• Title/Summary/Keyword: $UV/O_2$

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The Preparation and its Chemical Properties of Palladium Complexes with a series of Cycloamine (Cycloamine 계의 팔라듐 착물의 합성과 그 화학적 성질)

  • Sang-Oh Oh;Duck-Young Chung
    • Journal of the Korean Chemical Society
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    • v.29 no.4
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    • pp.406-413
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    • 1985
  • We synthesized Pd(II) complexes containing sulfoxide and cycloamine series on the basis of the fact that many workers had the foresight to suggest anticancer activites using Pd(II) complexes with sulfur, nitrogen, or nucleic acid relatives as ligands particulary. The identification and characterization of these complexes are followed; content rates of atoms and molecular weights are confirmed by Elemental Analysis and Mass spectra, bonding of metal and ligands by UV-Vis. spectra and NMR spectra, and donor sites of ligands and configuration of complexes by IR spectra. These are yellow crystals, soluble in methanol and chloroform, and insoluble in H2O and the other common organic solvents.

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Single layer antireflection coating on PET substrates for display applications

  • Gowtham, M.;Mangalaraj, D.;Seo, Chang-Ki;Shim, Myung-Suk;Hwang, Sun-Woo;Yi, Jun-Sin
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.988-991
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    • 2004
  • In the present investigation, we tried AR coating simulation by using the "Essential Macleod optical coating design and analysis" program. After various run of the program we selected appropriate materials which have specific refractive indices and for that thickness was optimized to get the low reflectance. By comparing the simulated results for the different materials,we found that $SiO_2$ and TiN are the appropriate materials for this Flat panel device (FPD) application. Thin films of these materials were deposited using RF magnetron sputtering and Inductively Coupled Plasma Chemical Vapour Deposition (ICPCVD) methods on Polyethyleneterephthalate (PET) substrates. Spectroscopic ellipsometer (SE MF-1000) and UV-Vis spectrophotometer (SCINCO) were used for the optical characterization. The obtained experimental results are in good agreement with the simulation results.

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The post annealing effect on the properties of AZO films (AZO 박막의 후 열처리에 따른 특성변화)

  • Ko, Ki-Han;Seo, Jae-Keun;Kim, Jae-Kwang;Cho, Hyung-Jun;Hong, Byung-You;Choi, Won-Seok
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.457-458
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    • 2009
  • In this work, transparent conducting Al-doped zinc oxide (AZO) films were prepared on Coming glass substrate by RF magnetron sputtering using an Al-doped ZnO target (Al: 2 wt.%) at room temperature and all films were deposited with athickness of 150 nm. We investigated the effects of the post-annealing temperature and the annealing ambient on structural, electrical and optical properties of AZO films. The films were annealed at temperatures ranging from 300 to $500^{\circ}C$ in steps of $100^{\circ}C$ using rapid thermal annealing equipment in oxygen. The thickness of the film was observed by field emission scanning electron microscopy (FE-SEM) and grain size was calculated from the XRD spectra using the Scherrer equation and their electrical properties were investigated using a hole measurement and the reflectance of AZO films was investigated by UV-VIS spectrometry.

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Sol-gel Mechanism of Self-patternable PZT Film Starting from Alkoxides Precursors

  • Hwang, Jae-Seob;Kim, Woo-Sik;Park, Hyung-Ho;Kim, Tae-Song
    • Journal of the Korean Ceramic Society
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    • v.40 no.4
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    • pp.385-392
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    • 2003
  • Sol-gel preparation technique using a chemical reaction of metal alkoxides has been widely used for the fabrication of various materials including ceramics. However, its mechanism has been studied till now because a number of chemical ways are possible from various alkoxides and additives. In this study, the mechanism of hydrolysis, condensation, and polymerization of alkoxides were investigated from the fabrication of lead-zirconate-titanate (PbZr$\_$x/Ti$\_$l-x/O$_3$; PZT) thin film that is used as various micro-actuator, transducer, and sensor because of its high electro-mechanical coupling factors and thermal stability. Furthermore, the fabrication process and characteristics of self-patternable PZT film using photosensitive stabilizer were studied in order to resolve the problem of physical damage and properties degradation during dry etching for device fabrication. Using an optimum condition to prepare the self-patternable PZT film, more than 5000 ${\AA}$ thick self-patternable PZT film could be fabricated by three times coating. The PZT film showed 28.4 ${\mu}$c/cm$^2$ of remnant polarization (Pr) and 37.0 kV/cm of coercive field (E$\_$c/).

