• Journal of Powder Materials
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• v.23 no.1
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• pp.8-14
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• 2016

A bulk-type Ta material is fabricated using the kinetic spray process and its microstructure and physical properties are investigated. Ta powder with an angular size in the range $9-37{\mu}m$ (purity 99.95%) is sprayed on a Cu plate to form a coating layer. As a result, ~7 mm-sized bulk-type high-density material capable of being used as a sputter material is fabricated. In order to assess the physical properties of the thick coating layer at different locations, the coating material is observed at three different locations (surface, center, and interface). Furthermore, a vacuum heat treatment is applied to the coating material to reduce the variation of physical properties at different locations of the coating material and improve the density. OM, Vickers hardness test, SEM, XRD, and EBSD are implemented for analyzing the microstructure and physical properties. The fabricated Ta coating material produces porosity of 0.11~0.12%, hardness of 311~327 Hv, and minor variations at different locations. In addition, a decrease in the porosity and hardness is observed at different locations upon heat treatment.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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• pp.1543-1545
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• 2002

A T$\longrightarrow$A mutation in the promoter region of porcine myostatin (MSTN) gene has been identified in our previous work. This study analyzed the associations of the myostatin genotypes (TT, TA) caused by this mutation with birth weigh in Yorkshire pigs. Data from 211 unrelated individuals were collected three times from one breeding farm. Detections of the mutation were carried out by PCR-RFLPs approach. The effects of MSTN genotypes (TT and TA) on birth weight were compared by least square means. The results showed that for birth weight of Yorkshire pigs, individuals with TA genotype were significantly higher than those with TT genotype (p<0.05), and the birth weight for pigs with TA genotype were 1.37 kg in average but only 1.25 kg for pigs with TT genotype, indicating a positive effect of birth weight for A allele.

• Journal of the East Asian Society of Dietary Life
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• v.11 no.1
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• pp.19-25
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• 2001

This study was performed to examine the antimutagenic and cytotoxic effects of potato vinegar and commercial vinegars(cider, brown rice, persimmon vinegars) on Salmonella typhimurium TA98, TA100 and cancer cell lines using Ames test and cytotoxicity assay, respectively. In Ames test, all vinegars did notexhibit any mutagenicity , but showed substantial inhibitory effects against N- methyl - N -nitro - N- nitrosog -uanidine(MNNG) , 4-nitroquinoline-1-oxide(4NQO), 3-amino-1,4-dimethyl-5H-pyrido(4,3-b)indol(Trp-P-1)and benzo( $\alpha$ )pyrene(B( $\alpha$ )P). The number of revertants per plate decreased significantly when these vinegars(80 ug/plate) were added to the assay system using TA100 strain. Especially, potato vinegar(80 ug/plate) showed high inhibition rate of 69.9% against mutagenicity of B( $\alpha$ )P on TA100 strain. In the cytotoxicity assay, these vinegars also showed prominent cytotoxic activity against human cancer cell lines. Potato vinegar(10 ug/well) showed the strongest cytotoxic effect against HT1080 (fibrosacoma cell) andK562 ( myelogenous leukemia) at the same concentration when compared with other vinegars.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.5
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• pp.383-387
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• 2002

N-channel metal-ferroelectric-insulator-semiconductor field-effect-transistors (MFISFET's) by using $SrBi_2Ta_2O_9$/Silicon Nitride/Si (100) structure were fabricated. The fabricated devices exhibit comfortable memory windows, fast switching speeds, good fatigue resistances, and long retention times that are suitable for advanced ferroelectric memory applications. The estimated switching time and polarization ($2P_r$) of the fabricated FET measured at applied electric field of 376 kV/cm were less than 50 ns and about 1.5 uC/$\textrm{cm}^2$, respectively. The magnitude of on/off ratio indicating the stored information performance was maintained more than 3 orders until 3 days at room temperature. The $I_DV_G$ characteristics before and after being subjected to $10^11$ cycles of fatigue at a frequency of 1 MHz remained almost the same except a little distortion in off state.

• Current Applied Physics
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• v.18 no.11
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• pp.1225-1229
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• 2018

In this paper, we investigated the electronic structures and defect states of $SrLaMgTaO_6$ (SLMTO) double perovskite structures by using resonant inelastic x-ray scattering. Recently, $Eu^{3+}$ doped SLMTO red phosphors have been vigorously investigated due to their higher red emission efficiency compared to commercial white light emitting diodes (W-LED). However, a comprehensive understanding on the electronic structures and defect states of host SLMTO compounds, which are specifically related to the W-LED and photoluminescence (PL), is far from complete. Here, we found that the PL spectra of SLMTO powder compounds sintered at a higher temperature, $1400^{\circ}C$, were weaker in the blue emission regions (at around 400 nm) and became enhanced in near infrared (NIR) regions compared to those sintered at $1200^{\circ}C$. To elucidate the difference of the PL spectra, we performed resonant inelastic x-ray spectroscopy (RIXS) at Ta L-edge. Our RIXS result implies that the microscopic origin of different PL spectra is not relevant to the Ta-related defects and oxygen vacancies.

