• Title/Summary/Keyword: Molecular Characteristics

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Study on Charge Transport in Nanoscale Organic Monolayers for Molecular Electronics Using Liquid Phase Electrodes

  • Hwang, Jin-Ha
    • Journal of the Microelectronics and Packaging Society
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    • v.12 no.3 s.36
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    • pp.235-241
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    • 2005
  • Incorporation of solid electrodes frequently involves plasma-based processing. The effect of plasma can influence the physical characteristics, depending on the magnitude in plasma. The undesired feature of plasma-induced damage should be prevented in characterizing the ultra-thin materials, such as ultra-thin films and organic monolayers. The current work at first proves the applicability of a liquid phase electrode in the electrical/dielectric properties through comparative work using Al and Hg on ultrathin $Al_2O_3$ films deposited through atomic layer deposition at low temperature: Two types of metals such as Aluminum (Al) and mercury (Hg) were used as electrodes in $Al_2O_3$ thin films in order to investigate the effect of electrode preparation on the current-voltage characteristics and impedance features as a function of thickness in $Al_2O_3$ film thickness. The success of Hg in $Al_2O_3$ thin films is applied to the AC and DC characterization of the organic monolayers obtained using the Langmuir-Blodgett method. From the DC current-voltage characteristics, the diode-like response is found to originate from the bulk response of the organic materials, evidenced by the fact and the capacitance is inversely related to the absolute thickness of organic layers.

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Chemical and Gelation characteristics of Pectins Obtained from Ripened and Unripened Crabapples (과일 내의 pectin 함량 및 성숙도에 따른 pectin 특성 변화에 관한 연구)

  • 문수재
    • Journal of the Korean Home Economics Association
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    • v.19 no.4
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    • pp.33-39
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    • 1981
  • This study was attempted to determine the pectin contents of various fruits(Cherry, strawberry, plum, peach, apricot, apple, crabapple) and to investigate the changes in the properties of pectin and pectin gel during crabapple ripening. Methoxyl content, molecular weight and intrinsic viscosity were measured in ripened and unripened crabapples. In order to determine the characteristics of pectin gel, percent sag was measured by exchange Ridgelimeter, hardness and textural characteristics of jellies were measured by a penetrometer and a texturometer. The experimental results are summarized as follows: 1. The pectin contents of various fruits were 1.16% for cherry, 3.17% fir strawberry, 4.29% for plum, 5.51% for apricot, and pectin contents of peaches and apples varies depends on varieties from 4.54% to 5.61% to 6.52, respectively. The pectin contents of unripened and ripened crabapple wee 9.21% and 9.84% respectively, indicating that pectin content increased with fruit maturity. 2. The methoxyl contents, which was 6.61%~6.95%, was very low and it increased significantly during fruit ripening. Further, a decrease in acetyl content, intrinsic viscosity, molecular weight occurred during the ripening of crabapples. 3. The percent sag of crabapple jellies increased with fruit maturity from 5.26% to 5.79%, and the corresponding jelly grade decreased in ripened crabapple. 4. The hardness of jellies determined by a penetrometer was 79.15 pp.U. for ripened crabapple jelly, 90.62 pp.U. for unripe ned crabapple jelly. 5. In the textural characteristics of gels measured by a texturometer, the gels made from unripened crabapple were shown to have the highest values in hardness, cohesiveness, adhesiveness and gumminess.

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Morphological Characteristics and Composition of Cell Wall Polysaccharides of Brassica campestris var. pekinensis (Baechu) (배추조직의 형태학적 특성과 세포벽 다당류의 조성)

  • Kim, Sun-Dong;Park, Hong-Deok;Kim, Mi-Gyeong
    • Food Science and Preservation
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    • v.4 no.3
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    • pp.301-309
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    • 1997
  • This study was conducted to examine morphological characteristics and the content of cell wall polysaccharides of Brassica campestris var. pekinensis(baechu). First of all, the variety of scientific name and naming of parts of baechu in the literatures of kimchi showed, which will unify marks. So, we propose not so much mid-rib and leaf blade of baechu leaf as white part and green part, respectively. On the other hand, the forms of vessel elements of white part in baechu consist in ring, sclariform and reticulate thickening. The proximate compositions and contents of cell wall polysaccharides of baechu has significant differences between its cultivars. The cell wall pectin from baechu exhibited four peals with molecular weights of 2,000,000, about 100,000 and less than 10,000 by gel filteration chromatography and hemicellulose did two peaks with molecular weights of 2,000,000 and 10,000.

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Comparison of Protein Internal Motion by Inter-helical Motional Correlations and Hydrogen Bond Ratio

  • Kim, Byoung-Kook;Yoon, Chang-No
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2005.09a
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    • pp.305-310
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    • 2005
  • Internal motion of the protein has been described in many papers with C$_{\alpha}$ correlation coefficients to find motional correlation and functional characteristics. To describe the secondary structural motion and stability in protein, we have studied molecular dynamics (MD) simulations on FADD Death Domain and FADD Death Effector Domain which have a similar structure but have different functional characteristics. After 10ns MD simulations, the inter-helical motional correlations and the hydrogen bond ratios were compared between the two domains. From these data we could distinctly compare the internal motions of them and could explain the differences in experimental thermodynamic melting behaviors at molecular level.

