• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.230.2-230.2
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• 2008

• Journal of Plant Biotechnology
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• v.35 no.3
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• pp.203-208
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• 2008

In order to micropropagate uniform plantlets of Philodendron cannifolium in vitro, the shoot tips were cultured on MS media supplemented with $0.5{\sim}10.0$ mg/L BA or $0.05{\sim}0.1$ mg/L thidiazuron(TDZ). The adventitious multi-bud clusters from basal part of shoots were formed on MS media containing $2.0{\sim}5.0$ mg/L BA or $0.05{\sim}0.1$ mg/L TDZ. But the shoots grown on MS media with TDZ showed necrosis by the lack of chlorophyll. The adventitious multi-bus clusters were cut into $5{\sim}7$ mm sections and cultured on MS media containing BA and TDZ for shoot proliferation. Shoots were proliferated vigorously on MS medium supplemented with $1.0{\sim}3.0$ mg/L BA with up to 30 shoots. But abnormally swollen hard calli were formed from basal parts of shoots on MS media with TDZ and high concentration of BA(10.0 mg/L). The proliferated shoots on same media also showed necrosis by the lack of chlorophyll. The shoot growth and rooting were favorable on MS media containing $0.5{\sim}2.0$ mg/L IBA. The rooted plantlets were acclimatizated effectively in soil mixed with perlite 1:vermiculite 1 or vermiculite alone. Fifteen mL of liquid medium containing 10 g/L activated charcoal and 30 g/L sucrose were added in same vessels after small shoots were proliferated to stimulate shoot growth and rooting. After 8 weeks in culture, the shoots were dipped into high concentration of IBA solution. and planted in soil mexed with perlite 1:vermiculite 1. The shoot growth and rooting were favorable in dipping treatments of $500{\sim}2,000$ ppm IBA solutions for 10 sec.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2073-2080
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• 2013

In this study the effects of adding alkaline-earth (IIA) metal oxides to NiZr-loaded Zeolite Y catalysts were investigated on hydrogen rich production by ethanol steam reforming (ESR). Four kinds of alkaline-earth metal (Mg, Ca, Sr, or Ba) oxides of 3.0% by weight were loaded between the $Ni_6Zr_4O_{14}$ main catalytic species and the microporous Zeolite Y support. The characterizations of these catalysts were examined by XRD, TEM, $H_2$-TPR, $NH_3$-TPD, and XPS. Catalytic performances during ESR were found to depend on the basicity of the added alkaline-earth metal oxides and $H_2$ production and ethanol conversion were maximized to 82% and 98% respectively in 27($Ni_6Zr_4O_{14}$)3MgO/70Zeolite Y catalyst at $600^{\circ}C$. Many carbon deposits and carbon nano fibers were seen on the surface of $30Ni_6Zr_4O_{14}$/70Zeolite Y catalyst but lesser amounts were observed on alkaline-earth metal oxide-loaded 27($Ni_6Zr_4O_{14}$)3MO/70Zeolite Y catalysts in TEM photos after ESR. This study demonstrates that hydrogen yields from ESR are closely related to the acidities of catalysts and that alkaline-earth metal oxides reduce the acidities of 27($Ni_6Zr_4O_{14}$)3MO/70Zeolite Y catalysts and promote hydrogen evolution by preventing progression to hydrocarbons.

• Elastomers and Composites
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• v.34 no.1
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• pp.3-10
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• 1999

Kinetics of solution photopolymerization of acrylonitrile(AN) with sensitizer, such as $NaSCN,\;KSCN,\;Ba(SCN)_2,\;NH_4SCN,\;ZnCl_2$ and $Na_2SeO_3$, were studied using UV crosslinker at various monomer concentrations($1.8{\sim}7.58mo1/1$), sensitizer concentrations($10{\sim}60%$), reaction temperature($10{\sim}70^{\circ}C$), energy intensities($1,000{\sim}9,900{\mu}J/cm^2$) at isothermal condition under nitrogen atmosphere. Under the irradiation of high pressure mercury lamp(${\lambda}=365nm$). High conversion and uniform molecular weight were obtained compare to thermal polymerization at reaction temperature of $50^{\circ}C$, reaction time of 3hr and 50% NaSCN without any initiator. Their kinetic model was as follows : $R_p=0.0142[M]^{0.82}[I]^{0.49}[S]^{0.52}$ exp(-1.33/RT).

