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Sample records for zinc iron vanadium

  1. A method for recovery of iron, titanium, and vanadium from vanadium-bearing titanomagnetite

    Science.gov (United States)

    Zhang, Yi-min; Wang, Li-na; Chen, De-sheng; Wang, Wei-jing; Liu, Ya-hui; Zhao, Hong-xin; Qi, Tao

    2018-02-01

    An innovative method for recovering valuable elements from vanadium-bearing titanomagnetite is proposed. This method involves two procedures: low-temperature roasting of vanadium-bearing titanomagnetite and water leaching of roasting slag. During the roasting process, the reduction of iron oxides to metallic iron, the sodium oxidation of vanadium oxides to water-soluble sodium vanadate, and the smelting separation of metallic iron and slag were accomplished simultaneously. Optimal roasting conditions for iron/slag separation were achieved with a mixture thickness of 42.5 mm, a roasting temperature of 1200°C, a residence time of 2 h, a molar ratio of C/O of 1.7, and a sodium carbonate addition of 70wt%, as well as with the use of anthracite as a reductant. Under the optimal conditions, 93.67% iron from the raw ore was recovered in the form of iron nugget with 95.44% iron grade. After a water leaching process, 85.61% of the vanadium from the roasting slag was leached, confirming the sodium oxidation of most of the vanadium oxides to water-soluble sodium vanadate during the roasting process. The total recoveries of iron, vanadium, and titanium were 93.67%, 72.68%, and 99.72%, respectively.

  2. Diel cycles in dissolved barium, lead, iron, vanadium, and nitrite in a stream draining a former zinc smelter site near Hegeler, Illinois

    Science.gov (United States)

    Kay, R.T.; Groschen, G.E.; Cygan, G.; Dupre, David H.

    2011-01-01

    Diel variations in the concentrations of a number of constituents have the potential to substantially affect the appropriate sampling regimen in acidic streams. Samples taken once during the course of the day cannot adequately reflect diel variations in water quality and may result in an inaccurate understanding of biogeochemical processes, ecological conditions, and of the threat posed by the water to human health and the associated wildlife. Surface water and groundwater affected by acid drainage were sampled every 60 to 90. min over a 48-hour period at a former zinc smelter known as the Hegeler Zinc Superfund Site, near Hegeler, Illinois. Diel variations related to water quality in the aquifer were not observed in groundwater. Diel variations were observed in the temperature, pH, and concentration of dissolved oxygen, nitrite, barium, iron, lead, vanadium, and possibly uranium in surface water. Temperature, dissolved oxygen, nitrite, barium, lead, and uranium generally attained maximum values during the afternoon and minimum values during the night. Iron, vanadium, and pH generally attained minimum values during the afternoon and maximum values during the night. Concentrations of dissolved oxygen were affected by the intensity of photosynthetic activity and respiration, which are dependent upon insolation. Nitrite, an intermediary in many nitrogen reactions, may have been formed by the oxidation of ammonium by dissolved oxygen and converted to other nitrogen species as part of the decomposition of organic matter. The timing of the pH cycles was distinctly different from the cycles found in Midwestern alkaline streams and likely was the result of the photoreduction of Fe3+ to Fe 2+ and variations in the intensity of precipitation of hydrous ferric oxide minerals. Diel cycles of iron and vanadium also were primarily the result of variations in the intensity of precipitation of hydrous ferric oxide minerals. The diel variation in the concentrations of lead, uranium

  3. TEM investigation of ductile iron alloyed with vanadium.

    Science.gov (United States)

    Dymek, S; Blicharski, M; Morgiel, J; Fraś, E

    2010-03-01

    This article presents results of the processing and microstructure evolution of ductile cast iron, modified by an addition of vanadium. The ductile iron was austenitized closed to the solidus (1095 degrees C) for 100 h, cooled down to 640 degrees C and held on at this temperature for 16 h. The heat treatment led to the dissolution of primary vanadium-rich carbides and their subsequent re-precipitation in a more dispersed form. The result of mechanical tests indicated that addition of vanadium and an appropriate heat treatment makes age hardening of ductile iron feasible. The precipitation processes as well as the effect of Si content on the alloy microstructure were examined by scanning and transmission electron microscopy. It was shown that adjacent to uniformly spread out vanadium-rich carbides with an average size of 50 nm, a dispersoid composed of extremely small approximately 1 nm precipitates was also revealed.

  4. Study on wear resistance of vanadium alloying compacted/vermicular graphite cast iron

    International Nuclear Information System (INIS)

    Park, Yoon Woo

    1987-01-01

    Wear resistance of the Compacted/Vermicular graphite cast irons was studied by changing the vanadium content in the cast irons. The results obtained in this work are summarized as follows. 1. When the same amount of vanadium was added to the flake graphite cast iron, spheroidal graphitecast iron and Compacted/Vermicular graphite cast iron, spheroidal graphite cast iron and Compacted/Vermicular graphite cast iron wear resistance decreased in following sequence, that is, flake graphite cast iron> spheroidal graphite cast iron>Compacted/Vermicular graphite cast iron. 2. Addition of vanadium to the Compacted/Vermicular cast iron leaded to a remarkable increase in hardness because it made the amount of pearlite in matrix increase. 3. Addition of vanadium to the compacted/Vermicular graphite cast iron significantly enhanced wear resistance and the maximum resistance was achieved at about 0.36% vanadium. 4. The maximum amount of wear apppeared at sliding speed of about 1.4m/sec and wear mode was considered to be oxidation abrasion from the observation of wear tracks. (Author)

  5. Analysis of molybdenum, chromium, vanadium and iron by polarographic techniques

    International Nuclear Information System (INIS)

    Al-Zand, T.K.

    1986-01-01

    The application of direct current Tast polarograph, differential pulse polarography and phase-selective alternative current Tast polarography to the problem of determining molybdenum, chromium, vanadium and iron in various supporting electrolytes is reported. The effect of the supporting electrolyte on the wave/peak potential and sensitivity of the metal ion have been examined. The polarographic methods were applied for simultaneous determination of chromium (3)/chromium (6), vanadium (4), vanadium (5) and iron (2)/iron (3) in different supporting electrolytes

  6. Comparison of damage microstructures in neutron-irradiated vanadium and iron

    International Nuclear Information System (INIS)

    Horton, L.L.; Farrell, K.

    1983-01-01

    The cavity morphology and dislocation loop geometry in bcc vanadium are compared with the previously reported observations for neutron-irradiated iron. The specimens were vanadium (V) with 100 wppM of interstitial impurities and vanadium with boron carbide additions (V-B 4 C) which were irradiated to approx. 1 dpa in the same Oak Ridge Research Reactor capsules as the iron specimens

  7. Ferrocenometric deterrination of vanadium and iron in the presence of each other

    International Nuclear Information System (INIS)

    Malyuta, V.F.; Solomatin, V.T.; Nemodruk, A.A.

    1983-01-01

    Real redox potentials have been measured for the V(4)/V(3), Fe(3)/Fe(2) and Fec + /Fec systems in HCl-H 3 PO 4 and H 2 SO 4 -H 3 PO 4 aqueous solutions. The mechanism is suggested for the reduction of vanadium (4) with ferrocene in the presence of iron (3). The possibility has been shown of differential titration of vanadium (4) and iron (3) by ferrocene in the presence of each other in aqueous solutions. A procedure of determining vanadium in steel and a procedure of determining vanadium and iron in ferrovanadium, vanadium slags and cobalt-based alloys have been worked out by the method of potentiometric and amperometric titration with ferrocene solution

  8. Associations between Dietary Iron and Zinc Intakes, and between Biochemical Iron and Zinc Status in Women

    Directory of Open Access Journals (Sweden)

    Karen Lim

    2015-04-01

    Full Text Available Iron and zinc are found in similar foods and absorption of both may be affected by food compounds, thus biochemical iron and zinc status may be related. This cross-sectional study aimed to: (1 describe dietary intakes and biochemical status of iron and zinc; (2 investigate associations between dietary iron and zinc intakes; and (3 investigate associations between biochemical iron and zinc status in a sample of premenopausal women aged 18–50 years who were recruited in Melbourne and Sydney, Australia. Usual dietary intakes were assessed using a 154-item food frequency questionnaire (n = 379. Iron status was assessed using serum ferritin and hemoglobin, zinc status using serum zinc (standardized to 08:00 collection, and presence of infection/inflammation using C-reactive protein (n = 326. Associations were explored using multiple regression and logistic regression. Mean (SD iron and zinc intakes were 10.5 (3.5 mg/day and 9.3 (3.8 mg/day, respectively. Median (interquartile range serum ferritin was 22 (12–38 μg/L and mean serum zinc concentrations (SD were 12.6 (1.7 μmol/L in fasting samples and 11.8 (2.0 μmol/L in nonfasting samples. For each 1 mg/day increase in dietary iron intake, zinc intake increased by 0.4 mg/day. Each 1 μmol/L increase in serum zinc corresponded to a 6% increase in serum ferritin, however women with low serum zinc concentration (AM fasting < 10.7 μmol/L; AM nonfasting < 10.1 μmol/L were not at increased risk of depleted iron stores (serum ferritin <15 μg/L; p = 0.340. Positive associations were observed between dietary iron and zinc intakes, and between iron and zinc status, however interpreting serum ferritin concentrations was not a useful proxy for estimating the likelihood of low serum zinc concentrations and women with depleted iron stores were not at increased risk of impaired zinc status in this cohort.

  9. Iron diminishes the in vitro biological effect of vanadium.

    Science.gov (United States)

    Mechanistic pathways underlying inflammatory injury following exposures to vanadium-containing compounds are not defined. We tested the postulate that the in vitro biological effect of vanadium results from its impact on iron homeostasis. Human bronchial epithelial (HBE) cells ex...

  10. Influence of iron supply on toxic effects of manganese, molybdenum and vanadium on soybean, peas, and flax

    Energy Technology Data Exchange (ETDEWEB)

    Warington, K

    1954-01-01

    The investigations were carried out in nutrient solution with iron as ferric citrate and nitrogen in the form of nitrate. The addition of 2.5 ppm vanadium to plants in which iron chlorosis was already established, either by a lack of iron or by excess manganese, failed to counteract the condition, and caused toxic symptoms. The reduction of the standard iron supply to 1/2 or 1/3 accentuated the toxicity of 2.5 or 5 ppm V to soybean and flax, but a similar reduction in phosphorus had no influence. The toxicity to peas, however, was increased when the phosphorus was reduced to 1/10, provided the iron level was high (20 ppm Fe). Raising the iron supply to 20 or 30 ppm counteracted the toxicity of manganese (10 ppm), molybdenum (40 ppm) and vanadium (2.5 ppm), but the result was less marked when these three elements were combined. Iron supplied in successive, small doses proved less efficient in overcoming molybdenum or vanadium, but not manganese excess, than the same amount of iron supplied in fewer and larger quantities. Varying the iron supply had little effect when the concentration of the three elements was low. When increased iron supply had reduced the chlorosis caused by high manganese or vanadium, it also reduced the manganese and vanadium contents of the shoot (ppm/dm), but the molybdenum content was only lowered by high iron when given in non-toxic concentrations (0.1 ppm Mo) combined with excess manganese. Yield data for soybean and flax indicated an interaction between manganese with both molybdenum and vanadium if the iron supply was low, but none between molybdenum and vanadium. The effect of all three metals was additive in respect to iron.

  11. Vanadium Influence on Iron Based Intermetallic Phases in AlSi6Cu4 Alloy

    Directory of Open Access Journals (Sweden)

    Bolibruchová D.

    2014-10-01

    Full Text Available Negative effect of iron in Al-Si alloys mostly refers with iron based intermetallic phases, especially Al5FeSi phases. These phases are present in platelet-like forms, which sharp edges are considered as main cracks initiators and also as contributors of porosity formation. In recent times, addition of some elements, for example Mn, Co, Cr, Ni, V, is used to reduce influence of iron. Influence of vanadium in aluminium AlSi6Cu4 alloy with intentionally increased iron content is presented in this article. Vanadium amount has been graduated and chemical composition of alloy has been analysed by spectral analysis. Vanadium influence on microstructural changes was evaluated by microstructural analysis and some of intermetallic particles were reviewed by EDX analysis.

  12. Zinc deficiency-induced iron accumulation, a consequence of alterations in iron regulatory protein-binding activity, iron transporters, and iron storage proteins.

    Science.gov (United States)

    Niles, Brad J; Clegg, Michael S; Hanna, Lynn A; Chou, Susan S; Momma, Tony Y; Hong, Heeok; Keen, Carl L

    2008-02-22

    One consequence of zinc deficiency is an elevation in cell and tissue iron concentrations. To examine the mechanism(s) underlying this phenomenon, Swiss 3T3 cells were cultured in zinc-deficient (D, 0.5 microM zinc), zinc-supplemented (S, 50 microM zinc), or control (C, 4 microM zinc) media. After 24 h of culture, cells in the D group were characterized by a 50% decrease in intracellular zinc and a 35% increase in intracellular iron relative to cells in the S and C groups. The increase in cellular iron was associated with increased transferrin receptor 1 protein and mRNA levels and increased ferritin light chain expression. The divalent metal transporter 1(+)iron-responsive element isoform mRNA was decreased during zinc deficiency-induced iron accumulation. Examination of zinc-deficient cells revealed increased binding of iron regulatory protein 2 (IRP2) and decreased binding of IRP1 to a consensus iron-responsive element. The increased IRP2-binding activity in zinc-deficient cells coincided with an increased level of IRP2 protein. The accumulation of IRP2 protein was independent of zinc deficiency-induced intracellular nitric oxide production but was attenuated by the addition of the antioxidant N-acetylcysteine or ascorbate to the D medium. These data support the concept that zinc deficiency can result in alterations in iron transporter, storage, and regulatory proteins, which facilitate iron accumulation.

  13. Determination of copper, iron and zinc in spirituous beverages by total reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    Capote, T.; Marcó, L. M.; Alvarado, J.; Greaves, E. D.

    1999-10-01

    The concentration of copper in traditional homemade alcoholic distillates produced in Venezuela (Cocuy de Penca) were determined by total reflection X-ray fluorescence (TXRF) using vanadium as internal standard. The results were compared to those obtained by flame atomic absorption spectrometry (FAAS). Three preparative methods of addition of vanadium were compared: classical internal standard addition, 'layer on layer' internal standard addition and in situ addition of internal standard. The TXRF procedures were accurate and the precision was comparable to that obtained by the FAAS technique. Copper levels were above the maximum allowed limits for similar beverages. Zinc and iron in commercial and homemade distilled beverages were also analyzed by TXRF with in situ addition of internal standard demonstrating the usefulness of this technique for trace metal determination in distillates.

  14. IRON, ZINC, AND FERRITIN ACCUMULATION IN COMMON BEANS

    DEFF Research Database (Denmark)

    Urbanski, Dorian Fabian; Sørensen, Kirsten; Jurkiewicz, Anna Malgorzata

    Iron and zinc malnutrition are major threats to human health and development around the world. The World Health Organization states that over two billion people are affected by iron deficiency. In particular children and pregnant women in developing countries are affected by iron deficiency...... in mature seeds, but the ferritin protein was suggested to be the major iron storing protein in legumes [1]. Both iron and zinc localization, as well as speciation, can have an impact on their nutritional availability. We will present detailed information about iron, zinc, and ferritin distribution...

  15. Gas-phase complexes formed between amidoxime ligands and vanadium or iron investigated using electrospray ionization mass spectrometry.

    Science.gov (United States)

    Mustapha, Adetayo M; Pasilis, Sofie P

    2016-08-15

    Amidoxime-functionalized sorbents can be used to extract uranium from seawater. Iron(III) and vanadium(V) may compete with uranium for adsorption sites. We use 2,6-dihydroxyiminopiperidine (DHIP) and N(1) ,N(5) -dihydroxypentanediimidamide (DHPD) to model amidoxime functional groups and characterize the vanadium(V) and iron(III) complexes with these ligands. We also examine the effect of iron(III) and vanadium(V) on uranyl(VI) complexation by DHIP and DHPD. The experiments were carried out in positive ion mode using a quadrupole ion trap mass spectrometer equipped with an electrospray ionization source. The effect on the mass spectra of changes in ligand, metal:ligand mole ratio, and pH was examined. Iron(III) formed a 1:2 metal:ligand complex with DHIP at all metal:ligand mole ratios and pH values investigated; it formed both 1:2 and 1:3 metal:ligand complexes with DHPD. Vanadium(V) formed 1:1 and 1:2 metal:ligand complexes with DHIP. A 1:2 metal:ligand complex was formed with DHPD at all vanadium(V):DHPD mole ratios investigated. Changes in solution pH did not affect the ions observed. The relative binding affinities of the metal ions towards DHIP followed the order iron(III) > vanadium(V) > uranyl(VI). This study presents a first look at the gas-phase vanadium(V)- and iron(III)-DHIP and -DHPD complexes using electrospray ionization mass spectrometry. These metals form stronger complexes with amidoxime ligands than uranyl(VI), and will affect uranyl(VI) adsorption to amidoxime-based sorbents. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Iron and zinc concentrations and 59Fe retention in developing fetuses of zinc-deficient rats

    International Nuclear Information System (INIS)

    Rogers, J.M.; Loennerdal, B.H.; Hurley, L.S.; Keen, C.L.

    1987-01-01

    Because disturbances in iron metabolism might contribute to the teratogenicity of zinc deficiency, we examined the effect of zinc deficiency on fetal iron accumulation and maternal and fetal retention of 59 Fe. Pregnant rats were fed from mating a purified diet containing 0.5, 4.5 or 100 micrograms Zn/g. Laparotomies were performed on d 12, 16, 19 and 21 of gestation. Maternal blood and concepti were analyzed for zinc and iron. Additional groups of dams fed 0.5 or 100 micrograms Zn/g diet were gavaged on d 19 with a diet containing 59 Fe. Six hours later maternal blood and tissues, fetuses and placentas were counted for 59 Fe. Maternal plasma zinc, but not iron, concentration was affected by zinc deficiency on d 12. Embryo zinc concentration on d 12 increased with increasing maternal dietary zinc, whereas iron concentration was not different among groups. On d 16-21 plasma iron was higher in dams fed 0.5 micrograms Zn/g diet than in those fed 4.5 or 100 micrograms/g, whereas plasma zinc was lower in dams fed 0.5 or 4.5 micrograms Zn/g than in those fed 100 micrograms Zn/g diet. On d 19 zinc concentration in fetuses from dams fed 0.5 micrograms/g zinc was not different from that of those fed 4.5 micrograms/g zinc, and iron concentration was higher in the 0.5 microgram Zn/g diet group. The increase in iron concentration in zinc-deficient fetuses thus occurs too late to be involved in major structural teratogenesis. Although whole blood concentration of 59 Fe was not different in zinc-deficient and control dams, zinc-deficient dams had more 59 Fe in the plasma fraction

  17. Determination of macro nickel, vanadium and iron in crude oil and residues by derivative spectrophotometry

    International Nuclear Information System (INIS)

    Liu, W.; Wang, L.; Li, X.

    1992-01-01

    In this paper, a new method with derivative spectrophotometry and 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol as the chromogenic reagent in buffer solution of different pH developed for determining micro amounts of nickel. Vanadium and iron in crude oil and residues is reported. Forth-, Second- and Third-, Fourth-order derivative spectrophotometry were applied to determine nickel, nickel and vanadium, nickel and iron in crude oil and residues, respectively. The derivative maximums chosen for the measurement were at 556 nm for nickel, 540 nm and 643 nm for nickel and vanadium, 524 nm and 604 nm for nickel and iron. Beer's law is valid for the range 1.0 x 10 -6 to 2.5 x 10 -5 M

  18. Effect of Consuming Zinc-fortified Bread on Serum Zinc and Iron Status of Zinc-deficient Women: A Double Blind, Randomized Clinical Trial.

    Science.gov (United States)

    Badii, Akbar; Nekouei, Niloufar; Fazilati, Mohammad; Shahedi, Mohammad; Badiei, Sajad

    2012-03-01

    After iron deficiency, zinc deficiency is the major micronutrient deficiency in developing countries, and staple food fortification is an effective strategy to prevent and improve it among at-risk-populations. No action has been taken to reduce zinc deficiency via flour fortification so far in Iran, and little is known about the influence of zinc fortification of flour on serum zinc and the iron status, and also about the optimum and effective amount of zinc compound that is used in food fortification. The objective of this study is to evaluate the influence of consuming zinc-fortified breads on the zinc and iron status in the blood serum. In this study, three types of bread were prepared from non-fortified and fortified flours, with 50 and 100 ppm elemental zinc in the form of sulfate. Eighty zinc-deficient women aged 19 to 49 years were randomly assigned to three groups; The volunteers received, daily, (1) a non-fortified bread, (2) a high-zinc bread, and (3) a low-zinc bread for one month. Serum zinc and iron were measured by Atomic Absorption before and after the study. Results showed a significant increase in serum zinc and iron levels in all groups (p 0.05). Absorption of zinc and iron in the group that consumed high-zinc bread was significantly greater than that in the group that received low-zinc bread (p bread improved iron absorption.

  19. Synthesis of nanoparticles of vanadium carbide in the ferrite of nodular cast iron

    CERN Document Server

    Fras, E; Guzik, E; Lopez, H

    2005-01-01

    The synthesis method of nanoparticles of vanadium carbide in nodular cast iron is presented. After introduction of this method, the nanoparticles with 10-70 nm of diameter was obtained in the ferrite. The diffraction investigations confirmed that these particles are vanadium carbides of type V/sub 3/C/sub 4/.

  20. Effect of consuming zinc-fortified bread on serum zinc and iron status of zinc-deficient women: A double blind, randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Akbar Badii

    2012-01-01

    Full Text Available After iron deficiency, zinc deficiency is the major micronutrient deficiency in developing countries, and staple food fortification is an effective strategy to prevent and improve it among at-risk-populations. No action has been taken to reduce zinc deficiency via flour fortification so far in Iran, and little is known about the influence of zinc fortification of flour on serum zinc and the iron status, and also about the optimum and effective amount of zinc compound that is used in food fortification. The objective of this study is to evaluate the influence of consuming zinc-fortified breads on the zinc and iron status in the blood serum. In this study, three types of bread were prepared from non-fortified and fortified flours, with 50 and 100 ppm elemental zinc in the form of sulfate. Eighty zinc-deficient women aged 19 to 49 years were randomly assigned to three groups; The volunteers received, daily, (1 a non-fortified bread, (2 a high-zinc bread, and (3 a low-zinc bread for one month. Serum zinc and iron were measured by Atomic Absorption before and after the study. Results showed a significant increase in serum zinc and iron levels in all groups (p 0.05. Absorption of zinc and iron in the group that consumed high-zinc bread was significantly greater than that in the group that received low-zinc bread (p < 0.01. It was concluded that fortification of flour with 50-100 ppm zinc was an effective way to achieve adequate zinc intake and absorption in zinc-deficient people. It also appeared that consuming zinc-fortified bread improved iron absorption.

  1. mRNA Levels of Placental Iron and Zinc Transporter Genes Are Upregulated in Gambian Women with Low Iron and Zinc Status.

    Science.gov (United States)

    Jobarteh, Modou Lamin; McArdle, Harry J; Holtrop, Grietje; Sise, Ebrima A; Prentice, Andrew M; Moore, Sophie E

    2017-07-01

    Background: The role of the placenta in regulating micronutrient transport in response to maternal status is poorly understood. Objective: We investigated the effect of prenatal nutritional supplementation on the regulation of placental iron and zinc transport. Methods: In a randomized trial in rural Gambia [ENID (Early Nutrition and Immune Development)], pregnant women were allocated to 1 of 4 nutritional intervention arms: 1 ) iron and folic acid (FeFol) tablets (FeFol group); 2 ) multiple micronutrient (MMN) tablets (MMN group); 3 ) protein energy (PE) as a lipid-based nutrient supplement (LNS; PE group); and 4 ) PE and MMN (PE+MMN group) as LNS. All arms included iron (60 mg/d) and folic acid (400 μg/d). The MMN and PE+MMN arms included 30 mg supplemental Zn/d. In a subgroup of ∼300 mother-infant pairs, we measured maternal iron status, mRNA levels of genes encoding for placental iron and zinc transport proteins, and cord blood iron levels. Results: Maternal plasma iron concentration in late pregnancy was 45% and 78% lower in the PE and PE+MMN groups compared to the FeFol and MMN groups, respectively ( P Zinc supplementation in the MMN arm was associated with higher maternal plasma zinc concentrations (10% increase; P zinc-uptake proteins, in this case zrt, irt-like protein (ZIP) 4 and ZIP8, were 96-205% lower in the PE+MMN arm than in the intervention arms without added zinc ( P zinc, the placenta upregulates the gene expression of iron and zinc uptake proteins, presumably in order to meet fetal demands in the face of low maternal supply. The ENID trial was registered at www.controlled-trials.com as ISRCTN49285450.

  2. Vanadium recovery process

    International Nuclear Information System (INIS)

    Pyrih, R.Z.; Rickard, R.S.

    1978-01-01

    A process for recovering vanadium values from carbonaceous type vanadium ores, and vanadium scrap, such as vanadium contaminated spent catalyst, is disclosed which comprises roasting the vanadium containing material in air at a temperature less than about 600 0 C to produce a material substantially devoid of organic matter, subjecting said roasted material to a further oxidizing roast in an oxygen atmosphere at a temperature of at least about 800 0 C for a period sufficient to convert substantially all of the vanadium to the soluble form, leaching the calcine with a suitable dilute mineral acid or water at a pH of neutral to about 2 to recover vanadium values, precipitating vanadium values as iron vanadate from the leach solution with a soluble iron compound at a pH from neutral to about 1, and recovering ferrovanadium from the iron vanadate by a reduction vacuum smelting operation. The conversion of vanadium in the ore to the soluble form by the oxidizing roast is accomplished without the addition of an alkaline salt during calcining

  3. Study of iron-zinc catalysts by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Arriola, S.H.

    1990-01-01

    The Moessbauer parameters were determined on a series of catalyst mixtures of iron and zinc oxides with variable quantities of zinc. A change in the crystal structure of the iron oxide when introducing zinc into the samples was observed. The corundum structure of the α-Fe 2 O 3 phase was transformed into the spinel type of zinc ferrite when zinc oxide was present in any quantity. A strong electronic interaction between the zinc ferrite and the zinc oxide present in excess was evident. The catalysts were analyzed using x-ray fluorescence and x-ray diffraction methods. (author) 10 refs.; 4 figs.; 2 tabs

  4. Effects of iron, tin, and copper on zinc absorption in humans

    International Nuclear Information System (INIS)

    Valberg, L.S.; Flanagan, P.R.; Chamberlain, M.J.

    1984-01-01

    Zinc absorption as measured by body retention of [65Zn]zinc chloride or a turkey test meal extrinsically labeled with 65Zn was determined in human subjects by whole body counting after 7 days. Average 65Zn absorption from zinc chloride in persons with a high iron-absorbing capacity was similar to persons with a low capacity to absorb iron. Inorganic iron, 920 mumol (51 mg), or HB iron, 480 mumol (26 mg), inhibited 65Zn absorption from 92 mumol (6 mg) of zinc chloride. When 610 mumol of iron (34 mg) was added to a turkey test meal containing 61 mumol of zinc (4 mg), 65Zn absorption was not inhibited. Tin, 306 mumol (36 mg), given with zinc chloride or turkey test meals (61 mumol, 4 mg, of Zn) significantly reduced 65Zn absorption. Copper, 79 mumol (5 mg), had no significant effect on the 65Zn absorption from 7.9 mumol (0.5 mg) of zinc chloride. In summary, the capacity to absorb iron did not influence 65Zn absorption, but both inorganic iron and heme-iron inhibited 65Zn absorption from zinc chloride. Inorganic iron had no effect, however, on 65Zn absorption from the turkey test meal. Tin in a large dose also inhibited 65Zn absorption from both zinc chloride and the turkey test meal

  5. Influence of iron and zinc status on cadmium accumulation in Bangladeshi women

    International Nuclear Information System (INIS)

    Kippler, Maria; Ekstroem, Eva-Charlotte; Loennerdal, Bo; Goessler, Walter; Akesson, Agneta; El Arifeen, Shams; Persson, Lars-Ake; Vahter, Marie

    2007-01-01

    Cadmium is a widespread environmental contaminant present in food. The absorption in the intestine increases in individuals with low iron stores, but the effect of zinc deficiency is not clear. The aim of the present study was to assess the influence of iron and zinc status on cadmium accumulation in pregnant Bangladeshi women. We measured cadmium in urine from 890 women using inductively coupled plasma mass spectrometry (ICPMS). Further, we also measured ferritin and zinc in plasma. The median cadmium concentration in urine was 0.59 μg/L (adjusted to mean specific gravity of 1.012 g/mL). Analysis of covariance (ANCOVA) showed that urinary cadmium was associated with plasma ferritin and plasma zinc via a significant interaction between dichotomized plasma ferritin and plasma zinc. The analysis was adjusted for age and socioeconomic status. Women with low iron stores and adequate zinc status had significantly higher urinary cadmium compared to women with both adequate iron stores and zinc status. There was no difference in urinary cadmium between women with both low iron stores and zinc status compared to those with both adequate iron stores and zinc status. In conclusion, low iron stores were associated with increased cadmium accumulation, but only at adequate zinc status

  6. Iron and Zinc Nutrition in the Economically-Developed World: A Review

    Directory of Open Access Journals (Sweden)

    Alison O. Booth

    2013-08-01

    Full Text Available This review compares iron and zinc food sources, dietary intakes, dietary recommendations, nutritional status, bioavailability and interactions, with a focus on adults in economically-developed countries. The main sources of iron and zinc are cereals and meat, with fortificant iron and zinc potentially making an important contribution. Current fortification practices are concerning as there is little regulation or monitoring of intakes. In the countries included in this review, the proportion of individuals with iron intakes below recommendations was similar to the proportion of individuals with suboptimal iron status. Due to a lack of population zinc status information, similar comparisons cannot be made for zinc intakes and status. Significant data indicate that inhibitors of iron absorption include phytate, polyphenols, soy protein and calcium, and enhancers include animal tissue and ascorbic acid. It appears that of these, only phytate and soy protein also inhibit zinc absorption. Most data are derived from single-meal studies, which tend to amplify impacts on iron absorption in contrast to studies that utilize a realistic food matrix. These interactions need to be substantiated by studies that account for whole diets, however in the interim, it may be prudent for those at risk of iron deficiency to maximize absorption by reducing consumption of inhibitors and including enhancers at mealtimes.

  7. Solubility of nitrogen in iron alloys with vanadium and niobium

    International Nuclear Information System (INIS)

    Pomarin, Yu.M.; Grigorenko, G.M.; Lakomskij, V.I.

    1975-01-01

    The solubility of nitrogen in the concentration range under study in Fe-N-V and Fe-N-Nb systems is in compliance with Syverts' law. An equation has been set up so as to estimate the nitrogen solubility in the iron alloys containing up to 10 per cent of vanadium and niobium in the wide temperature range

  8. An extraction process to recover vanadium from low-grade vanadium-bearing titanomagnetite

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Desheng; Zhao, Hongxin; Hu, Guoping [National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Beijing 100190 (China); Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Qi, Tao, E-mail: tqgreen@ipe.ac.cn [National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Beijing 100190 (China); Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Yu, Hongdong; Zhang, Guozhi [National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Beijing 100190 (China); Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Wang, Lina, E-mail: linawang@ipe.ac.cn [National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Beijing 100190 (China); Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Wang, Weijing [National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Beijing 100190 (China); Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China)

    2015-08-30

    Highlights: • The leaching solution contains high concentration of acid, iron, impurities and lower vanadium. • 99.4% of vanadium and 4.2% of iron were extracted by three-stage extraction process. • 99.6% of vanadium and 5.4% of iron were stripped by three-stage stripping process. • The stripping solution contains 40.16 g/L V{sub 2}O{sub 5}, 0.691 g/L Fe, 0.007 g/L TiO{sub 2} and 0.247 g/L CaO. • The vanadium product of V{sub 2}O{sub 5} with purity of 99.12%, 0.026% Fe and well crystallized. - Abstract: An extraction process to recover vanadium from low-grade vanadium-bearing titanomagnetite was developed. In this study, a mixed solvent system of di(2-ethylhexyl) phosphate (D2EHPA) and tri-n-butyl phosphate (TBP) diluted with kerosene was used for the selective extraction of vanadium from a hydrochloric acid leaching solution that contained low vanadium concentration with high concentrations of iron and impurities of Ca, Mg, and Al. In the extraction process, the initial solution pH and the phase ratio had considerable functions in the extraction of vanadium from the hydrochloric acid leaching solution. Under optimal extraction conditions (i.e., 30–40 °C for 10 min, 1:3 phase ratio (O/A), 20% D2EHPA concentration (v/v), and 0–0.8 initial solution pH), 99.4% vanadium and only 4.2% iron were extracted by the three-stage counter-current extraction process. In the stripping process with H{sub 2}SO{sub 4} as the stripping agent and under optimal stripping conditions (i.e., 20% H{sub 2}SO{sub 4} concentration, 5:1 phase ratio (O/A), 20 min stripping time, and 40 °C stripping temperature), 99.6% vanadium and only 5.4% iron were stripped by the three-stage counter-current stripping process. The stripping solution contained 40.16 g/L V{sub 2}O{sub 5}, 0.691g/L Fe, 0.007 g/L TiO{sub 2}, 0.006 g/L SiO{sub 2} and 0.247 g/L CaO. A V{sub 2}O{sub 5} product with a purity of 99.12% V{sub 2}O{sub 5} and only 0.026% Fe was obtained after the oxidation, precipitation

  9. Effect Of Joint Iron And Zinc Supplementation On Malarial Infection ...

    African Journals Online (AJOL)

    Adjusted geometric mean serum ferritin concentration in the Iron-zinc Group was significantly higher than in the Control Group (22.9 fg/L versus 16.9 fg/L), F (1, 156) = 6.336, p = 0.013. Conclusions: Joint iron and zinc supplementation appears to be a better option than iron-only supplementation in malaria-endemic areas.

  10. Study of Doppler broadened annihilation spectra in zinc and zinc-containing 0.05 at. % iron

    International Nuclear Information System (INIS)

    Troev, T.; Zolov, R.; Dimova, V.; Levay, B.

    1979-01-01

    The Doppler broadening of annihilation gamma spectra obtained from positron-electron annihilation in pure polycrystalline zinc and zinc-containing 0.05 at. % iron have been investigated. The line shapes were measured by a Ge(Li) detector in coincidence with a NaI(Tl) scintillation detector. The results are quite consistent with those expected from the trapping model. The positrons are trapped by impurity atoms and vacancy-impurity pairs in zinc containing 0.05 at. % iron. (author)

  11. A study of the levels of vanadium, cadmium, chromium and iron in ...

    African Journals Online (AJOL)

    Background: There is conflicting information on the adverse health effects of photocopier toner powder on operators.This study aims to determine the possible nephrotoxic effects of some commercially available photocopier toners and the levels of selected heavy metals (vanadium, cadmium, chromium and iron) for ...

  12. Serum Zinc, Iron and Copper Concentrations in Dogs Infected with Hepatozoon canis

    Directory of Open Access Journals (Sweden)

    Kamil Seyrek

    2009-01-01

    Full Text Available In Turkey, canine hepatozoonosis is an emerging infection with a large number of cases detected during the past five years. In the present study, serum zinc, copper and iron concentrations of dogs infected with Hepatozoon canis were measured for the first time. Compared to the controls (n = 10, serum zinc and iron concentrations in infected animals (n = 14 decreased significantly (p p p Hepatozoon canis infection may cause alterations in serum zinc iron and copper concentrations. Furthermore, in the treatment of infected animals addition of zinc and iron to the ration of infected animals should be taken into consideration.

  13. Counter diffusion of zinc and iron in alluvial soil

    International Nuclear Information System (INIS)

    Rattan, R.K.; Deb, D.L.

    1980-01-01

    Half cell technique showed that an increase in moisture tension and CaCO 3 content caused reduction in the counter diffusion coefficients of zinc and iron in an alluvial soil. Increases in bulk density, ambient temperature and concentration of synthetic chelating agents e.g. EDTA and DTPA increased the counter diffusion coefficients of both zinc and iron. (author)

  14. Alkaline Leaching of Low Zinc Content Iron-Bearing Sludges

    Directory of Open Access Journals (Sweden)

    Gargul K.

    2016-03-01

    Full Text Available Various types of waste materials containing zinc (e.g. dusts and sludges from gas dedusting process are obtained in steel industry. The contents of Zn in these materials may vary considerably. Even a low concentration of zinc in recirculated products precludes their recycling in ferrous metallurgy aggregates. Long storage of this type of material can lead to contamination of soil and water by zinc compounds which can be leached out by acid rain, for example. This paper focuses on research involving alkaline leaching tests of low zinc content iron-bearing materials. These tests were preceded by the analysis of the elemental, phase and grain size composition, and analysis of the thermodynamic conditions of the leaching process. The main aim of research was to decrease the content of the zinc in the sludge to the level where it is suitable as an iron-bearing material for iron production (~1% Zn. Leaching at elevated temperatures (368 K, 60 min has led to a decrease in the zinc content in the sludge of about 66%. The research revealed that long hour leaching (298 K, 100 hours carried out at ambient temperatures caused a reduction in zinc content by 60% to the value of 1.15-1.2% Zn.

  15. Zinc and iron status during pregnancy of Filipino women.

    Science.gov (United States)

    de Jong, Nynke; Romano, Aurora B Ampong; Gibson, Rosalind S

    2002-01-01

    Low birthweight is associated with maternal anaemia and, in some circumstances, with low iron and zinc status, but this relationship has not been investigated in the Philippines. In this study, we assessed the prevalence of anaemia and suboptimal iron and zinc status in pregnant women from three geographical regions (mountain, coast, city) of Zamboanga del Sur province at 24 weeks (n = 305). and again at 36 weeks (n = 127), gestation. At 24 weeks, 34% were anaemic (i.e., haemoglobin values (i.e., 11 x 10(9)/L; 19%) and serum C-reactive protein (> 15 mg/L; 3%). Of the women surveyed, 20% were iron depleted but not anaemic, and 15% were zinc deficient (i.e., serum zinc values at 24 weeks gestation had infants with lower birthweights than those with values > or = 105 g/L and > or = 7.1 micromol/L, respectively. However, in the multivariate model, the contribution of maternal haemoglobin to the variance in birthweight at 24 weeks gestation was non-significant, although modest for serum zinc. Anaemia and/or suboptimal zinc status during pregnancy may be related to low birthweight in the Philippines, and their aetiology deserves further study.

  16. Adsorption of poly(vinyl formamide-co-vinyl amine) (PVFA-co-PVAm) polymers on zinc, zinc oxide, iron, and iron oxide surfaces.

    Science.gov (United States)

    Seifert, Susan; Simon, Frank; Baumann, Giesela; Hietschold, Michael; Seifert, Andreas; Spange, Stefan

    2011-12-06

    The adsorption of poly(vinyl formamide) (PVFA) and the statistic copolymers poly(vinyl formamide-co-vinyl amine) (PVFA-co-PVAm) onto zinc and iron metal particles as well as their oxides was investigated. The adsorbates were characterized by means of XPS, DRIFT spectroscopy, wet chemical analysis, and solvatochromic probes. Dicyano-bis-(1,10-phenanthroline)-iron(II) (1), 3-(4-amino-3-methylphenyl)-7-phenyl-benzo-[1,2-b:4,5-b']difuran-2,6-dione (2), and 4-tert-butyl-2-(dicyano-methylene)-5-[4-(diethylamino)-benzylidene]-Δ(3)-thiazoline (3) as solvatochromic probes were coadsorbed onto zinc oxide to measure various effects of surface polarity. The experimental findings showed that the adsorption mechanism of PVFA and PVFA-co-PVAm strongly depends on the degree of hydrolysis of PVFA and pH values and also on the kind of metal or metal oxide surfaces that were employed as adsorbents. The adsorption mechanism of PVFA/PVFA-co-PVAm onto zinc oxide and iron oxide surfaces is mainly affected by electrostatic interactions. Particularly in the region of pH 5, the adsorption of PVFA/PVFA-co-PVAm onto zinc and iron metal particles is additionally influenced by redox processes, dissolution, and complexation reactions. © 2011 American Chemical Society

  17. The separation and determination of trace elements in iron ore

    International Nuclear Information System (INIS)

    Jones, E.A.

    1977-01-01

    The separation, concentration, and determination of trace elements in iron ores are described. After the sample has been dissolved, the iron is separated by liquid-liquid extraction with a liquid cation-exchanger, di-(2-ethylhexyl) phosphoric acid. The trace elements aluminium, cadmium, calcium, chromium, cobalt, copper, lead, magnesium, manganese, mercury, potassium, sodium, vanadium, and zinc are determined in the aqueous phase by atomic-absorption spectrophotometry

  18. Evaluation of Application Methods Efficiency of Zinc and Iron for Canola(Brassica napus L.

    Directory of Open Access Journals (Sweden)

    Ahmad BYBORDI

    2010-03-01

    Full Text Available In order to evaluation of application method efficiency of zinc and iron microelements in canola, an experiment was conducted in the Agricultural Research Station of Eastern Azerbaijan province in 2008. The experimental design was a RCBD with eight treatments (F1: control, F2: iron, F3: zinc, F4: iron + zinc in the form of soil utility, F5: iron, F6: zinc, F7: iron+ zinc in the form of solution foliar application, and F8: iron + zinc in the form of soil utility and foliar application. Analysis of variance showed that there were significant differences among treatments on given traits, antioxidant enzymes activity, fatty acids percentage, plant height, seed weight to capitulum weight ratio, protein percentage, oil percentage, oil yield, 1000 seed weight, seed yield, nitrogen, phosphorous and potassium percentage of leaves, zinc and iron content of leaves and capitulum diameters. The highest seed yield, oil yield, oil percentage, 1000 seed weight, seed weight to capitulum weight ratio and protein percentage were obtained from the soil and foliar application of iron + zinc treatments (F8. Also, the highest amounts of nitrogen, phosphorous and potassium concentration in leaves were achieved from control treatment which was an indication of non-efficiency of iron and zinc on the absorption rate of these substances in the leaves. The correlation between effective traits on the seed yield, such as, capitalism diameter, number of seed rows in capitulum, seed weight to capitulum weight ratio and 1000 seed weight were positively significant. In general, foliar and soil application of zinc and iron had the highest efficiency in aspect of seed production. The comparison of the various methods of fertilization showed that foliar application was more effective than soil application. Also, micronutrient foliar application increased concentration of elements, especially zinc and iron. Antioxidant enzymes activity was different in response to treatments also the

  19. Tissue levels of iron, copper, zinc and magnesium in iron deficient rats

    African Journals Online (AJOL)

    The effects of iron deficiency on the levels of iron, copper, zinc and magnesium in the brain, liver, kidney, heart and lungs of albino rats (Rattus novergicus) was investigated. Forty rats were divided into two groups and the first group was fed a control diet containing 1.09g iron/kg diet while the test group was fed diet ...

  20. New perspectives on the regulation of iron absorption via cellular zinc concentrations in humans.

    Science.gov (United States)

    Knez, Marija; Graham, Robin D; Welch, Ross M; Stangoulis, James C R

    2017-07-03

    Iron deficiency is the most prevalent nutritional deficiency, affecting more than 30% of the total world's population. It is a major public health problem in many countries around the world. Over the years various methods have been used with an effort to try and control iron-deficiency anemia. However, there has only been a marginal reduction in the global prevalence of anemia. Why is this so? Iron and zinc are essential trace elements for humans. These metals influence the transport and absorption of one another across the enterocytes and hepatocytes, due to similar ionic properties. This paper describes the structure and roles of major iron and zinc transport proteins, clarifies iron-zinc interactions at these sites, and provides a model for the mechanism of these interactions both at the local and systemic level. This review provides evidence that much of the massive extent of iron deficiency anemia in the world may be due to an underlying deficiency of zinc. It explains the reasons for predominance of cellular zinc status in determination of iron/zinc interactions and for the first time thoroughly explains mechanisms by which zinc brings about these changes.

  1. Vanadium-bearing titaniferous iron ores from the Rooiwater, Usushwana, Mambula, Kaffirskraal, and the Trompsburg igneous complexes

    International Nuclear Information System (INIS)

    Reynolds, A.M.

    1979-01-01

    The mineralogy and chemistry of some vanadium-bearing titaniferous iron ores from a number of smaller South African basic intrusions are reported, and an assessment is given of the potential of these ores for use as raw materials in the production of iron, high-titania slag, and vanadium pentoxide. The ores from each complex can be distinguised readily on the basis of their chemical composition and textural relations. The Rooiwater Complex represents the most promising area. It contains two layers of titaniferous magnetite, each approximately 8 m thick, in the eastern part, the lowest seam being chemically similar to the economically important main layer of titaniferous magnetite in the Bushveld Complex. The ores are silicate-poor and consist largely of multi-phase titaniferous-magnetite grains containing modified ilmenite and pleonaste micro-intergrowths. The coarse grain size of these ores favours beneficiation, and they can be partially treated to yield ilmenite concentrates and low-titania magnetite fractions in which the content of vanadium pentoxide is higher than that in the original ores. The Mambula ores are silicate-rich and would require extensive beneficiation. The Kaffirskraal ores consist of multi-phase grains of titaniferous magnetite containing crystallographically oriented ilmenite, ulvospinel, and pleonaste micro-intergrowths. Minor coarser-grained ilmenite is also present. The Usushwana ores are texturaly similar but contain abundant lamellar ilmenite in place of the ulvospinel. The ores from these two complexes cannot be beneficiated by conventional ore-dressing techniques, and would require direct metallurgical treatment for the recovery of iron, titania, and vanadium pentoxide [af

  2. Preparation Of Pure Vanadium Pentoxide From Red Cake

    International Nuclear Information System (INIS)

    ZAREH, M.M.; EL-HAZEK, M.N; BU ZAID, A.H.M; MOHAMED, H.S.

    2010-01-01

    The red cake, extracted from petroleum ash by acid leaching, contains some impurities such as iron, nickel, zinc, Cr and Cu. For purification the red cake, vanadium in the red cake was taken into solution by treating the red cake with soda ash solution at 90 o C, S /L 1/10 and leaching time of 6 h. The obtained leaching efficiency of vanadium reached 99 %. The solution was clarified by filtration and slurred with solid ammonium sulphate (50g/l) and ammonium chloride (50 g/l). The pH of the slurry was kept at 8-9 by adding ammonium hydroxide. Ammonium metavanadate was crystallized from the slurry at room temperature and during the crystallization step, the slurry was kept under mild agitation. The reaction between the sodium vanadate and ammonium sulphate led to the formation of ammonium metavanadate (AMV) 98.35 % (atomic adsorption techniques). The AMV crystals were separated from the residual liquor by filtration, washed with 5% ammonium chloride solution then dried at 100 o C. Over 98.35 % of the vanadium contained in the red cake was recovered by this way as AMV. Thermal decomposition of AMV at 350 o C 1 h yielded 99.32 % pure vanadium pentoxide.

  3. Instrumental neutron activation analysis of iron and zinc in compact cosmetic products

    International Nuclear Information System (INIS)

    Kanias, G.D.

    1987-01-01

    An instrumental neutron activation analysis method is described for the determination of iron and zinc in compact eye shadow, compact face powder and compact rouge make-up cosmetic products. The steps of the procedure are: Irradiation of samples with thermal neutrons, counting of gamma-radioactivity of the radioisotopes of iron and zinc produced by this irradiation and calculation of the concentration of these elements from the gamma-ray spectra of samples and standards. Analysis of the I.A.E.A. standard reference material by this procedure give results in close agreement with certified values. The limit of quantitation is 45 μg for iron and 0.35 μg for zinc. The developed procedure could possibly be established as an official method for the simultaneous determination of iron and zinc in compact cosmetic products. (orig.) [de

  4. Evaluation of exploitation alternatives of iron - titanium - vanadium ore from Campo Alegre de Lourdes (Bahia-Brazil)

    International Nuclear Information System (INIS)

    Cassa, J.C.S.; Ogasawara, T.; Silva, F.T. da; Cuellar, O.D.

    1987-01-01

    An evaluation of experiences carried out in order to develop an economic process for vanadium, is presented. The attempts which are being developed in the Metallurgical Engineering Program at COPPE/UFRJ, are described, and the other technical and economical possibilities of existing technologies, are analysed. The advantages and disadvantages of integrated steel making process to recover iron, titanium and vanadium contained in the ore from Campo Alegre de Lourdes deposit, in Bahia-Brazil are considered. (Author) [pt

  5. High performance liquid chromatographic determination of vanadium in crude oils and cobalt and iron in pharmaceutical preparations

    International Nuclear Information System (INIS)

    Khuhawar, M.Y.; Lanjwani, S.N.; Khaskhely, G.Q.

    1993-01-01

    High performance liquid Chromatographic (HPLC) method has ben developed for the determination of vanadium in crude oils, based on acid decomposition of oils, followed by complexation with bis (salicylaldehyde) tetramethyl ethylenediamine (H2SA2Ten). The complex is extracted in organic phase and is separated from copper and nickel using normal phase HPLC column. Detection is achieved using spectrophtmetric detector. The vanadium in oil is obtained at sub microgram/g level. Similarly cobalt(II), cobalt(III) and iron(II) are separated on reversed phase HPLC column. Pre column derivatization is used to develop HPLC method for the determination of cobalt and iron in pharmaceutical preparations. Finally results are compared using atomic absorption spectrometer. (author)

  6. IRON-ZINC SUPPLEMENTATION AMONG ADOLESCENT GIRLS AT ELEMENTARY SCHOOL IN KUPANG CITY, EAST TIMOR PROVINCE.

    Directory of Open Access Journals (Sweden)

    Yustina Anie Indriastuti Kurniawan

    2014-09-01

    Full Text Available Anemia is the main micronutrient deficiency problem among adolescent girls in Indonesia. Anemia due to iron deficiency often coexists with zinc deficiency. Both iron deficiency anemia and zinc deficiency can increase the risk of obstetric complications among pregnant women i.e. bleeding during labor and post-partum hemorrhage. Iron-folate supplementation among pregnant women had been conducting since long time ago throughout this country; however, effort to improve the nutritional status particularly among adolescent girls prior to pregnancy is still lack behind. Iron and zinc have antagonistic interaction. Therefore it was challenging to alleviate anemia problem among adolescent girls with appropriate ratio of iron-zinc supplementation, and will give a benefit to improve their nutritional status. This study was aimed to investigate the different ratios of ironzinc supplementation on reducing the prevalence of anemia as improving the nutritional status of adolescent school girls.A female elementary school students age 10-12 years old (n= 137 were screened in rural area of Kupang City, East Timor Province. Subjects were assigned randomly to one of the three groups for daily iron-zinc supplementation for 12 weeks; Group 1 (iron; 60 mg/day, Group 2 (iron and zinc; 30 mg and 15 mg/day, Group 3 (iron and zinc; 60 mg and 15 mg/day. Hemoglobin concentration was measured by cyanmethemoglobin method (Hemocue to determine the prevalence of anemia (Hb level < 120 g/L, while anthropometric assessment was conducted for measuring weight and height to determine the nutritional status. General characteristics was assessed through interview. At base line, 29.1% of subjects suffered from anemia and in general, the prevalence was reduced to around 13.1% after they took iron supplements with or without zinc. Hemoglobin concentration was significantly increased among all subjects euther suffered from anemia or not. The result of this study showed that subject who

  7. Effect of zinc and/or iron supplementations on ICF-level in prepubertal anaemic girls

    International Nuclear Information System (INIS)

    Ayad, S.K.; Noure Eldin, A.M.

    2003-01-01

    The study was carried out to evaluate the effects of iron and zinc supplementations separated or combined on levels of iron, zinc and insulin like growth factor-1 (IGF-) in prepuberal girls suffering from iron deficiency anaemia. Hematological and biochemical changes of thirty two anaemic prepubertal girls (mean age 10.5 ± 2.01 year) were compared with normal fifteen girls have the same age. The anaemic girls were divided into three groups according to treatment; groupA (iron, group B(zinc) and group C (iron+zinc)and received supplementations for 8 weeks. Significant decreases in erythrocytic counts (RBCs), hemoglobin (Hb), hematocrit % (Hct%) and reticulocytes%(Rt%) were recorded in blood samples of the three groups before supplementations while non-significant differences were detected in the values of other blood indices. Significant decreases were detected in iron, zinc and IGF-1 levels while non-significant decrease in ferritin was detected in group (A). Erythropoietin and total iron binding capacity (TIBC) showed significant increases in the same group. Total iron binding capacity, iron, zinc and IGF-1 levels showed significant decreases while there were significant increases in erythropoetin and ferritin in group (B). The results revealed that ferritin,iron, zinc and IGF-1 levels were significantly decreased while erythropoietin and TIBC were significantly increased in group (C). After treatment, group (B) showed sligh significant increases in the concentration of Hb, Hct% and Rt%. with non-significant increase in RBCs count but in group (C) the results revealed significant increases in RBCs count, Hb, Hct% and Rt%. Non- significant differences were detected in RBCs count, Hb and Hct% in group (A) while significant increase was detected in Rt% in the same group

  8. Effect of molybdenum, vanadium, boron on mechanical properties of high chromium white cast iron in as-cast condition

    Science.gov (United States)

    Nurjaman, F.; Sumardi, S.; Shofi, A.; Aryati, M.; Suharno, B.

    2016-02-01

    In this experiment, the effect of the addition carbide forming elements on high chromium white cast iron, such as molybdenum, vanadium and boron on its mechanical properties and microstructure was investigated. The high chromium white cast iron was produced by casting process and formed in 50 mm size of grinding balls with several compositions. Characterization of these grinding balls was conducted by using some testing methods, such as: chemical and microstructure analysis, hardness, and impact test. From the results, the addition of molybdenum, vanadium, and boron on high chromium white cast iron provided a significant improvement on its hardness, but reduced its toughness. Molybdenum induced fully austenitic matrix and Mo2C formation among eutectic M7C3 carbide. Vanadium was dissolved in the matrix and carbide. While boron was played a role to form fine eutectic carbide. Grinding balls with 1.89 C-13.1 Cr-1.32 Mo-1.36 V-0.00051 B in as-cast condition had the highest hardness, which was caused by finer structure of eutectic carbide, needle like structure (upper bainite) matrix, and martensite on its carbide boundary.

  9. Vanadium

    International Nuclear Information System (INIS)

    Duke, V.W.A.

    1983-07-01

    Although a relatively abundant element, vanadium occurs only rarely in sufficient concentration to be worked commercially. In most cases, vanadium is produced as a co-product of some other element, most commonly iron. The principal ore deposits of vanadium occur in titaniferous magnetites that have been formed by magnetic segregation. Important commercial deposits of vanadium also occur associated with uranium, and with phosphate deposits. The principal uses of vanadium are in the production of special purpose, particularly high-strength low-alloy steels, in the manufacture of titanium alloys, and as a catalyst, notably in the manufacture of sulphuric acid. Small quantities of vanadium, often in combination with niobium, are added to steel to bring about toughening through grain refinement, and increased tensile strength through precipitation hardening. Known world reserves of vanadium are very large and fully adequate to meet any foreseeable demand. By far the largest known deposits of vanadium occur in South Africa. Many other similar deposits are known, but are only exploited in the USSR and China. The present total world demand for vanadium amounts to about 40 000 tons of metal annually and this is produced primarily in four countries, South Africa, the USSR, the People's Republic of China and the United States of America, in that order. South Africa is the principal vanadium producing country in the world, supplying vanadium in various forms. Vanadium has a very low and non-accumulative toxicity; recovery plants can be operated in such a manner to ensure no air or steam pollution results

  10. Iron and zinc bioaccessibility of fermented maize, sorghum and millets from five locations in Zimbabwe.

    Science.gov (United States)

    Gabaza, Molly; Shumoy, Habtu; Muchuweti, Maud; Vandamme, Peter; Raes, Katleen

    2018-01-01

    The present study is an evaluation of iron and zinc bioaccessibility of fermented maize, sorghum, pearl millet and finger millet from five different locations in Zimbabwe. Iron and zinc contents ranged between 3.22 and 49.7 and 1.25-4.39mg/100gdm, respectively. Fermentation caused a reduction of between 20 and 88% of phytic acid (PA) while a general increase in soluble phenolic compounds (PC) and a decrease of the bound (PC) was observed. Bioaccessibility of iron and zinc ranged between 2.77 and 26.1% and 0.45-12.8%, respectively. The contribution of the fermented cereals towards iron and zinc absolute requirements ranged between 25 and 411% and 0.5-23% with higher contribution of iron coming from cereals that were contaminated with extrinsic iron. Populations subsisting on cereals could be more at risk of zinc rather than iron deficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Relation between Omega 3 Fatty Acid, Iron, Zinc and Treatment of ADHD

    Directory of Open Access Journals (Sweden)

    Maryam Shalileh

    2014-10-01

    Full Text Available In some studies, it is suggested that a number of dietary factors including essential fatty acid, iron and zinc deficiency, may be linked to attention-deficit/hyperactivity-disorder (ADHD. However, the exact mechanism of this relationship is yet unclear. The purpose of this study is to investigate the relationship between omega-3 fatty acids, zinc, and iron in etiopathology and management of ADHD. For the purpose of this study, Science Direct, PubMed, and Medline databases were explored and thirty-four relevant articles in english language were collected. Eighteen out of twenty-two studies confirmed the relationship between omega-3 fatty acid and ADHD. In addition, the role of insufficient store of iron in developing ADHD symptoms and the positive effect of iron supplement in improvement of ADHD behavioral symptoms have been shown. Also, plasma zinc concentration in children with ADHD was lower than the normal population, and the effect of zinc supplement on reducing on attentive-deficit symptoms was contradictory. Although polyunsaturated fatty acids (PUFA and iron supplements are not suggested as main treatment for ADHD, but if future studies confirm the positive results of that, use of these supplements as complementary treatment will affect ADHD symptoms. Considering the little amount of studies on zinc, more research is necessary.

  12. Daily dietary intake of iron, copper, zinc and manganese in a Spanish population.

    Science.gov (United States)

    Rubio, Carmen; Gutiérrez, Angel José; Revert, Consuelo; Reguera, Juan Ignacio; Burgos, Antonio; Hardisson, Arturo

    2009-11-01

    To evaluate the daily dietary intake of essential metals in the Canary Islands, the iron, copper, zinc and manganese contents in 420 food and drink samples collected in local markets were analysed by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The estimated daily dietary intakes of iron, copper, zinc and manganese are 13.161 mg/day, 2.098 mg/day, 8.954 mg/day and 2.372 mg/day, respectively. The iron dietary intake was found to be below the recommendations fixed for adult women, while the copper and manganese dietary intakes fulfilled the Recommended Dietary Allowances. The mean daily intake of zinc was below the Recommended Dietary Allowance. Cereals were found to be the food group that contributed most to the intake of these metals. While the island of El-Hierro presented iron, copper, zinc and manganese mean intakes over the estimated intakes for the whole archipelago, Fuerteventura island showed the lowest intakes. Tenerife and Fuerteventura showed the lowest iron intakes, being below the recommendations.

  13. Novel hybrid materials based on the vanadium oxide nanobelts

    Energy Technology Data Exchange (ETDEWEB)

    Zabrodina, G.S., E-mail: kudgs@mail.ru [G.A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Nizhny Novgorod 603950 (Russian Federation); Lobachevsky State University, Nizhny Novgorod 603950 (Russian Federation); Makarov, S.G.; Kremlev, K.V. [G.A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Nizhny Novgorod 603950 (Russian Federation); Lobachevsky State University, Nizhny Novgorod 603950 (Russian Federation); Yunin, P.A.; Gusev, S.A. [Institute for Physics of Microstructures Russian Academy of Sciences, Nizhny Novgorod 603087 (Russian Federation); Kaverin, B.S.; Kaverina, L.B. [G.A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Nizhny Novgorod 603950 (Russian Federation); Ketkov, S.Yu. [G.A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Nizhny Novgorod 603950 (Russian Federation); Lobachevsky State University, Nizhny Novgorod 603950 (Russian Federation)

    2016-04-15

    Graphical abstract: - Highlights: • Flat and curved vanadium oxide nanobelts have been synthesized. • Hybrid material was prepared via decoration of flexible nanobelts with zinc phthalocyanine. • Investigations of the thermal stability, morphologies and structures were carried out. - Abstract: Novel hybrid materials based on zinc phthalocyanine and nanostructured vanadium oxides have attracted extensive attention for the development of academic research and innovative industrial applications such as flexible electronics, optical sensors and heterogeneous catalysts. Vanadium oxides nanobelts were synthesized via a hydrothermal treatment V{sub 2}O{sub 5}·nH{sub 2}O gel with surfactants (TBAB, CTAB) used as structure-directing agents, where CTAB – cetyltrimethylammonium bromide, TBAB – tetrabutylammonium bromide. Hybrid materials were prepared decoration of (CTA){sub 0.33}V{sub 2}O{sub 5} flexible nanobelts with cationic zinc phthalocyanine by the ion-exchange route. Investigations of the thermal stability, morphologies and structures of the (CTA){sub 0.33}V{sub 2}O{sub 5}, (TBA){sub 0.16}V{sub 2}O{sub 5} nanobelts and zinc phthalocyanine exchange product were carried out. The hybrid materials based on the nanostructured vanadium oxide and zinc phthalocyanine were tested as photocatalysts for oxidation of citronellol and 2-mercaptoethanol by dioxygen.

  14. Textural and morphological studies on zinc-iron alloy electrodeposits

    Indian Academy of Sciences (India)

    Zinc-iron alloy electrodeposits have industrial significance, since they provide better corrosion resistance and with improved mechanical properties when compared to pure zinc coatings. This is due to the unique phase structure of the alloy formed. But this deposition belongs to anomalous deposition, where the ...

  15. Sublethal effects of cadmium, manganese, lead, zinc and iron on the ...

    African Journals Online (AJOL)

    The toxicological evaluations of cadmium, iron, manganese, lead and zinc were carried out against albino mice model, Mus musculus. On the basis of 96 hrLC50 value, cadmium (0.47 mM) was found to be the most toxic followed by zinc (2.40 mM), lead (2.42 mM), iron (4.25 mM) and manganese (5.70 mM) was least toxic.

  16. Isolation and characterization of Lotus japonicus genes involved in iron and zinc homeostasis

    DEFF Research Database (Denmark)

    Cvitanich, Cristina; Jensen, Winnie; Sandal, Niels Nørgaard

    . Legumes are frequently grown in soil with limited nutrient availability. Plants use finely tuned mechanisms to keep appropriated levels of iron and zinc in each of their organs. Several genes involved in iron and zinc homeostasis have been described in yeast, and a few orthologs have been studied...... in plants. We have used these sequences to search for L. japonicus ESTs and genomic loci that are likely to be involved in iron and zinc metabolism. We have identified sequences corresponding to ferritins, ferric reductases, metal transport proteins of the ZIP family, and cation transporters of the NRAMP......The goal of this project is to find ways to improve the nutritional value of legumes by identifying genes and proteins important for iron and zinc regulation in the model legume Lotus japonicus. Legumes are important staples in the developing world and are a major source of nutrients in many areas...

  17. Effect of Initial Iron Content in a Zinc Bath on the Dissolution Rate of Iron During a Hot Dip Galvanizing Process

    Science.gov (United States)

    Lee, Sang Myung; Lee, Suk Kyu; Paik, Doo-Jin; Park, Joo Hyun

    2017-04-01

    The mechanism of iron dissolution and the effect of initial Fe content in a Zn bath on the dissolution rate of iron were investigated using a finger rotating method (FRM). When the initial iron content, [Fe]°, in the zinc bath was less than the solubility limit, the iron content in the zinc bath showed a rapid increase, whereas a moderate increase was observed when [Fe]° was close to the solubility limit. Based on Eisenberg's kinetic model, the mass transfer coefficient of iron in the present experimental condition was calculated to be k M = 1.2 × 10-5 m/s, which was similar to the results derived by Giorgi et al. under industrial practice conditions. A dissolution of iron occurred even when the initial iron content in the zinc bath was greater than the solubility limit, which was explained by the interfacial thermodynamics in conjunction with the morphology of the surface coating layer. By analyzing the diffraction patterns using TEM, the outermost dendritic-structured coating layer was confirmed as FeZn13 ( ζ). In order to satisfy the local equilibrium based on the Gibbs-Thomson equation, iron in the dendrite-structured phase spontaneously dissolved into the zinc bath, resulting in the enrichment of iron in front of the dendrite tip. Through the diffusion boundary layer in front of the dendritic-structured layer, dissolved Fe atoms diffused out and reacted with Zn and small amounts of Al, resulting in the formation of dross particles such as FeZn10Al x ( δ). It was experimentally confirmed that the smaller the difference between the initial iron content in the zinc bath and the iron solubility limit at a given temperature, the lower the number of formed dross particles.

  18. Zinc toxicity among galvanization workers in the iron and steel industry.

    Science.gov (United States)

    El Safty, Amal; El Mahgoub, Khalid; Helal, Sawsan; Abdel Maksoud, Neveen

    2008-10-01

    Galvanization is the process of coating steel or cast iron pieces with zinc, allowing complete protection against corrosion. The ultimate goal of this work was to assess the effect of occupational exposure to zinc in the galvanization process on different metals in the human body and to detect the association between zinc exposure and its effect on the respiratory system. This study was conducted in 111 subjects in one of the major companies in the iron and steel industry. There were 61 subjects (workers) who were involved in the galvanization process. Fifty adult men were chosen as a matched reference group from other departments of the company. All workers were interviewed using a special questionnaire on occupational history and chest diseases. Ventilatory functions and chest X rays were assessed in all examined workers. Also, complete blood counts were performed, and serum zinc, iron, copper, calcium, and magnesium levels were tested. This study illustrated the relation between zinc exposure in the galvanization process and high zinc levels among exposed workers, which was associated with a high prevalence rate of metal fume fever (MFF) and low blood copper and calcium levels. There was no statistically significant difference between the exposed and control groups with regards to the magnesium level. No long-term effect of metals exposure was detected on ventilatory functions or chest X rays among the exposed workers.

  19. Extraction of copper zinc and iron from hydrochloric acid solutions by means of different extractants

    Energy Technology Data Exchange (ETDEWEB)

    Zhivkova, Svetlana [Institute of Chemical Engineering - Bulgarian Academy of Sciences, Sofia (Bulgaria)

    2011-07-01

    The extraction of copper, zinc and iron from hydrochloric acid solutions has been studied. The experiments have been carried out using various solvents, involving different extraction mechanisms – solvating, anion-exchange, cation-exchange, bifunctional . Mixtures of these extractants have been also used. The extraction properties of these extractant mixtures toward copper, zinc and iron, the effect of used modifiers and diluents have been also investigated. Key words: Copper, Zinc, Iron, Extraction, Extractant, Modifier, Diluent.

  20. Iron Bioavailability from Ferric Pyrophosphate in Extruded Rice Cofortified with Zinc Sulfate Is Greater than When Cofortified with Zinc Oxide in a Human Stable Isotope Study.

    Science.gov (United States)

    Hackl, Laura; Zimmermann, Michael B; Zeder, Christophe; Parker, Megan; Johns, Paul W; Hurrell, Richard F; Moretti, Diego

    2017-03-01

    Background: Extruded rice grains are often cofortified with iron and zinc. However, it is uncertain if the addition of zinc to iron-fortified rice affects iron absorption and whether this is zinc-compound specific. Objective: We investigated whether zinc, added as zinc oxide (ZnO) or zinc sulfate (ZnSO 4 ), affects human iron absorption from extruded rice fortified with ferric pyrophosphate (FePP). Methods: In 19 iron-depleted Swiss women (plasma ferritin ≤16.5 μ/L) aged between 20 and 39 y with a normal body mass index (in kg/m 2 ; 18.7-24.8), we compared iron absorption from 4 meals containing fortified extruded rice with 4 mg Fe and 3 mg Zn. Three of the meals contained extruded rice labeled with FePP ( 57 FePP): 1 ) 1 meal without added zinc ( 57 FePP-Zn), 2 ) 1 cofortified with ZnO ( 57 FePP+ZnO), and 3 ) 1 cofortified with ZnSO 4 ( 57 FePP+ZnSO 4 ). The fourth meal contained extruded rice without iron or zinc, extrinsically labeled with ferrous sulfate ( 58 FeSO 4 ) added as a solution after cooking. All 4 meals contained citric acid. Iron bioavailability was measured by isotopic iron ratios in red blood cells. We also measured relative in vitro iron solubility from 57 FePP-Zn, 57 FePP+ZnO, and 57 FePP+ZnSO 4 expressed as a fraction of FeSO 4 solubility. Results: Geometric mean fractional iron absorption (95% CI) from 57 FePP+ZnSO 4 was 4.5% (3.4%, 5.8%) and differed from 57 FePP+ZnO (2.7%; 1.8%, 4.1%) ( P iron bioavailabilities compared with 58 FeSO 4 were 62%, 57%, and 38% from 57 FePP+ZnSO 4 , 57 FePP-Zn, and 57 FePP+ZnO, respectively. In vitro solubility from 57 FePP+ZnSO 4 differed from that of 57 FePP-Zn (14.3%; P iron-depleted women, iron absorption from FePP-fortified extruded rice cofortified with ZnSO 4 was 1.6-fold (95% CI: 1.4-, 1.9-fold) that of rice cofortified with ZnO. These findings suggest that ZnSO 4 may be the preferable zinc cofortificant for optimal iron bioavailability of iron-fortified extruded rice. This trial was registered at

  1. Hydrometallurgical process for recovering iron sulfate and zinc sulfate from baghouse dust

    Science.gov (United States)

    Zaromb, Solomon; Lawson, Daniel B.

    1994-01-01

    A process for recovering zinc/rich and iron-rich fractions from the baghouse dust that is generated in various metallurgical operations, especially in steel-making and other iron-making plants, comprises the steps of leaching the dust by hot concentrated sulfuric acid so as to generate dissolved zinc sulfate and a precipitate of iron sulfate, separating the precipitate from the acid by filtration and washing with a volatile liquid, such as methanol or acetone, and collecting the filtered acid and the washings into a filtrate fraction. The volatile liquid may be recovered distillation, and the zinc may be removed from the filtrate by alternative methods, one of which involves addition of a sufficient amount of water to precipitate hydrated zinc sulfate at 10.degree. C., separation of the precipitate from sulfuric acid by filtration, and evaporation of water to regenerate concentrated sulfuric acid. The recovery of iron may also be effected in alternative ways, one of which involves roasting the ferric sulfate to yield ferric oxide and sulfur trioxide, which can be reconverted to concentrated sulfuric acid by hydration. The overall process should not generate any significant waste stream.

  2. Zinc Absorption from Micronutrient Powder Is Low but Is not Affected by Iron in Kenyan Infants

    Directory of Open Access Journals (Sweden)

    Fabian Esamai

    2014-12-01

    Full Text Available Interference with zinc absorption is a proposed explanation for adverse effects of supplemental iron in iron-replete children in malaria endemic settings. We examined the effects of iron in micronutrient powder (MNP on zinc absorption after three months of home fortification with MNP in maize-based diets in rural Kenyan infants. In a double blind design, six-month-old, non-anemic infants were randomized to MNP containing 5 mg zinc, with or without 12.5 mg of iron (MNP + Fe and MNP − Fe, respectively; a control (C group received placebo powder. After three months, duplicate diet collections and zinc stable isotopes were used to measure intake from MNP + non-breast milk foods and fractional absorption of zinc (FAZ by dual isotope ratio method; total absorbed zinc (TAZ, mg/day was calculated from intake × FAZ. Mean (SEM TAZ was not different between MNP + Fe (n = 10 and MNP − Fe (n = 9 groups: 0.85 (0.22 and 0.72 (0.19, respectively, but both were higher than C (n = 9: 0.24 (0.03 (p = 0.04. Iron in MNP did not significantly alter zinc absorption, but despite intakes over double estimated dietary requirement, both MNP groups’ mean TAZ barely approximated the physiologic requirement for age. Impaired zinc absorption may dictate need for higher zinc doses in vulnerable populations.

  3. Selectivity in the oxidative dehydrogenation of butene on zinc-iron oxide catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Kung, H.H.; Kundalkar, B.; Kung, M.C.; Cheng, W.H.

    1980-02-21

    Adsorption, temperature-programed desorption, and pulse reaction studies of cis-2-butene and butadiene on spinel zinc ferrite by previously described methods provided evidence that the selectivity for oxidative dehydrogenation of butenes increases when zinc is added to the iron oxide catalyst because selective oxidation and complete oxidation proceed on separate sites, as they do on pure iron; because the density of sites for selective oxidation is higher and the density of sites for complete combustion is lower than on pure iron oxide; and because the activity of the combustion sites is lower.

  4. Scaling-up biofortified beans high in iron and zinc through the school-feeding program

    NARCIS (Netherlands)

    Beintema, Joni J.S.; Gallego-Castillo, Sonia; Londoño-Hernandez, Luis F.; Restrepo-Manjarres, José; Talsma, Elise F.

    2018-01-01

    Iron and zinc deficiencies are global health problems, affecting mostly pregnant women and young children. In 2016, biofortified iron and zinc beans were introduced in Colombia. The incorporation of biofortified beans into the national school-feeding program could facilitate adoption and potentially

  5. [Interaction among the trace elements zinc, copper and iron after depletion and repletion of dairy cows with zinc].

