• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.2
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• pp.71-74
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• 2008

To investigate the sulfate utilization efficiency in different rape (Brassica napus) cultivars, sulfate uptake are analyzed under complete S-supply level (2.0mM ${SO_4}^{2-}$). This study used ten different genotypes of rape (Mokpo, Tamra, Youngsan, Naehan, Saturnin, Akela, Mosa, Capitol, Pollen and Colosse). For comparison of ${SO_4}^{2-}$ uptake among 10 cultivars, leaf number, leaf length and width, root length was also observed. Leaf length and width in all cultivars less variable among the cultivars examined. The longest root was shown in Saturnin (36.3 cm). ${SO_4}^{2-}$ uptake in Saturnin, Youngsan and Mokpo was significantly higher whereas that of Mosa and Pollen was relativety lower. Saturnin and Mokpo which have a high ${SO_4}^{2-}$ uptake exhibited a high ${NO_3}^-$ uptake.

• Journal of Hydrogen and New Energy
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• v.22 no.1
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• pp.51-59
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• 2011

Sulfur-Iodine (SI) cycle, which thermochemically splits water to hydrogen and oxygen through three stages of Bunsen reaction, HI decomposition, and $H_2SO_4$ decomposition, seems a promising process to produce hydrogen massively. Among them, the decomposition of $H_2SO_4$ ($H_2SO_4=H_2O+SO_2+1/2O_2$) requires high temperature heat over $800^{\circ}C$ such as the heat from concentrated solar energy or a very high temperature gas-cooled nuclear reactor. Because of harsh reaction conditions of high temperature and pressure with extremely corrosive reactants and products, there have been scarce and limited number of data reported on the pressurized $H_2SO_4$ decomposition. This work focuses whether the $H_2SO_4$ decomposition can occur at high pressure in a noble-metal reactor, which possibly resists corrosive acidic chemicals and possesses catalytic activity for the reaction. Decomposition reactions were conducted in a Pt-lined tubular reactor without any other catalytic species at conditions of $800^{\circ}C$ to $900^{\circ}C$ and 0 bar (ambient pressure) to 10 bar with 95 wt% $H_2SO_4$. The Pt-lined reactor was found to endure the corrosive pressurized condition, and its inner surface successfully carried out a catalytic role in decomposing $H_2SO_4$ to $SO_2$ and $O_2$. This preliminary result has proposed the availability of noble metal-lined reactors for the high temperature, high pressure sulfuric acid decomposition.

• Journal of Environmental Health Sciences
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• v.24 no.3
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• pp.114-123
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• 1998

Particulate matters(less than 10 $\mu$m, PM10) at Kanghwa and Yangyang, which are located in the western and the eastern coastal regions in Korea, were measured in using low volume air sampler from December 1995 to November 1996, and their characteristics were investigated from the view point of background level.(and in order to characterize the particulate matters.) The particulate matters were analyzed for major water soluble ionic components(SO$_{4}^{2-}$, NO$_{3}^{-}$, Cl$^{-}$, Na$^{+}$, NH$_{4}^{+}$, K$^{+}$, Mg$^{2+}$ and Ca$^{2+}$) by ion chromatography. Mass concentrations of particulate matters were $48.77 \pm 22.45 \mug/m^{3}$ at Kanghwa and $54.04 \pm 32.98 \mug/m^{3}$ at Yangyang and SO$_{4}^{2-}$, NO$_{3}^{-}$ and NH$_{4}^{+}$ contributed largely to water soluble ionic components. nss(non sea salt)-SO$_{4}^{2-}$, contributed more than 95 percentage to SO$_{4}^{2-}$ and nss-K$^{+}$ and nss-Ca$^{2+}$ also contributed high percentages to K$^{+}$ and Ca$^{2+}$. It was supposed that most SO$_{4}^{2-}$, was originated from anthropogenic sources, and K$^{+}$ and Ca$^{+}$ were mainty originated from soil. The results of factor analysis suggested possibility of interpreting the correlation between air pollutants and regional characteristics.

