• Journal of the Korean Chemical Society
• /
• v.58 no.6
• /
• pp.517-523
• /
• 2014

The micellization of TTAB(tetradecyltrimethylammonium bromide) and the solubilization of 4-halogenated phenol isomers in aqueous solution of that surfactant in water have been studied by the UV-Vis spectrophotometric method. Those properties in aqueous solutions of NaCl and n-butanol have been also measured to determine the interactions between the micelle and 4-halogenated phenols and the solubilized sites of those molecules in the micelle. The results show that the values of ${\Delta}G^o_m$ and ${\Delta}G^o_s$ are all negative and the trends of those values depend on both the kinds and the concentrations of additives. Namely, by adding NaCl both ${\Delta}G^o_m$ and ${\Delta}G^o_s$ values are all decreasing, but by adding n-butanol the ${\Delta}G^o_m$ value decreases and the ${\Delta}G^o_s$ value increases.

• Economic and Environmental Geology
• /
• v.44 no.5
• /
• pp.359-372
• /
• 2011

TA26 seamount, which is located at south part of Tonga arc, occurs widely hydrothermal plume and is area that sampled hostrock, hydrothermal ore and hydrothermal alteration rock for this study. Hostrocks are basalt and basaltic andesite. Altered rocks by hydrothermal solution consists of plagioclase, pyroxene, pyrite, ilmenite, amorphous silica, barite, smectite, iron sulfates, Fe-Si sulfates and Fe silicates. Gains and losses of major, trace and rare earth elements during wallrock alteration suggest that $K_2O$(+0.04~+0.45 g), $SiO_2$(-6.52~+10.56 g), $H_2O$(-0.03~+6.04 g), $SO_4$(-0.46~+17.54 g), S(-0.46~+13.45 g), total S(-0.51~+16.93 g), Ba(-7.60~+185078.62 g), Sr(-36.18~+3033.08 g), Ag(+54.83 g), Au(+1467.49 g), As(-5.80~+1030.80 g), Cd(+249.78 g), Cu(-100.57~+1357.85 g), Pb(+4.91~+532.65 g), Sb(-0.32~+66.59 g), V(-113.58~+102.94 g) and Zn(-49.56~+14989.92 g) elements are enriched from hydrothermal solution. Therefore, gained(enriched) elements(($K_2O$, $H_2O$, $SO_4$, S, total S, Ba, Sr, Ag, Au, As, Cd, Cu, Pb, Sb, V, Zn) represent a potentially tools for exploration of sea-floor hydrothermal deposits from the Tonga arc.

• BMB Reports
• /
• v.40 no.6
• /
• pp.899-910
• /
• 2007

Extracellular Regulated Kinases (ERK) and Protein Kinase B (Akt) are intermediaries in relaying extracellular growth signals to intracellular targets. Each pathway can become activated upon stimulation of G protein-coupled receptors mediated by $G_q$ and $G_{i/o}$ proteins subjected to regulation by RGS proteins. The goal of the study was to delineate the specificity in which cardiac RGS proteins modulate $G_{q^-}$ and $G_{i/o}$-induced ERK and Akt phosphorylation. To isolate $G_{q^-}$ and $G_{i/o}$-mediated effects, we exclusively expressed muscarinic $M_2$ or $M_3$ receptors in COS-7 cells. Western blot analyses demonstrated increase of phosphorylation of ERK 1.7-/3.3-fold and Akt 2.4-/6-fold in $M_{2^-}/M_{3^-}$ expressing cells through carbachol stimulation. In co-expressions, $M_3/G_q$-induced activation of Akt was exclusively blunted through RGS3s/RGS3, whereas activation of ERK was inhibited additionally through RGS2/RGS5. $M_2/G_{i/o}$ induced Akt activation was inhibited by all RGS proteins tested. RGS2 had no effect on $M_2/G_{i/o}$-induced ERK activation. The high degree of specificity in RGS proteins-depending modulation of $G_{q^-}$ and $G_{i/o}$-mediated ERK and Akt activation in the muscarinic network cannot merely be attributed exclusively to RGS protein selectivity towards $G_q$ or $G_{i/o}$ proteins. Counter-regulatory mechanisms and inter-signaling cross-talk may alter the sensitivity of GPCR-induced ERK and Akt activation to RGS protein regulation.

