• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.2
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• pp.95-104
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• 2005

Effects of the aluminum melting temperature, melting time and a kind of flux agents on the distribution of surrogate nuclide were investigated in the electric furnace at the aluminum melting including surrogate radionuclides(Co, Cs, Sr) in order to establish the fundamental research of the melting technology for the metallic wastes from the decommissioning of the TRIGA research reactor. It was verified that the fluidity of aluminum melt was increased by adding flux agent but it was slightly varied according to the sort of flux agents. The results of the XRD analysis showed that the surrogate nuclides move into the slag phase and then they were combined with aluminum oxide to form more stable compound. The weight of the slag generated from aluminum melting test increased with increasing melting temperature and melting time and the increase rate of the slag depended on the kind of flux agents added in the aluminum waste. The concentration of the cobalt in the ingot phase decreased with increasing reaction temperature but it increased in the slag phase up to 90$\%$according to the experimental conditions. The volatile nuclides such as Cs and Sr considerably transferred from the ingot phase to the slag and dust phase.

• Journal of the Korean Magnetics Society
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• v.14 no.1
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• pp.18-24
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• 2004

Ni-Zn ferrite powder was synthesized from metal nitrates, Fe(N $O_3$)$_3$$.$9 $H_2$O, Ni(N $O_3$)$_2$$.$6 $H_2$O, Zn(N $O_3$)$_2$$.$6 $H_2$O by wet direct process to make high permeability material. The composition of the ferrite powder is (N $i_{0.284}$F $e_{0.053}$Z $n_{0.663}$)F $e_2$ $O_4$. Ni-Zn ferrite powder is compounded by precipitating metal nitrates with NaOH in vessel at 90$^{\circ}C$ synthetic temperature for 8 hours. Calcination temperature and sintering temperature were 700$^{\circ}C$ and 1150$^{\circ}C$-1250$^{\circ}C$ respectively for 2 hours. The same compound powder was extracted from metal oxide by wet ballmilling. We compared the properties of powder and the electromagnetic characteristics of the sintered cores obtained from the two different processes. Wet direct process produces smaller particle size with narrower distribution and higher purified ferrite which cores has high permeability and high magnetization.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.1
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• pp.1-9
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• 2017

Acer tegmentosum Maxim (ATM) is known as traditional medicine for treatment of hepatic disorders such as hepatitis, related-inflammatory disease, and hepatic cancer. In this study, we evaluated the antioxidant and anti-inflammatory effects of ATM extracted with $80^{\circ}C$ water or 95% ethanol. Antioxidant activities of ATM extracts were measured based on DPPH and ABTS radical scavenging activities, total polyphenolic compound contents, and ferric reducing antioxidant power. The anti-inflammatory effects of ATM extract were assayed on release of nitric oxide, tumor necrosis factor $(TNF)-{\alpha}$, and interferon $(IFN)-{\gamma}$ from lipopolysaccharide (LPS)-induced macrophages. In these experiments, 95% ethanol extract of ATM showed stronger antioxidant and anti-inflammatory effects than water extract. Therefore, we determined the effects of ATM ethanol extract on an animal model of sepsis. Seven days oral gavage of ATM ethanol extract followed by LPS stimulation reduced the protein levels of $TNF-{\alpha}$ and $IFN-{\gamma}$ in serum as well as mRNA levels of $TNF-{\alpha}$ and interleukin-6 in intestinal epithelial cells. In addition, ATM ethanol extract reduced DNA damage in mouse lymphocytes. These results indicate that ATM extract has strong antioxidant and anti-inflammatory in vitro and in vivo effects and may be developed as a potential food material for prevention of inflammatory diseases.

• Korean Chemical Engineering Research
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• v.47 no.4
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• pp.465-469
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• 2009

Characteristics of oxidation reaction of four lanthanide chlorides(Ce, Nd, Pr and $EuCl_3$) in a oxygen-eutectic(LiCl-KCl) salt bubble column was investigated. From the results obtained from the thermochemical calculations by HSC chemistry software, the most stable lanthanide compounds in the oxygen-used rare earth chlorides system were oxychlorides(EuOCl, NdOCl, PrOCl) and oxides($CeO_2$, $PrO_2$), which coincide well with results of the Gibbs free energy of the reaction. In this study, similar to the thermochemical results, regardless of the sparging time and molten salt temperature, oxychlorides for Eu, Nd and Pr and oxides for Ce and Pr were formed as a precipitant by a reaction with oxygen. The structure of the rare earth precipitates was divided into two shapes : small cubic(oxide) and large tetragonal (oxychloride) structures. The conversion efficiencies of the lanthanide elements to their molten salt-insoluble precipitates(or compound) were increased with the sparging time and temperature, and Ce showed the best reactivity. In the conditions of $650^{\circ}C$ of the molten salt temperature and 420 min of the sparging time, the conversion efficiencies were over 99% for all the investigated lanthanide chlorides.

