• Journal of the Korean Ceramic Society
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• v.32 no.2
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• pp.197-208
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• 1995

${\gamma}$-LiAlO2 fibers for fiber reinforced molten carbonate fuel cell (MCFC) matrix have been produced from LiAlO2 complex polymeric sols using the sol-gel process. The stable and spinnable LiAlO2 sols could be synthesized by mixing LiNO3 alcohol solutions in aluminum complex polymeric sols prepared through the condensationpolymerization reaction of 1 more of aluminum tri-sec-butoxide with 0.55 mole of mixed chelates (mole ratio of acetylaceton/triethanolamine=0.25/0.3). It was found that the viscosity range for fiber-spinning should be higher than 30 poise. The defect-free flexible ${\gamma}$-LiAlO2 fibers with the average tensile strength of 350 MPa could be obtained when the spinned fibers were heat-treated to 120$0^{\circ}C$ on the specified heating schedule after dried at room temperature.

• Bulletin of the Korean Chemical Society
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• v.29 no.1
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• pp.159-164
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• 2008

Two kinds of CNT/TiO2 composite photocatalysts were synthesized with multi-walled carbon nanotubes (MWCNTs) and titanium(IV) n-butoxide (TNB) by a MCPBA oxidation method. Since MWCNTs had charge transfer and semiconducting, the CNT/TiO2 composite shows a good photo-degradation activity. The XRD patterns reveal that only anatase phase can be identified for MCT composite, but the HMCT composite synthesized with HCl treatment was observed the mixed phase of anatase and rutile. The EDX spectra were shown the presence as major elements of Ti with strong peaks. From the SEM results, the sample MCT and HMCT synthesized by the thermal decomposition with TNB show a homogenous sample with only individual MWCNTs covered with TiO2 without any jam-like aggregates between CNTs and TiO2. From the photocatalytic results, we could be suggested that the excellent activity of the CNT/TiO2 composites for organic dye and UV irradiation time could be attributed to combination effects between TiO2 and MWCNTs with plausible photodegradation mechanism.

• The Korean Journal of Ceramics
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• v.1 no.3
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• pp.147-151
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• 1995

Porous composite of $Al_2O_3$ and AIN based mullite and SiC can be prepared by alumium reaction synthesis and atmosphere controllied sintering in order to improve the durability of a gas filter body. The porous $Al_2O_3$-AIN-mullite, which has a strength of 168 kg/$\textrm{cm}^2$ and porosity of 51.59%, could be obtained by stmospheric firing at $1600^{\circ}C$ and the porous $Al_2O_3$-AIN-SiC with a porosity of 33% and strength of 977 kg/$\textrm{cm}^2$, could also be prepared. The average pore size has been changed from 0.2$\mu\textrm{m}$ in a reduction atmosphere and to 2$\mu\textrm{m}$ in an air atmosphere, respectively.

• Journal of The Korean Astronomical Society
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• v.40 no.3
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• pp.61-65
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• 2007

The 2-1 and 5-4 transitions of SiO have been observed toward the Sgr B2 region, including the Principal Cloud(the GMC containing Sgr B2(M)) and its surroundings. The morphology and velocity structure of the SiO emission show a close resemblance with the HNCO Ring feature, identified by Minh & Irvine(2006), of about 10 pc in diameter, which may be expanding and colliding with the Principal Cloud. Three SiO clumps have been found around the Ring, with total column densities $N_{SiO}{\sim}1{\times}10^{14}cm^{-2}$ at the peak positions of these clumps. The fractional SiO abundance relative to $H_2$ has been estimated to be ${\sim}(0.5-1){\times}10^{-9}$, which is about two orders of magnitude larger than the quiet dense cloud values. Our SiO observational result supports the existence of an expanding ring, which may be triggering active star formations in the Principal Cloud.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.196-199
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• 2007

The chemical states of oxygen on the surfaces of $Pr_{1-x}Sr_{x}CoO_{3}$ (x=0.5 and 0.7) oxide systems were investigated by X-ray photoelectron spectroscopy. Merged oxygen peaks of $Pr_{1-x}Sr_{x}CoO_{3}$ (x=0.5 and 0.7) oxides could be divided as five sub-peaks. These five sub-peaks could be defined as lattice oxygen ($O_{L}$). chemisorbed oxygen peaks ($O_{C}$) and hydroxyl condition oxygen peak ($O_{H}$). In case of the $Pr_{0.5}Sr_{0.5}CoO_{3}$ and $Pr_{0.3}Sr_{0.7}CoO_{3}$, the binding energy (BE) of oxygen lattice were located at same BE. However, the BE of chemisorbed oxygen peaks including oxygen vacancy shows different BE. Especially, it was found that BE of chemisorbed oxygen peaks was increased when more Sr were substituted. Comparing atomic percentages of oxygens of $Pr_{0.5}Sr_{0.5}CoO_{3}$ and $Pr_{0.3}Sr_{0.7}CoO_{3}$, the ratio of $Pr_{0.3}Sr_{0.7}CoO_{3}$ was higher than that of $Pr_{0.5}Sr_{0.5}CoO_{3}$. It showed more chemically adsorbed site including oxygen vacancies were existed in $Pr_{0.3}Sr_{0.7}CoO_{3}$.

