• Journal of the Korean Ceramic Society
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• v.41 no.5
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• pp.375-380
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• 2004

Pb(Ni$\_$1/3/Nb$\_$2/3/)O$_3$-PbZrO$_3$-PbTiO$_3$ thick films were screen-printed on platinized alumina substrates and fired at 800-1000$^{\circ}C$. Two kinds of powders with different particle size were prepared by attrition and ball milling methods. Effects of particle size of starting material on the microstructure and electrical properties of the thick films were investigated. Average particle size of attrition milled-powder (0.44 ${\mu}$m) was much smaller than that of ball milled-powder (2.87 ${\mu}$m). Average grain size of the thick film prepared from attrition-milled powder was smaller than that of the thick film prepared from ball-milled powder at the sintering temperature of 800$^{\circ}C$. However, the difference in average particle size became smaller with increasing the sintering temperature. Thick films prepared from attrition-milled powders showed more uniform and denser microstructures at all firing temperatures. Thick films prepared from attrition-milled powders had better electrical properties at the firing temperature above 900$^{\circ}C$ than thick films prepared from ball-milled powders. Dielectric constant, remanent polarization and coercive field of the thick film prepared from attrition-milled powders and fired at 900$^{\circ}C$ were 559, 16.3 ${\mu}$C/cm$^2$, and 51.3 kV/cm, respectively.

• Korean journal of food and cookery science
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• v.28 no.6
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• pp.805-811
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• 2012

This study was carried out in order to optimize the manufacturing condition of fried garlic flakes as well as to investigate the physicochemical properties of the flakes. Fried garlic flake samples were prepared as follows: garlic was sliced by a thickness of 1.5 mm, 2.0 mm, 2.5 mm, which were measured by a thickness gage. The samples were fried in vegetable oil under different temperatures of $140{\sim}150^{\circ}C$, $160{\sim}170^{\circ}C$ and $180{\sim}185^{\circ}C$. The compression strength depending on the height (h) was measured in order to find the thickness effect by the rheometer (force control: 50 N, h: 3.25 mm). Moreover, the sample with 1.5 mm thickness showed crisp phenomena of the split compared with the crush shape of the 2.0 mm and 2.5 mm thick samples. The result of strength for time dependence showed a sample with a thickness of 1.5 mm, which was measured 5~9 times more than the 2.0 mm and 2.5 mm thick samples. We thought the reason that the 1.5 mm sample had less response power equivalent to compression force than the other samples. Alliin has been found to affect the immune responses in the blood, it is a derivative of the amino acid cysteine and is also quite heat stable. The LC system with a UV detection at 210 nm consists of a separation on a Zorbax TMS column and isocratic elution with water and ACN as a mobile phase. The alliin contents of raw and fried garlic flake under $140{\sim}150^{\circ}C$, $160{\sim}170^{\circ}C$ and $180{\sim}185^{\circ}C$ were 18.10 mg/mL, 14.0 mg/mL, 11.6 mg/mL and 11.1 mg/mL, respectively. The decrement of alliin content under different temperature was a small quantity hence, we confirmed that the increasing manufacturing temperature was not affected by the alliin content. Examining for the particle structure of fried garlic flakes by a polarization microscope, the color of the sample treated at $160{\sim}170^{\circ}C$ was pure yellow. Furder, the fiber shaped particle, which has an effect on the tough texture, almost did not appear compared to the different temperature conditions. Finally, the sensory test for the preference of fried garlic flake under different conditions was carried out and the scores for various sensory characteristics were surveyed. According to the physicochemical measurements and sensory evaluation, we confirmed that the optimum manufacturing condition of fried garlic flake was 1.5 mm thick at a temperature of $160{\sim}170^{\circ}C$.

