• Title/Summary/Keyword: Green Bond

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Relationship between the Molecular Structure and the Absorption Band Shape of Organic Dye (유기색소의 흡수대 형태와 분자구조와의 상관성)

  • Jun, Kun;Gwon, Seon Yeong;Kim, Sung Hoon
    • Textile Coloration and Finishing
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    • v.27 no.4
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    • pp.270-274
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    • 2015
  • Molecules always show broad absorption band envelopes, and this results from the vibrational properties of bonds. The width of an absorption band can have an important influence on the color of a dye. A narrow band imparts a bright, spectrally pure color to the dye, whereas a broad band can give the same hue, but with a much duller appearance. Typically, half-band widths of cyanine dyes are about 25nm compared to value of over 50nm for typical merocyanine dyes. Thus, cyanine dyes are exceptionally bright. The factors influencing the width of an absorption band can be understood with reference to the Morse curves. The width of the absorption band depends on how closely the bond order of the molecules in the first excited state resembles that in the ground state. We have quantitatively evaluated the "molecular structure-absorption band shape" relationship of dye molecules by means of Pariser-Parr-Pople Molecular Orbital Method(PPP-MO).

Development of The Magnetic Abrasive Using Ba-Ferrite and GC, CBN (Ba-Ferrite와 GC, CBN을 이용한 자기 연마재 개발)

  • Kim, Hee-Nam;Yun, Yeo-Kwon
    • Journal of the Korean Society of Safety
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    • v.23 no.5
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    • pp.43-48
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    • 2008
  • The magnetic polishing is the useful method to finish some machinery fabrications by using magnetic power. This method is one of the precision polishing techniques and has an aim for clean technology in the transportation of the pure gas in the clean pipes. The magnetic abrasive polishing method is not so common in the field of machine that it is not known to widely. There are only few researchers in this field because of non-effectiveness of magnetic abrasive. Therefore, in this paper deals with development of the magnetic abrasive using Ba-Ferrite. In this development, abrasive grain GC and CBN has been made by using the resin bond fabricated at low temperature. And magnetic abrasive powder was fabricated from the Ba-Ferrite which was crushed into 200 mesh. The XRD analysis result shows that only GC, CBN and Ba-Ferrite crystal peaks were detected, explaining that resin bond was not any more to contribute chemical reaction. From SEM analysis, we found that GC, CBN abrasive and Ba-Ferrite were strongly bonding with each other.

The Americanization of a Canadian National Icon Anne of Green Gables (캐나다의 국가적 아이콘 『빨강머리 앤』의 미국화)

  • Kang, Suk Jin
    • Journal of English Language & Literature
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    • v.54 no.4
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    • pp.561-577
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    • 2008
  • L.M. Montgomery's Anne of Green Gables is not only confidently labelled a Canadian classic but also placed as a national icon along with the moose, the beaver, and the Habs in Canada. Anne's 'Canadianness' is partly due to its location in the rural world of Prince Edward Island. The fictional Avonlea is described as the ideal space where Canadian spirit can interact with the personified surrounding landscapes through Celtic imagination. Additionally, the communal bond of Avonlea fully demonstrates Scottish Canadian identities. The Scottish national character of Avonlea is responsible for clannishness of the Cuthberts and the Lyndes. The disrespect to the French is also due to Scottish heritage in Avonlea. As an outsider Anne wants to be integrated into the community of Avonlea, and successfully adapts herself to the regional shared values. Meanwhile she partly challenges the strictness and rigidness of the born Canadian Avonlea residents. Despite its Canadian origin, Anne of Green Gables is accepted as part of the American canon of children's literature in the Unite States. The configuration of Anne as an American heroine is noticeable among American scholars: by relocating it to the US the female Bildungsroman in the nineteenth century America, a group of literary critics adapt Anne as an American girl for American readers. The heroine of Anne of Green Gables is linked to American novels such as Louisa May Alcott's Little Women, Kate Douglas Wiggin's Rebecca of Sunnybrook Farm and Gene Stratten Porter's A Girl of the Limberlost. Anne is even classified as another Caddie by American literary critics: Anne is placed at the center of Caddie Woodlawn Syndrome as another Wisconsin pioneer child. Canadian identity of Anne is intentionally excluded and Anne was reborn as an American girl in the U.S. In this context, Anne functions as a sign of nation and a site for cross-national identity formation.