• Journal of the Korean Ceramic Society
• /
• v.29 no.12
• /
• pp.942-948
• /
• 1992

Ultrafine iron oxide powder, {{{{ gamma }}-Fe2O3 and $\alpha$-Fe2O3, were prepared by the thermal decomposition of organometallic compounds. The formation process of powder includes the thermal decomposition and oxidation of the organometallic precursors, Fe(N2H3COO)2(N2H4)2 (A) and N2H5Fe(N2H3COO)3.H2O (B). The organometallic precursors, A and B, were synthesized by the reaction of ferrous ion with hydrazinocarboxylic acid, and characterized by quantitative analysis and infrared spectroscopy. The mechanistic study for the thermal decomposition was performed by DAT-TG. The iron oxide powder was obtained by the heat treatment of the precursors at 20$0^{\circ}C$ and $600^{\circ}C$ for half an hour in air. The phases of the resulting product were proved {{{{ gamma }}-Fe2O3 and $\alpha$-Fe2O3 respectively. The particle shape was equiaxial and the particle size was less than 0.1 ${\mu}{\textrm}{m}$. Magnetic properties of the {{{{ gamma }}-Fe2O3 powder obtained from A and B was 234 Oe of coercivity, 64.26 emu/g of saturation magnetization, 23.59 emu/g of remanent magnetization and 24.1 Oe, 47.27 emu/g, 3.118 emu/g respectively. The value of $\alpha$-Fe2O3 powder was 1.494 Oe, 0.4862 emu/g, 0.1832 emu/g and 1,276 Oe, 0.4854 emu/g, 0.1856 emu/g respectively.

• Journal of the Korean Ceramic Society
• /
• v.53 no.4
• /
• pp.393-399
• /
• 2016

We have successfully fabricated 3D (3-dimensional) nanostructures of $TiO_2$ coated with a $g-C_3N_4$ layer via hydrothermal and sintering methods to enhance photoelectrochemical (PEC) performance. Due to the coupling of $TiO_2$ and $g-C_3N_4$, the nanostructures exhibited good performance as the higher conduction band of $g-C_3N_4$, which can be combined with $TiO_2$. To fabricate 3D nanostructures of $g-C_3N_4/TiO_2$, $TiO_2$ was first grown as a double layer structure on FTO (Fluorine-doped tin oxide) substrate at $150^{\circ}C$ for 3 h. After this, the $g-C_3N_4$ layer was coated on the $TiO_2$ film at $520^{\circ}C$ for 4 h. As-prepared samples were varied according to loading of melamine powder, with values of loading of 0.25 g, 0.5 g, 0.75 g, and 1 g. From SEM and TEM analysis, it was possible to clearly observe the 3D sample morphologies. From the PEC measurement, 0.5 g of $g-C_3N_4/TiO_2$ film was found to exhibit the highest current density of $0.12mA/cm^2$, along with a long-term stability of 5 h. Compared to the pristine $TiO_2$, and to the 0.25 g, 0.75 g, and 1 g $g-C_3N_4/TiO_2$ films, the 0.5 g of $g-C_3N_4/TiO_2$ sample was coated with a thin $g-C_3N_4$ layer that caused separation of the electrons and the holes; this led to a decreasing recombination. This unique structure can be used in photoelectrochemical applications.

• Microbiology and Biotechnology Letters
• /
• v.32 no.2
• /
• pp.166-171
• /
• 2004

In this study, we introduced enzymatic pretreatment method, together with ozone treatment for sludge digestion. We optimized the amount of enzyme and ozone, respectively for the successful sludge pretreatment. As a result, we found that as more enzyme is used, higher sludge hydrolysis efficiency was obtained. When we treated sludge by ozone ranging from 0.01g $O_3$/g SS to 0.04 g $O_3$/g SS without enzyme treatment, 0.04 g $O_3$/g SS showed the highest increase of SCOD. Meanwhile, when protease was used together with the same ozone dosage ranges, 0.03g $O_3$/g SS ozonation resulted in the highest increase of SCOD. The sludge pretreatment was optimized by controlling the amount of enzyme and ozone.

• Journal of Korean Society for Atmospheric Environment
• /
• v.13 no.5
• /
• pp.333-343
• /
• 1997

The cyclone/annular denuder system/filter pack sampling system (ADS) was used to collect the acidic air pollutants in Chongju city. The data set was collected on fifty -eight different days with 24 hour sampling period from October 27, 1995 through August 25, 1996. The chemical species measured were HN $O_3$, HN $O_2$, S $O_2$ and N $H_3$ in the gas phase, and PM2.5( $d_{p}$ ＜2.5 ${\mu}{\textrm}{m}$), S $O_4$$^{2-}$, N $O_3$$^{[-10]}$ and N $H_4$$^{+}$ in the Particulate Phase. Mean concentrations measured for this study were: 0.45 $\mu\textrm{g}$/㎥ for HN $O_3$, 3.39 $\mu\textrm{g}$/㎥ for HN $O_2$, 26.4 $\mu\textrm{g}$/㎥ for S $O_2$, 3.83$\mu\textrm{g}$/㎥ for N $H_3$, 44.2 $\mu\textrm{g}$/㎥ for P $M_{2.5}$, 8.22 $\mu\textrm{g}$/㎥ for S $O_4$$^{2-}$, 3.63 $\mu\textrm{g}$/㎥ for N $O_3$$^{[-10]}$ , and 2.84 $\mu\textrm{g}$/㎥ for N $H_4$$^{- }$. HN $O_3$ and N $H_3$ were higher during the summer. However, HN $O_2$ and S $O_2$ were higher during the fall and winter. P $M_{2.5}$ , S $O_4$/ sup 2-/ and N $H_4$$^{+}$ were not showed seasonal variations, but N $O_3$$^{[-10]}$ was higher in the winter.ter.r.

