• Polymer(Korea)
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• v.27 no.4
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• pp.330-339
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• 2003

Three kinds of macro-reticular bead-typed chelating resins having thiol groups were obtained from basic resins like poly(strene-co-divinylbenzene) (PSD) and poly(styrene-co-methyl methacrylate-co-divinylbenzene) (PSMD): the chelating resin (I) was prepared by chloromethylation of phenyl rings of PSD followed by thiolation using thiourea. The chelating resin (ll) was designed to provide enough space to chelate heavy metal ions; one chloromethyl group was obtained by chlorination of hydroxymethyl group provided by reduction of carboxylic ester group of PSMD and another chloromethyl group was obtained by direct chloromethylation of pendent phenyl group using chloromethyl methyl ether. Both of chloromethyl groups were thiolated by using thiourea. The chelating resin (III) was prepared by chlorosulfonation of phenyl rings of PSD followed by thiolation using sodium hydrosulfide. The adsorbtivity toward heavy metal ions was evaluated. The hydrophobic chelating resin (I) with thiol groups showed highly selective adsorption capacity f3r mercury ions. However, the chelating resin (II) with thiol groups showed mere effective adsorption capacity toward mercury ions than chelating resin (I) with thiol groups, and showed some adsorption capacity for other heavy metal ions like Cu$\^$2＋/, Pb$\^$2＋/, Cd$\^$2＋/ and Cr$\^$3＋/. On the other hand, the chelating resin (III) which have hydrophilic thiosulfonic acid groups was found to be effective adsorbents for some heavy metal ions such as Hg$\^$2＋/, Cu$\^$2＋/, Ni$\^$2＋/, Co$\^$2＋/, Cr$\^$3＋/ and especially Cd$\^$2＋/ and Pb$\^$2＋/.

• Resources Recycling
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• v.17 no.6
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• pp.34-42
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• 2008

The properties of sodium silicate solution were surveyed by using the yellow silicomolybdic method, and the formation of silica sol from sodium silicate solution and the growth of silica sol were investigated in this study. The $SiO_2$ content of 2 wt% in sodium silicate solution was proper to oxidize sodium silicate with sulfuric acid. After the removal of sodium ions in sodium silicate solution, the pH of silicate solution had to be controlled above 9 for the stabilization of silicate solution. The condensation between silicic acid species and silica nuclei surfaces has been studied at $20{\sim}80^{\circ}C$ and pH 10 in silicate solutions with silica nuclei. The reaction falls into two kinetics regimes, limited at high silicic acid species concentration by polymerization, but at lower concentration by a process whereby deposited silicic acid species condenses further to silica. The overall condensation is first-order in silicic acid species concentration, proceeded toward to pseudo equilibrium concentration, $C_x$, rather than the solubility of amorphous silica. The heat of solution of amorphous silica was 3.34 kcal/mol and exhibits an Arrhenius temperature dependence with an apparent activation energy of 3.16 kcal/mol in the range of $20{\sim}80^{\circ}C$.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.6
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• pp.905-913
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• 2018

Objective: To evaluate the effects of L-lysine (Lys)/L-arginine (Arg) on lipid and protein oxidation of emulsion sausage during storage and its possible mechanism. Methods: Four samples were prepared based on the presence or absence of additional sodium isoascorbate, Lys, or Arg: sample A (control), sample B (0.05 g of sodium isoascorbate), sample C (0.4 g of Lys), and sample D (0.4 g of Arg). Peroxide value (POV), thiobarbituric reactive substances (TBARS), protein carbonyls and thiols were measured. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical-scavenging, ferrous ion-chelating ability were also measured. Results: Compared with the control, the sample treated with sodium isoascorbate, Lys or Arg had significantly lower POV during the initial 20 days, TBARS during the initial 15 days. Protein carbonyls were significantly lower compared Sample B, C, and D with A during the later storage (10 to 25 days); basically, protein thiols became lower during storage when the samples were treated with sodium isoascorbate, Lys, or Arg. Both Lys and Arg had weak reducing power but strong ferrous ion-chelating activity and DPPH radical- and hydroxyl radical-scavenging activity. Conclusion: Both Lys and Arg effectively inhibited the oxidation of lipids and proteins in emulsion sausage by scavenging free radicals and chelating ferrous ions. The results obtained may be favorable for the prevention of lipid and protein oxidation during processing and storage of meat products.