• East Asian Journal of Business Economics (EAJBE)
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• v.8 no.3
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• pp.15-24
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• 2020

Purpose - New technologies allow service providers to integrate all the customer information within and between contact channels so that they can offer individualized services. The availability of new mobile devices enables retailers to interact with customers through countless channels (Rigby, 2011). The objective of this research is to examine customers' attitudes toward O2O (on-line to off-line) services and their intention to use based on the Technology Acceptance Model (TAM). Research design, data, and methodology - Utilizing the TAM model, the mediating effect of the users' attitudes toward O2O services on the relationship among perceived ease of use, perceived usefulness, perceived risks and intention to use are to be investigated. Results - The result shows that the perceived ease of use, perceived usefulness, perceived risks have a significant effect on customers' attitudes toward O2O services. It is also revealed that the attitude toward O2O services has a mediating effect among perceived ease of use, perceived usefulness, perceived risks and intention to use. Conclusions - The boundary between on-line and off-line is eroding and various services based on the O2O platform are growing. The results of this study and managerial implications can be applied to O2O platform operators or enterprises planning to sharp on their competitiveness edge through offering variations of service channels.

• Journal of the Korean Vacuum Society
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• v.12 no.4
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• pp.214-217
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• 2003

In this study, we prepared ZnO thin film on $SiO_2$/Si substrate by FTS (Facing Targets Sputtering) apparatus which can reduce damage on the thin film because the bombardment of high-energy Particles such as ${\gamma}$-electron can be restrained. And, properties of thin filnl grown with ZnO buffer-layer which can be suppress initial growth layer was investigated. The crystalline and the c-axis preferred orientation of ZnO thin film was also investigated by XRD. As a result, we noticed that the ZnO thin film has a good crystallographic characteristic at thickness of ZnO buffer layer 10, 20 nm and working pressure 1 mTorr.

• Journal of the Korean Applied Science and Technology
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• v.30 no.3
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• pp.423-430
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• 2013

Carbon coils could be synthesized using $C_2H_2/H_2$ as source gases and $SF_6$ as an incorporated additive gas under thermal chemical vapor deposition (CVD) system. Prior to the carbon coils deposition reaction, two kinds of samples having different combination of Ni catalyst and substrate were employed, namely, a commercially-made $Al_2O_3$ ceramic boat with Ni powders and a commercially-made $Al_2O_3$ substrate with Ni layer. By using a commercially-made $Al_2O_3$ ceramic boat, the synthesis of carbon coils could be enhanced as much as 10 times higher than that of $Al_2O_3$ substrate. Furthermore, the dominant formation of the microsized carbon coils could be obtained by using $Al_2O_3$ ceramic boat. The surface roughness of the supporting substrate of $Al_2O_3$ ceramic boat was understood to be associated with the large scale synthesis of carbon coils as well as the dominant formation of the larger-sized, namely the microsized carbon coils.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.251-254
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• 1998

The ($0.8BaTiO_3-0.1SrTiO_3-0.1MgTiO_3$)+$0.006Nb_2O_5$ ceramics were fabricated by conventional ceramic process. The dielectric property of specimen was investigated that the specimen was sintering temperature at 1,300C for 3hours and then annealed at $1,100^{\circ}C$ for 3hours in a atmosphere (air) to be painted on the surface with CuO paste. The results of the temperature and frequency are varied, the dielectric constant and loss tangent are unsuitable for BL capacitor. The dielectric constants were varied to be negative temperature coefficient(2.000-3,000) in the temperature range between -10 and $140^{\circ}C$, the dissipation factors (tan $\delta$) were some high(0.1-0.3). It was not grain insulation, in cause of the some difficult to be annealed temperature with CuO paste and fired atmosphere. But, we have some different annealing temperature and fired atmosphere, it will be suitable BL(Boundary Layer)capacitor.

• Journal of the Korean Applied Science and Technology
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• v.24 no.1
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• pp.1-9
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• 2007

It prepared the $TiO_2$ powder which has photo-catalytic activity in the visible-light by the wet process with titanium oxysulfate. The titanium $dioxide(TiO_2)$ by the wet process creates a new absorption band in the visible light region, and is expected to create photocatalytic activity in this region. Anatase $TiO_2$ powder which has photocatalytic activity in the visible light region, is treated using microwave and radio-frequency(RF) plasma. But, the $TiO_2$ powder for the visible light region, which also can be easily produced by wet process. The wet process $TiO_2$ absorbed visible light between 400nm and 600nm, and showed a high activity in this region, as measured by the oxidation removal of aceton from the gas phase. The AH-380 sample appears the yellow color to be strong, the catalytic activity in the visible ray was excellent in comparison with the plasma-treated $TiO_2$. The AH-380 $TiO_2$ powder, which can be easily produced on a large scale, is expected to have higher efficiency in utilizing solar energy than the plasma-treated $TiO_2$ powder.