• Journal of the Korean Magnetics Society
• /
• v.9 no.2
• /
• pp.78-84
• /
• 1999

$(Ni, Zn)Fe_2O_4$ powders were prepared through self-propagating high temperature synthesis reaction and the effects of initial zinc oxide powder size and oxygen pressure on the magnetic properties of the final combustion products were studied. The ferrite powders were combustion synthesized with iron, iron oxide, nickel oxide, and zinc oxide powders under various oxygen pressures of 0.5~10 atmosphere after blended in n-hexane solution for 5 minutes with a spex mill, followed by dried at 120 $^{\circ}C$ in vacuum for 24 hours. The maximum combustion temperature and propagating rate were about 1250 $^{\circ}C$ and 9.8 mm/sec under the tap density, which were decreased with decreasing ZnO size and oxygen pressure. The final product had porous microstructure with spinel peaks in X-ray spectra. As the ZnO particle size in the reactant powders and oxygen pressure during the combustion reaction increase, coercive force, maximum magnetization, residual magnetization, squareness ratio were changed from 1324 Oe, 43.88 emu/g, 1.27 emu/g, 0.00034 emu/gOe, 37.8$^{\circ}C$ to 11.83 Oe, 68.87 emu/g, 1.23 emu/g, 0.00280 emu/gOe, 43.9 $^{\circ}C$ and 7.99 Oe, 75.84 emu/g, 0.791 emu/g, 0.001937 emu/gOe, 53.8 $^{\circ}C$ respectively. Considering the apparent activation energy changes with oxygen pressure, the combustion reaction significantly depended on initial oxygen pressure and ZnO particle size.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2018.10a
• /
• pp.132-132
• /
• 2018

The aim of this study was to enhance the Tartary buckwheat growth and phenolic profile by the application of $SiO_2$ on potsin the glasshouse. The liquid of $SiO_2$ were applied at three times after three weeks of sowing at ten days interval. The doses of the $SiO_2$ was low (2.5 ml/5 L water), high (10 ml in 5 L water) and control experiment was done without $SiO_2$. In this study, it is clearly shown that high dose of $SiO_2$ increased the buckwheat plant growth including, plant height, leaf length and width, stem diameter, fresh weight and number of seed per plant compared to control treatment. In the same way, the total phenolic compound (1421 mg/100 g), total flavonoid (35.1 mg/100g), rutin (3,130 mg/100g) and DPPH (82%) in plant were also increased high dose of $SiO_2$ compared to control (1,175 mg/100g, 31.9mg/100g, 860 mg/100g, 59%, respectively). Moreover, higher phenolic compound (1,421 mg/100g) and DPPH (82%) was observed in plant compared to seed (196 mg/100mg, 72 %, respectively). In the contrary, total flavonoid (36.2 mg/100g) and rutin (1,400 mg/100g) was higher in buckwheat seed compared to plant (35.1 mg/100g, 3,130 mg/100g, respectively). Finally, it is concluded that higher dose of $SiO_2$ enhance buckwheat growth and phenolic profile. Further investigation is needed to evaluate the optimum dose of $SiO_2$ according to soil conditions in the field.

• Transactions on Electrical and Electronic Materials
• /
• v.15 no.6
• /
• pp.338-343
• /
• 2014

A $Fe_3O_4$-graphite nanofiber composite for use as an anode material was successfully synthesized by calcining $Fe_3O_4$ and graphite nanofiber (GNF) together in a $N_2$ atmosphere. Using this $Fe_3O_4$-GNF composite in a lithium ion battery resulted in a higher lithium storage capacity than that obtained using $Fe_3O_4$-graphite ($Fe_3O_4$-G). The $Fe_3O_4$-GNF (10 wt%) electrode exhibited a higher lithium ion diffusion coefficient ($2.29{\times}10^{-9}cm^2s^{-1}$) than did the $Fe_3O_4$-G (10%) ($3.17{\times}10^{-10}cm^2s^{-1}$). At a current density of $100mA\;g^{-1}$, the $Fe_3O_4$-GNF (10 wt%) anode showed a higher reversible capacity ($1,031mAh\;g^{-1}$) than did the $Fe_3O_4$-G (10%) anode ($799mAh\;g^{-1}$). Moreover, the $Fe_3O_4GNF$ electrodes showed good cycling performance without the addition of a conductive material.