Spectroscopic Comparison of Photo-oxidation of Outside and Inside of Hair by UVB Irradiation (자외선B 조사에 의한 모발 외부와 내부의 광산화에 관한 분광학적 비교)

  • Ha, Byung-Jo
    • Applied Chemistry for Engineering
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    • v.31 no.2
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    • pp.220-225
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    • 2020
  • Hair is made of proteins containing various amino acids. Ultraviolet (UV) radiation is believed to be responsible for the most damaging effects of sunlight, and also plays an important role in hair aging. The purpose of this study was to investigate the changes in morphological and chemical structures after ultraviolet B (UVB) irradiation of human hair. The UVB-irradiated hair showed characteristic morphological and structural changes, compared to those of the normal hair. The result from a scanning electron microscope (SEM) equipped with an energy dispersive X-ray diffractometer (EDX) showed that the scale of UV-irradiated hair appeared to be rough and the amount of oxygen element was higher than that of the normal hair. Fluorescence and three dimensional (3D) topographical images were obtained by a confocal laser scanning microscope (CLSM). In 3D images, the green emission intensity of normal hair was much higher than that of fluorescing UVB-irradiated hair. The intensity of green emission reflects the intrinsic fluorescence of hair protein. Also, a fluorescent imaging method using fluorescamine reagent was used to identify the free amino groups resulting from a peptide bond breakage in UVB-irradiated hair. Strong blue fluorescence of UVB-irradiated hair, which indicates a very high level of amino groups, was observed by CLSM. Therefore, the fluorescamine as an extrinsic fluorescence could provide a useful tool to identify the peptide bond breakage in UVB-irradiated hair. Infrared image mapping was also employed to assess the cross-sections of normal and UVB-irradiated specimens to examine the oxidation of disulfide bonds. The degree of peak areas with strong absorbance for the disulfide mono-oxide was spread from the outside to the inside of hair. The spectroscopic techniques used alone, or in combination, launch new possibilities in the field of hair cosmetics.

Bond Strength of TiO2 Coatings onto FTO Glass for a Dye-sensitized Solar Cell

  • Lee, Deuk Yong;Kim, Jin-Tae;Kim, Young-Hun;Lee, In-Kyu;Lee, Myung-Hyun;Kim, Bae-Yeon
    • Journal of Sensor Science and Technology
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    • v.21 no.6
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    • pp.395-401
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    • 2012
  • The bond strength of three types of $TiO_2$ coatings onto fluorine-doped $SnO_2$ (FTO) glass was investigated with the aid of a tape test according to ASTM D 3359-95. Transmittance was then measured using an UV-vis spectrophotometer in the wavelength range of 300 nm to 800 nm to evaluate the extent of adhesion of $TiO_2$ nanorods/nanoparticles on FTO glass. A sharp interface between the coating layer and the substrate was observed for single $TiO_2$ coating ($TiO_2$ nanorods/FTO glass), which may be detrimental to the bonding strength. In multicoating sample ($TiO_2$ nanorod/$TiO_2$ nanoparticle/$TiO_2$ nanoparticle/FTO glass), the tape test was not performed due to severe peeling-off prior to the test. On the other hand, the dual coating sample ($TiO_2$ nanorod/$TiO_2$ nanoparticle/FTO glass) showed minimum variation of transmittance (4%) after the test, suggesting that the topcoat adheres well with the FTO substrate due to the presence of the $TiO_2$ nanoparticle buffer layer. The use of a $TiO_2$ nanorod electrode layer with good adhesion may be attributed to the excellent dye sensitized solar cell performance.

Development of the Magnetic Abrasive Using Sr-Ferrite and GC (Sr-Ferrite와 GC를 이용한 자기연마재 개발)

  • Yun, Yeo-Kwon;Kim, Sang-Baek;Kim, Hee-Nam
    • Journal of the Korean Society of Safety
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    • v.26 no.2
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    • pp.13-19
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    • 2011
  • The magnetic polishing is the useful method to finish using magnetic power of magnet. That method is one of precision polishing techniques and has an aim of the clean technology using for the pure of gas and inside of the clean pipe. The magnetic abrasive polishing method is not so common for machine that it is not spreaded widely. There are rarely researcher in this field because of non-effectiveness of magnetic abrasive. Therefore, in this paper deals with development of the magnetic abrasive using Sr-Ferrite. In this development, abrasive grain GC used to resin bond fabricated low temperature. And Sr-Ferrite of magnetic abrasive powder fabricated that Sr-Ferrite was crused into 200 mesh. The XRD analysis result show that only GC abrasive and Sr-Ferrite crystal peaks detected which explains resin bond was not any more chemical reaction. From SEM analysis it is found that GC abrasive and Sr-Ferrite were strong bonding with each other by bond. The magnetic polishing is performed by polishing the surface of pipe by attracting magnetic abrasives with magnetic fields. This can be widely applied for finishing machinery fabrications such as various pipes and for other safety processes. In this paper, we could have investigated in to the changes of the movement of magnetic abrasive grain. In reference to this result, we could have made the experiment which is set under the condition of the magnetic flux density, polishing velocity according to the form of magnetic brush.