Removal of low concentration organic matter by reverse osmosis membranes in ultrapure water production process (초순수 제조 공정에서 역삼투 막의 저농도 유기물 제거)

  • Lee, Hongju;Kim, Suhan
    • Journal of Korean Society of Water and Wastewater
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    • v.28 no.4
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    • pp.391-396
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    • 2014
  • Ultrapure water (UPW) is water containing nothing but water molecule ($H_2O$). The use of UPW is increasing in many industries such as the thermal and nuclear power plants, petrochemical plants, and semiconductor manufacturers. In order to produce UPW, several unit processes such as ion exchange, reverse osmosis (RO), ultraviolet (UV) oxidation should be efficiently arranged. In particular, RO process should remove not only ions but also low molecular weight (LMW) organic matters in UPW production system. But, the LMW organic matter removal data of RO membranes provided by manufacturers does not seem to be reasonable because they tested the removal in high concentration conditions like 1,000 ppm of isopropyl alcohol (IPA, MW=60.1). In this study, bench-scale experiments were carried out using 4-inches RO modules. IPA was used as a model LMW organic matter with low concentration conditions less than 1 ppm as total organic carbon (TOC). As a result, the IPA removal data by manufacturers turned out to be trustable because the effect of feed concentration on the IPA removal was negligble while the IPA removal efficiency became higher at higher permeate flux.

Improvement of Aspergillus niger 55, a Raw Corn Meal Saccharifying Enzyme Hyperproducer, through Mutation and Selective Screening Techniques (옥수수 生 전분 당화 효소 高 생산성 변이주 개발)

  • Oh, Sung-Hoon;O, Pyong-Su
    • Microbiology and Biotechnology Letters
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    • v.19 no.2
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    • pp.140-146
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    • 1991
  • Mutation experiments were performed to select the mutant of Aspergillus niger 55, which had lost almost all the ability to produce transglucosidases but retained that of high productivity of raw meal saccharifying enzyme, by means of successive induction with N-methyl-N'-nitro-N-nitrosoguanidine(MNNG), ultraviolet(UV) light, and ${\gamma}$-rays. Also, we used the mutant enrichment techniques, such as liquid culture-filtration procedure and differential heat sensitivity of conidia, in order to increase the possibility of obtaining a mutant. The glucoamylase productivity of mutant PFST-38 was 11 times higher than that of the parent strain. The mutant PFST-38 was morphologically identical to the parent strain, except for the size of conidia, the tendency to form conidia and the lenght of conidiophore. Asp. niger mutant PFST-38 apeared to be useful for the submerged production of the raw corn meal saccharifying enzyme.

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Charaterization of structural, electrical, and optical properties of AZO thin film as a function of annealing temperature (열처리 온도에 따른 AZO 박막의 구조적, 전기적, 광학적 특성 분석)

  • Ko, Ki-Han;Seo, Jae-Keun;Lee, Sang-Joon;Hwang, Chae-Young;Bae, Eun-Kyung;Lim, Moo-Kil;Choi, Won-Seok
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1343_1344
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    • 2009
  • In this work, transparent conducting Al-doped zinc oxide (AZO) films were prepared on Corning glass substrate by RF magnetron sputtering using an Al-doped ZnO target (Al: 2 wt.%) at room temperature and all films were deposited with athickness of 150 nm. We investigated the effects of the post-annealing temperature and the annealing ambient on structural, electrical and optical properties of AZO films. The films were annealed at temperatures ranging from 300 to $500^{\circ}C$ in steps of $100^{\circ}C$ using rapid thermal annealing equipment in oxygen. The thickness of the film was observed by field emission scanning electron microscopy (FE-SEM) and grain size was calculated from the XRD spectra using the Scherrer equation and their electrical properties were investigated using a hole measurement and the reflectance of AZO films was investigated by UV-VIS spectrometry.

