• Bulletin of the Korean Chemical Society
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• v.33 no.4
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• pp.1279-1284
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• 2012

Silica supported $Cs_{2.5}H_{0.5}PMo_{12}O_{40}$ catalyst was prepared through sol-gel method with ethyl silicate-40 as silicon resource and characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy, nitrogen adsorption-desorption and potentiometric titration methods. The $Cs_{2.5}H_{0.5}PMo_{12}O_{40}$ particles with Keggin-type structure well dispersed on the surface of silica, and the catalyst exhibited high surface area and acidity. The catalytic performance of the catalysts for benzene liquid-phase nitration was examined with 65% nitric acid as nitrating agent, and the effects of various parameters were tested, which including temperature, time and amount of catalyst, reactants ratio, especially the recycle of catalyst was emphasized. Benzene was effectively nitrated to mononitro-benzene with high conversion (95%) in optimized conditions. Most importantly, the supported catalyst was proved has excellent stability in the nitration progress, and there were no any other organic solvent and sulfuric acid were used in the reaction system, so the liquid-phase nitration of benzene that we developed was an eco-friendly and attractive alternative for the commercial technology.

• Journal of Korea Water Resources Association
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• v.33 no.S1
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• pp.215-220
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• 2000

• Proceedings of the Plant Resources Society of Korea Conference
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• v.18 no.1
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• pp.170-170
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• 2005

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.628-635
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• 2001

Hydrodynamic behavior and response of vertical-cylindrical liquid-storage tank is considered. The equation of the liquid motion is shown by Laplace's differential equation with the fluid velocity potential. The solution of the Laplace's differential equation of the liquid motion is expressed with the modified Bessel functions. Only rigid tank is studied. The effective masses and heights for the tank contents are presented for engineering design model.

• The Plant Pathology Journal
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• v.16 no.6
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• pp.318-320
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• 2000

Potate tubers with slver scurf lesions were collected from the cold storage at Pyungchang, Kangwon province in Korea. The causal agent of the silver scurf was identified as Helminthosporium solani by mycological characteristics of conidia and conidiophores. Pathogenicity of the fungus was confirmed by artificial inoculation on the potato tuber. This is the first report of potato silver scarf by Helminthosporium solani in Korea.

• Food Science and Preservation
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• v.4 no.1
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• pp.27-32
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• 1997

Natural convection in agricultural-products storage system was analysed theoretically, The storage system was modelled by Internally heated fluid saturated porous layer. Darcy's law was used to explain characteristics of fluid motion. Stability equations were obtained under the linear stability theory and transfer characteristics were modelled by the shape assumption. Based on the modelling of transfer characteristics, heat trasnfer correlations were derived theoretically.

• Journal of the Korean Ceramic Society
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• v.31 no.8
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• pp.920-926
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• 1994

Ta doped PZT thin films were prepared by a reactive sputtering method with a 3-gun magnetron co-sputter, and effects of Ta doping on physical and electrical properties of the films were studied. Within the doping range of 0 to 3.6 at%, Ta doping enhanced the crystallographic orientation of (110), but reduced that of (100). Ta doped PZT had a larger grain size of about 20 ${\mu}{\textrm}{m}$ compared with that of 5 ${\mu}{\textrm}{m}$ for un-doped PZT. Pits and holes of PZT films which used to appear with annealing at high temperature due to evaporation of PbO were much suppressed with addition of Ta. The leakage current could be reduced down to 1.27$\times$10-8 A/$\textrm{cm}^2$ and the charge storge density as large as 25.8$\mu$C/$\textrm{cm}^2$ was obtained.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.3
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• pp.544-552
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• 2002

Recommended seismic design guide for the flat bottom vortical-cylindrical oil storage tanks in KS B 6225 is presented. Under earthquake excitations, the hydrodynamic pressure exerted on the tank walls produces overturning moment which may cause either a failure of the anchors or a buckling of the tank shell near its base. The basis for establishing design loads due to hydrodynamic pressure is described including seismic zone risk map in Korea, zone coefficients and the essential facilities factor. This procedure for calculating applied compressive stress on the shell base subjecting to seismic load and for estimating the allowable buckling stress is described.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.3
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• pp.487-496
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• 2002

Hydrodynamic behavior and response of vertical-cylindrical liquid-storage tank is considered. The equation of the liquid motion is shown by Laplace's differential equation with the fluid velocity potential. The solution of the Laplace's differential equation of the liquid motion is expressed with the modified Bessel functions. Only rigid tank is studied. The equivalent masses and heights for the tank contents are presented for engineering design model.

• Journal of the Korean Home Economics Association
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• v.27 no.4
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• pp.73-84
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• 1989

The purpose of this study is to induce user to use storage equipment as fixed storage space in urban housing. The object of investigation is limited to the resident of detached and apartment house in Daegu, analysised the problems and their attitueds of using storage equipments amount of cloths and bel-clothes. On the basis of these recommended the optimum volume of storage space for clothes and bed-clothes by family types. Applied to the standard of detached house, the optimum volume of storage space for clothes and bed-clothes in each rooms are as following. 1) The volume of master room is ranged 7.34M3 and 8.65M3 the average is 7.97M3. 2) Children's room is ranged 1.18M3 and 3.26M3, the average is 2.51M3 under number of users and their age. 3) The aged room is calculated average 6.53M3.