    Science.gov (United States)

    Kirchgessner, M; Schwarz, F J; Roth, H P; Schwarz, W A

    1978-12-01

    Imbalances in the supply with trace elements may be caused by the excessive administration of one or several elements or the insufficient administration in relation to other trace elements. This article deals with the interactions between the trace elements zinc and copper resp. zinc and iron under the conditions of the insufficient supply with Zn (6 mg per kg dry matter of the fodder) and the supply according to the demand with other trace elements (14 mg copper resp. 83 mg iron per dry matter of the fodder). For this purpose we investigated the copper, iron and zinc content of the milk and the serum of cows that were first depleted of zinc through a semi-synthetic zinc deficiency diet and then repleted with extra allowances of zinc. The closest connections exist between the copper and zinc content of the milk. Thus extreme Zn-deficiency feeding conditions the decreased Zn-content on the one hand and increased Cu-content on the other. In contrast to this, the cows' Zn-excretion in the milk increases after Zn-repletion whereas the Cu-content decreases. This shows a distinctly negative correlation. A loose connection could only be detected for the Cu- and Zn-content of the serum. Though the Zn-content changed considerably in dependence on the Zn-supply, the Cu-content remained largely uninfluenced. The Fe-content of both milk and serum shows no interaction with the nutritive Zn-supply. Only after 19 test weeks of extreme Zn-deficiency could a slight increase of the Fe-concentration be indicated.

  6. A COMMUNITY BASED RANDOMIZED CONTROLLED TRIAL OF IRON AND ZINC SUPPLEMENTATION IN INFANTS: EFFECTS ON GROWTH AND DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    T. Lind

    2006-01-01

    Full Text Available Deficiencies of iron and zinc are associated with delayed development, growth faltering, and increased infectious disease morbidity during infancy and childhood. Combined iron and zinc supplementation may therefore be a logical preventive strategy. Objective: the objective of the study was to compare the effects of combined iron and zinc supplementation in infancy with the effects of iron and zinc as single micronutrients on growth, psychomotor development, and incidence of infectious disease. Design: Indonesian infants (n = 680 were randomly assigned to daily supplementation with 10 mg Fe (Fe group, 10 mg Zn (Zn group, 10 mg Fe and 10 mg Zn (Fe + Zn group, or placebo from 6 to 12 mo of age. Anthropometric indexes, developmental indexes (bay ley scales of infant development; sid, and morbidity were recorded. Results: at 12 mo, two factor analysis of variance showed a significant interaction between Iron and Zinc for weight for age z score, knee heel length, and sid psychomotor development. Weight forage z score was higher in the Zn group than in the placebo and Fe + Zn groups, knee heel length was higher in the Zn and Fe groups than in the placebo group, and the sid psychomotor development index was higher in the Fe group than in the placebo group. No significant effect on morbidity was found. Conclusions: single supplementation with zinc significantly improved growth, and single supplementation with iron significantly improved growth and psychomotor development, but combined supplementation with iron and zinc had no significant effect on growth or development. Combined, simultaneous supplementation with iron and zinc to infants cannot be routinely recommended at the iron to zinc ratio used in this study.Key words: infants, growth, knee heel length, development, iron, zinc.

  7. Biofortification of wheat grain with iron and zinc: integrating novel genomic resources and knowledge from model crops

    Directory of Open Access Journals (Sweden)

    Philippa eBorrill

    2014-02-01

    Full Text Available Wheat, like many other staple cereals, contains low levels of the essential micronutrients iron and zinc. Up to two billion people worldwide suffer from iron and zinc deficiencies, particularly in regions with predominantly cereal-based diets. Although wheat flour is commonly fortified during processing, an attractive and more sustainable solution is biofortification, which requires developing new varieties of wheat with inherently higher iron and zinc content in their grains. Until now most studies aimed at increasing iron and zinc content in wheat grains have focused on discovering natural variation in progenitor or related species. However, recent developments in genomics and transformation have led to a step change in targeted research on wheat at a molecular level. We discuss promising approaches to improve iron and zinc content in wheat using knowledge gained in model grasses. We explore how the latest resources developed in wheat, including sequenced genomes and mutant populations, can be exploited for biofortification. We also highlight the key research and practical challenges that remain in improving iron and zinc content in wheat.

  8. Extraction-complexonometric determination of vanadium(4) in the presence of vanadium(3)

    International Nuclear Information System (INIS)

    Gordeeva, M.N.; Ryndina, A.M.; Stanevich, T.V.

    1976-01-01

    The extraction-complexonometric method has been investigated for determining vanadium(4) in the presence of vanadium (3) with high contents of these forms in the solution analyzed. The method of separation of V(4) and V(3) is based on extraction of the ion acetate of vanadium(4) with eriochrome red B(ERCB) and diphenyl quanidinium (DPG) by a mixture of chloroform and isoamyl alcohol (3:1). To control the content of V(4) and V(3) the method of reciprocal complexonometric titration is used (the titrating solution was a solution of thorium nitride, and xylenol orange was a solution of thorium nitride, and xylenol orange was used as metal indicator). Titration has been carried out in an acid solution at pH=2.8. The developed method has been applied to analysis of lithium-zinc spinels containing both forms of vanadium

  9. Vitamin A, iron and zinc deficiency in Indonesia : micronutrient interactions and effects of supplementation

    NARCIS (Netherlands)

    Dijkhuizen, M.A.; Wieringa, F.T.

    2001-01-01

    The research described in this thesis was concerned with vitamin A, iron and zinc deficiency in pregnant and lactating women and in infants. The effects of supplementation withβ-carotene, iron and zinc on micronutrient status, growth, pregnancy outcome and immune function, and interactions

  10. Iron and zinc absorption from weaning foods prepared from germinated cereals and legumes

    International Nuclear Information System (INIS)

    Kuizon, M.D.

    1992-01-01

    Iron deficiency anaemia is a public health problem in the Philippines especially in infants, children and pregnant women. The immediate cause is inadequate intake of available iron to meet increased iron requirements. Iron supplementation studies on pregnant women showed improvement in haemoglobin level and reduction of prevalence of anaemia. A project on iron fortification of rice with ferrous sulphate is going on. It is proposed to study iron and zinc absorption from weaning food prepared from germinated rice: mungbean, germinated rice: cowpea, and germinated corn:mungbean to support the finding that these formulations will alleviate not only protein-energy malnutrition but contribute to improvement of iron status as well since iron contents are higher and anti-nutritional factors (phytates and tannin) are either reduced or eliminated. This study aims to measure the iron and zinc absorption from weaning foods prepared from germinated rice-mungbean, germinated rice-cowpea, and germinated corn-mungbean and to indicate usefullness of modifying local foods to improve iron absorption. 24 refs, 4 figs

  11. Isotope aided studies on the bioavailability of iron and zinc from human diets consumed in India

    International Nuclear Information System (INIS)

    Raghuramulu, N.; Das, P.; Prasad, P.

    1994-01-01

    Total iron, and zinc, in-vitro ionizable iron and soluble zinc were estimated by the chemical and extrinsic isotope tag methods for comparison in various foodstuffs as such, and after processing, and also in diets. It has been observed that the values got were more or less similar by both the procedures. The in-vitro ionizable iron in groundnut was low with low total iron as well. Total iron and ionizable iron were also estimated in commonly consumed breakfast preparations. The effect of tea on ionizable iron when taken along with breakfast was also investigated. It was found that different breakfast preparations varied narrowly with regards to total iron (4.6-7.2 mg) and percent ionizable iron (25%-33%). However, tea had a pronounced effect on ionizable iron resulting in inhibition to various extents. Total and soluble zinc were analyzed in green leafy vegetables and groundnut. Though the total zinc was low and similar in both foodstuffs, the percent soluble Zn was found to be high in green leafy vegetables as compared to groundnut. Tannin and ascorbic acid contents were estimated in a few foodstuffs. Tannin content in green leafy vegetables was found to be about 150 mg. Ascorbic acid concentration was high in cereals (except in rice) and whole pulses. The split pulses (dals) were found to be poor sources of ascorbic acid. Ionizable iron and soluble zinc were found to increase to various extents on processing. Germination was found to increase ascorbic acid, whereas it had no effect on tannin. (author). 4 figs, 8 tabs

  12. A comparative study of all-vanadium and iron-chromium redox flow batteries for large-scale energy storage

    Science.gov (United States)

    Zeng, Y. K.; Zhao, T. S.; An, L.; Zhou, X. L.; Wei, L.

    2015-12-01

    The promise of redox flow batteries (RFBs) utilizing soluble redox couples, such as all vanadium ions as well as iron and chromium ions, is becoming increasingly recognized for large-scale energy storage of renewables such as wind and solar, owing to their unique advantages including scalability, intrinsic safety, and long cycle life. An ongoing question associated with these two RFBs is determining whether the vanadium redox flow battery (VRFB) or iron-chromium redox flow battery (ICRFB) is more suitable and competitive for large-scale energy storage. To address this concern, a comparative study has been conducted for the two types of battery based on their charge-discharge performance, cycle performance, and capital cost. It is found that: i) the two batteries have similar energy efficiencies at high current densities; ii) the ICRFB exhibits a higher capacity decay rate than does the VRFB; and iii) the ICRFB is much less expensive in capital costs when operated at high power densities or at large capacities.

  13. Binding of zinc and iron to wheat bread, wheat bran, and their components.

    Science.gov (United States)

    Ismail-Beigi, F; Faraji, B; Reinhold, J G

    1977-10-01

    Wholemeal wheat bread decreases the availability and intestinal absorption of divalent metals. To define this action further, binding of zinc in vitro to a wheat wholemeal bread (Tanok), dephytinized Tanok, and cellulose was determined at pH 5.0 to 7.5. Zinc binding by each was highly pH-dependent and reached a maximum at pH 6.5 to 7.5. Removal of phytate from Tanok did not reduce its binding capability. Wheat bran at pH 6.5 and 6.8 bound 72% of iron (0.5 microgram/ml of solution) and 82.5% of zinc (1.43 microgram/ml solution), respectively. Lignin and two of the hemicellulose fractions of wheat bran and high binding capabilities for zinc (85.6, 87.1, and 82.1%, respectively) whereas a third had a lower zinc-binding capability (38.7%). Binding of zinc to various celluloses and dextrans is also demonstrated. Formation of complexes of these metals with wheat fiber can explain, at least in part, the decreased availability of dietary iron and zinc in wholemeal wheat bread.

  14. Iron and Vitamin C Co-Supplementation Increased Serum Vitamin C Without Adverse Effect on Zinc Level in Iron Deficient Female Youth

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Khoshfetrat

    2014-01-01

    Full Text Available Background: Iron supplementation can decrease the absorption of zinc and influence other antioxidants levels such as vitamin C. This study aimed to investigate the effect of iron supplements alone and in combination with vitamin C on zinc and vitamin C status in iron deficient female students. Methods: In a double-blind randomized clinical trail, 60 iron deficient students were selected from 289 volunteers residing in dormitory. After matching, subjects were randomly assigned into two groups: Group I (50 mg elemental iron supplements and Group II (50 mg elemental iron + 500 mg ascorbic acid. Serum ferritin, iron, serum zinc, and plasma vitamin C concentrations were measured by using enzyme-linked immunosorbent assay, spectrophotometer, atomic absorption spectrometer, and colorimeter, respectively after 6 and 12 weeks supplementation. Student′s t-test and repeated measures analysis of variance were applied to analyze the data using SPSS software. Results: Serum zinc levels had no significant differences between 2 groups at the baseline; however, its concentration decreased from 80.9 ± 4.2-68.9 ± 2.7 μg/dl to 81.2 ± 4.5-66.1 ± 2.9 μg/dl (P < 0.001 in Groups I and II, respectively after 6 weeks of supplementation. Continuous supplementation increased serum zinc concentration to baseline levels (79.0 ± 2.9 μg/dl; P < 0.01 in Group I and 70.5 ± 3.1 μg/dl in Group II following 12 weeks of supplementation. Plasma vitamin C increased from 3 ± 0/1-3.3 ± 0.2 mg/dl to 2.7 ± 0. 1-4.2 ± 0.2 mg/dl (P < 0.01 in Groups I and II, respectively. At the end of study, plasma vitamin C significantly increased from 3.3 ± 0.3-4.7 ± 0.3 (P < 0.01 to 4.2 ± 0.2-7.1 ± 0.2 (P < 0.001 in Groups I and II, respectively. Conclusions: Iron supplementation with and without vitamin C led to reduction in serum Zn in iron-deficient female students after 6 weeks. However, the decreasing trend stops after repletion of iron stores and Zn levels returned to the

  15. Determination of cadmium in zinc ores by thermal neutron absorption analysis

    International Nuclear Information System (INIS)

    De Norre, L.; Op de Beeck, J.; Hoste, J.

    1983-01-01

    A method has been developed for routine determination of cadmium in zinc ores by thermal neutron absorption analysis, based on the attenuation of a thermal neutron flux passing through a neutron absorbing material. The thermal neutron flux in related to the 52 V activity induced in a vanadium detector, surrounded by pellets pressed from a mixture of powdered material with graphite. Besides cadmium, also the major constituents zinc, iron and sulfur contribute significantly to the total attenuation of the thermal neutron flux. Calibration lines for these elements are worked out. All irradiations are carried out for 200 s in the partially thermalized neutron flux of a 5 Ci 227 Ac-Be isotope neutron source. After a decay of 30 s, the 52 V activity of the vanadium detector is measured for 400 s with a NaI(Tl) scintillation detector. The analysis sequence, including the computation of the results from the counting data, is automated by means of a LSI-11 Microprocessor with 12Kx16 bit memory. Zinc ores, containing 0.02 to 1.45% cadmium, have been analyzed with a precision ranging from 12.6% to 0.54%, resp. As a test for the reliability of the method, two NBS standard reference materials were analyzed in the same way as the zinc ore samples. (author)

  16. ARTICLE - Path analysis of iron and zinc contents and others traits in cowpea

    Directory of Open Access Journals (Sweden)

    Jeane de Oliveira Moura

    2012-12-01

    Full Text Available The objective of this study was to estimate the direct and indirect effects of agronomic and culinary traits on iron and zinc contents in 11 cowpea populations. Correlations between traits were estimated and decomposed into direct and indirect effects using path analysis. For the study populations, breeding for larger grain size, higher number of grains per pod, grain yield, reduced cooking time, and number of days to flowering can lead to decreases in the levels of iron and zinc in the grain. Genetic gains for the iron content can be obtained by direct selection for protein content by indirect effects on the number of grains per pod, 100-grain weight and grain yield. The positive direct effect of grain size and protein content on the zinc content indicates the possibility of simultaneous gain by combined selection of these traits.

  17. Energy dispersive x-ray fluorescence spectrometric determination of phosphorus, calcium, iron, zinc, and strontium in human bones

    International Nuclear Information System (INIS)

    Ohta, Akishige; Matsubayashi, Takashi; Itoman, Moritoshi

    1981-01-01

    Phosphorus, calcium, iron, zinc and strontium in a human bone extracted by surgery were determined by energy dispersive X-ray fluorescence spectrometry. The bone was decomposed with nitric acid, then diluted with water. A specific quantity of the solution was naturally dried on polyethylene film, and subjected to X-ray analysis. For determining the calibration curves in a mixture of phosphorus, calcium, iron, zinc and strontium, for the analysis of phosphorus and calcium, germanium was used as the secondary target and aluminum as the filter; and for the analysis of iron, zinc and strontium, molybdenum and molybdenum-aluminum were used, respectively. Consequently, the calibration curves were able to be obtained with high precision in the ranges from 5 to 500 μg of phosphorus, from 1 to 50 μg of calcium and from 0.1 to 1.0 μg of iron, zinc and strontium. In this way, in 1 mg of the human bone by wet weight, phosphorus, calcium, iron, zinc and strontium were able to be determined. (J.P.N.)

  18. Microadditions of boron and vanadium in ADI

    Directory of Open Access Journals (Sweden)

    Rzychoń T.

    2007-01-01

    Full Text Available In the second part of the study, describing the role of vanadium and boron microadditions in the process of structure formation in heavy-walled castings made from ADI, the results of own investigations were presented. Within this study two series of melts of the ductile iron were made, introducing microadditions of the above mentioned elements to both unalloyed ductile iron and the ductile iron containing high levels of nickel and copper (the composition typical of ADI. Melts were conducted with iron-nickel-magnesium master alloy. Thermal analysis of the solidification process of the cast keel blocks was conducted, the heat treatment of the alloys was carried out, and then the effect of the introduced additions of boron and vanadium on the hardenability of the investigated cast iron was examined and evaluated.

  19. Medicago truncatula Zinc-Iron Permease6 provides zinc to rhizobia-infected nodule cells.

    Science.gov (United States)

    Abreu, Isidro; Saéz, Ángela; Castro-Rodríguez, Rosario; Escudero, Viviana; Rodríguez-Haas, Benjamín; Senovilla, Marta; Larue, Camille; Grolimund, Daniel; Tejada-Jiménez, Manuel; Imperial, Juan; González-Guerrero, Manuel

    2017-11-01

    Zinc is a micronutrient required for symbiotic nitrogen fixation. It has been proposed that in model legume Medicago truncatula, zinc is delivered by the root vasculature into the nodule and released in the infection/differentiation zone. There, transporters must introduce this element into rhizobia-infected cells to metallate the apoproteins that use zinc as a cofactor. MtZIP6 (Medtr4g083570) is an M. truncatula Zinc-Iron Permease (ZIP) that is expressed only in roots and nodules, with the highest expression levels in the infection/differentiation zone. Immunolocalization studies indicate that it is located in the plasma membrane of nodule rhizobia-infected cells. Down-regulating MtZIP6 expression levels with RNAi does not result in any strong phenotype when plants are fed mineral nitrogen. However, these plants displayed severe growth defects when they depended on nitrogen fixed by their nodules, losing of 80% of their nitrogenase activity. The reduction of this activity was likely an indirect effect of zinc being retained in the infection/differentiation zone and not reaching the cytosol of rhizobia-infected cells. These data are consistent with a model in which MtZIP6 would be responsible for zinc uptake by rhizobia-infected nodule cells in the infection/differentiation zone. © 2017 John Wiley & Sons Ltd.

  20. The Balance of Titanium and Vanadium in the Blast Furnace with the Use of Sinter Containing a Titanium-Vanadium-Magnetite Concentrate

    Directory of Open Access Journals (Sweden)

    Budzik, R.

    2007-01-01

    Full Text Available The investigation concerned the use of sinter containing a titanium-vanadium-magnetite concentrate for the production of pig iron. Sinter containing 0,46 to 0,51 % TiO2 and 0,056 to 0,060 % vanadium was used for pig iron production in the blast furnace. Introducing 200 kg of this concentrate to the1 Mg sinter mix did not cause any deterioration of sinter quality.

  1. Serum zinc, copper and iron status of children with coeliac disease on three months of gluten-free diet with or without four weeks of zinc supplements: a randomised controlled trial.

    Science.gov (United States)

    Negi, K; Kumar, R; Sharma, L; Datta, S P; Choudhury, M; Kumar, P

    2018-04-01

    Data about the effect of zinc supplementation with gluten-free diet on normalisation of plasma zinc, copper and iron in patients with coeliac disease are scanty. We evaluated the effect of zinc supplementation on serum zinc, copper and iron levels in patients with coeliac disease, by randomising 71 children newly diagnosed with coeliac disease into two groups: Group A = gluten-free diet (GFD); and Group B = gluten-free diet with zinc supplements (GFD +Zn). The rise in iron and zinc was significantly higher in the latter, but the mean rise of copper levels was slightly higher in the former, but the difference was not significant.

  2. Determination of iron, copper, manganese and zinc in the soils, grapes and wines of the Azores

    Directory of Open Access Journals (Sweden)

    María Teresa Ribeiro de Lima

    2004-06-01

    Full Text Available This paper describes the determination of iron, copper, manganese and zinc in the soils, grapes and wines of the three viticultural regions of the Azores. Iron, copper and zinc were determined by flame atomic absorption spectrometry and manganese by graphite furnace atomic absorption. The concentrations of the four elements differed in soils of the three regions; there was no difference in the concentration in grapes, whereas significant differences were observed for the wines as regards the amounts of iron, manganese and zinc. The concentrations of these four elements in wine correspond with the mean values observed for other European regions.

  3. Effects of calcium carbonate and hydroxyapatite on zinc and iron retention in postmenopausal women

    International Nuclear Information System (INIS)

    Dawson-Hughes, B.; Seligson, F.H.; Hughes, V.A.

    1986-01-01

    We measured the effect of calcium carbonate and hydroxyapatite on whole-body retention of zinc-65 in 11 and iron-59 in 13 healthy, postmenopausal women. In a single-blind, controlled, crossover study, each subject, on three occasions, ingested a standard test meal supplemented with iron-59 or zinc-65 and capsules containing placebo or 500 mg elemental calcium as calcium carbonate or hydroxyapatite. Whole-body countings were performed prior to, 30 min after, and 2 wk after each meal. Mean (SEM) zinc retention was 18.1 +/- 1.0% with placebo (control) and did not vary significantly with calcium carbonate (110.0 +/- 8.6% of control) or hydroxyapatite (106.0 +/- 7.9% of control). Iron retention, 6.3 +/- 2.0% with placebo, was significantly reduced with both calcium carbonate (43.3 +/- 8.8% of control, p = 0.002) and hydroxyapatite (45.9 +/- 10.0% of control, p = 0.003). Iron absorption may be significantly reduced when calcium supplements are taken with meals

  4. Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

    Science.gov (United States)

    Natalio, Filipe; André, Rute; Hartog, Aloysius F.; Stoll, Brigitte; Jochum, Klaus Peter; Wever, Ron; Tremel, Wolfgang

    2012-08-01

    Marine biofouling--the colonization of small marine microorganisms on surfaces that are directly exposed to seawater, such as ships' hulls--is an expensive problem that is currently without an environmentally compatible solution. Biofouling leads to increased hydrodynamic drag, which, in turn, causes increased fuel consumption and greenhouse gas emissions. Tributyltin-free antifouling coatings and paints based on metal complexes or biocides have been shown to efficiently prevent marine biofouling. However, these materials can damage the environment through metal leaching (for example, of copper and zinc) and bacteria resistance. Here, we show that vanadium pentoxide nanowires act like naturally occurring vanadium haloperoxidases to prevent marine biofouling. In the presence of bromide ions and hydrogen peroxide, the nanowires catalyse the oxidation of bromide ions to hypobromous acid (HOBr). Singlet molecular oxygen (1O2) is formed and this exerts strong antibacterial activity, which prevents marine biofouling without being toxic to marine biota. Vanadium pentoxide nanowires have the potential to be an alternative approach to conventional anti-biofouling agents.

  5. Iron and zinc absorption from weaning foods prepared from germinated cereals and legumes using isotope tracers

    Energy Technology Data Exchange (ETDEWEB)

    Valdez, D H; Kuizon, M D; Marero, L M; Mallillin, A C; Cruz, E M; Madriaga, J R [Department of Science and Technology, Manila (Philippines). Food and Nutrition Research Inst.

    1994-12-31

    Iron bioavailability from weaning foods prepared from 70:30 combination of germinated rice:mungbean (GRM); germinated rice: cowpea (GRC) and germinated corn:mungbean (GCM) was determined by radioisotopic measurements of iron absorption in human subjects. The gruels were prepared as plain with sugar and flavoring labeled by the extrinsic tag method, and served as hot porridge. It was estimated that iron-deficient infants would absorb 3.5% from GRM, 4.9% from GRC and 5.6% from GCM. Differences between absorption among the weaning foods were not statistically significant. Planning of diets for these age group should include other sources of iron especially heme. Zinc absorption from the weaning food formulations will be studied by the in vitro and in vivo methods. For the in vivo method on human subjects, the absorption of zinc will be determined from the measurement of the whole body retention of the isotope 14 days after intake of the labeled mean. Serum zinc level will be determined to assess the zinc status of the subjects. (author). 23 refs, 1 fig., 4 tabs.

  6. Iron and zinc absorption from weaning foods prepared from germinated cereals and legumes using isotope tracers

    International Nuclear Information System (INIS)

    Valdez, D.H.; Kuizon, M.D.; Marero, L.M.; Mallillin, A.C.; Cruz, E.M.; Madriaga, J.R.

    1994-01-01

    Iron bioavailability from weaning foods prepared from 70:30 combination of germinated rice:mungbean (GRM); germinated rice: cowpea (GRC) and germinated corn:mungbean (GCM) was determined by radioisotopic measurements of iron absorption in human subjects. The gruels were prepared as plain with sugar and flavoring labeled by the extrinsic tag method, and served as hot porridge. It was estimated that iron-deficient infants would absorb 3.5% from GRM, 4.9% from GRC and 5.6% from GCM. Differences between absorption among the weaning foods were not statistically significant. Planning of diets for these age group should include other sources of iron especially heme. Zinc absorption from the weaning food formulations will be studied by the in vitro and in vivo methods. For the in vivo method on human subjects, the absorption of zinc will be determined from the measurement of the whole body retention of the isotope 14 days after intake of the labeled mean. Serum zinc level will be determined to assess the zinc status of the subjects. (author). 23 refs, 1 fig., 4 tabs

  7. Combined in situ zymography, immunofluorescence, and staining of iron oxide particles in paraffin-embedded, zinc-fixed tissue sections.

    Science.gov (United States)

    Haeckel, Akvile; Schoenzart, Lena; Appler, Franziska; Schnorr, Joerg; Taupitz, Matthias; Hamm, Bernd; Schellenberger, Eyk

    2012-01-01

    Superparamagnetic iron oxide particles are used as potent contrast agents in magnetic resonance imaging. In histology, these particles are frequently visualized by Prussian blue iron staining of aldehyde-fixed, paraffin-embedded tissues. Recently, zinc salt-based fixative was shown to preserve enzyme activity in paraffin-embedded tissues. In this study, we demonstrate that zinc fixation allows combining in situ zymography with fluorescence immunohistochemistry (IHC) and iron staining for advanced biologic investigation of iron oxide particle accumulation. Very small iron oxide particles, developed for magnetic resonance angiography, were applied intravenously to BALB/c nude mice. After 3 hours, spleens were explanted and subjected to zinc fixation and paraffin embedding. Cut tissue sections were further processed to in situ zymography, IHC, and Prussian blue staining procedures. The combination of in situ zymography as well as IHC with subsequent Prussian blue iron staining on zinc-fixed paraffin-embedded tissues resulted in excellent histologic images of enzyme activity, protease distribution, and iron oxide particle accumulation. The combination of all three stains on a single section allowed direct comparison with only moderate degradation of fluorescein isothiocyanate-labeled substrate. This protocol is useful for investigating the biologic environment of accumulating iron oxide particles, with excellent preservation of morphology.

  8. The solvent extraction of zinc, iron, and indium from chloride solutions by neutral organophosphorus compounds

    International Nuclear Information System (INIS)

    Preston, J.S.; Du Preez, A.C.

    1985-01-01

    The preparation of several neutral organophosphorus compounds and their evaluation as selective extractants for zinc in chloride media are described. The compounds belong to the series trialkyl phosphates (RO) 3 PO, dialkyl alkylphosphonates R'PO(OR) 2 , alkyl dialkylphosphinates R 2 'PO(OR), and trialkyl-phosphine oxides R 3 'PO. They were characterized by measurement of their physical properties (melting and boiling points, refractive indices, and densities), and their purities were confirmed by osmometric determination of their molecular masses; by carbon and hydrogen microanalysis; by the titrimetric determination of acidic impurities; and, for liquid products, by comparison of their experimental molar refractivities with empirical values. Metal-distribution equilibria were determined for solutions of the extractants in xylene and aqueous phase containing 0,5 to 5,0 M sodium chloride. Moderately good selectivities were shown for zinc(II) over iron(III), and excellent selectivities were shown for zinc(II) over iron(II), copper(II), lead(II), and cadmium(II). The extraction of indium(III) was similar to that of zinc(II). The extraction of zinc(III), iron(III), and indium(III) increased markedly through the series. (RO) 3 PO 2 2 'PO(OR) 3 'PO. The incorporation of phenyl groups into the compounds led to weaker extraction. The extracted complexes of zinc(II), iron(III), and indium(III) have the stoichiometries ZnCl 2 L 2 ,FeCl 3 L 2 (H 2 O), and InCl 3 L 2 (H 2 O) respectively, where L represents the neutral organophosphorus compound

  9. Effects of separate delivery of zinc or zinc and vitamin A on hemoglobin response, growth, and diarrhea in young Peruvian children receiving iron therapy for anemia.

    Science.gov (United States)

    Alarcon, Karl; Kolsteren, Patrick W; Prada, Ana M; Chian, Ana M; Velarde, Ruth E; Pecho, Iris L; Hoeree, Tom F

    2004-11-01

    Anemia is the most prevalent nutritional deficiency in the world. Attempts to improve iron indexes are affected by deficiency of and interaction between other micronutrients. Our goal was to assess whether zinc added to iron treatment alone or with vitamin A improves iron indexes and affects diarrheal episodes. This was a randomized, placebo-controlled, double-blind trial conducted in Peru. Anemic children aged 6-35 mo were assigned to 3 treatment groups: ferrous sulfate (FS; n = 104), ferrous sulfate and zinc sulfate (FSZn; n = 109), and ferrous sulfate, zinc sulfate, and vitamin A (FSZnA; n = 110). Vitamin A or its placebo was supplied only once; iron and zinc were provided under supervision >/=1 h apart 6 d/wk for 18 wk. The prevalence of anemia was 42.97%. The increase in hemoglobin in the FS group (19.5 g/L) was significantly less than that in the other 2 groups (24.0 and 23.8 g/L in the FSZn and FSZnA groups, respectively). The increase in serum ferritin in the FS group (24.5 mug/L) was significantly less than that in the other 2 groups (33.0 and 30.8 mug/L in the FSZn and FSZnA groups, respectively). The median duration of diarrhea and the mean number of stools per day was significantly higher in the FS group than in other 2 groups (P < 0.005). Adding zinc to iron treatment increases hemoglobin response, improves iron indexes, and has positive effects on diarrhea. No additional effect of vitamin A was found.

  10. Visible photocatalytic properties of vanadium doped zinc oxide aerogel nanopowder

    Energy Technology Data Exchange (ETDEWEB)

    Slama, R. [Laboratoire de Physique des Materiaux et des Nanomateriaux appliquee a l' Environnement, Faculte des Sciences de Gabes, Universite de Gabes, Cite Erriadh Manara Zrig, 6072 Gabes (Tunisia); Unite de Recherche Environnement, Catalyse et Analyse des procedes URECAP (UR/99/11-20), Ecole Nationale d' Ingenieurs de Gabes, Universite de Gabes, Route de Medenine 6029 Gabes (Tunisia); Ghribi, F. [Laboratoire de Physique des Materiaux et des Nanomateriaux appliquee a l' Environnement, Faculte des Sciences de Gabes, Universite de Gabes, Cite Erriadh Manara Zrig, 6072 Gabes (Tunisia); Houas, A. [Unite de Recherche Environnement, Catalyse et Analyse des procedes URECAP (UR/99/11-20), Ecole Nationale d' Ingenieurs de Gabes, Universite de Gabes, Route de Medenine 6029 Gabes (Tunisia); Barthou, C. [Institut des NanoSciences de Paris (INSP), UPMC Universite Paris 6, CNRS UMR 7588, 140 rue de Lourmel, F-75015 Paris France (France); El Mir, L., E-mail: Lassaad.ElMir@fsg.rnu.tn [Laboratoire de Physique des Materiaux et des Nanomateriaux appliquee a l' Environnement, Faculte des Sciences de Gabes, Universite de Gabes, Cite Erriadh Manara Zrig, 6072 Gabes (Tunisia); College of Sciences, Department of Physics, Al-Imam Muhammad Ibn Saud University, Riyadh 11623 (Saudi Arabia)

    2011-06-30

    Vanadium-doped zinc oxide nanoparticles have been synthesized by sol-gel method. In our approach the water for hydrolysis used in the synthesis of nanopowder was slowly released followed by a thermal drying in ethyl alcohol at 250 deg. C. The obtained nanopowder was characterized by various techniques such as particle size analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and photoluminescence (PL). In the as-prepared state, the powder with an average particle size of 25 nm presents a strong luminescence band in the visible range. From photoluminescence excitation (PLE) the energy position of the obtained PL band depends on the excitation wavelength and this PL band can be also observed under visible excitations. This result is very promising for visible photo catalysis applications, which was confirmed by methylene blue photo-degradation using visible lamp as a light source. - Research Highlights: > We explore the impact of plot size on estimation of a small watershed outputs. > Different lengths and fixed width plots were installed on two slope aspects. > The performance of two similar sets of experimental plots was examined. > The optimal lengths for estimation of sediment and runoff were finally found.

  11. The Influence of Iron and Zinc Supplementation on the Bioavailability of Provitamin A Carotenoids from Papaya Following Consumption of a Vitamin A-Deficient Diet.

    Science.gov (United States)

    Kana-Sop, Marie Modestine; Gouado, Inocent; Achu, Mercy Bih; Van Camp, John; Amvam Zollo, Paul Henri; Schweigert, Florian J; Oberleas, Donald; Ekoe, Tetanye

    2015-01-01

    Iron deficiency anemia, zinc and vitamin A deficiencies are serious public health problems in Cameroon, as in many developing countries. Local vegetables which are sources of provitamin A carotenoids (PACs) can be used to improve vitamin A intakes. However, traditional meals are often unable to cover zinc and iron needs. The aim of this study was to determine the bioavailability of 3 PACs (α-carotene, β-carotene, and β-cryptoxanthin) in young men, who were fed with a vitamin A-free diet and received iron and zinc supplementation. Twelve healthy participants were divided into three groups and were supplemented with elemental iron (20 mg of iron fumarate), 20 mg of zinc sulfate or iron+zinc (20 mg of iron in the morning and 20 mg of zinc in the evening) for 11 d. They were given a vitamin A- and PAC-free diet from the 6th to the 11th day, followed by a test meal containing 0.55 kg of freshly peeled papaya as a source of PACs. Blood samples were collected four times successively on the 11th day (the test meal day), at T0 (just after the test meal), after 2 h (T2), after 4 h (T4) and after 7 h (T7). Ultracentrifugation was used to isolate serum chylomicrons. Retinol appearance and PAC postprandial concentrations were determined. The supplementation with zinc, iron and iron+zinc influenced the chylomicron appearance of retinol and PACs differently as reflected by retention times and maximum absorption peaks. Iron led to highest retinol levels in the chylomicron. Zinc and iron+zinc supplements were best for optimal intact appearance of α-carotene, β-carotene and β-cryptoxanthin respectively. Supplementation with iron led to the greatest bioavailability of PACs from papaya and its conversion to retinol.

  12. Impurity states of vanadium in cadmium and zinc tellurides

    International Nuclear Information System (INIS)

    Gnatenko, Yu.P.; Farina, I.A.

    1996-01-01

    Low-temperature optical (4.5 K) and photoelectrical properties of CdTe and ZnTe crystals doped by vanadium are invetigated. The energies of carrier transition to valence and conduction bands, Mott-Habbard energy for 3d 3 -ion vanadium in both crystals are determined. The resonance of the excited 4 T l ( 4 P)-state of V 2+ -ion with the conduction band of CdTe crystal is found. 8 bibl.; 4 figs

  13. Extraction of bivalent vanadium as its pyridine thiocyanate complex and separation from uranium, titanium, chromium and aluminium

    International Nuclear Information System (INIS)

    Yatirajam, V.; Arya, S.P.

    1975-01-01

    A simple method is described for the extraction of V(II) as its pyridine thiocyanate complex. Vanadate is reduced to V(II) in 1 to 2 N sulphuric acid by zinc amalgam. Thiocyanate and pyridine are added, the solution is adjusted to pH 5.2 to 5.5 and the complex extracted with chloroform. The vanadium is back-extracted with peroxide solution. Zinc from the reductant accompanies the vanadium but alkali and alkaline earth metal ions, titanium, uranium, chromium and aluminium are separated, besides those ions reduced to the elements by zinc amalgam. The method takes about 20 min and is applicable to microgram as well as milligram amounts of vanadium. (author)

  14. Association of Maternal Diet With Zinc, Copper, and Iron Concentrations in Transitional Human Milk Produced by Korean Mothers

    Science.gov (United States)

    Kim, Ji-Myung; Lee, Ji-Eun; Cho, Mi Sook; Kang, Bong Soo; Choi, Hyeon

    2016-01-01

    The aims of this study were to evaluate zinc, copper, and iron concentrations in the transitory milk of Korean lactating mothers and to investigate the relationship between these concentrations and maternal diet. Human milk samples were collected between 5 and 15 days postpartum from 96 healthy, lactating mothers in postpartum care centers in Seoul, Korea. Dietary intake during lactation was determined based on a 3-day dietary record. The mean zinc, copper, and iron concentrations in the human milk samples collected were 3.88 ± 1.74 mg/L, 0.69 ± 0.25 mg/L, and 5.85 ± 8.53 mg/L, respectively. The mothers who consumed alcoholic beverages during pregnancy had tended to have lower concentrations of zinc and copper, as well as significantly lower concentrations of iron, in their milk (p < 0.047). In contrast, the mothers who took daily supplements had much higher iron concentrations in their milk (p = 0.002). Dietary intakes of zinc, copper, and iron during lactation did not affect the concentrations of zinc, copper, and iron in the milk samples analyzed. Intakes of vitamin C, selenium, and iodine were associated with the concentration of copper in the milk samples analyzed, and consumption of food categorized as 'meat and meat products' was positively associated with the concentration of zinc. Consumption of rice was the top contributor to the concentrations of all three minerals. In conclusion, associations between maternal diet and nutrient concentrations in transitory human milk can provide useful information, particularly in regard to infant growth. PMID:26839873

  15. Zinc bioleaching from an iron concentrate using Acidithiobacillus ferrooxidans strain from Hercules Mine of Coahuila, Mexico

    Science.gov (United States)

    Núñez-Ramírez, Diola Marina; Solís-Soto, Aquiles; López-Miranda, Javier; Pereyra-Alférez, Benito; Rutiaga-Quiñónes, Miriam; Medina-Torres, Luis; Medrano-Roldán, Hiram

    2011-10-01

    The iron concentrate from Hercules Mine of Coahuila, Mexico, which mainly contained pyrite and pyrrhotite, was treated by the bioleaching process using native strain Acidithiobacillus ferrooxidans ( A. ferrooxidans) to determine the ability of these bacteria on the leaching of zinc. The native bacteria were isolated from the iron concentrate of the mine. The bioleaching experiments were carried out in shake flasks to analyze the effects of pH values, pulp density, and the ferrous sulfate concentration on the bioleaching process. The results obtained by microbial kinetic analyses for the evaluation of some aspects of zinc leaching show that the native bacteria A. ferrooxidans, which is enriched with a 9K Silverman medium under the optimum conditions of pH 2.0, 20 g/L pulp density, and 40 g/L FeSO4, increases the zinc extraction considerably observed by monitoring during15 d, i.e., the zinc concentration has a decrease of about 95% in the iron concentrate.

  16. Bioavailability of Iron, Zinc, Phytate and Phytase Activity during Soaking and Germination of White Sorghum Varieties

    Science.gov (United States)

    Afify, Abd El-Moneim M. R.; El-Beltagi, Hossam S.; Abd El-Salam, Samiha M.; Omran, Azza A.

    2011-01-01

    The changes in phytate, phytase activity and in vitro bioavailability of iron and zinc during soaking and germination of three white sorghum varieties (Sorghum bicolor L. Moench), named Dorado, Shandweel-6, and Giza-15 were investigated. Sorghum varieties were soaked for 20 h and germinated for 72 h after soaking for 20 h to reduce phytate content and increase iron and zinc in vitro bioavailability. The results revealed that iron and zinc content was significantly reduced from 28.16 to 32.16% and 13.78 to 26.69% for soaking treatment and 38.43 to 39.18% and 21.80 to 31.27% for germination treatments, respectively. Phytate content was significantly reduced from 23.59 to 32.40% for soaking treatment and 24.92 to 35.27% for germination treatments, respectively. Phytase enzymes will be activated during drying in equal form in all varieties. The results proved that the main distinct point is the change of phytase activity as well as specific activity during different treatment which showed no significant differences between the varieties used. The in vitro bioavailability of iron and zinc were significantly improved as a result of soaking and germination treatments. PMID:22003395

  17. Noninvasive analysis of skin iron and zinc levels in beta-thalassemia major and intermedia

    International Nuclear Information System (INIS)

    Gorodetsky, R.; Goldfarb, A.; Dagan, I.; Rachmilewitz, E.A.

    1985-01-01

    Diagnostic x-ray spectrometry, a method based on x-ray fluorescence analysis, was used for noninvasive determination of iron and zinc in two distinct skin areas, representing predominantly dermal and epidermal tissues, in 56 patients with beta-thalassemia major and intermedia. The mean iron levels in the skin of patients with beta-thalassemia major and intermedia were elevated by greater than 200% and greater than 50%, respectively, compared with control values. The zinc levels of both skin areas examined were within the normal range. The data indicate that the rate and number of blood transfusions, which correlated well with serum ferritin levels (r . 0.8), are not the only factors that determine the amount of iron deposition in the skin (r less than 0.6). Other sources of iron intake contribute to the total iron load in the tissues, particularly in patients who are not given multiple transfusions. The noninvasive quantitation of skin levels may reflect the extent of iron deposition in major parenchymal organs. Repeated DXS examinations of the skin could monitor the clearance of iron from the tissues of patients with iron overload in the course of therapy with chelating agents

  18. Influence of heat processing on the bioaccessibility of zinc and iron from cereals and pulses consumed in India.

    Science.gov (United States)

    Hemalatha, Sreeramaiah; Platel, Kalpana; Srinivasan, Krishnapura

    2007-01-01

    Influence of heat processing on the bioaccessibility of zinc and iron from food grains consumed in India was evaluated. Cereals - rice (Oryza sativa), finger millet (Eleusine coracana), sorghum (Sorghum vulgare), wheat (Triticum aestivum), and maize (Zea mays), and pulses - chickpea (Cicer arietinum) - whole and decorticated, green gram (Phaseolus aureus) - whole and decorticated, decorticated black gram (Phaseolus mungo), decorticated red gram (Cajanus cajan), cowpea (Vigna catjang), and French bean (Phaseolus vulgaris) were examined for zinc and iron bioaccessibility by employing an in vitro dialysability procedure. Both pressure-cooking and microwave heating were tested for their influence on mineral bioaccessibility. Zinc bioaccessibility from food grains was considerably reduced upon pressure-cooking, especially in pulses. Among cereals, pressure-cooking decreased zinc bioaccessibility by 63% and 57% in finger millet and rice, respectively. All the pressure-cooked cereals showed similar percent zinc bioaccessibility with the exception of finger millet. Bioaccessibility of zinc from pulses was generally lower as a result of pressure-cooking or microwave heating. The decrease in bioaccessibility of zinc caused by microwave heating ranged from 11.4% in chickpea (whole) to 63% in cowpea. Decrease in zinc bioaccessibility was 48% in pressure-cooked whole chickpea, 45% and 55% in pressure-cooked or microwave-heated whole green gram, 32% and 22% in pressure-cooked or microwave-heated decorticated green gram, and 45% in microwave-heated black gram. Iron bioaccessibility, on the other hand, was significantly enhanced generally from all the food grains studied upon heat treatment. Thus, heat treatment of grains produced contrasting effect on zinc and iron bioaccessibility.

  19. Iron, folacin, vitamin B12 and zinc status and immune response in the elderly

    International Nuclear Information System (INIS)

    Henry-Christian, J.R.; Johnson, A.A.; Walters, C.S.; Greene, E.J.; Lindsey, A.A.

    1986-01-01

    The relationships of iron, folacin, vitamin B 12 and zinc status to cell-mediated immune response were investigated among 125 healthy, elderly persons (60-87 years of age). Plasma ferritin, plasma and red cell folate, and plasma vitamin B 12 levels were assayed immuno-radiometrically. Plasma and hair zinc levels were determined by atomic absorption spectroscopy. Immune response was determined by transformation of peripheral blood lymphocytes after stimulation with phytohemagglutinin (PHA) and concanavalin A (con A), and in mixed lymphocyte reaction. Deficiencies of iron, folacin vitamin B 12 and zinc were each associated (independently) with significantly lower lymphocyte responses to PHA and con A, and mixed lymphocyte reaction (P 12 or zinc. Further, they suggest that deficiencies of these nutrients may play a role in the depression of cell-mediated immunity with age, which in turn may lead to increased susceptibility to infectious diseases and cancer in the elderly

  20. Bioavailability of iron and zinc in green leafy vegetables growing in river side and local areas of Allahabad district

    Directory of Open Access Journals (Sweden)

    Bhawna Srivastava

    2014-01-01

    Full Text Available Introduction: Green Leafy Vegetables (GLVs are the treasure trove of many micronutrients.Objective: The aim of the study is to find out the commonly growing vegetables in river side and local areas of Allahabad district and to access the bioavailability of iron and zinc in selected green leafy vegetables of river side and local areas of Allahabad district.Methods: Five to four commonly grown green leafy vegetables were selected from the Arailghat, Baluaghat, Gaughat, Mahewa, Muirabad, Rajapur, Rasullabad for the study. Total iron and zinc in sample were estimated by AOAC (2005 and bioavailability of zinc and iron from various food samples was determined in vitro method described by Luten (1996. Appropriate statistical technique was adopted for analysis of study.Result: Soya leaves, Radish leaves, Amaranth, Spinach were grown in both the areas except Kulpha and Karamwa, which are commonly grown in river side area. There was a significant difference between the bioavailability of iron and zinc in GLV grown in local and river side area.Conclusion: Hence it can be concluded that there is a contamination of heavy metals which binds with the iron and zinc and make them less bioavailable in the selected GLV.

  1. Effect of different home-cooking methods on the bioaccessibility of zinc and iron in conventionally bred cowpea (Vigna unguiculata L. Walp) consumed in Brazil.

    Science.gov (United States)

    Pereira, Elenilda J; Carvalho, Lucia M J; Dellamora-Ortiz, Gisela M; Cardoso, Flávio S N; Carvalho, José L V

    2016-01-01

    The cowpea (Vigna unguiculata L. Wap.) is an excellent source of iron and zinc. However, iron from plant sources is poorly absorbed compared with iron from animal sources. The objective of this study was to evaluate iron and zinc bioaccessibility in cowpea cultivars after processing. Zinc and iron bioaccessibilities in cowpea samples were determined based on an in vitro method involving simulated gastrointestinal digestion with suitable modifications. When water-soaked beans were cooked in a regular pan, the highest percentage of bioaccessible iron obtained was 8.92%, whereas when they were cooked in a pressure cooker without previous soaking, the highest percentage was 44.33%. Also, the percentage of bioaccessible zinc was 52.78% when they were cooked in a regular pan without prior soaking. Higher percentages of bioaccessible iron were found when cooking was done in a pressure cooker compared with regular pan cooking. In all cultivars, cooking of cowpea beans in both pressure cooker and in a regular pan yielded higher percentages of bioaccessible zinc compared with availability of bioaccessible iron. Iron bioaccessibility values suggest that cooking in a regular pan did not have a good effect on iron availability, since the percentage of bioaccessible iron was lower than that of zinc. The determination of iron and zinc bioaccessibility makes it possible to find out the actual percentage of absorption of such minerals and allows the development of efficient strategies for low-income groups to access foods with high levels of these micronutrients.

  2. Trace Elements Iron, Copper and Zinc in Vitreous of Patients with Various Vitreoretinal Diseases

    Directory of Open Access Journals (Sweden)

    Sulochana Konerirajapuram

    2004-01-01

    Full Text Available Purpose: To measure the concentrations of iron, copper and zinc in human vitreous and to interpret their levels with various vitreoretinal diseases like proliferative diabetic retinopathy, retinal detachment, intraocular foreign body, Eales′ disease and macular hole. Methods: Undiluted vitreous fluid collected during pars plana vitrectomy was used to measure trace elements using an atomic absorption spectrophotometer. Results: The level of vitreous iron increased threefold in Eales′ disease (1.85 ± 0.36 pg/ml, 2.5-fold in proliferative diabetic retinopathy (1.534 ± 0.17 pg/ml and 2.3-fold in eyes with intraocular foreign body (1.341 ± 0.25 pg/ml when compared with macular hole (0.588 ± 0.16 pg/ml. This was statistically significant (P < 0.05. Zinc was found to be low in Eales′ disease (0.57 ± 0.22 pg/ml when compared with other groups, though the difference was not statistically significant. Conclusion: The increased level of iron with decreased zinc content in Eales′ disease confirms the earlier reported oxidative stress mechanism for the disease. In proliferative diabetic retinopathy and intraocular foreign body the level of iron increases. This is undesirable as iron can augment glycoxidation, which can lead to increased susceptibility to oxidative damage, in turn causing vitreous liquefaction, posterior vitreous detachment and ultimately retinal detachment and vision loss

  3. Highly Stable Aqueous Zinc-ion Storage Using Layered Calcium Vanadium Oxide Bronze Cathode

    KAUST Repository

    Xia, Chuan; Guo, Jing; Li, Peng; Zhang, Xixiang; Alshareef, Husam N.

    2018-01-01

    Cost-effective aqueous rechargeable batteries are attractive alternatives to non-aqueous cells for stationary grid energy storage. Among different aqueous cells, zinc-ion batteries (ZIBs), based on Zn2+ intercalation chemistry, stand out as they can employ high-capacity Zn metal as anode material. Herein, we report a layered calcium vanadium oxide bronze as cathode material for aqueous Zn batteries. For the storage of Zn2+ ions in aqueous electrolyte, we demonstrate that calcium based bronze structure can deliver a high capacity of 340 mAh g-1 at 0.2 C, good rate capability and very long cycling life (96% retention after 3000 cycles at 80 C). Further, we investigate the Zn2+ storage mechanism, and the corresponding electrochemical kinetics in this bronze cathode. Finally, we show that our Zn cell delivers an energy density of 267 Wh kg-1 at a power density of 53.4 W kg-1.

  4. Highly Stable Aqueous Zinc-ion Storage Using Layered Calcium Vanadium Oxide Bronze Cathode

    KAUST Repository

    Xia, Chuan

    2018-02-12

    Cost-effective aqueous rechargeable batteries are attractive alternatives to non-aqueous cells for stationary grid energy storage. Among different aqueous cells, zinc-ion batteries (ZIBs), based on Zn2+ intercalation chemistry, stand out as they can employ high-capacity Zn metal as anode material. Herein, we report a layered calcium vanadium oxide bronze as cathode material for aqueous Zn batteries. For the storage of Zn2+ ions in aqueous electrolyte, we demonstrate that calcium based bronze structure can deliver a high capacity of 340 mAh g-1 at 0.2 C, good rate capability and very long cycling life (96% retention after 3000 cycles at 80 C). Further, we investigate the Zn2+ storage mechanism, and the corresponding electrochemical kinetics in this bronze cathode. Finally, we show that our Zn cell delivers an energy density of 267 Wh kg-1 at a power density of 53.4 W kg-1.

  5. Isotope - aided studies of the bioavailability of iron and zinc from human diets consumed in Poland

    International Nuclear Information System (INIS)

    Rafalski, H.

    1992-01-01

    The main aims of the study were: 1) the evaluation of iron and zinc status in women of Lodz aged 18-45 years, 2) adaptation of the whole body counter to in vivo measurements absorption of iron given to the gastro-intestinal tract of volunteers and 3) in rat model estimation iron bioavailability from fortified wheat flour combined with products usually consumed in Poland. During five months investigations thirty seven women were examined each one twice in two months interval. Following variables were measured: iron and zinc in blood serum, in public and scalp hair and in food, taste acuity score, serum ferritin, hemoglobin, total iron binding capacity, red blood cells, mean corpuscular concentration and corpuscular volume. Prevalence of iron deficiency and iron deficient anemia were assessed by two models in terms of the depression of serum ferritin and hemoglobin concentrations. 64 refs, 6 figs, 23 tabs

  6. Zinc transporter ZIP14 functions in hepatic zinc, iron and glucose homeostasis during the innate immune response (endotoxemia.

    Directory of Open Access Journals (Sweden)

    Tolunay Beker Aydemir

    Full Text Available ZIP14 (slc39A14 is a zinc transporter induced in response to pro-inflammatory stimuli. ZIP14 induction accompanies the reduction in serum zinc (hypozincemia of acute inflammation. ZIP14 can transport Zn(2+ and non-transferrin-bound Fe(2+ in vitro. Using a Zip14(-/- mouse model we demonstrated that ZIP14 was essential for control of phosphatase PTP1B activity and phosphorylation of c-Met during liver regeneration. In the current studies, a global screening of ZIP transporter gene expression in response to LPS-induced endotoxemia was conducted. Following LPS, Zip14 was the most highly up-regulated Zip transcript in liver, but also in white adipose tissue and muscle. Using ZIP14(-/- mice we show that ZIP14 contributes to zinc absorption from the gastrointestinal tract directly or indirectly as zinc absorption was decreased in the KOs. In contrast, Zip14(-/- mice absorbed more iron. The Zip14 KO mice did not exhibit hypozincemia following LPS, but do have hypoferremia. Livers of Zip14-/- mice had increased transcript abundance for hepcidin, divalent metal transporter-1, ferritin and transferrin receptor-1 and greater accumulation of iron. The Zip14(-/- phenotype included greater body fat, hypoglycemia and higher insulin levels, as well as increased liver glucose and greater phosphorylation of the insulin receptor and increased GLUT2, SREBP-1c and FASN expression. The Zip14 KO mice exhibited decreased circulating IL-6 with increased hepatic SOCS-3 following LPS, suggesting SOCS-3 inhibited insulin signaling which produced the hypoglycemia in this genotype. The results are consistent with ZIP14 ablation yielding abnormal labile zinc pools which lead to increased SOCS-3 production through G-coupled receptor activation and increased cAMP production as well as signaled by increased pSTAT3 via the IL-6 receptor, which inhibits IRS 1/2 phosphorylation. Our data show the role of ZIP14 in the hepatocyte is multi-functional since zinc and iron trafficking are

  7. Preparation Of Pure Carbon From Heavy Oil Fly Ash

    International Nuclear Information System (INIS)

    ABU ZAID, A.H.M.

    2010-01-01

    The Egyptian production of heavy oil is approximately 12 million tons of heavy oil per year and approximately 5.3 million tons of this amount is used as fuel in the electric power stations. Based on the fact that the ash content of Egyptian heavy oil is approximately 0.2 %, about 10600 tons of fly ash is produced per/year which causes a lot of environmental problems such as dusting, release of the acidic liquids and heavy metals such as vanadium, nickel, zinc and unburned carbon. Treatment of fly ash by leaching of vanadium and zinc was carried out under different conditions to achieve the best leaching efficiency of both vanadium and zinc by sodium hydroxide. The leaching efficiency obtained was 91% for vanadium and 98% for zinc. This study was concerned with the precipitation of zinc at pH 7.5 as zinc hydroxide and the precipitation of vanadium as ammonium metavanadate at pH 8.5. Leaching of nickel, iron and other elements from the residue was carried out by 2M HCl under different conditions. The achieved leaching efficiency of nickel was 95% where as that of iron was 92%. Precipitation efficiency of both nickel and iron were 99.9%. The residue, which contains mainly unburned carbon, have been washed two times with water and dried at 200 o C then ground to < 300μm. According to the achieved analysis of the obtained carbon, it can be characterized as pure carbon

  8. A novel process for recovery of iron, titanium, and vanadium from titanomagnetite concentrates: NaOH molten salt roasting and water leaching processes

    International Nuclear Information System (INIS)

    Chen, Desheng; Zhao, Longsheng; Liu, Yahui; Qi, Tao; Wang, Jianchong; Wang, Lina

    2013-01-01

    Highlights: ► The conversion of titanium is 96.6% in the rich titanium–vanadium slag. ► MgTi 2 O 5 and M 3 O 5 (M = Ti, Mg, Fe) were converted to Na 2 TiO 3 and NaMO 2 , respectively. ► Na 2 TiO 3 is converted to undefined structure of H 2 TiO 3 . ► NaMO 2 is converted to α-NaFeO 2 -type structure of HMO 2 . ► 87.3% of sodium, 42.3% of silicon, 43.2% of aluminum, 22.8% of manganese and 96.6% of vanadium were leached out. -- Abstract: A novel process for recovering iron, titanium, and vanadium from titanomagnetite concentrates has been developed. In the present paper, the treatment of rich titanium–vanadium slag by NaOH molten salt roasting and water leaching processes is investigated. In the NaOH molten salt roasting process, the metallic iron is oxidized into ferriferous oxide, MgTi 2 O 5 is converted to NaCl-type structure of Na 2 TiO 3 , and M 3 O 5 (M = Ti, Mg, Fe) is converted to α-NaFeO 2 -type structure of NaMO 2 , respectively. Roasting temperature and NaOH–slag mass ratio played a considerable role in the conversion of titanium in the rich titanium–vanadium slag during the NaOH molten salt roasting process. Roasting at 500 °C for 60 min and a 1:1 NaOH–slag mass ratio produces 96.3% titanium conversion. In the water leaching process, the Na + was exchanged with H + , Na 2 TiO 3 is converted to undefined structure of H 2 TiO 3 , and NaMO 2 is converted to α-NaFeO 2 -type structure of HMO 2 . Under the optimal conditions, 87.3% of the sodium, 42.3% of the silicon, 43.2% of the aluminum, 22.8% of the manganese, and 96.6% of the vanadium are leached out

  9. Multimicronutrient Slow-Release Fertilizer of Zinc, Iron, Manganese, and Copper

    Directory of Open Access Journals (Sweden)

    Siladitya Bandyopadhyay

    2014-01-01

    Full Text Available The process for the production of a slow-release micronutrient fertilizer is described. The compound contains zinc, iron, manganese, and copper as micronutrients and is produced by polymerizing a system containing phosphoric acid, zinc oxide, hematite, pyrolusite, copper sulfate, and magnesium oxide followed by neutralization of the polyphosphate chain with ammonium hydroxide. Changes in temperature, density, and viscosity of the reaction system during polymerization were studied. Reaction kinetics was studied at three different temperatures. Rate curves revealed a multistage process with essentially linear rates at each stage. Thus, each stage displayed zero order kinetics. The product was crystalline and revealed ordering of P-O-P chains. It had low solubility in water but high solubility in 0.33 M citric acid and 0.005 M DTPA. Three different field trials showed significant yield increments using the slow-release micronutrient fertilizer compared to the conventional micronutrients. Yield increments in rice were in the range of 10–55% over control (with no micronutrient and up to 17% over the conventional micronutrient fertilizers. There were significant increases in total uptake of zinc, iron, and manganese in the grain. Slow-release fertilizers also produced significant yield increases in potato as well as significant increase in vitamin C content of the tuber.

  10. ENVIRONMENTAL IMPACT OF THE STORED DUST-LIKE ZINC AND IRON CONTAINING WASTES

    Directory of Open Access Journals (Sweden)

    Tatyana A. Lytaeva

    2017-05-01

    On the basis of laboratory research and field observations of the environmental components in the impact area of the storage of dust-like zinc and iron containing wastes, the article describes regularities of formation of hydrogeochemical halos of contamination by heavy metals and iron. Results include also the description of changes in physico-chemical groundwater composition under the storage area.

  11. Effect of different home-cooking methods on the bioaccessibility of zinc and iron in conventionally bred cowpea (Vigna unguiculata L. Walp consumed in Brazil

    Directory of Open Access Journals (Sweden)

    Elenilda J. Pereira

    2016-03-01

    Full Text Available Background: The cowpea (Vigna unguiculata L. Wap. is an excellent source of iron and zinc. However, iron from plant sources is poorly absorbed compared with iron from animal sources. Objectives: The objective of this study was to evaluate iron and zinc bioaccessibility in cowpea cultivars after processing. Methods: Zinc and iron bioaccessibilities in cowpea samples were determined based on an in vitro method involving simulated gastrointestinal digestion with suitable modifications. Results: When water-soaked beans were cooked in a regular pan, the highest percentage of bioaccessible iron obtained was 8.92%, whereas when they were cooked in a pressure cooker without previous soaking, the highest percentage was 44.33%. Also, the percentage of bioaccessible zinc was 52.78% when they were cooked in a regular pan without prior soaking. Higher percentages of bioaccessible iron were found when cooking was done in a pressure cooker compared with regular pan cooking. In all cultivars, cooking of cowpea beans in both pressure cooker and in a regular pan yielded higher percentages of bioaccessible zinc compared with availability of bioaccessible iron. Conclusions: Iron bioaccessibility values suggest that cooking in a regular pan did not have a good effect on iron availability, since the percentage of bioaccessible iron was lower than that of zinc. The determination of iron and zinc bioaccessibility makes it possible to find out the actual percentage of absorption of such minerals and allows the development of efficient strategies for low-income groups to access foods with high levels of these micronutrients.

  12. Sonochemically synthesized iron-doped zinc oxide nanoparticles: Influence of precursor composition on characteristics

    International Nuclear Information System (INIS)

    Roy, Anirban; Maitra, Saikat; Ghosh, Sobhan; Chakrabarti, Sampa

    2016-01-01

    Highlights: • Sonochemical synthesis of iron-doped zinc oxide nanoparticles. • Green synthesis without alkali at room temperature. • Characterization by UV–vis spectroscopy, FESEM, XRD and EDX. • Influence of precursor composition on characteristics. • Composition and characteristics are correlated. - Abstract: Iron-doped zinc oxide nanoparticles have been synthesized sonochemically from aqueous acetyl acetonate precursors of different proportions. Synthesized nanoparticles were characterized with UV–vis spectroscopy, X-ray diffraction and microscopy. Influences of precursor mixture on the characteristics have been examined and modeled. Linear correlations have been proposed between dopant dosing, extent of doping and band gap energy. Experimental data corroborated with the proposed models.

  13. Maternal Cadmium, Iron and Zinc Levels, DNA Methylation and Birth Weight

    Science.gov (United States)

    BACKGROUND:Cadmium (Cd) is a ubiquitous and environmentally persistent toxic metal that has been implicated in neurotoxicity, carcinogenesis and obesity and essential metals including zinc (Zn) and iron (Fe) may alter these outcomes. However mechanisms underlying these relationsh...

  14. The shaping of zinc coating on surface steels and ductile iron casting

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2010-01-01

    Full Text Available The studies aimed at an analysis of the formation and growth kinetics of zinc coating on reactive silicon-killed steels in a zinc bath. The growth kinetics of the produced zinc coatings was evaluated basing on the power-law growth equation. As regards galvanizing of the surface of products, investigation was done for various steel grades and ductile iron (DI taking into account the quality and thickness of coating. It has been proved that the chemical constitution of basis significantly influences the kinetics of growth of the individual phases in a zinc coating. This relationship was evaluated basing on the, so called, silicon and phosphorus equivalent ESi,P and coating thickness dependences were obtained.

  15. Zinc recovery from iron and steel making wastes by conventional and microwave assisted leaching

    Directory of Open Access Journals (Sweden)

    Ján Vereš

    2011-12-01

    Full Text Available Significant quantities of sludge and dust are generated as a waste material or byproduct every day from iron and steel industries.Nowadays The occurrence and recovery of metallurgical wastes from steelmaking and iron making processes is a great problem, mainlydue to the big amount and environmental pollution of these wastes by heavy metals. The future technology of fine-grain metallurgicalwastes treatment is mainly the thing of ecological and financial limits. This work explains the removal of zinc from blast furnace sludgeby hydrometallurgical process. The aim of this work was to carry out a chemical, physical, structural, and morphologicalcharacterization of these waste materials and subsequently to find out the best suitable method for the hydrometallurgical treatment.The experimental work includes full plant experiments. Extraction conditions such as the effect of microwave power, leaching agent,acid concentration, S/L ratio and extraction time on the zinc removal efficiency were evaluated. The main goal is to set the bestconditions to transfer zinc into the solution while the iron should to remain in the solid phase.

  16. Ab initio study of spin-dependent transport in carbon nanotubes with iron and vanadium adatoms

    DEFF Research Database (Denmark)

    Fürst, Joachim Alexander; Brandbyge, Mads; Jauho, Antti-Pekka

    2008-01-01

    (majority or minority) being scattered depends on the adsorbate and is explained in terms of d-state filling. We contrast the single-walled carbon nanotube results to the simpler case of the adsorbate on a flat graphene sheet with periodic boundary conditions and corresponding width in the zigzag direction......We present an ab initio study of spin-dependent transport in armchair carbon nanotubes with transition metal adsorbates: iron or vanadium. The method based on density functional theory and nonequilibrium Green's functions is used to compute the electronic structure and zero-bias conductance...

  17. Effects of chloride, sulfate and natural organic matter (NOM) on the accumulation and release of trace-level inorganic contaminants from corroding iron.

    Science.gov (United States)

    Peng, Ching-Yu; Ferguson, John F; Korshin, Gregory V

    2013-09-15

    This study examined effects of varying levels of anions (chloride and sulfate) and natural organic matter (NOM) on iron release from and accumulation of inorganic contaminants in corrosion scales formed on iron coupons exposed to drinking water. Changes of concentrations of sulfate and chloride were observed to affect iron release and, in lesser extent, the retention of representative inorganic contaminants (vanadium, chromium, nickel, copper, zinc, arsenic, cadmium, lead and uranium); but, effects of NOM were more pronounced. DOC concentration of 1 mg/L caused iron release to increase, with average soluble and total iron concentrations being four and two times, respectively, higher than those in the absence of NOM. In the presence of NOM, the retention of inorganic contaminants by corrosion scales was reduced. This was especially prominent for lead, vanadium, chromium and copper whose retention by the scales decreased from >80% in the absence of NOM to chloride levels. Modeling indicated that the observed effects were associated with the formation of metal-NOM complexes and effects of NOM on the sorption of the inorganic contaminants on solid phases that are typical for iron corrosion in drinking water. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Anemia and iron, zinc, copper and magnesium deficiency in Mexican adolescents: National Health and Nutrition Survey 2006.

    Science.gov (United States)

    De la Cruz-Góngora, Vanessa; Gaona, Berenice; Villalpando, Salvador; Shamah-Levy, Teresa; Robledo, Ricardo

    2012-01-01

    To describe the frequency of anemia and iron, zinc, copper and magnesium deficiencies among Mexican adolescents in the probabilistic survey ENSANUT 2006. The sample included 2447 adolescents aged 12 to 19 y. Capillary hemoglobin and venous blood samples were collected to measure the concentrations of ferritin, sTFR, CRP, zinc, iron, copper and magnesium. Logistic regression models were constructed to assess the risk for mineral deficiencies. The overall prevalence of anemia was 11.8 and 4.6%, body iron deficiency 18.2 and 7.9% for females and males, respectively. Overall prevalence of tissue iron deficiency was 6.9%, low serum copper were 14.4 and 12.25%; zinc 28.4 and 24.5%, magnesium 40 and 35.3%; for females and males, respectively. There is a high prevalence of mineral deficiency in Mexican adolescents; females were more prone to have more mineral deficiencies. Nutritional interventions are necessaries in order to reduce and control them.

  19. Acceptability and solubility of iron and zinc contents of modified Moringa oleifera sauces consumed in the Far-north region of Cameroon.

    Science.gov (United States)

    Mawouma, Saliou; Ponka, Roger; Mbofung, Carl Moses

    2017-03-01

    Consumption of Moringa oleifera leaves is a local and inexpensive solution to iron and zinc deficiencies in the Far-north region of Cameroon. However, traditional household's cooking techniques result in sauces with high pH levels and low leaves incorporation rates that compromise the bioavailability of iron and zinc. The aim of our study was to investigate the effect of modifying a standard Moringa sauce on consumer acceptability and the solubility of iron and zinc, which is an indicator of their bioavailability. Lime juice or tamarind pulp was added to a standard recipe in order to reduce the pH by about one unit, and Moringa leaf powder was incorporated in each acidulated sauce at three levels (1, 2, and 4 g/100 g of sauce). All the formulations were evaluated for their acceptability by 30 housewives using a five-point hedonic scale. The pH was measured by a digital electronic pH-meter. Moisture and ash were determined by AOAC methods. Total iron and zinc contents were determined by atomic absorption spectrophotometry, and soluble iron and zinc by HCl-extractability. The lime juice-acidulated sauce and the tamarind pulp-acidulated sauce enriched with 1 g of Moringa leaf powder were the most acceptable formulations with scores of 3.4 and 3.6, respectively. Their chemical analysis showed a reduced pH (6.4 and 6.1, respectively), compared to the Control (7.2). Lime juice-acidulated sauce improved iron and zinc solubility from 42.19 to 66.38% and 54.03 to 82.03%, respectively. Tamarind pulp-acidulated sauce enriched with 1 g of Moringa leaf powder showed a decrease in iron solubility from 42.19 to 38.26% and an increase in zinc solubility from 54.03 to 72.86%. These results confirm the beneficial effect of lime juice in improving iron and zinc bioavailability.

  20. Role of a gas phase in the kinetics of zinc and iron reduction with carbon from slag melts

    Science.gov (United States)

    Chumarev, V. M.; Selivanov, E. N.

    2013-03-01

    The influence of the mass transfer conditions in the gas phase having formed at the carbon-slag melt interface on CO regeneration is approximately estimated in the framework of a two-stage scheme of metal reduction from slag melts by carbon. The effect of zinc vapors on the combined reduction of iron and zinc from slags is considered. The influence of the slag composition and temperature on the critical concentration of zinc oxide above which no iron forms as an individual phase is explained.

  1. The Effect of Ductile Cast Iron Matrix on Zinc Coating During Hot Dip Galvanising of Castings

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2012-12-01

    Full Text Available The growth kinetics of the zinc coating formed on the surface of casting made from ductile iron grade EN-GJS-500-3 was investigated. To produce homogenous metal matrix in test samples, the normalising and ferritising annealing was carried out. Studies showeda heterogeneous structure of cast iron with varying content of the phases formed. This was followed by hot dip galvanising treatment at450°C to capture the growth kinetics of the zinc coating (the time of the treatment ranged from 60 to 600 seconds. Nonlinear estimation of the determined growth kinetics of the alloyed layer of a zinc coating was made and an equation of the zinc coating growth was derived.Based on the results of the investigations it was concluded that thickness of the zinc coating formed on the surface of casting with a 100% pearlitic matrix makes 55% of the thickness of coating formed on the surface in 100% ferritic.

  2. The Effect of Ductile Cast Iron Matrix on Zinc Coating During Hot Dip Galvanising of Castings

    Directory of Open Access Journals (Sweden)

    Kopyciński D.

    2012-12-01

    Full Text Available The growth kinetics of the zinc coating formed on the surface of casting made from ductile iron grade EN-GJS-500-3 was investigated. To produce homogenous metal matrix in test samples, the normalising and ferritising annealing was carried out. Studies showed a heterogeneous structure of cast iron with varying content of the phases formed. This was followed by hot dip galvanising treatment at 450°C to capture the growth kinetics of the zinc coating (the time of the treatment ranged from 60 to 600 seconds. Nonlinear estimation of the determined growth kinetics of the alloyed layer of a zinc coating was made and an equation of the zinc coating growth was derived. Based on the results of the investigations it was concluded that thickness of the zinc coating formed on the surface of casting with a 100% pearlitic matrix makes 55% of the thickness of coating formed on the surface in 100% ferritic.

  3. Micronutrient (provitamin A and iron/zinc) retention in biofortified crops

    African Journals Online (AJOL)

    Degradation also occurs during the storage of dried products (e.g. from sweet potato, maize, cassava) at ambient temperature, and a short shelf life is a constraint that should be considered when foods are biofortified for provitamin A. Iron and zinc retention were high for common beans (Phaseolus vulgaris) and cowpeas ...

  4. The use of radioisotopes and low abundance stable isotopes for the study of bioavailability and the metabolism of iron, zinc and copper

    International Nuclear Information System (INIS)

    Aggett, P.J.; Fairweather Tait, S.

    1994-01-01

    The use of whole body counting and imaging with ''area of interest'' counting to monitor the metabolism of zinc in healthy volunteers and patients with coeliac diseases and cirrhosis is described as are studies of interaction between iron and copper. Stable isotopes of iron, copper and zinc have been used to investigate the metabolism of these elements in young infants and have proved useful in assessing the validity of current estimated requirements particularly of iron. Stable isotopes have also been used to improve the classic metabolic balance approach to the study of the homeostasis of zinc in zinc deprived volunteers, and have progressed to studies using plasma kinetic curves of the systemic compartmentation of zinc

  5. Interaction genotype by season and its influence on the identification of beans with high content of zinc and iron

    Directory of Open Access Journals (Sweden)

    Camila Andrade Silva

    2012-01-01

    Full Text Available The mineral contents in common bean seeds are influenced, in addition to genetic variation, by environmental crop conditions, especially by the soil type and chemical composition and by the genotype x environment interaction. This study was carried out to verify if the zinc and iron contents are affected by the crop growing period. Ten lines with high iron and zinc contents and ten with low contents were assessed in three seasons: "wet season" of 2009/2010 (sowing in November; "dry season" of 2010 (sowing in February and "winter season" of 2010 (sowing in July, in Lavras, Minas Gerais State, Brazil. The experimental design used was randomized blocks with three replications and plots consisting of two rows of two meters, with a spacing of 0.50 m. The seeds harvested were assessed in regard to iron and zinc mineral contents. The greatest contents were observed in the winter season and the smallest ones in the dry season, with sowing in February. It was observed that in the mean of the three harvests, the lines classified as having high iron and zinc content exhibited an iron quantity 11.0% and a zinc quantity 6.8% above those of low content. The lines by seasons interaction occurs. However, its interference in identification of the groups with high and low content of the two nutrients is not great.

