• Bulletin of the Korean Chemical Society
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• v.16 no.5
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• pp.454-458
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• 1995

Inhibiting action of semicarbazide, thiosemicarbazide, sym. diphenylcarbazide towards corrosion of zinc in hydrochloric acid has been investigated. The rate of corrosion depends on the nature of the inhibitor and its concentration. The values of inhibition efficiency from, weight loss, thermometric measurements are in good agreement with those obtained from polarization studies. From the polarization studies, the inhibitors used act as mixed absorption type inhibitors, increased adsorption resulting from an increase in the electron density at the reactive C=S and C=O groups and N-atoms. The thermodynamic parameters of adsorption obtained using Bockris-Swinkels adsorption isotherm reveal a strong interaction of these carbazides on zinc surface.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.166-166
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• 2012

We examined the distribution of Co ions of ferromagnetic n-type Zn(1-x)Co(x)O semiconducting films with the Co concentrations of 0.03~0.07 using x-ray absorption fine structure (XAFS) measurements at the Co and Zn K edges. Extended XAFS (EXAFS) revealed that Co ions mainly occupied the zinc sites of the films. X-ray absorption near edge structure (XANES) spectra demonstrated that the pre-edge peak of the Co K edge was substantially affected by the second neighboring Co ions at the zinc sites due to hybridizing of the Co 4p conduction electrons with the Co 3d bounded electrons. From XANES and EXAFS analysis using ab initio calculations, we found that Co ions uniformly occupied the zinc sites of the Zn (0.93) Co (0.07)O film, whereas the Co ions of the Zn (0.97) Co (0.03)O and Zn (0.95) Co (0.05)O films were substituted at localized zinc sites. The ferromagnetic properties of the Zn (0.93) Co(0.07)O film could be induced by direct interaction between the magnetic dipoles of the Co ions with a mean distance of 4.3 A or by Co 4p electron mediation.

• Bulletin of the Korean Chemical Society
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• v.24 no.10
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• pp.1490-1494
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• 2003

Noncovalently linked electron donor-acceptor dyad consisting of zinc tetratolylporphyrin and pyridine appended ruthenium trisbipyridine comlex was prepared, via axial coordination of pyridine moiety in ruthenium trisbipyridine complex on zinc tetratolylporphyrin. For the purpose of comparison, axial coordination of pyridine-appended 2,2'-bipyridine on zinc tetratolylporphyrin was also investigated. The Kvalues were detemined based on absorption of fluorescence studies. The fluorescence of zinc teratolylporphrin was efficiently quenched upon axial coordination of pyridine moiety, prbably due to the photoinduced electron transfer from zinc tetrtolylporphyrin to ruthenium trisbipyridine, supported by free enegy estimation.

• Journal of Preventive Medicine and Public Health
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• v.19 no.1 s.19
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• pp.76-84
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• 1986

Analyses of lead and zinc were made by means of standard addition method using atomic absorption spectrophotometer(Baird Ltd., Model A5100) with flameless method for lead and flame method for zinc. The blood samples used were merely diluted with triton x-100, because it was simple, rapid and minimal risk of contamination. Mean recovery rate for lead added to the blood ranged from 97.7 to 101.3% with coefficient of variation ranging from 1.9 to 10.7%, and that for the added zinc ranged from 99.0 to 102.2% with coefficient of variation ranging from 2.1 to 9.1%. In repeated measurements of zinc in the blood, good reproducibility and interindividual variation were proved(p<0.01). In comparison of the lead and zinc concentrations in the blood determined by the standard addition method and standard method, there were good correlations between 2 sets of data (r=0.9731 for lead and r=0.9785 for zinc), although lead levels were estimated higher by the former method(p<0.01) and zinc levels by the latter method(p<0.01). It can be concluded that lead and zinc levels in blood standard addition method is reliable for determination of lead and zinc in the blood with good accuracy and reproducibility.

• Bulletin of the Korean Chemical Society
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• v.29 no.7
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• pp.1353-1358
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• 2008

Benzyl arylether dendrimers with zinc porphyrin core and terminal vinyl groups have been synthesized and their photophysical properties and the influence of dendritic environments were investigated. Free base porphyrin-cored benzyl arylether dendrimers 1a-1c and 3a-3c, and their zinc derivatives 2a-2c and 4a-4c have been prepared. Absorption spectra are similar for all porphyrin-cored benzyl arylether dendrimers, except that absorption intensity at 280 nm increases in the higher generation of dendrimer. Fluorescence spectra are similar with two bands for all free base porphyrin dendrimers 1a-1c and 3a-3c, although fluorescence intensity ratio of shorter wavelength emission band to longer wavelength band varies with the generation of dendrimer. Emission efficiencies of 1a-1c and 3a-3c are lower than that of TTP. Emission efficiencies of 2a-2c and 4a-4c are higher than that of ZnTTP. Absorption and emission properties of 1a-1c, 2a-2c, 3a-3c, and 4a-4c were affected negligibly with dendritic environments.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10c
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• pp.139-144
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• 1998

This study is intended to devolop the self waterproof agents for high performance concrete by analyzing the properties of fresh and hardened mortar with various addition ratios of the inorganic admixture and zinc stearate. As the results of the test, the flow and air content increase with the addition of expansive additives. When the replacement rate of silica fume increases, the flow decreases for the increased viscidity. And the flow and sir content decrease with the addition of zinc stearate. At hardened state, the compressive strength, tensile strength and flexual strength decrease with the addition of expansive additives and zinc stearate. With the increase of silica fume's replacement, they show a little decrease at early age and then increase gradually. Also, absorption and permeability show a steep decrease when zinc stearate is added, and a slack decrease with the replacement of silica fume.

