• Title/Summary/Keyword: advanced characterization

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Synthesis and Characterization of N,O-Carboxymethylchitosan Hydrogel Crosslinked by γ-ray Irradiation

  • Gwon, Hui-Jeong;Lim, Youn-Mook;An, Sung-Jun;Youn, Min-Ho;Nho, Young-Chang
    • Journal of Radiation Industry
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    • v.2 no.1
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    • pp.15-19
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    • 2008
  • In order to develop a water-solubility and biocompatibility, chemically modified chitosan, N,O-carboxymethylchitosan (NOCC), was synthesized and the NOCC hydrogels were prepared by using ${\gamma}-ray$ irradiation instead of chemical reagents. The FT-IR spectroscopy, swelling behavior, gel content and mechanical property such as gel strength of the hydrogel were measured. When the NOCC solution concentration was 15 wt% and the dose of irradiation was less than 50 kGy, the NOCC hydrogels had an excellent hydrophilicity and exhibited a good swelling behavior and mechanical properties.

Fabrication and characterization of solution processable organosilane-modified colloidal titania nanoparticles and silica-titania hybrid films

  • Kang, Dong Jun;Park, Go Un;Lee, Hyeon Hwa;Ahn, Myeong Sang;Park, Hyo Yeol
    • Journal of Ceramic Processing Research
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    • v.13 no.spc1
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    • pp.78-81
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    • 2012
  • Colloidal titania nanoparticles were synthesized by a simple sol-gel process. The obtained nanoparticles showed high crystallinity and were of the anatase type. These crystalline colloidal titania nanoparticles were organically modified using methyl- and glycidyl-grafted silanes in order to enhance their stability and solution processability. The stabilized colloidal titania nanoparticles could be dispersed homogeneously without aggregation and converted into silica-titania hybrid films with the heterogeneous Si-O-Ti bonds by a low-temperature solution process. The fabricated silica-titania hybrid films showed high transparency (~ 90%) in the visible range, and low RMS roughness (<1 nm). Therefore, the organosilane-modified crystalline colloidal titania nanoparticles can be used in solution-processable functional coatings for electro-optical devices.

Extraction of Electrical Parameters for Single and Differential Vias on PCB (PCB상 Single 및 Differential Via의 전기적 파라미터 추출)

  • Chae Ji Eun;Lee Hyun Bae;Park Hon June
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.4 s.334
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    • pp.45-52
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    • 2005
  • This paper presents the characterization of through hole vias on printed circuit board (PCB) through the time domain and frequency domain measurements. The time domain measurement was performed on a single via using the TDR, and the model parameters were extracted by the fitting simulation using HSPICE. The frequency domain measurement was also performed by using 2 port VNA, and the model parameters were extracted by fitting simulation with ADS. Using the ABCD matrices, the do-embedding equations were derived probing in the same plane in the VNA measurement. Based on the single via characterization, the differential via characterization was also performed by using TDR measurements. The time domain measurements were performed by using the odd mode and even mode sources in TDR module, and the Parameter values were extracted by fitting with HSPICE. Comparing measurements with simulations, the maximum calculated differences were $14\%$ for single vias and $17\%$ for differential vias.

Synthesis and characterization of Star Shape Polycaprolactone containing 4-Arm Polycaprolactone Core (4개의 폴리카프로락톤 가지 코어를 가지는 스타형 폴리카프로락톤의 합성 및 분석)

  • An, Sung-Guk;Cho, Chang-Gi
    • Proceedings of the Korean Fiber Society Conference
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    • 2002.04a
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    • pp.199-202
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    • 2002
  • The synthesis of materials with controlled composition and architectures continues to be a focus of considerable current research. Dendritic multiarm polymers such as dendrimer, hyperbranched polymer, and star polymers are three dimensional macromolecules, in which a large number of linear arms of similar molecular weight and narrow molecular weight distribution emanate from a central core. (omitted)

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Corrosion in Batteries

  • Muniyandi, N.
    • Corrosion Science and Technology
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    • v.2 no.1
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    • pp.1-6
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    • 2003
  • A comprehensive coverage of corrosion in batteries is rendered difficult by the wide choice of materials, environments and physical features as obtained in practical settings. Understanding of the complex processes that occur in these electrochemical systems gets clearer as new theoretical approaches backed by sophisticated analytical and characterization techniques continue to provide valuable insights which aid in controlling/mitigating wasteful corrosion reactions which affect battery shelf-life, cycle life, rate capability and capacity. In the light of the above, I limit myself to a discussion on corrosion aspects in representative system such as conventional Leclanche, lead-acid battery and magnesium batteries, and advanced lithium systems.

Preparation and Characterization of Polyimide/Carbon Nanotube Composites by in-situ Polymerization (In-situ 중합법에 의한 Polyimide/Carbon Nanotube 복합재료의 제조 및 특성)

  • Seo, Min-Kang;Park, Soo-Jin
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10b
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    • pp.223-224
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    • 2003
  • Polyimides (PI) are widely used in applications ranging from microelectronics to aerospace. Due to their insulating nature, significant accumulation of electrostatic charge may result on their surface, causing local heating and premature degradation to electronic components or space structures. Over the past decade, several publications have been made in fabrication and charaterization of CNT nanocomposites [1,2]. (omitted)

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