• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.1873-1875
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• 2005

The effect of zinc oxide as an inhibitor for the corrosion of steel in concrete environment was studied by weight loss measurements, potential-time behaviour and anodic polarization technique. The salient features of the investigation were: in 100% OPC extracts, the passivity of steel was readily destroyed, however extracts containing various concentration of zinc oxide, the passivity of steel was maintained even in the presence of 30,000 ppm of chloride. Alkalinity of concrete was maintained by the addition of zinc oxide. The efficiency of the inhibitor was found to increase with increasing inhibitor concentration. Addition of zinc oxide in the range 3 to 4% by weight of cement was sufficient to protect the rebars.

• YAKHAK HOEJI
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• v.40 no.6
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• pp.659-665
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• 1996

Zinc white is mainly used as a mild astringent, protectant. and has weak antiseptic action. It is well known that the yield of zinc white produced is greatly affected by the syn thetic conditions such as the reactant concentration, reaction temperature, washing water temperature, mole ratio of reactants, and drying temperature, calcination temperature, etc. The purpose of this study is to investigate the optimal synthesis conditions of zinc white produced. A randomized complete block design suggested by G.E.P. Box and K.B. Wilson was applied for this purpose. Basic zinc carbonate was prepared by reacting zinc sulfate and sod. carbonate solution in this study. Zinc white comes when prepared by calcination of basic zinc carbonate. The optimum synthesis conditions of zinc white obtained from this study is as follows: 1) The reacting temperature range is: 92-100$^{\circ}C$, 2) The concentration of reactant solution is 23.6-27%, 3) The optimum mole-ratio: [ZnSO4]/[Na2CO3] is 1.74~1.96, 4) The washing water temperature is 36$^{\circ}C$, 5) The drying temperature range is 68-74$^{\circ}C$, 6) The calcination temperature is 600$^{\circ}C$. The outcome of DSC indicated a desolvation of basic zinc carbonate occurred at about 133.3$^{\circ}C$. The dehydration of the compound ceased at about 267.9$^{\circ}C$ and the decarboxylation ceased at about 379.9$^{\circ}C$. The physical and chemical properties of zinc white as medicine were studied by use of Volume Test.

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.61-65
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• 2003

Zinc occurs in the nature as sulfide, carbonate, silicate, and oxide. In natural water, zinc is generally in the form of the divalent cation $Zn^{2+}$ as well as in the form of fairly weakly bound complexes. Human activities introduce zinc ion to the hydrosphere in many ways. The zinc complexes in the aqueous environment are accumulated not only in aquatic organisms but also in human body ultimately through physico-chemical and/or biological processes. (omitted)

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.30 no.4
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• pp.136-142
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• 2020

Crystallization of zinc crystalline glaze requires demanding conditions such as the formation of a nucleating agent and the amount of nucleating agent, and growth of crystalline. Zinc crystalline glaze is hard to utilize in the industry because of its narrow range of the firing temperature, and the crystallization's dependency on the quality of zinc. Stimulation of zinc crystallization and formation of frit enable zinc crystalline glaze to be reconstituted in a various range of firing schedules, leading to the development of a competitive industrial glaze.

• Journal of Nutrition and Health
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• v.26 no.3
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• pp.347-356
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• 1993

Plasma concentrations of zinc and copper were measured in 59 non-pregnant women and 105 pregnant women(12 ; early pregant, 93 ; late pregnant) to estimate and compare both groups and to detect the effects of iron supplementation on the plasma zinc and copper concentrations in the pregant women. The mean plasma zinc concentration of the early pregnant group was not significantly different with those of the non-pregnant group. But in contrast, the mean plasma zinc concentration of the late pregnant group was significantly lower than those of the non-pregnant and early pregnant group. Mean plasma copper concentration were significantly elevated in ealry pregnant group and doubled in late pregnant compared to non-pregnant. In Fe supplemented group, mean plasma zinc concentrations were lower and mean plasma copper higher than those of Fe non-supplemented group. It appeared that Fe supplementation had effects on the decrease of plasma zinc concentrations in pregnancy.

• Korean Journal of Materials Research
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• v.26 no.1
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• pp.42-46
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• 2016

The properties of zinc oxynitride semiconductors and their associated thin film transistors are studied. Reactively sputtered zinc oxynitride films exhibit n-type conduction, and nitrogen-rich compositions result in relatively high electron mobility. Nitrogen vacancies are anticipated to act as shallow electron donors, as their calculated formation energy is lowest among the possible types of point defects. The carrier density can be reduced by substituting zinc with metals such as gallium or aluminum, which form stronger bonds with nitrogen than zinc does. The electrical properties of gallium-doped zinc oxynitride thin films and their respective devices demonstrate the carrier suppression effect accordingly.

