• Title/Summary/Keyword: bonding surface

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Degardatrion of Cellulosic Fibers by Electron Beam Irradiation

  • Han, Sung-Ok;Seo, Yung-Bum;Lee, Chun-Han
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.39 no.5
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    • pp.20-25
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    • 2007
  • Henequen fibers were treated by electron beam irradiation and by NaOH to make surface modification for better bonding in the manufacture of biocomposite. Impurity removal and carbonyl group formation were noticed in the previous study by electron beam irradiation, but extensive cellulose degradation were also noticed. To evaluate the effects of electron beam irradiation on cellulosic fibers further, henequen fibers, cotton pulp, cotton fibers, and cellophane were irradiated by electron beam, and their changes of cellulose viscosity, chemical composition, and tensile strength were measured and analyzed.

Evaluation of Salt, Microbial Transglutaminase and Calcium Alginate on Protein Solubility and Gel Characteristics of Porcine Myofibrillar Protein

  • Hong, Geun-Pyo;Chin, Koo-Bok
    • Food Science of Animal Resources
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    • v.30 no.5
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    • pp.746-754
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    • 2010
  • Response surface methodology was adopted to model and optimize the effects of microbial transglutaminase (TG) and calcium alginate (CA) systems of various ratios on the gelation characteristics of porcine myofibrillar protein (MP) at various salt levels. The CA system consisting of sodium alginate (SA), calcium carbonate (CC) and glucono-$\delta$-lactone (GdL) showed no remarkable changes in the salt-soluble fraction, and only minor effects on electrostatic interactions were observed. Increasing CA concentration caused acid-induced hydrophobic interactions in MPs, resulting in increased MP gel strength. The TG system, containing TG and sodium caseinate (SC), induced cold-set MP gelation by formation of covalent bonding. The main advantage of the combined system was a higher cooking yield when the MP gel was heated. These results indicated that 0.7% TG combined with 0.8% CA system can form a viscoelastic MP gel, regardless of salt levels.

An XPS Study of Oxyfluorinated Multiwalled Carbon Nano Tubes

  • Yun, Seok-Min;Kim, Ju-Wan;Jung, Min-Jung;Nho, Young-Chang;Kang, Phil-Hyun;Lee, Young-Seak
    • Carbon letters
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    • v.8 no.4
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    • pp.292-298
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    • 2007
  • In order to investigate functional groups on the surface of Multi-walled Carbon Nanotubes (MWCNTs) induced by oxyfluorination, XPS (X-ray photoelectron spectroscopy) analysis was carried out. All core level spectra of MWCNTs were deconvoluted to several Pseudo-Voigt functions (sum of Gaussian-Lorentzian functions). Both O1s and F1s binding energy of oxyfluorinated MWCNTs shifted high value as increment of fluorine mixing ratio. The carbon-fluorine covalent bonding concentration increased as increment of fluorine mixing ratio. The shape and intensity of OF10-MWCNTs are similar with those of as-received MWCNTs. However, the intensity and binding energies of main peak position of OF20-MWCNTs and OF30-MWCNTs were dramatically increased by oxyfluorination.

Effect of Double Schottky Barrier in Gallium-Zinc-Oxide Thin Film

  • Oh, Teresa
    • Transactions on Electrical and Electronic Materials
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    • v.18 no.6
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    • pp.323-329
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    • 2017
  • This reports the electrical behavior, bonding structure and Schottky contact of gallium-zinc-oxide (GZO) thin film annealed at $100{\sim}400^{\circ}C$. The mobility of GZO with high density of PL spectra and crystal structure was also increased because of the structural matching between GZO and Si substrate of a crystal structure. However, the GZO annealed at $200^{\circ}C$ with an amorphous structure had the highest mobility as a result of a band to band tunneling effect. The mobility of GZO treated at low annealing temperatures under $200^{\circ}C$ increased at the GZO with an amorphous structure, but that at high temperatures over $200^{\circ}C$ also increased when it was the GZO of a crystal structure. The mobility of GZO with a Schottky barrier (SB) was mostly increased because of the effect of surface currents as well as the additional internal potential difference.

Electrical Properties of Silicone Rubber for High-Voltage (고전압용 실리콘 고무의 전기적 특성)

  • 김왕곤;홍진웅
    • Journal of the Korean Society of Safety
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    • v.15 no.4
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    • pp.41-46
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    • 2000
  • Silicone rubbers are elastomeric materials and organic copolymers, of which backbone is siloxane with high bonding strength. Silicone rubbers have been used as an power insulator because they are well weather proof, ozone proof and have excellent electric characteristics, thermal stability, cold resistance and low surface energy. Especially, it is known that they have very excellent characteristics at 200[$^{\circ}C$]. For this study, we made silicone rubbers as specimens and measured volume resistivity due to applied voltage and a variation of temperature 25[$^{\circ}C$] to 180[$^{\circ}C$]. Also we measured dielectric loss tangent due to applied voltage at temperature range 25[$^{\circ}C$] to 180[$^{\circ}C$] and frequency range 20[Hz] to 1${\times}10^6$[Hz].