• Journal of the Korean Magnetics Society
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• v.22 no.1
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• pp.19-22
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• 2012

$Ba_2Mg_{0.5}Co_{1.5}(Fe_{0.99}In_{0.01})_{12}O_{22}$ was prepared by the conventional solid-state reaction method, and studied by x-ray diffractometer, vibrating sample magnetometer, and Mossbauer spectrometer. The crystal structure was determined to be a single-phased rhombohedral with space group R-3m. Magnetization value were $M_s$ = 28.6 emu/g at 295 K. The hysteresis loops indicate that all the samples are ferrimagnetic behaviors. Mossbauer spectra of $Ba_2Mg_{0.5}Co_{1.5}(Fe_{0.99}In_{0.01})_{12}O_{22}$ have been 6-sextet taken at various temperatures ranging from 4.2 to 620 K. Based on the isomer shift (${\delta}$) values of all samples, the charge states were found to be $Fe^{3+}$ state at all temperatures, the Curie temperature was determined to be 630 K by the ZVC curve.

• Korean Journal of Materials Research
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• v.13 no.12
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• pp.846-849
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• 2003

Doping effect of various ions in Bi-layered ferroelectric $SrBi_2$$Nb_2$$O_{9}$ (SBN) ceramics was studied. Undoped SBN ceramic and SBN ceramics doped with $Ba^{2＋}$, $Pb^{2＋}$,$ Ca^{2＋}$ , $Bi^{3＋}$ , $La^{3＋}$ , $Ti^{4＋}$ , $Mo^{6＋}$ , and $W^{6＋}$ ions were made by a solid state reaction. Dielectric constants were measured with temperature. Ferroelectric transition temperature decreased with $Pb^{2＋}$ , $Ba^{2＋}$ , $La^{3＋}$ doping, but the transition temperature increased with $Ca^{2＋}$ , $Bi^{3＋}$ , $Ti^{4＋}$, $Mo^{6＋}$ , or$ W^{6＋}$ ionic doping. These results show that the ion size plays an important role in the ferroelectricity of SBN ceramic.

• Resources Recycling
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• v.26 no.5
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• pp.97-104
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• 2017

Nuclear fuel cladding tubes are manufactured through pilgering and the annealing process. In order to remove the oxidized layer and impurities on the surface of the tube, a pickling process is required. Zirconium (Zr) is dissolved in a HF and $HNO_3$ acid mixture during the process and the pickling waste acid, including the dissolved Zr, is completely discarded after neutralization. This study observes the effects of the residual impurities (Ba) in the pickling solution regenerated from the $BaF_2$ precipitation process on the waste pickling solution. In addition, the concentration of Ba and Zr for the actual nuclear fuel cladding tube process was optimized. The regenerated pickling solution was tested through a pilot plant pickling process device that simulates the commercial pickling process of nuclear fuel cladding tubes, and the pickling efficiency was analyzed through AFM analysis of the roughness of the cladding tube surface.