• Clinical and Experimental Pediatrics
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• v.46 no.2
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• pp.198-202
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• 2003

Of all toxic inhalant exposures, chlorine is one of the most common toxic chemical inhalants. When acutely inhaled, it can be responsible for symptoms ranging from upper air way irritation to more serious respiratory effects. It can also deteriorate lung function and lead to death. Chlorine and its compounds such as chlorinated cyanurates and hypochlorites are commonly used in water disinfection. The chemical agents discussed in this article are sodium dichloroiso cyanurate and calcium hypochlorite which are the two most popular products for swimming pool chlorination. They are both strong oxidizing agents which are soluble in water. Between the above two alkali agents, acid-base interaction occurred and generated heat. And the acid drove the combination of hypochlorous and chloride ions to form chlorine gas. We have experienced, two boys who had inhalation injuries caused by an accidental explosion which occurred in a swimming pool by mixing two different chlorinating agents : sodium dichloroiso cyanurate and calcium hypochlorite. The children suffered from respiratory difficulties after the exposure. They both required intensive care management and one needed the support of mechanical ventilation.

• Journal of Applied Biological Chemistry
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• v.59 no.1
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• pp.83-90
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• 2016

The aim of the present study was to evaluate the degree of metal contamination of the Turag River water and its suitability for irrigation. Twenty water samples were analyzed for physicochemical parameters and metals viz., calcium, magnesium, potassium (K), sodium, copper (Cu), zinc (Zn), iron (Fe), manganese (Mn), lead (Pb), cadmium (Cd), chromium (Cr), and nickel (Ni). All water samples were slightly alkaline to alkaline. Regarding electrical conductivity (EC), all samples were suitable for crop in soils with moderate permeability and leaching. Water samples were medium salinity and low alkalinity hazard classes. In terms of total dissolved solids (TDS), all samples were classified as freshwater. As per sodium adsorption ratio (SAR) and soluble sodium percentage (SSP), all samples were classified as excellent. No residual sodium carbonate (RSC) was detected in any of the samples, indicating suitability for irrigation; and all samples were considered very hard. Cr and Mn contents in all samples were above FAO guideline values and, therefore, these metals were considered toxic. Zn, Cu, Pb, Cd, and Ni concentrations were below acceptable limit for irrigation and do not pose a threat to soil environment. Significant relationships were found between EC and TDS, SAR and SSP, SAR and RSC, and SSP and RSC. The combinations of ions such as K-Zn, K-Fe, K-Cu, K-Mn, K-Pb, Zn-Fe, Zn-Cu, Zn-Mn, Fe-Mn, Cu-Mn, Cu-Pb and Mn-Pb exhibited significant correlation. This study revealed that Turag River water samples are contaminated with Cr and Mn. This fact should not be ignored because water contamination by metals may pose a threat to human health through food chain.

• Analytical Science and Technology
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• v.5 no.4
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• pp.425-431
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• 1992

The concentration and determination of trace phosphate ion was studied by $La(OH)_3$ coprecipitaiton. Phosphate ions in 1.0L samples were coprecipitated with lanthanium hydroxide at pH 9.5 adjusted with ammonia solution. The precipitates were floated with the aid of mixed surfactant(1:8 sodium oleate/sodium dodecyl sulfate) and nitrogen gas bubbles. The floated precipitate was collected in suction flask from the solution. The precipitate were washed with dil. ammonia solution and dissolved in sulfuric acid. The phosphate ion in the concentrated solution was finally determinated by UV/VIS spectrophotometry using the molybdenium blue method. The proposed method could be applied to the determination of phosphate ion in tap water and river water.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.2
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• pp.68-74
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• 1983

A moderately halophilic bacterium, Listeria denitrificans HB-38, isolated from mud on the seashore in Sooyoung bay, Pusan, showed the requirement of $4\%$ sodium chloride for cell growth in a medium with salts typical of a marine environment, and showed that of $10\%$ in a medium with salts typical of a terrestrial environment. The optimum temperature and pH for growth were $40^{circ}C$ and pH 7.5 in the medium containing $10\%$ sodium chloride and ions typical of a terrestrial environment. Sodium chloride as a protoplast stabilizer gave more stability than sorbitol or sucrose, meanwhile the protoplast did not require higher concentration of stabilizer than that of E. coli protoplast. Succinic dehydrogenase of HB-38 had a halophilic property showing maximal activity in the presence of $9\%$ sodium chloride. The strain HB-38 did not harbor an extrach-romosomal DNA.

