• Korean Chemical Engineering Research
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• v.61 no.2
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• pp.196-201
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• 2023

In this study, a CNT fiber flexible electrode grafted with CuO nanoparticles (CuO NPs) and polyaniline (PANI) was developed and applied to a nonenzymatic electrochemical sensor for H₂O₂ detection. CuO NPs/PANI/CNT fiber electrode was fabricated through the synthesis and deposition of PANI and CuO NPs on the CNT fiber surface using an electrochemical method. Surface morphology and elemental composition of the CuO NPs/PANI/CNT fiber electrode were characterized by scanning electron microscope with energy dispersive X-ray spectrometry. And its electrochemical characteristics were investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA). Compared with a bare CNT fiber as a control group, the CuO NPs/PANI/CNT fiber electrode showed a 4.78-fold increase in effective surface area and a 8.33-fold decrease in electron transfer resistance, which leads to excellent electrochemical properties such as a good electrical conductivity and an efficient electron transfer. These improved characteristics were due to the synergistic effect through the grafting of CNT fiber, PANI and CuO NPs. As a result, this electrode enhanced the H₂O₂ sensing performance.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.10a
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• pp.187-187
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• 1997

Silicon nitride is the most excellent materials among structural ceramics. It has been reported that fracture toughness was improved with adding second phase particles, whisker, fiber etc. However, containing of second phase particles enhanced fracture toughness, however flexural strength was degraded. As adding nanosize SiC particles into silicon nitride, the physical properties of fluxural strength, fracture toughness, the modulus of elasticity. In this study, 2wt% $Al_2$O$_3$ and 4 wt% $Y_2$O$_3$ were added into UBE E-10 and 0, 10, 20, 30, 40, 50 vol% nano-SiC powder (Sumitomo T1 powder) were added, respectively. It is hot pressed at 185$0^{\circ}C$ for 1 hour. Most of structural ceramics for engineering application are wear resistance. In this study, wear behaviors (in water) of silicon nitride with varying the amount of nano-size silicon carbide were investigated, and was compared to physical properties. Simultaneously wear mechanism will be found out.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.2
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• pp.319-324
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• 2014

The wafer carrier is made of PP, PC, PE resin which have excellent heat and chemical resistance and electrical properties. However, particle generation has become a problem due to static electricity generated in the carrier. Some conductive material such as carbon black (CB) and carbon fiber (CF) are added for the purpose of anti-static, however, additional for motility and particle contamination problems due to high carbon content occurs. In this paper, the electrical characteristics and workability are observed and compared by adding low Carbon Nono Tube(CNT) to each PP, PC and PE resin to solve the problem.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.16 no.3
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• pp.106-111
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• 2006

The objective of this paper is to compare the surface features of two kinds of nano-porous activated carbon fiber (NPACF) treated with potassium and the variation of their properties by phosphoric acid pre-treatment. X-ray diffraction (XRD) patterns indicate that NPACF containing potassium species show better performance for potassium and potassium salts by pre-treatment with phosphoric acid. In order to present the causes of the differences in surface properties and specific surface area after the samples were treated with phosphoric acid, pore structure and surface morphology are investigated by adsorption analysis and SEM. For the chemical composition microanalysis for potassium loading of the NPACF pre-treated with phosphoric acid, samples were analyzed by EDX. Finally, the type and quality of oxygen groups are determined from the method proposed by Boehm.

• Journal of the Optical Society of Korea
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• v.7 no.1
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• pp.38-41
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• 2003

We present an analysis of highly-dispersive guided modes of two-dimensional photonic crystal waveguides. By the plane ave expansion method, band structures and mode profiles of two-dimensional photonic crystal waveguides are obtained. It is found that guided modes have very small group velocities and very large group velocity dispersions in the region near the f-point and in the region near the Brillouin zone edge. Especially, the group velocity dispersions are found to be millions of times larger than that of a conventional optical fiber. The contributions of the transverse resonance formed by two photonic band gap reflectors and the standing wave mode formed by periodic structures are discussed. We conclude that the highly-dispersive characteristics originate from the resonator-like aspect of the photonic crystal waveguide.