• Resources Recycling
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• v.31 no.3
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• pp.61-72
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• 2022

We investigated the electrochemical behavior of Sn (93.0 %)-Ag (4.06 %)-Cu (0.89 %) during electrolysis of Pb-free solder waste to recover tin and silver. A thin strip of the solder waste produced by high-temperature melting and casting was used as a working electrode to perform electrochemical analysis. During anodic polarization, the current peak of an active region decreased with an increase in the concentration of sulfuric acid used as an electrolyte. This resulted in the electro-dissolution of the working electrode in the electrolyte (1.0 molL^-1 sulfuric acid) for a constant current study. The study revealed that the thickening of an anode slime layer at the working surface continuously increased the electrode potential of the working electrode. At 10 mAcm^-2, the dissolution reaction continued for 25 h. By contrast, at 50 mAcm^-2, a sharp increase in the electrode potential stopped the dissolution in 2.5 h. During dissolution, silver enrichment in the anode slime reached 94.3% in the 1 molL^-1 sulfuric acid electrolyte containing a 0.3 molL^-1 chlorine ion, which was 12.7% higher than that without chlorine addition. Moreover, the chlorine enhanced the stability of the dissolved tin ions in the electrolyte as well as the current efficiency of tin electro-deposition at the counter electrode.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.37.1-37.1
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• 2015

It is suggested that relativistic jets associated with active galactic nuclei (AGNs) can have great impacts on the evolution of the host galaxy. However, the physical properties of AGN jets including the formation mechanism are not well known to date, and hence the AGN feedback on the host galaxy is yet poorly understood. OVV 1633+382 as a highly variable AGN source (a.k.a. blazer) with a compact core and very well developed jet components is an excellent laboratory to study the jet formation mechanism of radio-loud AGN. Near 2002, a major flare was reported at mm wavelength with a dramatic increase of the flux, which is likely to be followed by a dense and bright outflow. In order to probe the evolution of the innermost region of this radio-loud AGN, we have monitored using the Very Large Baseline Array (VLBA) and the Effelsberg 100m single-dish radio telescope in 12 epochs from 2002 and 2005. The observations were conducted at 22, 43 and 86 GHz in full polarization mode. In this work, we present the intensity and spectral index maps at 22 and 43 GHz from our monitoring observations. We probe the kinematics and geometry of individual jet components to discuss the evolution of the jet.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.9
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• pp.103-109
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• 2006

This research is contents about output characteristic of optic current sensor that use faraday effect. optic current sensor used in an experiment is consisted of three parts.(1) Source of light used laser diode of 1310[nm].(2) Sensor section manufactured circularly according to gas insulated switchgear. And $9/125[{\mu}m]$ standard single mode optical fiber for communication was installed winding 20 [turn] on sensor section core surroundings of diameter 31 [cm].(3) Electrical signal of PD(Photo detector) is collected using NI company's 16bit DAQ board via terminal block. Collected data analyzed by different three signal processing methods. NI company's $Labview^{TM}$ was used to signal processing software. As a result, In signal processing of optic current sensor, we could know that noise greatly more influences the error generation than fluctuation of light intensity. also, 1 class CT(current transformer) manufacture that have error rate less than 1[%] was available by removing these

• Electrical & Electronic Materials
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• v.8 no.4
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• pp.458-463
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• 1995

The optical and electrical properties of $C_{22}$-Quinolinium(TCNQ) Langmuir-Blodgett films have been studied depending on the annealing temperatures. The optimal properties were investigated using UV/visible(300-800[nm]) absorption spectra and FTIR(Fourier-transformed- infrared) absorption measurements. The electrical properties were investigated in a frequency range of 10[Hz]-13[MHz]. The UV/visible absorption spectra at room temperature show that there are four characteristic peaks at 320, 380, 494 and 678[nm]. These absorption peaks decrease very rapidly above the annealing temperature of 180[.deg. C], which is due to a structural change of TCNQ. The FTIR absorption measurements strongly support the result of the UV/visible absorption spectra, because the absorption peak of TCNQ- at 2181[$cm^{-1}$ /] also decreases above 140[.deg. C]. The frequency-dependent dielectric constant shows that there is a dielectric dispersion near 1[MHz] which is due to an orientational polarization of the molecules inside the film. The overall frequency-dependent dielectric constant is higher near 80[.deg. C]. It may be due to a softness of the alkyl chains.s.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.9
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• pp.429-433
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• 2006

PZT(80/0) powder was prepared by a sol-gel method and PZT thick films were fabricated by the screen-printing method on the alumina substrates. The coating and drying procedure was repeated 4 times. And then the PZT(20/80) precusor solution was spin-coated on the PZT thick films. A concentration of a coating solution was 0.5mol/L and the number of coating was varied from 0 to 6. The porosity decreased and the grain size increased with increasing the number of coatings. The thickness of the PZT-6(6: number of coatings) films was about $60{\mu}m$. The relative dielectric constant increased and the dielectric loss decreased with increasing the number of PZT(20/80) sol coatings. The relative dielectric constant and dielectric loss of the PZT-6 thick film were 275 and 3.5%, respectively. The remanent polarization, coercive field and breakdown strength of the PZT-6 film were $19.8{\mu}C/cm^2$, 13.7kV/cm and 130kV/cm, respectively.