Chiral Mesoporous Silica for Asymmetric Metal-free Catalysis: Enhancement of Chirality thorough Confinement Space by Plug Effect

  • Jeong, Eun-Yeong;Im, Cheong-Rae;Park, Sang-Eon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.199-199
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    • 2011
  • The addition of a carbanion to ${\yen}{\acute{a}}{\yen}{\hat{a}}$-unsaturated carbonyl compounds is of importance in the C-C bond formation reactions for modern pharmaceuticals and organic synthesis. Recently, heterogeneous asymmetric catalysis became more attractive area of research because of the easy recovery and separation of the catalyst from the reaction system. Most of synthetic methods for heterogeneous catalysts were grafting or immobilization of homogeneous catalyst onto the solid supports. Trans-1,2-Diaminocyclohexane(DACH) and L-proline ligands have been enormously used as chiral ligands in several catalytic transformation under homogenous conditions. Our group prepared l-proline functionalized mesoporous silica was synthesized under acidic condition using a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer template (EO20PO70EO20, Pluronic P-123, BASF). Furthermore, we successfully directly synthesized trans-1,2 diaminocyclohexane functionalized mesoporous silica by using microwave method. The direct functionalization of chiral ligand into the framework of mesoporous materials is expected to be useful for the heterogeneous asymmetric catalysis. So, we adopt the direct synthesis of chiral ligand functionalized mesoporous silica by using thermal and microwave irradiation. Then, chiral ligand functionalized mesoporous silicas were applied to enantioselective asymmetric catalytic reactions.

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Fabrication of Ceramic Heat Exchanger Cores by Doctor Blade Process (Doctor blade 공정에 의한 세라믹스 열교환기 소자의 제조)

  • 김상우;송휴섭;장성도
    • Journal of the Korean Ceramic Society
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    • v.29 no.3
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    • pp.241-251
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    • 1992
  • The effects of slip composition and processing conditions on the fabrication of ceramic heat exchanger cores by doctor blade process were investigated. Since the effects of those two variables were inter-dependent, the effects of binder system, binder plus plasticizer, were extensively studied for a limited range of processing conditions and a pre-determined ceramic composition. The content of binder system and the ratio of binder to plasticizer were identified as main variables to affect densities and mechanical properties of green sheets, compressive properties and bond strengths of laminates, and shrinkages and their anisotropy of sintered laminates. However, sintered densities and water absorptions of laminates were not influenced by either the content of binder system or the ratio of binder to plasticizer, when the debinded laminates had a relatively high density (relative density of >55% in this study).

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Electrical and transport properties of carbon chains encapsulated within CNT

  • KIM, Tae Hyung;KIM, Hu Sung;KIM, Yong-Hoon
    • Proceeding of EDISON Challenge
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    • 2017.03a
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    • pp.457-462
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    • 2017
  • A linear carbon chain with pure sp hybridization has been intensively studied for the application of its intrinsic electrical properties to electronic devices. Owing to the high chemical reactivity derived from its unsaturated bond, encapsulation by carbon nanotubes (CNT) is provided as a promising method to stabilize the geometry of the linear carbon chain. Although the influence of CNT on the carbon chain has extensively been studied in terms of both electronic structure and geometries, the electron transport properties has not been discussed yet. In this regard, we provide the systematic atomic-scale analyses of the properties of the linear carbon chain within CNT based on a computational approach combining density-functional theory (DFT) and matrix green function (MGF) method. Based on the DFT calculations, the influence of CNT on electronic structures of the linear carbon chain is provided as well as its electrical origin. Via MGF calculations, we also identify the electron transport properties of the carbon chain - CNT complex.

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Magnetic Abrasive Polishing for Internal Face of Seamless Stainless Steel Tube Using Sludge Abrasive Grain (슬러지 연마입자를 이용한 이음매 없는 스테인리스강 튜브내면의 자기연마)

  • Kim, Hee-Nam;Yun, Yeo-Kwon;Kim, Sang-Baek;Choi, Hee-Sung
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.6
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    • pp.151-157
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    • 2004
  • In this paper deals with behavior of the magnetic abrasive using sludge on polishing characteristics in a new internal finishing of seamless stainless steel tube applying magnetic abrasive polishing. The magnetic abrasive using sludge-abrasive grain WA and GC used to resin bond fabricated low temperature. And sludge of magnetic abrasive powder fabricated that sludge was crused into 200 mesh. The previous research have made an experiment in the static state the movement of magnetic abrasive grain is nevertheless in the dynamic state. In this paper, We could have investigated into the changes of the movement of magnetic abrasive grain. In reference to this result, we could have made the experiment which is set under the condition of the magnetic flux density, polishing velocity according to the form of magnetic brush.