• Journal of Technologic Dentistry
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• v.29 no.1
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• pp.121-131
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• 2007

A preparation process's conditions of aqueous sol which contains anatase-type nano titania particles with photocatalyic properties was established by using Yoldas process, so called, DCS(Destabilization of Colloidal Solution) process in this study. And crystal size change and phase transformation of titania particles in aqueous titania sol depending on reaction conditions was investigated by a light scattering method and XRD analysis of frozen dried powders, respectively. This sol with photo catalytic nano titania particles was used to the following hydrophilic hybrid coating film's fabrication and its properties was evaluated. Subsequently, for coating film using the above mentioned aqueous titania sol, non-aqueous titania sol was prepared without any chemical additives and its time stability according to aging time was investigate. By using the above mentioned aqueous titania sol and non-aqueous sol, a complex oxide coating sol for metal and ceramic substrate and a organic-inorganic hybrid coating sol for polymer substrate was prepared and it's hydrophilicity depending on UV irradiation conditions was evaluated. As a conclusions, the following results were obtained. (1)Aqueous titania sol The average particle size of titania in formed aqueous titania sol was distributed between 20$\sim$90nm range depending on reaction conditions. And the crystal phase of titania powders obtained by frozen drying method was changed from amorphous state to anatase and subsequently transformed to rutile crystal phase and it is attributed to concentration gradient in aqueous sol. (2)Non-aqueous titania sol Non-aqueous titania sol was prepared using methanol as a solvent and a little distilled water for hydrolysis and nitric acid as a catalyst were used. The obtained non-aqueous titania sol was stable at room temperature for 20 days. Additionally, non-aqueous titania sol with addition of chealating reagent such as acethylaceton and ethylene glycol prolonged the stability of sol by six months. (3)Complex sol and hybrid sol with super hydrophilicity The above mentioned aqueous titania sol as a main photocataylic component and non-aqueous titania sol as a binder for coating process was used to prepare a complex sol used for metal, ceramic and wood material substrate and also to prepare the organic-inorganic hybrid sol for polymer substrate such as polycarbonate and polyethylene, in which process APMS(3-Aminopropyltrimethoxysilane), GPTS(3-Glycidoxypropyl-trimethoxysilane) as a hydrophilic silane compound and HEMA(2-Hydroxyethyl methacrylate) as a forming network in hybrid coating film were used. The hybrid coating film such as prepared through this process showed a superhydrophilicity below 1$10^{\circ}$ depending on processing conditions and a pencil's hardness over 6 H.

• Biomolecules & Therapeutics
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• v.24 no.6
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• pp.595-603
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• 2016

(E)-3-Phenyl-1-(2-pyrrolyl)-2-propenone (PPP) is a pyrrole derivative of chalcone, in which the B-ring of chalcone linked to ${\beta}$-carbon is replaced by pyrrole group. While pyrrole has been studied for possible Src inhibition activity, chalcone, especially the substituents on the B-ring, has shown pharmaceutical, anti-inflammatory, and anti-oxidant properties via inhibition of NF-${\kappa}B$ activity. Our study is aimed to investigate whether this novel synthetic compound retains or enhances the pharmaceutically beneficial activities from the both structures. For this purpose, inflammatory responses of lipopolysaccharide (LPS)-treated RAW264.7 cells were analyzed. Nitric oxide (NO) production, inducible NO synthase (iNOS) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) mRNA expression, and the intracellular inflammatory signaling cascade were measured. Interestingly, PPP strongly inhibited NO release in a dose-dependent manner. To further investigate this anti-inflammatory activity, we identified molecular pathways by immunoblot analyses of nuclear fractions and whole cell lysates prepared from LPS-stimulated RAW264.7 cells with or without PPP pretreatment. The nuclear levels of p50, c-Jun, and c-Fos were significantly inhibited when cells were exposed to PPP. Moreover, according to the luciferase reporter gene assay after cotransfection with either TRIF or MyD88 in HEK293 cells, NF-${\kappa}B$-mediated luciferase activity dose-dependently diminished. Additionally, it was confirmed that PPP dampens the upstream signaling cascade of NF-${\kappa}B$ and AP-1 activation. Thus, PPP inhibited Syk, Src, and TAK1 activities induced by LPS or induced by overexpression of these genes. Therefore, our results suggest that PPP displays anti-inflammatory activity via inhibition of Syk, Src, and TAK1 activity, which may be developed as a novel anti-inflammatory drug.

