Loss Of Zn Research Articles

Influence of steel gauge on the microstructure and corrosion performance of zinc alloy coated steels

Zn–4.8 wt% Al coated steels exhibited a polynomial increase in Zn loss from the cut edge with increasing steel gauge for weight loss and SVET Zn loss in 0.1% NaCl in contrast to a linear increase observed for hot dipped galvanised (HDG) steels. Increasing steel gauge decreased nucleation and increased growth of Zn dendrites for Zn–4.8 wt% Al coated steels. SVET data showed larger Zn dendrites associated with thicker gauges produced more damaging anodes than small dendrites on thinner samples. A polynomial relationship was observed between dendrite size and Zn loss suggesting that microstructure influenced Zn loss in unison with the increased cathodic activity on thicker steels.

Effects of bamboo charcoal and bamboo vinegar on nitrogen conservation and heavy metals immobility during pig manure composting

Composting is an effective methodology for the treatment of organic waste like pig manure (PM) before land application. However, nitrogen loss through NH 3 volatilization during the thermophilic phase is one of the major disadvantages of composting. The presence of Cu and Zn in compost arising from pig feed additives is also an issue. In this study the effects of bamboo charcoal (BC) and bamboo vinegar (BV) added to composting piles on nitrogen conservation and immobility of Cu and Zn during PM composting was investigated. Total Kjeldahl nitrogen (TKN) loss and mobility of Cu and Zn decreased with increased BC addition. TKN loss and mobility of Cu and Zn in the treatment with 9% BC at the end of composting significantly decreased by 65%, 35% and 39% respectively, as compared to the control. Addition of BV further decreased TKN loss. After composting, TKN loss in the treatment with 3% BC + 0.4% BV was 23% lower than that in the treatment with 9% BC. The final results indicated that by adding BC or BC + BV into PM composting is an effective method to reduce TKN loss and control the mobility of Cu and Zn.

Effect of the deposition rate on thin films of CuZnAl obtained by thermal evaporation

AbstractThermal evaporation is used to deposit thin films of CuZnAl on silicon substrates. For this purpose, a CuZnAl shape memory alloy is used as evaporation source. The chemical composition and the phases present in the films are evaluated at two different deposition rates: 7 and 0.2 Å/s. The thin films are heat treated to promote the diffusion of the elements and characterized by X-ray Diffraction, Energy Dispersive X-ray Spectroscopy and Scanning Transmission Electron Microscopy (STEM). It is shown that the chemical composition of the thin films is significantly different to that of the CuZnAl alloy used as evaporation source. Moreover, the films produced at 7 Å/s show a significant loss of Zn, contrary to the results obtained using a deposition rate of 0.2 Å/s. It is also observed that the composition varies across the thickness of the film, suggesting that the various alloying elements are evaporated at different rates during the deposition process. Finally the predominant phases present in the films belong to the AlxCuy family.

Thermoelectric Characterization of Zone-Melted and Quenched Zn4Sb3

Because of its complex structure, Zn 4 Sb 3 exhibits relatively low thermal conductivity. This, in combination with large values of the Seebeck coefficient and moderate to high electrical conductivity, makes the material especially interesting for thermoelectric application in temperatures up to 400°C. The phase purity and thermal stability of Zn 4 Sb 3 are major issues for its thermoelectric performance and are strongly dependent on the synthesis method, atmosphere, density, and grain size. Therefore, Zn 4 Sb 3 was prepared by both zone melting and quenching in this study, and pressed samples from crushed powders of three different grain sizes were compared. The effect of thermal cycling was studied, along with repeated structural analysis and Seebeck mapping. It was found that zone melting leads to improved thermal stability regarding decomposition via Zn loss, which finally may result in the formation of ZnSb. Larger grain size seems to reduce the degradation, because of lower concentration of grain boundaries, thus hindering diffusion inside the material.