  6. Vanadium recycling in the United States in 2004

    Science.gov (United States)

    Goonan, Thomas G.

    2011-01-01

    As one of a series of reports that describe the recycling of metal commodities in the United States, this report discusses the flow of vanadium in the U.S. economy in 2004. This report includes a description of vanadium supply and demand in the United States and illustrates the extent of vanadium recycling and recycling trends. In 2004, apparent vanadium consumption, by end use, in the United States was 3,820 metric tons (t) in steelmaking and 232 t in manufacturing, of which 17 t was for the production of superalloys and 215 t was for the production of other alloys, cast iron, catalysts, and chemicals. Vanadium use in steel is almost entirely dissipative because recovery of vanadium from steel scrap is chemically impeded under the oxidizing conditions in steelmaking furnaces. The greatest amount of vanadium recycling is in the superalloy, other-alloy, and catalyst sectors of the vanadium market. Vanadium-bearing catalysts are associated with hydrocarbon recovery and refining in the oil industry. In 2004, 2,850 t of vanadium contained in alloy scrap and spent catalysts was recycled, which amounted to about 44 percent of U.S. domestic production. About 94 percent of vanadium use in the United States was dissipative (3,820 t in steel/4,050 t in steel+fabricated products).

  7. Genome Wide Identification of Orthologous ZIP Genes Associated with Zinc and Iron Translocation in Setaria italica.

    Science.gov (United States)

    Alagarasan, Ganesh; Dubey, Mahima; Aswathy, Kumar S; Chandel, Girish

    2017-01-01

    Genes in the ZIP family encode transcripts to store and transport bivalent metal micronutrient, particularly iron (Fe) and or zinc (Zn). These transcripts are important for a variety of functions involved in the developmental and physiological processes in many plant species, including most, if not all, Poaceae plant species and the model species Arabidopsis. Here, we present the report of a genome wide investigation of orthologous ZIP genes in Setaria italica and the identification of 7 single copy genes. RT-PCR shows 4 of them could be used to increase the bio-availability of zinc and iron content in grains. Of 36 ZIP members, 25 genes have traces of signal peptide based sub-cellular localization, as compared to those of plant species studied previously, yet translocation of ions remains unclear. In silico analysis of gene structure and protein nature suggests that these two were preeminent in shaping the functional diversity of the ZIP gene family in S. italica . NAC, bZIP and bHLH are the predominant Fe and Zn responsive transcription factors present in SiZIP genes. Together, our results provide new insights into the signal peptide based/independent iron and zinc translocation in the plant system and allowed identification of ZIP genes that may be involved in the zinc and iron absorption from the soil, and thus transporting it to the cereal grain underlying high micronutrient accumulation.

  8. Iron and zinc deficiencies in China: existing problems and possible solutions

    NARCIS (Netherlands)

    Guansheng Ma,

    2007-01-01

    Micronutrient deficiencies affect the health and development of the population of China as well as its socia] and economic development. Iron and zinc deficiencies are quite prevalent, while insufficient intake and poor bioavailability are the major causes. Phytate is be!ieved to bc a potent

  9. Identification of Ftr1 and Zrt1 as iron and zinc micronutrient transceptors for activation of the PKA pathway in Saccharomyces cerevisiae.

    Science.gov (United States)

    Schothorst, Joep; Zeebroeck, Griet V; Thevelein, Johan M

    2017-03-02

    Multiple types of nutrient transceptors, membrane proteins that combine a transporter and receptor function, have now been established in a variety of organisms. However, so far all established transceptors utilize one of the macronutrients, glucose, amino acids, ammonium, nitrate, phosphate or sulfate, as substrate. This is also true for the Saccharomyces cerevisiae transceptors mediating activation of the PKA pathway upon re-addition of a macronutrient to glucose-repressed cells starved for that nutrient, re-establishing a fermentable growth medium. We now show that the yeast high-affinity iron transporter Ftr1 and high-affinity zinc transporter Zrt1 function as transceptors for the micronutrients iron and zinc . We show that replenishment of iron to iron-starved cells or zinc to zinc-starved cells triggers within 1-2 minutes a rapid surge in trehalase activity, a well-established PKA target. The activation with iron is dependent on Ftr1 and with zinc on Zrt1, and we show that it is independent of intracellular iron and zinc levels. Similar to the transceptors for macronutrients, Ftr1 and Zrt1 are strongly induced upon iron and zinc starvation, respectively, and they are rapidly downregulated by substrate-induced endocytosis. Our results suggest that transceptor-mediated signaling to the PKA pathway may occur in all cases where glucose-repressed yeast cells have been starved first for an essential nutrient, causing arrest of growth and low activity of the PKA pathway, and subsequently replenished with the lacking nutrient to re-establish a fermentable growth medium. The broadness of the phenomenon also makes it likely that nutrient transceptors use a common mechanism for signaling to the PKA pathway.

  10. Identification of Ftr1 and Zrt1 as iron and zinc micronutrient transceptors for activation of the PKA pathway in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Joep Schothort

    2017-03-01

    Full Text Available Multiple types of nutrient transceptors, membrane proteins that combine a transporter and receptor function, have now been established in a variety of organisms. However, so far all established transceptors utilize one of the macronutrients, glucose, amino acids, ammonium, nitrate, phosphate or sulfate, as substrate. This is also true for the Saccharomyces cerevisiae transceptors mediating activation of the PKA pathway upon re-addition of a macronutrient to glucose-repressed cells starved for that nutrient, re-establishing a fermentable growth medium. We now show that the yeast high-affinity iron transporter Ftr1 and high-affinity zinc transporter Zrt1 function as transceptors for the micronutrients iron and zinc. We show that replenishment of iron to iron-starved cells or zinc to zinc-starved cells triggers within 1-2 minutes a rapid surge in trehalase activity, a well-established PKA target. The activation with iron is dependent on Ftr1 and with zinc on Zrt1, and we show that it is independent of intracellular iron and zinc levels. Similar to the transceptors for macronutrients, Ftr1 and Zrt1 are strongly induced upon iron and zinc starvation, respectively, and they are rapidly downregulated by substrate-induced endocytosis. Our results suggest that transceptor-mediated signaling to the PKA pathway may occur in all cases where glucose-repressed yeast cells have been starved first for an essential nutrient, causing arrest of growth and low activity of the PKA pathway, and subsequently replenished with the lacking nutrient to re-establish a fermentable growth medium. The broadness of the phenomenon also makes it likely that nutrient transceptors use a common mechanism for signaling to the PKA pathway.

  11. Effects of mine drainage on the River Hayle, Cornwall. Factors affecting concentrations of copper, zinc, and iron in water, sediments and dominant invertebrate fauna

    Energy Technology Data Exchange (ETDEWEB)

    Brown, B.E.

    1977-02-15

    Concentrations of copper, zinc and iron were measured in waters, sediments and invertebrates collected from the River Hayle. In river water at least 70% of copper and iron was associated with the ''particulate'' fraction whereas 80% of zinc was in the ''soluble'' form. Although total concentrations of zinc in water exceeded those of copper approximately ten fold, copper predominated over zinc in the sediments by a factor of approximately three. Iron was the most abundant metal recorded in both water and sediments. Seasonal differences in ''total'' metal content of waters suggested that concentrations of copper, zinc and iron increased during periods of high flow and decreased during lower flows. Copper concentrations in the sediment, unlike zinc and iron, showed markedly higher values during the summer sampling period when flows were minimal. In the ''free-living'' Trichoptera larvae, concentrations of copper and zinc in the tissue appeared to follow copper and zinc levels in the water. Similar relationships in Odonata and Plecoptera larvae were not obtained. Factors affecting animal/metal relationships are discussed with particular reference to adaptation shown by organisms exposed to high concentrations of heavy metals in their environment.

  12. Diffusion Coefficient in the Zinc Coating Shaped on the Surface of Cast Iron and Steel Alloys

    Directory of Open Access Journals (Sweden)

    Kopyciński D.

    2015-06-01

    Full Text Available The article presents the method to assess the diffusion coefficient D in the sub-layer of intermetallic phases formed during hot-dip galvanizing “Armco” iron and ductile cast iron EN-GJS-500-7. Hot-dip galvanizing is one of the most popular forms of long-term protection of Fe-C alloys against corrosion. The process for producing a protective layer of sufficient quality is closely related to diffusion of atoms of zinc and iron. The simulation consist in performed a hot-dip galvanizing in laboratory condition above Fe-C alloys, in the Department of Engineering of Cast Alloys and Composites. Galvanizing time ranged from 15 to 300 seconds. Then metallographic specimens were prepared, intermetallic layers were measured and diffusion coefficient (D were calculated. It was found that the diffusion coefficient obtained during hot-dip galvanizing “Armco” iron and zinc is about two orders of magnitude less than the coefficient obtained on ductile cast iron EN-GJS-500-7.

  13. Genome Wide Identification of Orthologous ZIP Genes Associated with Zinc and Iron Translocation in Setaria italica

    Directory of Open Access Journals (Sweden)

    Ganesh Alagarasan

    2017-05-01

    Full Text Available Genes in the ZIP family encode transcripts to store and transport bivalent metal micronutrient, particularly iron (Fe and or zinc (Zn. These transcripts are important for a variety of functions involved in the developmental and physiological processes in many plant species, including most, if not all, Poaceae plant species and the model species Arabidopsis. Here, we present the report of a genome wide investigation of orthologous ZIP genes in Setaria italica and the identification of 7 single copy genes. RT-PCR shows 4 of them could be used to increase the bio-availability of zinc and iron content in grains. Of 36 ZIP members, 25 genes have traces of signal peptide based sub-cellular localization, as compared to those of plant species studied previously, yet translocation of ions remains unclear. In silico analysis of gene structure and protein nature suggests that these two were preeminent in shaping the functional diversity of the ZIP gene family in S. italica. NAC, bZIP and bHLH are the predominant Fe and Zn responsive transcription factors present in SiZIP genes. Together, our results provide new insights into the signal peptide based/independent iron and zinc translocation in the plant system and allowed identification of ZIP genes that may be involved in the zinc and iron absorption from the soil, and thus transporting it to the cereal grain underlying high micronutrient accumulation.

  14. Effects of phytase, cellulase, and dehulling treatments on iron and zinc in vitro solubility in faba bean (Vicia faba L.) Flour and Legume Fractions.

    Science.gov (United States)

    Luo, Yu-Wei; Xie, Wei-Hua; Cui, Qun-Xiang

    2010-02-24

    Simulations of gastrointestinal digestion were used to try to identify the nature of the complexes between antinutritional factors and iron and zinc in faba bean and legume fractions. In digestible residue of raw faba bean flour, simultaneous action of cellulase and phytases made it possible to release about 28% units more iron than that released with the treatment without enzymes. About 49.8% of iron in raw faba bean flour was solubilized after in vitro digestion and simultaneous action of cellulase and phytase. In the hull fraction, the action of phytases and the simultaneous action of cellulase and phytase allowed about 7 and 35% units of additional zinc to be solubilized, respectively. Single enzymatic degradation of phytates from dehulled faba bean allowed solubilization from 65 to 93% of zinc, depending upon the treatment. In dehulled faba bean, iron was chelated by phytates and by fibers, whereas zinc was almost exclusively chelated by phytates. In the hull of faba bean, a high proportion of iron was chelated by iron-tannins, while the rest of iron as well as the majority of zinc were chelated in complexes between phytates and fibers.

  15. Enhanced iron and zinc accumulation in genetically engineered pineapple plants using soybean ferritin gene.

    Science.gov (United States)

    Mhatre, Minal; Srinivas, Lingam; Ganapathi, Thumballi R

    2011-12-01

    Pineapple (Ananas comosus L. Merr., cv. "Queen") leaf bases were transformed with Agrobacterium tumefaciens strain EHA 105 harboring the pSF and pEFESF plasmids with soybean ferritin cDNA. Four to eight percent of the co-cultivated leaf bases produced multiple shoots 6 weeks after transfer to Murashige and Skoog's medium supplemented with α-naphthalene acetic acid 1.8 mg/l, indole-3-butyric acid 2.0 mg/l, kinetin 2.0 mg/l, cefotaxime 400 mg/l, and kanamycin 50 mg/l. Putatively transformed shoots (1-2 cm) were selected and multiplied on medium of the same composition and elongated shoots (5 cm) were rooted on liquid rooting medium supplemented with cefotaxime 400 mg/l and kanamycin 100 mg/l. The rooted plants were analyzed through PCR, genomic Southern analysis, and reverse transcription PCR. The results clearly confirmed the integration and expression of soybean ferritin gene in the transformed plants. Atomic absorption spectroscopic analysis carried out with six independently transformed lines of pSF and pEFE-SF revealed a maximum of 5.03-fold increase in iron and 2.44-fold increase in zinc accumulation in the leaves of pSF-transformed plants. In pEFE-SF-transformed plants, a 3.65-fold increase in iron and 2.05-fold increase in zinc levels was observed. Few of the transgenic plants were hardened in the greenhouse and are being grown to maturity to determine the enhanced iron and zinc accumulation in the fruits. To the best of our knowledge this is the first report on the transformation of pineapple with soybean ferritin for enhanced accumulation of iron and zinc content in the transgenic plants.

  16. Recovery of vanadium (V) from spent catalysts used in sulfuric acid production units by acid or alkaline leaching

    International Nuclear Information System (INIS)

    Abdulbaki, M.; Stas, J.; Shino, O.; Asaad, K.; Al-Kassemi, H.; Al-Qabani, F.

    2008-01-01

    The present paper, studies the recovery of vanadium from the spent catalyst by using acidic or alkaline leaching technique. The optimal conditions of spent catalyst leaching have been studied. It has been shown that 20%(w/w) of sulfuric acid is the most suitable for leaching process at 70 Centigrade. The precipitation of vanadium using some alkaline media (Na 2 CO 3 , (NH 4 )CO 3 and NH 4 OH) has been also studied, it has been shown that ammonium hydroxide was the best at 60 degree, and iron was co-precipitated with vanadium which pollute the obtained red cake. So it is necessary to use liquid-liquid extraction technique for the separation between vanadium and iron and to have iron free red cake. (author)

  17. Effects of Basicity and MgO in Slag on the Behaviors of Smelting Vanadium Titanomagnetite in the Direct Reduction-Electric Furnace Process

    Directory of Open Access Journals (Sweden)

    Tao Jiang

    2016-05-01

    Full Text Available The effects of basicity and MgO content on reduction behavior and separation of iron and slag during smelting vanadium titanomagnetite by electric furnace were investigated. The reduction behaviors affect the separation of iron and slag in the direct reduction-electric furnace process. The recovery rates of Fe, V, and Ti grades in iron were analyzed to determine the effects of basicity and MgO content on the reduction of iron oxides, vanadium oxides, and titanium oxides. The chemical compositions of vanadium-bearing iron and main phases of titanium slag were detected by XRF and XRD, respectively. The results show that the higher level of basicity is beneficial to the reduction ofiron oxides and vanadium oxides, and titanium content dropped in molten iron with the increasing basicity. As the content of MgO increased, the recovery rate of Fe increased slightly but the recovery rate of V increased considerably. The grades of Ti in molten iron were at a low level without significant change when MgO content was below 11%, but increased as MgO content increased to 12.75%. The optimum conditions for smelting vanadium titanomagnetite were about 11.38% content of MgO and quaternary basicity was about 1.10. The product, vanadium-bearing iron, can be applied in the converter steelmaking process, and titanium slag containing 50.34% TiO2 can be used by the acid leaching method.

  18. Iron, zinc, copper and magnesium nutritional status in Mexican children aged 1 to 11 years.

    Science.gov (United States)

    Morales-Ruán, Ma del Carmen; Villalpando, Salvador; García-Guerra, Armando; Shamah-Levy, Teresa; Robledo-Pérez, Ricardo; Avila-Arcos, Marco Antonio; Rivera, Juan A

    2012-01-01

    To describe the micronutrient nutritional status of a national sample of 1-11 year old Mexican children surveyed in 2006 in National Health and Nutrition Survey (ENSANUT 2006) and their association with dietary and sociodemographic factors. Serum samples were used (n=5 060) to measure the concentrations of ferritin, transferrin receptor, zinc, copper and magnesium. Prevalence of deficiencies in 1-4 and 5-11y old children were for iron (using low ferritin) 26.0 and 13.0%; zinc, 28.1 and 25.8%, respectively; and copper, ≈30% in both age groups. Magnesium low serum concentrations (MLSC), were found in 12.0% and 28.4% of the children, respectively. Being beneficiary of Liconsa (OR=0.32; C.I.95%, 0.17-0.61) or belonging to higher socioeconomic status (OR=0.63; C.I.95%, 0.41-0.97) were protective against iron deficiency. Increasing age (OR=0.59; C.I.95%, 1.19-1.32) and living in the Central Region (OR=0.59; C.I.95%, 0.36-0.97) were protective against MLSC. Deficiencies of iron and zinc are serious public health problems in Mexican children.

  19. Transgenic expression of phytase in wheat endosperm increases bioavailability of iron and zinc in grains.

    Science.gov (United States)

    Abid, Nabeela; Khatoon, Asia; Maqbool, Asma; Irfan, Muhammad; Bashir, Aftab; Asif, Irsa; Shahid, Muhammad; Saeed, Asma; Brinch-Pedersen, Henrik; Malik, Kauser A

    2017-02-01

    Phytate is a major constituent of wheat seeds and chelates metal ions, thus reducing their bioavailability and so the nutritional value of grains. Transgenic plants expressing heterologous phytase are expected to enhance degradation of phytic acid stored in seeds and are proposed to increase the in vitro bioavailability of mineral nutrients. Wheat transgenic plants expressing Aspergillus japonicus phytase gene (phyA) in wheat endosperm were developed till T 3 generation. The transgenic lines exhibited 18-99 % increase in phytase activity and 12-76 % reduction of phytic acid content in seeds. The minimum phytic acid content was observed in chapatti (Asian bread) as compared to flour and dough. The transcript profiling of phyA mRNA indicated twofold to ninefold higher expression as compared to non transgenic controls. There was no significant difference in grain nutrient composition of transgenic and non-transgenic seeds. In vitro bioavailability assay for iron and zinc in dough and chapatti of transgenic lines revealed a significant increase in iron and zinc contents. The development of nutritionally enhanced cereals is a step forward to combat nutrition deficiency for iron and zinc in malnourished human population, especially women and children.

  20. Micronutrient supplementation adherence and influence on the prevalences of anemia and iron, zinc and vitamin A deficiencies in preemies with a corrected age of six months

    Directory of Open Access Journals (Sweden)

    Brunnella Alcantara Chagas de Freitas

    Full Text Available OBJECTIVE: To analyze adherence to the recommended iron, zinc and multivitamin supplementation guidelines for preemies, the factors associated with this adherence, and the influence of adherence on the occurrence of anemia and iron, zinc and vitamin A deficiencies. METHODS: This prospective cohort study followed 58 preemies born in 2014 until they reached six months corrected age. The preemies were followed at a referral secondary health service and represented 63.7% of the preterm infants born that year. Outcomes of interest included high or low adherence to iron, zinc and multivitamin supplementation guidelines; prevalence of anemia; and prevalences of iron, zinc, and vitamin A deficiencies. The prevalence ratios were calculated by Poisson regression. RESULTS: Thirty-eight (65.5% preemies presented high adherence to micronutrient supplementation guidelines. At six months of corrected age, no preemie had vitamin A deficiency. The prevalences of anemia, iron deficiency and zinc deficiency were higher in the low-adherence group but also concerning in the high-adherence group. Preemies with low adherence to micronutrient supplementation guidelines were 2.5 times more likely to develop anemia and 3.1 times more likely to develop zinc deficiency. Low maternal education level increased the likelihood of nonadherence to all three supplements by 2.2 times. CONCLUSIONS: Low maternal education level was independently associated with low adherence to iron, zinc and vitamin A supplementation guidelines in preemies, which impacted the prevalences of anemia and iron and zinc deficiencies at six months of corrected age.

  1. The Practical Realisation of Zinc-Iron CMA Coatings

    DEFF Research Database (Denmark)

    Jensen, Jens Dahl

    1998-01-01

    A detailed study of the production opportunities for composition modulated alloy electrodeposits by pulsed current techniques with Zinc-Iron alloys is reported. It is shown that by using a chloride solution, with the additional capability of variable agitation rates, a full range of alloy...... compositions is possible with nanometre layering attainable using single or double bath methods. Furthermore, by the use of a high concentration of ammonium chloride ostensibly as "conductivity" salt, the mechanism of deposition may be modified through control of a thin cathode oxide/hydroxide film....

  2. The effect of Mg dopants on magnetic and structural properties of iron oxide and zinc ferrite thin films

    Science.gov (United States)

    Saritaş, Sevda; Ceviz Sakar, Betul; Kundakci, Mutlu; Yildirim, Muhammet

    2018-06-01

    Iron oxide thin films have been obtained significant interest as a material that put forwards applications in photovoltaics, gas sensors, biosensors, optoelectronic and especially in spintronics. Iron oxide is one of the considerable interest due to its chemical and thermal stability. Metallic ion dopant influenced superexchange interactions and thus changed the structural, electrical and magnetic properties of the thin film. Mg dopped zinc ferrite (Mg:ZnxFe3-xO4) crystal was used to avoid the damage of Fe3O4 (magnetite) crystal instead of Zn2+ in this study. Because the radius of the Mg2+ ion in the A-site (tetrahedral) is almost equal to that of the replaced Fe3+ ion. Inverse-spinel structure in which oxygen ions (O2-) are arranged to form a face-centered cubic (FCC) lattice where there are two kinds of sublattices, namely, A-site and B-site (octahedral) interstitial sites and in which the super exchange interactions occur. In this study, to increase the saturation of magnetization (Ms) value for iron oxide, inverse-spinal ferrite materials have been prepared, in which the iron oxide was doped by multifarious divalent metallic elements including Zn and Mg. Triple and quaternary; iron oxide and zinc ferrite thin films with Mg metal dopants were grown by using Spray Pyrolysis (SP) technique. The structural, electrical and magnetic properties of Mg dopped iron oxide (Fe2O3) and zinc ferrite (ZnxFe3-xO4) thin films have been investigated. Vibrating Sample Magnetometer (VSM) technique was used to study for the magnetic properties. As a result, we can say that Mg dopped iron oxide thin film has huge diamagnetic and of Mg dopped zinc ferrite thin film has paramagnetic property at bigger magnetic field.

  3. Distributions of traces of metals on sorption from solutions of vanadium(V)

    International Nuclear Information System (INIS)

    Evseeva, N.K.; Turnaov, A.N.; Telegin, G.F.; Kremenskaya, I.N.

    1983-01-01

    A study is made of the distributions of traces of metals between aqueous solutions of vanadium(V) and a solid reagent made by introducing di-2-ethylhexylphosphoric acid into an inert matrix: a nonionic macroporous copolymer of polystyrene with divinyl benzene (wofatit Y 29). As regards degree of extraction, the trace components fall in the series zinc > cadmium > manganese > copper > cobalt, which resemble the extractability series. The vanadium content of the solution and the concentrations of the trace components have virtually no effect on the sorption. The process is effective in concentrating trace components from solutions containing vanadium(V)

  4. Distribution of microimpurities of metals at their sorption from vanadium (5) solutions

    International Nuclear Information System (INIS)

    Evseeva, N.K.; Turanov, A.N.; Telegin, G.F.; Kremenskaya, I.N.

    1983-01-01

    Distribution of metal microimpurities (Zn, Mn, Cu, Co, Fe) between aqueous solutions of vanadium (5) and solid extracting agent, prepared by means of introduction of di-2-ethylhexylphosphoric acid into inert matrix-nonionogeneous macropore copolymer of polystyrene with divinylbenzene (vofatit Y-29), has been studied. Accroding to the degree of extraction the microimpurities are arranged in the series: zinc > cadmium > manganese > copper > cobalt, which is similar to the series of extractability. Vanadium content in solution and concentration of microimpurities practically does not affect the sorption. It has been established that the process is effective for microimpurities concentration from solutions containing vanadium (5)

  5. Distribution of microimpurities of metals at their sorption from vanadium (5) solutions

    Energy Technology Data Exchange (ETDEWEB)

    Evseeva, N.K.; Turanov, A.N.; Telegin, G.F.; Kremenskaya, I.N.

    1983-01-01

    Distribution of metal microimpurities (Zn, Mn, Cu, Co, Fe) between aqueous solutions of vanadium (5) and solid extracting agent, prepared by means of introduction of di-2-ethylhexylphosphoric acid into inert matrix-nonionogeneous macropore copolymer of polystyrene with divinylbenzene (vofatit Y-29), has been studied. According to the degree of extraction the microimpurities are arranged in the series: zinc > cadmium > manganese > copper > cobalt, which is similar to the series of extractability. Vanadium content in solution and concentration of microimpurities practically does not affect the sorption. It has been established that the process is effective for microimpurities concentration from solutions containing vanadium (5).

  6. Concentration differences between serum and plasma of the elements cobalt, iron, mercury, rubidium, selenium and zinc determined by neutron activation analysis

    International Nuclear Information System (INIS)

    Kasperek, K.; Kiem, J.; Iyengar, G.V.; Feinendegen, L.E.

    1981-01-01

    The differences in concentrations of cesium, cobalt, iron, mercury, rubidium, selenium and zinc between serum and plasma were examined with the aid of instrumental neutron activation analysis. Eighty serum and plasma samples obtained from 13 donors were compared. Serum was prepared in plastic tubes immediately after clotting, and plasma was separated with heparin as anticoagulant. No significant differences in the concentrations of cesium, cobalt, mercury and selenium were observed. However, the concentrations of iron, rubidium and zinc were significantly higher in serum than in plasma. The average differences were 322, 12 and 20 ng/ml for iron, rubidium and zinc, respectively. The average differences found for cesium, rubidium and zinc were far below that which can be expected from a complete, or considerable release of these elements from platelets which aggregate or disintegrate during the clotting process in preparing serum. (orig.)

  7. The Effect of Low Dose Iron and Zinc Intake on Child Micronutrient Status and Development during the First 1000 Days of Life: A Systematic Review and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Nicolai Petry

    2016-11-01

    Full Text Available Adequate supply of micronutrients during the first 1000 days is essential for normal development and healthy life. We aimed to investigate if interventions administering dietary doses up to the recommended nutrient intake (RNI of iron and zinc within the window from conception to age 2 years have the potential to influence nutritional status and development of children. To address this objective, a systematic review and meta-analysis of randomized and quasi-randomized fortification, biofortification, and supplementation trials in women (pregnant and lactating and children (6–23 months delivering iron or zinc in doses up to the recommended nutrient intake (RNI levels was conducted. Supplying iron or zinc during pregnancy had no effects on birth outcomes. There were limited or no data on the effects of iron/zinc during pregnancy and lactation on child iron/zinc status, growth, morbidity, and psychomotor and mental development. Delivering up to 15 mg iron/day during infancy increased mean hemoglobin by 4 g/L (p < 0.001 and mean serum ferritin concentration by 17.6 µg/L (p < 0.001 and reduced the risk for anemia by 41% (p < 0.001, iron deficiency by 78% (ID; p < 0.001 and iron deficiency anemia by 80% (IDA; p < 0.001, but had no effect on growth or psychomotor development. Providing up to 10 mg of additional zinc during infancy increased plasma zinc concentration by 2.03 µmol/L (p < 0.001 and reduced the risk of zinc deficiency by 47% (p < 0.001. Further, we observed positive effects on child weight for age z-score (WAZ (p < 0.05, weight for height z-score (WHZ (p < 0.05, but not on height for age z-score (HAZ or the risk for stunting, wasting, and underweight. There are no studies covering the full 1000 days window and the effects of iron and zinc delivered during pregnancy and lactation on child outcomes are ambiguous, but low dose daily iron and zinc use during 6–23 months of age has a positive effect on child iron and zinc status.

  8. Solid-phase extraction of copper, iron and zinc ions on Bacillus thuringiensis israelensis loaded on Dowex optipore V-493

    Energy Technology Data Exchange (ETDEWEB)

    Tuzen, Mustafa; Melek, Esra [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Soylak, Mustafa [Erciyes University, Faculty of Science and Arts, Chemistry Department, 38039 Kayseri (Turkey)], E-mail: msoylak@gmail.com

    2008-11-30

    Bacillus thuringiensis israelensis loaded on Dowex optipore V-493 as new adsorbent for the separation-preconcentration of heavy metal ions has been proposed. The analytical conditions for the quantitative recoveries of copper(II), iron(III) and zinc(II) including pH, amounts of adsorbent, sample volume, etc. were investigated. The influences of alkaline and earth alkaline ions were also reported. The recovery values for the analytes are generally higher than 95%. The preconcentration factor was 37. The limit of detections of the analyte ions (k = 3, N = 21) were 1.14 {mu}g L{sup -1} for copper, 2.01 {mu}g L{sup -1} for iron and 0.14 {mu}g L{sup -1} for zinc. The relative standard deviations of the determinations were found to be lower than 9%. The procedure was validated by analyzing copper, iron and zinc contents in two certified reference materials, NRCC-SLRS-4 Riverine water and NIST SRM 1515 Apple leaves. Agreements between the obtained results and the certified values were achieved. The developed preconcentration method was applied in the flame atomic absorption spectrometric determination of copper, iron and zinc in several samples including a multivitamin-multimineral tablet, dialysis solutions, natural waters and some food samples.

  9. Pituitary gland levels of mercury, selenium, iron, and zinc in an Alzheimer`s disease study

    Energy Technology Data Exchange (ETDEWEB)

    Cornett, C.R.; Markesbery, W.R.; Wekstein, D.R.; Ehmann, W.D. [Univ. of Kentucky, Lexington, KY (United States)

    1996-12-31

    Mercury, iron, selenium, and zinc imbalances have been observed in comparisons between Alzheimer`s disease (AD) and control subject brains. Analyses of the pituitary gland have demonstrated that this organ retains relatively high concentrations of trace elements, including mercury, iron, and zinc. Our previous work has shown that the pituitary glands of AD and control subjects are typically higher in these trace elements than brain samples from the same subject. Instrumental neutron activation analysis (INAA) was used to compare the pituitary trace element levels of AD and control subjects. This study also describes the intrasubject relationships of brain trace element levels to those in the pituitary gland of AD and control subjects.

  10. Relative contribution of phytates, fibers, and tannins to low iron and zinc in vitro solubility in pearl millet (Pennisetum glaucum) flour and grain fractions.

    Science.gov (United States)

    Lestienne, Isabelle; Caporiccio, Bertrand; Besançon, Pierre; Rochette, Isabelle; Trèche, Serge

    2005-10-19

    In vitro digestions were performed on pearl millet flours with decreased phytate contents and on two dephytinized or nondephytinized pearl millet grain fractions, a decorticated fraction, and a bran fraction with low and high fiber and tannin contents, respectively. Insoluble residues of these digestions were then incubated with buffer or enzymatic solutions (xylanases and/or phytases), and the quantities of indigestible iron and zinc released by these different treatments were determined. In decorticated pearl millet grain, iron was chelated by phytates and by insoluble fibers, whereas zinc was almost exclusively chelated by phytates. In the bran of pearl millet grain, a high proportion of iron was chelated by iron-binding phenolic compounds, while the rest of iron as well as the majority of zinc were chelated in complexes between phytates and fibers. The low effect of phytase action on iron and zinc solubility of bran of pearl millet grain shows that, in the case of high fiber and tannin contents, the chelating effect of these compounds was higher than that of phytates.

  11. The kinetics of zinc coating growth on hyper-sandelin steels and ductile cast iron

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2007-12-01

    Full Text Available The studies aimed at an analysis of the formation and growth kinetics of zinc coating on reactive silicon-killed steels in a zinc bath. The growth kinetics of the produced zinc coatings was evaluated basing on the power-law growth equation. As regards galvanizing of the surface of products, investigation was done for various steel grades and ductile iron taking into account the quality and thickness of coating. It has been proved that the chemical constitution of basis significantly influences the kinetics of growth of the individual phases in a zinc coating. This relationship was evaluated basing on the, so called, silicon and phosphorus equivalent E = (Si+2.5P.103, and coating thickness dependences were obtained.

  12. Kinetics of atmospheric corrosion of mild steel, zinc, galvanized iron and aluminium at 10 exposure stations in India

    International Nuclear Information System (INIS)

    Natesan, M.; Venkatachari, G.; Palaniswamy, N.

    2006-01-01

    As a part of updating Corrosion Map of India project, atmospheric corrosion behaviour of commercially available engineering materials such as mild steel, galvanized iron, zinc and aluminium metals was studied in marine, industrial, urban, and rural environments by weight loss method at 10 exposure stations in India over a period of 5 years. The results of these studies demonstrated that galvanized iron, zinc and aluminium metals were several times more durable than mild steel. Compared to galvanized iron and zinc, aluminium provided superior protection in industrial and marine environment except at Mormugao Port Trust (MPT). It also offered much better resistance to corrosion in rural environments. At certain places, galvanized iron proved to be more durable than aluminium. The results obeyed well with the empirical kinetics equation of the form C = Kt n , where K and C are the corrosion losses in μm after 1 and 't' years of the exposure, respectively, and 'n' is a constant. Based on 'n' values, the corrosion mechanisms of these metals are predicted. The corrosion products formed on the metal samples in Chennai marine atmosphere were identified by X-ray diffraction analysis

  13. Genetic Variability, Genotype × Environment Interaction, Correlation, and GGE Biplot Analysis for Grain Iron and Zinc Concentration and Other Agronomic Traits in RIL Population of Sorghum (Sorghum bicolor L. Moench

    Directory of Open Access Journals (Sweden)

    Rahul M. Phuke

    2017-05-01

    Full Text Available The low grain iron and zinc densities are well documented problems in food crops, affecting crop nutritional quality especially in cereals. Sorghum is a major source of energy and micronutrients for majority of population in Africa and central India. Understanding genetic variation, genotype × environment interaction and association between these traits is critical for development of improved cultivars with high iron and zinc. A total of 336 sorghum RILs (Recombinant Inbred Lines were evaluated for grain iron and zinc concentration along with other agronomic traits for 2 years at three locations. The results showed that large variability exists in RIL population for both micronutrients (Iron = 10.8 to 76.4 mg kg−1 and Zinc = 10.2 to 58.7 mg kg−1, across environments and agronomic traits. Genotype × environment interaction for both micronutrients (iron and zinc was highly significant. GGE biplots comparison for grain iron and zinc showed greater variation across environments. The results also showed that G × E was substantial for grain iron and zinc, hence wider testing needed for taking care of G × E interaction to breed micronutrient rich sorghum lines. Iron and zinc concentration showed high significant positive correlation (across environment = 0.79; p < 0.01 indicating possibility of simultaneous effective selection for both the traits. The RIL population showed good variability and high heritabilities (>0.60, in individual environments for Fe and Zn and other traits studied indicating its suitability to map QTL for iron and zinc.

  14. Highly stable aqueous zinc-ion storage using a layered calcium vanadium oxide bronze cathode

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Chuan; Guo, Jing; Li, Peng; Zhang, Xixiang; Alshareef, Husam N. [Materials Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal (Saudi Arabia)

    2018-04-03

    Cost-effective aqueous rechargeable batteries are attractive alternatives to non-aqueous cells for stationary grid energy storage. Among different aqueous cells, zinc-ion batteries (ZIBs), based on Zn{sup 2+} intercalation chemistry, stand out as they can employ high-capacity Zn metal as the anode material. Herein, we report a layered calcium vanadium oxide bronze as the cathode material for aqueous Zn batteries. For the storage of the Zn{sup 2+} ions in the aqueous electrolyte, we demonstrate that the calcium-based bronze structure can deliver a high capacity of 340 mA h g{sup -1} at 0.2 C, good rate capability, and very long cycling life (96 % retention after 3000 cycles at 80 C). Further, we investigate the Zn{sup 2+} storage mechanism, and the corresponding electrochemical kinetics in this bronze cathode. Finally, we show that our Zn cell delivers an energy density of 267 W h kg{sup -1} at a power density of 53.4 W kg{sup -1}. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. MicroXRF tomographic visualization of zinc and iron in the zebrafish embryo at the onset of the hatching period

    Energy Technology Data Exchange (ETDEWEB)

    Bourassa, Daisy; Gleber, Sophie-Charlotte; Vogt, Stefan; Shin, Chong Hyun; Fahrni, Christoph J.

    2016-01-01

    Transition metals such as zinc, copper, and iron play key roles in cellular proliferation, cell differentiation, growth, and development. Over the past decade, advances in synchrotron X-ray fluorescence instrumentation presented new opportunities for the three-dimensional mapping of trace metal distributions within intact specimens. Taking advantage of microXRF tomography, we visualized the 3D distribution of zinc and iron in a zebrafish embryo at the onset of the hatching period. The reconstructed volumetric data revealed distinct differences in the elemental distributions, with zinc predominantly localized to the yolk and yolk extension, and iron to various regions of the brain as well as the myotome extending along the dorsal side of the embryo. The data set complements an earlier tomographic study of an embryo at the pharyngula stage (24 hpf), thus offering new insights into the trace metal distribution at key stages of embryonic development.

  16. Effects of Iron Concentration Level in Extracting Solutions from Contaminated Soils on the Determination of Zinc by Flame Atomic Absorption Spectrometry with Two Background Correctors

    Directory of Open Access Journals (Sweden)

    Christophe Waterlot

    2012-01-01

    Full Text Available Zinc and iron concentrations were determined after digestion, water, and three-step sequential extractions of contaminated soils. Analyses were carried out using flame absorption spectrometry with two background correctors: a deuterium lamp used as the continuum light source (D2 method and the high-speed self-reversal method (HSSR method. Regarding the preliminary results obtained with synthetic solutions, the D2 method often emerged as an unsuitable configuration for compensating iron spectral interferences. In contrast, the HSSR method appeared as a convenient and powerful configuration and was tested for the determination of zinc in contaminated soils containing high amounts of iron. Simple, fast, and interference-free method, the HSSR method allows zinc determination at the ppb level in the presence of large amounts of iron with high stability, sensitivity, and reproducibility of results. Therefore, the HSSR method is described here as a promising approach for monitoring zinc concentrations in various iron-containing samples without any pretreatment.

  17. Bioavailability of iron and zinc from human diets: Nutrient delivery technology salt fortification in human nutrition

    International Nuclear Information System (INIS)

    Raghuramulu, N.

    1992-01-01

    Iodine deficiency disorders (IDD), iron deficiency anaemia(IDA) and zinc deficiency are common problems in India. The discussions in this paper centers on the selection of the vehicles which could be used to successfully deliver essential nutrients into the daily diet of the general population of india and the identification of compounds which inhibit the intestinal absorption of zinc. 40 refs, 11 tabs

  18. Geochemistry of vanadium in an epigenetic, sandstone-hosted vanadium- uranium deposit, Henry Basin, Utah

    Science.gov (United States)

    Wanty, R.B.; Goldhaber, M.B.; Northrop, H.R.

    1990-01-01

    The epigenetic Tony M vanadium-uranium orebody in south-central Utah is hosted in fluvial sandstones of the Morrison Formation (Upper Jurassic). Measurements of the relative amounts of V+3 and V +4 in ore minerals show that V+3 is more abundant. Thermodynamic calculations show that vanadium was more likely transported to the site of mineralization as V+4. The ore formed as V+4 was reduced by hydrogen sulfide, followed by hydrolysis and precipitation of V+3 in oxide minerals or chlorite. Uranium was transported as uranyl ion (U+6), or some complex thereof, and reduced by hydrogen sulfide, forming coffinite. Detrital organic matter in the rocks served as the carbon source for sulfate-reducing bacteria. Vanadium most likely was derived from the dissolution of iron-titanium oxides. Uranium probably was derived from the overlying Brushy Basin Member of the Morrison Formation. Previous studies have shown that the ore formed at the density-stratified interface between a basinal brine and dilute meteoric water. The mineralization processes described above occurred within the mixing zone between these two fluids. -from Authors

  19. Cloud point extraction of iron(III) and vanadium(V) using 8-quinolinol derivatives and Triton X-100 and determination of 10(-7)moldm(-3) level iron(III) in riverine water reference by a graphite furnace atomic absorption spectroscopy.

    Science.gov (United States)

    Ohashi, Akira; Ito, Hiromi; Kanai, Chikako; Imura, Hisanori; Ohashi, Kousaburo

    2005-01-30

    The cloud point extraction behavior of iron(III) and vanadium(V) using 8-quinolinol derivatives (HA) such as 8-quinolinol (HQ), 2-methyl-8-quinolinol (HMQ), 5-butyloxymethyl-8-quinolinol (HO(4)Q), 5-hexyloxymethyl-8-quinolinol (HO(6)Q), and 2-methyl-5-octyloxymethyl-8-quinolinol (HMO(8)Q) and Triton X-100 solution was investigated. Iron(III) was extracted with HA and 4% (v/v) Triton X-100 in the pH range of 1.70-5.44. Above pH 4.0, more than 95% of iron(III) was extracted with HQ, HMQ, and HMO(8)Q. Vanadium(V) was also extracted with HA and 4% (v/v) Triton X-100 in the pH range of 2.07-5.00, and the extractability increased in the following order of HMQ HQ cloud point extraction was applied to the determination of iron(III) in the riverine water reference by a graphite furnace atomic absorption spectroscopy. When 1.25 x 10(-3)M HMQ and 1% (v/v) Triton X-100 were used, the found values showed a good agreement with the certified ones within the 2% of the R.S.D. Moreover, the effect of an alkyl group on the solubility of 5-alkyloxymethyl-8-quinolinol and 2-methyl-5-alkyloxymethyl-8-quinolinol in 4% (v/v) Triton X-100 at 25 degrees C was also investigated.

  20. Interactions of cadmium with copper, zinc, and iron in different organs and tissues of the rat

    Energy Technology Data Exchange (ETDEWEB)

    Julshamn, K.; Utne, F.; Brackkan, O.R.

    1977-01-01

    The effect of cadmium on tissue concentrations of iron, zinc and copper was studied in male rats. Two littermate groups were fed a stock diet with or without a supplement of 100 ..mu..g cadmium per g. Every three weeks ten animals from each group were sampled and the liver, kidneys, heart, lungs, spleen, testes, muscle, fur, feces and urine were individually analyzed. Except for the fur, all the other organs showed highly significantly increased levels of cadmium when compared with the control group. The iron levels were significantly depressed in all organs. As the content in the feces remained unchanged and the urinary excretion showed an increase, it could be concluded that the cadmium supplementation resulted in a depletion of the body stores of iron. The zinc levels showed a significant increase in the liver and testes and a correspondingly significant decrease in the spleen. The levels of copper generally showed no significant changes.

  1. Serum and tissue contents of copper, calcium, iron and magnesium elements in cases of acne vulgaris after zinc therapy

    International Nuclear Information System (INIS)

    El-Said, S.M.; El-Bedewi, A.F.

    2002-01-01

    The effect of zinc therapy on some trace elements contents in serum and skin was studied in normal group (forty) and patients group with acne vulgaris (26 males and 14 females) with age ranged between 14-30 year. They were under medical treatment with 330 mg oral zinc sulfate for 12 weeks. Highly significant decreases in both serum and tissue contents of copper and calcium were detected, as well as, highly significant decrease in the serum content of magnesium was recorded. The serum content of iron was highly significantly increased and that for tissue content was slightly significantly increased. It could be concluded that zinc therapy could be valuable through modulation of copper. calcium, iron and magnesium in acne patients

  2. The Role of Iron and Zinc on Tuber Yield and Yield Components of Potato

    Directory of Open Access Journals (Sweden)

    Elham Jam

    2015-08-01

    Full Text Available The soils of potato production fields in Ardabil due to alkalinity and not having a proper crop rotations are deficient in micronutrients. To evaluate the effect of these micronutrients on the yield and some traits affecting potato tubers an experiment was conducted in a complete randomized block design with three replications in Ardabil during 2012. Micronutrient treatments used were the various concentrations of iron and zinc (0.002, 0.004 and 0.008 concentrations of these elements as Fe1Zn1, Fe1Zn2, Fe1Zn3, Fe2Zn1, Fe2Zn2, Fe2Zn3, Fe3Zn1 and Fe3Zn2 and a control treatment (Fe0Zn0. Analysis of variance of traits under study showed statistically significant differences among treatments in terms of tuber yield, number of tubers per plant, tuber size, skin thickness and volumetric weight and dry weight of tubers. The highest tuber yield (48.10 t.ha-1 and maximum skin thickness were obtained from Fe1Zn3 treatment. The highest tuber number belonged to Fe2Zn1 (0.004 and 0.002 concentrations of iron and zinc and Fe1Zn3 (0.002 and 0.008 concentrations of iron and zinc. Tuber weights higher than 35 grams and higest volumetric tuber weight were produced by using Fe3Zn2. The conclusion is this that using Fe1Zn3 traetment (0.002 and 0.008 concentrations resulted in highest tuber yield and thickness of tuber skin.

  3. Iron, Magnesium, Vitamin D, and Zinc Deficiencies in Children Presenting with Symptoms of Attention-Deficit/Hyperactivity Disorder

    Directory of Open Access Journals (Sweden)

    Amelia Villagomez

    2014-09-01

    Full Text Available Attention-Deficit/Hyperactivity Disorder (ADHD is a neurodevelopmental disorder increasing in prevalence. Although there is limited evidence to support treating ADHD with mineral/vitamin supplements, research does exist showing that patients with ADHD may have reduced levels of vitamin D, zinc, ferritin, and magnesium. These nutrients have important roles in neurologic function, including involvement in neurotransmitter synthesis. The aim of this paper is to discuss the role of each of these nutrients in the brain, the possible altered levels of these nutrients in patients with ADHD, possible reasons for a differential level in children with ADHD, and safety and effect of supplementation. With this knowledge, clinicians may choose in certain patients at high risk of deficiency, to screen for possible deficiencies of magnesium, vitamin D, zinc, and iron by checking RBC-magnesium, 25-OH vitamin D, serum/plasma zinc, and ferritin. Although children with ADHD may be more likely to have lower levels of vitamin D, zinc, magnesium, and iron, it cannot be stated that these lower levels caused ADHD. However, supplementing areas of deficiency may be a safe and justified intervention.

  4. Probiotics lactobacillus reuteri DSM 17938 and lactobacillus casei CRL 431 modestly increase growth, but non iron and zinc status, among Indonesian children aged 1-6 years

    NARCIS (Netherlands)

    Agustina, R.; Bovee-Oudenhoven, I.M.J.; Lukito, W.; Fahmida, U.; Rest, van de O.; Zimmermann, M.B.; Firmansyah, A.; Wulanti, R.; Albers, R.; Heuvel, van den E.G.H.M.; Kok, F.J.

    2013-01-01

    Probiotics and milk calcium may increase resistance to intestinal infection, but their effect on growth and iron and zinc status of Indonesian children is uncertain. We investigated the hypotheses that cow milk with added probiotics would improve growth and iron and zinc status of Indonesian

  5. Seasonal study on Bothriocephalus as indicator of metal pollution in ...

    African Journals Online (AJOL)

    ... vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, arsenic, selenium, molybdenum, cadmium, tin, antimony, tellurium, barium, mercury, thallium, lead and uranium) were determined with an ICP-MS. Bioconcentration of metals (selenium, mercury, and lead during autumn; copper, zinc, selenium, cadmium, ...

  6. Vanadium

    Science.gov (United States)

    Kelley, Karen D.; Scott, Clinton T.; Polyak, Désirée E.; Kimball, Bryn E.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

    2017-12-19

    Vanadium is used primarily in the production of steel alloys; as a catalyst for the chemical industry; in the making of ceramics, glasses, and pigments; and in vanadium redox-flow batteries (VRBs) for large-scale storage of electricity. World vanadium resources in 2012 were estimated to be 63 million metric tons, which include about 14 million metric tons of reserves. The majority of the vanadium produced in 2012 was from China, Russia, and South Africa.Vanadium is extracted from several different types of mineral deposits and from fossil fuels. These deposits include vanadiferous titanomagnetite (VTM) deposits, sandstone-hosted vanadium (with or without uranium) deposits (SSV deposits), and vanadium-rich black shales. VTM deposits are the principal source of vanadium and consist of magmatic accumulations of ilmenite and magnetite containing 0.2 to 1 weight percent vanadium pentoxide (V2O5). SSV deposits are another important source; these deposits have average ore grades that range from 0.1 to greater than 1 weight percent V2O5. The United States has been and is currently the main producer of vanadium from SSV deposits, particularly those on the Colorado Plateau. Vanadium-rich black shales occur in marine successions that were deposited in epeiric (inland) seas and on continental margins. Concentrations in these shales regularly exceed 0.18 weight percent V2O5 and can be as high as 1.7 weight percent V2O5. Small amounts of vanadium have been produced from the Alum Shale in Sweden and from ferrophosphorus slag generated during the reduction of phosphate to elemental phosphorus in ore from shales of the Phosphoria Formation in Idaho and Wyoming. Because vanadium enrichment occurs in beds that are typically only a few meters thick, most of the vanadiferous black shales are not currently economic, although they may become an important resource in the future. Significant amounts of vanadium are recovered as byproducts of petroleum refining, and processing of coal, tar

  7. Iron Drinking Water Pipe Corrosion Products: Concentrators of Toxic Metals

    Science.gov (United States)

    2013-01-01

    health risk. In addition Pb corrosion products may be sinks for other metals such as chromium (Cr), copper (Cu), manganese (Mn), and zinc (Zn). These...Vanadium K-Edge X-ray Absorption Near-Edge Structure Interpretation: Application to the Speciation of Vanadium in Oxide Phases from Steel Slag ’, Journal

  8. Content of zinc, iron, calcium and their absorption inhibitors in foods commonly consumed in Ethiopia

    NARCIS (Netherlands)

    Umeta, M.; West, C.E.; Fufa, H.

    2005-01-01

    The zinc, iron, calcium, phosphorus, phytate, tannin and moisture content of 36 foods consumed in rural Ethiopia were analysed. The foods analysed included those based on cereals, starchy tubers and roots, and legumes and vegetables as well as some fruits. Although many foods were relatively rich in

  9. Soft Chemistry Preparation of lead Iron Vanadate

    International Nuclear Information System (INIS)

    Melghit, Khaled

    2011-01-01

    In order to prepare the new monoclinic Pb 2 FeV 3 O 11 at low temperature; an acidic solution of vanadium oxide, pH 2, was mixed with a corresponding amount of both lead and iron nitrate at boiling temperature. The yellow precipitate obtained is a mixture of lead pyrovanadate Pb 2 V 2 O 7 and an amorphous phase. At 500deg. C, the new monoclinic Pb 2 FeV 3 O 11 phase appears but mixed with Pb 2 V 2 O 7 . At higher temperature, 570deg. C, the monoclinic phase disappears and a new phase appears. This phase is similar to triclinic Pb 2 Fe 2 V 4 O 15 , recently reported, although the EDAX analysis shows the as-prepared sample with higher amount of vanadium and iron. To understand the mechanism involved, lead and iron nitrate solution were reacted separately with vanadium oxide solution. The phases formed were found to be sensitive to initial concentration and to stirring time

  10. Evaluation of iron, zinc, copper, manganese and selenium in oral hospital diets.

    OpenAIRE

    Moreira, Daniele Caroline Faria; Sá, Júlia Sommerlatte Manzoli de; Cerqueira, Isabel B.; Oliveira, Ana P. F. de; Morgano, Marcelo Antonio; Quintaes, Késia Diego

    2013-01-01

    Background & aims: Many trace elements are nutrients essential to humans, acting in the metabolism as constituents or as enzymatic co-factors. The iron, zinc, copper, manganese and selenium contents of hospital diets (regular, blend and soft) and of oral food complement (OFC) were determined, evaluating the adequacy of each element in relation to the nutritional recommendations (DRIs) and the percent contribution alone and with OFC. Methods: Duplicate samples were taken of six daily meals ...

  11. Differential pulmonary and cardiac effects of pulmonary exposure to a panel of particulate matter-associated metals

    International Nuclear Information System (INIS)

    Wallenborn, J. Grace; Schladweiler, Mette J.; Richards, Judy H.; Kodavanti, Urmila P.

    2009-01-01

    Biological mechanisms underlying the association between particulate matter (PM) exposure and increased cardiovascular health effects are under investigation. Water-soluble metals reaching systemic circulation following pulmonary exposure are likely exerting a direct effect. However, it is unclear whether specific PM-associated metals may be driving this. We hypothesized that exposure to equimolar amounts of five individual PM-associated metals would cause differential pulmonary and cardiac effects. We exposed male WKY rats (14 weeks old) via a single intratracheal instillation (IT) to saline or 1 μmol/kg body weight of zinc, nickel, vanadium, copper, or iron in sulfate form. Responses were analyzed 4, 24, 48, or 96 h after exposure. Pulmonary effects were assessed by bronchoalveolar lavage fluid levels of total cells, macrophages, neutrophils, protein, albumin, and activities of lactate dehydrogenase, γ-glutamyl transferase, and n-acetyl glucosaminidase. Copper induced earlier pulmonary injury/inflammation, while zinc and nickel produced later effects. Vanadium or iron exposure induced minimal pulmonary injury/inflammation. Zinc, nickel, or copper increased serum cholesterol, red blood cells, and white blood cells at different time points. IT of nickel and copper increased expression of metallothionein-1 (MT-1) in the lung. Zinc, nickel, vanadium, and iron increased hepatic MT-1 expression. No significant changes in zinc transporter-1 (ZnT-1) expression were noted in the lung or liver; however, zinc increased cardiac ZnT-1 at 24 h, indicating a possible zinc-specific cardiac effect. Nickel exposure induced an increase in cardiac ferritin 96 h after IT. This data set demonstrating metal-specific cardiotoxicity is important in linking metal-enriched anthropogenic PM sources with adverse health effects.

  12. A Study on Zinc-Iron Alloy Electrodeposition from a Chloride Electrolyte

    DEFF Research Database (Denmark)

    Jensen, Jens Dahl

    1998-01-01

    The electrodeposition of zinc-iron alloys from a chloride-based electrolyte has been studied using electrochemical polarisation techniques, Auger Electron Spectroscopy (AES), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDXA) and Computer Assisted Pulse Plating (CAPP...... this system ideal for production of compositional modulated alloy (CMA) electrodeposits. Chloride content, pH and agitation of the electrolyte have been observed to have a strong influence on the reaction at the cathode surface, just as the use of pulse reversal current during electrodeposition. A theory...

  13. Preparation of Highly Pure Vanadyl Sulfate from Sulfate Solutions Containing Impurities of Iron and Aluminum by Solvent Extraction Using EHEHPA

    Directory of Open Access Journals (Sweden)

    Dan Li

    2017-03-01

    Full Text Available The preparation of highly pure vanadyl sulfate from sulfate solutions containing impurities of iron and aluminumwas investigated by solvent extraction with 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester (EHEHPA and tri-n-butyl phosphate (TBP as the phase modifier. The extraction and stripping conditions of vanadium (IV and its separation from iron and aluminum were optimized. Under the optimal extraction conditions, the extraction of vanadium (IV and iron were 68% and 53%, respectively, while only 2% aluminum was extracted in a single contact, suggesting good separation of vanadium (IV from aluminum. Sulfuric acid solution was used for the stripping. Nearly 100% vanadium (IV and 95% aluminum were stripped, while only 10% iron was stripped under the optimal stripping conditions in a single contact, suggesting good separation of vanadium (IV from iron. After five stages of extraction and stripping, highly pure vanadyl sulfate containing 76.5 g/L V (IV with the impurities of 12 mg/L Fe and 10 mg/L Al was obtained, which is suitable for the electrolyte of a vanadium redox flow battery. Organic solution was well regenerated after stripping by oxalic acid solution to remove the remaining iron. The mechanism of vanadium (IV extraction using EHEHPA was also discussed based on the Fourier transform infrared spectroscopy (FT-IR analysis.

  14. A Low-Cost Neutral Zinc-Iron Flow Battery with High Energy Density for Stationary Energy Storage.

    Science.gov (United States)

    Xie, Congxin; Duan, Yinqi; Xu, Wenbin; Zhang, Huamin; Li, Xianfeng

    2017-11-20

    Flow batteries (FBs) are one of the most promising stationary energy-storage devices for storing renewable energy. However, commercial progress of FBs is limited by their high cost and low energy density. A neutral zinc-iron FB with very low cost and high energy density is presented. By using highly soluble FeCl 2 /ZnBr 2 species, a charge energy density of 56.30 Wh L -1 can be achieved. DFT calculations demonstrated that glycine can combine with iron to suppress hydrolysis and crossover of Fe 3+ /Fe 2+ . The results indicated that an energy efficiency of 86.66 % can be obtained at 40 mA cm -2 and the battery can run stably for more than 100 cycles. Furthermore, a low-cost porous membrane was employed to lower the capital cost to less than $ 50 per kWh, which was the lowest value that has ever been reported. Combining the features of low cost, high energy density and high energy efficiency, the neutral zinc-iron FB is a promising candidate for stationary energy-storage applications. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Iron, folacin, vitamin B12 and zinc status and immune response in elderly subjects in the Washington D.C. metropolitan area

    International Nuclear Information System (INIS)

    Henry-Christian, J.R.

    1986-01-01

    The iron, folacin, vitamin B 12 , and zinc status of a group of economically and socially disadvantaged elderly persons in the Washington Metropolitan Area was evaluated. Factors related to deficiencies of these nutrients, the relationships between the status of these nutrients and cell-mediated immunity, and the relationships of iron, folacin and vitamin B 12 status to hemoglobin levels in the subjects were also examined. It was also determined whether there were any interactions among iron, folacin, vitamin B 12 and zinc status in their relationships to cell-mediated immunity. Socio-demographic and nutritional data on the subjects were obtained using a questionnaire. Dietary data were obtained using a dietary record. A fasting blood sample was drawn and the levels of ferritin, folate and vitamin B 12 , and the erythrocyte levels of folate were determined by radioassay. Plasma and hair zinc levels were determined by atomic absorption spectrophotometry. Cell-mediated immune response was determined by transformation of peripheral blood lymphocytes after stimulation by mitogens, and by allogenic lymphocytes in the mixed lymphocyte reaction

  16. Microwave digestion for determination content of iron and zinc total in food

    International Nuclear Information System (INIS)

    Silva Trejos, Paulina

    2012-01-01

    The food digestion procedure was optimized by means of a microwave oven, to quantify the iron and total zinc in different matrices by atomic absorption spectroscopy. The optimum amount of concentrated HNO 3 was analyzed at 65% to digest sample mass determined by assessment of the percentage of recovery obtained with different amount of HNO 3 . The results have not differed from those obtained by officially recommended methods of acid digestion in open systems and calcination. (author) [es

  17. The Effects of Micro Elements of Iron and Zinc on Morphological Characteristics of Mycorrhized Barley (Hordeum vulgare L.

    Directory of Open Access Journals (Sweden)

    Shahab Khaghani

    2016-06-01

    Full Text Available Deficiency of micro-nutrients in human diet may cause health problems. To increase the amount of these elements in the edible parts of the plants would eliminate the incidence of these health problems. Thus, the effects of iron and zinc on seed yield and morphological characteristics of mycorrhized barley (cv. Bahman root was studied in Karaj, Iran, during growing season of 2013-14. It was carried out in afactorial experiment based on randomized complete block design with three replications. Treatments consisted two levels of mycorrhiza, non-inoculation (M0 and inoculation with 10 kg/ha of Glomus intraradices (M1, and three levels of iron from Fe-EDDHA (Sequestrene138 as control (F0, 2.5 kg/ha (F1 and 5kg/ha (F2 and three levels of zinc as zinc sulphate (ZnSO4 as control (Z0, 25 kg/ha (Z1 and 50 kg/ha (Z2. The results showed that application of mycorrhiza increased parameters like total root length (TRL, root length density (RLD, specific root length (SLR, root colonization percentage and grain yield by 900.6 cm, 0.52 cm/cm3, 1738.1 cm/g, 5.41% and 1ton/ha respectively. Mean comparisons also revealed that using iron, mycorrhiza and without Zn application increased levels of root dry weight (RDW by 2.81 g.

  18. Evaluation of iron and zinc bioavailability of beans targeted for biofortification using in vitro and in vivo models and their effect on the nutritional status of preschool children.

    Science.gov (United States)

    Vaz-Tostes, Maria das Graças; Verediano, Thaisa Agrizzi; de Mejia, Elvira Gonzalez; Brunoro Costa, Neuza Maria

    2016-03-15

    Biofortified beans have been produced with higher nutrient concentrations. The objective was to evaluate the in vitro and in vivo iron and zinc bioavailability of common beans Pontal (PO), targeted for biofortification, compared with conventional Perola (PE) and their effects on the iron and zinc nutritional status of preschool children. In Caco-2 cells, PO and PE beans did not show differences in ferritin (PO, 13.1 ± 1.4; PE, 13.6 ± 1.4 ng mg(-1) protein) or zinc uptake (PO, 15.9 ± 1.5; PE, 15.5 ± 3.5 µmol mg(-1) protein). In the rat, PO and PE beans presented high iron bioavailability (PO, 109.6 ± 29.5; PE, 110.7 ± 13.9%). In preschool children, no changes were observed in iron and zinc nutritional status comparing before and after PO consumption (ferritin, 41.2 ± 23.2 and 28.9 ± 40.4 µg L(-1) ; hemoglobin, 13.7 ± 2.2 and 13.1 ± 3.2 g dL(-1) ; plasma zinc, 119.2 ± 24.5 and 133.9 ± 57.7 µg dL(-1) ; erythrocyte zinc, 53.5 ± 13.8 and 59.4 ± 17.1 µg g(-1) hemoglobin). Iron and zinc bioavailability in PO and PE beans was not statistically different using either cell culture, animal or human models. Efforts should focus on increasing mineral bioavailability of beans targeted for biofortification. © 2015 Society of Chemical Industry.

  19. Iron and zinc complexation in wild-type and ferritin-expressing wheat grain: implications for mineral transport into developing grain

    DEFF Research Database (Denmark)

    Neal, Andrew L; Geraki, Kalotina; Borg, Søren

    2013-01-01

    of modified complexation of both metals in transgenic grain overexpressing wheat ferritin. For zinc, there is a consistent doubling of the number of complexing phosphorus atoms. Although there is some EXAFS evidence for iron phytate in ferritin-expressing grain, there is also evidence of a structure lacking......We have used synchrotron-based X-ray fluorescence and absorption techniques to establish both metal distribution and complexation in mature wheat grains. In planta, extended X-ray absorption fine structure (EXAFS) spectroscopy reveals iron phytate and zinc phytate structures in aleurone cells...... of ferritin-expressing grains is quite different from that in wild-type grain. This may explain why the raised levels of minerals transported to the developing grain accumulate within the crease region of the transgenic grain....

  20. Effect of excess dietary iron as ferrous sulfate and excess dietary ascorbic acid on liver zinc, copper and sulfhydryl groups and the ovary

    International Nuclear Information System (INIS)

    Edwards, C.H.; Adkins, J.S.; Harrison, B.

    1986-01-01

    Female guinea pigs of the NIH 13/N strain, weighing between 475 and 512 g, were fed diets supplemented with 50 to 2500 mg of iron per kg of diet as ferrous sulfate and 0.2 to 8.0 g of ascorbic acid per kg of diet. A significant effect was observed on tissue copper and zinc, ovary weight and liver protein sulfhydryl groups. The mean ovary weight for guinea pigs fed 2500 mg of iron was significantly less than that of animals fed 50 mg of iron, 0.045 +/- 0.012 g and 0.061 +/- 0.009 g, respectively. Liver zinc content of animals fed 2500 mg of iron and 200 mg of ascorbic acid per kg of diet was significantly less than that of animals fed 50 mg of iron and 200 mg of ascorbic acid, 16.3 +/- 3.3 μg and 19.6 +/- 1.6 μg, respectively. There was no difference in liver copper due to dietary iron, but when dietary ascorbic acid was increased to 8 g per kg of diet, there was a significant decrease (from 22.8 +/- 8.1 μg to 10.5 +/- 4.8 μg) in liver copper. Excess dietary ascorbic acid decreased ovarian zinc significantly when increased to 8 g per kg of diet, 2929 +/- 919 μg vs 1661 +/- 471 μg, respectively, when compared to the control group

  1. Fever and changes in plasma zinc and iron concentrations in the goat: The role of leukocytic pyrogen

    NARCIS (Netherlands)

    Verheijden, J.H.M.; Miert, A. S. J. P. A. M. Van; Duin, C.T.M. van; Schotman, A.J.H.; Nieuwenhuis, J.

    1984-01-01

    In goats with trypanosomiasis (T. vivax or T. congolense) no marked fall in plasma zinc concentration was seen despite high temperature peaks, whereas plasma concentrations of iron tended to undergo some decline. In goats infected with Ehrlichia phagocytophila, there was a marked decline in plasma

  2. Effect of iron on vanadium (001) strained surface magnetism

    Energy Technology Data Exchange (ETDEWEB)

    Elzain, M; Al-Barwani, M; Gismelseed, A; Al-Rawas, A; Yousif, A; Widatallah, H; Bouziane, K; Al-Omari, I, E-mail: elzain@squ.edu.o [Department of Physics, College Of Science, Box 36, Sultan Qaboos University, Al Khod 123 (Oman)

    2010-03-01

    The magnetism of the vanadium (001) surface has been a controversial subject on both theoretical and experiment fronts. Both strongly ferromagnetic and paramagnetic phases were reported. We have used the first principle full-potential linearized-augmented plane waves (FP-LAPW) as implemented in WIEN2k package to study the magnetic properties of strained surfaces of vanadium films as a function of film thickness. We found that for films thicker than about 11 monolayers, the magnetism of the strained surfaces converge to a constant value of about 0.15{mu}{sub B}. Introduction of Fe monolayers and impurities at the centre of the films affects the magnetic structure of thin films but has no influence on the surface magnetism of thicker films. For Fe monolayers positioned at the centre of thick films, the Fe atoms maintain magnetic moment of order 0.86{mu}{sub B}, a quadruple splitting of order -0.3 mm/s and a small negative isomer shift, while an Fe impurity has vanishing hyperfine fields and magnetic moment. In addition we have varied the location of the Fe monolayer and impurity within the V films and found that their position affects the surface magnetism.

  3. Structural characterization of hog iron oxide content glasses obtained from zinc hydrometallurgy wastes

    International Nuclear Information System (INIS)

    Romero, M.; Rincon, J.M.; Musik, S.; Kozhujharov, W.

    1997-01-01

    It has been carried out the structural characterization of high oxide content glasses obtained by melting of a goethite industrial waste from the zinc hydrometallurgy with other raw materials as dolomite and glass cullet. The structural characterization has been carried out by X-ray Diffraction (XRD), X-Ray Diffraction by Amorphous Dispersion (RDF) and Mossbauer spectroscopy. It has been determined the interatomic distance, the oxidation state and the coordination of iron atoms in these glasses. (Author) 16 refs

  4. Iron, zinc and phytic acid in rice from China: wet and dry processing towards improved mineral bioavailability

    NARCIS (Netherlands)

    Liang, J.

    2007-01-01

    Rice and rice products supply two thirds of Chinese people with their staple food. Mineral deficiencies, especially of iron and zinc, are prevalent in China, and are caused by insufficient intake and poor bioavailability. Rice and rice products contribute more than 50% of the antinutrient phytic

  5. EFFECT OF ALLOYING ON TEMPERATURE OF TRANSFORMATION «PEARLITE – AUSTENITE» IN COMPLEX-ALLOYED WHITE CAST IRONS

    Directory of Open Access Journals (Sweden)

    T. V. Pastukhova

    2014-11-01

    Full Text Available Purpose. Pearlite is not accepted in the microstructure of wear resistant steels and cast irons. To prevent the pearlite by means of appropriate selection of mode of quenching requires the knowledge of the temperature of the critical points Ac1 and Ac3 for various steels and cast irons. Purpose of work is determine the effect of V (5-10% and Cr (up to 9% on the temperature range of the phase-structural transformation "pearlite®austenite in the complex-alloyed V-Cr-Mn-Ni white cast irons with spheroidal vanadium carbides. Methodology. Nine Mg-treated cast irons smelted in laboratory furnace were used for investigation. The metallographic and optical dilatometric analysis methods as well as energy-dispersive spectroscopy were used. Findings. It is shown that in irons studied the critical point Ac1 is in a temperature range from 710-780 °C (lower limit up to 730-850 °C (upper limit. The data on the concentrations of chromium and vanadium in a matrix of iron are presented, the regression equation describing the effect of vanadium and chromium on the temperature limits of the transformation «pearlite ® austenite» are obtained. Originality. It is shown that increase the chromium content leads to growth of lower and upper limits of the temperature interval of transformation "pearlite ® austenite"; vanadium increases only the upper limit of the range. It was found that the effect of chromium on the critical point Ac1 is attributed to its solubility in the metallic matrix (concentration of Cr in the austenite reaches 7%; vanadium, due to its slight dissolution in the matrix (vanadium content does not exceed 1.75%, affects the critical point indirectly by increasing of chromium concentration in the matrix due to enhanced carbon sequestration in VC carbides. Practical value. The temperature ranges of heating for quenching of V-Cr-Mn-Ni cast irons with spheroidal vanadium carbides, which provides the formation of austenitic-martensitic matrix without

  6. Effects of various anesthesia maintenance on serum levels of selenium, copper, zinc, iron and antioxidant capacity

    Directory of Open Access Journals (Sweden)

    Mehmet Akin

    2015-02-01

    Full Text Available BACKGROUND AND OBJECTIVES: In this study, we aimed to investigate the effects of sevoflurane, desflurane and propofol maintenances on serum levels of selenium, copper, zinc, iron, malondialdehyde, and glutathion peroxidase measurements, and antioxidant capacity. METHODS: 60 patients scheduled for unilateral lower extremity surgery which would be performed with tourniquet under general anesthesia were divided into three groups. Blood samples were collected to determine the baseline serum levels of selenium, copper, zinc, iron, malondialdehyde and glutathion peroxidase. Anesthesia was induced using 2-2.5 mg kg-1 propofol, 1 mg kg-1 lidocaine and 0.6 mg kg-1 rocuronium. In the maintenance of anesthesia, under carrier gas of 50:50% O2:N2O 4 L min-1, 1 MAC sevoflorane was administered to Group S and 1 MAC desflurane to Group D; and under carrier gas of 50:50% O2:air 4 L min-1 6 mg kg h-1 propofol and 1 µg kg h-1 fentanyl infusion were administered to Group P. At postoperative blood specimens were collected again. RESULTS: It was observed that only in Group S and P, levels of MDA decreased at postoperative 48th hour; levels of glutathion peroxidase increased in comparison to the baseline values. Selenium levels decreased in Group S and Group P, zinc levels decreased in Group P, and iron levels decreased in all three groups, and copper levels did not change in any groups in the postoperative period. CONCLUSION: According to the markers of malondialdehyde and glutathion peroxidase, it was concluded that maintenance of general anesthesia using propofol and sevoflurane activated the antioxidant system against oxidative stress and using desflurane had no effects on oxidative stress and antioxidant system.

  7. Anemia and iron, zinc, copper and magnesium deficiency in Mexican adolescents: National Health and Nutrition Survey 2006 Anemia y deficiencia de hierro, zinc, cobre y magnesio en adolescentes mexicanos: resultados de la ENSANUT 2006

    Directory of Open Access Journals (Sweden)

    Vanessa De la Cruz-Góngora

    2012-04-01

    Full Text Available OBJETIVE: To describe the frequency of anemia and iron, zinc, copper and magnesium deficiencies among Mexican adolescents in the probabilistic survey ENSANUT 2006. MATERIALS AND METHODS: The sample included 2447 adolescents aged 12 to 19 y. Capillary hemoglobin and venous blood samples were collected to measure the concentrations of ferritin, sTFR, CRP, zinc, iron, copper and magnesium. Logistic regression models were constructed to assess the risk for mineral deficiencies. RESULTS: The overall prevalence of anemia was 11.8 and 4.6%, body iron deficiency 18.2 and 7.9% for females and males, respectively. Overall prevalence of tissue iron deficiency was 6.9%, low serum copper were14.4 and 12.25%; zinc 28.4 and 24.5%, magnesium 40 and 35.3%; for females and males, respectively. CONCLUSIONS: There is a high prevalence of mineral deficiency in Mexican adolescents; females were more prone to have more mineral deficiencies. Nutritional interventions are necessaries in order to reduce and control them.OBJETIVO: Describir la prevalencia de anemia y deficiencia de hierro, zinc, cobre y magnesio en adolescentes mexicanos en la encuesta probabilística ENSANUT 2006. MATERIAL Y MÉTODOS: La muestra incluyó 2447 adolescentes de 12 a 19 años de edad. Se tomó hemoglobina capilar y muestras de sangre venosa para medir las concentraciones séricas de ferritina, sTFR, CRP, zinc, hierro, cobre y magnesio. Se construyeron modelos de regresión logística para evaluar el riesgo de deficiencia de minerales. RESULTADOS: La prevalencia de anemia fue de 11.8% en mujeres y 4.6% en hombres. Las deficiencias de hierro fueron de 18.2 y 7.9% La deficiencia tisular de hierro fue 6.9%; la baja concentración de cobre fue de 14.4 y 12.25% la de zinc de 28.4 y 24.5%, la de magnesio fue 40 y 35.3% en mujeres y hombres, respectivamente. CONCLUSIONES: Existe una alta prevalencia de deficiencia de minerales en los adolescentes; las mujeres tuvieron mayor riesgo. Son necesarias

  8. Geochemistry of the furnace magnetite bed, Franklin, New Jersey, and the relationship between stratiform iron oxide ores and stratiform zinc oxide-silicate ores in the New Jersey highlands

    Science.gov (United States)

    Johnson, C.A.; Skinner, B.J.

