• Journal of Powder Materials
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• v.29 no.1
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• pp.41-46
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• 2022

In this study, we report the microstructure and characteristics of Ag-SnO₂-Bi₂O₃ contact materials using a controlled milling process with a subsequent compaction process. Using magnetic pulsed compaction (MPC), the milled Ag-SnO₂-Bi₂O₃ powders have been consolidated into bulk samples. The effects of the compaction conditions on the microstructure and characteristics have been investigated in detail. The nanoscale SnO₂ phase and microscale Bi2O3 phase are well-distributed homogeneously in the Ag matrix after the consolidation process. The successful consolidation of Ag-SnO₂-Bi₂O₃ contact materials was achieved by an MPC process with subsequent atmospheric sintering, after which the hardness and electrical conductivity of the Ag-SnO₂-Bi₂O₃ contact materials were found to be 62-75 HV and 52-63% IACS, respectively, which is related to the interfacial stability between the Ag matrix, the SnO₂ phase, and the Bi₂O₃ phase.

• Current Photovoltaic Research
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• v.11 no.1
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• pp.13-17
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• 2023

Functional transparent electrode was achieved by metal oxide-metal-Metal oxide (OMO) structure. Tailoring of metal oxide and metal layers, optically transparent and electrically excellent OMO films were investigated. Silver (Ag) is adopted for the metal layer and Ag oxide (AgO) is reactively formed by flowing O₂ gas during the sputtering process. This spontaneous AgO formation from Ag simultaneously provides the good electrical interface with high transparency. Due to the feature of transparent electrode of OMO, it endows the shielding effect (SE) function of electromagnetic interference. Optically transparent and electrically conductive OMO electrode shows the high transmittance (83.7%) and low sheet resistance (6.5 Ω/☐) with SE of 29.54 dB.

• Current Photovoltaic Research
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• v.10 no.1
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• pp.28-32
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• 2022

We investigated the optical and electrical characteristics of ITO/Ag/ITO (IAI) 3-layer thin films prepared by using RF/DC sputtering. To measure the thickness of all thin film samples, we used scanning electron microscopy. As a function of Ag thickness we characterized the optical transmittance and sheet resistance of the IAI samples by using UV-Visible spectroscopy and Hall measurement system, respectively. While the thickness of both ITO thin films in the 3-layered IAI samples were fixed at 50 nm, we varied Ag layer thickness in the range of 0 nm to 11 nm. The optical transmittance and sheet resistance of the 3-layered IAI thin films were found to vary strongly with the thickness of Ag film in the ITO (50 nm)/Ag(t₀)/ITO (50 nm) thin film. For the best transparent conducting oxide (TCO) electrode, we obtained a 3-layered ITO (50 nm)/Ag (t₀ = 8.5 nm)/ITO (50 nm) that showed an avrage optical transmittance, AVT = 90.12% in the visible light region of 380 nm to 780 nm and the sheet resistance, R_□ = 7.24 Ω/□.

• Bulletin of the Korean Chemical Society
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• v.10 no.3
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• pp.243-247
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• 1989

Two crystal structures of dehydrated $Ag^+\;and\;Ca^{2+}$ exchanged zeolite A, $Ag_2Ca_$5-A, reacting with 0.01 Torr of Cs vapor at $200^{\circ}C$ for 2 hours and 0.1 Torr of Cs vapor at $250^{\circ}C$ for 48 hours, respectively, have been determined by single crystal X-ray diffraction techniques. Their structures were solved and refined in the cubic space group Pm3m at $21(1)^{\circ}C$. The stoichiometry of first crystal was $Ag_2Ca_5$-A (a = 12.294(1)${\AA}$), indicating that Cs vapor did not react with cations in zeolite A and that of second crystal was $Ag_2Cs_{10}$-A (a = 12.166(1)${\AA}$), indicating that all $Ca^{2+}$ ions were reduced by Cs vapor and replaced by $Cs^+$ ions. Full-matrix least-squares refinements of $Ag_2Ca_5-A\;and\;Ag_2Cs_{10}$-A has converged to the final error indices, $R_1\;=\;0.041\;and\;R_2$ = 0.048 with 227 reflections, and $R_1\;=\;0.117\;an\;n\;fdd\;R_2$ = 0.120 with 167 reflections, respectively, for which I > $3{\sigma}$(I). In the structure of $Ag_2Ca_5$-A, both $Ag^+$ ions and $Ca^{2+}$ ions lie on two crystal symmetrically independent threefold axis sites on the 6-rings; $2\;Ag^+$ ions are recessed 0.33 ${\;AA}$ from the (111) planes of three O(3) oxygens and 5 $Ca^{2+}$ ions lie on the nearly center of each 6-oxygen planes. In the structure of $Ag_2Cs_{10}-A,\;Cs^+$ ions lie on the 5 different crystallographic sites. 3 $Cs^+$ ions lie at the centers of the 8-rings at sites of D4h symmetry. 6 $Cs^+$ ions lie on the threefold axes of unit cell: $4\;Cs^+$ ions are found deep in the large cavity and 2 $Cs^+$ ions are found in the sodalite cavity. One $Cs^+$ ion is found in the large cavity near a 4-ring.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.04a
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• pp.3-6
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• 2002