Impact of soaking and phytase treatments on phytic acid, calcium, iron and zinc in faba bean fractions

SummaryWith the aim to maximise phytic acid removal and minimise losses of dry matter and minerals (Ca, Fe, Zn) in faba bean, fractions of faba beans (whole faba beans, dehulled faba beans, hulls) and flours, were soaked in demineralised water at 10 °C (SDW), NaAc buffer of pH 3.5 at 10 °C (SAB), and 500 U L−1 phytase of pH 5.5 at 50 °C (SPS). In whole seeds and flour, SAB removed 20–51% phytic acid from seeds, and SPS 100% from flour depending upon different preheating treatments; dry matter, Ca, Fe, and Zn losses were 1.8–18%, 20–61%, 33–61% and 8–51%. In dehulled seeds flour, phytic acid could be removed 100% by SPS treatments. In dehulled seeds and flour, losses of dry matter, Ca, Fe were 2.4–18.6%, 12–63%, 11–43%, and Zn apparent gain was 12–73% respectively. In hulls flour, SPS removed 80–82% phytic acid, and SAB 48–50% depending upon different preheating treatments; dry matter, Ca, Zn losses were 6.4–28.7%, 16–46%, 60–72%, and Fe apparent gain was 2–73%, respectively. Phytase application is an effective method to rapidly remove phytic acid while preserving relatively more dry matter and minerals than other soaking approaches in faba bean fractions.

Sewage sludge application on cultivated soils: effects on runoff and trace metal load

The use of sewage sludge in agricultural soils as a macro and micronutrient source and as a soil conditioner has been one of the alternatives for its disposal. However, sewage sludge contains trace metals, which are potential sources of pollution. The goal of this study was to evaluate the effect of sewage sludge application on surface water contamination through runoff when it was applied in a soil cultivated with corn. The effect of sludge application on the concentration and load of copper, nickel and zinc and the volume of runoff water and sediment were evaluated. The experiment was set up in plots used to study erosion losses in Campinas, Sao Paulo State, Brazil. The soil is a clayey Rhodic Hapludox. Three treatments were studied: no sewage sludge, sewage sludge to supply the N required by the crop and twice that amount, with four replications. The water and sediment lost by runoff were measured after each rainfall, and sampled for chemical analysis. The volumes of water and sediment lost by runoff decreased after sewage sludge application. The waste application increased trace metal concentration in the runoff water and sediment, especially zinc, which was present in high concentration in the sewage sludge used. Nevertheless, the load of trace metals transported from the plot was mostly dependent on the total runoff volume. Most of the Cu, Zn and Ni losses were via sediment, and occurred in a few highly erosive rainfall events in the period studied.

The effects of applied crop residues on losses of Fe, Mn, Cu and Zn in run‐off from a soil prone to crusting

AbstractTillage practices may reduce the organic matter content in near‐surface soil horizons causing crust formation. Surface conditions may cause an increase in surface run‐off, thus enhancing contaminant transfer of heavy metals or an acceleration in nutrient loss. This study examines the effect of applying crop residues to the surface of tilled soils on heavy metal losses by run‐off. Losses in iron (Fe), manganese (Mn), zinc (Zn) and copper (Cu) were analysed. Run‐off and sediment yield were measured on 1 m2 plots using a rainfall simulator with a constant 65 mm/h intensity. Four successive rainfall applications were performed, the first three at 25 mm each and the last at 65 mm. Added corn straw varied between 0 and 4 t/ha in the five studied treatments. After 140 mm cumulative rainfall, total heavy metal losses were as follows: Fe from 137 to 950 mg/L, Mn from 2.3 to 12.83 mg/L, Cu from 0.09 to 0.72 mg/L and Zn from 0.31 to 2.46 mg/L. Dissolved fractions were as follows: Fe from 0.014 to 0.229 mg/L, Mn from 0.034 to 1.45 mg/L, Cu from 0.002 to 0.013 mg/L and Zn from 0.02 to 0.12 mg/L. Total concentrations of the studied elements decreased exponentially due to the effect of corn straw on soil loss. However, dissolved contents of Fe and Cu scarcely varied. Significant positive linear correlations were observed between total heavy metal content and soil and sediment loss by run‐off. It is concluded that the addition of straw to a soil of low fertility prevents heavy metal loss.

