• Journal of the Korean Chemical Society
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• v.39 no.11
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• pp.856-862
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• 1995

The tungsten oxo-nitrosyl complexes (n-Bu4N)2[W5O12(NO)2{RC(NH2)NHO}2{RC(NH)NO}2] (R=(CH3)2CH, CH3CH2CH2, CH3SCH2) have been synthesized by the reactions of polyoxotungsten complex (n-Bu4N)2[W6O19] and tungsten dinitrosyl monomeric complex [W(NO)2(acac)(CH3CN)2](BF4) with butylamidoxime derivatives. The prepared complexes have been characterized by elemental analysis, infrared, UV-visible, 1H NMR and 13C NMR spectroscopy. The pentanuclear species was formed by the interaction of the electron-withdrawing {W(NO)2}2+ unit between the two dinuclear tungsten {W2O5}2+ cores. We can estimate to exist large proton interactions viewed from the four doublet in 1H NMR spectrum of (n-Bu4N)2[W5O12(NO)2{(CH3)2CHC(NH2)NHO}2{(CH3)2CHC(NH)NO}2]. We also drew informations of the two different coordination mode and symmetry of the complexes because two ligands appear in 13C NMR spectra instead of four. The {W(NO)2}2+ unit has been cis-form and C2v symmetry in geometric structure.

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.581-587
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• 2014

The antioxidant and alcohol-degrading enzyme activities of soybean sprout sugar solutions (oligosaccharide and sucrose, $50^{\circ}Bx$) were characterized under different soaking conditions. The ratio of sugar solution to sprout content was 25%, 50%, and 75% (w/w), and the soaking times studied were 1, 3, 6, 12, and 24 h. Higher 1,1-diphenyl-2-pycrylhydrazyl (DPPH) radical-scavenging activity was detected in case of the oligosaccharide solution, compared to the sucrose solution. A similar tendency was observed for alcohol-degrading enzyme activity. When the ratio of sugar solution to sprout content was 50% (w/w), the total phenol and flavonoid contents were found to be higher, compared to those observed at 20% (w/w). However, we did not observe a significant difference between 50% and 75% (w/w). Soaking time did not significantly affect the antioxidant and alcohol-degrading enzyme activities of the solutions. As a result, when oligosaccharide solution was used for soaking soy sprouts at a ratio of >50% (w/w), higher antioxidant and alcoholdegrading enzyme activities were observed.

• Resources Recycling
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• v.29 no.5
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• pp.38-47
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• 2020

In this study, factors affecting the adsorption reaction for the separation/recovery of V and W using Lewatit monoplus MP 600, a strong basic anion exchange resin, from the leachate obtained through the soda roasting-water leaching process from the spent SCR DeNO_X catalyst investigated and the adsorption mechanism was discussed based on the results. In the case of the mixed solution of V and W, both ions showed a high adsorption ratio at pH 2-6, but the adsorption of W was greatly reduced at pH 8. In the adsorption isothermal experiment, both V and W were fitted well at the Langmuir adsorption isotherm, and the reaction kinetics were fitted well at pseudo-second-order. As a result of conducting an adsorption experiment by adjusting the pH with H₂SO₄ to remove Si, which inhibits the adsorption of V and W from the leachate, the lowest W adsorption ratio was shown at pH 8.5. Desorption of W was hardly achieved in strongly acidic solutions, and desorption of V was well performed in both strongly acidic and strongly basic solutions.

• Journal of Soil and Groundwater Environment
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• v.12 no.3
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• pp.29-35
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• 2007

Titanium was oxidized with oxygen plasma and calcinated with rapid thermal annealing for degradation of humic acid dissolved in water. Titania photocatalytic plate was produced by titanium surface oxidized with oxygen plasma by Plasma Enhanced Chemical Vapor Deposition (PECVD). RF-power and deposition condition is controlled under 100 W, 150 W, 300 W and 500 W. Treatment time was controlled by 5 min and 10 min. The film properties were evaluated by the X-ray Photoelectron Spectroscopy (XPS) and X-Ray Diffraction (XRD). From the experimental results, we found the optimal condition of titania film which exhibited good performance. Moreover photocatalytic capacity was about twice better than thermal spray titania film, and also as good as titania powder.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.12
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• pp.949-954
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• 2012

The K-PCS and W-CDMA dual band dielectric duplexer and bandpass filters have been designed and fabricated. The dual band duplexer consists of the separate monoblock K-PCS and W-CDMA duplexers using common antenna port. The coupling capacitance and I/O impedance matching have been designed to minimize the cross interference between the bands. Isolations of crosspoint between Tx and Rx in K-PCS and W-CDMA dualband were about 47 dB and 100 dB, respectively. On the other hand, isolations of Tx and Rx in K-PCS and W-CDMA were about 66 dB and 65 dB, respectively. The difference between 47 dB and 100 dB originated from the different center frequencies in Tx and Rx of K-PCS and W-CDMA bands. The coupling capacitance of the bandwidth, I/O capacitance of I/O matching and impedance matching, and various capacitances were important role to fabricate the dielectric duplexer and bandpass filters.