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Characterization of the effect of RF power on the properties of AZO films deposited at room temperature (RF 파워에 따른 상온에서 합성한 AZO 투명전도막의 특성분석)

  • Seo, Jae-Keun;Ko, Ki-Han;Kim, Jae-Kwang;Lee, Jong-Hwan;Lee, You-Sung;Choi, Won-Seok
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1345_1346
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    • 2009
  • In this study, transparent and conductive Al-doped zinc oxide (AZO) films were prepared on glass substrate by RF magnetron sputtering method using an Al-doped ZnO target (Al: 2wt.%) at room temperature as the thickness of 150 nm. We investigated the effects of the RF power between 100~350 W in the steps of 50 W on structural, electrical and optical properties of AZO films. The thickness and cross-sectional images of films were observed by field emission scanning electron microscopy (FE-SEM) and all of the films were kept to be constant about 150 nm on glass substrate. The grain size of AZO films figured out X-ray diffraction (XRD) on using the Scherrer' equation and their electrical properties investigated Hall effect electronic transport measurement system. Moreover, we measured transmittance of AZO films by UV/VIS spectrometer.

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A Sesquiterpene ortho-Naphthoquinone from the Root Bark of Ulmus davidiana Planch

  • Kim, Jong-Pyung;Kim, Won-Gon;Park, Jong-Hee;Jung, Jin;Koshino, Hiroyuki;Yoo, Ick-Dong
    • Korean Journal of Pharmacognosy
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    • v.27 no.1
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    • pp.26-31
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    • 1996
  • A sesquiterpene ortho-naphtpoquinone was isolated from the 80% aqueous methanolic extract of root bark of Ulmus davidiana Planch whose stem and root bark have been used as an oriental medicine for the treatment of edema, mastitis, gastric cancer and inflammation. On the basis of spectral data obtained from UV-vis, IR, HR-EIMS and NMR spectrometry, including the pulse field gradient (PFG) HMQC and HMBC techniques, the structure of this compound was determined as 2,3-dihydro-3-hydroxy-3,6,9-trimethylnaphtho(1,8-b,c)pyran-7,8-dione which has been known as mansonone 1. This compound has been isolated only from the heart-wood of Mansonia altissima Chev, a Sterculiacea from West Africa. Thus, this compound was isolated for the second time from natural source in this study. This is the first report to present the carbon chemical shift assignment of mansonone I.

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Quantitative Analysis for the Quality Evaluation of Scutellariae Radix by HPLC/UVD

  • Jeong, Su-Yang;Moon, Dong-Cheul;Son, Kun-Ho;Son, Jong-Keun;Min, Byung-Sun;Woo, Mi-Hee
    • Natural Product Sciences
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    • v.17 no.4
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    • pp.321-327
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    • 2011
  • In this study, quantitative analysis was developed using HPLC/UVD for the quality evaluation of Scutellariae Radix. For quantitative analysis, six major bioactive compounds were assessed. The separation conditions employed for HPLC/UVD were optimized using Phenomenex $C_{18}$ column ($250{\times}4.6$ mm, 5 ${\mu}m$) with a gradient of solvent A (1% acetic acid of $H_2O$) and solvent B (acetonitrile : methanol : acetic acid = 70 : 30 : 1) as the mobile phase at a flow rate of 1.0 mL/min and a detection wavelength of 275 nm. These methods were fully validated with respect to linearity, accuracy, precision and recovery. The HPLC/UVD method was applied successfully to the quantification of six major compounds in the extract of Scutellariae Radix. The results indicate that the established HPLC/UVD method is suitable for the quantitative analysis and quality control of multicomponents in Scutellariae Radix.