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Antimicrobial Effects of Laundering and Colloidal Silver Treatment on a Cotton Fabric (은 용액 처리와 세탁 조건에 따른 면직물의 항균효과)

  • Chung, Hae-Won;Kim, Mi-Kyung
    • Fashion & Textile Research Journal
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    • v.7 no.3
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    • pp.333-338
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    • 2005
  • We examined the antimicrobial effects of the cotton fabrics which were laundered at different conditions and treated with a colloidal silver solution using Staphylococcus aureus. Colloidal silver solution was made from commercial colloidal silver generator by electrolysis. The fabric which was innoculated and washed with water before drying had no more Staphylococcus aureus, but which was innoculated and dried before washing with detergent solution had lower reduction rate. The fabric washed with oxygen bleach did not have an antimicrobial effect, but rinsed with 0.07% fabric softener showed antimicrobial properties. The fabric rinsed with 0.7ppm colloidal silver solution had better antimicrobial effects. As the treating concentration of silver solution increased, the antimicrobial property of the fabric was increased. The fabric treated with 5% silver solution sustained reflectance and whiteness of untreated fabric. The colloidal silver treated fabric lost antimicrobial property after washing because nano-sized silver particles were located on uneven fiber surface without chemical bonding forces.

Generation and Detection of Torsional Waves in a Rotating Shaft Using a Magnetostrictive Patch Array (자기변형 패치 배열을 이용한 회전축에서의 비틀림파 발생 및 감지)

  • Cho Seung-Hyun;Han Soon-Woo;Park Chan-Il;Kim Yoon-Young
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.3 s.246
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    • pp.342-348
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    • 2006
  • A new magnetostrictive patch array transducer for the generation and detection of torsional waves is developed fur the on-line health monitoring of rotating shafts. Even though the torsional wave is useful in nondestructive evaluation due to its non-dispersive property, a transducer generating torsional waves in rotating shafts has not been developed so far. In this research, a torsional wave transducer using the magnetostrictive effect is newly developed. By bonding an away of magnetostrictive rectangular patches on the outer surface of the shaft at an oblique angle of $45^{\circ}$ and encircling the array by a solenoid coil, we have successfully generated and measured torsional waves by the developed transducer. Several experiments were carried out to check the transducer performance.

A Study on Microstructures and Mechanical Properties of A356/coated SiC Composites Fabricated by Squeeze Casting (Squeeze Casting법에 의해 제조된 A356/coated SiC복합재료의 미세조직과 기계적 특성에 관한 연구)

  • Lee, Kyung-Ku;Lee, Doh-Jae
    • Journal of Korea Foundry Society
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    • v.14 no.5
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    • pp.429-437
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    • 1994
  • Influence of interfacial structure between matrix and particle in A356/coated SiC composite fabricated by squeeze casting method was studied. Experimental variables are types of coated metallic film on SiC particles such as Cu, Ni-P, and applied pressure for squeeze casting. It was found that coating treatment on SiC particles improves the wetting of liquid A356 alloy on SiC particles. SiC particle distribution is very homogeneous in A356 matrix alloy which is fabricated by squeeze casting. Analysing the surface morphology of fractured A356/coated SiC, it was concluded that metallic thin film by coating treatment on SiC particle improves the interfacial bonding between particle and matrix, and so does on mechanical properties such as tensile strength. However, there was on significant difference in hardness between those composite made of as-received SiC particle and coated SiC particle.

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Study on Development of Automotive Door Trim Rail including Texturing Skin (텍스쳐링 스킨을 포함하는 자동차 도어트림 레일의 개발에 관한 연구)

  • Lee, Eun-Jong;Kim, Key-Sun
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.12 no.1
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    • pp.28-34
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    • 2013
  • For the senses of beauty and texture, internal components of small passenger cars are manufactured by texturing plastic with drawplate but those of deluxe passenger cars are manufactured by bonding pre-embossed skin to the surface of drawplate. As the pre-embossed skin is bonded at high temperature and pressure, the pattern of skin is distorted. The corner part is hardened and its dimension tolerance is changed by resulting in the increase with its defective rate. This study provides the method to design and manufacture the door trim track by vacuuming the non-patterned skin to upper-side drawplate which forms the pattern of descending skin. It is pressed to the plastic product with hot-press method and the damage of bossed-pattern is prevented. Valuation in this study has been done by analyzing, designing and experimenting method.

Bio-functionalization of the Single Layer Graphene for Detecting the Cancer Cell

  • Oh, Hyung Sik;Park, Wanjun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.429.1-429.1
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    • 2014
  • We present a method of surface functionalization of a single layer graphene for linking and detecting MDA-MB-231 human breast cancer cell. The methodology is done by utilizing 1-pyrenebutanoic acid and succinimidyl ester for immobiling CD44 antibodies. This work shows that the single layer graphene is an efficient fixing substance to capture the MDA-MB-231 human breast cancer cell, selectively. The immobilization method of the cancer cell on the graphene layer will be an effective cell counting system. Moreover usage of the linking with non-covalent bonding is expected to develope a sensor scheme of electrical cell-detecting diagnosis system.

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