• Title/Summary/Keyword: Absorption ability

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Antioxidant Activity of Solvent Extract Isolated from Barley Leaves (보리잎에서 분리된 용매 추출물의 항산화 작용)

  • 이영철;손종연
    • The Korean Journal of Food And Nutrition
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    • v.7 no.4
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    • pp.332-337
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    • 1994
  • The antioxidant activity of solvent extracts isolated from barley leaves was investigated by measuring peroxide value. The fractions of methanol extract obtained from preparative TLC was also studies, with UV-Visible spectrum, total phenol contents and hydrogen donating ability(HDA) The antioxidant activity of various solvent extracts was, in decreasing order, methanol> ethyl ether> methylene chloride $\geq$ ethyl acetate $\geq$acetone> hexane. The antioxidant activity of the fractions of methanol extract was, in decreasing order, fraction 2> fraction 3> fraction 1 and their activity was all superior to that of tocopherol at 500 ppm level. All fraction(1, 2 and 3) exhibited a strong UV absorption at 280 m which would be specifically produced by phenolic compound. UV absorption at 280 m of fraction 2 was greater than those of fraction 1 and 3. In the visible spectrum of these fractions, the maximum .absorption wavelengths of fraction 1, 2 and 3 were 660, 460 and 460 m, respectively. Antioxidant activity of barley leaves seemed to be due to the flavonoids containing phenolic group by UV spectrum and total phenol content.

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Dyeability and Functionality of Pine Needles Extract (Part II) -Dyeing Properties of Protein Fiber- (솔잎 추출물의 염색성과 기능성 (제2보) -단백질섬유에 대한 염색성-)

  • Woo, Hyo-Jung;Lee, Jung-Soon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.35 no.4
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    • pp.466-475
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    • 2011
  • The dyeing properties of protein fiber with pine needles colorants were studied through an investigation of the effect of dyeing conditions such as dye concentration, dyeing temperatures and time on dye uptakes, effect of mordants, and color change. In addition, the various colorfastness of dyed silk and wool fabrics were evaluated for practical use. The antimicrobial ability, ultraviolet-cut ability, and deodorant ability were also estimated. The dye uptake increased as the dyeing concentration increased and this enabled the obtainment of the Langmuir absorption isotherm. The dye uptake increased as the dyeing time and temperature increased. Pine needles colorants showed relatively good affinity to protein fiber and produced a yellow color. Post-mordanting was more effective than the pre-mordanting, and the dye uptake of fabrics improved by mordanting. Except for washing, the colorfastness of dyed fabrics showed a low rating. However, the colorfastness to light and the dry cleaning of fabrics mordanted with N.Cu, and the friction fastness of fabrics mordanted with Cu improved. The guide 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.

A Study on The Relationship Between Technological Innovation, Technology Absorption Capacity, and Business Performance in Ship Parts Manufacturing (선박 부품 제조업의 기술혁신, 기술흡수역량과 경영성과 상호 간의 관계 연구)

  • Lee, Dong-Gyun
    • The Journal of the Korea Contents Association
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    • v.22 no.2
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    • pp.617-629
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    • 2022
  • This study empirically analyzed the mediating effect of technology absorption capacity in the relationship between technological innovation of ship parts manufacturing companies on business performance. Through this, it will be possible to provide implications for improvement plans for management strategy establishment related to technology development in the future. In order to achieve the purpose of this study, R&D, marketing, production·A total of 362 people working in manufacturing and finance/accounting departments were selected as subjects for this study. As a result of this study, it was found that technological innovation and technology absorption capacity of ship parts manufacturing companies have a positive (+) effect on business performance. The conclusion based on these research results is that the potential absorption capacity and realized absorption capacity constituting technology absorption capacity are judged to be the main key factors between technological innovation and management performance, such as continuous technological capacity accumulation. From a practical point of view, the ship parts manufacturing industry needs to focus on its ability to absorb smart parts process technology.