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A Study on the Characteristics of Natural Organic Matter and Disinfection By-Product Formation in the Juam Reservoir

  • Shin, Dae-Yewn;Moon, Ok-Ran;Yoon, Mi-Ran;Kim, Nam-Joung;Kang, Gang-Unn;Seo, Gwang-Yeob
    • Proceedings of the Korean Environmental Health Society Conference
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    • 2005.06a
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    • pp.259-262
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    • 2005
  • This study aims to identify the relationship between characteristics of aqueous organic matter and chlorination by-products formation potential according to temporal effect of Juam reservoir in Sun-Choen. The molecular weight distribution and chemical composition of precursors and their relationship with disinfection by-products(DBPs) were investigated. Most of the organic matters was responsible for the major DBP precursors in the raw water are small compounds with a molecular weight less than IKDa, Aromatic contents determined by SUVA correlated well with DBPs, THMs, and HAAs formation. Especially, THMFP/DOC showed better correlation with SUVA than HAAFP/DOC and DBPFP/DOC with SUVA in Juam reservoir. Therefore, effective removal of small molecules or hydrophobic organic matter prior to disinfection process will significantly reduce the DBP concentration in the finished water.

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J-aggregation Property of Merocyanine Dye LB Thin Film by UV Irradiation (UV 조사에 의한 메로시아닌 색소 LB박막의 J-aggregation 특성)

  • Yang, Chang-Heon;Lee, Ji-Yoon;Kwon, Young-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.04c
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    • pp.123-124
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    • 2008
  • We investigate characteristics of J-aggregation as take advantage of LB technic. In order to confirm the applications possible for the molecular electronic device, the morphological properties of merocyanine dye were investigated by AFM. $\pi$-A curves investigated the surface pressure of the LB film from a liquid to a solid state ranged between 90 and 100 mN/m. We observed aggregation and it's characteristics by using visible reflection spectroscopy. This paper focuses on results obtained in mercocyanide dye. When LB films of merocyanine dye are mixed with arachidic acid, J-aggregate formation is exhibited. J-aggregate formation has been serving as typical systems in revealing the physical and structural aspects of nano-sized molecular aggregates constructed as muiltilayers.

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The investigation into Merocyanine Dye J-aggregation of characteristic by STM (STM을 이용한 Merocyanine Dye J-aggregation 특성관찰)

  • Yang, Chang-Heon;Lee, Ji-Yoon;Choi, Won-Suk;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
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    • 2008.05a
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    • pp.165-166
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    • 2008
  • We investigate characteristics of J-aggregation as take advantage of LB technic. In order to confirm the applications possible for the molecular electronic device, the morphological properties of merocyanine dye were investigated by AFM. $\pi$-A curves investigated the surface pressure of the LB film from a liquid to a solid state ranged between 90 and 100 mN/m. We observed aggregation and it's characteristics by using visible reflection spectroscopy. We have observed morphology of merocyanine dye on gold surface by STM. focuses on results obtained in mercocyanide dye of J-aggregation. When LB films of merocyanine dye are mixed with arachidic acid, J-aggregate formation is exhibited. J-aggregate formation has been serving as typical systems in revealing the physical and structural aspects of nano-sized molecular aggregates constructed as muiltilayers.

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A Study on the Characteristics of ELB Insulating Material deteriorated by Salt water (염수에 의해 열화된 누전차단기 절연재료의 특성에 관한 연구)

  • Kim, Hyung-Rae;Kim, Dong-Ook;Kim, Hyeog-Soo;Choi, Chung-Seog;Kim, Hoon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.878-881
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    • 2001
  • In this paper, we analyzed the characteristics of insulating material with ELB(earth leakage circuit breaker) through tracking experiment and the study was carried out three different types of samples. The tracking is breakdown phenomenon of material surface that is generated on the organic insulating material. The test method applied IEC publication 587. The result of the sample breakdown by tracking was carbonized and resistance of between the electrodes is approximately 300$\Omega$. In the result of DSC analysis, the caloric peak was detected before 100$^{\circ}C$ in product of tracking. It appeared weight loss of 10.87% at 537$^{\circ}C$ on TGA. IR spectrum analysis showed carbon-hydrogen(C-H)bond on molecular structure that is the sample of tracking.

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Electro-luminescence Characteristics of Nano-Structural Thin Film (나노구조 박막의 EL 특성)

  • Choi, Yong-Sung;Cho, Jang-Hoon;Song, Jin-Won;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.274-275
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    • 2006
  • A new thin film materials can be built up at the molecular level, and the relationship between these artificial structures and the properties of materials can be explored. In this paper, in order to confirm the application possibility to the molecular electronic device of the organic materials, we have investigated electro-luminescent (EL) characteristics of organic EL device using $Alq_3$, PBD as emitting material. Current and luminance can be seen that express a similar relativity in voltage and could know that luminance is expressing current relativity.

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Small Molecular Organic Nonvolatile Memory Cells Fabricated with in Situ O2 Plasma Oxidation

  • Seo, Sung-Ho;Nam, Woo-Sik;Park, Jea-Gun
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.8 no.1
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    • pp.40-45
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    • 2008
  • We developed small molecular organic nonvolatile $4F^2$ memory cells using metal layer evaporation followed by $O_2$ plasma oxidation. Our memory cells sandwich an upper ${\alpha}$-NPD layer, Al nanocrystals surrounded by $Al_2O_3$, and a bottom ${\alpha}$-NPD layer between top and bottom electrodes. Their nonvolatile memory characteristics are excellent: the $V_{th},\;V_p$ (program), $V_e$ (erase), memory margin ($I_{on}/I_{off}$), data retention time, and erase and program endurance were 2.6 V, 5.3 V, 8.5 V, ${\approx}1.5{\times}10^2,\;1{\times}10^5s$, and $1{\times}10^3$ cycles, respectively. They also demonstrated symmetrical current versus voltage characteristics and a reversible erase and program process, indicating potential for terabit-level nonvolatile memory.