• Title/Summary/Keyword: force spectroscopy

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The Middle Lamella Remainders on the Surface of Various Mechanical Pulp Fibres

  • Li, Kecheng;Tan, Xuequan;Yan, Dongbo
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2006.06a
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    • pp.51-59
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    • 2006
  • The surface of various mechanical pulp fibres including thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), and alkaline peroxide mechanical pulp (APMP) fibres, were characterized using SEM, AFM, and XPS. With SEM and AFM, middle lamella material was observed to be non-fibrillar, patch-like, while fibre secondary wall was observed to have a microfibrillar structure. It was found that after the first-stage refiner, lignin-rich middle lamella remainders are present on the fibre surface of all three pulps, although most of the fibre surfaces expose microfibrillar structure. After the final-stage refining, large amounts of granules are present on the TMP fibre surface. In contrast, most middle lamella remainders remain on the surface of CTMP fibres after final stage refining and even after peroxide bleaching. XPS results have confirmed that the non-fibrillar surface material is the lignin-rich middle lamella remainder., and the remainders of middle lamella contribute to the high surface lignin concentration.

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Composition of nickel-chromium alloy on the centrifugal casting and the influence of quantitative of oxides on the casting temperature (원심 주조한 니켈-크롬 합금의 성량 변화 및 주조 온도에 따른 산화물 측정)

  • Kim, Won-Soo
    • Journal of Technologic Dentistry
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    • v.34 no.4
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    • pp.361-368
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    • 2012
  • Purpose: The aim of this study was to analysis the composition on the centrifugal casting and the oxide on the casting temperature. Methods: The nickel based alloy were used in this study. Wax pattern specimens (10*10*2) were invested with phosphate-bonded investment in metal rings, the liquid/powder ratio and overall burn-out schedules for these investments were followed in accordance with the manufacturer's instructions. After casting, the alloy specimens were evaluated as regards composition(EPMA). The casting temperatures were as follows: $1400^{\circ}C$ and $1700^{\circ}C$. The quantitative analysis of oxides were scanning electron microscope(SEM), energy dispersive spectroscopy(EDS) and line scanning. Results: Nearer the injection lines showed that there is a large amount of nickel. Quantitative of oxides of Ni-Cr alloy cast from $1400^{\circ}C$ is lager than Ni-Cr alloy cast from $1700^{\circ}C$. Conclusion: Casting when using a centrifugal casting machine centrifugal force affects the composition of the alloy. The higher the temperature, the amount of oxide that is generated many.

Effect of 3C-SiC buffer layer on the characteristics of AlN films supttered on Si Substrates (3C-SiC 버퍼층이 Si 기판위에 스퍼터링된 AlN 막의 특성에 미치는 영향)

  • Ryu, Kyeong-Il;Chung, Gwiy-Sang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.04b
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    • pp.3-6
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    • 2009
  • Aluminum nitride (AIN) thin films were deposited on a polycrystalline 3C-SiC intermediate layer by a pulsed reactive magnetron sputtering system. Characteristics of the AIN/SiC heterostructures were investigated by field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The columnar structure of AIN thin films was observed by FE-SEM. The surface roughness of AlN films on the 3C-SiC buffer layer was measured using AFM. The XRD pattern of AlN films on SiC buffer layers was highly oriented at (002). Full width at half maximum (FWHM) of the rocking curve near (002) reflections was $1.3^{\circ}$. The infrared absorbance spectrum indicated that the residual stress of AIN thin films grown on SiC buffer layers was nearly negligible. The 3C-SiC intermediate layers are promising for the realization of nitride based electronic and mechanical devices.

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Dispersion Characteristics of Surface-Modified Graphene Nanoplate in Organic Solvent for Development of Graphene / Epoxy Paint to Protect Concrete (콘크리트 보호용 그래핀/에폭시 도료개발을 위해 표면개질한 그래핀 나노플레이트의 유기용매 분산특성)

  • Seo, Won-Woo;Kim, Gyu-Yong;Yoon, Min-Ho;Lee, Sang-Kyu;Hwang, Eui Chul;Son, Min-Jae
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.05a
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    • pp.244-245
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    • 2017
  • This study aims to develop high durability graphene / epoxy paint for durability improvement of construction structure. For the development of graphene / epoxy coatings, first, graphene must remain stable in the polymer. Second, the integrity of graphene and polymer should be ensured. Accordingly, in order to obtain dispersibility, surface modification of graphene nanoplate(GnP) with CH and COOH functional groups and its dispersibility in organic solvents were investigated. Also, Fourier Transform Infrared Spectroscopy(FT-IR) analysis and Atomic Force Microscope(AFM) analysis were performed to confirm whether the functional groups were synthesized by surface modification. As a result, FT-IR and AFM analysis did not confirm the surface modification, but GnP was found to be stable when dispersed in an organic solvent.