    2003-01-01

    The New Jersey Highlands terrace, which is an exposure of the Middle Proterozoic Grenville orogenic belt located in northeastern United States, contains stratiform zinc oxide-silicate deposits at Franklin and Sterling Hill and numerous massive magnetite deposits. The origins of the zinc and magnetite deposits have rarely been considered together, but a genetic link is suggested by the occurrence of the Furnace magnetite bed and small magnetite lenses immediately beneath the Franklin zinc deposit. The Furnace bed was metamorphosed and deformed along with its enclosing rocks during the Grenvillian orogeny, obscuring the original mineralogy and obliterating the original rock fabrics. The present mineralogy is manganiferous magnetite plus calcite. Trace hydrous silicates, some coexisting with fluorite, have fluorine contents that are among the highest ever observed in natural assemblages. Furnace bed calcite has ??13C values of -5 ?? 1 per mil relative to Peedee belemnite (PDB) and ??18O values of 11 to 20 per mil relative to Vienna-standard mean ocean water (VSMOW). The isotopic compositions do not vary as expected for an original siderite layer that decarbonated during metamorphism, but they are consistent with nearly isochemical metamorphism of an iron oxide + calcite protolith that is chemically and minerlogically similar to iron-rich sediments found near the Red Sea brine pools and isotopically similar to Superior-type banded iron formations. Other magniferous magnite + calcite bodies occur at approximately the same stratigraphic position as far 50 km from the zinc deposits. A model is presented in which the iron and zinc deposits formed along the western edge of a Middle Proterozoic marine basin. Zinc was transported by sulfate-stable brines and was precipitated under sulfate-stable conditions as zincian carbonates and Fe-Mn-Zn oxides and silicates. Whether the zincian assemblages settled from the water column or formed by replacement reactions in shallowly

  9. Co-ordinated research programme on isotope-aided studies of the bioavailability of iron and zinc from human diets

    International Nuclear Information System (INIS)

    1992-01-01

    Nutritional deficiencies of essential micronutrients (particularly of iron, but also of zinc and selenium) are known to affect hundreds of millions of people throughout the world, mainly in developing countries. Such deficiencies can lead to significant deficits in mental development, growth, work performance, immune competence and other biological parameters. In many of the population groups that are affected, the deficiencies are thought to be due not to an absolute lack of the element in the diet but rather to is poor bioavailability. Much work has already been done on this subject, particularly in some developed countries and particularly with respect to iron. However, there is still appears to be a need for more research on factors affecting bioavailability and the means to improve it by simple dietary modification and fortification using food products of the kind that may be locally available in developing countries. Isotope techniques potentially have a large role to play in studies of the bioavailability of iron and other trace elements. To support work in this area, the IAEA initiated a Co-ordinated Research Programme (CRP) at the end of 1990 on ''Isotope-Aided Studies of the Bioavailability of Iron and Zinc from Human Diets''. The first Research Co-ordination Meeting (RCM) of participants in this CRP is the subject of the present report. Refs, figs and tabs

  10. Characterization of copper oxides, iron oxides, and zinc copper ferrite desulfurization sorbents by X-ray photoelectron spectroscopy and scanning electron microscopy

    Science.gov (United States)

    Siriwardane, Ranjani V.; Poston, James A.

    1993-05-01

    Characterization of copper oxides, iron oxides, and zinc copper ferrite desulfurization sorbents was performed by X-ray photoelectron spectroscopy and scanning electron microscopy/energy-dispersive spectroscopy at temperatures of 298 to 823 K. Analysis of copper oxides indicated that the satellite structure of the Cu22p region was absent in the Cu(I) state but was present in the Cu(II) state. Reduction of CuO at room temperature was observed when the ion gauge was placed close to the sample. The satellite structure was absent in all the copper oxides at 823 K in vacuum. Differentiation of the oxidation state of copper utilizing both Cu(L 3M 4,5M 4,5) X-ray-induced Auger lines and Cu2p satellite structure, indicated that the copper in zinc copper ferrite was in the + 1 oxidation state at 823 K. This + 1 state of copper was not significantly changed after exposure to H 2, CO, and H 2O. There was an increase in Cu/Zn ratio and a decrease in Fe/Zn ratio on the surface of zinc copper ferrite at 823 K compared to that at room temperature. These conditions of copper offered the best sulfidation equilibrium for the zinc copper ferrite desulfurization sorbent. Analysis of iron oxides indicated that there was some reduction of both Fe 2O 3 and FeO at 823K. The iron in zinc copper ferrite was similar to that of Fe 2O 3 at room temperature but there was some reduction of this Fe(III) state to Fe(II) at 823 K. This reduction was more enhanced in the presence of H 2 and CO. Reduction to Fe(II) may not be desirable for the lifetime of the sorbent.

  11. Experimental observation of zinc dialkyl dithiophosphate (ZDDP)-induced iron sulphide formation

    Energy Technology Data Exchange (ETDEWEB)

    Soltanahmadi, Siavash, E-mail: s.soltanahmadi@leeds.ac.uk [Institute of Functional Surfaces, School of Mechanical Engineering, University of Leeds, LS2 9JT (United Kingdom); Morina, Ardian [Institute of Functional Surfaces, School of Mechanical Engineering, University of Leeds, LS2 9JT (United Kingdom); Eijk, Marcel C.P. van; Nedelcu, Ileana [SKF Engineering and Research Centre, 3430 DT Nieuwegein (Netherlands); Neville, Anne [Institute of Functional Surfaces, School of Mechanical Engineering, University of Leeds, LS2 9JT (United Kingdom)

    2017-08-31

    Graphical abstract: Chemical analysis of ZDDP-induced tribofilm under severe boundary lubricated regime in nano and micro-meter scales.▪ - Highlights: • A ZDDP-derived locally formed iron-sulphide layer is detected on the steel surface. • The iron-sulphide is a 5–10 nm thin distinct layer at steel-phosphate interface. • Near the surface-crack site the elemental distribution of the tribofilm is altered. • Sulphur concentration is enhanced in the iron-sulphide layer near the cracked-site. • ZDDP elements are detected inside the crack with a greater contribution of sulphur. - Abstract: Zinc dialkyl dithiophosphate (ZDDP) as a well-known anti-wear additive enhances the performance of the lubricant beyond its wear-protection action, through its anti-oxidant and Extreme Pressure (EP) functionality. In spite of over thirty years of research attempting to reveal the mechanism of action of ZDDP, there are still some uncertainties around the exact mechanisms of its action. This is especially the case with the role of sulphide layer formed in the tribofilm and its impact on surface fatigue. Although iron sulphide on the substrate is hypothesised in literature to form as a separate layer, there has been no concrete experimental observation on the distribution of the iron sulphide as a dispersed precipitate, distinct layer at the steel substrate or both. It remains to be clarified whether the iron sulphide layer homogeneously covers the surface or locally forms at the surface. In the current study a cross section of the specimen after experiment was prepared and has been investigated with Transmission Electron Microscopy (TEM) and Energy-Dispersive X-ray (EDX) elemental analysis. A 5–10 nm iron sulphide layer is visualised on the interface as a separate layer underneath the phosphate layer with an altered distribution of tribofilm elements near the crack site. The iron sulphide interface layer is more visible near the crack site where the concentration of the

  12. Experimental observation of zinc dialkyl dithiophosphate (ZDDP)-induced iron sulphide formation

    International Nuclear Information System (INIS)

    Soltanahmadi, Siavash; Morina, Ardian; Eijk, Marcel C.P. van; Nedelcu, Ileana; Neville, Anne

    2017-01-01

    Graphical abstract: Chemical analysis of ZDDP-induced tribofilm under severe boundary lubricated regime in nano and micro-meter scales.▪ - Highlights: • A ZDDP-derived locally formed iron-sulphide layer is detected on the steel surface. • The iron-sulphide is a 5–10 nm thin distinct layer at steel-phosphate interface. • Near the surface-crack site the elemental distribution of the tribofilm is altered. • Sulphur concentration is enhanced in the iron-sulphide layer near the cracked-site. • ZDDP elements are detected inside the crack with a greater contribution of sulphur. - Abstract: Zinc dialkyl dithiophosphate (ZDDP) as a well-known anti-wear additive enhances the performance of the lubricant beyond its wear-protection action, through its anti-oxidant and Extreme Pressure (EP) functionality. In spite of over thirty years of research attempting to reveal the mechanism of action of ZDDP, there are still some uncertainties around the exact mechanisms of its action. This is especially the case with the role of sulphide layer formed in the tribofilm and its impact on surface fatigue. Although iron sulphide on the substrate is hypothesised in literature to form as a separate layer, there has been no concrete experimental observation on the distribution of the iron sulphide as a dispersed precipitate, distinct layer at the steel substrate or both. It remains to be clarified whether the iron sulphide layer homogeneously covers the surface or locally forms at the surface. In the current study a cross section of the specimen after experiment was prepared and has been investigated with Transmission Electron Microscopy (TEM) and Energy-Dispersive X-ray (EDX) elemental analysis. A 5–10 nm iron sulphide layer is visualised on the interface as a separate layer underneath the phosphate layer with an altered distribution of tribofilm elements near the crack site. The iron sulphide interface layer is more visible near the crack site where the concentration of the

  13. African leafy vegetables consumed by households in the Limpopo ...

    African Journals Online (AJOL)

    pureed green leafy vegetables was shown to have a beneficial effect ..... was regarded as very nutritious; “having it is just like having meat”. ...... chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, and zinc.

  14. Vanadium Bioleaching Behavior by Acidithiobacillus ferrooxidans from a Vanadium-Bearing Shale

    Directory of Open Access Journals (Sweden)

    Dunpei Wei

    2018-01-01

    Full Text Available This study investigated bioleaching behavior of vanadium from a vanadium-bearing shale using Acidithiobacillus ferrooxidans (A. ferrooxidans. Results showed a maximum recovery of 62% vanadium in 1.2-day bioleaching, which was 22.45% higher than the controls. Then, the vanadium leaching efficiency decreased significantly, only 24% of that was obtained on the tenth day. The vanadium extraction in 1.2 days was mainly attributed to the dissolution of vanadium in free oxides of shale. Fe3+ produced by A. ferrooxidans promoted the dissolution process. X-ray diffraction (XRD patterns of the leached residues confirmed the generation of jarosite. SEM-EDS analysis of the residues indicated that jarosite adsorbed on the shale and inhibited the further dissolution of vanadium. The relevance of V, Fe, S, O was quite good in the energy disperse X-ray spectrometry (EDS element mapping of jarosite, and acid-washing of the jarosite resulted in 31.6% of the vanadium in the precipitates desorption, indicating that the decrease of vanadium leaching efficiency in bioleaching process was caused by both adsorption and co-precipitation with jarosite.

  15. A review of phytate, iron, zinc, and calcium concentrations in plant-based complementary foods used in low-income countries and implications for bioavailability.

    Science.gov (United States)

    Gibson, Rosalind S; Bailey, Karl B; Gibbs, Michelle; Ferguson, Elaine L

    2010-06-01

    Plant-based complementary foods often contain high levels of phytate, a potent inhibitor of iron, zinc, and calcium absorption. This review summarizes the concentrations of phytate (as hexa- and penta-inositol phosphate), iron, zinc, and calcium and the corresponding phytate:mineral molar ratios in 26 indigenous and 27 commercially processed plant-based complementary foods sold in low-income countries. Phytate concentrations were highest in complementary foods based on unrefined cereals and legumes (approximately 600 mg/100 g dry weight), followed by refined cereals (approximately 100 mg/100 g dry weight) and then starchy roots and tubers (source foods and/or fortification with minerals. Dephytinization, either in the household or commercially, can potentially enhance mineral absorption in high-phytate complementary foods, although probably not enough to overcome the shortfalls in iron, zinc, and calcium content of plant-based complementary foods used in low-income countries. Instead, to ensure the World Health Organization estimated needs for these minerals from plant-based complementary foods for breastfed infants are met, dephytinization must be combined with enrichment with animal-source foods and/or fortification with appropriate levels and forms of mineral fortificants.

  16. In Vitro Bioavailability of Calcium, Magnesium, Iron, Zinc, and Copper from Gluten-Free Breads Supplemented with Natural Additives.

    Science.gov (United States)

    Regula, J; Cerba, A; Suliburska, J; Tinkov, A A

    2018-03-01

    The aim of this study was to measure the content of calcium, magnesium, iron, zinc, and copper and determine the bioavailability of these ingredients in gluten-free breads fortified with milk and selected seeds. Due to the increasing prevalence of celiac disease and mineral deficiencies, it has become necessary to produce food with higher nutritional values which maintains the appropriate product characteristics. This study was designed for gluten-free breads fortified with milk and seeds such as flax, poppy, sunflower seeds, pumpkin seeds or nuts, and flour with amaranth. Subsequently, digestion was performed in vitro and the potential bioavailability of the minerals was measured. In the case of calcium, magnesium, iron, and copper, higher bioavailability was observed in rice bread, and, in the case of copper and zinc, in buckwheat bread. This demonstrated a clear increase in bioavailability of all the minerals when the bread were enriched. However, satisfactory results are obtained only for the individual micronutrients.

  17. Zinc and the iron donor frataxin regulate oligomerization of the scaffold protein to form new Fe-S cluster assembly centers.

    Science.gov (United States)

    Galeano, B K; Ranatunga, W; Gakh, O; Smith, D Y; Thompson, J R; Isaya, G

    2017-06-21

    Early studies of the bacterial Fe-S cluster assembly system provided structural details for how the scaffold protein and the cysteine desulfurase interact. This work and additional work on the yeast and human systems elucidated a conserved mechanism for sulfur donation but did not provide any conclusive insights into the mechanism for iron delivery from the iron donor, frataxin, to the scaffold. We previously showed that oligomerization is a mechanism by which yeast frataxin (Yfh1) can promote assembly of the core machinery for Fe-S cluster synthesis both in vitro and in cells, in such a manner that the scaffold protein, Isu1, can bind to Yfh1 independent of the presence of the cysteine desulfurase, Nfs1. Here, in the absence of Yfh1, Isu1 was found to exist in two forms, one mostly monomeric with limited tendency to dimerize, and one with a strong propensity to oligomerize. Whereas the monomeric form is stabilized by zinc, the loss of zinc promotes formation of dimer and higher order oligomers. However, upon binding to oligomeric Yfh1, both forms take on a similar symmetrical trimeric configuration that places the Fe-S cluster coordinating residues of Isu1 in close proximity of iron-binding residues of Yfh1. This configuration is suitable for docking of Nfs1 in a manner that provides a structural context for coordinate iron and sulfur donation to the scaffold. Moreover, distinct structural features suggest that in physiological conditions the zinc-regulated abundance of monomeric vs. oligomeric Isu1 yields [Yfh1]·[Isu1] complexes with different Isu1 configurations that afford unique functional properties for Fe-S cluster assembly and delivery.

  18. Reducing elution in anion exchange chromatography as a pretreatment of colorimetry of chromium(VI) and vanadium(V)

    International Nuclear Information System (INIS)

    Shigetomi, Yasumasa; Hatamoto, Takeji; Nagoshi, Kimie; Yamashige, Takashi.

    1976-01-01

    In order to increase the selectivity of the colorimetry of chromium and vanadium, the separation by means of anion exchange chromatography was tested. The column, phi 0.8x5.0 cm packing (50--100 mesh) Dowex 1x4 anion exchange resin was used for the separation of chromium. The solution containing chromium (VI), zinc(II), cadmium(II), iron(III) and reducing organic substances contained in industrial waste water was introduced into the column and then the substances other than chromium(VI) were removed by washing the column with distilled water. Finally chromium(VI) was reduced to chromium(III) by hydroxylamine in the eluent and eluted. The concentration of sulfuric acid and hydroxylamine in the eluent were 0.1 mol/l and 0.001 mol/l respectively. For analyzing chromium(III) in the mixture of chromium(VI) and chromium(III), after removal of chromium(VI) it should be oxidized to chromium(VI) anion with the oxidant, e.g., sodium peroxide or hydrogen peroxide, before introducing it into the column. In terms of the pretreatment by using the acetate form resin column, chromium (VI) and chromium(III) can be determined separately in the solution whose concentration ranges from 0.05 ppm to 0.5 ppm despite the presence of contaminants, which interfere with the colorimetric determination of chromium(VI) using diphenylcarbonohydrazide, in the original solution. The separation of vanadium(V) in the solution containing copper(II), cobalt(II) and etc. was made using the mixed solution of hydrochloric acid (2 mol/l) and hydroxylamine (0.2 mol/l) similarly to chromium(VI). In terms of the similar pretreatment vanadium could be determined precisely as far as 0.1 ppm by the colorimetry using 4-(2-pyridylazo) resorcinol despite the presence of copper(II), cobalt(II), nickel(II) and etc in the original solution. (auth.)

  19. Iron-binding haemerythrin RING ubiquitin ligases regulate plant iron responses and accumulation

    Science.gov (United States)

    Kobayashi, Takanori; Nagasaka, Seiji; Senoura, Takeshi; Itai, Reiko Nakanishi; Nakanishi, Hiromi; Nishizawa, Naoko K.

    2013-01-01

    Iron is essential for most living organisms. Plants transcriptionally induce genes involved in iron acquisition under conditions of low iron availability, but the nature of the deficiency signal and its sensors are unknown. Here we report the identification of new iron regulators in rice, designated Oryza sativa Haemerythrin motif-containing Really Interesting New Gene (RING)- and Zinc-finger protein 1 (OsHRZ1) and OsHRZ2. OsHRZ1, OsHRZ2 and their Arabidopsis homologue BRUTUS bind iron and zinc, and possess ubiquitination activity. OsHRZ1 and OsHRZ2 are susceptible to degradation in roots irrespective of iron conditions. OsHRZ-knockdown plants exhibit substantial tolerance to iron deficiency, and accumulate more iron in their shoots and grains irrespective of soil iron conditions. The expression of iron deficiency-inducible genes involved in iron utilization is enhanced in OsHRZ-knockdown plants, mostly under iron-sufficient conditions. These results suggest that OsHRZ1 and OsHRZ2 are iron-binding sensors that negatively regulate iron acquisition under conditions of iron sufficiency. PMID:24253678

  20. Researches on vanadium and its compounds; Recherches sur le Vanadium et ses composes

    Energy Technology Data Exchange (ETDEWEB)

    Morette, Andre

    1937-06-03

    In this research thesis, the author proposes a new study of the action of some reduction agents on two groups of vanadium compounds, oxides and chlorides. Thus, he reports the study of the circumstances of reduction of vanadium oxides by carbon and of vanadium carburization from these compounds. He also reports the determination of the composition of vanadium melts obtained at high temperatures (either in a vacuum furnace or with an electric arc furnace). In order to determine in which conditions the processing of vanadium oxides could produce the pure metal, the author studied the action of calcium and magnesium on the vanadium pentoxide and trioxide. The second part of the thesis addresses the preparation of pure vanadium from vanadium anhydride chlorides. Then, the author reports the development of processes which could easily produce powdered vanadium [French] Nous nous sommes propose de reprendre l'etude de l'action de quelques reducteurs sur les deux groupes de composes du vanadium, oxydes et chlorures. Nous avons ete ainsi amene a preciser les circonstances de la reduction des oxydes de vanadium par le carbone et de la carburation du vanadium a partir de ceux-ci, puis a determiner la constitution des fontes de vanadium obtenues a haute temperature, soit au four a vide, soit au four a arc. D'autre part, en vue de determiner dans quelles conditions le traitement des oxydes de vanadium pourrait conduire au metal pur, nous avons repris et complete des travaux anterieurs concernant l'action du calcium et du magnesium sur le pentoxyde ou eventuellement le trioxyde de vanadium. Une seconde partie de notre these a ete consacree a la preparation du vanadium pur a partir des chlorures anhydres de vanadium. Nous nous sommes attache a trouver le mode operatoire le plus favorable pour l'obtention de chacun d'eux. Il nous a ete donne ainsi l'occasion de preciser certaines de leurs proprietes physiques et chimiques. Puis, a la suite d'essais systematiques, nous avons

  1. Simultaneous determination of a binary mixture: kinetic method for determination of uranium and vanadium

    International Nuclear Information System (INIS)

    Jianhua, W.; Ronghuan, H.

    1993-01-01

    A kinetic method for simultaneous determination of a binary mixture is proposed, and a procedure for simultaneous determination of uranium (IV) and vanadium (IV) is established based on their inductive effect on chromium (VI)-iodide redox reaction in a weak acidic medium. The reaction was monitored by FIA-spectrophotometry using the I 3 - -starch complex as indicator. The calibration graphs are linear for uranium (IV) and vanadium (IV) within the range of 0 ∼ 3.6 μg/ml and 0 ∼ 2.5 μg/ml respectively. Most foreign ions, except for iron (II) and antimony (III), do not interfere with the determination. The uranium and vanadium content in different samples was determined, and the results were satisfactory. (author). 2 tabs., 2 figs., 9 refs

  2. Polarographic methods for the analysis of beryllium metal and its alloys

    International Nuclear Information System (INIS)

    Wells, J.M.

    1975-10-01

    This report describes polarographic methods for the analysis of beryllium metal and its alloys. The elements covered by these methods are aluminium, bismuth, cadmium, cobalt, copper, iron, lead, molybdenum, nickel, thallium, tungsten, uranium, vanadium and zinc. (author)

  3. Acute inhibition of iron bioavailability by zinc: studies in humans.

    Science.gov (United States)

    Olivares, Manuel; Pizarro, Fernando; Ruz, Manuel; de Romaña, Daniel López

    2012-08-01

    Iron (Fe) and zinc (Zn) deficiencies constitute two of the most important nutritional and public health problems affecting developing countries. Combined supplementation or fortification with Zn and Fe are strategies that can be used to improve the Zn and Fe status of a population. However, there is concern about potential negative interactions between these two micronutrients due to a competitive binding to DMT1 and Zip14 transporter. Studies performed in humans have shown an inhibitory effect of Zn on Fe absorption when both minerals are given together as a solution in fasting conditions. We found that at low doses of iron (0.5 mg) the threshold for the inhibition of iron bioavailability was at a Zn:Fe wt/wt ratio ≥5.9:1, whereas at higher doses of Fe (10 mg) this inhibition occurred at 1:1 Zn:Fe wt/wt ratio. This differential response could be explained by the variation in the abundance of both cations as they compete for a limited number of shared transporters at the enterocyte. Conflicting results have been obtained when this interaction was studied in different food matrices. A negative interaction was not observed when Fe and Zn were provided in a composite hamburger meal, premature formula, human milk, or cow milk. A decrease on Fe absorption was observed in only 1 of 3 studies when Fe and Zn were supplied in wheat flour. The possibility of a negative interaction should be considered for supplementation or fortification programs with both microminerals.

  4. Sulfur dioxide leaching of spent zinc-carbon-battery scrap

    Energy Technology Data Exchange (ETDEWEB)

    Avraamides, J.; Senanayake, G.; Clegg, R. [A.J. Parker Cooperative Research Centre for Hydrometallurgy, Murdoch University, Perth, WA 6150 (Australia)

    2006-09-22

    Zinc-carbon batteries, which contain around 20% zinc, 35% manganese oxides and 10% steel, are currently disposed after use as land fill or reprocessed to recover metals or oxides. Crushed material is subjected to magnetic separation followed by hydrometallurgical treatment of the non-magnetic material to recover zinc metal and manganese oxides. The leaching with 2M sulfuric acid in the presence of hydrogen peroxide recovers 93% Zn and 82% Mn at 25{sup o}C. Alkaline leaching with 6M NaOH recovers 80% zinc. The present study shows that over 90% zinc and manganese can be leached in 20-30min at 30{sup o}C using 0.1-1.0M sulfuric acid in the presence of sulfur dioxide. The iron extraction is sensitive to both acid concentration and sulfur dioxide flow rate. The effect of reagent concentration and particle size on the extraction of zinc, manganese and iron are reported. It is shown that the iron and manganese leaching follow a shrinking core kinetic model due to the formation of insoluble metal salts/oxides on the solid surface. This is supported by (i) the decrease in iron and manganese extraction from synthetic Fe(III)-Mn(IV)-Zn(II) oxide mixtures with increase in acid concentration from 1M to 2M, and (ii) the low iron dissolution and re-precipitation of dissolved manganese and zinc during prolonged leaching of battery scrap with low sulfur dioxide. (author)

  5. Intercalation compounds of vanadium pentoxide hydrated with metalporphyrins and lanthanide ions

    International Nuclear Information System (INIS)

    Oliveira, Herenilton Paulino

    1994-01-01

    The lamellar structure of the vanadium pentoxide matrix allows the intercalation of organic molecules, ions and conductor polymers. It is important to emphasize that the vanadium oxide matrix is an intrinsic semiconductor and presents electrochromic properties. In the beginning of this work the method of synthesis and the electrochemical and electrochromic properties were extensively explored. The effect of alkaline metal and lanthanide ions on the structure of vanadium oxide matrix was studied by X-ray and infrared spectroscopy. Moreover, the influence of those ions in the electrochemical, spectro electrochemical and magnetic properties were studied. Finally, some intercalation compounds containing porphyrins were prepared and characterized by elemental analysis, X-ray diffraction, and electronic, vibrational, Moessbauer and X-ray fluorescence spectroscopy. The electrochemical and spectro electrochemical properties were investigated. And the performance of an iron porphyrin based intercalation compound as catalyst for molecular oxygen reduction was evaluated using the rotating ring-disc electrode technique. (author)

  6. APS- and XPS-investigations of vanadium, vanadium carbide and graphite

    Energy Technology Data Exchange (ETDEWEB)

    Bradshaw, A M; Krause, U [Technische Univ. Muenchen (F.R. Germany). Inst. fuer Physikalische Chemie und Theoretische Chemie

    1975-11-01

    Soft X-ray appearance potential spectroscopy (APS) and X-ray photoelectron spectroscopy (XPS) have been used to study vanadium, vanadium carbide, and graphite. The chemical shifts for vanadium carbide with respect to metallic vanadium and graphite are compared for the two methods. The Csub(K) structure in APS and the valence band in XPS for vanadium carbide show good agreement with the band structure calculations of Neckel and co-workers. Using the band structure calculations of Painter et al. it is also shown how the multi-peak structure in the APS spectrum of graphite is possibly due to density of states effects. It would therefore appear that plasmon coupling plays only a minor role.

  7. Ab initio Investigation of Helium in Vanadium Oxide Nanoclusters

    Science.gov (United States)

    Danielson, Thomas; Tea, Eric; Hin, Celine

    Nanostructured ferritic alloys (NFAs) are strong candidate materials for the next generation of fission reactors and future fusion reactors. They are characterized by a large number density of oxide nanoclusters dispersed throughout a BCC iron matrix, where current oxide nanoclusters are primarily comprised of Y-Ti-O compounds. The oxide nanoclusters provide the alloy with high resistance to neutron irradiation, high yield strength and high creep strength at the elevated temperatures of a reactor environment. In addition, the oxide nanoclusters serve as trapping sites for transmutation product helium providing substantially increased resistance to catastrophic cracking and embrittlement. Although the mechanical properties and radiation resistance of the existing NFAs is promising, the problem of forming large scale reactor components continues to present a formidable challenge due to the high hardness and unpredictable fracture behavior of the alloys. An alternative alloy has been previously proposed and fabricated where vanadium is added in order to form vanadium oxide nanoclusters that serve as deflection sites for crack propagation. Although experiments have shown evidence that the fracture behavior of the alloys is improved, it is unknown whether or not the vanadium oxide nanoclusters are effective trapping sites for helium. We present results obtained using density functional theory investigating the thermodynamic stability of helium with the vanadium oxide matrix to make a comparison of trapping effectiveness to traditional Y-Ti-O compounds.

  8. Isotope-aided studies of the bioavailability of iron and zinc from human diets consumed in Chile and Ecuador

    International Nuclear Information System (INIS)

    Hertrampf, E.; Pizarro, F.; Olivares, M.; Fuenmayor, G.; Yepes, R.; Soria, A.; Walter, T.

    1994-01-01

    Currently it is accepted that iron absorbed from infant formulas is less than 10%. However, the composition of such formulas has changed considerably and there is no recent information on the effects of these modifications. Iron bioavailability from infant formulas with different levels of iron fortification (8 and 12 mg of iron/L) and from a standard meal based on a wheat cream (''farina'' flour) was measured by a double radioisotopic technique (Eakins and Brown) in 13 adult female volunteers. Iron bioavailability in infant formulas was very high. Eighteen and 20.6 percent of the iron was absorbed in the 8 and 12 mg iron/L fortified formulas respectively (geometric means corrected to 40% of reference dose absorption). The corresponding value for iron absorption from the standard meal was 6.7%. These high and non significant differences in iron bioavailability from the two formulas and the fact that daily consumption of 750 ml of formula supplies more iron than recommended would permit a lowering of the current iron fortification level of 12 mg/L. Iron availability of the Standard Meal measured with FLAIR modifications of Miller's in vitro technique was 4.42%. The percentage of dialyzable zinc was 2.04%. Research activities for next year will be based on the validation and application of the in vitro technique in Chilean and Ecuadorian foods. (author). 26 refs, 4 tabs

  9. Isotope-aided studies of the bioavailability of iron and zinc from human diets consumed in Chile and Ecuador

    Energy Technology Data Exchange (ETDEWEB)

    Hertrampf, E; Pizarro, F; Olivares, M [Chile Univ., Santiago (Chile). Inst. de Nutricion y Tecnologia de los Alimentos (INTA); Fuenmayor, G; Yepes, R [Universidad Central del Ecuador, Quito (Ecuador). Lab. de Investigaciones en Metabolismo y Nutricion (LIMN); Soria, A [Carabobo Univ., Valencia (Venezuela). Facultad de Ciencias de la Salud; Walter, T

    1994-12-31

    Currently it is accepted that iron absorbed from infant formulas is less than 10%. However, the composition of such formulas has changed considerably and there is no recent information on the effects of these modifications. Iron bioavailability from infant formulas with different levels of iron fortification (8 and 12 mg of iron/L) and from a standard meal based on a wheat cream (``farina`` flour) was measured by a double radioisotopic technique (Eakins and Brown) in 13 adult female volunteers. Iron bioavailability in infant formulas was very high. Eighteen and 20.6 percent of the iron was absorbed in the 8 and 12 mg iron/L fortified formulas respectively (geometric means corrected to 40% of reference dose absorption). The corresponding value for iron absorption from the standard meal was 6.7%. These high and non significant differences in iron bioavailability from the two formulas and the fact that daily consumption of 750 ml of formula supplies more iron than recommended would permit a lowering of the current iron fortification level of 12 mg/L. Iron availability of the Standard Meal measured with FLAIR modifications of Miller`s in vitro technique was 4.42%. The percentage of dialyzable zinc was 2.04%. Research activities for next year will be based on the validation and application of the in vitro technique in Chilean and Ecuadorian foods. (author). 26 refs, 4 tabs.

  10. Vanadium Electrolyte Studies for the Vanadium Redox Battery-A Review.

    Science.gov (United States)

    Skyllas-Kazacos, Maria; Cao, Liuyue; Kazacos, Michael; Kausar, Nadeem; Mousa, Asem

    2016-07-07

    The electrolyte is one of the most important components of the vanadium redox flow battery and its properties will affect cell performance and behavior in addition to the overall battery cost. Vanadium exists in several oxidation states with significantly different half-cell potentials that can produce practical cell voltages. It is thus possible to use the same element in both half-cells and thereby eliminate problems of cross-contamination inherent in all other flow battery chemistries. Electrolyte properties vary with supporting electrolyte composition, state-of-charge, and temperature and this will impact on the characteristics, behavior, and performance of the vanadium battery in practical applications. This Review provides a broad overview of the physical properties and characteristics of the vanadium battery electrolyte under different conditions, together with a description of some of the processing methods that have been developed to produce vanadium electrolytes for vanadium redox flow battery applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Effects of HIP and forging on fracture behaviour in cast iron with spheroidal vanadium carbides dispersed within martensitic-matrix microstructure

    International Nuclear Information System (INIS)

    Uematsu, Y.; Tokaji, K.; Nishigaki, K.; Okajima, D.; Ogasawara, M.

    2010-01-01

    The cast iron with spheroidal vanadium carbides dispersed within martensitic-matrix microstructure was developed as a die material due to its high hardness. In order to achieve high performances of dies, not only the hardness but also the mechanical properties such as fracture toughness and fatigue crack propagation (FCP) resistance should be improved. In this paper, hot isostatic pressing (HIP) or forging was applied to the cast iron to improve mechanical properties, and the fracture behaviour, such as flexural strength, fracture toughness and FCP, was studied. The average flexural strength was reduced by forging because of the enhanced notch sensitivity due to the increase in the hardness. The fracture toughness was not affected by HIP nor forging while its scatter was significantly reduced by both post-treatments. The intrinsic FCP resistance taking account of crack closure was the same regardless of the application of HIP or forging, indicating that a slight change in the microstructure resulting from both treatments and the presence of casting defects exerted little influence on FCP behaviour. It could be concluded that both HIP and forging could improve the hardness of the material, while fracture toughness and FCP resistance were maintained.

  12. Physicochemical characterization of mineral (iron/zinc) bound caseinate and their mineral uptake in Caco-2 cells.

    Science.gov (United States)

    Shilpashree, B G; Arora, Sumit; Kapila, Suman; Sharma, Vivek

    2018-08-15

    Milk proteins (especially caseins) are widely accepted as good vehicle for the delivery of various bioactive compounds including minerals. Succinylation is one of the most acceptable chemical modification techniques to enhance the mineral binding ability of caseins. Addition of minerals to succinylated proteins may alter their physicochemical and biochemical properties. Physicochemical characteristics of succinylated sodium caseinate (S.NaCN)-mineral (iron/zinc) complexes were elucidated. Chromatographic behaviour and fluorescence intensity confirmed the structural modification of S.NaCN upon binding with minerals. The bound mineral from protein complexes showed significantly higher (P < 0.05) in vitro bioavailability (mineral uptake) than mineral salts in Caco-2 cells. Also, iron bound S.NaCN showed higher cellular ferritin formation than iron in its free form. These mineral bound protein complexes with improved bioavailability could safely replace inorganic fortificants in various functional food formulations. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Vanadium - 1977

    International Nuclear Information System (INIS)

    Broderick, G.N.

    1977-01-01

    This report, with pertinent references, is a comprehensive description and analysis of the vanadium industry. Included is information on industry structure, size and organization; definitions, grades, and specifications; reserves and resources; geology; production and capacity; uses; technology; byproducts and coproducts; strategic considerations; economic and operating factors and problems; supply-demand relationships; and forecasts of supply and demand. Vanadium is used principally as an alloy in steel. Other important uses are in titanium alloys and in various chemical catalytic processes. The world supply of vanadium is sufficient to last far beyond the year 2000 at the present and projected rates of consumption. Almost all of the resources will economically yield vanadium only in conjunction with a coproduct

  14. Principles for prevention of toxic effects from metals

    DEFF Research Database (Denmark)

    Landrigan, Philip J.; Kotelchuk, David; Grandjean, Philippe

    2007-01-01

    of the Toxic Effects of Metals Aluminum Antimony Arsenic Barium Beryllium Bismuth Cadmium Chromium Cobalt Copper Gallium and Semiconductor Compounds Germanium Indium Iron Lead Manganese Mercury Molybdenum Nickel Palladium Platinum Selenium Silver Tellurium Thallium Tin Titanium Tungsten Uranium Vanadium Zinc...

  15. Toxic effects of various pollutants in 11B7501 lymphoma B cell line from harbour seal (Phoca vitulina)

    International Nuclear Information System (INIS)

    Frouin, Heloise; Fortier, Marlene; Fournier, Michel

    2010-01-01

    Although, heavy metals and polycyclic aromatic hydrocarbons (PAHs) have been reported at high levels in marine mammals, little is known about the toxic effects of some of these contaminants. In this study, we assessed the immunotoxic and genotoxic effects of seven heavy metals (arsenic, vanadium, selenium, iron, zinc, silver and chromium) and one PAH (benzo[a]pyrene or B[a]P) on a lymphoma B cell line from harbour seal (Phoca vitulina). A significant reduction in lymphocyte proliferation was registered following an exposure to 0.05 μM of B[a]P, 5 μM of arsenic or selenium, 50 μM of vanadium, 100 μM of silver and 200 μM of iron. On the contrary, zinc increased the lymphoproliferative response at 200 μM. Decreased phagocytosis was observed at 20 μM of arsenic, 50 μM of B[a]P or selenium, 200 μM of zinc and 500 μM of vanadium. Micronuclei induction occurred with 0.2 μM of B[a]P, 100 μM of vanadium and with 200 μM of arsenic or selenium. Exposure to 50 μM of arsenic decreased G 2 /M phase of the cell cycle. Chromium did not induce any effects at the concentrations tested. Concentrations of heavy metals (except silver and vanadium) and B[a]P inducing an toxic effect are within the environmental ranges reported in the blood tissue of pinnipeds. The reduction of some functional activities of the harbour seal immune system may cause a significant weakness capable of altering host resistance to disease in free-ranging pinnipeds.

  16. Characteristics of Vanadium Doped And Bamboo Activated Carbon Coated LiFePO4 And Its Performance For Lithium Ion Battery Cathode

    Directory of Open Access Journals (Sweden)

    Nofrijon Sofyan

    2018-04-01

    Full Text Available Vanadium doped and bamboo activated carbon coated lithium iron phosphate (LiFePO4 used for lithium ion battery cathode has been successfully prepared. Lithium iron phosphate was prepared through a wet chemical method followed by a hydrothermal process from the starting materials of LiOH, NH4H2PO4, and FeSO4.7H2O. The dopant variations of 0 wt.%, 3 wt.%, 5 wt.%, and 7 wt.% of vanadium and a fixed 3 wt.% of bamboo activated carbon were carried out via a solid-state reaction process each by using NH4VO3 as a source of vanadium and carbon pyrolyzed from bamboo tree, respectively. The characterization was carried out using X-ray Diffraction (XRD for the phase formed and its crystal structure, Scanning Electron Microscope (SEM for the surface morphology, Electrochemical Impedance Spectroscopy (EIS for the conductivity, and battery analyzer for the performance of lithium ion battery cathode. The XRD results show that the phase formed has an olivine based structure with an orthorhombic space group. Morphology examination revealed that the particle agglomeration decreased with the increasing level of vanadium concentrations. Conductivity test showed that the impedance of solid electrolyte interface decreased with the increase of vanadium concentration indicated by increasing conductivity of 1.25 x 10-5 S/cm, 2.02 x 10-5 S/cm, 4.37 x 10-5 S/cm, and 5.69 x 10-5 S/cm, each for 0 wt.%, 3 wt.%, 5 wt.%, and 7 wt.% vanadium, respectively. Vanadium doping and bamboo activated carbon coating are promising candidate for improving lithium ion battery cathode as the initial charge and discharge capacity at 0.5C for LiFePO4/C at 7 wt.% vanadium is in the range of 8.0 mAh/g.

  17. Roll-to-Roll Processing of Inverted Polymer Solar Cells using Hydrated Vanadium(V)Oxide as a PEDOT:PSS Replacement

    DEFF Research Database (Denmark)

    Martinez, Nieves Espinosa; Dam, Henrik Friis; Tanenbaum, David M.

    2011-01-01

    roll-to-roll (R2R) processing of all layers. The devices were prepared on flexible polyethyleneterphthalate (PET) and had the structure PET/ITO/ZnO/P3HT:PCBM/V2O5·(H2O)n/Ag. The ITO and silver electrodes were processed and patterned by use of screen printing. The zinc oxide, P3HT:PCBM and vanadium(V)oxide......The use of hydrated vanadium(V)oxide as a replacement of the commonly employed hole transporting material PEDOT:PSS was explored in this work. Polymer solar cells were prepared by spin coating on glass. Polymer solar cells and modules comprising 16 serially connected cells were prepared using full...... layers were processed by slot-die coating. The hydrated vanadium(V)oxide layer was slot-die coated using an isopropanol solution of vanadyl-triisopropoxide (VTIP). Coating experiments were carried out to establish the critical thickness of the hydrated vanadium(V)oxide layer by varying the concentration...

  18. Impact of sorghum processing on phytate, phenolic compounds and in vitro solubility of iron and zinc in thick porridges

    NARCIS (Netherlands)

    Kayodé, A.P.P.; Linnemann, A.R.; Nout, M.J.R.; Boekel, van M.A.J.S.

    2007-01-01

    This study focussed on the impact of process variables on levels of phytate and phenolic compounds, and in vitro solubility of iron (Fe) and zinc (Zn) in sorghum porridges, a major staple in semi-arid tropics. The aim was to identify practices that enhance the mineral availability in this type of

  19. THE INFLUENCE OF PRE-HEAT TREATMENT ON WHITE CAST IRONS PLASTICITY

    Directory of Open Access Journals (Sweden)

    T. M. Myronova

    2013-11-01

    Full Text Available Purpose. The development of heat treatment modes of white cast irons for structure changes in their eutectic constituent, namely in disturbing the monolithic structure of ledeburite colonies cementite structure and eutectic net continuity. Also the mentioned heat treatment modes are targeted to the eutectic net shift for the most suitable position from the point of plastic deforming. Methodology. The hypoeutectic white cast irons with 2.92…3.35 % carbon content and additionally alloyed by 3.18 % vanadium have been used as the research materials. The mentioned alloys have been pre-heat treated and hot twist tested. Findings. The research results showed that the carbide net breaking by plastic deforming leads to cast irons mechanical properties increasing but has difficulties in implementation due to the white cast irons low plasticity. The influence of different pre-heat treatment modes on structure and plasticity of white hypoeutectic cast irons have been investigated. They include the isotherm soaking under the different temperatures as well as multiply soakings and thermo-cycling. The influence of eutectic level, as well as pre heat treatment modes on different composition white cast irons hot plasticity have been investigated. Originality. It was determined that the heat treatment, which leads to double α→γ recrystallization under 860 – 950 °С and reperlitization under 720-680 °С results in significant increase of plasticity, as well as in un-alloyed and alloyed by vanadium white cast irons. It takes place due to carbide matrix phase separation in ledeburite colonies by new phase boundaries forming especially due to carbide transformations under vanadium alloying. Practical value. The implementation of pre-heat treatment with phase recrystallization resulted in hypoeutectic white cast irons plasticity increasing. The obtained level of cast iron plasticity corresponds to the one of carbide class steels, which ensures the successful

  20. EPR Study of Vanadium Ion in Zinc-Boro-Vanadate Glasses

    International Nuclear Information System (INIS)

    Renuka, C.; Gowda, V. C. Veeranna; Chakradhar, R. P. S.; Reddy, C. Narayana

    2011-01-01

    This paper describes EPR studies on x V 2 O 5 -(40-x)ZnO-60B 2 O 3 (where x 5, 10, 15 and 20 mol %) glass system. These studies indicate a strong compositional dependent trend and existence of characteristic boro-vanadate groups in these glasses. The EPR spectra show a distinct hyperfine structure of 51 V. Spectral analysis shows that the vanadium is present in the glass as vanadyl ion [VO] 2+ at tetragonally distorted octahedral site. The decrease of A || and A perpendicular with increase of V 2 O 5 concentration suggests an increase in the covalence between the central atom and the surrounding oxygen ligands.

  1. Leaching characteristics of vanadium in mine tailings and soils near a vanadium titanomagnetite mining site

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jinyan; Tang, Ya; Yang, Kai [College of Architecture and Environment, Sichuan University, Chengdu 610065 (China); Rouff, Ashaki A. [School of Earth and Environmental Sciences, Queens College City University of New York, 65-30 Kissena Boulevard, Flushing, NY 11367 (United States); Elzinga, Evert J. [Department of Earth and Environmental Sciences, Rutgers University, Newark, NJ (United States); Huang, Jen-How, E-mail: jen-how.huang@unibas.ch [Institute of Environmental Geosciences, University of Basel, CH-4056 Basel (Switzerland)

    2014-01-15

    Highlights: • Vanadium in the soil and mine tailings has low solubility. • The leachability of vanadium in the mine tailings is lower than in the soil. • Low risk of vanadium migrating from the soil and mine tailings into the surrounding environment. • Drought and rewetting increase vanadium release from the soil and mine tailings. • Soil leaching processes control vanadium transport in soils overlain with mine tailings. -- Abstract: A series of column leaching experiments were performed to understand the leaching behaviour and the potential environmental risk of vanadium in a Panzhihua soil and vanadium titanomagnetite mine tailings. Results from sequential extraction experiments indicated that the mobility of vanadium in both the soil and the mine tailings was low, with <1% of the total vanadium readily mobilised. Column experiments revealed that only <0.1% of vanadium in the soil and mine tailing was leachable. The vanadium concentrations in the soil leachates did not vary considerably, but decreased with the leachate volume in the mine tailing leachates. This suggests that there was a smaller pool of leachable vanadium in the mine tailings compared to that in the soil. Drought and rewetting increased the vanadium concentrations in the soil and mine tailing leachates from 20 μg L{sup −1} to 50–90 μg L{sup −1}, indicating the potential for high vanadium release following periods of drought. Experiments with soil columns overlain with 4, 8 and 20% volume mine tailings/volume soil exhibited very similar vanadium leaching behaviour. These results suggest that the transport of vanadium to the subsurface is controlled primarily by the leaching processes occurring in soils.

  2. Fracture toughness and fatigue crack propagation in cast irons with spheroidal vanadium carbides dispersed within martensitic matrix microstructure

    International Nuclear Information System (INIS)

    Uematsu, Y.; Tokaji, K.; Horie, T.; Nishigaki, K.

    2007-01-01

    Fracture toughness and fatigue crack propagation (FCP) have been studied using compact tension (CT) specimens of as-cast and subzero-treated materials in a cast iron with spheroidal vanadium carbides (VCs) dispersed in the martensitic matrix microstructure. X-ray diffraction (XRD) analysis revealed that retained austenite was transformed to martensite by subzero treatment. Vickers hardness was increased from 738 for the as-cast material to 782 for the subzero-treated material, which could be attributed to retained austenite to martensite transformation. The subzero-treated material exhibited lower fracture toughness than the as-cast material because soft and ductile retained austenite which possesses high fracture toughness was transformed to martensite in the subzero-treated material. Intrinsic FCP resistance after taking account of crack closure was decreased by the subzero treatment, which was attributed to the predominant crack propagation through the interface between VCs and the matrix and the straight crack path in the matrix microstructure

  3. Effects of vanadium on population growth and Na-K-ATPase activity of the brackish water hydroid Cordylophora caspia

    Energy Technology Data Exchange (ETDEWEB)

    Ringelband, U.; Karbe, L. [Institut fuer Hydrobiologie und Fischereiwissenschaft, Hamburg (Germany)

    1996-07-01

    Vanadium, a relatively abundant heavy metal, enters the environment naturally through rock weathering. A large fraction of vanadium input is of human origin. The combustion of petroleum- and coal-products, which contain relatively high concentrations of vanadium, is one of the most important sources of the enrichment of vanadium in the environment. As it is used as an alloy, and vanadium rich iron-ores of various origin are used in steel production, the residual slag-stones of the steel industry can contain considerable vanadium concentrations. Wherever slag-stones serve as a cheap and convenient material in riverbank reinforcement, vanadium can leach into the aquatic environment. Vanadium is regarded as an essential trace element for higher animals. Cantley et al. indicated a regulatory function of vanadate in vivo. Although considerable information is available on the toxic effects of vanadium on humans, very little is known about the toxicity of vanadium towards aquatic organisms, especially invertebrates. Bell and Sargent have shown an inhibition of Na-K-ATPase activity in gills of the eel Anguilla anguilla. Holleland and Towle have demonstrated the inhibition of Na-K-ATPase activity in the gills of the shore crab Carcinus maenas. The aim of this study was to determine the toxicity of vanadium towards the brackish water hydroid Cordylophora caspia. Hydroids are known to be particularly sensitive to heavy metals and their asexual reproduction can be used in a well-established population growth test. Furthermore, the effects of vanadium on Na-K-ATPase activity in hydroids were studied in in vivo experiments, wherein the animals were exposed to sublethal concentrations of vanadium. In addition, the inhibition of Na-K-ATPase was measured in vitro, by adding vanadium to a microsomal preparation. 16 refs., 4 figs.

  4. Effect of food processing of pearl millet (Pennisetum glaucum) IKMP-5 on the level of phenolics, phytate, iron and zinc

    NARCIS (Netherlands)

    Zanabria Eyzaguirre, R.; Nienaltowska, K.; Jong, de L.E.Q.; Hasenack, B.B.E.; Nout, M.J.R.

    2006-01-01

    Pearl millet is consumed as a staple food in semi-arid tropical regions. With a view to upgrading the micronutrient status of pearl millet-based foods, the effects of single operations and of porridge preparation scenarios on levels and in vitro solubility (IVS) of iron and zinc and mineral

  5. Protein, Calcium, Zinc, and Iron Contents of Finger Millet Grain Response to Varietal Differences and Phosphorus Application in Kenya

    Directory of Open Access Journals (Sweden)

    Wekha N. Wafula

    2018-02-01

    Full Text Available This study was carried out to investigate the influence of phosphorus fertilizers on the concentrations of nutrients, particularly calcium, protein, zinc, and iron in finger millet grains grown in different agro-ecologies in Kenya. The on-station experiments were carried out at Kiboko (Eastern Kenya, Kakamega, and Alupe (Western Kenya in 2015 during the short and long rainy seasons. The trials were laid out in a randomized complete block design (RCBD in a 4 × 3 factorial arrangement with three replicates. The treatments comprised of four levels of phosphorus (0, 12.5, 25.0 and 37.5 kg ha−1 P2O5 and three finger millet varieties (U-15, P-224 and a local variety. Application of phosphorus significantly (p ≤ 0.05 increased the protein content of finger millet grain in varieties in all the three sites. Variety U-15 had the highest protein content (11.0% at 25 kg ha−1 P2O5 with the control (zero P on variety P-224 eliciting the lowest (4.4% at Kiboko. At Kakamega, the 25 kg ha−1 P2O5 treatment with U-15 variety had the highest protein content (15.3% while the same variety at 12.5 kg ha−1 P2O5 rate elicited the highest protein content (15.0% at Alupe. Phosphorus application significantly enhanced the nutritional quality of finger millet grains specifically protein, calcium, iron, and zinc. Variety P-224 had the highest calcium content in all sites and highest iron content at Kakamega while the local varieties had the highest zinc content in all sites. The varieties responded differently to each quality component but generally, based on the protein content, the 25 kg ha−1 P2O5 is recommended.

  6. Determination of trace vanadium using its catalytic effect on the oxidation of gallic acid by bromate

    International Nuclear Information System (INIS)

    Yamane, Takeshi; Fukasawa, Tsutomu

    1976-01-01

    The oxidation of gallic acid by bromate with trace vanadium as catalyst was followed spectrophotometrically by measurements of absorbance change at 420 nm. The reaction rate was obtained graphically from the absorbance vs. time curve in the range of about 15 to 40 min. reaction time. The reaction rate was proportional to the concentration of vanadium(V) in the range 0--120 ng (under the conditions of 5.3x10 -3 M gallic acid, 6.0x10 -3 M potassium bromate, pH 3.8) and 0--30 ng (1.1x10 -2 M gallic acid, 2.7x10 -2 M potassium bromate, pH 3.8). Using this relationship, the concentration of vanadium as low as 0.1 ng/ml can be determined. The relative standard deviations at 50 ng and 20 ng of vanadium were 3.5% (n=14) and 4.0% (n=10), respectively. Iron(III) interfered seriously even when present in 20 times the amounts of vanadium. Up to 60 times, W(VI), Mo(VI) and iodide did not interfere. Many of the other ions examined were found to have no effect or slight effect even when present in 1000 times the amounts of vanadium. Other factors affecting the reaction rate were also studied. (auth.)

  7. Lithium-Vanadium bronzes as model catalysts for the selective reduction of nitric oxide

    NARCIS (Netherlands)

    Bosch, H.; Bongers, Annemie; Enoch, Gert; Snel, Ruud; Ross, Julian R.H.

    1989-01-01

    The effect of alkali metals on the selective reduction of nitric oxide with ammonia has been studied on bulk iron oxide and bulk vanadium oxide. The influence of additions of LiOH, NaOH and KOH on the activity was screened by pulse experiments carried out in the absence of gaseous oxygen; FTIR

  8. Magnetite Crisis in Miniature: Vanadium, Sulfur, and Iron Valence State Measurements in Melt Inclusions from Nyamuragira Volcano (D.R. Congo, Africa)

    Science.gov (United States)

    Head, E.; Lanzirotti, A.; Sutton, S.; Newville, M.

    2017-12-01

    Sulfur (S), vanadium (V), and iron (Fe) K-edge micro-X-ray absorption near edge structure (micro-XANES) spectroscopy of melt inclusions (MI) from Nyamuragira volcano (D.R. Congo, Africa) shows that diffusive loss of H from olivine-hosted melt inclusions may lead to crystallization of submicron magnetite and sulfide crystallites that are imperceptible petrographically or via electron microscopy. Micro-XANES was used to constrain the evolution of oxygen fugacity (fO2) and sulfur speciation for MI preserved in Nyamuragira tephra (1986 and 2006) and lava (1938 and 1948). The S, V, and Fe valence state oxybarometry for 1938, 1948, and 2006 MI are all consistent with equilibration at FMQ-1, and sulfur in MI from these three eruptions are sulfide-dominated (water loss in olivine-hosted MIs.

  9. Shaping optimal zinc coating on the surface of high-quality ductile iron casting. Part I – Moulding technologies vs. zinc coating

    Directory of Open Access Journals (Sweden)

    Szczęsny A.

    2017-03-01

    Full Text Available Studies have demonstrated that in the process of hot dip galvanizing the decisive influence on the mechanism of zinc coating formation and properties has the quality of the mechanically untreated (raw surface layer of the galvanized product. The terms “casting surface layer” denote various parameters of the microstructure, including the type of metal matrix, the number of grains and the size of graphite nodules, possible presence of hard spots (the precipitates of eutectic cementite and parameters of the surface condition. The completed research has allowed linking the manufacturing technology of ductile iron castings with the process of hot dip galvanizing.

  10. Analysis of vanadium slags, roasted and leached products. Determination of contents of total vanadium, chromium, sodium, and soluble vanadium

    International Nuclear Information System (INIS)

    Hasek, Z.

    1975-01-01

    Accurate, rapid and simple methods were elaborated of determining total vanadium, chromium, and sodium in vanadium slags, and in roasted and leached products in one sample batch. The analysis was conducted in a teflon vial using inorganic acids. A method od determining soluble vanadium in similar materials was also elaborated and verified. (B.S.)

  11. Bio-accumulation of copper, zinc, iron and manganese in oyster Saccostrea cucullata, Snail Cerithium rubus and Clam Tellina angulata from the Bombay coast

    Digital Repository Service at National Institute of Oceanography (India)

    Krishnakumari, L.; Nair, V.R; Moraes, C.

    accumulation was high in S. cucullata, manganese in C. rubus and iron in T. angulata. Similarly, copper and zinc in S. cucullata and copper in C. rubus were found occasionally higher than accepted health standards...

  12. Magnetic concentration of iron-titanium ore with vanadium concentrate from campo Alegre de Lourdes - Bahia, Brazil

    International Nuclear Information System (INIS)

    Delgado, O.; Silva, F.T. da; Ogasawara, T.; Soares, G.F.

    1988-01-01

    The feasibility studies of magnetic concentration of the Campo Alegre de Lourdes ore were carried out, trying to obtain a maximum recovery of vanadium. As a consequence of the complex nature of the ore, mainly due to the presence of ilmenite as a exolutions in the interior of hematite/martite particles, it was not possible to separate the hematite-ilmenite eficiently, wich would be necessary for obtaining a high grade vanadium concentrate with low titanium content. (author) [pt

  13. Iron and zinc availability in maize lines

    Directory of Open Access Journals (Sweden)

    Valéria Aparecida Vieira Queiroz

    2011-09-01

    Full Text Available The aim of this study was to characterize the Zn and Fe availability by phytic acid/Zn and phytic acid/Fe molar ratios, in 22 tropical maize inbred lines with different genetic backgrounds. The Zn and Fe levels were determined by atomic absorption spectrophotometry and the P through colorimetry method. Three screening methods for phytic acid (Phy analysis were tested and one, based on the 2,2'-bipyridine reaction, was select. There was significant variability in the contents of zinc (17.5 to 42 mg.kg-1, iron (12.2 to 36.7 mg.kg-1, phosphorus (230 to 400 mg.100 g-1, phytic acid (484 to 1056 mg.100 g-1, phytic acid P (140 to 293 mg.100 g-1 and available-P (43.5 to 199.5 mg.100 g-1, and in the available-P/total-P ratio (0.14 to 0.50, Phy/Zn (18.0 to 43.5 and Phy/Fe (16.3 to 45.5 molar ratios. Lines 560977, 560978 and 560982 had greater availability of Zn and lines 560975, 560977, 561010 and 5610111 showed better Fe availability. Lines 560975, 560977 and 560978 also showed better available-P/total-P ratio. Thus, the lines 560975, 560977 and 560978 were considered to have the potential for the development of cultivars of maize with high availability of Fe and/or Zn.

  14. Determination of calcium, copper, chromium, iron, magnesium, manganese, potassium, sodium and zinc in ethanol by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Fernandes, E.A.N.

    1981-01-01

    The direct determinacao of calcium, copper, chomium, iron, magnesium, manganese, potassium, sodium and zinc in ethanol by atomic absorption spectrometry with, air-acetylene flame is proposed. Effects of fuel/oxidant ratio, burner height and water content in the samples were investigated in detail. The method allows the determition of the elements with good precision (r.s.d. -1 for the elements tested. (author) [pt

  15. In vitro solubility of calcium, iron and zinc in relation to phytic acid levels in rice-based consumer products in China.

    Science.gov (United States)

    Liang, Jianfen; Han, Bei-Zhong; Nout, M J Robert; Hamer, Robert J

    2010-02-01

    In vitro solubility of calcium, iron and zinc in relation to phytic acid (PA) levels in 30 commercial rice-based foods from China was studied. Solubility of minerals and molar ratios of PA to minerals varied with degrees of processing. In primary products, [PA]/[Ca] values were less than 5 and [PA]/[Fe] and [PA]/[Zn] similarly ranged between 5 and 74, with most values between 20 and 30. [PA]/[mineral] molar ratios in intensively processed products were lower. Solubility of calcium ranged from 0% to 87%, with the lowest in brown rice (12%) and the highest in infant foods (50%). Iron solubility in two-thirds of samples was lower than 30%, and that of zinc narrowly ranged from 6% to 30%. Solubility of minerals was not significantly affected by [PA]/[mineral]. At present, neither primary nor intensively processed rice-based products are good dietary sources of minerals. Improvements should be attempted by dephytinization, mineral fortification or, preferably, combination of both.

  16. Adverse health effects in Canada geese (Branta canadensis) associated with waste from zinc and lead mines in the Tri-State Mining District (Kansas, Oklahoma, and Missouri, USA).

    Science.gov (United States)

    van der Merwe, Deon; Carpenter, James W; Nietfeld, Jerome C; Miesner, John F

    2011-07-01

    Lead and zinc poisoning have been recorded in a variety of bird species, including migrating waterfowl such as Canada Geese (Branta canadensis), at sites contaminated with mine waste from lead and zinc mines in the Tri-State Mining District, Kansas, Oklahoma, and Missouri, USA. The adverse health impacts from mine waste on these birds may, however, be more extensive than is apparent from incidental reports of clinical disease. To characterize health impacts from mine waste on Canada Geese that do not have observable signs of poisoning, four to eight apparently healthy birds per site were collected from four contaminated sites and an uncontaminated reference site, and examined for physical and physiologic evidence of metals poisoning. Tissue concentrations of silver, aluminum, arsenic, barium, cadmium, cobalt, chromium, copper, iron, magnesium, manganese, molybdenum, nickel, lead, selenium, thallium, vanadium, and zinc were determined by inductively coupled plasma mass spectroscopy. Adverse health effects due to lead were characterized by assessing blood δ-aminolevulinic acid dehydratase (ALAD) enzyme activity. Adverse effects associated with zinc poisoning were determined from histologic examination of pancreas tissues. Elevated tissue lead concentrations and inhibited blood ALAD enzyme activities were consistently found in birds at all contaminated sites. Histopathologic signs of zinc poisoning, including fibrosis and vacuolization, were associated with elevated pancreatic zinc concentrations at one of the study sites. Adverse health effects associated with other analyzed elements, or tissue concentrations indicating potentially toxic exposure levels to these elements, were not observed.

  17. Zinc phosphate conversion coatings

    Science.gov (United States)

    Sugama, Toshifumi

    1997-01-01

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

  18. One-shot flow injection spectrophotometric simultaneous determination of copper, iron and zinc in patients' sera with newly developed multi-compartment flow cell

    International Nuclear Information System (INIS)

    Teshima, Norio; Gotoh, Shingo; Ida, Kazunori; Sakai, Tadao

    2006-01-01

    We propose here an affordable flow injection method for simultaneous spectrophotometric determination of copper, iron and zinc in patients' sera. The use of a newly designed multi-compartment flow cell allowed the simultaneous determination of the three metals with a single injection ('one-shot') and a double beam spectrophotometer. The chemistry relied on the reactions of these metals with 2-(5-nitro-2-pyridylazo)-5-[N-propyl-N-(3-sulfopropyl)amino]phenol (nitro-PAPS) to form corresponding colored complexes. At pH 3.8, only copper-nitro-PAPS complex was formed in the presence of pyrophosphate as a masking agent for iron, and then the copper and iron(II) complexes were formed in the presence of reductant (ascorbic acid) at the same pH, and finally all three metals reacted with nitro-PAPS at pH 8.6. The characteristics were introduced into the flow system to determine each metal selectively and sensitively. Under the optimum conditions, linear calibration curves for the three metals were obtained in the range of 0.01-1 mg L -1 with a sample throughput rate of 20 h -1 . The limits of detection (3σ) were 3.9 μg L -1 for copper, 4.1 μg L -1 for iron and 4.0 μg L -1 for zinc. The proposed method was applied to analysis of some patients' sera

  19. Economical characteristics of base types of minerals. 1. Metallic minerals

    International Nuclear Information System (INIS)

    Khasanov, A.Kh.

    1990-01-01

    Metallic minerals is raw materials base of black and colour metallurgy. In this article of book author describes the group of black metals (iron, manganese, chromium), group of tempers (titanium, vanadium, nickel, cobalt, molybdenum, tungsten), colour metals (copper, lead, zinc, aluminium, tin, mercury, antimony, bismuth) and etc.

  20. Effects of metal compounds with distinct physicochemical properties on iron homeostasis and antibacterial activity in the lungs: chromium and vanadium.

    Science.gov (United States)

    Cohen, Mitchell D; Sisco, Maureen; Prophete, Colette; Yoshida, Kotaro; Chen, Lung-chi; Zelikoff, Judith T; Smee, Jason; Holder, Alvin A; Stonehuerner, Jacqueline; Crans, Debbie C; Ghio, Andrew J

    2010-02-01

    In situ reactions of metal ions or their compounds are important mechanisms by which particles alter lung immune responses. The authors hypothesized that major determinants of the immunomodulatory effect of any metal include its redox behavior/properties, oxidation state, and/or solubility, and that the toxicities arising from differences in physicochemical parameters are manifest, in part, via differential shifts in lung iron (Fe) homeostasis. To test the hypotheses, immunomodulatory potentials for both pentavalent vanadium (VV; as soluble metavanadate or insoluble vanadium pentoxide) and hexavalent chromium (CrVI; as soluble sodium chromate or insoluble calcium chromate) were quantified in rats after inhalation (5h/day for 5 days) of each at 100 microg metal/m3. Differences in effects on local bacterial resistance between the two VV, and between each CrVI, agents suggested that solubility might be a determinant of in situ immunotoxicity. For the soluble forms, VV had a greater impact on resistance than CrVI, indicating that redox behavior/properties was likely also a determinant. The soluble VV agent was the strongest immunomodulant. Regarding Fe homeostasis, both VV agents had dramatic effects on airway Fe levels. Both also impacted local immune/airway epithelial cell Fe levels in that there were significant increases in production of select cytokines/chemokines whose genes are subject to regulation by HIF-1 (whose intracellular longevity is related to cell Fe status). Our findings contribute to a better understanding of the role that metal compound properties play in respiratory disease pathogenesis and provide a rationale for differing pulmonary immunotoxicities of commonly encountered ambient metal pollutants.

  1. Impact of brewing process operations on phytate, phenolic compounds and in vitro solubility of iron and zinc in opaque sorghum beer

    NARCIS (Netherlands)

    Kayodé, A.P.P.; Hounhouigan, J.D.; Nout, M.J.R.

    2007-01-01

    Opaque sorghum beer is a significant component of the diet of millions of poor people in rural Africa. This study reports the effect of traditional brewing operations on its level of micronutrients, especially iron and zinc. The example of a West African sorghum beer, tchoukoutou, in Northern Benin

  2. Study to determine the content of vanadium, aluminum, nickel, sodium, iron and copper in a catalytic cracking catalyst, by using Atomic Absorption Spectrometry

    International Nuclear Information System (INIS)

    Gomez, J.; Alonso, A.; Tumbarell, O.; Bustanmete, E.

    2003-01-01

    Atomic Absorption Spectrometry (AAS), has the advantage of its simplicity, speed and low cost. All this, together with its high sensibility and selectivity, makes the AAS one the most widely used analytic techniques. The present work shows, the study to determine the content of vanadium, aluminum, nickel, sodium, iron and copper in a catalytic cracking catalyst of a refinery, by using this technique. The results are compared to those of two laboratories which use the ICP-AES and AAS techniques and shows the processing of the statistics with the use of the t of Student and the F of Snedecor. The results using different methods are also shown as well as the recommended application of this results in the chemical characterization of this type of catalysts

  3. Thermodynamics of oxygen in solid solution in vanadium and niobium--vanadium alloys

    International Nuclear Information System (INIS)

    Steckel, G.L.

    1977-01-01

    A thermodynamic study was made of the vanadium-oxygen and niobium-vanadium-oxygen systems utilizing the solid state galvanic cell technique. Investigations were made with a ThO 2 /Y 2 O 3 electrolyte over the temperature ranges 700 to 1200 0 C (973 to 1473 K) for the binary system and 650 to 1150 0 C (923 to 1423 K) for the ternary system. The activity of oxygen in vanadium obeys Henry's law for the temperatures of this investigation for concentrations up to 3.2 at. percent oxygen. For higher concentrations the activity coefficient shows positive deviations from Henry's law. The terminal solubility of oxygen in vanadium was determined. The activity of oxygen in Nb--V alloys obeys Henry's law for the temperatures of this study for oxygen concentrations less than approximately 2 at. percent. For certain Nb/V ratios Henry's law is obeyed for concentrations as high as 6.5 at. percent oxygen. First order entropy and enthalpy interaction coefficients have been determined to describe the effect on the oxygen activity of niobium additions to vanadium-rich alloys with dilute oxygen concentrations. Niobium causes relatively small decreases in the oxygen activity of V-rich alloys and increases the oxygen solubility limit. Vanadium additions to Nb-rich alloys also increases the oxygen solubility and causes substantial decreases in the dilute solution oxygen activities. The change in the thermodynamic properties when molecular oxygen dissolves in vanadium and niobium--vanadium alloys and the equilibrium oxygen pressure over the binary and ternary systems were also determined

  4. Visualizing Iron Deposition in Multiple Sclerosis Cadaver Brains

    International Nuclear Information System (INIS)

    Habib, Charbel A.; Zheng Weili; Mark Haacke, E.; Webb, Sam; Nichol, Helen

    2010-01-01

    Aim: To visualize and validate iron deposition in two cases of multiple sclerosis using rapid scanning X-Ray Fluorescence (RS-XRF) and Susceptibility Weighted Imaging (SWI). Material and Methods: Two (2) coronal cadaver brain slices from patients clinically diagnosed with multiple sclerosis underwent magnetic resonance imaging (MRI), specifically SWI to image iron content. To confirm the presence of iron deposits and the absence of zinc-rich myelin in lesions, iron and zinc were mapped using RS-XRF. Results: MS lesions were visualized using FLAIR and correlated with the absence of zinc by XRF. XRF and SWI showed that in the first MS case, there were large iron deposits proximal to the draining vein of the caudate nucleus as well as iron deposits associated with blood vessels throughout the globus pallidus. Less iron was seen in association with lesions than in the basal ganglia. The presence of larger amounts of iron correlated reasonably well between RS-XRF and SWI. In the second case, the basal ganglia appeared normal and acute perivascular iron deposition was absent. Conclusion: Perivascular iron deposition is seen in some but not all MS cases, giving credence to the use of SWI to assess iron involvement in MS pathology in vivo.

  5. In vitro solubility of calcium, iron and zinc in relation to phytic acid levels in rice-based consumer products in China

    NARCIS (Netherlands)

    Liang, J.; Han, B.Z.; Nout, M.J.R.; Hamer, R.J.

    2010-01-01

    In vitro solubility of calcium, iron and zinc in relation to phytic acid (PA) levels in 30 commercial rice-based foods from China was studied. Solubility of minerals and molar ratios of PA to minerals varied with degrees of processing. In primary products, [PA]/[Ca] values were less than 5 and

  6. X-ray radiometric analysis of lead and zinc concentrates using germanium radiation detector

    International Nuclear Information System (INIS)

    Vajgachev, A.A.; Mamysh, V.A.; Mil'chakov, V.I.; Shchekin, K.I.; Berezkin, V.V.

    1975-01-01

    The results of determination of lead, zinc and iron in lead and zinc concentrates by the X-ray-radiometric method with the use of germanium semiconductor detector are presented. In the experiments the 57 Co source and tritium-zirconium target were used. The activity of 57 Co was 2 mc. The area of the germanium detector employed was 5g mm 2 , its thickness - 2.3 mm. In lead concentrates zinc and iron were determined from the direct intensity of K-series radiation. In the analysis of zinc concentrates the same conditions of recording and excitation were used as in the case of lead concentrates, but the measurements were conducted in saturated layers. It is demonstrated that the use of germanium semiconductor detectors in combination with the suggested methods of measurements makes it possible to perform determination of iron, zinc and lead in zinc and lead concentrates with permissible error

  7. Effects of zinc supplementation and zinc chelation on in vitro β-cell function in INS-1E cells

    DEFF Research Database (Denmark)

    Nygaard, Sanne Bjørn; Larsen, Agnete; Knuhtsen, Astrid

    2014-01-01

    BACKGROUND: Zinc is essential for the activities of pancreatic β-cells, especially insulin storage and secretion. Insulin secretion leads to co-release of zinc which contributes to the paracrine communication in the pancreatic islets. Zinc-transporting proteins (zinc-regulated transporter, iron......-regulated transporter-like proteins [ZIPs] and zinc transporters [ZnTs]) and metal-buffering proteins (metallothioneins, MTs) tightly regulate intracellular zinc homeostasis. The present study investigated how modulation of cellular zinc availability affects β-cell function using INS-1E cells. RESULTS: Using INS-1E...... cells, we found that zinc supplementation and zinc chelation had significant effects on insulin content and insulin secretion. Supplemental zinc within the physiological concentration range induced insulin secretion. Insulin content was reduced by zinc chelation with N,N,N',N-tektrakis(2-pyridylmethyl...

  8. Vanadium in South Africa

    International Nuclear Information System (INIS)

    Rohrman, B.

    1985-01-01

    This paper deals briefly with the history of vanadium and its uses, price movement, and world resources. It then describes the titanomagnetite ore of the Bushveld Complex, and the production of vanadium from this ore at Highveld Steel and Vanadium Corporation Limited, giving details of the various processes used, including the roast-leach, rotary-kiln, electric-smelting, shaking-ladle, and basic-oxygen-furnace operations. The paper concludes with a very brief account of the treatment of Highveld slags in Europe for the production of vanadium pentoxide and ferrovanadium

  9. Iron and zinc partitioning between coexisting stannite and sphalerite: a possible indicator of temperature and sulfur fugacity

    Science.gov (United States)

    Shimizu, M.; Shikazono, N.

