• Journal of the Korean Chemical Society
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• v.48 no.2
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• pp.129-136
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• 2004

Titanium and [titanium+Na(K)] substituted 11${\AA}$ tobermorites solids synthesized under hydrothermal conditions at 180$^{\circ}C$ exhibit cation exchange properties toward heavy transition metal cations, such as Fe$^{2+},\;Zn^{2+},\;Cd^{2+}\;and/or\;Pb^{2+}$. The amount of heavy metal cations taken up by these solids was found in the order: Fe$^{2+}>Zn^{2+}>Cd^{2+}>Pb^{2+}$, and reached maximum at 10% [Ti+K]-substituted tobermorite. The total cation exchange capacity of the 10% Ti+Na (K) - substituted tobermorites synthesized here range from 71 to 89 meq/100 g, and 50-56 meq/100g for Ti-substituted only. Results indicated that 10% [Ti+K] substitution exhibit cation exchange capacity more 2.4 times than the unsubstituted-tobermorite. This is due to the increase of the number of active sites on the exchangers. The incorporation of Ti and/or [Ti+Na(K)] in the lattice structure of synthesized tobermorites is due to exchange of Ti$^{4+}{\Leftrightarrow}2Ca^{2+}\;and/or\;Ti^{4+}+2Na^+(K^+){\Leftrightarrow}3Ca^{2+}$, respectively. The mechanism of Ti and [Ti+Na(K)] incorporations in the crystal lattice of the solids during synthesis and the heavy metal cations uptaken by these solids is studied.

• Clean Technology
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• v.29 no.4
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• pp.313-320
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• 2023

In order to increase the usability of H₂-SCR, the NOx removal characteristics with catalyst powder of PtNi/CeO₂-W-TiO₂ using Ce as a co-catalyst was synthesized and coated on a porous metal structure (PMS) were evaluated. Catalyst powder of PtNi/CeO₂-W-TiO₂(PtNi nanoparticles onto W-TiO₂, with the incorporation of ceria (CeO₂) as a co-catalysts) was synthesized and coated onto a porous metal structure (PMS) to produce a Selective Catalytic Reduction (SCR) catalyst. H₂-SCR with CeO₂ as a co-catalyst exhibited higher NOx removal efficiency compared to H₂-SCR without CeO₂. Particularly, at a 10wt% CeO₂ loading ratio, the NOx removal efficiency was highest at 90℃. As the amount of catalyst coating on PMS increased, the NOx removal efficiency was improved below 90℃, but it was decreased above 120℃. When the space velocity was changed from 4,000 h^-1 to 20,000 h^-1, the NOx removal efficiency improved at temperatures above 120℃. It was expected that the use of the catalyst could be reduced by applying the PMS with excellent specific surface area as a support.

• Journal of Korea Foundry Society
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• v.21 no.3
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• pp.163-178
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• 2001

The squeeze infiltration process is potentially of considerable industrial importance. The performance enhancements resulting from incorporation of short alumina fiber into aluminum are well documented. These are particularly significant for certain automobile components. Aluminum matrix composite automotive parts, such as diesel engine pistons or engine blocks are produced using squeeze casting apparatus or pressure die-casting apparatus. But the solidification process gets complicated with manufacturing parameters and the factors for porosity formation have not fully understood yet. In this study the formation of porosity during squeeze infiltration has been studied experimentally to achieve an improved understanding of the squeeze infiltration process for manufacture of short-fiber-reinforced components, particularly the mechanism of porosity formation. Al-based MMCs produced under a range of conditions were examined metallographically and the porosity characterised;a kind of matrix, an initial temperature of melt, and a volume fraction of reinforcement. The densimetry and the microscopic image analysis were done to measure the amount of porosity. A correlation between manufacturing parameters and defects was investigated through these.

• Corrosion Science and Technology
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• v.15 no.3
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• pp.129-134
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• 2016

The effects of Ti on the high temperature oxidation of Ni-based superalloys were investigated by cyclic oxidation at $850^{\circ}C$ and $1000^{\circ}C$. The oxide scale formed at $850^{\circ}C$ consists of $Cr_2O_3$, $Al_2O_3$, and $NiCr_2O_4$ layers, while a continuous $Al_2O_3$ layer was formed at $1000^{\circ}C$. The oxidation rate of the alloy with higher Ti content was higher than the alloy with less Ti content at $850^{\circ}C$, possibly due to the increase in the metal vacancy concentration in the $Cr_2O_3$ layer involved by incorporation of $Ti^{4+}$. However, Ti improved the oxidation resistance of the superalloy at $1000^{\circ}C$ by reducing oxygen vacancy concentration in $Al_2O_3$ layer.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.347.2-347.2
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• 2016