• Korean Chemical Engineering Research
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• v.44 no.4
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• pp.356-362
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• 2006

The $SO_2$ reduction using CO and $H_2$ over Sn-Zr based catalysts was performed in this study. Sn-Zr based catalysts with Sn/Zr molar ratio (0/1, 1/4, 1/1, 2/1, 3/1, 1/0) were prepared by the precipitation and co-precipitation method. The effect of the temperature on the reaction characteristics of the $SO_2$ reduction with a reducing agent such as $H_2$ and CO was investigated under the conditions of space velocity of $10,000ml/g_{-cat.}h$, $([CO(or\;H_2)]/[SO_2])$ of 2.0. As a result, the activity of Sn-Zr based catalysts were higher than $SnO_2$ and $ZrO_2$. The reactivity for the $SO_2$ reduction with CO was higher than that with $H_2$, and sulfur yield in the $SO_2$ reduction by $H_2$ was higher than that by CO. The reactivity for the $SO_2$ reduction with $H_2$ was increased with the reaction temperature regardless of Sn-Zr based catalyst with a Sn/Zr molar ratio. $SnO_2-ZrO_2$ (Sn/Zr=1/4) had highest activity at $550^{\circ}C$, in the $SO_2$ reduction with $H_2$ and $SO_2$ conversion of 94.4％ and sulfur yield of 66.4％ were obtained at $550^{\circ}C$. On the other hand, in the $SO_2$ reduction by CO, the reactivity was decreased with the increase over $325^{\circ}C$. At the optimal temperature of $325^{\circ}C$, $SO_2$ conversion and sulfur yield were about 100％ and 99.5％, respectively, in the $SO_2$ reduction over $SnO_2-ZrO_2$ (Sn/Zr=3/1). Also, the $SO_2$ reduction using syngas with $CO/H_2$ ratio over $SnO_2-ZrO_2$ (Sn/Zr=2/1) was performed in order to investigate the application possibility of the simulated coal gas as the reductant in DSRP. As a result, the reactivity of the $SO_2$ reduction using syngas with $CO/H_2$ ratio was increased with increasing the CO content of syngas. Therefore, it could be known that DSRP using the simulated coal gas over Sn-Zr based catalyst is possible to be realized in IGCC system

• Journal of Environmental Science International
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• v.5 no.6
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• pp.739-748
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• 1996

This study was carried out to investigate the chemical characteristics ol rainwater sampled in Cheju City from July 1994 to June 1996. Concentrations of major ions (Cl-,$SO_4^{2-}$, NO_3^-$, $Na^+$, $K^+$, Ca^{2+}$, $Mg^{2+}$ and NH_4^+$) were determined. The pH of rainwater, calculated from the volume weighted H+ concentration, was found to be 5.61, indicating extensive neutralization of the acidity in the rain. The relative magnitude of average ionic concentrations followed the relation Cl-> $SO_4^{2-}$) $Na^+$> Ca^{2+}$> NH_4^+$> NO_3^-$> $Mg^{2+}$> $K^+$. The ions associated with sea salt, namely $Na^+$ and $Cl^-$, dominated the total concentration of ions in the rainwater and the $SO_4^{2-}$ ion accounts for 20% of total concentration. [H+][nss-SO42-+NO3] ratio and a multiple regression for $SO_4^{2-}$ and NO3- ions against $H^+$, $Ca^{2+}$ and $NH_4^+$ suggested that all of $SO_4^{2-}$ and $NO_3^-$ in rainwater was not necessarily associated with $H_2SO_4$ and $HNO_3$, but might also occur in combination with $NH_4^+$ or Ca^{2+}$. The monthly mean concentrations of $SO_4^{2-}$-, Ca^{2+}$ and $NH_4^+$ in spring time was higher than those in other seasons. These results may De attributed to the fertilizer application as the local sources and the yellow sand phenomina as a regional-scale sources.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.4
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• pp.407-413
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• 1998