    1985-10-01

    Stannite and sphalerite coexisting with iron sulfides (pyrite and/or pyrrhotite) from Japanese ore deposits associated with tin mineralization were analyzed. Based on the iron and zinc partitioning between stannite and sphalerite, the formation temperature and sulfur fugacity for this mineral assemblage were estimated. A good correlation between stannite-sphalerite temperatures and filling temperatures of fluid inclusions and sulfur isotope temperatures was obtained. This good correlation suggests that the stannite-sphalerite pair is a useful indicator of temperature and sulfur fugacity. It is deduced that the formation temperatures are not different for skarn-type, polymetallic vein-type and Sn-W vein-type deposits, whereas the sulfur fugacities are different; sulfur fugacities increase from the skarn-type through the Sn-W vein-type to the polymetallic vein-type deposits.

  10. Effect of vanadium treatment on tissue distribution of biotrace elements in normal and streptozotocin-induced diabetic rats. Simultaneous analysis of V and Zn using radioactive multitracer

    International Nuclear Information System (INIS)

    Yasui, Hiroyuki; Takino, Toshikazu; Fugono, Jun; Sakurai, Hiromu; Hirunuma, Rieko; Enomoto, Shuichi

    2001-01-01

    Because vanadium ions such as vanadyl (VO 2+ ) and vanadate (VO 3- ) ions were demonstrated to normalize blood glucose levels of diabetic animals and patients, the action mechanism of vanadium treatment has been of interest. In this study, we focused on understanding interactions among trace elements in diabetic rats, in which a multitracer technique was used. The effects of vanadyl sulfate (VS)-treatment on the tissue distribution of trace vanadium ( 48 V) and zinc ( 65 Zn) in normal and streptozotocin (STZ)-induced diabetic rats were examined, and were evaluated in terms of the uptake ratio. The uptake ratio of both elements in tissues significantly changed between STZ-rats and those treated with VS. These results indicated that vanadium treatment in STZ-rats alters the tissue distribution of endogenous elements, suggesting the importance of the relationship between biotrace elements and pathophysiology. (author)

  11. The zinc-myoglobin relationships in porcine muscles

    International Nuclear Information System (INIS)

    Fogd Joergensen, P.; Wegger, I.

    1976-01-01

    Zinc and myoglobin content in muscles from pigs were studied under various conditions. Zinc concentration was considerably higher in red than in white muscles. In muscles, where the metabolic pattern changes from glycolytic to oxidative during the period from birth to weaning, a simultaneous increase in zinc content was seen. A significant positive correlation exists between myoglobin and zinc content under normal conditions. However, while myoglobin concentration decreases due to iron deficiency anaemia no changes occur in zinc content. It is concluded that no functional link seems to exist between zinc metabolism and myoglobin synthesis in porcine muscles. (author)

  12. Solubility Measurements and Modeling of Zinc, Lead and Iron Sulfides at High Temperatures and High Pressures

    DEFF Research Database (Denmark)

    Carolina Figueroa Murcia, Diana; Fosbøl, Philip Loldrup; Thomsen, Kaj

    Solubility measurements of sulfides in aqueous solutions are necessary to understand the behaviour of these scaling minerals in geothermal and oil reservoirs. The low solubility levels of Zinc Sulfide (ZnS), Lead Sulfide (PbS) and Iron Sulfide (FeS) make the solubility measurements a challenging...... oxygen atmosphere to avoid the risk of oxidation of sulfide minerals. The solution is kept in an equilibrium cell at constant temperature and pressure with continuous stirring. The concentration of Zn2+, Pb2+, Fe2+ and S2- are measured using Inductively Coupled Plasma Optical Emission spectrometry (ICP...

  13. Roll-to-Roll Processing of Inverted Polymer Solar Cells using Hydrated Vanadium(VOxide as a PEDOT:PSS Replacement

    Directory of Open Access Journals (Sweden)

    Frederik C. Krebs

    2011-01-01

    Full Text Available The use of hydrated vanadium(Voxide as a replacement of the commonly employed hole transporting material PEDOT:PSS was explored in this work. Polymer solar cells were prepared by spin coating on glass. Polymer solar cells and modules comprising 16 serially connected cells were prepared using full roll-to-roll (R2R processing of all layers. The devices were prepared on flexible polyethyleneterphthalate (PET and had the structure PET/ITO/ZnO/P3HT:PCBM/V2O5·(H2On/Ag. The ITO and silver electrodes were processed and patterned by use of screen printing. The zinc oxide, P3HT:PCBM and vanadium(Voxide layers were processed by slot-die coating. The hydrated vanadium(Voxide layer was slot-die coated using an isopropanol solution of vanadyl-triisopropoxide (VTIP. Coating experiments were carried out to establish the critical thickness of the hydrated vanadium(Voxide layer by varying the concentration of the VTIP precursor over two orders of magnitude. Hydrated vanadium(Voxide layers were characterized by profilometry, scanning electron microscopy, energy dispersive X-ray spectroscopy, and grazing incidence wide angle X-ray scattering. The power conversion efficiency (PCE for completed modules was up to 0.18%, in contrast to single cells where efficiencies of 0.4% were achieved. Stability tests under indoor and outdoor conditions were accomplished over three weeks on a solar tracker.

  14. Methanesulfonic acid solution as supporting electrolyte for zinc-vanadium redox battery

    International Nuclear Information System (INIS)

    Tang Chao; Zhou Debi

    2012-01-01

    Highlights: ► Methanesulfonic acid as supporting electrolyte for V(V)/V(IV) was discussed. ► V(V)/V(IV) concentration as high as 3 mol L −1 was obtained. ► A Zn-V battery was assembled. ► The assembled Zn-V battery has good cycle performance and high cell voltage. - Abstract: The present work was performed in order to evaluate methanesulfonic acid (MSA) as electrolyte medium for V(IV)/V(V) redox couple as positive species applied in redox flow battery (RFB). V-MSA solutions containing more than 3.0 mol L −1 vanadium ions were obtained. Conductivity and viscosity of 3.0 mol L −1 V(IV)/V(V) electrolyte were determined to be 0.10 cm s −1 and 12.37 mPa s respectively. Cyclic voltammetry was conducted to investigate the electrochemical behavior of V(IV)/V(V) redox couple. The diffusion coefficients of V(IV) on Pt electrode in 1.0, 2.0 and 3.0 mol L −1 V(IV)/V(V) electrolytes determined were 3.606 × 10 −6 , 1.813 × 10 −6 and 0.5244 × 10 −6 cm 2 s −1 , respectively. A Zn-V battery was assembled with V(IV)/V(V)-MSA positive species and Zn/Zn(II)-MSA negative species. The cell voltage in charged state was 1.9–2.0 V and discharge voltage reached up to 1.7 V. The average coulombic efficiency and energy efficiency of the assembled cell were 95.85% and 63.90% respectively and it showed a good cyclic charge–discharge performance, which indicates that MSA has a promise application prospect in vanadium redox battery.

  15. The triad of Iron deficiency anemia, hepatosplenomegaly and ...

    African Journals Online (AJOL)

    2014-12-04

    Dec 4, 2014 ... In conclusion, iron deficiency anemia occurring in the triad without zinc deficiency as .... a negative zinc balance and mask existing zinc deficiency.[10] ... erythropoiesis‑stimulating agents in men with chronic kidney disease.

  16. Cytotoxicity, Intestinal Transport, and Bioavailability of Dispersible Iron and Zinc Supplements

    Directory of Open Access Journals (Sweden)

    Jae-Min Oh

    2017-04-01

    Full Text Available Iron or zinc deficiency is one of the most important nutritional disorders which causes health problem. However, food fortification with minerals often induces unacceptable organoleptic changes during preparation process and storage, has low bioavailability and solubility, and is expensive. Nanotechnology surface modification to obtain novel characteristics can be a useful tool to overcome these problems. In this study, the efficacy and potential toxicity of dispersible Fe or Zn supplement coated in dextrin and glycerides (SunActive FeTM and SunActive ZnTM were evaluated in terms of cytotoxicity, intestinal transport, and bioavailability, as compared with each counterpart without coating, ferric pyrophosphate (FePP and zinc oxide (ZnO nanoparticles (NPs, respectively. The results demonstrate that the cytotoxicity of FePP was not significantly affected by surface modification (SunActive FeTM, while SunActive ZnTM was more cytotoxic than ZnO-NPs. Cellular uptake and intestinal transport efficiency of SunActive FeTM were significantly higher than those of its counterpart material, which was in good agreement with enhanced oral absorption efficacy after a single-dose oral administration to rats. These results seem to be related to dissolution, particle dispersibility, and coating stability of materials depending on suspending media. Both SunActiveTM products and their counterpart materials were determined to be primarily transported by microfold (M cells through the intestinal epithelium. It was, therefore, concluded that surface modification of food fortification will be a useful strategy to enhance oral absorption efficiency at safe levels.

  17. Effect of vanadium treatment on tissue distribution of biotrace elements in normal and streptozotocin-induced diabetic rats. Simultaneous analysis of V and Zn using radioactive multitracer

    Energy Technology Data Exchange (ETDEWEB)

    Yasui, Hiroyuki; Takino, Toshikazu; Fugono, Jun; Sakurai, Hiromu [Department of Analytical and Bioinorganic Chemistry, Kyoto Pharmaceutical University, Kyoto (Japan); Hirunuma, Rieko; Enomoto, Shuichi [Radioisotope Technology Division, Cyclotron Center, Institute of Physical and Chemical Research (RIKEN), Wako, Saitama (Japan)

    2001-05-01

    Because vanadium ions such as vanadyl (VO{sup 2+}) and vanadate (VO{sup 3-}) ions were demonstrated to normalize blood glucose levels of diabetic animals and patients, the action mechanism of vanadium treatment has been of interest. In this study, we focused on understanding interactions among trace elements in diabetic rats, in which a multitracer technique was used. The effects of vanadyl sulfate (VS)-treatment on the tissue distribution of trace vanadium ({sup 48}V) and zinc ({sup 65}Zn) in normal and streptozotocin (STZ)-induced diabetic rats were examined, and were evaluated in terms of the uptake ratio. The uptake ratio of both elements in tissues significantly changed between STZ-rats and those treated with VS. These results indicated that vanadium treatment in STZ-rats alters the tissue distribution of endogenous elements, suggesting the importance of the relationship between biotrace elements and pathophysiology. (author)

  18. Melting technique for vanadium containing steels

    Energy Technology Data Exchange (ETDEWEB)

    Grishanov, M P; Gutovskij, I B; Vakhrushev, A S

    1980-04-28

    To descrease cost price of high-quality vanadium steels a method of their melting in open-hearth furnaces with acid lining using slag-metal fraction of vanadium, which is loaded in the content of 2.1-4.7% of melting mass, is suggested. Introduction of slag-metal fraction of vanadium ensures the formation of slag with composition that guarantees the necessary content of vanadium in steel and does not require introduction of expensive vanadium-containing ferroalloys into the melt.

  19. Roll-to-Roll Processing of Inverted Polymer Solar Cells using Hydrated Vanadium(V)Oxide as a PEDOT:PSS Replacement.

    Science.gov (United States)

    Espinosa, Nieves; Dam, Henrik Friis; Tanenbaum, David M; Andreasen, Jens W; Jørgensen, Mikkel; Krebs, Frederik C

    2011-01-11

    The use of hydrated vanadium(V)oxide as a replacement of the commonly employed hole transporting material PEDOT:PSS was explored in this work. Polymer solar cells were prepared by spin coating on glass. Polymer solar cells and modules comprising 16 serially connected cells were prepared using full roll-to-roll (R2R) processing of all layers. The devices were prepared on flexible polyethyleneterphthalate (PET) and had the structure PET/ITO/ZnO/P3HT:PCBM/V₂O₅·(H₂O) n /Ag. The ITO and silver electrodes were processed and patterned by use of screen printing. The zinc oxide, P3HT:PCBM and vanadium(V)oxide layers were processed by slot-die coating. The hydrated vanadium(V)oxide layer was slot-die coated using an isopropanol solution of vanadyl-triisopropoxide (VTIP). Coating experiments were carried out to establish the critical thickness of the hydrated vanadium(V)oxide layer by varying the concentration of the VTIP precursor over two orders of magnitude. Hydrated vanadium(V)oxide layers were characterized by profilometry, scanning electron microscopy, energy dispersive X-ray spectroscopy, and grazing incidence wide angle X-ray scattering. The power conversion efficiency (PCE) for completed modules was up to 0.18%, in contrast to single cells where efficiencies of 0.4% were achieved. Stability tests under indoor and outdoor conditions were accomplished over three weeks on a solar tracker.

  20. The impact of steeping, germination and hydrothermal processing of wheat (Triticum aestivum L.) grains on phytate hydrolysis and the distribution, speciation and bio-accessibility of iron and zinc elements.

    Science.gov (United States)

    Lemmens, Elien; De Brier, Niels; Spiers, Kathryn M; Ryan, Chris; Garrevoet, Jan; Falkenberg, Gerald; Goos, Peter; Smolders, Erik; Delcour, Jan A

    2018-10-30

    Chelation of iron and zinc in wheat as phytates lowers their bio-accessibility. Steeping and germination (15 °C, 120 h) lowered phytate content from 0.96% to only 0.81% of initial dry matter. A multifactorial experiment in which (steeped/germinated) wheat was subjected to different time (2-24 h), temperature (20-80 °C) and pH (2.0-8.0) conditions showed that hydrothermal processing of germinated (15 °C, 120 h) wheat at 50 °C and pH 3.8 for 24 h reduced phytate content by 95%. X-ray absorption near-edge structure imaging showed that it indeed abolished chelation of iron to phytate. It also proved that iron was oxidized during steeping, germination and hydrothermal processing. It was further shown that zinc and iron bio-accessibility were respectively 3 and 5% in wheat and 27 and 37% in hydrothermally processed wheat. Thus, hydrothermal processing of (germinated) wheat paves the way for increasing elemental bio-accessibility in whole grain-based products. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Determination of vanadium in sea water by graphite furnace atomic absorption spectrometry with a tube coated with pyrolytic graphite

    International Nuclear Information System (INIS)

    Shimizu, Tokuo; Sakai, Kaoru

    1981-01-01

    The trace amount of vanadium in sea water was determined by graphite furnace atomic absorption spectrometry with a tube coated with pyrolytic graphite. To correct the background absorption, a deuterium lamp with a higher-brilliant thermal cathode was used. The sensitivity for vanadium increased 10 -- 20 fold by the use of the tube coated with pyrolytic graphite, and the utility lifetime of the tube was greatly extended. Vanadium(V) - 4-(2-pyridylazo)resorcinol (PAR) complexes were extracted into chloroform as an ion-pair with benzyldimethyltetradecylammonium (Zephiramine) cation alternatively. The sample of sea water, which was made to 0.1 N in sulfuric acid and 0.1% in hydrogen peroxide, was loaded onto the column of Dowex 1-X 4 resin (SO 4 2- -form). Vanadium was then eluted from the resin with 1 N sulfuric acid-0.1% hydrogen peroxide or 1 N hydrochloric acid-0.1% hydrogen peroxide evaporated to dry. After dissolution of the elute in 0.2 N nitric acid, vanadium was extracted. Secondly, the sample of sea water was adjusted to pH 5.0, and loaded onto the column of Chelex-100 resin. Vanadium was eluted from the resin with 2 N ammonia. The above two methods took much time, but the coprecipitation method was not so and recommended for the determination of vanadium in sea water. Vanadium was coprecipitated with iron(III) hydroxide-hydrous titanium(IV) oxide at pH 6.0. The precipitate was digested with nitric acid-hydrogen peroxide. The solution was diluted to 50 ml with water. The resulting solutions were employed to determine the vanadium concentration by the graphite furnace atomic absorption measurement. The trace amounts of vanadium in various kinds of the coastal sea water were determined by the coprecipitation method. (author)

  2. VANADIUM ALLOYS

    Science.gov (United States)

    Smith, K.F.; Van Thyne, R.J.

    1959-05-12

    This patent deals with vanadium based ternary alloys useful as fuel element jackets. According to the invention the ternary vanadium alloys, prepared in an arc furnace, contain from 2.5 to 15% by weight titanium and from 0.5 to 10% by weight niobium. Characteristics of these alloys are good thermal conductivity, low neutron capture cross section, good corrosion resistance, good welding and fabricating properties, low expansion coefficient, and high strength.

  3. Sol-gel growth of vanadium dioxide

    International Nuclear Information System (INIS)

    Speck, K.R.

    1990-01-01

    This thesis examines the chemical reactivity of vanadium (IV) tetrakis(t-butoxide) as a precursor for the sol-gel synthesis of vanadium dioxide. Hydrolysis and condensation of the alkoxide was studied by FTIR spectroscopy. Chemical modification of the vanadium tetraalkoxide by alcohol interchange was studied using 51 V NMR and FTIR. Vanadium dioxide thin films and powders were made from vanadium tetrakis(t-butoxide) by standard sol-gel techniques. Post-deposition heating under nitrogen was necessary to transform amorphous gels into vanadium dioxide. Crystallization of films and powders was studied by FTIR, DSC, TGA, and XRD. Gel-derived vanadium dioxide films undergo a reversible semiconductor-to-metal phase transition near 68C, exhibiting characteristic resistive and spectral changes. The electrical resistance decreased by two to three orders of magnitude and the infrared transmission sharply dropped as the material was cycled through this thermally induced phase transition. The sol-gel method was also used to make doped vanadium dioxide films. Films were doped with tungsten and molybdenum ions to effectively lower the temperature at which the transition occurs

  4. Chloroquine is a zinc ionophore.

    Directory of Open Access Journals (Sweden)

    Jing Xue

    Full Text Available Chloroquine is an established antimalarial agent that has been recently tested in clinical trials for its anticancer activity. The favorable effect of chloroquine appears to be due to its ability to sensitize cancerous cells to chemotherapy, radiation therapy, and induce apoptosis. The present study investigated the interaction of zinc ions with chloroquine in a human ovarian cancer cell line (A2780. Chloroquine enhanced zinc uptake by A2780 cells in a concentration-dependent manner, as assayed using a fluorescent zinc probe. This enhancement was attenuated by TPEN, a high affinity metal-binding compound, indicating the specificity of the zinc uptake. Furthermore, addition of copper or iron ions had no effect on chloroquine-induced zinc uptake. Fluorescent microscopic examination of intracellular zinc distribution demonstrated that free zinc ions are more concentrated in the lysosomes after addition of chloroquine, which is consistent with previous reports showing that chloroquine inhibits lysosome function. The combination of chloroquine with zinc enhanced chloroquine's cytotoxicity and induced apoptosis in A2780 cells. Thus chloroquine is a zinc ionophore, a property that may contribute to chloroquine's anticancer activity.

  5. Study on the pre-treatment of oxidized zinc ore prior to flotation

    Science.gov (United States)

    He, Dong-sheng; Chen, Yun; Xiang, Ping; Yu, Zheng-jun; Potgieter, J. H.

    2018-02-01

    The pre-treatment of zinc oxide bearing ores with high slime content is important to ensure that resources are utilized optimally. This paper reports an improved process using hydrocyclone de-sliming, dispersion reagents, and magnetic removal of iron minerals for the pre-treatment of zinc oxide ore with a high slime and iron content, and the benefits compared to traditional technologies are shown. In addition, this paper investigates the damage related to fine slime and iron during zinc oxide flotation, the necessity of using hydrocyclone de-sliming together with dispersion reagents to alleviate the influence of slime, and interactions among hydrocyclone de-sliming, reagent dispersion, and magnetic iron removal. Results show that under optimized operating conditions the entire beneficiation technology results in a flotation concentrate with a Zn grade of 34.66% and a recovery of 73.41%.

  6. Effect of different iron levels on 65Zn uptake and transport in maize seedlings

    International Nuclear Information System (INIS)

    Rathore, V.S.; Sharma, D.; Kandala, J.C.

    1974-01-01

    Uptake and translocation of 65 Zn was studied in two week old maize seedlings at 0.01, 0.1, 1 and 5 ppm iron levels in half-strength Hoagland's solution. Four different zinc levels viz., 0.04, 0.4, 4 and 8 ppm were taken. Total 65 Zn uptake and translocation to shoots at 2, 4, 6 and 12 hours showed that increasing iron levels in the uptake medium reduced Zn-uptake in all combinations and at all uptake hours studied. This antagnnistic effect of iron on zinc uptake was more pronounced at the initial stages and could be partly inhibited by increasing zinc concentration in the uptake medium. Translocation of 65 Zn to shoots increased with increase in uptake time. Increasing iron levels in the medium decreased zinc dislocation to shoots at all zinc levels. (author)

  7. Iron, Zinc, Folate, and Vitamin B-12 Status Increased among Women and Children in Yaoundé and Douala, Cameroon, 1 Year after Introducing Fortified Wheat Flour.

    Science.gov (United States)

    Engle-Stone, Reina; Nankap, Martin; Ndjebayi, Alex O; Allen, Lindsay H; Shahab-Ferdows, Setareh; Hampel, Daniela; Killilea, David W; Gimou, Marie-Madeleine; Houghton, Lisa A; Friedman, Avital; Tarini, Ann; Stamm, Rosemary A; Brown, Kenneth H

    2017-07-01

    Background: Few data are available on the effectiveness of large-scale food fortification programs. Objective: We assessed the impact of mandatory wheat flour fortification on micronutrient status in Yaoundé and Douala, Cameroon. Methods: We conducted representative surveys 2 y before and 1 y after the introduction of fortified wheat flour. In each survey, 10 households were selected within each of the same 30 clusters ( n = ∼300 households). Indicators of inflammation, malaria, anemia, and micronutrient status [plasma ferritin, soluble transferrin receptor (sTfR), zinc, folate, and vitamin B-12] were assessed among women aged 15-49 y and children 12-59 mo of age. Results: Wheat flour was consumed in the past 7 d by ≥90% of participants. Postfortification, mean total iron and zinc concentrations of flour samples were 46.2 and 73.6 mg/kg (target added amounts were 60 and 95 mg/kg, respectively). Maternal anemia prevalence was significantly lower postfortification (46.7% compared with 39.1%; adjusted P = 0.01), but mean hemoglobin concentrations and child anemia prevalence did not differ. For both women and children postfortification, mean plasma concentrations were greater for ferritin and lower for sTfR after adjustments for potential confounders. Mean plasma zinc concentrations were greater postfortification and the prevalence of low plasma zinc concentration in women after fortification (21%) was lower than before fortification (39%, P 50% greater postfortification. Conclusion: Although the pre-post survey design limits causal inference, iron, zinc, folate, and vitamin B-12 status increased among women and children in urban Cameroon after mandatory wheat flour fortification.

  8. Influence of coal ash and slag dumping on dump waste waters of the Kostolac power plants (Serbia)

    Energy Technology Data Exchange (ETDEWEB)

    Popovic, A.; Djinovic, J. [University of Belgrade, Belgrade (Serbia)

    2006-10-01

    The content of selected trace and major elements in the river water used for transport, as well as in the subcategories of the waste waters (overflow and drainage) were analyzed in order to establish the influence of transport and dumping of coal ash and slag from the 'Kostolac A' and 'Kostolac B' power plants located 100 km from Belgrade (Serbia). It was found that during transport of coal ash and slag to the dump, the water used for transport becomes enriched with manganese, nickel, zinc, chromium, vanadium, titanium, cobalt, arsenic, aluminum, and silicon, while more calcium, iron, cadmium, and lead are adsorbed by the ash and slag than is released from them. There is also an equilibrium between the release and adsorption processes of copper and magnesium during transport. The vertical penetration of the water used for transport results in a release of calcium, magnesium, manganese, and cadmium to the environment, while iron, nickel, zinc, chromium, copper, lead, vanadium, titanium, cobalt, and arsenic are adsorbed by the fractions of coal ash and slag in the dump.

  9. Relationship between the level of essential metal elements in human hair and coronary heart disease

    International Nuclear Information System (INIS)

    Bor-Tsung Hsieh; Kai-Yuan Cheng; Ying-Chen Chang

    2011-01-01

    Studies on epidemics have demonstrated the relationship between coronary heart disease (CHD) and mineral substances, such as selenium, calcium, magnesium, sodium, potassium, copper, zinc, iron, manganese, and vanadium, in human bodies. In this study, instrumental neutron activation analysis (INAA) and flame atomic absorption spectrophotometry (FAAS) were applied to evaluate the levels of selenium, calcium, magnesium, sodium, potassium, copper, zinc, and iron in healthy individuals and CHD patients. Hair samples were collected from 42 healthy participants and 28 diagnosed CHD patients. Calcium, magnesium, copper, and zinc levels in healthy individuals are significantly higher than the levels found in the patients (p < 0.01). Calcium/selenium ratio is also significantly higher in healthy individuals (p < 0.05). Based on the possible synergies and/or antagonisms of elements and their absorption and metabolism, magnesium/calcium, zinc/copper, and sodium/potassium ratios showed positive relevance (p < 0.01). (author)

  10. Criticality of iron and its principal alloying elements.

    Science.gov (United States)

    Nuss, Philip; Harper, E M; Nassar, N T; Reck, Barbara K; Graedel, T E

    2014-04-01

    Because modern technology depends on reliable supplies of a wide variety of materials and because of increasing concern about those supplies, a comprehensive methodology was created to quantify the degree of criticality of the metals of the periodic table. In this paper, we apply this methodology to iron and several of its main alloying elements (i.e., vanadium, chromium, manganese, and niobium). These elements represent the basic metals of any industrial society and are vital for national security and economic well-being. Assessments relating to the dimensions of criticality - supply risk, vulnerability to supply restriction, and environmental implications - for 2008 are made on the global level and for the United States. Evaluations of each of the multiple indicators are presented, with aggregate results plotted in "criticality space", together with Monte Carlo simulation-derived "uncertainty cloud" estimates. Iron has the lowest supply risk, primarily because of its widespread geological occurrence. Vanadium displays the highest cradle-to-gate environmental implications, followed by niobium, chromium, manganese, and iron. Chromium and manganese, both essential in steel making, display the highest vulnerability to supply restriction, largely because substitution or substitution at equal performance is not possible for all end-uses. From a comprehensive perspective, we regard the overall criticality as low for iron and modest for the alloying elements we evaluated.

  11. Determination of hafnium, molybdenum, and vanadium in niobium and niobium-based alloys by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Ide, Kunikazu; Kobayashi, Takeshi; Sudo, Emiko.

    1985-01-01

    The analytical procedure is as follows: Weigh 1 g of a sample and put it into a 100 cm 3 PTFE beaker. Add 5 ml of distilled water and 5 ml of hydrofluoric acid, and then heat the solution on a hot plate, adding 3 ml of nitric acid dropwise. Dilute the solution to 100 cm 3 with distilled water. When hafnium is determined, add 2 g of diammonium titanium hexafluoride ((NH 4 ) 2 TiF 6 )) before dilution. Working standard solutions are prepared by adding the stock standard solutions of hafnium, molybdenum, and vanadium into niobium solutions. When hafnium is determined, add 2 g of (NH 4 ) 2 TiF 6 and the alloying elements in amounts corresponding to those in sample solutions into the working standard solutions. The tolerable amounts of hydrofluoric acid were 2.9 M, 2.1 M, and 3.1 M and those of nitric acid were 1.0 M, 1.6 M, and 1.6 M for hafnium, molybdenum, and vanadium, respectively. It was found that (NH 4 ) 2 TiF 6 greatly increased the sensitivity for hafnium determination. Niobium showed minus effect for hafnium and plus effect for molybdenum and vanadium. The atomic absorption of molybdenum and vanadium were not influenced by the presence of 20 % of each alloying element, while the atomic absorption of hafnium was given plus effect by 20 % of zirconium, iron, cobalt, nickel, manganese, chromium or vanadium and minus effect by 20 % tungsten. The analytical values of hafnium, molybdenum, and vanadium in niobium-based alloys by this method showed a good agreement with those by X-ray fluorescence analysis. The lower limits of determination (S/N=2) were 0.05, 0.001, and 0.002 % and the relative standard deviation were 3, 1, and 1.5 % for hafnium, molybdenum, and vanadium, respectively. (author)

  12. Iron, zinc, copper and magnesium nutritional status in Mexican children aged 1 to 11 years Estado nutricio de hierro, zinc, cobre y magnesio en niños mexicanos de 1 a 11 años de edad

    Directory of Open Access Journals (Sweden)

    Ma. del Carmen Morales-Ruán

    2012-04-01

    Full Text Available OBJECTIVE: To describe the micronutrient nutritional status of a national sample of 1-11 year old Mexican children surveyed in 2006 in National Health and Nutrition Survey (ENSANUT 2006 and their association with dietary and sociodemographic factors. MATERIALS AND METHODS: Serum samples were used (n=5 060 to measure the concentrations of ferritin, transferrin receptor, zinc, copper and magnesium. RESULTS: Prevalence of deficiencies in 1-4 and 5-11y old children were for iron (using low ferritin 26.0 and 13.0%; zinc, 28.1 and 25.8%, respectively; and copper, ≈30% in both age groups. Magnesium low serum concentrations (MLSC, were found in 12.0% and 28.4% of the children, respectively. Being beneficiary of Liconsa (OR=0.32; C.I.95%, 0.17-0.61 or belonging to higher socioeconomic status (OR=0.63; C.I.95%, 0.41-0.97 were protective against iron deficiency. Increasing age (OR=0.59; C.I.95%, 1.19-1.32 and living in the Central Region (OR=0.59; C.I.95%, 0.36-0.97 were protective against MLSC. CONCLUSIONS: Deficiencies of iron and zinc are serious public health problems in Mexican children.OBJETIVO: Describir el estado nutricio de micronutrimentos en niños de 1-11 años de edad de la Encuesta Nacional de Salud y Nutrición 2006 y su asociación con factores dietéticos y sociodemográficos. MATERIAL Y MÉTODOS: Se usaron muestras séricas (n=5060 para medir las concentraciones de ferritina, receptor de transferrina, zinc, cobre y magnesio. RESULTADOS: La prevalencias de deficiencias en niños de 1-4 y de 5 a 11 años fueron para ferritina, 26.0 y 13%; zinc, 28.1 y 25.8% respectivamente y cobre ≈30% en ambos grupos. Las concentraciones bajas de magnesio (CBM fueron 12.0 y 28.4%, respectivamente. Ser beneficiario de Liconsa (RM=0.32; IC 95%: 0.17-0.61 y pertenecer al nivel socioeconómico alto (RM=0.63; IC, 95%: 0.41-0.97 fueron protectores para deficiencia de hierro. La edad (RM=1.26; IC, 95%: 1.19-1.32 y vivir en la región Centro (RM=0.59; IC, 95

  13. Shaping optimal zinc coating on the surface of high-quality ductile iron casting. Part II – Technological formula and value of diffusion coefficient

    Directory of Open Access Journals (Sweden)

    Kopyciński D.

    2017-03-01

    Full Text Available The completed research presented in the first part of the article has allowed linking the manufacturing technology of ductile iron castings with the process of hot dip galvanizing. On the basis of these data simulations were carried out to examine the behaviour of zinc diffusion coefficient D in the galvanized coating. The adopted model of zinc coating growth helped to explain the cases of excessive growth of the intermetallic phases in this type of coating. The paper analyzes covered the relationship between the roughness and phase composition of the top layer of product and the thickness and kinetics of zinc coating growth referred to individual sub-layers of the intermetallic phases.Roughness and phase composition in the surface layer of product were next related to the diffusion coefficient D examined in respective sublayers of the intermetallic phases.

  14. Johor strait as a hotspot for trace elements contamination in peninsular Malaysia.

    Science.gov (United States)

    Zulkifli, Syaizwan Zahmir; Ismail, Ahmad; Mohamat-Yusuff, Ferdaus; Arai, Takaomi; Miyazaki, Nobuyuki

    2010-05-01

    Present study was conducted to evaluate current status of trace elements contamination in the surface sediments of the Johor Strait. Iron (2.54 +/- 1.24%) was found as the highest occurring element, followed by those of zinc (210.45 +/- 115.4 microg/g), copper (57.84 +/- 45.54 microg/g), chromium (55.50 +/- 31.24 microg/g), lead (52.52 +/- 28.41 microg/g), vanadium (47.76 +/- 25.76 microg/g), arsenic (27.30 +/- 17.11 microg/g), nickel (18.31 +/- 11.77 microg/g), cobalt (5.13 +/- 3.12 microg/g), uranium (4.72 +/- 2.52 microg/g), and cadmium (0.30 +/- 0.30 microg/g), respectively. Bioavailability of cobalt, nickel, copper, zinc, arsenic and cadmium were higher than 50% of total concentration. Vanadium, copper, zinc, arsenic and cadmium were found significantly different between the eastern and western part of the strait (p Johor Strait is suitable as a hotspot for trace elements contamination related studies.

  15. Effect of provision of daily zinc and iron with several micronutrients on growth and morbidity among young children in Pakistan: A cluster-randomised trial

    International Nuclear Information System (INIS)

    Soofi, Sajid

    2014-01-01

    Full text: Background: Powders containing iron and other micronutrients are recommended as a strategy to prevent nutritional anaemia and other micronutrient deficiencies in children. We assessed the effects of provision of two micronutrient powder formulations, with or without zinc, to children in Pakistan. Methods: We did a cluster randomised trial in urban and rural sites in Sindh, Pakistan. A baseline survey identified 256 clusters, which were randomly assigned (within urban and rural strata, by computer-generated random numbers) to one of three groups: non-supplemented control (group A), micronutrient powder without zinc (group B), or micronutrient powder with 10 mg zinc (group C). Children in the clusters aged 6 months were eligible for inclusion in the study. Powders were to be given daily between 6 and 18 months of age; follow-up was to age 2 years. Micronutrient powder sachets for groups B and C were identical except for colour; investigators and field and supervisory staff were masked to composition of the micronutrient powders until trial completion. Parents knew whether their child was receiving supplementation, but did not know whether the powder contained zinc. Primary outcomes were growth, episodes of diarrhoea, acute lower respiratory tract infection, fever, and incidence of admission to hospital. This trial is registered with ClinicalTrials.gov, number NCT00705445. Results: The trial was done between Nov 1, 2008, and Dec 31, 2011. 947 children were enrolled in group A clusters, 910 in group B clusters, and 889 in group C clusters. Micronutrient powder administration was associated with lower risk of iron-deficiency anaemia at 18 months compared with the control group (odds ratio [OR] for micronutrient powder without zinc = 0•20, 95% CI 0•11–0•36; OR for micronutrient powder with zinc = 0•25, 95% CI 0•14–0•44). Compared with the control group, children in the group receiving micronutrient powder without zinc gained an extra 0•31 cm

  16. Extraction of Vanadium from Vanadium Slag Via Non-salt Roasting and Ammonium Oxalate Leaching

    Science.gov (United States)

    Li, Meng; Du, Hao; Zheng, Shili; Wang, Shaona; Zhang, Yang; Liu, Biao; Dreisinger, David Bruce; Zhang, Yi

    2017-10-01

    A clean method featuring non-salt roasting followed by (NH4)2C2O4 leaching to recover vanadium from vanadium slag was proposed. The carcinogenic Cr6+ compounds and exhaust gases were avoided, and the water generated from vanadate precipitation may be recycled and reused in this new leaching process. The leaching residues may be easily used by a blast furnace. Moreover, (NH4)2C2O4 solution was used as a leaching medium to avoid expensive and complicated ammonium controlling operations as a result of the stability of (NH4)2C2O4 at a high temperature. The transformation mechanisms of vanadium- and chromium-bearing phases were systematically investigated by x-ray diffraction analysis and scanning electron microscopy with energy-disperse x-ray spectrometry, respectively. In addition, the effects of oxygen concentration, roasting temperature, and holding time on vanadium recovery were investigated. Finally, the effects of leaching variables on the vanadium leaching rate were also examined.

  17. Expression of zinc transporter genes in rice as influenced by zinc-solubilizing Enterobacter cloacae strain ZSB14

    Directory of Open Access Journals (Sweden)

    Selvaraj eKrithika

    2016-04-01

    Full Text Available Zinc (Zn deficiency in major food crops has been considered as an important factor affecting the crop production and subsequently the human health. Rice (Oryza sativa is sensitive to Zn deficiency and thereby causes malnutrition to most of the rice-eating Asian populations. Application of zinc solubilizing bacteria (ZSB could be a sustainable agronomic approach to increase the soil available Zn which can mitigate the yield loss and consequently the nutritional quality of rice. Understanding the molecular interactions between rice and unexplored ZSB is useful for overcoming Zn deficiency problems. In the present study, the role of zinc solubilizing bacterial strain Enterobacter cloacae strain ZSB14 on regulation of Zn-regulated transporters and iron (Fe-regulated transporter-like protein (ZIP genes in rice under iron sufficient and deficient conditions was assessed by quantitative real-time reverse transcription PCR. The expression patterns of OsZIP1, OsZIP4 and OsZIP5 in root and shoot of rice were altered due to the Zn availability as dictated by Zn sources and ZSB inoculation. Fe sufficiency significantly reduced the root and shoot OsZIP1 expression, but not the OsZIP4 and OsZIP5 levels. Zinc oxide in the growth medium up-regulated all the assessed ZIP genes in root and shoot of rice seedlings. When ZSB was inoculated to rice seedlings grown with insoluble zinc oxide in the growth medium, the expression of root and shoot OsZIP1, OsZIP4 and OsZIP5 was reduced. In the absence of zinc oxide, ZSB inoculation up-regulated OsZIP1 and OsZIP5 expressions. Zinc nutrition provided to the rice seedling through ZSB-bound zinc oxide solubilization was comparable to the soluble zinc sulphate application which was evident through the ZIP genes’ expression and the Zn accumulation in root and shoot of rice seedlings. These results demonstrate that zinc solubilizing bacteria could play a crucial role in zinc fertilization and fortification of rice.

  18. Effects of dietary vanadium in mallard ducks

    Science.gov (United States)

    White, D.H.; Dieter, M.P.

    1978-01-01

    Adult mallard ducks fed 0, 1, 10, or 100 ppm vanadyl sulfate in the diet were sacrificed after 12 wk on treatment; tissues were analyzed for vanadium. No birds died during the study and body weights did not change. Vanadium accumulated to higher concentrations in the bone and liver than in other tissues. Concentrations in bones of hens were five times those in bones of drakes, suggesting an interaction between vanadium and calcium mobilization in laying hens. Vanadium concentrations in most tissues were significantly correlated and increased with treatment level. Lipid metabolism was altered in laying hens fed 100 ppm vanadium. Very little vanadium accumulated in the eggs of laying hens.

  19. Impact of sorghum processing on phytate, phenolic compounds and in vitro solubility of iron and zinc in thick porridges

    OpenAIRE

    Kayodé, A.P.P.; Linnemann, A.R.; Nout, M.J.R.; Boekel, van, M.A.J.S.

    2007-01-01

    This study focussed on the impact of process variables on levels of phytate and phenolic compounds, and in vitro solubility of iron (Fe) and zinc (Zn) in sorghum porridges, a major staple in semi-arid tropics. The aim was to identify practices that enhance the mineral availability in this type of staple food. We studied the example of the West African porridge `dibou' for which the processing methods involve grain cleaning, milling, sieving and cooking. Regional variations occur in the proces...

  20. Zinc Biochemistry: From a Single Zinc Enzyme to a Key Element of Life12

    Science.gov (United States)

    Maret, Wolfgang

    2013-01-01

    The nutritional essentiality of zinc for the growth of living organisms had been recognized long before zinc biochemistry began with the discovery of zinc in carbonic anhydrase in 1939. Painstaking analytical work then demonstrated the presence of zinc as a catalytic and structural cofactor in a few hundred enzymes. In the 1980s, the field again gained momentum with the new principle of “zinc finger” proteins, in which zinc has structural functions in domains that interact with other biomolecules. Advances in structural biology and a rapid increase in the availability of gene/protein databases now made it possible to predict zinc-binding sites from metal-binding motifs detected in sequences. This procedure resulted in the definition of zinc proteomes and the remarkable estimate that the human genome encodes ∼3000 zinc proteins. More recent developments focus on the regulatory functions of zinc(II) ions in intra- and intercellular information transfer and have tantalizing implications for yet additional functions of zinc in signal transduction and cellular control. At least three dozen proteins homeostatically control the vesicular storage and subcellular distribution of zinc and the concentrations of zinc(II) ions. Novel principles emerge from quantitative investigations on how strongly zinc interacts with proteins and how it is buffered to control the remarkably low cellular and subcellular concentrations of free zinc(II) ions. It is fair to conclude that the impact of zinc for health and disease will be at least as far-reaching as that of iron. PMID:23319127

  1. Development and optimization of iron- and zinc-containing nanostructured powders for nutritional applications

    Energy Technology Data Exchange (ETDEWEB)

    Hilty, F M; Hurrell, R F; Zimmermann, M B [Human Nutrition Laboratory, Institute of Food Science and Nutrition, ETH Zurich (Switzerland); Teleki, A; Buechel, R; Pratsinis, S E [Particle Technology Laboratory, Department of Mechanical and Process Engineering, ETH Zurich (Switzerland); Krumeich, F, E-mail: michael.zimmermann@ilw.agrl.ethz.c [Electron Microscopy Center (EMEZ), ETH Zurich (Switzerland)

    2009-11-25

    Reducing the size of low-solubility iron (Fe)-containing compounds to nanoscale has the potential to improve their bioavailability. Because Fe and zinc (Zn) deficiencies often coexist in populations, combined Fe/Zn-containing nanostructured compounds may be useful for nutritional applications. Such compounds are developed here and their solubility in dilute acid, a reliable indicator of iron bioavailability in humans, and sensory qualities in sensitive food matrices are investigated. Phosphates and oxides of Fe and atomically mixed Fe/Zn-containing (primarily ZnFe{sub 2}O{sub 4}) nanostructured powders were produced by flame spray pyrolysis (FSP). Chemical composition and surface area were systematically controlled by varying precursor concentration and feed rate during powder synthesis to increase solubility to the level of ferrous sulfate at maximum Fe and Zn content. Solubility of the nanostructured compounds was dependent on their particle size and crystallinity. The new nanostructured powders produced minimal color changes when added to dairy products containing chocolate or fruit compared to the changes produced when ferrous sulfate or ferrous fumarate were added to these foods. Flame-made Fe- and Fe/Zn-containing nanostructured powders have solubilities comparable to ferrous and Zn sulfate but may produce fewer color changes when added to difficult-to-fortify foods. Thus, these powders are promising for food fortification and other nutritional applications.

  2. Development and optimization of iron- and zinc-containing nanostructured powders for nutritional applications

    International Nuclear Information System (INIS)

    Hilty, F M; Hurrell, R F; Zimmermann, M B; Teleki, A; Buechel, R; Pratsinis, S E; Krumeich, F

    2009-01-01

    Reducing the size of low-solubility iron (Fe)-containing compounds to nanoscale has the potential to improve their bioavailability. Because Fe and zinc (Zn) deficiencies often coexist in populations, combined Fe/Zn-containing nanostructured compounds may be useful for nutritional applications. Such compounds are developed here and their solubility in dilute acid, a reliable indicator of iron bioavailability in humans, and sensory qualities in sensitive food matrices are investigated. Phosphates and oxides of Fe and atomically mixed Fe/Zn-containing (primarily ZnFe 2 O 4 ) nanostructured powders were produced by flame spray pyrolysis (FSP). Chemical composition and surface area were systematically controlled by varying precursor concentration and feed rate during powder synthesis to increase solubility to the level of ferrous sulfate at maximum Fe and Zn content. Solubility of the nanostructured compounds was dependent on their particle size and crystallinity. The new nanostructured powders produced minimal color changes when added to dairy products containing chocolate or fruit compared to the changes produced when ferrous sulfate or ferrous fumarate were added to these foods. Flame-made Fe- and Fe/Zn-containing nanostructured powders have solubilities comparable to ferrous and Zn sulfate but may produce fewer color changes when added to difficult-to-fortify foods. Thus, these powders are promising for food fortification and other nutritional applications.

  3. Development and optimization of iron- and zinc-containing nanostructured powders for nutritional applications.

    Science.gov (United States)

    Hilty, F M; Teleki, A; Krumeich, F; Büchel, R; Hurrell, R F; Pratsinis, S E; Zimmermann, M B

    2009-11-25

    Reducing the size of low-solubility iron (Fe)-containing compounds to nanoscale has the potential to improve their bioavailability. Because Fe and zinc (Zn) deficiencies often coexist in populations, combined Fe/Zn-containing nanostructured compounds may be useful for nutritional applications. Such compounds are developed here and their solubility in dilute acid, a reliable indicator of iron bioavailability in humans, and sensory qualities in sensitive food matrices are investigated. Phosphates and oxides of Fe and atomically mixed Fe/Zn-containing (primarily ZnFe2O4) nanostructured powders were produced by flame spray pyrolysis (FSP). Chemical composition and surface area were systematically controlled by varying precursor concentration and feed rate during powder synthesis to increase solubility to the level of ferrous sulfate at maximum Fe and Zn content. Solubility of the nanostructured compounds was dependent on their particle size and crystallinity. The new nanostructured powders produced minimal color changes when added to dairy products containing chocolate or fruit compared to the changes produced when ferrous sulfate or ferrous fumarate were added to these foods. Flame-made Fe- and Fe/Zn-containing nanostructured powders have solubilities comparable to ferrous and Zn sulfate but may produce fewer color changes when added to difficult-to-fortify foods. Thus, these powders are promising for food fortification and other nutritional applications.

  4. Metal-metal interaction mediates the iron induction of Drosophila MtnB

    International Nuclear Information System (INIS)

    Qiang, Wenjia; Huang, Yunpeng; Wan, Zhihui; Zhou, Bing

    2017-01-01

    Metallothionein (MT) protein families are a class of small and universal proteins rich in cysteine residues. They are synthesized in response to heavy metal stresses to sequester the toxic ions by metal-thiolate bridges. Five MT family members, namely MtnA, MtnB, MtnC, MtnD and MtnE, have been discovered and identified in Drosophila. These five isoforms of MTs are regulated by metal responsive transcription factor dMTF-1 and play differentiated but overlapping roles in detoxification of metal ions. Previous researches have shown that Drosophila MtnB responds to copper (Cu), cadmium (Cd) and zinc (Zn). Interestingly in this study we found that Drosophila MtnB expression also responds to elevated iron levels in the diet. Further investigations revealed that MtnB plays limited roles in iron detoxification, and the direct binding of MtnB to ferrous iron in vitro is also weak. The induction of MtnB by iron turns out to be mediated by iron interference of other metals, because EDTA at even a partial concentration of that of iron can suppress this induction. Indeed, in the presence of iron, zinc homeostasis is altered, as reflected by expression changes of zinc transporters dZIP1 and dZnT1. Thus, iron-mediated MtnB induction appears resulting from interrupted homeostasis of other metals such as zinc, which in turns induced MtnB expression. Metal-metal interaction may more widely exist than we expected. - Highlights: • Metallothionein B expression is regulated by iron in Drosophila melanogaster. • MtnB has limited physiological roles in iron detoxification. • Binding affinity of MtnB to iron is weak in vitro. • Induction of Drosophila MtnB by iron is mediated indirectly through metal-metal interaction.

  5. Oxygen stabilized zirconium-vanadium-iron alloy

    International Nuclear Information System (INIS)

    Gruen, D.M.; Mendelsohn, M.H.

    1982-01-01

    An oxygen stabilized intermetallic compound having the formula (Zrsub(1-x)Tisub(x))sub(2-u)(Vsub(1-y)Fesub(y))Osub(z) where x = 0.0 to 0.9, y = 0.01 to 0.9, z = 0.25 to 0.5 and u = 0 to 1. The compound is capable of reversibly sorbing hydrogen at temperatures from -196 deg C to 200 deg C at pressures down to 10 - 6 torr. The compound is suitable for use as a hydrogen getter in low pressure, high temperature applications such as magnetic confinement fusion devices, and the iron content may be substituted by nickel, cobalt or manganese. (author)

  6. Oxygen stabilized zirconium-vanadium-iron alloy

    International Nuclear Information System (INIS)

    Gruen, D.M.; Mendelsohn, M.H.

    1982-01-01

    An oxygen stabilized intermetallic compound having the formula (Zrsub(1-x)Tisub(x))sub(2-u)(Vsub(1-y)Fesub(y))Osub(z) where x=0.0 to 0.9, y=0.01 to 0.9, z=0.25 to 0.5 and u=0 to 1. The compound is capable of reversibly sorbing hydrogen at temperatures from -196 0 C to 200 0 C at pressures down to 10 - 6 torr. The compound is suitable for use as a hydrogen getter in low pressure, high temperature applications such as magnetic confinement fusion devices, and the iron content may be substituted by nickel, cobalt or manganese. (author)

  7. A new oxidimetric reagent: potassium dichromate in a strong phosphoric acid medium--VII. Photometric titration of vanadium(IV) and of cerium(III) alone and in mixtures with iroN(II).

    Science.gov (United States)

    Rao, G G; Rao, P K

    1967-01-01

    Vanadium(IV) can be accurately titrated with potassium dichromate in media containing phosphoric acid of 3-12M concentration: the change in absorption of vanadium(IV) is followed in the region 660 mmicro using a red filter. It is more convenient to carry out the titration in 3M phosphoric acid because at higher concentrations chloride, nitrate, cerium(III) and manganese(II) may interfere. Photoelcetric titration is more convenient than potentiometric because the former can be made in a 3M phosphoric acid medium, whereas the latter is possible only in 12M phosphoric acid. The simultaneous differential photometric titration of iron(II) and vanadium(IV) is also possible. Conditions have been found for the photometric titration of cerium(III) and of cerium(III) plus iron(II). The titration is carried out (at 450 mmicro or with a blue filter) in about 10.5M phosphoric acid. Application of the method to a cerium mineral is considered.

  8. Contribution of meat to vitamin B₁₂, iron and zinc intakes in five ethnic groups in the USA: implications for developing food-based dietary guidelines.

    Science.gov (United States)

    Sharma, S; Sheehy, T; Kolonel, L N

    2013-04-01

    To describe the sources of meat and their contributions to vitamin B₁₂, iron and zinc in five ethnic groups in the USA. Dietary data for the Multiethnic Cohort, established in Hawaii and Los Angeles, were collected using a quantitative food frequency questionnaire from more than 215,000 subjects, aged 45-75 years at baseline (1993-1996). Participants included African American, Latino, Japanese American, Native Hawaiian and Caucasian men and women. Servings of meat items were calculated based on the US Department of Agriculture recommendations and their contributions to intakes of total meat, red meat, vitamin B₁₂, iron and zinc were determined. Of all types of meat, poultry contributed the most to meat consumption, followed by red meat and fish among all ethnicities, except for Latino (born in Mexico and Central/South America) men who consumed more beef. Lean beef was the most commonly consumed red meat for all ethnic-sex groups (9.3-14.3%), except for Native Hawaiian and Japanese American men, and Japanese American women whose top contributor was stew/curry with beef/lamb and stir-fried beef/pork with vegetables, respectively. The contribution of meat was most substantial for zinc (11.1-29.3%) and vitamin B₁₂ (19.7-40%) and, to a lesser extent, for iron (4.3-14.2%). This is the first large multiethnic cohort study to describe meat sources and their contributions to selected nutrients among ethnic minorities in the USA. These findings may be used to develop ethnic-specific recommendations for meat consumption aiming to improve dietary quality among these groups. © 2013 The Authors Journal of Human Nutrition and Dietetics © 2013 The British Dietetic Association Ltd.

  9. Efficient Separation and Extraction of Vanadium and Chromium in High Chromium Vanadium Slag by Selective Two-Stage Roasting-Leaching

    Science.gov (United States)

    Wen, Jing; Jiang, Tao; Xu, Yingzhe; Liu, Jiayi; Xue, Xiangxin

    2018-04-01

    Vanadium and chromium are important rare metals, leading to a focus on high chromium vanadium slag (HCVS) as a potential raw material to extract vanadium and chromium in China. In this work, a novel method based on selective two-stage roasting-leaching was proposed to separate and extract vanadium and chromium efficiently in HCVS. XRD, FT-IR, and SEM were utilized to analyze the phase evolutions and microstructure during the whole process. Calcification roasting, which can calcify vanadium selectively using thermodynamics, was carried out in the first roasting stage to transfer vanadium into acid-soluble vanadate and leave chromium in the leaching residue as (Fe0.6Cr0.4)2O3 after H2SO4 leaching. When HCVS and CaO were mixed in the molar ratio CaO/V2O3 (n(CaO)/n(V2O3)) of 0.5 to 1.25, around 90 pct vanadium and less than 1 pct chromium were extracted in the first leaching liquid, thus achieving the separation of vanadium and chromium. In the second roasting stage, sodium salt, which combines with chromium easily, was added to the first leaching residue to extract chromium and 95.16 pct chromium was extracted under the optimal conditions. The total vanadium and chromium leaching rates were above 95 pct, achieving the efficient separation and extraction of vanadium and chromium. The established method provides a new technique to separate vanadium and chromium during roasting rather than in the liquid form, which is useful for the comprehensive application of HCVS.

  10. Efficient Separation and Extraction of Vanadium and Chromium in High Chromium Vanadium Slag by Selective Two-Stage Roasting-Leaching

    Science.gov (United States)

    Wen, Jing; Jiang, Tao; Xu, Yingzhe; Liu, Jiayi; Xue, Xiangxin

    2018-06-01

    Vanadium and chromium are important rare metals, leading to a focus on high chromium vanadium slag (HCVS) as a potential raw material to extract vanadium and chromium in China. In this work, a novel method based on selective two-stage roasting-leaching was proposed to separate and extract vanadium and chromium efficiently in HCVS. XRD, FT-IR, and SEM were utilized to analyze the phase evolutions and microstructure during the whole process. Calcification roasting, which can calcify vanadium selectively using thermodynamics, was carried out in the first roasting stage to transfer vanadium into acid-soluble vanadate and leave chromium in the leaching residue as (Fe0.6Cr0.4)2O3 after H2SO4 leaching. When HCVS and CaO were mixed in the molar ratio CaO/V2O3 (n(CaO)/n(V2O3)) of 0.5 to 1.25, around 90 pct vanadium and less than 1 pct chromium were extracted in the first leaching liquid, thus achieving the separation of vanadium and chromium. In the second roasting stage, sodium salt, which combines with chromium easily, was added to the first leaching residue to extract chromium and 95.16 pct chromium was extracted under the optimal conditions. The total vanadium and chromium leaching rates were above 95 pct, achieving the efficient separation and extraction of vanadium and chromium. The established method provides a new technique to separate vanadium and chromium during roasting rather than in the liquid form, which is useful for the comprehensive application of HCVS.

  11. Zinc Deficiency in Humans and its Amelioration

    OpenAIRE

    Yashbir Singh Shivay

    2015-01-01

    Zinc (Zn) deficiency in humans has recently received considerable attention. Global mortality in children under 5 years of age in 2004 due to Zn deficiency was estimated at 4,53,207 as against 6,66,771 for vitamin A deficiency; 20,854 for iron deficiency and 3,619 for iodine deficiency. In humans 2800-3000 proteins contain Zn prosthetic group and Zn is an integral component of zinc finger prints that regulate DNA transcription. Zinc is a Type-2 nutrient, which means that its concentration in ...

  12. Monitoring of occupational exposure in manufacturing of stainless steel constructions. Part I: Chromium, iron, manganese, molybdenum, nickel and vanadium in the workplace air of stainless steel welders.

    Science.gov (United States)

    Kucera, J; Bencko, V; Pápayová, A; Saligová, D; Tejral, J; Borská, L

    2001-11-01

    Exposure to workplace airborne pollutants was examined in a group of 20 workers dealing mainly with welding, polishing, drilling and assembling of stainless steel constructions. Airborne particulate matter (APM) collected using both personal and stationary samplers was analyzed by instrumental neutron activation analysis (INAA). Quality assurance procedures of both sampling and analytical stages are described. Of the elements determined, results are presented for chromium, iron, manganese, molybdenum, nickel and vanadium. The median values of element concentrations exceeded the maximum admissible limits for workplace pollutants only for chromium, while for nickel the limit was exceeded in several individual cases. Sampling of hair, nails, blood, urine and saliva to be used for biological monitoring of the exposed and control groups is also described.

  13. Comparison of Ultrasound-Assisted and Regular Leaching of Vanadium and Chromium from Roasted High Chromium Vanadium Slag

    Science.gov (United States)

    Wen, Jing; Jiang, Tao; Gao, Huiyang; Liu, Yajing; Zheng, Xiaole; Xue, Xiangxin

    2018-02-01

    Ultrasound-assisted leaching (UAL) was used for vanadium and chromium leaching from roasted material obtained by the calcification roasting of high-chromium-vanadium slag. UAL was compared with regular leaching. The effect of the leaching time and temperature, acid concentration, and liquid-solid ratio on the vanadium and chromium leaching behaviors was investigated. The UAL mechanism was determined from particle-size-distribution and microstructure analyses. UAL decreased the reaction time and leaching temperature significantly. Furthermore, 96.67% vanadium and less than 1% chromium were leached at 60°C for 60 min with 20% H2SO4 at a liquid-solid ratio of 8, which was higher than the maximum vanadium leaching rate of 90.89% obtained using regular leaching at 80°C for 120 min. Ultrasonic waves broke and dispersed the solid sample because of ultrasonic cavitation, which increased the contact area of the roasted sample and the leaching medium, the solid-liquid mass transfer, and the vanadium leaching rate.

  14. The effects of a lipid‐based nutrient supplement and antiretroviral therapy in a randomized controlled trial on iron, copper, and zinc in milk from HIV‐infected Malawian mothers and associations with maternal and infant biomarkers

    Science.gov (United States)

    Shahab‐Ferdows, Setareh; Gertz, Erik; Flax, Valerie L.; Adair, Linda S.; Bentley, Margaret E.; Jamieson, Denise J.; Tegha, Gerald; Chasela, Charles S.; Kamwendo, Debbie; van der Horst, Charles M.; Allen, Lindsay H.

    2017-01-01

    Abstract We evaluated effects of antiretroviral (ARV) therapy and lipid‐based nutrient supplements (LNSs) on iron, copper, and zinc in milk of exclusively breastfeeding HIV‐infected Malawian mothers and their correlations with maternal and infant biomarkers. Human milk and blood at 2, 6, and 24 weeks post‐partum and blood during pregnancy (≤30 weeks gestation) were collected from 535 mothers/infant‐pairs in the Breastfeeding, Antiretrovirals, and Nutrition study. The participants received ARV, LNS, ARV and LNS, or no intervention from 0 to 28 weeks post‐partum. ARVs negatively affected copper and zinc milk concentrations, but only at 2 weeks, whereas LNS had no effect. Among all treatment groups, approximately 80–90% of copper and zinc and negatively correlated with milk iron at 2 and 6 weeks (r = −.18, p milk minerals with each other were the strongest correlations observed (r = .11–.47, p milk higher in iron when ferritin was higher or TfR lower. At 6 weeks, higher maternal α‐1‐acid glycoprotein and C‐reactive protein were associated with higher milk minerals in mildly anaemic women. Infant TfR was lower when milk mineral concentrations were higher at 6 weeks and when mothers were moderately anaemic during pregnancy. ARV affects copper and zinc milk concentrations in early lactation, and maternal haemoglobin during pregnancy and lactation could influence the association between milk minerals and maternal and infant iron status and biomarkers of inflammation. PMID:28851037

  15. Trimetallic oxide nanocomposites of transition metals titanium and vanadium by sol-gel technique: synthesis, characterization and electronic properties

    Science.gov (United States)

    Kumar, Amit; Mishra, Neeraj Kumar; Sachan, Komal; Ali, Md Asif; Soaham Gupta, Sachchidanand; Singh, Rajeev

    2018-04-01

    Novel titanium and vanadium based trimetallic oxide nanocomposites (TMONCs) have been synthesized using metal salts of titanium-vanadium along with three others metals viz. tin, aluminium and zinc as precursors by the sol-gel method. Aqueous ammonia and hydrazine hydrate were used as the reducing agents. The preparations of nanocomposites were monitored by observing the visual changes during each step of synthesis. The synthesized TMONCs were characterized using UV–vis, SEM, EDX, TEM and DLS. Band gap of the synthesized TMONCs ranges from 3–4.5 eV determined using tauc plot. FTIR study revealed the molecular stretching and bending peaks of corresponding M–O/M–O–M bonds thus confirming their formation. Molecular composition and particle size were determined using EDX and DLS respectively. Molecular shape, size and surface morphology have been examined by SEM and TEM.

  16. Fabrication of vanadium cans for neutron diffraction experiments

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Chin man; Baik, Sung Hoon; Park, Sun Kyu

    1999-12-01

    The laser weld technique of vanadium developed to experiment for neutron diffraction of HANARO. The demands for this laser welding technique were applied to process control in vanadium film welding and to fabricate various sizing vanadium cans. The vanadium can had a advantage to have less coherent in neutron. KAERI developed the fabrication jig of 6-12 mm diameter cans using 0.125 mm vanadium thin film, and investigated the laser welding procedure for making the various diameter and length of vanadium cans using the fabricated jigs and Nd:YAG laser. (author)

  17. Iron, zinc and selenium status of urban and rural populations in Pakistan, their bioavailability in the diet and their dietary interaction

    International Nuclear Information System (INIS)

    Manser, W.W.T.; Zaki Hasan, K.; Iliyas, M.; Zaidi, Z.

    1992-01-01

    In spite of the diversity of diet for rural and urban populations of Pakistan, anemias are very common. This paper contains a discussion of deficiencies of iron, zinc, selenium and magnesium in the population. Included are discussions on the bioavailability of these elements from the local diet, the various dietary interactions with other elements, and several methods used for identifying the trace element in blood samples from a test group. 28 refs, 7 tabs

  18. Physicochemical properties of vanadium impregnated Al-PILCs: Effect of vanadium source

    Energy Technology Data Exchange (ETDEWEB)

    Balci, Suna, E-mail: sunabalci@gazi.edu.tr; Tecimer, Aylin

    2015-03-01

    Graphical abstract: - Highlights: • Vanadium was incorporated into Al-PILC using NaVO{sub 3} or VOSO{sub 4}·3H{sub 2}O precursors by wet impregnation, washing after wet impregnation and impregnation from solution methods. • The layered structure of the supports was retained after the vanadium incorporation. • Incorporation took place both by settling and ion exchange mechanism with the treatment VOSO{sub 4}·3H{sub 2}O precursor while settling was dominant in the use of NaVO{sub 3} precursor. • Treatment with VOSO{sub 4}·3H{sub 2}O which was acidic in solution resulted in more structural deformation. • V{sub 2}O{sub 5} and VO{sub 2} were found as the major oxide forms on the impregnated samples. Loading of vanadyl sulfate hydrate (VOSO{sub 4}·H{sub 2}O) resulted in higher V/Si ratio. Most of the vanadium was bonded in +5 oxide form. • Changes in the FTIR signals after vanadium incorporation caused by Brønsted and Lewis sites, silanol, water and vanadium vibrations were occured. • Dehydroxylation of the structure took place around 300 °C. Samples obtained by impregnation and washing after wet impregnation methods resulted in similar mass losses and the wet impregnated sample showed the highest mass loss among the impregnated samples. - Summary: Clay from the Middle Anatolian previously pillared by Al{sub 13}-Keggin ions and then calcined at 300 °C (Al-PILC) was impregnated with aqueous solutions of vanadium precursors by impregnation from solution (I), wet impregnation (WI) and washing after wet impregnation (WWI) methods. The crystal and textural properties were evaluated by X-ray powder diffraction (XRD), nitrogen sorption and transmission electron microscopy (TEM) images. Vanadium incorporation into the Al-PILC resulted decreases in the basal spacing from 1.75 nm to 1.35 nm with the preserved typical layered structure. The use of sodium metavanadate (NaVO{sub 3}) as the source and the impregnation from solution as the incorporation method

  19. Bioleaching of vanadium from barren stone coal and its effect on the transition of vanadium speciation and mineral phase

    Science.gov (United States)

    Wang, Xin; Lin, Hai; Dong, Ying-bo; Li, Gan-yu

    2018-03-01

    This study determined the optimal conditions required to obtain maximum vanadium extraction and examined the transition of mineral phases and vanadium speciation during the bioleaching process. Parameters including the initial pH value, initial Fe2+ concentration, solid load, and inoculum quantity were examined. The results revealed that 48.92wt% of the vanadium was extracted through bioleaching under optimal conditions. Comparatively, the chemical leaching yield (H2SO4, pH 2.0) showed a slower and milder increase in vanadium yield. The vanadium bioleaching yield was 35.11wt% greater than the chemical leaching yield. The Community Bureau of Reference (BCR) sequential extraction results revealed that 88.62wt% of vanadium existed in the residual fraction. The bacteria substantially changed the distribution of the vanadium speciation during the leaching process, and the residual fraction decreased to 48.44wt%. The X-ray diffraction (XRD) and Fourier transform infrared (FTIR) results provided evidence that the crystal lattice structure of muscovite was destroyed by the bacteria.

  20. Leaching of vanadium from sulphuric acid manufacture spent catalysts

    Directory of Open Access Journals (Sweden)

    García, Diego Juan

    2001-02-01

    Full Text Available Recovery of vanadium contained in spent catalysts from the manufacture of sulphuric acid has been studied in this work, resulting in an industrial multistage process for the treatment of them avoiding direct deposition or dumping. Characterization of supplied spent catalysts samples, confirmed vanadium levels showed in the literature. The study of variables influencing leaching process: type of leaching agent, leaching agent concentration, S/L ratio, stirring speed and temperature, allows to fix the most advantageous conditions using industrial application criterion and verifying that the process is difusión controlled. The work is completed by developing an industrial leaching cycle simulation with the aim of reproducing real performance of spent catalyst, proposing operating conditions, and verifying the non-toxic character of the final residue obtained.

    En el presente trabajo se ha estudiado la recuperación del vanadio contenido en los catalizadores agotados procedentes de la fabricación del ácido sulfúrico, planteando un proceso industrial multietapa para el tratamiento de estos residuos, evitando su deposición o vertido directos. La caracterización de las muestras de catalizadores agotados disponibles confirmó los valores encontrados en la bibliografía. Se estudiaron las variables que influyen en el proceso de lixiviación (tipo de agente de lixiviación y concentración del mismo, relación S/L, velocidad de agitación y temperatura definiendo las condiciones más adecuadas desde el punto de vista industrial y verificando que el proceso está controlado por mecanismos difusionales. El trabajo se completa con la simulación de un ciclo industrial de lavado del catalizador y la verificación de la nula toxicidad de los lixiviados obtenidos por degradación del residuo final. 24 Aplicación de la resistencia de ruido al estudio de pinturas ricas en zinc Noise resistance applied to the study of zinc rich paints

  1. Recovery of vanadium oxide

    International Nuclear Information System (INIS)

    Bates, C.P.; Clark, N.E.

    1985-01-01

    This invention relates to the recovery of vanadium oxide from molten metal. The invention provides a method for recovering vanadium oxide from molten metal, which includes passing oxygen and at least one coolant gas or shroud into the molten metal by way of at least one elongate lance. The invention also provides an arrangement for the recovery of vanadium oxide from molten metal, which includes at least one elongate lance extending into the molten metal. The lance is provided with at least one elongate bore extending therethrough. Means are provided to allow at least oxygen and at least one coolant gas to pass through the lance and into the molten metal

  2. Nanosized zero-valent iron as Fenton-like reagent for ultrasonic-assisted leaching of zinc from blast furnace sludge

    Energy Technology Data Exchange (ETDEWEB)

    Mikhailov, Ivan, E-mail: ivan.mikhailov@misis.ru [National University of Science and Technology “MISiS”, 4 Leninskiy prospekt, Moscow, 119049 (Russian Federation); Komarov, Sergey [Tohoku University, 6-6-02 Aramaki Aza Aoba, Aoba-ku, Sendai, 980-8576 (Japan); Levina, Vera; Gusev, Alexander; Issi, Jean-Paul; Kuznetsov, Denis [National University of Science and Technology “MISiS”, 4 Leninskiy prospekt, Moscow, 119049 (Russian Federation)

    2017-01-05

    Highlights: • nZVI is used as Fenton-like reagent for activation of Zn leaching from the BFS. • nZVI has positive effect on kinetics of Zn leaching though with some loss of efficiency. • A complex ultrasonic-assisted method for BFS recycling is proposed. - Abstract: Ultrasonic-assisted sulphuric acid leaching combined with a Fenton-like process, utilizing nanoscale zero-valent iron (nZVI), was investigated to enhance the leaching of zinc from the blast furnace sludge (BFS). The leaching of iron (Fe) and zinc (Zn) from the sludge was investigated using Milli-Q water/BFS ratio of 10 and varying the concentration of hydrogen peroxide, sulphuric acid, the temperature, the input energy for ultrasound irradiation, and the presence or absence of nZVI as a Fenton reagent. The results showed that with 1 g/l addition of nZVI and 0.05 M of hydrogen peroxide, the kinetic rate of Zn leaching increased with a maximum dissolution degree of 80.2%, after 5 min treatment. In the absence of nZVI, the maximum dissolution degree of Zn was 99.2%, after 15 min treatment with 0.1 M of hydrogen peroxide. The rate of Zn leaching at several concentrations of hydrogen peroxide is accelerated in the presence of nZVI although a reduction in efficiency was observed. The loss of Fe was no more than 3%. On the basis of these results, the possible route for BFS recycling has been proposed (BFS slurry mixed with sulphuric acid and hydrogen peroxide is recirculated under ultrasonic irradiation then separated).

  3. Determination of Zinc Status in Humans: Which Indicator Should We Use?

    Directory of Open Access Journals (Sweden)

    Frank T. Wieringa

    2015-05-01

    Full Text Available Zinc deficiency has serious wide-ranging health consequences and is thought to be one of the most prevalent micronutrient deficiencies in the world. However, reliable indicators or biomarkers to assess zinc status are not available at present. Indirect indicators such as the prevalence of stunting or anemia, iron deficiency, as well as more direct indicators such as plasma zinc concentrations are being used at present to estimate the prevalence of zinc deficiency in populations. However, as this paper shows by using data from a recent national micronutrient survey in Vietnam, the estimates of the prevalence of zinc deficiency using these different indicators can vary widely, leading to inconsistencies. In this paper, zinc deficiency among children is four times more prevalent than iron deficiency and 2.3 times more than stunting prevalence for example. This can lead not only to confusion concerning the real extent of the prevalence of zinc deficiency in populations, but also makes it hard to inform policy on whether action is needed or not. Moreover, evaluation of programs is hampered by the lack of a clear indicator. Efforts should be made to identify the most suitable indicator to evaluate the impact of programs aimed at improving zinc status and health of populations.

  4. Contribution of meat to vitamin B-12, iron, and zinc intakes in five ethnic groups in the U.S.: Implications for developing food-based dietary guidelines

    Science.gov (United States)

    Sharma, Sangita; Sheehy, Tony; Kolonel, Laurence N

    2016-01-01

    Background To describe the sources of meat and their contributions to vitamin B-12, iron, and zinc in five ethnic groups in the USA. Methods Dietary data for the Multiethnic Cohort, established in Hawaii and Los Angeles, were collected using a quantitative food frequency questionnaire from more than 215,000 subjects aged 45–75 years at baseline (1993–1996). Participants included African American, Latino, Japanese American (JpAm), Native Hawaiian (NH) and Caucasian men and women. Servings of meat items were calculated based on the USDA recommendations and their contributions to intakes of total meat, red meat, vitamin B-12, iron, and zinc were determined. Results Of all types of meat, poultry contributed the most to meat consumption, followed by red meat and fish among all ethnicities, except for Latino (born in Mexico and Central/South America) men who consumed more beef. Lean beef was the most commonly consumed red meat for all ethnic-sex groups (9.3–14.3%), except for NH and JpAm men, and JpAm women whose top contributor was stew/curry with beef/lamb and stir-fried beef/pork with vegetables respectively. The contribution of meat was most substantial for zinc (11.1–29.3%) and vitamin B-12 (19.7–40%), and to a lesser extent for iron (4.3–14.2%). Conclusions This is the first large multiethnic cohort study to describe meat sources and their contributions to selected nutrients among ethnic minorities in the U.S. These findings may be used to develop ethnic-specific recommendations for meat consumption to improve dietary quality among these groups. PMID:23398393

  5. Determination of vanadium

    International Nuclear Information System (INIS)

    Stepin, V.V.; Kurbatova, V.I.; Fedorova, N.D.

    1980-01-01

    Titrimetric and potentiometric methods of vanadium determination in ferrovanadium are developed. The essence of the titrimetric method using phenylanthranilic acid as indicator is in the following. Ferrovanadium weighed amount is dissolved in H 2 SO 4 , vanadium is oxidated by potassium permanganate to V(5) and is titrated by a solution of double salt of sulfuric Fe(2) and ammonium in the presence of indicator. Potentiometric titration is carried out using the same indicator [ru

  6. Slag recycling of irradiated vanadium

    International Nuclear Information System (INIS)

    Gorman, P.K.

    1995-01-01

    An experimental inductoslag apparatus to recycle irradiated vanadium was fabricated and tested. An experimental electroslag apparatus was also used to test possible slags. The testing was carried out with slag materials that were fabricated along with impurity bearing vanadium samples. Results obtained include computer simulated thermochemical calculations and experimentally determined removal efficiencies of the transmutation impurities. Analyses of the samples before and after testing were carried out to determine if the slag did indeed remove the transmutation impurities from the irradiated vanadium

  7. Methods for making lithium vanadium oxide electrode materials

    Science.gov (United States)

    Schutts, Scott M.; Kinney, Robert J.

