• Journal of Preventive Medicine and Public Health
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• v.25 no.1 s.37
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• pp.13-25
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• 1992

This study was conducted to investigate the mechanism of protective effect by sodium selenite in methylmercuric chloride neurotoxicity, increasing intracellular $Ca^{2+}$concentration of the neuron. Methylmercuric chloride of 3mg/kg of body weight was administered simultaneously with sodium selenite of 5mg/kg and pretreatment of sodium selenite via intraperitoneal injection to rats. Also, effect of methylmercuric chloride($25{\mu}M,\;50{\mu}M,\;100{\mu}M$) and sodium selenite($200{\mu}M$) on free intrasynaptosomal $Ca^{2+}$ concentration were studied using the fluorescent $Ca^{2+}$ indicator fura -2 in vitro. After the treatment, at 6, 24, and 48 hours later, mercury in the cerebral cortex, liver and kidney tissues, succlnic dehydrogenase activities, adenosin-5'-triphosphate concentration, acetylcholinesterase activities, and intracellular $Ca^{2+}$ concentration in the cerebral cortex were determined in vivo. Cerebral synaptosomes of rats were incubated with methylmercuric chloride and sodium selenite in Hepes buffer for 10 minutes and free intrasynaptosomal $Ca^{2+}$ concentration were measured with fura-2 in vitro. The results were summarized as follows ; 1. The combined administration of $CH_3HgCl$ and $Na_2SeO_3$ and pretreatment of $Na_2SeO_3$ according to time significantly more increased in the cerebral cortex and decreased in the liver, kidney mercury concentrations compared to the administration of $CH_3HgCl$ only. 2. The combined administration of $CH_3HgCl$ and $Na_2SeO_3$ and pretreatment of $Na_2SeO_3$ increased more succinic dehydrogenase and acetylcholinesterase activities compared to the administration of $CH_3HgCl$ only. Particularly pretreatment of $Na_2SeO_3$ significantly more compared to the administration of $CH_3HgCl$ only. The concentration of adenosine-5'-triphosphate in $Na_2SeO_3$ treatment groups revealed a favourable effect compared to the administration of $CH_3HgCl$ only. 3. Intracellular $Ca^{2+}$ concentration in administration of $CH_3HgCl$ only was increased significantly more than control group in all test hours but was increased significantly more at 48 hours only after treatment in combined administration of $CH_3HgCl$ and $Na_2SeO_3$ and pretreatment of $Na_2SeO_3$ according to time interval more decreased significantly intracellular $Ca^{2+}$ concentration compared to the administration of $CH_3HgCl$ only. 4. Free intrasynaptosomal $Ca^{2+}$ concentration in the combined administration of $CH_3HgCl$ and $Na_2SeO_3$ was decreased ($24%{\sim}40%$) significantly more than the administration of $CH_3HgCl$ only. From the above results, the specific dosage of $Na_2SeO_3$ decreased increment of intracellular $Ca^{2+}$ concentration induced by administration of $CH_3HgCl$. These findings suggest the protective mechanism of $Na_2SeO_3$ on the neurotoxicity of $CH_3HgCl$.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.789-794
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• 2015

In this study, we investigated the stability with respect to the Langmuir-Blodgett(LB) monolayer films of stearic acid and phospholipid(L-${\alpha}$-dimyristoylphosphatidyl choline, DMPC) mixture. LB films of stearic acid and DMPC monolayer were deposited by the LB method on the indium tin oxide(ITO) glass. The electrochemical properties measured by cyclic voltammetry with three-electrode system in $0.05N\;NaClO_4$ solution, -0.3 V initial, 1650 mV switching potential and -1350 mV final potential. As a result, monolayer LB films of stearic acid and phospholipid mixture was appeared on irreversible process caused by the oxidation current from the cyclic voltammogram. Diffusion coefficient (D) of stearic acid and DMPC mixture(molar ratio 1:1, 1:2, 1:3) was calculated $1.4{\times}10^{-3}$, $1.7{\times}10^{-3}$ and $1.6{\times}10^{-3}(cm^2/s)$ in $0.05N\;NaClO_4$ solution, respectively.