Zinc Redistribution in a Soil Developed from Limestone During Pedogenesis

The long-term redistribution of Zn in a naturally Zn-enriched soil during pedogenesis was quantified based on mass balance calculations. According to their fate, parent limestones comprised three Zn pools: bound to calcite and pyritesphalerite grains, bound to phyllosilicates and bound to goethite in the inherited phosphate nodules. Four pedological processes, i.e., carbonate dissolution, two stages of redox processes and eluviation, redistributed Zn during pedogenesis. The carbonate dissolution of limestones released Zn bound to calcite into soil solution. Due to residual enrichment, Zn concentrations in the soil are higher than those in parent limestones. Birnessite, ferrihydrite and goethite dispersed in soil horizon trapped high quantities of Zn during their formation. Afterwards, primary redox conditions induced the release of Zn and Fe into soil solution, and the subsequent individualization of Fe and Mn into Zn-rich concretions. Both processes and subsequent aging of the concretions formed induced significant exportation of Zn through the bottom water table. Secondary redox conditions promoted the weathering of Fe and Mn oxides in cements and concretions. This process caused other losses of Zn through lateral exportation in an upper water table. Concomitantly, eluviation occurred at the top of the solum. The lateral exportation of eluviated minerals through the upper water table limited illuviation. Eluviation was also responsible for Zn loss, but this Zn bound to phyllosilicates was not bioavailable

Electrokinetic recovery of Cd, Cr, As, Ni, Zn and Mn from waste printed circuit boards: Effect of assisting agents

The printed circuit boards (PCBs) contains large number of heavy metal such as Cd, Cr, As, Ni, Zn and Mn. In this study, the use of electrokinetic (EK) treatment with different assisting agents has been investigated to recover the heavy metals from waste PCBs, and the effectiveness of different assisting agents (HNO 3, HCl, citric acid) was evaluated. The PCBs were first pre-treated by supercritical water oxidation (SCWO) process, then subjected to EK process. The heavy metal speciation, migration and recovery efficiency in the presence of different assisting agents during EK process were discussed. The mass loss of Cd, Cr, As and Zn during the SCWO process was negligible, but approximately 52% of Ni and 56% of Mn were lost in such a process. Experimental results showed that different assisting agents have significant effect on the behavior and recovery efficiency of different heavy metals. HCl was highly efficient for the recovery of Cd in waste PCBs due to the low pH and the stable complexation of Cl −. Citric acid was highly efficient for the recovery of Cr, Zn and Mn. HNO 3 was low efficient for recovery of most heavy metals except for Ni.

Iron and zinc deficiencies affect zinc kinetic parameters in rats

Co‐occurrence of zinc (Zn) and iron (Fe) deficiencies is common. The epidemiological studies suggested dietary origin of the co‐occurrence. The aim of this study was to test whether Fe deficiency affects Zn kinetics using rats and the stable Zn tracer. Forty 4‐wk‐old male SD rats were assigned into 4 dietary groups of 10: Zn deficiency (ZD), Fe deficiency (FD), Zn/Fe deficiency (ZFD), and Control (AIN‐93G). After rats were fed experimental diets for 4 weeks, baseline blood was collected from the jugular vein and the intravenous 67‐Zn tracer was administered via the femoral vein. Then, blood samples were collected 2‐128 min after the intravenous dose. The plasma 67‐Zn/68‐Zn isotope ratios were measured using ICP‐MS, and Zn kinetic parameters were calculated using the two‐compartment model. The Zn kinetic parameters of FD were not different from those of Control. The rats in ZD had the significantly smaller central and peripheral Zn pool sizes, and the significantly smaller Zn transfer rate between the two compartments and Zn loss from the system. The rats in ZFD had the significantly smaller Zn transfer rate and Zn loss, whereas the Zn pool sizes were not different. In conclusion, simple Zn deficiency induces changes in Zn kinetics. Although simple Fe deficiency does not affect Zn kinetics, it modulates Zn deficiency‐induced changes in Zn kinetics.

Relationship between Endogenous Fecal Zinc and Zinc Absorbed Revisited

Knowledge of the relationship between the quantity of endogenous zinc (Zn) excreted in the feces (EFZ, mg/d) and the quantity of exogenous Zn absorbed (TAZ, mg/d) at that time is necessary for estimating physiologic requirements for Zn. The objective of this project was to reevaluate this relationship utilizing all available total diet data (means), including new data since the publication of Dietary Reference Intakes for Zn. There were 30 datum including 11 male (M), 18 female (F) and 1 mixed gender. Results of linear regression analysis of EFZ vs TAZ and of TAZ at intercepta are summarized in the table:aintercept of regression line for EFZ + other endogenous Zn losses versus TAZ with line of equality; bintercept based on using F other endogenous losses.Lack of significant positive slope for F data is offset by higher y‐intercept resulting in similar intercepts for the F and combined data. The resulting difference in estimation of physiologic requirement for F is only 0.2 mg Zn/d, with actual figures depending on constants used for secondary routes of endogenous Zn excretion. The observed difference between M and F slopes and intercepts has no apparent physiologic explanation but could be attributable in part to limited range of TAZs for F data.