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Study on Damage Reduction of (Ba0.6Sr0.4)TiO3 Thin Films in Ar/CF4 Plasma (Ar/CF4 유도결합 플라즈마에서 식각된 (Ba0.6Sr0.4)TiO3 박막의 손상 감소)

  • 강필승;김경태;김동표;김창일
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.6
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    • pp.460-464
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    • 2003
  • The barium strontium titannate ((Ba,Sr)TiO$_3$:BST) thin films were etched in an inductively coupled plasma (ICP) as a function of CF$_4$/Ar gas mixing ratio. Under CF$_4$(20%)/Ar(80%), the maximum etch rate of the BST films was 400 $\AA$/min. Etching products were redeposited on the surface of BST and then the nature of crystallinity were varied. Therefore, we investigated the etched surface of BST by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The plasma damages were evaluated in terms of leakage current density by Agilent 4145C and dielectric constant by HP 4192 impedance analyzer. After the BST thin films exposed in the plasma, the leakage current density and roughness increases. After annealing at 600 $^{\circ}C$ for 10 min in $O_2$ ambient, the leakage current density, roughness and nonvolatile etch byproducts reduced. From this results, the plasma induced damages were recovered by annealing process owing to the relaxation of lattice mismatches by Ar ions and the desorption of metal fluorides in high temperature.

Zinc Metal Solubilization by Gluconacetobacter diazotrophicus and Induction of Pleomorphic Cells

  • Saravanan, Venkatakrishnan Sivaraj;Osborne, Jabez;Madhaiyan, Munusamy;Mathew, Lazar;Chung, Jong-Bae;Ahn, Ki-Sup;Sa, Tong-Min
    • Journal of Microbiology and Biotechnology
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    • v.17 no.9
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    • pp.1477-1482
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    • 2007
  • Gluconacetobacter diazotrophicus strain PA15 exhibited a minimum inhibitory concentration value of 11 mM in an LGI medium amended with $ZnCl_2$. When an LGI medium was amended with Zn metal, solubilization halos were observed in a plate assay, and further solubilization was confirmed in a broth assay. The maximum solubilization was recorded after 120 h with a 0.1% Zn metal amendment. During solubilization, the culture growth and pH of the broth were indirectly correlated. Using a Fourier Transform Infrared Spectroscopy analysis, one of the agents solubilizing the Zn metal was identified as gluconic acid. When the Zn-amended broth was observed under a bright field microscope, long involution cells were observed, and further analysis with Atomic Force Microscopy revealed highly deformed, pleomorphic, aggregate-like cells.

Detection of Escherichia coli O157:H7 Using Immunosensor Based on Surface Plasmon Resonance

  • Oh, Byung-Keun;Kim, Young-Kee;Bae, Young-Min;Lee, Won-Hong;Choi, Jeong-Woo
    • Journal of Microbiology and Biotechnology
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    • v.12 no.5
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    • pp.780-786
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    • 2002
  • An immunosensor based on surface plasmon resonance (SPR) with a self-assembled protein G layer was developed for the detection of Escherichia coli O157:H7. A self-assembled protein C layer on a gold (Au) surface was fabricated by adsorbing the mixture of 11-mercaptoundecanoic acid (MUA) and hexanethiol at various molar ratios and by activating chemical binding between free amine (-$NH_2$) of protein G and 11-(MUA) using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDAC) in series. The formation of a self-assembled protein G layer on an Au substrate and the binding of the antibody and antigen in series were confirmed by SPR spectroscopy. The surface morphology analyses of the self-assembled protein G layer on the Au substrate, monoclonal antibody (Mab) against E. coli O157:H7 which was immobilized on protein G, and bound E. coli O157:H7 extracts on Immobilized Mab against E. coii O157:H7 were performed by atomic force microscopy (AFM). The detection limit of the SPR-based immunosensor for E. coli O157:H7 was found to be about $10^4$ cells/ml.