• Advances in nano research
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• v.13 no.5
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• pp.487-497
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• 2022

This study investigates the stability of protein tissues regarding the vibration analysis based on the classical beam theory coupled with the nonlocal elasticity theory concerning the exercise impact. As reported in the previous research, four different types of protein tissues are supposed, and the influence of sports training is investigated. The protein tissues are made of protein fibers surrounded by an elastic foundation. The exercise enhances the muscle area and plays an essential role in the stability and strength of protein and muscle tissues. The results are examined in detail to examine the impact of different parameters on the stability of nano protein fibers.

• Journal of Bio-Environment Control
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• v.25 no.4
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• pp.302-307
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• 2016

The aim of this study was to examine the optimum wattage and installation height using nano-carbon fiber infrared heating lamp (NCFIHL) for heating energy saving and plug seedling production in plug seedling production greenhouse in winter season. NCFIHL of 700 and 900 W was installed over the bed ($1.2{\times}2.4m$) as 0.7, 1.0, and 1.3 m height, respectively, for the production of grafted watermelon seedling in venlo-type glasshouse. Watermelon (Citrullus lanatus (Thunb.) Manst.) 'Jijonggul' and gourd (Lagenaria leucantha Rusby.) 'Sunbongjang' were used as scions and rootstocks, respectively. The scions and rootstocks were grafted by single cotyledon ordinary splice grafting. Light intensity of NCFIHL was below the $1{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ in all treatment. Spectral distributions of NCFIHL presented mostly infrared area. When outside air temperature was below $10^{\circ}C$, 700 and 900 W NCFIHL installed with 0.7 m height treatment and 900 W NCFIHL installed with 1.0 m height treatment maintained the setting air temperature ($20^{\circ}C$) at night. In the result of taking thermal imaging, the grafted watermelons were getting warm fast in 900 W NCFIHL installed with 0.7 m height treatment at night. Compactness of the grafted watermelons was the greatest in 700 W NCFIHL installed with 1.3 m height treatment. The results indicate that NCFIHL installed above 1.0 m height using 700 W was suitable for production of plug seedling.

• Journal of Bio-Environment Control
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• v.31 no.1
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• pp.8-13
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• 2022

This study was carried out to investigate the proper wattage and installation distance for the efficient use of nano-carbon fiber infrared heating lamp (NCFIHL), a heating device advantageous for heating energy saving, when the production of watermelon plug seedlings in the plug seedling nursery in winter season. Six small beds were divided into plastic film, and 700 W and 900 W nano-carbon fiber infrared heating lamps were installed at 100 cm above the bed. 1 lamp at central (control), 60 cm interval (2 lamps), and 40 cm interval (3 lamps) heating lamps were installed in each bed inside the greenhouse. All treatments, except the control, were set to keep the night air temperature at 20℃ after lighting the NCFIHL. The leaf temperature showed a tendency to increase fast as the install distance was narrow. The leaf length and leaf width tended to increase as the installation distance of the 700 W heating lamp was narrow. The compactness was high in 700 W heating lamp with 40 cm of installation distance. Therefore, in consideration of maintaining the set temperature at night, installing 700 W electric lamps at 40 cm was an efficient power and installation distance for watermelon grafted seedlings considering economic feasibility.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.171-172
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• 2003

In recent years, interest in electrospinning has been quickly increased, because electrospinning is a process capable of making polymer fibers in the range of nano to a few microns diameters[1,2]. The electrospinning was patented by Formhals in 1934[2] and most of studies reported on the subject of electrospinning have been focused on its phenomena[3] and on processing parameters [4-5]. (omitted)

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.179-182
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• 2003

Chitin is the most abundant natural amino polysaccharide and is estimated to be produced annually almost as much as cellulose. It has become of great interest not only as an under utilized resource, but also as a new functional material of high potential in various fields. In addition, chitin and chitosan are recommended as suitable functional materials, because these natural polymers have excellent properties such as biocompatibility, biodegradability, non-toxicity and adsorption properties, etc. (omitted)