• Archives of Pharmacal Research
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• v.17 no.2
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• pp.80-86
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• 1994

The bioavailability of digoxin generic tablets manufactures in Korea (formulations A & B) wwere compared to a standard (formulation C; Lanoxin brand digoxin, Burroughs Wellcome, USA) in 12 healthy Korean male volunteers (mean age 31.4 years) in a single dose, randomized, complete block crossover study. Using a latin square design, each of the subjects was randomized to the order number and allocated to each of the three treatments of 0.5mg oral digoxin. Digoxin conc4ntrations in serum and urine samples collected for 48 hours after dosing were measured by fluoprescence polarization immunoassy and radioimmunoassy, respectively. Treatments were compared by using nonlinear least squares regession analysis to evaluate the following pharmacokinetic parameters : maximum serum concentation $(C_{max})$; time of maximum serum concentation $(T_{max})$; area under the serum concentration-time curve $AUC_{0-12}$, $C_{max}$\;and\;(AUC_{0-12})$; and cummulative urinary excretion for 0-48 hours $(CLE_{0-48}.\;Mean\;AUC_{0-12},\;C_{max},\;and\;CUE_{0-48}$ values for formulations B and C were significantly different from formulation A (P<0.001), but not significantly diffeerent form each other. Basede on $AUL_{0-12}\;and\;CUE_{0-48}$ respectively, the relative availability of formulation B was 87.5% and 89.6% and the relative availability of formultation A was 43% and 35% when compared to formulation C(the standard).

• Korean Journal of Materials Research
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• v.25 no.6
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• pp.293-299
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• 2015

In this study, nitrogen ions were implanted into STS 316L austenitic stainless steel by plasma immersion ion implantation (PIII) to improve the corrosion resistance. The implantation of nitrogen ions was performed with bias voltages of -5, -10, -15, and -20 kV. The implantation time was 240 min and the implantation temperature was kept at room temperature. With nitrogen implantation, the corrosion resistance of 316 L improved in comparison with that of the bare steel. The effects of nitrogen ion implantation on the electrochemical corrosion behavior of the specimen were investigated by the potentiodynamic polarization test, which was conducted in a 0.5 M $H_2SO_4$ solution at $70^{\circ}C$. The phase evolution and texture caused by the nitrogen ion implantation were analyzed by an X-ray diffractometer. It was demonstrated that the samples implanted at lower bias voltages, i.e., 5 kV and 10 kV, showed an expanded austenite phase, ${\gamma}_N$, and strong (111) texture morphology. Those samples exhibited a better corrosion resistance.

• Transactions of the Korean hydrogen and new energy society
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• v.3 no.2
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• pp.45-54
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• 1992

An applicability microencapsulation, using electroless copper plating, of hydrogen storage alloy powder as an anode material for nickel-hydrogen secondary batteries was investigated. Alloys employed were $LaNi_{4.7}Al_{0.3}$ and $MmNi_{4.5}Al_{0.5}$(Mm=mischmetal) which have an appropriate equilibrium pressure and capacity. The microencapsulation of the alloy powder was found to accelerate initial activation of electrodes and to increase capacity which is about 285mAh/g for $LaNi_{4.7}Al_{0.3}$. In addition, other charge and discharge characteristics, such as polarization and flatness of charge and discharge potential, were improved due to the role of copper layer as a microcurrent collector and an oxidation barrier of the alloy powder. $MmNi_{4.5}Al_{0.5}$ alloy showed lower capacity than $LaNi_{4.7}Al_{0.3}$ because of higher equilibrium pressure. Cyclic characteristics of both alloys were somewhat poor because of mainly shedding and partial oxidation of alloy powder during the cycling. However, it was considered that the microencapsulation method is effective to improve the performances of the hydrogen storage alloy electrodes.