• Journal of Environmental Health Sciences
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• v.28 no.5
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• pp.59-64
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• 2002

The photocatalytic decolorization of the Rhodamine B (RhB) was studied using a UV/TiO$_2$ reactor. Yakuri titanium dioxide(anatase) was used as the suspended photocatalyst and proved to be effective for decolorization irradiated with UV light (254 mm). The photocatalyzed dioxide concentrations, light intensity and air flow rates. In 0.01 mM RhB, color could be completely photodegraded after 3 hours. Absorption spectrum of an aqueous solution containing RhB showed a continued diminution of the RhB concentration in the solution bulk : concomitantly, no new absorption peaks appeared. This confirmed the decolorization of RhB, i.e., the break up of the chromopore. The optimum loaded titanium dioxide for the decolorization was 0.75 g/(equation omitted). The light intensity showed exponential decay with distance. The decay of light intensity of RhB solution showed different tendency from TiO$_2$. These results suggested that the photocatalytic decolorization of dyes may be available method for decolorizing in wastewater.

• Progress in Superconductivity and Cryogenics
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• v.21 no.4
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• pp.9-12
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• 2019

We performed Raman spectroscopy on two different over-doped Bi₂Sr₂CaCu₂O_8+x (BSCCO), of which superconducting transition temperatures are 89 K and 77 K. Line-shape analysis of the Raman-spectrum was done, focused on B_1g bond buckling mode which have drawn a lot of attention, since photoemission studies showed an evidence for strong coupling between the mode and electron. The line-shapes show asymmetry and are well fitted by the Fano line-shape formula. Remarkably, we found that the peak line-widths from B_1g bond buckling mode in BSCCO show much broader than those in YBa₂Cu₃O_7-x. The broad line width can be attributed to the superstructure modulation of BSCCO. Our results imply that B_1g bond buckling mode may have close relation to the origin of superconductivity or to boosting the superconducting transition temperature in BSCCO.

• Membrane Journal
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• v.25 no.2
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• pp.115-122
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• 2015

$SiO_2{\cdot}B_2O_3$ was prepared by trimethylborate (TMB)/tetraethylorthosilicate (TEOS) mole ratio 0.01 at $800^{\circ}C$. PDMS[poly(dimethysiloxane)]-$SiO_2{\cdot}B_2O_3$ composite membranes were prepared by adding porous $SiO_2{\cdot}B_2O_3$ to PDMS. To investigate the characteristics of PDMS-$SiO_2{\cdot}B_2O_3$ composite membrane, we observed PDMS-$SiO_2{\cdot}B_2O_3$ composite membrane using TG-DTA, FT-IR, BET, X-ray, and SEM. PDMS-$SiO_2{\cdot}B_2O_3$ composite membrane was studied on the permeabilities of $H_2$ and $N_2$ and the selectivity ($H_2/N_2$). Following the results of TG-DTA, BET, X-ray, FT-IR, $SiO_2{\cdot}B_2O_3$ was the amorphous porous $SiO_2{\cdot}B_2O_3$ with $247.6868m^2/g$ surface area and $37.7821{\AA}$ the mean of pore diameter. According to the TGA measurements, the thermal stability of PDMS-$SiO_2{\cdot}B_2O_3$ composite membrane was enhanced by inserting $SiO_2{\cdot}B_2O_3$. SEM observation showed that the size of dispersed $SiO_2{\cdot}B_2O_3$ in the PDMS-$SiO_2{\cdot}B_2O_3$ composite membrane was about $1{\mu}m$. The increasing of $SiO_2{\cdot}B_2O_3$ content in PDMS leaded the following results in the gas permeation experiment: the permeability of both $H_2$ and $N_2$ was increased, and the permeability of $H_2$ was higher than $N_2$, but the selectivity($H_2/N_2$) was decreased.

