• Resources Recycling
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• v.26 no.6
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• pp.29-37
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• 2017

Nuclear fuel cladding tube is fabricated by pilgering and annealing process. In order to remove impurity and oxygen layer on the surface, pickling process is carried out. When Zirconium(Zr) is dissolved and saturated in acid solution during the pickling process, all the waste acid including Zr is disposed. Therefore, $BaF_2$ is added into the waste acid to extract Zr and $Ba_2ZrF_8$ is subsequently formed. To recycle Zr by electrowinning process, $Ba_2ZrF_8$ is used as electrolyte, but it has high melting point ($1053^{\circ}C$). $ZrF_4$ should be added into $Ba_2ZrF_8$ to decrease the melting point. In this paper, it was investigated that $Ba_2ZrF_8$ was separated to $BaF_2$ and $ZrF_4$ by vacuum distillation. Firstly, $BaF_2$ with different particle size ($1{\mu}m$, $35{\mu}m$, $110{\mu}m$) was added into the waste acid and the respective precipitation property was estimated. $BaF_2$ obtained by vacuum distillation was shattered by ball-milling with different time. The precipitation efficiency was compared with $1{\mu}m$ of ${BaF_2}^{\prime}s$ one, which was not used as precipitation agent.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.1
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• pp.151-159
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• 1998

Elelctrical properties of $BaTiO_3$ were characterized with addition of $Y_2O_3, CaO,SiO_2$ and Mn to develope the composition of PTC thermistor suitable as a current limiting device for automobile motor system. With the addition of 0.2 mol% $Y_{2}O_3$ to $BaTiO_3$, the minimum resistance of 16.5 ${\Omega}{\cdot}$cm was obtained at room temperature. $(Ba_{0.996}Y_{0.004})TiO_3$ exibited a minimum resistance of 50${\Omega}{\cdot}$cm with addition of 1.6 mol% $SiO_2$. The grain size of $(Ba_{0.996}Y_{0.004})TiO_3$ decreased from 34.95 ${\mu}$m to 13.4 ${\mu}$m and thus breakdown voltage could be improved by changing the composition as $(Ba_{0.996}Y_{0.004}Ca_{0.05}) TiO_3$ with substition of 5 mol% Ca into Basites. When 0.04 mol% Mn was added, the optimum PTCR properties could be obtained : the resistivity at room temperature and ${\rho}_{max}/{\rho}_{min}$ were 30~40${\Omega}{\cdot}$cm and $1.5{\times}10^5$ respectively.

• Journal of the Korean Ceramic Society
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• v.39 no.6
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• pp.604-609
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• 2002

Nanosized $BaCeO_3$ powders with the stoichiometric composition of a molecular level were synthesized by the citrate process based on the Pechini method. Polymeric precursor was formed by use of citric acid and ethylen glycol, as chelating agent of metal ions and reaction medium, respectively. Single phase orthorhombic structured $BaCeO_3$powders, about 100 nm sized and uniform shaped were obtained through the calcination of the polymeric precursor at $900^{\circ}C$ for 4 h. Extremely small quantities of carbonate ions($CO_^{2-}$) were completely decomposed at over $1100^{\circ}C$. The mean size of the powders was increased twice, however, it has very uniform distribution in its size and shape.

• Food Science of Animal Resources
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• v.33 no.6
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• pp.701-707
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• 2013

The present study was carried out to investigate the antiobesity and hypocholesterolemic effects of Bifidobacteria animalis DY-64 (B. animalis DY-64), a lactic acid bacterium isolated from the human intestine, in rats fed a high-fat/high-cholesterol diet for 4 weeks. Forty male Sprague-Dawley rats were divided into four groups and fed either a normal (N) or high-fat/high-cholesterol (HFC) diet without or with oral administration of B. animalis DY-64 (N-BA, HFC-BA). The gain in body weight, and liver and adipose tissue weights of the HFC group were heavier than that of the HFC-BA group. Serum total cholesterol (TC), LDL-cholesterol, and leptin levels of the HFC group, which were significantly elevated compared to those of the N group, dropped by 19, 18, 21, and 13% in the HFC-BA group, respectively, whereas the serum HDL-cholesterol level markedly increased. However, serum TG, LDL-cholesterol, HDL-cholesterol, and leptin levels were not significantly different among the N groups (N, N-BA) with or without B. animalis DY-64 administration. TC and TG levels of the liver as well as the TG level of the adipose tissue were significantly reduced in the HFC-BA group. In addition, HR-LPL activity in adipose tissue was also lower in the HFC-BA group than in the HFC group. These results suggest that B. animalis DY-64 isolated from the human intestine exerts hypocholesterolemic effects by reducing serum and liver cholesterol levels and plays a role in the prevention of obesity induced by HFC diet.

