• Title/Summary/Keyword: ultraviolet absorption

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Removal of Rhodamine B in Water by Ultraviolet Radiation Combined with Electrolysis(II) (전기분해와 UV 조사에 의한 수중 Rhodamine B의 제거(II))

  • Kim, Dong-Seog;Park, Young-Seek
    • Journal of Environmental Science International
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    • v.18 no.6
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    • pp.667-674
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    • 2009
  • This study has carried out to evaluate the effect of NaCI as electrolyte of single (electrolysis and UV process) and complex (electrolysis/UV) processes for the purpose of removal and mineralization of Rhodamine B (RhB) dye in water. It also evaluated the synergetic effect on the combination of electrolysis and UV process. The experimental results showed that RhB removal of UV process was decreased with increase of NaCl, while RhB removal of electrolysis and electrolysis/UV process was increased with increase of NaCI. The decolorization rate of the RhB solution in every process was more rapid than the mineralization rate identified by COD removal. The latter took longer time for further oxidation. Absorption spectra of an aqueous solution containing RhB showed a continued diminution of the RhB concentration in the bulk solution: concomitantly, no new absorption peaks appeared. This confirmed the decolorization of RhB, i.e., the breakup of the chromophores. It was observed that RhB removal in electrolysis/UV process is similar to the sum of the UV and electrolysis. However, it was found that the COD of RhB could be degraded more efficiently by the electrolysis/UV process than the sum of the two individual process. A synergetic effect was demonstrated in electrolysis/UV process.

Study on UV Absorption Materials Derived from Red Algae Gloiopeltis fucatas and Mazzaella sp. in Russia

  • Lee, Moon-Hee;Kim, Yeon-Kye;Yoon, Na Young;Shim, Kil Bo;Aminina, Natalya M.;Kadnikova, Irina A.;Lim, Chi-Won
    • Fisheries and Aquatic Sciences
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    • v.15 no.4
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    • pp.361-363
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    • 2012
  • We investigated ultraviolet (UV) absorption materials from Russian seaweeds. First, the UV absorptivities of five seaweeds Gloiopeltis fucatas, Mazzaella sp., Mastocarpus pacificus, Laminaria cichorioides, Saccharina japonica were evaluated by a UV spectrometer. Of these seaweeds, Gloiopeltis fucatas and Mazzaella sp. showed high levels of UV absorption. Column chromatography of active 50% aqueous ethanol extracts from Gloiopeltis fucatas and Mazzaella sp. resulted in the purification of two known compounds. Spectroscopic techniques identified their structures as shinorine and palythine. These materials exhibited UV absorptive capabilities at wavelengths of 333 and 320 nm, respectively. These results suggest that Gloiopeltis fucatas and Mazzaella sp. may be useful as natural cosmeceutical sources.

Fluorescence Analysis of Harmful Food Colors -Establishment of Fluorescence Assay Method by the Use of Filter Paper Adsorption- (유해성(有害性) 식품착색료(食品着色料)의 형광검사(螢光檢査) -여지흡착(濾紙吸着)을 이용한 형광분석법(螢光分析法)의 확립-)

  • Lee, Mie-Soon
    • Korean Journal of Food Science and Technology
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    • v.13 no.2
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    • pp.114-120
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    • 1981
  • A rapid and simple method for detecting colors was attempted on the basis of absorption and emission spectra of reflected light at $45^{\circ}$ angle from color-adsorbed filter paper illuminated by ultraviolet light through interference filter. Absorption spectra of prepared samples revealed more characteristic patterns than emission spectra. Detection of colors was readily accomplished by the investigation of wave length range, distribution pattern, the number of absorption bands and the degree of quenching.

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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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Design of an Electron Ohmic-Contact to Improve the Balanced Charge Injection in OLEDs

