugal machine to control the washout of microbes in the reactor. T-N removal efficiency rate in HRT 24 hr with centrifugation is 80.0%, and it is desirable to operate less than $1.3kgN/m^3{\cdot}d$ for 70% of T-N removal efficiency rate. T-P removal efficiency rate in HRT 24 hr is 68.2%, and become higher 71.3% after centrifugation. Considering in the 28.6% T-N removal efficiency rate, the nitrogen contents of the effluent from reactor is 0.34% to satisfy the liquid fertilizer.

Lindera erythrocarpa Makino extract reduces obesity induced by high-fat diet in rats

  • Ahn, Mee-Jung;Yang, Won-Jun;Kang, So-Hi;Kang, Min-Chul;Ko, Ryeo-Kyeong;Kim, Gi-Ok;Shin, Tae-Kyun
    • Advances in Traditional Medicine
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    • v.10 no.4
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    • pp.288-293
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    • 2010
  • Lindera erythrocarpa Makino (LE) is widely distributed on Jeju Island, where it has been used for various traditional therapies. Effects of a crude extract of LE were examined in rats with obesity induced by a high-fat diet (HFD). Anti-obesity effects were followed in rats receiving orally administered vehicle, 100mg/kg extract, or 250 mg/kg LE extract, for 56 days. LE extract (250 mg/kg) suppressed increases in body weight and epididymal fat, with amelioration of fatty changes in the liver. Additionally, serum levels of alanine aminotransferase, aspartate aminotransferase, and total cholesterol were significantly decreased compared with those of vehicle-treated groups (p < 0.05). These results suggest that oral administration of LE extract reduced rat obesity induced by HFD, possibly through the reduction of fat accumulation.

A Study on the Production and Decomposition of Litters Related to Altitude (한라산, 소백산 및 태백산의 고도에 따른 낙엽의 생산과 분해에 관한 연구)

  • Chang, Nam Kee;Hi Chung Kwon
    • The Korean Journal of Ecology
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    • v.10 no.3
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    • pp.109-118
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    • 1987
  • The production and decomposition rates of litters were studied in three mountains, Mt. Halla, Mt. So-back and Mt. Tae-back. The amounts of N, P, K, Ca and Na in the soils were measured and the relationships between the mineral nutrients and decay rates were reserched, The annual litter production was the most as $1, 077.3g/m^2$ and the least as $248.0g/m^2$ in a stand of Quercus acutissima at 820m of the Mt. So-back and at 1, 350m of the Mt. So-back among the study sites, respectively. The decay rates of litter was the highest as k=0.448 and the lowest as k=0.082 in a stand of Q. acutissima at 820m of the Mt. So-back and at 1, 450m of the Mt. Tae-back at 1, 450m of the Mt. Tae-back among the study sites. The higher altitude was, the slower the decay rates were. The annual contents of mineral nutrient and their amounts inputted into the forest soil were proportional to the decay rate of organic metters.

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MOLECULAR CORES OF THE HIGH-LATITUDE CLOUD MBM7

  • MINH Y. C.;KIM H. G.;KIM S. J.;BERGMAN P.;JOHANSSON L. E. B.
    • Journal of The Korean Astronomical Society
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    • v.33 no.1
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    • pp.37-45
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    • 2000
  • We have investigated the properties of the high-latitude cloud MBM 7 using the 3 mm transitions of CO, CS, HCN, $HCO^+,\;C_3H_2,\;N_2H^+$, and SiO. The molecular component of MBM 7 shows a very clumpy structure with a size of $\le$0.5 pc, elongated along the northwest-southeast direction, perpendicularly to an extended HI component, which could be resulted from shock formation. We have derived physical properties for two molecular cores in the central region. Their sizes are 0.1-0.3 pc and masses 1-2 M$\bigodot$ having an average volume density $\~2{\times}10^3 cm^{-3}$ at the peak of molecular emission. We have tested the stability of the cores using the full version of the virial theorem and found that the cores are stabilized with ambient medium, and they are expected not to be dissipated easily without external perturbations. Therefore MBM 7 does not seem to be a site for new star formation. The molecular abundances in the densest core appear to be much less (by about one order of magnitude) than the 'general' dark cloud values. If the depletions of heavy elements are not significant in the HLCs compared with those in typical dark clouds, our results may suggest different chemical evolutionary stages or different chemical environments of the HLCs compared with dense dark clouds in the Galactic plane.

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