• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.106-107
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• 1998

To minimize the failure rate of medical devices, the maintenance records for general X-ray, R/F X-ray, mobile X-ray, artificial dialyzer, ventilator, and automatic chemistry analyzer was analysed with regard to the cause of the failure. The parts responsible for the most frequent system failure was then worked intensively during the preventive maintenance. After this procedure, the faliure of the systems in a month decreased from 1.8 on average to 0.3.

• 한국초전도학회:학술대회논문집
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• 2009.07a
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• pp.47-47
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• 2009

• 한국초전도학회:학술대회논문집
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• 2009.07a
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• pp.18-18
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• 2009

• Journal of the Mineralogical Society of Korea
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• v.2 no.1
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• pp.8-10
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• 1989

Sphene from the McDonald pegmatite near Bancroft, Ontario, Canada was analyzed using EPMA. It contains 4.3 to 6.3 weight percent of Nb2O5 with an average formula Ca1.02(Ti0.62Al0.22Nb0.07Fe0.06Ta0.01)Si0.99(O4.85F0.16). Three types of subtitutions are possible; 1)2Ti4+=(Nb, Ta)5+ + (Al, Fe3+), 2) Ti + O = (Al, Fe3+) + (F, OH), and 3) 2Ti + O = Fe2+ + (Nb, Ta)5+ + (F, OH). T재 different schemes of substitutions for balancing the analysis are considered when the iron is either all ferric or all ferrous. Assuming stoichiometry fo Ca and Si, a general formula derived from the two different schemes is Ca(Ti0.64Al0.22Fe3+0.06-X {{{{Fe_{x}^{2+} }} Nb0.01)Sio4.80-XF0.16(OH)0.04+x.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.138-138
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• 2015

In this study, highly ordered nanotubular surface of Ti-25Ta-xHf alloys for dental applications was researched. Ti-25Ta-xHf alloys were contained from 0% to 15% Hf content. Formation of nanotubular structure was achieved by an electrochemical method in 1M $H_3PO_4$ electrolytes containing 0.8%wt. % NaF.

• Solar Energy
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• v.6 no.1
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• pp.12-23
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• 1986

The PECVD $SiN_x:H$ films were made from the $SiH_4-N_2$ gas mixtures under such deposition conditions as 0.01 to 1.0 of $SiH_4/N_2$ volume ratio, 0.1 to $0.8W/cm^2$ of RF power, and 100 to $400^{\circ}C$ of substrate temperature. The deposition rate, refractive index, hydrogen concentration, N/Si composition, optical gap and electric conductivity were measured, and the thermal stability and the optimum deposition conditions were investigated for the application of these films to the solar cell materials.

• International Journal of Naval Architecture and Ocean Engineering
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• v.3 no.1
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• pp.1-8
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• 2011

In this paper, CFD simulation results for a tanker model are compared with experimental data over a range of wave conditions to verify a capability to predict the sea-keeping performance of practical hull forms. CFD simulations are conducted using WISDAM-X code which is capable of unsteady RANS calculations in arbitrary wave conditions. Comparisons are made of unsteady surface pressures, added resistance and ship motions in regular waves for cases of fully-loaded and ballast conditions of a large tanker model. It is shown that the simulation results agree fairly well with the experimental data, and that WISDAM-X code can predict sea-keeping performance of practical hull forms.

• Korean Journal of Bronchoesophagology
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• v.8 no.1
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• pp.87-91
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• 2002

Solitary fibous tumor of pleura is a rare and slow vowing neoplasm. The histogenesis of this tumor is thought as mesenchymal origin by immunohistochemical and ultrastructural bases. This case report is of a 69-year-old female who presented severe dyspnea and orthopnea with long-term history. Preoperative chest X-ray an chest CT revealed huge and hemithorax-occupying heterogenous mass and cardiomegaly. She underwent surgical resection and a 22 X 18 X 10 cm sized visceral pleural based mass was evacuated. Histologic findings of tumor showed patternless proliferation in a fibrocollagenous and well vasculized stroma. Immnohistochemical staining revealed strong positive in CD34, that are compatible with solitary fibrous tumor of pleura. The patient was discharged without any complications and no evidence of recurrence was found after 2 years.

• Journal of the Korean Ceramic Society
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• v.30 no.8
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• pp.635-642
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• 1993

To obtain a higher dielectric constant material, we investigated Ca substitution for Pb in PbZrO3. In this study, the four mixtures of (Pb0.68Ca0.32)ZrO3, (Pb0.65Ca0.37)ZrO3, (Pb0.63Ca0.37)ZrO3, and (Pb0.60Ca0.40)ZrO3 were prepared by coprecipitation reaction of Pb(NO3)2, ZrOCl2, and CaCl2 with (NH4)2CO3 and NH4OH in aqueous solution. The (Pb1-xCax)ZrO3 with different x mole fractions (x=0.35, 0.37) showed not only high dielectric constant, but also high Q values and low temperature coefficient of the capacitance.

• Journal of the Korean Ceramic Society
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• v.25 no.2
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• pp.154-160
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• 1988

Almost single phase of Y1Ba2Cu3Ox, which exhibits the onset of superconducting transition at 90K, has been prepared via a conventional ceramic processing route followed by an anneal for a period of 10 hours at 45$0^{\circ}C$ in an atmosphere of 100% O2. The mean value for the oxygen content has been determined as x=6.85$\pm$0.02 by an iodometric titration technique. X-ray photoemission spectra are found to be consistent with a mixture of the d8(Cu3+) and d9(Cu2+) as the ground state and reveals that the local concentration of Cu3+ decreases with depth from the surface where x corresponds to 7.0. This is explained as being associated with the intercalation of oxygen during cooling from the annealing temperature.