A Study on Multi-Layered EM Wave Absorber Using Natural Lacquer as a Binder

  • Choi, Dong-Han;Kim, Dong-Il;Choi, Chang-Mook;Li, Rui
    • Journal of Navigation and Port Research
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    • v.30 no.9
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    • pp.767-772
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    • 2006
  • Generally, a silicone rubber and a chlorinated polyethylene(CPE) have been used as a binder for the development of high-performance composite EM(Electro Magnetic) wave absorbers. In this paper, the EM wave absorption performance of natural lacquer, which is newly proposed as a binder was investigated. The prepared MnZn ferrite EM wave absorbers are mixed with natural lacquer showed excellent EM wave absorption characteristics compared with MnZn ferrite EM wave absorbers which are mixed with the conventional binders. MnZn ferrite EM wave absorbers mixed with natural lacquer were prepared and their absorption ability was also investigated The EM wave absorbers are fabricated in different proportions of MnZn, or NiZn ferrite and natural lacquer, and their reflection coefficients are measured. The permittivity and permeability are calculated by using the measured reflection coefficients. The EM wave absorption abilities are calculated according to different thicknesses of the EM wave absorbers.

A Study on the Absorption Characteristics of Absorbents in Duct System with the Air Cavity (공기층을 갖는 공조덕트 구조물에서 흡음재의 흡음특성에 관한 연구)

  • 김찬묵;김도연;방극호
    • Journal of KSNVE
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    • v.10 no.5
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    • pp.892-897
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    • 2000
  • In this paper, experimental methods to find acoustic characteristics of acoustically treated air-conditioning duct system are proposed. Existing methods to analyze acoustic properties of duct with absorbent material have dilemma which has to assume the wave in duct to be a plane wave. Under this assumption. applicable frequency limitation makes accurate analysis of practical air-conditioning system impossible. In order to analyze the properties of in-lined treated absorbent with high degree of accuracy, in this experiments the range of exciting frequency of sound source is broadband, which means that source speaker excited higher mode of in-duct sound field. Also, to define the relations of air cavity to the acoustic characteristics, acoustic experiments on ducts with air cavity of different depth are operated. In conclusion, air-cavity makes the absorbing ability of duct improved in low frequency range. Due to the interactions between the air cavity depth and the depth of absorbents, according to depth of cavity, the magnitude of absorption coefficients vs frequencies in specific range is changed. In lower frequency range, the absorption of sound energy by air cavity is more dominant than by absorbent itself, in higher range, the inversion is true.

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Density Functional Theory Study on D-π-A-type Organic Dyes Containing Different Electron-Donors for Dye-Sensitized Solar Cells

  • Song, Jing;Xu, Jie
    • Bulletin of the Korean Chemical Society
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    • v.34 no.11
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    • pp.3211-3217
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    • 2013
  • Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations have been employed to investigate the molecular structures and absorption spectra of three D-${\pi}$-A-type organic dyes (C1-1, D5 and TH208) containing identical ${\pi}$-spacers and electron acceptors, but different aromatic amine electron-donating groups (tetrahydroquinoline, triphenylamine and phenothiazine). The coplanar geometries indicate that the strong conjugation is formed in the dyes. The electronic structures suggest that the intramolecular charge transfer from the donor to the acceptor occurs, and the electron-donating ability of tetrahydroquinoline is stronger than those of triphenylamine and phenothiazine. The computed orbital energy levels of these dyes confirm that the electrons could be injected from the excited dyes to the semiconductor conduction band and the oxidized dyes could be reduced effectively by electrolyte. The TD-DFT results show that the CAM-B3LYP/6-31+G(d, p) is suitable for calculating the absorption spectra. The first absorption band for these dyes is assigned to the HOMO${\rightarrow}$LUMO and HOMO-1${\rightarrow}$LUMO transitions.

A Study on Multi-Layered EM Wave Absorber Using Natural Lacquer as a Binder

  • Choi, Dong-Han;Kim, Dong-Il;Choi, Chang-Mook;Li, Rui
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.1
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    • pp.157-161
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    • 2006
  • Generally, a silicone rubber and a chlorinated polyethylene(CPE) have been used as a binder for the development of high-performance composite EM(Electro Magnetic) wave absorbers. In this paper, the EM wave absorption performance of natural lacquer, which is newly proposed as a binder was investigated. The prepared MnZn ferrite EM wave absorbers are mixed with natural lacquer showed excellent EM wave absorption characteristics compared with MnZn ferrite EM wave absorbers which are mixed with the conventional binders. MnZn ferrite EM wave absorbers mixed with natural lacquer were prepared and their absorption ability was also investigated. The EM wave absorbers are fabricated in different proportions of MnZn, or NiZn ferrite and natural lacquer, and their reflection coefficients are measured. The permittivity and permeability are calculated by using the measured reflection coefficients. The EM wave absorption abilities are calculated according to different thicknesses of the EM wave absorbers.

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