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        검색결과 8

        1.
        2024.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In recent years, the energy storage sector has experienced a notable transition toward the use of organic electrodes. This shift is largely attributed to their superior energy density, cost-effectiveness, and eco-friendliness. However, there is a main drawback that the organic molecules oftentimes suffer shuttle phenomenon across the separator due to their high solubility in the organic electrolyte. In addition, the low electrical conductivity of organic materials is also detrimental, thereby requiring a large amount of carbon additives (up to 40 wt. %) in the electrode. In this perspective, addition of carbon additives with the desirable amount, which can prevent organic molecules from being dissolved into the liquid phase as well as provide the electrical conductivity. While N,Nʹ-dimethylphenazine (DMPZ) was investigated as a model material, we compared two carbon additives with different surface areas and functional groups. We carefully scrutinized the structural effect of carbon additives on the cycle-life performance of the organic electrode.
        4,000원
        2.
        2020.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The co-doping effect of aliovalent metal ions such as Mg2+, Ca2+, Sr2+, Ba2+, and Zn2+ on the photoluminescence of the Y2O3:Eu3+ red phosphor, prepared by spray pyrolysis, is analyzed. Mg2+ metal doping is found to be helpful for enhancing the luminescence of Y2O3:Eu3+. When comparing the luminescence intensity at the optimum doping level of each Mg2+ ion, the emission enhancement shows the order of Zn2+ Ba2+ > Ca2+ > Sr3+> Mg2+. The highest emission occurs when doping approximately 1.3% Zn2+, which is approximately 127% of the luminescence intensity of pure Y2O3:Eu3+. The highest emission was about 127% of the luminescence intensity of pure Y2O3:Eu3+ when doping about 1.3% Zn2+. It is determined that the reason (Y, M)2O3:Eu3+ has improved luminescence compared to that of Y2O3:Eu3+ is because the crystallinity of the matrix is improved and the non-luminous defects are reduced, even though local lattice strain is formed by the doping of aliovalent metal. Further improvement of the luminescence is achieved while reducing the particle size by using Li2CO3 as a flux with organic additives.
        4,000원
        3.
        2020.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The goal of this study was to evaluate effects of various microbial and organic additives on chemical compositions, fermentation indices, and aerobic stability of barley silage. Youngyang barley harvested at 31.5% dry matter (DM), and ensiled into 20 L bucket silo for 0, 1, 3, 7, 48, and 100 d in quadruplicates with four additives following: sterile destilled water at 1% of fresh forage (CON); Lactobacillus plantarum at 1.2 x 105 cfu/g of fresh forage (CL); Lactobacillus buchneri at rate of 1.2 x 105 cfu/g fresh forage (LB); Fermented Persimmon Extract at 1% of fresh forage (FPE); and Essential Oil at 1% of fresh forage (EO). On 100 d of ensiling, CL and FPE silages had lower (p<0.05) DM than CON silage. Additionally, FPE silage had higher (p<0.05) crude protein than CON silage. All silages with additives, except EO, had higher (p<0.05) neutral detergent fiber (NDF) than CON silage. Silage treated with CL, LB, and FPE had lower in vitro DM digestibility than CON silage, and silages treated with LB and FPE had higher in vitro NDF digestibility (IVNDFD) on 100 d of ensiling. The PFE silage produced the highest (p<0.05) lactate during ensiling period, while LB silage produced the highest (p<0.05) acetate. All inoculated silages had higher (p<0.05) LAB count than control silage. Only CL silage had higher (p<0.05) yeast count than control silage, while the other silages were not differ compared to CON silage. The aerobic stability was higher (p<0.05) in LB and FPE silages than in CON silage. In conclusion, FPE could be an alternative additive to increase IVNDFD, fermentation indices, and aerobic stability of barley silage.
        4,000원
        4.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Spherical-type zirconia granules are successfully fabricated by a spray-drying process using a water solvent slurry, and the change in the green density of the granule powder compacts is examined according to the organic polymers used. Two organic binders, polyvinyl alcohol (PVA) and 2-hydroxyethyl methacrylate (HEMA), which are dissolved in a water solvent and have different degrees of polymerization, are applied to the slurry with a plasticizer (polyethylene glycol). The granules employing a binder with a higher degree of polymerization (PVA) are not broken under a uniaxial press; consequently, they exhibit a poor green density of 2.4 g/cm3. In contrast, the granule powder compacts employing a binder with a lower degree of polymerization (HEMA) show a higher density of 2.6 g/cm3 with an increase in plasticizer content. The packing behavior of the granule powders for each organic polymer system is studied by examining the microstructure of the fracture surface at different applied pressures.
        4,000원
        5.
        2015.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this article, poly methyl triethoxy silane was compounded with an inorganic waterproof admixture at a certain ratio to improve the performance of gypsum products; a new type of high-efficiency compound water-proofing additive was also investigated. Furthermore, the waterproof mechanism and the various properties on the hardened gypsum plaster were investigated in detail by XRD and SEM. The results show that the intenerate coefficient of gypsum plaster increased to more than 0.9; the water absorbing rate decreased to less than 10 %. Both the bending strength and the compressive strength of gypsum plaster increased by various degrees. The intenerate coefficient reached a maximum value of 0.73 and the strength of the samples showed almost no change when 5 % cement alone was added. In this new type of the high-efficiency compound with waterproof additive, the optimal technological parameters for formulas were obtained to be: 5 % cement, 18 % mineral powder, and 0.8 % poly methyl triethoxy silane, to compound gypsum plaster. Meanwhile, the production of high performance gypsum as a building material has become possible.
        4,000원
        6.
        2014.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study reports on the influenceof N-butyl-N-methylpyrrolidinium tetrafluoroborat (PYR14BF4) ionic liquid additive on the conducting and interfacial properties of organic solvent based electrolytes against a carbon electrode. We used the mixture of ethylene carbonate/dimethoxyethane (1:1) as an organic solvent electrolyte and tetraethylammo-nium tetrafluoroborate(TEABF4) as a common salt. Using the PYR14BF ionic liquid as additive produced higher ionic conductivity in the electrolyte and lower interface resis-tance between carbon and electrolyte, resulting in improved capacitance. The chemical and electrochemical stability of the electrolyte was measured by ionic conductivity me-ter and linear sweep voltammetry. The electrochemical analysis between electrolyte and carbon electrode was examined by cyclic voltammetry and electrochemical impedance spectroscopy.
        4,000원
        7.
        2012.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In an effort to overcome the problems which arise when fabricating high-aspect-ratio TSV(through silicon via), we performed experiments involving the void-free Cu filling of a TSV(10~20 μm in diameter with an aspect ratio of 5~7) by controlling the plating DC current density and the additive SPS concentration. Initially, the copper deposit growth mode in and around the trench and the TSV was estimated by the change in the plating DC current density. According to the variation of the plating current density, the deposition rate during Cu electroplating differed at the top and the bottom of the trench. Specifically, at a current density 2.5 mA/cm2, the deposition rate in the corner of the trench was lower than that at the top and on the bottom sides. From this result, we confirmed that a plating current density 2.5 mA/cm2 is very useful for void-free Cu filling of a TSV. In order to reduce the plating time, we attempted TSV Cu filling by controlling the accelerator SPS concentration at a plating current density of 2.5 mA/cm2. A TSV with a diameter 10 μm and an aspect ratio of 7 was filled completely with Cu plating material in 90 min at a current density 2.5 mA/cm2 with an addition of SPS at 50 mg/L. Finally, we found that TSV can be filled rapidly with plated Cu without voids by controlling the SPS concentration at the optimized plating current density.
        4,000원