• Journal of the Korean Chemical Society
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• v.13 no.2
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• pp.157-164
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• 1969

Aoolphane was treated with 30% Hydrochloric acid at $18^{\circ}C$ for two hows with stirring in order to obtain the insoluble form of SiO2 gel and to extract quantitatively both $Al_2O_3$as and $Fe_2O_3AlCl_3{\cdot}6H_2O Fe$ and $Cl_3{\cdot}6H_2O$ forms, respectively, at the same time. $SiO_2$ gel was filtered and to the filterate Ammonia was added to precipitate $Al(OH)_3[Fe(OH)_3 Contaminated ]$ The precipitate was separated by filteration and the filterate was recovered as the form of $NH_4Cl$. The precipitate was treated with 200g (NaOH)/l Concentration of NaOH a little excessively to the equivalent at $65~70^{\circ}C$ as $Fe(OH)_3$ formed was insoluble, it was filtered of and to the filterate containing $NaAl(OH)_4(OH_2)_2$Carbon dioxide gas was bubbled at $50^{\circ}C~90^{\circ}C$ to obtain the precipitate with excellent filterability and crystallinity. The product was certified to be Dawsonite $(NaAl(OH)_2CO_3)$ by X-Ray diffraction analysis at below $40^{\circ}C$, when $CO_2$ gas was bubbled into the relatively lower concentration of $NaAl(OH)_4(OH_2)_2$ solution, the precipitate of very fine particles was formed, which was hard to filter and with the Composition of $\alpha-Al_2O_3-H_2O$ (Boehmite).

• Korean Journal of Environmental Agriculture
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• v.7 no.2
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• pp.96-101
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• 1988

It is important to assess the effects of ionic strength and type of anions when studying the adsorption of heavy metals on zeolite because the background salt may complex with heavy metals and compete for adsorption sites. This experiment was carried out to determine the effect of ionic strength and anion species($Cl^-$, $SO^{2-}\;_4$, and $ClO^-\;_4$) on heavy metal adsorption. Heavy metal adsorption by zeolite from solutions in the range of 10 to 50ppm was studied in the presence of NaCl, $Na_2SO_4$ and $NaClO_4$, with different concentrations. The ionic strength ranged from 0.01 to 1.00. Adsorption of heavy metal cations could be described by the Freundlich isotherm equation. Increasing the ionic strength of equilibrium solutions, the amounts of heavy metal adsorbed on the zeolite surfaces decreased in all three of the anion systems. This fact could be attributed to the competition of background salt cation and the decrease in initial activity of heavy metal cations. In the presence of Cl anion, less adsorption resulted than in the presence of $SO_4$ or $ClO_4$ anions of the same ionic strength, indicating the presence of uncharged and negatively charged complexes of heavy metal with Cl ligands.

• Mass Spectrometry Letters
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• v.3 no.4
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• pp.108-111
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• 2012

An experimental study on the nascent product of the OH heterogeneous reaction with NaCl was performed under dry and wet conditions using a bead-filled flow tube system coupled to a high-pressure chemical ionization mass spectrometer. The ozone concentration in the flow tube for the atomic hydrogen removal was varied in order to control the conversion reaction of molecular chlorine into HCl for the identification of the nascent product. The mass spectrometric observation was that the $O_3$ introduction reduced the concentration HCl, while it increased the concentration of $Cl_2$ and ClO. Based on the experimental results, we suggest that the nascent product of the titled reaction is gaseous $Cl_2$, which is followed by fast conversion into HCl in presence of H. No significant difference in the concentration profile between under dry and wet (RH = 2%) conditions was observed.

• KSBB Journal
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• v.6 no.2
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• pp.207-213
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• 1991

In this study poly (1-methyl-4-vinylpyridinium iodide-co-styrene) membrane with pyridinium cation as a fixed carrier was synthesized and the transport characteristics of the membrane was examined over various factors. As the concentration of the fixed carrier in the membrane was increased, the water content was increased. Meanwhile, the counter current of the organic anion and the chloride ion, the following results were obtained. Initial flux of Cl-, organic anion and Na+ decreased with the increasing thickness of membrane, and as the concentration of the fixed carrier increases, the initial flux of Cl- and organic anion increase but the initial flux of Na+ decreased. The flux equation of the organic anion, CCl3COO- was obtained from saturation kinetics as follows;$V_{o}=\frac{(8.67{\times}10^{-5}){\cdot}[NaCl]}{9.63{\times}10^{-2}+[NaCl]} mol/cm^2h$

• Journal of Microbiology and Biotechnology
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• v.17 no.2
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• pp.313-319
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• 2007

The nutritional medium requirement for biosurfactant production by Bacillus licheniformis K51 was optimized. The important medium components, identified by the initial screening method of Plackett-Burman, were $H_3PO_4,\;CaCl_2,H_3BO_3$, and Na-EDTA. Box-Behnken response surface methodology was applied to further optimize biosurfactant production. The optimal concentrations for higher production of biosurfactants were (g/l): glucose, $1.1;NaNO_3,\;4.4;MgSO_4{\cdot}7H_2O,\;0.8;KCl,\;0.4;CaCl_2,\;0.27;H_3PO_4,\;1.0ml/l;\;and\;trace elements\;(mg/l):H_3BO_3,\;0.25;CuSO_4,\;0.6;MnSO_4,\;2.2;Na_{2}MoO_4,\;0.5;ZnSO_4,\;6.0;FeSO_4,\;8.0;CoCL_2,\;1.0;$ and Na-EDTA, 30.0. Using this statistical optimization method, the relative biosurfactant yield as critical micelle dilution (CMD) was increased from $10{\times}\;to\;105{\times}$, which is ten times higher than the non-optimized rich medium.

