• Journal of the Korean Chemical Society
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• v.44 no.4
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• pp.350-355
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• 2000

The compounds, CaAl$_2$(BO$_3$)$_2$O, SrAl$_2$(BO$_3$)$_2$O and BaAl$_2$(BO$_3$)$_2$O, are good host lattices for highly efficient $Eu^{2+}$ luminescence. The europium emission peaks at 450 nm in $Eu^{2+}$:CaAl$_2$(B0$_3$)$_2$O, 411 nm in $Eu^{2+}$: SrAl$_2$(BO$_3$)$_2$O and 375 nm in $Eu^{2+}$: BaAl$_2$(BO$_3$)$_2$O. The $Eu^{2+}$: CaAl$_2$(BO$_3$)$_2$O Phosphor shows a high output and should be a good maintenance in VUV Xe lamps. It is ideally suited for use in PDP phosphors. The $Eu^{2+}$ ion is interesting because the Stokes shift emission is a strong host dependent. The difference in the Stokes shift is oneimportant factor leadingto a difference in wavelength. If the 5d level of $Eu^{2+}$ ion is lower in energy,according to a decrease in the doping lattice size, then the emission wavelength will be longer and the Stokes shift will be smaller. Therefore, a knowledge of the relationship between the crystal lattice size and the Stokes shift. (orthe energy of the 5d level),is essential for beingable to predict $Eu^{2+}$ emission properties.

• Korean Journal of Crystallography
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• v.13 no.1
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• pp.25-30
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• 2002

The M/sub 1-x/Na/sub 2x/Al₂(BO₃)₂O (M = Ca and Sr) solid solution systems have been shown interstitial solid solutions and continuous substitutional solid solutions. The symmetry around the Eu site of yEu/sup 3+/ : M/sub 1-x/Na/sub 2x/Al/sub 2-y/Mg/sub /(BO₃)₂O (M = Ca and Sr) changes the intensities and the chromaticities of transitions. The Eu/sup 3+/ion can be very bright and efficient and have the desired emission wave-length depending on the site symmetry of the Eu/sup 3+/ion site. As the amount of Na in the Eu/sup 3+/ion doped Ca/sub 1-x/Na/sub 2x/Al₂(BO₃)₂O system increases, the Eu site symmetry is going to be a noncentrosymmetric site. With increasing x, the decreased intensity in the /sup 5/D/sub 0/→/sup 7/F₁(590 nm) transition relates to the low symmetry of the Eus/up 3+/-doped Ca/sub 1-x/Na/sub 2x/Al₂(BO₃)₂O system, because of the Ca-centered octahedron in the CaAl₂(BO₃)₂O compound. The SrAl₂(BO₃)₂O compound also provides an improved chromaticity due to the lower site symmetry of Eu/sup 3+/ion.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.105-109
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• 2000

The purpose of this study is to investigate on the water quality of the upper region of Wonchun stream located in Suwon city by chemical analysis and EROD-microbioassay methods using rat hepatoma cell line H4IIE. The water samples were collected at 6 sampling sites from sept. to Nov. 1999 and determined the quantitative toxic effects. Higher levels of BO $D_{5}$, CO $D_{Cr}$ and CO $D_{Mn}$ were determined at M6 site where the influent contains domestic and industrial wastewater. EROD activity of water samples was ranged from 3.43$\pm$0.08 to 9.05$\pm$0.10 pmol/mg protein/min. High correlation with EROD activities and COD values was observed. From the results, the upper region of Wonchun stream water area was presumed to be highly polluted with various persistent organic chemicals.s.

• Journal of the Korean Ceramic Society
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• v.20 no.3
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• pp.193-198
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• 1983

This experiment has been carried out for the purpose of investigating the effect of $V_2O_5$ and $H_3BO_3$ additives on sintering of magnesium oxide over the temperature range of 1300-150$0^{\circ}C$ MgO powder has been obtained by calcin-ing extra reagent grade magnesium carbonate(basic) at 90$0^{\circ}C$ for 30 minutes. The specimens were prepared by compression with pressure of 700Kg/cm2 then fired at 1300-150$0^{\circ}C$ for 0-5hrs. Sintering behaviour and microstructure of fired specimens were examined. Densification rates obeyed the equation D=K 1n t+C. The ratio of density in case of addition of $V_2O_5$ to theoretical density of pure periclase was 95-99% Activation energy of densification in case of $V_2O_5$ addition was 30.15 Kcal/mole. The range of average grain size in case of addition of $V_2O_5$ was 40-50$\mu\textrm{m}$. $H_3BO_3$ addtivie had not an effect on densification of MgO.