    2000-01-01

    A method of making vanadium oxide formulations is presented. In one method of preparing lithium vanadium oxide for use as an electrode material, the method involves: admixing a particulate form of a lithium compound and a particulate form of a vanadium compound; jet milling the particulate admixture of the lithium and vanadium compounds; and heating the jet milled particulate admixture at a temperature below the melting temperature of the admixture to form lithium vanadium oxide.

  8. Zinc therapy on children with Psoriasis modulates trace elements in serum and tissue

    International Nuclear Information System (INIS)

    El-Said, S. A.

    2013-01-01

    This study illustrates the effect of zinc therapy on some trace elements in either serum and skin which has been done on twenty patients with psoriasis with age range between 4 -13 years. They were under medical treatment with 5 milligram; oral zinc sulfate for 12 weeks. A significant increase in both serum and tissue copper and iron levels was detected by atomic absorption spectrophotometer . In addition, a significant decrease in both serum and tissue calcium and magnesium in psoriatic patients. It has been concluded that zinc therapy could be valuable through modulation of copper, calcium, iron and magnesium in psoriatic patients.

  9. Vanadium recycling for fusion reactors

    International Nuclear Information System (INIS)

    Dolan, T.J.; Butterworth, G.J.

    1994-04-01

    Very stringent purity specifications must be applied to low activation vanadium alloys, in order to meet recycling goals requiring low residual dose rates after 50--100 years. Methods of vanadium production and purification which might meet these limits are described. Following a suitable cooling period after their use, the vanadium alloy components can be melted in a controlled atmosphere to remove volatile radioisotopes. The aim of the melting and decontamination process will be the achievement of dose rates low enough for ''hands-on'' refabrication of new reactor components from the reclaimed metal. The processes required to permit hands-on recycling appear to be technically feasible, and demonstration experiments are recommended. Background information relevant to the use of vanadium alloys in fusion reactors, including health hazards, resources, and economics, is provided

  10. Vacancy distribution in nonstoichiometric vanadium monoxide

    International Nuclear Information System (INIS)

    Gusev, A.I.; Davydov, D.A.; Valeeva, A.A.

    2011-01-01

    Graphical abstract: Display Omitted Research highlights: → A certain fraction of vanadium atoms in disordered cubic vanadium monoxide VO y and ordered tetragonal phase V 52 O 64 is located in tetrahedral positions of a basic cubic lattice. → These positions are never occupied by any atoms in other strongly nonstoichiometric carbides, nitrides and oxides. → Both disordered and ordered structures of vanadium monoxide are characterized by the presence of short-range order of displacements in the oxygen sublattice and short-range order of substitution in the metal sublattice. → The short-range order of displacement is caused by the local displacements of O atoms from V (t) atoms occupying tetrahedral positions. The short-range order of substitution appears because V (t) atoms in the tetrahedral positions are always in the environment of four vacancies □ of the vanadium sublattice. - Abstract: Structural vacancy distribution in the crystal lattice of the tetragonal V 52 O 64 superstructure which is formed on the basis of disordered superstoichiometric cubic vanadium monoxide VO y ≡V x O z is experimentally determined and the presence of significant local atomic displacements and large local microstrains in a crystal lattice of real ordered phase is established. It is shown that the relaxation of local microstrains takes place owing to the basic disordered cubic phase grain refinement and a formation of ordered phase domains. The ordered phase domains grow in the direction from the boundaries to the centre of grains of the disordered basic cubic phase. Isothermal evolution at 970 K of the average domain size in ordered VO 1.29 vanadium monoxide is established. It is shown that the short-range order presents in a metal sublattice of disordered cubic VO y vanadium monoxide. The character of the short-range order is such that vanadium atoms occupying tetrahedral positions are in the environment of four vacant sites of the vanadium sublattice. This means that the

  11. Evaluation of iron, zinc, copper, manganese and selenium in oral hospital diets.

    Science.gov (United States)

    Moreira, Daniele C F; de Sá, Júlia S M; Cerqueira, Isabela B; Oliveira, Ana P F; Morgano, Marcelo A; Quintaes, Késia D

    2014-10-01

    Many trace elements are nutrients essential to humans, acting in the metabolism as constituents or as enzymatic co-factors. The iron, zinc, copper, manganese and selenium contents of hospital diets (regular, blend and soft) and of oral food complement (OFC) were determined, evaluating the adequacy of each element in relation to the nutritional recommendations (DRIs) and the percent contribution alone and with OFC. Duplicate samples were taken of six daily meals and of the OFC on two non-consecutive days from a hospital in Belo Horizonte (MG, Brazil) in May and September of 2010 and January of 2011. The elements were determined by ICP OES. Of the diets, the soft diet showed the highest elements content. Offering the OFC was insufficient to provide adequate levels of the trace elements. The oral hospital diets were inadequate in relation to the RDAs for the trace elements studied and the use of the OFCs was insufficient to compensate the values. Copyright © 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  12. Possible Cardiotoxic Effects of Vanadium

    Directory of Open Access Journals (Sweden)

    Parveen Parkash

    1990-12-01

    Full Text Available Vanadium, a ubiquitous element, is physiologically and pharmacologically an active substance and is present in most of mammalian tissues Jandhala and Horn, 1983. Large corpus of information exists on the mode of action of vanadium on cardiac muscles (Jandhala and Horn, 1983., Solaro et al, 1980, but the basis of pharma­cological lesion underlying its cardiac toxi­city is still poorly understood. Except for the solitary report of Lewis (1958 to best of our knowledge no information exists on the effect of vanadium on the functioning of heart as shown by electrocardiography.Large amounts of vanadium are relea­sed into atmosphere by combustion of fossil fuel (Vouk, 1979 and due to rapid indus­trialisation its environmental concentra­tion is reported to be increasing (Goldberg et al, 1974., Jaffe and Walters, 1977., Vouk, 1979. This necessitates the monitoring of its environmental and occupational hazards. In the present study cardiac side effects of vanadium, as revealed through ECG has been investigated in rabbits, since the electrocardiogram of rabbit resembles with of man in essential details (Weisborth et al, 1974.

  13. Thermophysical data of liquid vanadium

    International Nuclear Information System (INIS)

    Pottlacher, G.; Huepf, T.; Wilthan, B.; Cagran, C.

    2007-01-01

    Although vanadium is commonly used as an additive in the steel production, literature data for thermophysical properties of vanadium around the melting point are sparse and show, where available a variation over a wide range. This manifests especially in the melting temperature (variation of ±30 K), heat of fusion, or specific enthalpy. This recent work presents the results of thermophysical measurements on vanadium including normal spectral emissivity at 684.5 nm. The aim was to obtain another full dataset of properties (enthalpy, heat of fusion, electrical resistivity, thermal conductivity, emissivity) of liquid vanadium to either confirm existing recommendations for certain properties or presenting newer measurements for comparison leading towards such recommendations. Summarizing, the following results for thermophysical properties at the melting point have been obtained: radiance temperature at melting (650 nm) T r,m = 1993 K, melting temperature T m = 2199 K, normal spectral emissivity at melting (684.5 nm) ε = 0.353. An observed feature of all measured data and results is, that a much better agreement with literature references exists for the liquid phase than in the solid state, thus we have restricted the presentation to liquid vanadium

  14. Structure of Stenotrophomonas maltophilia FeoA complexed with zinc: a unique prokaryotic SH3-domain protein that possibly acts as a bacterial ferrous iron-transport activating factor

    International Nuclear Information System (INIS)

    Su, Yi-Che; Chin, Ko-Hsin; Hung, Hui-Chih; Shen, Gwan-Han; Wang, Andrew H.-J.; Chou, Shan-Ho

    2010-01-01

    The crystal structure of FeoA from Stenotrophomonas maltophilia has been determined to a resolution of 1.7 Å using an Se single-wavelength anomalous dispersion (Se-SAD) approach and revealed a unique dimer cross-linked by two zinc ions and six chloride ions. Iron is vital to the majority of prokaryotes, with ferrous iron believed to be the preferred form for iron uptake owing to its much better solubility. The major route for bacterial ferrous iron uptake is found to be via an Feo (ferrous iron-transport) system comprising the three proteins FeoA, FeoB and FeoC. Although the structure and function of FeoB have received much attention recently, the roles played by FeoA and FeoC have been little investigated to date. Here, the tertiary structure of FeoA from Stenotrophomonas maltophilia (Sm), a vital opportunistic pathogen in immunodepressed hosts, is reported. The crystal structure of SmFeoA has been determined to a resolution of 1.7 Å using an Se single-wavelength anomalous dispersion (Se-SAD) approach. Although SmFeoA bears low sequence identity to eukaryotic proteins, its structure is found to adopt a eukaryotic SH3-domain-like fold. It also bears weak similarity to the C-terminal SH3 domain of bacterial DtxR (diphtheria toxin regulator), with some unique characteristics. Intriguingly, SmFeoA is found to adopt a unique dimer cross-linked by two zinc ions and six anions (chloride ions). Since FeoB has been found to contain a G-protein-like domain with low GTPase activity, FeoA may interact with FeoB through the SH3–G-protein domain interaction to act as a ferrous iron-transport activating factor

  15. Determination of Zinc Status in Humans: Which Indicator Should We Use?

    OpenAIRE

    Wieringa, Frank T.; Dijkhuizen, Marjoleine A.; Fiorentino, Marion; Laillou, Arnauld; Berger, Jacques

    2015-01-01

    Zinc deficiency has serious wide-ranging health consequences and is thought to be one of the most prevalent micronutrient deficiencies in the world. However, reliable indicators or biomarkers to assess zinc status are not available at present. Indirect indicators such as the prevalence of stunting or anemia, iron deficiency, as well as more direct indicators such as plasma zinc concentrations are being used at present to estimate the prevalence of zinc deficiency in populations. However, as t...

  16. Vanadium alloys for structural applications in fusion systems: A review of vanadium alloy mechanical and physical properties

    Energy Technology Data Exchange (ETDEWEB)

    Loomis, B.A.; Smith, D.L.

    1991-12-16

    The current knowledge is reviewed on (1) the effects of neutron irradiation on tensile strength and ductility, ductile-brittle transition temperature, creep, fatigue, and swelling of vanadium-base alloys, (2) the compatibility of vanadium-base alloys with liquid lithium, water, and helium environments, and (3) the effects of hydrogen and helium on the physical and mechanical properties of vanadium alloys that are potential candidates for structural materials applications in fusion systems. Also, physical and mechanical properties issues are identified that have not been adequately investigated in order to qualify a vanadium-base alloy for the structural material in experimental fusion devices and/or in fusion reactors.

  17. Vanadium alloys for structural applications in fusion systems: A review of vanadium alloy mechanical and physical properties

    International Nuclear Information System (INIS)

    Loomis, B.A.; Smith, D.L.

    1991-01-01

    The current knowledge is reviewed on (1) the effects of neutron irradiation on tensile strength and ductility, ductile-brittle transition temperature, creep, fatigue, and swelling of vanadium-base alloys, (2) the compatibility of vanadium-base alloys with liquid lithium, water, and helium environments, and (3) the effects of hydrogen and helium on the physical and mechanical properties of vanadium alloys that are potential candidates for structural materials applications in fusion systems. Also, physical and mechanical properties issues are identified that have not been adequately investigated in order to qualify a vanadium-base alloy for the structural material in experimental fusion devices and/or in fusion reactors

  18. Vanadium bioavailability in soils amended with blast furnace slag

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Maja A., E-mail: maja.larsson@slu.se [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, 750 07 Uppsala (Sweden); Baken, Stijn, E-mail: stijn.baken@ees.kuleuven.be [Department of Earth and Environmental Sciences, Leuven University, Kasteelpark Arenberg 20 bus 2459, 3001 Leuven (Belgium); Smolders, Erik, E-mail: erik.smolders@ees.kuleuven.be [Department of Earth and Environmental Sciences, Leuven University, Kasteelpark Arenberg 20 bus 2459, 3001 Leuven (Belgium); Cubadda, Francesco, E-mail: francesco.cubadda@iss.it [Department of Food Safety and Veterinary Public Health, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161 (Italy); Gustafsson, Jon Petter, E-mail: jon-petter.gustafsson@slu.se [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, 750 07 Uppsala (Sweden); Division of Land and Water Resources Engineering, KTH Royal Institute of Technology, Brinellvägen 28, 100 44 Stockholm (Sweden)

    2015-10-15

    Blast furnace (BF) slags are commonly applied as soil amendments and in road fill material. In Sweden they are also naturally high in vanadium. The aim of this study was to assess the vanadium bioavailability in BF slags when applied to soil. Two soils were amended with up to 29% BF slag (containing 800 mg V kg{sup −1}) and equilibrated outdoors for 10 months before conducting a barley shoot growth assay. Additional soil samples were spiked with dissolved vanadate(V) for which assays were conducted two weeks (freshly spiked) and 10 months (aged) after spiking. The BF slag vanadium was dominated by vanadium(III) as shown by V K-edge XANES spectroscopy. In contrast, results obtained by HPLC-ICP-MS showed that vanadium(V), the most toxic vanadium species, was predominant in the soil solution. Barley shoot growth was not affected by the BF slag additions. This was likely due to limited dissolution of vanadium from the BF slag, preventing an increase of dissolved vanadium above toxic thresholds. The difference in vanadium bioavailability among treatments was explained by the vanadium concentration in the soil solution. It was concluded that the vanadium in BF slag is sparingly available. These findings should be of importance in environmental risk assessment.

  19. Leaching and recovery of zinc and copper from brass slag by sulfuric acid

    Directory of Open Access Journals (Sweden)

    I.M. Ahmed

    2016-09-01

    Full Text Available Leaching and recovery processes for zinc and copper from brass slag by sulfuric acid were carried out and iron and aluminum were also precipitated as hydroxides in addition to silica gel. The factors affecting the performance and efficiency of the leaching processsuch as agitation rate, leaching time, acid concentration and temperature were separately investigated. The results obtained revealed that zinc and copper are successfully recovered from these secondary resources, where the percent recovery amounts to 95% and 99% for zinc and copper, respectively. The experimental data of this leaching process were well interpreted with the shrinking core model under chemically controlled processes. The apparent activation energy for the leaching of zinc has been evaluated using the Arrhenius expression. Based on the experimental results, a separation method and a flow sheet were developed and tested to separate zinc, copper, iron, aluminum and silica gel from the brass slag.

  20. Spectrophotometric determination of zinc in impure solutions

    International Nuclear Information System (INIS)

    Rodriguez Hernandez, B.; Reyes Tamaral, A.

    1972-01-01

    A dithizone colorimetric method is described for determining zinc concentrations of 0.001 to 5 g/l in aqueous solutions from Rio Tinto Mines, containing copper, iron and other impurities. Citrate, cyanide and bis-2hydroxyethyl)-dithiocarbamate are added to the aqueous sample of masking several metals, and zinc is extracted at pH 5 with a solution of dithizone in carbon tetrachloride. Excess of dithizone is removed with sodium sulphide, and optical density of zinc dithionate in organic solution is measured at 5.35 nm. Calibration curves obey Beer's law up to 0.5 micro Zn/ml. (Author) 5 refs

  1. Determination of Leachable Vanadium (V) in Sediment

    African Journals Online (AJOL)

    NICO

    A method for speciation of vanadium in solid samples was developed for quantification of vanadium(+5) in solid samples of sediment Certified Reference Materials ... element in such environmental samples as soil, sediments and plants.3,4–5 Validation of the ... Sample Preparation for the Determination of. Vanadium(+5).

  2. Overexpression of ZmIRT1 and ZmZIP3 Enhances Iron and Zinc Accumulation in Transgenic Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Suzhen Li

    Full Text Available Iron and zinc are important micronutrients for both the growth and nutrient availability of crop plants, and their absorption is tightly controlled by a metal uptake system. Zinc-regulated transporters, iron-regulated transporter-like proteins (ZIP, is considered an essential metal transporter for the acquisition of Fe and Zn in graminaceous plants. Several ZIPs have been identified in maize, although their physiological function remains unclear. In this report, ZmIRT1 was shown to be specifically expressed in silk and embryo, whereas ZmZIP3 was a leaf-specific gene. Both ZmIRT1 and ZmZIP3 were shown to be localized to the plasma membrane and endoplasmic reticulum. In addition, transgenic Arabidopsis plants overexpressing ZmIRT1 or ZmZIP3 were generated, and the metal contents in various tissues of transgenic and wild-type plants were examined based on ICP-OES and Zinpyr-1 staining. The Fe and Zn concentration increased in roots and seeds of ZmIRT1-overexpressing plants, while the Fe content in shoots decreased. Overexpressing ZmZIP3 enhanced Zn accumulation in the roots of transgenic plants, while that in shoots was repressed. In addition, the transgenic plants showed altered tolerance to various Fe and Zn conditions compared with wild-type plants. Furthermore, the genes associated with metal uptake were stimulated in ZmIRT1 transgenic plants, while those involved in intra- and inter- cellular translocation were suppressed. In conclusion, ZmIRT1 and ZmZIP3 are functional metal transporters with different ion selectivities. Ectopic overexpression of ZmIRT1 may stimulate endogenous Fe uptake mechanisms, which may facilitate metal uptake and homeostasis. Our results increase our understanding of the functions of ZIP family transporters in maize.

  3. Synthesis and application of iron and zinc doped biochar for removal of p-nitrophenol in wastewater and assessment of the influence of co-existed Pb(II)

    International Nuclear Information System (INIS)

    Wang, Pei; Tang, Lin; Wei, Xue; Zeng, Guangming; Zhou, Yaoyu; Deng, Yaocheng; Wang, Jingjing; Xie, Zhihong; Fang, Wei

    2017-01-01

    Highlights: • Iron and zinc doped biochar was developed with larger specific surface area, new generated hydroxyl groups, and beneficial magnetism compared with pristine biochar. • Fe/Zn-biochar presented good performance both for PNP and Pb(II) adsorption as well as their simultaneous removal. • Mechanism of the enhanced adsorption for low concentrations of co-existing PNP and Pb(II) was proposed. - Abstract: The modification of biochar as a low-cost adsorbent is essential to improve its surface properties and shows great potential in water decontamination. The iron and zinc doped sawdust biochar (Fe/Zn-biochar) with large apparent surface area (518.54 m 2 /g) proposed in this work showed good performance for p-nitrophenol (PNP) removal compared with the pristine biochar (P-biochar), iron doped biochar (Fe-biochar) and zinc doped biochar (Zn-biochar) respectively. The batch experiments turned out that Fe/Zn-biochar exhibited larger PNP adsorption capacity under acidic pH solution, and the ionic strength had slightly negative impact on PNP adsorption. The adsorption kinetics and isotherms were discussed, and the experimental data fitted well the Pseudo-second-order equation and Langmuir model. The thermodynamic study indicated that the PNP adsorption was a spontaneous endothermic process. Furthermore, the simultaneous removal for PNP and Pb(II) by Fe/Zn-biochar was investigated. It implied that the adsorption of PNP and Pb(II) at their low concentration might be enhanced by the complexing-bridging mechanism of PNP and Pb(II) ascribing to the affinity between PNP and hydrophobic sites, in addition to the affinity between Pb(II) and oxygen-containing hydrophilic sites on Fe/Zn-biochar surface. However, the predominated competition between PNP and Pb(II) at their high concentrations with Fe/Zn-biochar suppressed their adsorption.

  4. Synthesis and application of iron and zinc doped biochar for removal of p-nitrophenol in wastewater and assessment of the influence of co-existed Pb(II)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Pei [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, Hunan (China); Tang, Lin, E-mail: tanglin@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, Hunan (China); Wei, Xue [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, Hunan (China); Zeng, Guangming, E-mail: zgming@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, Hunan (China); Zhou, Yaoyu [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, Hunan (China); College of Resources and Environment, Hunan Agricultural University, Changsha 410128 (China); Deng, Yaocheng; Wang, Jingjing; Xie, Zhihong; Fang, Wei [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, Hunan (China)

    2017-01-15

    Highlights: • Iron and zinc doped biochar was developed with larger specific surface area, new generated hydroxyl groups, and beneficial magnetism compared with pristine biochar. • Fe/Zn-biochar presented good performance both for PNP and Pb(II) adsorption as well as their simultaneous removal. • Mechanism of the enhanced adsorption for low concentrations of co-existing PNP and Pb(II) was proposed. - Abstract: The modification of biochar as a low-cost adsorbent is essential to improve its surface properties and shows great potential in water decontamination. The iron and zinc doped sawdust biochar (Fe/Zn-biochar) with large apparent surface area (518.54 m{sup 2}/g) proposed in this work showed good performance for p-nitrophenol (PNP) removal compared with the pristine biochar (P-biochar), iron doped biochar (Fe-biochar) and zinc doped biochar (Zn-biochar) respectively. The batch experiments turned out that Fe/Zn-biochar exhibited larger PNP adsorption capacity under acidic pH solution, and the ionic strength had slightly negative impact on PNP adsorption. The adsorption kinetics and isotherms were discussed, and the experimental data fitted well the Pseudo-second-order equation and Langmuir model. The thermodynamic study indicated that the PNP adsorption was a spontaneous endothermic process. Furthermore, the simultaneous removal for PNP and Pb(II) by Fe/Zn-biochar was investigated. It implied that the adsorption of PNP and Pb(II) at their low concentration might be enhanced by the complexing-bridging mechanism of PNP and Pb(II) ascribing to the affinity between PNP and hydrophobic sites, in addition to the affinity between Pb(II) and oxygen-containing hydrophilic sites on Fe/Zn-biochar surface. However, the predominated competition between PNP and Pb(II) at their high concentrations with Fe/Zn-biochar suppressed their adsorption.

  5. The role of phosphate additive in stabilization of sulphuric-acid-based vanadium(V) electrolyte for all-vanadium redox-flow batteries

    Science.gov (United States)

    Roznyatovskaya, Nataliya V.; Roznyatovsky, Vitaly A.; Höhne, Carl-Christoph; Fühl, Matthias; Gerber, Tobias; Küttinger, Michael; Noack, Jens; Fischer, Peter; Pinkwart, Karsten; Tübke, Jens

    2017-09-01

    Catholyte in all-vanadium redox-flow battery (VRFB) which consists of vanadium salts dissolved in sulphuric acid is known to be stabilized by phosphoric acid to slow down the thermal aging at temperatures higher than 40 °C. To reveal the role of phosphoric acid, the thermally-induced aggregation is investigated using variable-temperature 51V, 31P, 17O, 1H nuclear magnetic resonance (NMR) spectroscopy and dynamic light scattering (DLS). The results indicate that the thermal stabilization of vanadium(V) electrolyte is attained by the involvement of monomeric and dimeric vanadium(V) species in the reaction with phosphoric acid which is concurrent to the formation of neutral hydroxo-aqua vanadium(V) precipitation precursor. The dimers are stabilized by counter ions due to association reaction or if such stabilization is not possible, precipitation of vanadium pentoxide is favored. The evolution of particles size distributions at 50 °C in electrolyte samples containing 1.6 M vanadium and 4.0 M total sulphate and the pathways of precipitate formation are discussed. The optimal total phosphate concentration is found to be of 0.15 M. However, the induction time is assumed to be dependent not only on the total phosphate concentrations, but also on the ratio of total vanadium(V) to sulphate concentrations.

  6. Evaluation of the nanomechanical properties of vanadium and native oxide vanadium thin films prepared by RF magnetron sputtering

    International Nuclear Information System (INIS)

    Mamun, M.A.; Zhang, K.; Baumgart, H.; Elmustafa, A.A.

    2015-01-01

    Graphical abstract: - Highlights: • V films of 50, 75, 100 nm thickness were deposited on Si by RF magnetron sputtering. • We studied structural/mechanical properties by XRD, FE-SEM, AFM, and nanoindentation. • The hardness increased from 9.0 to 14.0 GPa for 100 to 50 nm. • The modulus showed no correlation with thickness or native oxide formation. • Native oxide formation resulted in grain enlargement and roughness reduction. - Abstract: Polycrystalline vanadium thin films of 50, 75, and 100 nm thickness were deposited by magnetron sputtering of a vanadium metal target of 2 inch diameter with 99.9% purity on native oxide covered Si substrates. One set of the fabricated samples were kept in moisture free environment and the other set was exposed to ambient air at room temperature for a long period of time that resulted in formation of native oxide prior to testing. The crystal structure and phase purity of the vanadium and the oxidized vanadium thin films were characterized by X-ray diffraction (XRD). The XRD results yield a preferential (1 1 0), and (2 0 0) orientation of the polycrystalline V films and (0 0 4) vanadium oxide (V 3 O 7 ). The vanadium films thickness were verified using field emission scanning electron microscopy and the films surface morphologies were inspected using atomic force microscopy (AFM). AFM images reveal surface roughness was observed to increase with increasing film thickness and also subsequent to oxidation at room temperature. The nanomechanical properties were measured by nanoindentation to evaluate the modulus and hardness of the vanadium and the oxidized vanadium thin films. The elastic modulus of the vanadium and the oxidized vanadium films was estimated as 150 GPa at 30% film thickness and the elastic modulus of the bulk vanadium target is estimated as 135 GPa. The measured hardness of the vanadium films at 30% film thickness varies between 9 and 14 GPa for the 100 and 50 nm films, respectively, exhibiting size effects

  7. Color and vanadium valency in V-doped ZrO2

    International Nuclear Information System (INIS)

    Ren, Feng; Ishida, Shingo; Takeuchi, Nobuyuki

    1993-01-01

    The distribution and chemical states of vanadium in V-doped ZrO 2 were studied to clarify the origin of the color of vanadium-zirconium yellow pigment in comparison with vanadium-tin yellow pigment. ESCA data and measurements of lattice constants of V-doped ZrO 2 revealed that vanadium was dissolved mainly as V 4+ substituting for Zr in ZrO 2 lattice, and its solubility limit was 0.5 wt% as V 2 O 5 . It was found that the yellow color of vanadium-zirconium yellow was produced predominantly by the dissolved vanadium and that the contribution of vanadium oxide on ZrO 2 grains to the yellow color was about 1.30 of that of the dissolved vanadium when compared on the basis of equimolar quantity of vanadium. Most of the undissolved vanadium oxide was in an amorphous or a poorly crystallized state

  8. Iron concentrations in breast milk and selected maternal factors of human milk bank donors.

    Science.gov (United States)

    Mello-Neto, Julio; Rondó, Patrícia H C; Morgano, Marcelo A; Oshiiwa, Marie; Santos, Mariana L; Oliveira, Julicristie M

    2010-05-01

    The aim of this study was to evaluate the relationship between iron concentration in mature breast milk and characteristics of 136 donors of a Brazilian milk bank. Iron, vitamin A, zinc, and copper concentrations were assessed in human milk and maternal blood. Data were collected on maternal anthropometrics, obstetric, socioeconomic, demographic, and lifestyle factors. Iron, zinc, and copper in milk and zinc and copper in blood were detected by spectrophotometry. Vitamin A in milk and blood was determined by high-performance liquid chromatography. Hemoglobin was measured by electronic counting and serum iron and ferritin by colorimetry and chemoluminescence, respectively. Transferrin and ceruloplasmin were determined by nephelometry. According to multivariate linear regression analysis, iron in milk was positively associated with vitamin A in milk and with smoking but negatively associated with timing of breast milk donation (P milk of Brazilian donors may be influenced by nutritional factors and smoking.

  9. Increased iron bioavailability from lactic-fermented vegetables is likely an effect of promoting the formation of ferric iron (Fe(3+)).

    Science.gov (United States)

    Scheers, Nathalie; Rossander-Hulthen, Lena; Torsdottir, Inga; Sandberg, Ann-Sofie

    2016-02-01

    Lactic fermentation of foods increases the availability of iron as shown in a number of studies throughout the years. Several explanations have been provided such as decreased content of inhibitory phytate, increased solubility of iron, and increased content of lactic acid in the fermented product. However, to our knowledge, there are no data to support that the bioavailability of iron is affected by lactic fermentation. The objective of the present study was to investigate whether the bioavailability of iron from a vegetable mix was affected by lactic fermentation and to propose a mechanism for such an event, by conducting human and cell (Caco-2, HepG2) studies and iron speciation measurements (voltammetry). We also investigated whether the absorption of zinc was affected by the lactic fermentation. In human subjects, we observed that lactic-fermented vegetables served with both a high-phytate and low-phytate meal increased the absorption of iron, but not zinc. In vitro digested fermented vegetables were able to provoke a greater hepcidin response per ng Fe than fresh vegetables, indicating that Fe in the fermented mixes was more bioavailable, independent on the soluble Fe content. We measured that hydrated Fe(3+) species were increased after the lactic fermentation, while there was no significant change in hydrated Fe(2+). Furthermore, lactate addition to Caco-2 cells did not affect ferritin formation in response to Fe nor did lactate affect the hepcidin response in the Caco-2/HepG2 cell system. The mechanism for the increased bioavailability of iron from lactic-fermented vegetables is likely an effect of the increase in ferric iron (Fe(3+)) species caused by the lactic fermentation. No effect on zinc bioavailability was observed.

  10. A new oxidimetric reagent: potassium dichromate in a strong phosphoric acid medium-VI Potentiometric titration of vanadium(III) alone and in mixture with vanadium(IV).

    Science.gov (United States)

    Rao, G G; Rao, P K

    1966-09-01

    Vanadium(III) can be titrated at room temperature with potassium dichromate in an 8-12M phosphoric acid medium. Two potential breaks are observed in 12M phosphoric add with 0.2N potassium dichromate, the first corresponding to the oxidation of vanadium(III) to vanadium(IV) and the second to the oxidation of vanadium(IV) to vanadium(V). In titrations with 0.05N dichromate only the first break in potential is clearly observed. The method has been extended to the titration of mixtures of vanadium(III) and vanadium(IV). Conditions have also been found for the visual titration of vanadium(III) using ferroln or barium diphenylamine sulphonate as indicator.

  11. A combined theoretical-experimental study of interactions between vanadium ions and Nafion membrane in all-vanadium redox flow batteries

    Science.gov (United States)

    Intan, Nadia N.; Klyukin, Konstantin; Zimudzi, Tawanda J.; Hickner, Michael A.; Alexandrov, Vitaly

    2018-01-01

    Vanadium redox flow batteries (VRFBs) are a promising solution for large-scale energy storage, but a number of problems still impede the deployment of long-lifetime VRFBs. One important aspect of efficient operation of VRFBs is understanding interactions between vanadium species and the membrane. Herein, we investigate the interactions between all four vanadium cations and Nafion membrane by a combination of infrared (IR) spectroscopy and density-functional-theory (DFT)-based static and molecular dynamics simulations. It is observed that vanadium species primarily lead to changes in the IR spectrum of Nafion in the SO3- spectral region which is attributed to the interaction between vanadium species and the SO3- exchange sites. DFT calculations of vanadium -Nafion complexes in the gas phase show that it is thermodynamically favorable for all vanadium cations to bind to SO3- via a contact pair mechanism. Car-Parrinello molecular dynamics-based metadynamics simulations of cation-Nafion systems in aqueous solution suggest that V2+ and V3+ species coordinate spontaneously to SO3-, which is not the case for VO2+ and VO2+ . The interaction behavior of the uncycled membrane determined in this study is used to explain the experimentally observed changes in the vibrational spectra, and is discussed in light of previous results on device-cycled membranes.

  12. Isotope-aided studies of the bioavailability of iron from Myanmar diets

    Energy Technology Data Exchange (ETDEWEB)

    Naing, Khin Maung [Department of Medical Research, Yangon (Myanmar). Nutrition Research Div.; Khin, Myo [Department of Medical Research, Yangon, (Myanmar). Nuclear Medicine Research Div.

    1994-12-31

    A study was conducted to determine the dietary intakes and serum levels of iron and zinc in twenty apparently healthy Myanmar adults (10 males and 10 females), using atomic absorption spetrophotometry. The mean iron intake of females was found to be lower than the FAO/WHO recommended allowance whereas for men it was found to be adequate. The mean serum iron concentration in females was found to be significantly lower than in males (p < 0.05). It was observed that zinc intakes of males was significantly higher than in females (p < 0.01) but there was no significant difference in serum zinc level between the two groups. Dietary zinc intakes of both groups were found to be low. There was a weak positive correlation between dietary intake and serum concentrations of these minerals. Laboratory scale production of iron-fortified salt containing 1 mg of Fe/g salt was conducted by mixing 5g of FeSO{sub 4{center_dot}}7H{sub 2}O, and 5g of sodium-hexa-metaphosphate thoroughly and then the mixture was again mixed with 1 kg of salt. This was done in July 1992. Stability of iron-fortified salt (i.e. change in colour of salt) as well as ferrous and ferric iron content of iron-fortified salt, were determined at monthly intervals. Iron-fortified salt was found to be stable up to the time of report writing, i.e. 3rd week of October, 1992. The ferrous iron content of salt was found to range between 0.95 to 0.98 mg Fe/g salt. Bioavailability studies of iron from two types of standard meals, one containing staple rice, 32 g of fish, water cress, watery fish paste and cucumber, and another containing boiled peas in place of fish, were conducted on two groups of male subjects using {sup 59}Fe as an extrinsic tag. Bioavailability studies of iron from the above two types of meals cooked with iron-fortified salt (1 mg/g salt) were also conducted on the same groups of subjects using {sup 59}Fe as an extrinsic tag. Reference dose absorption of iron will be conducted. This work is in progress.

  13. Biopharmaceutical characterisation of ciprofloxacin-metallic ion interactions: comparative study into the effect of aluminium, calcium, zinc and iron on drug solubility and dissolution.

    Science.gov (United States)

    Stojković, Aleksandra; Tajber, Lidia; Paluch, Krzysztof J; Djurić, Zorica; Parojčić, Jelena; Corrigan, Owen I

    2014-03-01

    Ciprofloxacin bioavailability may be reduced when ciprofloxacin is co-administered with metallic ion containing preparations. In our previous study, physicochemical interaction between ciprofloxacin and ferrous sulphate was successfully simulated in vitro. In the present work, comparative in vitro ciprofloxacin solubility and dissolution studies were performed in the reactive media containing aluminium hydroxide, calcium carbonate or zinc sulphate. Solid phases collected from the dissolution vessel with aluminium hydroxide, calcium carbonate and zinc sulphate were investigated for their properties. The results obtained indicate that different types of adducts may form and retard ciprofloxacin solubility and dissolution. In the case of aluminium, no phase changes were observed. The solid phase generated in the presence of calcium carbonate was identified as hydrated ciprofloxacin base. Similarly to iron, a new complex consistent with Zn(SO4)2(Cl)2(ciprofloxacin)2 × nH2O stoichiometry was generated in the presence of relatively high concentrations of ciprofloxacin hydrochloride and zinc sulphate, indicating that small volume dissolution experiments can be useful for biorelevant dissolution tests.

  14. Biopharmaceutical characterisation of ciprofloxacin-metallic ion interactions: Comparative study into the effect of aluminium, calcium, zinc and iron on drug solubility and dissolution

    Directory of Open Access Journals (Sweden)

    Stojković Aleksandra

    2014-03-01

    Full Text Available Ciprofloxacin bioavailability may be reduced when ciprofloxacin is co-administered with metallic ion containing preparations. In our previous study, physicochemical interaction between ciprofloxacin and ferrous sulphate was successfully simulated in vitro. In the present work, comparative in vitro ciprofloxacin solubility and dissolution studies were performed in the reactive media containing aluminium hydroxide, calcium carbonate or zinc sulphate. Solid phases collected from the dissolution vessel with aluminium hydroxide, calcium carbonate and zinc sulphate were investigated for their properties. The results obtained indicate that different types of adducts may form and retard ciprofloxacin solubility and dissolution. In the case of aluminium, no phase changes were observed. The solid phase generated in the presence of calcium carbonate was identified as hydrated ciprofloxacin base. Similarly to iron, a new complex consistent with Zn(SO42(Cl2(ciprofloxacin2 × nH2O stoichiometry was generated in the presence of relatively high concentrations of ciprofloxacin hydrochloride and zinc sulphate, indicating that small volume dissolution experiments can be useful for biorelevant dissolution tests.

  15. Vaporization study on vanadium monoxide and two-phase mixture of vanadium and vanadium monoxide by mass-spectrometric method

    International Nuclear Information System (INIS)

    Banchorndhevakul, W.; Matsui, Tsuneo; Naito, Keiji

    1986-01-01

    The vapor pressures over single phase vanadium monoxide VO 1.022 (s) and the two-phase mixture of vanadium metal (β phase) and vanadium monoxide were measured by mass-spectrometric method in the temperature range of 1,803 ∼ 1,990 and 1,703 ∼ 1,884 K, respectively. The main gas species over both systems were found to be VO(g) and V(g). The vapor pressure of VO(g) over the two-phase mixture of V(s) and VO(s) was a little lower than that over single phase VO(s). The vapor pressure of V(g) over the two-phase mixture was nearly equal to that over single phase. From the vapor pressure data, the enthalpies of vaporization, the enthalpies of formation for VO(g) and V(g) and the dissociation energy of VO(g) were determined. The oxygen partial pressure was calculated as a function of temperature from the vapor pressures of VO(g) and V(g), from which the partial molar enthalpies and entropies of oxygen in both systems were obtained. (author)

  16. Dietary Zinc Intake and Plasma Zinc Concentrations in Children with Short Stature and Failure to Thrive.

    Science.gov (United States)

    Yazbeck, Nadine; Hanna-Wakim, Rima; El Rafei, Rym; Barhoumi, Abir; Farra, Chantal; Daher, Rose T; Majdalani, Marianne

    2016-01-01

    The burden of zinc deficiency on children includes an increased incidence of diarrhea, failure to thrive (FTT) and short stature. The aim of this study was to assess whether children with FTT and/or short stature have lower dietary zinc intake and plasma zinc concentrations compared to controls. A case-control study conducted at the American University of Beirut Medical Center included 161 subjects from 1 to 10 years of age. Cases had a statistically significant lower energy intake (960.9 vs. 1,135.2 kcal for controls, p = 0.010), lower level of fat (30.3 vs. 36.5 g/day, p = 0.0043) and iron intake (7.4 vs. 9.1 mg/day, p = 0.034). There was no difference in zinc, copper, carbohydrate and protein intake between the 2 groups. The plasma zinc concentration did not differ between the cases and controls (97.4 vs. 98.2 μg/dl, p = 0.882). More cases had mild-to-moderate zinc deficiency when compared to controls with 10.3 vs. 3.6%, p = 0.095. Our study did not show statistically significant difference in dietary zinc intake and plasma zinc concentrations between children with FTT and/or short stature compared to healthy controls. A prospective study is planned to assess the effect of zinc supplementation on growth parameters in FTT children. © 2016 S. Karger AG, Basel.

  17. Effective Recovery of Vanadium from Oil Refinery Waste into Vanadium-Based Metal-Organic Frameworks.

    Science.gov (United States)

    Zhan, Guowu; Ng, Wei Cheng; Lin, Wenlin Yvonne; Koh, Shin Nuo; Wang, Chi-Hwa

    2018-03-06

    Carbon black waste, an oil refinery waste, contains a high concentration of vanadium(V) leftover from the processing of crude oil. For the sake of environmental sustainability, it is therefore of interest to recover the vanadium as useful products instead of disposing of it. In this work, V was recovered in the form of vanadium-based metal-organic frameworks (V-MOFs) via a novel pathway by using the leaching solution of carbon black waste instead of commercially available vanadium chemicals. Two different types of V-MOFs with high levels of crystallinity and phase purity were fabricated in very high yields (>98%) based on a coordination modulation method. The V-MOFs exhibited well-defined and controlled shapes such as nanofibers (length: > 10 μm) and nanorods (length: ∼270 nm). Furthermore, the V-MOFs showed high catalytic activities for the oxidation of benzyl alcohol to benzaldehyde, indicating the strong potential of the waste-derived V-MOFs in catalysis applications. Overall, our work offers a green synthesis pathway for the preparation of V-MOFs by using heavy metals of industrial waste as the metal source.

  18. Effect of substrate temperature on thermochromic vanadium dioxide thin films sputtered from vanadium target

    Science.gov (United States)

    Madiba, I. G.; Kotsedi, L.; Ngom, B. D.; Khanyile, B. S.; Maaza, M.

    2018-05-01

    Vanadium dioxide films have been known as the most promising thermochromic thin films for smart windows which self-control the solar radiation and heat transfer for energy saving, comfort in houses and automotives. Such an attractive technological application is due to the fact that vanadium dioxide crystals exhibit a fast semiconductor-to-metal phase transition at a transition temperature Tc of about 68 °C, together with sharp optical changes from high transmitive to high reflective coatings in the IR spectral region. The phase transition has been associated with the nature of the microstructure, stoichiometry and stresses related to the oxide. This study reports on the effect of the crystallographic quality controlled by the substrate temperature on the thermochromic properties of vanadium dioxide thin films synthesized by reactive radio frequency inverted cylindrical magnetron sputtering from vanadium target. The reports results are based on X-ray diffraction, Atomic force microscopy, and UV-Visible spectrophotometer. The average crystalline grain size of VO2 increases with the substrate temperature, inducing stress related phenomena within the films.

  19. Peculiarities of powder metallurgy of vanadium and its alloys

    International Nuclear Information System (INIS)

    Radomysel'skij, I.D.; Solntsev, V.P.; Evtushenko, O.V.

    1987-01-01

    Literature data on preparation of vanadium powder and powder materials on the vanadium base are generalized. Application of powder metallurgy engineering, allowing simulaneously to introduce practically any strengthening and solid-lubricating components as well as to alloy vanadium, permits undoubtedly to develop composite materials on the vanadium base

  20. Reaction between vanadium trichloride oxide and hydrogen sulfide

    International Nuclear Information System (INIS)

    Yajima, Akimasa; Matsuzaki, Ryoko; Saeki, Yuzo

    1978-01-01

    The details of the reaction between vanadium trichloride oxide and hydrogen sulfide were examined at 20 and 60 0 C. The main products by the reaction were vanadium dichloride oxide, sulfur, and hydrogen chloride. In addition to these products, small amounts of vanadium trichloride, vanadium tetrachloride, disulfur dichloride, and sulfur dioxide were formed. The formations of the above-mentioned reaction products can be explained as follows: The first stage is the reaction between vanadium trichloride oxide and hydrogen sulfide, 2VOCl 3 (l) + H 2 S(g)→2VOCl 2 (s) + S(s) + 2HCl(g). Then the resulting sulfur reacts with the unreacted vanadium trichloride oxide, 2VOCl 3 (l) + 2S(s)→2VOCl 2 (s) + S 2 Cl 2 (l). The resulting disulfur dichloride subsequently reacts with the unreacted vanadium trichloride oxide, 2VOCl 3 (l) + S 2 Cl 2 (l)→2VCl 4 (l) + S(s) + SO 2 (g). The resulting vanadium tetrachloride reacts with the sulfur formed during the reaction, 2VCl 4 (l) + 2S(s)→2VCl 3 (s) + S 2 Cl 2 (l), and also reacts with hydrogen sulfide, 2VCl 4 (l) + H 2 S(g)→2VCl 3 (s) + S(s) + 2HCl(g). (auth.)

  1. Boron solubility in Fe-Cr-B cast irons

    International Nuclear Information System (INIS)

    Guo Changqing; Kelly, P.M.

    2003-01-01

    Boron solubility in the as-cast and solution treated martensite of Fe-Cr-B cast irons, containing approximately 1.35 wt.% of boron, 12 wt.% of chromium, as well as other alloying elements, has been investigated using conventional microanalysis. The significant microstructural variations after tempering at 750 deg. C for 0.5-4 h, compared with the original as-cast and solution treated microstructures, indicated that the matrix consisted of boron and carbon supersaturated solid solutions. The boron solubility detected by electron microprobe was between 0.185-0.515 wt.% for the as-cast martensite and 0.015-0.0589 wt.% for the solution treated martensite, much higher than the accepted value of 0.005 wt.% in pure iron. These remarkable increases are thought to be associated with some metallic alloying element addition, such as chromium, vanadium and molybdenum, which have atomic diameters larger than iron, and expand the iron lattice to sufficiently allow boron atoms to occupy the interstitial sites in iron lattice

  2. Determination of vanadium in steel and geological samples by its extraction and spectrophotometric determination using 2,3-dihydroxynaphthalene

    International Nuclear Information System (INIS)

    Mondal, R.K.; Tarafder, P.K.; Rathore, D.P.S.

    2013-01-01

    A new and simple method for extraction and spectrophotometric determination of vanadium has been described. Iron has been removed from the sample solution by its prior extraction with MIBK from concentrated HCl medium (∼6 M). Vanadium has been determined in the form of a colored complex with 2,3-dihydroxynaphthalene after its extraction into MIBK. The method is at least 5 fold more sensitive to BPHA method. The molar absorptivity of the complex at 530 nm being 1.5 x 10 4 Lmol -1 cm -1 . For samples having >5 fold excess concentration of TiO 2 , a prior separation of TiO 2 as its (Ti (OH) (HND) 3 ) complex is a must. The method has been successfully applied to different rock, soil and steel samples. (author)

  3. Evaluation of High Temperature Particle Erosion Resistance of Vanadium-Boride Coating

    International Nuclear Information System (INIS)

    Lee, E. Y.; Kim, J. H.; Jeong, S. I.; Lee, S. H.; Eum, G. W.

    2015-01-01

    The components in ultra super critical (USC) steam turbine, which is under development for high efficient power generation, are encountering harsher solid particle erosion by iron oxide scales than ones in the existing steam turbines. Therefore, the currently used boride coating will not be able to hold effective protection from particle erosion in USC system and should be replaced by new particle erosion resistant coatings. One of the best protective coatings developed for USC steam turbine parts was found to be vanadium-boride (V-boride) coating which has a hardness of about 3000 HV, much higher than that of boride, 1600∼2000 HV. In order to evaluate particle erosion resistance of the various coatings such as V-boride, boride and Cr-carbide coatings at high temperature, particle erosion test equipment were designed and manufactured. In addition, erosion particle velocity was simulated using FLUENT software based on semi-implicity method for pressure linked equations revised (SIMPLER). Based on experimental results of this work, the vanadium-boride coating was found to be superior to others and to be a candidate coating to replace the boride coating

  4. Evaluation of High Temperature Particle Erosion Resistance of Vanadium-Boride Coating

    Energy Technology Data Exchange (ETDEWEB)

    Lee, E. Y.; Kim, J. H.; Jeong, S. I. [Andong National University, Andong (Korea, Republic of); Lee, S. H.; Eum, G. W. [Corporate R and D Institute Doosan Heavy Industries and Construction Co., Changwon (Korea, Republic of)

    2015-04-15

    The components in ultra super critical (USC) steam turbine, which is under development for high efficient power generation, are encountering harsher solid particle erosion by iron oxide scales than ones in the existing steam turbines. Therefore, the currently used boride coating will not be able to hold effective protection from particle erosion in USC system and should be replaced by new particle erosion resistant coatings. One of the best protective coatings developed for USC steam turbine parts was found to be vanadium-boride (V-boride) coating which has a hardness of about 3000 HV, much higher than that of boride, 1600∼2000 HV. In order to evaluate particle erosion resistance of the various coatings such as V-boride, boride and Cr-carbide coatings at high temperature, particle erosion test equipment were designed and manufactured. In addition, erosion particle velocity was simulated using FLUENT software based on semi-implicity method for pressure linked equations revised (SIMPLER). Based on experimental results of this work, the vanadium-boride coating was found to be superior to others and to be a candidate coating to replace the boride coating.

  5. Roasting and leaching behaviors of vanadium and chromium in calcification roasting-acid leaching of high-chromium vanadium slag

    Science.gov (United States)

    Wen, Jing; Jiang, Tao; Zhou, Mi; Gao, Hui-yang; Liu, Jia-yi; Xue, Xiang-xin

    2018-05-01

    Calcification roasting-acid leaching of high-chromium vanadium slag (HCVS) was conducted to elucidate the roasting and leaching behaviors of vanadium and chromium. The effects of the purity of CaO, molar ratio between CaO and V2O5 ( n(CaO)/ n(V2O5)), roasting temperature, holding time, and the heating rate used in the oxidation-calcification processes were investigated. The roasting process and mechanism were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetry-differential scanning calorimetry (TG-DSC). The results show that most of vanadium reacted with CaO to generate calcium vanadates and transferred into the leaching liquid, whereas almost all of the chromium remained in the leaching residue in the form of (Fe0.6Cr0.4)2O3. Variation trends of the vanadium and chromium leaching ratios were always opposite because of the competitive reactions of oxidation and calcification between vanadium and chromium with CaO. Moreover, CaO was more likely to combine with vanadium, as further confirmed by thermodynamic analysis. When the HCVS with CaO added in an n(CaO)/ n(V2O5) ratio of 0.5 was roasted in an air atmosphere at a heating rate of 10°C/min from room temperature to 950°C and maintained at this temperature for 60 min, the leaching ratios of vanadium and chromium reached 91.14% and 0.49%, respectively; thus, efficient extraction of vanadium from HCVS was achieved and the leaching residue could be used as a new raw material for the extraction of chromium. Furthermore, the oxidation and calcification reactions of the spinel phases occurred at 592 and 630°C for n(CaO)/ n(V2O5) ratios of 0.5 and 5, respectively.

  6. Local structure of vanadium in doped LiFePO4

    International Nuclear Information System (INIS)

    Zhao, Ting; Xu, Wei; Ye, Qing; Cheng, Jie; Zhao, Haifeng; Chu, Wangsheng; Wu, Ziyu; Univ. of Science and Technology of China, Hefei; Xia, Dingguo

    2010-01-01

    LiFePO 4 composites with 5 at.% vanadium doping are prepared by solid state reactions. X-ray absorption fine-structure spectroscopy is used as a novel technique to identify vanadium sites. Both experimental analyses and theoretical simulations show that vanadium does not enter into the LiFePO 4 crystal lattice. When the vanadium concentration is lower then 1 at.%, the dopant remains insoluble. Thus, a single-phase vanadium-doped LiFePO4 cannot be formed and the improved electrochemical properties of vanadium doped LiFePO 4 previously reported cannot be associated with crystal structure changes of the LiFePO 4 via vanadium doping. (orig.)

  7. Stress induced reorientation of vanadium hydride

    International Nuclear Information System (INIS)

    Beardsley, M.B.

    1977-10-01

    The critical stress for the reorientation of vanadium hydride was determined for the temperature range 180 0 to 280 0 K using flat tensile samples containing 50 to 500 ppM hydrogen by weight. The critical stress was observed to vary from a half to a third of the macroscopic yield stress of pure vanadium over the temperature range. The vanadium hydride could not be stress induced to precipitate above its stress-free precipitation temperature by uniaxial tensile stresses or triaxial tensile stresses induced by a notch

  8. Chemistry related to the procurement of vanadium alloys

    International Nuclear Information System (INIS)

    Smith, H.M.; Chung H.M.; Tsai, H.C.

    1997-01-01

    Evaluation of trace element concentrations in vanadium alloys is important to characterize the low-activation characteristics and possible effects of trace elements on the properties. Detailed chemical analysis of several vanadium and vanadium alloy heats procured for the Argonne vanadium alloy development program were analyzed by Johnson-Matthey (UK) as part of a joint activity to evaluate trace element effects on the performance characteristics. These heats were produced by normal production practices for high grade vanadium. The analyses include approximately 60 elements analyzed in most cases by glow-discharge mass spectrometry. Values for molybdenum and niobium, which are critical for low-activation alloys, ranged from 0.4 to 60 wppm for the nine heats

  9. Chemistry related to the procurement of vanadium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Smith, H.M.; Chung H.M.; Tsai, H.C. [Argonne National Lab., IL (United States)

    1997-08-01

    Evaluation of trace element concentrations in vanadium alloys is important to characterize the low-activation characteristics and possible effects of trace elements on the properties. Detailed chemical analysis of several vanadium and vanadium alloy heats procured for the Argonne vanadium alloy development program were analyzed by Johnson-Matthey (UK) as part of a joint activity to evaluate trace element effects on the performance characteristics. These heats were produced by normal production practices for high grade vanadium. The analyses include approximately 60 elements analyzed in most cases by glow-discharge mass spectrometry. Values for molybdenum and niobium, which are critical for low-activation alloys, ranged from 0.4 to 60 wppm for the nine heats.

  10. Exploring electrolyte preference of vanadium nitride supercapacitor electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bo; Chen, Zhaohui; Lu, Gang [Department of Electrical Engineering and Automation, Luoyang Institute of Science and Technology, Luoyang 471023 (China); Wang, Tianhu [School of Electrical Information and Engineering, Jiangsu University of Technology, Changzhou 213001 (China); Ge, Yunwang, E-mail: ywgelit@126.com [Department of Electrical Engineering and Automation, Luoyang Institute of Science and Technology, Luoyang 471023 (China)

    2016-04-15

    Highlights: • Hierarchical VN nanostructures were prepared on graphite foam. • Electrolyte preference of VN supercapacitor electrodes was explored. • VN showed better capacitive property in organic and alkaline electrolytes than LiCl. - Abstract: Vanadium nitride hierarchical nanostructures were prepared through an ammonia annealing procedure utilizing vanadium pentoxide nanostructures grown on graphite foam. The electrochemical properties of hierarchical vanadium nitride was tested in aqueous and organic electrolytes. As a result, the vanadium nitride showed better capacitive energy storage property in organic and alkaline electrolytes. This work provides insight into the charge storage process of vanadium nitride and our findings can shed light on other transition metal nitride-based electrochemical energy storage systems.

  11. The triad of Iron deficiency anemia, hepatosplenomegaly and ...

    African Journals Online (AJOL)

    A triad of iron deficiency anemia, hepatosplenomegaly and growth retardation occurring in tandem with zinc deficiency has been reported in the past as components of either Prasad's syndrome or hypopituitarism. There are no documented cases of such triad occurring in the presence of normal serum zinc levels. We report ...

  12. Large zinc cation occupancy of octahedral sites in mechanically activated zinc ferrite powders

    International Nuclear Information System (INIS)

    Oliver, S. A.; Harris, V. G.; Hamdeh, H. H.; Ho, J. C.

    2000-01-01

    The cation site occupancy of a mechanically activated nanocrystalline zinc ferrite powder was determined as (Zn 0.55 2+ Fe 0.18 3+ ) tet [Zr 0.45 2+ Fe 1.82 3+ ] oct O 4 through analysis of extended x-ray absorption fine structure measurements, showing a large redistribution of cations between sites compared to normal zinc ferrite samples. The overpopulation of cations in the octahedral sites was attributed to the ascendance in importance of the ionic radii over the crystal energy and bonding coordination in determining which interstitial sites are occupied in this structurally disordered powder. Slight changes are observed in the local atomic environment about the zinc cations, but not the iron cations, with respect to the spinel structure. The presence of Fe 3+ on both sites is consistent with the measured room temperature magnetic properties. (c) 2000 American Institute of Physics

  13. QUANTITATIVE CHANGES OF IRON, MANGANESE, ZINC AND COPPER IN PINE BARK COMPOSTED WITH PLANT MASS AND EFFECTIVE MICROORGANISMS

    Directory of Open Access Journals (Sweden)

    Jacek Czekała

    2014-10-01

    Full Text Available The objective of the investigation was to ascertain changes in the total contents, as well as water-soluble forms of iron, manganese, zinc and copper during the process of composting of pine bark with plant material (PM, with or without the addition of effective microorganisms (EM. Experiments were carried out at a forest nursery area and comprised the following treatments: pile 1. pine bark, pile 2. pine bark + PM, pile 3. pine bark + PM + EM. Compost piles were formed from pine bark (4 m3 and as described above, 2 Mg of plant material were added to pile 2 and to pile 3 – plant material and effective microorganisms in the amount of 3 dm3·m-3 bark. All compost files were also supplemented with 0.3 kg P2O5·m-3 (in the form of superphosphate 20% P2O5 and 0,1 kg K2O·m-3 (in the form of potassium salt 60%. The plant material comprised a mixture of buckwheat, field pea, serradella and vetch harvested before flowering. Piles were mixed and formed with the tractor aerator. At defined dates, using the method of atomic spectrophotometry, total contents of iron, manganese, zinc and copper, as well as their water-soluble forms were determined. It was found that all the examined elements underwent changes, albeit with different dynamics. This was particularly apparent in the case of water-soluble forms. This solubility was, in general, high during the initial days of the process and declined with the passage of time. No significant impact of effective microorganisms on the solubility of the examined chemical elements was determined, especially in mature composts.

  14. Complexation of vanadium with amidoxime and carboxyl groups. Uncovering the competitive role of vanadium in uranium extraction from seawater

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Cong-Zhi; Wu, Qun-Yan; Lan, Jian-Hui; Shi, Wei-Qun [Chinese Academy of Sciences, Beijing (China). Inst. of High Energy Physics; Chai, Zhi-Fang [Chinese Academy of Sciences, Beijing (China). Inst. of High Energy Physics; Soochow Univ., Suzhou (China). School of Radiological and Interdisciplinary Sciences (RAD-X); Wu, Guo-Zhong [Chinese Academy of Sciences, Shanghai (China). Shanghai Inst. of Applied Physics

    2017-09-01

    At present, amidoxime-based adsorbents are considered to be the most promising materials for extraction of uranium from seawater. However, the high concentrations of transition metals especially vanadium strongly compete with uranium in the sequestration process, which is extremely limited the commercial use of amidoxime-based adsorbents. In this work, the coordination modes, bonding nature, and stabilities of possible vanadium(IV) (VO{sup 2+}) and (V) (VO{sub 2}{sup +}, VO{sup 3+}, V{sup 5+}) complexes with amidoximate (AO{sup -}), carboxyl (Ac{sup -}), glutarimidedioximate (HA{sup -}) and deprotonated glutarimidedioximate (A{sup 2-}) on single and double alkyl chains (R=C{sub 13}H{sub 26}) are systematically explored by quantum chemical calculations. Different from the uranyl (UO{sub 2}{sup 2+}) complexes, the AO{sup -} groups of the vanadium(IV) and (V) complexes prefer to coordinate as monodentate and chelate ligands, while few species with AO{sup -} groups in η{sup 2}-binding mode have been observed in the vanadium complexes. Besides, the vanadium complexes are predicted to have obvious covalent metal-ligand bonds. According to thermodynamic stability analysis, all the vanadium complexes with AO{sup -}, Ac{sup -}, HA{sup -} and A{sup 2-} ligands on double alkyl chains are found to be more stable than corresponding complexes with ligands on a single chain. The synergistic effect of the amidoxime and carboxyl groups can be observed in most of VO{sub 2}{sup +} and VO{sup 3+} complexes with mixed ligands (AO{sup -}/Ac{sup -}). The vanadium(IV) and (V) complexes are more stable than the corresponding uranyl complexes, and the adsorption capability of the amidoxime-based adsorbents toward vanadium(V) ions decrease in the order of VO{sub 2}{sup +}>VO{sup 3+}> V{sup 5+}. The dioxovanadium cation VO{sub 2}{sup +} is predicted to form multinuclear vanadium complex in the sequestration process, possibly resulting in higher stable VO{sub 2}{sup +} complexes. Therefore

  15. Effects of Zinc and Ferritin Levels on Parent and Teacher Reported Symptom Scores in Attention Deficit Hyperactivity Disorder

    Science.gov (United States)

    Oner, Ozgur; Oner, Pinar; Bozkurt, Ozlem Hekim; Odabas, Elif; Keser, Nilufer; Karadag, Hasan; Kizilgun, Murat

    2010-01-01

    Objective: It has been suggested that both low iron and zinc levels might be associated with Attention Deficit Hyperactivity Disorder (ADHD) symptoms. However, the association of zinc and iron levels with ADHD symptoms has not been investigated at the same time in a single sample. Method: 118 subjects with ADHD (age = 7-14 years, mean = 9.8,…

  16. Aggregative stability of fungicidal nanomodifier based on zinc hydrosilicates

    Science.gov (United States)

    Grishina, Anna; Korolev, Evgeniy

    2018-03-01

    Currently, there is a strong need of high performance multi functional materials in high-rise construction. Obviously, such materials should be characterized by high strength; but for interior rooms biosafety is important as well. The promising direction to obtain both high strength and maintain biosafety in buildings and structures is to manage the structure of mineral binders by means of fungicidal nanomodifier based on zinc hydrosilicates. In the present work the aggregative stability of colloidal solutions of zinc hydrosilicates after one year of storage was studied. It has been established that the concentration of iron (III) hydroxide used to prepare the precursor of zinc hydrosilicates has a significant effect on the long-term aggregative stability: as the concentration of iron (III) hydroxide increases, the resistance of the fungicidal nanomodifier increases. It was found that, despite the minimal concentration of nano-sized zinc hydrosilicates (0.028%), the colloidal solution possesses a low long-term aggregative stability; while in the initial period (not less than 14 days) the colloidal solution of the nanomodifier is aggregatively stable. It is shown that when the ratio in the colloidal solution of the amount of the substance CH3COOH / SiO2 = 0.43 is reached, an increase in the polymerization rate is observed, which is the main cause of low aggregative stability. Colloidal solutions containing zinc hydrosilicates synthesized at a concentration of iron (III) hydroxide used to produce a precursor equal to 0.7% have a long-term aggregative stability and do not significantly change the reduced particle. Such compositions are to be expediently used for the nanomodifying of building composites in order to control their structure formation and to create conditions that impede the development of various mycelial fungi.

  17. Prevalence of vitamin a, zinc, iodine deficiency and anaemia among ...

    African Journals Online (AJOL)

    Children are the most nutritionally vulnerable group of society as children are dependants and they are also at a critical stage of the growing process. They need adequate vitamin A, zinc, iron and iodine for their development and school performance. Most often iron deficiency causes anaemia with resultant fatigue and low ...

  18. Niger Republic mineral planning : Part four Second volume : Main mineral substances specific study and their geological context

    International Nuclear Information System (INIS)

    Franconi, Antoine; Joo', Julien; Zibo, Idde

    1981-01-01

    This volume describes Niger Republic mineral substances capable of rising economic interest. After relating minerals occurrence , indices and deposits types, conclusions and recommendations have been made for mineral prospecting. Mineral substances described are : Copper, lead and zinc, molybdena, iron, manganese, titanium, vanadium, nickel and chrome ( cobalt and platinoid ), lithium, lignite, diamond and diverse substances rare earth, beryllium, silver, bismuth arsenic and antimony, barytine, alunite, talc and asbestos ( graphite and diatomite) [fr

  19. Composites having an intermetallic containing matrix

    International Nuclear Information System (INIS)

    Nagle, D.C.; Brupbacher, J.M.; Christodoulou, L.

    1990-01-01

    This paper describes a composite material. It comprises: a dispersion of in-situ precipitated second phase particles selected from the group consisting of borides, carbides, nitrides, and sulfides, in an intermetallic containing matrix selected from the group consisting of the aluminides, silicides, and beryllides of nickel, copper, titanium, cobalt, iron, platinum, gold, silver, niobium, tantalum, zinc, molybdenum, hafnium, tin, tungsten, lithium, magnesium, thorium, chromium, vanadium, zirconium, and manganese

  20. BWR fuel experience with zinc injection

    International Nuclear Information System (INIS)

    Levin, H.A.; Garcia, S.E.

    1995-01-01

    In 1982 a correlation between low primary recirculation system dose rates in BWR's and the presence of ionic zinc in reactor water was identified. The source of the zinc was primarily from Admiralty brass condensers. Plants with brass condensers are called ''natural zinc'' plants. Brass condensers were also a source of copper that was implicated in crude induced localized corrosion (CILC) fuel failures. In 1986 the first BWR intentionally injected zinc for the benefits of dose rate control. Although zinc alone was never implicated in fuel degradation of failures, a comprehensive fuel surveillance program was initiated to monitor fuel performance. Currently there are 14 plants that are injecting zinc. Six of these plants are also on hydrogen water chemistry. This paper describes the effect on both Zircaloy corrosion and the cruding characteristics as a result of these changes in water chemistry. Fuel rod corrosion was found to be independent of the specific water chemistry of the plants. The corrosion behavior was the same with the additions of zinc alone or zinc plus hydrogen and well within the operating experience for fuel without either of these additions. No change was observed in the amounts of crude deposited on the fuel rods, both for the adherent and loosely held deposits. One of the effects of the zinc addition was the trend to form more of the zinc rich iron spinel in the fuel deposits rather than the hematite deposits that are predominantly formed with non additive water chemistry

  1. Enrichment, Distribution of Vanadium-Containing Protein in Vanadium-Enriched Sea Cucumber Apostichopus japonicus and the Ameliorative Effect on Insulin Resistance.

    Science.gov (United States)

    Liu, Yanjun; Zhou, Qingxin; Zhao, Yanlei; Wang, Yiming; Wang, Yuming; Wang, Jingfeng; Xu, Jie; Xue, Changhu

    2016-05-01

    Sea cucumbers are a potential source of natural organic vanadium that may improve insulin resistance. In this work, vanadium was accumulated rapidly in blood, body wall, and intestine by sea cucumber Apostichopus japonicus. Furthermore, water-soluble vanadium-containing proteins, the main form of the organic vanadium, were tentatively accumulated and isolated by a bioaccumulation experiment. It was also designed to evaluate the beneficial effect of vanadium-containing proteins (VCPs) from sea cucumber rich in vanadium on the development of hyperglycemia and insulin resistance in C57BL/6J mice fed with a high-fat high-sucrose diet (HFSD). HFSD mice treated with VCPs significantly decreased fasting blood glucose, serum insulin, and HOMA-IR values as compared to HFSD mice, respectively. Serum adiponectin, resistin, TNF-α, and leptin levels in insulin-resistant mice were dramatically reduced by a VCP supplement. These results show an ameliorative effect on insulin resistance by treatment with VCPs. Such compound seems to be a valuable therapy to achieve and/or maintain glycemic control and therapeutic agents in the treatment arsenal for insulin resistance and type 2 diabetes.

  2. Anti frictional materials iron-pig iron-brass manufacture using shaving waste products of pig-iron

    International Nuclear Information System (INIS)

    Nasamov, S. N.; Krivij, N.; Gudenau, H. W.; Babich, A. I.; Garcia, L. L.; Formoso, A.; Cores, A.

    2003-01-01

    Parts based on iron and steel powders are widely used in the manufacture of automobile and domestic equipment. This work was done to study the anti-friction properties of iron-pig iron-brass compositions of materials which were obtained by pressing and sintering from a mix of iron powders and industrial by products of cast-iron turnings, brass, talc and technical sulphur. Experiments were performed using cold pressure technology in the flowing matrix of the powder composite without solid lubricants. The subsequent sintering was carried out at 1200 degree centigree under isothermal conditions in a nitrogen atmosphere in the sintering zone during 1 h. The physical-mechanical and anti-friction properties were almost double by the active drainage of the gases from the compression mould. The study of the microstructure of the sintered materials showed that free cementite existed between the particle limits and around the pores. large agglomerations of dark inclusions could be observed, consisting of graphite, zinc and iron oxides, which were points of tension in the materials that reduce its durability and, therefore, its wear resistance to dry friction. (Author) 34 refs

  3. Vanadium and affective disorders

    International Nuclear Information System (INIS)

    Naylor, G.J.

    1985-01-01

    The oxidation reduction state of vanadium will influence its inhibitory effect, and it has been suggested that the control of this oxidation reduction could be a physiological means of controlling Na-K ATPase and hence membrane transport. However, there is no general agreement on this. For such a hypothesis to be true, tissue concentrations of vanadium would need to be sufficient to cause inhibition of Na-K ATPase. There has been considerable variation in the concentration of vanadium reported to be present in human blood and plasma - e.g., 8.4 μmoleliter, 0.11 μmoleliter, 0.04 μmoleliter and 0.0006-0.018 μmliter. Methods of assay have varied, even including enzymic methods, but the two major methods now used are neutron activation analysis and atomic absorption spectrophotometry using an electrical flameless atomizer. Using neutron activation analysis, difficulties arise from the short half-ife of V 52 (3.76 min) and for the need to separate Na 24 and Cl 36 from the sample since their radiation interfere with those from V 52 . Results from preirradiation separation agree well with those from atomic absorption spectrophotometry, but those from postirradiation separation are usually much lower. Though there is no agreement on the physiological role of vanadium there is evidence that it plays a part in the etiology of manic-depressive psychosis

  4. Niger Republic mineral planning : Part four Second volume : Main mineral substances specific study and their geological context; Plan mineral de la Republique du Niger : Tome IV : 2e Volume : Etude specifique des principales substances minerales et leur contexte geologique

    Energy Technology Data Exchange (ETDEWEB)

    Franconi, Antoine; Joo' , Julien; Zibo, Idde

    1981-07-01

    This volume describes Niger Republic mineral substances capable of rising economic interest. After relating minerals occurrence , indices and deposits types, conclusions and recommendations have been made for mineral prospecting. Mineral substances described are : Copper, lead and zinc, molybdena, iron, manganese, titanium, vanadium, nickel and chrome ( cobalt and platinoid ), lithium, lignite, diamond and diverse substances rare earth, beryllium, silver, bismuth arsenic and antimony, barytine, alunite, talc and asbestos ( graphite and diatomite) [French] Ce volume decrit les substances susceptibles de presenter un interet economique au Niger. Apres avoir relate leurs occurrences , indices et types de gisement auxquels elles appartiennent des conclusions et recommendations ont ete faites pour la prospection. Les substances ainsi decrites sont : le cuivre, le plomb et le zinc, le molybdene, le fer, le manganese, le titane et le vanadium, le nickel et le chrome (Cobalt et platinoides), le lithium, le lignite, le diamant et les substances diverses ( terres rares, beryllium), argent, bismuth, arsenic et antimoine, barytine, alunite, talc et amiante (graphite et diatomite)

  5. Spectrophotometric determination of zinc in impure solutions; Determinacion Espectrofotometrica de Zinc en muestras de rio-Tinto prvia estracciond el Ditizonato con Tetracloruro

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Hernandez, B; Reyes Tamaral, A

    1972-07-01

    A dithizone colorimetric method is described for determining zinc concentrations of 0.001 to 5 g/l in aqueous solutions from Rio Tinto Mines, containing copper, iron and other impurities. Citrate, cyanide and bis-(2hydroxyethyl)-dithiocarbamate are added to the aqueous sample of masking several metals, and zinc is extracted at pH 5 with a solution of dithizone in carbon tetrachloride. Excess of dithizone is removed with sodium sulphide, and optical density of zinc dithionate in organic solution is measured at 5.35 nm. Calibration curves obey Beer's law up to 0.5 micro Zn/ml. (Author) 5 refs.

  6. Spectrophotometric determination of zinc in impure solutions; Determinacion Espectrofotometrica de Zinc en muestras de rio-Tinto prvia estracciond el Ditizonato con Tetracloruro

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Hernandez, B.; Reyes Tamaral, A.

    1972-07-01

    A dithizone colorimetric method is described for determining zinc concentrations of 0.001 to 5 g/l in aqueous solutions from Rio Tinto Mines, containing copper, iron and other impurities. Citrate, cyanide and bis-(2hydroxyethyl)-dithiocarbamate are added to the aqueous sample of masking several metals, and zinc is extracted at pH 5 with a solution of dithizone in carbon tetrachloride. Excess of dithizone is removed with sodium sulphide, and optical density of zinc dithionate in organic solution is measured at 5.35 nm. Calibration curves obey Beer's law up to 0.5 micro Zn/ml. (Author) 5 refs.

  7. Determination of vanadium (4) and (5) in the presence of both

    International Nuclear Information System (INIS)

    Malyuta, V.F.; Solomatin, V.T.; Berezhnoj, A.I.

    1983-01-01

    A study was made on the possibility of vanadium (4) and (5) determination in the presence of both by titration with ferrocene in aqueous solutions. 5-6 M H 2 SO 4 is the optimal medium for vanadium (5) titration. Vanadium (4) is titrated in the mixture of 2-2.5 M H 2 SO 4 and 8-10 M H 3 PO 4 . The method for vanadium (4) and (5) determination in vanadium catalysts was developed. Vanadium (5) is titrated amperometrically or potentiometrically by propanol solution of ferrocence in H 2 SO 4 . Concentrated H 3 PO 4 is added and the summary vanadium (4) is titrated. The relative standard deviations for 0.04-2% vanadium (4) content and 0.3-4% vanadium (5) content equal 0.06-0.03 and 0.05-0.02, respectively

  8. Clean hydrometallurgical route to recover zinc, silver, lead, copper, cadmium and iron from hazardous jarosite residues produced during zinc hydrometallurgy

    International Nuclear Information System (INIS)

    Ju Shaohua; Zhang Yifei; Zhang Yi; Xue Peiyi; Wang Yihui

    2011-01-01

    Highlights: → The extraction fractions of various valuable metals during NH 4 Cl leaching are very high. The sintered residue was leached in 6 mol L -1 aqueous NH 4 Cl solution at 105 o C, followed by filtration. The leaching extraction of Zn, Pb, Cu, Cd and Ag are more than 95%. → The process can detoxified the hazardous elements such as Pb, As, Cd thoroughly. Then the NH 4 Cl leaching residue were leached again in 30 wt% aqueous NaOH solution for 1 h at 160 o C, and about 94% of As and 73% of Si were removed from the residue. → The final residue contains about 55 wt% Fe, and have the potential to be used as iron concentrate. - Abstract: A hydrometallurgical process for treating the hazardous jarosite residue from zinc hydrometallurgy was proposed, for not only detoxifying the residue, but also recovering the contained valuable metal components. The jarosite was initially activated and decomposed by sintering at 650 o C for 1 h. The sintered residue was leached in 6 mol L -1 aqueous NH 4 Cl solution at 105 o C, followed by filtration. The leaching extraction of Zn, Pb, Cu, Cd and Ag are more than 95%. During reduction with Zn powder, more than 93% of Pb, Cu, Ag and Cd can be simultaneously recovered. Then the NH 4 Cl leaching residue were leached again in 30 wt% aqueous NaOH solution for 1 h at 160 o C, and about 94% of As and 73% of Si were removed from the residue. The final residue was almost completely detoxified, and contains about 55 wt% Fe, which can be used as an iron concentration.