• Clean Technology
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• v.17 no.1
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• pp.78-82
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• 2011

For effectively photochemical hydrogen production, P (negative semiconductor) and B (positive semiconductor) ions (0.1, 0.2, 0.5, and 1.0 mol%) incorporated $TiO_2$ (P- and B-$TiO_2$) nanometer sized particles were prepared using a solvothermal method as a photocatalyst. The characteristics of the synthesized P- and B-$TiO_2$ photocatalysts were analyzed by X-ray Diffraction (XRD), Transmission electron microscopy (TEM), W-visible spectroscopy (UV-Vis), and Photoluminescence spectra (PL). The evolution of $H_2$ from methanol/water (1:1) photo-splitting over B-$TiO_2$ photocatalysts was enhanced compared to those over pure $TiO_2$ and P-$TiO_2$ photocatalysts; 0.42 mL of $H_2$ gas was evolved after 10 h when 0.5 g of a 1.0 mol% B-$TiO_2$ catalyst was used.

• Applied Chemistry for Engineering
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• v.22 no.6
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• pp.711-717
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• 2011

Two dimensional simulation results of a capacitively coupled oxygen plasma in a cylindrical reactor geometry are presented. Detailed electron impact reaction rates, which strongly depend on electron energy, are computed from collision cross sections of electrons with $O_2$ and O. Through the coupling of a three moment plasma model with a neutral chemistry/transport model are predicted spatiotemporal distributions of both charged species (electron, $O_2{^+}$, $O^+$, $O_2{^-}$, and $O^-$) and neutral species including ground states ($O_2$ and O) and metastables, known to play important roles in oxygen plasma, such as $O_2(a^1{\Delta}_g)$, $O_2(b^1{{\Sigma}_g}^+)$, $O(^1D)$, and $O(^1S)$. The simulation results clearly verify the existence of a double layer near sheath boundaries in the electronegative plasma.

• Korean Journal of Pharmacognosy
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• v.17 no.4
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• pp.292-301
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• 1986

The combined preparations of the traditional Korean prescriptions, Sahyangsohap-won (A1) and Woohwangporyong-hwan (B1) were evaluated on pharmacological actions in rats and mice, in parallel with the preparations of their modified prescriptions (A2 and B2). The acute toxicities of the four preparations were very low of which $LD_{50}$ values were more than 4g/kg, p.o. and no systematic symptoms were found at the doses. All the preparations showed sedative action by prolongation of sleeping time induced with hexobarbital sodium. The action was more potent in the modified preparations than in the original ones. All the preparations had no anticonvulsant action both in chemoshock seizures induced by pentetrazole and strychnine and in electroshock seizure. In rat fundus preparation, A1 and A2 elicited strong contraction at the concentration of $1{\times}10^{-3}\;g/ml$ in bath, whereas B1 and B2 did neither contraction nor relaxation at the same concentration. The four preparations had no inhibitory effect against acetylcholine induced spasm. In rat intestinal preparation, the four preparations exhibited neither contraction nor relaxation. However, A1 and A2 had antagonistic effect against spasm at the concentration of $1{\times}10^{-3}\;g/ml$. Single administration of each preparation at the dose of 0.24g/kg, p.o. stimulated the secretion of pepsin in rat stomach without inciting the secretion of gastric juice. Their stimulating actions were more marked in B1 and B2 than in A1 and A2, and were more promptly exhibited in the modified preparations (A2 and B2). Accelerating action of bile secretion by single administration of each preparation was found at the dose of 0.24g/kg, p.o. in rats. All the preparations except A2 also stimulated the secretion of bile acid.

• BMB Reports
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• v.54 no.2
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• pp.142-147
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• 2021

Synthetic oligodeoxynucleotides (ODNs) containing unmethylated CpG phosphorothioate (PS CpG-ODN) are known to decrease IgE synthesis in Th2 allergy responses. Nonetheless, the therapeutic role of PS CpG-ODN is limited due to cytotoxicity. Therefore, we developed a phosphodiester (PO) form of CpG-ODN (46O) with reduced toxicity but effective against allergies. In this study, we first compared the toxicity of 46O with CpG-ODNs containing a PS backbone (1826S). We also investigated the therapeutic efficacy and mechanism of 46O injected intravenously in a mouse model of ovalbumin (OVA)-induced atopic dermatitis (AD). To elucidate the mechanism of 46O underlying the inhibition of IgE production, IgE- and TGF-β-associated molecules were evaluated in CD40/IL-4- or LPS/IL-4-stimulated B cells. Our data showed that the treatment with 46O was associated with a lower hematological toxicity compared with 1826S. In addition, injection with 46O reduced erythema, epidermal thickness, and suppressed IgE and IL-4 synthesis in mice with OVA-induced AD. Additionally, 46O induced TGF-β production in LPS/IL-4-stimulated B cells via inhibition of Smad7, which suppressed IgE synthesis via interaction between Id2 and E2A. These findings suggest that enhanced TGF-β signaling is an effective treatment for IgE-mediated allergic conditions, and 46O may be safe and effective for treating allergic diseases such as AD and asthma.