• Journal of the Korean Ceramic Society
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• v.40 no.2
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• pp.184-190
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• 2003

$Sr_{0.9}Bi_{2.1}Ta_2O_9$thin films were deposited on $IrO_2$ electrode by spin coating method using photosensitive sol-gel solution. To ensure the UV-exposure effect on SBT thin films, UV irradiated films and non-UV irradiated films were analyzed by XRD, SEM. As a result, UV-irradiation on SBT thin films promoted grain growth of SBT compared with no UV irradiation. In case of the UV irradiated films annealed at$740{\circ}C$for 1 h in an oxygen ambient, the 2Pr value and Pr/Ps at${pm}5$V were$11.48{mu}C/cm^2$and 0.53, respectively. 2Pr values of the UV irradiated SBT thin films at$660-740{circ}C were approximately 12% higher than those of non-UV irradiated thin films.

• Journal of Sensor Science and Technology
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• v.11 no.4
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• pp.247-253
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• 2002

For fabrication of the pyroelectric IR sensor $(Pb,La)TiO_3(PLT)$/$LiTaO_3$/(LTO)/PLT ferroelectric thin films was deposited by rf magnetron sputtering followed by rapid thermal annealing and the crystallinity as a function of annealing temperature and time was investigated. Permittivity and dielectric loss factor of ferroelectric thin films as a function of c-axis preffered orientation was measured. Also pyroelectric coefficient of ferroelectric thin films with largest c-axis preffered orientation was measured and obtain figure of merit of voltage response($F_V$) and detectivity($F_D$). In this case $F_V$, $F_D$ was $5.63{\times}10^{-10}\;C{\cdot}cm/J$, $1.98{\times}10^{-8}\;C{\cdot}cm/J$, respectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.11
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• pp.1123-1129
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• 2010

Angular Deviation(AD) on transparency applied to TA-50 Aircraft deteriorates armament system's accuracy because it makes a difference in between actual and theoretical targets. In order to increase accuracy, therefore, TA-50 Aircraft measures AD on transparency and provide the measured values for the integrated mission display computer as a type of AD coefficients. This makes AD revised so that pilots can accurately see the actual target on their head-up display. In order to implement such mechanism into a real field, we develop a new device and system automatically measuring AD for the first time. We also deal with basic concept including AD induction formula as well as operating systems. As a consequence of testing the accuracy and precision for verifying reliability of the system, we got satisfactory results. In specific, the accuracy was within the resultant criterion of 1%. The precision was also satisfied with respect to the whole criteria. The system developed through this research is qualified as a military standard equipment for transparency of the canopy.

• Journal of the Korean Ceramic Society
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• v.40 no.3
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• pp.279-285
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• 2003

Ferroelectric S $r_{0.9}$B $i_{2.1}$T $a_{1.8}$N $b_{0.2}$ thin films with 200 nm thicknesses were deposited on Pt/Ti $O_2$/ $SiO_2$/Si Substrates by a sol-gel method. In these experiments, Sr(O $C_2$ $H_{5}$)$_2$, Bi(TMHD)$_3$, Ta(O $C_2$ $H_{5}$)$_{5}$ and Nb(O $C_2$ $H_{5}$)$_{5}$ were used as precursors, which were dissolved in 2-methoxyethanol. After UV-irradiation and RTA processes, the remanent polarization value (2 $P_{r}$) of SBTN thin films with annealed at $650^{\circ}C$ was 8.49 and 11.94 $\mu$C/$\textrm{cm}^2$ at 3 V and 5 V, respectively.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.662-668
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• 2004

Ames test revealed most methanol extracts of 13 Korean wild mushroom species have strong antimutagenic effects against N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and benzo(a)pyrene[B(a)P]. Methanol extracts of Coriolus versicolor and Phaeolepiota aurea showed 74-94 and 83-88% antimutagenic effects against MNNG and B(a)P in Salmonella typhimurium TA100 strain, while 89 and 91% inhibitions were observed against B(a)P in TA98 strain, respectively. Most water extracts of wild mushrooms did not show antimutagenic activeiy on MNNG and B(a)P. Wild mushrooms extracts inhibited human colon carcinoma cells (HT29), human hepatoma cell (HepG2), and humann histiocytic lymphoma cell (U937) dose-dependently, with most methanol extracts exhibiting stronger effect than water extracts, Highest toxicity was observed against HT-29 cells in methanol extracts of Coriolus versicolor and Phaeolepiota aurea, showing 84% inhibition at 1 mg/mL, whereas C. versicolor water extract showed 53-65% inhibition against HepG2 and U937. These extracts did not show cytotoxic effects against human lymphocyte. Results revealed wild mushrooms have strong antimutagenic and in vitro cytotoxic effects.