• Ceramist
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• v.18 no.4
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• pp.5-12
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• 2015

• Journal of Plant Biotechnology
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• v.46 no.3
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• pp.189-204
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• 2019

In this study, we analyzed the changes in glucosinolate content and gene expression in TO1000DH3 and Early big seedling upon methyl jasmonate (MeJA) treatment. Analysis of glucosinolate contents after MeJA treatment at $200{\mu}M$ concentration showed that the total glucosinolate content increased by 1.3-1.5 fold in TO1000DH3 and 1.3-3.8 fold in Early big compared to those before treatment. Aliphatic glucosinolates, progoitrin and gluconapin, were detected only in TO1000DH3, and the changes in the content of neoglucobrassicin were the greatest at 48 hours after MeJA treatment in TO1000DH3 and Early big. The transcriptomic analysis showed that transcripts involved in stress or defense reactions, or those related to growth were specifically expressed in TO1000DH3, while transcripts related to nucleosides or ATP biosynthesis were specifically expressed in Early big. GO analysis on transcripts with more than two-fold change in expression upon MeJA treatment, corresponding to 12,020 transcripts in TO1000DH3 and 13,510 transcripts in Early big, showed that the expression of transcripts that react to stimulus and chemical increased in TO1000DH3 and Early big, while those related to single-organism and ribosome synthesis decreased. In particular, the expression increased for all transcripts related to indole glucosinolate biosynthesis, which is associated with increase in glucobrassicin and neoglucobrassicin contents. Upon MeJA treatment, the expression of AOP3 (Bo9g006220, Bo9g006240), TGG1 (Bo14804s010) increased only in TO1000DH3, while the expression of Dof1.1 (Bo5g008360), UGT74C1 (Bo4g177540), and GSL-OH (Bo4g173560, Bo4g173550, Bo4g173530) increased specifically in Early big.

• Korean Journal of Materials Research
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• v.22 no.3
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• pp.145-149
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• 2012

Red phosphors of $Gd_{1-x}Al_3(BO_3)_4:{Eu_x}^{3+}$ were synthesized by using the solid-state reaction method. The phase structure and morphology of the phosphors were measured using X-ray diffraction (XRD) and field emission-scanning electron microscopy (FE-SEM), respectively. The optical properties of $GdAl_3(BO_3)_4:Eu^{3+}$ phosphors with concentrations of $Eu^{3+}$ ions of 0, 0.05, 0.10, 0.15, and 0.20 mol were investigated at room temperature. The crystals were hexagonal with a rhombohedral lattice. The excitation spectra of all the phosphors, irrespective of the $Eu^{3+}$ concentrations, were composed of a broad band centered at 265 nm and a narrow band having peak at 274 nm. As for the emission spectra, the peak wavelength was 613 nm under a 274 nm ultraviolet excitation. The intensity ratio of the red emission transition ($^5D_0{\rightarrow}^7F_2$) to orange ($^5D_0{\rightarrow}^7F_1$) shows that the $Eu^{3+}$ ions occupy sites of no inversion symmetry in the host. In conclusion, the optimum doping concentration of $Eu^{3+}$ ions for preparing $GdAl_3(BO_3)_4:Eu^{3+}$ phosphors was found to be 0.15 mol.

• Journal of Animal Environmental Science
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• v.8 no.3
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• pp.129-134
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• 2002

This study was carried out to investigate the characteristic change of piggery slurry during the storage time and depth. The Piggery slurry was settled in a 10.0m diameter$\times$3.0m high storage tank for 6 months and then divided into three layers according to the storage time. The pollutants concentration, BODs(Biochemical Oxygen demand), CO $D_{Mn}$ (Chemical Oxygen demand) and SS(Suspended Solids) of the piggery slurry used in this study were 25,134, 15,840, 23,800mg/$\ell$, respectively. The initial fertilizer content of piggery slurry, N(Nitrogen), $P_2$ $O_{5}$(Phosphoric acid) and $K_2$O(Potassium oxide), were 0.69, 0.33, 0.40%, respectively. 6 months later, BO $D_{5}$, CO $D_{Mn}$ and SS of the Piggery slurry were 16,040, 8,098, 3,300mg/$\ell$ in top layer, 15,806, 8,309, 5,900mg/$\ell$ in middle layer and 39,530, 23,958, 51,000mg/$\ell$ in bottom layer, respectively. The fertilizer content of piggery slurry after 6 months, N, $P_2$ $O_{5}$ and $K_2$O, were 0.47, 0.07, 0.46% in top layer, 0.43, 0.08, 0.47% in middle layer and 0.60, 0.44, 0.40% in bottom layer, respectively. Consequently, in course of storage time, the pollutant concentration and fertilizer content were the highest in the bottom layer compared with the top and middle layer.

• YAKHAK HOEJI
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• v.40 no.1
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• pp.46-51
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• 1996

Eight new D-1.3-dioxolanyl and L-1,3-oxathiolanyl nucleosides containing 5-phenyl- selenyl pyrimidine bases which are expected to have antiviral activity were synthesized. Condensation of D-1,3-dioxolane acetate and L-1,3-oxathiolane acetate with 5-phenylselenyl pyrimidines gave anomeric mixtures of their nucleosides which were separated by silicagel column chromatography.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.792-794
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• 2002

Uniform cylinder-shaped precursors for (Y,Gd)$BO_3$:Eu phosphors were prepared by urea hydrolysis reaction. After heating the precursors at lower temperature than general synthetic methods, the phosphor powders were well dispersed and held their original shapes. Their emissions under vacuum-ultraviolet (VUV) excitation appeared with the peaks at 593nm due to magnetic dipole transition from $^5D_0$ to $^7F_1$, 612nm and 627nm due to electric dipole transition from $^5D_0$ to $^7F_2$