• Macromolecular Research
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• v.17 no.6
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• pp.424-429
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• 2009

In this study, we demonstrate that the biological unnatural amino acid incorporation method can be utilized in vivo to synthesize an alkyne-terminated telechelic protein, Synthesis of terminally-functionalized polymers such as telechelic polymers is recognized to be important, since they can be employed usefully in many areas of biology and material science, such as drug delivery, colloidal dispersion, surface modification, and formation of polymer network. The introduction of alkyne groups into polymeric material is particularly interesting since the alkyne group can be a linker to combine other materials using click chemistry. To synthesize the telechelic recombinant protein, we attempted to incorporate the L-homopropargylglycine into the recombinant GroES fragment by expressing the recombinant gene encoding Met at the codons for both N- and C-terminals of the protein in the Met auxotrophic E. coli via Hpg supplementation. The Hpg incorporation rate was investigated and the incorporation was confirmed by MALDI-TOF analysis of the telcchelic recombinant protein.

• Environmental Engineering Research
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• v.22 no.2
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• pp.131-140
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• 2017

The use of electronic cigarettes (ECs) is recognized as a source of many pollutants, just like conventional cigarettes (CCs). The analysis of EC aerosol samples has confirmed the presence of various metallic species. Most of these metals originate from various parts of the cartomizer, e.g., solder joints, wires, and silicate beads. The metal concentration levels in EC samples were shown to be generally two to four orders of magnitude lower than those of CCs. However, the use of ECs can still pose significant human health hazards as consumers are exposed to the toxicity of those metals and many other hazardous pollutants released simultaneously via the vaping of ECs. The review also describes the detection and quantification of various metals in ECs and CCs. This review was carried out to assess the level of metal species released from ECs and to suggest proper guidelines to control consumer exposure.

• KSBB Journal
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• v.22 no.6
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• pp.387-392
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• 2007

Recently, microfluidic biochips for DNA microarray are providing a number of advantages such as, reduction in reagent volume, high-throughput parallel sample screening, automation of processing, and reduction in hybridization time. Particularly, the enhancement of target probe hybridization by decrease of hybridization time is an important aspect highlighting the advantage of microfluidic DNA microarray platform. Fundamental issues to overcome extremely slow diffusion-limited hybridization are based on physical, electrical or fluidic dynamical mixing technology. So far, there have been some reports on the enhancement of the hybridization with the microfluidic platforms. In this review, their principle, performance, and outreaching of the technology are overviewed and discussed for the implementation into many bio-applications.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.528-528
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• 2007

Cu CMP widely has been using for the formation of multilevel metal interconnects by the Cu damascene process. And lower dielectric constant materials are required for the below 45nm technology node. As the dielectric constant of dielectric materials are smaller, the strength of dielectric materials become weaker. Therefore these materials are easily damaged by high down pressure during conventional CMP. Also, technical problems such as surface scratches, delamination, dishing and erosion are also occurred. In order to overcome these problems in CMP, the ECMP (electro-chemical mechanical planarization) has been introduced. In this process, abrasive free electrolyte, soft pad and low down force were used. The electrolyte is one of important factor to solve these problems. Also, additives are required to improve the removal rate, uniformity, surface roughness, defects, and so on. In this study, KOH and $NaNO_3$ based electrolytes were used for Cu ECMP and the electrochemical behavior was evaluated by the potentiostat. Also, the Cu surface was observed by SEM as a function of applied voltage and chemical concentration.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.78-78
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• 2007

In semiconductor devices, Cu has been used for the formation of multilevel metal interconnects by the damascene technique. Also lower dielectric constant materials is needed for the below 65 nm technology node. However, the low-k materials has porous structure and they can be easily damaged by high down pressure during conventional CMP. Also, Cu surface are vulnerable to have surface scratches by abrasive particles in CMP slurry. In order to overcome these technical difficulties in CMP, electro-chemical mechanical planarization (ECMP) has been introduced. ECMP uses abrasive free electrolyte, soft pad and low down-force. Especially, electrolyte is an important process factor in ECMP. The purpose of this study was to characterize KOH and $KNO_3$ based electrolytes on electro-chemical mechanical. planarization. Also, the effect of additives such as an organic acid and oxidizer on ECMP behavior was investigated. The removal rate and static etch rate were measured to evaluate the effect of electro chemical reaction.

• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.169-179
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• 2005

Porous materials are useful in a wide range of applications including bio/electronic products. The preparation and processing of these materials are mainly progressed by using an organic solvent, which gives rise to air pollution by its emissions. Alternatively, supercritical fluids are well suited to the production of functional porous materials due to a number of specific physical, chemical, and toxicological advantages. In this review, we will introduce the preparation and processing techniques for the formation of the nano/macro pore structure and their morphology, which can be controled by using supercritical fluids.

• Journal of Radiation Industry
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• v.6 no.3
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• pp.273-279
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• 2012

Silica hybrid silver nanoparticles showing the strong antimicrobial activity, in which nano-silver is bound to silica molecules, has been synthesized using ${\gamma}-irradiation$ at room temperature. The present study relates to an antimicrobial composition for coating fiber products comprising silica hybrid silver nanoparticles. In this study, we describe antimicrobial fiber products coated with the silica hybrid silver nanoparticles and a method of antimicrobially treating fiber products by coating the fiber products with the silica hybrid silver nanoparticles. The antimicrobial fiber products exhibited excellent antimicrobial effects. In detailed practice, when the present composition comprising nanosized silica-silver was applied to a cloth (fabric) in a concentration of $6.4mg\;yard^{-1}$, the viable cell number decreased to less than 10 cells before and after laundering, resulting in a reduction of 99.9% or greater in the viable cell number. The present composition displays long-lasting potent disinfecting effects on bacteria. Also, we investigated the toxicity of silica hybrid silver nanoparticles in rats. The skin of rats was treated with a 30 ppm nanoparticles solution ($2ml\;Kg^{-1}$) for 8 days. No toxicity was detected in the treatment. These results suggest that the fiber products coated with the silica hybrid silver nanoparticles can be used to inhibit the growth of various microorganisms.

• Korean Journal of Metals and Materials
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• v.50 no.6
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• pp.449-454
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• 2012

Nanopowder of FeAl and $Al_2O_3$ was synthesized from FeO and Al powders by high energy ball milling. Using the pulsed current activated sintering method, the nanocystalline $Al_2O_3$ reinforced FeAl composite was consolidated within two minutes from mechanically synthesized powders. The advantage of this process is that it allows very quick densification to near theoretical density and prohibits grain growth in nanostuctured materials. The grain size, sintering behavior and hardness of sintered $FeAl-Al_2O_3$ composite were investigated.

• Nuclear Engineering and Technology
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• v.51 no.4
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• pp.1142-1153
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• 2019

This paper presents the effect of fusion procedure on the fusion performance of the thermal butt fusion in the safety class III buried HDPE piping per various tests performed, including high speed tensile impact, free bend, blunt notched tensile, notched creep, and PENT tests. The suitability of fusion joints and qualification procedures was evaluated by comparing test results from the base material and buttfusion joints. From the notched tensile test result, it was found that the fused joints have much lower toughness than the base material. It was also identified that the notched tensile test is more desirable than the high speed tensile impact and free bend tests presented in the ASME Code Case N-755-3 as a fusion qualification test method. In addition, with regard to the single low-pressure fusion joint performances, the procedure given by the ISO 21307 was determined to be better that the one specified in the Code Case N-755-3.

• Journal of Microbiology and Biotechnology
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• v.33 no.5
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• pp.698-705
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• 2023

Rapid diagnosis of methicillin-resistant Staphylococcus aureus (MRSA) is essential for guiding clinical treatment and preventing the spread of MRSA infections. Herein, we present a simple and rapid MRSA screening test based on the aggregation effect of mannose-binding lectin (MBL)-conjugated gold nanoparticles (AuNP), called the MRSA probe. Recombinant MBL protein is a member of the lectin family and part of the innate immune system. It can recognize wall teichoic acid (WTA) on the membrane of MRSA more specifically than that of methicillin-sensitive Staphylococcus aureus (MSSA) under optimized salt conditions. Thus, the MRSA probe can selectively bind to MRSA, and the aggregation of the probes on the surface of the target bacteria can be detected and analyzed by the naked eye within 5 min. To demonstrate the suitability of the method for real-world application, we tested 40 clinical S. aureus isolates (including 20 MRSA specimens) and recorded a sensitivity of 100%. In conclusion, the MRSA probe-based screening test with its excellent sensitivity has the potential for successful application in the microbiology laboratory.