Effect of Ag additive element on microstructure of $Fe_{87-x}Zr_7B_6Ag_x$, magnetic thin films on Si(001) substrates has been investigated using Transmission Electron Microscopy(TEM) and X-ray Diffraction(XRD). All samples with additive Ag element were made by DC-sputtering and subjected to annealing treatments of $300^{\circ}C{\siim}600^{\circ}C$ for 1 hr. TEM and XRD showed that perfectly amorphous state in Ag-free Fe-based films was observed in as-deposited condition. The as-deposited Fe-based films with the presence of Ag constituent have a mixture of Fe-based amorphous and nano-sized Ag crystalline phases. In this case, additive element, Ag was soluted into Fe-based matrix. With the increase in additive element, Ag, insoluble nano-crystalline Ag particles were dispersed in the Fe-based amorphous matrix. Crystallization of Fe-based amorphous phase in the matrix of $Fe_{82}Zr_7B_6Ag_5$ thin films occurred at an annealing temperature of $400^{\circ}C$. Upon annealing, the amorphous-Ag crystalline state of Fe-Zr-B-Ag films was transformed into the mixture of Ag crystalline phase + Fe-based amorphous phase + ${\alpha}$-Fe cluster followed by the crystallization process of ${\alpha}$-Fe nanocrystalline + Ag crystalline phases.

• Microbiology and Biotechnology Letters
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• v.40 no.4
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• pp.403-408
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• 2012

Gelatin/Ag nanoparticle (AgNP) biocomposite was synthesized using the solution plasma process (SPP) that has been recently introduced as an effective method for synthesis of nanoparticles. In this study, gelatin/AgNP biocomposite was synthesized using various concentrations of Ag precursor ($AgNO_3$) and gelatin in the range of 1-5 mM and 1-3% (w/w), respectively, without using any chemical reducing agent. Physical properties of the gelatin/AgNP biocomposites were analyzed using EDS, FE-SEM, and TEM. The results indicated that spherical AgNPs with approximately 12~20 nm in diameter were synthesized successfully in the gelatin matrix by SPP. As the concentration of gelatin was increased (3%, w/w), disperse stability of AgNP was improved and micro-pores of gelatin became smaller and denser in the 3D scaffold. Bactericidal activity of the AgNPs was examined against Staphylococcus aureus and Escherichia coli by measuring zone of growth inhibition and decrease in colony forming unit (CFU). CFUs of S. aureus and E. coli were decreased approximately to 56% and 0%, respectively, by the gelatin/AgNP biocomposite, Ag5G3.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.1
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• pp.7-11
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• 2014

Recently, the buffer layers consisting of poly (3,4-ethylenedioxythiophene): poly (styrenesulfonate) (PEDOT-PSS) are extensively used to improve power conversion efficiency (PCE) of organic solar cells. However, PEDOT-PSS is not suitable for mass production of organic solar cells due to its intrinsic acid and hygroscopic properties. Moreover, because of chemical reactions between indium tin oxide (ITO) layer and PEDOT-PSS layer, the interface is not stable. For these reasons, alternative materials such as $V_2O_5$ have been developed to be an effective buffer layer. In this work, we used $V_2O_5$/Ag/ITO multilayer structure for the anode buffer layer. With variation of thickness of Ag layer, we investigated the optical and electrical properties of $V_2O_5$/Ag/ITO multi-layer films. As a result, we found that the electrical properties were improved with increasing Ag thickness while optical transmittance decreases in visible wavelength region. From the calculation of figure of merit (FOM) which is used to evaluate proper structure for transparent of optoelectronic, $V_2O_5$/Ag/ITO multilayer electrode was optimized with 4 nm thick Ag layer in optical (88% in transmittance) and electrical ($4{\times}10^{-4}{\Omega}cm$) properties. This indicates that $V_2O_5$/Ag/ITO multilayer electrode could be a candidate for the anode of optoelectronic devices.