The influence of the microstructure of high noble gold-platinum dental alloys on their corrosion and biocompatibility in vitro

The aim of this work was to compare the microstructures of two high noble experimental Au-Pt alloys with similar composition with their corrosion and biocompatibility in vitro. We showed that Au-Pt II alloy, composed of 87.3 wt.% Au, 9.9 wt.% Pt, 1.7 wt.% Zn and 0.5 wt.% Ir + Rh + In, although possessing better mechanical properties than the Au-Pt I alloy (86.9 wt.% Au, 10.4 wt.% Pt, 1.5 wt.% Zn and 0.5 wt.% Ir + Rh + In), exerted higher adverse effects on the viability of L929 cells and the suppression of rat thymocyte functions, such as proliferation activity, the production of Interleukin-2 (IL-2), expression of IL-2 receptor and activation — induced apoptosis after stimulation of the cells with Concanavalin-A. These results correlated with the higher release of Zn ions in the culture medium. As Zn2+, at the concentrations which were detected in the alloy’s culture media, showed a lesser cytotoxic effect than the Au-Pt conditioning media, we concluded that Zn is probably not the only element responsible for alloy cytotoxicity. Microstructural characterization of the alloys, performed by means of scanning electron microscopy in addition to energy dispersive X-ray and X-ray diffraction analyses, showed that Au-Pt I is a two-phase alloy containing a dominant Au-rich α1 phase and a minor Pt-rich α2 phase. On the other hand, the Au-Pt II alloy additionally contained three minor phases: AuZn3, Pt3Zn and Au1.4Zn0.52. The highest content of Zn was identified in the Pt3Zn phase. After conditioning, the Pt3Zn and AuZn3 phases disappeared, suggesting that they are predominantly responsible for Zn loss, lower corrosion stability and subsequent lower biocompatibility of the Au-Pt II alloy.

Effect of H 2O on Cu-based catalyst in one-step slurry phase dimethyl ether synthesis

One-step dimethyl ether (DME) synthesis in slurry phase was catalyzed by a hybrid catalyst composed of a Cu-based methanol synthesis catalyst and a γ-Al 2O 3 methanol dehydration catalyst under reaction conditions of 260 °C and 5.0 MPa. It was found that instability of the Cu-based catalyst led to rapid deactivation of the hybrid catalyst. The stability of the Cu-based catalyst under DME synthesis conditions was compared with that under methanol synthesis conditions. The results indicated that harmfulness of water, which formed in DME synthesis, caused the Cu-based catalyst to deactivate at a high rate. Surface physical analysis, elemental analysis, XRD and XPS were used to characterize the surface physical properties, components, crystal structures and surface morphologies of the Cu-based catalysts. It was found that Cu 0 was the active component for methanol synthesis and Cu 2O might have less activity for the reaction. Compared with methanol synthesis process, crystallite size of Cu became bigger in DME synthesis process, but carbon deposition was less severe. It was also found that there was distinct metal loss of Zn and Al caused by hydrothermal leaching, impairing the stability of the catalyst. In slurry phase DME synthesis, a part of Cu transformed into Cu 2(OH) 2CO 3, causing a decrease in the number of active sites of the Cu-based catalyst. And some ZnO converted to Zn 5(OH) 6(CO 3) 2, which caused the synergistic effect between Cu and ZnO to become weaker. Crystallite size growth of Cu, carbon deposition, metal loss of Zn and Al, formation of Cu 2(OH) 2CO 3 and Zn 5(OH) 6(CO 3) 2 were important reasons for rapid deactivation of the Cu-based catalyst.