  9. Repletion of Zinc and Iron Deficiencies Improve Cognition of Premenopausal Women

    Science.gov (United States)

    1998-10-01

    Altshuler H. Neonatal and maternal hair zinc levels in a nonhuman primate model of the fetal alcohol syndrome. Alcoholism: Clinical and Research...Coupled Plasma-Mass bpectroscopy ( rCP -MS). Before ICP-MS analysis A sets of plasma were digested with hydrogen peroxide and the zinc extracted, and 10

  10. Transformation and precipitation in vanadium treated steels

    Science.gov (United States)

    Vassiliou, Andreas D.

    A series of carbon manganese steels containing varying amounts of carbon, vanadium and nitrogen was investigated in relation to the solubility of VC and VN in austenite, the grain coarsening characteristics of austenite, the tempering of martensite and other structures, the transformation during continuous cooling, the effect of vanadium addition and increasing nitrogen content on the thermo-mechanical processing of austenite, and the transformation of various morphologies of austenite to ferrite.The sites for preferential nucleation and growth of ferrite were identified and the effect of ferrite grain size inhomogeneity was investigated with a view to minimising it.The C/N ratio in the V(CN) precipitates was largely controlled by C/N ratio in the steel and it was also influenced by the austenitising treatment. As expected, the solubility of VN was less than that of VC.A systematic investigation of austenitising time and temperature on the grain coarsening characteristics was carried out showing the effects of vanadium, carbon and nitrogen. It was tentatively suggested that C-C and N-N clustering in the vanadium free steels controlled the grain growth whereas in the presence of vanadium, it was shown that VN and VC pinned the austenite grain boundaries and restricted grain growth. However coarsening or solution of VC and VN allowed the grain bondaries to migrate and grain coarsening occurred. The grain coarsening temperature was controlled predominantly by VN, whilst the VC dissolved frequently below the grain coarsening temperature.In the as quenched martensite, increasing nitrogen progressively increased the as quenched hardness, and the hardness also greatly increased with increasing carbon and vanadium added together. Examining the precipitation strengthening in tempered martensite showed that in the absence of vanadium, martensite softened progressively with increasing temperature and time. Vanadium additions increased the hardness level during low temperature

  11. Large zinc cation occupancy of octahedral sites in mechanically activated zinc ferrite powders

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, S. A. [Center for Electromagnetic Research, Northeastern University, Boston, Massachusetts 02115 (United States); Harris, V. G. [Complex Materials Section, Code 6342, Naval Research Laboratory, Washington, DC 20375 (United States); Hamdeh, H. H. [Department of Physics, Wichita State University, Wichita, Kansas 67260 (United States); Ho, J. C. [Department of Physics, Wichita State University, Wichita, Kansas 67260 (United States)

    2000-05-08

    The cation site occupancy of a mechanically activated nanocrystalline zinc ferrite powder was determined as (Zn{sub 0.55}{sup 2+}Fe{sub 0.18}{sup 3+}){sub tet}[Zr{sub 0.45}{sup 2+}Fe{sub 1.82}{sup 3+}]{sub oct}O{sub 4} through analysis of extended x-ray absorption fine structure measurements, showing a large redistribution of cations between sites compared to normal zinc ferrite samples. The overpopulation of cations in the octahedral sites was attributed to the ascendance in importance of the ionic radii over the crystal energy and bonding coordination in determining which interstitial sites are occupied in this structurally disordered powder. Slight changes are observed in the local atomic environment about the zinc cations, but not the iron cations, with respect to the spinel structure. The presence of Fe{sup 3+} on both sites is consistent with the measured room temperature magnetic properties. (c) 2000 American Institute of Physics.

  12. Phonon dispersion in vanadium

    International Nuclear Information System (INIS)

    Ivanov, A.S.; Rumiantsev, A.Yu.

    1999-01-01

    Complete text of publication follows. Phonon dispersion curves in Vanadium metal are investigated by neutron inelastic scattering using three-axis spectrometers. Due to extremely low coherent scattering amplitude of neutrons in natural isotope mixture of vanadium the phonon frequencies could be determined in the energy range below about 15 meV. Several phonon groups were measured with the polarised neutron scattering set-up. It is demonstrated that the intensity of coherent inelastic scattering observed in the non-spin-flip channel vanishes in the spin-flip channel. The phonon density of states is measured on a single crystal keeping the momentum transfer equal to a vector of reciprocal lattice where the coherent inelastic scattering is suppressed. Phonon dispersion curves in vanadium, as measured by neutron and earlier by X-ray scattering, are described in frames of a charge-fluctuation model involving monopolar and dipolar degrees of freedom. The model parameters are compared for different transition metals with body-centred cubic-structure. (author)

  13. Low activation vanadium alloys

    International Nuclear Information System (INIS)

    Witzenburg, W. van.

    1991-01-01

    The properties and general characteristics of vanadium-base alloys are reviewed in terms of the materials requirements for fusion reactor first wall and blanket structures. In this review attention is focussed on radiation response including induced radioactivity, mechanical properties, compatibility with potential coolants, physical and thermal properties, fabricability and resources. Where possible, properties are compared to those of other leading candidate structural materials, e.g. austenitic and ferritic/martensitic steels. Vanadium alloys appear to offer advantages in the areas of long-term activation, mechanical properties at temperatures above 600 deg C, radiation resistance and thermo-hydraulic design, due to superior physical and thermal properties. They also have a potential for higher temperature operation in liquid lithium systems. Disadvantages are associated with their ability to retain high concentrations of hydrogen isotopes, higher cost, more difficult fabrication and welding. A particular concern regarding use of vanadium alloys relates their reactivity with non-metallic elements, such as oxygen and nitrogen. (author). 33 refs.; 2 figs.; 2 tabs

  14. Coprecipitation synthesis of zinc ferrit (FE 2 O 3 /ZNO) nanoparticles ...

    African Journals Online (AJOL)

    Zinc ferrite (Fe2O3/ZnO) nanocomposites were successfully synthesized by simple co-precipitation method via iron (III) nitrate 9-hydrate (Fe(NO3)3.9H2O) and zinc nitrate hexahydrate (Zn(NO3)2.6H2O) as precursor in the presence of cetyltrimethylammonium bromide (CTAB) surfactant. The samples were characterized by ...

  15. Determination of 18 kinds of trace impurities in the vanadium battery grade vanadyl sulfate by ICP-OES

    Science.gov (United States)

    Yong, Cheng

    2018-03-01

    The method that direct determination of 18 kinds of trace impurities in the vanadium battery grade vanadyl sulfate by inductively coupled plasma atomic emission spectrometry (ICP-OES) was established, and the detection range includes 0.001% ∼ 0.100% of Fe, Cr, Ni, Cu, Mn, Mo, Pb, As, Co, P, Ti, Zn and 0.005% ∼ 0.100% of K, Na, Ca, Mg, Si, Al. That the influence of the matrix effects, spectral interferences and background continuum superposition in the high concentrations of vanadium ions and sulfate coexistence system had been studied, and then the following conclusions were obtained: the sulfate at this concentration had no effect on the determination, but the matrix effects or continuous background superposition which were generated by high concentration of vanadium ions had negative interference on the determination of potassium and sodium, and it produced a positive interference on the determination of the iron and other impurity elements, so that the impacts of high vanadium matrix were eliminated by the matrix matching and combining synchronous background correction measures. Through the spectral interference test, the paper classification summarized the spectral interferences of vanadium matrix and between the impurity elements, and the analytical lines, the background correction regions and working parameters of the spectrometer were all optimized. The technical performance index of the analysis method is that the background equivalent concentration -0.0003%(Na)~0.0004%(Cu), the detection limit of the element is 0.0001%∼ 0.0003%, RSD<10% when the element content is in the range from 0.001% to 0.007%, RSD< 20% even if the element content is in the range from 0.0001% to 0.001% that is beyond the scope of the method of detection, recoveries is 91.0% ∼ 110.0%.

  16. Pepspectives of chlorine application in metallurgy of vanadium

    International Nuclear Information System (INIS)

    Korshunov, B.G.; Kutsenko, S.A.

    1983-01-01

    The most expedient variants of reprocessing of vanadium technical oxide (5), ferrovanadium and converter slags by chlorine technology with production of pure metal are considered. It is shown that production of vanadium by the way of electro- or metallothermal reduction of chlorides provides more plastic metal in comparison with reduction from oxides. The methods of production of VOCl 3 , VCl 4 and vanadium lowest chlorides are considered. Necessity of expansion of production of vanadium chlorine derivatives is dictated as well by their increasing application in different areas of national economy, in particular, as catalysts in organic synthesis

  17. Aqueous vanadium ion dynamics relevant to bioinorganic chemistry: A review.

    Science.gov (United States)

    Kustin, Kenneth

    2015-06-01

    Aqueous solutions of the four highest vanadium oxidation states exhibit four diverse colors, which only hint at the diverse reactions that these ions can undergo. Cationic vanadium ions form complexes with ligands; anionic vanadium ions form complexes with ligands and self-react to form isopolyanions. All vanadium species undergo oxidation-reduction reactions. With a few exceptions, elucidation of the dynamics of these reactions awaited the development of fast reaction techniques before the kinetics of elementary ligation, condensation, reduction, and oxidation of the aqueous vanadium ions could be investigated. As the biological roles played by endogenous and therapeutic vanadium expand, it is appropriate to bring the results of the diverse kinetics studies under one umbrella. To achieve this goal this review presents a systematic examination of elementary aqueous vanadium ion dynamics. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Enthalpy of formation of vanadates of iron, chromium, and aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Kesler, Y.A.; Cheshnitskii, S.M.; Fotiev, A.A.; Tret' yakov, Y.D.

    1985-09-01

    The study of vanadates of iron, aluminum and chromium is of importance for the analysis of the functioning of catalysts of organic synthesis reactions and for the study of vanadium corrosion of structural materials. Of principal interest, however, are the processes in the treatment of vanadium-containing metallurgical slags and waste from thermal power plants, in which these compounds play a major role. At the same time, the thermochemical properties of these substances, which are necessary for creating the physicochemical foundations of industrially important processes, have not been investigated sufficiently. The authors therefore undertake here a study of the compounds FeVO/sub 4/, AIVO/sub 4/, CrVO/sub 4/ and FeCr(VO/sub 4/)/sub 2/, to determine their enthalpies of formation.

  19. Structural and silver/vanadium ratio effects on silver vanadium phosphorous oxide solution formation kinetics: impact on battery electrochemistry.

    Science.gov (United States)

    Bock, David C; Takeuchi, Kenneth J; Marschilok, Amy C; Takeuchi, Esther S

    2015-01-21

    The detailed understanding of non-faradaic parasitic reactions which diminish battery calendar life is essential to the development of effective batteries for use in long life applications. The dissolution of cathode materials including manganese, cobalt and vanadium oxides in battery systems has been identified as a battery failure mechanism, yet detailed dissolution studies including kinetic analysis are absent from the literature. The results presented here provide a framework for the quantitative and kinetic analyses of the dissolution of cathode materials which will aid the broader community in more fully understanding this battery failure mechanism. In this study, the dissolution of silver vanadium oxide, representing the primary battery powering implantable cardioverter defibrillators (ICD), is compared with the dissolution of silver vanadium phosphorous oxide (Ag(w)VxPyOz) materials which were targeted as alternatives to minimize solubility. This study contains the first kinetic analyses of silver and vanadium solution formation from Ag0.48VOPO4·1.9H2O and Ag2VP2O8, in a non-aqueous battery electrolyte. The kinetic results are compared with those of Ag2VO2PO4 and Ag2V4O11 to probe the relationships among crystal structure, stoichiometry, and solubility. For vanadium, significant dissolution was observed for Ag2V4O11 as well as for the phosphate oxide Ag0.49VOPO4·1.9H2O, which may involve structural water or the existence of multiple vanadium oxidation states. Notably, the materials from the SVPO family with the lowest vanadium solubility are Ag2VO2PO4 and Ag2VP2O8. The low concentrations and solution rates coupled with their electrochemical performance make these materials interesting alternatives to Ag2V4O11 for the ICD application.

  20. Creep and creep rupture properties of unalloyed vanadium and solid-solution-strengthened vanadium-base alloys

    International Nuclear Information System (INIS)

    Kainuma, T.; Iwao, N.; Suzuki, T.; Watanabe, R.

    1982-01-01

    The creep and creep rupture properties of vanadium and vanadium-base alloys were studied at 700 and 1000 0 C. The alloys were vanadium-base binary alloys containing about 5 - 21 at.% Al, Ti, Nb, Ta, Cr, Mo or Fe, three V-20wt.%Nb-base ternary alloys containing 5 or 10 wt.% Al, Cr or Mo, V-10wt.%Ta-10wt.%Al and V-25wt.%Cr-0.8wt.%Zr. The creep rupture stress of the binary alloys, except the V-Al and V-Ti alloys, increased linearly with increasing concentration of the alloying elements. The V-Nb alloy had the best properties with respect to the rupture stress and creep rate at 700 0 C and the rupture stress at 1000 0 C, but the V-Mo alloy appeared likely to have better creep properties at longer times and higher temperatures. Of the five ternary alloys, V-20wt.%Nb-5wt.%Cr and V-20wt.%Nb-10wt.%Mo showed the best creep properties. The creep properties of these two alloys were compared with those of other vanadium alloys and of type 316 stainless steel. (Auth.)

  1. Manufacturing development of low activation vanadium alloys

    International Nuclear Information System (INIS)

    Smith, J.P.; Johnson, W.R.; Baxi, C.B.

    1996-10-01

    General Atomics is developing manufacturing methods for vanadium alloys as part of a program to encourage the development of low activation alloys for fusion use. The culmination of the program is the fabrication and installation of a vanadium alloy structure in the DIII-D tokamak as part of the Radiative Divertor modification. Water-cooled vanadium alloy components will comprise a portion of the new upper divertor structure. The first step, procuring the material for this program has been completed. The largest heat of vanadium alloy made to date, 1200 kg of V-4Cr-4Ti, has been produced and is being converted into various product forms. Results of many tests on the material during the manufacturing process are reported. Research into potential fabrication methods has been and continues to be performed along with the assessment of manufacturing processes particularly in the area of joining. Joining of vanadium alloys has been identified as the most critical fabrication issue for their use in the Radiative Divertor Program. Joining processes under evaluation include resistance seam, electrodischarge (stud), friction and electron beam welding. Results of welding tests are reported. Metallography and mechanical tests are used to evaluate the weld samples. The need for a protective atmosphere during different welding processes is also being determined. General Atomics has also designed, manufactured, and will be testing a helium-cooled, high heat flux component to assess the use of helium cooled vanadium alloy components for advanced tokamak systems. The component is made from vanadium alloy tubing, machined to enhance the heat transfer characteristics, and joined to end flanges to allow connection to the helium supply. Results are reported

  2. Crystal structure and spin state of mixed-crystals of iron with zinc and cobalt for the assembled complexes bridged by 1,3-bis(4-pyridyl)propanes

    Energy Technology Data Exchange (ETDEWEB)

    Dote, Haruka [Hiroshima University, Graduate School of Science (Japan); Nakashima, Satoru, E-mail: snaka@hiroshima-u.ac.jp [Hiroshima University, Natural Science Center for Basic Research and Development (Japan)

    2012-03-15

    Mixed crystals of cobalt and zinc were synthesized using 1,3-bis(4-pyridyl)propane (bpp) as bridging ligand and NCS{sup - } as anion. Red crystals and blue crystals were obtained. Powder X-ray diffraction patterns showed that the former is in 2D interpenetrated structure, while the latter has the same structure with Zn(NCS){sub 2}(bpp). Iron ion was introduced both into the red crystals and blue crystals of the mixed crystals of cobalt with zinc. {sup 57}Fe Moessbauer spectrum of the red crystals showed a main doublet of Fe{sup II} high-spin state at 78 K, while the spectrum of blue crystals did not show Fe{sup II} high-spin state at 78 K.

  3. Crystal structure and spin state of mixed-crystals of iron with zinc and cobalt for the assembled complexes bridged by 1,3-bis(4-pyridyl)propanes

    International Nuclear Information System (INIS)

    Dote, Haruka; Nakashima, Satoru

    2012-01-01

    Mixed crystals of cobalt and zinc were synthesized using 1,3–bis(4–pyridyl)propane (bpp) as bridging ligand and NCS  −  as anion. Red crystals and blue crystals were obtained. Powder X-ray diffraction patterns showed that the former is in 2D interpenetrated structure, while the latter has the same structure with Zn(NCS) 2 (bpp). Iron ion was introduced both into the red crystals and blue crystals of the mixed crystals of cobalt with zinc. 57 Fe Mössbauer spectrum of the red crystals showed a main doublet of Fe II high-spin state at 78 K, while the spectrum of blue crystals did not show Fe II high-spin state at 78 K.

  4. Mineralogy and geochemistry of vanadium in the Colorado Plateau

    Science.gov (United States)

    Weeks, A.D.

    1961-01-01

    The chief domestic source of vanadium is uraniferous sandstone in the Colorado Plateau. Vanadium is 3-, 4-, or 5-valent in nature and, as oxides or combined with other elements, it forms more than 40 minerals in the Plateau ores. These ores have been studied with regard to the relative amounts of vanadium silicates and oxide-vanadates, uranium-vanadium ratios, the progressive oxidation of black low-valent ores to high-valent carnotite-type ores, and theories of origin. ?? 1961.

  5. Essential minerals and inorganic contaminants (barium, cadmium, lithium, lead and vanadium in dried bee pollen produced in Rio Grande do Sul State, Brazil

    Directory of Open Access Journals (Sweden)

    José Augusto Gasparotto SATTLER

    2016-01-01

    Full Text Available Abstract Like other beehive products, such as honey, royal jelly and propolis, bee pollen has attracted great interest because of the health benefits it can provide when consumed. Bee pollen has high contents of sugars and proteins and a low content of lipids, it is also a rich source of vitamins and other bioactive compounds, which makes it an attractive micronutrient supplement. However, few studies have investigated its composition. Therefore, the aim of this study was to characterize the essential minerals and inorganic contaminants present in bee pollen produced at apiaries in Rio Grande do Sul State, Brazil. Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES revealed the presence of 8 essential minerals (calcium, iron, copper, chromium, manganese, molybdenum, phosphorus and zinc in the 5 analyzed samples; 6 of them were in sufficiently high amounts to meet dietary requirements. Of the 5 inorganic contaminants assessed (barium, cadmium, lithium, lead and vanadium, only cadmium was present at levels over the International Honey Commission’s standards. All bee pollen samples showed a high content of the 8 essential minerals. Contamination usually results from the use of pesticides, fertilizers and other chemicals in agriculture; thus, monitoring of its levels must be included in bee pollen analysis.

  6. Vanadium bioavailability and toxicity to soil microorganisms and plants.

    Science.gov (United States)

    Larsson, Maja A; Baken, Stijn; Gustafsson, Jon Petter; Hadialhejazi, Golshid; Smolders, Erik

    2013-10-01

    Vanadium, V, is a redox-sensitive metal that in solution, under aerobic conditions, prevails as the oxyanion vanadate(V). There is little known regarding vanadium toxicity to soil biota, and the present study was set up to determine the toxicity of added vanadate to soil organisms and to investigate the relationship between toxicity and vanadium sorption in soils. Five soils with contrasting properties were spiked with 7 different doses (3.2-3200 mg V kg(-1)) of dissolved vanadate, and toxicity was measured with 2 microbial and 3 plant assays. The median effective concentration (EC50) thresholds of the microbial assays ranged from 28 mg added V kg(-1) to 690 mg added V kg(-1), and the EC50s in the plant assays ranged from 18 mg added V kg(-1) to 510 mg added V kg(-1). The lower thresholds were in the concentration range of the background vanadium in the untreated control soils (15-58 mg V kg(-1)). The vanadium toxicity to plants decreased with a stronger soil vanadium sorption strength. The EC50 values for plants expressed on a soil solution basis ranged from 0.8 mg V L(-1) to 15 mg V L(-1) and were less variable among soils than corresponding values based on total vanadium in soil. It is concluded that sorption decreases the toxicity of added vanadate and that soil solution vanadium is a more robust measure to determine critical vanadium concentrations across soils. © 2013 SETAC.

  7. Optical spectra of vanadium (5, 4) compounds during extraction by di-2-ethylhexylphosphoric acid

    International Nuclear Information System (INIS)

    Kurbatova, L.D.; Medvedeva, N.I.

    2000-01-01

    Optical spectra of vanadium (5, 4) complexes with HDEHP are studied using literature data on quantum-chemical calculations of vanadium (5) and vanadium (4) oxides. Extraction of vanadium is conducted by undiluted HDEHP from sulfuric acid solutions. Absorption electron spectra (AES) of vanadium (5), vanadium (4) and vanadium (5, 4) compounds are presented. In AES of vanadium (5, 4) four absorption bands at 24000, 17000, 14500 and 13500 cm -1 appear. Comparison with spectra of vanadium (5) and vanadium (4) shows that band 17000 cm -1 which appears only during mutual extraction of vanadium (5) and vanadium (4) is caused by transitions appearing between filled and empty levels of d-zone broadened by vanadium (5) and vanadium (4) interaction [ru

  8. Improvement the nutritional status of pre-school children following intervention with a supplement containing iron, zinc, copper, vitamin A, vitamin C and prebiotic

    Directory of Open Access Journals (Sweden)

    Luiza Carla Vidigal Castro

    Full Text Available Abstract This study investigated the effects of a vitamin and mineral fortified powder product supplemented with inulin, on the iron and vitamin A status of 110 pre-schools childrens in Viçosa, MG, Brazil. The 2 to 5-year-old children were submitted to anthropometric (weight and height, biochemical (erythrocytes, hemoglobin, mean corpuscular volume – MCV, mean corpuscular hemoglobin - MCH, serum iron, ferritin and serum retinol and dietary (direct food weighing, 24 h recall, and food intake record evaluations, at the beginning and at the end of a 45-day intervention. The supplement (30 g was provided daily as part of the afternoon snack, diluted in 100 mL of water, 5 times/week and it supplied 30% of the recommended daily doses of iron, zinc, copper and vitamins A and C. Dietary and biochemical data was compared by the Wilcoxon test, and anthropometric data by the paired t-test. Values of z-scores for weight and height, erythrocytes, hemoglobin, MCV, MCH and ferritin were significantly higher after intervention; no change was observed in serum retinol. The prebiotic-containing supplement significantly increased the intake of energy, macro and micronutrients, and was effective in improving the iron and anthropometric status.

  9. Determination of Leachable Vanadium (V) in Sediment

    African Journals Online (AJOL)

    NICO

    A method for speciation of vanadium in solid samples was developed for quantification of ... Experimental ... Sediments for Trace Metals), obtained from the National Research ... Determination of vanadium is not a simple task using ET-AAS.

  10. Effect of vanadium compounds on acid phosphatase activity.

    Science.gov (United States)

    Vescina, C M; Sálice, V C; Cortizo, A M; Etcheverry, S B

    1996-01-01

    The direct effect of different vanadium compounds on acid phosphatase (ACP) activity was investigated. Vanadate and vanadyl but not pervanadate inhibited the wheat germ ACP activity. These vanadium derivatives did not alter the fibroblast Swiss 3T3 soluble fraction ACP activity. Using inhibitors of tyrosine phosphatases (PTPases), the wheat germ ACP was partially characterized as a PTPase. This study suggests that the inhibitory ability of different vanadium derivatives to modulate ACP activity seems to depend on the geometry around the vanadium atom more than on the oxidation state. Our results indicate a correlation between the PTPase activity and the sensitivity to vanadate and vanadyl cation.

  11. Neutron Elastic Scattering Cross Sections of Iron and Zinc in the Energy Region 2.5 to 8.1 MeV

    International Nuclear Information System (INIS)

    Holmqvist, B.; Johansson, S.G.; Lodin, G.; Wiedling, T.; Kiss, A.

    1966-12-01

    Angular distributions were measured for the elastic scattering of neutrons from iron at five energies between 3.0 and 8. 1 MeV and from zinc at eight energies between 2.5 and 8.1 MeV. Time-of-flight technique was used. Corrections for neutron flux attenuation, multiple elastic scattering, and the finite geometry of the source-sample detector system were made by using a Monte Carlo program. An optical model potential with Saxon-Woods form factors was used to fit theoretical angular distributions to the experimental ones. The parameter values giving the best fits to the experimental distributions were calculated by a computer

  12. Neutron Elastic Scattering Cross Sections of Iron and Zinc in the Energy Region 2.5 to 8.1 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Holmqvist, B; Johansson, S G; Lodin, G; Wiedling, T [AB Atomenergi, Nyko eping (Sweden); Kiss, A [Inst. for Experimental Physics, Univ. of Debrecen, De brecen (Hungary)

    1966-12-15

    Angular distributions were measured for the elastic scattering of neutrons from iron at five energies between 3.0 and 8. 1 MeV and from zinc at eight energies between 2.5 and 8.1 MeV. Time-of-flight technique was used. Corrections for neutron flux attenuation, multiple elastic scattering, and the finite geometry of the source-sample detector system were made by using a Monte Carlo program. An optical model potential with Saxon-Woods form factors was used to fit theoretical angular distributions to the experimental ones. The parameter values giving the best fits to the experimental distributions were calculated by a computer.

  13. Topotactic synthesis of vanadium nitride solid foams

    International Nuclear Information System (INIS)

    Oyama, S.T.; Kapoor, R.; Oyama, H.T.; Hofmann, D.J.; Matijevic, E.

    1993-01-01

    Vanadium nitride has been synthesized with a surface area of 120 m 2 g -1 by temperature programmed nitridation of a foam-like vanadium oxide (35 m 2 g -1 ), precipitated from vanadate solutions. The nitridation reaction was established to be topotactic and pseudomorphous by x-ray powder diffraction and scanning electron microscopy. The crystallographic relationship between the nitride and oxide was {200}//{001}. The effect of precursor geometry on the product size and shape was investigated by employing vanadium oxide solids of different morphologies

  14. Recycling of Ammonia Wastewater During Vanadium Extraction from Shale

    Science.gov (United States)

    Shi, Qihua; Zhang, Yimin; Liu, Tao; Huang, Jing

    2018-03-01

    In the vanadium metallurgical industry, massive amounts of ammonia hydroxide or ammonia salt are added during the precipitation process to obtain V2O5; therefore, wastewater containing a high level of NH4 + is generated, which poses a serious threat to environmental and hydrologic safety. In this article, a novel process was developed to recycle ammonia wastewater based on a combination of ammonia wastewater leaching and crystallization during vanadium extraction from shale. The effects of the NH4 + concentration, temperature, time and liquid-to-solid ratio on the leaching efficiencies of vanadium, aluminum and potassium were investigated, and the results showed that 93.2% of vanadium, 86.3% of aluminum and 96.8% of potassium can be leached from sulfation-roasted shale. Subsequently, 80.6% of NH4 + was separated from the leaching solution via cooling crystallization. Vanadium was recovered via a combined method of solvent extraction, precipitation and calcination. Therefore, ammonia wastewater was successfully recycled during vanadium extraction from shale.

  15. Nickel and vanadium extraction from the Syrian petroleum coke

    International Nuclear Information System (INIS)

    Shlewit, H.; Alibrahim, M.

    2007-01-01

    Syrian petroleum coke samples were characterized and submitted for salt-roasting treatment in electric furnace to evaluate the convenience of this procedure for the extraction of the vanadium, nickel and sulfur from coke. Both solution and solid residue remaining after salt roasting were separated by filtration and were analyzed for vanadium, nickel and sulfur. The solution was analyzed by UV-Visible spectroscopy for vanadium and nickel and gravimetrically for sulfur. The solid residue and the untreated samples of petroleum coke were analyzed by XRF spectrometry. Results showed that more than 90% of sulfur and 60% of vanadium could be extracted by salt roasting treatment. An alternative procedure has been suggested, in which, more than 80% of sulfur and small percentage of vanadium can be leached by 0.75 M of Na 2 CO 3 solution at 70-80 Co. Vanadium was selectively extracted by DEHPA/TBP from the loaded leached solution. The extraction procedure flowsheet was also suggested. (authors)

  16. Chloride supporting electrolytes for all-vanadium redox flow batteries.

    Science.gov (United States)

    Kim, Soowhan; Vijayakumar, M; Wang, Wei; Zhang, Jianlu; Chen, Baowei; Nie, Zimin; Chen, Feng; Hu, Jianzhi; Li, Liyu; Yang, Zhenguo

    2011-10-28

    This paper examines vanadium chloride solutions as electrolytes for an all-vanadium redox flow battery. The chloride solutions were capable of dissolving more than 2.3 M vanadium at varied valence states and remained stable at 0-50 °C. The improved stability appeared due to the formation of a vanadium dinuclear [V(2)O(3)·4H(2)O](4+) or a dinuclear-chloro complex [V(2)O(3)Cl·3H(2)O](3+) in the solutions over a wide temperature range. The all-vanadium redox flow batteries with the chloride electrolytes demonstrated excellent reversibility and fairly high efficiencies. Only negligible, if any, gas evolution was observed. The improved energy capacity and good performance, along with the ease in heat management, would lead to substantial reduction in capital cost and life-cycle cost, making the vanadium chloride redox flow battery a promising candidate for stationary applications. This journal is © the Owner Societies 2011

  17. Nicotianamine Secretion for Zinc Excess Tolerance

    NARCIS (Netherlands)

    Aarts, M.G.M.

    2014-01-01

    Plants acquire micronutrients such as iron (Fe), zinc (Zn), manganese, or copper from soil. These micronutrients are often not readily available and they need to be mobilized to the proper free ionic form in order to be taken up by plant roots. Perhaps the only exception to this is the uptake of Fe

  18. Vanadium Compounds as PTP Inhibitors

    Directory of Open Access Journals (Sweden)

    Elsa Irving

    2017-12-01

    Full Text Available Phosphotyrosine signaling is regulated by the opposing actions of protein tyrosine kinases (PTKs and protein tyrosine phosphatases (PTPs. Here we discuss the potential of vanadium derivatives as PTP enzyme inhibitors and metallotherapeutics. We describe how vanadate in the V oxidized state is thought to inhibit PTPs, thus acting as a pan-inhibitor of this enzyme superfamily. We discuss recent developments in the biological and biochemical actions of more complex vanadium derivatives, including decavanadate and in particular the growing number of oxidovanadium compounds with organic ligands. Pre-clinical studies involving these compounds are discussed in the anti-diabetic and anti-cancer contexts. Although in many cases PTP inhibition has been implicated, it is also clear that many such compounds have further biochemical effects in cells. There also remain concerns surrounding off-target toxicities and long-term use of vanadium compounds in vivo in humans, hindering their progress through clinical trials. Despite these current misgivings, interest in these chemicals continues and many believe they could still have therapeutic potential. If so, we argue that this field would benefit from greater focus on improving the delivery and tissue targeting of vanadium compounds in order to minimize off-target toxicities. This may then harness their full therapeutic potential.

  19. A theoretical and experimental study of calcium, iron, zinc, cadmium, and sodium ions absorption by aspartame.

    Science.gov (United States)

    Mahnam, Karim; Raisi, Fatame

    2017-03-01

    Aspartame (L-Aspartyl-L-phenylalanine methyl ester) is a sweet dipeptide used in some foods and beverages. Experimental studies show that aspartame causes osteoporosis and some illnesses, which are similar to those of copper and calcium deficiency. This raises the issue that aspartame in food may interact with cations and excrete them from the body. This study aimed to study aspartame interaction with calcium, zinc, iron, sodium, and cadmium ions via molecular dynamics simulation (MD) and spectroscopy. Following a 480-ns molecular dynamics simulation, it became clear that the aspartame is able to sequester Fe 2+ , Ca 2+ , Cd 2+ , and Zn 2+ ions for a long time. Complexation led to increasing UV-Vis absorption spectra and emission spectra of the complexes. This study suggests a potential risk of cationic absorption of aspartame. This study suggests that purification of cadmium-polluted water by aspartame needs a more general risk assessment.

  20. Iron, transferrin and myelinogenesis

    International Nuclear Information System (INIS)

    Sergeant, C.; Vesvres, M.H.; Deves, G.; Baron, B.; Guillou, F.

    2003-01-01

    Transferrin (Tf), the iron binding protein of vertebrates serum, is known to be synthesized by oligodendrocytes (Ols) in the central nervous system. It has been postulated that Tf is involved in Ols maturation and myelinogenesis. This link is particularly important in the understanding of a severe human pathology: the multiple sclerosis, which remains without efficient treatment. We generated transgenic mice containing the complete human Tf gene and extensive regulatory sequences from the 5 ' and 3 ' untranslated regions that specifically overexpress Tf in Ols. Brain cytoarchitecture of the transgenic mice appears to be normal in all brain regions examined, total myelin content is increased by 30% and motor coordination is significantly improved when compared with non-transgenic littermates. Tf role in the central nervous system may be related to its affinity for metallic cations. Normal and transgenic mice were used for determination of trace metals (iron, copper and zinc) and minerals (potassium and calcium) concentration in cerebellum and corpus callosum. The freeze-dried samples were prepared to allow proton-induced X-ray emission and Rutherford backscattering spectrometry analyses with the nuclear microprobe in Bordeaux. Preliminary results were obtained and carbon distribution was revealed as a very good analysis to distinguish precisely the white matter region. A comparison of metallic and mineral elements contents in brain between normal and transgenic mice shows that iron, copper and zinc levels remained constant. This result provides evidence that effects of Tf overexpression in the brain do not solely relate to iron transport

  1. Use of radioisotopes in studying iron metabolism in humans in Sri Lanka

    International Nuclear Information System (INIS)

    Liyanage, C.E.; Thabrew, M.I.

    1994-01-01

    Anaemia due to iron deficiency is the commonest haematological problem found in Sri Lankan pregnant women and pre-school children. The reported prevalence rates amongst pregnant and lactating women ranged from 60-80%. The present study revealed that 3% of pregnant women had satisfactory iron stores and 57% had virtually no iron stores. Routine iron supplementation is justified not only to correct the anaemia but also to build up the maternal iron stores. In a longitudinal study of 100 pregnant women a very high prevalence was observed in spite of the fact that the population studied was on iron supplementation. A very poor compliance on iron therapy was seen. The incidence of low birth weight observed was 32%, quite similar to that has been reported previously for Sri Lanka. Therefore, further longitudinal studies have been designed to find out the efficacy of the present supplementary programme. In Galle District 54.5% of the pre-school children were found clearly anaemic and another 20% had evidence of iron depletion. As the dietary intake of iron was marginal, the weaning foods that are in practice were tested for iron availability. Iron absorption/availability studies by in-vivo (extrinsic tag method) and in-vitro (using radioiron 59 Fe tracer) methods have shown a very poor (less than 5%) availability in many of the commonly used weaning foods. A statistically significant decrease in iron availability was seen with increase in amount of polyphenols mainly in some of the preparations made with green leaves. Addition of ascorbic acid rich food items showed an increase in iron availability (by 2-6 times). Dietary zinc intake of 46 children (2-5 yrs) was found 2-4 mg/1000 kcal, relating to total energy intake. Mean plasma zinc concentration of these children was 13.8±0.8 μmol/L. Therefore further studies on the improvement of zinc and iron availability in weaning foods have been designed to be done in future. (author). 3 refs, 1 fig

  2. Micronutrient problems in Brazilian soils with special emphasis on zinc

    International Nuclear Information System (INIS)

    Stewart, J.W.B.; Neptune, A.M.L.; Sao Paulo Univ., Piracicaba

    1975-01-01

    Brazil, with approximately 50% of the total land area in South America, has areas in which different micronutrient deficiencies (zinc, boron, copper, iron, manganese and molybdenum) have been noted in specific crops. This paper reviews the published research on such deficiencies and puts special emphasis on zinc which appears to be the most widespread deficiency. The need for an integrated approach to determining the extent of micronutrient deficiencies is discussed. (author)

  3. Trend overtime of total haemoglobin, iron metabolism and trace minerals in veal calves fed high amounts of two different solid feeds

    Directory of Open Access Journals (Sweden)

    Anna-Lisa Stefani

    2010-01-01

    Full Text Available Fifty Polish Friesian veal calves were administrated high amounts of two different solid feeds (maize grain and a mix diet containing 10% of straw and 8% of soy in addition to the traditional milk replacer diet. Compared to the mix diet, maize grain had a lower content of iron, copper and zinc and a minor fibre level. Effects of the two diets on calves’ blood haemoglobin, iron, iron metabolism parameters, copper and zinc concentrations were studied. Haemoglobin concentration resulted higher at the end of the fattening for calves fed the mix diet, as expected. Values remained, however, within ranges that allowed acceptable carcass paleness. Haematic iron, unsaturated iron binding capacity (UIBC and total iron binding capacity (TIBC levels were not significantly different between the two solid feeds. Lower copper and zinc blood concentrations resulted for calves fed the mix diet were likely due to the feed fibre interfering with the bioavailability of the two minerals, according to what happens for iron.

  4. Vanadium extraction from slimes by the lime-bicarbonate method

    International Nuclear Information System (INIS)

    Lishchenko, T.V.; Vdovina, L.V.; Slobodchikova, R.I.

    1978-01-01

    Some main parameters of the lime-bicarbonate method of extracting vanadium from residues obtained in washing waters of mazut boilers on thermal stations have been determined. To study the process of vanadium extraction during caking of the residues with lime and subsequent leaching of water-soluble vanadium, a ''Minsk-22'' computer has been used for computation. Analysis of the equation derived has shown that a change in temperature of vanadium leaching, density of pulp, and a kind of heating of the charge affect the process only slightly. It has also been shown that the calcination temperature is expedient to be kept above 850 deg C and consumption temperature is expedient to be kept above 85O deg C and consumption of lime must not exceed 20% of the residues weight. Bicarbonate consumption exerts a decisive influence on completeness of vanadium extraction and must be increased up to >35%; duration of leaching should be raised up to 30-45 minutes. With increasing calcination temperature the duration of leaching decreases. When temperature and duration of calcination increase, the formation of water-soluble vanadium intensifies. With the aid of optimization program seven variants have been chosen, which ensure vanadium extraction into solution by 95-100%

  5. Sensitivity Calculation of Vanadium Self-Powered Neutron Detector

    International Nuclear Information System (INIS)

    Cha, Kyoon Ho

    2011-01-01

    Self-powered neutron detector (SPND) is being widely used to monitor the reactor core of the nuclear power plants. The SPND contains a neutron-sensitive metallic emitter surrounded by a ceramic insulator. Currently, the rhodium SPND has been used in many nuclear power plants. The lifetime of rhodium is too short (about 3∼5 years) to operate the nuclear power plant economically. The vanadium (V) SPND is also primarily sensitive to neutrons like rhodium, but is a somewhat slower reaction time as that of a rhodium SPND. The benefit of vanadium over rhodium is its low depletion rate, which is a factor of 7 times less than that of rhodium. For this reason, a vanadium SPND has been being developed to replace the rhodium SPND which is used in OPR1000. Some Monte Carlo simulations were accomplished to calculate the initial sensitivity of vanadium emitter material and alumina (Al 2 O 3 ) insulator with a cylindrical geometry. An MCNP-X code was used to simulate some factors (neutron self shielding factor and electron escape probability from the emitter) necessary to calculate the sensitivity of vanadium detector. The simulation results were compared with some theoretical and experimental values. The method presented here can be used to analyze the optimum design of the vanadium SPND

  6. Effect of vanadium compounds on acid phosphatase activity

    OpenAIRE

    Vescina, Cecilia M.; Sálice, Viviana C.; Cortizo, Ana María; Etcheverry, Susana B.

    1996-01-01

    The direct effect of different vanadium compounds on acid phosphatase (ACP) activity was investigated. Vanadate and vanadyl but not pervanadate inhibited the wheat germ ACP activity. These vanadium derivatives did not alter the fibroblast Swiss 3T3 soluble fraction ACP activity. Using inhibitors of tyrosine phosphatases (PTPases), the wheat germ ACP was partially characterized as a PTPase. This study suggests that the inhibitory ability of different vanadium derivatives to modulate ACP activi...

  7. Correlations in distribution and concentration of calcium, copper and iron with zinc in isolated extracellular deposits associated with age-related macular degeneration

    Science.gov (United States)

    Flinn, Jane M; Kakalec, Peter; Tappero, Ryan; Jones, Blair F.; Lengyel, Imre

    2014-01-01

    Zinc (Zn) is abundantly enriched in sub-retinal pigment epithelial (RPE) deposits, the hallmarks of age-related macular degeneration (AMD), and is thought to play a role in the formation of these deposits. However, it is not known whether Zn is the only metal relevant for sub-RPE deposit formation. Because of their involvement in the pathogenesis of AMD, we determined the concentration and distribution of calcium (Ca), iron (Fe) and copper (Cu) and compared these with Zn in isolated and sectioned macular (MSD), equatorial (PHD) and far peripheral (FPD) sub-RPE deposits from an 86 year old donor eye with post mortem diagnosis of early AMD. The sections were mounted on Zn free microscopy slides and analyzed by microprobe synchrotron X-ray fluorescence (μSXRF). Metal concentrations were determined using spiked sectioned sheep brain matrix standards, prepared the same way as the samples. The heterogeneity of metal distributions was examined using pixel by pixel comparison. The orders of metal concentrations were Ca ⋙ Zn > Fe in all three types of deposits but Cu levels were not distinguishable from background values. Zinc and Ca were consistently present in all deposits but reached highest concentration in MSD. Iron was present in some but not all deposits and was especially enriched in FPD. Correlation analysis indicated considerable variation in metal distribution within and between sub-RPE deposits. The results suggest that Zn and Ca are the most likely contributors to deposit formation especially in MSD, the characteristic risk factor for the development of AMD in the human eye.

  8. Survey of heavy metal pollution (copper, lead, zinc, cadmium, iron and manganese in drinking water resources of Nurabad city, Lorestan, Iran 2013

    Directory of Open Access Journals (Sweden)

    GHodratolah Shams Khorramabadi

    2016-09-01

    Full Text Available Background: Healthy water passes through the pipelines from supply resources to consuming places in which passing from these stages may cause some cases of contamination like heavy metal contamination. Therefore, the aim of this study was to evaluate the contamination of heavy metals (copper, lead, zinc, cadmium, iron, and manganese in water resources of Nurabad city of Lorestan in 2013. Materials and Methods: In this cross-sectional study, samples were collected from 7 wells of drinking water and 2 water storage tanks during 6 months in Nurabad. So that, heavy metal parameters such as copper, lead, zinc, cadmium, iron, and manganese were measured using an atomic absorption device and also electrical conductivity, sulfate, chloride and total dissolved solids were also measured in accordance with standard methods. Results: Results indicated that the concentration of studied metals in water sources was lower than the national standards and World Health Organization standard, and in the water supply system the concentration of some metals was more than standard level. Moreover, the results showed that the concentration of studied heavy metals were more in winter than in autumn. Conclusion: Generally, in the water resources of Nurabad city the concentration of studied heavy metals was lower than the national standards and World Health Organization standard and there are not problems for water consumers. However, due to public health and the presence of a high concentration of these metals in the distribution supply, the heavy metal concentration in drinking water of this region should be monitored regularly by responsible organizations.

  9. Vanadium carbide coatings: deposition process and properties

    International Nuclear Information System (INIS)

    Borisova, A.; Borisov, Y.; Shavlovsky, E.; Mits, I.; Castermans, L.; Jongbloed, R.

    2001-01-01

    Vanadium carbide coatings on carbon and alloyed steels were produced by the method of diffusion saturation from the borax melt. Thickness of the vanadium carbide layer was 5-15 μm, depending upon the steel grade and diffusion saturation parameters. Microhardness was 20000-28000 MPa and wear resistance of the coatings under conditions of end face friction without lubrication against a mating body of WC-2Co was 15-20 times as high as that of boride coatings. Vanadium carbide coatings can operate in air at a temperature of up to 400 o C. They improve fatigue strength of carbon steels and decrease the rate of corrosion in sea and fresh water and in acid solutions. The use of vanadium carbide coatings for hardening of various types of tools, including cutting tools, allows their service life to be extended by a factor of 3 to 30. (author)

  10. Impact of rice fortified with iron, zinc, thiamine and folic acid on laboratory measurements of nutritional status of preschool children

    Directory of Open Access Journals (Sweden)

    Ceres Mattos Della Lucia

    Full Text Available Abstract Fortification of food constitutes an important strategy for the control of micronutrient deficiency and has advantages such as high population coverage and maintenance of eating habits. This study aimed to assess the impact of using fortified rice (Ultra Rice® - UR® on the nutritional status of preschoolers. Ninety-nine children enrolled in two philanthropic preschools participated of the study. Children of one of the preschools were offered UR® mixed with polished rice, as part of school meals (test group and the children of another preschool were offered pure polished rice (control group. Biochemical evaluations were performed before and after 4 months of intervention. Dietary assessment and sensory evaluation of UR® mixed with polished rice were performed during the study. The fortified rice improved the concentrations of zinc (p < 0.001, thiamine (p < 0.001, folic acid (p = 0.003, mean corpuscular hemoglobin (p < 0.001 and mean corpuscular hemoglobin concentration (p < 0.001. The fortified rice showed good acceptability among preschoolers. This study demonstrated the effectiveness of using rice fortified with iron, zinc, thiamine and folic acid on the nutritional status of children.

  11. Ion-exchange preparation of high-purity vanadium acid from industrial liquors

    International Nuclear Information System (INIS)

    Sajdakhmedov, U.A.; Arslanov, Sh.S.; Vulikh, A.I.

    1994-01-01

    The results of investigations on production of special-purity vanadium acid and vanadium oxide directly from process solutions (technical grade liquors) using ionites are presented. Potentiality of thorough purification of vanadium(5) oxide, when producing vanadium acid on the KU-2 cationite with subsequent purification on anionite, is shown. On the basis of the results obtained a principle flowsheet of ion-exchange production of high-purity vanadium(5) oxide from industrial liquors has been developed. 2 refs.; 1 fig.; 4 tabs

  12. Acceptability of Iron- and Zinc-Biofortified Pearl Millet (ICTP-8203)-Based Complementary Foods among Children in an Urban Slum of Mumbai, India.

    Science.gov (United States)

    Huey, Samantha Lee; Venkatramanan, Sudha; Udipi, Shobha A; Finkelstein, Julia Leigh; Ghugre, Padmini; Haas, Jere Douglas; Thakker, Varsha; Thorat, Aparna; Salvi, Ashwini; Kurpad, Anura V; Mehta, Saurabh

    2017-01-01

    Biofortification, a method for increasing micronutrient content of staple crops, is a promising strategy for combating major global health problems, such as iron and zinc deficiency. We examined the acceptability of recipes prepared using iron- and zinc-biofortified pearl millet (FeZnPM) (~80 ppm Fe, ~34 ppm Zn, varietal ICTP-8203), compared to conventional pearl millet (CPM) (~20 ppm Fe, ~19 ppm Zn) in preparation for an efficacy trial. Our objective was to examine the acceptability of FeZnPM compared to CPM among young children and mothers living in the urban slums of Mumbai. Standardized traditional feeding program recipes ( n  = 18) were prepared with either FeZnPM or CPM flour. The weight (g) of each food product was measured before and after consumption by children ( n  = 125) and the average grams consumed over a 3-day period were recorded. Mothers ( n  = 60) rated recipes using a 9-point hedonic scale. Mean intakes and hedonic scores of each food product were compared using t -tests across the two types of pearl millet. There were no statistically significant differences in consumption by children (FeZnPM: 25.27 ± 13.0 g; CPM: 21.72 ± 6.90 g) across the food products ( P  = 0.28). Overall mean hedonic scores for all recipes were between 7 to 9 points. CPM products were rated higher overall (8.22 ± 0.28) compared to FeZnPM products (7.95 ± 0.35) ( P  = 0.01). FeZnPM and CPM were similarly consumed and had high hedonic scores, demonstrating high acceptability in this population. These results support using these varieties of pearl millet in a proposed trial [http://Clinicaltrials.gov ID: NCT02233764; Clinical Trials Registry of India (CTRI), reference number REF/2014/10/007731, CTRI number CTRI/2015/11/006376] testing the efficacy of FeZnPM for improving iron status and growth.

  13. [Reference values of iron, iodine, zinc, selenium, copper, molybdenum, vitamin C, vitamin E, vitamin K, carotenoids and polyphenols for the Venezuelan population].

    Science.gov (United States)

    García-Casal, Maria Nieves; Landaeta, Maritza; Adrianza de Baptista, Gertrudis; Murillo, Carolain; Rincón, Mariela; Bou Rached, Lizet; Bilbao, Arantza; Anderson, Hazel; García, Doris; Franquiz, Julia; Puche, Rafael; Garcia, Omar; Quintero, Yurimay; Peña-Rosas, Juan Pablo

    2013-12-01

    The review on iron, iodine, zinc, selenium, copper, molybdenum, vitamin C, vitamin E, vitamin K, carotenoids and polyphenols recommendations for Venezuela comprise the definitions adopted worldwide known as Dietary Reference Intakes (DRIs) that include Recommended Dietary Allowance (RDA), Estimated Average Requirement (EAR), Adequate Intake (AI) and Tolerable Upper Intake Levels (UL). The RDA for iron: 11 mg/day for infants Vitamin C: 40-50 mg/day for infants, 15-45 mg/ day for children, 75 mg/day for male adolescents, 65 mg/day for female adolescents, 90 mg/day for adult males, 75 mg/day for adult females, 80-85 mg/day during pregnancy and 115-120 mg/day during lactation. Recommendations for copper, selenium, molybdenum, vitamins E, K, carotenoids and polyphenols are also presented. These recommendations will help to design adequate and efficient policies that could help to avoid or to treat the consequences derived from the deficiency or the excess of these nutrients.

  14. The addition zirconium effect on the solubility and activity of sulfur in liquid iron

    International Nuclear Information System (INIS)

    Burylev, B.P.; Mojsov, L.P.

    1994-01-01

    Critical analysis of reference data on thermodynamic properties of zirconium sulfides is conducted for evaluation of zirconium desulfonation ability in liquid steel. Sulfur solubility dependence on zirconium concentration in liquid iron is presented. Curves of sulfur solubility in liquid iron in the presence of other elements, including titanium, manganese, vanadium and chromium are presented for comparison. It is shown that equilibrium concentration of sulfur is much lower than standard sulfur concentrations in steel, therefore zirconium appears to be the best desulfonator among the metals considered

  15. The effect of iron and copper impurities on the wettability of sphalerite (110) surface.

    Science.gov (United States)

    Simpson, Darren J; Bredow, Thomas; Chandra, Anand P; Cavallaro, Giuseppe P; Gerson, Andrea R

    2011-07-15

    The effect of impurities in the zinc sulfide mineral sphalerite on surface wettability has been investigated theoretically to shed light on previously reported conflicting results on sphalerite flotation. The effect of iron and copper impurities on the sphalerite (110) surface energy and on the water adsorption energy was calculated with the semi-empirical method modified symmetrically orthogonalized intermediate neglect of differential overlap (MSINDO) using the cyclic cluster model. The effect of impurities or dopants on surface energies is small but significant. The surface energy increases with increasing surface iron concentration while the opposite effect is reported for increasing copper concentration. The effect on adsorption energies is much more pronounced with water clearly preferring to adsorb on an iron site followed by a zinc site, and copper site least favorable. The theoretical results indicate that a sphalerite (110) surface containing iron is more hydrophilic than the undoped zinc sulfide surface. In agreement with the literature, the surface containing copper (either naturally or by activation) is more hydrophobic than the undoped surface. Copyright © 2011 Wiley Periodicals, Inc.

  16. Comparative studies on acid leaching of zinc waste materials

    Science.gov (United States)

    Rudnik, Ewa; Włoch, Grzegorz; Szatan, Leszek

    2017-11-01

    Three industrial waste materials were characterized in terms of their elemental and phase compositions, leaching behaviour in 10% sulfuric acid solution as well as leaching thermal effects. Slag from melting of mixed metallic scrap contained about 50% Zn and 10% Pb. It consisted mainly of various oxides and oxy-chlorides of metals. Zinc spray metallizing dust contained about 77% Zn in form of zinc and/or zinc-iron oxides, zinc metal and Zn-Fe intermetallic. Zinc ash from hot dip galvanizing was a mixture of zinc oxide, metallic zinc and zinc hydroxide chloride and contained about 80% Zn. Dissolution efficiency of zinc from the first material was 80% (independently on the solid to liquid ratio, 50-150 kg/m3), while decrease of the efficacy from 80% to 60% with increased solid to liquid ratio for the two remaining materials was observed. Both increase in the temperature (20 °C to 35 °C) and agitation rate (300 rpm to 900 rpm) did not improve seriously the leaching results. In all cases, transfer of zinc ions to the leachate was accompanied by different levels of solution contamination, depending on the type of the waste. Leaching of the materials was exothermic with the similar reaction heats for two high oxide-type products (slag, zinc ash) and higher values for the spray metallizing dust.

  17. Vanadium research recharged

    International Nuclear Information System (INIS)

    Luntz, Stephen

    2011-01-01

    US President Barack Obama has described Maria Skyllas-Kazacos’ research as “one of the coolest things I’ve ever said out loud”. Vanadium redox batteries could be electricity’s ultimate storage mechanism.

  18. Determination of the corrosion rate of zinc by measuring the polarization resistance

    International Nuclear Information System (INIS)

    Roeschenbleck, B.; Koenig, W.

    1982-01-01

    Zinc is an important common metal. It should be noticeably attacked just by water as a result of its basic character. However, this is not the case, firstly because it tends to form protective layers and furthermore pure zinc has a high hydrogen overpressure. Zinc is often used as cathodic protection of iron. In order to assess the protective effect, the corrosion rate depending on the pH-value is important. A report is given here on the problems involved in determining these values. (orig./RW) [de

  19. Low-temperature direct synthesis of mesoporous vanadium nitrides for electrochemical capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hae-Min [Institute of NT-IT Fusion Technology, Ajou University, 206 Worldcup-ro, Yeongtong-gu, Suwon 16499 (Korea, Republic of); Jeong, Gyoung Hwa [Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Banyeon 100, Ulsan 44919 (Korea, Republic of); Kim, Sang-Wook [Department of Molecular Science and Technology, Ajou University, 206 Worldcup-ro, Yeongtong-gu, Suwon 16499 (Korea, Republic of); Kim, Chang-Koo, E-mail: changkoo@ajou.ac.kr [Department of Chemical Engineering and Department of Energy Systems Research, Ajou University, 206 Worldcup-ro, Yeongtong-gu, Suwon 16499 (Korea, Republic of)

    2017-04-01

    Highlights: • Vanadium nitrides were directly synthesized by a one-step chemical precipitation method. • This method was carried out at a low temperature of 70 °C. • Vanadium nitrides had a specific capacitance of 598 F/g. • The equivalent series resistance of the vanadium nitride electrode was 1.42 Ω after 5000 cycles. - Abstract: Mesoporous vanadium nitrides are directly synthesized by a one-step chemical precipitation method at a low temperature (70 °C). Structural and morphological analyses reveal that vanadium nitride consist of long and slender nanowhiskers, and mesopores with diameters of 2–5 nm. Compositional analysis confirms the presence of vanadium in the VN structure, along with oxidized vanadium. The cyclic voltammetry and charge-discharge tests indicate that the obtained material stores charges via a combination of electric double-layer capacitance and pseudocapacitance mechanisms. The vanadium nitride electrode exhibits a specific capacitance of 598 F/g at a current density of 4 A/g. After 5000 charge-discharge cycles, the electrode has an equivalent series resistance of 1.42 Ω and retains 83% of its initial specific capacitance. This direct low-temperature synthesis of mesoporous vanadium nitrides is a simple and promising method to achieve high specific capacitance and low equivalent series resistance for electrochemical capacitor applications.

  20. Influence of V2O5 Content on the Gas-Based Direct Reduction of Hongge Vanadium Titanomagnetite Pellets with Simulated Shaft Furnace Gases

    Science.gov (United States)

    Li, Wei; Fu, Guiqin; Chu, Mansheng; Zhu, Miaoyong

    2018-01-01

    The influence of V2O5 content on the gas-based direct reduction of Hongge vanadium titanomagnetite pellets (HVTMP) was investigated with simulated shaft furnace gases, and the content levels were selected as 0 wt.%, 2 wt.%, 4 wt.%, and 6 wt.%, respectively. The results indicated that, with the increase of V2O5 content, the reduction was accelerated at an early stage due to the increase of the original porosity of the HVTMP. However, as the reduction proceeded, a slowing down in the reduction rate was observed, which was attributed to the formation of hardly reducible Fe2VO4. Major phases of reduced HVTMP were Fe2VO4, FeTiO3, and metallic iron. The morphology showed that the size of metallic iron particles of reduced HVTMP decreased with the increase of V2O5 content, V-bearing oxides embedded into the Ti-rich phases, and further reduction was restricted. This study not only established a relationship between the V2O5 content of HVTMP and its reduction behavior but could also contribute greatly to the effective utilization of Hongge vanadium titanomagnetite in shaft furnace.

  1. Fatigue of vanadium--hydrogen alloys

    International Nuclear Information System (INIS)

    Lee, K.S.; Stoloff, N.S.

    1975-01-01

    Hydrogen contents near and above the room temperature solubility limit increase the high cycle fatigue life but decrease low cycle life of polycrystalline vanadium. Changes in endurance limit with hydrides may be a consequence of decreased cyclic strain hardening coefficient, n'. 132 ppM hydrogen in solution has only a slightly beneficial effect on stress controlled fatigue life and essentially no effect on low cycle fatigue life. Unalloyed vanadium exhibits profuse striations, while hydrides produce cleavage cracks in fatigued samples. 10 fig

  2. Determination of Vanadium Binding Mode on Seawater-Contacted Polyamidoxime Adsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhicheng [Lawrence Berkeley National Laboratory (LBNL); Rao, Linfeng [Lawrence Berkeley National Laboratory (LBNL); Abney, Carter W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bryantsev, Vyacheslav [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ivanov, Aleksandr [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-09-01

    Adsorbents developed for the recovery of uranium from seawater display poor selectivity over other transition metals present in the ocean, with vanadium particularly problematic. To improve selectivity, an indispensable step is the positive identification of metal binding environments following actual seawater deployment. In this work we apply x-ray absorption fine structure (XAFS) spectroscopy to directly investigate the vanadium binding environment on seawater-deployed polyamidoxime adsorbents. Comparison of the x-ray absorption near edge spectra (XANES) reveal marked similarities to recently a reported non-oxido vanadium (V) structure formed upon binding with cyclic imidedioxime, a byproduct of generating amidoxime functionalities. Density functional theory (DFT) calculations provided a series of putative vanadium binding environments for both vanadium (IV) and vanadium (V) oxidation states, and with both amidoxime and cyclic imidedioxime. Fits of the extended XAFS (EXAFS) data confirmed vanadium (V) is bound exclusively by the cyclic imidedioxime moiety in a 1:2 metal:ligand fashion, though a modest structural distortion is also observed compared to crystal structure data and computationally optimized geometries which is attributed to morphology effects from the polymer graft chain and the absence of crystal packing interactions. These results demonstrate that improved selectivity for uranium over vanadium can be achieved by suppressing the formation of cyclic imidedioxime during preparation of polyamidoxime adsorbents for seawater uranium recovery.

  3. Digestión en horno de microondas para determinación de contenido de hierro y zinc totales en alimentos Microwave digestion for determination of iron and zinc content of total food

    Directory of Open Access Journals (Sweden)

    Paulina Silva Trejos

    2012-11-01

    Full Text Available En el presente estudio se optimizó el procedimiento de digestión de alimentos por medio de un horno de microondas, para cuantificar el hierro y el zinc totales en diferentes matrices por espectroscopía de absorción atómica. Se analizó la cantidad óptima de HNO3 concentrado al 65% para digerir determinada masa de muestra por evaluación del porcentaje de recuperación obtenido con diferente cantidad de HNO3. Los resultados no difieren de los obtenidos por los métodos recomendados oficialmente de digestión ácida en sistemas abiertos y de calcinación.In this study, the procedure was optimized digestion of food by means of a microwave oven, to quantify the total iron and zinc in different matrices by atomic absorption spectroscopy. We analyzed the optimal amount of 65% concentrated HNO3 to digest sample mass determined by evaluating the percent recover y obtained with different amounts of HNO3.The results are similar to those obtained by the methods recommended officially acid digestion in open systems and calcination.

  4. Vanadium dioxide formed by the sol-gel process

    International Nuclear Information System (INIS)

    Potember, R.S.; Speck, K.R.; Hu, H.S.

    1990-01-01

    This patent describes a process for the deposition of a crystalline vanadium dioxide thin film. It comprises: providing a solution comprising a vanadium tetraalkoxide and solvent; allowing hydrolysis and condensation reactions to progressively form a homogeneous sol from the solution, applying a coating of the sol to the substrate; allowing a gel to form from the sol on the substrate by evaporating the solvent; dehydrating the gel by heat treatment under an inert atmosphere to form the crystalline vanadium dioxide film

  5. Vanadium alloys for the radiative divertor program of DIII-D

    International Nuclear Information System (INIS)

    Smith, J.P.; Johnson, W.R.; Stambaugh, R.D.; Trester, P.W.; Smith, D.; Bloom, E.

    1995-10-01

    Vanadium alloys provide an attractive solution for fusion power plants as they exhibit a potential for low environmental impact due to low level of activation from neutron fluence and a relatively short half-life. They also have attractive material properties for use in a reactor. General Atomics along with Argonne National Laboratory (ANL) and Oak Ridge National Laboratory (ORNL), has developed a plan to utilize vanadium alloys as part of the Radiative Divertor Project (RDP) modification for the DIII-D tokamak. The goal for using vanadium alloys is to provide a meaningful step towards developing advanced materials for fusion power applications by demonstrating the in-service behavior of a vanadium alloy (V-4Cr-4Ti) in a tokamak in conjunction with developing essential fabrication technology for the manufacture of full-scale vanadium alloy components. A phased approach towards utilizing vanadium in DIII-D is being used starting with small coupons and samples, advancing to a small component, and finally a portion of the new double-null, slotted divertor will be fabricated from vanadium alloy product forms. A major portion of the program is research and development to support fabrication and resolve key issues related to environmental effects

  6. The bioavailability of iron, zinc, protein and vitamin A is highly variable in French individual diets: Impact on nutrient inadequacy assessment and relation with the animal-to-plant ratio of diets.

    Science.gov (United States)

    Perignon, Marlène; Barré, Tangui; Gazan, Rozenn; Amiot, Marie-Josèphe; Darmon, Nicole

    2018-01-01

    Nutritional adequacy depends on nutrient intakes and bioavailability which strongly varies with the plant- or animal-origin of foods. The aim was to estimate iron, zinc, protein and vitamin A bioavailability from individual diets, and investigate its relation with the animal-to-plant ratio (A/P) of diets. Bioavailability was estimated in 1899 French diets using diet-based algorithms or food-group specific conversion factors. Nutrient inadequacy was estimated based on i) bioavailability calculated in each individual diet and ii) average bioavailability assumed for Western-diets. Mean iron absorption, zinc absorption, protein quality and β-carotene conversion factor were 13%, 30%, 92%, and 17:1, respectively. Bioavailability displayed a high variability between individual diets, poorly explained by their A/P. Using individual bioavailability led to different inadequacy prevalence than with average factors assumed for Western-diets. In this population, the A/P does not seem sufficient to predict nutrient bioavailability and the corresponding recommended intakes. Nutritional adequacy should be assessed using bioavailability accounting for individual diets composition. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Experimental method for investigating helium effects in irradiated vanadium

    International Nuclear Information System (INIS)

    Smith, D.L.; Matsui, H.; Greenwood, L.; Loomis, B.

    1987-10-01

    Analyses have been performed which indicate that an effective method for experimentally investigating helium effects in neutron irradiated vanadium base alloys can be developed. The experimental procedure involves only modest modifications to existing procedures currently used for irradiation testing of vanadium-base alloys in the FFTF reactor. Helium is generated in the vanadium alloy by decay of tritium which is either preinjected or generated within the test capsule. Calculations indicate that nearly constant He/dpa ratios of desired magnitude can be attained by proper selection of experimental parameters. The proposed method could have a major impact on the development of vanadium base alloys for fusion reactor applications. 8 refs., 4 figs

  8. Iron, transferrin and myelinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Sergeant, C. E-mail: sergeant@cenbg.in2p3.fr; Vesvres, M.H.; Deves, G.; Baron, B.; Guillou, F

    2003-09-01

    Transferrin (Tf), the iron binding protein of vertebrates serum, is known to be synthesized by oligodendrocytes (Ols) in the central nervous system. It has been postulated that Tf is involved in Ols maturation and myelinogenesis. This link is particularly important in the understanding of a severe human pathology: the multiple sclerosis, which remains without efficient treatment. We generated transgenic mice containing the complete human Tf gene and extensive regulatory sequences from the 5{sup '} and 3{sup '} untranslated regions that specifically overexpress Tf in Ols. Brain cytoarchitecture of the transgenic mice appears to be normal in all brain regions examined, total myelin content is increased by 30% and motor coordination is significantly improved when compared with non-transgenic littermates. Tf role in the central nervous system may be related to its affinity for metallic cations. Normal and transgenic mice were used for determination of trace metals (iron, copper and zinc) and minerals (potassium and calcium) concentration in cerebellum and corpus callosum. The freeze-dried samples were prepared to allow proton-induced X-ray emission and Rutherford backscattering spectrometry analyses with the nuclear microprobe in Bordeaux. Preliminary results were obtained and carbon distribution was revealed as a very good analysis to distinguish precisely the white matter region. A comparison of metallic and mineral elements contents in brain between normal and transgenic mice shows that iron, copper and zinc levels remained constant. This result provides evidence that effects of Tf overexpression in the brain do not solely relate to iron transport.

  9. Vanadium-base alloys for fusion reactor applications

    International Nuclear Information System (INIS)

    Smith, D.L.; Loomis, B.A.; Diercks, D.R.

    1984-10-01

    Vanadium-base alloys offer potentially significant advantages over other candidate alloys as a structural material for fusion reactor first wall/blanket applications. Although the data base is more limited than that for the other leading candidate structural materials, viz., austenitic and ferritic steels, vanadium-base alloys exhibit several properties that make them particularly attractive for the fusion reactor environment. This paper presents a review of the structural material requirements, a summary of the materials data base for selected vanadium-base alloys, and a comparison of projected performance characteristics compared to other candidate alloys. Also, critical research and development (R and D) needs are defined

  10. Vanadium-base alloys for fusion reactor applications

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.L.; Loomis, B.A.; Diercks, D.R.

    1984-10-01

    Vanadium-base alloys offer potentially significant advantages over other candidate alloys as a structural material for fusion reactor first wall/blanket applications. Although the data base is more limited than that for the other leading candidate structural materials, viz., austenitic and ferritic steels, vanadium-base alloys exhibit several properties that make them particularly attractive for the fusion reactor environment. This paper presents a review of the structural material requirements, a summary of the materials data base for selected vanadium-base alloys, and a comparison of projected performance characteristics compared to other candidate alloys. Also, critical research and development (R and D) needs are defined.

  11. Preconcentration and atomic absorption spectrometric determination of cadmium, cobalt, copper, iron, lead, manganese, nickel and zinc in water samples using 6-methyl-2-pyridinecarboxaldehyde-4-phenyl-3-thiosemicarbazone

    International Nuclear Information System (INIS)

    Khuhawar, M.Y.; Das, P.; Dewani, V.K.

    2005-01-01

    The reagent 6-methyl-2-pyridinecarboxaldehyde-4-phenyl-3-thiosemicarbazone (MPAPT) has been examined for the pre-concentration of metal ions and determination using air acetylene flame atomic absorption spectrometer. The method is based on the complexation and extraction of cadmium (II), cobalt(III), copper(II), lead(II), nickel(II), iron(II), iron(II), manganese(II) and zinc(II) in chloroform. The metal iron are back extracted in nitric acid (1:1) or after evaporation of solvent the residue is digested in nitric acid. After necessary adjustment of volume the metal ions were determined in aqueous solution. Pre-concentration is obtained 10-25 times. Metal ions recovery was 95.4-100.8% with coefficient of variation 0.2-7.5%. The method used for the determination of metals in canal and sewerage waters, within 2-6433 mu g/L with C. V 0.-5.2%. (author)

  12. Flow-Injection Solid Phase Partial Least-Squares Spectrophotometric Simultaneous Determination of Iron, Nickel and Zinc

    Directory of Open Access Journals (Sweden)

    Teixeira Leonardo S. G.

    2002-01-01

    Full Text Available A PLS-2 multivariate calibration method has been developed for the simultaneous determination of iron, nickel and zinc in ternary mixtures by solid phase spectrophotometry associated with flow injection analysis. Fe(II, Ni(II and Zn(II form color complexes with 1-(2-thiazolylazo-2-naphthol (TAN, immobilized on a C18 bonded silica support, at pH 6.4. The proposed procedure is based on the different reaction/retention ratios of the studied ions on the solid support. Bilinear spectrophotometric data of the analytes, fixed in the solid support, were recorded in the 400-800 nm wavelength range as a function of time and a partial least squares (PLS-2 algorithm was used to predict results of synthetic samples. The calibration set employed was integrated by 8 ternary mixture standards and a blank solution. Mixtures containing 0.040 to 0.20 mg L-1, of each species, were successfully resolved, using 3 factors for each analyte and a restricted number of absorbance data obtained in the wavelength range from 560 to 650 nm.

  13. Effect of drying method on properties of vanadium-molybdenum oxide catalysts

    International Nuclear Information System (INIS)

    Gorshkova, T.P.; Savchenko, L.A.; Tarasova, D.V.; Tret'yakov, Yu.D.; Olen'kova, I.P.; Nikoro, T.A.; Maksimov, N.G.

    1981-01-01

    Effect of drying method of molybdenum and vanadium salt solutions on physicochemical and catalytical properties of vanadium-molybdenum catalysts is studied. It is shown that the drying method of solutions determines the completeness of vanadium binding into oxide vanadium-molybdenum compounds and thus effects the activity and selectivity of catalysts in acrolein oxidation into acrylic acid. Besides the drying method determines the porous structure of catalysts [ru

  14. Recent progress on gas tungsten arc welding of vanadium alloys

    Energy Technology Data Exchange (ETDEWEB)

    King, J.F.; Grossbeck, M.L.; Goodwin, G.M.; Alexander, D.J. [Oak Ridge National Lab., TN (United States)

    1997-04-01

    This is a progress report on a continuing research project to acquire a fundamental understanding of the metallurgical processes in the welding of vanadium alloys. It also has the goal of developing techniques for welding structural vanadium alloys. The alloy V-4Cr-4Ti is used as a representative alloy of the group; it is also the prime candidate vanadium alloy for the U.S. Fusion Program at the present time. However, other alloys of this class were used in the research as necessary. The present work focuses on recent findings of hydrogen embrittlement found in vanadium alloy welds. It was concluded that the atmosphere in the inert gas glove box was insufficient for welding 6mm thick vanadium alloy plates.

  15. Optimization of Removal Efficiency and Minimum Contact Time for Cadmium and Zinc Removal onto Iron-modified Zeolite in a Two-stage Batch Sorption Reactor

    Directory of Open Access Journals (Sweden)

    M. Ugrina

    2018-01-01

    Full Text Available In highly congested industrial sites where significant volumes of effluents have to be treated in the minimum contact time, the application of a multi-stage batch reactor is suggested. To achieve better balance between capacity utilization and cost efficiency in design optimization, a two-stage batch reactor is usually the optimal solution. Thus, in this paper, a two-stage batch sorption design approach was applied to the experimental data of cadmium and zinc uptake onto iron-modified zeolite. The optimization approach involves the application of the Vermeulen’s approximation model and mass balance equation to kinetic data. A design analysis method was developed to optimize the removal efficiency and minimum total contact time by combining the time required in the two-stages, in order to achieve the maximum percentage of cadmium and zinc removal using a fixed mass of zeolite. The benefits and limitations of the two-stage design approach have been investigated and discussed

  16. Absorption of hydrogen by vanadium-palladium alloys

    International Nuclear Information System (INIS)

    Artman, D.; Lynch, J.F.; Flanagan, T.B.