  • Park, Jin-U;Im, Jong-Tae;Yeom, Geun-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.283-283
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    • 2011
  • The n-doping effect by doping metal carbonate into an electron-injecting organic layer can improve the device performance by the balanced carrier injection because an electron ohmic contact between cathode and an electron-transporting layer, for example, a high current density, a high efficiency, a high luminance, and a low power consumption. In the study, first, we investigated an electron-ohmic property of electron-only device, which has a ITO/$Rb_2CO_3$-doped $C_{60}$/Al structure. Second, we examined the I-V-L characteristics of all-ohmic OLEDs, which are glass/ITO/$MoO_x$-doped NPB (25%, 5 nm)/NPB (63 nm)/$Alq_3$ (32 nm)/$Rb_2CO_3$-doped $C_{60}$(y%, 10 nm)/Al. The $MoO_x$doped NPB and $Rb_2CO_3$-doped fullerene layer were used as the hole-ohmic contact and electron-ohmic contact layer in all-ohmic OLEDs, respectively, Third, the electronic structure of the $Rb_2CO_3$-doped $C_{60}$-doped interfaces were investigated by analyzing photoemission properties, such as x-ray photoemission spectroscopy (XPS), Ultraviolet Photoemission spectroscopy (UPS), and Near-edge x-ray absorption fine structure (NEXAFS) spectroscopy, as a doping concentration at the interfaces of $Rb_2CO_3$-doped fullerene are changed. Finally, the correlation between the device performance in all ohmic devices and the interfacial property of the $Rb_2CO_3$-doped $C_{60}$ thin film was discussed with an energy band diagram.

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Dyeability and Functionality of Pine Needles Extract (part I) -Characteristics of Pine Needles Extract and Dyeing Properties of Cellulose Fiber- (솔잎 추출물의 염색성과 기능성 (제1보) -솔잎 추출물의 특성과 셀룰로오스섬유에 대한 염색성-)

  • Woo, Hyo-Jung;Lee, Jung-Soon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.35 no.2
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    • pp.218-229
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    • 2011
  • Dyeing properties of cotton and ramie fabrics with pine needles colorants were studied by investigating the analysis of pine needles colorants, the effect of dyeing conditions (such as dye concentration, dyeing temperatures and times on dye uptakes), effect of mordants, and color change. The various colorfastness of dyed fabrics were evaluated for practical use; in addition, the antimicrobial ability, ultraviolet-cut ability, and deodorant ability were estimated. In the UV-Visible spectrum, the wavelength of the maximum absorption for pine needles extract was 285nm, and pine needles colorants produced a yellow color. From FT-IR and GC-MS results, it was assumed that chromophoric substance from pine needles extracts were mixed with flavonol tannin and flavanol tannin. An increased dyeing concentration resulted in a larger dye uptake and a Freundlich absorption isotherm was obtained. A larger dye uptake occurred as the dyeing time and temperature increased. Post-mordanting was more effective than pre-mordanting and the dye uptake of fabrics improved by mordanting. The colorfastness of dyed fabrics showed a low rating; however, colorfastness to washing and dry cleaning of cotton fabrics mordanted with N.Cu, and friction fastness of ramie fabric mordanted with Cu improved. The dyed fabrics showed very good antimicrobial abilities of 99.9%. In addition, the ultraviolet-cut ability and deodorant ability improved in fabrics dyed with pine needles extracts.

Dyeability and Functionality of Bamboo Extracts (Part I) -Characteristics of Bamboo Extracts and Dyeing Properties of Cotton- (대나무 추출물의 염색성과 기능성 (제1보) -대나무 추출물의 특성과 면직물에 대한 염색성-)

  • Jung, Go-Eun;Lee, Jung-Soon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.35 no.2
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    • pp.206-217
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    • 2011
  • The dyeing properties of cotton fabrics with bamboo colorants were studied by investigating the analysis of bamboo colorants, the effect of dyeing conditions (dye concentrations, dyeing temperatures and times on dye uptakes), effect of mordants, and color change. The various colorfastness of dyed fabrics were evaluated for practical use; in addition, the antimicrobial ability, ultraviolet-cut ability, and deodorant ability were also estimated. In the UV-Visible spectrum, the wavelength of the maximum absorption for bamboo stems and leaves extracts was found to be 280nm and 295nm, respectively; in addition, bamboo colorants produced a yellow color. From the FT-IR and GC-MS results, it was assumed that the chromophoric substance from bamboo extracts was composed of flavones substances with tricin. An increased dyeing concentration resulted in a larger dye uptake and a Freundlich absorption isotherm was obtained. A larger dye uptake occurred as the dyeing time and temperature increased. The post-mordanting was more effective than pre-mordanting. Mordants, Fe and N.Fe, were effective for an increased dye uptake. The color of fabrics mordanted with Cu and N.Cu changed to GY. Regardless of mordanting, the colorfastness on the washing of dyed fabrics showed a low rating compared to other fastness. Mordanting adversely affected the lightfastness of dyed fabric. The dyed fabric showed very good antimicrobial abilities of 99.9%. In addition, the ultraviolet-cut ability and deodorant ability improved in cotton fabric dyed with bamboo extracts.

