Papers by Keyword: Zinc

Abstract: Taking plateau red soil as research object, using the ultrasonic-assisted organic acid extraction the heavy metal zinc in it, and analyze the form of zinc. Results showed that the extraction rate can reach 68%, with the increase of time, the extraction effect of zinc is obviously enhanced in this method. Ultrasonic-assisted citric acid extraction soil can increase the extraction rate of exchangeable, bound to carbonates and bound to iron and manganese oxides relatively.

Abstract: This paper describes the fabrication, characterization and application of an environment-friendly tin film/gold nanoparticles (Sn/AuNPs) modified gold microelectrode for square wave stripping voltammetric (SWSV) determination of copper, lead and zinc. The microelectrode chips were fabricated by Micro Electro-Mechanical System (MEMS) technique. The sensitivity of the modified microelectrode was largely improved due to the large surface area of AuNPs and the formation of alloys between target metals and Sn. The influence of hydrogen overflow was reduced and the current response was enhanced because AuNPs made the stripping potential shift positively and Sn extended the stripping potential range. Combining AuNPs with Sn, the obtained microelectrode exhibited satisfied linearity ranges from 5 to 500 μg L-1 for copper and lead, from 10 to 500 μg L-1 for zinc, with a limit of detection of 2 μg L-1 for copper, 3 μg L-1 for lead and 5 μg L-1 for zinc. The Sn/AuNPs/gold microelectrode was successfully applied for simultaneous detection of copper, lead and zinc in tap water sample.

Abstract: A new solid phase extractant silica aerogel immobilized with Cyanex 301 {bis (2,4,4-trimethylpentyl) dithiophosphinic acid} (SAWC) was prepared via a sol-gel method and investigated for the extraction of Zn (II) from aqueous solution by a batch extraction technique. It is found that SAWC can extract about 100% zinc at equilibrium pH 1.7. Prepared SAWC was characterized by FT-IR, BET, EDX and SEM which proved the presence of Cyanex 301 into silica aerogel. Moreover, the material is also easily regenerated and reused in the subsequent removal of Zn (II) in five cycles. Therefore, it could be concluded that it may perform as a solid phase extractant in the extraction of metal ions from the aqueous solution.

Abstract: Typical as-cast microstructure of the MgZnRE-Zr alloys consists primarily of Mg matrix, MgZn and MgRE phases. Although the electrical conductivity was a slightly reduced by Ce-rich RE addition, the conductivity was remained high. Microhardness at room temperature and tensile strength at 200°C were clearly enhanced by the addition. Fluidity as mold filling ability was observed to increase significantly with the RE addition partly due to reduced grain size and solidification range, however the corrosion resistance predicted from polarization curves was little decreased.

Abstract: Layered double hydroxide (LDH) hybrid materials of Zn-Al-layered double hydroxide-3,4-dichlorophenoxy acetate acidnanocomposites (ZADs) were prepared by direct self-assembly method. The pH of the solution was adjusted to 7.5 using 2M NaOH. Various Zn2+ to Al3+ molar ratios, R ranging from 1 to 6 were used with a fixed concentration of 3,4-D at 0.3 M. The Powder X-ray diffraction (PXRD) patterns showed the formation of well-ordered nanocomposite with the expansion of basal spacing from 8.9 Å in the Zinc-Aluminium-Layered Double Hydroxide (ZAL) to 18.7 - 22.1 Å in the resulting nanocomposites. The Fourier transform infrared (FTIR)spectra for the nanocomposites showed features for both ZAL and ZAD, showing the successful intercalation of the organic moiety into the LDH interlayer. The percentage loading of 3,4-dichlorophenoxy acetati acid(3,4-D) in LDH was found to be increased from 34.7-48.1 % (w/w), as the mole fraction of Al decreased from 0.44-0.15. This study shows that the mole fraction of zinc ion was replaced by aluminium ion in the LDH plays an important role in controlling the physic-chemical properties of the resulting material.

Abstract: Experimental study of twin wire arc sprayed Zn/Al coating on low carbon steel substrate has been undertaken in the present paper. The spray distances have a pronounced effect on the coating microstructure and it’s resistance against corrosion. Structural and surface morphological analyses of the Zn/Al coatings were performed using XRD, SEM, microhardness, metallographic microscope and gravimetric measurement analysis. The XRD analysis shows an effect only on the critallinity of the phases. The results obtained from SEM analysis show that the coating prepared at 100 mm present higher hardness, low porosity fraction compared to other prepared coatings. Metallographic microscopy and gravimetric measurement result reveals that the coating prepared at 100 mm present a best corrosion resistance when exposed to seawater solution. These studies have been made for a spray distance ranging from 100 to 140 mm.

Abstract: We reported the spin-on Zincsilicafilm dopant content of the diffusion process and the formation of the p+ layer were applied to fabricate GaAs solar cells and their characteristics were investigated. The p-n junction was formed by a thermal furnace from the diffusion of zinc into the GaAs substrate. It was found that the GaAs substrate must be covered by a 100-nm-thick SiO2 layer. This reduced the damage to the GaAs substrate surface morphology that occurred during high temperature treatment and made the cleaning of the residual solvate on the surface easier

Abstract: Effects of nitrogen on uptake, accumulation and partitioning of zinc throughout the development of wheat were studied under pot-culture conditions. The results showed that under low zinc application (0.2 mg kg-1) the grain zinc content increased by 140% when nitrogen fertilizer increased from 50 mg kg-1 to 150 mg kg-1. Under high zinc application (5 mg kg-1) the grain zinc content increased by 61%. Increasing nitrogen application under low zinc fertilizer, the grain zinc mainly comes from the root zinc uptake. While increasing nitrogen application under high zinc fertilizer, the grain zinc mainly comes from the straw zinc remobilization.

Abstract: For over a decade, metal foams have attracted a growing research interest because of the development of certain production processes. The advantages of metal foams most cited in the scientific literature are their low weight. However, one of the obstacles to their use on an industrial scale is the dispersion of their mechanical properties, in part because of their microstructural heterogeneity.

Abstract: This study selected 16 families and 20 genera 20 species of garden plant as the research object, and through pot experiment, study the influence of cadmium, zinc, lead on plant growth, determine the content of heavy metal in the plant organs, determine the ability of heavy metal enrichment to different plants, in order to provide scientific basis through repairing the soil use these plants and configurating the garden plant reasonable.