Evaluation of anti-osteoporosis in ovariectomized Wistar rats treated with antler blood by synchrotron radiation X-ray fluorescence microprobe

To evaluate the anti-osteoporotic effect of antler blood, the relationship between the change of element content and the bone mineral density (BMD) increase in femur was investigated. Female Wistar rats were randomly divided into three groups: sham-operated group (SHAM,n=5), ovariectomized group (OVX,n=5) and ovariectomized group with antler blood treatment (n=5). The femoral BMD was analyzed by dual-energy X-ray absorptiometry (DXA) and the element relative content was determined by synchrotron radiation X-ray fluorescence (SRXRF) microprobe. The results showed that the femoral BMD in ovariectomized rats was significantly lower than that of sham-operated rats (p<0.05) but reversed by antler blood treatment (p<0.05). A further study demonstrated that the relative contents of phosphorus (P), calcium (Ca), zinc (Zn) and strontium (Sr) were obviously lower in ovariectomized rats compared to sham-operated rats but only the relative contents of P, Ca and Zn were normalized by antler blood treatment (p<0.05). Our experiments revealed that loss of element Ca, P, Zn and Sr was closely related to the BMD reduction in ovariectomized rats and the anti-osteoporotic effect of antler blood was mediated by increasing the contents of P, Ca and Zn.

Evaluation of anti-osteoporosis in ovariectomized Wistar rats treated with antler blood by synchrotron radiation X-ray fluorescence microprobe

To evaluate the anti-osteoporotic effect of antler blood, the relationship between the change of element content and the bone mineral density (BMD) increase in femur was investigated. Female Wistar rats were randomly divided into three groups: sham-operated group (SHAM, n = 5), ovariectomized group (OVX, n = 5) and ovariectomized group with antler blood treatment (n = 5). The femoral BMD was analyzed by dual-energy X-ray absorptiometry (DXA) and the element relative content was determined by synchrotron radiation X-ray fluorescence (SRXRF) microprobe. The results showed that the femoral BMD in ovariectomized rats was significantly lower than that of sham-operated rats (p < 0.05) but reversed by antler blood treatment (p < 0.05). A further study demonstrated that the relative contents of phosphorus (P), calcium (Ca), zinc (Zn) and strontium (Sr) were obviously lower in ovariectomized rats compared to sham-operated rats but only the relative contents of P, Ca and Zn were normalized by antler blood treatment (p < 0.05). Our experiments revealed that loss of element Ca, P, Zn and Sr was closely related to the BMD reduction in ovariectomized rats and the anti-osteoporotic effect of antler blood was mediated by increasing the contents of P, Ca and Zn.

Effect of soaking and phytase treatment on phytic acid, calcium, iron and zinc in rice fractions

Abstract With the aim to maximise phytic acid removal and minimise losses of dry matter and minerals (Ca, Fe, Zn) in rice, three products (whole kernels and flour milled from white and brown rice; and bran, all from the same batch of variety Kenjian 90-31) were soaked in demineralized water at 10 °C (SDW), NaAc buffer of pH 3.5 at 10 °C (SAB), and 500 U L−1 phytase of pH 5.5 at 50 °C (SPS). In whole kernels and flour of white rice, phytic acid removal was 100% by all treatments; losses of dry matter, Ca, Fe, and Zn were 2–5%, 12–63%, 9–10%, and apparent gain of 63–72%, respectively. In whole brown rice, SAB removed 75% phytic acid, and SPS 100% from flour; dry matter, Ca, Fe, and Zn losses were 1–16%, 26–56%, 39–45%, and 23–24%. In rice bran, SPS removed 92% phytic acid, and SAB 50%; dry matter, Ca, Zn, and Fe losses were 20%, 48%, 63%, and apparent gain of 5%, respectively.

Corrosion Performance Evaluation of Zn/Al Galvanized Steels Using the Scanning Vibrating Electrode Technique (SVET)

The scanning vibrating electrode technique (SVET) provides a useful and rapid means to measure corrosion performance. It enables the number, location and intensity of anodic and cathodic events in corroding systems to be quantified. Strip steel samples were Zn galvanized with Al additions from 5wt% to 6.1wt%. Following microstructural characterization the samples were subjected to corrosion testing in 0.1% NaCl solution. Increasing the Al level in the galvanized layer for commercial strip steel improves corrosion performance with SVET determined Zn loss of 288µg at 5% compared to 148µg at 6.1% additions respectively. With addition of 5.5wt% Al, it may also be possible to reduce the coating weight of the galvanized layer without adversely affecting the corrosion performance with Zn loss of 238.78µg at the surface and 134.32µg at the cut edge.

