• Title, Summary, Keyword: uv-spectra

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On the UV Spectra of AcBr Lignins from Softwoods grown in Mt. Jiri (지리산산(智異山産) 침엽수재(針葉樹材) AcBr Lignin의 UV Spectra에 대(對)하여)

  • Jo, Jong-Soo;Moon, Chang-Kuck
    • Journal of the Korean Wood Science and Technology
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    • v.12 no.3
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    • pp.35-40
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    • 1984
  • The ultraviolet absorption spectra of AcBr lignin (Acetyl Bromide lignin) from 10 species grown in Mt. Jiri were determined. There were 3 peak positions, at 249nm (max peak), at 267-268 nm (shallow min. peak) and at 280 nm (lower max. peak). The Bjorkman lignin and lignin sulfonic acid spectra had shoulders, but the AcBr lignin had not them. Average absorbances and absorptivities of the AcBr lignins at peak positions were $0.367{\pm}0.0015$, $24.56{\pm}0.0535$, at 249 nm, $0.278{\pm}0.0016$, $18.50{\pm}0.0569$, at 267-268 nm and $0.306{\pm}0.0016$, $20.42{\pm}0.0627$ at 280 nm, respectively.

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Studies on the Antifungal Antibiotics Produced by a Streptomyces sp. (Part 2) The Occurrence of trans-Cinnamamide in Streptomyces No. 297 (Streptomyces sp. 가 생산하는 항진균성 항생물질에 관한 연구(제 2 보) 항진균성 항생물질 trans-Cinnamamide의 생성)

  • Bae, Moo;Ko, Young-Hee;Lee, Hwa-Seok;Cho, Jin-Ho
    • Microbiology and Biotechnology Letters
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    • v.10 no.1
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    • pp.39-43
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    • 1982
  • t-Cinnamamide has been isolated from the culture filtrate of the isolates, Streptomyces. sp. No.297 The identity of the compound was established by UV and IR spectra, NMR, mass spectra and by chemical reactions. Through antimicrobial activity test using a two-fold serial agar dilution mothjod, t-cinnamamide showed strong growth inhibitory activity against Pellicularia sasakii, Pyriculario oryzae and some pathogenic fungi, but not inhibitory over procaryotes tested.

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Comparative Studies on Two Fluoro-Substituted 2-Pyrazoline Derivatives with Experimental and Theoretical Methods

  • Guo, Huan-Mei;Wang, Xian;Jian, Fang Fang;Xiao, Hai Lian;Zhao, Pu Su
    • Bulletin of the Korean Chemical Society
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    • v.30 no.5
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    • pp.1061-1066
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    • 2009
  • Two fluoro-substituted 2-pyrazoline derivatives, 1-phenyl-3-(4-methoxyphenyl)-5-(4-fluorophenyl)-2-pyrazoline (1) and 1-phenyl-3-(4-methoxyphenyl)-5-(2-fluoro-phenyl)-2-pyrazoline (2) have been synthesized and characterized by elemental analysis, IR, UV-Vis and fluorescence spectra. The crystal structure of 1 has been determined by X-ray single crystal diffraction. For the two compounds, density functional theory (DFT) calculations of the structures and natural population atomic charge analysis (NPA) have been performed at B3LYP/6-311G** level of theory. By using TD-DFT method, electron spectra of 1 and 2 have been predicted, which are very approximate with the experimental ones. Comparative studies on 1 and 2 indicate that the location change of fluorine atom in 5-position phenyl ring of 2-pyrazoline does not make significant change of geometries and electronic transition bands, but it leads to evident change of atomic charge distributions and peak intensities of UV and fluorescence spectra.

Optical and electrical properties of $C_{22}$-quinolinium(TCNQ) langmuir-glodgett films depending on the annealing temperatures ($C_{22}$-quinolinium(TCNQ) langmuir-blodgett 박막의 열처리 온도에 따른 광학적 및 유전특성)

  • 홍언식;유덕선;김태완
    • Electrical & Electronic Materials
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    • v.8 no.4
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    • pp.458-463
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    • 1995
  • The optical and electrical properties of $C_{22}$-Quinolinium(TCNQ) Langmuir-Blodgett films have been studied depending on the annealing temperatures. The optimal properties were investigated using UV/visible(300-800[nm]) absorption spectra and FTIR(Fourier-transformed- infrared) absorption measurements. The electrical properties were investigated in a frequency range of 10[Hz]-13[MHz]. The UV/visible absorption spectra at room temperature show that there are four characteristic peaks at 320, 380, 494 and 678[nm]. These absorption peaks decrease very rapidly above the annealing temperature of 180[.deg. C], which is due to a structural change of TCNQ. The FTIR absorption measurements strongly support the result of the UV/visible absorption spectra, because the absorption peak of TCNQ- at 2181[$cm^{-1}$ /] also decreases above 140[.deg. C]. The frequency-dependent dielectric constant shows that there is a dielectric dispersion near 1[MHz] which is due to an orientational polarization of the molecules inside the film. The overall frequency-dependent dielectric constant is higher near 80[.deg. C]. It may be due to a softness of the alkyl chains.s.