• Journal of the Korean Vacuum Society
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• v.17 no.6
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• pp.481-486
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• 2008

The different degrees of blackening were observed at the inner surface of borosilicate, soda-lime, and aluminosilicate glass tubes having different sodium (Na) contents. The sodium contents ($Na_2O$) within the borosilicate, soda-lime, and aluminosilicate glass tubes were found to be 4%, 14%, and 0.06%, respectively. The degree of blackening was shown to increase as the sodium content within the glass of the fluorescent lamp containing Ne+Ar+Hg gas mixture. Higher degree of blackening was observed from the inner surface of the glass tube coated with $Y_2O_3$. The blackening was found to be originated from the amalgam of $NaHg_2$ generated by the chemical reaction between the mercury ions within the discharge gas and sodium within the glass tube during operation.

• Journal of Sericultural and Entomological Science
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• v.25 no.2
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• pp.44-50
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• 1984

The effects of sodium pyrophosphate, sodium tripolyphosposphate and ethylene diamine tetraacetic acid as a degumming aid reagent were investigated under the conditions of underground water and dimineralized water for the scouring water sources. The changes of water qualities by adding the condensed sodium phosphates and the physical properties of scoured silk fabric were examined, respectively. 1. The water hardness of underground water was decreased by adding the condensed sodium phosphates and it was further reduced according to the increasing temperature. The water hardness reducing power of sodium pyrophosphate was a little stronger than that of sodium tripolyphosphate. 2. The sodium silicate as an alkaline reagant for scouring decreased the water hardness, but the sodium carbonate increased it in the underground water. 3. The pH value of 0.4% soap and 0.25% sodium silicate mixed solution after boiling was. 9.80, but it was leveled upto 9.90 by adding 0.05% sodium pyrophosphate and upto 9.95 by 0.02% ehtylene diamine tetraacetic acid, respectively. 4. The masking action of Fe$\^$3+/ ions dissolved in the scouring water was more remarkable by ethylene diamine tetraacetic acid than by the condensed sodium phosphates. Of the condensations, sodium tripolyphosphate was more effective than sodium pyrophosphate in the action. 5. Genrally, the dimineralized water scouring increased the boil-off ratio with reducing the flexural rigidity of fabric which was negatively related with the favorablility of hand-touch more than the underground one did. 6. Under the underground water scouring, the addition of ethylene diamine tetraacetic acid increased the boil-of ratio and compressive elasticity of fabric with reducing the flexural rigidity more than that of the condensed sodium phosphates did. 7 The additions of sodium tripolyphosphate and ethylene diamine tetraacetic acid reduced the flexural rigidity of fabric with raising the boil-off ratio even in the dimineralized water scouring, but there was no sifnificant difference between both of them.

• Corrosion Science and Technology
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• v.4 no.2
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• pp.45-50
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• 2005

A 3% NaCl solution of 1 $dm^3$ circulated with 1.5 $dm^3/min$ by a pump for 24 h in the presence of magnetic field. An iron plate immersed in a $100cm^3$ of test solution for 24 h. The rest potential and pH on surface fixed after 3 h. Containing 0~120 ppm of Fe(II) ion, the dissolution in the magnetically treated solution rose comparing with that in the non-magnetically treated solution. The dissolution amount reached to maximum at 50 ppm, then fixed in the non-magnetically treated solution. When Fe(II) ion existed in the magnetically treated solution, dissolution accelerated a little. In the non-magnetic treated solution containing 10~125 ppm of Fe(III) ion existed, the dissolution accelerated. The dissolution amounts reached to maximum at 50 ppm, then decreased from maximum value. In the magnetically treated solution, the dissolution amounts reached to minimum until 50 ppm, then increased from minimum value. The dissolution amounts affected larger with increasing of magnetic flux density. Fe(II), Fe(III) ions and magnetic treatment affected to formation of $Fe(OH)_2$ and/or $Fe_3O_4$ films. The magnetically treated effects memorized about one month.