• KSBB Journal
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• v.27 no.1
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• pp.28-32
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• 2012

In this study, the treatment ability of the wastewater containing perchlorate by non-salt tolerant perchlorate reducing bacterial consortium (N-PRBC) was evaluated in a continuous stirred tank bioreactor (CSTR). To obtain the optimal operating condition the bioreactor was operated with the different wastewater empty bed retention time (EBRT). The treatment performance in the bioreactor could be maintained at 100 $mg-ClO_4{^-}L^{-1}$ up to a EBRT of 3 h, and the removal capacity in the CSTR was about 3.3 times higher than that in a batch operation. With a decrease from 9 h to 2 h in a EBRT, the volumetric perchlorate reduction rate was increased from 11.1 $mg-ClO_4{^-}L^{-1}h^{-1}$ to 50.0 $mg-ClO_4{^-}L^{-1}h^{-1}$, and the specific perchlorate reduction rates were increased from 3.01 $mg-ClO_4{^-}g-DCW^{-1}h^{-1}$. In conclusion, the treatment capacities in a CSTR were much better than those obtained in a batch operation.

• Bulletin of the Korean Chemical Society
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• v.10 no.1
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• pp.102-103
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• 1989

Four coordinated rhodium(Ⅰ) complexes, Rh($ClO_4$)(CO)$(PPh_3)_2$ and [$Rh(CO)(PPh_3)_3$]$ClO_4$(2) catalyze the iosmerization of allylic alcohols to the corresponding carbonyl compounds at room temperature under nitrogen. The isomerization is faster with 2 than with 1, which is understood in terms of relative ease of the last step of the catalytic cycle, the reductive elimination of enol. Relative rates of the isomerization with 1 and 2 for different allylic alcohols are also explained by the relative ease of the enol elimination step in part. The first step of the catalytic cycle, the complex formation of the allylic alcohol through the ${\pi}-system$ of the olefinic group of the allylic alcohol and the following step, formation of hydridoallyl complex also seem to affect the overall rate of the isomerization.

• Journal of Applied Biological Chemistry
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• v.50 no.4
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• pp.239-243
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• 2007

Effects of aqueous chlorine dioxide ($ClO_2$) treatment on the microbial growth and the quality of iceberg lettuce during storage were examined. Lettuce samples were treated with 0, 5, 10, and 50 ppm of $ClO_2$ solution and stored at $4^{\circ}C$. Aqueous $ClO_2$ treatment significantly decreased the populations of total aerobic bacteria, yeasts and molds, and coliforms on the shredded lettuce. Fifty ppm $ClO_2$ treatment reduced the initial populations of total aerobic bacteria, yeasts and molds, and coliforms by 1.77, 1.34, 1.10 log CFU/g, respectively. Aqueous $ClO_2$ treatment caused negligible changes in the Hunter color L, a, and b values during storage. Sensory evaluations exhibited that there were no significant changes among treatments. These results indicate that the aqueous $ClO_2$ treatment can be useful in improving the microbial safety of the iceberg lettuce during storage and extending the shelf life.

• Food Science and Biotechnology
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• v.17 no.4
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• pp.878-882
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• 2008

The efficacy of citric acid-aqueous chlorine dioxide ($ClO_2$) treatment of radish seeds artificially contaminated with Escherichia coli was studied. Radish seeds were inoculated with E. coli. Following inoculation, samples were stored at $4^{\circ}C$ and soaked in citric acid or aqueous $ClO_2$ for 10 min. The treatment of radish seeds using 200 ppm aqueous $ClO_2$ solution caused a 1.5 log CFU/g reduction in the population of E. coli. Compared to the aqueous $ClO_2$ treatment, soaking radish seeds in 2.0% citric acid solution for 10 min was more effective in reducing E. coli populations on radish seeds. The efficacy of spray application of chlorine (100 ppm) or 0.5% citric acid to eliminate E. coli during the germination and growth of radish was investigated. Radish seed inoculated with E. coli was treated for the duration of the growth period. Although it resulted in a decrease in the E. coli population, the spray application of 100 ppm chlorine during the growth period was not significantly effective. In contrast, the combined treatment of seeds using 200 ppm aqueous $ClO_2$ and treatment of sprouts with 0.5% citric acid solution during sprout growth was hardly effective in eliminating E. coli.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3233-3238
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• 2013

Two new Cu(II) complexes, $[Cu_2(acpy-mdtc)_2(HBA)(ClO_4)]{\cdot}H_2O$ (1) (acpy-mdtc- = 2-acetylpyridine S-methyldithiocarbamate and $HBA^-$ = benzilic acid anion) and $[Cu_2(acpy-phtsc)_2(HBA)]{\cdot}ClO_4$ (2) (acpy-$phtsc^-$ = 2-acetylpyridine 4-phenyl-3-thiosemicarbazate) have been synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, and single crystal X-ray diffraction. The X-ray analysis reveals that the structures of 1 and 2 are dinuclear copper(II) complexes bridged by two thiolate sulfur atoms of Schiff base ligand and bidentate bridging $HBA^-$ anion. For 1, each of the two copper atoms has different coordination environments. Cu1 adopts a five-coordinate square-pyramidal with a $N_2OS_2$ donor, while Cu2 exhibits a distorted octahedral geometry in a $N_2O_2S_2$ manner. For 2, two Cu(II) ions all have a five-coordinate square-pyramidal with a $N_2OS_2$ donor. In each complex, the Schiff base ligand is coordinated to copper ions as a tridentate thiol mode.