• Journal of the Korean Magnetics Society
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• v.6 no.4
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• pp.204-210
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• 1996

M type hexa-ferrites were prepared by means of a solid state reaction using mill scale, $Fe_{2}O_{3}$, and the mixture of mill scale and $Fe_{2}O_{3}$. The mixture of powders were calcined at $1150^{\circ}C$ for 2 hrs. and sintered at $1250^{\circ}C$ for 2 hrs, with varing the mole ratio of $Fe_{2}O_{3}$/$BaCO_{3}$, by 5.2~6.0. And the magnetic properties and morphologies of Baferrites with impurities such as $SiO_{2},\;Al_{2}O_{3},\;MgO,\;CaO\;and\;Na_{2}O$ in the mill scale were investigated. The magnetic properties were worsened by the addition of $Na_{2}O because of non-reacted iron oxide and intermediate compound of $BaFe_{2}O_{4}$ but they were improved apparently by the addition of $Si_{2}$ and $Al_{2}O_{3}$ in the composition of $BaO.5.6Fe_{2}O_{3}$. Moreover, $M_{s}$ decreased but $_{B}H_{C}$ increased through the addition of $Al_{2}O_{3}$ in Ba-ferrite. ${(BH)}_{max}$ of sintered BM($BaCO_{3}$, mill scale mixture) and BFM($BaCO_{3}$, $Fe_{2}O_{3}$, and null scale mixture) were 0.86 and 1.04 MGOe, respectively, and the magnetic properties were changed around $440^{\circ}C$.

• Applied Chemistry for Engineering
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• v.3 no.1
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• pp.88-99
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• 1992

For the development of semiconducting photoelectrode to be more stable and efficient in the process of photoelectrolysis of the water, pure titanium rods were oxidized by anodic oxidation, furance oxidation and flame oxidation and used as electrodes. The Indium islands were formed by electrodeposition of "In" thin film on $TiO_2$ and Ti by electrodeposition. Also $A1_2O_3$ and NiO islands were coated on Ti by the electron-beam evaporation technique. The maximum photoelectrochemical conversion efficiency(${\eta}$) was 0.98% for flame oxidized electrode($1200^{\circ}C$ for 2min in air). Anodically oxidized electrodes have photoelectrochemical conversion efficiency of 0.14%. Furnace oxidized electrode($800^{\circ}C$ for 10min in air) has 0.57% of photoelectrochemical efficiency and shows a band-gap energy of about 2.9eV. The $In_2O_3$ coated $TiO_2$ exhibits 0.8% of photoelectrochemical efficiency but much higher value of ${\eta}$ was obtained with the Increase of applied blas voltage. However, $Al_2O_3$ or NiO coated $TiO_2$ shows much low value of ${\eta}$. The efficiency was dependent on the presence of the metallic interstitial compound $TiO_{0+x}$(x<0.33) at the metal-semiconductor interface and the thickness of the suboxide layer and the external rutile scale.

• Biomolecules & Therapeutics
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• v.18 no.1
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• pp.39-47
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• 2010

Brain-derived neurotrophic factor (BDNF) is a neurotrophic factor involved in neuronal differentiation, plasticity, survival and regeneration. BDNF draws massive attention mainly due to the potential as a therapeutic target in neurological diseases such as depression and Alzheimer's disease. In a primary screening for the natural compounds enhancing BDNF release from cultured rat primary cortical neuron, we found that compounds such as baicalein, tanshinone IIa, cinnamic acid, epiberberine, genistein and wogonin among many others increased BDNF release. All the compounds at $0.1{\mu}M$ of concentration barely showed stimulatory effect on BDNF induction, however, their combination (mixture 1; baicalein, tanshinone IIa and cinnamic acid, mixture 2; epiberberine, genistein and wogonin) showed synergistic increase in BDNF release as well as mRNA and protein expression. The level of BDNF expression was comparable to the maximum BDNF stimulation attainable by a positive control oroxylin A ($20{\mu}M$) without cell toxicity as determined by MTT analysis. Both mixtures synergistically increased the phosphorylation of extracellular signal-regulated kinase (ERK) as well as cAMP response element binding protein (CREB), an immediate and essential regulator of BDNF expression. Similar to these results, mixture of these compounds synergistically inhibited the up-regulation of inducible nitric oxide synthase (iNOS) induced by lipopolysaccharide treatments in rat primary astrocytes. These results suggest that the combinatorial treatment of natural compounds in lower concentration might be a useful strategy to obtain sufficient BDNF stimulation in neurological disease condition such as depression, while minimizing potential side effects and toxicity of higher concentration of a single compound.

• Journal of the Korean Society of Radiology
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• v.14 no.2
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• pp.149-155
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• 2020

Most of radiation protection clothing is made of lead with excellent radiation shielding because it has excellent process ability and economic efficiency and has a high atomic number. However, lead is classified as a hazardous heavy metal, and there is a risk of lead poisoning. Recently, research to replace lead has been actively conducted. In this study, a research on a shielding sheet with improved physical properties while maintaining the radiation shielding ability equivalent to that of conventional materials by mixing two materials that are harmless to the human body, such as BaSO₄ and Bi₂O₃, and a silicone material binder Was performed. For comparison evaluation with the existing lead shielding sheet, the shielding rate was evaluated using a 40 degree shielding sheet having the highest porosity. As a result, it was analyzed that the shielding rate was superior to 9 % or more at the same thickness. In addition, as a result of studies to improve the physical properties of the shielding sheet, it was analyzed that the shielding sheet mixed with BaSO₄/nylon/Bi₂O₃ was the best.