• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3743-3748
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• 2013

A tetradentate ligand of 2-phenyl-4,6-di(pyridin-2-yl)pyrimidine (L) has been synthesized and its complexes with $ZnI_2$ and CuI have been obtained by hydrothermal method. single crystal X-ray diffraction analysis indicates that ligand L coordinates with Zn(II) ions to form a simple four-coordinate di-nuclear complex, while the complexation of L with Cu(I) constructs a one-dimensional chain polymer. The existence of $I^-$ ion hampers the L to assemble grid-type complexes with Zn(II) and Cu(I). Fluorescence spectra show that the L emits blue fluorescence while its Cu(I) polymer decrease the fluorescence intensity and Zn(II) complex quenches the fluorescence.

• Journal of Environmental Health Sciences
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• v.21 no.3
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• pp.77-86
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• 1995

Lead(II) removal efficiency by natural kaolinite was investigated through laboratory experiments. This study was conducted in two phases-sorption and desorption. In the adsorption study, the influence of sorption kinetics and sorption isotherm and various parameters such as pH, temperature, coexisting other heavy metal ions on the lead adsorption was investigated. And desorption study was carried out in order to find the re-usability of kaolinite as an adsorbent. The results of the study are as follows. 1. Sorption kinetics was investigated under the condition of 2.5 mg/l adsorbent concentration, pH 6.5$\pm$0.05, temperature $30\pm 0.5\circ$C, initial lead(II) concentration 25 mg/l. Adsorption rate was initially rapid and the extent of adsorption arrived at adsorption equilibrium with 73% adsorption efficiency in an hour. 2. The sorption isotherm experiment was made with different initial lead(II) concentration. A linearized Freundlich equation was used to fit the acquired experimental data. As a result, Freundlich constants, the sorption intensity (1/n) was 0.47 and the measure of sorption (k) was 2.44. So, it was concluded that sorption of lead(II) by kaolinite is effective. 3. The effect of pH on lead(II) sorption by kaolinite shows that at a pH of 3, only 6% of the total lead(II) was adsorbed and at a pH 9, 97% of the lead(II) was removed. And the effect of temperature on lead(II) sorption by kaolinite shows that as the temperature increased, the amount of lead(II) sorption per unit weight of kaolinite increased. But the effect was minor (p<0.05). 4. Sorption isotherm of lead coexisting cadmium (II) or zinc (II) was lower than that of lead itself. It was caused by the result of competitive sorption to adsorption site. And there was no difference between the sorption isotherm of cadmium and zinc. 5. In desorption studies, only 5.12% desorption took place in distilled water, while 52.08% in 0.1 N hydrochloric acid. Consequently used kaolinite could be regenerated by hydrochoric acid.

• Bulletin of the Korean Chemical Society
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• v.19 no.1
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• pp.135-137
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• 1998

• Nuclear Engineering and Technology
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• v.11 no.1
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• pp.47-54
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• 1979

A field experiment has been carried out to evaluate the residual effect of zinc fertilizers by rice plant grown under flooded conditions in the field. The results obtained are summarized as fellows ; Residual effect of zinc fertilizers on yields of rough and hulled grains showed slight increases. Effect of zinc application methods on yields of the grains were shown that zinc mixed treatment could be more effectively utilized than treatment of zinc on the soil surface. In case of levels of zinc application, 5 kg zinc per hectare represented high yields of the grains than those obtained from 10kg and 20kg zinc placement per hectare respectively. Regarding the form of zinc fertilizers, the urea-zinc complex showed less effective on yields of the grains than did the zinc sulfate. This phenomenon was consistent with the previous result. Yields of total zinc in rice plant grown on the rice straw added soils (Treatment No. 2 and 8) and the urea-zinc complex treated soil were increased markedly as compared to those data obtained from the previous year. The percentage of zinc derived from fertilizer decreased largely as compared to that of the first year crop. The yield of fertilizer zinc in rice plant decreased slightly in the most zinc treatments but in the case of treatments of zinc mixed with the straw added soil and the urea-zinc complex increased reversely as compared to the previous results. The mixed application of zinc with soil showed higher yield of fertilizer zinc than the soil surface placement. Approximately from 4.6 to 24.3 per cent of zinc taken up by rice plants were derived from the fertilizer zinc. Zinc fertilizer use efficiency ranged from 0.213 to 0.584 per cent when 5 kg zinc per hectare applied.