• Journal of Environmental Health Sciences
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• v.22 no.1
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• pp.91-98
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• 1996

산업장이나 생활환경에서 접하기 쉬운 수용성 염화물을 중심으로 19개 원소 24종의 금속화합물이 Chinese Hamster Don 세포에 있어서의 sister chromatid exchange(SCE) 출현빈도에 미치는 영향을 조사하였다. Chinese Hamster Don 세포에 대한 자매염색분체 교환출현빈도의 증가가 $CrO_3, K_2CrO_4, K_2Cr_2O_7, MnCl_2, K_2SeO_3, CH_3HgCl$ (p<0.01), $CoCl_2, Na_2HAsO_4, HgCl_2$ (p<0.05) 9종의 금속화합물에서 나타났으며, dose-response relationships이 현저한 금속화합물은 6가 크로화합물과 $K_2SeO_3$이었다.

• Korean journal of food and cookery science
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• v.24 no.4
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• pp.445-451
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• 2008

This study compared the effects of chlorine dioxide and a commercial chlorine sanitizer for inhibiting foodborne pathogens, including Salmonella enterica serovar Typhimurium, Listeria monocytogenes, and Escherichia coli O157 : H7, on lettuce leaves. The lettuce samples were inoculated with each cocktail of the three strains, and were then treated with chemical sanitizers [distilled water, 100 ppm commercial chlorine and 50 ppm, 100 ppm, 200 ppm chlorine dioxide ($ClO_2$)] for 1 min, 5 min, and 10 min at room temperature($22{\pm}2^{\circ}C$). Following inoculation of the leaves, initial populations of E. coli O157:H7, L. monocytogenes, and S. Typhimurium were approximately 5.54, 4.47, and 5.12 log CFU/g, respectively these levels were not significantly reduced by the treatment with water,whereas the 100 ppm commercial chlorine sanitizer treatment and $ClO_2$ (at all tested concentrations) were effective at reducing levels of all three pathogens. The treatment of 200 ppm $ClO_2$ for 10 min was most effective at inhibiting the three pathogens, and reduction levels of E. coli O157 : H7, L. monocytogenes, and S. Typhimurium were 2.28, 1.95, 1.76 log, respectively. The inhibitory effect of $ClO_2$ increased with increasing treatment concentration of $ClO_2$, but there was no significant difference by the treatment times. When chemically injured cells of E. coli O157 : H7 and L. monocytogenes and S. Typhimurium were examined by SPRAB and selective overlay methods, respectively, it was observed that the commercial chlorine sanitizer generated greater numbers of injured L. monocytogenes than the $ClO_2$ treatment. From the overall results, $ClO_2$ was more effective at inhibiting pathogenic bacteria compared to the commercial chlorine sanitizer therefore, it has potential to be utilized as an alternative sanitizer to increase the microbial safety of fresh produce.

• Bulletin of the Korean Chemical Society
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• v.33 no.1
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• pp.204-208
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• 2012

A novel chemiluminescence (CL) flow injection method for the determination of balofloxacin is described. The method is based on the weak CL signal arising from the reaction of $KBrO_3$ with $Na_2S_2O_4$ in acidic medium being significantly enhanced by balofloxacin in the presence of europium (III) ion and sodium dodecyl benzene sulfonate (SDBS). The experimental conditions that affected CL intensity were carefully optimized and the CL reaction mechanism was briefly discussed. Under the optimum conditions, the relative CL intensity was proportional to the concentration of balofloxacin in the range of $7.0{\times}10^{-11}$ to $3.0{\times}10^{-7}g\;mL^{-1}$. The detection limit was $2.7{\times}10^{-11}g\;mL^{-1}$ and the relative standard deviation was 2.1% for $7.0{\times}10^{-10}g\;mL^{-1}$ balofloxacin (n = 13). The proposed method was successfully applied to the determination of balofloxacin in pharmaceutical formulations and biological fluids.

• Journal of the Korean Magnetic Resonance Society
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• v.23 no.2
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• pp.40-45
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• 2019

The phase transition temperatures and thermodynamic properties of $(NH_4)_2MnCl_4{\cdot}2H_2O$ grown by the slow evaporation method were studied using differential scanning calorimetry and thermogravimetric analysis. A structural phase transition occurred at temperature $T_{C1}$ (=264 K), whereas the changes at $T_{C2}$ (=460 K) and $T_{C3}$ (=475 K) seemed to be chemical changes caused by thermal decomposition. In addition, the chemical shift and the spin-lattice relaxation time $T_{1{\rho}}$ were investigated using $^1H$ magic-angle spinning nuclear magnetic resonance (MAS NMR), in order to understand the role of $NH_4{^+}$ and $H_2O$. The rise in $T_{1{\rho}}$ with temperature was related to variations in the symmetry of the surrounding $H_2O$ and $NH_4{^+}$.

• Journal of the Korean Ceramic Society
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• v.28 no.3
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• pp.225-233
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• 1991

In this study, we tried to find out the appropriate synthetic condition and magnetic properties of Ni-Zn ferrite {(NixZn1-x)Fe2O4} powders (where X=0, 0.1, 0.2, 0.3, ……0.9, 1). Ferrite powders were prepared by wet-direct method at 86℃ for 6hrs from FeCl36H2O, NiCl26H2O, and ZnCl2. The powders of (NixZn1-x)Fe2O4 (where X=0.4, 0.5, 0.6) have a good crystallinity, but the other ferrite powders consist of crystal and precursor ferrite. The ferrite powder's lattice constant is increased when ratio of ZnO contant is increased in the ferrite composition. And initial permeability was measured after sintering, result indicated regular pattern except (Ni0.4Zn0.6)Fe2O4 when the frequency were changed 10KHz to 10MHz.