• Journal of Environmental Science International
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• v.20 no.7
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• pp.891-898
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• 2011

The aim of this research was to evaluate the effect of combination of disinfection process (electrolysis, UV process) on Escherichia coli (E. coli) disinfection and oxidants (OH radical, $ClO_2$, HOCl, $H_2O_2$ and $O_3$) generation. The effect of electrolyte type (NaCl, KCl and $Na_2SO_4$) on the E. coli disinfection and oxidants generation were evaluated. The experimental results showed that performance of E. coli disinfection of electrolysis and UV single process was similar. Combination of electrolysis and UV process enhanced the E. coli disinfection and 4-carboxybenzaldehyde (4-CBA, indicator of the generation of OH radical) degradation. It is clearly showed synergy effect on disinfection and OH radical formation. However chlorine ($ClO_2$, HOCl) and oxygen type ($H_2O_2$, $O_3$) oxidants were decreased with the combination of two process. In electrolysis + UV complex process, electro-generated $H_2O_2$ and $O_3$ were reacted with UV light of UV-C lamp and increased 4-CBA degradation(increase OH radical). Disinfection of electrolyte of chlorine type was higher than that of the sulfate type electrolyte due to the higher generation of OH radical and oxidants.

• The Journal of Engineering Geology
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• v.28 no.4
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• pp.565-582
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• 2018

We investigated the hydrochemical properties of ChusanYongchulso Spring located in Buk-myeon, Ulleung Island, focusing on the formation and characteristics of aquifers in and around the Nari caldera. Abundant pumice with high permeability and numerous fractures (including faults and joints) that formed as a result of caldera subsidence are widely distributed in the subsurface, favoring the formation of aquifers. Because of the presence of porous pyroclastic rocks with a high internal surface area, the water type of the springs is characterized by $NaHCO_3$, with upper stream waters and the upper spring being characterized by $NaHCO_3$ and NaCl, respectively. Components with a high coefficient of determination with EC are $HCO_3$, Na, F, Ca, Mg, Cl, $SiO_2$, and $SO_4$. The high concentrations of Na and Cl might be attributable to the main lithologies in the area, given that alkaline volcanic rocks are distributed extensively across Ulleung Island. Eh and pH, which are considered to be important indicators of water-rock interaction, are unrelated to most components. According to the results obtained from factor analysis, the variance explained by factor 1 is 54% and by factor 2 is 25.8%. Components with a high loading on factor 1 are F, Na, EC, Cl, $HCO_3$, $SO_4$, $SiO_2$, Ca, $NO_3$, and Mg, whereas components with a high loading on factor 2 are Mg and Ca, along with K, $NO_3$, and DO with negative loadings. It is suggested that the high concentrations of Na, Cl, F, and $SO_4$ are closely related to the presence of fine-grained alkaline pyroclastic rocks with high permeability and porosity, which favorintensewater-rock interaction. However, a wide-ranging investigation that encompasses methods such as geophysical prospecting and geochemical analysis (including isotope, trace-element, and tracer techniques) will be necessary to gain a better understanding of the groundwater chemistry, aquifer distribution, and water cycling of Ulleung Island.

• Applied Biological Chemistry
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• v.38 no.2
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• pp.100-105
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• 1995

Media optimization for the production of MR-387A and B, novel aminopeptidase M inhibitors by Streptomyces sp. SL-387 isolated from a soil was studied. Optimized medium was consisted of 1% glucose, 3% soybean meal, 0.2% yeast extract, 0.1% beef extract, 0.3% NaCl, 0.01% $K_2HPO_4$, 0.3% $CaCO_3$, 0.001% $MnCl_2{\cdot}4H_2O$, 0.001% $ZnCl_2{\cdot}7H_2O$, and 0.0005% $MgSO_4{\cdot}7H_2O$, and adjusted to pH 7.0 before autoclaving. When the optimized medium was used as a fermentation medium, maximum productivity of MR-387 was reached at 120 hours of fermentation, and total productivity was 909.1 U/ml.