• Proceedings of the Korean Nuclear Society Conference
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• 1999.10a
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• pp.187.1-187
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• 1999

• Proceedings of the Korean Nuclear Society Conference
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• 1999.10a
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• pp.359.2-359
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• 1999

• Bulletin of the Korean Chemical Society
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• v.13 no.4
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• pp.355-357
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• 1992

• Proceedings of the Korean Magnestics Society Conference
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• 2003.06a
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• pp.94-95
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• 2003

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.7
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• pp.209-214
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• 2012

RFID(Radio Frequency IDentification) is an emerging technology which brings enormous productivity benefits in applications where objects have to be identified automatically. But despite of RFID's advantage, it is not easy to realize the RFID technology in business world. The failure to read RFID tags is the most urgent problem that should be solved for RFID application. Specially, in metal and liquid material, recognition rate of RFID tag is lower than others. Though some special tags for metal and liquid have been invented, it has not prevalent in business world on account of high price. In this paper, styrofoam pad is suggested to improve recognition rate of RFID tag for metal pipe which is used in fish cultivating industry. We makes experiment using Taguchi method and analyze the effects on styrofoam thickness, attachment location of tag, and angle of antenna.

• Journal of the Korean Ceramic Society
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• v.50 no.3
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• pp.238-243
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• 2013

We investigated the effect of Pb-metal filler added to a hybrid paste(PbO-$Bi_2O_3-B_2O_3$-ZnO glass frit and Pb-powder), for joining flip-chip sat lower temperatures than normal. The glass transition temperature was detected at $250^{\circ}C$ and the softening point occurred at $330^{\circ}C$. As the temperature increased, the specific density decreased due to the volatility of the Pb-metal and boron component in the glass. When the glass was heat-treated at $350^{\circ}C$ for 5 min, XRD results revealed a crystalline $Pb_4Bi_3B_7O_{19}$ phase that had been initiated by the addition of Pb-filler in the hybrid paste. The addition of the Pb-metal filler caused are action between the Pb-metal and glass that accelerated the formation of the liquid phase. The liquid phase that formed, promoted bonding between the flip-chip substrate sat lower temperature.

• Journal of the Korean Chemical Society
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• v.41 no.2
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• pp.77-81
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• 1997

The transport rates of transition metal cations were increased in order of Ni(II)$(NtnOenH_4)$and 1,12,15-triaza-3,4;9,10-dibenzo-5,8-dioxacyclo-heptadecane$(NdienOenH_4)$as carriers. The transport rates of transition metal cations was found to be of first order to the salt concentrations. It was also found that the dissociation process in the transport process is rate determining step. From the measurements of the transport rates at various temperatures, the partition free energies of hydration$({\Delta}G_p)$for the transition metal cations were calculated. The results showed that the order of transport rates of transition metal cations was found to be proportional to the magnitudes of negative value of the partition free energies of hydration$({\Delta}G_p)$.

• Analytical Science and Technology
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• v.13 no.1
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• pp.27-33
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• 2000

Simultaneous separation and analysis of Ni(II), Pd(II), Co(II), Cu(II) and Hg(II) in peperidinedithiocarbamate (PDTC) chelates were investigated by reversed phase liquid chromatography. The optimum conditions for the separation of PDTC metal chelates were examined with respect to the pH, extraction solvent, and mobile phase strength on Novapak $C_{18}$ column using methanol/water mixture as mobile phase. All metal PDTC chelates were eluted in an acceptable range of capacity factor value ($0{\leq}log\;k^{\prime}{\leq}1$). The linear calibration curves were obtained in the concentration range of $0{\sim}1.2{\mu}g/mL$ for five metal ions, and also good precision in the range of 1.96~3.41% RSD was obseved. Under the optimum conditions, trace metat ions in the composite water sample were successfully separated and determined with relative error of ${\pm}2.0%$.

• Tribology and Lubricants
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• v.37 no.6
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• pp.253-260
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• 2021

Metal pipes are used in a wide range of applications, from plumbing systems of large construction sites to small devices such as medical tools. When a liquid is enforced to flow through a metal pipe, a higher flow rate is beneficial for higher efficiency. Using high pressures can enhance the flow rate yet can be harmful for medical applications. Thus, we consider an optimal geometrical design to increase the flow rate in medical devices. In this study, we focus on cannulas, which are widely used small metal pipes for surgical procedures, such as liposuction. We characterize the internal flow rate driven by a negative pressure and explore its dependence on the key design parameters. We quantitatively analyze the suction characteristics for each design variable by conducting computational fluid dynamics simulations. In addition, we build a suction performance measurement system which enables the translational motion of cannulas with pre-programmed velocity for experimental validation. The inner diameter, section geometry, and hole configuration are the design factors to be evaluated. The effect of the inner diameter dominates over that of section geometry and hole configuration. In addition, the circular tube shape provides the maximum flow rate among the elliptical geometries. Once the flow rate exceeds a critical value, the rate becomes independent of the number and width of the suction holes. Finally, we introduce a slippery liquid-infused nanoporous surface (SLIPS) coating using nanoparticles and hydrophobic lubricants that effectively improves the flow rate and antifouling property of cannulas without altering the geometrical design parameter.

• Fashion & Textile Research Journal
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• v.8 no.4
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• pp.458-464
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• 2006

The adsorption ability of heavy metal ions from the aqueous solution by chitosan, which it is well known natural biopolymer, has been investigated. The fundamental study in this research is focusing on the physicochemical adsorption utilizing the chitosan as a organic chelating adsorbent, adsorb especially heavy metal ions from the waste liquid solution. The adsorption ability of the chitosan between metal ions, having different characteristics with Mw of 188,600, 297,200, and 504,200 g/mol and degree of deacetylation (DD) of 86.92% and 100% were investigated targeting on the $Ni^{2+}$, $Co^{2+}$, $Zn^{2+}$, and $Pb^{2+}$ ions, respectively. The uptake of heavy metal ions with chitosan was performed by atomic absorption flame emission spectrophotometer (AAS) as conducted residual metal ions. It was found that chitosan has an strong adsorption capacity for some metals under certain conditions. Chitosan, which have 100% degree of deacetylation showed high adsorption recovery ratio and have an affinity for all kinds of heavy metals. In contrast, the molecular weight of chitosan was not completely affected on metal ion adsorption.