The influence of the anion composition of simulated acid rain on cation leaching of two soils with different surface charge properties was examined. Four mixtures of mole ratio of $SO_4:NO_3$(1:0, 2:1, 1:1, 0:1) with pH 2.0 simulated acid rain were applied to an Inceptisols(Gyuam series) and Andisols(Pyeongdae series). The Andisols had higher $SO_4{^{2-}}$ adsorption capacity than the Inceptisols because of its higher point of zero charge(PZC, pH 6.5) than Inceptisols(PZC pH 3.1). Cation leaching in Andisols varied directly with the $NO_3$ content of the leaching input due to higher mobility of $NO_3$ compared with $SO_4$ that was absorbed. The pH of the Andisols was higher with the addition of $Na_2SO_4$ than the addition of $NaNO_3$ indicating that this soil behaves as a base and has a high $SO_4$ adsorption capacity. The relative $NO_3{^-}/SO_4{^{2-}}$ content input had no effect on cation leaching of the Inceptisols. Amounts of leaching on the Andisols by simulated acid rain were higher than Inceptisols. This experiment explained that anion composition of acid rain plays a significant role in the cation leaching of soils which are able to adsorb $SO_4$.

• Journal of the Korean Magnetic Resonance Society
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• v.14 no.1
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• pp.18-27
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• 2010

The NMR spectrum and spin-lattice relaxation times, $T_1$, of the $^{1}H$ nuclei in $(NH_{4})_{2}Cd_{2}(SO_{4})_{3}$ single crystals were obtained. The two minima in $T_1$ in the paraelectric phase are attributed to the reorientational motions of the $NH_{4}^{+}$ groups. The $^{1}H\;T_1$ of the $(NH_{4})_{2}Cd_{2}(SO_{4})_{3}$ crystals can be described with Bloembergen- Purcell-Pound (BPP) theory. The experimental value of $T_1$ can be expressed in terms of an isotropic correlation time ${\tau}_H$ for molecular motions by using the BPP theory, and determine the role of protons in these processes.

• KSBB Journal
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• v.8 no.4
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• pp.409-414
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• 1993

This study was designed to reveal the conditions for $\beta$-glucosidase production from Aspergillus niger. The maximal enzyme production was obtained when the fungus was cultured at $30^{\circ}C$ for 5~6 days in the optimal medium containing 0.8% CMC, 0.5% beef extract, 0.3% Ca(NO3)2, 0.03% K2HPO4, 0.03% FeSO4, 0.05% Li2SO4, 0.2% tween 80, trace solution 1.0ml and initial pH 4.0, and then final enzyme activity under above conditions was 8.5-9.8 unit/ml culture filtrate.

• Journal of Food Hygiene and Safety
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• v.10 no.4
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• pp.231-237
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• 1995

Bacillus subtilis SH-1 have been isolated and identified from coastal sea, in Pusan, The optimal cultural characterization of Bacillus subtilis SH-1 for 속 production of bacteriolytic enzyme was determained. Bacillus subtilis SH-1 produced the bacteriolytic enzyme well in the medium consist of 1.0% glucose, 1.0% yeast extract, 1.0% NaCI, 0.02% $K_2HPO_4,\;0.002%\;MgSo_4{\cdot}7H_2O,\;0.001%\;MnSO_4{\cdot}5H_2O,\;0.0001%\;FeSO_4{\cdot}7H_2O$. The optimal medium pH, incubation temperature, and shaking tome for the highest production of the enzyme were 8.0, $30^{\circ}C$ and 28 hours respectively.

• Journal of Electrochemical Science and Technology
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• v.9 no.2
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• pp.85-92
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• 2018

Olivine structure of $LiFePO_4$ (LFP) is one of the most commonly used materials in aqueous rechargeable lithium batteries (ARLBs), and can store and release charge through the insertion/de-insertion of $Li^+$ between LFP and FP. We have fabricated LFP and LFP/FP electrodes on titanium paper and studied their electrochemical properties in 2 M $Li_2SO_4$. The LFP/FP electrode was determined to be a suitable electrode for electo-ostmotic pump (EOP) in terms of efficiency in water and 0.5 mM $Li_2SO_4$ solution. Experiments to determine the effect of cations and anions on the performance of EOP using LFP/FP electrode have shown that $Li^+$ is the best cation and that the anion does not significantly affect the performance of the EOP. As the concentration of $Li_2SO_4$ solution was increased, the current increased. The flow rate peaked at $4.8{\mu}L/30s$ in 1.0 mM $Li_2SO_4$ solution and then decreased. When the EOP was tested continuously in 1.0 mM $Li_2SO_4$ solution, the EOP transported approximately 35 mL of fluid while maintaining a stable flow rate and current for 144 h.