• Korean Journal of Plant Tissue Culture
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• v.26 no.3
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• pp.211-217
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• 1999

The effect of auxins and cytokinins on the formation of adventitious shoots, adventitious roots, trichomes, and calli in MS basal medium was investigated in leaf segments from ecotype Columbia of Arabidopsis thaliana. Adventitious shoots, adventitious roots, trichome, and calli were formed from leaf segments by a wide range of hormone concentrations and combinations. Adventitious shoots were formed respectively in treatment with 0.1mg/L IAA and 10 mg/L BA. Adventitious roots were formed in treatments with low concentration of IAA and NAA. Trichomes and calli were formed by increasing the concentration of IAA and NAA. The optimal combination was 0.5mg/L NAA and 0.1mg/L BA for trichome formation, 10mg/L NAA and 10mg/L BA for calli formation. When NAA was treated alone in culture media, adventitious roots were formed in 0.1mg/L, trichomes were formed in 2.0mg/L, and calli were formed in 10mg/L. Inductive time for formation of adventitious roots, trichomes and calli were determined at 6,7 and 18 days respectively by periodical transfer of leaf segments from NAA containing medium to NAA free medium.

• Bulletin of the Korean Chemical Society
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• v.30 no.6
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• pp.1267-1273
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• 2009

The correlation between the sintering temperature and dielectric properties in the $Nb^{5+}\;and\;Ta^{5+}$ doped BaTi$O_3$ solid solutions have been investigated. The samples were sintered at temperatures ranging from 1250 to 1350 ${^{\circ}C}$ for 4 h in air. SEM, XRD and SEM/EDS techniques were used to examine the structure of the samples with particular focus on the incorporation of $Nb^{5+}\;and\;Ta^{5+}$ ions into the BaTi$O_3$ crystal lattice. The X-ray diffraction peaks of (111), (200) and (002) planes of BaTi$O_3$ solid solution doped with different fractions of $Nb^{5+}\;and\;Ta^{5+}$ were investigated. The dielectric properties were analyzed and the relationship between the properties and structure of doped BaTi$O_3$ was established. The fine-grain and high density of the doped BaTi$O_3$ ceramics resulted in excellent dielectric properties. The dielectric properties of this solid solutions were improved by adding a small amount of dopants. The transition temperature of the 1.0 mole% $Ta^{5+}$ doped BaTi$O_3$ solid solution was $\sim$110 ${^{\circ}C}$ with a dielectric constant of 3000 at room temperature. At temperatures above the Curie temperatures, the dielectric constant followed the Curie-Weiss law.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.6
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• pp.759-764
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• 2011

Mixed-conducting oxide powders, $BaCe_{0.9}Y_{0.1}O_{2.95}$ (BCY) and $SrCe_{0.9}Y_{0.1}O_{2.95}$ (SCY) powders have been prepared by a solid-state reaction method. Xray diffraction patterns of the prepared powders showed the sharp peaks of the $BaCe_{0.9}Y_{0.1}O_{2.95}$ and $SrCe_{0.9}Y_{0.1}O_{2.95}$ phases. The oxide powders that were prepared by attrition milling showed rather large particles and severe necking between particles in FE-SEM images as well as residual reactant ($BaCO_3$) and secondary phases ($SrCeO_3$ and $CeO_2$) in XRD patterns. The oxide powders prepared using ball milling showed particles under approximately 500 nm and typical XRD patterns of the $BaCe_{0.9}Y_{0.1}O_{2.95}$ and $SrCe_{0.9}Y_{0.1}O_{2.95}$ phases. Ceramic membranes of the $BaCe_{0.9}Y_{0.1}O_{2.95}$ and $SrCe_{0.9}Y_{0.1}O_{2.95}$ phases were fabricated by the aerosol deposition method using the oxide powders synthesized.

• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1535-1544
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• 2020

The primary objective of this study was to isolate and identify amine oxidase-producing probiotic Bacillus strains from traditional fermented soybean paste. Biogenic amines (BA)-forming bacteria isolated from the samples were identified as Bacillus sp. TS09, Bacillus licheniformis TS17, Bacillus subtilis TS19, Bacillus cereus TS23, Bacillus sp. TS30, Bacillus megaterium TS31, B. subtilis TS44, Bacillus coagulans TS46 and Bacillus amyloliquefaciens TS59. Meanwhile, B. subtilis TS04 and TS50 isolated from the same samples exhibited good probiotic properties, including the tolerance to artificial gastric juice and bile salts, the adhesion to intestinal epithelial cells, and the production of bacteriocin(s) active against BA-forming bacteria (Bacillus sp. TS30 and B. subtilis TS44). In addition, the amine oxidase produced by B. subtilis TS04 and TS50 significantly decreased the formation of BA, especially cadaverine, putrescine, and tyramine, therefore, these strains could be considered good potential probiotic candidates to prevent or reduce BA accumulation in food products.

• The Korea Journal of Herbology
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• v.38 no.6
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• pp.45-52
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• 2023

Objectives : Effects of baicalein (BA) on oxidative stress in RAW 264.7 mouse macrophages stimulated with peptidoglycan (PG) and lipopolysaccharide (LPS) were investigated. Methods : RAW 264.7 co-stimulated with LPS and PG were incubated with BA at concentrations of 25 and 50 µM. Incubation time was 18 h, 20 h, 22 h, 24 h, and 26 h. After incubation, the production of hydrogen peroxide in RAW 264.7 was measured with dihydrorhodamine 123 assay. Additionally, RAW 264.7 stimulated with PG were incubated with BA at concentrations of 25 and 50 µM for 24 h. After incubation, NO production was evaluated by griess reagent assay. Results : BA significantly inhibited hydrogen peroxide productions (p <0.05). In details, production of hydrogen peroxide in 'LPS and PG'-stimulated RAW 264.7 treated for 18 h with BA at concentrations of 25 and 50 µM was 91.27% and 89.22% of the control group treated with LPS and PG only, respectively; the production of hydrogen peroxide for 20 h was 92.19% and 90.58%, respectively; production of hydrogen peroxide for 22 h was 91.69% and 89.89%, respectively; production of hydrogen peroxide for 24 h was 92.4% and 90.19%, respectively; production of hydrogen peroxide for 26 h was 91.7% and 89.04%, respectively. Additionally, BA at the concentration of 50 and 100 µM significantly inhibited NO production in PG-induced RAW 264.7 (p <0.05). Conclusions : BA might have anti-oxidative activity related to its inhibition of hydrogen peroxide production in 'LPS and PG'-stimulated RAW 264.7 macrophages.

• Journal of Powder Materials
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• v.30 no.6
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• pp.521-527
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• 2023

Piezoelectric technology, which converts mechanical energy into electrical energy, has recently attracted drawn considerable attention in the industry. Among the many kinds of piezoelectric materials, BaTiO₃ nanotube arrays, which have outstanding uniformity and anisotropic orientation compared to nanowire-based arrays, can be fabricated using a simple synthesis process. In this study, we developed a flexible piezoelectric energy harvester (f-PEH) based on a composite film with PVDF-coated BaTiO₃ nanotube arrays through sequential anodization and hydrothermal synthesis processes. The f-PEH fabricated using the piezoelectric composite film exhibited excellent piezoelectric performance and high flexibility compared to the previously reported BaTiO₃ nanotube array-based energy harvester. These results demonstrate the possibility for widely application with high performance by our advanced f-PEH technique based on BaTiO₃ nanotube arrays.