• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1993.11a
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• pp.97-102
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• 1993

According as the high integrity of the semi conductor devices is definited required, the concern on the multi-layered wiring, and three-dimensional devices is growing these days. Therefore, plasma-enhanced chemical vapored deposition(PECVD) enables low-teperature process and is widely used, but it causes the instability of the devices due to a lot of impurities within the film. The PECVD oxynitride was formed by changing the gas ratio of (N$_2$O) to (N$_2$+NH$_3$). It's contained a small portion of hydrogen, had higher refrctive index and capacitance than oxide, and showed the capacitance increasement and the chemical stabi1ity. This is caused by nitrogen distribution increase of the interface lather than within the film.

• Journal of Magnetics
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• v.11 no.4
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• pp.160-163
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• 2006

We have prepared crystalline Ag nanoparticles with an average size of 4 nm in diameter by using an inductively coupled plasma reactor equipped with the liquid nitrogen cooling system. Our magnetic data show that the nano-sized effect of Ag nanoparticles on the magnetic properties is ferromagnetic, instead of a diamagnetic component of the Ag bulk and a superparamagnetic component of magnetic nanoparticles. We have also studied the magnetic properties of Ag-Cu nanocomposites with an opposite concentration profile between surface and core. These comparisons indicate that the ferromagnetic component strongly depends on the surface of Ag nanoparticles, while the paramagnetic component is strongly affected by the outer oxide layer, with the background of a diamagnetic component from the core of Ag.

• Bulletin of the Korean Chemical Society
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• v.35 no.11
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• pp.3213-3218
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• 2014

A metal organic framework-supported Nickel nanoparticle (Ni-MOF-5) was successfully synthesized using a simple impregnation method. The obtained solid acid catalyst was characterized by Powder X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption-desorption and thermogravimetric analysis (TGA). The catalyst was highly crystalline with good thermodynamic stability (up to $400^{\circ}C$) and high surface area ($699m^2g^{-1}$). The catalyst was studied for the oxidation of ethyl benzene, and the results were monitored via gas chromatography (GC) and found that the Ni-MOF-5 catalyst was highly effective for ethyl benzene oxidation. The conversion of ethyl benzene and the selectivity for acetophenone were 55.3% and 90.2%, respectively.

• Journal of the Korean Ceramic Society
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• v.16 no.2
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• pp.69-76
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• 1979

This study attempted to characterize the powder and sintered specimen of Mn-Zn ferrite that was prepared by Hot Petroleum Drying Method. The results of the experiment were as follows: 1. The mixed sulfate powder prepared by Hot Petroleum Drying Method was homogeneous and very reactive. The ferrite formation of this powder occurred at lower temperature than the one prepared by Sulfate Dry Mixing Method. 2. The calcined oxide powder prepared by Hot Petroleum Drying Method was found to be agglomerated, and therefore it was very difficult to compact this powder. 3. The sintered density was 4.95g/㎤, 97% of the theoretical density, when the specimen was prepared by Hot Petroleum Drying method, calcined at 90$0^{\circ}C$ in air for 3h, sintered at 1,30$0^{\circ}C$ in air for 3h, and then cooled in nitrogen. 4. The discontinuous grain growth occurred at lower temperature in the specimen prepared by Hot Petroleum Dyring Method than in the one prepared by Sulfate Dry Mixing Method. The discontinuous grain growth was considered to be due to the presence of liquid formed by addition of CaO and $SiO_2$.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.1
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• pp.25-28
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• 2012

Tin-oxide ($SnO_2$) nanowires have been synthesized on one-dimensional (1D) carbonization cotton fabric using chemical vapour deposition method. One-dimensional (1D) carbonization cotton fabric has been synthesized from cotton fabric using annealing process in nitrogen gas at $1000^{\circ}C$. The $SnO_2$ nanowires are single-crystalline rutile structures with 20 nm in diameter and 10 ${\mu}m$ in length. Scanning electron microscopy (SEM), x-ray photoelectron spectroscopy, Raman spectroscopy, transmission electron microscopy and photoluminescence (PL) spectroscopy were utilized to characterize the as-synthesized products.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.9
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• pp.442-445
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• 2006

In order to realize the commercial application of HTSC materials, it is necessary to develop the fabrication process of high Tc oxide superconductor materials with desired shape and for practical application and high critical current density as well as good mechanical strength which can withstand high lorenz force generated at high magnetic field. Much studies have been concentrated to develop the fabrication technique for high critical current density but still there are a lot of gap which should be overcome for large scale application of HTSC materials at liquid nitrogen temperature. Recently some new fabrication techniques have been developed for YBaCuO bulk superconductor with high mechanical strength and critical current density. In this project, the establishment of fabrication condition and additive effects of second elements were examined so as to improve the related properties to the practical use of YBaCuO superconductor, and we reported the production of the YBaCuO high Tc superconductor by the pyrolysis method.

• Journal of the Korean Ceramic Society
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• v.32 no.1
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• pp.31-36
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• 1995

(100) Si was oxidized in N2O ambient, and the film properties of oxynitride dielectrics were compared with pure SiO2. The growth rate, after pre-oxidation in O2/N2 ambient with raising temperature, is faster than that of O2/N2O treatment during the same condition. Nitrogen piles up at the interface of SiO2 and Si substrate and the content is about 2atom%. Comparing with pure SiO2, oxynitride dielectrics shows less dielectric breakdown failures and flat-band voltage shift, and good diffusion barrier property to dopant(BF2) is also observed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.04b
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• pp.38-41
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• 2002

The variation of photoluminescence(PL) properties of Si thin films was investigated by changing deposition temperatures, Si-rich silicon oxide films on p-type (100) Si substrate have been fabricated by pulsed laser deposition(PLD) technique using a Nd:YAG laser. During deposition, the substrates were kept at the temperature range of room temperature(RT) to $400^{\circ}C$. After deposition, samples were annealed at $800^{\circ}C$ in nitrogen ambient, Strong Blue PL has been observed on RT-deposited Si nanocrystallites. When the deposition temperature was increased over $100^{\circ}C$, PL intensities abruptly decreased. The experimental results show the growing mechanism of Si nanocrystallites by PLD.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.5
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• pp.79-84
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• 2011

Air pollutants from a small marine diesel engine are increasing and the IMO(International Marine Organization) regulation asked for its reduction. In this study, NOx reduction technologies such as improvement of various cooling systems are applied to the small marine diesel engine. The various cooling systems are a intercooler, a heat exchanger for engine coolant, and an exhaust manifold by water cooling. These systems are tested on an engine dynamometer and a exhaust gas analyzer by a marine diesel engine test regulation. Test results are shows that the small marine engine are satisfied the IMO NOx regulations; Tire II.

• Journal of Korea Foundry Society
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• v.10 no.2
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• pp.162-170
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• 1990

The major effects of RSP sre 1) extension of solid solubilities, 2) formation of metastable phaeses, 3) microstructural refinement 4) segregationless. The main trust of this study was to investigate the effects of superimposing RSP on the structure and properties of HSLA steels. Powder was made by NGA (Nitrogen Gas Atomization) process, and consolidated by HIP. The high grain-coarsening resistance of NGA-HIP steels was attributed to a fine dispersion of oxide precipitates. The average grain size for the NGA-HIP steels was somewhat finer than that for the conventional HSLA steels, The impact properteis of NGA-HIP steels were improved over those of the conventional HSLA steels.