Development of a Compartmental Model of Zinc Kinetics in Mice

To investigate zinc (Zn) kinetics in mice, tracer (65Zn) was administered orally to 9-wk-old female mice in the fed state and tracer and Zn concentration were measured in 21 tissues over the following 8 d. Data were analyzed by compartmental modeling using WinSAAM. A published model for Zn kinetics in rats was modified to fit the data from mice and to calculate transfer rates and pool sizes of Zn. Parallel studies were performed in mice lacking genes for metallothionein (MT), MT-I and MT-II (MT−/−), to quantify differences in Zn kinetics in the absence of these proteins in vivo. We confirmed that tracer time course in most tissues was similar in wild-type mice and those lacking MT, except for the pancreas of MT−/−, which retained less tracer. By fitting tissue and intestinal data simultaneously, we found that intestinal tracer could be explained by unabsorbed isotope and loss of Zn from pancreas went through plasma. Differences in pancreatic data in MT−/− were explained by Zn turning over twice as fast in this tissue (4 h) compared with wild type (9 h). These kinetic studies provide parameter values for normal, fed mice that can be used to assess Zn kinetics in abnormal conditions, as demonstrated by the higher turnover of Zn in the pancreas of MT knockout mice.

Residual effects of natural Zn chelates on navy bean response, Zn leaching and soil Zn status

A greenhouse experiment was conducted on weakly acidic and calcareous soils to evaluate the aging and residual effects of three natural organic Zn chelates [Zn-ethylenediaminedisuccinate (Zn-EDDS), Zn-polyhydroxyphenylcarboxylate and Zn-aminelignosulfonate] each administered in a single application to a first navy bean (Phaseolus vulgaris L.) crop at several different Zn application rates. In a second navy bean crop, we determined the following parameters: the extent of Zn leaching, the amount of available Zn remaining in soils, the amount of easily leachable Zn, the size of Zn fractions in soils, the pH and redox potential, the dry matter yield, and the soluble and total Zn concentrations in plants. The residual effect after 2 years of Zn fertilization mainly depended on the aging effect of Zn chelates and losses due to Zn leaching. The data relating to the evolution from the first to the second crop showed that the aging effect was noticeable in the calcareous soil. In the latter soil, the Zn-S,S-EDDS treatments showed greater decreases in the Zn uptake by plants than the other Zn treatments and the greatest Zn uptake by plants occurred when Zn was applied as Zn-aminelignosulfonate (10 mg Zn kg−1 rate, 6.85 mg Zn per lysimeter; 5 mg Zn kg−1 rate, 3.36 mg Zn per lysimeter). In contrast, in the calcareous soil, the maximum amount of Zn uptake, for the three chelates was 0.82 mg Zn per lysimeter. Consequently, a further application of Zn would be needed to prevent Zn deficiencies in the plants of a subsequent crop. The behaviour of the pH and Eh parameters in the soils and leachates did not depend on the natural Zn sources applied. In this study, the easily leachable Zn estimated by BaCl2 extraction was not adequate to predict Zn leaching from the soils in subsequent crops.

Growth and characterization of epitaxial Ba(Zn 1/3Ta 2/3)O 3 (1 0 0) thin films

We have synthesized and characterized epitaxial and stoichiometric Ba(Zn 1/3Ta 2/3)O 3 (1 0 0) dielectric thin films grown on MgO (1 0 0) substrates by pulsed laser deposition. Advanced electronic structure calculations were used to guide the interpretation of the experimental data. Zn-enriched targets and high oxygen pressures were used to compensate for Zn loss during film growth. The Ba(Zn 1/3Ta 2/3)O 3 films had an indirect optical band gap of ∼3.0 eV and a refractive index of 1.91 in the visible spectral range. Zn–Ta B-site ordering was not observed in the Ba(Zn 1/3Ta 2/3)O 3 thin film X-ray diffraction data. A dielectric constant of 25 and dissipation factor of 0.0025 at 100 kHz were measured using the interdigital capacitor method. The Ba(Zn 1/3Ta 2/3)O 3 films exhibited a small thermally activated ohmic leakage current at high fields (<250 kV cm –1) and high temperatures (<200 °C) with an activation energy of 0.85 eV.