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UV-cut Lens Manufacture using Optical Absorption Edge Control (광흡수단을 제어를 이용한 UV 차단렌즈 개발)

  • Kim, Yong Geun;Park, Dong Hwa;Sung, Jung Sub
    • Journal of Korean Ophthalmic Optics Society
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    • v.7 no.1
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    • pp.29-34
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    • 2002
  • Because do dilution (5%) in Venzotriazol distilled water and is kept UV interception departure woe which make to time each 1, 2, 5, 15, 20, 30 minutes by dip method, produced sample ore of UV interception lens. Spectrum of transmittance for each sample are measured in 320~450nm sacred grounds. The result optical absorption edge is each 403, 408, 414, 419nm regions, and absorption edge appeared in each band of 3.07, 3.04, 2.99, 2.96 eV. UV-cut lens departure solution make 2-Hydroxy-4-n-octoxyhenzophenones of 5%, 10% because solvent methanol and UV-cut lens made by Spray pyrolysis method. Transmission edge of each lens that do spray to same warelength showed sameinwavelength spectra. Being storehouse absorption edgethat increase 385, 398 and 417nm region of when do spray for 2, 4 and 6 minutes, band is accomplishing each 3.22, 3.11, 2.97 eV.

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Studies on the Natural dyes( I ) -extraction and UV, VIS spectrum of coloring matter of gromwell- (천연염료에 관한 연구 ( I ) -자근색소의 추출 및 자외가시분광특성-)

  • Cho Kyung Rae
    • Journal of the Korean Society of Clothing and Textiles
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    • v.11 no.3
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    • pp.25-32
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    • 1987
  • The purpose of this study is to investigate optical behaviour of coloring matter of gromwell -extracted by water, acetic acid/methanol, and the other solvents. The results were as following: UV, VIS spectra of the solution of coloring matter of gromwell extracted by water at below $80^{\circ}C$ did not reveal in the range of the visible light wavelength and coloring matter of gromwell decomposed to blue particle at $95^{\circ}C$. The solution extracted by acetic acid/methanol was tinged with reddish purple and its spectra shifted to the longer wavelength according to increase of the solvent temperature. The color of the solution extracted by water became extinct as time went by, but that extracted by acetic acid/methanol kept up original color. In case of dried gromwell, extraction by acetic acid/methanol was easier than by water, and variation of spectra did not appear but showed hypochromic shift.

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Investigating the relation between AGN gas metallicity and their host galaxy stellar metallicity using a sample of local Seyfert 1 galaxies

  • Shin, Jae-Jin;Woo, Jong-Hak
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.72.1-72.1
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    • 2011
  • We investigate the relation between AGN gas metallicity and their host galaxy stellar metallicity using a sample of local Seyfert 1 galaxies. Stellar metallicity is measured from stellar absorption lines while AGN gas metallicity is derived from the flux ratios of UV emission lines. We use a high quality spectra obtained from the Lick AGN Monitoring Project, to obtain pure host galaxy spectra based on the spectral decomposition analysis, leading to accurate measurements of the Mg2 (5175) and Fe (5270) indices. In the case of AGN gas metallicity, we measure the ratio of NV1240 to CIV1549 lines using UV spectra from the archival IUE and HST STIS data. We will present the results of metallicity measurements and comparison between AGN and stellar metallicity, and discuss the implications of the results.

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Partially Folded States of Mutant Ubiquitin in Mild Denaturing Conditions

  • Park, Soon-Ho
    • Bulletin of the Korean Chemical Society
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    • v.30 no.7
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    • pp.1567-1572
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    • 2009
  • Conformational change of ubiquitin variant with valine to alanine mutation at sequence position 26 was studied by varying solvent pH. Fluorescence emission spectra indicated that this variant ubiquitin has some residual structures in acidic and basic solution as compared to denaturant-induced unfolded state. Far-UV circular dichroic spectra indicated that the base-denatured state had more secondary structure than the acid-denatured state. Near-UV circular dichroic spectra indicated that the aromatic side-chains were in the relatively more rigid environment in the base-denatured state than those in the acid-denatured state. Although it appears that the more tertiary structure present in the base-denatured state, refolding reactions measured by stopped-flow fluorescence device suggest that both the acid- and base-denatured states occur before the major folding transition state. The acid- and base-denatured states are considered to reflect the early event of protein folding process.