• Journal of Animal Science and Technology
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• v.61 no.5
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• pp.285-293
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• 2019

The objective of this study was to verify the best mating age of gilts at the first parity. Gilts (n = 86) were divided into nine groups in a factorial arrangement with three Ages (AG1, ${\leq}220d$; AG2, 220 to 240 d; AG3, $240{\leq}d$), and three weights (WT1 ${\leq}140kg$; WT2, 140 to 149 kg; WT3, $150{\leq}kg$). A higher body weight gain in AG2 sows during gestation. Sows in AG2 group showed a higher body weight gain at first parity and backfat gain in the parity 2 and 3 during gestation. A greater insulin-like growth factor-1 (IGF-1) was observed in AG1 sows compared with AG3 sows at weaning in the second parity. Sows in WT1 group showed a significant positive effect on the plasma IGF-1 at breeding and weaning time in parity 2. Sows in AG3 group showed a higher plasma leptin at breeding, farrowing, and weaning in the parity 1, and at farrowing in parity 2. Sows in WT3 group showed a higher plasma leptin at breeding, farrowing, and weaning in the parities 1 and 2. Considering the insignificant longevity results, the most efficient time for gilts insemination can be at 220 d when their body weight is 140 kg or lower.

• Journal of Electrochemical Science and Technology
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• v.3 no.4
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• pp.185-189
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• 2012

A.c. impedances of mechanically polished CP-Ti specimens were measured at open-circuit potential (OCP) with immersion time and under applied anodic potentials between -0.2 and 1 $V_{Ag/AgCl}$ in 0.1 M NaOH solution. Capacitances of native oxide films ($C_{ox,na}$) grown naturally and capacitances of anodic oxide films ($C_{ox,an}$) formed under applied anodic potentials were obtained to examine the growth of native and anodic oxide films in 0.1 M NaOH solution and how to use $C_{ox,na}$ for the surface area measurement of Ti specimen. $1/C_{ox,na}$ and $1/C_{ox,an}$ appeared to be linearly proportional to OCP and applied potential ($E_{app}$), with proportional constants of 0.086 and 0.051 $uF^{-1}\;V^{-1}$, respectively. The $C_{ox,na}$ also appeared to be linearly proportional to geometric surface area of the mechanically polished CP-Ti fixture specimen, with proportional constants of 11.3 and $8.5{\mu}F\;cm^{-2}$ at -0.45 $V_{Ag/AgCl}$ and -0.25 $V_{Ag/AgCl}$ of OCPs, respectively, in 0.1 M NaOH solution. This linear relationship between $C_{ox,na}$ and surface area is suggested to be applicable for the measurement of real surface area of Ti specimen.

• Journal of the Korean Vacuum Society
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• v.7 no.s1
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• pp.50-56
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• 1998

Ion beam assisted deposition (IBAD) was successfully used to produce a dense and ultra-adherent Hydroxyapatite (HA) film on titanium alloy and alumina. Recently it is also proved that the HA coatings on alumina substrate treated with 20 ppm $AgNO_3$ had the structure of $(Ag, Ca)_10(PO_4)6(OH)_2$, which exhibited excellent antimicrobial effects. The present paper aims to morphlogically characterize the adhesion of macrophages on newly developed Ag-HA coated alumina and Ti6A14V substrates and to evaluate the biocompatibility of the coatings in vitro. It can be found that the cell number on alumina of the concentration of $AgNO_3$ in the treatment, the cell number on Ag-HA coatings decreased. Up to 20 ppm $AgNO_3$ by Ag-treatment, the morphological development of the cells on Ag-HA coating was similar to that of the cells on HA coating, suggesting the biotolerance of the Ag-HA coatings.