• Journal of Microbiology
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• v.37 no.3
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• pp.159-167
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• 1999

The effects of bicarbonate concentration, atmospheric carbon dioxide level, and reduced atmospheric oxygen on biomass and geosmin production and geosmin/biomass (G/B) values for Streptomyces halstedii, a producer of the off-flavor compound geosmin, were determined. In addition, a study was performed to determined possible synergistic relationships between a cyanobacterium, Oscillatoria tenuis UTEX #1566, and S. halstedii in the enhancement of actinomycete growth and/or geosmin production. These studies took into consideration those conditions that can occur during cyanobacterial bloom die-offs. Increasing bicarbonate concentration caused slight decreases in geosmin production and G/B for S. halstedii. Increasing atmospheric oxygen promoted geosmin production and G/B while lower oxygen levels resulted in a decrease in geosmin production and G/B by S. halstedii. Biomass production by S. halstedii was adversely affected by reduced oxygen levels while changes in bicarbonate concentration and atmospheric carbon dioxdie levels had little effect on biomass production. Sonicated cells of O. tenuis UTEX #1566 promoted biomass production by S. halstedii, and O. tenuis culture (cells and extracellular metabolites) and culture supernatnat (extracellular metabolites) each promoted geosmin and G/B yields for S. halstedii. In certain aquatic systems, environmental conditions resulting from cyanobacterial blooms and subsequent bloom die-offs could favor actinomycete growth and off-flavor compound by certain actinomycetes.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.8
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• pp.823-830
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• 2008

The feasibility study for the application of the photoelectrocatalytic decolorization of Rhodamine B(RhB) was performed in the slurry photoelectrochemical reactor with powder TiO$_2$. The photoelectrocatalytic process was consisted of powder TiO$_2$, Pt electrode and three 8 W UV-C lamps. The effects of operating conditions, such as current, electrolyte, air flow rate and electrode material were evaluated. The experimental results showed that optimum TiO$_2$ dosage and current in photoelectrocatalytic process were 0.4 g/L and 0.02 A, respectively. It was found that the RhB could be degraded more efficiently by this photoelectrocatalytic process than the sum of the two individual oxidation processes(photocatalytic and electrolytic process). It demonstrated a synergetic effect between the photo- and electrochemical catalysis. Photoelectrocatalytic process was affected to air flow rate and optimum air flow rate was 2 L/min. The electrode material and NaCl effect of decolorization of RhB were not significant within the experiment conditions.

• Electrical & Electronic Materials
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• v.8 no.3
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• pp.324-331
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• 1995

0.36[wt%l $SiO_{2}$ and 0.1[wt%] $H_{3}$B $O_{3}$ were added to strontium ferrite magnets of the magnetoplumbite phase SrO.5.7F $e_{2}$ $O_{3}$ to hinder grain growth and accelerate sintering, respectively. This experiment was carried out to investigate effect of particle size distribution as a function of milling time(20, 30, 40, 50, 60, 70 hours) on the magnetic properties of SrO.5.7F $e_{2}$ $O_{3}$ ferrite magnet. The B-H curve, density and the degree of orientation were measured. And the microstructure of ferrite magnets was examined with a SEM. The optimal conditions and properties of the typical sample are the following : The milling time was 60 hours. Magnetic and physical properties are $B_{r}$=4, 000[G], $_{b}$ $H_{c}$=3, 330[Oe], (BH)max=3.786[MGOe], $_{I}$ $H_{c}$=3, 525[Oe], density=5.0063[g/c $m^{3}$] and orientation factor f=0.813.0.813.3.3.