    1976-01-01

    Pressure composition isotherms (273-373 K) have been determined for the absorption of hydrogen by a series of six palladium alloys (f.c.c) in the composition range from 1 to 8 at.% vanadium. At a given hydrogen content, the equilibrium hydrogen pressure progressively increases with vanadium content. Thermodynamic parameters for the absorption of hydrogen are reported at infinite dilution of hydrogen and for the formation of the nonstoichiometric hydride from the hydrogen-saturated alloy. The relative, partial molar enthalpy of solution of hydrogen at infinite dilution increases slightly with vanadium content. The presence of vanadium, which absorbs hydrogen itself in its normal b.c.c. structure, greatly inhibits the ability of palladium to absorb hydrogen. For example, the isobaric solubility of hydrogen (1 atm, 298K) decreases from H/Pd=0.7 (palladium) to 0.024 (V(6%)-Pd). The lattice expansion due to the presence of interstitial hydrogen has been determined by X-ray diffraction. From these data it can be concluded that the formation of two non-stoichiometric hydride phases does not occur at vanadium contents greater that 5 at.% (298 K). Electrical resistance has been measured as a function of the hydrogen content of the alloys. The electrical resistance increases more markedly with hydrogen content for these alloys than for any of the palladium alloys previously examined. (Auth.)

  17. Characterization of vanadium flow battery

    Energy Technology Data Exchange (ETDEWEB)

    Bindner, H.; Ekman, C.; Gehrke, O.; Isleifsson, F.

    2010-10-15

    This report summarizes the work done at Risoe DTU testing a vanadium flow battery as part of the project 'Characterisation of Vanadium Batteries' (ForskEl project 6555) with the partners PA Energy A/S and OI Electric A/S under the Danish PSO energy research program. A 15kW/120kWh vanadium battery has been installed as part of the distributed energy systems experimental facility, SYSLAB, at Risoe DTU. A test programme has been carried out to get hands-on experience with the technology, to characterize the battery from a power system point of view and to assess it with respect to integration of wind energy in the Danish power system. The battery has been in operation for 18 months. During time of operation the battery has not shown signs of degradation of performance. It has a round-trip efficiency at full load of approximately 60% (depending on temperature and SOC). The sources of the losses are power conversion in cell stacks/electrolyte, power converter, and auxiliary power consumption from pumps and controller. The response time for the battery is limited at 20kW/s by the ramp rate of the power converter. The battery can thus provide power and frequency support for the power system. Vanadium battery is a potential technology for storage based services to the power system provided investment and O and M cost are low enough and long term operation is documented. (Author)

  18. Effect of replacement of vanadium by iron on the electrochemical behaviour of titanium alloys in simulated physiological media

    Directory of Open Access Journals (Sweden)

    Mareci, D.

    2009-02-01

    Full Text Available The electrochemical behaviour of Ti6Al4V, Ti6Al3.5Fe and Ti5Al2.5Fe alloys has been evaluated in Ringer’s solution at 25 °C. The effect of the substitution of vanadium in Ti6Al4V alloy has been specifically addressed. The evaluation of the corrosion resistance was carried out through the analysis of the open circuit potential variation with time, potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS tests. Very low current densities were obtained (order of nA/cm2 from the polarization curves and EIS, indicating a typical passive behaviour for all investigated alloys. The EIS results exhibited relative capacitive behaviour (large corrosion resistance with phase angle close to –80° and relative high impedance values (order of 105 Ω•cm2 at low and medium frequencies, which are indicative of the formation of a highly stable film on these alloys in Ringer’s solution. In conclusion, the electrochemical behaviour of Ti6Al4V is not affected by the substitution of vanadium with iron.

    El comportamiento electroquímico de las aleaciones Ti6Al4V, Ti6Al3.5Fe y Ti5Al2.5Fe fue evaluado en una disolución Ringer a 25 °C. Se ha estudiado especialmente el efecto de la sustitución del vanadio en la aleación Ti6Al4V. La evaluación de la resistencia a la corrosión se ha llevado a cabo a través del análisis de la variación del potencial de un circuito abierto con el tiempo, las curvas de polarización potenciodinámicas y los ensayos de espectroscopía de impedancia electroquímica (EIS. Se han obtenido densidades de corriente muy bajas (del orden de nA/cm2 en las curvas de polarización y EIS, indicando un comportamiento pasivo típico para todas las aleaciones investigadas. Los resultados de la EIS mostraron un comportamiento capacitivo relativo (gran resistencia a la corrosión con ángulos de fase próximos a –80° y valores de impedancia relativamente altos (del orden de

  19. Enhanced magnetization in VxFe3−xO4 nanoparticles

    International Nuclear Information System (INIS)

    Pool, V.L.; Kleb, M.T.; Chorney, C.L.; Arenholz, E.; Idzerda, Y.U.

    2015-01-01

    Nanoparticles of V x Fe 3−x O 4 with up to 33% vanadium doping (x=0 to 1) and a 9 nm diameter are investigated in order to determine the site preference of the vanadium and the magnetic behavior of the nanoparticles. The iron and vanadium L 23 -edge X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (MCD) spectra are used to identify that vanadium initially substitutes into the tetrahedral iron site as V 3+ and that the average iron moment is observed to increase with vanadium concentration up to 12.5% (x=.375). When the vanadium incorporation exceeds 12.5%, the XAS and MCD show that the vanadium begins substituting as V 2+ in the octahedral coordination. This coincides with a rapid reduction of the average moment to zero by 25% (x=.75). The frequency-dependent alternating-current magnetic susceptibility (ACMS) displays a substantial increase in blocking temperature with vanadium concentration and indicated substantial variation in the strength of inter-particle interactions. - Highlights: • Vanadium initially substitutes into the tetrahedral iron site as V 3+ . • The average iron moment increases with vanadium concentration up to 12.5% vanadium (x=.375). • There is a substantial increase in blocking temperature with vanadium concentration. • Above 12.5% vanadium doping, the vanadium substitutes as V 2+ in the octahedral coordination

  20. Arsenic, chromium, copper, iron, manganese, lead, selenium and ...

    African Journals Online (AJOL)

    Arsenic, chromium, copper, iron, manganese, lead, selenium and zinc in the tissues of the largemouth yellowfish, Labeobarbus kimberleyensis (Gilchrist and Thompson, 1913), from the Vaal Dam, South Africa, and associated consumption risks.

  1. Acute toxicity of vanadium to the threespine stickleback, Gasterosteus aculeatus

    Energy Technology Data Exchange (ETDEWEB)

    Gravenmier, J.J.; Johnston, D.W.; Arnold, W.R. [Blasland Bouck & Lee Inc, Petaluma, CA (US)

    2005-02-15

    Vanadium is widely distributed, occurring in many types of minerals, coal, and petroleum. Anthropogenic sources of vanadium originate from the production, processing, and wastes of these materials. The aquatic toxicity of vanadium to fish species is not well characterized. This study focused on the three-spined stickleback, Gasterosteus aculeatus, a small and widely distributed euryhaline species of fish. The three-spined stickleback is used as an effluent-monitoring species in both Canada and the United States. Five 96-h static renewal acute toxicity tests were performed in moderately hard water with adult fish. The geometric mean and range of the five 96-h LC{sup 50}s based on measured concentrations of total vanadium in the test solution were 3.17 and 2.35-4.07 mg V/L, respectively. A conservative estimation of a safe concentration of vanadium that would not affect survival of adult three-spined sticklebacks over a 96-h exposure period in moderately hard water is approximately 0.30 mg V/L. A comparison with other fish species previously tested suggests that the three-spined stickleback is intermediate in sensitivity to vanadium. Information reported from this study may be useful in effluent toxicity identification evaluations and ecological risk assessments related to vanadium.

  2. Calcium, potassium, iron, copper and zinc concentrations in the white and gray matter of the cerebellum and corpus callosum in brain of four genetic mouse strains

    International Nuclear Information System (INIS)

    Sergeant, C.; Vesvres, M.H.; Deves, G.; Guillou, F.

    2005-01-01

    In the central nervous system, metallic cations are involved in oligodendrocyte maturation and myelinogenesis. Moreover, the metallic cations have been associated with pathogenesis, particularly multiple sclerosis and malignant gliomas. The brain is vulnerable to either a deficit or an excess of available trace elements. Relationship between trace metals and myelinogenesis is important in understanding a severe human pathology : the multiple sclerosis, which remains without efficient treatment. One approach to understand this disease has used mutant or transgenic mice presenting myelin deficiency or excess. But to date, the concentration of trace metals and mineral elements in white and gray matter areas in wild type brain is unknown. The aim of this study is to establish the reference concentrations of trace metals (iron, copper and zinc) and minerals (potassium and calcium) in the white and gray matter of the mouse cerebellum and corpus callosum. The brains of four different genetic mouse strains (C57Black6/SJL, C57Black6/D2, SJL and C3H) were analyzed. The freeze-dried samples were prepared to allow PIXE (Proton-induced X-ray emission) and RBS (Rutherford backscattering spectrometry) analyses with the nuclear microprobe in Bordeaux. The results obtained give the first reference values. Furthermore, one species out of the fours testes exhibited differences in calcium, iron and zinc concentrations in the white matter

  3. Calcium, potassium, iron, copper and zinc concentrations in the white and gray matter of the cerebellum and corpus callosum in brain of four genetic mouse strains

    Energy Technology Data Exchange (ETDEWEB)

    Sergeant, C. [CNRS-Universite de Bordeaux I, UMR 5084, Chimie Nucleaire Analytique et Bio environnementale, Le Haut Vigneau, BP120, 33175 Bordeaux-Gradignan (France)]. E-mail: sergeant@cenbg.in2p3.fr; Vesvres, M.H. [CNRS-Universite de Bordeaux I, UMR 5084, Chimie Nucleaire Analytique et Bio environnementale, Le Haut Vigneau, BP120, 33175 Bordeaux-Gradignan (France); Deves, G. [CNRS-Universite de Bordeaux I, UMR 5084, Chimie Nucleaire Analytique et Bio environnementale, Le Haut Vigneau, BP120, 33175 Bordeaux-Gradignan (France); Guillou, F. [INRA-CNRS-Universite de Tours-Haras nationaux, UMR 6175, Physiologie de la Reproduction et des Comportements, 37380 Nouzilly (France)

    2005-04-01

    In the central nervous system, metallic cations are involved in oligodendrocyte maturation and myelinogenesis. Moreover, the metallic cations have been associated with pathogenesis, particularly multiple sclerosis and malignant gliomas. The brain is vulnerable to either a deficit or an excess of available trace elements. Relationship between trace metals and myelinogenesis is important in understanding a severe human pathology : the multiple sclerosis, which remains without efficient treatment. One approach to understand this disease has used mutant or transgenic mice presenting myelin deficiency or excess. But to date, the concentration of trace metals and mineral elements in white and gray matter areas in wild type brain is unknown. The aim of this study is to establish the reference concentrations of trace metals (iron, copper and zinc) and minerals (potassium and calcium) in the white and gray matter of the mouse cerebellum and corpus callosum. The brains of four different genetic mouse strains (C57Black6/SJL, C57Black6/D2, SJL and C3H) were analyzed. The freeze-dried samples were prepared to allow PIXE (Proton-induced X-ray emission) and RBS (Rutherford backscattering spectrometry) analyses with the nuclear microprobe in Bordeaux. The results obtained give the first reference values. Furthermore, one species out of the fours testes exhibited differences in calcium, iron and zinc concentrations in the white matter.

  4. TiAl doping by vanadium: ab initio study

    International Nuclear Information System (INIS)

    Smirnova, E.A.; Isaev, Eh.I.; Vekilov, Yu.Kh.

    2004-01-01

    Tetragonality degree in TiAl and vanadium doping effect on it were studied using the methods of calculation based on approximation of coherent potential and ab initio pseudopotentials. It is shown that vanadium substitution for Ti sublattice atoms entails increase in tetragonality degree but with substitution of the atoms in aluminium sublattice the tetragonality of the TiAl:V alloy decreases and at the content of vanadium about 8 at. % the lattice becomes actually cubical. In its turn, it may result in increase in TiAl ductility, the alloy being brittle at low temperatures [ru

  5. Effects of hydrogen on fatigue of vanadium and niobium. Annual report

    International Nuclear Information System (INIS)

    Stoloff, N.S.; Chung, D.W.

    1977-01-01

    The fatigue behavior of unalloyed vanadium and niobium as well as their alloys with hydrogen is described. The response of vanadium-hydrogen alloys to cyclic loading is shown to depend markedly upon the presence or absence of notches, the hydrogen level, method of test, and frequency. In general, hydrides improve high cycle life of unnotched alloys, but are detrimental in the presence of a notch. Low test frequencies also lead to reduced fatigue lives. Stress-assisted hydride growth in previously hydrided alloys has been noted both in fatigue and in delayed failure experiments. Unalloyed vanadium and solid solution vanadium-hydrogen alloys do not undergo delayed failure. Preliminary tests on unalloyed niobium and several niobium-vanadium alloys reveal improvements in stress-controlled fatigue life and decreased low cycle life, in agreement with previous observations on vanadium-hydrogen alloys

  6. Vanadium supply and demand outlook. Final report

    International Nuclear Information System (INIS)

    1978-01-01

    A review has been made of the reserves and resources for vanadium minerals in the United States and foreign countries. Foreign sources are presently used to provide a substantial part of national demand because of price advantages. There are so many functioning foreign sources for vanadium that it is difficult to conceive of circumstances that would shut all of them off. The basis for the national stockpile is described. A recommendation is made to add the 65V-35Al alloy as a component of the stockpile for titanium alloy production in a national emergency. Estimated consumption growth rates to 1990 vary from one to five percent per year depending on the end product involved. Fission reactor use of vanadium-base alloys has not developed because of technical problems. In the chemical field, a slow steady growth of five to six percent per year is projected. Technical preferences for vanadium in various steel applications will continue although other alloying alternatives are generally available. Overall environmental effects do not appear to be a serious industrial problem

  7. Iron from nanocompounds containing iron and zinc is highly bioavailable in rats without tissue accumulation.

    Science.gov (United States)

    Hilty, Florentine M; Arnold, Myrtha; Hilbe, Monika; Teleki, Alexandra; Knijnenburg, Jesper T N; Ehrensperger, Felix; Hurrell, Richard F; Pratsinis, Sotiris E; Langhans, Wolfgang; Zimmermann, Michael B

    2010-05-01

    Effective iron fortification of foods is difficult, because water-soluble compounds that are well absorbed, such as ferrous sulphate (FeSO(4)), often cause unacceptable changes in the colour or taste of foods. Poorly water-soluble compounds, on the other hand, cause fewer sensory changes, but are not well absorbed. Here, we show that poorly water-soluble nanosized Fe and Fe/Zn compounds (specific surface area approximately 190 m(2) g(-1)) made by scalable flame aerosol technology have in vivo iron bioavailability in rats comparable to FeSO(4) and cause less colour change in reactive food matrices than conventional iron fortificants. The addition of Zn to FePO(4) and Mg to Fe/Zn oxide increases Fe absorption from the compounds, and doping with Mg also improves their colour. After feeding rats with nanostructured iron-containing compounds, no stainable Fe was detected in their gut wall, gut-associated lymphatics or other tissues, suggesting no adverse effects. Nanosizing of poorly water-soluble Fe compounds sharply increases their absorption and nutritional value.

  8. The vanadium/oxygen system in the analysis of sodium for oxygen

    International Nuclear Information System (INIS)

    Walker, J.A.J.; Price, W.B.

    1981-05-01

    An investigation of the V-O-Na system at 1023 K is described for oxygen in sodium contents of 5 to 25 ppm. Electron spectroscopy combined with depth profiling is used to determine the vanadium/oxygen ratios inwards from the surface of vanadium foil and these ratios are compared with theoretical predictions. The validity of the vanadium wire technique as an analytical method is examined and a model for the vanadium oxidation is suggested. (author)

  9. Process of coke less without waste treatment of direct vanadium allowing steel melting

    International Nuclear Information System (INIS)

    Lisienko, V.G.; Droujinina, O.G.; Morozova, V.A.; Ladigina, N.V.; Yusfin, Yu.S.; Parenkev, A.E.

    2003-01-01

    The development of new methods of steel production are now conducted with the purpose of energy consumption and harmful emissions reduction. The choice of technology and equipment in this case plays a marginal role. It is well known that vanadium alloying steel has increased service properties. The known classical scheme of vanadium steel melting is very power-intensive, as includes such power-intensive processes as blast furnace process and chemical processing of vanadium slag therewith sintering and by-product coke processes are accompanied by significant harmful emissions. In so doing the vanadium losses may run to 60%. In view of requests of environment protection and economical efficiency the new process of coke less without wastes processing of vanadium-bearing raw material with direct vanadium allowing of steel - LP-process is developed. Its purpose is the melting on the basis of vanadium-bearing titanomagnetite of vanadium allowing steel with increase of vanadium concentration in steel and diminution of vanadium losses without application coke and natural gas with use of any coals and carbon-bearing wastes. LP-process consists of three aggregates and corresponding processes: process of liquid-phase reduction, process of vanadium-bearing pellets metallization in the shaft furnace, and process of alloying steel melting in the arc electric furnace. The obtained results have shown, that the LP-process is more energy saving on a comparison with other methods of vanadium allowing steel production. (Original)

  10. Fortification of staple foods with zinc for improving zinc status and other health outcomes in the general population.

    Science.gov (United States)

    Shah, Dheeraj; Sachdev, Harshpal S; Gera, Tarun; De-Regil, Luz Maria; Peña-Rosas, Juan Pablo

    2016-06-09

    , extracted data from included studies, and assessed the risk of bias of the included studies. We included eight trials (709 participants); seven were from middle-income countries of Asia, Africa, Europe, and Latin America where zinc deficiency is likely to be a public health problem. Four trials compared the effect of zinc-fortified staple foods with unfortified foods (comparison 1), and four compared zinc-fortified staple foods in combination with other nutrients/factors with the same foods containing other nutrients or factors without zinc (comparison 2). The interventions lasted between one and nine months. We categorised most trials as having unclear or high risk of bias for randomisation, but low risk of bias for blinding and attrition. None of the studies in comparison 1 reported data on zinc deficiency.Foods fortified with zinc increased the serum or plasma zinc levels in comparison to foods without added zinc (mean difference (MD) 2.12 µmol/L, 95% confidence interval (CI) 1.25 to 3.00 µmol/L; 3 studies; 158 participants; low-quality evidence). Participants consuming foods fortified with zinc versus participants consuming the same food without zinc had similar risk of underweight (average risk ratio 3.10, 95% CI 0.52 to 18.38; 2 studies; 397 participants; low-quality evidence) and stunting (risk ratio (RR) 0.88, 95% CI 0.36 to 2.13; 2 studies; 397 participants; low-quality evidence). A single trial of addition of zinc to iron in wheat flour did not find a reduction in proportion of zinc deficiency (RR 0.17, 95% CI 0.01 to 3.94; very low-quality evidence). We did not find a difference in serum or plasma zinc levels in participants consuming foods fortified with zinc plus other micronutrients when compared with participants consuming the same foods with micronutrients but no added zinc (MD 0.03 µmol/L, 95% CI -0.67 to 0.72 µmol/L; 4 studies; 250 participants; low-quality evidence). No trial in comparison 2 provided information about underweight or stunting.There was

  11. UPTAKE OF HEAVY METALS IN BATCH SYSTEMS BY A RECYCLED IRON-BEARING MATERIAL

    Science.gov (United States)

    An iron-bearing material deriving from surface finishing operations in the manufacturing of cast-iron components demonstrates potential for removal of heavy metals from aqueous waste streams. Batch isotherm and rate experiments were conducted for uptake of cadmium, zinc, and lead...

  12. Zinc ferrite nanoparticles as perspective functional materials for applications in casting technologies

    Directory of Open Access Journals (Sweden)

    A. Kmita

    2017-01-01

    Full Text Available In this article it discuss on possible application of magnetic oxide nanoparticles, namely non-stoichiometric zinc ferrite nanoparticles as a functionalizing agent in foundry processes. Thermal analysis showed a weight loss of the sample at 1 273 K in an amount of 7,7 %, which is a result of the following processes taking place in different temperature ranges. Upon its thermal treatment Zn0,4Fe2,6O4 decomposes to zinc oxide and iron (III oxide (first stage and next to iron (II,III oxide and oxygen (second stage. The degree of decomposition was expressed as Fe2+ / Fetotal. Mössbauer spectroscopy showed that the over 30 % of Fe3+ present in starting material was reduced to Fe2+.

  13. Recycling of Zn-containing Fe-bearing steelmaking waste by the reducing smelting process in pig iron. I. Laboratory tests

    Directory of Open Access Journals (Sweden)

    Kendera Ján

    1997-09-01

    Full Text Available Results of the laboratory test treatment of the zinc containing steelwork dusts in a hot liquid pig iron are described. These results show that it is necessary to use an external reductant. The zinc content of the dust emission is ca. 20 %. The charge of the steel-works dusts diminished the Si and Mn content of pig iron.

  14. A novel comprehensive utilization of vanadium slag: As gamma ray shielding material

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Mengge [School of Metallurgy, Northeastern University, Shenyang 110004 (China); Liaoning Key Laboratory of Metallurgical Resources Recycling Science, Shenyang 110004 (China); Xue, Xiangxin, E-mail: xuexx@mail.neu.edu.cn [School of Metallurgy, Northeastern University, Shenyang 110004 (China); Liaoning Key Laboratory of Metallurgical Resources Recycling Science, Shenyang 110004 (China); Yang, He; Liu, Dong [School of Metallurgy, Northeastern University, Shenyang 110004 (China); Liaoning Key Laboratory of Metallurgical Resources Recycling Science, Shenyang 110004 (China); Wang, Chao [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Li, Zhefu [Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2016-11-15

    Highlights: • A novel comprehensive utilization method for vanadium slag is proposed. • Shielding properties of vanadium slag are better than ordinary concrete. • HVL of vanadium slag is between Lead and concrete to shield {sup 60}Co gamma ray. • HVL of composite is higher than concrete when adding amount of vanadium slag is 900. • Composite can be used as injecting mortar for cracks developed in concrete shields. - Abstract: New exploration of vanadium slag as gamma ray shielding material was proposed, the shielding properties of vanadium slag was higher than concrete when the energy of photons was in 0.0001 MeV–100000 MeV. Vanadium slag/epoxy resin composites were prepared, shielding and material properties of materials were tested by {sup 60}Co gamma ray, simultaneous DSC-TGA, electronic universal testing machine and scanning electron microscopy, respectively. The results showed that the shielding properties of composite would be better with the increase of vanadium slag addition amount. The HVL (half value layer thickness) of vanadium slag was between Lead and concrete while composite was higher than concrete when the addition amount of vanadium slag was 900 used as material to shield {sup 60}Co gamma ray, also the resistance temperature of composite was about 215 °C and the bending strength was over 10 MPa. The composites could be used as injecting mortar for cracks developed in biological concrete shields, coating for the floor of the nuclear facilities, and shielding materials by itself.

  15. Effect of zinc therapy in patients with psoriasis and a topic dermatitis on some trace elements in serum and skin

    International Nuclear Information System (INIS)

    ElBedewl, A.E.; ElSaid, S.M.

    2002-01-01

    The effects of zinc therapy on some trace elements in serum and skin had been studied in forty patients with psoriasis and a topic dermatitis with age range between 20-65 years. Patients were treated with 330 mg oral zinc sulfate for 12 week. Significant increases in both serum and skin copper levels were detected. Also, serum and skin calcium and magnesium levels in both psoriatic and a topic patients were significantly decreased, while iron level was significantly increased in psoriasis and significantly decreased in a topic patients. It could be conclude that zinc therapy could affect copper, calcium, iron and magnesium levels in both psoriatic and a topic patients

  16. Cobalt-, zinc- and iron-bound forms of adenylate kinase (AK) from the sulfate-reducing bacterium Desulfovibrio gigas: purification, crystallization and preliminary X-ray diffraction analysis

    International Nuclear Information System (INIS)

    Kladova, A. V.; Gavel, O. Yu.; Mukhopaadhyay, A.; Boer, D. R.; Teixeira, S.; Shnyrov, V. L.; Moura, I.; Moura, J. J. G.; Romão, M. J.; Trincão, J.; Bursakov, S. A.

    2009-01-01

    Adenylate kinase (AK) from D. gigas was purified and crystallized in three different metal-bound forms: Zn 2+ –AK, Co 2+ –AK and Fe 2+ –AK. Adenylate kinase (AK; ATP:AMP phosphotransferase; EC 2.7.4.3) is involved in the reversible transfer of the terminal phosphate group from ATP to AMP. AKs contribute to the maintenance of a constant level of cellular adenine nucleotides, which is necessary for the energetic metabolism of the cell. Three metal ions, cobalt, zinc and iron(II), have been reported to be present in AKs from some Gram-negative bacteria. Native zinc-containing AK from Desulfovibrio gigas was purified to homogeneity and crystallized. The crystals diffracted to beyond 1.8 Å resolution. Furthermore, cobalt- and iron-containing crystal forms of recombinant AK were also obtained and diffracted to 2.0 and 3.0 Å resolution, respectively. Zn 2+ –AK and Fe 2+ –AK crystallized in space group I222 with similar unit-cell parameters, whereas Co 2+ –AK crystallized in space group C2; a monomer was present in the asymmetric unit for both the Zn 2+ –AK and Fe 2+ –AK forms and a dimer was present for the Co 2+ –AK form. The structures of the three metal-bound forms of AK will provide new insights into the role and selectivity of the metal in these enzymes

  17. Relationship of dietary factors with dialyzable iron and in vitro iron bioavailability in the meals of farm women.

    Science.gov (United States)

    Singh, Anamika; Bains, Kiran; Kaur, Hapreet

    2016-04-01

    Sixty rural women with age varying between 25 and 35 were selected randomly to determine the role of dietary factors on bioavailability of iron in their diets. Food samples of selected subjects were collected for three major meals i.e. breakfast, lunch and dinner for three consecutive days. The samples were analyzed for meal constituents associated with iron absorption as well as for total and dialyzable iron. Based on dietary characteristics, the diets of the farm women were in the class of intermediate diets as per FAO/WHO classification with iron bioavailability of 8.11 %. The statistical analysis revealed that the meal constituents which were found to influence iron absorption positively were ascorbic acid and β-carotene in breakfast and only β-carotene in dinner. The meal constituents which affected iron absorption negatively were zinc and calcium in breakfast as well as lunch and phytates and NDF in dinner, however, polyphenols present in the meals of the subjects did not show any relationship with iron absorption.

  18. Hydrometallurgic treatment of a mineral containing uranium, vanadium and phosphorus

    International Nuclear Information System (INIS)

    Echenique, Patricia; Fruchtenicht, Fernando; Gil, Daniel; Vigo, Daniel; Bouza, Angel; Vert, Gabriela; Becquart, Elena

    1987-01-01

    A preliminary study of a mineral has been made towards the hydrometallurgy separation of uranium, vanadium and phosphorus. After the ore dressing, work on sulfuric acid with oxidation leaching has been made, to get the uranium, vanadium and phosphorus in solution. For the separation and purification of these elements, two alternative solvent extraction methods have been tested. One of them has been the extraction of uranium and vanadium and a selective stripping of both elements. The second one has been the selective extraction of uranium and vanadium at different aqueous solutions pH. In both methods, the same reagent has been used: di(2-ethylhexyl) phosphoric acid, kerosene as diluent with two different synergistic agents: TOPO (tri-n-octyl phosphine oxide) and TBP (tri-n-butyl phosphate). Batch studies have been made to determine the equilibrium isotherms for uranium and vanadium. A continuous countercurrent simulation method has been used to get the best phase ratio and to test different stripping agents. For the first method, an important loss of uranium and vanadium at the feed solution conditioning for the extraction step has been observed. For the second method, a good recovery of uranium has been reached, but there has been losses of vanadium in pH adjustment. Nevertheless, among these processes, the last seems to work better in this mineral hydrometallurgy. (Author) [es

  19. Oxidation of methyl heterocyclic compounds on vanadium oxide catalysts

    International Nuclear Information System (INIS)

    Shimanskaya, M.V.; Lejtis, L.A.; Iovel', I.G.; Gol'dberg, Yu.Sh.; Skolmejstere, R.A.; Golender, L.O.

    1985-01-01

    Data on vapor-phase oxidation of methyl derivatives of thiophene, Δ 2 - thiazo line, pyridine, pyrazine and pyramidine on oxide vanadium-molybdenum catalysts to corresponding heterylaldehydes are generalized. The dependence of catalytic properties of oxide vanadium-molybdenum systems in oxidation reactions of methylheterocyclic compounds on V:Mo ratio in the catalyst is revealed. It is shown that heterocyclic compounds are coordinated by a heteroatom on Lewis centres of V-Mo-O-catalyst primarily with partially reduced vanadium ions

  20. Vanadium and titanium determination by resorcinalhydrazide of salicylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Karpova, O I; Pilipenko, A T; Lukachina, V V [AN Ukrainskoj SSR, Kiev. Inst. Kolloidnoj Khimii i Khimii Vody

    1979-02-01

    The complexing of titanium and vanadium with resorcinalhydrazyl of salicylic acid (RHSA) in water-organic media is studied. Titanium (4) forms a complex at pH 0.8-1.8, vanadium - at pH 2.5-5.6, and at pH 7.6-9.8. The complexes are well extracted by polar and nonpolar solvents from acid solutions. The techniques are developed for the determination of titanium and vanadium by the RHSA agent in nickel alloys.

  1. The Recovery of Zinc Heavy Metal from Industrial Liquid Waste

    International Nuclear Information System (INIS)

    Panggabean, Sahat M.

    2000-01-01

    It had been studied the recovery of zinc heavy metal from liquid waste of electroplating industry located at East Jakarta. The aim of this study was to minimize the waste arisen from industrial activities by taking out zinc metal in order to reused on-site. The method of recovery was two steps precipitation using NaOH reagent and pH variation. The first step of precipitation at pH optimum around 6 yielded iron metal. The second step at pH optimum around 10 yielded zinc metal. The zinc metal was taken out assessed to the possibility of reused at that fabric. By applying its, it will yield the volume reduction of sludge waste about 36.1% or 53.2% of zinc metal containing in the waste. It means the cost of waste treatment will be lower. Beside its, the effluent arisen from the method had fulfill the maximum limit and it allowed to release to the environment. (author)

  2. Effect of excess supply of heavy metals on the absorption and translocation of iron (/sup 59/Fe) in barley

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, C P; Bisht, S S; Agarwala, S C [Lucknow Univ. (India). Dept. of Botany

    1978-03-01

    The effects of an excess supply of manganese, copper, zinc, cobalt, and nickel on the absorption and translocation of iron tagged with /sup 59/Fe were xamined in 15 days old barley seedlings raised in solution culture. Excess heavy metal treatments and /sup 59/Fe were administered in three different ways: (i) both excess heavy metals and iron supplied through roots- Series A; (ii) excess heavy metal supplied as foliar spray and iron through roots- Series B; and (iii) excess heavy metal supplied through roots and iron as foliar spray-Series C. Results obtained revealed that excess concentrations of manganese, zinc, cobalt, and a to a lesser extent copper interfered with the absorption of iron from the rooting medium, but excess nickel enhanced the absorption and translocation of iron. Thus, unlike other metals, a toxic supply of nickel does not induce iron deficiency.

  3. Enhanced magnetization in V{sub x}Fe{sub 3−x}O{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Pool, V.L. [Dept. of Physics, Montana State University, Bozeman, MT 59715 (United States); Kleb, M.T. [Dept. of Chemistry, Montana Tech, Butte, MT 59701 (United States); Ctr. Advanced Supramolecular and Nanoscale Systems, Montana Tech, Butte, MT 59701 (United States); Chorney, C.L. [Dept. of Chemistry, Montana Tech, Butte, MT 59701 (United States); Arenholz, E. [Advanced Light Source, Lawrence Berkeley Nat. Labs, Berkeley, CA 94720 (United States); Idzerda, Y.U., E-mail: Idzerda@montana.edu [Dept. of Physics, Montana State University, Bozeman, MT 59715 (United States)

    2015-12-15

    Nanoparticles of V{sub x}Fe{sub 3−x}O{sub 4} with up to 33% vanadium doping (x=0 to 1) and a 9 nm diameter are investigated in order to determine the site preference of the vanadium and the magnetic behavior of the nanoparticles. The iron and vanadium L{sub 23}-edge X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (MCD) spectra are used to identify that vanadium initially substitutes into the tetrahedral iron site as V{sup 3+} and that the average iron moment is observed to increase with vanadium concentration up to 12.5% (x=.375). When the vanadium incorporation exceeds 12.5%, the XAS and MCD show that the vanadium begins substituting as V{sup 2+} in the octahedral coordination. This coincides with a rapid reduction of the average moment to zero by 25% (x=.75). The frequency-dependent alternating-current magnetic susceptibility (ACMS) displays a substantial increase in blocking temperature with vanadium concentration and indicated substantial variation in the strength of inter-particle interactions. - Highlights: • Vanadium initially substitutes into the tetrahedral iron site as V{sup 3+}. • The average iron moment increases with vanadium concentration up to 12.5% vanadium (x=.375). • There is a substantial increase in blocking temperature with vanadium concentration. • Above 12.5% vanadium doping, the vanadium substitutes as V{sup 2+} in the octahedral coordination.

  4. Structure and Corrosion Behavior of Arc-Sprayed Zn-Al Coatings on Ductile Iron Substrate

    Science.gov (United States)

    Bonabi, Salar Fatoureh; Ashrafizadeh, Fakhreddin; Sanati, Alireza; Nahvi, Saied Mehran

    2018-02-01

    In this research, four coatings including pure zinc, pure aluminum, a double-layered coating of zinc and aluminum, and a coating produced by simultaneous deposition of zinc and aluminum were deposited on a cast iron substrate using electric arc-spraying technique. The coatings were characterized by XRD, SEM and EDS map and spot analyses. Adhesion strength of the coatings was evaluated by three-point bending tests, where double-layered coating indicated the lowest bending angle among the specimens, with detection of cracks at the coating-substrate interface. Coatings produced by simultaneous deposition of zinc and aluminum possessed a relatively uniform distribution of both metals. In order to evaluate the corrosion behavior of the coatings, cyclic polarization and salt spray tests were conducted. Accordingly, pure aluminum coating showed susceptibility to pitting corrosion and other coatings underwent uniform corrosion. For double-layered coating, SEM micrographs revealed zinc corrosion products as flaky particles in the pores formed by pitting on the surface, an indication of penetration of corrosion products from the lower layer (zinc) to the top layer (aluminum). All coatings experienced higher negative corrosion potentials than the iron substrate, indicative of their sacrificial behavior.

  5. Low-temperature direct synthesis of mesoporous vanadium nitrides for electrochemical capacitors

    Science.gov (United States)

    Lee, Hae-Min; Jeong, Gyoung Hwa; Kim, Sang-Wook; Kim, Chang-Koo

    2017-04-01

    Mesoporous vanadium nitrides are directly synthesized by a one-step chemical precipitation method at a low temperature (70 °C). Structural and morphological analyses reveal that vanadium nitride consist of long and slender nanowhiskers, and mesopores with diameters of 2-5 nm. Compositional analysis confirms the presence of vanadium in the VN structure, along with oxidized vanadium. The cyclic voltammetry and charge-discharge tests indicate that the obtained material stores charges via a combination of electric double-layer capacitance and pseudocapacitance mechanisms. The vanadium nitride electrode exhibits a specific capacitance of 598 F/g at a current density of 4 A/g. After 5000 charge-discharge cycles, the electrode has an equivalent series resistance of 1.42 Ω and retains 83% of its initial specific capacitance. This direct low-temperature synthesis of mesoporous vanadium nitrides is a simple and promising method to achieve high specific capacitance and low equivalent series resistance for electrochemical capacitor applications.

  6. Complexing of vanadium(3) with chromotropic acid derivatives

    International Nuclear Information System (INIS)

    Babenko, N.L.; Busev, A.I.; Sukhorukova, N.V.; Frolova, O.S.

    1976-01-01

    A spectrophotometric study has been made of the complex formation of vanadium (3) with arsenazo(1), arsenazo(3) and some monosubstituted derivatives of chromotropic acid and sulphanylamides. In acid medium vanadium (3) reacts with each of these reagents to produce a 1:1 complex. Optimum conditions of the complex formation was found. The effect of H + on the complex formation of vanadium (3) with chromotropic acid derivatives was established. It was found by the graphical method that the formation of the complex is accompanied by the elimination of one proton. Patterns were found of the influence of the nature of substituents in the organic compound on the ionization constants of acid groups and stability of complexes. Molar extinction coefficients, equilibrium constants of the formation reactions and instability constants for the complexes were calculated. The structure of complexes was suggested. Similar behaviour of all the reagents was established in the complex formation with vanadium (3)

  7. Nanostructured Electrocatalysts for All-Vanadium Redox Flow Batteries.

    Science.gov (United States)

    Park, Minjoon; Ryu, Jaechan; Cho, Jaephil

    2015-10-01

    Vanadium redox reactions have been considered as a key factor affecting the energy efficiency of the all-vanadium redox flow batteries (VRFBs). This redox reaction determines the reaction kinetics of whole cells. However, poor kinetic reversibility and catalytic activity towards the V(2+)/V(3+) and VO(2+)/VO2(+) redox couples on the commonly used carbon substrate limit broader applications of VRFBs. Consequently, modified carbon substrates have been extensively investigated to improve vanadium redox reactions. In this Focus Review, recent progress on metal- and carbon-based nanomaterials as an electrocatalyst for VRFBs is discussed in detail, without the intention to provide a comprehensive review on the whole components of the system. Instead, the focus is mainly placed on the redox chemistry of vanadium ions at a surface of various metals, different dimensional carbons, nitrogen-doped carbon nanostructures, and metal-carbon composites. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Tackling capacity fading in vanadium flow batteries with amphoteric membranes

    Science.gov (United States)

    Oldenburg, Fabio J.; Schmidt, Thomas J.; Gubler, Lorenz

    2017-11-01

    Capacity fading and poor electrolyte utilization caused by electrolyte imbalance effects are major drawbacks for the commercialization of vanadium flow batteries (VFB). The influence of membrane type (cationic, anionic, amphoteric) on these effects is studied by determining the excess and net flux of each vanadium ion in an operating VFB assembled with a cation exchange membrane (CEM), Nafion® NR212, an anion exchange membrane (AEM), Fumatech FAP-450, and an amphoteric ion exchange membrane (AIEM) synthesized in-house. It is shown that the net vanadium flux, accompanied by water transport, is directed towards the positive side for the CEM and towards the negative side for the AEM. The content of cation and anion exchange groups in the AIEM is adjusted via radiation grafting to balance the vanadium flux between the two electrolyte sides. With the AIEM the net vanadium flux is significantly reduced and capacity fading due to electrolyte imbalances can be largely eliminated. The membrane's influence on electrolyte imbalance effects is characterized and quantified in one single charge-discharge cycle by analyzing the content of the four different vanadium species in the two electrolytes. The experimental data recorded herewith conclusively explains the electrolyte composition after 80 cycles.

  9. Comparison of sodium, potassium, calcium, magnesium, zinc, copper and iron concentrations of elements in 24-h urine and spot urine in hypertensive patients with healthy renal function.

    Science.gov (United States)

    Zhang, Tianjing; Chang, Xiaoyu; Liu, Wanlu; Li, Xiaoxia; Wang, Faxuan; Huang, Liping; Liao, Sha; Liu, Xiuying; Zhang, Yuhong; Zhao, Yi

    2017-12-01

    Sodium, potassium, calcium, magnesium, zinc, copper and iron are associated with the sequela of hypertension. The most reliable method for testing those elements is by collecting 24-h urine samples. However, this is cumbersome and collection of spot urine is more convenient in some circumstance. The aim of this study was to compare the concentrations of different elements in 24-h urine and spot urine. Data was collected from a sub-study of China Salt Substitute and Stroke Study. 240 participants were recruited randomly from 12 villages in two counties in Ningxia, China. Both spot and 24-h urine specimens were collected from each patient. Routine urine test was conducted, and concentration of elements was measured using microwave digestion and Inductively Coupled Plasma-Optical Emission Spectrometry. Partial correlation analysis and Spearman correlation analysis were used to investigate the concentration of different elements and the relationship between 24- h urine and spot urine. A partial correlation in sodium, potassium, calcium, magnesium and iron was found between paired 24-h urine and spot urine samples except copper and zinc: 0.430, 0.426, 0.550, 0.221 and 0.191 respectively. Spot urine can replace 24-h urine for estimating some of the elements in hypertensive patients with normal renal function. Copyright © 2017 Elsevier GmbH. All rights reserved.

  10. Vanadium bioavailability and toxicity to soil microorganisms and plants

    OpenAIRE

    Larsson, Maja A; Baken, Stijn; Gustafsson, Jon Petter; Hadialhejazi, Golshid; Smolders, Erik

    2013-01-01

    Vanadium, V, is a redox-sensitive metal that in solution, under aerobic conditions, prevails as the oxyanion vanadate(V). There is little known regarding vanadium toxicity to soil biota, and the present study was set up to determine the toxicity of added vanadate to soil organisms and to investigate the relationship between toxicity and vanadium sorption in soils. Five soils with contrasting properties were spiked with 7 different doses (3.2-3200mgVkg(-1)) of dissolved vanadate, and toxicity ...

  11. Methods of preparing deposits containing iron oxides for recycling

    Directory of Open Access Journals (Sweden)

    T. Lis

    2013-04-01

    Full Text Available The metallurgical industry is one of the largest sources of wastes. Some of them, however, owing to their content of metals such as zinc or iron, may become valuable secondary raw materials. In order to achieve that purpose, they require appropriate preparation. This article provides a discussion on the methods of preparation of scrap from steelworks, namely deposits containing iron oxides, enabling their recycling.

  12. National reports on raw materials economy. Vol. 6

    International Nuclear Information System (INIS)

    Haude, H.; Weber, R.

    1975-06-01

    A review is given of the ore deposits, mine production, and use of mineral resources in Argentina (oil, gas, asphalt, oil shale, coal, uranium, thorium, iron, manganese, chrome, tungsten, vanadium, copper, lead, zinc, tin, antimony, gold, silver, aluminium, beryllium, boron, sulfur, and fluorite). Argentina is dependent on imports of nearly all mineral resources. Only exports of zinc, tungsten, fluorite, and borate have been possible and the only other significant production has been of energy resources, iron, manganese, and lead. The extreme concentration of population in the east, the great distances to the Andes in the west, and the as yet inadequate transport network with the west has limited the mining activity up to the present. As part of industrial development, the government has made great efforts to increase the supply of raw materials through intensive prospecting and use of Argentina's own natural resources. Newly discovered ore deposits confirm that extensive parts of the country are prospective for mineral resources. (orig.) [de

  13. Determination of vanadium in stainless steel and Ni-base alloys by NBPHA spectrophotometric method combined with chloroform extraction separation in media of sulfuric-hydrofluoric acid

    International Nuclear Information System (INIS)

    Sakai, Fumiaki; Ohuchi, Yoshifusa; Ochiai, Kenichi; Motoyama, Sigeji; Tsutsumi, Ken-ichi

    1975-01-01

    A new method of rapid vanadium analysis was proposed. In this method, vanadium is directly extracted and determined from sample solutions in sulfuric-hydrofluoric acid. The interference of the coexisting elements can be ignored in this method. Take one gram of sample into a 200 ml beaker, and add 30 ml of aqua regia. Then heat and dissolve it, and add 14 ml of sulfuric acid (1+1) and 5 ml of phosphoric acid. After cooling, dissolve the salts with a small amount of water. Thereafter, transfer it with use of water into a polyethylene separatory funnel, add 10 ml of 46% hydrofluoric acid, and dilute to 50 ml. Then, add 4 ml iron (II) ammonium sulfate solution (10%) and mix it thoroughly. Allow to stand for two or three minutes, add 10 ml of 45% ammonium persulfate solution and mix it thoroughly again. Allow to stand for about five minutes. Then, add exactly 20 ml of BPHA-chloroform solution (0.1%) and shake and mix it vigorously for two minutes. After a while, transfer the chloroform complex into a 10 mm cell through a piece of absorbent cotton. Then, determine vanadium by measuring the absorbance at the wave length of 530 nm against a chloroform reference. This method can be applicable to the analysis of vanadium in other metals and alloys than stainless steel and Ni-base alloys. (Iwakiri, K.)

  14. Efeito da suplementação com ferro na biodisponibilidade de zinco em uma dieta regional do nordeste do Brasil Effects of supplementation with iron on the bioavailability of zinc in the regional diet of northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Lúcia F. C. Pedrosa

    1993-08-01

    Full Text Available Foram investigados os efeitos da suplementação com ferro na biodisponibilidade de zinco de uma dieta "regional" do Nordeste (DRNE, em ratos albinos Wistar, consumindo rações à base da referida dieta (DRNE e rações controle. As rações DRNE, continham 16 mg de Zn/kg e níveis de 35 mg, 70 mg e 140mg Fe/kg. As rações controle foram elaboradas segundo o "Committee on Laboratory Animal Diets", contendo níveis de proteína, ferro e zinco ajustados aos das rações experimentais DRNE. Os parâmetros utilizados para medir a biodisponibilidade do zinco foram: Índice de Absorção Aparente do Zn e nível total de Zn nos fêmures. Os resultados obtidos demonstraram que a suplementação com ferro diminuiu a biodisponibilidade do Zn, e os efeitos dessa interferência foram influenciados pela qualidade da dieta e pelas proporções Fe:Zn. Tal fato deve ser considerado nas práticas que envolvem fortificação de alimentos e/ou suplementos medicamentosos, comuns nas populações com carências nutricionais.The effects of supplementation with iron on the zinc bioavailability of the regional diet of northeastern Brazil (RDN, were investigated. One assay with Wistar rats, feed on RDN and control diets was carried out. The RDN diets contained 16 mg Zn/kg and levels of 35 mg, 70 mg and 140 mg Fe/kg, respectively. The control diets were prepared according to the standards of the Committee on Laboratory Animal Diets, with levels of protein, iron and zinc identical to those of RDN diets. Index of apparent absorption and zinc retained in the femur of the animals were the parameters utilized to measure zinc bioavailability. The results demonstrated that the supplementation with iron decreased the zinc bioavailability, and the effects were seen to affect diet quality and the Fe:Zn ratio. This fact must be taken into consideration in practices such as the fortying of foodstuffs and the administration of vitamin-mineral supplements to populations with

  15. Effectively suppressing vanadium permeation in vanadium redox flow battery application with modified Nafion membrane with nacre-like nanoarchitectures

    Science.gov (United States)

    Zhang, Lesi; Ling, Ling; Xiao, Min; Han, Dongmei; Wang, Shuanjin; Meng, Yuezhong

    2017-06-01

    A novel self-assembled composite membrane, Nafion-[PDDA/ZrP]n with nacre-like nanostructures was successfully fabricated by a layer-by-layer (LbL) method and used as proton exchange membrane for vanadium redox flow battery applications. Poly(diallyldimethylammonium chloride) (PDDA) with positive charges and zirconium phosphate (ZrP) nanosheets with negative charges can form ultra-thin nacre-like nanostructure on the surface of Nafion membrane via the ionic crosslinking of tightly folded macromolecules. The lamellar structure of ZrP nanosheets and Donnan exclusion effect of PDDA can greatly decrease the vanadium ion permeability and improve the selectivity of proton conductivity. The fabricated Nafion-[PDDA/ZrP]4 membrane shows two orders of magnitude lower vanadium ion permeability (1.05 × 10-6 cm2 min-1) and 12 times higher ion selectivity than those of pristine Nafion membrane at room temperature. Consequently, the performance of vanadium redox flow batteries (VRFBs) assembled with Nafion-[PDDA/ZrP]3 membrane achieved a highly coulombic efficiency (CE) and energy efficiency (EE) together with a very slow self-discharge rate. When comparing with pristine Nafion VRFB, the CE and EE values of Nafion-[PDDA/ZrP]3 VRFB are 10% and 7% higher at 30 mA cm-2, respectively.

  16. Thermal conductivity of high purity vanadium

    International Nuclear Information System (INIS)

    Jung, W.D.

    1975-01-01

    The thermal conductivity, Seebeck coefficient, and electrical resistivity of four high-purity vanadium samples were measured over the temperature range 5 to 300 0 K. The highest purity sample had a resistance ratio (rho 273 /rho 4 . 2 ) of 1524. The highest purity sample had a thermal conductivity maximum of 920 W/mK at 9 0 K and had a thermal conductivity of 35 W/mK at room temperature. At low temperatures, the thermal resistivity was limited by the scattering of electrons by impurities and phonons. The thermal resistivity of vanadium departed from Matthiessen's rule at low temperatures. The electrical resistivity and Seebeck coefficient of high purity vanadium showed no anomalous behavior above 130 0 K. The intrinsic electrical resistivity at low temperatures was due primarily to interband scattering of electrons. The Seebeck coefficient was positive from 10 to 240 0 K and had a maximum which was dependent upon sample purity

  17. Zinc estimates in ore and slag samples and analysis of ash in coal samples

    International Nuclear Information System (INIS)

    Umamaheswara Rao, K.; Narayana, D.G.S.; Subrahmanyam, Y.

    1984-01-01

    Zinc estimates in ore and slag samples were made using the radioisotope X-ray fluorescence method. A 10 mCi 238 Pu was employed as the primary source of radiation and a thin crystal NaI(Ti) spectrometer was used to accomplish the detection of the 8.64 keV Zinc K-characteristic X-ray line. The results are reported. Ash content of coal concerning about 100 samples from Ravindra Khani VI and VII mines in Andhra Pradesh were measured using X-ray backscattering method with compensation for varying concentrations of iron in different coal samples through iron-X-ray fluorescent intensity measurements. The ash percent is found to range from 10 to 40. (author)

  18. Fundamental aspects of alluminothermic reduction of vanadium pentoxide

    International Nuclear Information System (INIS)

    Mourao, M.B.; Capocchi, J.D.T.

    1982-01-01

    The aluminothermic process for the reduction of vanadium pentoxide is considered. Its thermochemistry features are presented, as well as the heat transfer and the rate phenomena concerning such a reaction system. It is pointed out also the effect of the process parameters on the recovery of metallic vanadium. (Author) [pt

  19. Vanadium Recovery from Oil Fly Ash by Carbon Removal and Roast-Leach Process

    Science.gov (United States)

    Jung, Myungwon; Mishra, Brajendra

    2018-02-01

    This research mainly focuses on the recovery of vanadium from oil fly ash by carbon removal and the roast-leach process. The oil fly ash contained about 85% unburned carbon and 2.2% vanadium by weight. A vanadium-enriched product was obtained after carbon removal, and the vanadium content of this product was 19% by weight. Next, the vanadium-enriched product was roasted with sodium carbonate to convert vanadium oxides to water-soluble sodium metavanadate. The roasted sample was leached with water at 60°C, and the extraction percentage of vanadium was about 92% by weight. Several analytical techniques, such as inductively coupled plasma atomic emission spectroscopy (ICP-AES), x-ray fluorescence (XRF), and thermogravimetric and differential thermal analysis (TG-DTA), were utilized for sample analyses. Thermodynamic modeling was also conducted with HSC chemistry software to explain the experimental results.

  20. Temperature dependence of the damage microstructures in neutron-irradiated vanadium

    International Nuclear Information System (INIS)

    Horton, L.L.; Farrell, K.

    1983-01-01

    Vanadium and vanadium with boron carbide additions (V-B 4 C) were irradiated to approx. 1 dpa in the Oak Ridge Research Reactor at controlled temperatures ranging from 455 to 925 K. The V-B 4 C alloy was enriched in 10 B, which produced approx. 3900 at. ppM helium. In the vanadium specimens, the dislocation microstructures varied from clusters of small ( . The V-B 4 C specimens contained only tangled dislocation segments. Cavities were observed in all specimens. The cavity concentration decrease and the average diameter increased with increasing irradiation temperature. At 725 K, the maximum swelling was observed in both the vanadium (0.1%) and V-B 4 C (1.4%). At comparable temperatures the cavities in the V-B 4 C specimens were smaller and more numerous than those in the vanadium specimens. Helium bubbles were found on the grain boundaries in all of the V-B 4 specimens

  1. Vanadium Extraction from Shale via Sulfuric Acid Baking and Leaching

    Science.gov (United States)

    Shi, Qihua; Zhang, Yimin; Liu, Tao; Huang, Jing

    2018-01-01

    Fluorides are widely used to improve vanadium extraction from shale in China. Sulfuric acid baking-leaching (SABL) was investigated as a means of recovering vanadium which does not require the use of fluorides and avoids the productions of harmful fluoride-containing wastewater. Various effective factors were systematically studied and the experimental results showed that 90.1% vanadium could be leached from the shale. On the basis of phase transformations and structural changes after baking the shale, a mechanism of vanadium extraction from shale via SABL was proposed. The mechanism can be described as: (1) sulfuric acid diffusion into particles; (2) the formation of concentrated sulfuric acid media in the particles after water evaporation; (3) hydroxyl groups in the muscovite were removed and transient state [SO4 2-] was generated; and (4) the metals in the muscovite were sulfated by active [SO4 2-] and the vanadium was released. Thermodynamics modeling confirmed this mechanism.

  2. Optimal Location of Vanadium in Muscovite and Its Geometrical and Electronic Properties by DFT Calculation

    Directory of Open Access Journals (Sweden)

    Qiushi Zheng

    2017-02-01

    Full Text Available Vanadium-bearing muscovite is the most valuable component of stone coal, which is a unique source of vanadium manufacture in China. Numbers of experimental studies have been carried out to destroy the carrier muscovite’s structure for efficient extraction of vanadium. Hence, the vanadium location is necessary for exploring the essence of vanadium extraction. Although most infer that vanadium may substitute for trivalent aluminium (Al as the isomorphism in muscovite for the similar atomic radius, there is not enough experimental evidence and theoretical supports to accurately locate the vanadium site in muscovite. In this study, the muscovite model and optimal location of vanadium were calculated by density functional theory (DFT. We find that the vanadium prefers to substitute for the hexa-coordinated aluminum of muscovite for less deformation and lower substitution energy. Furthermore, the local geometry and relative electronic properties were calculated in detail. The basal theoretical research of muscovite contained with vanadium are reported for the first time. It will make a further influence on the technology development of vanadium extraction from stone coal.

  3. Directed synthesis of bio-inorganic vanadium oxide composites using genetically modified filamentous phage

    International Nuclear Information System (INIS)

    Mueller, Michael; Baik, Seungyun; Jeon, Hojeong; Kim, Yuchan; Kim, Jungtae; Kim, Young Jun

    2015-01-01

    Highlights: • Phage is an excellent seeding for bio-templates for environmentally benign vanadium oxide nanocomposite synthesis. • The synthesized bio-inorganic vanadium oxide showed photodegradation activities. • The fabricated wt phage/vanadium oxide composite exhibited bundle-like structure. • The fabricated RSTB-phage/vanadium oxide composite exhibited a ball with a fiber-like nanostructure. • The virus/vanadium oxide composite could be applied in photocatalysts, sensors and nanoelectronic applications. - Abstract: The growth of crystalline vanadium oxide using a filamentous bacteriophage template was investigated using sequential incubation in a V 2 O 5 precursor. Using the genetic modification of the bacteriophage, we displayed two cysteines that constrained the RSTB-1 peptide on the major coat protein P8, resulting in vanadium oxide crystallization. The phage-driven vanadium oxide crystals with different topologies, microstructures, photodegradation and vanadium oxide composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), quartz microbalance and dissipation (QCM-D) and X-ray photoelectron spectroscopy (XPS). Non-specific electrostatic attraction between a wild-type phage (wt-phage) and vanadium cations in the V 2 O 5 precursor caused phage agglomeration and fiber formation along the length of the viral scaffold. As a result, the addition of recombinant phage (re-phage) in V 2 O 5 precursors formed heterogeneous structures, which led to efficient condensation of vanadium oxide crystal formation in lines, shown by QCM-D analysis. Furthermore, re-phage/V x O x composites showed significantly enhanced photodegradation activities compared with the synthesized wt-phage-V 2 O 5 composite under illumination. This study demonstrates that peptide-mediated vanadium oxide mineralization is governed by a complicated interplay of peptide sequence, local structure, kinetics and the presence of a mineralizing

  4. Effect of NaFeEDTA-fortified soy sauce on zinc absorption in children.

    Science.gov (United States)

    Li, Min; Wu, Jinghuan; Ren, Tongxiang; Wang, Rui; Li, Weidong; Piao, Jianhua; Wang, Jun; Yang, Xiaoguang

    2015-03-01

    NaFeEDTA has been applied in many foods as an iron fortificant and is used to prevent iron deficiency in Fe-depleted populations. In China, soy sauce is fortified with NaFeEDTA to control iron deficiency. However, it is unclear whether Fe-fortified soy sauce affects zinc absorption. To investigate whether NaFeEDTA-fortified soy sauce affects zinc absorption in children, sixty children were enrolled in this study and randomly assigned to three groups (10 male children and 10 female children in each group). All children received daily 3 mg of (67)Zn and 1.2 mg of dysprosium orally, while the children in the three groups were supplemented with NaFeEDTA-fortified soy sauce (6 mg Fe, NaFeEDTA group), FeSO₄-fortified soy sauce (6 mg Fe, FeSO₄ group), and no iron-fortified soy sauce (control group), respectively. Fecal samples were collected during the experimental period and analyzed for the Zn content, (67)Zn isotope ratio and dysprosium content. The Fe intake from NaFeEDTA-fortified and FeSO₄-fortified groups was significantly higher than that in the control group (P sauce does not affect Zn bioavailability in children.

  5. Calculations of oscillation spectra of disordered interstitial solid solutions of vanadium-oxygen system

    International Nuclear Information System (INIS)

    Danilkin, S.A.

    1978-01-01

    The frequency spectra calculation of disordered solid interstitial solutions of a vanadium-oxygen system for oxygen concentration of 5.9% and 15.8% (V 16 O and V 16 O 3 ) is carried out. The axially-symmetric model of crystal lattice dinamics with consideration of vanadium-oxygen and vanadium-vanadium interactions up to the second coordination sphere is used. On the whole, the obtained spectra are in qualitative agreement with experiment and reflect correctly all the changes in frequency spectra of pure vanadium on doping with oxygen

  6. Spectrophotometric determination of vanadium in environmental and biological samples

    International Nuclear Information System (INIS)

    Rekha, D.; Krishnapriya, B.; Subrahmanyam, P.; Reddyprasad, P.; Dilip Kumar, J.; Chiranjeevi, P.

    2007-01-01

    The method is based on oxidation of p-nitro aniline by vanadium (V) followed by coupling reaction with N-(1-naphthalene-1-y1)ethane-1, 2-diaminedihydrochloride (NEDA) in basic medium of pH 8 to give purple colored derivative. The derivative having an λ max 525nm is stable for 10 days. Beer's law is obeyed for vanadium (V) in the concentration range of 0.03-4.5 μg ml -1 . The proposed method was successfully applied to the analysis of vanadium in environmental and biological samples. (author)

  7. Determination of acute toxicity of petroleum refinery effluents in various stages of treatment for Daphnia similis; Determinacao da toxicidade aguda de efluentes de refinaria de petroleo em diversas etapas de tratamento para Daphnia similis

    Energy Technology Data Exchange (ETDEWEB)

    Damato, Murilo; Alem Sobrinho, Pedro; Morita, Dione Mari [Sao Paulo Univ., SP (Brazil). Escola Politecnica. Dept. de Engenharia Hidraulica e Sanitaria]. E-mail: palem@usp.br

    1997-07-01

    The organisms from fresh water are sensible to variations of environmental parameters. The criteria of water quality for these animals are derived from laboratorium tests. The following physical and chemical parameters have been determined: DO, BOD, COD, alkalinity, hardness, ammoniacal nitrogen, sulphides, chlorides, cyanides, oils and greases, aluminium, arsenium, cadmium, chromium, copper, iron, lead, vanadium, zinc, phenols, benzene, toluene, xylene, solids in total suspensions. Acute toxicity tests have been performed on Daphnia similis. The flotation and activated waste systems was efficient in removing acute toxicity.

  8. Study on the distribution of radioactive trace elements in vitamin D-overloaded rats using the multitracer technique

    International Nuclear Information System (INIS)

    Hirunuma, Rieko; Enomoto, Shuichi; Ambe, Fumitoshi; Endo, Kazutoyo; Ambe, Shizuko

    1999-01-01

    The uptake and distribution of radioisotopes of beryllium, calcium, scandium, vanadium, chromium, manganese, iron, cobalt, nickel, zinc, gallium, arsenic, strontium and barium in vitamin D (VD)-overloaded rats were investigated and compared with those in control rats, using the multitracer technique. Each element revealed its characteristic distribution among various organs in control and VD-overloaded rats. For some elements, such as cobalt and chromium, the distribution patterns in them were significantly different. These results are discussed in terms of the metabolism of the elements in rats

  9. Amphoteric Ion-Exchange Membranes with Significantly Improved Vanadium Barrier Properties for All-Vanadium Redox Flow Batteries.

    Science.gov (United States)

    Nibel, Olga; Rojek, Tomasz; Schmidt, Thomas J; Gubler, Lorenz

    2017-07-10

    All-vanadium redox flow batteries (VRBs) have attracted considerable interest as promising energy-storage devices that can allow the efficient utilization of renewable energy sources. The membrane, which separates the porous electrodes in a redox flow cell, is one of the key components in VRBs. High rates of crossover of vanadium ions and water through the membrane impair the efficiency and capacity of a VRB. Thus, membranes with low permeation rate of vanadium species and water are required, also characterized by low resistance and stability in the VRB environment. Here, we present a new design concept for amphoteric ion-exchange membranes, based on radiation-induced grafting of vinylpyridine into an ethylene tetrafluoroethylene base film and a two-step functionalization to introduce cationic and anionic exchange sites, respectively. During long-term cycling, redox flow cells containing these membranes showed higher efficiency, less pronounced electrolyte imbalance, and significantly reduced capacity decay compared to the cells with the benchmark material Nafion 117. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Utilization of vanadium alloys in the DIII-D Radiative Divertor Program

    International Nuclear Information System (INIS)

    Smith, J.P.; Johnson, W.R.; Stambaugh, R.D.; Trester, P.W.; Smith, D.; Bloom, E.

    1995-10-01

    Vanadium alloys are attractive candidate structural materials for fusion power plants because of their potential for minimum environmental impact due to low neutron activation and rapid activation decay. They also possess favorable material properties for operation in a fusion environment. General Atomics (GA), in conjunction with Argonne National Laboratory (ANL) and Oak Ridge National Laboratory (ORNL), has developed a plan for the utilization of vanadium alloys as part of the Radiative Divertor (RD) upgrade for the DIII-D tokamak. The plan will be carried out in conjunction with General Atomics and the Materials Program of the US Department of Energy (DOE). This application of a vanadium alloy will provide a meaningful step in the development of advanced materials for fusion power devices by: (1) developing necessary materials processing technology for the fabrication of large vanadium alloy components, and (2) demonstrating the in-service behavior of a vanadium alloy (V-4Cr-4Ti) in a tokamak environment. The program consists of three phases: first, small vanadium alloy coupon samples will be exposed in DIII-D at positions in the vessel floor and within the pumping plenum region of the existing divertor structure; second, a small vanadium alloy component will be installed in the existing divertor, and third, during the forthcoming Radiative Divertor modification, scheduled for completion in mid-1997, the upper section of the new double-null, slotted divertor will be fabricated from vanadium alloy product forms. This program also includes research and development (R and D) efforts to support fabrication development and to resolve key issues related to environmental effects

  11. Utilization of vanadium alloys in the DIII-D radiative divertor program

    International Nuclear Information System (INIS)

    Smith, J.P.; Johnson, W.R.; Stambaugh, R.D.; Trester, P.W.; Smith, D.; Bloom, E.

    1996-01-01

    Vanadium alloys are attractive candidate structural materials for fusion power plants because of their potential for minimum environmental impact due to low neutron activation and rapid activation decay. They also possess favorable material properties for operation in a fusion environment. General Atomics in conjunction with Argonne National Laboratory and Oak Ridge National Laboratory has developed a plan for the utilization of vanadium alloys as part of the radiative divertor upgrade for the DIII-D tokamak. The plan will be carried out in conjunction with General Atomics and the Materials Program of the US Department of Energy. This application of a vanadium alloy will provide a meaningful step in the development of advanced materials for fusion power devices by: (1) developing necessary materials processing technology for the fabrication of large vanadium alloy components and (2) demonstrating the in-service behavior of a vanadium alloy (V-4Cr-4Ti) in a tokamak environment. The program consists of three phases: first, small vanadium alloy coupon samples will be exposed in DIII-D at positions in the vessel floor and within the pumping plenum region of the existing divertor structure; second, a small vanadium alloy component will be installed in the existing divertor, and third, during the forthcoming radiative divertor modification, scheduled for completion in mid-1997, the upper section of the new double-null, slotted divertor will be fabricated from vanadium alloy product forms. This program also includes research and development efforts to support fabrication development and to resolve key issues related to environmental effects. (orig.)

  12. The structural studies of vanadium substituted lithium-bismuth-boro-tellurite glass

    Science.gov (United States)

    Madhu, A.; Eraiah, B.

    2018-05-01

    The structural studies of vanadium substituted lithium-bismuth-boro-tellurite glass is successfully prepared and certain analysis like XRD,FTIR,DTA/TGA with density, molar volume are done. The amorphous phase has been identified based on X-ray diffraction analysis. The vanadium oxide plays the role as a glass-modifier and influences on BO3 ↔ BO4 conversion. The observed nonlinear variation in Tg with vanadium oxide increase, it reflects structural changes. The nonlinear variation of density and molar volume can be attributed to vanadium oxide incorporation have increased the number of Non-bridging oxygen (NBO'S).

  13. Iron-based alloy and nitridation treatment for PEM fuel cell bipolar plates

    Science.gov (United States)

    Brady, Michael P [Oak Ridge, TN; Yang, Bing [Oak Ridge, TN; Maziasz, Philip J [Oak Ridge, TN

    2010-11-09

    A corrosion resistant electrically conductive component that can be used as a bipolar plate in a PEM fuel cell application is composed of an alloy substrate which has 10-30 wt. % Cr, 0.5 to 7 wt. % V, and base metal being Fe, and a continuous surface layer of chromium nitride and vanadium nitride essentially free of base metal. A oxide layer of chromium vanadium oxide can be disposed between the alloy substrate and the continuous surface nitride layer. A method to prepare the corrosion resistant electrically conductive component involves a two-step nitridization sequence by exposing the alloy to a oxygen containing gas at an elevated temperature, and subsequently exposing the alloy to an oxygen free nitrogen containing gas at an elevated temperature to yield a component where a continuous chromium nitride layer free of iron has formed at the surface.

  14. Positron lifetime in vanadium oxide bronzes

    International Nuclear Information System (INIS)

    Dryzek, J.; Dryzek, E.

    2003-01-01

    The positron lifetime (PL) and Doppler broadening (DB) of annihilation line measurements have been performed in vanadium oxide bronzes M x V 2 O 5 . The dependence of these annihilation characteristics on the kind and concentration of the metal M donor has been observed. In the PL spectrum only one lifetime component has been detected in all studied bronzes. The results indicate the positron localization in the structural tunnels present in the crystalline lattice of the vanadium oxide bronzes. (copyright 2003 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Vanadium alloys for fusion reactor applications

    International Nuclear Information System (INIS)

    Mattas, R.F.; Loomis, B.A.; Smith, D.L.

    1992-01-01

    This paper reports that fusion reactors will produce a severe operating environment for structural materials. The material should have good mechanical strength and ductility to high temperature, be corrosion resistant to the local environment, have attractive thermophysical properties to accommodate high heat loads, and be resistant to neutron damage. Vanadium alloys are being developed for such applications, and they exhibit desirable properties in many areas Recent progress in vanadium alloy development indicates good strength and ductility to 700 degrees C, minimal degradation by neutron irradiation, and reduced radioactivity compared with other candidate alloy systems

  16. Chemistry, spectroscopy and the role of supported vanadium oxides in heterogeneous catalysis

    NARCIS (Netherlands)

    Weckhuysen, B.M.; Keller, D.E.

    2003-01-01

    Supported vanadium oxide catalysts are active in a wide range of applications. In this review, an overview is given of the current knowledge available about vanadium oxide-based catalysts. The review starts with the importance of vanadium in heterogeneous catalysis, a discussion of the molecular

  17. A heterojunction photocatalyst composed of zinc rhodium oxide, single crystal-derived bismuth vanadium oxide, and silver for overall pure-water splitting under visible light up to 740 nm.

    Science.gov (United States)

    Kobayashi, Ryoya; Takashima, Toshihiro; Tanigawa, Satoshi; Takeuchi, Shugo; Ohtani, Bunsho; Irie, Hiroshi

    2016-10-12

    We recently reported the synthesis of a solid-state heterojunction photocatalyst consisting of zinc rhodium oxide (ZnRh 2 O 4 ) and bismuth vanadium oxide (Bi 4 V 2 O 11 ), which functioned as hydrogen (H 2 ) and oxygen (O 2 ) evolution photocatalysts, respectively, connected with silver (Ag). Polycrystalline Bi 4 V 2 O 11 (p-Bi 4 V 2 O 11 ) powders were utilized to form ZnRh 2 O 4 /Ag/p-Bi 4 V 2 O 11 , which was able to photocatalyze overall pure-water splitting under red-light irradiation with a wavelength of 700 nm (R. Kobayashi et al., J. Mater. Chem. A, 2016, 4, 3061). In the present study, we replaced p-Bi 4 V 2 O 11 with a powder obtained by pulverizing single crystals of Bi 4 V 2 O 11 (s-Bi 4 V 2 O 11 ) to form ZnRh 2 O 4 /Ag/s-Bi 4 V 2 O 11 , and demonstrated that this heterojunction photocatalyst had enhanced water-splitting activity. In addition, ZnRh 2 O 4 /Ag/s-Bi 4 V 2 O 11 was able to utilize nearly the entire range of visible light up to a wavelength of 740 nm. These properties were attributable to the higher O 2 evolution activity of s-Bi 4 V 2 O 11 .

  18. Isotope aided studies on the bioavailability of iron and zinc from human diets

    International Nuclear Information System (INIS)

    Raghuramulu, N.

    1992-01-01

    Iron deficiency anaemia is a major public health problem in many developing countries including India. Recent multicentric studies indicated that in rural population of India, 60% of preschool children and 40-60 % of women of child bearing age may suffer from anaemia. Studies by Sood et al indicated that iron stores are generally lower in the population as compared to populations in other countries. It is therefore possible that prelatent iron deficiency may be even higher who look otherwise healthy and adequately nourished. Iron absorption from habitual diets of Indians has been determined in the past by the chemical balance methods. Iron absorption determined by this method may be a gross over estimate. A more reliable estimate of iron absorption from composite meals can be obtained by the radio isotopic methods in which foods are extrinsically or intrinsically tagged with radio iron ( 55 Fe or 59 Fe). Using these methods iron absorption from a few habitual diets was studied. 15 refs

  19. Compatibility of niobium, titanium, and vanadium metals with LMFBR cladding

    International Nuclear Information System (INIS)

    Wilson, C.N.

    1975-10-01

    A series of laboratory capsule annealing experiments were conducted to assess the compatibility of niobium, vanadium, and titanium with 316 stainless steel cladding in the temperature range of 700 to 800 0 C. Niobium, vanadium, and titanium are cantidate oxygen absorber materials for control of oxygen chemistry in LMFBR fuel pins. Capsule examination indicated good compatibility between niobium and 316 stainless steel at 800 0 C. Potential compatibility problems between cladding and vanadium or titanium were indicated at 800 0 C under reducing conditions. In the presence of Pu/sub 0.25/U/sub 0.75/O/sub 1.98/ fuel (Δanti G 02 congruent to -160 kcal/mole) no reaction was observed between vanadium or titanium and cladding at 800 0 C

  20. Ambient redox synthesis of vanadium-doped manganese dioxide nanoparticles and their enhanced zinc storage properties

    Energy Technology Data Exchange (ETDEWEB)

    Alfaruqi, Muhammad Hilmy; Islam, Saiful; Mathew, Vinod; Song, Jinju; Kim, Sungjin; Tung, Duong Pham; Jo, Jeonggeun; Kim, Seokhun; Baboo, Joseph Paul; Xiu, Zhiliang; Kim, Jaekook, E-mail: jaekook@chonnam.ac.kr

    2017-05-15

    Highlights: • The V-doped MnO{sub 2} was prepared by a simple ambient redox reaction. • The V-doped MnO{sub 2} was tested as a cathode in aqueous zinc-ion batteries (ZIBs). • The doped cathode showed better zinc-storage properties than the bare cathode. • The present study facilitates the development of safe and reliable aqueous ZIBs. - Abstract: In this work, we demonstrate the first use of a V-doped MnO{sub 2} nanoparticle electrode for zinc-ion battery (ZIB) applications. The V-doped MnO{sub 2} was prepared via a simple redox reaction and the X-ray diffraction studies confirmed the formation of pure MnO{sub 2}, accompanied by an anisotropic expansion of MnO{sub 2} lattice, suggesting the incorporation of V-ions into the MnO{sub 2} framework. V doping of MnO{sub 2} not only increased the specific surface area but also improved the electronic conductivity. When Zn-storage properties were tested, the V-doped MnO{sub 2} electrode registered a higher discharge capacity of 266 mAh g{sup −1} compared to 213 mAh g{sup −1} for the pure MnO{sub 2} electrode. On prolonged cycling, the doped electrode retained 31% higher capacity than that of the bare MnO{sub 2} electrode and thereby demonstrated superior cycling performance. This study may pave the way towards understanding the enhancement of the energy storage properties via doping in electrodes of aqueous ZIB applications and also furthers the efforts for the practical realization of a potential eco-friendly battery system.