• Korean Journal of Veterinary Research
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• v.25 no.2
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• pp.145-148
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• 1985

Nickel toxicity and interactions of nickel with zinc, copper, and lead were studied in glowing chicks fed supplemented diet. Feed intake and growth rate of the chick were reduced by 250mg nickel as a sulfate salt per kg of feed. The toxicity of nickel was decreased by zinc or copper supplementation, but not lead. High nickel feed increased nickel level in kidney and decreased zinc levels in tibia and plasma. However, low zinc levels in tibia and in plasma were reversed by zinc supplementation. Hemoglobin, packed cell volume, and aortic elastin content were increased in chicks fed nickel. These results suggest that nickel toxicity is induced by interference with zinc metabolism.

• Toxicological Research
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• v.16 no.3
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• pp.179-185
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• 2000

Zinc is known to generate reactive oxygen species (ROS) including superoxide anion and hydrogen peroxide ($H_2O_2$), which eventually contribute to cytotoxicity in a variety of cell types. Here in, we demonstrated that zinc decreased the viability of C6 glial cells in a time and dose-dependent manner, which was revealed as apoptosis characterized by ladder-pattern fragmentation of genomic DNA. chromatin condensation and DNA fragmentation in Hoechst dye staining. Zinc-induced apoptosis of C6 glial cells was prevented by the addition of catalase and antioxidants including reduced glutathione (GSH), N-acetyl-L-cysteine (NAC) and pyrrolidinedithiocarbamate (PDTC). Wefurther confirmed that zinc decreased intrac-ellular levels of GSH and generated $H_2O_2$in C6 glial cells. Moreover, antioxidants also decreased the generation of zinc-induced $H_2O_2$ in C6 glial cells. These data indicated that zinc-induced the apoptotic death of C6 glial cells via generation of reactive oxygen species such as $H_2O_2$.

• Corrosion Science and Technology
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• v.9 no.5
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• pp.175-186
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• 2010

The auto industry is demanding more ductile high-strength steel grades to build lighter and stronger car bodies. The hot-dip galvanizing problems of these new steel grades are creating a demand for an improved method to control zinc wettability. The simplest way to improve zinc wettability on industrial hot-dip galvanizing lines is to increase the strip immersion temperature at zinc bath entry for enhancing the aluminothermic reaction. However, this practice increases the reactivity due to overheating the zinc in the snout which induces the formation of brittle Fe-Zn compounds at the strip/coating interface with the formation of higher amounts of dross in the zinc bath and snout contamination. Thus, this simple practice can only be utilized for short production periods of one to two hours without deteriorating coating quality. This problem has been solved by employing a technique that allows the use of a higher and attuned strip immersion temperature at zinc bath entry while still maintaining a constantly low zinc bath temperature. This has been proven to provide the solution for both the improved wettability and a significant reduction in the amounts of dross in the zinc bath.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.3
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• pp.195-200
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• 2009

Zinc released from excited glutamatergic neurons accelerates amyloid ${\beta}$ (A ${\beta}$) aggregation, underscoring the therapeutic potential of zinc chelation for the treatment of Alzheimer's disease (AD). Zinc can also alter A ${\beta}$ concentration by affecting its degradation. In order to elucidate the possible role of zinc influx in secretase-processed A ${\beta}$ production, SH-SY5Y cells stably expressing amyloid precursor protein (APP) were treated with pyrrolidine dithiocarbamate (PDTC), a zinc ionophore, and the resultant changes in APP processing were examined. PDTC decreased A ${\beta}$ 40 and A ${\beta}$ 42 concentrations in culture media bathing APP-expressing SH-SY5Y cells. Measuring the levels of a series of C-terminal APP fragments generated by enzymatic cutting at different APP-cleavage sites showed that both ${\beta}$-and ${\alpha}$-cleavage of APP were inhibited by zinc influx. PDTC also interfered with the maturation of APP. PDTC, however, paradoxically increased the intracellular levels of A ${\beta}$ 40. These results indicate that inhibition of secretase-mediated APP cleavage accounts -at least in part- for zinc inhibition of A ${\beta}$ secretion.