• Progress in Superconductivity and Cryogenics
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• v.6 no.3
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• pp.16-20
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• 2004

YB $a_2$C $u_3$$O_{7-x}$ (YBCO) films were deposited on (100) SrTi $O_3$ single crystal substrates by a metal organic chemical vapor deposition (MOCVD) system of hot-wall type using single liquid source. Under the condition of the mole ratio of Y(tmhd)$_3$:Ba(tmhd)$_2$:Cu(tmhd)$_2$= 1:2.1:2.9. the deposition pressure of 10 Torr. the MO source line speed of 15 cm/min. the Ar/ $O_2$ flow rate of 800/800 sccm. YBCO films were prepared at the deposition temperatures of 780∼89$0^{\circ}C$. In case of the YBCO films with 2.2 ${\mu}{\textrm}{m}$ thickness deposited for 6 minutes at 86$0^{\circ}C$. XRD pattern showed complete c-axis growth and SEM morphology showed dense and crack-free surface. The atomic ratios of Ba/Y and Cu/Ba in the film were 1.92 and 1.56. respectively. The deposition rate of the film was as high as 0.37 ${\mu}{\textrm}{m}$/min. The critical temperature ( $T_{c.zero}$) of the film was 87K. The critical current of the film was 104 A/cm-width. and the critical current density was 0.47 MA/$\textrm{cm}^2$. For the thinner film of 1.3 ${\mu}{\textrm}{m}$ thickness. the critical current density of 0.62 MA/$\textrm{cm}^2$ was obtained.d.

• Analytical Science and Technology
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• v.15 no.4
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• pp.321-328
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• 2002

From May 1999 to July 2000, concentration of 17 metals (Al, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, Pb, Sr, V, Zn), 4 ions (${NH_4}^+$, $Cl^-$, ${NO_3}^-$, ${SO_4}^{2-}$) and pH in rainwater were investigated. The volume-weighted mean concentrations (VWM) of ${NO_3}^-$ and ${SO_4}^{2-}$ were 16.0 and $17.0{\mu}mol\;L^{-1}$. The average pH was 4.53, which ranged from 3.83 to 6.06. The characteristic variations of these species were investigated in terms of the source of these species by principal component analysis (PCA) and interelement correlation coefficients. The elements were classified into three categories: anthropogenic source (Cd, Cu, Fe, Ni, Pb, V, Zn, ${NH_4}^+$, ${NO_3}^-$, ${SO_4}^{2-}$ and $H^+$), soil and crust dust (Al, Ba, Ca, Fe, Mn) and sea salts (Mg, Na, $Cl^-$). In addition, we compared the concentrations in rainwater, which were taken on the same day in three sites (Higashi-Hiroshima, an urban-facing area and a mountain-facing area of Mt. Gokurakuji) in order to examine the regional effect against the concentrations in them. At the urban-facing area of Mt. Gokurakuji, the concentrations of chemical compositions were higher than other areas.

• Journal of Plant Biotechnology
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• v.50
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• pp.82-88
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• 2023

Shoot-tip culture was used to produce clonal plants of radish stock seeds. Using 6-benzyladenine (BA), the largest number of RA2 line multi-shoots were formed with an average of 14.67 shoots on 1.33 µM BA in early seedlings and 11.33 shoots on 1.78 µM BA in juvenile seedlings. The largest number of RA4 line multi-shoots were formed with an average of 11.67 shoots on 2.22 µM BA in early seedlings and 13.67 shoots on 1.33 µM BA in juvenile seedlings. There was little difference in the significance level by BA concentration in both lines. Using Thidiazuron (TDZ), the number of RA2 line multi-shoots increased with increasing TDZ concentration, forming the largest number of multi-shoots in 0.45 µM TDZ (7.0 and 3.0 multi-shoots for early and juvenile seedlings, respectively), but few multi-shoots were formed from TDZ 2.25 and 4.5 µM. RA4 line produced almost no multi-shoots in early seedlings, and 3.7 multi-shoots were produced in 0.23 and 0.45 µM TDZ in juvenile seedlings, but not at higher concentrations. Analysis of the tissue culture seedlings grown by cultivating the generated multi-shoots with Radish Foundation seeds using SSR marker revealed a weak pattern of mutation in the generated tissue culture seedlings, but there was no mutant. In addition, in terms of root roots, both RA2 and RA4 lines generally had the best rooting, number of roots, and degree of root development in 4.9 µM indol-3- butyric acid (IBA).