• Bulletin of the Korean Chemical Society
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• v.27 no.6
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• pp.918-920
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• 2006

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1743-1746
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• 2010

• Journal of the Korean Geotechnical Society
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• v.16 no.4
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• pp.157-170
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• 2000

In this study, we conducted a combined adsorption-sequential extraction analysis(CASA) to investigate temperature effects of single and competitive adsorption of zinc and copper on natural clays. As a result, it was found out that in a single adsorption of zinc, the adsorption was mostly in the exchangeable phase, with increase n temperature. In a competitive adsorption of zinc, this trend was so strong that the exchangeable phase adsorption increase up to 80~90%. On the other hand, about 50% of copper was adsorbed in the carbonate occluded phase in single and competitive adsorptions. In the single adsorption the adsorption of carbonate occluded phase increased by 5% with the temperature increase and in the competitive adsorption the increase rate is about twice. The adsorption of zinc and copper on natural clays is an endothermic reaction with the exception of exchangeable phase adsorption.

• Analytical Science and Technology
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• v.6 no.1
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• pp.131-139
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• 1993

The separation of gallium and indium from the matrix elements such as zinc and other ions, especially form Fe(III) ion was studied for the determination of trace level of them in zinc ores and zinc blendes by inductively coupled plasma atomic emission spectrometry(ICP-AES). Gallium and indium were extracted from the sample solution with a solvent of tributyl phosphate(TBP). The type and concentration of acid, interferences of other ions, the ratio of aqueous phase to organic phase, TBP concentration, sripping efficiency were optimized for the effective extraction. Gallium and indium were separated from other ions in the 5N hydrochloric acid solution of the samples by the extraction with 100% TBP. In this time, Fe(III) was reduced to Fe(II) with hydroxylamine hydrochloride to prevent its coextraction prior to the main extraxtion. After stripped from organic phase by the back-extraction with 0.02N HCl, they were determined in the aqueous phase by ICP-AES. This method was known to be quantitative from the overall extraction of more than 95%.

• Journal of Microbiology and Biotechnology
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• v.18 no.3
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• pp.483-489
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• 2008

Nine newly isolated mushroom strains were tested to assess both their zinc tolerance and potential for zinc removal from an aqueous solution. Four strains of ectomycorrhizal fungi, namely Clavariadelphus truncatus (T 192), Rhizopogon roseolus (T 21), Lepista nuda (T 373), and Tricholoma equestre (T 174), along with five strains of white rot fungi, Lenzites betulina (S 2), Trametes hirsuta (T 587), Ganoderma spp. (T 99), Polyporus arcularius (T 438), and Ganoderma carnosum (M 88), were investigated using zinc-amended solid and liquid media. Their biosorption properties were also determined. The colony diameter and dry weight were used as tolerance indices for fungal growth. C. truncatus and T. equestre were not strongly inhibited at the highest concentrations of (225 mg/l) zinc in solid media. The most tolerant four strains with solid media, C. truncatus, G carnosum, T. hirsuta, and T. equestre, were then chosen for tolerance tests in liquid media. An ectomycorrhizal strain, C. truncatus, was also detected as the most tolerant strain in liquid media. However, the metal-tolerant strains demonstrated weak activity in the biosorption studies. In contrast, the highest biosorption activity was presented by a more sensitive strain, G. carnosum. In addition, seven different biosorbent types from G. carnosum (M 88) were compared for their Zn (II) biosorption in batch experiments.

• Journal of Oriental Neuropsychiatry
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• v.3 no.1
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• pp.56-59
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• 1992

The zinc, copper and chromium contents in the hair in 103 healthy Korean and 126 Korean with schizophrenic(aged 20 to 59 years in Yanbian district)by atomic absorbtion spectrometer(Type WFZ-II). Research Period : from May 1985 to September 1986. The zinc, copper and chromium contents in the schizophrenic hair are significantly lower than those of healthy persons, respectively. The standard rates of discriminant from healthy persons and the patients by method of (Department of Pathophysiology, Yanbian Medical Colloge ; Yanbian Neuropsychosis Hospital, Yanji Jilin Prov, P.R. China) Fisher discrominant analysis are 72.9% and 84.4%, respectively. The rates of the contribution of the target for the functional equation of zinc, copper chromium are 12.3%, 5.9% and 81.8%, respectively. Zinc contents in hair of male patients are significantly higher than those of female patients ; copper contents in hair of the female are sign