Characterization of the Chemical Mechanical Micro Machining for Single Crystal Silicon (실리콘의 화학기계적 미세가공 특성)

  • Jeong, Sang-Cheol;Park, Jun-Min;Lee, Hyeon-U;Jeong, Hae-Do
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.1
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    • pp.186-195
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    • 2002
  • The mechanism of micro machining of reacted layer on silicon surface were proposed. The depth of reacted layer and the change of mechanical property were measured and analyzed. Depth of hydrated layer which is created on the surface of silicon by potassium hydrate was analyzed with SEM and XPS. The decrease of the micro victors hardness of silicon surface was shown with the increase of the concentration of potassium hydrate and the change of the dynamic friction coefficient by chemical reacted layer was measured due to the readiness of machining. The experiment of groove machining was done with 3-axis machine with constant load. With chemical mechanical micro machining the surface crack and burrs generated by both brittle and ductile micro machining were diminished. And the surface profile and groove depth was shown in accordance with the machining speed and reaction time with SEM and AFM.

Ag/Ta/glass 다층박막의 Ta seeding이 전기적 광학적 특성에 미치는 효과

  • Park, Seon-Ho;Jo, Hyeon-Cheol;Lee, Gi-Seon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.69-69
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    • 2010
  • 현대 건축물에서 건물에너지의 손실은 대부분은 창호를 통하여 유출되어지고 있으며 에너지 절감을 위해서는 창호의 단열성을 향상시켜야한다. 저방사(Low Emissivity) 코팅유리는 건축물의 냉난방비용을 절약할 수 있는 대표적인 건축재료로써 외부에서 유입되는 태양광의 가시광선 영역은 높은 투과율을 가지면서 적외선 영역과 겨울철 실내 난방열을 반사하는 특징을 지니는 박막코팅기술이다. 이 코팅유리는 일반적으로 유전체/금속/유전체 다층박막 구조로 되어있으며, 유전체층은 내구성 증진과 금속층의 반사를 낮추어 투과율이 향상된다. 금속층은 적외선영역의 복사에너지를 반사하는 역할을 하며 전도성이 우수한 Ag 또는 Au, Pt 등을 이용하고 있다. Ag의 경우 산화물기판 위에 증착하였을 경우 island 성장을 하고 이들의 합체는 전기적, 광학적 특성에 큰 영향을 미치게 된다. 본 연구에서는 DC-sputtering법으로 제조된 Ag/glass, Ag/Ta/glass 박막을 제조하고 Ta seeding이 Ag의 전기적, 광학적 성질에 미치는 영향을 관찰하였다. 박막의 표면 미세구조는 FE-SEM(Field Emission Scanning Electron Microscope)과 AFM(Atomic Force Microscope)으로, 표면저항은 4 point probe로 분석하였다. 광투과율은 UV-Vis spectroscopy와 FT-IR로 측정하였으며 측정파장범위는 각각 200~1100nm와 1400~2400nm 이다.

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Study on the eletronic absorption and surface morphology of phthalocyanine double layer thin films

  • Heo, Il-Su;Ryu, Il-Hwan;Hong, Da-Jeong;Im, Sang-Gyu
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.337-337
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    • 2011
  • The elecronic absorption and surface morphology evolution of two types of molecular double layer thin films, copper phthalocyanine(CuPc) layer deposited on top of chloro[subphtalocyaninato]boron(III) (SubPc) layer, denoted as SubPc/CuPc, and vice versa, at various thicknesses were invertigated using ultraviolet(UV)-visible spectroscopy and atomic force microscopy (AFM). Both types of double layer structures showed similar broadened absorption patterns in UV-visible region which were well consistent with fitted spectra by a simple linear combination of single layer absorption spectra of two materials. In contrast, the surface morphology of double layer structures was dependent on the order of deposition. For CuPc/SubPc structures, the surface morphology was characterized by elongated grains, characteristic of SubPc thin films, indicating the morphological influence of underlying CuPc layer on subsequent SubPc layer was not large. For SubPc/CuPc structures, however, the underlying SubPc layer acted as a morphological template for the subsequently deposited CuPc layer. It was also observed that the grain size of CuPc layer varied by the thickness of underlying SubPc layer.

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