• Polymer(Korea)
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• v.30 no.6
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• pp.556-562
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• 2006

Quarternized poly(4-vinyl pyridine)s have been prepared by the reaction of poly (4-vinyl pyridine)s (Mw=50 kg/mol and 200 kg/mol) and alkylating agents varying the carbon numbers of the alkyl groups (m):dimethyl sulfate (m=1) as well as bromoalkane (m= 5, 8, 12, 16, and 22) was used as an alkylating agent. The degree of alkylation was determined by using an elemental analysis and NMR spectroscopy. As a result, polyelectrolytes were obtained by the almost full alkylation of poly (4-vinyl pyridine)s. The critical aggregation concentration (CAC) was determined by measuring the change of turbidity occurred by addition of sodium dodecyl sulfate (SDS) into aqueous solution of quarternized poly-(4-vinyl pyridine)s, and the dependence of molecular weight of polymer, the length of N-alkyl group and concentration of NaCl upon CAC was investigated. As a result, as the molecular weight or the length of alkyl group was increased, less amount of SDS Gould induce the aggregation.

• Journal of Aquaculture
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• v.21 no.1
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• pp.7-12
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• 2008

Toxicity of ten commercial disinfectants(hydrogen peroxide, sodium hypochlorite, chlorine dioxide, povidon iodine, formaldehyde, glutaraldehyde, quaternary ammonium compounds(QAC), didecyl dimethyl ammonium chloride(DDAC), ortho-dichlorobenzene, and copper sulfate) was measured by chinook salmon embryo-214 cell line and three fish species: flounder Paralichthys olivaceus, black rockfish Sebastes pachycephalus, and black sea bream Acanthopagrus schlegelii. The $LC_{50}$ levels of 24 hours acute toxicity with the ten disinfectants were tested in three species of fish. Effectiveness of ten chemical disinfectants were varied by each chemical as well as by species. Hydrogen peroxide showed the higest activity at 201, 269, and 139 ppm in the flounder, the black rockfish, and black sea bream, respectively. DDAC showed the lowest activity at 2.1, 1.0, and 1.5 ppm in the flounder, the black rockfish, and black sea bream, respectively. The highest variation was observed in copper sulfate by both the chemicals and the species.

• Journal of Korean Society on Water Environment
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• v.25 no.1
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• pp.151-158
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• 2009

The objective of this study was to determine on optimum ratio of oxidant and catalyst and to evaluate affecting factors such as anions and cations on persulfate oxidation of organic pollutant. Fe(II) activated the persulfate anion to produce a sulfate free radicals and thus effectively used to degrade the target organic pollutant in aqueous system. The chloride ions reacted with sulfate radical produced the $Cl^{\cdot}$ atom and had positive effects on the oxidation of organic pollutant at the initial stage. However, it was observed that chloride ions had the scavenging effects on the rate of oxidation of organic pollutant. Cations and some heavy metals were partly able to activate the persulfate anion to generate a sulfate free radical. However, high levels of cations inhibited the oxidation of organic pollutant.

• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3539-3543
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• 2012

Butacaine sulfate is an ester of p-aminobenzoic acid which has been widely used as a local anaesthetic and it is a long standing agent particularly for spinal anaesthesia. For this reason, a kinetic study of oxidation of butacaine sulfate by sodium N-chlorobenzenesulfonamide (chloramine-B or CAB) has been carried out in $HClO_4$ medium at 303 K in order to explore this redox system mechanistic chemistry. The rate shows a first-order dependence on both $[CAB]_o$, and $[substrate]_o$, and a fractional-order dependence on acid concentration. Decrease of dielectric constant of the medium, by adding methanol, increases the rate of the reaction. Variation of ionic strength and addition of benzenesulfonamide or NaCl have no significant effect on the rate. The reaction was studied at different temperatures and the activation parameters have been evaluated. The stoichiometry of the reaction has been found to be 1:2 and the oxidation products have been identified by spectral analysis. The observed results have been explained by plausible mechanism and the related rate law has been deduced.

• Food Science and Preservation
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• v.10 no.4
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• pp.554-559
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• 2003

The optimal culture conditions on bacteriocin producing of Lactobacillus sp. FF-3 isolated from Korean Dongchimi, were studied for enhancing its production with regard to environmental and nutritional factors. The optimal cultivation time, initial pH and temperature were 21 hours, pH 7.0 and 30∼37$^{\circ}C$ respectively. Optimal compositions of culture medium for bacteriocin production were glucose 3% as carbon source, tryptone 4% as nitrogen source, and manganese sulfate 0.005% as inorganic salt with other basal components. The maximum antimicrobial activity was 484 BU/mL under the optimal culture condition.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.1 s.49
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• pp.51-58
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• 2005