• The Research Journal of the Costume Culture
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• v.11 no.1
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• pp.66-74
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• 2003

This study is to improve the worst lightfastness of a natural dye. To modify the fiber surface, low temperature oxygen plasma was carried out on silk fabric. The result is followed below after the examination of surface shape, dyeability, color change, UV absorbent influence and lightfastness. 1. When electric discharge outputs are 60W, 80W and 100w, and processing times are 10minutes, 20minutes and 40minutes, the etching effect of surface increased as electric discharge outputs and processing times increased. 2. When examined UV absorbent for 5hours, 10hours, 20hours, 40hours and 80hours, the value changes of E are 1.47, 2.51, 2.91, 3.71, 4.51 and 5.31 in case of Al pre-mordanting/ prasma 80W, 20min./ UVabsorbent 5% (100:1), 2.31, 2.47, 3.84, 3.90, 3.61 and 4.42 in case of Al pre-mordanting/prasma 80W, 20min.1 UV absorbent 5% (o.w.f.). The lightfastness decreased when UV absorbent increased. 3. Dyeability of the samples pre-treated with five different methods was in the following order: plasma processing for 20minutes at 60W/Al pre-mordanting > Al pre-mordanting > plasma processing for 20minutes at 60W > Al after-mordanting. non mordanting Plasma treatment had superior effect on dyeability. 4. When UV absorbent was applied in fabric, the sample under higher electric discharge out puts showed more effective in improving lightfastness.

• Applied Chemistry for Engineering
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• v.9 no.6
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• pp.846-851
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• 1998

An experimental research on the preparation of zinc oxide fine particles in w/o emulsions was conducted. Precipitation solutions were zinc nitrate aqueous solutions with hexamethylenetetramine(HMTA) as precipitant. The precipitation solutions formed stable w/o emulsions with kerosine in the presence of Span 80. Homogeneous precipitation reaction occurred in the w/o emulsion after the resultant w/o emulsion was heated above the decomposition temperature of HMTA and zinc oxide particles were precipitated. In some case, zinc oxide particles of bi-modal distribution were obtained. However, zinc oxide fine particles of narrow particle size distribution could be obtained, even when the initial zinc concentration of precipitation solution and the conversion to zinc oxide are both higher that those in bulk homogeneous precipitation.

• Journal of Ocean Engineering and Technology
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• v.11 no.2
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• pp.145-153
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• 1997

This paper constructs a data base to create the Hull lines prior to piece manufacture and nesting steps with a personal computer using the data of created as the advanced software, TRIBON. The lines are plotted smoohtly, which are called the spline. The S/W is excellentlt estimated on the ptrcision among shipping exclusive S/W, which are currentlyused So, the S/W is mainly used as as shipping CAD program. High-cost H/W and high-performance S/W(TRIBON etc.) sre used with the bases of technique and capital power in the big shipbuilding yard; but small but small and medium-sized shipbuilding yard and related companycan't purchase dueto the high-cost product. To bring upthe small and medium sized shipbuilding yard lacking little competitive power, the data base S/W is joined with the CADRA of graphic S/W and is developed to create the Hull lines to be needed on as automatic cutting process usiing the personal computer.

• Korean Journal of Materials Research
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• v.11 no.11
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• pp.953-959
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• 2001

Homogeneous spherical W-Co salt powders were made by spray drying of aqueous solution of ammonium $metatungstate(NH_4)_6(H_2W_{12}O_{40}){\cdot}4H_2O,\; AMT)$ and cobalt nitrate $hexahydrate(Co(NO_3)_2{\cdot}6H_2O)$. The thermal decomposition process of spray dried W-Co salt powders was studied by TG, XRD, SEM, TEM and FT-IR. Spray dried W-Co salt powders were calcined for 1 hour in the temperature from$ 350^{\circ}C$ to $800^{\circ}C$ in atmosphere of air. At the temperatures over $600^{\circ}C$, spherical $CoWO_4/WO_3$ composite oxide powders were obtained. The primary particle size of W/Co composite oxide powders increased with increasing thermal decomposition temperature due to the particle growth. The observed crystallite size by TEM was in the range of 60nm and that of $CoWO_4$ calculated by Scherrer's formula at $800^{\circ}C$ was smaller than 55nm. The crystallite site was identified by XRD and TEM.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.5
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• pp.27-34
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• 2004

In this paper, we designed the electronic ballast for the 400[W] hight pressure sodium lamp using the half-bridge inverter Inductance and capacitance in the proposed equivalent LC series resonant circuit are calculated theoretically. We performed the simulation of the LC series half-bridge inverter circuit using the IsSPICE and the electronic ballast for the high pressure sodium lamp were implemented for verifing the simulation results. In the experimental results, the specification of the implemented electronic ballast are almost same with the simulated one. The experimental results show the good performance as PF 99.3[%], $A_{THD}$ 10.01[%], lamp efficiency 119[lm/W] at the output 400[W].].