• Journal of Preventive Medicine and Public Health
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• v.22 no.4 s.28
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• pp.486-494
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• 1989

Lead, iron, and zinc concentrations in whole blood were determined by atomic absorption spectrophotometry, using a simple one-step dilution procedure, which were measured in 3 groups, 98 officers unexposed to dust or to metal, 58 coal miners without pneumoconiosis, and 113 coal workers' pneumoconiosis (CWP) patients. The results were as follows : 1. The precisions (C. V.%) of lead, iron, and zinc in blood were $12.65{\pm}6.95%,\;1.47{\pm}1.25%\;and\;6.35{\pm}3.34%$, respectively. 2. Lead and zinc in blood showed the log-normal distribution unlike iron in blood which showed normal distribution. 3. Lead, iron, and zinc concentrations in blood of 3 groups were follows : There was significant difference of concentration for zinc in blood by groups statistically. 4. The difference of lead, iron, and zinc concentrations in blood was not significant (p>0.05) by profusion on chest radiographs.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1649-1651
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• 2000

Optical properties of $Cd_{1-x}Zn_{x}S$ films deposited by :chemical bath deposition(CBD), which is a very attractive method for low-cost and large-area solar cells, are presented, Especially, in order to control more effectively the zinc component of the films, zinc acetate, which used as the zinc source, mixed in reaction solution after preheating and the pH of the reaction solution decreased with increasing the concentration of zinc acetate. The films prepared after preheating and pH control had larger zinc component and higher optical band gap. As the more zinc substituted for Cd in the films, the optical transmittance improved, while the absorption edge shifts to a shorter wavelength and the optical band gap increased. The photo conductivity of the films was larger than the dark conductivity, while the ratio of those increased with increasing the mole ratio of zinc acetate.

• Journal of Ginseng Research
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• v.46 no.2
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• pp.248-254
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• 2022

Background: Zinc homeostasis is essential for human health and is regulated by several zinc transporters including ZIP and ZnT. ZIP4 is expressed in the small intestine and is important for zinc absorption from the diet. We investigated in the present study the effects of Panax ginseng (P. ginseng) extract on modulating Zip4 expression and cellular zinc levels in mouse Hepa cells. Methods: Hepa cells were transfected with a luciferase reporter plasmid that contains metal-responsive elements, incubated with P. ginseng extract, and luciferase activity was measured. Using ⁶⁵ZnCl₂, zinc uptake in P. ginseng-treated cells was measured. The expression of Zip4 mRNA and protein in Hepa cells was also investigated. Finally, using a luciferase reporter assay system, the effects of several ginsenosides were monitored. Results: The luciferase activity in cells incubated with P. ginseng extract was significantly higher than that of control cells cultured in normal medium. Hepa cells treated with P. ginseng extract exhibited higher zinc uptake. P. ginseng extract induced Zip4 mRNA expression, which resulted in an enhancement of Zip4 protein expression. Furthermore, some ginsenosides, such as ginsenoside Rc and Re, enhanced luciferase activity driven by intracellular zinc levels. Conclusion: P. ginseng extract induced Zip4 expression at the mRNA and protein level and resulted in higher zinc uptake in Hepa cells. Some ginsenosides facilitated zinc influx. On the basis of these results, we suggest a novel effect of P. ginseng on Zip4-mediated zinc influx, which may provide a new strategy for preventing zinc deficiency.

• Journal of Animal Science and Technology
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• v.58 no.5
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• pp.21.1-21.8
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• 2016

Background: The aim of the present study was to determine the effects of feeding trace mineralsfortified mixed microbial culture (TMC) on ruminal fermentation, nutrient digestibility, blood electrolyte status, nitrogen balance, and trace mineral balance in sheep. Methods: Mixed microbes [0.6 % (v/w) of Enterobacter sp., Bacillus sp., Lactobacillus sp., and Saccharomyces sp.] were cultured with 99 % feedstuffs and 0.4 % trace minerals including zinc and copper for ensiling. Six sheep (a mean body weight of $46.5{\pm}1.2kg$) were fed two diets: a control diet (concentrate mix and rye straw) and an experimental diet (a control diet + 3.1 % TMC). Results: TMC feeding did not induce negative effects on ruminal fermentation, nutrient digestibility, blood electrolytes, and nitrogen balance in sheep. Feeding with TMC increased the intake of trace minerals (p < 0.05) and did not affect absorption of trace minerals in the whole digestive tract. Feeding with TMC increased fecal excretion and absorbable intake, and retention of zinc and copper (p < 0.05) by 71 % and 77 %, respectively. Conclusion: Feeding with TMC resulted in higher zinc and copper bioavailability and retention without any adverse effects on sheep performance.