Alkyl ethoxy sulfate type surfactants, widely used in commercial cleansers, are easily adsorbed to skin to often cause skin irritation and inflammation if not thoroughly rinsed nut. In order to replace or complement existing surfactants, we screened the existing surfactants through protein denaturation method, cell cytotoxicity assay and human IL-1$\alpha$ assay, etc. Fourteen surfactants have been chosen from among too irritant anionic, cationic and/or zwitter-ionic ones and investigated for cell cytotoxicity in human fibroblast cell lines using monolayer culture with the thirteen commercially available cleansers for sensitive skin. From these results, we selected 5 surfactants and 2 commercial cleansers (names not shown), such as sodium laureth sulfate (anionic), sodium cocoyl isethionate (anionic), sodium lauroamphoacetate (zwitter-ionic), and cocamidopropyl betaine (zwitter-ionic), alkyl polyglycoside (non-ionic). 20 formulations were made out of 5 surfactants and five of them were chosen through a protein denaturation method (lower than 3 M sodium dodecyl sulfate solution ($13.2\%$)), cell cytotoxicity and human patch test. These five selected formulations containing preservatives were compared to two selected commercial cleansers by cell cytotoxicity and human IL-1$\alpha$ ELISA assay using dermal equivalent. Finally, we selected the best formulation. To this formulation, fructan ($3\%$ or $5\%$) or/and portulaca extract ($3\%$ or $5\%$) well known for its anti-inflammatory and moisturizing effects were added and investigated for cell cytotoxicity using dermal equivalent. In cytotoxicity assay using dermal equivalent, two formulations containing $5\%$ fructan and $3\%$ or $5\%$ portulaca extract were less toxic than the others. In cytotoxicity assay and human IL-1$\alpha$ ELISA using 3D culture, the selected formulation containing $5\%$ fructan and $5\%$ portulaca extract showed better efficiency than those of the others and 2 commercial cleansers. As a result, we could develop a low irritant and safe liquid cleanser.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.5
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• pp.503-513
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• 2003

A single particle analytical technique, called low-Z electron probe X-ray microanalysis (low-Z EPMA) was applied to characterize atmospheric particles collected in Busan, Korea, over a daytime period in Dec. 2001. The ability to quantitatively analyze the low-Z elements, such as C, N, and 0, in microscopic volume enables the low-Z EPMA to specify the chemical composition of individual atmospheric particle. Various types of atmospheric particles such as organics, carbon-rich, aluminosilicates, silicon oxide, calcium carbonate, iron oxide, sodium chloride, sodium nitrate, ammonium sulfate, and titanium oxide were identified. In the sample collected in Busan, sodium nitrate particles produced as a result of the reaction between sea salt and nitrogen oxides in the atmosphere were most abundantly encountered both in the coarse and fine fractions. On the contrary, original sea salt particles were rarely observed. The fact that most of the carbonaceous particles were distributed in the fine fraction implies that their origin is anthropogenic.

• Journal of the Korean Applied Science and Technology
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• v.18 no.4
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• pp.249-253
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• 2001

A proposed method of determining the composition of mixed micelles in equilibrium with monomer of known composition is described. The systems were sodium ${\alpha}-sulfonated$ dodecanoyl ethyl esther (${\alpha}-SR_{12}Et$) or sodium dodecyl sulfate(SDS)-polyoxyethylene 23 lauryl ether (Brij 35) un water and in 0.1M sodium chloride solution at $25^{\circ}C$. This technique applies the Gibbs-Duhem equation to the mixed micelles, which is treated as a pseudophase. This proposed methodology, which needs only critical micelle concentration data as a function of monomer composition, is applied to an anionic/nonionic surfactant pair. The calculated monomer-micelle equilibrium is found to be very similar to the much-used regular solution for nonideal systems.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.3
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• pp.201-206
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• 1990

The optimal cultural conditions for production of the bluish purple prgment by the cultivation of Streptomyces californicus KS-89 were determined with various substrates. The carbon and nitrogen sources on the production of pigment indicated that soluble strarch and glycerol as carbon sources and sodium glutamate sodium nitrate as nitrogen sources given a mzimum yield of the pigment at 3$0^{\circ}C$ for 7 days. The addition of ferrous sulfate was essential. The highest production of pigment was observed with cultivation in a medium containing 2.0% soluble starch 1% glycerol 0.5% sodium glutamate 0.05% sodim nitrate 0.001% L-proline 0.025% K2HPO4 0.005% MgSO4 .7H2O, 0.04% FeSO4.7H2O, 0.001% thiamine.HCl and pH7.0.

• Journal of the Korean Society of Groundwater Environment
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• v.5 no.2
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• pp.66-79
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• 1998

This study purposes to elucidate the characteristics of local water quality and the evolutional process of the spring water have been studied with the samples from 55 selected springs, from the coast region to the Baegrogdam, a caldera lake of Halla mountain in Cheju Island. Results of hydrochemical analyses in the 55 spring water show that Gwaneumsa is pollued with high hydrogen concentration, and spring waters from Yusuarmchun, Jangsumul, Dukjisemmul, Sinch'onk'nmul, Youngchunsa, Woonyangchun, Harwontongmul, Dongheamul, Seakdalsengsu, Andukkyekok, Dotimul, Kinmul, Harkangmul and Jungkeummul are polluted by the pollution sources from the surface surrounding ground. Spring waters of Samyang3suwon, Meungbusa, Sernurungmul, Tosanmul, Jungkeummul, Kwakgimul, Aewolharmul, Konemul and Nokgomul are also polluted from the sea water intrusion. The electrical conductivity, pH and the concentration of nitrate nitrogen and bicarbonate increase when the precipitation increases, but the concentration of sodium, chloride and sulphate decrease when the precipitation increases. The concentrations of potassium, magnessium and calcium are nearly independent of the precipitaion. Quality characteristics of spring water show complicated group of spring water through piper's trilinear diagram. The high mountain region consists of groups of sodium or potassium type and bicarbonate type; the middle mountain region consists of groups of sodium or potassium type and no dominant type; the low mountain consists of groups of no dominant type and sulfate or nitrate type; the coast region consists of groups of sodium or potassium type and chloride type or no dominant type. These characteristics indicate that the spring waters are changed from bicarbonate type in the high and middle mountain regions into non-bicarbonate type in the coastal region, as the precipitated waters flow downslope.