Recently, in order to improve the performance of the colloidal quantum dot solar cells (CQDSCs), various efforts such as the modification of the cell architecture and surface treatment for quantum dot (QD) passivation have been made. Especially, the incorporation of halides into the QD matrix was reported to improve the performances significantly via passivating QD trap states that lower the life-time of the minority-carrier. In this work, we fabricated a lead sulfide (PbS) QD bilayer treated with different ligands and utilized it as a photoactive layer of the CQDSCs. The bottom and top PbS layer was treated using metal iodide ($MI_x$ and butanedithiol (BuDT), respectively. All the depositions and ligand treatments were carried out in air using layer-by-layer spin-coating process. The fabrication of the active layers as well as the n-type zinc oxide (ZnO) layer was successfully carried out on the bendable indium-tin-oxide (ITO)-coated polyethylene terephthalate (PET) substrate, which implies that this technique can be applied to the fabrication of flexible and/or wearable solar cells. The power conversion efficiency (PCE) of the CQDSCs with the architecture of $PET/ITO/ZnO/PbS-MI_x/PbS-BuDT/MoO_x/Ag$ reached 4.2 %, which is significantly larger than that of the cells with single QD (PbS-BuDT) layer.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.6
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• pp.280-284
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• 2015

Au doped $TiO_2$ nanoparticles have been synthesized using a reverse micelle technique combined with metal alkoxide hydrolysis and condensation. Au doped $TiO_2$ was coated with glass substrate. The size of the particles and thickness of the coating can be controlled by manipulating the relative rates of the hydrolysis and condensation reaction of TTIP within the micro-emulsion. The average size of synthesized Au doped $TiO_2$ nanoparticle was about in the size range of 15 to 25 nm and the Au particles formed mainly the range of 2 to 10 nm in diameter. The effect of synthesis parameters, such as the molar ratio of water to TTIP and the molar ratio of water to surfactant, are discussed. The synthesized nanopaticles were coated on glass substrate by a spin coating process. The thickness of thin film was about 80 nm. The degradation of MB on a $TiO_2$ thin film was enhanced over 20 % efficiency by the incorporation of Au.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.117-118
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• 2008

High-pressure deuterium annealing process is proposed and investigated for enhanced electrical and reliability properties of 512Mb DDR2 DRAM without increase in process complexity. High pressure deuterium annealing (HPDA) introduced during post metal anneal (PMA) improves not only DRAM performance but also reliability characteristics of MOSFET. Compared with a control sample annealed in a conventional forming gas, additional annealing in a high pressure deuterium ambient at $400^{\circ}C$ for 30 min decreased G1DL current and junction leakage. The improvements can be explained by deuterium incorporation at $SiO_2$/Si substrate interface near isolation trench edge.

• Journal of Environmental Health Sciences
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• v.21 no.1
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• pp.47-55
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• 1995

Minari(Oenanthe stolonifera DC.) lived in serious polluted water is able to remove chemical elements from batch system. This study attempted to compare the incorporation of cadmium and lead in batch system. Different concentrations of Cd(0.02 0.1 0.5 1.00 5.00 mg/l) and Pb(0.1 0.5 1.0 5.0 10.0 mg/l) were used. Toxic effects were obvious at Cd 1.00 mg/l and Pb 5.00 mg/l. The detrimental effects on minari were chlorosis of leaves and stunted roots and reduction in the number of lateral roots. There was reduction in growth rates exposed above Cd 1.00 mg/l and lead 5.0 mg/l. The minari capacities to remove Cd were 34.1-74.2% and Pb were 53.0~91.5%. The removal rates by minari in Cd and Pb solution were decreased with increased exposure concentration(in Cd r=0.97, in Pb r=0.88). The removal rates by minari in Cd and Pb solution were increased with increased growth rate(in Cd r=0.93 in Pb r=0.92). Recovery rates on minari are 67.3~95.2% in Cd water and 72.6~88.3% in Pb water. The rates are increased with increased growth rates and decreased initial concentrations.

• JSTS:Journal of Semiconductor Technology and Science
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• v.6 no.2
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• pp.106-113
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• 2006

Electrical properties of $Si_{0.88}Ge_{0.12}(C)$ p-MOSFETs have been exploited in an effort to investigate $Si_{0.88}Ge_{0.12}(C)$ channel structures designed especially to suppress diffusion of dopants during epitaxial growth and subsequent fabrication processes. The incorporation of 0.1 percent of carbon in $Si_{0.88}Ge_{0.12}$ channel layer could accomodate stress due to lattice mismatch and adjust bandgap energy slightly, but resulted in deteriorated current-voltage properties in a broad range of operation conditions with depressed gain, high subthreshold current level and many weak breakdown electric field in gateoxide. $Si_{0.88}Ge_{0.12}(C)$ channel structures with boron delta-doping represented increased conductance and feasible use of modulation doped device of $Si_{0.88}Ge_{0.12}(C)$ heterostructures.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.116-119
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• 2002

A different route to the synthesis of $Eu^{3+}$ - activated matrices such as $YAlO_{3}$ and $GdAlO_{3}$ and luminiscent properties of these compounds, were studied. The new route (Combustion method) consist of the redox reactions between the respective metal nitrates and urea in a preheated furnace at ${500^{\circ}C}$. The Phosphor thus obtained were then heated at ${1000^{\circ}C}$ for 2-3 hours to get better luminiscent properties. The incorporation of $Eu^{3+}$ activator in these phosphors were checked by luminiscence investigations. Scanning electron microscopy (SEM) studies were carried out to understand surface morphological features and the particle size. X-ray energy dispersive analysis (EDAX) was also performed for the qualitative analysis of the phosphors.