Assessment and Applications of Multi-Degradable Polyethylene Films as Packaging Materials

  • Chung, Myong-Soo;Lee, Wang-Hyun;You, Young-Sun;Kim, Hye-Young;Park, Ki-Moon;Lee, Sun-Young
    • Food Science and Biotechnology
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    • v.15 no.1
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    • pp.5-12
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    • 2006
  • Degradation performance of environmentally friendly plastics that can be disintegrated by combination of sunlight, microbes in soil, and heat produced in landfills was evaluated for use in industries. Two multi-degradable master batches (MCC-101 and MCC-102 were manufactured, separately mixed with polyethylene using film molding machine to produce 0.025 mm thick films, and exposed to sunlight, microbes, and heat. Low- and high-density polyethylene (LDPE and HDPE) films containing MCC-101 and MCC-102 became unfunctional by increasing severe cleavage at the surface and showed high reduction in elongation after 40 days of exposure to ultraviolet light. LDPE and HDPE films showed significant physical degradation after 100 and 120 days, respectively, of incubation at $68{\pm}2^{\circ}C$. SEM images of films cultured in mixed mold spore suspension at $30^{\circ}C$ and 85% humidity for 30 days revealed accelerated biodegradation on film surfaces by the action of microbes. LDPE films containing MCC-l01 showed absorption of carbonyls, photo-sensitive sites, at $1710\;cm${-1}$ when exposed to light for 40 days, whereas those not exposed to ultraviolet light showed no absorption at the same frequency. MCC-101-based LDPE films showed much lower $M_w$ distribution after exposure to UV than its counterpart, due to agents accelerating photo-degradation contained in MCC-101.

Optical properties of epitaxial $Gd_2$O_3:EU^{3+}$luminescent thin films depending on crystallinity ($Gd_2$O_3:EU^{3+}$ 형광체 박막의 결정성에 따른 발광특성 연구)

  • 장문형;최윤기;정권범;황보상우;장홍규;노명근;조만호;손기선;김창해
    • Journal of the Korean Vacuum Society
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    • v.12 no.4
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    • pp.275-280
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    • 2003
  • Epitaxial Gd$_2O_3:Eu^{3+}$luminescent thin films have been grout on Si(III) substrates using ionized Cluster Beam Deposition (ICBD). After the film growing, they were implanted and post annealed to change the crystal structure. The initial growth stage was monitored by using in-situ Reflection High Energy Electron Diffraction (RHEED). The formed crystal structure was identified with X-ray diffraction (XRD) technique and Fourier transform infrared (FT-R) spectroscopy. The electronic states variations were investigated by Near Edge X-ray Absorption Fine Structure (NEXAFS). Photoluminescence (PL), Cathodoluminescence (CL). and Vacuum ultraviolet (VUV) spectrum were used for examining the optical properties. We report the optical property changes depending on crystal structure and the electronic states.

The Study of DEP Degradation Properties by Combination US and UV Lamp of Different Wavelength (초음파 (US)와 다양한 파장범위의 자외선 (UV) 조사에 따른 DEP 분해특성에 관한 연구)

  • Na, Seung-Min;Cai, Jinhua;Shin, Dong-Hoon;Cui, Mingcan;Khim, Jee-Hyeong
    • Journal of Environmental Science International
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    • v.21 no.7
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    • pp.845-853
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    • 2012
  • Diethyl phthalate (DEP) is widely spread in the natural environment as an endocrine disruption chemicals (EDs). Therefore, in this study, ultrasound (US) and ultraviolet (UVC), including various applied power density (10-40 W/L), UV wavelengths (365 nm, 254 nm and 185 nm) and frequencies (283 kHz, 935 kHz) were applied to a DEP contaminated solution. The pseudo-first order degradation rate constants were in the order of $10^{-1}$ to $10^{-4}\;min^{-1}$ depending on the processes. Photolytic and sonophotolytic DEP degradation rate also were high at shortest UV wavelength (VUV) due to the higher energy of photons, higher molar absorption coefficient of DEP and increased hydroxyl radical generation from homolysis of water. Sonolytic DEP degradation rate increased with increase of applied input power and the dominant reaction mechanism of DEP in sonolysis was estimated as hydroxyl radical reaction by the addition of t-BuOH, which is a common hydroxyl radical scavenger. Moreover, synergistic effect of were also observed for sonophotolytic degradation with various UV irradiation.